Brake Calculations
Information courtesy of
Torque at brake disk
MB = ML + MR
Load Torque : ML = m * g (vO/ωO) = ............. Nm
Braking Torque : MB = SF * ML = ...............Nm
Retardation Torque : MR = MB - ML = .............Nm
Safety factor MB / ML > 2 SF = ...............(MB) Installed braking torque.
MB = Fb * (D0 - 0.22) / 2 This value is only valid for BSFG400 and BSFH500, for other values see table below.
| Svendborg Model |
W |
| BSFH200 BSFI200 |
0.068 |
| BSFH300 BSFI300 |
0.13 |
| BSFG400 BSFH500 |
0.22 |
| BSFI3000 | 0.20 |
| BSFA600 | 0.30 |
In a closed mechanical system the following relationship are valid for Power = P = F * vO = M * ωO.
The relationship between Force and Torque is then :F * (vO / ωO) = M
This equation can be used to calculate the load torque (ML) on the braked shaft.
ML = m * g * (vO / ωO)
Note: inclined plane
Specific standards and safety regulations sometimes stipulate the value of SF to be used.
Data required: Maximum load torque ML
Safely factor SFThe factor SF is generally chosen between 1.75 and 3.
For the lifting machinery of cranes, the factor is usually chosen > 2.Load torque as calculation basis.
In lifting machinery, the maximum load torque ML will decide the choice of braking torque MB.
MB = SF * ML (Nm)
