An engine

Abstract

An engine or pump comprises a casing having a chamber 510, 520, a shaft extending through the casing, and a vane 570, 580 extending radially from the shaft into the chamber to divide the chamber into

Description

The present invention relates generally to an engine, and finds particular, although not exclusive, utility in an engine having a rotatably oscillating output. Reciprocating engines are known to convert thermal energy to motion using a reciprocating linear piston. An intermediary connection, such as a connecting rod, is located between the reciprocating linear piston and a crankshaft, and may convert the linear motion of the piston into a unidirectional rotational motion of an output shaft, in use. An alternative engine is an oscillating engine. An oscillating engine may comprise a vane arranged to rotatably oscillate within a chamber, wherein the vane is directly connected to an output shaft, such that an intermediary connection is not required. In this way, the construction of an oscillating engine may provide a greater power density than a reciprocating engine, wherein the power density is defined as the power produced per swept volume (of the piston / chamber). Valves may control the flow of a working fluid into the engines, wherein the valves may be operated by secondary systems comprising timing mechanisms such as cam belts, servomechanisms, or other electronic actuators. In a first aspect, the present invention provides an engine comprising a casing having a chamber; an output shaft extending through the casing, the output shaft being rotatable about its longitudinal axis; a vane arranged to extend radially from the output shaft into the chamber, to divide the chamber into a first sub-chamber and a second subchamber, the vane further arranged to rotatably oscillate about the longitudinal axis of the output shaft, to increase the volume of one of the first sub-chamber and the second subchamber, and correspondingly decrease the volume of the other of the first sub-chamber and the second sub-chamber, in use; the chamber comprising a first end wall extending in a plane perpendicular to the longitudinal axis of the output shaft, the first end wall comprising a first inlet through which working fluid is arranged to enter the first subchamber, and a second inlet through which working fluid is arranged to enter the second sub-chamber; an inlet valve connectable to the output shaft and arranged adjacent to the first end wall, wherein the inlet valve is arranged to rotatably oscillate about the longitudinal axis of the output shaft between a first inlet position, in which the inlet valve is arranged to allow working fluid to enter the first sub-chamber but prevent working fluid entering the second sub-chamber, and a second inlet position, in which the inlet valve is arranged to allow working fluid to enter the second sub-chamber but prevent working fluid entering the first sub-chamber; the chamber further comprising a second end wall extending in a plane perpendicular to the longitudinal axis of the output shaft, the second end wall comprising a first outlet through which working fluid is arranged to exit the first sub-chamber, and a second outlet through which working fluid is arranged to exit the second sub-chamber; and an outlet valve connectable to the output shaft and arranged adjacent to the second end wall, wherein the outlet valve is arranged to rotatably oscillate about the longitudinal axis of the output shaft between a first outlet position, in which the outlet valve is arranged to allow working fluid to exit the first sub-chamber but prevent working fluid exiting the second sub-chamber, and a second outlet position, in which the outlet valve is arranged to allow working fluid to exit the second sub-chamber but prevent working fluid exiting the first sub-chamber; wherein the vane, inlet valve, and outlet valve are arranged to rotatably oscillate in synchrony with each other. In use with a working fluid arranged to expand within the first or second subchamber, the vane may rotatably oscillate as a direct result of the expansion of the working fluid, the output shaft may rotatably oscillate as a direct result of the vane’s movement, and the inlet and outlet valves may rotatably oscillate as a direct result of the output shaft’s movement, with the vane, inlet valve, and outlet valve rotatably oscillating in synchrony with each other. In this way, the engine may actuate the valves without need of a secondary system, reducing the number working parts within the engine. By reducing the number of working parts within the engine, a simplified construction may be achieved, resulting in fewer components which may be susceptible to damage or malfunction in a harsh working environment. Additionally, if damage or malfunction does occur to the engine in a harsh working environment, an engine having a relatively simple construction and fewer engine components may be stripped down and rebuilt more easily and quickly than current engines. Moreover, secondary systems may include timing mechanisms such as cam belts, servomechanisms, or other electronic actuators, which may be prone to timing errors. Consequently, periodic tuning or changes of cam belts may be required. By connecting the valves of the engine directly to the output shaft, the need for periodic tuning or changes of cam belts may be avoided. This is because the angular positions of the valves of the engine may be directly related to the angular position of the output shaft, such that the timing of the valves is directly dependent on the output shaft. Furthermore, by integrating the actuation of the valves directly with the output shaft, the engine may be relatively compact. As such, the engine may provide equivalent power to an alternative engine, but may take up a smaller volume of a working environment. The working fluid may comprise, for example, a fuel / air mix, steam, compressed gas, or hot air. The fuel of the fuel / air mix may include, for example, petrol, diesel, biodiesel, or hydrogen. Expansion of the working fluid may comprise the working fluid providing an increased pressure on the vane to cause rotation of the vane. For example, for a fuel / air mix, igniting the fuel / air mix may cause gases in the first or second sub-chamber to expand, providing