| 摘要 |
A windshield wiper drive mechanism (66) which interconnects a motor (32) and a wiper assembly which is movable between an in-wipe position and an out-wipe position on a windshield. The drive mechanism (66) includes an elliptical gear (120) set having a pair of eccentric gears (106,108) driven by the motor (32) and mounted on first and second idler shafts (96,98) which are rotatable about first and second axes; respectively. An elliptical output gear (120) is mounted on an output shaft which, in turn, is rotatable about an output axis. The elliptical output gear (120) is disposed between the pair of eccentric gears (106,108) such that the first and second eccentric gears (106,108) engage the elliptical gear at positions 180 DEG opposite one another on the elliptical gear (120) and so that the respective axes of the first and second idler shafts (96,98) as well as the output axis of the output shaft lie in a single plane. The elliptical gear set (120) operatively drives the wiper assembly through the output shaft with the gear ratio varying sinusoidally to produce minimum torque at the in-wipe and out-wipe positions during blade reversal and a minimum torque at a predetermined position therebetween. In addition, the elliptical gear set (120) causes the velocity of the wiper assembly to vary sinusoidally from a minimum at the in-wipe and out-wipe positions to a maximum at predetermined positions therebetween. |
