An electric machine is presented. The electric machine includes a hollow rotor; and a stator disposed within the hollow rotor, the stator defining a flow channel. The hollow rotor includes a first end portion defining a fluid inlet, a second end portion defining a fluid outlet; the fluid inlet, the fluid outlet, and the flow channel of the stator being configured to allow passage of a fluid from the fluid inlet to the fluid outlet via the flow channel; and wherein the hollow rotor is characterized by a largest cross-sectional area of hollow rotor, and wherein the flow channel is characterized by a smallest cross-sectional area of the flow channel, wherein the smallest cross-sectional area of the flow channel is at least about 25% of the largest cross-sectional area of the hollow rotor. An electric fluid pump and a power generation system are also presented.

A reversible water pump and hydroturbine including a housing and a rotor is provided. The housing includes two end boards, which have the same shape, and a sideboard that connects the two end boards respectively. Each end board includes two coaxial semicircle boards having two different radiuses, that is, a large semicircular board and a small semicircular board which are joined together at their diameter; the side board includes a first round sideboard and a second round sideboard, two inlets/outlets, i.e. a first inlet/outlet and a second inlet/outlet, are formed at the ends of the first round sideboard. The rotor includes a rotary shaft, a rotary wheel and at least two blades, a service channel forms between the rotary wheel and the second round sideboard, and a return channel forms between the rotary wheel and the first round sideboard.

A water wheel includes a casing to carry a fluid flow through an inside of the casing, a pipe extending in the inside of the casing, a rotor unit having a shaft to be inserted in the inside of the casing, and a support. The shaft is directed toward the pipe. The rotor unit is detachably attached to the casing from outside. The support supports the rotor unit at a predetermined position relative to the pipe when the rotor unit is attached to the casing. A hydraulic power generation device includes the water wheel and a generator driven by the water wheel. A hydraulic power generation system includes the hydraulic power generation device and a flow path with the hydraulic power generation employed in the flow path.

A combined pump and turbine (electromechanical converter), which may be operable as a motorized centrifugal pump for starting a siphon and as an electromechanical turbine particularly for transmission of a liquid, such as water, in a water treatment plant.

The present invention relates to a hydraulic energy store (1) having a first (2) and a second fluid reservoir (6), the fluid levels (4, 12) of which extend at different heights, which are connected to one another via a turbine/pump arrangement (10) and during the operation of which a fluid (3) can be moved to and fro between the first (2) and second fluid reservoir (6) and energy can be converted in the process. The second fluid reservoir (6) is configured as a container which is arranged within the fluid (3) in the first fluid reservoir (2), wherein, during operation, the fluid level (12) in the second fluid reservoir (6) can be changed in such a way that, as a result, the immersion depth (h.sub.t) of said second fluid reservoir (6) in the first fluid reservoir (2) can be changed owing to buoyancy.

The present invention relates to a hydraulic device of reversible type adapted to be used both as a water turbine and a hydraulic pump. Said device has characteristics of simplicity of construction and use. In the case of use as a water turbine it does not require distributors of a particular shape and does not require drops of great heights being adapted to take advantage of the pressure of the fluid and not only of the speed thereof.

An hydroelectric unit extends along a longitudinal axis and includes a least one rim-driven hydraulic machine comprising an impeller provided with at least two blades, and at least one motor/generator configured to selectively supply mechanical energy to the impeller or convert mechanical energy produced by the impeller into electricity. The motor/generator includes an annular rotor arranged about the impeller and an annular stator arranged, at a distance, about the annular rotor; the annular rotor being coupled to the impeller and including a plurality of rotor poles, which are distributed along an annular surface, are arranged parallel one to another and extend transversal to a plane containing the longitudinal axis forming a first angle with the plane containing the longitudinal axis. The annular stator includes a plurality of stator windings and a plurality of stator slots configured to guide the magnetic flux and to house respective stator windings. The stator slots are arranged parallel one to another and extend transversal to a plane containing the longitudinal axis forming a second angle with the plane containing the longitudinal axis.

A fluid connection for a hydromotive machine or fluid-control valve having a first duct and a second duct. The first duct includes a mid-portion between a first end of the first duct and a second end of the first duct that has a non-circular cross-section. A second end of the first duct is wholly within the second end of the second duct. A first end of the second duct is wholly outside of the first duct.

A fluid connection for a hydromotive machine or fluid-control valve having a first duct and a second duct. The first duct includes a mid-portion between a first end of the first duct and a second end of the first duct that has a non-circular cross-section. A second end of the first duct is wholly within the second end of the second duct. A first end of the second duct is wholly outside of the first duct.