keystone-type piston ring

例句：

1. 1.The keystone piston ring plays a crucial role in the engine's performance.
   键石式活塞环在发动机性能中起着至关重要的作用。
2. 2. The manufacturer has introduced a new design for the keystone piston ring to improve fuel efficiency.
   制造商推出了一种新的设计，以改进燃料效率的键石式活塞环。
3. 3. The engineer carefully selected the keystone piston ring based on its durability and compatibility with the engine.
   工程师根据其耐用性和与发动机的兼容性仔细选择了键石式活塞环。