1) two-position selector spool
双位选择器滑阀
2) displacement selector spool
位移选择器滑阀
3) three-position selector spool
三位选择器滑阀
4) selector spool
选择器滑阀
5) selector valve spool
选择器阀滑阀
6) directional selector spool
转向选择器滑阀
参考词条