A hydraulic machine has a runner of the Francis type, a head cover and a lower cover. A crown has a seal that seals the space between the crown and the head cover against water from the high pressure side. The runner is formed with at least one passage that is capable to drain high pressure leakage water passing the seal to the low pressure side. The passage is formed with an inlet aperture located in a portion of the crown which during operation is exposed to high pressure leakage water. The passage is located within one of the blades and leads from the inlet aperture to the band, where the passage forms an opening leading to the space between the band and the lower cover. The head cover is formed with an air inlet to admit air to the chamber between the head cover and the crown.

A hydraulic turbine includes a rotor with a runner, which is concentrically surrounded by a stator, whereby the runner comprises a plurality of runner blades arranged and distributed in a ring around a rotor axis, and each runner blade extends between a runner crown and a runner band; whereby the stator comprises a plurality of guide vanes arranged and distributed in a ring around the rotor axis, and each guide vane extends between an upper stator ring and a lower stator ring; and whereby a predetermined clearance is provided at least between the runner band and the lower stator ring. A substantial reduction of pressure pulsations in the vane-less gap between said runner blades of said runner is achieved by substantially increasing said predetermined clearance.

The invention concerns an inter-blade profile (14) for a turbine runner blade, said inter-blade profile (14) comprising a profile (16), and a plug (18), forming a basis of the profile (16) and intended for being inserted into a corresponding hole (21) made in a blade.

A runner for a hydraulic turbine or pump has a plurality of blades. Each of the blades is defined by a pressure surface, an oppositely facing suction surface, a leading edge and a spaced-apart trailing edge. At least one of the blades has a device for supplying a flow of oxygen containing gas to the trailing edge of the same blade. The device includes at least two separate gas inlet apertures and at least two separate gas passages, each extending from one of the separate gas inlet apertures to a separate group of orifices in the trailing edge of the same blade. Each of the separate group of orifices has at least one orifice to admit gas out of the corresponding separate gas passage to the passing fluid during the operation of the runner.

A hydraulic turbine includes a rotor with a runner, which is concentrically surrounded by a stator, whereby the runner comprises a plurality of runner blades arranged and distributed in a ring around a rotor axis, and each runner blade extends between a runner crown and a runner band; whereby the stator comprises a plurality of guide vanes arranged and distributed in a ring around the rotor axis, and each guide vane extends between an upper stator ring and a lower stator ring; and whereby a predetermined clearance is provided at least between the runner band and the lower stator ring. A substantial reduction of pressure pulsations in the vane-less gap between said runner blades of said runner is achieved by substantially increasing said predetermined clearance.

A hydraulic machine including a runner of Francis type, a head cover and a lower cover, the runner includes a low and a high pressure side, a crown, a band, and a plurality of blades, the crown having a sealing element to seal the space between the crown and head cover against water from the high-pressure side, whereas the runner has at least one passage to drain high-pressure leakage water passing the sealing element to the low-pressure side, and the passage has an inlet aperture located in a portion of the crown which during operation is exposed to high-pressure leakage water, the passage being located within one of the blades and leads from the inlet aperture to the band, where the passage forms an opening leading to the space between the band and the lower cover.

A runner for a hydraulic turbine configured to reduce fish mortality. The runner includes a hub and a plurality of blades extending from the hub. Each blade includes a root connected to the hub and a tip opposite the root. Each blade further includes a leading edge opposite a trailing edge, and a ratio of a thickness of the leading edge to a diameter of the runner can range from about 0.06 to about 0.35. Further, each blade has a leading edge that is curved relative to a radial axis of the runner.

A Francis turbine runner including a shortened band length and a shortened blade length combined with a reversed runner blade leading edge having a junction of the leading edge with the band forerunning a junction of the leading edge with the crown in the rotational direction, and a bandless runner including a shortened periphery length and a shortened blade length combined with a reversed runner blade leading edge having a corner of the leading edge at the outer periphery of the runner that is in advance of where the leading edge joins the crown in the rotational direction. Additional feature includes an inverted trailing edge curvature design on the runner blade that further shortens the blade length.

Provided is a hydraulic machine that allows water to smoothly flow in a flow path and has excellent power generation efficiency. In a hydraulic machine 1 including: a casing 2; and a runner 3 rotatably disposed in a central portion of the casing 2, at least one of a plurality of runner vanes 33 included in the hydraulic machine 1 has a pressure surface that receives pressure in an inflow direction from water flowing into the runner 3 through a fixed flow path 21, and, in a cross section of the runner vane 33 perpendicular to the direction of the rotation axis, an outlet angle is 0? or more and less than 20?, the outlet angle being formed between a tangent at a tip portion on an outlet side of the water of the pressure surface and a line segment connecting the rotation axis and the tip portion on an outlet side of the pressure surface.

A hydraulic machine of the Francis-type includes: an impeller with blades; a guide vane assembly with a ring of guide vanes, a vane-free space extending between the impeller and the guide vane assembly; and at least three resonators for suppressing pressure fluctuations, the resonators respectively including a chamber and a tube connector, the tube connector being connected to the chamber, the tube connector including an end that faces away from the chamber and that opens into the vane-free space, the resonators being configured for suppressing the pressure fluctuations occurring during the operation of the hydraulic machine, the resonators being arranged at a uniform distance from each other in a circumferential direction around the impeller, and the resonators being adjusted to a resonant frequency which is one and the same relative to one another.