Worm gear

A worm gear is a screw-rolling gear which transfers the rotational movement of a cylindrical shaft to a rotating gear which is offset by 90°. Snail transmissions allow a particularly high transmission to narrow space and are therefore outstandingly suitable for demanding space conditions.
Snail gears work highly precise, are very powerful and in addition are able to reliably compensate for axial offsets. For this reason, the low-noise and insensitive transmissions are used worldwide in demanding applications such as conveyor systems, extrusion machines, separation machines or profile machining machines.

Technical foundations for worm gears

The worm gear consists essentially of the linear, helical worm and a gear wheel which is offset by 90 degrees and which is referred to as a worm gear. While the worm is usually responsible for driving the gear, the worm wheel represents the output. In addition, however, there are also embodiments in which the worm wheel represents the drive.

In contact between the worm and worm gear—unlike rolling gears—there is not only a form-fit power transmission but also a sliding motion between the components. This sliding results from the relative movement of the contact surfaces and ensures the worm gear operates with very low noise. On the downside, this sliding reduces the overall efficiency.

The multiple tooth engagement between the worm and the worm gear enables very high power transmission and load capacity. Worm gears can therefore transmit powerful rotational movements in a compact space.

In the transmission of particularly large transmissions with low gear numbers, self-locking due to sliding friction occurs in the worm gear. This effect has the result that the worm gear can be used exclusively for speed reduction. Self-locking is used, for example, in the design of the brakes on elevator drives or chain hoists.

Which components are worm gears?

In addition to the worm housing, the worm gear consists essentially of the worm and the worm gear.

Depending on the design of the two main components, the following types of worm gears are distinguished:

• Cylindrical worm gear
• Globoid worm gear
• Globoid gear
• OTT screw gear (adjustable clearance worm gear)
• Duplex worm gear

The cylindrical worm gear is characterized by the cylindrical shape of the worm and the globoid curvature of the worm gear, making it the most widely used type of worm gear.

As a result of the sliding friction occurring in the worm gear, cooling is generally also necessary for the reliable removal of the occurring heat development.

What are the challenges in manufacturing?

In terms of construction and production, the bearing in the transmission is a challenge. Due to their construction, worm gears are characterized by the occurrence of high axial forces and must therefore be secured with axial bearings.

Furthermore, the bending stress of the transmission must also be taken into account. This has the result that the bearing of the worm has to be dimensioned elastically or angle-compensating in order to ensure a uniform load.

Find companies for worm gears

If you are looking for a Worm Gear, Techpilot – Europe's largest platform for jobs in drawing parts – is right. The application connects suppliers and buyers to establish new contacts and build long-term customer relationships. Over 24,000 suppliers are currently registered with Techpilot and send offers to enquiries set by buyers.

Buyers have the opportunity to use all functions such as the extensive supplier search with a variety of filter functions after their free registration. Interesting contacts can be stored on the personal list. Inquiries are either sent directly to matching companies or published on the platform. The incoming offers are clearly managed and compared with each other quickly and easily.

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