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The bearing model is generally selected by the user’s technicians according to the service conditions and load of supporting products. Business personnel mainly know whether the user’s actual load is consistent with the selected bearing. If the bearing fails to meet the use requirements, they should advise the customer to change the model as soon as possible, but there will be no problem in selecting the model unless special products.
when purchasing bearings, users generally only tell what model and grade, and rarely put forward requirements for bearing clearance. Business personnel must ask about the service conditions of bearings, including bearing speed, temperature and fit tolerance, which are directly related to the selection of bearing clearance imported by fag. Generally, CM clearance is mostly used for motors with speed below 3500 rpm. For example, relatively large clearance is required for high-temperature and high-speed motors. After assembly, the bearing clearance will be reduced due to the increase of inner hole and the reduction of outer circle. The reduction of clearance = interference × 60% (unless the bearing housing is aluminum). For example, if the clearance before bearing assembly is 0.01mm and the interference during assembly is 0.01mm, the clearance after bearing assembly is 0.004mm. Theoretically, the noise and service life of the bearing reach a good state when there is zero clearance, but considering the problems such as temperature rise in actual operation, the clearance of the bearing after assembly is 0.002mm-0.004mm.
the selection of grease is generally based on the speed, temperature resistance, noise requirements and starting torque of the bearing. The business personnel are required to understand the performance of various grease.
the lubrication of fag imported bearings can be divided into oil lubrication and grease lubrication. Oil lubricated bearings are generally formal bearings, and grease lubricated bearings are generally sealed with dust covers or rubber seals. The dust cover is suitable for parts with high temperature or good service environment. The seals are divided into contact seal and non-contact seal. The contact seal has good dust-proof performance but large starting torque, and the non-contact seal has small starting torque, but the sealing performance is not as good as the contact seal.
The inner diameter and outer diameter of rolling bearings are manufactured according to standard tolerances. The fit tightness of bearing inner ring and shaft, outer ring and seat hole can only be realized by controlling the tolerance of journal and seat hole. The matching of bearing inner ring and shaft adopts base hole system, and the matching of bearing outer ring and seat hole adopts machine shaft system. To correctly select the fit, we must know the actual load conditions, working temperature and other requirements of fag imported bearings, which is actually very difficult. Therefore, in most cases, the matching is selected according to the use of fine grinding. Load size: The win-win amount between the ferrule and the shaft or shell depends on the load. The heavier load adopts the larger win-win amount, and the lighter load adopts the smaller win-win amount.