The piston parts of a piston air compressor are key components that make up the compression volume and realize gas compression. The piston must have good sealing, sufficient strength, rigidity and surface hardness, and at the same time be light and have good manufacturing processability. The basic structural forms of the piston include cylindrical, disc and stepped pistons.

1.Cylinder piston: Mainly used in single-acting air compressors without a crosshead. It is connected to the small end of the connecting rod through a piston pin, and plays a role in both compression and guiding the crosshead.

2.Disc piston: Generally hollow structure to reduce weight, with internal ribs to increase rigidity and reduce wall thickness. The number of ribs on a disc piston depends on the diameter of the piston, usually 3 to 8.

3.Differential piston: In differential cylinders used in series with more than two compressor stages, the high-pressure stage piston may bend, so its diameter should be 0.8 to 1.2 mm smaller than the cylinder diameter to avoid friction.

The piston ring is an important part of the piston, and is mainly divided into two types: oil ring and gas ring. The main function of the oil ring is to remove the lubricating oil on the inner wall of the cylinder and make the oil film evenly distributed, while the gas ring ensures the airtightness between the piston and the cylinder wall. Piston rings generally use elastic rings with cuts. The cuts are mainly in three forms: overlap, bevel and straight. Each cut has different application scenarios.

The piston rod is a component that connects the piston and the crosshead to transmit the piston force. The piston rod is divided into two types: through-piston rod and no-through-piston rod. It is usually connected to the piston through a conical surface and a cylindrical boss, and anti-loosening measures are required.

The crosshead is a part that connects the piston rod and the connecting rod and bears the lateral force. It has a guiding function. The crosshead consists of a crosshead body, a slide plate, a crosshead pin, etc. It can be divided into two types: integral and detachable. The crosshead pin is an important part that transmits all piston forces and is required to have the characteristics of toughness, wear resistance, and fatigue resistance.

Other parts of the piston air compressor include cylinder, piston rod, slider, connecting rod, crank, suction valve and exhaust valve, etc. These parts work together to complete the suction, compression and exhaust process of the air compressor to ensure the stable operation of the air compressor.