Abstract: A passive elastic teeter bearing for an aircraft rotor, including, rotatably arranged on an rotational axis of said rotor, a teeter beam, configured for attaching the rotor which has rotor blades, with the teeter beam being configured for performing a teetering motion, and having two pairs of first lugs arranged at opposite ends thereof at a distance with respect to the rotational axis; and a hub piece located below the teeter beam, the hub piece having two arms that extend outwardly in a radial direction, each having a second lug arranged at a distance with respect to said rotational axis. Each second lug is located between the two lugs of a respective pair of first lugs, and respective connecting pins pass through the first and second lugs on either side of the rotational axis. A pair of elastic bushings are arranged on each connecting pin between a first one of the first lugs and the second lug and between a second one of said first lugs and the second lug, respectively.

Abstract: A passive elastic teeter bearing (3c) for an aircraft rotor (3b), including, rotatably arranged on an rotational axis (RA) of said rotor (3b), a teeter beam (3d), configured for attaching the rotor which has rotor blades, with the teeter beam being configured for performing a teetering motion, and having two pairs of first lugs (3j1, 3j2) arranged at opposite ends thereof at a distance with respect to the rotational axis; and a hub piece (3f) located below the teeter beam, the hub piece having two arms (3g1, 3g2) that extend outwardly in a radial direction, each having a second lug (3k) arranged at a distance with respect to said rotational axis. Each second lug is located between the two lugs of a respective pair of first lugs, and respective connecting pins (3n) pass through the first and second lugs on either side of the rotational axis.

Abstract: A screen valve (210) to control fluid flow comprising at least one multi-apertured valve plate (220) movable laterally relative to a multi-apertured valve seat (230) between a closed configuration whereby the apertures are not registered to prevent fluid flow, and an open configuration whereby the apertures are registered to permit fluid flow, wherein the valve plate is supported by a multi-apertured carrier plate (240) that moves laterally in synchrony with the valve plate (220) to maintain a predetermined lateral registration between their respective apertures as the valve plate moves between the open and closed configurations, the valve plate being movable relative to the carrier plate so as to be able to lift off and return into contact with the valve seat. The co-moving carrier plate shields the valve plate so as to minimize pressure locking. Aerodynamic features may be incorporated to urge the valve plate (220) towards or away from the carrier plate (240).

Abstract: A thermal energy store comprising a chamber having a gas inlet and a gas outlet and a plurality of successive, downstream, gas permeable thermal storage layers disposed between them, each layer comprising gas permeable thermal storage media, the store being configured for gas flow from the gas inlet to gas outlet through the layers for transfer of thermal energy to or from the thermal storage media, wherein at least one of the layers is a valved layer provided with at least one valve operable selectively to allow or prevent at least some gas flow through that layer via the valve so as to bypass the thermal storage media. A control system may selectively alter the flow path of the gas flowing from inlet to outlet in response to the progress of a thermal front, so as to bypass thermal storage layers upstream of the thermal front, where transfer is complete, or downstream thereof, where transfer is minimal.

Abstract: System (2) for carrying out a gas based thermodynamic cycle in which a gas is compressed in at least one compressor (8) in one part of the cycle and is expanded in at least one expander (10) operating simultaneously in an upstream or downstream part of the cycle, wherein the change in absolute internal power with gas mass flow rate differs as between the compressor and the expander and wherein the system comprises a control system configured to make selective adjustments so as individually to control, either directly or indirectly, the respective gas mass flow rates through each of the compressor and expander. The system may be an energy storage system including a pumped heat energy storage system configured to provide independent graduated control of system pressure and output power by selective adjustment of the respective gas mass flow rates through each half-engine.

Abstract: A heat storage system (400) comprising a system gas inlet (460), a system gas outlet (470), and at least two thermal stores (401, 402) connected together in series therebetween, wherein each store comprises a chamber having a gas inlet (461,462), a gas outlet (471,472), and a gas-permeable thermal storage media 431 disposed therebetween, the system further comprising flow controllers (451, 452, 453, 454, 457) operatively connected to bypass passageways and so configured that, during operation, the flow path of a gas flowing through the system (400) for transfer of thermal energy to or from the storage media (431) can be selectively altered in respect of which stores (401, 402) in the series are used in response to the progress of the thermal transfer.

Abstract: Heat storage apparatus comprising at least one thermal store (300) comprising a chamber (301) having a gas inlet (306), a gas outlet (307), and a gas-permeable thermal storage media (303) disposed therebetween, the apparatus being configured such that, during operation, the flow path of a gas flowing through the chamber (301) from inlet (306) to outlet (307) for transfer of thermal energy to or from the storage media (303) can be selectively altered in response to the progress of the thermal transfer, thereby enabling the flow path to bypass inactive upstream or downstream regions of the storage media where thermal transfer is complete or minimal, so as to minimize the pressure drop across the storage media. A baffle system (305) in a main flow passageway (312) may be used to control the gas flow path.

