machine screw jack,electric machine screw actuator,electrical mechanical actuators,manual actuator lifts manufacturer -


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machine screw jack,electric machine screw actuator,electrical mechanical actuators,manual actuator lifts features:
1. Lifting force 2.5kN to 1000kN. Under max. lifting force, input shaft required torque, high ratio 10.83Nm to 2040Nm, low ratio 0.42Nm to 1278Nm.
2. Machine screw diameter 12 mm to 150 mm, screw pitch 3 mm to 20 mm.
3. Worm gear ratio 1/5 to 1/36.
4. Translating screw, rotating screw, keyed screw configurations in upright or inverted mounting orientation.
5. Heavy duty, precision positioning, self-locking machine screw, low efficiency, low frequency, low travel speed, low duty cycle.
6. electric machine screw jack by 3-phase or single phase electric motor/gearmotor, manual machine screw jack by handle/crank.
7. Machine screw ends include top plate, clevis end, plain end and threaded end.
8. Individually or multiple machine screw jack lift system arrangements are available.
9. Application in steel, pipe, tube, plate, roll forming roller adjustment, feeder straightener rolls adjustment, adjusting synchronous coil feed lines rolls, precision roller leveler, coil sheet slitter line, paint coating line, cut to length line, tension levelling line, continuous galvanizing line, beverage production line, foam concrete cutting machine, sanding machine, heavy vehicles mobile lifting platform, bottle monitoring system height adjustment, conveyor adjustment, plate saw angle adjustment, spray infeed conveyor lift system, theatre stage lifting platform, solar tracker, satellite dish antenna azimuth, raising sluice gate, screw scissor lift table, synchronized lifting system, food processing lifting system, extrusion machine, cnc steel leveling machine, blow molding machine, curing oven lifts, bolted tank, steel shuttering concrete beams adjustment, vintage industrial crank desk, solar panel tracking system, railway maintenance lifting jack, damper adjustment, continuous casting, cnc cut to length machine, robotics arm raising, palletizer, extrusion machine, motorized self-raising tower system, angle tilt adjustments with double clevis, aircraft docking system, open and close flood gates, metallurgy industry, mining industry, chemical industry, construction industry and irrigation industry.

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machine screw jack,electric machine screw actuator,electrical mechanical actuators,manual actuator lifts manufacturer -

  1. 1. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com1JTM Series Machine Screw Jack
  2. 2. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com2ContentsGeneral Information --------------------------------------------------------------------------- 3Configurations----------------------------------------------------------------------------------- 4Specifications------------------------------------------------------------------------------------ 5Selection Guides1. Jack Brand ---------------------------------------------------------------------------------------- 62. Jack Series ---------------------------------------------------------------------------------------- 63. Load Capacity ------------------------------------------------------------------------------------- 64. Screw Configurations & Mounting Orientation -------------------------------------------------- 65. Travel Stroke--------------------------------------------------------------------------------------- 66. Gear Ratio ----------------------------------------------------------------------------------------- 77. Screw End Fittings--------------------------------------------------------------------------------- 78. Worm Shaft Input Type---------------------------------------------------------------------------- 79. Accessories ---------------------------------------------------------------------------------------- 7-8Type Selection1. Determination of Screw Jack Type --------------------------------------------------------------- 92. Verification Of Input Power ------------------------------------------------------------------------ 93. Verification Of The Screw Stability --------------------------------------------------------------- 104. Verification Of Critical Speed --------------------------------------------------------------------- 115. Permissible Radial Force (N) --------------------------------------------------------------------- 11-126. Verification The Strength Of The Shaft ----------------------------------------------------------- 12Dimensions1. Model JTM2.5 (Tr12x3) --------------------------------------------------------------------------- 132. Model JTM5 (Tr16x4) ----------------------------------------------------------------------------- 143. Model JTM10 (Tr20x4) ---------------------------------------------------------------------------- 154. Model JTM25 (Tr26x5) ---------------------------------------------------------------------------- 165. Model JTM50 (Tr40x8) ---------------------------------------------------------------------------- 176. Model JTM100 (Tr50x10) ------------------------------------------------------------------------- 187. Model JTM150 (Tr55x10) ------------------------------------------------------------------------- 198. Model JTM200 (Tr65x12) ------------------------------------------------------------------------- 209. Model JTM300 (Tr85x16) ------------------------------------------------------------------------- 2110. Model JTM500 (Tr120x16) ---------------------------------------------------------------------- 2211. Model JTM750 (Tr130x16) ---------------------------------------------------------------------- 2312. Model JTM1000 (Tr150x20) -------------------------------------------------------------------- 24Machine Screw Jack System --------------------------------------------------------------- 25Application Examples ------------------------------------------------------------------------- 26Operation Manual ------------------------------------------------------------------------------- 27-31Frequently Asked Questions ---------------------------------------------------------------- 32-35Company History -------------------------------------------------------------------------------- 36Contact Us ----------------------------------------------------------------------------------------- 37
