Bearing outer ring process analysis
1.Anti-outer ring channel edge convex method
The outer channel of the self-aligning ball bearing is a spherical surface, but at the point A, the raceway is convex. This kind of protrusion affects the self-aligning performance of the self-aligning ball bearing, and even cannot be aligned, and has a convex side on the bearing. When rotating, it will generate frictional resistance to the steel ball, which will accelerate the wear of the steel ball and reduce the service life.
The reason for this phenomenon is that the thickness of the grinding wheel is small and the grinding wheel consumes quickly at the edge of the groove. The outer ring of the self-aligning bearing of the branch is a grooved machining groove, such as 3MZ1410SA. If the thickness of the grinding wheel is smaller than the width of the outer ring, the edge of the groove will not be worn and a protrusion will be formed. In order to eliminate this defect, a grinding wheel having a thickness greater than the outer ring width of 1 to 1.5 mm may be selected.
Because the edge of the outer ring of the bearing is very sharp, and the grinding wheel consumes very fast in the process, if the processing personnel do not adjust it properly in time, it is difficult to ensure that the entire outer ring can be evenly ground. The plane is prone to high and low unevenness, which seriously affects the quality of the product. Therefore, in order to solve this problem better, the processing personnel can adjust the number of dressings appropriately, and increase the compensation amount of the dresser, so as to ensure that the blunt grinding wheel can also get a lot of corrections. In addition, due to the different processing requirements of rough grinding and fine grinding, there are also large differences in the choice of grinding wheel size. Therefore, the processing personnel must select the grinding wheel with the appropriate particle size after the final confirmation of the grinding method, so as to avoid the uneven quality of the outer ring edge of the self-aligning ball bearing.
2.Method for reducing the position error of the outer groove spherical surface
The center position of the spherical surface cannot be completely coincident with the theoretical center position, and there will be some errors. This is completely controlled by the detection method that the outer ring width is different from each other to control the outer ring on the M7675B double end grinding machine. The mutual difference can be controlled to be small. Within the range (within 0.015mm). The center position of the outer ring sphere has been measured by the position template. The sample is divided into the maximum limit size and the minimum limit size. When the outer channel is measured on the side of the maximum limit position of the spherical position template, there is a "light gap" near the inner side of the template. There is a "light gap" on the outside. This measurement is completely dependent on visual inspection and the error is large. In order to reduce the error, the instrument is measured by D923 inner diameter measuring instrument. The height of the measuring point is generally h=3mm (the smaller the chamfering size h is, the better). When measuring, the two sides are measured. By adjusting the feeding position of the grinding wheel, both sides The closer the measurement results are, the more symmetrical the two sides of the spherical surface are, that is, the spherical center position and the theoretical center position are close to each other. If the mutual difference of the outer ring widths is considered, the error can be basically controlled to about 0.015 mm. By changing to the instrument measurement, the error of the center position of the spherical surface can be controlled within a relatively ideal range.
3.Method for guaranteeing the radius of curvature of a spherical surface
It is well known that the outer ring channel of the self-aligning ball is a circular arc-shaped spherical surface. The most fundamental purpose of this design is to ensure that the inner ring of the bearing can produce better alignment on the outer ring, although this is a basic The design theory concept, but in the actual processing and production, there is still a certain error. Among them, poor pairing is one of the most common problems. Most of the processing personnel use the pistol watch measurement method when measuring the diagonal difference. The main working principle is to keep the pistol table in motion, and the outer ring swing measurement, and the diagonal difference is strict. Control is within reasonable limits. At the same time, in order to control the error within the minimum technical requirements, it is necessary to ensure the consistency of the spherical curvature. Every time before the product is processed, the grinding wheel is fully repaired, and the grinding wheel dresser is not guaranteed during the processing. Make adjustments to improve the processing efficiency and quality of the product.
Reprinted from the network