The crosshead is an important transmission component in the air compressor. Its main function is to connect the piston rod and the connecting rod, bear the lateral force, and play a guiding role. It converts the rotational motion of the crankshaft into the reciprocating linear motion of the piston through the connecting rod. The crosshead needs to have sufficient strength, rigidity, wear resistance, and light weight to ensure the reliability of the work.

The structure of the crosshead mainly includes the crosshead body, slide plate, crosshead pin and other parts. According to the connection method between the crosshead body and the slide plate, the crosshead can be divided into two types: integral type and detachable type. Integral crossheads are mostly used in small air compressors. They have the advantages of light structure and convenient manufacturing, but are not conducive to adjustment after wear. Detachable crossheads are mostly used in large and medium-sized air compressors, which are convenient for adjusting the gap between the crosshead slide plate and the slideway.

The main connection methods between the crosshead and the piston rod include threaded connection, connector connection and flange connection. All connection methods should take anti-loosening measures to ensure the reliability of the connection. The threaded connection has a simple structure, light weight and reliable use, but the clearance volume between the cylinder and the piston needs to be readjusted after each maintenance. The connector connection and flange connection structures are reliable to use and easy to adjust, making it easy to align the piston rod and the crosshead without being affected by the deviation of the thread center line and the piston rod center line, but the structure is relatively bulky and is mostly used in large air compressors.

As the main part for transmitting all piston forces, the cross pin is required to have the characteristics of toughness, wear resistance and fatigue resistance. It is usually made of 20# steel, and the surface is carburized and quenched to achieve certain hardness and surface roughness requirements. The cross pin has conical, cylindrical and combined styles. The cylindrical cross pin has a simple structure and uniform wear, which is suitable for small air compressors; the conical cross pin has a larger taper and is easy to disassemble, which is suitable for medium and large air compressors.

In terms of maintenance, inspection and maintenance of the crosshead components are essential to ensure the stable operation of the air compressor. It is necessary to regularly check the wear, connection tightness and lubrication of the crosshead and adjust or replace it as needed.