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What role can the piston ring and piston pin of a diesel generator play?

What role can the piston ring and piston pin of a diesel generator play?

A metal split ring with a certain elasticity is installed around the piston ring groove. This metal ring is called a piston ring. Piston ring is one of the key components of diesel generator, and its working performance directly affects the qualitative and reliability of diesel generator.
According to the different uses of piston rings, piston rings are divided into gas ring and oil ring.
The main function of the gas ring is to form a sealed combustion chamber space with the piston, cylinder head and cylinder liner, and prevent high-temperature and high-pressure gas in the combustion chamber from flowing into the crankcase from the gap between the piston and the cylinder wall.
The main function of the oil ring is to ensure uniform distribution of the oil on the inner wall of the cylinder liner and prevent the oil from entering the combustion chamber. If the engine oil enters the combustion chamber, it will cause the diesel generator to burn engine oil and blue smoke from the exhaust pipe. It will also increase the carbon deposits in the exhaust valve and the combustion chamber and increase the amount of oil.

Piston rings are prone to serious wear, weakened elasticity, internal glue and breakage during long-term use.
The structure of the piston ring is mainly determined according to the shape of the opening and the cross section. The shape of the opening is generally straight, oblique, and stepped. These three open-shaped piston rings have their own advantages and disadvantages, but the piston rings with straight and oblique ports are currently the most used. According to the section state of the gas ring, it can be generally divided into rectangular ring, twisted ring, conical ring, barrel surface ring and trapezoidal ring. It is widely used in various piston rings because of the convenient processing of rectangular rings and better thermal conductivity.
According to the different structure of the oil ring, it can be generally divided into ordinary oil ring, spring expander oil ring, and combined steel sheet oil ring. Among these three types of oil rings, spring expander oil ring and ordinary oil ring are used more frequently. .
Piston pins are usually made of low-carbon steel or low-carbon alloy steel. The surface is carburized and quenched to have a high hardness to improve its wear resistance. The internal toughness is maintained to facilitate the bearing and impact load.
The piston pin is generally made into a hollow short round tube shape. The outer circle has high machining accuracy and smoothness, and no grooves and gaps are allowed. The inner hole is generally made into a cylindrical shape. Depending on the bearing condition of the piston pin, some of the inner hole is made into a tapered structure.
The main function of the piston pin is to connect the piston and the connecting rod, and to transmit the gas pressure on the top of the piston and the inertial force of the reciprocating movement of the piston group to the connecting rod.
At present, there are two types of combination of piston pin and piston pin seat and connecting rod small end bushing hole, one is a “semi-floating” piston pin, and the other is a “full floating” piston pin, that is, piston pin and pin. The seat hole is a transition (or clearance) fit, and it is a clearance fit with the small end bushing hole of the connecting rod. At present, “full-floating” piston pins are more commonly used in high-speed diesel engines, because the piston pins of this matching form rotate slowly and can ensure the uniformity of wear along the circumference.