Screw rotor profile and method for generating
AssigneeAmerican Standard Inc.
InventorLaurenz Rinder
Life of this patent
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Abstract
A screw rotor profile for both male and female rotors is generated from a single rack in which each individual rack segment includes four discrete circular arc segments and two discrete straight line segments. The leading and trailing flanks of the lobes of both the male and female rotors generated by the rack include involute portions disposed between tangent circular-arc-generated portions. A method for developing the rack is also disclosed.
Claims19
A screw rotor having a plurality of lobes with convex flanks, where the profile of an individual lobe of the rotor in a plane transverse to the axis of the rotor comprises:
- a leading flank having a discrete involute portion disposed between discrete portions of trochoidal fillet;
- and
- a trailing flank having a discrete involute portion disposed between discrete portions of trochoidal fillet.
A screw rotor having a plurality of lobes with concave flanks, where the profile of an individual lobe of the rotor in a plane transverse to the axis of the rotor comprises:
- a leading flank having a discrete involute portion disposed between discrete portions of trochoidal fillet;
- and
- a trailing flank having a discrete involute portion disposed between discrete portions of trochoidal fillet.
A pair of cooperating male and female helical screw rotors having parallel axes, each of said rotors having a plurlity of lobes having leading and trailing flanks, each of said flanks on each of said lobes of each of said male and female rotor having a profile comprising a discrete involute portion disposed between discrete portions of trochoidal fillet.
Cooperating male and female screw rotors each having profiles, in a plane transverse to the axes of said rotors, generated from a single rack having a plurality of identical individual rack segments, each of the identical individudal rack segments having two straight line segments and four circular arc segments, the profiles of both said male and female rotors being generated as the line normal to each point on the rack passes through the pitch point of said rotors while the pitch circles of said rotors are rotated to drive said rack parallel to the pitch line of said rotors, the profile of each flank on each lobe of said male and female rotors including a discrete involute portion generated by a straight line rack segment disposed between discrete curved portions generated by two of said circular arc rack segments.
Dependencies are inferred from the claim text.