As a manufacturer of high precision rolling bearings and partner to our customers for customised solutions in small and large quantities, we offer you a professional bearing design service as part of a shaft calculation.

The calculation software is specially designed to map spindles, motor spindles, electric motors, screw compressors and many other applications via shaft systems and to carry out a well-founded service life calculation with IBC rolling bearings.

For more information you can download the document Lifetime Calculation here

Failures can occur even under appropriate operating conditions and correct mounting. This is because the lifetime of high precision rolling bearings is limited by a wide variety of influences. For example, material fatigue, vibrations, contamination or lubricant failure can occur during the lifetime.

This does not take into account causes that can lead to the failure of the high precision rolling bearing without significant advance notice. These include, for example, design faults, inadequate maintenance, installation errors and incorrect bearing design.

Fatigue

Fatigue of the high precision rolling bearing material is caused by the swelling stress on the material when high precision rolling bearings rotate under load. At the end of the running time, ‘pitting’ occurs in the running surfaces or on the rolling elements, which can result in progressive peeling or pitting of the material. Numerous factors are involved in the fatigue of the material, meaning that these can only be determined statistically. The definition of a theoretical comparative value ‘fatigue life’ therefore refers to a very large number of similar rolling bearings running under the same conditions. The fatigue life is reached when 10% of the rolling bearings have failed. It can be related to the running time in hours or the number of revolutions. In addition to the fatigue life, the lifetime of the lubricant is also decisive for the high-precision rolling bearing. Separate calculation rules apply here. Other parameters can also be decisive for the lifetime of permanently monitored high precision rolling bearings. These include, for example, temperature, bearing noise and vibrations.

Nominal lifetime 

By definition, 10% of a large number of similar high precision rolling bearings can fail within the basic nominal lifetime L₁₀ under similar operating conditions. The basic nominal lifetime can also be specified as the time L_10,h at constant speed.

Basic dynamic load rating

The dynamic load rating C is the constant load on a high precision rolling bearing with a rotating inner ring at which 1 million revolutions are achieved with a 90% probability. It is considered to be a centric radial load that is constant in size and direction. On the basis of numerous tests, it is a parameter that can be calculated according to empirical rules.

Basic static load rating 

The static load carrying capacity of a high precision rolling bearing is described by the static load rating C_o. It is the load that the static high precision rolling bearing can withstand with a permanent plastic deformation of a maximum of 1/10,000 of the rolling element diameter.

Further information can be found in the document ‘Lifetime calculation’ which can be downloaded here.