No matter what mechanical equipment and vacuum pump assembly, there will be common parts assembly and special parts assembly. When the rolling bearing is in interference fit, the bearing race will be deformed. For example, the diameter of the inner ring increases and the diameter of the outer ring decreases, thus reducing the radial clearance between the raceway surface and the ball. If the installation is improper, the clearance will be too small, so that the bearing ball may be jammed, which will affect the normal operation of the bearing.
There is no gap between the bearing inner ring and the shaft, outer ring and bearing box, because it can not make the shaft reach the required centring accuracy. Therefore, when assembling rolling bearings, the following rules must be observed:
(1) before the assembly, the bearings should be cleaned in the mixture of gasoline and mineral oil (6~8%). After washing, the bearing must be placed on clean paper and dried.
(2) before installing the bearing, the fitting points on the axle and bearing box should also be carefully washed and dried.
(3) when bearing is mounted on the shaft, the seat shall not be hammered directly. And the pipe should be knocked on the hardwood rod or inside the inner ring, and the percussion force should be evenly distributed along the whole end face of the seat ring.
(4) when the bearing is installed, a sealing felt pad should be placed in the oil groove of the bearing box end cover, and the felt pad shall be impregnated with hot oil.
(5) grease in the 2/3 space should be filled in the bearing housing.
The heating temperature of the general bearing can be selected in the range of 60~100 C, because the tempering temperature of the bearing is between 150~180 and C, if the heating temperature is more than l00 C, it is easy to cause the tempering. The heated bearing is quickly sleeved on the shaft and gently hammered into it.
When assembling the rolling bearing, when the outer ring of the bearing is rotated by hand, it should be smooth and not jammed, and the noise is not big. It is also necessary to use the feeler gauge to check whether the contact between the end face of the seat ring and the shoulder is tightly attached to the shaft shoulder, and at the same time, it does not resist chamfering. The skew of bearings on the shaft is a serious drawback. They should be checked for reasons.
When removing bearings, use dismantling tools instead of hammering directly.