| 摘要 |
PROBLEM TO BE SOLVED: To solve problems of improper rotation balance and the deterioration of sealing performance while avoiding needless work in a screw pump. SOLUTION: On a first thread-number changing surface 38, a first curve A1C1 is shifted for an angular differenceαo from a third curve 46A to a rear side of a rotation direction W of a first screw rotor, and on the first thread number changing surface 38, the angular differenceαo is smaller than an angleθ1 formed of a line L11 connecting one end 422A of a two-thread outer peripheral part 42A and a center point P1 and a line L12 connecting the other end 421A of the two-thread outer peripheral part 42A and the center point P1. Furthermore, on a second thread-number changing surface 39, the angular differenceαo is smaller than an angleθ2 formed of a line L21 connecting one end 422B of a two-thread outer peripheral part 42B and a center point P2 and a line L22 connecting the other end 421B of the two-thread outer peripheral part 42B and the center point P2. COPYRIGHT: (C)2011,JPO&INPIT |