  3. 3. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com3General Information* Models JTM2.5, JTM5, JTM10, JTM25, JTM50, JTM100, JTM150, JTM200, JTM300, JTM500,JTM750, JTM1000* Lift force from 2.5kN to 980kN, customized higher lift force screw jack* Self locking machine screw, precise positioning, uniform lifting speed* Translating screw, anti-rotation keyed screw and rotating screw configurations* Upright mounting, inverted mounting, double clevis pivot mounting* Top plate, threaded end, clevis end and plain end fittings* Hand operated, electric driven or both* Individual or multiple screw jack system arrangements* Each jack has two worm gear ratios, high speed, low speed* No standard travel length, all screw jack stroke produced following your needsJack Screw ConfigurationsTranslating Screw DesignA translating screw jack has a jack screw translates through the jack housing, Whenthe jack screw is held to prevent rotation, the jack screw will move linearly throughthe housing to push or pull the load. The screw may produce rotary force when lifting,so anti-rotation measures should be adopted.Rotating Screw (Travel Nut) DesignA rotating screw jack has a jack screw which turns moving a travel nut. The jackscrew is fixed to the worm gear. The load is attached to the travel nut, to move alongthe jack screw. Due to its cylindric structure, supporting mode is often used at thescrew end to ensure good transmission of long stroke.Keyed Screw (Anti-Rotation) DesignThe jack screw of a translating jack must be attached to the load which prevents thejack screw from rotating. Otherwise, the jack screw and the load will turn and nottranslate. A keyed screw jack can prevent jack screw rotation, With square protectivetube anti-rotation device, the screw travels up and down only and produces no rotaryforce.
  4. 4. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com4ConfigurationsSelf Locking Acme Screw1. Acme screw rotary cutting processing machine, high precision2. 40Cr or C45 steel material, customized stainless steel screw3. Minimum friction for smooth operation and longer life4. Self-locking, load holding without brake mechanism and locking system, accurate positioning5. Minimum axial backlashTapered Roller Bearing1. Preloaded for reduced assembly spring rate and high thrust load2. Provides excellent support for side loading and horizontal applications3. Maintains exact gear alignment under separating and thrust forces4. Bearing sized for endurance and maximum loading conditionsBronze Worm Gear1. Precison hobbing machine for processing2. Phosphor bronze 10-1 or Tin bronze ZCuSn10Pb1 10-1 material, high hardness, excellent wearresistance3. Worm gear center design for long lifeWorm Shaft1. Worm rotary cutting processing machine and grinding machine processing, high precision2. High frequency heat treatment of worm, 40Cr or C45 steel material, high hardness, customizedstainless steel worm shaftRugged Housing1. CNC precision automatic lathe processing2. Cast iron or ductile cast iron material, customized alloy steel materialGrease Seals1. Double lip grease seal, prevent grease leak
  5. 5. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com5Specifications
  6. 6. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com6JT - M - 100 - UR - 300 - H - II - C - HW1 2 3 4 5 6 7 8 9Selection Guides1. Jack BrandJT: “Jacton” brand screw jack2. Jack SeriesM series machine screw jackM: Machine screw3. Load CapacityFrame No. 2.5 5 10 25 50 100 150 200 300 500 750 1000Load capacity (kN) 1.9 4.9 9.8 24.5 49 98 147 196 294 490 735 9804. Screw Configuration & Mounting OrientationUS: upright translating screw UK: upright keyed screw UR: upright rotating screwIS: inverted translating screw IK: inverted keyed screw IR: inverted rotating screw5. Travel Stroke300, means travel stroke 300mmNo standard travel stroke, all screw jack stroke produced following your needs
  7. 7. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com76. Gear RatioEach JTM machine screw jack model has two gear ratios.H: high gear ratio L: low gear ratioFrame No. 2.5 5 10 25 50 100H 1/5 1/5 1/5 1/6 1/6 1/8L 1/20 1/20 1/20 1/24 1/24 1/24Frame No. 150 200 300 500 750 1000H 1/8 1/8 10 2/3 10 2/3 10 2/3 12L 1/24 1/24 1/32 1/32 1/32 1/367. Screw End FittingsI: Top Plate II: Clevis End III: Plain End IV: threaded End8. Worm Shaft Input TypesB: right side worm shaftA: left side worm shaftC: double worm shaftM4: right side motor flange with worm shaftM2: right side motor flange without worm shaftM3: left side motor flange with worm shaftM1: left side motor flange without worm shaft9. AccessoriesN: no accessory PP: protective pipe BB: bellows boot BG: miter gearboxHW: hand wheel EM: electric motor GR: gear reducer LS: limit switchesSN: stop nut DC: digital counter SP: swivel plate FC: flexible couplingCS: connecting shaft SM: swivel mounting base PB: pillow block bearing
