Double row deep groove ball bearings radial clearance means the one ring is immovable while the other ring in the direction moves from one extreme location to another location perpendicular to the axis of double row deep groove ball bearings. Selection of bearing clearance is correct or not, has a great deal of influence to running accuracy, bearing life, mechanical friction, temperature, vibration and noise of bearings. For example, when spherical bearings radial clearance is small, the number of rolling elements bearing the load increases contact stress reduces, and stably operates, but frictional resistance will increase, and temperature also increases. Therefore, depending on the bearings’ using conditions, choose the most suitable clearance values, is of great significance. Selecting bearing clearance, must fully take into account the following key factors:
1, Tightness between double row deep groove ball bearings with shaft and housing bore will result in changes of bearing clearance value. Generally, bearing clearance values after installation will reduce;
2, During the operation of double row deep groove ball bearings, due to the different cooling conditions of the axis and the shell, it makes the temperature difference between inner and outer rings, which will lead to the clearance values reducing;
3, Due to different coefficients of expansion of the shaft and housing materials, clearance value will reduce or increase too.