| 摘要 |
A drive unit comprised of a pair of axially aligned electrical motors, each motor having a stator, a rotor within the stator and a shaft coupled to the rotor for rotation therewith. The shaft of one motor is tubular to rotatably receive the shaft of the other motor. A ring gear is rigid to the tubular shaft, and a sun gear within the ring gear is rigid to the other shaft. Planetary gear means couples the ring and the sun gears together, the planetary gear means having arm structure for coupling the same to the shaft of a fluid compressor to be driven, the compressor forming part of a heat pump. Three speeds are obtainable by operating one or both motors. Relatively high speed is obtained by operating both motors, an intermediate speed is obtained by operating the motor coupled to the ring gear, and a relatively low speed is obtained by operating the motor coupled to the sun gear. Sprags are used on the two shafts to prevent their idling backwards when only one motor is operating. |
