During the grinding operation of the grinding wheel, there is often intense heat generation at the contact area between the workpiece and the grinding wheel, which leads to a sudden increase in temperature in that area. According to theoretical analysis and actual measurement of heat conduction, this instantaneous temperature may reach 1000 to 1500 degrees Celsius. This extreme high temperature can have various effects on the surface of the workpiece, such as the formation of oxide layers, the formation of amorphous structures, high-temperature tempering, and secondary quenching, thereby affecting the performance of the bearing.

Formation of oxide layer: When the surface of the workpiece reaches high temperature in an instant, it reacts with oxygen in the air to form a very thin layer of iron oxide, with a thickness of about 20 to 30 nanometers. The thickness of this oxide film is closely related to the quality of grinding and is an important indicator for measuring the grinding process. Amorphous tissue layer: Under high temperature conditions, the surface of the workpiece will melt and form a very thin layer of amorphous tissue after cooling, with a thickness of about 10 nanometers. Although this layer of tissue has high hardness and toughness, it is easily removed during precision grinding. High temperature tempering layer: Due to the effect of instantaneous high temperature, the temperature within a certain depth range on the surface of the workpiece will rise above its tempering temperature. Without reaching the austenitization temperature, high-temperature tempering microstructure changes corresponding to the heating temperature will occur layer by layer, resulting in a decrease in hardness. The higher the heating temperature, the more significant the decrease in hardness.

To address the issue of bearing heating, the following are some effective solutions:

Select bearings that meet the specified accuracy level to improve the accuracy of the bearings. Repair the spindle or casing to eliminate the problem of spindle bending or non concentric casing holes. Reasonably adjust the tightness of the belt to avoid excessive tension. Use designated brand lubricating materials and keep them clean to ensure good lubrication effect. Improve assembly quality and ensure correct installation of bearings. Replace bearings and other worn components to prevent the inner and outer shells of the bearings from running out. Clean and adjust the gap of the sealing ring to be between 0.2 and 0.3 millimeters, while adjusting the diameter of the impeller balance hole and verifying the static balance value to reduce axial force. If damaged bearings are found, they should be replaced in a timely manner.

By taking the above measures, the heating problem of bearings can be effectively solved, ensuring their normal operation.