a pushing force against the vane. For working fluids such as steam, compressed gas, or hot air, increasing the amount of such working fluid into the first or second sub-chamber may increase the pressure within the first or second sub-chamber, which may in turn provide a pushing force against the vane. The pushing force may be a torque. The chamber may be a hollow interior portion of the casing. The chamber may have the internal shape of a sector of a cylinder, or a sector of an annulus. However, it will be appreciated that the chamber may have any internal shape arranged to allow the vane to bisect the chamber into two sub-chambers, but also allow the vane to rotate within the chamber to change the volumes of the sub-chambers relative to each other. The casing may have a different outer shape compared to the internal shape of the chamber. The longitudinal axis of the output shaft may be the axis along which the length of the output shaft is measured, and may be collinear with the axis around which the output shaft rotates. The output shaft may be adjacent to a wall of the chamber. If the chamber has the internal shape of a sector of a cylinder, the output shaft may extend along the radially central longitudinal axis of the cylinder. The vane may comprise an arm attachable to the output shaft. The arm may extend in a radial direction relative to the longitudinal axis of the output shaft. The vane may be rigidly attached to the output shaft, such that rotational movement of the vane about the output shaft’s axis of rotation is arranged to cause rotation of the output shaft about its axis of rotation, in use. The vane may be substantially rigid. The vane may extend from the output shaft to a wall of the chamber opposite to the output shaft, such that the vane bisects the chamber to form two sub-chambers, wherein each sub-chamber is enclosed and separated from the other sub-chamber. Seals may be arranged between the vane and the internal surfaces of the chamber, to ensure working fluid does not pass between the first and second sub-chambers. Rotatable oscillation of the vane may comprise the vane being arranged to rotate over a first angular distance in a first direction, through an angle between 0 degrees and 360 degrees, and subsequently rotate in a second direction, through an angle between 0 degrees and 360 degrees. For example, the vane may rotate between 30 degrees to 180 degrees in the first and second directions. The rate of rotation in the first direction may be equal to the rate of rotation in the second direction. The rate of rotation may depend on the rate of expansion of the working fluid within the chamber. The rotation in the first and second directions may alternate continuously whilst the engine is in use, thereby providing rotational oscillation of the vane. The chamber may comprise limiting means arranged to prevent the vane from rotating a greater distance than the first angular distance. The limiting means may comprise a first radial wall extending in a plane perpendicular to the longitudinal axis of the output shaft, and a second radial wall extending in a plane perpendicular to the longitudinal axis of the output shaft. The vane may be arranged to rotate between the first radial wall and the second radial wall. The limiting means may define the maximum angular position to which the vane may travel in each of the first and second directions. Rotatable oscillation of the inlet valve, or the outlet valve, may comprise the inlet valve, or the outlet valve, being arranged to rotate over a second angular distance in the first direction, through an angle between 0 degrees and 360 degrees, and subsequently rotate in the second direction, through an angle between 0 degrees and 360 degrees. For example, the inlet valve, or outlet valve, may rotate between 5 degrees and 90 degrees in each direction. The rate of rotation in the first direction may be equal to the rate of rotation in the second direction. The rate of rotation may depend on the rate of expansion of the working fluid within the chamber. The rotation in the first and second directions may alternate continuously whilst the engine is in use, thereby providing rotational oscillation of the inlet valve and outlet valve. The second angular distance may be less than the first angular distance. The second angular distance may be a portion of the first angular distance. For example, the second angular distance may be the portion of the first angular distance wherein the vane approaches its maximum angular position in either the first direction or second direction. The inlet and outlet valves rotating in synchrony with the vane may comprise the inlet, outlet valve, and vane being arranged to reach their maximum angular position at the same time. The first end wall may comprise a substantially planar surface forming an internal surface of the chamber. The first and second inlets may each comprise apertures located within the first end wall. The second end wall may comprise a substantially planar surface forming an internal surface of the chamber. The first and second outlets may each comprise apertures located within the second end wall. Reference throughout the description to “inlet” may be in reference to the first inlet and / or the second inlet. Reference throughout the description to “outlet” may be in reference to the first outlet and / or the second outlet. The inlet valve may comprise an inlet blocking means arranged to control the flow of working fluid into the chamber. The outlet valve may comprise an outlet blocking means arranged to control the flow of working fluid out of the chamber. In this way, the respective blocking means may be arranged to control the flow of working fluid by substantially blocking or obstructing an aperture of an inlet or outlet to prevent a working fluid passing through the aperture, or not blocking or obstructing the aperture of the inlet or outlet to allow a working fluid to pass through the aperture. The first inlet position of the inlet valve may comprise the inlet blocking means being arranged to block completely the aperture of the second inlet but not the aperture of the first inlet. The second inlet position of the inlet valve may comprise the inlet blocking means being arranged to block completely the aperture of the first inlet but not the