| 摘要 |
PURPOSE:To prevent cavitation, by providing recessed parts each of which is opened both to the inner circumferential surface of an outer rotor and to the end surface in such a position as the central part of tooth space between the effective engaging part of the circular arc tooth for an inner rotor and a circular arc tooth is avoided. CONSTITUTION:The tooth height of an inner rotor 3 is made equal to that of an outer rotor 1. In the outer rotor 1, recessed parts 5 each of which is opened both to the inner circumferential surface of the rotor and to the end surface are provided. Each recessed part 5 is provided in the outer rotor 1 in such a position as the central part of tooth space between the effective engaging part of the circular arc tooth 2 for the inner rotor 3 and the circular arc tooth is avoided. Thus, the cavitation attributable to the insufficiency in the inlet area of a pumping chamber can be prevented. |
