Correct application method of high-speed constant cross-section bearing:
High-speed constant cross-section bearing is a very important part of mechanical equipment, and its device cooperation and adjustment are also very important. Next, let's introduce the installation of high-speed constant cross-section bearings and the matters needing attention.
The cooperation and clearance of high-speed bearings with equal cross-section should not only meet the requirements of high-precision bearings with equal cross-section, but also the requirements of high-temperature bearings with equal cross-section. When considering the cooperation and clearance, the following two points should be taken into account: (1) scale change and hardness change from room temperature to high temperature; (2) centrifugal force at high-speed The change of force system and shape caused by it.
In summary, under the conditions of high speed and high temperature, it is difficult to insist on the accuracy and operation performance of equal cross-section bearings in terms of cooperation and clearance selection. When the top screw on the protruding end of the inner ring of the bearing is fastened on the shaft, the allowable axial load shall not exceed 20% of the rated dynamic load.
In order to ensure that the raceway deformation of the equal cross-section bearing device is small, the interference of interference cooperation can not be too large, while the centrifugal force at high speed and thermal expansion at high temperature, or offset the normal pressure of the cooperation surface. When the top screw on the protruding end of the inner ring of the bearing is fastened on the shaft, the allowable axial load shall not exceed 20% of the rated dynamic load. Or make the cooperation surface loose, so interference must be carefully calculated on the premise of considering the above two factors. Useful interference at room temperature and speed may be ineffective for high-speed bearings with equal cross-section.
If the contrast between the calculation results is too big, only two-layer smoothing method, i.e. under-ring smoothing method and hydrostatic smoothing method, is adopted, and this plan may break the DMN value of the bearing with equal cross-section by 3 million yuan.
Thermal expansion at high temperatures, or offset the normal pressure on the surface of the cooperation. Bearing with seat is a high-precision component product composed of grease-sealed deep groove ball bearings and bearing seats of various shapes. Bearing components can be installed directly on the main body of the mechanical device through several bolts, which has the function of adjusting the center and can supplement the grease. It is a very simple product for installation and use. Or make the cooperation surface loose, so interference must be carefully calculated on the premise of considering the above two factors. Useful interference at room temperature and speed may be ineffective for high-speed bearings with equal cross-section.
If the contrast between the calculation results is too big, only two-layer smoothing method, i.e. under-ring smoothing method and hydrostatic smoothing method, is adopted, and this plan may break the DMN value of the bearing with equal cross-section by 3 million yuan.
When considering the clearance of high-speed constant cross-section bearings, not only the above factors should be taken into account, but also the influence of the thermal elongation of the shaft on the clearance. It is required that the equal cross-section bearings have the best clearance in the working state, i.e. at the operating temperature, and that the clearance is formed in the state of accurately positioning the center of the inner and outer ring grooves. Because high-speed bearings with equal cross-section strive to reduce relative sliding and internal conflict, it is better not to choose the method of relative dislocation of inner and outer rings along the axis to adjust the clearance of ball bearings with equal cross-section.
When considering the cooperative interference and clearance of bearings with equal cross-section, it should be noted that the material becomes soft and easily deformed at high temperature, and the possibility of permanent deformation caused by repeated temperature changes from room temperature to high temperature.
Above is what we need to pay attention to in the process of high-speed constant cross-section bearing device and operation.