aperture of the second inlet. The first outlet position of the outlet valve may comprise the outlet blocking means being arranged to block completely the aperture of the second outlet but not the aperture of the first outlet. The second outlet position of the outlet valve may comprise the outlet blocking means being arranged to block completely the aperture of the first outlet but not the aperture of the second outlet. The working fluid may be arranged to flow into the chamber in a direction substantially parallel to the longitudinal axis of the output shaft. The working fluid may be arranged to flow out of the chamber in a direction substantially parallel to the longitudinal axis of the output shaft. The engine may further comprise a valve actuation means arranged to move the respective blocking means along a predetermined portion of the vane’s angular travel, wherein the predetermined portion of the vane’s angular travel is less than the vane’s full angular travel. The vane’s angular travel may be the first angular distance. The predetermined portion of the vane’s angular travel may be the second angular distance. The valve actuation means may connect the inlet valve, or the outlet valve, to the output shaft, for only a portion of the outlet shaft’s rotational oscillation. The valve actuation means may be arranged to connect the outlet valve, or inlet valve, to the output shaft only when the vane is rotating through the second angular distance. The lag between the motion of the valve actuator and the motion of the inlet valve, or outlet valve, is lost motion. The valve actuator may rotate through the majority of its angular travel without actuating the inlet valve, or outlet valve. The valve may rotate through a minority of its angular travel actuating the inlet valve, or outlet valve. The engine may further comprise an inlet closing delay means for delaying the closing of the first or second inlet, in use. The engine may further comprise an outlet closing delay means for delaying the closing of the first or second outlet, in use. In this way the inlet valve, or outlet valve, may be held fully open during the valve actuator’s lost motion, to enable a greater volume of fluid to flow through the inlet, or outlet, per cycle of the vane’s rotatable oscillation. This may be necessary to prevent the inlet valve, or outlet valve, from moving as a result of its own momentum during its period of lost motion. The inlet closing delay means may comprise a first securing means arranged to releasably secure the respective blocking means at a first predetermined angular position of the vane, in use. The outlet closing delay means may comprise a first securing means arranged to releasably secure the respective blocking means at a first predetermined angular position of the vane, in use. The first securing means may be arranged to releasably connect the respective blocking means to the casing. In this way, the delayed closing of the inlet, or outlet, may be achieved by securing the respective inlet valve, or outlet valve, in an open position for a predetermined period of time. For example, the predetermined period of time may be the time until the vane has travelled the first angular distance minus the second angular distance. The engine may further comprise an inlet opening delay means for delaying the opening of the first or second inlet, in use. The engine may further comprise an outlet opening delay means for delaying the opening of the first or second outlet, in use. In this way the inlet valve, may be held fully closed to prevent working fluid from flowing through the incorrect inlet, and the or outlet valve may be held fully closed to prevent working fluid from flowing out of the engine too early. This may be necessary to prevent the inlet valve, or outlet valve, from moving as a result of its own momentum during its period of lost motion. The inlet opening delay means may comprise a second securing means arranged to releasably secure the blocking means at a second predetermined angular position of the vane, in use. The outlet opening delay means may comprise a second securing means arranged to releasably secure the blocking means at a second predetermined angular position of the vane, in use. The second securing means may be arranged to releasably connect the blocking means to the casing. In this way, the delayed opening of the an inlet, or an outlet, may be achieved by securing the respective inlet valve or outlet valve in a closed position for a predetermined period of time. For example, the predetermined period of time may be the time until the vane has travelled the first angular distance minus the second angular distance. The inlet blocking means and the outlet blocking means may each comprise a valve plate rotatable about the longitudinal axis of the output shaft, the valve plate comprising an opening, wherein, in use, the opening may be arranged to align with a respective inlet or outlet, to allow working fluid to flow through the respective inlet or outlet. In particular, the opening of the valve plate may be aligned with the aperture of the respective inlet or outlet, to enable a working fluid to flow through both the opening and aperture. The valve plate may be further positioned such that the valve plate opening is not aligned with a respective inlet or outlet, so as to prevent working fluid from flowing through the respective inlet or outlet. A plurality a valve plates may be provided in the inlet valve and / or outlet valve, for example, two valve plates. Each valve plate of the plurality of valve plates within the inlet valve, or outlet valve, may be arranged axially adjacent to each other, relative to the longitudinal axis of the output shaft. Each valve plate of the plurality of valve plates may be rotatable independently to the other valve plates. For example, each valve plate may be independently connected to the output shaft. Each valve plate of the plurality of valve plates may comprise an opening radially offset relative to the opening of an adjacent valve plate. In this way, a respective inlet, or outlet, may be temporarily unblocked just before the valve plate reaches the maximum angular position to which the valve plate may travel, in use. The inlet valve, or outlet valve, may then not open again until the valve plate is rotated