piston vacuum pump overhaul

For the maintenance of piston vacuum pump, it is generally necessary to disintegrate the pump thoroughly, check comprehensively, measure the clearance between the sliding valve and the pump body (normal clearance is 0.04-0.12 mm); check whether there are cracks on the surface of the eccentric wheel of the sliding valve and guide rail pump in the pump, replace them immediately; replace all the sealing parts in the pump dynamically; and measure the clearance between the sliding valve and the pump body (normal clearance is 0.04-0.12 mm). A vibration tester can be used to test the vibration of the pump every week.

According to the measured data, the wear condition of bearing, sliding valve and other components can be preliminarily determined. When the accuracy of bearing motion is reduced, it is replaced to avoid the impact and friction between sliding valve and pump chamber caused by the wear of bearing. Vacuum gauge is used to test the limit pressure of the repaired mechanical pump to determine its performance and repairing effect. For old pumps with long service time, the clearance of the pump is greater than 0.1 mm and less than 0.2 mm. The limit vacuum requirement is not very strict. Vacuum pump oil with 150 mm2/s kinematic viscosity can also be selected to meet the normal operation of the pump.

Because of the wear of pump chamber, the gap between slide valve and pump chamber is larger than 0.2mm. It needs to cooperate with the pump manufacturer. According to the wear condition of pump chamber, the slide valve, eccentric wheel and guide rail are specially made to keep normal gap with pump chamber. For the serious wear and scratch of pump chamber, the time of emptying and the limit pressure can not be used. If the cost of spare parts is close to half of the price of the new pump, the value of maintenance has been lost. A new piston vacuum pump should be replaced.


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