How to choose bearing clearance?

The so-called bearing clearance, that is, when the bearing is not installed in the shaft or bearing box, the inner ring or outer ring side fixed, and then not fixed side of the radial or axial movement of the amount of movement. According to the direction of movement, can be divided into radial clearance and axial clearance. The size of the clearance (called the working clearance) during operation affects the rolling fatigue life, temperature rise, noise, vibration and other properties of the bearing. When measuring the clearance of the bearing, in order to obtain a stable measurement, the specified load is normally applied to the bearing. Thus, the resulting measured value is greater than the true clearance (called the theoretical clearance), which increases the amount of elastic deformation produced by the measured load. But for the roller bearing, because the elastic deformation is small, can be ignored. The internal clearance of the front bearing is usually expressed in theoretical clearance.

● Specification value (unit: um) Nominal diameter d MC1 group MC2 group MC3 group MC4 group MC5 group MC6 group minimum max maximum min max max min min max min max max min max max max 0 ~ 9 0 5 3 8 5 10 8 13 13 20 20 28 Nominal diameter d C2 group EMQ group C0 group C3 group C4 group C5 group 0 ~ 10 0 7 4 11 2 13 8 23 14 29 20 37 10 ~ 18 0 9 4 11 3 18 11 25 18 33 25 45 18 ~ 24 0 10 5 12 5 20 13 28 20 36 28 48 24 to 30 1 11 5 12 5 20 13 28 23 41 30 53

The choice of clearance from the theoretical clearance minus the bearing installed in the shaft or the shell when the interference caused by the expansion of the collar or shrinkage after the gap called "installation clearance." In the installation of the gap on the increase and decrease due to the internal temperature difference between the size of the changes in the amount of clearance called "effective clearance." Bearings are mechanically loaded with a certain load when the clearance, that is, the effective clearance with the bearing load after the elastic deformation of the amount of so called "work clearance." When the working clearance is slightly negative, the fatigue life of the bearing is the longest, but with the increase of the negative clearance, the fatigue life decreases significantly. Therefore, the choice of bearing clearance, the general working clearance is zero or slightly is appropriate. In addition, the need to improve the rigidity of the bearing or to reduce the noise, the work clearance to take a negative value, and in the bearing temperature rise, the work clearance will have to take a positive value, etc., must also be based on the use of specific conditions of analysis The

Post date :2018-02-06