push-back cam

例句：

1. 1. The push-back cam is used to control the speed of the engine.
   推回式凸轮用于控制发动机的速度。
2. 2. The push-back cam was designed to improve fuel efficiency.
   推回式凸轮被设计来提高燃油效率。
3. 3. The push-back cam has been proven to be an effective solution for reducing emissions.
   推回式凸轮已被证明是减少排放的有效解决方案。