  8. 8. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com8Example>>>>>> JT-M-100-UR-1000-L-I-C-PP/BB/HW1. Machine Screw Type2. 98kN3. Upright Rotating Screw4. 1000mm Stroke5. Low Gear Ratio 1/246. Top Plate End Fitting7. Double Worm Shaft Input8. Protective Pipe9. Bellows Boot10. Hand Wheel
  9. 9. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com9Type Selection1. Determination of Screw Jack TypeCalculation of total equivalent load Ws (N)Ws=Wmax x f1(N)Driven Machine Factor (f1):Calculation of equivalent load of single jack W(N)Initial selection of jack typeMake an initial selection of jack type by fully considering load, speed, travel, efficiency and drive source.Make final determination of jack type in view of stroke, ambient environment and top end fittings.2. Verification Of Input PowerIf the input power required is greater than the permissible input power, increase the size of the screw jack ordecrease the speed of the screw.Calculation of input power required:V: lifting speed of the screw (or traveling nut) m/minL1: pitch of screw(m), i: worm gear ratioW: equivalent load of single screw jackЛ: pi, η: overall efficiency T0: no-load torque (N.m)(See L1, i, η and T0 in the table of basic parameters)
  10. 10. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com103. Verification Of The Screw StabilityVerify the screw stability when the axial compression load exists. If the load is greater than the critical load,increase the sizes before calculation.The critical load is calculated with the following formula:Pcr: critical load, d: screw root diameter mm(see 4thpage of specifications)fm: support factor, La: distance between action points, mmW: equivalent load of single jack(N), SF: safety factor(generally SF=4)For verification of the screw stability, choose La(based sizes) and fm (on the support factor) as follows(1) Jack fixed shaft terminal support, fm=10×104(2) Jack fixed shaft terminal free, fm=2.5×104(3) Jack fixed – top plate fixed, fm=20×104
  11. 11. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com114. Verification Of Critical SpeedIf select travelling nut type, the rotary speed of the screw must be lower the critical speed; if vice versa,increase the size before critical speed r/min, ns: screw speed, d: screw root diameter mm(see 4thpage of specifications)n1: input speed r/min, fn: length factor, i: ratio, Lb: distance between supports, mmLb (as per the sizes) and fn (length factor) are as follows in verifying the rotary speed of screw.Please make sure: nc>nsTake JTM200-U-R-1200-H-I-1-C-N for example:input speed 1200r/min, operating under supporting shaft end In reference to its size and the transmissioncapacity, we get d=49.3, Lb=14375. Permissible Radial Force (N)When there is radial load, please add guiding device.
  12. 12. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com12When there is an excess of permissible radial force in JTMplease add a guiding device. See the illustrations below:6. Verification The Strength Of The ShaftWhen two or more screw jacks are arranged in the same axial line as below, verify the strength of the shaftend of each jack please.Ta: Input torque required for jack a.Tb: Input torque required for jack b.The torque required by the motor T1=Ta+Tb < permissible input torque of jack a
  13. 13. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com13Model JTM2.5 (Tr12x3) DimensionsDimensions
  14. 14. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com14Model JTM5 (Tr16x4) Dimensions
  15. 15. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com15Model JTM10 (Tr20x4) Dimensions
  16. 16. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com16Model JTM25 (Tr26x5) Dimensions
  17. 17. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com17Model JTM50 (Tr40x8) Dimensions
  18. 18. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com18Model JTM100 (Tr50x10) Dimensions
  19. 19. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com19Model JTM150 (Tr55x10) Dimensions
  20. 20. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com20Model JTM200 (Tr65x12) Dimensions
  21. 21. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com21Model JTM300 (Tr85x16) Dimensions
  22. 22. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com22Model JTM500 (Tr120x16) Dimensions
  23. 23. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com23Model JTM750 (Tr130x16) Dimensions
  24. 24. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com24Model JTM1000 (Tr150x20) Dimensions
  25. 25. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com25Machine Screw Jack SystemTwo Machine Screw Jack SystemFour Machine Screw Jack SystemEight Machine Screw Jack System
  26. 26. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com26Application ExamplesJTM series screw jack is applications in sluice gate lifting mechanism, solar panel tracking system,satellite dish antenna azimuth and elevation, theatre stage lift system and orchestra pit lifts, screwscissor lift table, railway maintenance lifting jack, coil sheet slitter, drop table synchronized liftingsystem, spray infeed conveyor lift system, damper adjustment, welding positioning equipment,continuous casting, welding positioner, headbox adjustment, adjust sawmills saw blade, slip formpaver, oven conveyor, lifting railway, roller gap adjustment, pu or pir discontinuous for freezing andrefrigeration panel, vacuum furnace lid lifter, calendar stack, palletizer, extrusion machine, hydrauliccylinder replacement, blow molding machine and anywhere required raising, lowering, pulling,pushing and rolling linear motions.
