Page 12 - needle bearings

Classification and Characteristics of Bearings
NTN

The track roller bearing is a needle roller bearing with thick outer ring, which is applied to cam roller, guide roller,
eccentric roller and rocker arm.
The track roller bearings are mainly categorized into a yoke type track roller bearing (roller follower) and a stud type
track roller bearing (cam follower). Various types of the roller follower and the cam follower are available as described
hereunder.

Roller follower ʕʕ Without axial guide ʕʕ

This roller follower is a bearing designed for
rotation of the outer ring wherein a needle roller and
cage assembly and a synthetic rubber seal
reinforced with steel plate are assembled in the thick-
walled outer ring.
¡The outer ring, the needle roller and cage
assembly, and the rubber seal are non-separable
from each other.
¡The outer ring is thick-walled type so that it is
resistible to high load and impact load.
¡The shaft must be provided with a thrust washer
and a flange, because of the outer ring with no
ribs (or face ring) and no axial guide function.
¡The outer surface is available in both spherical
(crowning) profile and cylindrical profile.
¡The bearing with spherical outer ring is effective in
damping bias load which is caused by deviation in
installing.
¡The bearing with cylindrical outer ring is suitable to
the cases of large load and low-hardness track
surface,due to its large area of contact with the
mating track surface.

Roller follower ʕʕ With axial guide ʕʕ

This roller follower is a bearing designed for
rotation of the outer ring wherein a needle roller and
cage assembly, an inner ring, and a face ring are
assembled in the thick-walled outer ring.
This bearing uses needle rollers as its rolling
element and furthermore classified into bearing with
cage and full complement roller bearing without
cage. The outer ring is guided axially by a face ring
which is press-fitted in the inner ring.
¡The outer ring is thick-walled type so that it is
resistible to high load and impact load.
¡The outer surface is available in both spherical
(crowning) profile and cylindrical profile.
¡The bearing with spherical outer ring is effective in
damping bias load which is caused by deviation in
installing.
¡The bearing with cylindrical outer ring is suitable to
the cases of large load and low-hardness track
surface,due to its large area of contact with the
mating track surface.
¡This bearing is easier to handle because it needs
no mounting of a guide (thrust washer, etc.) on the
shaft unlike other types without axial guide
(RNA22, NA22).

A-8