technical service manual - nook · pdf fileciency of the drive mechanism. ... the lifting...

2 • Nook Industries, Inc. • www.nookindustries.com

CAUTION: The ActionJac™

Electric Cylinders may be self-low-ering, therefore the customer mustprovide some means of holdingthe load.

The user is responsible for provid-ing stops at either end of travel.Limit Switches or external safetystops are recommended, sincefailure of brake or system compo-nents could cause self-lowering.Your Electric Cylinder is equippedwith internal stops. These stopscan cause damage to the cylinderbecause most electric motors willdeliver stall torques much higherthan their rated torques and motorinertia can cause severe shockloads. The stops are for over trav-el only. For hand operation, the inter-nal mechanical stops can be utilized.

General InstructionsYour ActionJac™ Electric Cylinder isa high quality, sturdy unit designedto give many hours of trouble-freeservice. However, certain precau-tions and procedures must beobserved in handling, installing andservicing the unit in order to obtainoptimum performance.

1. Any apparent or suspecteddamage sustained by equip-ment manufactured or furnishedby Nook Industries during trans-port from the factory to the usershould be immediately reportedto both Nook Industries and tothe carrier.

2. Upon delivery all equipment fur-nished should be carefullyinventoried against shippingpapers to determine whetherany shortages exist in delivered

material. Any such shortagesmust immediately be reported toNook Industries and the carrier.

3. The installation of NookIndustries ActionJac™ ElectricCylinders does not normallyrequire the services of a factoryengineer. These services are notincluded in the selling price ofthe equipment unless specifical-ly agreed upon in writingbetween the seller and purchaser.

4. The Seller’s warranty appliesinsofar as the unit is operatedwithin the rating and serviceconditions which might typicallyinclude vibratory loads due tocritical speeds, severe shockloading, mechanical or thermaloverloads or side loads if theseller was not fully advised oftheir existence at time of order.

5. Adequate installation, mainte-nance and safety instructionsmust be given by the user topersonnel directly responsiblefor the installation and operationof the equipment.

6. In the event of malfunction with-in the warranty period, the man-ufacturer must be informedwithin thirty days if it is intendedthat the warranty is to cover theincident.

Ordering SpareAnd Repair PartsThis booklet contains generalinstruction, operating, maintenanceand troubleshooting instructions foryour ActionJac™ Electric Cylinder. Inthe event spare or repair parts are

Technical Service Manual 3/25/03 2:26 PM

www.nookindustries.com • Nook Industries, Inc. • 3

required, call your local representa-tive or contact Nook Industries at216-271-7900 or 800-321-7800.

Please provide the following infor-mation when requesting spare /repair parts:

• Serial Number (located on hous-ing nameplate)

• Part Description (see pages 6-7)

CAUTION: UNITS ARE NOTMEANT FOR PERSONNEL SUP-PORT. Refer all applications forpotential personnel support to thefactory for review.

General SpecificationsThe worm gear driven ActionJac™

Electric Cylinder incorporates analloy steel worm gear, accuratelymachined to the high standards ofNook Industries for maximum loadcarrying capacity and uniformity ofmotion transmission. All shafts aremounted on heavy duty, anti-frictionbearings to increase operating effi-ciency of the drive mechanism.Thrust bearings are provided tosupport the rated thrust load ofeach unit. Housings are made ofhigh strength material, well propor-tioned to handle the rated thrustand torque loads of each size unit.Actuator tubes are ground and hardchrome plated for use in industrialenvironments.

The lifting screw cover along withactuator tubes are designed to keepthe lifting screw threads free of for-eign material.

The lifting screw is made of 4100Series steel. The threads of the lift-

ing screw should be well lubricatedand kept free of grit, dirt or otherabrasive contaminates. For this rea-son, the actuator tubes areequipped with seals and lubricationfittings.

CAUTION: DD and RADElectric Cylinders should not beoperated at input speeds over1,800 RPM without consulting thefactory. ILA and ILAK ElectricCylinder speeds are a function ofthe critical speed of the screw.Consult factory if exceeding cata-log ratings.

DD and RAD Electric Cylinders aredesigned for a maximum intermit-tent duty cycle of:

Ball Screw versions = 35%Acme Screw versions = 25%

Housing temperature should bemonitored and kept below 200°F.

LubricationGear Box EnclosureElectric Cylinders are shipped withgrease in the unit. However, beforeoperating any unit, remove thehousing plug and check the condi-tion of the lubricant. Lubricationinspection is recommended at regu-lar intervals. Usually one monthintervals are satisfactory unlessexperience indicates that regreas-ing should occur at shorter orlonger intervals. Severe operatingconditions will shorten the lubrica-tion inspection interval.

Each Electric Cylinder is furnishedwith a grease fitting and a pipe plug



on opposite sides of the gear hous-ing. After removing the pipe plug, fillunit with grease until lubricantseeps from the pipe plug.

