Pair of co-operating screw rotors, a screw rotor and a rotary screw machine
First Claim
1. A pair of co-operating screw rotors, comprising:
- a male rotor having helically extending lobes and intermediate grooves; and
a female rotor having helically extending lobes and intermediate grooves which intermesh with the helically extending lobes and intermediate grooves of said male rotor;
wherein said male rotor has an external radius RM and a pitch radius RMP defining a pitch circle CMP ;
wherein each lobe of the male rotor in a predetermined section has a leading lobe flank and a trailing lobe flank which are substantially convex, said predetermined section being perpendicular to an axis OM of the male rotor and an axis OF of the female rotor;
wherein each lobe of the female rotor in said predetermined section has a leading lobe flank and a trailing lobe flank which are substantially concave;
wherein each lobe of the male rotor and each lobe of the female rotor has an asymmetric profile in said predetermined section;
wherein each of the leading flank and the trailing flank of at least one of the male rotor lobes has a male circular arc segment having a center of curvature A1M, A2M and a radius of curvature R1, R2, said center of curvature A1M, A2M being on the pitch circle CMP, and said radius of curvature R1, R2 deviating from a difference between the external radius RM of the male rotor and the pitch radius RMP of the male rotor;
wherein each of the leading flank and the trailing flank of at least one of the female rotor lobes has a female circular arc segment having a center of curvature A1F, A2F and the same radius of curvature R1, R2 as the male circular arc segment;
wherein said female circular arc segments cooperate with said male circular arc segments at a moment of contact therebetween; and
wherein the radius of curvature R1 of the leading flank of the male rotor lobe is in a range from 0.2 to 0.9 times the difference in radius between the external radius RM of the male rotor and the pitch radius RMP of the male rotor, and the radius of curvature R2 of the trailing flank of the male rotor lobe is in a range from 1.1 to 2.0 times the difference in radius between the external radius RM of the male rotor and the pitch radius RMP of the male rotor.
1 Assignment
0 Petitions
Accused Products
Abstract
A pair of co-operating screw rotors include a male rotor and a female rotor each having helically extending lobes and intermediate grooves which intermesh. The male rotor has an external radius RM and a pitch radius RMP defining a pitch circle CMP, and each lobe of the male rotor in a predetermined section has a leading lobe flank and a trailing lobe flank which are substantially convex. The predetermined section is perpendicular to an axis OM of the male rotor and an axis OF of the female rotor, and each lobe of the female rotor in the predetermined section has a leading lobe flank and a trailing lobe flank which are substantially concave. Each lobe of the male rotor and each lobe of the female rotor has an asymmetric profile in the predetermined section. Each of the leading flank and the trailing flank of at least one of the male rotor lobes has a male circular arc segment having a center of curvature A1M, A2M and a radius of curvature R1, R2. The center of curvature A1M, A2M is on the pitch circle CMP, and the radius of curvature R1, R2 deviates from a difference between the external radius RM of the male rotor and the pitch radius RMP of the male rotor. Each of the leading flank and trailing flank of at least one of the female rotor lobes has a female circular arc segment having a center of curvature A1F, A2F and the same radius of curvature R1, R2 as the male circular arc segment. The female circular arc segments cooperate with the male circular arc segments at a moment of contact therebetween.
