Changes of interference caused by the temperature of the differences between the bearings

Bearing the changes caused by the interference temperature difference between effective jamming bearing temperature rise due to runtime. If the temperature difference between the spherical roller bearing shell for & T ( ℃) , and then the temperature difference between the shaft and the installation of the inner ring surface estimation is about ( 0. 1 to 0. 15) & T axis is cooled. Interference to reduce inner ring due to the temperature difference and can use the formula: d T & d T = ( 0. 10 to 0. 15) × tα; ⋅ dH0。 0015 &t⋅ d× 10 - 3. 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 。 T & D: reduce the interference of inner ring due to temperature difference ( mm） & T: bearing temperature difference between internal and surrounding parts ( ° C) α = 12: linear expansion coefficient of bearing steel. 5× 10 - 6 ( 1 /℃） D: bearing nominal aperture ( mm） In addition, depending on the temperature difference between outer ring and shell, or differences in their linear expansion coefficient, interference is likely to increase. Changes caused by the interference temperature differences between bearing: consider the effective intervention of the shaft and the surface treatment due to the roughness of the surface reduce in the process of assembly, assembly interference become smaller than the obvious interference effectively. The number of interference reduction depends on the roughness of the surface you can use the following equation: used for ground axis machining axis & d: effective interference ( mm） A: & d apparent interference ( mm） D: bearing nominal aperture ( mm） According to the equation ( 9. 4) And ( 9. 5) , effective bearing of 30 ~ 150 mm diameter is about 95% of the apparent interference. Stress and ring expansion shrinkage joint bearing installation interference shaft or in shell, ring or expand or contract and pressure. Excessive interference may damage the bearing; Therefore, as a general guide, the maximum interference in about 7/10 000 shaft diameter shall be maintained. Matching between the surface pressure, expansion or ring contraction and circumferential stress. As mentioned earlier, many factors, such as the characteristics of the bearing load and size, temperature difference, bearing installation must consider when the choice of appropriate fit. If the shell is very thin or bearing installed on a hollow shaft, than ordinary tits matter. A split type usually make the bearing shell forming oval shape; Therefore, we should avoid split housing when need to work closely with the outer ring. With the inner ring and outer ring should be on bearing vibration by applications is closely. Recommend suitable for the application of some common usage in unusual cases, LTD bearings.