back in an opposite direction. The engine may be arranged such that when the inlet valve is in its first inlet position, the outlet valve may be in its second outlet position, and when the inlet valve is in its second inlet position, the outlet valve may be in its first outlet position. In this way, working fluid may enter first sub-chamber, and simultaneously exit the second subchamber. The first and second sub-chambers comprise a fuel ignition means, and in use the engine is arranged to receive a fuel / air mix within the chamber via the first inlet or second inlet. In this way, the engine may be operated as an internal combustion engine, in use. The engine is arranged to receive a compressed gas within the chamber via the first inlet or second inlet, wherein the compressed gas is arranged to be from a source external to the engine. In this way, the engine may be operated by an energy source external to the engine, in use. The engine may comprise a plurality of chambers, wherein each chamber may comprise a vane, and each vane may be attachable to the output shaft. In this way, each chamber may each have the shape of a sector of a cylinder, and together the chambers may form the shape of a whole cylinder. The engine may further comprise a conversion mechanism to convert the rotational oscillation of the output shaft to a continuous unidirectional rotation of a drive shaft. Each vane of the plurality of chambers may be rigidly attachable to the output shaft, such that the rotatable oscillation of each vane may be in synchrony with each other vane. In a second aspect, the invention provides a pump comprising: a casing having a chamber; an input shaft extending through the casing, the input shaft being rotatable about its longitudinal axis; a vane arranged to extend radially from the input shaft into the chamber, to divide the chamber into a first sub-chamber and a second sub-chamber, the vane further arranged to rotatably oscillate about the longitudinal axis of the input shaft, to increase the volume of one of the first sub-chamber and the second sub-chamber, and correspondingly decrease the volume of the other of the first sub-chamber and the second sub-chamber, in use; the chamber comprising a first end wall extending in a plane perpendicular to the longitudinal axis of the input shaft, the first end wall comprising a first inlet through which working fluid is arranged to enter the first sub-chamber, and a second inlet through which working fluid is arranged to enter the second sub-chamber; an inlet valve connectable to the input shaft and arranged adjacent to the first end wall, wherein the inlet valve is arranged to rotatably oscillate about the longitudinal axis of the input shaft between a first inlet position, in which the inlet valve is arranged to allow working fluid to enter the first sub-chamber but prevent working fluid entering the second sub-chamber, and a second inlet position, in which the inlet valve is arranged to allow working fluid to enter the second sub-chamber but prevent working fluid entering the first sub-chamber; the chamber further comprising a second end wall extending in a plane perpendicular to the longitudinal axis of the output shaft, the second end wall comprising a first outlet through which working fluid is arranged to exit the first sub-chamber, and a second outlet through which working fluid is arranged to exit the second sub-chamber; and an outlet valve connectable to the input shaft and arranged adjacent to the second end wall, wherein the outlet valve is arranged to rotatably oscillate about the longitudinal axis of the input shaft between a first outlet position, in which the outlet valve is arranged to allow working fluid to exit the first sub-chamber but prevent working fluid exiting the second sub-chamber, and a second outlet position, in which the outlet valve is arranged to allow working fluid to exit the second sub-chamber but prevent working fluid exiting the first sub-chamber; wherein the vane, inlet valve, and outlet valve are arranged to rotatably oscillate in synchrony with each other. It will be appreciated that the optional features described in relation to the first aspect, individually or in combination, may also be utilised with the pump of the second aspect. The above and other characteristics, features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. This description is given for the sake of example only, without limiting the scope of the invention. The reference figures quoted below refer to the attached drawings. Figure 1 is a perspective view of an engine; Figure 2 is a perspective view of a working module of the engine of Figure 1; Figure 3 is a perspective view of an inlet valve of the engine of Figure 1; Figure 4 is a central portion of an inlet valve plate and a valve driver, in a plane parallel to the plane in which the inlet valve plate extends; Figure 5 is a valve movement regulator, in the same plane as Figure 4; Figure 6 is the valve movement regulator of Figure 5. The present invention will be described with respect to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. Each drawing may not include all of the features of the invention and therefore should not necessarily be considered to be an embodiment of the invention. In the drawings, the size of some of the elements may be exaggerated and not drawn to scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention. Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other sequences than described or illustrated herein. Likewise, method steps described or claimed in a particular sequence may be understood to operate in a different sequence. Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other orientations than described or illustrated herein. It is to be noticed that the term “comprising”, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising means A and B” should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B. Reference throughout this specification to “an embodiment” or “an aspect” means that a particular feature, structure or characteristic described in connection with the embodiment or aspect is included in at least one embodiment or aspect of the present invention. Thus, appearances of the phrases “in one embodiment”, “in an embodiment”, or “in an aspect” in various places throughout this specification are not necessarily all referring to the same embodiment or aspect, but may refer to different embodiments or aspects. Furthermore, the particular features, structures or characteristics of any one embodiment or aspect of the invention may be combined in any suitable manner with any other particular feature, structure or characteristic of another embodiment or aspect of the invention, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments or aspects. Similarly, it should be appreciated that in the description various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Moreover, the description of any individual drawing or aspect should not necessarily be considered to be an embodiment of the invention. Rather, as the following claims reflect, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention. Furthermore, while some embodiments described herein include some features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form yet further embodiments, as will be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination. In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practised without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description. In the discussion of the invention, unless stated to the contrary, the disclosure of alternative values for the upper or lower limit of the permitted range of a parameter, coupled with an indication that one of said values is more highly preferred than the other, is to be construed as an implied statement that each intermediate value of said parameter, lying between the more preferred and the less preferred of said alternatives, is itself preferred to said less preferred value and also to each value lying between said less preferred value and said intermediate value. The use of the term “at least one” may mean only one in certain circumstances. The use of the term “any” may mean “all” and / or “each” in certain circumstances. The principles of the invention will now be described by a detailed description of at least one drawing relating to exemplary features. It is clear that other arrangements can be configured according to the knowledge of persons skilled in the art without departing from the underlying concept or technical teaching, the invention being limited only by the terms of the appended claims. Figure 1 shows a perspective view of an engine 10 comprising a casing 20. The casing 20 is a prism comprising a cross-sectional shape of a square with rounded comers. Other cross-sectional shapes are also contemplated, for example square, circular, or hexagonal. The shape may be configured to accommodate a coolant and / or lubrication system. The casing includes a first face 25, corresponding with an end of the prism. An output shaft 30 extends out of the casing 20 through the centre of the first face 25, such that the longitudinal axis of the output shaft 30 extends in a direction perpendicular to the plane in which the first face 25 lies. The output shaft 30 is shown to have a circular cross-section for ease of understanding the drawings; however, in use the output shaft 30 may comprise at least one spline extending radially from the longitudinal axis of the shaft, to allow for the rigid coupling of driven components (described below). Alternatively, the output shaft 30 may comprise a key or keyway, to allow for the rigid coupling of driven components. The central axis of the casing 20 is collinear with the longitudinal axis of the output shaft 30. The casing 20 is comprised of an inlet valve 40, a working module 50, and an outlet valve 60. The inlet valve 40, working module 50, and outlet valve 60 are divided from each other in planes parallel to the plane in which the first face 25 lies. The inlet valve 40, working module 50, and outlet valve 60 share the central axis of the casing 20. The outlet valve 60 is located adjacent to the first face 25, the working module 50 is located adjacent to the outlet valve 60, and the inlet valve 40 is located adjacent to the working chamber 50. In this way, the working module 50 is shown to be located between the inlet valve 40 and the outlet valve 60. The width of the working module 50 is shown to be greater than the width of the inlet valve 40 and the outlet valve 60, in a direction parallel to the longitudinal axis of the output shaft 30. A gasket (not shown), may be provided between the inlet valve 40 and the working module 50, and between the outlet valve 60 and the working module 50. In use, the output shaft 30 is arranged to rotatably oscillate about an axis perpendicular to the plane in which the first face 25 lies. A conversion mechanism (not shown) may be attached to the output shaft 30 to convert the rotational oscillation to continuous unidirectional rotation. The conversion mechanism may be within the casing 20. Figure 2 shows a perspective view of the working module 50 of the engine 10 of Figure 1. An end wall of the working module 50 has been removed to show the interior of the working module 50. The output shaft 30 has been omitted for clarity. The outer perimeter of the working module 50 is shown to be a square with rounded comers. A first chamber 510 is shown in the lefthand half of the working module 50, and a second chamber 520 is shown in the righthand half of the working module 50. The first and second chambers 510, 520 are symmetrical to each other, about a plane extending vertically through the centre of the working module 50. The first and second chambers 510, 520 are each shown to have an internal shape of a sector of a cylinder. In this way, the first and second chambers 510, 520 are each shown to have a first radial wall 530 extending radially with respect to the central axis of the working module 50, a second radial wall 540 extending radially with respect to the central axis of the working module 50, and an arced wall 550 extending between the first and second radial walls 530, 540. The first and second radial walls 530, 540 are shown to extend approximately 170 degrees relative to each other. A central hub 560 is located at the centre of the working module 50. The central hub 560 is substantially cylindrical, and thus has a substantially circular cross-section. The central hub 560 is arranged such that its circular cross-section is in a plane perpendicular to the central axis of the working module 50. A first