Development of high speed rotation micro traction drive modified from angular ball bearing (1st report, experimental manufacture and evaluation)

Micro traction drive is a transmission by using of modified ball bearing. The traction force is generated by the thrust pre-load between inner race and outer race. The driving force is transmitted by using of retainer that is connected to output shaft. Test-drives of micro traction drive have been carried out as single stage type (reduction ratio around 2.0) and as tandem stage type (reduction ratio 7.3). The dimension of the micro traction drive is 10 mm inner diameter, and 30 mm outer diameter. As a result of the test, we have found that single stage type traction drive can transmit higher torque, higher number of revolution with lower noise and vibration than planetary gear head. Tandem type traction drive has been successfully operated at maximum speed 20 000 rpm.