| 摘要 |
PURPOSE:To increase the strength of a runner used in a hydraulic machine, by forming rib plates on the surfaces of a runner crown and a runner band to extend in the radial and circumferential directions, and selecting the thickness of the radial rib plates and that of the circumferential rib plates to take particular different ratios respectively to the thickness of a cover plate. CONSTITUTION:A runner is composed of a runner crown 2a, a runner band 2b and a plurality of runner blades 2c held between the runner crown 2a and the runner band 2b. A plurality of rib plates 3 are arranged on the surfaces of the runner crown 2a and the runner band 2b to extend in the radial and circumferential directions, in the manner of forming a grid-like structure, and the opening of each grid is covered by a cover plate 4. Here, providing that the thickness of the cover plates 4 is T, the thickness tR of the radial rib plates is selected to satisfy the following relationship, tR>=(2T)<1/2>, and the thickness tC of the circumferential rib plates is selected to satisfy the following relationship, tc>=T. |