Lift Shaft EnclosureThe lift shafts inside the ElectricCylinder actuator tube receive lubri-cation through the fittings on theoutside of the housing tube.Lubrication added to the housingtube can pass to the screw regard-less of the actuator tube position,but there is a guide at the bottomoutside of the actuator tube whichruns along the inside of the housingtube. The best way to lubricate thissection of the cylinder is to addsome lubricant when the cylinder isfully retracted and additional lubri-cant when the cylinder is extendedbeyond where the guide is past thelube port (see pages 6 – 7).

The type of lubricant used shouldnot be corrosive to gears, ball orroller bearings and must be neutralin reaction. The lubricant must notcontain any grit or dirt, abrasives orfillers. It should not precipitate sed-iment, nor separate at temperaturesup to 300°F. The lubricant must alsohave resistance to oxidation andmust be non-channeling. We rec-ommend the following extremepressure greases or equivalents.For operating conditions outsidethese limits consult factory.

Company/Trade Name Temp. RangeExxon / Lidok EP#1 -30 to 225°FMobil / Mobilux EP#1 -20 to 225°FGulf / Gulf Crown EP#1 0 to 300°FShell / Aeroshell #22 -85 to 400°F

In normal environmental range (32°Fto 160°F), oil or a good grade of

light bearing grease may be used.Grease containing graphite or moly-disulfide should not be used. Useonly enough lubricant to maintain athin, continuous film.

All units are suitable for intermittentoperation in ambient temperaturesup to 200°F with proper grease.

Installation InstructionsWhen an Electric Cylinder is used tomove a load, the actuator tube mustbe secured to prevent rotation. Thereaction torque required to preventrotation varies with lead of thescrew and the amount of load puton the cylinder. See product specifi-cation sheets in Nook IndustriesLinear Motion Design Guide forappropriate reaction torque values.

Set limit switches before operating.Allow for drift when setting the posi-tion. The actuator tube can move(rotate) until the unit is installed.Turn the actuator tube in or out toget the cylinder to a known positionbefore installation to prevent over-travel.

1. Be certain that the rating load ofthe Electric Cylinder exceedsthe maximum load that may beimposed upon it.

2. The foundation and/or mountingbracket must be rigid enough tomaintain correct alignment withconnected machinery and haveample strength to carry the max-imum load.

3. For flange mounted units, thefoundation must have a flatmounting surface to uniformlysupport the Electric Cylinder.



4. It is extremely important that theElectric Cylinder be installed sothat the actuator tube is exactlyplumb and that any connectingshafting is aligned with theworm input shaft.

5. After precise alignment, eachmember must be securely bolt-ed down. It is essential whenusing flange mounted units, thatthe electric cylinder be securelybolted down to its foundationusing bolts of the proper diame-ter to fit mounting holes.Bolts should be S.A.E. Grade5 or equivalent.

CAUTION: For proper align-ment and prevention of Cylinderfailure, the load should beattached to the actuator tubemount only when the load is in theposition of travel closest to thehousing tube (closed position).

Torque values for bolting are as follows:Bolt Approx.Size Torque Value

Inches Foot Pounds1/4 63/8 201/2 505/8 1003/4 1657/8 2651 400

1-1/4 8301-1/2 13501-3/4 2500

2 3650

IMPORTANT: Tighten mount-ing bolts evenly to avoid damagingthe housing.

6. After the Electric Cylinders,mitre boxes, couplings, etc. areinstalled and aligned; thereshould be no signs of binding ormisalignment.

7. Shaft coupling guards are theresponsibility of the customerand are not provided by NookIndustries unless specificallyquoted to and ordered by thecustomer.

8. Caution must be taken whenoperating your Electric Cylinderat either extreme of travel. Ifpossible, limit switches or hardexternal stops should be provided.

9. Travel Stops are not standard.A limit switch and a brakeshould be used to stop themotor. Mechanical stops cancause damage to the cylindersbecause most electric motorswill deliver stall torques muchhigher than their rated torquesand motor inertia can causesevere shock loads. For handoperation, mechanical stopscan be provided.

10. Due to the inherently high trans-lational efficiency of the BallScrew Electric Cylinders, cau-tion must be taken to preventthe load from lowering. Somemeans should be taken tosecure the load while installingor removing the ElectricCylinder.

CAUTION: Limit switches fur-nished by Nook Industries are NOTfactory set. Limit switches shouldbe set by carefully moving to theset position by hand or jogging the



unit. Care must be taken to avoidrunning lifting screws out of the unit.

General Maintenance• The actuator tube should be

kept free of dirt. If possible, theactuator should be returned toretracted position when not in use.

• For Acme Cylinders, lashbetween the lift shaft and travelnut greater than 1/4 the screwpitch indicates the need forreplacement of the cylinder liftshaft components.

• For machine screw or ball screwworm gear Electric Cylinders,check for excessive backlashbetween the worm and wormgear. Lash in excess of 30° forratios 5:1 to 8:1 and 60° forratios 20:1 to 24:1 indicates theneed to replace the worm andworm gear.

