Causes and preventive measures of oil leakage on dynamic joint surface of Cummins diesel generator set

1. the reason why

(1) The sealing of the dynamic contact surface is mainly the function of the oil seal. The quality of the oil seal itself directly affects the quality of the oil seal. Therefore, the installation of oil seal rubber lip edge should be strictly checked, no incomplete, aging or incision defects. When hitting the oil seal, the point of force should be at the shoulder position of the platform with skeleton in the near outer diameter, and the force should be uniform to ensure the assembly quality.

(2) the matching size of shaft and oil seal will affect the sealing property of oil seal. If the size of the shaft is too large, although it can ensure the sealing, it is easy to cause early wear of the oil seal and greatly shorten the service life.

(3) When the diesel generator is in operation, the high-speed rotating shaft is always in contact with the static oil seal, resulting in friction, and the speed of wear is closely related to the journal surface roughness, hardness and eccentricity of the shaft oil seal surface. Therefore, the journal surface roughness at the installation of oil seal is required to be 1.6 ~ 1.4, and the hardness is HRC4560. The eccentricity of the sealing surface of the shaft is generally not greater than 0.025mm. With the increase of the speed, the eccentricity is allowed to be reduced, otherwise it is easy to produce oil leakage.

(4) Oil leakage phenomenon occurs in cracking or fracture of oil pipe joint, which is generally caused by diesel generator I and VI two-cylinder high-pressure oil pipe which is easier to fracture than other cylinders. In addition to the quality of the tubing itself, the main reason is to fix the high-pressure tubing clamp or install it in an inappropriate position when repairing and dismantling the fuel injection pump. The oil leakage may be caused by the loose sealing of the conical surface of the connection of the high pressure tubing, injector and fuel injection pump. Through the inspection, after eliminating the oil leakage causes of fuel injection pump and fuel injector, check whether the cold heading cone surface of the high-pressure oil pipeline product meets the requirements of the drawings and whether there is any error in the bending size. Due to the vibration of high-pressure tubing and the installation stress caused by the bending error of high-pressure tubing, it is possible to aggravate the loose sealing of the sealing cone.

(5) Aging of oil seal sealing ring will lead to oil leakage of diesel generator, which needs to replace the sealing ring;

(6) poor lubrication in the supercharger, easy to make the parts friction caused by parts wear and oil leakage, this situation needs to add oil or replace worn parts;

(7) Supercharger damage will appear oil leakage phenomenon, this situation to directly replace the supercharger.

2. measures

(1) The installation method must be paid attention to when installing the oil seal, otherwise it is easy to cause the inconsistency between the center line of the oil seal and the center line of the shaft, or damage the oil seal, resulting in oil leakage. Therefore, when installing oil seals, we should try to adjust the sealing seat and the bearing and rotating shaft to keep concentric, which requires that the installation tools and methods be considered.

(2) Pay attention to cleaning when installing oil seal.

(3) Keep the oil loop unblocked, is an important measure to prevent oil leakage.

(4) in order to ensure the accuracy requirement of the seal cone shape, size, recommended in high pressure oil pipe connection after a head cold heading forming, tubing bending shape before, add a finishing grinding cone craft, through grinding, ensure the accuracy of the size and the shape cone generally every root high-pressure tubing grinding 0.02 ~ 0.05 mm, to form the complete accurate cone, Individual to grind more than 1.0mm. Also in the cold heading forming after the protective sleeve storage, can completely solve the problem of parts bruise.

Jiangsu Meao Power Technology Co., Ltd. focuses on the development and manufacture of diesel generator sets, and has accumulated rich experience in manufacturing and service in this field. As a professional generator manufacturer, MEAOPOWER attaches great importance to product development, innovation and service quality, and maintains close strategic cooperation with famous domestic and international enterprises such as Cummins, Perkins, Doosan, Yuchai, Weichai, Shangchai, Wuxi Wandi, Lillesomer, Stanford, Marathon and so on.