tumbler gear

例句：

1. 1. The car's engineis running smoothly with the right tumblergear setting.
   汽车的发动机在正确的变速器齿轮设置下运行平稳。
2. 2. Themechanic replaced the worn outgears in the old car.
   机械师更换了旧车磨损的齿轮。
3. 3. The engineer tested the gearsto ensure they were functioning properly.
   工程师测试齿轮以确保它们正常工作。