Factor for tooth root stress

The factor for root loading is made up of the following individual factors:

${\mathrm{K}}_{\mathrm{F}}={\mathrm{K}}_{\mathrm{A}}·{\mathrm{K}}_{\mathrm{\nu }}·{\mathrm{K}}_{\mathrm{F\beta }}·{\mathrm{K}}_{\mathrm{F\alpha }}$

Due to the elastic properties of thermoplastics, the following simplifications can be made:

${\mathrm{K}}_{\mathrm{F}}\approx {\mathrm{K}}_{\mathrm{A}}$

Requirement:

$\frac{\mathrm{b}}{{\mathrm{m}}_{\mathrm{n}}}\le 12$

If the width of the gear is further increased, effects occur in the load distribution over the face width due to the deformation of the shaft-bearing system.

These effects can be taken into account via K_Fβ. For this purpose, the entry "K_F = K_A * K_Fbeta (analytical load distribution) can be selected from the list and the shaft-bearing system can be specified.

Source: VDI 2736 Part 2 (2014), Section 3.2.2