Screw jacks in short SHG are lifting or adjusting devices. The basis is a combination of worm drive (worm and worm wheel) and a trapezoidal or ball screw drive.

They can be used where rotary movements are to be converted into translational movements.
In this way, swiveling, lifting or lowering movements, positioning or feed tasks as well as tensile or compressive force absorption can be realized easily and cost-effectively. They can also be used as a replacement for pneumatic or hydraulic actuators.

All-round machined housings and the cube-shaped design as well as the same load capacity on tensile and compressive forces make the worm gear screw jacks of Wirths & Werres GmbH ideal assemblies in your design.
Since we manufacture our gearboxes ourselves, we can deliver quickly. Usually our delivery times for SHG 05 to SHG 50 with trapezoidal screw drive are 2-3 weeks, SHG 100 to SHG 200 with trapezoidal screw drive 3-6 weeks.

Special requests such as single-sided shaft ends, extended drive journals, ball screws, modified screw dimensions or special nuts can also be supplied within a few weeks.

Two gear ratios are available:

Normal gear reduction

The stroke per revolution of the drive shaft is 1 mm. The gear is not always self-locking; a holding brake may have to be provided on the motor side.


Fine reduction gear

A modified gear reduction reduces the stroke per revolution of the drive shaft to 0.25 mm for more accurate positioning or slower stroke speed. In addition, a holding brake can often be omitted due to the larger worm reduction and the resulting self-locking effect.


For simple adjustment tasks with manual operation, our cost-reduced lightweight versions LV are available in sizes LV 05 to LV 25. You will find more details here.

Ausführung A

Rotation of the worm shaft causes the worm wheel to rotate at a reduced speed. The worm wheel contains a standard trapezoidal thread in which the spindle moves. This converts the rotational movement of the drive shaft into a translational stroke movement of the screw.

The screw jack is prevented from rotating by constructive measures in the adjacent construction and/or by a special design of the screw jack (VD design, non-rotating, please note when ordering, subsequent assembly only possible in the factory), so that the screw moves into or out of the screw jack due to the rotary movement of the worm wheel.

At the end of the spindle there is a clevis (special accessory GK), a mounting plate (special accessory BG), a standard thread (metric) or a customer-specific spindle end (special design on request). This connects the spindle to the connection structure and raises/lower the load or moves the machine part to be driven.

The stroke is 1mm per revolution of the drive axle for normal reduction, for fine reduction 0.25mm per revolution of the drive axle. Other pitches are available on request.

Ausführung B

Here, the spindle is positively connected to the worm wheel and rotates at the speed of rotation of the worm wheel. The travelling nut moves on the spindle and converts the rotation into a stroke movement.

The spindle nut must be secured against rotation. This is usually done by screwing the nut to the adjacent construction.

The stroke is 1mm per revolution of the drive axle for normal reduction, for fine reduction 0.25mm per revolution of the drive axle. Other pitches are available on request.

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