19 Citations
28 Claims
-
1. A pair of co-operating screw rotors, comprising:
-
a male rotor having helically extending lobes and intermediate grooves; and a female rotor having helically extending lobes and intermediate grooves which intermesh with the helically extending lobes and intermediate grooves of said male rotor; wherein said male rotor has an external radius RM and a pitch radius RMP defining a pitch circle CMP ; wherein each lobe of the male rotor in a predetermined section has a leading lobe flank and a trailing lobe flank which are substantially convex, said predetermined section being perpendicular to an axis OM of the male rotor and an axis OF of the female rotor; wherein each lobe of the female rotor in said predetermined section has a leading lobe flank and a trailing lobe flank which are substantially concave; wherein each lobe of the male rotor and each lobe of the female rotor has an asymmetric profile in said predetermined section; wherein each of the leading flank and the trailing flank of at least one of the male rotor lobes has a male circular arc segment having a center of curvature A1M, A2M and a radius of curvature R1, R2, said center of curvature A1M, A2M being on the pitch circle CMP, and said radius of curvature R1, R2 deviating from a difference between the external radius RM of the male rotor and the pitch radius RMP of the male rotor; wherein each of the leading flank and the trailing flank of at least one of the female rotor lobes has a female circular arc segment having a center of curvature A1F, A2F and the same radius of curvature R1, R2 as the male circular arc segment; wherein said female circular arc segments cooperate with said male circular arc segments at a moment of contact therebetween; and wherein the radius of curvature R1 of the leading flank of the male rotor lobe is in a range from 0.2 to 0.9 times the difference in radius between the external radius RM of the male rotor and the pitch radius RMP of the male rotor, and the radius of curvature R2 of the trailing flank of the male rotor lobe is in a range from 1.1 to 2.0 times the difference in radius between the external radius RM of the male rotor and the pitch radius RMP of the male rotor. - View Dependent Claims (2)
-
-
3. A pair of co-operating screw rotors, comprising:
-
a male rotor having helically extending lobes and intermediate grooves; and a female rotor having helically extending lobes and intermediate grooves which intermesh with the helically extending lobes and intermediate grooves of said male rotor; wherein said male rotor has an external radius RM and a pitch radius RMP defining a pitch circle CMP ; wherein each lobe of the male rotor in a predetermined section has a leading lobe flank and a trailing lobe flank which are substantially convex, said predetermined section being perpendicular to an axis OM of the male rotor and an axis OF of the female rotor; wherein each lobe of the female rotor in said predetermined section has a leading lobe flank and a trailing lobe flank which are substantially concave; wherein each lobe of the male rotor and each lobe of the female rotor has an asymmetric profile in said predetermined section; wherein at least one predetermined flank of one of the male rotor lobes has a male circular arc segment having a center of curvature A1M, A2M and a radius of curvature R1, R2, said center of curvature A1M, A2M being on the pitch circle CMP, and said radius of curvature R1, R2 deviating from a difference between the external radius RM of the male rotor and the pitch radius RMP of the male rotor; wherein at least one predetermined flank of one of the female rotor lobes has a female circular arc segment having a center of curvature A1F, A2F and the same radius of curvature R1, R2 as the male circular arc segment; wherein said female circular arc segment cooperates with said male circular arc segment at a moment of contact therebetween; and wherein an angle β
F1, β
F2 formed in a plane perpendicular to the axis OM of the male rotor and the axis OF of the female rotor is greater than zero, said angle β
F1, β
F2 being defined as the angle between;
(i) a first line traversing the axis OF female rotor and the axis OM of the male rotor, and (ii) a second line traversing the axis OF of the female rotor and the center of curvature A1F, A2F of the female circular arc segment, when said first line traverses an innermost point of a groove between succeeding lobes of the female rotor. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
-
-
16. A pair of co-operating screw rotors, comprising:
-
a male rotor having helically extending lobes and intermediate grooves; and a female rotor having helically extending lobes and intermediate grooves which intermesh with the helically extending lobes and intermediate grooves of said male rotor; wherein said male rotor has an external radius RM and a pitch radius RMP defining a pitch circle CMP ; wherein each lobe of the male rotor in a predetermined section has a leading lobe flank and a trailing lobe flank which are substantially convex, said predetermined section being perpendicular to an axis OM of the male rotor and an axis OF of the female rotor; wherein each lobe of the female rotor in said predetermined section has a leading lobe flank and a trailing lobe flank which are substantially concave; wherein each lobe of the male rotor and each lobe of the female rotor has an asymmetric profile in said predetermined section; wherein at least one predetermined flank of one of the male rotor lobes has a male circular arc segment which at least at end portions thereof has a shape of a circular arc having a center of curvature A1M, A2M and an equal radius of curvature R1, R2, said center of curvature A1M, A2M being on the pitch circle CMP, and said radius of curvature R1, R2 deviating from a difference between the external radius RM of the male rotor and the pitch radius RMP of the male rotor; wherein at least one predetermined flank of one of the female rotor lobes has a female circular arc segment having a center of curvature A1F, A2F and the same radius of curvature R1, R2 as the male circular arc segment; wherein said female circular arc segment coincides with at least the end portions of said male circular arc segment at a moment of contact between said female circular arc segment and said male circular arc segment; and wherein an angle β
F1, β
F2 formed in a plane perpendicular to the axis OM of the male rotor and the axis OF of the female rotor is greater than zero, said angle β
F1, β
F2 being defined as the angle between;
(i) a first line traversing the axis OF female rotor and the axis OM of the male rotor, and (ii) a second line traversing the axis OF of the female rotor and the center of curvature A1F, A2F of the female circular arc segment, when said first line traverses an innermost point of a groove between succeeding lobes of the female rotor. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
-
Specification