  27. 27. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com27Operation ManualRead this manual before installation or operation of screw jack. Failure to understand this manual,install or operate screw jack properly could result in damage to the Jack and or serious personalinjury.Do not exceed the screw jack ratings including design load, travel, and input speed. Install, align andshield all moving parts properly. Proper machinery installation practices should be followed. Safetycodes for mechanical power transmissions apparatus are to be followed. Check for and adhere to allapplicable safety codes. Bolts should be sized to fit the screw jack base mounting holes, at leastgrade 5 and tightened to the appropriate torque. Mounting bases should be flat and sufficiently strongto support the load on the jack. Properly lubricate and maintain the screw jacks. Use the operationmanual only for the intended application. Failure to install, operation or maintain screw jacks couldresult in product failure and personal injury.This screw jack operation manual is applicable to all screw jacks models. Information representstypical configuration and may different slightly from the actual screw jack being installed or repaired.Notices Before InstallationYour screw jack was manufactured to high quality standards and is designed to provide long servicelife. Certain safety measures and procedures must be followed in handling, installing and servicingthe screw jack to insure long trouble free service.1. Any obvious or suspected damage to screw jack during transport from the factory must beimmediately taken pictures and reported to Jacton corresponding sales and the carrier, The sales willsubmit this problem to Jacton engineers teams immediately.2. Upon delivery all of the screw jack should be inventoried to determine if shortages exist. Allshortages must be immediately taken pictures and reported to Jacton corresponding sales and thecarrier, The sales will submit this problem to Jacton QC teams and warehousers immediately.3. Installation, maintenance and safety instructions must be given to personnel directly responsiblefor the installation, maintenance and operation of the jack.Caution!Screw jacks are normally self-locking. Vibration could cause a screw jack to self-lower or creep.Stop nut is used to prevent lifting screw moving out of the screw jack base. Jacton standard screwjacks are not equipped with stop nuts unless special requirements in your purchase order.Screwjacks are not meant for personnel support. All applications designed for personnel supportmust be approved by Jacton engineers team.
  28. 28. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com28Installation Instructions1. Be certain that the screw jack load capacity exceeds the maximum load that may be applied to it.2. Be assured the screw jack input speed is not be exceeded. Specifications show the max. speed.3. The foundation for the screw jack should be rigid enough to maintain correct alignment withconnected machinery and have sufficient strength to support the maximum load.4. The foundation should have a flat mounting surface in order to assure uniform support for thescrew jack. Be assured the opening in the foundation for the protective pipe or the lifting screw is assmall as possible in order that the jack is supported over the greatest possible area.5. Check the method of stopping the screw rotation, maybe translation will occur is sufficiently strong.When individual screw jack application without be guided, will need keyed screw jack.6. It is extremely important that the screw jack be installed so that the lifting screw is perfectly plumband all connecting shafts are aligned with the worm shaft.7. After precise alignment, each member must be securely bolted and if possible doweled in place.Doweling will assure exact repositioning if ever removed. It is essential that a gear unit be securelybolted down to the foundation using bolts of proper diameter to fit the mounting holes.8. After the screw jacks, bevel gearboxes, couplings, connecting shafts are installed and aligned,there should be no signs of binding or misalignment.9. Couplings and connecting shaft are the responsibility of the customer and are not provided byJacton side, unless special requirements in your purchase order.10. Caution must be taken when operating your jack at either extreme of travel. If possible, hardexternal stop nuts should be provided.11. If operating at the upper limits of the screw jack capacity, don’t stop the downward travel of thejack by running the lifting screw attachments or the load against the gearbox without checking withJacton side, as serious damage to the internal mechanism may result.12. The customer is responsible for providing mechanical stops and limit switches for control of theprime mover. None are included unless special requirements in your purchase order. If limit switchesare furnished by Jacton, normally, we install limit switches for controlling full travel stroke, alsofollowing customers special requirements.The foundation of the screw jack is critical to insure alignment. Mount the jack and check that the axisof the lifting screw is parallel to the movement of the load and centered with respect to the load. Shimunder the base to achieve this if needed. Both eccentric load or side load will cause premature wear
