elevation synchro gear

例句：

1. 1.The elevator synchro gear is responsible for the smooth movement of the elevator.
   电梯同步齿轮负责电梯平稳运行。
2. 2. The synchro gear in the machine is crucial to its operation.
   机器中的同步齿轮对机器的运行至关重要。
3. 3. The engineer had to replace the synchro gear due to wear and tear.
   工程师不得不更换磨损的同步齿轮。