An air compressor cylinder head includes a valve seat plate, a manifold plate and a cylinder cover that sequentially cover each other; and an inner cavity of the manifold plate is provided with an air channel and a liquid channel. The air channel is provided with a plurality of air inlets and outlets, the liquid channel is provided with a plurality of liquid inlets and outlets, and the air inlets and outlets and the liquid inlets and outlets are distributed on an end face of the cylinder cover, a side wall of the manifold plate and an end face of the valve seat plate.

An alternative compressor head arrangement is provided. The alternative compressor head arrangement is configured to eliminate the occurrence of friction wear in the bending areas of the operation valves. For this, an interface blade arranged between the valve blade and the stop blade is used, so that the interface between the static end of the operation valve of the valve blade and the valve stop of the stop blade is fully carried out by the interface blade.

An unloading device is applied to an air compressor including a plurality of cylinders, and includes: a plurality of unloading valves, each unloading valve movably covering an unloading hole of one cylinder; an unloading cavity in communication with the unloading hole; an intake cavity in communication with the unloading cavity; and a piston member connected to the plurality of unloading valves by means of a shift fork. In an unloading state, the piston member is capable of driving, by means of the shift fork, the unloading valve to move to uncover the unloading hole, so that air in the plurality of cylinders circulates back and forth through the unloading cavity to make the air compressor enter the unloading state, and the air compressor maintains an optimal unloading state by using the intake cavity in communication with the unloading cavity.

A valve assembly for a piston compressor, in particular an oil-free piston compressor for generating compressed air in a rail vehicle, includes a valve plate having a compressed-air opening, a valve retainer and a valve lamina which is flexible and/or movable in relation to the valve retainer and is provided for opening and closing the compressed-air opening; wherein a damping and/or braking device is provided which is associated with the valve lamina.

A valve arrangement is for a piston compressor, the valve arrangement having: a suction valve section; and a discharge valve section; wherein the suction valve section and discharge valve section together form a working chamber head section, and the suction valve section has a frustopyramidal form.

A compressor includes fixed and movable members with a discharge port penetrating the fixed member and a discharge valve body to open and close the discharge port. An inflow end of the discharge port has a hydraulic diameter Di=4(Ai/Li), where Ai is an area of the inflow end and Li is a circumferential length at the inflow end. An outlet flow path is formed between an outflow end of the discharge port and the valve body. The outlet flow path has a cross-sectional area Ao=Loho, and a hydraulic diameter Do=4{Ao/(Lo+Lv)}, where Lo is a circumferential length at the outflow end, ho is a reference lift amount of the valve body, and Lv is a circumferential length of a valve head of the valve body in contact with the outflow end. A ratio Do/Di at the inflow end is 0.602 to 0.740.