  29. 29. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com29and possible bending and failure of the screw jack. Once the alignment is correct hand tighten themounting bolts.The next step is to align the input shaft with the worm shaft of the screw jack. This alignment can bejust as critical to proper operation. Test the alignment by rotating the shafts by hand and fully extendthe lifting screws.If the hand operation turns freely and the other components of the system are in alignment, tightenthe mounting fasteners and attach the load to the screw jack. Start-up should be and break-in periodsof several minutes with careful observation are required. Any vibrations, binding or excessiveamperage draw of motors is reason to shut down and repeat the entire alignment procedure.Finally the lifting screw should be re-greased with a light film, and the screw jack gearbox be checkedthat it is full of grease.TroubleshootingYour screw jack will perform satisfactorily if the suggestions described in the booklet are carefullyfollowed. It is estimated the approximately 98 percent of screw jack failures can be attributed toimproper lubrication, misapplication and misalignment.Trouble Inspection Point Solutions1. Jack OverloadReduce load or replace with unit ofsufficient capacity2. Improper SupportJack should be supported over entirebase area, not just at bolt hole locations.3. High Shock Select larger UnitGearbox Failure4. Uneven Bolting Torque Take up evenly on mounting bolts1. Type of CouplingRigid Couplings can cause shaft Failure.Replace with coupling which will provideadequate flexibility and lateral float2. Coupling Alignment Re-align as required3. Excessive Overhung Load Check Jack for allowable loads4. Jack Overload See Gearbox failure #15. Shock Loading Install coupling capable of absorbingshock and if necessary replace with jackof sufficient capacity. Shock loads cansignificantly increase apparent deadweightWorm Shaft Failure6. “Ganging” Jacks If several jacks are in-line, the wormshaft of the first jack will be subjected tothe combined torque of all the jacks. Ifthis torque exceeded 300% of the ratedinput torque you must replace with alarger jack
  30. 30. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com301. Jack Overload See Gearbox failure #12. Coupling Alignment See Worm Shaft Failure #23. Excessive Overhung Load See Worm Shaft Failure #34. Coupling Lateral AlignmentAdjust spacing between connectingshafts to relieve end pressure5. Bearing Adjustment Bearings must be preloaded6. Bearing LubricationProper levels and grade must bemaintained at all timesBearing Failure7. Shock Loading See Worm Shaft Failure #51. Jack Overload See Gearbox failure #12. Load Screw Alignment Lifting Screws must be perfectly plumb3. Lubrication See Bearing Failure #64. Duty Cycle Limit ExceededReduce the number of cycles per houror reduce the load. Contact factory forthe maximim allowable cycles per hourWorm Gear Failure5. Side load Eliminate side load1. Jack Overload See Gearbox failure #12. Load Screw Alignment See Worm Gear Failure #2Lifting Screw Failure3. Side Load See Worm Gear Failure #5LubricationThe lubricant should not be corrosive to worm gear, ball or roller bearings and must be neutral inreaction. The lubricant must not contain any contamination that may be detrimental to operation ofthe screw jack. The lubricant must have resistance to oxidation and must be non-channeling.Operating temperatures must be considered when selecting a lubricant for a screw jack. Werecommended the following extreme pressure greases or their equivalents. For applications outsidethese limits contact Jacton.The screw jack normal working temperature -20 deg. C ~ +80 deg. C, Filled with NLGI EP 1 or 2grade grease, Special working temperature, need special grease, please contact Jacton.Jacton screw jacks are lubricated prior to shipment. Lubrication inspection is recommended atregular intervals. Intervals are determined by the duty cycles of the screw jack, but should beperformed a minimum of once every two months.Each screw jack is furnished with a grease nipple. The screw jack should be filled with grease untillubricant begins to seep from the lifting screw opening. For the screw jack is equipped with boots,remove the boot at the jack before you check for proper grease levels. Severe operating conditionsmay require more frequent lubrication.Lifting screw must be checked regularly to insure that they are adequately lubricated. This isespecially critical for the rotating design screw jacks where no lubrication is deposited because thelifting screw does not translate through the screw jack gearbox into the protective pipe.
