When inscribed die

摘要

PROBLEM TO BE SOLVED: To prevent the occurrence of trapping of a fluid and improve transfer efficiency.;SOLUTION: A first angle θ1 formed by a first straight line L1 and a second straight line L2 is made 1.4 or more times larger and 1.8 or less times or less smaller than a second angle θ2 formed by a third straight line L3 and the second straight line L2. The first straight line L1 connects a rotation center of an inner rotor 20 to an edge part 21d of external gear teeth 21 along the rotating direction F of both of the rotors 20, 30. Then the second straight line L2 connects the rotation center to the engagement part 21a of the external teeth 21, and the third straight line L3 connects the rotation center to the tooth bottom 21e of the external gear teeth 21.;COPYRIGHT: (C)2007,JPO&INPIT