manual cm-760_780 ingles

April 17,

CM 760 & CM 780 Training Manual2003 52320207-1

Index

General Hydraulic Information---------------------------Chapt. 1

Hydraulic pumps----------------------------------------------Chapt. 2

Cooling and Return circuits-------------------------------Chapt. 3

Pilot Circuits----------------------------------------------------Chapt. 4

Tramming Circuits--------------------------------------------Chapt. 5

Feed Circuit-----------------------------------------------------Chapt. 6

Rotation Circuit------------------------------------------------Chapt. 7

Air Compressor System------------------------------------Chapt. 8

Dust Collector System--------------------------------------Chapt. 9

Rod Changing System--------------------------------------Chapt. 10

Electrical System---------------------------------------------Chapt. 11

Drilling Information------------------------------------------Chapt. 12

Service Training Manual CM 760/780

General Information Page 1 Chapter 1

Working line

Pilot line

Drain line

Enclosure line

Squares or combinationsof squares indicate valves

Circles indicate pumps,gauges or rotary actuators

Arrows indicate variability,adjustability or direction of flow

Check valve

Accumulator-gas charged

The diamond shape indicates fluid conditioners

Check valve-spring loaded

Hydraulic symbolsBasic building blocks

Spring--an arrow through the spring indicates an adjustmentpoint



ININ

IN

ReliefValve

Pressure reducingvalve

Directional Control ValveThree position four way valves

Flow control valves

Fluid conditioners

A B

P T

A B

P T

A B

T P

A B

T P

A B

P T

A B

P T

Open centerClosed port

Open centerOpen port

Closed centerOpen port

Closed centerClosed port

Open centerClosed port

Open centerOpen port

Pressure reducing/relieving valve

Bypass type flowcontrol with return

check valve

Pressure &temperaturecompensated

Filter w/ bypass CoolerFixed Variable

Orifice

Hydraulic Symbols

Pressure &temperaturecompensated

Restrictive type flowcontrol with return

check valve



Hydraulic Symbols

MotorsPumps

Fixed displacementunidirectional(Gear or Vane)

Fixed displacementundirectional

(Gear or Vane or piston)

Variable displacement

(piston)

Fixed displacementbidirectional

(Gear Vane or Piston

bidirectional

Variable displacementunidirectional piston pump

Pressure & flow compensated(Load sensing)

Variable displacementbidirectional piston pump

(Hydrastatic pump)



Hydraulic Symbols

Valve operators

VentedReservoir

Line to reservoirabove fluid level

Pressurizedreservoir Line to reservoir

below fluid level

Pressure switchManual shutoffvalveShuttle valve

Double acting cylinderPressure gauge Temperature gauge

LeverPilot operator Solenoid operator

Spring Cam or rolleroperator

Valve detents(hash mark indicates nuetral)



DEFINITION OF SYMBOLS

1. Working line: Any line used to carry working fluid. This includessuction lines, pressure lines, and cylinder or motor connections andreturn lines.

2. Pilot line: Pressure used internally or externally to control valveoperation. The dashed line is used to differentiate pilot lines fromothers on a schematic.

3. Drain line: Drain lines are always connected to the reservoir andare used for pump or motor case lines as well as a case drainconnection for certain types of valves. Drain line pressure shouldtypically be less than 5 PSI and be subjected to minimal spiking of thepressure.

4. Enclosure lines: This line will be used on a schematic aroundmore than one component symbol. This indicates that all of the itemsenclosed on the schematic are located in a single component on themachine.

5. Relief valve: Relief valves are used to limit maximum pressure toprotect a circuit. They may be pilot circuit relief valves or full flowsystem relief valves. Relief valves may be direct acting (spring over apoppet or spool) or pilot operated style (2-stage type). Pilot operatedrelief valves are more stable with high flows or where flows may varygreatly. The downstream side of any relief valve must be connectedto low pressure or to the reservoir.

6. Sequence valve: A pressure operated valve similar to a reliefvalve, which at its setting, directs flow to a secondary line whileholding a predetermined minimum pressure in the primary line. Usedin circuits that utilize a single directional valve to operate twofunctions in sequence.

7. Pressure reducing valve: A valve that limits pressure at its outletregardless of the inlet pressure. Frequently used to reduce systempressure to a lower PSI to perform a specific function.



8. Flow control valve, pressure and temperature compensated,restrictive type. A valve that is used to control the fluid flow througha circuit. The pressure and temperature compensated designationmean that the regulated flow rate passed by the valve will remainconstant regardless of system pressure and fluid temperature. Arestrictive type valve is used with a variable pump system becausethe pump can match its output to the flow requirements determinedby the flow control valve.

9. Flow control valve, pressure and temperature compensated,bypass type: This valve is also used to control flow through a circuit.The bypass type valve is normally used with a fixed displacementhydraulic pump. Excess flow is bypassed to the reservoir by thevalve.

10. Orifice or restriction: An orifice is a restriction used forcontrolling flow (speed). It can be of fixed size or variable (such as aneedle valve). They are the simplest forms of flow control device.

11. Shuttle valve: A valve used to allow the highest of two pressuresources to used downstream to perform a function. An examplecould be a hydraulic released traction brake system. The pressuredeveloped on the pressure side of the circuit is used to release thebrake via the shuttle valve.

12. Check valve: A valve that allows free flow in one direction butblocks flow in the other. They can be equipped with a spring-loadedpoppet that increases the cracking (opening) pressure of the valve.Some check valves are pilot operated that means they can beopened with pilot pressure to allow reverse flow.

13. Pumps and motors: The flow arrow pointing outward identifiesPumps. An arrow drawn through the circle at an angle indicates thepump or motor is variable. If the flow arrow points inward thecomponent is a motor.

14. Filters: A diamond shape indicates a fluid conditioning device,the dotted line through the diamond identifies the device as a filter.The bypass is shown as either a spring loaded check valve or a reliefvalve around the filter. Not all filters are equipped with a bypass.



15. Cooler or heat exchanger: The diamond shape with arrowspointing outward indicates a cooler or heat exchanger. The symbolcan represent a cooler that uses either air or water as the coolingmedium.16. Dual pilot operated check valve: Used as a load holding devicenormally with a hydraulic cylinder. Utilizes two pilot operated checkvalves in the same valve housing. Pilot pressure from the inlet sideof the valve is used to open the outlet check valve.

17. Counterbalance valve: Also a load holding device but a moresophisticated valve than a pilot operated check valve. Commonlyused in a dual configuration so pressure at the inlet of the valveopens the outlet. When lowering a load using a dual counterbalancevalve the load cannot free fall. If load attempts to lower faster thanthe supply of incoming fluid the pressure at the inlet of the valve willdrop and the outlet of the valve will begin to close. This createshydraulic backpressure and slows the descent of the load.Counterbalance valves also can function as a relief valve. If the loadis great enough, the valve will open and relieve the excessivepressure.



HELPFUL INFORMATION

1. Pascals Law: Pressure exerted on a confined fluid is transmittedundiminished in all directions and acts with equal force on all equalareas and at right angles to them.

2. The force in pounds exerted by a hydraulic cylinder can bedetermined by multiplying the piston area in square inches by thepressure applied (PSI).

3. To determine the volume (cubic inches) required to move a pistona given distance, multiply the piston area in sq. in. ( r) by the strokelength required (inches). Volume = Area x Length.

4. The weight of hydraulic fluid will vary with changes in viscosity. 55to 58 pounds per cubic ft. covers the viscosity range from 150 SUS to900 SUS at 100 degrees f.

5. Flow through an orifice or restriction will cause a pressure dropacross that restriction. The more flow that attempts to pass through agiven restriction the greater the pressure drop.

6. Hydraulic hoses are designated by their nominal inside diameter.With some exceptions, a dash number representing the number ofsixteenth inch increments in their inside diameter indicates this.

Example: 1. 8/16 or 8

2. 16/16 or -16

7. One horsepower (HP) = 33,000 ft. lbs. per minute.

One HP =746 watts.

One HP = 42.4 BTU per minute.



8. To find the HP required for a given flow rate at a known pressureuse the formula:

Pump output HP = GPM x PSI x .000583 or,

HP = GPM x PSI 1714 x Efficiency

Piston pumps in good condition are normally 90% to 95% efficient.Gear pumps in good condition are normally 80% to 90% efficient.

10. To find the uphole velocity of a drilling application use theformula:

144 x CFM: H2 - H1 = Up Hole Velocity (ft./ minute).

H2 = hole diameter

H1 = Drill rod or stem diameter

11. To calculate the pressure required to open a pilot operatedcounterbalance valve use the formula:

Pilot Pressure = Relief Setting - Load Pressure Pilot Ratio

12. The relationship between torque and HP is:

Torque (in. lbs.) = 63205 x HP RPM or,

HP = Torque (in. lbs.) x RPM 63205

13. To find pump volume when displacement (cu. in.) is known, usethe formula:

Volume = RPM x Displacement 231

There are 231 cu. in. in one US gallon.

