Static and dynamic application factors fAs and fAd

Static and dynamic application factors f_As and f_Ad

The ratio of the braking torque to the load torque of the application, which is important for ensuring proper brake function, is defined for brakes on servomotors using 2 application factors:

• Static application factor f_As
• The factor represents the ratio between the static characteristic value M_4,100°C and the static load torque M_L (referenced to the motor shaft). By definition, the factor f_As always assumes a value of >> 1 and describes the limit state required to reliably hold a static load at standstill.
• Dynamic application factor f_Ad
• The factor represents the ratio between the dynamic characteristic value M₁ and the static load torque M_L (referenced to the motor shaft). By definition, the factor f_Ad always assumes a value of >> 1 and describes the limit state that is required to reliably bring a moving application with a defined dynamic load to a standstill.

The term "reliable" is to be understood in the statistical sense. Intended use of the brakes requires compliance with the specified minimum factors f_As and f_Ad as well as with all other conditions specified in the project planning specifications and the operating instructions.

You can find a table with values for the application factors f_As and f_Ad in the technical data under "Static and dynamic application factors f_As and f_Ad"  .

Neither factor is a safety factor in the true sense. This definition would require the failure limit to be 1. By contrast, f_As and f_Ad are to be regarded as mandatory dimensioning factors; i.e., the onset of functional failure may also occur at values > 1.

If the actual values fall below the specified minimum values for f_As and f_Ad, the characteristic safety values B_10D no longer apply to the use case.