护油环 meaning in English

oil control ring

Internal combustion engines - piston rings - oil control rings
内燃机.活塞环.护油环
Internal combustion engines ; piston rings ; oil control rings ; identical with iso 6625 : 1986
内燃机.活塞环.护油环
Internal combustion engines - piston rings - expander segment oil control rings
内燃机.活塞环.撑胀器组合式护油环
Internal combustion engines - piston rings - coil spring loaded oil control rings
内燃机.活塞环.螺旋弹簧定位的护油环