Worm and worm wheel
A screw and gear pair that reduces speed at a high ratio in a single stage between non-intersecting, perpendicular shafts.
What is a worm drive used for?
A worm drive consists of a screw (the worm) and a mating gear (the worm wheel). It is used between two perpendicular shafts whose axes do not intersect to achieve high ratios such as 1:20, 1:40 or 1:60 in a single stage.
With a suitable design the drive is self-locking: the worm turns the wheel, but the wheel cannot turn the worm back. This is an advantage in lifting and positioning applications.
Where are they used?
- Worm gearboxes
- Crane, hoist and tensioning mechanisms
- Door, shutter and valve drives
- Conveyor and dosing systems
- Dividing heads and rotary tables of machine tools
Production details
The worm and wheel must be made to work together. The worm is usually made of hardened steel and the wheel of a friction-reducing material such as bronze. For a quote we need the module, the number of worm starts, the number of teeth of the wheel and the centre distance.
Questions about Worm and worm wheel
Can I replace only the worm wheel?
If the worm is undamaged, only the wheel can be made. However, wear usually affects both parts; share a photo of the worm too and we will assess it.
Why is the worm wheel made of bronze?
Bronze gives low friction and good wear resistance against a steel worm. In this mechanism with heavy sliding contact, a bronze wheel protects the worm and extends service life.
How do I calculate the gear ratio?
The ratio is the number of teeth of the wheel divided by the number of worm starts. For example, a 40-tooth wheel with a single-start worm gives a ratio of 1:40.
Which machines do we make this gear for?
Material, heat treatment and tolerances depend on the machine the part runs in. Open your own sector to see the parts we make most often.
Other gear types
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Spur gears
The most common gear type: teeth parallel to the axis, transmitting motion and power between parallel shafts.
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Helical gears
Gears with teeth cut at an angle to the axis, running more quietly and carrying higher loads than spur gears.
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Bevel gears
Cone-shaped gears that transmit motion between intersecting shafts, usually at 90°.
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Timing pulleys
Toothed pulleys that transmit synchronous motion with a toothed belt, without slipping.
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Sprockets
Gears with teeth cut to the chain pitch, transmitting motion and power with a roller chain.
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Racks and pinions
A toothed bar (rack) and pinion gear that convert rotary motion into linear motion.
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Couplings
A connecting element that joins two shafts to transmit torque while tolerating misalignment.
Send a drawing or photo of your part
Quotes are free. We reply with price and lead time within 48 hours.