Description
NSK Self-Aligning Ball Bearings, Cylindrical Bore Bearings 2208 ,D=40
Bearing
Numbers |
Boundary Dimensions
(mm) |
Basic Load Ratings
(kN) |
Limiting Speeds
(min-1) |
Constant
e |
Axial Load
Factors |
Mass
(kg)
approx. |
|
| d |
D |
B |
r
min. |
Cr
|
C0r
|
Grease |
Oil |
| Y2
|
Y3
|
Y0
|
| 2208 |
40 |
80 |
23 |
1.1 |
22.4 |
7.35 |
7500 |
9000 |
0.33 |
3 |
1.9 |
2 |
0.477 |
DESIGN, TYPES, AND FEATURES
The outer ring of a self-aligning ball bearing has a spherical raceway and its center of curvature coincides with that of the bearing; therefore, the axis of the inner ring, balls and cage can deflect to some extent around the bearing center. This type is recommended when the alignment of the shaft and housing is difficult and when the shaft may bend. Since the contact angle is small, axial load capacity is low.
Pressed-steel cages are usually used.
PROTRUSION AMOUNT
Some self-aligning ball bearings have balls that protrude from the side face as shown below. This protrusion amount b1 is listed in the following table.
PERMISSIBLE MISALIGNMENT
The permissible misalignment of self-aligning ball bearings is approximately 0.07 to 0.12 radian (4° to 7°) under normal loads. However, depending on the surrounding structure, such an angle may not be possible. Take care in the design of the bearing surroundings.
