| 摘要 |
A groove wall of a roller support groove opened to both end faces of a pump wheel comprises such a cam face wherein a roller rotates and rolls and is displaced from release operation position a to pump operation position b with rotation of the pump wheel in a pump operation direction from a release operation state and wherein the roller remains immobile and is displaced from the pump operation position b to the release operation position a with rotation of the pump wheel in a release operation direction from a pump operation state. |