Abstract: An apparatus (10) for compressing and expanding a gas includes a chamber (22), a positive displacement device (24) moveable relative thereto, first and second valves (26, 28) activatable to control flow of gas into and out of the chamber (22), and a controller (80) for controlling activation of the valves (26, 28) that selectively switches operation between a compression and an expansion mode with selective switching between modes being achieved by selectively changing the activation timing of at least one of the valves during the first mode. An energy storage system including the device may be operatively coupled via a rotary device for power transmission to an input/output device, whereby the direction and speed of rotation are preserved during switching, and the input/output device may be synchronized to the grid.

Abstract: A screen valve (210) to control fluid flow comprising at least one multi-apertured valve plate (220) movable laterally relative to a multi-apertured valve seat (230) between a closed configuration whereby the apertures are not registered to prevent fluid flow, and an open configuration whereby the apertures are registered to permit fluid flow, wherein the valve plate is supported by a multi-apertured carrier plate (240) that moves laterally in synchrony with the valve plate (220) to maintain a predetermined lateral registration between their respective apertures as the valve plate moves between the open and closed configurations, the valve plate being movable relative to the carrier plate so as to be able to lift off and return into contact with the valve seat. The co-moving carrier plate shields the valve plate so as to minimise pressure locking. Aerodynamic features may be incorporated to urge the valve plate (220) towards or away from the carrier plate (240).

Abstract: Apparatus (1) for storing energy includes a high pressure storage vessel (10) for receiving high pressure gas, the high pressure storage vessel (10) including a high pressure heat store including a first chamber housing a first gas-permeable heat storage structure (14); and a low pressure storage vessel (11,12) for receiving low pressure gas, the low pressure storage vessel (11,12) including a low pressure heat store including a second chamber housing a second gas-permeable heat storage structure (16,18. The first heat storage structure (14) has a mean surface area per unit volume which is higher than a mean surface area per unit volume of the second heat storage structure (16,18).

Abstract: A sliding screen valve for controlling fluid flow comprises a multi-apertured valve plate (50, 90) configured for sliding movement relative to a multi-apertured valve seat between closed and open configurations and comprises an array of apertures (60, 100) separated from one another by elongate interstitial elements angled at between 15 to 45 degrees from the axis of motion. The valve plate may be operatively connected via an actuator frame (274) controlling its movement to an actuator for sliding movement relative to the valve seat, and may be connected to the actuator via a resilient support element (272) configured to allow a floating movement of the valve plate normal to the valve plate. Initiation or termination of the sliding movement may be damped by at least one damping mechanism. The screen valve may be configured for lateral reciprocating movement and be used in gas compression and/or expansion equipment such as piston compressors or expanders.

Abstract: Apparatus for transmitting energy comprising an electrical machine arranged to convert between electrical and mechanical energy, and comprising a rotor (20) and control means (42, 44, 90) arranged to regulate the motion of the rotor to ensure that the power angle of the electrical machine is maintained within a range of a predetermined power angle. A signal generator (2, 6), such as a synchronous machine and associated flywheel, may generate a reference signal relating to the predetermined power angle and be powered by a frequency regulated electrical supply. The control means (42, 44, 90) may be a mechanical control linkage or servo control system and may regulate the output of the motion of the rotor in response to a change in its motion which the control means or a dedicated detection device detects. The electrical machine may be an electric motor, an electricity generator, or a machine switchable between motor and generator modes.

Abstract: A system includes a primary, combustion turbine based system that includes one or more power shaft assemblies including a generator or motor/generator, a compressor and an expansion turbine associated with the one or more power shaft assemblies, and a combustor to feed the expansion turbine. The primary system includes a first flow network allowing outlet air from the compressor to pass downstream to the combustor for combustion and the expansion turbine for expansion. The primary system is modified by integration of an adiabatic compressed air energy storage sub-system that includes a compressed air store and a thermal energy storage system for removing and returning thermal energy to the compressed air upon charging and discharging the store. The sub-system includes a second flow network allowing outlet air from the compressor to pass, upon charging, to the compressed air store, and to pass, upon discharging, back to the combustor and/or expansion turbine.

