The cylinder is composed of cylinder, end cover, piston, piston rod and seals, and its internal structure is shown in the "SMC cylinder schematic diagram" :
The inner diameter of the cylinder represents the output force of the cylinder. The piston should do smooth reciprocating sliding in the cylinder, the surface roughness of the cylinder inner surface should reach Ra0.8μm.
SMC, CM2 cylinder piston adopts combined sealing ring to achieve two-way sealing, piston and piston rod with pressure riveting link, no nut.
2) end cover
The end cover is provided with an inlet and exhaust vent, and some are also provided with a buffer mechanism in the end cover. Sealing ring and dustproof ring are arranged on the end cover of the rod side to prevent air leakage from the piston rod and prevent external dust from mixing into the cylinder. Guide sleeve is arranged on the end cover of the rod side to improve the guiding accuracy of the cylinder, bear a small amount of transverse load on the piston rod, reduce the bending when the piston rod extends, and extend the service life of the cylinder. The guide sleeve is usually made of sintered oil-bearing alloy, forward-tipped copper castings. The end cover used to be malleable cast iron, in order to reduce weight and rust, aluminum alloy die casting is often used, and the miniature cylinder uses brass materials.
3) the piston
A piston is a pressurized part of a cylinder. Piston sealing ring is provided to prevent the left and right cavities of the piston from channeling each other. The wear ring on the piston can improve the steering of the cylinder, reduce the wear of the piston seal ring, reduce friction resistance. Wear-resistant ring long use of polyurethane, ptfe, cloth synthetic resin and other materials. The width of the piston is determined by the size of the seal ring and the necessary length of the sliding part. The sliding section is too short to cause early wear and jam. The material of the piston is usually aluminum alloy and cast iron, and the piston of the small cylinder is made of brass. See Figure 2
4) Piston rod
The piston rod is the most important force component in the cylinder. Usually high carbon steel with hard chrome plating or stainless steel is used to prevent corrosion and improve the wear resistance of the sealing ring.
5) Sealing ring
Rotary or reciprocating motion parts of the seal is called dynamic seal, static parts of the seal is called static seal.
The connection methods of cylinder and end cover are mainly as follows:
Integral type, riveting type, thread connection type, flange type, pull rod type.
6) The cylinder should be lubricated by the oil mist in the compressed air. There are also small parts of lubricating free cylinders