| 摘要 |
The invention relates to a wheel (R) of the Francis type that comprises a ring (1) with revolution symmetry about the rotation axis (Z) of the wheel (R), and curved blades (21, 22) connected to the ring (1) and each having an outer peripheral edge (212, 222) and an inner central edge (211, 221). The connection points (B21, B22) between the ring (1) and the inner central edges (211, 221) of the blades (21, 22) are located on a same circle (C20) centered on the axis (Z). The connection points (A21, A22) between the ring (1) and the outer peripheral edges (212, 222) of the blades (21, 22) are located on at least two distinct circles (C21, C22) (D21, D22) centered on the axis (Z). |