14. Area of a circle A = r2 or A = .7845 d2 15. Pressure conversions, 1 bar = 100 kPa = 1.02 kg/cm2 = 14.5 PSI



DUAL COUNTERBALANCE VALVE

Dual counterbalance (CB) valves are commonly used in load holdingor load controlling applications. They are rated by PSI and PILOTRATIO. Examples might be 3000 PSI/ 10:1 pilot ratio, 5000 PSI/ 3:1ratio. They are available in many different variations. The pressurerating of a CB valve is the pressure at which the valve will open whensubjected to direct pressure. As an example; if an external load isapplied to a hydraulic cylinder and causes the pressure in the cylinderto increase beyond the pressure rating of the CB valve, the valve willfunction as a relief valve and relieve the excess pressure to the returnline. For this relief function to work it is necessary that the valvecontain a motor spool which connects the two working ports to thereturn line when the valve spool is in neutral. The pilot ratiodetermines the pilot pressure required to open the valve. There is asimple formula for determining pilot pressure:

Pilot pressure = Relief Setting - Load Pressure Pilot RatioIf the values are inserted the formula looks like this:

Pilot Pressure = 3000 PSI - 0 PSI (no load) 10 (pilot ratio) 300 =3000

10By making this simple calculation we can determine that 300 PSI isthe pilot pressure required to open the valve. In a dual CB valve thepressure on the inlet side of the valve is used to pilot the outlet open.

In a tram circuit for example, the sequence of events to tram themachine occur as follows:

1. The tram valve lever is moved from the neutral position.

2. The open valve allows fluid to move toward the CB valveand the tram motor.

3. At the same time the pressure created by fluid movingtoward the load is diverted to the load sensing porting in the valve.



4. Pressure begins to build in the load sensing line. This line isconnected to the load sensing connection on the main pump. Thepressure signals the main pump to come "ON STROKE". As thepump comes on stroke more fluid is delivered by the pump to thetram valve.

5. At the CB valve fluid moves through the free flow checkvalve and toward the motor. The motor is a positive displacementdevice that means that fluid entering will cause the motor to attemptto rotate. As the motor tries to rotate any fluid already in the motormust be expelled and it must pass through the counterbalance valve.The outlet side of the CB valve will be closed initially and must bepiloted open by pressure from the inlet side of the circuit.

In the example used above, the 3000 PSI 10:1 (the pilot ratio), thepressure at the inlet side of the circuit must be 300 PSI to pilot openthe outlet. What this means is that if the motor attempts to rotatefaster (as in tramming downhill) than the oil supply coming in at theinlet side of the CB valve, the pressure will drop. As the pressuredrops toward 300 PSI, the outlet side of the valve will began to closeand create a hydraulic restriction against the motor slowing it downand controlling its speed. This action prevents an overrunning loadcondition so the machine can be safely be trammed down hills. In ahydraulic cylinder circuit the action described above will prevent freefall of the load as the directional valve is opened.

In the tram motor circuit a spring set / hydraulically released staticbrake is used. The counterbalance valve is equipped with a shuttlevalve that directs pressure from the working side of the circuit torelease the brake. Usually the pressure required to release the brakeis lower than the opening pressure of the CB valve thereby allowingthe brake to fully release before the machine is allowed to move.



To review: The counterbalance valve has three major functions:

1. It provides load-holding capabilities when the cylinder ormotor is in a static condition.

2. The valve protects the machine from overrunning loadconditions and prevents free fall of hydraulic cylinders or downhillrunaway of a machine.

3. The valve also provides for a specified minimum pressure sothat external devices such as a holding brake can be released prior tomovement of the load.



3000PSI

3000PSI

Equipped with shuttle valve for brake release

All counterbalance valve will have a specified pilot ratio.This determines the pilot pressure required to open theoutlet port of the valve.



LOAD SENSING

The Ingersoll-Rand ECM series crawler drills are equipped with loadsensing hydraulic systems. Load sensing requires piston pumps thatincorporate a dual control system. Dual control means that the pumpcan be regulated by either maximum pressure or by load generatedpressure. The pumps used by Ingersoll-Rand are variabledisplacement axial piston units. Load sensing is one of the moreefficient means of controlling a hydraulic system. This is becausewhen no fluid is required to operate a machine function the pumppressure drops to the standby mode. The standby pressure will varywith different units. When the machine is in an operational mode, forexample; drilling, the pump is required to operate at only the highestpressure required plus the standby pressure

In the load sensing system, valves are used that are proportional.This means that for any given handle position there is acorresponding flow rate. The drifter and feed circuits are equippedwith controls that also regulate or limit pressure. All of the valves onthe machine are closed center, this means that when a valve is in theneutral position pump flow is blocked. Internally in each individualvalve section there is porting which directs load pressure (i.e.: actualpressure created by the load) toward the load sensing port on thepump control. This is frequently referred to as the signal pressure.The internal signal of each valve section is directed through a seriesof shuttle valves so that only the highest signal pressure reaches thepump load sense control.

With the unit running but no hydraulic functions being operated thepressure present at the outlet of the pump will be standby pressure. Itis also important to know that pressure on the load sensing line willbe 0 PSI. This is because when the valves are in neutral the internalload sensing circuitry is connected to the return or tank side of thecircuit. We will use the rotation circuit to demonstrate circuitoperation. If we mentally slow down the system function for thisexercise it will help to understand the operation of the circuit. First,the valve lever for the rotation function is operated. This opens a flowpath through the valve toward the rotation motor. When this flow pathopens the first thing that happens is that the standby pressure beingmaintained in the high-pressure side of the circuit begins to drop. The



load sensing control on the pump constantly compares the actualdischarge pressure with the pressure signal being received at theload sensing port. With all valves in neutral the load sensing lineshows 0 PSI so the control only allows the pump to build to standby.The load sense control can be described as a variable compensator.As stated previously when the valve is moved the load sensingcontrol recognizes that the outlet pressure is starting to drop. Thecontrol responds by causing the pump swash plate to come on stroke(move the swash plate to an angle so fluid is being moved). At thistime fluid moving toward to rotation motor will began to generatesome pressure. This pressure generates a pressure signal in theload sense signal line. As long as the pressure differential is lessthan standby the pump control will continue to increase flow until aPSI differential equal to the standby pressure is reached between thepump discharge and the load sense signal port. As an example, letus assume that the rotation valve is limited to 10 gallons per minute,as soon as the flow reaches 10 GPM no additional flow is deliveredby the pump because the pressure differential between the pumpoutlet and the load is equal to the standby pressure. If the bit were tostall (become jammed) the pressure would began to climb. If thisincrease in pressure was allowed to continue unchecked, somethingwould break. Because the pump is dual controlled, the pressurecompensator will override the load sensing and limit system pressureto the maximum allowed which is the maximum pressure setting ofthe pump. Each individual circuit works the same as describedabove. The feed and drifter circuits have the additional feature ofbuilt in pressure control. This limits the pressure of these circuits toless than maximum pump pressure. Load sensing and compensator Pump Control:

Standbycompensator

Pressurecompensator



LSSHUTTLE VALVE

DUAL CONTROLPUMP(PRESSURECOMPENSATEDAND LOADSENSING)

Simplified load sense circuit



Lx

Ls

A

B

Xb Xa

Lx

Ls

ABXb Xa

"B" Supply to Valve

"X""L1"

"S"DestrokeServo

StrokingServo

A

B

Rotation

Feed

s

or Ls

Load Sensing



MP 18 and MP 22 DIRECTIONAL VALVES

These valves are load-sensing pressure compensated proportionalvalves. They control the volume, direction of flow and maintain aconstant flow regardless of changing load conditions. A valve mayalso have a feature that allows limits the pressure within its circuit tobe limited to less than maximum pump pressure. Individual valveswithin the system may have different maximum flow rates. This isdetermined by the design of the directional spools as well as the styleof compensator spool provided. Different compensator spring rateswill also affect maximum flow.

Each valve section contains a compensator spool and spring, aprimary shuttle valve and a secondary shuttle valve as well as thedirectional spool. These valves may be manually controlled,electrically controlled or pilot controlled. The valves used for theECM 720 are pilot controlled. The compensator spool in each valvesection regulates the flow. With the main spool in neutral, both theprimary and secondary shuttle valves are vented to the return or tank.At the same time, standby pressure from the pump is directed to thebottom of the compensating spool and shifts the spool to the closedposition. When the main directional valve spool is operated, thepressure generated by the load is directed via the primary shuttle tothe spring end of the pressure-compensating spool. Thecompensating spool begins to move to the open position. Dependenton the pressure drop between the section compensator anddirectional spool opening, a specific volume now flows to the functionbeing metered by the compensator spool. The load signal alsosimultaneously communicates to the secondary shuttle and on to theload-sensing valve on the pump causing the pump to come on stroketo deliver the flow required to satisfy the directional spool opening.Shifting the directional spool open to different positions creates anorifice of different size requiring more or less flow from the pump.