  31. 31. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com31Maintenance InstructionsAll mounting bolts must be retightened after a short period of operation. Under extreme operatingconditions, the wear on the worm gear must be checked at shorter intervals, depending on thepower-on time, by inspecting the play in the thread. The worm gear must be replaced if the axialbacklash with a single-start thread is more than one-quarter of the thread pitch. After checking thewear, screw jack should be re-assembled by a fitter. Check carefully that rotation is smooth and lightand free from axial play.The Lifting screw must be kept free of contaminants and should be lubricated. If possible, liftingscrew should be booted or returned to retracted position when its not in use.Along with periodic inspection, check the alignment of the lifting screw to the load. Misalignment willcause premature wear and possible failure. The load should be centered on the axis of the liftingscrew and motion should be parallel to the axis of the lifting screw. The power output shafting mustbe aligned with respect to the screw jack input shaft. Binding during rotation will cause prematurewear. After the screw jacks, connecting shafts, couplings, bevel gearboxes and gear reducers arecoupled together in a system, it should be possible to rotate the shafts to fully extend the unloadedscrew jacks by hand.The screw jacks are lubricated by the Jacton and are ready for operation on delivery. The translatingscrew configurations must be lubricated via their grease nipples with one of the greases specifiedbelow at intervals of 30 – 50 operating hours. The lifting screw should be cleaned and greased at thesame time. We recommend that the screw jack gearbox be cleaned to remove old grease and refilledwith fresh grease after every 600 operating hours or every 18 months. The screw jacks candisassembly and assembly easily:1. dismount the screw jack and clean.2. disassemble the lifting screw and lifting screw protective pipe (only for translating screw).3. Remove locking screws for screw jack gearbox cover.4. Wash out the screw jack gearbox and components with a suitable wash medium.5. Refill with grease
  32. 32. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com32What is the difference between an acme screw jack and a ball screw jack?The acme screw jack uses an acme threaded screw that is completely self-locking, meaning it willhold its position without a brake mechanism or locking systems. Ball screw jack use ball screws toconvert rotary motion to linear movement, and require approx. 1/3 the horsepower compared to aacme screw jack. Due to the efficiency of the ball screw, brake mechanism must be used to stop andhold the load screw in position. Brake mechanism is also recommended for use on any screw jack ifvibration is present.Why use an acme screw jack and a ball screw jack?One type of screw jack is usually better suited to the operating conditions. Typically, fast travel speedand frequent cycle times may be more suited to a ball screw jack, particularly as the load approachesthe rated capacity of the screw jack. High load at slow travel speed, less frequent cycles and theability to hold the load in position when the system is at rest may be better suited for an acme screwjack.How do I operate the screw jack?Most screw jacks are operated by electric motor, but air motors and hydraulic motors can also beused. Hand wheel or crank handle can be used for manual operation.Can I use a larger motor than required in specifications?Yes, but it is not recommended. The screw jack or jack system components could bedamaged if an oversize motor is used. Travel limit switches control must be used for each end oftravel to stop the motor. If using solid mechanical stops, screw jack components can be subject toshock load conditions and oversize motors can cause catastrophic failure of stops and othercomponents.How do I stop the screw jack at the travel limits?Limit switches or other controls must be used to shut off the motor when the screw jack has reachedits full extended or retracted position. Solid mechanical stops are not recommended. Their continueduse can cause severe damage to the screw jack.Can different size screw jacks be used in the same system?Yes, as long as the equal travel length per full turn of worm shaft input. This is sometimes done toaccommodate varying load conditions.What is the screw jack system efficiency?2 screw jack system efficiency is 95%, 3 screw jack system efficiency is 90%, 4 screw jack systemefficiency is 85%, 6 screw jack system efficiency is 80%. Bevel gearbox efficiency is 98%. Singlereduction helical gear reducer efficiency is 98%, Double reduction helical gear reducer efficiency is97%. Worm gear reducer efficiency is horsepower out x 100 / horsepower inFrequently Asked Questions
