Clearance is an important index of rolling bearing and an important parameter in bearing application.Different bearing clearance will have different effects on the operation of the machine, among which the most obvious is vibration and noise, and the other is bearing heating and abnormal damage.Should choose according to the regulation so, cannot use wrong.

The clearance sizes of Merck bearings are divided into groups 0, 1, 2, 3, 4 and 5.

W1- gap 1 group meeting the standard, less than 2 groups.

W2- 2 groups of clearance meeting the standard, less than 0 groups.

W3- clearance meets the standard set of 0, omitted in code, not denoted.

W4- clearance meets the standard for 4 groups, more than 3 groups.

W5- the 5 groups of clearance that meet the standard are divided into 4 groups.

Non-standard clearance. In the case of special radial clearance and axial clearance, the relevant limit value should be represented by um after letter A (radial clearance) or B (axial clearance), and Numbers should be separated by dots.

In the commonly used rolling bearing clearance, group 0, group 2, group 3, group 4 -- among which group 0 is called standard clearance or basic group.The basic group is suitable for general working conditions and should be preferred;The radial clearance of group 3, 4 and 5 is larger than that of the basic group, which is suitable for the use of a tight interference fit between the bearing and the shaft (or bearing pedestal), or when the temperature difference between the inside and outside of the trap is large, or when the friction torque is low;The radial direction of the second group is smaller than that of the basic group, which is suitable for situations where the rotation accuracy of the axis is required to be higher and the axial displacement should be strictly limited.