The pressure limiting feature of the valve is used control hammerpressure, feed pressure and rotation pressure during rod changing.The valve compensator section can be used as a pressure-limitingdevice when connected to a pilot relief valve. This allows anindividual valve section to operate at a limited pressure level lessthan the main pump compensator. In the case of the feed circuit the



pressure is limited by the feed pressure control in the cab. A remotepilot relief valve controls the hammer pressure.

Drawing above is a typical MP style valve. The color coding indicatesthe various internal passages. This valve is equipped with a solidcompensator and a motor spool. The valve is also pilot operated.



A

B

P

T

LsLxPilot connection

Pilot connection

Remote pressurecontrol connection

used on some valves

This orifice is onlyused with remotepressure control

feature

1

2

3

1. Primary shuttle valve2. Secondary shuttle valve3. Compensator valve



Typical MP valves.

Manual MP style valve equipped with a hollow compensator. Note the location of the shuttle valve.

Pilot operated MP Style valve equipped with a solidcompensator. This example is fitted with a compensator reliefvalve.

Primary Shuttle

Secondary shuttle valve

Compensator

Port relief valve

circuit relief



Typical MP22 pilot operated valve.

The inlet and outlet ports are located on the backside of thevalve. The LS load sense port is on the same section as theinlet and outlet ports.

The A and B (working) ports are on top of the valve.

End CapEnd Cap

Valve compensator section

Main valve spool

Remote port



ECM 710/720 System Pressure Settings

Hydraulic System Settings

Hydraulic Pump Compensator 3600 PSI (245 Bar) (Pump #1) Load Sense Standby Pressure 300 PSI (20 Bar) (Pump #1) Hydraulic Pump Compensator 3600 PSI (245 Bar) (Pump #2) Hydraulic Pump Standby Pressure 250 PSI (17 Bar) (Pump #2) System Relief Valve Setting 4200 PSI (289 Bar) Hydraulic Pilot Pressure 400 PSI (27 Bar) Rod Changer Pressure 2500 PSI (172 Bar) Dust Collector Pressure 2000 PSI (136 Bar) Maximum Feed Brake Pressure 300 PSI (20 Bar Rotation Pressure 1900 PSI (131 Bar(Rotation pressure in ARC mode) 1500 PSI (103 Barf)

Cooling Fan Motor Speed Variable(two separate units)

Air System Settings

Main air system pressure Max 150 PSI (10.2 Bar) Service Air Pressure 100 PSI (7.3 Bar) Grease Pump Pressure 80 PSI (5.5 Bar Dust collector Pressure 50-60 PSI (4 Bar)



Fluid Capacities

Hydraulic reservoir* 128 Gallons (485 Liters)

Fuel Tank 155 Gallons (587 Liters) Cooling System 17 Gallons (64 Liters) Compressor 10 Gallons (38 Liters) Tram Final Drive Planetarys 1.8 to 2 Quarts (1.9 Liters) Engine Oil 29 Quarts (28 Liters) *The hydraulic reservoir volume does not include refilling thehydraulic lines on the machine.

All the remainder of the capacities listed are for a complete refill.


Hydraulic Pumps Page 1 Chapter 2

Hydraulic pumps

The CM 760/780 units are equipped with 5 hydraulic pumps. Theyconsist of two axial piston, variable displacement pumps and threegear pumps. The piston pumps are of equal size and are mountedon pads at the rear of the engine. Both of these pumps are 5.18 in.3(85cc). The left-hand pump supplies the left-hand tram circuit and thefeed circuit. The right-hand pump supplies the right-hand tram circuitand the rotary head rotation circuit. The pump drives on the rearmounted gear box have a 1.3 : 1 speed increase.

The engine operates normally at 1800 RPM during drilling or highspeed tramming although engine speed can be lowered through theuse of a throttle control in the operators cab. The two piston pumpsare operating at 1.3 X engine speed. This means that the pumps areturning at 2340 RPM.

Maximum pump output is 52 GPM (223 liters).

Maximum pump pressure is 3600 PSI (248 Bar).

Both of the pump circuits are load sensing circuits. The standbypressure setting of both pumps is 250 PSI (17 Bar). Mounted on theauxiliary drive on the LH side (cab side) of the engine is a doublegear pump. The double pumps provide fluid for the two cooler fanmotors. The cooler circuits are discussed in chapter 3 of this manual.Just below the double pumps there is a single gear pump. This pumpprovides fluid for the drill positioning valve bank, rod changer valvesand the dust collector. Following is the technical data regardingthese pumps:

Double gear pumps (each unit) operate at 1.14 X engine speed.

2.54 In3 (41.6cc)

Volume @ 1800 RPM---------------22.5 GPM (85 LPM)

The single gear pump is mounted directly below the double pumpalso on the LH side (cab side) of the engine.



Single gear pump

1.37 In3 (22.5cc)Volume @ 1800 RPM---------------15 GPM (57 LPM)

Piston pump adjustment procedure

NOTE: These or any adjustments should be done with the hydraulicsystem at normal operating temperature.

Left-Hand Pump

1. Install a 5000 PSI (350 Bar) test gauge at the pump outlet test portfor the left-hand pump. The pump pressure test ports are locatedeither adjacent to the shuttle valve assembly mounted just above thepumps or on the test panel found in the enclosure access doorbehind the cab.

2. Disconnect the feed stop solenoid on the mode valve located inthe engine enclosure. (See chapter 4 for a description of the modevalve).

3. Place the drill/tram selector switch in the drill mode.

4. Start the machine and observe the test gauge. The reading on thegauge at this time should be standby pressure (250 PSI or 17 Bar).Set this pressure by adjusting the standby pressure control on thepump.



5. Have the operator or assistant place the feed control in thereverse position and depress the fast feed button. This will bring theleft-hand pump on stroke at its maximum setting.

6. Adjust the maximum pressure on the maximum pressureadjustment to set the pump pressure. The pressure value is 3600PSI (248 Bar).

Note: The pressure adjustments discussed here can be adjusted withthe engine in the idle mode. To prevent the engine from going to highidle, disconnect the load sense pressure switch located directly abovethe pumps at the back of the engine.

Be sure to reconnect the feed stop solenoid after the adjustment tothis pump are complete.

Right-Hand Pump

1. Install a 5000 PSI (350 Bar) test gauge at the pump outlet test portfor the right-hand pump. The pump pressure test ports are locatedeither adjacent to the shuttle valve assembly mounted just above thepumps or on the test panel found in the enclosure access doorbehind the cab.

2. Place the drill/tram control into the drill position.

3. Use the feed control and position the drill pipe under the rotaryhead so the breakout fork can be extended to lock the pipe. Loosenthe top thread and extend the rod lock over the end of the pipe.

4. Check and adjust the pump standby pressure.

5. Place the rotation control in the cab into the reverse position. Thiswill load the pump at maximum pressure.

6. Adjust the maximum pressure on the maximum pressureadjustment to set the pump pressure. The pressure value is 3600PSI (248 Bar).



Cross section of variable displacement piston pump used onCM760/780.

There is a system protection relief valve located in the inlet section ofeach of the main valves. To check the setting of this relief valve, it isnecessary to follow the same procedures as described above. Themaximum pressure setting of the pump must be increased to thepressure setting of the relief valve. The relief valve is set at 4200 PSI(290 Bar). Disconnect the load sense pressure switch to prevent theengine from automatically ramping up to high idle. Load the pump asdescribed in the appropriate section above. Slowly turn in themaximum pressure adjustment screw. Pay close attention to thesound of the engine, when the pump pressure reaches the reliefvalve setting the engine will start to lug. If this occurs at the properpressure no adjustment is required to the relief valve. This proceduredoes not need to be performed each time the pressure is checked



1.3:1 speed increaseEngine RPM=1800

"B" Supply to Valve

1.3:1 speed increaseEngine RPM=1800

"B" Supply to Valve

Pressure Compensator 3600 PSI (248 Bar)Standby pressure 250 PSI (17Bar)

"X""L1"

"S"

"X""L1"

"S"

Pressure Compensator 3600 PSI (248 Bar)

Note: The shaft speed ofeach pump is 2340 RPM

StrokingServo

DestrokeServoDestroke

Servo

StrokingServo

3

85 cc

Standby pressure 250 PSI (17 Bar)

5.18 in. 385 cc5.18 in.

