flat faced pulley

例句：

1. 1.The engineer designed a flat-faced pulley to increase the efficiency of the machine.
   工程师设计了一个平脸滑轮，以提高机器的效率。
2. 2. The flat-faced pulley was used in the elevator system to reduce friction and increase speed.
   平脸滑轮被用于电梯系统中，以减少摩擦并提高速度。
3. 3.The flat-faced pulley was installed on the conveyor belt to improve its smoothness and reduce wear.
   在输送带上安装了平脸滑轮，以改善其平滑度和减少磨损。