KOYO railway bearing clearance problem analysis of the cause of failure

In railway bearing grinding, grinding wheel and workpiece contact zone, consume large amounts of energy, to produce a large number of grinding heat, local transient high temperature caused by grinding area. On the basis of the theory of linear motion heat source heat transfer formula derivation, calculation or by the method of infrared ray and measured experiment under the condition of instantaneous temperature thermocouple method, can be found in 0. 1 to 0. The grinding area within 001 ms instantaneous temperature up to 1000 ~ 1500 ℃. The instantaneous high temperature, which would have made certain depth on the surface of the work surface to produce high temperature oxidation, amorphous group, high temperature tempering, secondary hardening, and even burn cracking and other changes. First is the viscosity of the grease KOYO bearing railway bearing grease is usually make a similar viscosity or apparent viscosity, said when, on the viscosity of grease must specify the temperature and shear rate. Similar viscosity index can be used to control the low temperature fluidity and pumping. Second, low temperature fluidity of the bearing grease bearing grease performance at low temperature is one of the important index measured torque at low temperature under low temperature ( - 20 ° c below) Grease block railway bearing rotational degree of low speed flows, the low temperature torque by the starting torque of the grease and rotation torque after 60 mm average said. The third is the evaporation of KOYO bearing grease the evaporative (railway bearing grease C) Said in the long-term use under condition of high temperature grease, grease oil volatilization, evaporative as small as possible. The evaporative mainly depends on the nature of the lubricating oil and fat fractions. Fourth is KOYO bearing grease the oxidation stability of oxidation stability refers to the grease when used in long-term storage or long-term high temperature resistance to heat and oxygen, permanent changes in their ability to maintain its nature will not occur. Due to oxidation, are often free alkali content reduced or free organic acid content increases, drop point drop, dark appearance, appear different smell, consistency, ultimate strength, similar viscosity decreased, generated corrosive product and destroy the material of grease, soap oil separation. In long-term storage of grease, therefore, should be stored in dry and ventilated environment, prevent sun, and shall regularly check free base or free change of the project such as organic acid, corrosion resistance, to ensure its quality and performance. Fifth, bearing the thixotropy of the grease railway bearing grease is the most basic features, is the thixotropy. When applying an external force, the flow of the grease in gradually become soft, the apparent viscosity decreased, but when at rest, after a period of time ( A very short) Again, the consistency ( Restore) This feature is called thixotropy. Decides the characteristics of grease, it can be at the site of the is not suitable for lubricating oil lubrication, and showed its excellent performance. Railway bearing inspection is immediately after the completion of delivery or rust counting process, seize the completion of the inspection process should be as far as possible don't last long due to corrosion. Pay attention to the pure gasoline use clean oil, also can cause corrosion. Bearing manufacturing materials are qualified and KOYO bearing failure must be a factor to consider, in the detection of bearing failure usually is based largely on a large number of materials in Beijing, data analysis, failure conditions, the forging process, find out the main factors of bearing failure, and get rid of, convenient bearing continuous optimization, service life, and to increase the efficiency. Prolonging bearing, avoid premature failure of the bearing of the sudden. Installation conditions is one of the primary factor of use factor, railway bearings are often caused by improper installation of a complete set of change the stress of bearing between various parts, bearing in the abnormal state run and early failure. According to KOYO bearing installation, use, maintenance, maintenance of technical requirements, the operation of the bearing on the load, speed, temperature, vibration, noise and lubrication condition monitoring and inspection, found that abnormal immediately to find the reason, adjustment, so that it is back to normal.