Interpretation of the structure of the oil pump, working principle and troubleshooting methods summary

First, the structure and working principle of the oil pump (A) The structure of the oil pump As shown, the oil pump is installed between the pump body 1 and the pump cover 7 and a pair of pump body cavity height and meshing with each other outside the rotor 6 and the inner rotor assembly 2. External rotor and the pump radial clearance is generally 0.09 ~ 0.12mm, internal and external rotor meshing gap of 0.07 ~ 0.12mm, inside and outside the rotor and the pump cover clearance 0.03 ~ 0.075mm. Figure by the plunger 3, The spring 5 and the screw plug 4 constitute the oil pump regulating (limiting) pressure system, and its role is to adjust the pressure of the oil pump outlet. Shanghai Wuyue specializes in producing all kinds of spring safety valve, GB safety valve, American Standard safety valve, German standard Safety valve, Japanese standard safety valve, pressure reducing valve, gas valve, ball valve (B) the working principle of the oil pump cycloid rotor pump. As shown in a, the cycloid pump consists of a pair of internal meshing rotors. The inner rotor 1 is an external gear and the center of rotation is O 1. The outer rotor is an internal gear, the center of rotation is O 2, and the eccentric distance between O1 and O2 is 0. The outer rotor has one tooth more than the inner rotor, The inner rotor is 6 teeth. In general, the number of teeth of the inner rotor Z 1 may be 4, 6, 8, and 10, and the number of teeth of the outer rotor Z 2 = Z 1 + 1. The inner rotor of the oil pump has four teeth and the outer rotor has five teeth. The profile of the inner rotor and the profile of the outer rotor are composed of a pair of conjugate curves so that the profile on the inner rotor meshes with the profile on the outer rotor teeth to form a number of independent sealed working spaces The volume of space changes with the meshing rotation of the inner and outer rotors. When the inner rotor is driven by the motor to rotate counterclockwise around O 1, the outer rotor rotates in the same direction about the inner rotor about O 2, and the following zero point starts from one tooth on the inner rotor and 1 'on the outer rotor The change of the volume of A cavity in the back of the tooth was analyzed. The volume of chamber A is the smallest when position 2a is shown. When the rotor rotates from position a to position b, c, the volume of chamber A gradually increases to form a partial vacuum, and oil is sucked from the tank through the oil distribution window b on the side plate (indicated by the dotted line in the figure) . When the rotation position d, A cavity volume maximum (A = A max), the end of the oil absorption process. Turn around the position d, A cavity volume gradually decreases, the cavity of the oil pressure from the oil discharge window a (shown in dashed lines) discharge, this process is the discharge process. When rotated to position f, A cavity volume is the smallest (A = Amin), oil discharge process is completed. From the above analysis we can see that the cycloid pump rotor in the course of their work, a tooth of the inner rotor each turn a week, resulting in a work cycle to complete the oil drain each time. For one revolution per revolution of the inner rotor with Z1 teeth, there will be Z1 working cycles identical to the A cavity so that oil and oil discharge can be continuously performed. Second, the common fault analysis of the oil pump (A) low oil pressure, lack of fuel, the engine abnormal noise, and even cause research Van and research shaft and other failures. The reason is low oil pump flow, resulting in low pump oil flow May be the pressure valve opening pressure early or inside and outside the rotor, rotor and pump body, pump cover and rotor clearance is too large. Sometimes the rotor and shaft connection is not strong, the rotor shaft and turn when the rotor does not turn is caused by low oil pump causes. (B) high oil pressure will make the engine power loss, the impact of oil leakage phenomenon seal. When the pressure is too high, it will damage the oil filter cartridge, so that the oil can not be filtered. Produce high oil pressure is due to open the oil pressure limit valve is open late or not, failed to play a role in regulating the pressure out of the port. The main reason that the pressure limiting valve opens late or can not be opened is that the plunger is not flexible in the hole. Plunger and hole clearance is small, the surface roughness is low, or the plunger hole taper, etc. may affect the pressure limiting valve opens, resulting in high oil pressure. Clogged cylinder block, filter clogging can also cause high oil pressure. Third, the acceptance of the oil pump (A) The main performance requirements of the oil pump 1, the fuel supply; see Table 2, the pressure limiting valve opening pressure (0.343 ~ (B) the preparation before the test 1, check the accuracy of the pressure gauge Whether to meet the test range, flow, speed, temperature figures show the stability is accurate, whether in the inspection cycle. 2, check the kinematic viscosity of the test oil used to meet the technical requirements. 3, the first acceptance of measuring cup directly measure the flow rate per minute Whether it is consistent with the figures show the flow 4, measuring an oil pump, record its flow data as a standard pump to proofread the test bench or test oil viscosity basis (3) the main performance check 1, check the oil pump oil Volume 3 shows the pressure is 0.25Mpa, the test oil is 20 # mechanical oil measured at 55 ℃ ± 2 when the number of revolutions curve.From the curve it can be seen that the flow rate is proportional to the speed, so in the test in addition to ensuring the pressure And the oil temperature in the rated range of speed must be controlled within the rated speed of ± 10 revolutions, so that the measured data can be accurate. 2, check the opening pressure is 20 # 55 ℃ engine oil speed 1500r / min measured when the pressure characteristic curve from the curve shows that when the pressure limiting valve open point after the flow rate increases with the pressure decreased significantly while the curve is made by the number of test points made point by point, It can be seen from the graph that the flow of a section of the curve before the pressure-limiting valve opens drops little when the pressure increases as the plunger does not leave the discharge orifice and the decreasing flow is due to the pump itself being sealed Good and leaked.So when checking the pressure limiting valve to open the pressure must flow changes, Practice has proved that when the pressure is 0.245Mpa when the flow rate decreases with the increase of 1-1.5L when the pressure value is pressure limiting valve open Pressure.At the same time also depends on the flow value of 0.49Mpa is in line with the requirements.In short, to identify the pressure-limiting valve should be open to grasp the principle that its flow is a significant decline.From the pump fault can be seen in the common machine Pump failure and pressure limiting valve, so the acceptance should pay special attention is worth noting that the pressure limiting valve plunger in the flexibility of the plunger hole is directly related to the acceptance of the time to focus Check the plunger with holes and roughness of the gap, to ensure flexibility in the movement of the piston bore.