Worm gearboxes

A worm gearbox reduces rotational speed through a worm working with a worm wheel. The compact build and the high ratios available make it standard on transport and packing machines, gate drives and lifts. It is also used on conveyor systems, mixer drives, technical lifts and sorting equipment, wherever the drive needs controlled movement and low noise.

Self-locking is one of the properties of worm gearing: the drive can hold its position without a separate brake. The other advantages over other gear types are quiet running, high ratios in a small housing and tolerance of overload. Tell us if the load has to be held in place and we will confirm it for the exact unit we quote.

The ratio, the permissible load, the efficiency, the mounting type and the sealing class of the housing. Check it against the motor or the inverter it will work with, since the gearbox is one part of a drive system rather than a component on its own. Mounting options run from flange and foot to hollow and solid output shafts.

Modern worm gearboxes are built for efficiency that often passes 80%. Where the job is low speed and high torque, a worm gear reducer can work out more effective than other arrangements, because it reaches the ratio in one compact stage. We check the figure for the exact ratio and size before we quote it.

Start with how the gearbox is driven and how it mounts. RMI and VMR cover most standard drives, with feet or flange mounting and a wide size range. UMI suits machines where the unit has to sit in an unusual orientation, or where overload is likely. VR and VR-E suit drives with no motor on the gearbox, turned by handwheel or belt.