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MGM Electric Motors Worm Gearboxes


While predominantly known for their excellent brake motors, MGM Electric Motors also manufacture a high quality range of worm gearboxes.

MGM worm gearboxes are gears that consist of a shaft featuring a spiral thread that engages with and drives a wheel with teeth. They look like a screw that has its threads linked with what looks like a standard spur gear, but with the teeth slightly more angled and curved.

The purpose of a worm gearbox is to adjust the rotational movement by 90 degrees. This movement also changes the plane of movement because of the new angle adopted by the worm on the wheel. They work by an electric motor applying rotational power to the worm shaft, which then rotates against the wheel with the screw face pushing into the wheel teeth to apply force to the load.

Here we take a closer look at the MGM worm gearboxes known as the U Series and R Series.

MGM Worm Gearboxes – U Series and R Series

The housing and flanges of the U Series worm gearboxes are made of aluminium die cast, while the housing and flanges of the R Series are made of grey die cast. The U Series sizes 40-50 do not feature any special coating, while the sizes 63-75-90-110 are painted with thermoset powder-coating (RAL 5010) based on polyester resins that have been modified with epoxy resins. Only the sizes 130-150-180 from the R Series feature such coating.

The steel worm shafts of both series are case-hardened and ground, which increases the worm gear’s durability for gearing compared to forged worm shafts. The profiled thread grinding also improves the contact which enhances the performance and reduces noise.

Tapered roller bearings or radial ball bearings are used in the MGM Electric Motors worm gearboxes as they produce a longer life than other types. The size of the bearings is also optimised for maximum durability while ensuring mechanical efficiency. The tapered roller bearings also provide maximum overhang load


Two inputs are available for the U Series and R Series, including motor flanges UMI and RMI, with the connecting motor for the UMI made with a steel coupling connection between the electric motor and gearbox. The RMI version does not feature a coupling. The worm wheel is made from shell-cast high strength phosphor bronze, with the shell-casting making the worm wheel extra durable and reliable.

Recommended lubrication for both the U Series and R Series is synthetic oil with ISO 320 viscosity, such as Omala S4 WE.

Other MGM Gearboxes

As well as the U Series and R Series of MGM gearboxes, they also manufacture other models that will be better suited to a variety of different applications. They manufacture both in-line and shaft mounted gearboxes, as well as bevel helical and parallel shaft gearboxes.

If you require any worm gearboxes from MGM Electric Motors such as the U Series or R Series worm gearboxes, then contact YB Components who are the UK’s leading MGM Electric Motors suppliers.