心轴

例句：

1. 1. The machine's heart is the gearbox, which drives the entire assembly.
   这台机器的心脏是齿轮箱，它驱动整个装配。
2. 2. The car's steering wheel is connected to the engine's crankshaft via aflexible coupling.
   汽车的方向盘通过一个柔性连接件与发动机的曲轴相连。
3. 3.The pivot of the system is the control panel, which allows for easy adjustment of settings.
   系统的枢轴是控制板，它允许轻松调整设置。