Load sense pressureswitch (engine throttle)

To Pilot Pressure-Reducing Valve

Left Hand Pump Right Hand Pump

Left-hand Trammingand Feed

Right-hand Trammingand Rotation



Auxiliary Fan pump circuits

As was stated previously in this chapter, the double gear pumpsupplies fluid for the two cooler fan circuits. The operation of eachcooler circuit is the same. Because the pumps are positivedisplacement pumps, whenever the engine is operating, there is fluiddelivered to each circuit. The operation of these systems isdiscussed in chapter 3.

Single Auxiliary Gear Pump

The single section auxiliary pump supplies fluid for the dust hood,centralizer and dust collector/pipe changing functions as well as fluidto the positioning valve in the cab. It is a fixed displacement gearpump that operates a 1.41 X engine speed. Its displacement is 1.37in.3 (22 cc). Engine speed is 1800 RPM and that means that thepump is operating at 2538 RPMs. Pump volume at 1800 engineRPMs is 15 GPM (56 LPM).

3800 PSI(262 Bar)

3-section valve bankOPEN CENTER1. Dust hood2. Centralizers

7-section valve bankin cab (OPEN CENTER)

1.41:1

1.37 in.(22 cc)

3

3. Dust Coll/ARC



Notes:


Cooling & Return circuits Page 1 Chapter 3

Cooler Circuits

The cooler packages on the CM 760/780 consist of two separate coolerunits. They are; the engine radiator, which is mounted at the boom endof the engine enclosure and the hydraulic oil cooler and compressor oilcooler, which is mounted at the rear of the enclosure. A hydraulicallypowered fan moves air through each cooler. The fans are mounted tothe outside of the unit and pulls air through the cooler. This means thatoutside air is drawn through the power unit enclosure and exhausted bythe cooler fan.

Each fan circuit is equipped with its own hydraulic pump and motor. Avariable fan regulator valve controls fan speed.

General description of fan control circuit

The fan drive control assembly (FDCA) is an electrically controlled,normally closed proportional solenoid valve that provides a pilotpressure signal to the hydraulic fan drive system.

The system consists of an electronic module mounted on an aluminummanifold block containing a proportional solenoid relief valve. Theelectronic module receives temperature and auxiliary switch inputsignals and outputs a pulse width modulated signal to the valveproducing a pilot signal that is proportional to cooling demand. The pilotpressure provides a signal to the primary flow control device thatmodulates the fan speed.

In this gear pump/gear motor fan drive system, a switch valve ismounted near the motor inlet. The switch valve is normally closed andopens to divert fluid away from the fan motor to the reservoir.

When cooling demand is high, the FDCA increases pilot pressure,signaling the switch valve to divert more fluid flow to the fan motor, thusincreasing fan speed. As the cooling demand diminishes, the controldecreases pilot pressure signaling the switch to bypass fluid away fromthe fan motor, thus decreasing fan speed.



The regulating switch for the engine cooling fan is located in the engineblock. The switch for the compressor is in the discharge of thecompressor. The switch for the hydraulic system is located in thehydraulic return manifold. These switches are variable resistance typeswitches. As the temperature of the fluid passing across the switchincreases, the resistance across the switch decreases. This results in ahigher output signal from the fan control module. The highest output isapplied to the fan motor control valve. This results in a higher fan speedas the temperature increases.

Each of the temperature switches has a different control range. Theyare as follows:

Crack Full Open Shut Down Fan Start Full Fan

Hydraulic 1400F600C

1600F710C

1800F820C

1600F710C

1700F770C

Engine 1800F820C

2030F950C

2200F1040C

2050F960C

2120F1000C

Compressor 1800F820C

2050F960C

2480F1200C

2050F960C

2350F1100C

Note that the shutdown temperature of each circuit is shown in thechart.

Maximum fan speed is approximately 2100 RPM. Because the fancontrol system will normally operate at less than maximum speed,fan speed tests should be done with the fan motor control moduledisconnected.

Note: Because the control valve used in this circuit is normallyclosed, the fan will default to its high speed setting in the event ofan electrical fault.

The control module used in this circuit can only be tested using acomputer-based program. In the event of a problem with the fan circuitcontact the factory.



Fan control module

Shown on the following page is the hydraulic schematic for one fancontrol circuit. The circuit is the same on both of the cooler packages.

Variable Relief Valve

Pilot control module



Coo

ler

fan

mot

orco

ntro

l mod

ule

Flui

d su

pplie

d to

sec

ond

cool

er f

an c

ontr

ol.

Bot

hci

rcui

ts a

re id

enti

cal

Coo

ler

fan

spee

dco

ntro

l man

ifol

d

"PP

""P

"

"T"

3000

PS

I

204

Bar

Gea

r M

otor

2.01

in.

33 c

c.

3

1.14

:1 s

peed

incr

ease

Bot

h se

ctio

ns2.

54 in

. (4

2 cc

)3

To

retu

rn m

anif

old

Por

t R

m1

or R

m12

Eng

ine

RP

M=1

800,

pum

p sh

aft

spee

d 20

52M

axim

um f

low

eac

h pu

mp

22 G

PM

(83

LP

M)



Return Circuit

The return circuit consists of the plumbing and components that areinvolved in returning the working fluid back to the reservoir. It is madeup of the following:

1. Hydraulic reservoir

2. Return filters (dual canister with bypass)

3. Hydraulic oil cooler

4. Return manifold

5. Drain manifold

There are no adjustments required to the return circuit.



Ret

urn

filt

ers

Hyd

raul

ic c

oole

r

Ret

urn

man

ifol

d

140

F0

60 C0

10 P

SI

.7 B

ar

Res

ervo

irTank

bre

athe

r &

vac

uum

bre

ak

Hyd

raul

ic s

yste

mfi

ll pu

mp

Byp

ass

25 P

SI

1.7

Bar

10 M

icro

n

Abs

olut

e

Byp

ass

chec

k va

lve-

150

PS

I (1

0 B

ar)

Cas

e dr

ain

from

pist

on p

umps

Cas

e dr

ain

from

hydr

aulic

dri

fter

Dra

inm

anif

old

5 P

SI

Air

pre

ssur

e fr

om c

ompr

esso

r



Return Manifold

Return filters



NOTES:


Pilot Circuits Page 1 Chapter 4

Pilot Circuits

The drilling and tramming valves used in the CM760/780 arecontrolled by pilot pressure. Pilot pressure is supplied by either of themain hydraulic pumps through a shuttle valve to the drill/tram selectorvalve. The selector valve contains a pressure reducing valve thatlimits the pressure in the pilot circuit to 400 PSI (28 Bar). Incomingpressure from the main pumps may be as low as 250 PSI (17 Bar) oras high as 3600 PSI (248 Bar) under some circumstances.Remember, stroking either of the pumps will supply higher pressure tothe valve.

Adjustment of the pilot pressure valve:

The drill/tram selector valve can be identified as it has two solenoid-operated cartridges and an adjustable cartridge. There is also a largehex plug that exposes a screen filter. There is also a quick connecttest port on the valve body.

If the machine is running but neither the drill or tram functions arebeing used, the incoming pressure to the drill/tram selector valve isonly 250 PSI (17 Bar). This means that it is necessary to stroke oneof the main pumps to bring it on stroke and create a high enoughpressure to enable the setting of the pilot pressure cartridge. This iseasily accomplished by using the feed to lower the bit to the groundand leaving the feed lever in the forward or down position. Dial in thefeed pressure to at least 500 PSI (34 Bar) to be certain that the pumpoutlet pressure is over 400 PSI (28 Bar).

DM

Pilot pressure totram pilot valve

TC P DC

DR

400 PSI27 Bar

4

Test

Pilot pressure toFeed and Rotation

pilot valves

Supply pressure from shuttle valve at main pumps

Drill/tramselector valve



Tramming:

When the tram position is selected, the tram solenoid becomesenergized. This opens a flow path for fluid to be directed to the tramjoystick control in the cab. When the joystick is operated, pilotpressure is metered to shift the spool in one or both of the tramdirectional valves. This action directs fluid from the pump to the trammotors. The tram control used in the CM760/780 is a single levercontrol. Moving the lever straight forward or backward, directs fluidthrough both tram valves simultaneously so the machine will operatein a straight line. Moving the lever to either side will cause the tracksto counter-rotate turning the machine.



Drilling:

When the drill position is selected, the drill solenoid is energized. Theselector valve opens and directs pilot pressure to the drill control pilotcontrollers in the cab. There is one controller for the feed circuit and asecond controller that operates the rotation circuit. The forward portof the rotation controller is connected to a pressure-reducing valve.This pressure-reducing valve is used to regulate the rotation pilotpressure to the forward control port of the rotation valve. Theschematic on the following page shows the feed and rotation pilotcircuits.