vane 570 is shown to extend radially from the central hub 560 into the first chamber 510. A second vane 580 is shown to extend radially from the central hub 560 into the second chamber 520. The distal ends of the first and second vanes 570, 580 are shown to contact the arced walls 550 of the first and second chambers 510, 520. Whilst not shown, a seal may be provided between the respective distal end of the vanes 550, 560 and the respective arced wall 540. The first and second vanes 570, 580 are fixed relative to each other, and arranged to move as one. The first vane and second vane 570, 580 are arranged to extend 180 degrees relative to each other. The first and second vanes 570, 580 may be connected directly to the output shaft (not shown). The first vane 570 is shown to be in the lower half of the first chamber 510, and the second vane 580 is shown to be in the upper half of the second chamber 520. The first and second vanes 560, 570 are shown to bisect each of the first and second chambers 510, 520 into two sub-chambers. A first sub-chamber 510a is formed by the first vane 570, the first radial wall 530 of the first chamber 510, and the arced wall 550 of the first chamber 510. A second sub-chamber 510b is formed by the first vane 570, the second radial wall 540 of the first chamber 510, and the arced wall 550 of the first chamber 510. A third sub-chamber 520a is formed by the second vane 580, the first radial wall 530 of the second chamber 520, and the arced wall 550 of the second chamber 520. A fourth sub-chamber 520b is formed by the second vane 580, the second radial wall 540 of the second chamber 520, and the arced wall 550 of the second chamber 520. The volume of the first and second chambers 510, 520 may define the displacement of the engine, that being the volume swept by the first and second vanes 570, 580. A first end wall 590 is shown to be located at the rear of the working module 50, and is shown to extend in a plane perpendicular to the central axis of the working module 50. The first end wall 590 is parallel to the plane in which the first end face 25 of Figure 1 extends. It will be appreciated that a second end wall may be provided to enclose the first and second chambers 510, 520; however, as explained above, the second end wall has been removed to show the interior of the working module 50. An inlet 595 is shown in each of the sub-chambers 510a, 510b, 520a, 520b. Each inlet 595 is shown to be hole located within the first end wall 590, wherein each inlet 595 is located adjacent to the first and second radial walls 530, 540 of the first and second chambers 510, 520. In use, working fluid may enter the second sub-chamber 510b and the third subchamber 520a, via their respective inlets 595. Working fluid may be prevented from entering the first sub-chamber 510a or the fourth sub-chamber 520b, for example, by a valve (not shown) preventing the flow of working fluid. The working fluid may expand within the second sub-chamber 510b and the third sub-chamber 520a, increasing the pressure within the second and third sub-chambers 510b, 520a, and exert a torque on the first and second vanes 570, 580. This torque may cause the first vane 570 to rotate in a clockwise direction from the second radial wall 540 of the first chamber 510 to the first radial walls 530, and the second vane 580 to rotate in a clockwise direction from the first radial wall 530 of the second chamber 520 to the second radial wall 540. Once the first and second vanes 570, 580 have rotated until they are adjacent to the respective first or second radial wall 530, 540, the working fluid may be arranged to enter the first sub-chamber 510a and the fourth sub-chamber 520b, via their inlets 595. Working fluid may be prevented from entering the second sub-chamber 510b or the third sub-chamber 520b, for example, by a valve (not shown) preventing the flow of working fluid. In this way, the rotation of the first and second vanes 570, 580 may be reversed. As the first and second vanes 570, 580 rotate in the opposite direction, in use, the working fluid in the second sub-chamber 510b and the third sub-chamber 520a may be allowed to exit through outlets (not shown) in the end wall that has been removed for clarity. A continuation of this cycle will result in a rotatable oscillation of the first and second vanes 570. An output shaft receiving hole 565 is located in the central hub 560. The output shaft receiving hole 565 may be arranged to receive the output shaft such that relative rotational movement between the central hub 560 and the output shaft is prevented. In this way, the central hub 560 and the output shaft may rotate together, in use. Whilst two chambers are shown, it will be appreciated that other numbers of chambers are also considered. For example, the engine 10 may comprise one chamber, three chambers, four chambers, or five chambers. In each case, it will be appreciated that a vane may be located in each chamber, to split each chamber into a first and second subchamber. Each vane may be connected to a single central hub. Figure 3 shows a perspective view of the inlet valve 40 of Figure 1. The inlet valve 40 is shown in an exploded view, comprising a back plate 410, an inlet valve plate 420, and a front plate 430, each extending in a plane perpendicular to the central axis of the inlet valve 40. The inlet valve plate 420 is shown to be located between the back plate 410 and the front plate 430. The back plate 410, and / or the front plate 430, may be of a sufficient thickness to substantially shield the inlet valve 40 from the high pressures and temperatures produced by the working module 50. The back plate 410 is shown to comprise a recess 450 in the surface adjacent to the valve plate 430. The recess 450 includes a central recess portion 451, a first recess wing 453 extending from the central recess portion 451, and a second recess wing 455 extending from the central recess portion 451. The front plate 430 may comprise a corresponding recess (not shown) in its surface adjacent to the valve plate 420. Alternatively, the front plate 430 may comprise a recess instead of the back plate 410. The inlet valve plate 420 is shown to be located within the recess 450. The inlet valve plate 420 comprises a central portion 421 of the valve plate 420, a first valve wing 423, and