As a professional knight, it is necessary for us to understand every "cell" function of our partners in order to pay more attention to their "health" problems and timely "treatment". Safety is not when you drive carefully. It's when you drive safely. It's when you ride sick that you are most important.

Acting force

The forces acting on the piston ring include gas pressure, elastic force of the ring itself, inertia force of reciprocating motion of the ring, friction force between the ring and the cylinder and ring groove, etc. as shown in the figure. Because of the action of these forces, the ring will produce basic motions such as axial motion, radial motion and rotary motion. In addition, because of its motion characteristics, accompanied by irregular motion, the piston ring will inevitably appear suspension and axial vibration, radial irregular motion and vibration, twisting motion caused by irregular axial motion. These irregular movements often prevent the piston ring from functioning. When designing piston rings, we should give full play to the advantageous movement and control the disadvantageous side.

Thermal conductivity

The high heat generated by combustion is transmitted to the cylinder wall through the piston ring, so it can play the role of cooling the piston. The heat dissipated from the piston ring to the cylinder wall can generally reach 30-40% of the heat absorbed by the top of the piston.

Air tightness

The first function of the piston ring is to keep the seal between the piston and the cylinder wall and to minimize air leakage. This function is mainly borne by the gas ring, that is, under any operating conditions, the leakage of compressed air and gas should be controlled to a minimum to improve thermal efficiency; to prevent the cylinder and piston or between cylinder and ring caused by leakage; to prevent the failure caused by deterioration of lubricating oil, etc.

Oil control

The second function of the piston ring is to properly scrape off the lubricating oil attached to the cylinder wall and maintain normal fuel consumption. When excessive lubricating oil is supplied, it will be sucked into the combustion chamber, which will increase the fuel consumption. Moreover, the carbon deposit produced by combustion will have a very bad effect on the engine performance.

Supporting nature

Because the piston is slightly smaller than the inner diameter of the cylinder, if there is no piston ring, the piston is unstable in the cylinder, and can not move freely. At the same time, the ring should also prevent the piston from directly contacting with the cylinder to play a supporting role. Therefore, the piston ring moves up and down in the cylinder, and the sliding surface of the piston ring is borne by the ring.