SKF - Rolling Bearings

6 Needle roller bearings
Shaft and housing tolerances
The following tables provide tolerance classes
to obtain suitable fits and an appropriate
operating clearance († Operating clearance,
page 700) for the following needle roller bearing
types:
• drawn cup needle roller bearings
• needle roller bearings with machined inner
and outer rings
• alignment needle roller bearings
• combined needle roller bearings
The tolerances of raceways on shafts and in
housings for needle roller and cage assemblies
and of raceways on shafts for machined needle
roller bearings without an inner ring, significantly
influence the operating clearance of the
bearing and, therefore, are provided under
Operating clearance († page 700).
For additional information about raceways,
refer to Raceways on shafts and in housings (†
page 210).
Table 15
Shaft and housing tolerance classes for drawn cup and
alignment needle roller bearings
Drawn cup needle roller bearings
Table 15 provides suitable tolerance classes
for the housing bore and shaft for drawn cup
needle roller bearings with or without an inner
ring.
Needle roller bearings with machined rings
Table 16 provides suitable tolerance classes
for the shaft for needle roller bearings with
machined inner and outer rings.
The recommended housing fits for needle
roller bearings with machined inner and outer
rings are provided in tables 4 and 5
(† pages 174 and 175) .
Alignment needle roller bearings
Table 15 provides suitable tolerance classes
for the housing bore and shaft for alignment
needle roller bearings with or without an inner
ring.
Table 16
Shaft tolerance classes for needle roller bearings with
machined inner and outer rings on solid steel shafts
Housing Tolerance classes 1)
material 2) Housing bore Raceway on
seat 3) the shaft
Shaft inner
ring seat
Conditions
Shaft
diameter
– mm –
Tolerance
classes 1)
Steel,
cast iron
N6 h5 k5
N7 h6 j6
Light alloy R6 h5 k5
R7 h6 j6
Rotating inner ring load or direction of load
indeterminate
Light and variable loads ≤ 10 k5
(P ≤ 0,05 C) > 10 to 25 k6
> 25 to 100 m6
Normal to heavy loads ≤ 25 k5
(0,05 C < P ≤ 0,1 C) > 25 to 60 m6
> 60 to 100 n6
> 100 to 400 p6 2)
Heavy to very heavy loads > 50 to 100 n6 2)
(P > 0,1 C) > 100 to 200 p6 2)
> 200 r6 2)
Stationary inner ring load
Easy axial displacement of
the inner ring on the shaft
desirable
g6
1) All ISO tolerance classes are valid with the envelope
requirement (such as H7VE ) in accordance with
ISO 14405-1.
2) For drawn cup needle roller bearings that are mounted in
housings that are not rigid, the shaft tolerance giving the
desired radial clearance must be determined by trial and
error.
3) The geometrical accuracy in accordance with ISO 1101
for the housing bore of drawn cup needle roller bearings
must correspond to IT5/2 tolerance grade.
Easy axial displacement of
the inner ring on the shaft
unnecessary
1) All ISO tolerance classes are valid with the envelope
requirement (such as h7VE ) in accordance with
ISO 14405-1.
2) Bearings with radial internal clearance greater than
Normal may be necessary.
h6
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