Noun:
-
an outer gear that revolves about a central sun gear of an epicyclic train
- Planetary gear systems are also used in many automatic transmissions.
行星齿轮组也同样用于许多汽车变速器中。
- The bike chain drives a sun gear on the rear axle, which transmits power to planetary gears situated around it.
自行车的链条会驱动后轮轮轴上的太阳齿轮,将动力传送到四周的行星齿轮。