Analysis of Phenomenon of Insufficient or No Oil Pressure in External Technical Exchange Gear Pumps

When the gear oil pump is in use, it often happens that there is not enough oil or there is no oil pressure. We analyze the fault as follows to facilitate troubleshooting and repair of the gear oil pump.

phenomenon:

(1) The work apparatus is promoted slowly, shivering or not being promoted during promotion;

(2) There are air bubbles in the tank or tubing;

(3) The hydraulic system issued a "bang and bang" sound when promoted;

(4) The working device can be promoted when the tractor is just started. After the oil temperature rises for a period of time, the promotion will be slow or unable to be promoted;

(5) It can be promoted at light load and cannot be promoted at heavy load.

Gear pump failure reason:

(1) The oil level in the hydraulic tank is too low;

(2) The hydraulic oil was not used according to the season;

(3) The inlet pipe is seriously blocked by dirt;

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

(5) The “O”-shaped seal ring of the gear oil pump inlet and outlet joints or elbow joints is damaged, the fastening bolts of the elbow joints or the nuts of the inlet and outlet oil pipes are not tightened, and the air enters the hydraulic system;

(6) Internal leakage of the oil pump, aging of the sealing ring;

(7) The end surface of the oil pump or the main and driven gear bushings is worn or scratched, and the unevenness of the end surfaces of the two shaft sleeves is excessive;

(8) Internal leakage caused by incorrect assembly of internal parts of the gear pump;

(9) "Left swivel" installed "right-handed" oil pump, causing damage to the skeleton oil seal;

(10) Dirty hydraulic oil.

Gear oil pump exclusion method:

(1) According to the season, add or replace the oil that meets the required grade to the designated oil level. Pull out the foreign matter in the tubing and tighten the bolt or nut at the joint;

(2) Replace aging or damaged skeleton oil seals or "O" seal aprons;

(3) Replace the worn gear oil pump or the oil pump bushing. When the wear is slight, flatten the end surface on the flat plate. The unevenness promises an error of 0.03mm; the end of the upper bushing is lower than the upper plane of the pump body (normal value is lower than 2.5-2.6mm), if it is out of tolerance, 0.1-0.2mm copper sheet should be added to the lower bushing to compensate, and when it is installed, Should be put on the rear axle sleeve to install;

(4) The unloading plate and the sealing ring must be installed in the oil inlet cavity. The two shaft sleeves can maintain the balance. The unloading seal ring should have a preload of 0.5mm;

(5) The guide wire elasticity should be able to twist the upper and lower bushings at the same time towards the rotation direction of the driven gear by a small angle, so that the machining planes of the two bushings of the main and driven gears can be closely fitted.

(6) The unloading groove on the sleeve must be installed on the side of the low pressure chamber to eliminate harmful dead volume when the gear meshes;

(7) Before pressing into the self-tightening oil seal, a layer of lubricating oil shall be applied to the surface of the self-tightening oil seal, and the edge of the impeding oil shall also be directed toward the front cover, and it shall not be installed in reverse;

(8) The "right-handed" pump cannot be mounted on a "left-handed" machine, otherwise it will damage the skeleton seal;

(9) Before installing the pump cover, pour a small amount of oil into the pump casing and roll the gear by hand;

(10) Before installing the gear pump cover without tightening the bolt, check whether the clearance between the pump cover and the pump body is between 0.3 and 0.6 mm. If the clearance is too small, replace the big seal ring and the pressure relief part. After the hydraulic oil pump is installed, it should be flexible and non-stuck.