DM

8

Right forward tram

Left reverse tram

Left forward tram

Right reverse tram

Left turnpoppet

Right turnpoppet

Forward travelpoppet

Reverse travelpoppet

Pilot pressure fromdrill/tram selector

valve Port TC

P

T

D

C

B

A



Feed control in cab

UP

2

Down

1

P

T

2

1

P

T

Rotation control in cab

FWD

REV

Pilot pressure fromDrill/Tram selector valve

Connections to feed valve in theengine enclosure

Rotation speed control in cab

Connection to reverse rotation

port on valve

Connection to forward rotation

port on valve



Notes:


Tram Circuits Page 1 Chapter 5

Tramming circuits

The tramming system on the CM 760/780 consists of right and left-hand track drive units. These are planetarys driven by hydraulicpiston motors. The tram valves are pilot operated valves and arecontrolled by a single lever joystick in the operators cab. Seechapter 4 for information on the pilot circuit.

Each tram motor is equipped with a dual counterbalance valve thatprovides dynamic braking while tramming. The counterbalancevalves on this unit are spool type CB valves. Earlier machine modelsused poppet style valves. The spool type valves allow for smootherstarting and stopping of the machine. Each final drive has a brake.The brake is a spring set-hydraulic release unit and serves as aparking brake. This prevents movement of the machine while it is setup for drilling.

As the tram valve is shifted the fluid it supplies is directed to themotor through the inlet check valve which is found in thecounterbalance valve manifold. Pressure begins to build at the motorinlet port but the motor cannot rotate because the brake is still in theset position. As stated in the previous paragraph the brake is aspring set-hydraulically released static unit. At the same time fluidcannot leave the motor because the outlet of the motor is blocked bythe counterbalance valve spool. When the pressure builds highenough the brake will release. The motor still cannot rotate until pilotpressure in the counterbalance valve increases to shift the spool toan open position. It is important to know that the brake releasepressure is always lower than the counterbalance valve setting. Thebrake releases, the counterbalance valve spool shifts to the openposition and the machine will begin to move.

NOTE: simply stated, pressure building at the inlet of the motoris used to open the outlet of the motor. The counterbalancevalve accomplishes this task.

The machine is equipped with a drill/tram selector switch. The tramcontrol is a single joystick control. The control joystick is a variablepressure pilot controller. Full speed control of the units is assured byfeathering the control lever.



There is button located in the upper portion of the control lever thatoperates the horn. When the selector switch is placed in the tramposition, pilot pressure at 400 PSI (27 Bar) is supplied to the tramjoystick located in the cab.

Turning the unit while tramming is accomplished by moving thejoystick control either right or left while tramming. Moving the leverforward and to the left will cause the machine to move forward whileexecuting a left turn. Moving the lever forward and to the right willcause the machine to move forward while executing a right turn.Moving the joystick directly to the left or right position will cause theunit to counter rotate in that direction. If the joystick is moved to therear for reverse tramming and at the same time moved to the side toexecute a turn it is important to note that the unit will turn the oppositedirection in which the lever is moved.

Adjustments: No adjustments should be required to this circuit.



APa B

Pb

APa B

Pb

Left Tram

Right TramA

B

A

B Left tram motor

Right tram motor

Pilot pressure fomdrill/tram selector

Tram pilot valve

D

C

A

B

Tram Valves-42 GPM (158 LPM) Maximum flow

BackupAlarmSwitch Final drive

74.3:1 reduction

Tram Motors5.05 in. /rev.83.6 cc/rev.

3

400 PSI (27 Bar)

Flow from Left-hand Pump

Flow from Right-hand PumpNOTE: The left-hand tram valve

is one section of a two-valve stackthat includes the feed valve.

The right-hand tram valve is one section of a two-stack valve that

includes the rotation valve



Notes:

SERVICE TRAINING MANUAL CM760/780

Feed System Page 1 Chapter 6

FEED SYSTEM

The feed system contains the following components:

1. Feed control joystick in the operators cab. This control is apilot control valve. Pilot pressure is regulated depending on theposition of the control lever. The control lever also is equippedwith the push button used to activate fast feed.

2. Feed pressure control located on the drill console in thecab. This control is a pilot relief valve, which sets the maximumfeed force applied to the bit.

3. Feed valve located in engine enclosure.

4. Feed motor counterbalance and brake valve. The valve islocated adjacent to the feed motor on the drill guide. The manifoldcontains the counterbalance cartridges and a pressure reducingcartridge valve for limiting the pressure applied to the feed brake.

5. Feed motor and brake assembly. The motor is a radial pistonunit with integral brake unit. The feed motor directly drives thefeed chain, no intermediate gearing is used. The displacement ofthe feed motor is 64.3 in.3 (1054 cc).

Operation of the feed circuit:

When the Drill/Tram selector switch is placed in the drill position, pilotpressure at 400 PSI (27 Bar) is directed by the drill tram selector valveto the joystick controls found on the operators seat arms. The feedjoystick is a proportional pilot control valve. Moving the joystick leverforward activates down or forward feed, moving the lever back activatesretract or reverse feed. Pilot pressure developed by moving the joystickis directed to the mode valve. When slow feed is being used, pilotpressure passes through the mode valve and shifts the slow feed spoolto the appropriate position. When depressing the fast feed buttonactivates fast feed, both of the fast feed solenoid valves located in themode valve are activated. This directs the pilot pressure generated bythe joystick also to the fast feed valve spool. When using fast feed, both



feed valves are activated. Control of the fast feed is still proportionaldue to the ability of the feed joystick to regulate pilot pressure.

When drilling, only the slow feed valve supplies the slow feed fluid.From the slow feed valve, fluid is directed to the Stratasense manifold.The operation of the Stratasense manifold is discussed in Chapter 6 ofthis manual. It is important to remember that the slow feed valve isproportional and is pressure limited by the feed pressure control in thecab. This means that even though the slow feed valve has a 5 GPM (19LPM) maximum flow rate the flow actually supplied will be only enoughto maintain the feed pressure as set in the cab. When fast feed is used,the fluid from the fast feed valve is directed to the feed motordownstream of the Stratasense feed control spool.

The last component of the feed circuit is the feed motor andcounterbalance valve. These components are mounted as the base ofthe drill guide. The feed motor is a Poclain 47.3in.3 (775cc) radial pistonunit with and integral brake. The Brake is a spring set/hydraulic releaseunit. The brake is 50% released at 100 PSI (7 Bar) and fully released at170 PSI (11.5 Bar).

The counterbalance valve package includes two (2) cartridge valves setat 3000 PSI (204 Bar). The opening pilot ratio of these valves is 10:1.The purpose of the counterbalance valves is the load-holding capability.The brake valve located in the counterbalance manifold is set at 300 PSI(20 Bar). There is a quick connect test port located on the manifold forchecking and adjusting the brake release pressure. It should be notedhere that the brake unit on the feed motor is rated for 475 PSI (32 Bar).Operating the feed with a brake valve setting higher than the maximumpressure capability will result in brake housing failure.

ADJUSTMENTS-FEED COUNTERBALANCE & BRAKE VALVE

The operator has full control of the feed pressure while drilling. The feedpressure adjustment is located on the tram console to the right of thedrill/rotation control joystick. The other components that may requireadjustment are the feed counterbalance valves and brake valve. Toadjust the counterbalance valves:



1. Use the feed lever and lower the drifter to the bit is on theground or the drifter to the bottom of the drill guide. This is veryimportant so the drifter cannot fall during the adjustmentprocedure.

SERIOUS INJURY CAN RESULT IF THE DRIFTER FALLSUNCONTROLLED.

2. Disconnect the feed motor working lines from the motor and jointhese two hoses together with a tee fitting. Connect a 1000 PSI (150Bar) gauge to the open port of the tee. Cap the motor ports to preventdirt from entering the motor.

3. Start the engine and place the feed valve in the forward position.Observe the test gauge. If the counterbalance valve is properlyadjusted, the gauge should indicate 300 PSI (20 Bar). If not, locate thecounterbalance valve cartridge opposite the FF (forward feed) port.Remove the dust cap. To lower the pressure, turn the adjustment screwin (clockwise). To increase the pressure, turn the adjustment screw out(counter clockwise). Be sure the retighten the locknut.4. To adjust the reverse feed counterbalance valve, have an assistanthold the feed lever in the reverse position and repeat the previousparagraph in reverse. If no help is available, the two counterbalancecartridges can be exchanged and use the same procedure as describedin paragraph 3. Reconnect the lines

To adjust the brake valve, lower the drifter so either the bit is onthe ground or the drifter is at the bottom of the drill guide.

1. Remove the brake line from the feed motor brake unit. Install a 1000PSI (150 Bar) gauge in the end of the hose. Cap the open brake port.The brake valve test port may also be used for this adjustment.

2. With the engine running and the drill / tram selector switch in the drillposition, place the feed lever in the down feed position. Check the feedpressure gauge and adjust the feed pressure to 1000 PSI (68 Bar) orhigher. Observe the test gauge. It should indicate



300 PSI (20 Bar). If it does not, remove the dust cap from the feedbrake pressure-reducing valve. Turn the adjustment screw out (CCW)to decrease the pressure or in (CW) to increase the pressure. Retightenthe locknut and replace the dust cap. If removed replace the brakehose.