  33. 33. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com33What is the maximum input speed?Jacton screw jack can be run at 1500Rpm. A gear motor, helical gear reducer, or a worm gearreducer is used to reduce the input Rpm to the screw jack to provide the required travel speed of thelifting screw. Many Jacton screw jacks can be driven directly by 1500Rpm and 900Rpm electricmotors. Electric motors and reducers are available mounted directly to many Jacton screw jacksmodels.What causes heat build up in the screw jack?The screw jack is a mechanical gearbox assembly. The friction of the worm and worm gear, liftingscrew and worm gear, bearings and seals generate heat while the screw jack is operating. Thecombination of travel, loading, and input speed all affect the temperature rise of the screw jack.Jacton screw jack sizing calculations take these variables into account to insure that you select theright screw jack model for your application.What is the screw jack load capacity and travel?This is based on the relationship of the lifting screw diameter and the length. Lifting screws in tensionare rated for the full capacity of the screw jack, regardless of length, providing they do not rotatefaster than the critical speed. For the lifting screw in compression, capacity is limited by the screwjack’s permissible buckling load. The permissible buckling load of a lifting screw is reduced as thelifting screw gets longer. Use the maximum extended lifting screw length when using the permissiblebuckling load charts to determine screw jack load capacity.How do I determine the full-extended lifting screw length?The extended lifting screw length is normally equal to the travel stroke. If screw jack is equipped withbellows boot and stop nut, must be added the bellows boot full retract length and the addition stopnut or special closed height. These must be increased the extended lifting screw length. For invertedscrew jack, the thickness of the mounting structure must be included. This total extended lifting screwlength should be used when determining the permissible buckling load of the screw jack.Should the load being positioned be guided?It is highly recommended that the load be guided, however, it is not necessary. A guided system willprovide more column stability and allow longer screw jack travel. Column length is greatly reduced onunguided systems. External load forces common with unguided systems are detrimental to the lifeand operation of the screw jack.Can the screw jack withstand side loading or a bending moment?Yes, but this is not recommended. Consult Jacton if this condition will be present. These types ofloads apply greater forces on the screw jack and housing assembly causing premature wear. Guidesare highly recommended and should be used to eliminate side and bending loads.Can the screw jack withstand shock loading?This is not recommended. Oversized screw jacks are required to handle shock loads. Solid thrustbearings are also available in many screw jack models when constant vibration and shock arepresent in an application.
  34. 34. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com34What is the difference between upright and inverted screw jack configurations?The difference between an upright and an inverted screw jack is the location at which the lifting screwexits the jack relative to the jack gearbox. For example, an upright screw jack’s lifting screw exits thejack opposite the gearbox. An inverted screw jack’s lifting screw exits the jack on the same side asthe gearbox. The choice between inverted and upright screw jack is dependent upon the application.Note: An upright screw jack mounted upside down is still referred to as an upright screw jack.How is the linear travel speed calculated?Each screw jack has an inherent number show lifting screw travel per full turn of worm shaft input.The result of the screw jack is equal to the lifting screw pitch divided by worm gear ratio. Forexample, JT-10T model screw jack, screw pitch 8mm, high worm gear ratio 1/8, the lifting screwtravel is 1mm per full turn of worm shaft input. If 900Rpm is applied to the worm shaft, the lineartravel speed is 900Rpm multiplied by 1mm/r, equal to 900 millimeter per minute.Are screw jacks lubricated prior to shipment?All Jacton worm gear screw jacks and ball screw jacks are lubricated with an extreme pressure NLGIgrade #1 or 2grease before leaving the factory. Bevel gear screw jacks are lubricated with NLGIgrade #1 grease or VG220 gear oil. The upper bearing and jack screw are grease lubricated whilethe remaining internal components are oil lubricated. They are grease lubricated prior to shipment.What electric motors options are available?Electric motor options vary among product lines. Customers can use AC 3-phase motor, ACsingle-phase motor, DC motor. Standard voltage of China is 380V/220V, 3-phase, 50Hz, or 220V,single-phase, 50Hz. Customized international voltage motors like America 110V-single phase-60hz,240V/480V-three phase-60Hz, other voltages 230V/240V-single phase-50hz, 400V/415V/440V-threephase-50hz etc.Are screw jacks corrosion resistant?Stainless steel screw jacks are inherently corrosion resistant. All exposed surfaces are stainless steeland aluminum bronze. Most other screw jacks can be modified with special finishes, coatings, andseals.Can bellows boots be supplied for an screw jack model with inverted screw?Yes, but allowance must be made in the length of the lifting screw for both the closed height of theboot and structure thickness. Since we can make no provision for attaching a boot on the undersideof your structure, we suggest that a circular plate similar to the lifting screw top plate be welded orbolted to the bottom of your structure supporting the screw jack, thereby making it possible to use astandard bellows boot.Is there backlash between the lifting screw and worm gear?Yes. This is necessary to allow for sliding or rolling action of the lifting screw through the worm gear.Anti-backlash nut screw jack is available when the backlash needs to be minimized. Input torquerequirements are greater for anti-backlash nut screw jack.