Abstract: In an energy storage and recovery system, working fluid from a first vessel is compressed by power machinery and passes, via a regenerator, into a second vessel, where it is forced to condense, the temperature and pressure of the saturated working liquid/vapour mixture continuously rising during storage. The stored energy is recovered by the vapour returning through the regenerator and power machinery where it expands to produce work before condensing back into the first vessel. The regenerator comprises a gas permeable, solid thermal storage medium which, during storage, stores superheat and some latent heat from the vapour passing through it in respective downstream regions that exhibit continuously increasing temperature profiles during storage and a small temperature difference with the surrounding vapour, thereby minimising irreversible losses during the thermal energy transfers.

Abstract: A heat engine (10) comprising: a feeder stage (20) comprising: a first compressor (24) for compressing first gas received at pressure P1 from a gas source to an elevated pressure and temperature; a reactor (28) for receiving gas compressed by the first compressor (24) and combining the compressed gas with fuel to generate an exothermic reaction; and a primary stage comprising (40); a circuit (42) for recirculating a gas flow comprising a second gas; a mixing chamber (44) in fluid communication with the circuit (42) for combining the products of the exothermic reaction from the feeder stage (20) with the gas flow in the circuit (42) at pressure P2, wherein P2 is greater than P1, an expander (48) for expanding gas received from the mixing chamber (44) to generate mechanical work; and a second compressor (58) for compressing gas expanded by the expander (48).

Abstract: System (2) for carrying out a gas based thermodynamic cycle in which a gas is compressed in at least one compressor (8) in one part of the cycle and is expanded in at least one expander (10) operating simultaneously in an upstream or downstream part of the cycle, wherein the change in absolute internal power with gas mass flow rate differs as between the compressor and the expander and wherein the system comprises a control system configured to make selective adjustments so as individually to control, either directly or indirectly, the respective gas mass flow rates through each of the compressor and expander. The system may be an energy storage system including a pumped heat energy storage system configured to provide independent graduated control of system pressure and output power by selective adjustment of the respective gas mass flow rates through each half-engine.

Abstract: A thermal energy store comprising a chamber having a gas inlet and a gas outlet and a plurality of successive, downstream, gas permeable thermal storage layers disposed between them, each layer comprising gas permeable thermal storage media, the store being configured for gas flow from the gas inlet to gas outlet through the layers for transfer of thermal energy to or from the thermal storage media, wherein at least one of the layers is a valved layer provided with at least one valve operable selectively to allow or prevent at least some gas flow through that layer via the valve so as to bypass the thermal storage media. A control system may selectively alter the flow path of the gas flowing from inlet to outlet in response to the progress of a thermal front, so as to bypass thermal storage layers upstream of the thermal front, where transfer is complete, or downstream thereof, where transfer is minimal.

Abstract: A piston assembly (12) comprising a reciprocating sleeve (14) incorporating an integral internal piston surface (28), which sleeve is slidably mounted upon a cylinder head (18) so as to define a piston chamber (26) therewith, the piston chamber being sealed in the vicinity of the cylinder head (18) by a circumferential static seal (20) that acts to seal against the reciprocating sleeve (14). The static seal (20) may occupy a horizontal plane and may include sacrificial wear zones and be formed from a graphite-based material. The piston assembly may be an oversquare assembly for use in an oil-free environment for processing high temperature gases, for example, a hot gas engine or heat pump or heat engine such as may be used in an energy storage system.

Abstract: Apparatus for transmitting energy comprising an electrical machine arranged to convert between electrical and mechanical energy, and comprising a rotor (20) and control means (42, 44, 90) arranged to regulate the motion of the rotor to ensure that the power angle of the electrical machine is maintained within a range of a predetermined power angle. A signal generator (2, 6), such as a synchronous machine and associated flywheel, may generate a reference signal relating to the predetermined power angle and be powered by a frequency regulated electrical supply. The control means (42, 44, 90) may be a mechanical control linkage or servo control system and may regulate the output of the motion of the rotor in response to a change in its motion which the control means or a dedicated detection device detects. The electrical machine may be an electric motor, an electricity generator, or a machine switchable between motor and generator modes.

Abstract: A hydrofoil section comprises first and second faces that create, in operation at speeds above a ventilation speed, a ventilated cavity defined by a first cavity face which departs from the first hydrofoil face and a second cavity face which departs from the second hydrofoil face. Each cavity face represents a free surface and each face separating from the said free surface at a discontinuity on that surface, the separated faces forming a continuation of the faces of arbitrary shape and enclosed by the free surfaces without contacting the said free surfaces. Below the speed at which full ventilation occurs the arbitrarily shaped portion of each face is configured to provide a modified flow configuration resulting in changed lift and or drag and or pitching moment under partial, or unventilated operation.