e

eccentricity

yin-e

y-coordinate of epicycloidal curve of inner rotor

re

radius of rolling circle of epicycloid

yin-h

y-coordinate of hypocycloidal curve of inner rotor

rh

radius of rolling circle of hypocycloid

yin

y-coordinate of inner rotor profile

R1

radius of pitch circle of inner rotor

yout

y-coordinate of outer rotor profile

R2

radius of pitch circle of outer rotor

Z1

lobe number of inner rotor

xin-e

x-coordinate of epicycloidal curve of inner rotor

Z2

lobe number of outer rotor

xin-h

x-coordinate of hypocycloidal curve of inner rotor

β

parameter of epicycloid or hypocycloid

xin

x-coordinate of inner rotor profile

θ

rotary angle of inner rotor center

xout

x-coordinate of outer rotor profile