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CONSTRUCTION
STANDARD STUD TYPE BEARINGS are
recommended where loads and shock are moderate. Bearing capacity is more
limited by the strength of the stud, as indicated by the rating chart
depicted in this catalog.
HEAVY STUD TYPE BEARINGS are recommended
for light load and shock applications; and where deflection should be
held to a minimum. Rollers and outer races are identical to the standard
series.
YOKE TYPE CAM FOLLOWERS are of similar
internal construction except an inner race for shaft or clevis mounting
replaces the threaded stud. Generally, heavier loads can be supported by
the yoke mounting arrangement since stud deflection is removed from
consideration as a load factor.
ECCENTRIC BEARINGS permit easy radial
adjustment for precise positioning which may make installation less
expensive. The eccentric construction accommodates for wear that may be
caused in the application. A lock nut should be employed to secure the
bearing in position, when practical.
CROWNED BEARINGS are recommended where
the track or cam may cause excessive angular loading. This construction
can reduce the possibility of edge loading of rollers. Thrust on the
rollers is minimized and reliability is improved.
HEX SOCKET TYPE BEARINGS are favorable
for most applications where the bearing is installed in a blind or
threaded hole. This allows for easier and more secure installation and
removal.
SCREWDRIVER SLOT TYPE BEARINGS are
available in standard stud and heavy stud type bearings. This means of
tightening will be supplied unless the hex socket type is requested.
They are recommended for economy.
SEALED CAM FOLLOWERS are furnished with
molded acetal full contact seals contained within the outer race
undercuts at both ends of the bearing. This is a low friction material
which keeps drag to a minimum yet is stable and unaffected by corrosive
agents or lubricants. The seals provide both an effective means of
protection from contaminants and ensure lubricant retention. They are
designed with a small vent to allow for purging during relubrication
without causing seal displacement.
The outer race on sealed cam followers is
provided with a machined groove in the bore which acts as a grease
reservoir and extends the period between relubrications. All sealed
bearings are dimensionally interchangeable with the unsealed
configuration of the same series.
TYPICAL SEAL CONFIGURATION
STOCK:
Most standard bearings listed in this
catalog are stocked at the factory or available from your local ABC,
Smith Cam Follower distributor. Stock conditions vary depending upon
bearing size and current demand. Eccentric, Crowned and larger size
bearings are not stocked in depth.
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MATERIALS AND
FINISHES:
Cam follower materials and finishes are
selected to provide a minimum of friction and to assure dependable
performance for the required service life.
Outer Race -- High-carbon chrome
bearing steel, through-hardened and ground.
Inner Race -- Low-carbon alloy
steel, carburized, and deferentially hardened. A special heat treating
process is used whereby progressive differential hardness provides
maximum strength in the critically loaded raceway area. The threaded end
is maintained in a softer condition, therefore, providing the best
characteristics of a strong bolt which is subject to tensile, shear and
bending stresses. The race and stem are centerless ground.
Needle Rollers -- High-carbon
chrome bearing steel, through-hardened ground and lapped.
Retaining Washers -- Low-carbon
alloy steel, case-hardened and ground.
MOUNTING CAM
FOLLOWERS:
Proper cam follower mounting requires a
snug fit between the stud and housing bore. Where feasible, the
recommended bore sized shown in the dimensional tables should be
followed. An arbor press is the preferred means of stud installation
with pressure applied to the central area, not to the outer flange
edges.
In positioning the cam follower, the end
washer should be firmly backed up by a flat housing shoulder or surface
of the machine member which is square with the center line of the stud.
The shoulder should be at least as large as the minimum boss diameter
given in the tables. It is also important that alignment be maintained
between the bearing axis and the cam or track surface to prevent edge
loading of the bearing outer race. The dimensional tables list the
recommended torque to be applied to the nut. Excessive torque, in
particular with smaller sizes, may damage the internal elements. If the
threads or nut are lubricated, the torque value should be reduced by one
half.
TYPICAL STUD TYPE MOUNTING
MOUNTING, CAM YOKE
ROLLERS:
The mounting of cam yoke rollers should
provide for endwise clamping to prevent axial movement and displacement
of the end washer. The washer should be firmly backed up by a flat
housing shoulder which is square with the centerline of the bearing. The
shoulder should be at least as large as the minimum clamping diameter
shown in the tables to provide adequate washer support.
The recommended shaft diameters listed in
the dimensional tables provide for either a slip or press fit. In
heavily loaded applications, the shaft should be heat treated and press
fit in the bearing bore. With moderate loads, a hardened shaft should be
used but a slip fit is sufficient. In lightly loaded applications, a
slip or push fit may be used with an unhardened shaft.
TYPICAL YOKE ROLLER MOUNTING
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