a second valve wing 425, each located within the corresponding portion of the recess 450. The width of each of the first and second valve wings 423, 425 is less than the width of each of the first and second recess wings 453, 455. In this way, the inlet valve plate 420 may be arranged to rotate, about the central axis of the inlet valve 40, within the recess 450. The edges of the recess 450 may define the maximum angle to which the valve plate 430 may rotate. It will be appreciated that other means to demarcate the maximum angle to which the valve plate 430 may rotate. For example, the front and / or back plate 410, 430 may comprise stops against which the valve plate 420 may abut, in use. The back and front plates 410, 430 include end plate apertures 460. The end plate apertures 460 are shown to be in corresponding locations to each other on each of the back and front plates 410, 420. It will be appreciated that the end plate apertures 460 are intended to align with the inlets 595 shown in Figure 2. The valve plate 420 is shown to include valve apertures 470, located in the first and second valve wings 423, 425. In use, it will be appreciated that with the valve apertures 470 aligned with the end plate apertures 460, working fluid may pass through the inlet valve 40. Conversely, with the valve apertures 470 not aligned with the end plate apertures 460, working fluid may be prevented from passing through the inlet valve 40. It will be appreciated that the outlet valve portion 60 may comprise a similar assembly. However, the valve plate of the outlet valve portion 60 may have a different arrangement of valve apertures from the valve apertures 470 in the inlet valve 40. Figure 4 shows the connection between the inlet valve plate 420 and a valve driver 70, in a plane parallel to the plane in which the inlet valve plate 420 extends. The central portion 421 of the valve plate 420 is shown. The central portion 421 of the valve plate 420 includes a central hole 480. Two valve cams 485 are shown to extend part-way, radially inward, from the central portion 421 of the valve plate 420 into the central hole 480. The two valve cams 485 are located on opposite sides of the central hole 485 to each other. A valve driver 70 is shown to be located within the central hole 480. The valve driver 70 has a circular cross-section, in a plane parallel to the plane in which the valve plate 420 extends. The diameter of the circular-cross section is substantially equal to the distance between the two valve cams 485, across the central hole 480. Two valve driver cams 71 extend radially outward from the valve driver 70. The valve driver cams 71 are located on opposite sides of the valve driver 70 to each other. Another output shaft receiving hole 565 is located in the centre of the valve driver 70. The output shaft receiving hole 565 may be arranged to receive the output shaft (not shown) such that relative rotational movement between the valve driver 70 and the output shaft is prevented. In this way, the valve driver 70 and the output shaft may rotate together, in use. Voids 80 are located between the two valve cams 485, the central valve portion 421, and the valve driver 70. In use, the driver cams 71 may rotate through the voids 80, without contacting the valve cams 485. In this way, the valve driver 70 may rotate through the majority of its travel without driving the inlet valve plate 420. When the driver cams 71 contact the valve cams 485, rotational movement of the inlet driver 70, provided by the output shaft (not shown), may be transferred to the inlet valve plate 420. The inlet valve plate 420 and the valve driver 70 may rotate together when they are connected. The rotation of the inlet valve plate 420 by the valve driver 70 may align the valve apertures 470 with the end plate apertures 460 of Figure 3 to allow working fluid to flow through, or block the end plate apertures 460 to prevent working fluid from flowing through. It will be appreciated that when the valve driver 70 rotates in the opposite direction, the driver cams 71 will again travel through the voids 80 for a period of time without contacting the valve cams 480. In this period of time, the inlet valve plate 420 may remain in position, to maintain the valve open or closed. Also shown in Figure 4 is a valve movement regulator 90. The valve movement regulator 90 is shown in more detail in Figure 5; however, its interaction with the inlet valve plate 420 is shown in Figure 4. The valve movement regulator 90 includes first and second brackets 91, 93, extending in a plane parallel to the plane in which the inlet valve plate 420 extends. The first bracket 91 is shown to extend from behind the inlet valve plate 420 to the left. The second bracket 93 is shown to extend from behind the inlet valve plate 420 to the right. Clamp members 95 are shown to extend from the first and second brackets 91, 93 perpendicularly to the plane in which the first and second brackets 91, 93 extend. A first pair of indents 490 is shown on the left side of the valve plate 420. A second pair of indents 495 is shown on the right side of the valve plate 420. The clamp member 95 on the first bracket 91 is shown to be located in one of the indents of the first pair of indents 490. The clamp member 95 on the second bracket is shown to be located in one of the indents of the second pair of indents 495. In use, with the clamp members 95 located in the indents, the inlet valve plate 420 may be prevented from rotating (for instance, due to vibration or recoil from its end of travel) when the inlet valve plate 420 is not being driven by the valve driver 70. This may allow the inlet to remain unblocked, and thus open, for longer, such that a greater volume of working fluid may flow through the inlet. The period of time in which the inlet is open may be based on the required phasing of the inlet valve. The valve movement regulator 90 may be arranged to move the first and second brackets 91, 93 away from each other, to release the clamp members 95 from the respective indents. With the clamp members 95 removed from the respective indents, the inlet valve plate 420 may be free to rotate when driven by the valve driver 70. The valve movement regulator 90 may be further arranged to move the first and second brackets 91, 93 towards each other, to