Patent ID: 8128389
Filing Date: 2012-03-06
Classification: F01C

Abstract:
1. A positive-displacement machine design comprising a stator, a rotor eccentrically installed in the stator, a planetary train composed of a large gear and a small gear, where the large gear is fixedly arranged from the outside of the small gear and in engagement therewith, the small gear being made with the possibility of running around the large gear of the planetary train, the stator is connected to the large gear, and the rotor is connected to the small gear of the planetary train, the external surface profile of the rotor in its cross section is an envelope of a straight line family, and the straight line y z , which generates the said family, is fixedly connected to the large gear and is set, in the O 1 X 1 Y 1 coordinate system the beginning of which is at the center of the large gear, by the following equation: where: A is the inclination angle of the straight line y z to the axis O 1 X 1 , (0≦A≦π); x B is the inclination angle of a section connecting the beginning O a is length of the section connecting the beginning O and the profile is made in accordance with the following parametric equation: where: x, y are current coordinates of the profile points along the axes X, Y of the OXY Cartesian coordinate system the beginning of which is at the center of the small gear; e is an eccentricity value; z is an engagement parameter, z=2, 3 . . . ; α=(z+1)Ψ, Ψ is a rotation angle of the large gear relative to the small gear, which is counted from the X axis in the OXY coordinate system the beginning of which is at the center of the small gear, serving as a parameter, 0≦Ψ≦2π, a* is a form parameter defined as a*=a/e and satisfying the following condition: and the inner surface profile of the stator in its cross section is made of z+1 rectilinear sections, each of them made corresponding to the following parametric equation: where: x k=0, 1, . . . z is the number of a rectilinear section, χ is a rotation angle of the small gear relative to the large gear, which is counted from the axis X where adjacent rectilinear sections of the stator profile are conjugated between them by z+1 curvilinear sections, each of the latter being made as an arch corresponding either to the following parametric equation: where x′, y′ are current coordinates of the conjugating arches along the axes O θ is parameter defined on the section if k is an even number and B−A<0, or if k is an odd number and B−A>0; or θ is parameter defined on the section if z is an even number, k is an odd number and B−A<0, or if z is an even number, k if an odd number and B−A>0, or to the following parametric equation: where: θ is parameter defined on the section if z is an odd number, k is an odd number and B−A<0; or θ is parameter defined on the section if z is an odd number, k if an even number and B−A>0.