Eaton Char-Lynn Motor – Motor: Cylinder Wear Rules And Reasons
motor cylinder wear exceeding the allowable standard will seriously reduce the power and economy of automobiles. Therefore, to understand the causes of cylinder liner wear and to grasp the wear law of cylinder is convenient for correct and reasonable use, so as to slow down the wear of cylinder and prolong the service life of motor.
Wear law of cylinder:
The wear of motor cylinder is uneven in use. The general rule is along the axis direction of the cylinder. Above the cylinder liner, the wear of the first air ring is the greatest at the slightly lower upper dead center, while the wear of the piston ring is the smallest below the lower dead center. From the cross section of wear, the cylinder is grinded into non-standard cylindricity. Generally speaking, the wear of the first and sixth cylinders is more serious than that of other cylinders. The main reason is poor cooling.
The main causes of motor cylinder wear are mechanical wear, abrasive wear and chemical corrosion. The wear characteristics of Eaton Char-lynn Motor are described respectively.
(1) Mechanical wear: Mechanical wear is caused by mechanical friction. The degree of mechanical wear is affected by the processing accuracy of cylinders and piston rings, matching quality, lubrication conditions, working temperature and mutual pressure in friction. When the motor works, the upper temperature is high, the lubricating oil is affected and thinned, and the quality of the oil film is poor. The back pressure of the first piston ring (high pressure gas enters the piston ring groove and tightly compresses the piston ring on the cylinder wall) is the largest. Therefore, the wear of the first piston ring in the upper part and slightly lower part of the cylinder is the largest, while the wear of the lower part is smaller.
(2) Abrasive wear: Abrasive wear is the main wear. Abrasive is a mixture of metal impurities in oil and impurities in air, which can accelerate the wear of machine parts. During the intake process, the pressurized intake flow directly rushes into the cylinder wall opposite to the intake valve. When the motor is running at low temperature, the diesel spray is not good enough, and the diesel oil particles that are not fully burned weaken the oil, causing the oil to dilute and damage the oil film. At the same time, due to the damage of the air filter core, the dust and sand brought by the intake air flow adhere to the cylinder wall opposite the intake valve, resulting in serious abrasive wear. Abrasive wear not only causes the wear of the upper and lower parts of the first piston ring, but also makes the cross section of the cylinder elliptical. The main causes of abrasive wear are: the damage of filter element of air filter, the shedding, cracking or breaking of rubber pipe from supercharger to intercooler or supercharger to intake pipe connection, and the serious abrasive wear caused by air short circuit into cylinder; some users overemphasize the replacement of motor oil according to its quality, the long service time of motor oil, the deterioration, thinning and increase of impurities of motor oil, and the serious mixing of metal impurities. Abrasive wear. In units where laboratory equipment is not yet available, it is best to replace oil periodically. Replacement of oil and oil filter core and air filter core is the best maintenance method for each secondary maintenance (12000 km).
(3) Chemical corrosion: When the motor cylinder wall temperature is low and the cylinder pressure is high, the water vapor in the cylinder will form droplets on the cylinder wall. These droplets contact with the exhaust gas to form acidic substances, which attach to the cylinder wall and corrode the cylinder. The lower the working temperature of the cylinder, the easier the acidic substance to form and the greater the corrosion effect. Corrosion and wear are mainly caused by improper operation. The correct operation should be to start the motor, idle for a few minutes, after the water temperature and oil pressure are normal, gradually increase the motor speed, so that the motor temperature remains normal, the water temperature of the motor during driving should be 80-90 degrees Celsius. Driving at low temperature is very harmful to the motor and corrosive wear is also increased.