FANADE Industry (HongKong) Ltd is a professional provider of Fag 6321 Bearing Supplier ,specialized in supplying miniature or medium-sized bearings covering Ball Bearing Series:Deep Groove Ball,Thrust Ball(Single Row Double-Directino/Doubel Row Single-Direction),Radial Ball,Self-aligning Ball,Filling Slot Ball,Counterbored Ball,Three/Four Point Contact Ball.Roller Bearing Series:Spherical Roller,Radial Roller,Cylindrical Roller,Tapered Roller,Needle Roller,Drawn Cup Needle Roller,Convex Roller,Concave Roller,Crossed Roller,Thrust Roller,Cylindrical Roller Thrust,Tapered Roller Thrust,Needle Roller Thrust,Spherical Thrust Roller.FANADE Bearing Seals Type include:RS,2RS,Z,2Z,2RZ,DDU,LLU,VV.Bearing Row:Single-Row,Double-Row,Four-Row.With imported and domestic original famous brands as SKF,FAG,NSK,TIMKEN,NTN,NACHI,IKO,INA,KOYO,FYH and so on from Swenden,Germany,France,Japan,India,USA,Canada,Brazil and other country in European/Asia and North America/South America.FANADE Bearing website provide Structure、Dimensions、Net Weight and all Parameter and Details of all kind of bearings.We have gained a wide acclamation among their customers with reasonable prices.Here we'd like to talk about Bearing processing technology.
Deep groove sealed ball bearings in China and the foreign advanced products internal structure parameters are almost the same, but the vibration and noise level of our country this kind of product is far with foreign products, the main reason is that in the manufacturing and working condition of factors. From the Angle of bearing industry, condition factors can put forward reasonable requirements of the host to solve, and how to reduce the vibration caused by manufacture factors and noise are bearing industry must solve the problem.
At home and abroad a large number of experiments show that keep the frame, ring, steel ball processing quality of bearing vibration with different degree of influence, one of the steel ball processing quality had evident effects on bearing vibration, the second is the ring of the processing quality, is the most important factors affecting the steel ball and ring roundness, surface roughness and surface waviness and knocked wounded, etc.
Steel ball products in China's most prominent problem is discrete vibration value is big, serious surface defect (single points, group, pits, etc.), although the surface roughness, size, shape, error is not lower than outside, but after close set of bearing vibration value is high, and even produce different sound, the main problem is a striation no control (top, without proper test and analysis instrument), at the same time of machine tool vibration resistance is poor, grinding wheel, grinding disc, cooling liquid, the process parameters all problems; On the other hand to improve the level of management, avoid knock against injury, scratches, burns over time such as the quality problem.
For ring, affect the bearing vibration is the most severe channel on the surface roughness and waviness. For example, small and medium-sized deep groove ball bearings, both inside and outside channel roundness is greater than 2 microns, will significantly influence on bearing vibration, both inside and outside channel waviness is greater than 0.7 microns, the bearing vibration value increase with the increase of waviness, rising vibration of the cutting channel serious injury can make more than 4 db, appear even different sounds.
