A system for extracting energy for landing gear retraction may comprise a wheel pump rotationally coupled to a wheel via a pinion gear. A landing gear control valve assembly may be fluidly coupled to an output of the wheel pump. A secondary pump may be fluidly coupled to the landing gear control valve assembly, and an electric motor may be operationally coupled to the secondary pump.

A system for extracting energy for landing gear retraction may comprise a wheel pump rotationally coupled to a wheel via a pinion gear. A landing gear control valve assembly may be fluidly coupled to an output of the wheel pump. A secondary pump may be fluidly coupled to the landing gear control valve assembly, and an electric motor may be operationally coupled to the secondary pump.

Three controls, three variable gear assemblies, an optional hatch or variable propeller pitch, and a variable overlap generator (VO generator), as well as one or more commutator and brush-less free direct current generators may be used independently and together to provide constant frequency and voltage output power and to increase the amount of output power generated with the same input water flow or wind speed in a plurality of embodiments useful in wind power generation and water renewable energy generators for any of tidal and ocean current or wave conditions. Two Transgear assemblies side-by-side and sharing the same central shaft may comprise a constant speed motor control, produce required constant frequency and voltage and be reduced in part count and complexity. The variable overlap generator of a marine hydrokinetic or wind power generator may be used as a low torque generator, a high power-rated generator or a control in these applications and may generate more electric power than a conventional fixed power generator (the rotor axially aligned to overlap the stator in a conventional manner) over a wider input range. An electromotive force (EMF) embodiment generates alternating current at constant frequency and voltage in varying wind and water speed conditions.

Three controls, three variable gear assemblies, an optional hatch or variable propeller pitch, and a variable overlap generator (VO generator), as well as one or more commutator and brush-less free direct current generators may be used independently and together to provide constant frequency and voltage output power and to increase the amount of output power generated with the same input water flow or wind speed in a plurality of embodiments useful in wind power generation and water renewable energy generators for any of tidal and ocean current or wave conditions. Two Transgear assemblies side-by-side and sharing the same central shaft may comprise a constant speed motor control, produce required constant frequency and voltage and be reduced in part count and complexity. The variable overlap generator of a marine hydrokinetic or wind power generator may be used as a low torque generator, a high power-rated generator or a control in these applications and may generate more electric power than a conventional fixed power generator (the rotor axially aligned to overlap the stator in a conventional manner) over a wider input range. An electromotive force (EMF) embodiment generates alternating current at constant frequency and voltage in varying wind and water speed conditions.

A Francis turbine includes a waterway, an impeller disposed in the waterway, a distributor apparatus disposed in the waterway and an additional element for adjusting the flow of water through the turbine. The additional element is disposed in the waterway upstream of the impeller in the water flow direction, and the additional element includes a perforated metal sheet that may be brought into the waterway. A method for operating such a turbine is also provided.

A Francis turbine includes a waterway, an impeller disposed in the waterway, a distributor apparatus disposed in the waterway and an additional element for adjusting the flow of water through the turbine. The additional element is disposed in the waterway upstream of the impeller in the water flow direction, and the additional element includes a perforated metal sheet that may be brought into the waterway. A method for operating such a turbine is also provided.

System for power generation from a flow of fluid, comprising a fluid driven device connected to a tether wherein the tether is coupled with a base station to convert energy from the flow of fluid into transportable energy, wherein the fluid driven device comprises a frame provided with adjustable vanes, and wherein the vanes are adjustable for setting into a predefine position relative to the flow of fluid. The fluid driven device comprises a working mode and a retraction mode, wherein in the working mode the vanes are set in a first predetermined position to generate a lift force from the flow of fluid, and wherein in the retraction mode the vanes are set in a second predetermined position to provide a low drag level to the flow of fluid, and wherein the work performed during working mode is larger than the work supplied during retraction mode.

System for power generation from a flow of fluid, comprising a fluid driven device connected to a tether wherein the tether is coupled with a base station to convert energy from the flow of fluid into transportable energy, wherein the fluid driven device comprises a frame provided with adjustable vanes, and wherein the vanes are adjustable for setting into a predefine position relative to the flow of fluid. The fluid driven device comprises a working mode and a retraction mode, wherein in the working mode the vanes are set in a first predetermined position to generate a lift force from the flow of fluid, and wherein in the retraction mode the vanes are set in a second predetermined position to provide a low drag level to the flow of fluid, and wherein the work performed during working mode is larger than the work supplied during retraction mode.

An energy generating device for generating energy from a flowing fluid, especially from a wind flow and/or from a water flow, comprises: a rotation body, the rotation body extending along an axis of rotation between a first point and a second point and the rotation body being adapted to rotate about the axis of rotation and the rotation body being formed from at least a first, a second, and a third rotation segment, wherein the rotation segments are joined together and arranged along the axis of rotation, and they form a region at least partly surrounded by fluid, wherein the second rotation segment is situated between the first and the third rotation segment and has a different diameter than the first and third rotation segment; and a generator device mechanically connected to the rotation body, wherein the generator device is adapted to generate energy which is produced from the rotation of the rotation body.

An energy generating device for generating energy from a flowing fluid, especially from a wind flow and/or from a water flow, comprises: a rotation body, the rotation body extending along an axis of rotation between a first point and a second point and the rotation body being adapted to rotate about the axis of rotation and the rotation body being formed from at least a first, a second, and a third rotation segment, wherein the rotation segments are joined together and arranged along the axis of rotation, and they form a region at least partly surrounded by fluid, wherein the second rotation segment is situated between the first and the third rotation segment and has a different diameter than the first and third rotation segment; and a generator device mechanically connected to the rotation body, wherein the generator device is adapted to generate energy which is produced from the rotation of the rotation body.