The thermal reference speed according (ISO 15312, 2003) and the thermal permissible speed according (DIN 732, 2010) are calculated by the software. The calculation can be run separately under menu ‘Calculation’->’Thermal permissible speed’.
Most of the parameters can be overwritten by the user. Note that the calculation is just according to the standard. The equivalent load is calculated by axial and radial load, moment load is not considered. Also clearance is not considered.
For the thermal permissible speed in addition to DIN 732, the friction forces can be derived from ISO 14179-2. The ISO standard provides different factors for grease and oil lubrication. As default the lubricant temperature as defined in the main window is used. Clearing the option "Assume fixed temperature for lubricant" uses the bearing temperature for the oil viscosity. The bearing temperature is the temperature of bearing surroundings plus temperature increase for the bearing.
If a bearing geometry is not considered in the standard, the input values for f0r, f1r and f1 can be entered by the user and the calculation can be run.
The results for thermal reference speed and for thermal permissible speed are also shown in the main report.