Ball and Roller Bearings - Ntn-snr.com

Technical Data
Fitted surface pressure
Pm
kgf/mm 2 MPa
5 50
4 40
3 30
2
1
0.5
0.4
0.3
0.2
0.1
20
10
5
4
3
2
1
20 30 50 70 100 200 300 500
MPa
250
200
150
Fig. 17.4.1 Average fit interference as it relates to surface
pressure and max. allowable stress
js5
n6
m5
100
50
40
30
Nominal bearing bore diameter (Class 0) mm
k5
p6
20
10
5
kgf/mm2
25
20
15
10
5
4
3
2
1
t max
0.5
Maximum allowable stress
17.5 Necessary press fit and pullout force
Equations (7.1) and (7.2) below can be used to
calculate the necessary pullout force for press fit for inner
rings and shafts or outer rings and housings.
For shaft and inner rings:
Kd = PdB (7.1)
KD = PDB (7.2)
Where,
Kd : Inner ring press fit or pullout force Nkgf
KD : Outer ring press fit or pullout force Nkgf
P : Fitted surface pressure MPakgf/mm 2
(Refer to Table 17.4.1)
d : Shaft diameter, inner ring bore diameter mm
D : Housing inner diameter, outer ring outer
diameter mm
B : Inner or outer ring width
: Sliding friction coefficient (Refer to Table 17.5.1)
Fitted surface pressure
Pm
kgf/mm 2 MPa
MPa
10 100
kgf/mm 2
400 40
300 30
250 25
5 50
40
200 20
4
3 30
150 15
p6
2
100 10
20
n6
m5
k5
1 10
js5
50 5
40 4
0.5
0.4
0.3
5
4
3
10 1
0.2 2
20 30 50 70 100 200 300 500
Nominal bearing bore diameter (Class 0) mm
30
20
3
Maximum allowable stress
2
t max
Table 17.5.1 Press fit and pullout sliding friction coefficient
Type
Inner (outer) ring press fit onto cylindrical shaft (bore)
Inner (outer) ring pullout from cylindrical shaft (bore)
Inner ring press fit onto tapered shaft or sleeve
Inner ring pullout from tapered shaft
Sleeve press fit onto shaft/bearing
Sleeve pullout from shaft/bearing
0.12
0.18
0.17
0.14
0.30
0.33
Fig. 17.4.2 Maximum fit interference as it relates to surface
pressure and max. allowable stress
A-99