The basic components of hydraulic door closers include supporting guides, transmission gears, return springs, one-way valves, rack plungers, throttle valve cores and housings, end caps, sealing rings and connecting rods. The shell and the connecting rod play the role of fixing the door closer and connecting the door leaf and the door frame.
The types of door closers can be divided into: exterior and built-in door top door closers, built-in door middle door closers, door bottom door closers (floor springs), vertical door closers (built-in vertical closing Door closers) and other types of door closers.