2021 - rolling bearing clearance is introduced
01 -
14 (
Source: dmdbearing)
1.
Clearance clearance refers to the classification of the bearing clearance between inner ring and outer ring, rolling body.
The clearance of rolling bearings are divided into radial clearance and axial clearance (
A) shown in the diagram below
, that is, in the condition of no load, along the direction at any Angle, relative another ring from a radial (a ring
The axial)
Eccentric limit position moves to the opposite extreme position of the radial (
The axial)
The arithmetic mean of the radial distance (
The axial)
Load.
In the actual work, often divides into the clearance original clearance, installation clearance and work clearance.
Figure 1 (
1)
The original clearance refers to before installation clearance;
（
2)
After installation clearance refers to the bearing clearance, bearing after installation to the shaft or bearing for coordination, lead to inner ring expansion outer contraction, cause the radial clearance decreased;
（
3)
Work clearance refers to the bearing in the actual operation conditions of clearance.
In general, installation clearance is less than the original clearance, clearance is greater than the installation work clearance.
Bearing clearance and the bearing of life, temperature rise, vibration and noise are closely linked.
2.
Clearance of the grouping of centripetal bearing radial clearance is generally divided into 2 groups, group 0, 3, 4, and 5 groups;
Particular, double row and four row circular cone roller bearings clearance can be divided into 1 group, 2, 0, 3, 4 and 5 groups, four-point contact ball bearing axial clearance is divided into 2 groups, 0, 3 groups and 4 groups.
Clearance value from small to large, clearance in English the letter 'C', said such as C3, which is three groups of clearance.
3.
The choice of clearance (
1)
Ball bearing radial clearance were close to zero, rigid than ball bearings, roller bearings in order to avoid caused by temperature difference on inner and outer radial jammed, roller bearing should retain certain radial clearance.
And for rigid or rotating accuracy requirements of bearing, such as automobile wheel hub double row angular contact ball bearing, also need to impose certain pre-tightening force, forming 'negative clearance.
（
2)
Light load, high speed, high precision, low working temperature, bearing choose smaller clearance group, choose large clearance group conversely.
4.
Clearance of the bearing clearance measurement using special clearance measurement instrument (
Figure 2)
, also can use feeler or dial gauge (
FIG. 3)
To measure.
Maximum load position with feeler to check and confirm the rolling bearing, in its 180 & deg;
The rolling element and outside (
)
Between circle into feeler, elastic fitting for feeler thickness is the radial clearance of the bearing.
This method is widely used in self-aligning bearings and cylindrical roller bearing;
Measured with a dial indicator, dial gauge to zero, the first and then jacked up rolling bearing outer ring, the reading of the dial gauge is bearing radial clearance.
