Abstract: Helical screw rotors for a screw rotor machine wherein, for both the male and female rotor, the rotor profile includes involute curves for the male and female rotor lobe tip portion and rotor root portion, thereby generating mating involute curved surfaces of the corresponding groove, root and tip portion for the female rotor, resulting in low leakage path between the high and low pressure volumes when the rotors are in mesh, and causing ramps on the lobe tips of both the male and female rotors to form high points thereof which act as sealing strips during intermesh rotation of the rotors and in conjunction with the screw rotor machine casing.

Abstract: Helical screw rotors for a screw rotor machine wherein, for both the male and female rotor, the rotor profile includes involute curves for the male and female rotor lobe tip portion and rotor root portion, thereby generating mating involute curved surfaces of the corresponding groove, root and tip portion for the female rotor, resulting in low leakage path between the high and low pressure volumes when the rotors are in mesh, and causing ramps on the lobe tips of both the male and female rotors to form high points thereof which act as sealing strips during intermesh rotation of the rotors and in conjunction with the screw rotor machine casing.

Abstract: Helical screw rotors for a screw rotor machine having improved profiles on both male and female rotors, wherein the female rotor leading and trailing flanks comprise first and second circular arcs with the first circular arc subscribed by a first radius whose center lies inside the pitch circle and a second circular arc subscribed by a second radius whose center also lies inside the pitch circle. The leading and trailing flank portions of the male rotor are travel generated by first and second radii on the female rotor resulting in effective driving and driven lobe surfaces on the leading and trailing lobe surfaces. This also results in minimized blowholes and effective sealing surfaces on the intake and discharge sides of the screw rotor machine. The female rotor lobes have a main peripheral surface defined by a true circular arc swung from the axis of the female rotor.

Abstract: Helical screw rotors for a screw rotor machine having improved asymmetric screw profiles on both male and female rotors, wherein the male rotor lobe leading flank comprises solely first and second circular arcs with the first circular arc subscribed by a first radius which lies on a radial line through the male rotor center at an offset angle to the male rotor lobe center line in the direction of the trailing flank of the rotor lobe to create a male rotor tip point inherently including a male rotor lobe sealing strip.

Abstract: An improved screw compressor for the compression and axial displacement of a gas is set forth. The compressor is of the type having a housing formed with an axially extending passage. The axially extending passage has at one axial end thereof a gas inlet and at the other axial end thereof a gas outlet. A one piece male rotor is positioned in the passage and extends axially therein. The male rotor is formed with a plurality of helical ribs having generally convex flanks and root regions which are at least partially formed as involutes in cross section. Each rib of the male rotor has a profile consisting of a leading flank formed at least partially as an involute generated from a first base circle and a trailing flank at least partially formed as an involute generated from a second base circle. The second base circle has a diameter greater than the first base circle.

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.

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.