Using a JSM-5610LV scanning electron microscope (SEM), the microstructures and morphologies at the position of the tooth top, the dividing circle, and the dedendum of the tooth section in two groups were observed.
In the images, from top to bottom, the position of addendum, pitch, and dedendum are at the distances of 0.1mm, 0.5 mm, and 0.9 mm, from left to right.
The degree of grain deformation at the pitch position is between those at the dedendum and addendum.
The residual stress is larger at the dedendum than are those at the pitch and the addendum, and it is smallest at the addendum.
As shown in Figure 14, the peak residual compressive stress of the spline at the dedendum is larger than the peak residual compressive stress at the pitch.
As shown in Figure 15, at different rotational speeds, the peak residual compressive stress at the dedendum, pitch, and the addendum of the cold rolling spline increased with an increase in the feed rate.
As shown in Figure 16, within the range of the cold roll-beating rotational speed and spline feed rate in the experiment, the residual compressive stress layer depth in the superficial spline profile in cold roll-beating indicates that the residual compressive stress layer depth at the dedendum is deeper than the residual compressive stress layer depth at the pitch.
(4), the equation for asymmetric tooth thickness at any portion along the face width of the bevel gear at any circle like, addendum, dedendum and pitch circle can be obtained as,
Where i=1, 2 (i=1 for pinion and i=2 for gear) j = A, P, D (A- Addendum circle, P- Pitch circle, D- Dedendum circle) and b = Face width, B =cone distance of the bevel gear.