DIMENSION TOLERANCE AND GEOMETRICAL PRECISION The tolerance limit related to needle bearings and cylindrical roller bearings in this book are stipulated as per section 2.3 DIN620. The precision of RTL roller bearings belongs generally to P0 grade. For the bearings with of higher precision requirement , the tolerance limit can be reduced to the values of Grade P6 and P5 (P4 for thrusting roller bearings) . In RTL needle and cylindrical roller bearings , the radical sectional height is smaller and the walls of inner and outer rings are thinner . Therefore , its geometric shape after assembling is dependent on the geometric shapes of shaft or bearing seats.
|
Tolerance
symbols and definitions |
||
|
d |
Nominal
inner diameter |
|
|
△dmp |
Mean inner diameter deviation on the single plane |
|
|
Vdp |
Mean inner diameter variation on the single radical plane |
Circularity |
|
Vdmp |
The mean inner diameter variation |
Parallelism |
|
D |
Nominal outer diameter |
|
|
△Dmp |
Mean outer diameter deviation on the single plane |
|
|
VDp |
Mean outer diameter variation on the single radical plane |
Circularity |
|
VDmp |
Mean outer diameter variation |
Parallelism |
|
△Bs |
Single inner ring width deviation |
|
|
VBs |
Inner ring width variation |
Parallelism |
|
△Cs |
Single outer ring width deviation |
|
|
VCS |
Outer ring width variation |
Parallelism |
|
Kia |
Inner ring radical skip of the bearing set |
Radical skip |
|
Kea |
Outer ring radical skip of the bearing set |
Radical skip |
|
Sd |
End surface skip to the inner hole |
End face skip |
|
SD |
Slope variation of the outer surface bus bar related to basic face |
End face skip |
|
T |
Nominal height of the single directional thrusting bearing |
|
|
Si |
Thickness variation of the bearing tray to the ground face |
|
|
Se |
Thickness variation of seat ring tray to ground face |
|
|
The
tolerance limit of centripetal bearings |
Table 18（μm）
|
D m m |
△
dmp Warp |
Vdp (O)2) Diameter series |
Vdmp (//) |
Kia ( ↗ ) |
△
Bs Warp |
VBs (//) |
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|
8.9 |
0 |
2.3 |
|
|||||||||
|
Exceed |
To |
High |
Low |
Max. |
Max. |
Max. |
High |
Low |
Max. |
|
||
|
0.6 |
2.5 |
0 |
-8 |
10 |
8 |
6 |
6 |
10 |
0 |
-40 |
12 |
|
|
2.5 |
10 |
0 |
-8 |
10 |
8 |
6 |
6 |
10 |
0 |
-120 |
15 |
|
|
10 |
18 |
0 |
-8 |
10 |
8 |
6 |
6 |
10 |
0 |
-120 |
20 |
|
|
18 |
30 |
0 |
-10 |
13 |
10 |
8 |
8 |
13 |
0 |
-120 |
20 |
|
|
30 |
50 |
0 |
-12 |
15 |
12 |
9 |
9 |
15 |
0 |
-120 |
20 |
|
|
50 |
80 |
0 |
-15 |
19 |
19 |
11 |
11 |
20 |
0 |
-150 |
25 |
|
|
80 |
120 |
0 |
-20 |
25 |
25 |
15 |
15 |
25 |
0 |
-200 |
25 |
|
|
120 |
180 |
0 |
-25 |
31 |
31 |
19 |
19 |
30 |
0 |
-250 |
30 |
|
|
180 |
250 |
0 |
-30 |
38 |
38 |
23 |
23 |
40 |
0 |
-300 |
30 |
|