弹簧活门控制液压制退机的英文

spring-valve controlled hydraulic brake

• 弹簧:    spring; mechanical ...
• 活门:    valve; bib
• 控制:    control; dominate; ...
• 液压:    hydraulic pressure
• 制:    make; manufacture
• 退:    retreat; draw back ...
• 机:    machine; engine