Stock Gear Catalog - Online Version > Design Considerations: Bearing Loads

Tangential Load Coefficients for Bearing Loads
The normal load on spiral bevel gear tooth surfaces may be resolved into three (3) components: (Wt) tangential; (Wx) axial and (Wr) radial.

The tangential and radial components act in a plane perpendicular to the gear axis and produce radial bearing loads. The axial component acts in a direction parallel to the axis producing thrust plus additional radial bearing loads.

The value of the axial and radial loads can be determined by multiplying the tangential load at mid face (Wtm) by the applicable coefficient (Kx) or (Kr) for the concave or convex load face of either the pinion (p) or the gear (g).

Fig. 24 is a table of coefficients (Kx) and (Kr) vs. gear ratios for 35 degree spiral bevel gears with 90 degree shaft angles and 20 degree pressure angle. Note the (+) values indicate forces tending to separate the two gears and the (-) values indicate forces drawing the gears into tighter mesh.