Steel ball and ring, waviness produced in grinding, ultra lapping although can improve the waviness and lower roughness, but the most fundamental measures is to reduce the waviness in the grinding process of superfinishing, avoid randomness knocked wounded, there are mainly two aspects:
One is to reduce the vibration of the rolling surface grinding superfinishing, obtain good surface processing precision and surface shape of grain quality in order to reduce vibration, super grinding machine tools must have good vibration resistance, lathe bed and other important structures with vibration absorption, superfinishing machine oil stone oscillation system has good vibration resistance; Raising the speed of the grinding, grinding abroad 6202 outer raceway generally used 60000 motorized spindle, grinding speed of 60 m/s above, domestic generally much lower, mainly restricted by main shaft and main bearing performance. Small when high speed grinding, grinding force, grinding metamorphic layer thin, is not easy to burn, and can improve the machining accuracy and efficiency, a great influence on low noise bearings; The spindle static stiffness and speed characteristic of low noise ball bearing grinding vibration influence is very big, the higher the stiffness, the less sensitive to the change of grinding force in grinding speed and grinding system vibration is smaller; To improve the spindle bearing stiffness, the random dynamic balance technology, improve the grinding spindle vibration resistance. Foreign grinding head vibration velocity (such as Gamfior) is about one over ten of the domestic general spindle; Improve the quality of grinding wheel abrasive cutting performance and dressing is very important. Grinding wheel sharpening stone in our country at present the main problem is the organizational structure uniformity is poor, the serious influence and low noise ball bearing grinding machining quality. Cooled sufficiently, improve the filtering accuracy; Improve the feed of essence to system resolution, reduce feed inertia; Reasonable grinding machining process parameters and machining process are the factors that can not be ignored, grinding allowance, shape tolerance strictly, small and medium-sized ball bearing outside diameter is unfavorable use ultra lapping, coarse fine grinding ultra should not be separated, to ensure the good surface quality.
The second is to improve the machining precision of datum, reduce the error in the process of super grinding machining and rerun diameter end is the locating datum in the process of super grinding processing. The error of the outer diameter of the channel superfinishing rerun is through the outside diameter of grinding groove, groove grinding to ditch the error of the super rerun the indirect transmission. If the workpiece in the process of our passing knock against injury, will be rerun directly to the raceway machining on the surface, affect the bearing vibration. So you have to take the following measures: improve the locating datum surface shape accuracy; Pass in the manufacturing process of smooth, without knock against injury; Workpieces' allowance error cannot too big, especially in the allowance is small, too big error will cause the final precision grinding and super finishing at the end of the shape has yet to improve the quality of the final demand, seriously affect the processing quality consistency.
It is not hard to see from the above analysis, automatic line of high performance, high stability of the machine tool system way grinding ultra low noise processing ball bearing is the most appropriate, can avoid knock against injury, reduce the transmission error, eliminate artificial factors, improve the machining efficiency and quality consistency, lower production cost, improve the efficiency of the enterprise.
How to reduce the ball bearing noise? Should from the following two aspects to:
(a) manufacturing process. Process the elaboration, mainly refers to the process as short as possible, process, production without intermediate inventory, effectively reduce the factors influencing the low noise ball bearing performance process; Clean production, and this is a system of technology, including grinding fluid, super semen, cleaning fluid, air, high pressure air, such as production technology; Whole process automation, processing to the car assembly automation, less people or unmanned; Scale, this kind of bearing mute ball bearing, in particular, have to form large scale, to the global market competition ability.
(2) equipment. High speed grinding, precision of motorized spindle, stiffness, and a variety of life perfect testing protection performance of grinding machining accuracy and efficiency plays a main role; Grinding technology, foreign internal grinder is generally have high speed grinding, the ac servo control, feed resolution of 0.25 mu, simple operation, automatic self-diagnosis function, etc.; Superfinishing technology, precision machine mainly in Osaka, Japan, represented by centerless superfinishing and supporting two workstation represented by Germany ladder Aaron house hydraulic centering 4 Labour superfinishing two ways; Online detection technology, since the 1980 s, Japan's bearing industry to the active measurement closed feedback control of automatic grinding ultra-short application is most common. In our country in this way of grinding are more mature, super automatic line application at present domestic 100 or so. With the advanced industrial countries hosting technology constantly improve, on-line more and more simple, gradually reduce active measurement and closed to test or not; Centerless external cylindrical grinding machine, outside the circle (KOYO, MIKROSA, etc.) generally used rolling bearing grinding wheel spindle unit, high rigidity, high precision, long life, easy handling, use a * and a series of advantages; Lathe bed with damping reduction properties; Feed micro ac servo system with high precision, stable transmission, idler pulley adjusting system can have intelligent online random measurement, which can realize CBN grinding wheel grinding, etc., which can realize automatic on-line, roundness can be up to 0.3 mu m, scattered size up to 3 microns.