How to Improve Ball Bearing Vibration and Noise Reduction Technology and Process Equipment

At present, the internal structure parameters of bearings in my country are almost the same as those of advanced foreign companies. However, the vibration and noise levels of such products in my country are far from those of foreign products. The main reason is the influence of manufacturing and working conditions. From the perspective of the bearing industry, the working conditions can be solved by putting forward reasonable requirements for the host, and how to reduce the vibration and noise caused by manufacturing factors is a problem that the bearing industry must solve.

A large number of tests at home and abroad have shown that the machining quality of cage, ferrule and steel ball has different degrees of influence on bearing vibration. Among them, the machining quality of steel ball has obvious influence on bearing vibration, followed by the machining quality of ferrule, which is the main influencing factor. It is the roundness, waviness, surface roughness, and surface bumps of steel balls and ferrules.

The outstanding problems of my country's steel ball products are that the vibration value is scattered and the surface defects are serious (single point, group point, pit, etc.). Although the surface roughness, size, shape, and error are not lower than the level outside the circle, after the fit The vibration value of the bearing is high, and even abnormal sound is produced. The main problem is that the waviness is not controlled (no standard, no suitable test and analysis instrument), and at the same time, it shows that the vibration resistance of the machine tool is poor, and there are problems with the grinding wheel, grinding disc, coolant, and process parameters; On the other hand, it is necessary to improve the management level and avoid random quality problems such as bumps, scratches, and burns.

For the ferrule, it is also the channel waviness and surface roughness that affect the bearing vibration more seriously. For example, when the roundness of the inner and outer channels of a small and medium-sized ball bearing is greater than 2 μm, it will have a significant impact on the bearing vibration. When the inner and outer channel waviness is greater than 0.7 μm, the bearing vibration value increases with the increase of the waviness, and the channel is seriously damaged. Vibration rises more than 4dB, and even abnormal sound occurs.

Whether it is a steel ball or a ferrule, the waviness is generated by grinding. Although ultra-finishing can improve the waviness and reduce the roughness, the fundamental measure is to reduce the waviness in the ultra-finishing process and avoid random bumps. Injury, mainly in two aspects:

The first is to reduce the vibration of rolling surface grinding during super-finishing, and obtain good surface machining shape accuracy and surface texture quality. The whetstone oscillation system of the precision machine tool has good anti-vibration performance; to improve the grinding speed, 60,000 electric spindles are generally used for grinding 6202 outer raceways abroad, and the grinding speed is more than 60m/s, which is generally much lower in China, mainly affected by the spindle and Limitation of main bearing performance. In high-speed grinding, the grinding force is small, the grinding metamorphic layer is thin, it is not easy to burn, and the machining accuracy and efficiency can be improved, which has a great impact on low-noise ball bearings; Grinding vibration has a great influence, the higher the stiffness, the less sensitive the grinding speed is to the change of grinding force, and the smaller the vibration of the grinding system; the rigidity of the spindle bearing support is improved, and the random dynamic balancing technology is adopted to improve the anti-vibration of the grinding spindle sex. The vibration speed of foreign grinding heads is about one tenth of that of domestic general spindles; it is very important to improve the cutting performance and dressing quality of grinding wheel oilstone.

At present, the main problems of grinding wheel oilstone in my country are poor uniformity of structure and structure, which seriously affects the quality of grinding and ultra-processing of low-noise ball bearings; sufficient cooling to improve filtration accuracy; improve the feed resolution of the precision feeding system and reduce the feed inertia; reasonable grinding and ultra-processing Technological parameters and processing flow are factors that cannot be ignored. The grinding allowance should be small, and the shape and position tolerances should be strict. The outer diameter of small and medium-sized ball bearings should not be super-finished, and the rough and fine grinding should not be separated to ensure good surface quality.