pedal crank

例句：

1. 1. The bike has a pedal crank that makes it easy to start and stop.
   这辆自行车有一个踏板式助力装置，使启动和停止变得容易。
2. 2.The old lady uses her pedal crank to push the cart along the street.
   老妇人使用她的踏板式助力装置推着小车沿着街道前进。
3. 3. The car's pedal crank is designed to make driving easier for people with disabilities.
   这款车的踏板式助力装置设计成让残疾人驾驶更轻松。