Wheel hub bearing tapered roller color analysis

Wheel hub bearing tapered roller 2020 - color analysis 11 - 07 roller color is due to the bearing in the process of operation caused by heating the surface color change. In addition, some chemicals in under the effect of temperature lubricant adhesion, wear and tear of metal powder and other impurities in the roller surface, cause the roller color change, this kind of color is also called blotch. Roller surface colors usually pale yellow, yellow, dark brown, brownish red, blue, purple and dark blue, etc. , are not ordinary fever caused by color depth. To use the deep color, such as the bearing if violet or blue-black, may be formed burns. Parts corrosion can also cause color change, but this kind of color has a certain depth. For wheel hub bearing, Grease lubrication) With tapered roller discoloration problem, in order to analysis to determine roller bearing whether can continue to use after color change, combined with market failure parts made 'color contrast electronic template, for your reference. Influence factors: poor lubrication grease metamorphic load is too large, Preloading is too big) Local stress concentration high speed work clearance of small metal particles and other foreign matter invasion axis, and the low machining precision of the bearing, axis deflection of large amount of poor heat dissipation condition grease filling improper discoloration prevention: choose the right means of lubricant and lubricating oil flow ( Oil lubrication) And timely supply to improve the lubrication effect is correctly installed bearing bearing cooling conditions appropriate to improve manufacturing accuracy to prevent stress concentration and so on with a front wheel bearing as an example, it USES the grease lubrication, lubricants for cars gm lithium base grease ( 2 lithium base grease) , fatliquoring quantity for bearing internal space commonly two-thirds ( Each manufacturer on the different way) 。 For rolling body color separation: sorting out the magnitude 7 color points difference, from shallow to deep, level 1 ~ 6 roller color can be used normally; Level 0 for unused ( Not listed) ； Seven small rolling body burns, cannot normal use; 8 roller large end start peeling off, can't normal use, Not listed) 。 Level 1 ~ 7, from left to right, from shallow to deep, in the order: light yellow, pale yellow, deep yellow, brown, blue, red brown, purple grade 1 ~ 8 hardness and organization bearing parts in the process of operation, can produce a large amount of heat due to friction, general use for a long time temperature does not exceed 120 & deg; 150 & deg C, a short time; C well, If a special heat treatment, such as high temperature tempering, the use of temperature can reach 350 & deg; C or higher) 。 If insufficient lubrication or cooling condition is poor, the spread of the heat is not timely, the heat accumulation can make the bearing temperature rise quickly, temperature can make the attached to the bearing oil film on the surface of the parts produced oxidation phenomenon, form a beige oxidation, deposit adhesion on the surface of roller. But the color does not affect the use of the bearing, so allow to save. When the bearing is caused by improper installation, Such as the installation tilt) , poor lubrication, corrosion of the bearing is in an abnormal working state, cause temperature rise sharply, the bearing of the local temperature may exceed the tempering temperature of bearing parts, or even higher, produce a serious change color such as dark blue or purplish blue, forming burn phenomenon! The color of this kind of circumstance bearing can no longer continue to use. So bearing color should be used in accordance with the relevant requirements and performance to determine, not one vote negative for failure. （ Source: drive horizon)