| 摘要 |
PURPOSE:To improve the vibratory strength of the runner of a Francis type hydraulic machinery by forming annular projections concentric with the runner on the opposite side to the intermediate runner vane of one of a runner crown and a runner band. CONSTITUTION:Annular projections 2a2 and 2b2 having a width of B L/3 are formed on the opposite side to a runner vane 2c in the intermediate part having a length L on the outer peripheral side from the seal rings 2a1 and 2b1 of a runner crown 2a and a runner band 2b respectively. Each thickness tma, tmb of the annular projections 2a2 and 2b2 satisfies the following equation: tma>=1.5ta, tmb>=1.5tb, with each thickness ta, tb at the outer peripheral edge of the runner crown 2a and the runner band 2b, and each thickness ta, tb is determined within a range for permitting the projections to be accommodated into a runner chamber 5. |
