motor with reciprocating movement

例句：

1. 1. The car's engine is sound, but the brakes are not working properly.
   这辆车的发动机运转正常，但刹车不工作。
2. 2. The new electric car uses a motor to drive its wheels.
   这款新型电动汽车使用电动机驱动车轮。
3. 3. The robot has a motor that can move it around easily.
   这个机器人有一个电机，可以轻松地移动它。