Tips For DisassemblyAnd ReassemblyCAUTION: Never perform anywork on the Electric Cylinder orassociated transmission equip-ment (mitre boxes, couplings, etc.)until absolutely certain that thecylinder motor cannot be remotelyor automatically started (PowerLockout). Also make certain thatload cannot affect personnel ormachinery when the ElectricCylinder, brake or other holdingdevices are removed. Be sure dis-assembly area is relatively clean toprevent contamination of parts.Store all machined parts to preventdamage to machined surfaces.

Before starting disassembly, careful-ly review a typical parts list or certi-fied assembly drawing of the unit.

When removing end caps, be sureto tape shaft extension keywaysand other sharp edges to avoiddamaging oil seals.

Notes1. Be sure to clean and dry all

parts before rebuilding.

2. It is advisable to replace oldseals when the unit is rebuilt.

3. Remove any protective coatingson replacement parts beforeinstalling.

4. On Electric Cylinders withTapered Roller Bearings, removalof the bearings from the drivesleeve may result in damage.

Disassembly InstructionsRefer to typical parts assembly,pages 6 – 7.

These instructions are necessarilygeneral, and as such, cannot pro-vide for minor details of construc-tion, which may vary from unit to unit.

For specific questions, consult fac-tory giving order number and serialnumber from housing nameplate.

1. Remove setscrews from hous-ing tube.

2. Unscrew housing tube and care-fully remove.

3. Remove end caps on wormshaft assembly.

CAUTION: Handle shims care-fully to avoid damage.

4. While tapping one end of the

Technical Service Manual 3/25/03 2:26 PM Page 8


worm shaft with a wooden mal-let, rotate the worm shaft. Thiswill loosen the bearing cup tofacilitate removal.

5. Remove the worm shaft bearingcups.

6. Drive sleeve and gear, alongwith the ball nut, lifting screwand actuator tube can now beremoved from the housing.

7. For ball nut disassembly, con-sult factory.

Reassembly InstructionsYour Electric Cylinder can easily bereassembled by reversing the disas-sembly procedure as previouslyoutline. In reversing disassemblyprocedure, be sure to pack worm,worm gear and all bearings withgrease. Also coat all seal areas withgrease. After unit is reassembled, fillwith grease, see page 3 for lubrica-tion details.

Trouble Shooting TipsYour ActionJac™ Electric Cylinderwill perform satisfactory if sugges-tions described in this booklet arecarefully followed. It is estimatedthat approximately 98 percent ofBall Screw or Machine ScrewCylinder failures can be attributedto improper lubrication, misapplica-tion and misalignment.



Trouble: Housing Failure

What To Inspect Action1. Unit Overload Reduce load or replace with unit of

sufficient capacity.2. Improper Support Unit should be supported over entire base area,

not just at bolthole locations.3. High Shock Select different material.4. Uneven Bolting Torque Take up evenly on mounting bolts.

Trouble: Worm Shaft Failure

What To Inspect Action1. Type of Coupling Rigid Couplings can cause shaft failure. Replace

with coupling that will provide adequate flexibilityand lateral float.

2. Coupling Alignment Realign as required.3. Presence of

Excessive OverhungLoad Check Electric Cylinder for allowable loads.

4. Unit Overload See Housing Failure No. 1.5. Shock Loading Apply coupling capable of absorbing shock and,

if necessary, replace with unit of sufficient capacity. Shock loads can significantly increase apparent dead weight loads.

6. "Ganging Units" If several units are "in-line", the worm shaft of the first unit can assume 300% of the rated inputtorque. If this value is exceeded, you must replace with a larger unit.

Trouble: Bearing Failure

What To Inspect Action1. Unit Overload See Housing Failure No. 1.2. Excessive Overhung

Load See Worm Shaft Failure No. 3.3. Coupling Alignment See Worm Shaft Failure No. 2.4. Coupling Lateral

Alignment Adjust spacing between connecting shafts to relieve end pressure.

5. Bearing Adjustment Bearings must not be pinched. Adjustable tapered bearings must be set at proper lateral clearance. All shafts should turn freely when disconnected from the load.

Trouble Shooting Guide



(continued) Trouble: Bearing Failure

What To Inspect Action6. Bearing Lubrication Add Lubricant as necessary.7. Shock Loading See Worm Shaft Failure No. 5.

Trouble: Drive Sleeve and Worm Gear Wear

What To Inspect Action1. Unit Overload See Housing Failure No. 1.2. Bearing Adjustment See Bearing Failure No. 6.3. Lubrication Proper levels and grade must be maintained.

See lubrication page.

Trouble: Nut Failure

What To Inspect Action1. Unit Overload See Housing Failure No. 1.2. Alignment Lifting shafts must be perfectly plumb.3. Lubrication See Gear wear No. 3.4. Improper Selection Refer to load/life predictability chart in Nook

Industries Linear Motion Design Guide.

Trouble: Lifting Screw Failure

What To Inspect Action1. Unit Overload See Housing Failure No. 1.2. Alignment See Nut Failure No. 2.3. Side Load Check with Nook Industries Engineering

Department for allowable side load.4. Improper Selection See Nut Failure No. 4.


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