Bearing is an important component in contemporary mechanical equipment. Its main function is to support the rotating body of mechanical NTN bearing, reduce the friction coefficient in its movement and ensure its rotation accuracy. Rolling bearing is generally composed of outer ring, inner ring, rolling element and cage. In bearing production, grinding is complex in the whole machining process. Therefore, for grinding, one of the key processes in bearing production, how to use new processes and technologies to complete the grinding process with high precision, high efficiency and low cost is the main task of grinding.
High speed grinding can achieve the two goals pursued by modern manufacturing technology and improve quality and efficiency. In high speed grinding, the grinding wheel should not only have sufficient strength, but also ensure good grinding performance in order to obtain high grinding effect.
Due to the good machining characteristics of cubic boron nitride wheel, the manufacturing technology, dressing technology, special bearing grinder and grinding oil of new grinding wheel are being upgraded to meet the progress of grinding process.
Numerical control technology can ensure positioning accuracy at high speed and low speed, and can complete fast jump, fast trend, dressing compensation and coarse and fine grinding, which greatly simplifies the feed mechanism of the machine tool and greatly improves the performance and reliability.
During bearing grinding, the large outer circle and process angle after correcting the accuracy can avoid the axial runout of the grinding of the middle hole seat surface.
Cutting allowance is an important parameter to ensure high efficiency and high precision bearing grinding. Usually, the fine grinding allowance is controlled at the micron level.
Modern grinding technology adopts high-speed grinding to ensure that the grinding debris will not stick to the grinding wheel and maintain good self sharpening.
The rotation speed of the workpiece is related to the diameter of the grinding surface of the bearing. The rotation speed of the workpiece will have a great impact on the grinding mark and surface roughness. Too low rotation speed will produce ripples on the grinding surface and increase the surface residual stress. Too high rotation speed will cause burns on the grinding surface.
Bearing accuracy is mainly formed by the combination of machine tool accuracy, fixture accuracy and grinding process parameters. Therefore, reasonably determining the grinding coordinate of NC machine tool, the grinding wheel correction coordinate and the position of fag bearing are also important parameters to promote the workpiece quality.
In the process of bearing grinding, the phenomenon of grinding burn will occur if the process parameters are unreasonable or the dimensional accuracy of the blank is not well controlled. The main factors of grinding burn include low linear speed of the grinding wheel, low cutting force, large normal force on the surface of the grinding wheel and workpiece, etc.
When the grinding parameters are unreasonable, cracks or fine cracks will appear on the grinding surface of the middle hole seat surface after grinding, especially the cracks at the pressure chamber of the seat surface will cause cavitation corrosion at the front edge of the seat surface and reduce the fatigue strength of the bearing.
The special grinding oil contains vulcanized extreme pressure anti-wear additives, which can effectively protect the abrasive tools and improve the process accuracy.
The special grinding oil has good chemical stability and will not harm the equipment, human body and environment.
The special grinding oil has passed strict tests in viscosity, flash point, pour point and thermal conductivity to meet various process requirements.