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electric worm gear screw jacks
Motorized Electric Screw Jack Actuators Price

Electric screw jack actuators  is a basis jack-up part, accomplish the functions such as lifting, drop, push and inverting through worm gear drives screw.

electric worm gear screw jack lift
Two-set Linkage Screw Jack System

Two-set linkage screw jack system can be "L", I and T configuration.  It usually consists bevel gearbox, screw jack, electric motor, gear reducer, hand wheel, pillow block bearing, jaw coupling, line shafting.

 Automatic Screw Jack Lift System
Good Performance Screw Jack Lift System

Screw jack lift system structures include miter gearboxes, screw jacks, electric motor or gear reducer, hand wheel, pillow block bearings, jaw couplings and line shaftings.  Screw Jack System Features: 1. Heavy duty, self-locking, positioning precision, uniform lifting speed, fully synchronization, easy installation, easy operation 2. Two screw jacks system, three screw jacks system..forty screw jacks system. 3. Extremely high capacity requirements of need very precise up or down control. It's of high mechanical, they are an excellent choice when hydraulic, pneumatic or chain systems are prohibitive choices. 4. Widely used in wood working machines, plastics processing machines, textile machines, assembly equipment in the automobile and aircraft industries, food and beverage production equipment as well as packaging machines.

acme ball screw jacks screw lift
Four-set Linkage Screw Jacks System

Four-set linkage screw jack system can be  I and T configuration, transmission efficiency can be 85% .

worm screw jack lift table
High Efficiency Worm Gear Screw Jack Systems

Screw jack lift system structures include miter gearboxes, screw jacks, electric motor or gear reducer, hand wheel, pillow block bearings, jaw couplings and line shaftings.

SE enclosed housing slewing drive
Slewing Drive for Aerial platform

Slewing drives are powered with hourglass worm technology for maximum gear torque and the smoothest rotation.

Worm Gear Slewing Drive
Slewing Drive WE Series

WE Series Slewing drive is combined by the curved tooth slewing ring and worm, gear and worms are more touch supply larger torque.

spiral bevel gear unit
HD Series Spiral Bevel Gearbox

HD Series spiral bevel gearbox is hexahedron,which can fit different direction mounting.

worm gear ball and acme screw jacks
Worm Gear Screw Jack with reducer and motor

Screw jack is used in applications where linear motion is required. Lifting of any load, pushing or pulling of mechanical equipment, adjusting of tight clearances of mechanical parts can be done by screw jacks.

Spiral Gear screw jack
High-speed Lifting Bevel Gear Screw Jack

High-speed lifting bevel gear screw jacks are partly completed machines and intended for installation in complete machines or to be used for assembly with a totality of machinery to create systems.The bevel gear transmission makes high lifting speeds and a high duty cycle possible.

acme mechanical screw jacks lifts
Trapezoidal Machine Screw Jacks 5Ton

Worm Gear Machine Screws Jacks are common worm gear screw jacks,can be upright or inverted,with anti-rotation or self-locking functions.

high efficiency electric lift cylinder
Energy Saving Electric Linear Actuator with DC Motor

An Electric Linear Actuator is an actuator that creates motion in a straight line, in contrast to the circular motion of a conventional electric motor.

right angle bevel gearboxes
T Series Bevel Spiral Gearbox

T series bevel gearbox is standardized with many varieties. The deceleration ratio is 1:1, 1.5:1, 2:1, 2.5:1 and 3:1, which are all actual transmission ratios.

Acme Screw Linear Actuator
ACME Screw Linear Actuator with AC Motor

A Electric Linear Actuator is a mechanical device that converts energy (power from air, electricity or liquid) to create motion in a straight line.

ball screw electric cylinder
Ball screw lifting electric linear actuator

An electric linear actuator is a device that converts the rotational motion of a motor into linear motion – that is push and pull movements.

Self-locking and back-driving conditions


Trapezoidal screw jack has self-locking function which means when the rotational force on the screw is removed, it will remain motionless where it was left and will not rotate backwards, regardless of how much load it is supporting. Self-locking function is very important for some applications.

worm gear machine screw jack

Self-locking and back-driving conditions are defined in the following 4 situations:

1)Static self-locking: not running screw jack without load vibrations; the application of a push or pull
force (until the maximum allowed) does not cause the linear movement of the acme screw (Model A)
or of the travelling bronze nut (Model B).

This condition happens when the direct efficiency value is lower than 0.30.

2)Dynamic self-locking
  • Working screw jack with a load opposite the motion: by interrupting the motor power supply the screw jack stops.This condition happens when the direct efficiency value is lower than 0.25.

  • Working screw jack with a load applied on the same direction of the motion: the screw jack’s stop is not guaranteed by interrupting the motor power supply. The screw jack stops only if the direct efficiency value is lower than 0.20 and, anyway, it stops in an unrepeatable position.

In  this  case,  we  recommend  to  use  a  brake  motor  to  stop  the  load  and  keep  it  in  position, avoiding the motion start in case of pushes or vibrations.

3)Uncertain self-locking

with direct efficiency values between 0.30 and 0.50, the screw jacks are in  an  uncertain  self-locking  condition.  The  self-locking  depends  on  the  load  and  the  inertia  of  the system. In  this  case  we  recommend  to  use  a  brake  motor  to  guarantee  the  self-locking  condition  or  to  contact Lude Transmission to evaluate the application.

4)Back-driving: screw jacks with direct efficiency value higher than 0.50 are never self-locking.

We remind you that, in any case, also to start a not self-locking screw jack a certain minimum load must be applied. To define this load value please contact Lude Transmission.

Learn more about self locking screw jacks at (Screw jacks supplier China)

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+86 15684332999

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NO.2758 Mengyin Road, Ecomomic&Technical Development Zone, Dezhou, Shandong, China

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