Formula for calculating bearing life?

Last Update: October 15, 2022

This is a question our experts keep getting from time to time. Now, we have got a complete detailed explanation and answer for everyone, who is interested!

If you work with linear ball or roller bearings, you're familiar with the L10 bearing life equation, which states that bearing life is equal to the bearing's rated dynamic load capacity, divided by the applied load, raised to a power of 3 (for ball elements) or 10/3 (for roller elements).

How is bearing life calculated?

Bearing Rating Life Calculation

C = Dynamic Capacity (dN or Lbs) P = Equivalent Bearing Load (N or Lbs) N = Rotating speed in RPM. e = 3.0 for ball bearings, 10/3 for roller bearings.

What is a bearing lifespan?

Bearing life is essentially the length of time a bearing can be expected to perform as required in predefined operating conditions. It is based primarily on the probable number of rotations a bearing can complete before it starts showing symptoms of fatigue, such as spalling or cracking due to stress.

What is B10 bearing life?

The “BX” or “Bearing Life” nomenclature, which refers to the time at which X% of items in a population will fail, speaks to these roots. So then, B10 life is the time at which 10% of units in a population will fail.

How do you calculate bearing number from shaft diameter?

It is important to note that our bearing measurements are all done in the following order: Inside diameter (ID) x Outside diameter (OD) x Width (W).

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How is bearing load rating calculated?

For a single bearing, L10 also refers to the life associated with 90% reliability. The rated life (L10) can be computed from the formula: L10 = (C/Pr)3 x 106 revolutions, where: C = dynamic radial load rating (lb) The dynamic radial load (C) can be found on the product listing pages.

What are the units of life of bearing?

Bearing life is usually expressed as the number of hours an individual bearing will operate before the first evidence of metal fatigue develops. The usual life rating for industrial applications is called “L-10” life. Simply put the L-10 life is the number of hours in service that 90% of bearings will survive.

What is L50 life of a bearing?

The L50 or average life is accepted as the bearing life associated with a 50% reliability, i.e., after a stated amount of time, only 50% of a group of identical bearings will not yet have developed metal fatigue. L50 life equals five times the L10 life.

What is bearing characteristic number?

Bearing characteristic number = N. p. μ It is a non-dimensional number, where µ is the viscosity, N is the speed of the.

What is service life of bearing?

As defined by Machine Design, bearing service life is, “The life of a bearing under actual operating conditions before it fails or needs to be replaced.” ...

How do you determine bearing size?

The bearing size is selected based on the basic static load rating C0 (product tables). For an equivalent static bearing load P0, the selected bearing must have a C0 value ≥ the value of the requisite basic static load rating C0req (table 1).

What is C and c0 in bearing?

Static load capacity, C0, is the amount of load a bearing can withstand before the sum of the ball and raceway deformation equals 0.01 percent of (0.0001 times) the ball diameter, as defined by ISO 14728-2.

Why do bearing fail?

While it may seem like common sense, standard wear and tear is one of the leading causes of bearing failure. Eventually all bearings fail due to wear, however, excessive load, vibration or force can cause a bearing to wear out long before it should. Most of this excess force is caused by improper installation.

How do you choose a shaft bearing?

Selection of bearing type
1. Installation space. Bearing can be installed in target equipment. ...
3. Rotational speed. Response to rotational speed of equipment in which bearings will be installed. ...
4. Running accuracy. ...
5. Rigidity. ...
6. Misalignment. ...
7. Mounting and dismounting.

What is SKF in bearing?

AB SKF (Swedish: Svenska Kullagerfabriken; 'Swedish Ball Bearing Factory') is a Swedish bearing and seal manufacturing company founded in Gothenburg, Sweden, in 1907. ... SKF is the world's largest bearing manufacturer, and employs 44,000 people in 108 manufacturing units.

What are the rolling contact bearing?

The term rolling contact bearings refers to the wide variety of bearings that use spherical balls or some other type of roller between the stationary and the moving elements. The most common type of bearing supports a rotating shaft, resisting purely radial loads or a combination of radial and axial (thrust) loads.

Why are double row bearings employed?

Double row bearings are made to carry heavier radial and thrust forces. The single row bearings will withstand a small misalignment or deflection of the shaft.

What is axial load on a bearing?

Axial bearings, or thrust bearings, are designed to withstand force in the same direction as the shaft. This is called an axial load, or thrust load. In some applications, ceramic bearings, a type of radial bearing, are used to withstand high rotational speeds.

What is basic load rating on a bearing?

The basic dynamic load rating is the load which a bearing can theoretically endure for a basic rating life of one million revolutions. This is expressed as pure radial load for radial bearings and pure axial load for thrust bearings.

How do you read a SKF bearing number?

The first digit indicates the width or height series (dimensions B, T or H). The second digit identifies the diameter series (dimension D). The last two digits of the basic designation identify the size code of the bearing bore. The size code multiplied by 5 gives the bore diameter (d) in mm.

What is the bearing number?

A bearing number is composed of a basic number and a supplementary code, denoting bearing specifications including bearing type, boundary dimensions, running accuracy, and internal clearance. ... As well as these bearing numbers, JTEKT uses supplementary codes other than those provided by JIS.

How do you read a bearing code?

The first digit indicates the width or height series (dimensions B, T or H). The second digit identifies the diameter series (dimension D). The last two digits of the basic designation identify the size code of the bearing bore. The size code multiplied by 5 gives the bore diameter (d) in mm.