The main task of rolling inlet bearing assembly is to sort the inner ring, outer ring and rolling body, and to ensure the radial clearance or width satisfying the requirements after assembly.One of the main procedures in the assembly process of rolling inlet bearing is the selection of matching sleeve. First, the diameter and size of raceway of the ring shall be divided into different groups, and then the inner ring, outer ring and rolling body of each group shall be matched together to form a "set" of imported bearing according to the clearance or width tolerance required by the imported bearing.

In the processing of the bearing ring imported, for various reasons, the raceway size will be too dispersed or the tolerance zone center will be offset, or even beyond the tolerance zone, these problems will reduce the matching rate.For this reason, before matching, the bearing rings imported from stock should be selected to grasp the size of the raceway, and according to the size of the rolling body, the customized machining tolerance order of matching parts (inner ring or outer ring) should be timely proposed to the grinder working area.After receiving the customized tolerance order, the grinder working area shall process in strict accordance with the customized tolerance size.In this way, the matching rate of imported bearing assembly can be improved.

The selection group is to measure the actual dimension deviation of the raceway diameter of matching set of plaques one by one, and divide a batch of parts into several groups with the approximate dimension deviation.The size difference of grouping is based on the size of radial clearance tolerance.In general, the selection of ring size difference by less than one third of the radial clearance tolerance for grouping.Considering the matching precision, the finer the grouping difference is the better. However, due to the limitation of the working site, the grouping difference should not be too small.

The main factors affecting the radial clearance or width of rolling are the diameter deviation of the raceway of the inner and outer rings and the diameter deviation of the rolling body.Because of the importance of rolling inlet bearing, there are strict requirements for its clearance value or width (height) tolerance.Under the influence of processing factors and so on, the rolling import bearing assembly, in addition to the individual inlet bearing with detachable ring (such as the outer ring of single-row tapered roller, the inner ring of cylindrical roller) USES interchangeably assembly method, can not use interchangeable assembly method, but can only use optional method.

Ring inner and outer raceway and rolling body surface in end mill and the ultra lapping machining process, the accuracy of machine tools, the operator's technical level, parts of material, the quality of the job card measuring tool, measurement error, the selection of cutting specifications, production environment and other factors, every batch of products in the dimensional deviation between the various parts of the difference between each other.The size fluctuates within a certain range, while the size is concentrated in the inter-towel value and less close to the size limit. The size deviation distribution conforms to the normal distribution curve.The characteristics of normal distribution are similar to those of the rings sorted on the assembly table. There are many rings in the middle size, but few at both ends. The height of the rings placed is high in the middle and low at both ends.