mainshaft intermediate gear

例句：

1. 1.The car's engine is running smoothly on the mainshaft.
   汽车的引擎在主轴上运行平稳。
2. 2. The engineer carefully checked the mainshaft before starting the machine.
   工程师在启动机器之前仔细检查了主轴。
3. 3.Mainshaft failure can lead to a complete breakdown of the engine.
   主轴故障可能导致发动机完全失效。