How to reduce vibration and noise of deep groove ball bearings caused by manufacturing factors

How to reduce vibration and noise of deep groove ball bearings caused by manufacturing factors
At present, the internal structure parameters of deep groove sealed ball 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 that in manufacturing and working conditions influence of factors. 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 the cage, the ferrule and the steel ball has different degrees of influence on the bearing vibration. The machining quality of the steel ball has the most obvious impact on the bearing vibration, followed by the machining quality of the ferrule. The factors are the roundness, waviness, surface roughness, surface bumps, etc. of the steel ball and the ferrule.
The most prominent problems of my country’s steel ball products are the large dispersion of vibration values ​​and serious surface defects (single points, group points, pits, etc.). The vibration value of the rear bearing is high, and even abnormal sound is produced. The main problem is that the waviness is not controlled (no standard, no suitable testing and analysis instruments), and it also 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 to avoid random quality problems such as bumps, scratches and burns. For the ring, the most serious impact on bearing vibration is the channel waviness and surface roughness. For example, when the roundness of the inner and outer channels of a small and medium-sized deep groove 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. The vibration can be increased by more than 4dB, and even abnormal sound can appear.
Whether it is a steel ball or a ferrule, the waviness is generated by the grinding process. Although ultra-finishing can improve the waviness and reduce the roughness, the most fundamental measure is to reduce the waviness during the grinding process and avoid randomness. There are two main measures for bump damage: the deep groove ball bearing reduces vibration. One is to reduce the vibration of the rolling surface grinding super-precision to obtain good surface machining shape accuracy and surface texture quality. In order to reduce vibration, the grinding machine must have a good quality. Vibration resistance, the important structural parts such as the bed have vibration absorption, and the oilstone oscillation system of the ultra-precision machine tool has good anti-vibration performance; to increase the grinding speed, 60,000 electric spindles are generally used for grinding 6202 outer raceways abroad, and the grinding speed Above 60m/s, which is generally much lower in China, mainly limited by the performance of the main shaft and main bearing. 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 (such as Gamfior) is about one-tenth of that of general domestic spindles; it is very important to improve the cutting performance and dressing quality of grinding wheel whetstone. 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.
The second is to improve the accuracy of the machining datum surface and reduce the error in the grinding process. The outer diameter and the end face are the positioning benchmarks in the grinding process. The error complex mapping of the outer diameter to the groove super-precision is indirectly transmitted through the error complex mapping of the outer diameter to the groove grinding and the groove grinding to the groove super precision. If the workpiece is bumped during the transfer process, it will be directly reflected on the machined surface of the raceway, affecting the bearing vibration. Therefore, the following measures must be taken: improve the shape accuracy of the positioning reference surface; the transmission is stable during processing without bumps; the shape and position error of the blank allowance should not be too large, especially when the allowance is small, the excessive error will cause final grinding and superfinishing. At the end, the shape accuracy has not been improved to the final quality requirements, which seriously affects the consistency of the machining quality.
It is not difficult to see from the above analysis that the automatic line grinding and ultra-processing low-noise ball bearings composed of a high-performance and high-stability machine tool system is the most suitable, which can avoid bumps, reduce transmission errors, eliminate artificial factors, and improve processing efficiency and quality consistency. , reduce production costs and improve enterprise efficiency.