Key technology of bushing

- Jul 22, 2019-

1.The set angle difference of the set sleeve must be good. The national standard is indicated by △D1mp-△d3mp. The tolerance of different size ranges from +0.018-0.09 is the upper bias. The tightening angle of the set sleeve can only be large but not small, that is, big end. It is necessary to cooperate with the contact, the small end of the cone can be a little gap, the cone hole is not well matched, and the matched spherical roller bearing will form a single row of roller force, the operation is not stable, the vibration is large, the music is loud, easy to loose, the bearing The life span is short, and the taper angle difference of the high-precision adapter sleeve should also be ≤0.005, ensuring that the mating contact area is not less than 90%.

2.The radial runout of the outer cone of the bushing facing the inner hole (that is, the wall thickness difference usually called) should be high-precision. Otherwise, the rotating shaft will have a centripetal force due to the fairness, and it cannot be jolted, the vibration is large, the music is loud, and the wall A thickness difference of "0" is an ideal form. The maximum value of the national standard rule is less than 1/2 of the maximum clearance of the bearing specification group, and the maximum clearance value of the C-class precision is very large. Therefore, the national standard qualified adapter product is used in the fine-level heavy load. The bearing package is not acceptable.

3.The straightness of the outer taper surface and the inner hole of the tightening sleeve is better, that is, the geometrical tolerance is better, and the cylindricity accuracy is better. This national standard has no rule. Any single cross-sectional dimension is qualified in the tolerance field, so that is formed. The outer cone surface has poor linearity control, especially the outer tapered surface is ground and grinded. The blank itself is not linear, the grinding wheel is not well corrected, the linearity of the outer surface is very poor, and the ordinary enterprise has no profile test, so this The project has a great problem in the products of the tightening industry in China, which seriously affects the matching accuracy and the supporting stability, and the bearing function is not good.

4.The threaded locking function of the adapter sleeve is driven by the rotation of the lock nut. The end face of the inner sleeve of the compression bearing is tightened so that the adapter sleeve and the inner bore of the bearing are tapered, and the bearing is fixed on the rotating shaft. Therefore, the threaded fit of the bearing nut and the tightening bushing must be good, and it must meet the national standard requirements of ordinary threads.