expansion cam

例句：

1. 1. The expansion cam is responsible for expanding the gasket.
   膨胀机负责扩张垫圈。
2. 2. The expansion cam is used to control the flow of oil in the engine.
   膨胀机用于控制发动机中油的流动。
3. 3. The expansion cam is an important component of the engine's combustion chamber.
   膨胀机是发动机燃烧室的重要部件。