straight-side flank splines

例句：

1. 1.The machine has a straight-side flank spline that makes it easy to adjust the tension.
   这台机器有一个直边侧翼花键，使得调整张力变得很容易。
2. 2.The tool is designed with a straight-side flank spline to ensure accurate cutting.
   这个工具设计有直边侧翼花键，以确保精确切割。
3. 3. The engineer used a straight-side flank spline to fix the broken part of the machine.
   工程师使用直边侧翼花键来固定机器的损坏部分。