四作用手摇泵
quadruple-action hand pump
中子-质子相互作用作用
neutron proton interaction
单活塞杆双作用缸
single rod double acting cylinder
拉压双作用
tension and compression double action
双作用常接触弹性滚子旁承
double acting
constant contact
resilient roller side bearing
双作用单活塞杆液压缸
two-action single-rod hydraulic cylinder