Matching Selection Of Rolling Bearing
Matching Selection Of Rolling Bearing
2021年12月25日
Problems Needing Attention During Installation Of Centripetal Thrust Ball Bearing
Problems Needing Attention During Installation Of Centripetal Thrust Ball Bearing
2021年12月26日

Several Problems Needing Attention In Installation

Installation

a. The thickness of inner and outer spacer rings must be matched, and the parallelism of two surfaces of spacer rings shall not exceed 0.002mm.

b. Bearings must be optional. The inner diameter difference and outer diameter difference of each group of bearings shall be between 0.002-0.003mm, and a clearance of 0.004-0.008mm with the shell hole and 0.0025-0.005mm with the journal shall be maintained. In actual installation, fit the bearing that can be just pushed in with both hands and thumbs.

c. The roundness of bearing seat hole and journal, the coaxiality at both ends of shell hole and the radial runout of journal shall not exceed 0.003mm.

Several Problems Needing Attention In Installation

d. The end face of parts in contact with the end face of bearing ring shall be painted for inspection, and the contact area shall not be less than 80%.

e. Must be installed directionally. That is, align the high point of radial runout of all bearing inner rings with the low point of journal radial runout, and the high point of radial runout of bearing outer rings shall be in a straight line when installed in the housing hole.

Key points for installation and maintenance of rotary table bearing

Installation Of Angular Contact Ball Bearing

The installation of angular contact ball bearings is more complex than that of deep groove ball bearings. They are mostly installed in pairs, and preloading is required. Good installation can greatly improve the working accuracy and bearing life of the host; Otherwise, not only the accuracy can not meet the requirements, but also the service life will be affected.

Installation form

The installation forms of angular contact ball bearings include back-to-back, face-to-face and series arrangement. When installing back-to-back (the wide end faces of the two bearings are opposite), the contact angle line of the bearing diffuses along the rotation axis, which can increase its radial and axial support angle rigidity and deformation resistance; face to face (the narrow end faces of the two bearings are opposite)

during installation, the contact angle line of the bearing converges towards the rotation axis, and the ground bearing angle rigidity is small. Because the inner ring of the bearing extends out of the outer ring, when the outer rings of the two bearings are pressed together, the original clearance of the outer ring is eliminated, which can increase the preload of the bearing; arranged in series (the wide end faces of the two bearings are in the same direction)

during installation, the contact angle lines of the bearings are in the same direction and parallel, so that the two bearings can share the working load in the same direction. However, when using this installation form, in order to ensure the axial stability of installation, two pairs of bearings arranged in series must be installed opposite at both ends of the shaft.

Acquisition of preload

The preload can be obtained by grinding the end face of a ferrule in the bearing, or placing two spacer rings with different thickness between the inner and outer rings of a pair of bearings to clamp the bearings together so that the steel ball is in close contact with the raceway.

The preload has a great impact on the service life of the bearing. According to relevant data, when the bearing is equipped with 0.012mm interference, the service life is reduced by 38%, and when there is 0.016mm interference, the service life is reduced by 50%; When the bearing is equipped with a clearance of 0.004mm, the service life decreases significantly. When there is a clearance of 0.008mm, the service life decreases by 70%.

Therefore, it is very important to select the preload reasonably. Generally, small preload should be selected for high speed and large preload should be selected for low speed. At the same time, the preload shall be slightly greater than or equal to the axial working load.