Maintenance of plunger pump

How to repair the matching pair between the plunger ball head and the ball socket in the slipper?

Generally, only 0.015 ~ 0.025mm is reserved between the plunger ball head and the sliding shoe ball socket when the pump leaves the factory, but after a long time of use, the gap between them will greatly increase. As long as it is not more than 0.3mm, it can still be used, but the gap is too large, which will lead to the fault of increasing the pulsation of pump outlet pressure and flow, and in serious cases, it will lead to shoe loosening and shoe falling off, It may even lead to a serious accident in which the pump is damaged due to taking off its boots. When there are signs of pressure and flow pulsation, it is necessary to check whether the shoes may be taken off due to loose shoes as soon as possible, and re wrap the shoes as soon as possible, which must not be ignored.

How to repair the swashplate (thrust plate)?

After the swashplate is used for a long time, the concave phenomenon will appear on the plane. It can be ground flat and then nitrided. If the original nitriding layer is not completely removed by the size (e.g. 0.2mm), nitriding may not be carried out, but the surface of the swashplate must be inspected for hardness.

What are the precautions for replacing bearings?

If the piston pump has clearance, the normal clearance between the above friction pairs cannot be guaranteed, and the oil film thickness of the hydrostatic support of each friction pair in the pump will be damaged, so as to reduce the service life of the piston pump. The average service life of general bearings can reach 1000h, which is equivalent to more than two years. If it exceeds this time, it should be replaced as appropriate. When replacing the bearing, it shall be replaced with the bearing with the same model marked on the removed old bearing or the bearing that can be replaced. For the radial piston pump, refer to the above contents. When the swashplate plane is scraped out of the groove by the plunger ball head, the method of laser cladding alloy powder can be used for repair. The laser cladding technology can not only ensure the bonding strength of the material, but also ensure the hardness of the remelting material, and will not reduce the hardness of the surrounding tissue. It can also use chromium phase electrode for manual surfacing, The plane of the swashplate repaired by welding needs to be re heat treated. It is best to use nitriding furnace for heat treatment. No matter which method is adopted to repair the swashplate, the original dimensional accuracy, hardness and surface roughness must be restored.