Vacuum pump is no stranger to us. When it is used, sometimes it will wear. What is the reason?

1、 Causes of vacuum pump wear

The wear of the journal surface is uneven. The radial wear of the main journal and the connecting rod journal is mainly elliptical, and the maximum wear parts of the vacuum pump correspond to each other, that is, the maximum wear place of each main journal is close to the side of the connecting rod journal; and the maximum wear place of the connecting rod journal is also close to the side of the main journal. The crankshaft journal also has conical wear along the axial direction. The elliptical wear of the journal is caused by the uneven distribution of the force acting on the journal along the circumferential direction.

When the engine is working, the comprehensive force acting on the connecting rod journal always acts on the inner side of the connecting rod journal, and the direction is outward along the radius of the crankshaft, resulting in the maximum wear on the inner side of the connecting rod journal and forming an ellipse. The wear of the connecting rod journal is caused by the wear of the connecting rod journal in the cone-shaped oil channel, which is caused by the eccentric wear of the connecting rod journal under the action of the oil accumulation in the rotary Journal of the pump.

In addition, the bending of the connecting rod, the cylinder center line and the vacuum pump center line are not vertical and other reasons, will make the journal along the axial force uneven, and make wear deflection. The wear of the main journal is elliptical, which is mainly due to the influence of centrifugal force of connecting rod, connecting rod journal and crank arm, which makes the relative wear between the side close to the connecting rod journal and the bearing larger. In addition, abrasions and burns may occur on the surface of the journal. Scuffing is mainly due to the oil is not clean, which large hard mechanical impurities in the journal surface scratch caused. The burn on the surface of journal is caused by Bush burning, which is mainly caused by insufficient lubrication, too thin oil and blocked oil circuit.

Therefore, we should pay attention to the maintenance of the vacuum pump and deal with the problems in time to prolong the service life.

2、 Solutions to wear and tear

The traditional methods are mainly repair welding and brush plating spraying, but these two methods can not fundamentally solve this problem, and the disadvantages are obvious. First of all, the thermal stress generated by various methods under high temperature can not be completely eliminated, which can not only repair the damaged parts, but also cause damage to the material This method is limited by the thickness of the coating, so it is easy to peel off. The metal repair method like this can not repair the damaged parts very well, but also may cause secondary wear and damage.

In view of the above problems, modern western countries often use the repair method of polymer composite material to repair it. The repair method of polymer material has the characteristics of no disassembly and no machining. It will not be affected by the thermal stress of repair welding, and will not be limited by the repair thickness. In addition, it is also yielding and can absorb the impact vibration of equipment, In this way, the possibility of re abrasion is avoided, and the service life of equipment components is prolonged.