Timken Spherical Roller Bearing Catalog

ENGINEERING
BEARING TYPES AND CAGES
RADIAL SPHERICAL ROLLER BEARING TYPES AND CAGES
The principle styles of radial spherical roller bearings that Timken
offers are:
• ≤400 mm outer diameter: EJ, EM and EMB
• >400 mm outer diameter: YM, YMB, YMD and YP
Above suffixes correspond to different types of designs depending
on a bearing size and geometry. Main differences are the cage
type used in the assembly. Spherical roller bearings with an EJ
cage suffix are fitted with a stamped-steel cage. YM/EM/YMB and
YMD suffixes are used with brass cage designs. YP is a pin-type
cage specific for large diameter bearings.
The newly redesigned Timken ® EJ, EM and EMB bearings offer
higher load ratings, increased thermal speed ratings and reduced
operating temperatures compared to the previous offering.
In addition to these improvements, cage designs vary between
the different styles as noted below. See the cage section for
more details.
Style
EJ
EM/YM
EMB/YMB
YMD
YP
Cage Design
Land-riding steel cage; one per row
Roller-riding one-piece brass cage
Land-riding one-piece brass cage
Land-riding two-piece brass cage
Steel pin-type cage
Most Timken spherical roller bearings are available with a
cylindrical bore as well as a tapered bore. Tapered bore bearing
part numbers are designated with a K suffix.
A taper of 1:12 is standard except for 240, 241 and 242 series,
which have a taper of 1:30.
OPTIONAL FEATURES AVAILABLE WITH
TIMKEN SPHERICAL ROLLER BEARINGS
W33 lubrication groove and oil holes
A lubrication groove and three oil holes are provided in the
bearing outer ring as standard. This is designated by the W33
suffix. It eliminates the expense of machining a channel in the
housing bore for introducing lubricant to the bearing. This design
feature allows the lubricant to flow between the roller paths,
through a single lubrication fitting. The lubricant moves laterally
outward from the center of the bearing, reaching all contact
surfaces and flushing the bearing. To order, add the suffix W33
to the bearing number (e.g. 22216EMW33).
Bearings for vibratory applications
Timken offers specific spherical roller bearing designs for
vibratory applications. They are designated by the W800
modification code and made to a C4 clearance. Specify W800
when ordering. This design provides:
• A lubrication groove on the outer ring with three lubrication
holes to facilitate bearing lubrication.
• Extra-close running accuracy (P5) with high and low points
marked on the bearing.
• Reduced bore and outside diameter tolerances.
• Radial internal clearance is made in upper two-thirds of
C4 clearance range.
These bearings are available with either a cylindrical or tapered
bore. Other optional features are available. See page 61, table 27
or consult with your Timken engineer.
CAGES
EJ
YMD
EM/YM and EMB/YMB
YP
Cages (also referred to as rolling element retainers) serve several
purposes in the proper operation of a rolling element bearing.
Cages separate the rolling elements and prevent rolling element
on rolling element contact and wear. Cages align the rolling
elements on the inner ring to prevent rolling element sliding,
skidding, and skewing to facilitate true rolling motion. For handling
purposes, cages retain the rolling elements on the inner ring
assembly to allow for bearing installation. In some instances,
cages also improve flow of the lubricant to the bearing raceway
or rib contacting surfaces.
The following sections discuss the common types of cages
used for each major bearing design type (tapered, cylindrical,
spherical, and ball bearing). The basic design geometry, material,
and manufacture are discussed for each cage type.
Fig. 3. Radial spherical roller bearings.
12 TIMKEN SPHERICAL ROLLER BEARING CATALOG