As the working time of any machine continues to lengthen, the skills of gear pump will continue to decline, eventually leading to various problems. Among them, the two most common faults are insufficient pump oil and no pump oil of gear pump. There are many reasons for these two faults, which can be basically classified as component wear, including the wear of driving shaft and bushing, the wear of central hole and shaft pin of driven gear, the wear of inner cavity of pump housing and gear, and the wear of gear end face and pump cover. When we repair the gear pump, we should know how to solve the damage of each part and make a correct judgment.
1. Wear of driving shaft and bushing:
When the driving shaft and bushing of the gear pump are worn, the matching clearance will increase, which will inevitably affect the oil volume of the pump. In this case, the normal fit clearance can be restored by repairing the driving shaft or bushing. If the driving shaft is slightly worn, just press out the old bushing and replace it with a standard bushing, and the fit clearance can be restored to the allowable range. If the driving shaft and bushing are seriously worn and the fit clearance exceeds the standard, not only the bushing shall be replaced, but also the diameter of the driving shaft shall be increased by chromium plating or vibration surfacing, and then ground to the standard size to restore the fit requirements with the bushing.
2. Repair of lubricating oil pump shell repair of shell crack:
Shell cracks can be repaired with cast 508 nickel copper welding rod. The weld must be tight and free of air holes, and the flatness error of the joint surface with the pump cover shall not be greater than 0.05mm.
3. Repair of pump cover:
Repair of working plane: if the working plane of the pump cover is slightly worn, the wear trace can be eliminated by manual grinding, that is, put a little valve sand on the platform or thick glass plate, and then put the pump cover on it for grinding until the wear trace is eliminated and the working surface is flat. When the wear depth of the working plane of the pump cover exceeds 0.1mm, it shall be repaired by turning first and then grinding.
4. Overturning of gears:
The gear wear of gear pump is mainly at the tooth thickness, while the wear of gear end face and tooth top is relatively light. The gear is worn on one side at the tooth thickness, so the gear can be turned 180 degrees for use. When the gear end face is worn, the end face can be ground flat, and the joint surface of the lubricating oil pump housing can be ground at the same time to ensure that the clearance between the gear end face and the pump cover is within the standard range.
