Common quality problems on the surface of rolling bearing rings

Bearing ring raceway is the work surface of rolling bearing, its quality will directly affect the working performance and service life of rolling bearing. In the process of use, we will often find some common quality problems on the surface of the bearing collar, so how the quality problems are generated? I collect and collate multiple data and information to tell you the common quality problems and causes of bearing collar surface.

(1) surface roughness is not good

Causes: insufficient superfinishing time, grinding stone pressure is too high, grinding stone vibration frequency is relatively too high, precision superfinishing workpiece speed is too low.

(2) Super finishing tumor

The raised particles of different sizes and shapes formed on the machined surface after superfinishing are mainly due to the grinding particles sintered on the machined surface under the action of instant high temperature and pressure, and its existence increases the vibration value of the rolling bearing and reduces the service life of the rolling bearing.

Causes: High pressure of grinding stone. The surface roughness value before super finishing is too high, the workpiece speed is too high, the cutting lubricant cooling is not sufficient, and the residual magnetism of the bearing ring grinding process is too large.

(3) Fillet

The net-like scratches produced on the machined surface after super finishing machining.

Causes: too many impurities in the grinding stone and uneven particle size; impurities in the cutting fluid and insufficient flushing.

(4) Comet marks

Super finishing process, because individual larger diamond particles off or blocked in the workpiece surface of the low concave, with the super finishing pressure and the rotation of the workpiece to form comet marks.

Causes: correct choice of grinding stone, reduce the grinding stone pressure.

(5) grinding wheel flower

Reasons: The grinding wheel is too coarse when processing the surface, the workpiece speed is too high when coarse superfinishing, the coarse superfinishing time is too short, the grinding stone pressure is too small when coarse superfinishing, and the grinding stone swing angle is too small.

(6) The axial runout of the end face is too large

Causes: The eccentricity of the workpiece is too small, resulting in unstable rotation of the workpiece, large radial circular runout, non-coincidence between the middle of the grinding stone swing and the middle of the curvature of the workpiece raceway, debris on the end support surface when positioning the workpiece, resulting in excessive axial runout of the end face, poor geometric accuracy of the grinding process, and the workpiece being reworked several times.

(7) Poor roundness and corrugation

Causes: The eccentricity of the workpiece is too small; the speed of the workpiece is too large for fine super-finishing machining, causing machine vibration; the width of the grinding stone is not enough and the wrap angle is too small; the support angle is too small when the roller bar is positioned and cannot drive the normal rotation of the collar; the roundness and corrugation of the grinding process are too large.

(8) Poor curvature of the raceway after super-finishing of the ball bearing raceway

Causes: The middle of swing does not overlap with the middle of raceway curvature: the width of grinding stone is too large, and the angle of package is too large.