Method of making screw rotor machine rotors
AssigneeJoy Manufacturing Company
InventorRobert A. Ingalls
Life of this patent
Estimating the term…
Abstract
Screw rotors for a screw compressor or expander incorporating improved screw profiles on both male and female rotors wherein certain mating portions of the two rotor screws have involute profiles to provide conjugate action of these screw portions with minimum sliding motion of such mating portions and with the remaining non-involute screw portions having generally circular arc profiles so that gear cutting and measuring techniques can be used in the production of such screw rotors.
Claims8
A method of producing a male rotor for a screw rotor machine comprising:
- hobbing a rotor blank to produce an elongated formed male rotor rotatable about a central longitudinal axis and having a pitch circle centered on such axis and a plurality of elongated helical lobes extending longitudinally of said rotor and circumferentially spaced about said pitch circle so as to provide intervening grooves therebetween with a major portion of each of said lobes extending generally radially outward from such pitch circle with the profile of each of said lobes in a plane perpendicular to such axis having a tip portion and respective generally convex leading and trailing flank portions extending intermediate said tip portion and the root portion of the respective adjacent groove;
- and
- forming of said hobbing process the profile of said leading flank portion of involute curvature extending between said respective root portion and an intermediate point and traversing said pitch circle, and a circular arc portion extending between said intermediate point and said tip portion with said circular arc portion formed of at least two circular arcs of different radii, and the profile of said trailing flank consisting of involute curvature extending between the other of said respective root portions and said tip portion and traversing said pitch circle.
A method of producing a female rotor for a screw rotor machine comprising:
- hobbing a rotor blank to produce an elongated formed female rotor rotatable by a central elongated axis and having a pitch circle centered on such axis and a plurality of elongated helical lobes extending longitudinally of said rotor and circumferentially spaced about said pitch circle so as to provide intervening grooves therebetween with a major portion of each of said lobes extending generally radially inwardly of said pitch circle, and the profile of each of said lobes in a plane perpendicular to said axis having a tip portion and respective generally concave leading and trailing flank portions extending intermediate said tip portion and the root portion of the respective adjacent groove;
- and
- forming by said hobbing process the profiles of each of said leading and trailing flank portions of involute curvature extending between said tip portion and respective intermediate point and traversing said pitch circle with a circular arc portion extending between said respective intermediate point and the root portion of said respective adjacent groove and said circular arc portion consisting of at least two circular arcs of different radii.
Dependencies are inferred from the claim text.