| 主权项 |
1. A drive apparatus comprising:
a driving section; a driven section driven by the driving section; and a speed reducer disposed between the driving section and the driven section and arranged to transmit rotation at a reduced speed from an input shaft connected with the driving section to an output shaft connected with the driven section; the speed reducer being a wave motion gearing speed reducer including, a rigid gear including an inside circumference formed with internal teeth, a wave generator disposed coaxially in the rigid gear, and a flexible gear which is disposed coaxially between the wave generator and the rigid gear, which is arranged to be deflected elastically into an elliptical shape by the wave generator, and which includes an outside circumference formed with external teeth engaging with the internal teeth at two positions in a direction of a major axis of the elliptical shape, the flexible gear and the rigid gear being arranged to rotate relative to each other by an amount corresponding to a teeth number difference which is a difference of numbers of the internal teeth and the external teeth when the wave generator is rotated one revolution, the drive apparatus further comprising, an input shaft rotation sensing section to sense a rotational position of the input shaft of the speed reducer, an output shaft rotation sensing section to sense a rotational position of the output shaft of the speed reducer, and a judging section to judge occurrence of a ratcheting that is slipping of an engaging position of the internal teeth and the external teeth when a discrepancy quantity between a sensed quantity of the input shaft rotation sensing section and a sensed quantity of the output shaft rotation sensing section is greater than or equal to a predetermined value. |
