Effect of Sealed Dearing residual magnetic field on service life
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| Time：2017.12.11 News Sources：Shandong Xinkaite bearing Co.,Ltd. Views：
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The generation of residual magnetism is mainly due to the influence of clamping and positioning of various electrical equipments and electromagnetic fixtures during the processing of Sealed Dearing parts, which is inevitably magnetized and produces strong magnetism. Due to the existence of this magnetism, the fine metal powder produced during the processing of Sealed Dearing parts (grinding and finishing) is adsorbed on the Sealed Dearing channel and rolling body, so it is not easy to wash away. When Sealed Dearing is used, the fine metal powder remaining in Sealed Dearing channel or raceway has great influence on the noise, vibration, rotation accuracy and service life of Sealed Dearing, resulting in Sealed Dearing temperature rise and early damage.
The burn on the work surface is mainly due to the fact that when the operator is grinding Sealed Dearing, the outer ring and raceway, too much feed, inadequate cooling or grinding wheel is not able to repair in time, it is possible to produce high temperature locally on the machined surface, causing local annealing to produce burns. Have a direct impact on the service life of the Sealed Dearing Sealed Dearing of surface burn, Sealed Dearing on the one hand work guide rotation, while under high load, because the Sealed Dearing parts work surface burns, the hardness decreased, resulting in the channel or the raceway surface early fatigue spalling, greatly reduces the service life of Sealed Dearing.
The basic rated dynamic load C acts on the calculation of the Sealed Dearing under the dynamic stress, that is, the Sealed Dearing that rotates under the load. The expression shows the Sealed Dearing load when the basic rated life of ISO 281:1990 is 1000000 rpm. The size and direction of the load are assumed to be constant. For radial Sealed Dearing, the load is a pure radial load, and for the thrust Sealed Dearing, it is the axial load of the Sealed Dearing center.
Rolling Sealed Dearing life is defined as the first time that a Sealed Dearing can achieve a revolution on the Sealed Dearing ring or rolling body before it shows signs of metal fatigue (peeling or breaking).
It has been proved that the same Sealed Dearing on the surface will still have a different life span under the same working conditions. Therefore, the term "life" must be defined more clearly when calculating the size of Sealed Dearing. All information provided for basic rated load is based on a sufficiently large number of identical Sealed Dearing on the surface, and 90% is able to achieve over life.
There are several different definitions of Sealed Dearing lifespan. One of them is "working life", which indicates that Sealed Dearing has the actual life expectancy before the actual working conditions. It must be noted that the lifetime of individual Sealed Dearing can only be predicted by statistical methods. Life calculation is only about 90% for the reliability of the Sealed Dearing population and a certain program. Failure in actual use is usually caused by fatigue. More pollution is caused by contamination, wear, misalignment, corrosion, or failure caused by cage, lubricant or seal.
Another "life" is the "prescribed life", designated by the authorities or the industry standard institutions, and based on a assumed load and speed. This is basically the basic rated life of the Sealed Dearing, which is generally based on the experience obtained by similar applications.
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