The precision of koyo bearing installation effect on life

Koyo bearings after completion of installation in the host, such as the measurement of spindle radial runout, can be found that the each measured value of a certain change; Continuous measurement, can be found that after a certain number of revolution, this change will approximately duplicated. Measure for cyclic rotation accuracy degree of the change, change the approximately duplicated the revolution, on behalf of cyclic rotation accuracy 'cycle', the value of the amplitude changed in quasi cycle, is the cycle rotation accuracy is poor. Such as the proper preload on the spindle, the speed decreases gradually to close to compulsory rotational speed, on bearing the 'break-in' effect, can improve the circulation of the spindle rotation accuracy. Trial-manufacture delicate instruments in one power plant, the type 6202 / P2 koyo bearing spindle and its precision is still cannot meet the requirements, the bold shaft neck and on the race to replace the inner ring, and the steel ball precision measurement, to size every three grain of a group, each group of steel ball in the interval of close to 120 °, because added a heavy machining surface, and added the weight with the surface, at the same time can increase the stiffness of the shaft and bearing system, and the three largest grain and minimum three grain of steel ball nearly equidistant spread, and improves the precision of drive shaft rotation, and meet the requirement of the precision of the instrument. Inner ring and the shaft to interference fit, interference was 0 ~ + 4 microns ( At light load, high precision of 0) ; Outer ring with koyo bearing hole clearance fit, the interval 0 ~ + 6 microns ( But on the free end bearing application of angular contact ball bearing, still can increase the clearance) ; Shaft and hole surface roundness error in under 2 microns, bearing the face of baffle used parallelism in under 2 microns, shaft shoulder end foreign face beat in under 2 microns; Axis bearing hole block shoulder to beat under 4 microns; Spindle axis inside the front cover end face beat under 4 microns. Bearing the right tools should be used carefully install and remove. Industry experts estimate that 16% of premature bearing failure is due to incorrect installation. For large installation ( In the production plant, for example) Installation, usually we will strictly control conditions, also can use appropriate bearing installation equipment. But, in the maintenance or replacement work, the environment is varied. Therefore, in order to ensure the longest service life of bearing, the comprehensive preparations for bearing installation is necessary. First, the relevant documents, such as drawings, maintenance manual, product manuals, etc need to carefully study. Next, all bearing components, such as shaft, spacer ring, must be perfectly clean, cover, washer, etc from pollution. The condition of adjacent parts also check carefully. According to different applications and the erection and dismantling of cautious bearing size and type, select the appropriate installation method ( Mechanical or hydraulic) And tools. Here are some of the basic principles of bearing installation: 1. Don't impose on rolling element installed power, this could easily lead to the rolling element and contact area of local overload, leading to premature failure of bearing. 2. Do not use any hard tool ( For example, a hammer, screwdriver, etc. ) Knock on the bearing surface directly, which can lead to koyo bearing ring fracture or fracture.