For a Sun-Planet mesh in a planetary gear train, there will be a deflection $\delta_{sn}=\delta_{s}-\delta_{n}$ along the pressure line and the position of the planet will be determined by $\psi_{n}$, and by looking at the geometry of the picture the sun-planet mesh angle will be $\psi_{sn}=\psi_{sn}-\alpha_s$, where $\alpha_s$ is the pressure angle of the gears.
As for the Planet-Ring mesh, I can't find any literature defining the deflection and meshing angles, considering the ring is an internal gear, how would the geometry work here?
