| 摘要 |
PURPOSE:To make it possible to measure an accurate flow rate, by specifying the profile curves of an internal gear and an external gear, reducing a slip ratio, thereby obtaining substantially perfect rolling contact. CONSTITUTION:A rotary piston is constituted of an internal gear 1, which has a pitch curve of N lobes and constitutes a cabinet, and an external gear 4, which operates as a valve for output and input ports 2a and 3a of the cabinet and has the pitch curve of (N-1) lobes. The profile of the internal gear 1 is determined by the envelop of the small curve, which is protruded to the outside of the pitch curve around the top of the pitch curve of the external gear 4, and the pitch curve of the external gear 4. Said small curve is obtained when the pitch curve of the external gear 4 rolls on the pitch curve of the internal gear 1 without slipping. The profile of the external gear 4 is determined by the envelop of the profile of the internal gear 1, which is drawn on a plane fixed to the external gear 4. |
