Marine diesel engine parts：

1. Pump assembly

The function of the pump is to pressurize the cooling water to ensure it circulates in the cooling system. In a forced circulation cooling system, a centrifugal water pump is used to increase the pressure of the cooling water to accelerate the circulation of water in the cooling system. Because the centrifugal water pump has the advantages of simple structure, small size, reliable operation, and easy manufacture, it is widely used. When the water pump impeller driven by the crankshaft rotates counterclockwise, the water in the water pump is driven to rotate together. Under the action of centrifugal force, the water is sucked to a certain pressure on the edge of the pump casing, and flows out from the water outlet. At the center of the impeller, the water is lowered by the outer edge of the crucible, and the water in the tank is sucked into the pump through the inlet pipe and then pumped out by the impeller.

2, the piston

The function of the piston is to withstand the pressure of the gas in the cylinder and transmit this force to the connecting rod. The top of the piston also forms a combustion chamber with the cylinder head, and the fuel entering the cylinder is burned in this space.

3, piston ring (trapezoidal ring, cone ring, oil ring)

The piston ring is divided into two types: the gas ring and the oil ring. Their functions and requirements are different, so they also have their own characteristics. The function of the gas ring is to ensure the seal between the piston and the cylinder wall, preventing the high pressure gas in the upper part of the piston from leaking into the crankcase. In addition to the sealing action, the gas ring also acts as a heat transfer. Most of the heat absorbed by the top of the piston is transmitted to the cylinder wall through the gas ring and then carried away by the external cooling medium. There are many cross-sectional shapes of the gas ring. The most common shapes are the following: rectangular ring, twisted ring, micro-cone ring, barrel ring and trapezoidal ring; oil ring is divided into common oil ring and combined oil ring. The function of the oil ring is mainly to scrape off excess oil on the cylinder wall and flow back into the crankcase to reduce the consumption of oil.