What should I do if the shaft head of the vacuum pump is worn? What are the causes of wear and tear

Polymer composite materials can also be used to repair the wear of the shaft head on site, such as Fushilan 2211F metal repair material, which has solved many transmission parts wear problems, such as the wear of the bearing position, bearing chamber and other transmission parts of motors, fans, crushers, pumps, reducers and other equipment.

Common repair methods for shaft head wear:

At present, the common methods of repairing the wear of the shaft head in China are the bushing, pitting, surfacing welding, brush plating, thermal spraying, laser cladding, etc., the emergence of these repair processes promotes the improvement and development of technical processes at the same time, but also is limited by complex process conditions and on-site environment, especially in the face of some sudden emergency, huge equipment, complex disassembly and other equipment problems, these processes are obviously more than enough and insufficient. The method of inlaying the shaft sleeve and making pitting is a very old shaft repair method, and the repair effect is poor, so it is rarely used at present. Here is a brief analysis of several other remediation methods:

1. Surfacing welding (repair welding) process.

Hardfacing welding is a welding process in which a layer of wear-resistant, corrosion-resistant, heat-resistant and other metal layers is deposited on the surface or edge of the workpiece. Different workpieces and overlay welding rods should adopt different surfacing processes in order to obtain satisfactory surfacing results. The most common problem encountered in hardfacing is cracking.

Generally, heat treatment and machining are required after surfacing (repair welding). The biggest disadvantage of repair welding is that the thermal stress is concentrated, the heat affected zone is large, and it is easy to cause the deformation of the shaft.

2. Thermal spraying process.

Thermal spraying is a metal surface processing method in which the molten sprayed material is atomized and sprayed on the surface of the part through high-speed air flow to form a spray coating. Thermal spraying requires professional spraying tools, and the main disadvantages of thermal spraying are that the bond strength between the spray coating and the base metal is insufficient, and the spray coating has defects such as porosity, which is not easy to machine.

3. Brush plating process.

Brush plating is the process of obtaining a coating on the surface of a workpiece by electrolytic methods. Its advantage is that it can be repaired, and its disadvantages are very obvious. The brush plating coating of the brush plating process is limited by the amount of wear, and the brush plating thickness of the brush plating coating is generally less than that.

When the amount of wear is greater, the brush plating efficiency will be doubled, and when the brush plating layer is too thick, the brush plating is easy to fall off during use, and the service life is short.

4. Laser cladding process.

Laser cladding, also known as laser cladding or laser deposition, is a new surface modification technology. It forms an additive cladding layer on the surface of the substrate by adding cladding material to the surface of the substrate and using a high-energy density laser beam to melt it together with the thin layer on the surface of the substrate. The advantage of laser cladding is that the heating of the substrate is not affected by the metal matrix, and the deposition metal cools quickly.

Its disadvantage is that the construction period is long and expensive; The cladding layer is still a combination of electric fusion pools, which has large internal stress, is easy to deform, and has the possibility of cracks.

Dirt or hard solid particles enter the vacuum pump, and friction and collision with the rotary vane for a long time, resulting in damage to the rotary vane.

3.The performance of the rotary vane vacuum pump is better, with uniform pumping, low noise and less power consumption. After a long period of use, due to the wear of the rotary vane, the sealing performance will be reduced, so that the pumping volume and vacuum will be greatly reduced.

The normal wear of the rotary vane is also a very important reason, and the wear of the rotary vane will increase when the vacuum pump oil is emulsified.

The solution is 1If the vane is the most worn, the vane is corrected first based on the minimum size of the vane. You can use a fine file to push it flat, and measure the size and diagonal ruler while grinding until you can't see the translucent gap.

2.If the rotary vane wears too much, the grinder is put on the machine first, and then the two ends of the rotor and the pump chamber are scraped and ground according to the selected clearance value to ensure the matching clearance between the three. 3.

After the rotor vane wears out greatly, if the processing capacity permits, it is best to replace it with a new one, because it is more convenient to replace the rotary vane than grinding the end face of the pump chamber.

Pronotek screw vacuum pumps wear out for several reasons:

1.Fillers such as calcium carbonate and glass fiber can accelerate the wear of the screw and barrel.

2.In the compression and homogenization sections, if the melt state of the plastic is uneven, it will also cause wear to increase.

3.Some plastics are reinforced with reinforcing agents such as fiberglass, minerals or other fillers. These substances tend to have a much greater friction on metal than molten plastic.

The reasons for the insufficient pumping capacity of the dry oil-free screw vacuum pump are as follows: 1. Whether the power supply is normal 2. Whether the selection is appropriate 3. Pipeline leakage and liquid leakage 4. Excessive impeller wear.