Method and apparatus for machining scroll wraps

A method of machining the respective involute wrap faces of a complementary pair of fixed and orbiting scroll members for use in a scroll compressor, comprising the steps of:

• holding the fixed and orbiting scroll members in fixed relationship to one another such that they are axially aligned and their respective involute wrap faces face in axially opposite directions;
• engaging the involute wrap faces of the fixed and orbiting scroll members with a respective pair of cutting tools, each of said pair of cutting tools facing a respective involute wrap face of the fixed and orbiting scroll members;
• and
• simultaneously rotating the fixed and orbiting scroll members and causing relative linear movement of said pair of cutting tools and the fixed and orbiting scroll members.

A matched scroll member pair having respective predetermined involute wrap geometries that seal along a radially inwardly moving sealing line of contact when said scroll member pair are operably intermeshed and one scroll member is orbited relative the other, wherein random deviations from said respective predetermined involute wrap geometries are complementary, thereby enhancing the seal between the scroll members, said matched scroll member pair being manufactured by a process comprising the steps of:

• holding said scroll member pair in respective generally axially aligned positions such that respective wrap surfaces of said scroll member pair face in axially opposite directions;
• engaging said wrap surfaces of said scroll member pair with a respective pair of cutting tools, each of said pair of cutting tools facing a respective wrap surface of said scroll member pair;
• and
• moving said scroll member pair and said pair of cutting tools relative one another to simultaneously cut said predetermined involute wrap geometry in each of said scroll member pair, such that throughout said relative movement said pair of cutting tools simultaneously engage respective portions of said wrap surfaces of said scroll member pair that form said radially inwardly moving line of contact when said scroll member pair are operably engaged.

A method of machining the respective involute wrap faces of a scroll for use in a scroll compressor, wherein the involute wrap geometry is generally formed by the combined linear travel of a cutting tool and rotational and linear movement of the scroll member, the scroll member being rotated about the center of a wrap circle generally defining the involute wrap geometry and the cutting tool being moved relatively linearly comprising the steps of:

• moving the scroll member to an angular position dependent upon the desired location of an inner valve tip of the involute wrap and the diameter of the cutting tool while the cutting tool remains out of cutting engagement with said scroll member;
• moving the cutting tool linearly into cutting engagement with the involute wrap while said scroll member remains stationary in a rotational sense, thereby forming a flat surface between an inner wall and an outer wall of the involute wrap;
• machining the desired involute into respective involute wrap faces of said scroll member;
• and
• machining an outer wall of the involute wrap such that an intersection of the machined outer wall and the flat surface defines the radially innermost valve tip of the involute wrap of said scroll member.