Terms and Glossary
A.B.E.C. Annular Bearing Engineering Committee
A.B.E.C. 1-3-5-7-9 -- Grades of precision as determined by A.B.E.C.
Adapter Assembly Metric/inch sleeve with locknut and lock washer
Adapter Sleeve -- Axially slotted sleeve with cylindrical
bore, tapered outside surface and male screw thread at small end used with
locknut and lock washer for mounting of bearings with tapered bore on
cylindrical outside surface of shaft.
Aircraft Bearing Bearings that have been designed & approved
for aircraft use.
Angular Contact Bearing A type of bearing that has one ring shoulder
partially or totally removed.
Anti-friction Bearing Any bearing with a rolling element used to
Axial Internal Clearance The amount of possible movement parallel to the
bearing axis of the inner ring in relation to the outer ring, also known as
bearing end play.
Axial Load Amount of load applied to the axis in a parallel
manner, also known as thrust load.
Axis An imaginary straight line
about which an object rotates.
Ball An individual spherical rolling element used in bearings.
Ball Bearing A
complete bearing unit assembled using balls as the rolling element.
Ball Cage A device
which is used in a ball bearing to retain, separate and guide the balls.
Ball Complement The number of balls used in a complement ball
Ball Contact The point of contact between raceways and the ball,
usually measured in degrees.
Ball Diameter The
dimension of ball measured on the axis across the ball.
Ball Pocket The receptacle
in which the ball sits in its retainer
Basic Dynamic Load Rating -- Basic dynamic load rating, Cr, is the calculated
constant radial load (thrust load for thrust bearings) which a group of
identical bearings with stationary outer rings can theoretically endure for
rating life of 1 million revolutions of inner ring.
Bore -- The inside diameter of a
bearings inner ring.
-- Anti-friction roller bearing for
use in cam or track following applications.
Cartridge Bearing An extra wide bearing that allows greater shaft
support in addition to greater grease capacity.
the same center. Most commonly a type of locking collar used on mounted
Cone The inner ring of a roller assembly or taper bearing.
Conrad A single deep groove ball bearing named
after Joseph Conrad, the inventor of its assembly method.
Contact Angle Nominal angle between the ball to race contact
line and a plane through the ball centers, perpendicular to the bearing axis.
bored Ball Bearing -- Where the inner or outer race has one shoulder
partially or completely removed. In most cases the outer ring is counter bored.
Double Row Bearing A bearing with standard inner and outer
dimensions that has two rows of rolling elements.
Double Row Maximum Capacity -- A
bearing that has a solid inner and outer with two raceways and filling notches
to permit the maximum number of balls to be inserted.
Drawn Cup Needle Roller Bearing --
Needle roller radial bearing with thin
pressed steel outer ring (drawn cup), which may have one closed end or both
ends open, usually employed without an inner ring.
Duplex Bearing A bearing that
has both faces flush ground for mounting in duplex arrangements.
Dynamic Load The measurement of
capacity denoted by the rotation of the inner ring while a stationary radial
load is applied.
Eccentric -- Not
having the same center. Most commonly a type of locking collar used on mounted
End Play -- The amount of possible
movement parallel to the bearing axis of the inner ring in relation to the
outer ring, also known as bearing end play.
Face The side surface of a
Fillet Radius The clearance
needed to allow an inner race or outer race to seat next to a shoulder.
Filling Notch A ball size groove
in the inner ring of a bearing to allow the loading of balls into the bearing.
Finish The smoothness of a
materials surface as a result of machining.
Fit The shaft of housing
tolerances determined by operating characteristics.
Fixed Bearing A bearing that is
locked to the shaft or housing so that it can not float or move.
Floating Bearing A bearing that
was designed to allow movement axially between shaft and housing.
Full Complement Bearing A
bearing with out a cage or rolling element retainer.
Housing, Bearing The opening in which a bearing is positioned or
held to ensure proper positioning.
Housing Fit The clearance
necessary to hold a bearing in place based on use.
I.D. The internal diameter or bore of an inner ring.
Inner Ring The part of a rolling element bearing that is
mounted on a shaft.
Inner Ring Raceway The path the
rolling element follows on the outside diameter of the inner ring.
Internal Clearance The initial clearance before a bearing is
mounted on a shaft or in a housing.
Internal Race The pathway for
the rolling element on the inner ring.
Lock Nut A threaded nut which is
slotted on the o.d and is used to hold bearings in place. Most commonly used
with a lock washer.
Lock Washer A stamped metal washer with tangs that will
mate with the slots in the lock nut.
Loose Fit A bearing with greater
internal clearance than normal.
Maximum Capacity Bearing A ball
bearing that uses the maximum number of balls inserted in the bearing.
Misalignment When a shaft or
housing is not perpendicular to the axis.
Needle Roller A long small
diameter cylindrical steel roller.
O.D. The outside diameter or
Outer Ring The outer part of a bearing that fits into the
housing and contains the inner race, cage and rolling elements.
Preload A pre-determined axial load to increase rigidity
in a bearing mounting.
Pre-lubricated Bearing A
shielded or sealed bearing that are pre-packed with greases or lubricants
Raceway The path in which the
rolling element follows.
Radial Clearance The internal
clearance or space that is built into the bearing based on operating
Radial Load A downward load or
perpendicular load on a bearing.
Radial Play The amount of movement (play) when one ring is
fixed and the other is moved up and down.
Radial Type Bearing A bearing thats primary use is for that of
Rating Life The number of revolutions that 90% of a group of
bearings will complete before the first evidence of fatigue develops.
Retainer The ball separator or cage.
Seal A positive contact rubber element that usually rides on the outer
Self Aligning Ball Bearing A ball bearing with two rows of rolling elements
but a common raceway thus allowing the inner race and ball assembly to self
Separable A bearing that may be separated completely or
partially into its component parts.
Shaft Fit Tolerances based of
type, use and operating conditions of rolling element bearings.
Shield A non contact metal plate
used generally on ball bearings.
Shoulder -- The side
of a ball race, also a surface in a bearing application or shaft which axially
positions a bearing and takes the thrust load.
Single Row One row of rolling elements
Snap Ring A removable ring used to locate and prevent a bearing from moving on a shaft or in a
Solid Cage -- A solid ring
type separator used in a radial or angular contact type bearings.
Spherical Roller Bearing Self-aligning, radial rolling bearing with
convex rollers or concave rollers as rolling elements. With convex rollers
outer ring has spherical raceway, with concave rollers inner ring has spherical
Standard Bearing -- A rolling element bearing design approved as
standard by Anti-friction Bearing Manufacturers Association.
Static Load The load acting on a non rotating bearing.
Thrust Load Load exerted parallel to the axis of the shaft on
which the bearing is mounted, also called thrust load.
Bearing A rolling element
bearing designed purely for axial load.
Thrust Face The large shoulder or inner/outer ring on which
the housing or shaft pushes.
Tolerance The measurement of leeway in manufacturing
bearings, shafts and housings.
Wide Inner Ring Bearing A
bearing with an extended inner race to give greater shaft support.