Feed Motor, Brake and Counterbalance Valve

Brake

Feed Motor

Brake valve

Counterbalance valves



Cross section of typical feed motor



Feed counterbalanceand brake valve

300 PSI(20 Bar)

FVb

FVa

10:1 Pilot Ratio

3000 PSI(200 Bar)

3

Spring set-hydraulicrelease brake

Feed Circuit

Feed Motor64.3 in. (1054 cc)

17 GPM64 LPM

5 GPM19 LPM

A BA B Remote

P

Ls

T

FeedLeft Tram

Ls

T

P

XB

Up

XA Down

PCV2PCV1 CFV

XB

XA 1 2 3

4

56

7

8

9

FRRRP TDT

CRVPCV3

1. Feed up synchronizing valve2. Feed down synchronizing valve3. Fast feed solenoid valve4. Feed travel stop solenoid valve5. Forward rotation torque limit relief valve6. Reduced feed pressure up relief valve7. Solenoid valve that selects reduced up feed or normal up feed8. Fast feed solenoid for maximum up feed pressure9. Pilot valve for maximum reverse rotation pressure

2500 PSI(172 Bar)

1800 PSI(124 Bar)

Mode Control Valve

Service Training Manual ECM 710/720

Chapter 9 Page 7 Feed Circuit

Port identification (mode valve)

Port T is connected to the #1 port of the feed pressure relief valve inthe cab

Port DT is connected to the drain manifold.

Port F is connected to the forward feed pilot port of joystick in thecab.

Port R is connected to the reverse feed pilot port of the joystick in thecab.

Port RRP is connected to the reverse rotation port of the rotationjoystick in the cab.

Port PCV3 connects to the reverse pilot port on the rotation valve.

Port CRV connects to the remote pressure control port of the rotationvalve.

Port PCV1 connects to the reverse or up feed pilot port of the feedvalve.

Port PCV2 connects to the forward or down feed pilot port of the feedvalve.

Port CFV connects to the remote pressure control port of the feedvalve.



1. Adjusting the feed counterbalance valve and brake valve.

1. Use the feed lever and lower the drifter to the bit is on theground or the drifter to the bottom of the drill guide. This is veryimportant so the drifter cannot fall during the adjustmentprocedure.

SEVERE INJURY CAN RESULT IF THE DRIFTER FALLSUNCONTROLLED.

2. Disconnect the feed motor working lines from the motor and jointhese two hoses together with a tee fitting. Connect a 1000 PSI (150Bar) gauge to the open port of the tee. Cap the motor ports toprevent dirt from entering the motor.

3. Start the engine and place the feed valve in the forward position.Observe the test gauge. If the counterbalance valve is properlyadjusted, the gauge should indicate 300 PSI (20 Bar). If not, locatethe counterbalance valve cartridge opposite the FF (forward feed)



port. Remove the dust cap. To lower the pressure, turn theadjustment screw in (clockwise). To increase the pressure, turn theadjustment screw out (counter clockwise). Be sure the retighten thelocknut.

4. To adjust the reverse feed counterbalance valve, have anassistant hold the feed lever in the reverse position and repeat theprevious paragraph in reverse. If no help is available, the twocounterbalance cartridges can be exchanged and use the sameprocedure as described in paragraph 3. Reconnect the lines

To adjust the brake valve, lower the drifter so either the bit is onthe ground or the drifter is at the bottom of the drill guide.

1. Remove the brake line from the feed motor brake unit. Install a1000 PSI (150 Bar) gauge in the end of the hose. Cap the openbrake port. There is also a test port on the counterbalancevalve/brake valve manifold. This can be used to perform thisadjustment.

2. With the engine running and the drill / tram selector switch in thedrill position, place the feed lever in the down feed position. Checkthe feed pressure gauge and adjust the feed pressure to 1000 PSI(68 Bar) or higher. Observe the test gauge. It should indicate 300 PSI (20 Bar). If it does not, remove the dust cap from the feedbrake pressure-reducing valve. Turn the adjustment screw out(CCW) to decrease the pressure or in (CW) to increase the pressure.Retighten the locknut and replace the dust cap. Replace the brakehose.

2. Adjustments to the feed mode valve.


Rotation Circuit Page 1 Chapter 7

Rotation Circuit

One section of a double section MP18 valve (the other section is forright-hand tramming) controls rotary head rotation. During drilling thefluid supplied to the rotation comes from the right-hand hydraulicpump. As covered previously in this manual, the rotation pump is a5.18 in.3 (85-cc) displacement unit. The pump displacement isvariable with load sensing control. This means that the rotation valveis a load-sensing valve. The valve has a maximum flow rate of 33GPM (125 LPM). The valve also has a pressure compensated flowcontrolled inlet. Fluid flow to the rotation motor is determined by theposition of the main spool in the valve. The main spool is shifted bypilot pressure and by varying the pilot pressure the position of thespool can be changed. Pilot pressure can be adjusted in the cab toregulate rotary head forward rotation speed, which is necessary sothat rotation speed always remains the same for drilling. A singlelever pilot controller located on the right-hand armrest of the operatorseat controls rotation functions. Moving the lever forward activatesthe forward rotation; this is the normal drilling position. When thecontrol lever is moved to its rear position, reverse rotation isactivated. When the rotation lever is moved to the forward position,and drilling is taking place, pilot pressure from the forward rotationpoppet is being directed through the speed control pressure-reducingvalve. If the rotation lever is all of the way forward, the pilot pressurebeing delivered to the pressure-reducing valve will be 400 PSI (27Bar). The pressure-reducing valve lowers the incoming pilot pressureto deliver a lower pressure to the pilot operator port on the rotationvalve. This means that the rotation spool only opens proportionally tothe level of pilot pressure it receives. When the unit is placed in thepipe changing mode, a solenoid valve opens and bypasses pilotpressure around the pressure-reducing valve directing full pilotpressure to the rotation spool, it opens fully the rotation speed is at itsmaximum level. By setting the feed speed during pipe changing thecoupling and uncoupling can be synchronized to prevent undue wearto the threads on the pipe.

The rotation circuit is torque or pressure limited in the forward mode.This pressure is set on the mode valve. Reverse rotation pressure islimited only by the pressure compensator on the right-hand pump.



The rotation valve is equipped with a remote pressure control port.This port is connected to the remote relief valve. During drilling thisrelief valve is limiting forward rotation pressure. Forward rotationpressure is normally set at 2500 PSI (172 Bar). When the rotationcontrol is placed in reverse, a pilot controlled on/off valve is closed.This action isolates the remote relief valve out of the circuit and thepump compensator then limits the circuit pressure. The pressurecompensator is set at 3600 PSI (248 Bar). This means that there ismore pressure available for breaking out the pipe thread than thatdeveloped during makeup and drilling.

Adjustment:

To adjust the rotation torque limit valve it will be necessary to stall therotation. This can be accomplished by closing the centralizer on thebit. Place the drill/tram switch in the drill mode. Move the rotationjoystick to the forward position. This action will stall the rotary headand cause the rotation circuit to develop the maximum forwardpressure. The standard setting of the rotation is 2500 PSI (172 Bar).



Lx

Xb Xa

Ls

ABXb Xa

42 GPM158 LPM

33 GPM124 LPM

Remote port

PCV2PCV1 CFV

FRRRP TDT

CRVPCV3

2500 PSI(172 Bar)

1800 PSI(124 Bar)

Mode Control Valve

Rotation ValveRight-hand Tram Valve

1

2

Pilot pressure fromDrill/Tram Selector

Forward Rotation

Reverse Rotation

Rotation Speed Control Rotation ControlJoystick

Rotation Torque LimitRelief Valve

To RotaryHead

P

T

Rotation torque limitpilot valve

RotationCircuit



Rod Lock Sleeve System

To facilitate the pipe handling system on the CM 760/780, the rotaryhead is equipped with an extendable sleeve that slips over the squareend of the drill pipe. This is required when removing the pipe from adrilled hole. At this time, the pipe joint under the rotary head isloosened slightly so the sleeve can be extended of the square end.The breakout fork is extended to engage the lower pipe and the jointis loosened and uncoupled so the pipe can be place back into thecarousel. At this time full reverse torque can be applied to the jointthrough the rod lock sleeve.

There is a constant pressure maintained on the sleeve retract side ofthe sleeve. This pressure is supplied through the auxiliary controlvalve. This is a manifold valve assembly. The valve is located in theengine enclosure behind the operators cab. The rod lock sleevesection of the manifold is essentially separate from the otherfunctions of the manifold. . Pressure is supplied to the rod locksleeve from the auxiliary pump. This pressure is directed from theoutlet of the pump before its connection to the three-section valve.This pressure is directed to a pressure-reducing valve located in themanifold. This valve is normally set at 450 PSI (31 Bar). Becausethe auxiliary pump circuit always has a residual pressure of 500 PSI(34 Bar), there is always enough pressure to operate the rod locksleeve.

