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 peller device with a flap is an apparatus used to enhance the capabilities and efficiency of water circulation and aeration systems. The apparatus is configured to act as both a propeller and an impeller as necessary for a particular water circulation requirement. A flap is an addition to the blade tip which propels a fluid by pushing against the fluid, thus enabling the peller to function as a propeller. In addition, the flap facilitates the generation of a sucking force so the peller can also function efficiently as an impeller. The peller assembly can be encased in circular housings having a vertical axis in which the peller assembly is mounted for rotation on the central axis of the housing. The peller assembly is formed with a hub and a plurality of blades symmetrically positioned around the hub. The flap of the apparatus is attached to the base of the peller assembly.

The invention relates to an impeller for a pump or turbine, comprising at least one blade, which blade is provided on the pressure side thereof with a standing edge on its outer peripheral edge zone. The invention also relates to a pump for pumping water or a turbine for generating energy from water and having a casing and such an impeller.

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 technique facilitates operation of a pump such as a multiphase pump. The pump may be provided with an impeller having a plurality of impeller blades. The impeller blades have blade tips which extend over an axial length. A ring is positioned along the blade tips to stiffen the impeller and to thus provide stability. However, the axial length of the ring is limited relative to the axial length of the impeller to enable flow, e.g. leakage, across the blade tips in a manner which causes active phase mixing during pumping of a fluid, e.g. a multiphase fluid.

The present disclosure relates to a fluid pump having a pump housing and an inlet wall portion positioned adjacent the pump housing. The inlet wall portion has an extending portion which extends generally parallel to an inner surface of the pump housing. A motor is housed within the pump housing. An impeller is included which is responsive to the motor. An impeller retainer is disposed adjacent the impeller and includes a radiused corner portion. An O-ring is positioned at the radiused corner portion. The O-ring exerts a force non-perpendicular to the inner surface of the pump housing to form a seal against the inner surface of the pump housing and the extending portion of the inlet wall portion.