Worm planetary drive is based on a simple worm and worm wheel drive combined with planetary gear mechanism.

Worm planetary drives offer high level of output torque transmission in compact and space saving design compared to conventional worm drive. Worm planetary drives have the following features:

	High power to weight ratio.		Compact design.
	Higher efficiency compared to equivalent worm drive.		Higher ratios available in same size as of a conventional worm drive.