internal keyway

例句：

1. 1. The internal keyway iscrucial for the operation of the machine.
   内部键道对于机器的运行至关重要。
2. 2. The engineerdesigned an internal keyway to improve theefficiency of the machinery.
   工程师设计了一个内部键道来提高机械的效率。
3. 3. The internal keyway was used to connect the two partsof the machine together.
   内部键道被用来将机器的两个部分连接在一起。