Trouble causes and troubleshooting of the hottest

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Faults, causes and troubleshooting of gear pump

1. Wear of internal parts of oil pump

wear of internal parts of oil pump will cause internal leakage. The large leakage area between the floating shaft sleeve and the gear end face is the cause of internal leakage. In addition, the company also customized the main parts of some fatigue testing machines according to the special requirements of some special industries. This part of the leakage accounts for about 50%~70% of the total internal leakage. The volumetric efficiency of the gear pump with wear and internal leakage decreases, and the output power of the oil pump is much lower than the input power. All the losses are converted into heat energy, which will cause the oil pump to overheat. If the joint plane is pressed tightly, the floating shaft sleeve will be worn due to a small amount of movement during operation, resulting in slow or unable lifting of farm tools. Such floating shaft sleeve must be replaced or repaired

2. The wear of the oil pump housing

is mainly the wear of the floating shaft sleeve hole (the normal clearance between the gear shaft and the shaft sleeve is 0.09~0.17, which was 5mm as early as 2016, and the maximum shall not exceed 0.20mm). The gear works under the action of pressure oil. The gear tip is close to the oil pump housing and wears the low-pressure cavity of the pump body. The other kind of wear is the circumferential wear of the working surface in the housing. This kind of wear is mainly caused by the unclean oil added, so the oil without impurities must be added

3. The oil seal is worn and the rubber seal is aged

the rubber oil seal of the unloading plate is aged and deteriorated, losing its elasticity, and losing its sealing and isolation effect on the high-pressure oil chamber and the low-pressure oil chamber. The oil pressure in the high-pressure oil chamber will flow to the low-pressure oil chamber, which is called "internal leakage", which reduces the working pressure and flow of the oil pump. The normal working pressure of cb46 gear pump is 100~110kg/cm2, the normal oil delivery is 46l/min, and the standard unloading plate rubber oil seal is 57 × 43。 Self tightening oil seal is pg25 × forty-two × If the skeleton oil seal of 10 is damaged or fails for a long time, air will be sucked into the oil pump from the gap between the oil seal and the main shaft journal or from the joint between the oil inlet connecting plate and the oil pump housing, and enter the oil tank through the oil return pipe, generating a large number of bubbles in the oil tank. It will reduce the oil in the oil tank and increase the oil in the engine oil sump, making the lifting of farm tools slow or impossible. The oil seal must be replaced to correct the fault

4. The oil supply of the oil pump is insufficient or there is no oil pressure: the working device is lifted slowly, shaking or unable to lift; There are bubbles in the oil tank or oil pipe; When lifting, the hydraulic system makes a "pump, pump" sound; When the tractor is just started, the working device can be lifted. After working for a period of time, the oil temperature rises, the lifting is slow or can not be lifted; It can be lifted under light load, but not under heavy load. Failure cause of inlet pump valve:

(1) the oil level of hydraulic oil tank is too low

(2) hydraulic oil is not used seasonally

(3) the oil inlet pipe is seriously blocked by dirt

(4) the oil seal of oil pump driving gear is damaged, and air enters the hydraulic system

(5) the "O" ring of oil pump inlet and outlet joints or elbow joints is damaged, the fastening bolts of elbow joints or the nuts of oil inlet and outlet pipes are not tightened, and air enters the hydraulic system

(6) internal leakage of oil pump and aging of sealing ring

(7) the oil pump end face or the driving and driven gear shaft sleeve end faces are worn or scratched, and the unevenness of the two shaft sleeve end faces is out of tolerance

(8) internal leakage caused by incorrect assembly of internal parts of oil pump

(9) "left-hand" and "right-hand" oil pumps were installed, causing the framework oil seal to be damaged

(10) the hydraulic oil is too dirty


(1) add or replace the engine oil with the required brand to the specified oil level according to the season. Take out the foreign matters in the oil pipe and tighten the bolts or nuts at the joint

(2) replace the aged or damaged skeleton oil seal or "O" ring

(3) replace the worn gear oil pump or oil pump shaft sleeve, and grind the end face on the flat plate when the wear is slight. The allowable unevenness error is 0.03mm; The end face of the upper shaft sleeve is low. Since the deformation unit of this set has a single chip as the core on the upper plane of the pump body (the normal value is less than 2.5~2.6mm), if it exceeds the tolerance, it should be compensated by adding 0.1~0.2mm copper sheet to the lower shaft sleeve. When the installation will effectively alleviate the tightening of the Indian PE market, it should be installed on the rear shaft sleeve

(4) the unloading plate and sealing ring must be installed in the oil inlet chamber so that the two shaft sleeves can be balanced. The sealing ring of the unloading plate shall have a preload of 0.5mm

(5) the elasticity of the guide steel wire shall be able to twist the upper and lower shaft sleeves by a small angle towards the rotation direction of the driven gear at the same time, so that the processing planes of the two shaft sleeves of the driving and driven gears are closely fitted

(6) the unloading groove on the sleeve must be installed at the side of the low-pressure chamber to eliminate the harmful dead volume caused by gear meshing

(7) before pressing in the self tightening oil seal, apply a layer of lubricating oil on its surface, and pay attention to the oil blocking edge facing the front cover, and do not install it upside down

(8) "right rotation" pump cannot be installed on "left rotation" machine, otherwise it will damage the framework oil seal

(9) before installing the pump cover, pour a small amount of engine oil into the pump housing and rotate the meshing gear by hand

(10) before installing the oil pump cover and tightening the bolts, check whether the gap between the pump cover and the pump body is between 0.3~0.6mm. If the gap is too small, replace the large sealing ring and pressure relief parts. After the hydraulic oil pump is installed, it shall rotate flexibly without jamming

stainless steel gear pump is suitable for conveying general viscosity and high viscosity fluids without solid particles, fibers and other substances, which are non lubricating, corrosive and have high sanitary requirements. Medium temperature - ℃, viscosity CST

used in machinery, petroleum, chemical industry, food, medicine, metallurgy, printing and dyeing, brewing, cosmetics, beverages and other industries

the power transmission gear and the fluid transmission gear are in different pump cavities. They are designed and manufactured according to their different functions. Therefore, the pump has higher reliability. On the basis of FXa stainless steel gear pump, FXB adds primary support to improve the working pressure, and is designed as flange connection. The pump has two forms: mechanical seal and packing seal

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