Ceramic bearing fit

Fix the inner ring and outer ring of the rolling element on the shaft or bearing box. When it is under load, the matching surface of the ring and the shaft or bearing box will not undergo relative movement in the radial, axial and rotational directions. This This relative motion will cause friction, friction corrosion or friction cracks on the mating surface, causing damage to the bearing, shaft and bearing box, and then the wear powder will mix into the inside of the bearing, causing poor operation, abnormal heating or vibration. .

1. Interference amount

Regarding the way to fix the bearing, it is best to leave an interference amount on the mating surface between the ring and the shaft or the bearing box and perform a static fit. This fit can make the load of the thin-walled ring evenly distributed on the circumference. Without affecting the load capacity of the bearing

However, when a static fit is used, in addition to the inconvenience of installing and disassembling the bearing, if the bearing is a release bearing, it cannot move axially, so it cannot be used in all situations.

2. Choice of coordination
The selection of coordination is generally based on the following principles:

1. According to the direction and nature of the load acting on the bearing and which side of the inner and outer rings rotates, the load borne by each ring can be divided into rotating load, static load, or non-directional load. The sleeves that bear rotating load and non-directional load Rings should have a static fit (interference fit). Rings that bear a static load can have a transition fit or a dynamic fit (clearance fit). When the bearing load is large or it is subjected to vibration or impact loads, the interference must be increased. Use For hollow shafts, thin-walled bearing boxes or bearing boxes made of light alloy or plastic, the interference must also be increased.

2. When it is required to maintain high rotational accuracy, high-precision bearings must be used, and the dimensional accuracy of the shaft and bearing box must be improved to avoid excessive interference. If the interference is too large, the geometric accuracy of the bearing or shaft box may affect the bearing. The geometric shape of the ring will damage the rotation accuracy of the bearing. If the inner and outer rings of non-separable bearings (such as deep groove ball bearings) adopt static fit, the installation and disassembly of the bearing will be extremely inconvenient. It is best to use a dynamic fit on one side of the outer ring. .

3. Recommended fit. Regarding the shaft diameter and hole diameter tolerances of the shaft and bearing box where the bearing is installed, in the metric series, ISO283 (Dimensional Tolerance and Fit) has corresponding standards. Therefore, the fit tolerance has been determined by the selected shaft diameter and hole diameter. Depends on tolerance.