Double-lobe type rotor design process

A double-lobe type rotor design process, being adapted for forming a defined rotor and a conjugate rotor intermeshing and conjugating to each other, comprising:

• a process for forming a defined rotor, including:
• designating maximum radius R and width D of the defined rotor, pitch circles of the defined rotor and the conjugate rotor with a pitch circle radius Rp and a first center t1 and a third center t3 respectively, wherein a distance between the center t1 and the third center t3 is 2Rp, the pitch circle radius Rp is smaller than R, and R is in appropriate ratio with respect to Rp;
• designating the first center t1 as a center of the defined rotor, a reference horizontal line h1 being defined through the first center t1 and the third center t3 as assistant line, a base point p0 on the reference horizontal line h1 being spaced a distance R from the first center t1, a conjugate curve E′ is created when the base point p0 rotating about the first center t1, a curve E being drawn symmetrically to the conjugate curve E′ about the tangent point p7 of the two pitch circles of defined rotor and conjugate rotor, the curve E serving as a portion of a first lobe of the defined rotor, third point p3 being the intersection of curve E and horizontal line h1;
• determining a first point p1 on a profile curve of the defined rotor 1 being defined by a first central angle α and the first center t1 and a radius of R, a first arc A being defined between the base point p0 and the first point p1 and smoothly connecting with the curve E;
• taking a second line h2 being defined by the reference horizontal line h1 and the first central angle α, a second center t2 being located on the second line h2 and being spaced a distance rB apart from the first point p1, rB being defined by a trigonometric function equation, a second arc B being defined with a center of t2 and a radius of rB and connecting with the first point p1 and a second point p2, the second point p2 being located on a vertical line through the second center t2 and over the second center t2, the second arc B serving as a portion of the first lobe of the defined rotor;
• taking the third center t3 of the pitch circle of the conjugate rotor 2 being located on the reference horizontal line h1 and being spaced a distance 2Rp apart from the first center t1, a fourth point p4 being defined by a second central angle β and a circle with a center of t3 and a radius of R, a third arc F being defined by connecting with the third point p3 and the fourth point p4;
• taking a third line h3 being defined by the reference horizontal line h1 and a second central angle β, a fourth center t4 being located on the third line h3 and being spaced a distance rC apart from the fourth point p4, rC being defined by a trigonometric function equation, a fourth arc C being defined with a center of t4 and a radius of rC and connecting with the fourth point p4 and a fifth point p5, the fifth point p5 being located on a vertical line through the fourth center t4 and under the fourth center t4;
• taking a second horizontal line Y being defined by connecting the second point p2 and a seventh point p6 which is symmetric to the fifth point p5 about the first center t1;
• connecting the curve E, the first arc A, the second arc B, the third arc F, the fourth arc C and the horizontal line Y together to form a profile of the first lobe of the defined rotor, a profile of a second lobe of the defined rotor being drawn symmetrically to the profile of the first lobe;
• a process for forming the conjugate rotor, including:
• creating the conjugate rotor by connecting respective conjugate curves of the curve E, the first arc A, the second arc B, the third arc F, the fourth arc C and the horizontal line Y.