Speeds 
The calculation of reference speeds is standardised in 
Limiting speed 
The 
The limiting speeds indicated in the product tables must not be exceeded even under favourable operating conditions without prior consultation with Schaeffler. 
Thermal speed rating 

The thermal 
A speed limit taking account of the thermal balance can be calculated using the thermally safe operating speed. 
Reference conditions 
The reference conditions are based on the normal operating conditions of the most significant bearing types and sizes. 
They are defined as follows in 

for radial bearings, bearing seat Ar ≦ 50 000 mm2➤ Equation: 
for radial bearings, bearing seat Ar ＞ 50 000 mm2➤ Equation: 
for axial bearings, bearing seat Ar ≦ 50 000 mm2➤ Equation: 
for axial bearings, bearing seat Ar ＞ 50 000 mm2➤ Equation: 
The following lubricants and lubrication ╳ 

Thermally safe operating speed 

The permissible operating temperature ╳ 
The calculation method is not valid for: 


The 
Calculate thermally safe operating speed 

In order to calculate the thermally safe operating speed n_{ϑ} at a constant operating temperature ϑ, the frictional power generated and the total dissipated heat flow of the rolling bearing ╳ 

The generated frictional power of the rolling bearing ╳ 
The frictional power is equal to the dissipated heat flow 



The speed ratio f_{n} can be calculated by means of iteration or in the normal operating range of 
Figure 1 K_{L} = lubricant parameter K_{P} = load parameter 

The thermally safe operating speed n_{ϑ} is calculated by multiplying the thermal speed rating n_{ϑr} by the speed ratio f_{n} 

The lubricant ╳ 

The load ╳ 

Heat dissipation via the bearing seating surfaces ╳ 
Figure 2 A_{S} = heatdissipating bearing seating surface Reference condition for axial bearings Reference condition for radial bearings 

Heat dissipation via the lubricant ╳ 

