planet differential gear

例句：

1. 1. The planetary differential gear is used to reduce the load on the drive shaft.
   行星差速齿轮用于减少驱动轴上的负荷。
2. 2. The planetary differential gear is crucial for maintaining the smooth operation of the vehicle.
   行星差速齿轮对于保持车辆平稳运行至关重要。
3. 3. The planetary differential gear was designed to improve fuel efficiency and reduce emissions.
   行星差速齿轮被设计用来提高燃油效率并减少排放。