Assembling the axial thrust ball bearing:
There are two key points in the assembly of axial thrust ball bearing. One is the control of the pressing quality of the cage and the steel ball, and the other is the control of the nominal height T after the bearing is assembled. In addition, since the shaft ring and the seat ring can be separated, it brings a management problem. It is to prevent the mixing of imported bearing parts.
The M-type stamping cage uses a flanged assembly die. After pressing, the steel ball is required to rotate flexibly in the pocket, but it cannot fall off from the pocket, and the technical regulations check the amount of movement of the steel ball in the pocket. If the solid cage is imprinted too deeply, the movement of the steel ball will be small, and the connection between the embossed convex part and the cage is too small and the strength is insufficient. There is little difference between the inner diameter of the small axial thrust ball bearing seat and the shaft washer, and there is no obvious difference between the two sets.
In order to prevent the phenomenon of mixed sets, it is found that two sets of bearings are both seat washers or shaft washers in the assembled set of bearings. This requires certain measures. Usually, the drawing ring and the seat group are distinguished by auxiliary tooling when the sleeve is assembled, or the inner diameter size is checked with an inner diameter plug gauge before sampling the nominal height. For the convenience of checking the inner diameter, put the seat ring on the bottom and the shaft ring on the top. If the inner diameter of the seat ring has obvious quenching and heating oxidation color or has not been ground, it is not necessary to check the inner diameter size, and the difference between the shaft washer and the seat ring can be clearly seen, and it is not easy to mix.
After the axial thrust ball bearing is assembled, the nominal height T should be measured to confirm whether it is qualified. When measuring, calibrate with a height block or standard part, and measure the load, the bearing needs to be rotated dozens of times, and the minimum height must be reached.
When the axial thrust ball bearing operates at high speed, the contact angle between the steel ball and the radial plane of the raceway will be affected by centrifugal force, which will cause the steel ball to slide relative to the raceway. Adhesive wear from this sliding can damage the bearing. To prevent this damage, the minimum load on the axial thrust ball bearing must be guaranteed, see Equation 1 or Equation 2, whichever is the greater of the calculated values.
Formula 1: Famin=K・n*n
Formula 2: Famin=Coa/1000
Famin: Minimum axial load (N)
K: Minimum axial load factor
n: rotation speed (per minute)
Coa: Basic static load rating (N)
The one-way axial thrust ball bearing can only bear the load in one direction. If it bears the load in two directions, the two-way thrust ball bearing must be selected. A minimum load or preload must be applied to the axial thrust ball bearing. When the shaft is vertical, the weight of the shaft usually exceeds the minimum load. At this time, the acting load may be reduced due to the influence of the axial external load in the opposite direction.
