1. Cutting of bearing
When the surface of the grinding wheel contacts the convex peak of the rough raceway surface, due to the small contact area, the force on the unit area is large. Under a certain pressure, the grinding wheel is first subjected to the "reverse cutting" of the bearing workpiece, which causes some abrasive grains on the grinding wheel surface to fall off and break, exposing some new sharp abrasive grains and edges.
At the same time, the surface peaks of the bearing workpiece are rapidly cut, and the peaks and grinding deterioration layer on the surface of the thin section bearing workpiece are removed by the action of cutting and reverse cutting. This stage is called the cutting stage, in which most of the metal allowance is removed.
2. Half-cutting process
With the continuous processing, the surface of thin-walled bearing workpiece is gradually polished. At this time, the contact area between the grinding wheel and the workpiece surface increases, the pressure on the unit area decreases, the cutting depth decreases, and the cutting ability decreases. At the same time, the pores on the surface of the grinding wheel are blocked, and the grinding stone is in a semi cutting state.
This stage is called the half cutting stage of bearing superfinishing. In the half cutting stage, the cutting trace on the surface of the bearing workpiece becomes shallow, and a darker luster appears.
3. Finishing stage
This is the next step in the super finishing of bearings. As the workpiece surface is gradually smoothed, the contact area between the grinding stone and the workpiece surface is further increased. In addition, the grinding stone and the workpiece surface of thin-walled bearing are gradually separated by the lubricating oil film. The pressure on the unit area is very small, and the cutting effect is reduced, so the cutting is automatically stopped.
This stage is called the finishing stage. In the finishing stage, there is no cutting trace on the surface of the workpiece, and the bearing presents a bright finished luster.