crankshaft connecting rod system

例句：

1. 1. Thecar's engine is running smoothly because the crankshaft is working properly.
   这辆车的发动机运行平稳，因为曲轴工作正常。
2. 2. The mechanic was able to diagnose the problem and replace the crankshaft.
   这位机械师能够诊断出问题并更换曲轴。
3. 3. The new transmission system uses a more efficient crankshaft design.
   新的传动系统采用了更高效的曲轴设计。