Patent ID: 7540728

Claim:
A method of transforming a motion in a volume screw machine, said machine having at least two sets of conjugated elements ( 80 , 70 ; 60 , 50 ), each of the sets further comprising: a first element ( 80 , 60 ) having an inner screw surface ( 180 , 160 ) centered around a first axis passing through center O; and a second element ( 70 , 50 ) having an outer screw surface ( 270 , 250 ) centered around a second axis passing through centers Om 2 , Om 1 of the respective set of conjugate elements, wherein the first element has a symmetry order n f =3 and the second element has symmetry order n m =2, wherein an inner set ( 50 , 60 ) of the conjugated elements is placed coaxially in at least one cavity of the second element of an outer set ( 80 , 70 ) of conjugated elements, wherein the first and second axes passing through the centers O, Om 1 , and Om 2 are parallel and distances E 1 and E 2 , from the respective second axes, are offset in opposite directions relative to the center O, wherein at least one of said first and second elements of each set is rotatable about its axis, said method comprising: creating a rotary motion of at least one element in each of the sets.