The role of the oil pump in the lubrication system: The role of the oil pump is to raise the oil to a certain pressure and force the ground pressure to the moving surface of the engine parts.
The structure of oil pump can be divided into gear type and rotor type.
Gear type oil pump is divided into internal gear type and external gear type, generally called the latter gear type oil pump.
Oil pump In a lubricating system, a device that forces oil from the oil pan to moving parts of the engine.
Oil pump is used to increase the oil pressure and ensure a certain amount of oil, to the friction surface of the forced supply of oil components.
▶Gear type and rotor type oil pump are widely used in internal combustion engines.
▶The gear type oil pump has the advantages of simple structure, convenient processing, reliable operation, long service life and high pump pressure, so it has been widely used.
▶Rotor pump rotor shape is complex, multi-purpose powder metallurgy pressing. This pump has the same advantages as gear pump, but compact structure, small volume, smooth operation, low noise.
▶The number of internal and external rotor teeth of cycloid rotor pump is only one tooth difference. When they do relative movement, the sliding speed of the tooth surface is small, and the meshing point is constantly moving along the tooth profile of the internal and external rotor.
▶Therefore, the mutual wear of the two rotor tooth surfaces is small.
①Structure and working principle of oil pump
▶The oil pump is composed of an outer rotor and an inner rotor which are arranged between the pump body and the pump cover and are equal in height and the pump body cavity.
▶The radial clearance between the outer rotor and the pump body is generally 0.09 ~ 0.12mm, the meshing clearance between the inner and outer rotor is 0.07 ~ 0.12mm, and the clearance between the inner and outer rotor and the pump cover is 0.03 ~ 0.075mm.
▶The regulating (limiting) pressure system of the oil pump is composed of plunger, spring and screw plug. Its function is to adjust the pressure of the oil outlet of the oil pump.
②Oil pump classification
▶▶External gear pump
Agencie:Two gears with equal number of teeth, housing, oil inlet, oil outlet, relief valve, etc.
Working process: The two gears rotate at high speed.
① Oil port, two gears out of meshing, so that the volume of the oil inlet chamber increases, suction, oil through the oil pan into the oil chamber.
② Oil outlet, the two gears are close to meshing, and the output chamber capacity.
▶▶Internal meshing gear pump
Structure:Inner teeth, outer teeth, crescent-shaped step, oil inlet, oil outlet, shell, etc.
Working process:The inner teeth are driven by the crankshaft, and the outer teeth are driven gears.
① oil port; The inner and outer teeth are out of meshing, and the volume of the oil chamber increases, generating suction, and the oil is sucked into the oil chamber through the oil pan.
② oil outlet; The inner and outer gears are close to meshing, the volume of the oil outlet chamber decreases, the pressure increases, and the oil flows out of the oil outlet chamber.
▶▶Rotor oil pump
Structure; Inner and outer rotor, oil inlet, oil outlet, shell composition.
Ø characteristic; The inner rotor is active, the outer rotor is driven, the inner rotor is less than the outer rotor a tooth, the inner and outer rotor eccentric installation.
1.Oil inlet; The internal and external rotor out of meshing, oil chamber volume increases, suction, oil through the oil pan into the oil chamber.
2.oil outlet; The inner and outer rotor meshes, the volume of the oil outlet chamber decreases, the pressure increases, and the oil flows out of the oil outlet chamber.
③Common fault analysis of oil pump
▶▶Low oil pressure, insufficient oil supply, abnormal engine sound, and even cause tile and shaft failure.
1.The reason is that the flow of the oil pump is low, which may be caused by the early opening pressure point of the pressure limiting valve or the internal and external rotor, rotor and pump body, and the gap between the pump cover and the rotor is too large.
2.Sometimes the inner rotor is not firmly connected with the shaft, and the shaft does not turn when it turns to the inner rotor, which is also the reason for the low flow of the oil pump.
▶▶High oil pressure will make the engine power loss, affect the sealing oil leakage phenomenon.
1.When the pressure is too high, it will damage the oil filter element, so that the oil can not be filtered.
2.The reason for the high oil pressure is that the pressure limiting valve of the oil pump is opened late or not opened, which fails to adjust the pressure of the oil outlet.
3.The main reason for the late opening or not opening of the pressure limiting valve is that the plunger movement in the hole is not flexible.
4.The gap between the plunger and the hole is small, the surface roughness is low, or the plunger hole has a taper, etc., may affect the opening of the pressure limiting valve, resulting in high oil pressure.
5.Block oil passage blockage, filter blockage will also cause high oil pressure.
From the common faults of the oil pump, it can be seen that the faults of the oil pump are related to the pressure limiting valve, so special attention should be paid to the acceptance.
It is worth noting that the flexibility of the plunger in the pressure limiting valve has a direct relationship with the plunger hole. In the acceptance, we should focus on checking the roughness of the plunger and the clearance of the hole to ensure the flexibility of the plunger movement in the hole.
Copyright © 2021 1D AUTO PARTS CO., LTD. - All Rights Reserved.