In operation, there is pressure directed to the bottom of the sleeve.The sleeve contains a .030 orifice that constantly bleeds fluid to thetop side of the sleeve. During drilling the top of the sleeve isconnected to return. This bleed prevents the fluid in the sleeve areafrom overheating and also maintains constant pressure to keep thesleeve from extending. When the sleeve is extended to remove pipefrom the hole, 450 PSI is directed by the control valve to the top ofthe sleeve. Because of the greater area of the top of the sleevecompared to the bottom of the sleeve the sleeve extends.



1500

PS

I

A2

B2

A5

B5

A4

B4

100

Bar

P

T

A3

B3

IP

.030

Air

Con

nect

ion

FRR

RR

otar

y

Mot

or

Rod

Lock

D RLE

RLR

Cha

inW

renc

hC

arou

sel

Rot

atio

nR

ear

Jack

(op

t)G

roun

dW

inch

(opt

)

450

PS

I31

Bar

3400

PS

I

234

Bar

EP

RLR

1

Pre

ssur

e fr

omA

uxili

ary

Pum

p

Pre

ssur

e in

thi

s lin

e w

ill n

orm

ally

be a

t le

ast

500

PS

I (3

4 B

ar)

whi

chis

ade

quat

e to

ope

rate

the

rod

lock

slee

ve.

AR

C/D

CV

alve

Rod lock circuit



DDRH Rotary Head (early style)

Early CM 760 and CM 780 units were manufactured with the latestversion of the DDRH rotary head. This style head is fitted with a topmounted air swivel arrangement. The rotary motor drive system is adirect drive 64 in.3 (1048 cc) radial piston motor. The rotary headuses the breakout sleeve system for pipe thread breakout. The airswivel is fitted with chevron packing. A hand-operated grease gun isrequired to keep the packing loaded. The grease fitting in thepacking housing does not have a built in check valve so excessivegrease pressure cannot be applied.

Note: Do not use standard grease fittings in place of the pointindicated with the red arrow. Remove the spring and ball from thefitting so excessive grease pressure cannot be applied to the packing.



Spindle adapter

The spindle adapter is the replaceable part found in the end of therotary head hollow shaft. It has 3 1/2 API male thread to engage thespindle and the female thread will either be 2 or 2 Z thread.

Replacing the Spindle Adapter

The spindle adapter is a wear part that will require replacement. Thiscan be accomplished with the rotary head at the bottom of the drillguide and the guide vertical. Allow some space below the loweredhead for removal of the parts. Blocking should be installed underthe rotary head mounting plate for additional safety.

Removal and replacement of the spindle adapter requires theremoval of the front housing and rod lock sleeve. This willexpose the adapter, which is threaded into the end of the rotaryhead spindle.

1. Vent the air pressure from the hydraulic tank by removing thepressure gauge temporarily. Apply a vacuum to the vent port on thehydraulic tank if available. Remove all of the hydraulic lines from thelower section of the rotary head. Plug, cap and tag all open hosesand connections. Remove the rod lock housing by removing the12mm socket head screws from the bottom. There are two threadedholes that can be used for drawing the front housing loose. The rodlock sleeve may come out with the lower housing so be careful, asthese parts are heavy. With the lower housing and rod lock sleeveremoved, the flats on the spindle adapter are now accessible.

2. The rotary head spindle must be locked before the adapter can beremoved. Use capscrews from the rod lock housing to install thelocking plate (52129111). The locking plate slips over flats machinedinto the spindle. The spindle may need to be rotated to align thethreaded holes in the bearing housing with the locking plate.

3. Attach the appropriately sized J wrench to the breakout cylinderto loosen the adapter. The breakout cylinder must be extended toloosen the adapter. The locking plate may need to be indexed



relative to the spindle adapter to allow for maximum torque to beapplied to the J wrench.

Note: It may be necessary to increase the extend pressure forthe breakout cylinder to loosen the adapter.4. After the old adapter has been removed, thoroughly clean the APIthreads in the end of the spindle as well as on the new adapter.

5. When installing the new adapter, use LOCTITE primer #T747 andcoat the threads with LOCTITE #680 (cpn #51948727) thread lock.Install the adapter into the spindle and torque to 4500 lb-ft. (6100Nm.) If the breakout cylinder is used for the retorque of the spindleadapter, it will be necessary to increase the pressure to the retractside of the cylinder to 2500 PSI. (175 Bar) to develop an adequateamount of torque.

Note: the breakout cylinder will deliver maximum torque when itis almost fully retracted.

6. Allow ample curing time for the LOCTITE #680. If the primer isused, the bond will be partially cured in 5 minutes and fully cured in 4to 6 hours. If the primer is not used the partial cure time is extendedto 30 minutes.

7. After the replacement of the spindle adapter is complete,reassemble the rod lock and front housing to the rotary head. Usecare during the installation process to prevent damage to the rod lockseals. Reconnect all hydraulic lines.

Replacing the Chevron Air Packing

To replace the chevron air packing the following steps should befollowed:

1. Remove the six (6) socket head 3/8 cap screws that secure thegooseneck to the air swivel.

2. Remove the ten (10) socket head M16 cap screws the secure thebase of the air swivel housing to the rotary head.



3. The chevron packing can then be removed from the swivelhousing.

4. Inspect the washpipe for wear and/or looseness on the threads atthe end of the spindle.

5. The thread on the end of the spindle is a left-hand thread. Ifretightening is required, apply LOCTITE as described on page 14or page 27 of this section of the manual. A special tool cpn52291176 is required for this operation.

6. When the LOCTITE is applied, be sure to allow ample curing timeto prevent loosening prematurely.

7. Install the new chevron packing as shown on the drawing on page28 of this section.

8. Reinstall the swivel housing and gooseneck after grease has beenapplied to the new chevron packing.

9. Grease both grease fittings on the swivel before restarting the unit.

Replacing the spindle and/or spindle bearings

The drawing on page 11 can be used to identify various parts ofthe rotary head.

1. Remove the rod lock assembly and swivel housing as described previously in this section.

2. Unthread the washpipe from the end of the spindle. This willrequire the special tool cpn 52291176. NOTE: The threads in thewashpipe are left-handed. Remove the seal plate directly underthe washpipe.

3. Remove the twelve (12) M16 socket head capscrews that retainthe hydraulic motor assembly to the bearing housing. Set themotor assembly aside being careful to keep the assembly clean.



4. Remove the twelve (12) M16 socket head capscrews that securethe top bearing plate. NOTE: The bearing plate is designed toprovide the proper preload on the spindle bearings when tighteneddown.

5. At the bottom of the bearing housing, remove the eight- (8) M12capscrews that retain the lower seal plate. Remove the seal platefrom the housing.

6. Remove the spindle from the bearing housing. The top bearingcup is a slip fit into the housing.

7. If the bearings (cups and cones) are to be reused, carefullyremove the cones from the spindle. These will have to be pressedonto the new spindle.

8. If the bearings are being replaced, the cone for the lower bearingwill have to be pressed into place.

9. To reassemble the head, reverse the disassembly procedure. Thewashpipe and spindle adapter must be installed with LOCTITE.Use LOCTITE primer #T747 and coat the threads with LOCTITE#680 (cpn #51948727).

The torque specifications for the fasteners used in the rotary head areas follows:

M12 (grade 10.9) (lubricated threads)-------------55 lb-ft or 100 Nm.

M16 (grade 10.9) (lubricated threads)-----------138 lb-ft or 250 Nm.


Air System Page 1 Chapter 8

Air System

Compressed air for operation of the down hole hammer as well as thedust collector and thread greasing system is provided by an HR2compressor in the CM 760 and an HR2.5 in the CM 780. The CM760 supplies 636 CFM at a maximum pressure of 350 PSI (24 Bar).The CM 780 supplies 855 CFM at a maximum pressure of 350 PSI(24 Bar).

The compressor on each of these units is fitted with a normally closedinlet valve. A solenoid valve is used to load the compressor. Thisvalve is energized only when the drill/tram mode switch is placed inthe drill mode. This means that the compressor will remain at lowpressure, 100-120 PSI (6.8-8.3 Bar) during warm up and duringtramming.

Unloader Components

The inlet unloader includes the airflow regulation valve, the anti-rumble valve, pressure regulation and the blowdown valve within theunloader housing. The inlet valve is also equipped with a high-lowpressure feature.

