s01 hydraulic cylinders - tmk

C 47150 -- 3 en 0205 / JKn

HYDRAULIC CYLINDERS1 (8)

2005SANDVIK TAMROCKCORP.,TamperePlant,P.O.Box 100FIN--33311 TAMPERE, FinlandTel. +358 205 44 121Telefax +358 205 44 120

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REPAIR AND ADJUSTMENT

CONTENTS

1. GENERAL 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.1. Structure 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2. SAFETY 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3. OVERCENTER VALVE 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.1. Operation 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4. COMPONENTS 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5. DISMANTLING 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.1. Cylinder 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.2. Piston 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.3. Inspection 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.4. Replacing of bearings bushing 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6. ASSEMBLING 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.1. Assembling of cylinder 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7. TESTING OF CYLINDER 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.1. Line A, inspection 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.2. Line B, inspection 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2 (8) C 47150 -- 3 en 0205 / JKn

HYDRAULIC CYLINDERS

2005 SANDVIK TAMROCK CORP., Tampere Plant,P.O.Box 100FIN--33311 TAMPERE, FinlandTel. +358 205 44 121Telefax +358 205 44 120

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1. GENERAL

1.1. Structure

The main structural differences between hydraulic cylinders are:D single and double actingD cylinder boreD strokeD overcenter valve equipment

Stroke can be limited with a spacermounted either to the piston side or the piston rod side.Correct type of spacer is given in the spare parts list.

2. SAFETY

Acquaint yourself with the service and user instructions before startingto work on a cylinder. Learn to know all the components that you will beworking on.

Follow the installation instructions issued by Tamrock

Installation, adjustment and repair work can only be carried out by aperson who has the necessary qualifications and knows the equipment.

Proper use and service guarantee longer life of the hydraulic cylinder.

Use all necessary safety devices and check their condition.

Before starting the rig, make sure that nobody is working close to, orunder the rig

Never disconnect any hydraulic hoses or valves beforemaking sure thatthere is no static load in the system.

CAUTION

CAUTION

CAUTION

CAUTION

CAUTION

WARNING

WARNING

C 47150 -- 3 en 0205 / JKn



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3. OVERCENTER VALVE

3.1. Operation

Most hydraulic cylinders are equipped with an overcenter valve. They are either built--inor connected to the hydraulic circuit via hydraulic hoses.

1

Overcenter valves are one--piece components and they cannot be readjusted. Sets ofseal rings (1) are provided. The four tasks of an overcenter valve are:

-- If a hose connected to the hydraulic cylinder breaks, the overcenter valve acts asa safety valve.

-- During drilling, the overcenter valve prevents oil flow from the cylinder to the oiltank. Theboommaintains accurately the position towhich it wasmoved to by usingthe boom control valves.

-- When the boom is moved, the overcenter valve does not allow oil to flow from thereturn side until the pressure on the pressured side rises high enough. Boommovements are smoother and more accurate, and the boom’s own weight cannotaccelerate the speed movement.

-- If an external force raises the pressure in the cylinder higher than the set value ofthe overcenter valve, the valve opens and lets oil out of the cylinder. This enablesthe boom to yield under external force, and mechanical damage to the boom canbe avoided.

The set value of the overcenter valves for different purposes aredifferent. Therefore, youmust replace an overcenter valvewith one froma other cylinder. the set value of the valve is punched on the top of thevalve.CAUTION

4 (8) C 47150 -- 3 en 0205 / JKn

HYDRAULIC CYLINDERS


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4. COMPONENTS

4 76 3

58

92

110

10

Components of a cylinder

1. Socket screw 6. Locking plate

2. Cylinder cover 7. Rod nut

3. Piston 8. Piston rod

4. Overcenter valves 9. Spacer

5. Cylinder tubes 10. Bearing bushing

476 3

58

92

10

10

Components of a cylinder (threaded cylinder cover)

C 47150 -- 3 en 0205 / JKn



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5. DISMANTLING

Before starting to remove the cylinder,make sure that the boom is properly supported, andany static loads of the cylinder are removed. Disconnect the hydraulic hoses to thecylinder and plug the open hose ends and cylinder adapters.