  35. 35. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com35How is the lifting screw protected?Standard translating screw jack is fitted with a lifting screw protective pipe that stores the lifting screwwhen the screw jack is in the closed position. Bellows boot is available and recommended to protectthe lifting screw in the extended position. Double bellows boots are required for rotating screw jackwith traveling nut.How do I attach the load to be positioned to the lifting screw?For translating screw jack, the lifting screw has a standard threaded end that can be used to attachthe load, top plate, clevis end, plain end and forked head are also available. For traveling nut design,the traveling nut has a flange with mounting holes. The screw jack gearbox has a mounting base andis also available with a clevis mount for double clevis requirements.Will the lifting screw rotate?Yes. You need to prevent the lifting screw from rotating to produce linear motion. The lifting screw willnot rotate in a multiple screw jack system with all the lifting screws attached to the same structure. Ifrotation of the screw cannot be prevented in the application design, a keyed screw configuration isavailable for either the acme screw jack and ball screw jack. Input torque will increase for keyedscrew jack and the capacity may be reduced to 25% of rating.What is the maximum and minimum operating temperature?Standard Jacton screw jacks are designed to operate at maximum 80 deg.C (185 deg.F) ambienttemperature. For higher temperatures, special grease and seals are required, contact Jacton of thesespecial requirements. Minimum minus 20 deg.C (minus 4 deg.F) ambient temperature. For lowertemperatures, special grease and seals are required, contact Jacton of these special requirements.How do I lubricate a screw screw jack?Use the proper grease. Fill the gearbox by pumping grease into the grease fittings supplied in thescrew jack housing. The lifting screws should have grease applied directly to them with a rag orpaintbrush. This must be done as part of a regularly scheduled maintenance program.
  36. 36. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com36Company ProfilesIn 1997, Established Jacton Hardware Fabrication Plant, mainly processing kinds of hardwarefollowing customers requirements. Occupied 500 square meters.In 2000, Established domestic sales department, started to develop local market, mainly processinggear transmission parts such as worm and worm gear, acme threads screw, square threads screwand acme lead screw nut. Meanwhile, sales also sell straight bevel gear and spiral bevel gears forcustomers.In 2002, According to some regular customers of steel plants and machines manufacturers, whichused Taiwan screw jacks and miter gearboxes, due to long delivery and high price, would affect thenormal operations. Jacton Hardware Fabrication Plant started to processing JT acme screw jack andJT miter gearbox following above customers samples.In 2003, Established engineering department, research and development others models of JT acmescrew jack and JT miter gearbox, and draw some factory production drawings and local salescustomers drawing with 2d autocad software.In 2005, According to local market demands, Jacton Hardware Fabrication Plant is committed toresearch and development JB/T8809-1998 standard JTW worm screw jack, JTM machine screwjack, JTB ball screw jack and JTP cubic body miter gearbox.In 2006, Because of local markets fiercely competitive. Established Hongkong office-JactonInternational Limited with own US dollars and EURO account. Established international salesdepartment, focused on overseas markets. Meanwhile, "JACTON" as company only brand.In 2008, According to intl sales market report, cubic body screw jacks and another type cubic bodymiter gearboxes are very popular in Europe and America markets. After managements meetings, westarted to develop JTC cubic screw jack, JTS high speed bevel gear jack, JTV cubic body mitergearbox and JTA corrosion resistance aluminium body miter gearbox.In 2009, Jacton Hardware Fabrication Plant extension, occupied 5000 square meters. Companyimproves the processes and products through technology investment, brings in advancedtechnology, production and testing equipment.In 2010, Jacton Hardware Fabrication Plant Passed ISO9001:2008 quality management system, weare strictly implement the work flow of ISO9001:2008 certifications, which ensures oversea and localcustomers are satisfaction with our screw jacks and miter gearboxes and fast delivery time.In 2012, In order to facilitating management, according to management decisions, sales departmentand design department moved to Taibao business building. Meanwhile, Jacton Hardware FabricationPlant changed to be Dongguan Jacton Electromechanical Co.,Ltd.
  37. 37. Jacton Electromechanical Co.,Ltd http://www.screw-jack.com37Contact UsJacton Electromechanical Co.,Ltd1118, Taibao Business Building, No.1Langwei Rd, Xinan, Changan, Dongguan,Guangdong, ChinaPhone: 86 769 81585852Fax: 86 769 81585810Email: sales@screw-jack.comWebsite: www.screw-jack.comJacton International LimitedOffice 17,9/F.,Tower A,New MandarinPlaza,No.14,Science Museum Road,Tsimshatsui,Kowloon,HongkongTel: 852-2793-5511Fax: 852-3590-2333Website: