Project Title:

Roller-Gear Drive for Robotic Manipulators

05.03-1391A
Roller-Gear Drive for Robotic Manipulators
Transmission Research, Inc.
Division of NASTEC, Inc.
10823 Magnolia Drive
Cleveland, OH 44106
William J. Anderson  (216-231-6570)
LeRC -- NAS3-25282

Abstract:

	 Multi-roller, planetary traction drives offer a unique combination of compactness,
high efficiency, and high torsional stiffness in high ratio drives. They have the
added advantages of back-lash-free operation, low noise and vibration, no gear cogging,
and smooth torque transfer in bi-directional operation. Combining traction rollers
and gears yields further benefits in compactness (high torque capability) without
the sacrifice of the inherent advantages of roller-gear drives. A typical drive employs
a planetary arrangement of gears and rollers consisting of a sun roller gear, two
concentric clusters of stationary, roller-gear planets, and a ring gear. The low
torque, high speed input is supplied to the sun gear, and the high-torque, low-speed
output is taken from the ring gear.
	Preliminary designs of three roller-gear and two roller drives were completed in
Phase I to assess their feasibility for use in a laboratory telerobotic manipulator.
These include a dual-input, pitch-yaw joint drive utilizing cone rollers and zerol
bevel gears, drives for a wrist-roll and hinge joint utilizing cylindrical rollers
and spur gears, and planetary roller drives for the wrist-roll joint and large gearhead.
The five roller-gear and roller drives examined in this program are technically feasible
for robotic positioning devices.

Potential Commercial Application:

Potential Commercial Application: Roller-gear drives are ideally suited for both
terrestrial and space applications, for servo positioning devices, actuators, and
high-speed, compliant-motion robots being developed for manufacturing assembly tasks,
and in speed changers for office and other light duty commercial machines.