Selection of Bearing Type

Rolling bearings come in a wide variety of types shapes and dimensions. The factor to consider in bearing selection is a bearing that will enable the machine or part to satisfactorily perform. While there are no hard-and-fast rules in selecting a bearing, things to be kept in mind are:

Operating conditions and environment
Gather an accurate and comprehensive knowledge of which part of the machine or equipment and the operating requirements and environment. One may require following data:

Equipment's function and construction Bearing location Bearing load (direction and magnitude) Bearing speed Vibration and shock load Bearing temperature Environment

Performance Requirements
The required performance capacity and function demands are defined in accordance with the bearing application and operating conditions.

Understand the machine and the type of bearing Define all demand factors Select shape Select arrangement Select dimensions Select mounting method

Arrangement Selection
Shaft assemblies generally require two bearings to support and locate the shaft both radially and axially relative to the stationary housing. These two bearings are called the fixed and floating bearings.

Fixed bearing takes both radial and axial loads and "locates" the shaft axially in relation to the housing. The floating bearing relieves stress caused by expansion and contraction of the shaft and also allows for misalignment caused by fitting errors.

Bearings which can support axial loads in both directions are considered most suitable as fixed bearings. In floating bearings the axial displacement can take place in the raceway or along the fitting surfaces. There is also the "cross location" arrangement in which both bearings act as fixing and non-fixing bearings simultaneously. This arrangement is used mainly in comparatively short shaft applications.

Dimension selection
Bearing dimension selection is based on the operating load and the bearing's life expectancy requirements.

Design selection
The most suitable bearing design can be selected by comparing bearing functions and performance demands with the characteristics of each bearing type.

Axial Disp. Possible in Bearing

Pure Radial Load

Pure Axial load

Combined Load

Moment Load

High Speed

High Running Accuracy

High Stiffness

Quiet Running

Low Friction

Comp. for Errors of Alignment During Operation

Comp. for Errors of Alignment  (Initial)

Location Bearing Installation

Non-location Bearing Installation

Axial Disp. Possible in Bearing

Ball Single - Row

C

C

C

F

A

A

C

A

A

F

F

B

C

NR

C Ball Single Double - Row

C

C

C

C

C

C

C

C

B

NR

NR

C

C

NR

Ball Self - Aligning

C

F

F

NR

B

B

F

B

B

A

B

C

C

NR

Ball Angular Contact

C

C

B

F

B

A

C

B

B

F

F

B

NR

NR

Ball Angular Contact Back - to - Back

B

C

B

C

C

B

B

C

C

NR

NR

B

C

NR

Ball Four - Point Contact

F

C

C

C

B

C

C

C

C

NR

NR

B

F

NR

Cylindrical Roller N, NU

B

NR

NR

NR

A

B

B

B

B

F

F

NR

A

A

Cylindrical Roller NJ, NUP

B

C

C

NR

A

B

B

C

B

F

F

C

C

C

Cylindrical Roller Double Row

A

NR

NR

C

A

A

A

B

B

NR

NR

NR

A

A

Full Complement Cylinder Roller

A

C

F

NR

F

C

A

F

F

F

F

C

C

C

Full Cylinder Roller Double  - Row

A

C

F

C

F

C

A

F

F

NR

NR

C

C

C

Needle Roller

B

NR

NR

NR

C

C

B

C

F

NR

NR

NR

A

A

Spherical Roller

A

C

A

NR

C

C

B

C

C

A

B

B

C

NR

Taper Roller

B

B

A

NR

C

B

B

C

C

F

F

B

NR

NR

Taper Roller ( Face - to - Face)

A

B

A

F

C

C

A

C

C

F

F

A

C

NR

Thrust Ball

NR

C

NR

NR

C

B

C

F

C

NR

NR

C

NR

NR

Thrust Bal with Spherical Housing Washer

NR

C

NR

NR

C

C

C

F

C

NR

-

C

NR

NR

Thrust Cylinder Roller

NR

B

NR

NR

F

B

B

F

F

NR

NR

C

NR

NR

Thrust Needle Roller

NR

B

NR

NR

F

C

B

F

F

NR

NR

C

NR

NR

Thrust Spherical Roller

NR

A

C

NR

C

C

B

F

C

A

B

B

NR

NR

Buyers Guide :
Selection of Bearing Type | Selection of Bearing Sizes | Application of Bearings | Lubrication and Maintenance | Mounting and Dismounting