Assembly and selection of thrust ball bearings

There are two key points in the assembly of thrust ball bearings. One is the control of the quality of the cage and steel ball pressing, and the other is the control of the nominal height T after bearing assembly. Due to the separation of the collar and seat ring, there are management issues to prevent imported bearing parts from being mixed in.

The M-type stamping cage adopts a flange assembly mold. After pressurization, it is required that the steel ball rotates flexibly inside the bag, but cannot fall off from the bag. The movement of the steel ball inside the bag should be checked according to technical regulations. The embossing of the solid cage is too deep, the movement of the steel ball is small, the connection between the embossed protruding part and the cage is too small, the strength is insufficient, and it is easy to cause block damage, resulting in the cage being scrapped. There is a slight difference in the inner diameter between the small thrust ball bearing seat ring and the shaft ring, but there is no significant difference between the two groups. To prevent mixing, the assembled bearing assembly may get stuck in the race or shaft ring. This requires certain measures to be taken.

Usually, when assembling sleeves, auxiliary fixtures are used to distinguish between rings and seat groups, or inner diameter plug gauges are used to check the inner diameter size before sampling the nominal height. For the convenience of checking the inner diameter, place the seat ring below and the collar above. If there is obvious quenching and heating oxidation color or unground on the inner diameter of the valve seat, there is no need to check the inner diameter size, and the difference between the shaft and the seat ring can be clearly seen, making it difficult to mix the sleeves. After the assembly of thrust ball bearings, the nominal height T needs to be measured to confirm that all are qualified. When measuring, use height blocks or standard parts to calibrate and measure the load. The bearing needs to rotate dozens of times and must reach a lower height.

When the 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, causing the steel ball to slide relative to the raceway. The adhesive wear caused by this sliding will damage the bearings. To prevent such damage, it is necessary to ensure that the small load on the thrust ball bearing is the larger of the calculated values.

A unidirectional thrust ball bearing can only withstand loads in one direction. If it can withstand loads in two directions, a bidirectional thrust ball bearing must be selected. Thrust ball bearings must be subjected to small loads or preloads. When the axis is vertical, the weight of the axis usually exceeds the small load. At this point, due to the influence of axial external loads in the opposite direction, the applied load may decrease.