Remove the locking rings of the cylinder pins, support and secure the cylinder so that itcannot fall down. Tap the pins out.

Wash the cylinder externally before starting to dismantle it. Mount the cylinder firmly at thelug in the cylinder tube end.

5.1. Cylinder

If you can use hydraulic pressure, connect the hoses to the cylinder and run the pistonrod (8) out, remove the overcenter valves (4). Unscrew the socket screws off of the cover(2) or, if the cover is thread mounted, open the cover with a suitable tool. Screw theovercenter valves (4) back, and run the piston rod (8) and the cylinder cover (2) out.Whenpressing out, support the piston rod (8) properly to get it out smoothly.

5.2. Piston

Mount the piston rod firmly from the eye end, and tap out the locking washer lug from thegroove of the nut, and remove the nut (7). Remove the piston (3) together with the seals.Pull the cylinder cover (2) off the piston rod and remove the cylinder cover seals and thewiper and replace them. Unscrew the overcenter valves (4) from the cylinder tube andvisually check their condition. Wash all components.

5.3. Inspection

Replace all seals and wipers. Check all sliding surfaces. If scratches, big enough to feelwith a fingernail are found, should the components be replaced because the sealing abilityof the surfaces is no longer good. Also check the piston rod for straightness. If the rod isdistorted, check that it is not caused by a incorrect spacer. Check the condition of thebearing bushings (10), and replace them if there are any marks of wear.

5.4. Replacing of bearings bushing

If the cylinder already has been removed from the rig, support the cylinder well and tapthe old bearing bushings out using a suitable drift and a copper hammer.

The new bearing bushings are easier to install if they are cooled in a freezer, and thecylinder eye is warmed up with a torch.

6 (8) C 47150 -- 3 en 0205 / JKn

HYDRAULIC CYLINDERS


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6. ASSEMBLINGIf the stroke of the cylinder is limited with a spacer and it is left out, thecylinder can be damaged in use. Check that you install the correct typespacer.

6.1. Assembling of cylinder

Grease the seal grooves and install theO--rings, the lip seal and the guide rings onthe cylinder cover (2). Install the cover ofthe piston rod (8). If a spacer (9) is used tolimit the maximum stroke of the cylinder,install the bushing on the piston rod beforeinstalling the piston.

Grease the seal grooves and install thepiston seal (10). When installing thepiston’s O--ring (11), be careful not todamage it in the piston rod thread. Installthe locking plate (6) and the locking nut (7).Tighten the nut and lock it in a place byturning a tang of the locking plate into itsgroove.

The piston rod and the cover assembly

CAUTION

2

8

9

11

7

6

10

C 47150 -- 3 en 0205 / JKn



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Check if the minimum stroke of the cylinder is limited. If it is, the spacer must be insertedinto the cylinder first. Push the piston assembly into the cylinder. Remember to lubricatethe seals before assembling!

Push the cylinder cover (2) in and insert the socket screws (1) through the cover andtighten them. If the cylinder cover is thread--mounted, use a special tool for tightening.

Install the overcenter valves (4) and the adapters, and test the cylinder.

4

2 1

A assembled cylinder

8 (8) C 47150 -- 3 en 0205 / JKn

HYDRAULIC CYLINDERS


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7. TESTING OF CYLINDER

1012

11

13

A

B

14

Testing of cylinder

7.1. Line A, inspection

Run the piston rod completely out. Disconnect line A, and pressurize line B. Check lineA for leaking oil. If oil leaks out, one of the seals (10, 11 or 12) or overcenter valve is faulty.

7.2. Line B, inspection

Run the piston rod completely in. Disconnect line B, and pressurize line A. Check line Bfor leaking. If oil leaks out, one of the seals (10, 11 or 12) or the overcenter valve is faulty.If oil comes out from between the cylinder cover and the cylinder tube, the cylinder coverO--ring (13) is faulty. If oil comes out from between the cylinder cover and the piston rod,the cylinder cover O--ring (14) is faulty.

s01 hydraulic cylinders - tmk

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