Bearing basic data
Technical data of rolling bearing
Bearing classification
Grading bearing according to the tolerances for size and rotation accuracy.
The standard of tolerance of for radial bearings (except tapered roller bearings) is divided into five, namely.P0(G), P6(E), P4( C), P2(B) level, precision lever from low to high.
Bearing material
Bearing ring and body of rolling is made from GCr12 or GCr15SiMn. when customers have any other requirment, can consulation using other material.
The hardness of bearing parts
When manufacturing bearing ring and dody of rolling with the material GCr15 or ZGCr15, the hardness of bearing ring and body of rollings is HRC60~64, the hardness of steel ball is HRC61~65; the hardness of wheel bearing ring is HRC58~62.
The surface of bearing and roughness of the bearing edge
The maximum of the surface roughness for bearing, shaft and housing with the end of the surface shall not exceed the values in table1.
Table 1 Roughness value with surface and end surface for bearing coordination
|
Surface name |
Bearing tolerance standard |
|
||
|
Bearing metric diameter(mm) |
||||
|
Exceed |
30 |
80 |
||
|
Till 30 |
80 |
500 |
||
|
Ra(um) |
||||
|
Surface of inner ring bore |
P0(G) |
0.8 |
0.8 |
1 |
|
P6(E) |
0.63 |
0.63 |
1 |
|
|
P5(D) |
0.5 |
0.5 |
0.8 |
|
|
P4(C) |
0.25 |
0.25 |
0.5 |
|
|
P2(B) |
0.16 |
0.2 |
0.4 |
|
|
/Surface of outer ring cylinder |
P0(G) |
0.63 |
0.63 |
1 |
|
P6(E) |
0.32 |
0.32 |
0.63 |
|
|
P5(D) |
0.32 |
0.32 |
0.63 |
|
|
P4(C) |
0.25 |
0.25 |
0.5 |
|
|
P2(B) |
0.16 |
0.2 |
0.4 |
|
|
Ferrule edge |
P0(G) |
0.8 |
0.8 |
1 |
|
P6(E) |
0.63 |
0.63 |
1 |
|
|
P5(D) |
0.5 |
0.5 |
0.8 |
|
|
P4(C) |
0.4 |
0.4 |
0.63 |
|
|
P2(B) |
0.32 |
0.32 |
0.4 |
|
Clearance
The clearance means the bearing under the situation of non-load, when a ring fixed, the mobile contents another ring relate to the fixed ring by an extreme position to another extreme position. For ridial movment are known as ridial clearance for axial movement are called axial clearance.
Tipically, the original radial clearance is greater than the working clearance of the bearing. The bearing clearance is greatly affected the life, temperature and nosie of the bearing. It must consider as following when deciding the radial clearance of the bearing.
Interference with the installation, the expansion of the inner ring and the outer ring contraction leading to reduced the clearance.
In the operating temperature, the temperature difference between the inner ring, out ring and the thermal expansion of it's related parts led to changes of the clearance.
The clearance of ball bearing should close to zero in the operating temperature. For roller bearing, under the normal operating conditions should left a certain ridial clearance.
