|
Bearing Resources
Loading
|
DEEP GROOVE BALL BEARINGS
In a deep-groove radial bearing, the race dimensions are close to the dimensions of the balls that run in it. Deep-groove bearings have higher load ratings for their size than shallow-groove, but are also less tolerant of misalignment of the inner and outer races. A misaligned shallow-groove bearing may support a larger load than the same sized deep-groove bearing with similar misalignment.
Series: 6004,6205,6302,6406,4204,4308…
|
|
ANGULAR CONTACT BALL BEARINGS
An angular contact ball bearing uses axially asymmetric races. An axial load passes in a straight line through the bearing, whereas a radial load takes an oblique path that tends to want to separate the races axially. So the angle of contact on the inner race is the same as that on the outer race. Angular contact bearings better support "combined loads" (loading in both the radial and axial directions) and the contact angle of the bearing should be matched to the relative proportions of each. The larger the contact angle (typically in the range 10 to 45 degrees), the higher the axial load supported, but the lower the radial load. In high speed applications, such as turbines, jet engines, and dentistry equipment, the centrifugal forces generated by the balls changes the contact angle at the inner and outer race. Ceramics such as silicon nitride are now regularly used in such applications due to their low density (40% of steel). These materials significantly reduce centrifugal force and function well in high temperature environments. They also tend to wear in a similar way to bearing steel—rather than cracking or shattering like glass or porcelain.
Series: Single row 7201,7306…
Series: Double row 3203,3313…
|
|
FOUR-POINT BEARINGS
Four point contact bearings are single row angular contact ball bearings and therefore require significantly less space in an axial direction than double row designs.
The bearings comprise solid outer rings, split inner rings and ball and cage assemblies with brass or polyamide cages. Due to the two-piece inner rings, a large number of balls can be accommodated. The halves of the inner ring are matched to the specific bearing and must not be interchanged with those of bearings of the same size. The outer ring with the ball and cage assembly can be fitted separately from the halves of the inner ring.
Series: QJ207,QJ311…
|
 |
SELF-ALIGNING BALL BEARING
Self-aligning ball bearings are constructed with the inner ring and ball assembly contained within an outer ring that has a spherical raceway. This construction allows the bearing to tolerate a small angular misalignment resulting from deflection or improper mounting.
Series: 1205,1304,2206,2307…
|
|
CYLINDRICAL ROLLER BEARINGS
Common roller bearings use cylinders of slightly greater length than diameter. Roller bearings typically have higher load capacity than ball bearings, but a lower capacity and higher friction under loads perpendicular to the primary supported direction. If the inner and outer races are misaligned, the bearing capacity often drops quickly compared to either a ball bearing or a spherical roller bearing.
Roller bearings are the earliest known type of rolling-element-bearing, dating back to at least 40 BC.
Series: Single row NU205,NJ307,NUP309,N310…
Series: Double row NCF2912,NNF5005…
|
 |
TAPERED ROLLER BEARINGS
Tapered roller bearings use conical rollers that run on conical races. Most roller bearings only take radial or axial loads, but tapered roller bearings support both radial and axial loads, and generally can carry higher loads than ball bearings due to greater contact area. Taper roller bearings are used, for example, as the wheel bearings of most cars, trucks, buses, and so on. The downsides to this bearing is that due to manufacturing complexities, tapered roller bearings are usually more expensive than ball bearings; and additionally under heavy loads the tapered roller is like a wedge and bearing loads tend to try to eject the roller; the force from the collar which keeps the roller in the bearing adds to bearing friction compared to ball bearings.
Series: 30205,30306,32207,31311,32310,32020,33208…
|
|
|
BARREL ROLLER BEARINGS
Barrel roller bearings are single row, self-aligning roller bearings. They comprise solid outer rings with a concave raceway, solid inner rings with two ribs and a cylindrical or tapered bore and barrel rollers with cages. The bearings cannot be dismantled.
Barrel roller bearings are particularly suitable where high radial shock type loads occur and misalignments must be compensated, see Compensation of angular misalignments. Their axial load carrying capacity is small.
|
 |
SPHERICAL ROLLER BEARING
Spherical roller bearings use rollers that are thicker in the middle and thinner at the ends; the race is shaped to match. Spherical roller bearings can thus adjust to support misaligned loads. However, spherical rollers are difficult to produce and thus expensive, and the bearings have higher friction than a comparable ball bearing since different parts of the spherical rollers run at different speeds on the rounded race and thus there are opposing forces along the bearing/race contact.
Series: 22210,21305,22314,23226,24044…
|
© 1995-2011 BearingNet Ltd.
|