motor barrel

例句：

1. 1. The engineer used a motor barrel to power the machine.
   工程师使用一个动力筒来给机器供电。
2. 2. The construction crew was working on the motor barrel when it suddenly stopped.
   建筑工人在维修动力筒时，它突然停止工作了。
3. 3. The new design uses a motor barrel that is more efficient than the old one.
   新设计使用了比旧设计更高效的动力筒。