Gapless screw rotor device

A screw rotor device for positive displacement of a working fluid, comprising:

• a female rotor comprising a major diameter and a helical groove receding from said major diameter, said helical groove comprising a bottom land situated between a leading side and a trailing side, said leading side and said trailing side respectively comprising a leading ridge and a trailing ridge at said major diameter;
• and
• a male rotor comprising a minor diameter and a helical thread extending from said minor diameter and rotatably intermeshing in phase with said helical groove, said helical thread comprising a top land situated between a leading face and a trailing face, said leading face and said trailing face comprising a leading edge and a trailing edge, respectively, wherein said top land is in a first sealing relationship with said bottom land, wherein said trailing face is in a second sealing relationship with said trailing ridge, wherein said trailing edge is in a third sealing relationship with said trailing side, wherein said leading face is in a fourth sealing relationship with said leading ridge, wherein said leading edge is in a fifth sealing relationship with said leading side;
• and
• a housing enclosing said female rotor and said male rotor, said housing comprising a front side, a back side, a first end, a second end, an inlet port, an outlet port, and a pair of cylindrical bores extending between said first end and said second end along a length of said front side and said back side, said pair of cylindrical bores comprising a front cusp extending along said length of said front side and a back cusp extending along said length of said back side of said housing, wherein said third sealing relationship and said fifth sealing relationship are connected through said first sealing relationship at said bottom land and respectively extend continuously to said bottom land along said trailing side and said leading side from said front cusp and said back cusp, said front cusp and said back cusp being in close tolerance with said major diameter of said female rotor.

A screw rotor product for positive displacement of a working fluid, comprising:

• a housing comprising a first end, a second end, an inlet port, an outlet port, and a pair of cylindrical bores extending between said first end and said second end, said pair of cylindrical bores comprising a front cusp extending along a length of a front side of said housing and a back cusp extending along a length of a back side of said housing;
• a female rotor comprising a major diameter and a helical groove receding from said major diameter, said helical groove comprising a bottom land situated between a leading side and a trailing side, said female rotor being rotatably mounted in said housing with said major diameter in close tolerance with one of said pair of cylindrical bores to form a first peripheral sealing area;
• and
• a male rotor comprising a minor diameter and a helical thread extending from said minor diameter, said male rotor rotatably mounted in said housing, said helical thread comprising a top land situated between a leading face and a trailing face, a cross-sectional profile of said helical thread respectively comprising a top land line situated between a leading line and a trailing line, said leading line and said trailing line being selected from a group consisting of a concave line, a straight line, a convex line, and any combination thereof, said top land being in close tolerance with another one of said pair of cylindrical bores to form a second peripheral sealing area, said helical thread intermeshing in phase and in close tolerance with said helical groove to form an intermeshing sealing area, said intermeshing sealing area extending continuously from a back region at a back intersection between said leading face, said leading side, and said back cusp to a front region at a front intersection between said trailing face, said trailing side and said front cusp.

A screw rotor system for positive displacement of a working fluid, comprising:

• a housing comprising a first end, a second end, an inlet port, an outlet port, and a pair of cylindrical bores extending between said first end and said second end, said pair of cylindrical bores comprising a first cusp extending along a length of a first side of said housing and a second cusp extending along a length of a second side of said housing;
• a female rotor comprising a major diameter and a helical groove receding from said major diameter, said helical groove comprising a bottom land situated between a leading side and a trailing side, said leading side and said trailing side comprising a leading ridge and a trailing ridge at said major diameter, said major diameter being in a first sealing relationship with one of said pair of cylindrical bores;
• and
• a male rotor comprising a minor diameter and a helical thread extending from said minor diameter and rotatably intermeshing in phase with said helical groove within said housing, said minor diameter being in a second sealing relationship with said major diameter of said female rotor, said helical thread comprising a top land in a third sealing relationship with another of said pair of cylindrical bores, wherein said top land is also in a fourth sealing relationship with said bottom land, said top land being situated between a leading face and a trailing face, said trailing face being in a fifth sealing relationship with said trailing ridge, said trailing face further comprising a trailing edge in a sixth sealing relationship with said trailing side, wherein said trailing ridge and said trailing edge are in a seventh sealing relationship with each other and with said first cusp of said pair of cylindrical bores.

A screw rotor product for positive displacement of a working fluid, comprising:

• a housing comprising an inlet port at a first end and an outlet port at a second end and a pair of cylindrical bores extending therebetween, said pair of cylindrical bores comprising a front cusp extending along a length of a front side of said housing and a back cusp extending along a length of a back side of said housing;
• a female rotor comprising a major diameter and a plurality of helical grooves receding from said major diameter to a bottom land diameter, wherein said female rotor is rotatably mounted within said first end and said second end of said housing and wherein said major diameter is in close tolerance with said housing;
• and
• a male rotor comprising a minor diameter and a plurality of helical threads extending from said minor diameter to a top land diameter, wherein said male rotor is rotatably mounted within said housing and counter-rotates with respect to said female rotor, wherein said top land diameter is in close tolerance with said housing, wherein said plurality of threads are identical in number with said plurality of grooves and intermesh in phase with each other in a plurality of thread-groove pairs, each of said thread-groove pairs defining an intermeshing sealing area extending continuously from a back intersection defined by said female rotor major diameter and said top land diameter simultaneously in close tolerance with said back cusp to a front intersection defined by said female rotor major diameter and said top land diameter simultaneously in close tolerance with said front cusp, and wherein said thread-groove pairs bound a plurality of non-communicating spaces within said cylindrical bores, seal the working fluid within said housing, and transition between meshing with each other and sealing around said housing while maintaining said sealing of the working fluid in said non-communicating spaces.

A screw rotor product for positive displacement of a working fluid, comprising:

• a housing comprising an inlet port, an outlet port, and a pair of cylindrical bores, said pair of cylindrical bores comprising a front cusp extending along a length of a front side of said housing and a back cusp extending along a length of a back side of said housing;
• a female rotor comprising at least one helical groove receding from a ridge at a major diameter to a bottom land, wherein said female rotor is rotatably mounted within said housing;
• and
• a male rotor comprising at least one helical thread extending from a root at a minor diameter to a top land, wherein said male rotor is rotatably mounted within said housing and counter-rotates with respect to said female rotor, wherein said helical thread intermeshes in phase with said helical groove and defines an intermeshing sealing area extending continuously between said helical thread and said helical groove from said back cusp to said front cusp, wherein at least one of a front blow hole and a back blow hole is not provided between said helical thread, said helical groove, said front cusp, and said back cusp, and wherein said major diameter of said female rotor and said minor diameter of said male rotor define a non-intermeshing sealing area extending between said male rotor and said female rotor from a seal at said ridge and said root.