Permissible speed

For polymer deep groove ball bearings, the limiting speed (→ product table) is to be used as the determining factor to estimate the permissible speed.
The permissible speed depends on the applied load and the operating temperature. When both values are known, the adjustment factor for speed fn can be calculated using

fnadjustment factor for speed
Papplied bearing load [kN]
fTadjustment factor for temperature (diagram 1)
Climdynamic load limit [kN] (→ product table)

Starting with the calculated adjustment factor for speed fn from the y-axis (diagram 1), the percentage of the limiting speed can be determined and the permissible speed can be calculated.

Calculation example

  • Input data
    Bearing 6301/HR11TN, P = 0,245 kN, T = 90 °C (195 °F)
  • Calculate the adjustment factor for speed fn

    From the product table:
    Clim = 0,31 kN
    From diagram 1:
    With T = 90 °C (195 °F) and rings made of POM → fT ≈ 0,87

  • Calculate the permissible speed
    From the product table:

    nlim= 1 300 r/min
    From diagram 1:
    With fn= 0,91 and rings made of POM the percentage of nlim ≈ 40%

permissible speed [r/min]
limiting speed [r/min] (→ product table)

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