Startup

The unloader allows the engine to start with the compressorunloaded. This provides for easier starting, especially in coldweather. For the first minute of running, the compressor cannot beloaded. This gives the engine time to achieve stable operation andestablish full oil flow through the engine and compressor. Allowseveral minute of idle run time before operating any system on themachine. This allows the engine to warm up before putting it underload. The engine can only be started with the drill/tram switch in theneutral or center position. The compressor is unloaded at this time.During the warm up time period, the compressor receiver tank willslowly build up to 100 PSI (6.8 Bar) to 120 PSI (8.2 Bar). Thisnormally takes about one minute. Once the receiver tank pressurehas reached this level, the compressor can be loaded. If thepressure buildup takes too long, switching the drill/tram selector tothe drill position will speed up the process.



Running Loaded

When the drill/tram selector switch is placed in the drill position, thereceiver tank will build up to the maximum pressure setting of the inletunloader. There is a low-high pressure switch on the left-handjoystick that allows the operator to select either setting. The lowpressure setting is 200 PSI (13.7 Bar) and the high-pressure settingis 370 PSI (25.5 Bar). The compressor pressure will build up to thepressure setting that is selected. If the switch in the cab is set forhigh pressure, it can be switched at any time to the low setting.Receiver tank pressure will then begin to drop to the low-pressuresetting. This reduction of pressure may take a minute or more. Itmay in some cases, be desirable to collar the hole at the low settingto prevent excessive blowout of the top of the hole.

Shutting down

When the unit is to be shut down, it should be allowed to run forseveral minutes with the compressor in the low-pressure mode beforestopping the engine. In an emergency the unit can be stopped withthe compressor in any operating mode. In any shutdown situation,the compressor will blow down through the inlet valve. The noiseduring blow down is much less noticeable than with older unloadersystems so be sure that the pressure has dropped to 0 PSI beforedisconnecting any lines on the air system. To be absolutely safe,open the manual blowdown on the top of the receiver tank.



Adjustment of the unloader

The illustration above shows the adjustments required to theunloader.

High Pressure Adjustment:

The high-pressure adjustment screw set the pressure at which theunit will unload on the hi-pressure setting. Run the unit loaded andwhen warm, turn the screw indicated clockwise to raise the pressure.Set the warm unloaded pressure to 380 to 390 PSI (26-27 Bar). Thissetting will allow the unit to start unloading at 350 PSI (24 Bar). Lockthe screw in position with the nut. New units often needreadjustment after the first hours of running,



Low Pressure Adjustment:

After the high pressure is set, the low-pressure screw will set the lowpressure setting. Place the hi/low switch in the cab to the low-pressure position. Turn the screw clockwise to raise the low pressuresetting. The minimum pressure available is 200 PSI (13 Bar). Lockthe screw in position with the nut.

NOTE: Always set the high pressure prior to setting the lowpressure.

Unload Stability Adjustment:

The Unload Stability Adjustment Screw adjusts the leak rate into theunloader to compensate for different tolerances of the unloaderinternal parts. This adjustment can solve several annoying problems,such as too much discharge pressure oscillation at idle/unload. Asmall amount of oscillation is acceptable, for example: cyclingbetween 370 and 390 PSI (25-27 Bar) over a period of about 30seconds. A good starting point for adjusting this screw is 1.25(31mm.) between the screw head and the top of the nut. This is themaximum leakage rate position and screwing it out any further will nothave any additional effect. Turn the screw in to reduce unloadedcycling. Another potential problem is if the start/unload pressure isless than 100 PSI (6.8 Bar) (unload/run switch is set to the unloadposition). If this pressure is to low, the unloader will not respondquickly when the unload/switch is switched to run. Screw the stabilityscrew in to raise the start/unload pressure to 100 PSI (6.8 Bar) toobtain proper response. Use this adjustment screw carefully. If thescrew is turned in to far, then pressure will build up in the receivertank during normal unloading when the switch is set to run. This cancause pressure in the receiver tank to climb high enough to pop thesafety relief valve. Always check to see that the unloaded pressure isstable during normal unloading after adjusting this screw. Lock thescrew in position with the nut after adjustment.



The above picture shows the major components of the unloadervalve. Refer to previous 2 pages for adjustment procedures.



Inlet valve removed from compressor

Operation of inlet valve:

As stated previously in this chapter, the inlet valve is a normallyclosed valve. The inlet valve consists of two main components. Firstis the check valve that is spring loaded to the closed position.Whenever the unit is making air, the inlet valve is pulled open by theairflow. It the airflow stops (for example the engine runs out of fuel),the check valve will close and prevent oil from entering the aircleaner. Second, the inlet valve sleeve that opens and closes toregulate or shut off inlet airflow to the compressor. Control airpressure from the regulation system opens the sleeve valve (see thediagram on the page 12). In this diagram the green represents thepressure signal from the receiver tank, the blue represents controlpressure and the light green is connected to atmosphere (airendinlet). When the control pressure is less than 50 PSI (3.4 Bar), theinlet valve is closed (unloaded). From 50 PSI (3.4 Bar) to 120 PSI(8.2 Bar), the inlet sleeve regulates to full open. Above 120 (8.2 Bar),

Start/RunSolenoid

High/lowSolenoid



the inlet valve is fully open. Control pressure opens the inlet valve inthis system, whereas in most systems, the inlet valve is closed bycontrol pressure. When it is closed there is no control pressure to liftthe inlet valve and the compressor does not make air. When theengine is running the compressor will slowly build pressure up toabout 100 PSI (7 Bar) even when the start/run solenoid is off and theinlet sleeve valve is closed. This brings the system pressure up sothe unit is ready to run. When the start/run solenoid is energized,receiver pressure is directed to the air chamber under the regulatorspool (bottom of the three ports on the side of the unloader housing).The bottom of this spool has clearance to allow receiver pressure toleak by and become control pressure (the middle of the three ports onthe unloader housing). This control pressure opens the inlet valve.When the inlet pressure reaches 200 PSI (13.7 Bar) (high/low valvein the low pressure position), there is enough force on the bottom ofthe regulator spool to lift it up against the spring to open the vent tothe inlet (top of the three ports on the unloader housing). This ventsthe control pressure back to zero, causing the inlet sleeve valve to falland close the inlet. When the high/low valve is in the high-pressureposition, the top red spool is pushed down so that it compresses thespring. In this case, the lower red spool valve will not lift and vent thecontrol pressure until the compressor discharge pressure reaches350 PSI (24 Bar). In either case, high discharge pressure or lowdischarge pressure, the control pressure opens the inlet valve from50 PSI (3.4 Bar) to 120 PSI (8.2 Bar). The high/low solenoid is anormally off (not energized). This means that pressure on top of thered spool is vented to inlet and cannot build up to compress thespring. When the high/low solenoid is energized (closed), pressurecan build up to compress the spring. The unloader assembly alsoincludes an anti-rumble valve. The diagram on page 14 depicts across section of this part of the assembly. Whenever the controlpressure (middle port) drops below 50 PSI (3.4 Bar) (inlet valveclosed), this valve opens and lets a small amount of air enter theairend to keep the rotors from rumbling. Air will also vent into theinlet (past the stability screw) to keep the separator tank pressurefrom building up and popping the safety valve. When the engine isshut down, this valve opens up automatically to blow down theseparator tank. This blowdown air goes into the airend inlet pipeand comes out of the air filter.



It is important to note that receiver pressure that is directed to the airmanifold on the unloader housing is mostly dry air. However, a smallamount of wet air (oil mist) is directed through a .030 orifice tolubricate the internal components of the inlet valve.



The drawing above shows the inlet valve open and the compressordelivering air to the receiver tank. The upper red spool is held downby receiver pressure.



When the unit is to be shut down, the high/low switch in the cabshould be placed in the low position and the unit allowed to run forseveral minutes prior to stopping the engine. When the engine isstopped, the inlet valve is closed and air pressure in the compressorunit closes the red check ball. This prevents air and oil from backingup into the inlet filter and into the control circuits. Pressure from theair receiver tank bleeds through the anti-rumble/blow down valve atthis time. Always be sure that the pressure in the receiver tank iscompletely evacuated before opening any line on the unit.



The HR2 & HR2.5 use synthetic fluid in its operating cycle. The unitis shipped with Ingersoll-Rand XHP505 fluid from the factory. Do notuse any other fluid that may not be compatible with the recommendedfluid.

PRINCIPAL OF OPERATION:

Up to this point we have discussed the control principals of the HR2 &HR2.5 system. Air is allowed to enter the primary or low-pressurestage of the compressor through the open inlet sleeve valve. The airenters because the rotating compressor rotors create a vacuum atthe inlet end of the unit. The primary stage handles a large volume ofincoming air. The incoming air is trapped by the rotors and carriedforward between the rotors and the compressor housing to the outletof the primary unit. At this point the air from the primary rotors issupplied to the secondary rotors. The air is compressed further anddelivered to the receiver tank. When the machine is drilling, the high-pressure air from the receiver tank is

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