# Wheel bearing calculation

> [HTML Version](wheel-bearing-calculation.html)

The wheel bearing calculation allows a calculation for wheel bearings with special inputs for the loading.  The load is defined by inputs for the load on axis as mass 'ma', a wheel radius 'rW' and an offset from load position to bearing center 'dx'.

**(./images/WheelBearingGUI.png)**

The default cycle is defined by a radial force factor 'fr', an axial force factor 'fa', a rotation speed 'n' and the number of rotations.  
If the wheel is connected to the inner ring the load spectrum forces are defined as:

$F_x = f_a\cdot m_a\cdot(9.81/2) \\	F_y = f_r\cdot m_a\cdot(9.81/2) \\	M_z = 0.001\cdot(-F_y\cdot \delta_x + F_x\cdot r_W)$

If the wheel is connected to the outer ring, the opposite sign is used.

The life factor 'fL' is defined as $f_L=(L_{10rh}/500)^{1/p}$ so it is a safety factor proportional to the load and 1.0 for 500h.

A graphic is shown for a variation of the axial offset and three axis loads to see the sensitivity of the results:

**(./images/WheelBearingGraphic.png)**