Special Issue; Products for Industrial Machinery - NTN

High Load Capacity Cylindrical Roller Bearings
Test conditions
Test pieceJIS 7113
No. 1 dumbell test piece
Oil used for immersion
Synthetic oil equivalent to VG320
from Company A
Synthetic oil equivalent
to VG320
from Company B
Immersion temperature100˚C
Immersion duration2000 hrs.
Tensile strength MPa
80
60
40
20
0
A
B
0 500 1000 1500 2000
Immersion duration h
Fig. 5 Oil resistance of separator
4. Evaluation Test (2)
Additional tests were performed with an N-type
cylindrical roller bearing (a type that has a doubleribbed
inner ring). This type of bearing is often used in
planetary gear applications.
On certain planetary gears, the bore surface of the
gear may be used as a raceway surface for the outer
ring. With this type of arrangement, an N-type
cylindrical roller bearing that lacks an outer ring is
often used (Fig. 6). Bearings for planetary gearing are
usually used with their outer rings allowed to rotate.
However, for the these tests, the inner ring was
allowed to rotate.
4.1 Test bearings
In Table 3, the technical data for the conventional
design (full complement roller bearing) is compared
with that for the new keystone design.
Fig. 6 Example of using N type
Planetary gear
Table 3 Test bearings
Conventional design
(full complement roller bearing)
Type
New design
(complete with rolling element separator assembly)
Appearance
101.6190.276.6
29.560
17
Bearing size mm
Roller size mm
Number of rollers
16
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