engage the clamp members 95 in the other of the indents of the first and second pairs of indents 490, 495. In this way, the valve movement regulator 90 may prevent the inlet valve plate 420 from rotating (for instance, due to vibration or recoil from its end of travel) when the inlet valve plate 420 is not being driven by the valve driver 70. This may allow the inlet to remain blocked, and thus closed, for longer, such that no working fluid may enter the incorrect sub-chamber of the engine 10. The period of time in which the inlet is closed may be based on the required phasing of the inlet valve. Figure 5 shows the valve movement regulator 90, in the same plane as Figure 4, without the inlet valve 420 in position. An annulus 96 is shown to be arranged concentrically around the valve driver 70. Two regulator cams 97 extend from the annulus 95 into the centre hole of the annulus 95. The regulator cams 97 are arranged on opposite sides of the centre hole of the annulus 96 to each other. Voids 80 are located between the two regulator cams 97 and the valve driver 70, and in use may be arranged such that they lie in the same position and orientation as the voids 80 located between the two valve cams 485, the central valve portion 421, and the valve driver 70 of Figure 4. In use, the driver cams 71 may rotate through the voids 80, in a similar fashion to that of the voids 80 in the valve plate 420 of Figure 4. That is, the driver cam 71 may rotate through the majority of their travel without contacting the regulator cams 97. When the driver cams 71 do contact the regulator cams 97, rotational movement of the inlet driver 70, provided by the output shaft (not shown), may be transferred to the annulus 96. In this way, the annulus 96 and the valve driver 70 may rotate together, about the central axis of the inlet valve 40, when they are in contact with each other. The annulus 96 further comprises annulus cams 99 extending from the outer perimeter of the annulus 96. The annulus cams 99 are arranged on opposite sides of the annulus 95 to each other. The first and second brackets 91, 93 each include a bracket cam 92 extending from the respective bracket towards the annulus 96. The annulus cams 99 are shown to be adjacent to a respective bracket cam 92. In use, with the annulus 96 being rotated by the valve driver 70, the annulus cams 99 and bracket cams 92 may rotatably slide relative to each other. It will be appreciated that additional annulus cams and bracket cams may be provided. Figure 6 also shows the valve movement regulator 90 without the inlet valve 420 in position. However, the first and second brackets 91, 93 are shown to have moved away from each other by the action of the valve movement regulator 90. The annulus cams 99 are shown to have rotated anti-clockwise, such that the distal end of each annulus cam 99 abuts the distal end of its respective bracket cam 92. The first and second brackets 91, 93 are shown to have moved linearly away from each other to the left and right respectively. As a consequence, the clamp members 95, which are connected to the first and second brackets 91, 93, have also moved away from each other linearly. In this way, the clamp members 95 may be released from the first and second pairs of indents 490, 495, shown in Figure 4, by the rotation of the annulus 96 and the interaction of the annulus cams 99 and bracket cams 92. As a result, the inlet valve plate 420 may be free to rotate about the central axis of the inlet valve 40 to either open the valve, or close the valve. The rotation may be driven by the valve driver 70. Continued rotation of the annulus 96 may result in the annulus cams 99 passing over the bracket cams 99, such that they come to rest at the other side of the annulus cams 99 than where they started. A biasing means may be arranged to urge the first and second brackets 91, 93 towards each other. In this way, with the annulus cams 99 having moved past the bracket cams 92, the biasing means may push, or pull, the first and second brackets 91, 93 such that they move towards each other. Whilst not shown, the biasing means may include, for example, springs or tensioning rings. For example, a tensioning ring may be attached to the first and second brackets 91, 93, and may be arranged concentrically around the annulus 96. The regulator cams 97 may be longer circumferentially than the valve cams 485, in a direction around the edge of the central hole 480 of the inlet valve plate 420. In this way, the driver cams 71 may contact the regulator cams 97 before they contact the valve cams 485. Consequently, the valve movement regulator 90 may be arranged to disengage the clamp members 95 from the first and second pairs of indents 490, 495 before the valve driver 70 begins to rotate the inlet valve plate 420. It will be appreciated that the outlet valve plate (not shown) of the outlet valve portion 60 of the engine 10 of Figure 1 my also be driven by the valve driver 70 as described above, and the movement of the outlet valve plate may also be regulated by the valve movement regulator 90 described above. The engine 10 of Figure 1 may have a simplified and compact engine construction, resulting in fewer components which may be susceptible to damage or malfunction in a harsh working environment.

Claims

1. An engine comprising:a casing having a chamber;an output shaft extending through the casing, the output shaft being rotatable about its longitudinal axis;a vane arranged to extend radially from the output shaft into the chamber, to divide the chamber into a first sub-chamber and a second sub-chamber, the vane further arranged to rotatably oscillate about the longitudinal axis of the output shaft, to increase the volume of one of the first sub-chamber and the second sub-chamber, and correspondingly decrease the volume of the other of the first sub-chamber and the second sub-chamber, in use;the chamber comprising a first end wall extending in a plane perpendicular to the longitudinal axis of the output shaft, the first end wall comprising a first inlet through which working fluid is arranged to enter the first sub-chamber, and a second inlet through which working fluid is arranged to enter the second sub-chamber;an inlet valve connectable to the output shaft and arranged adjacent to the first end wall, wherein the inlet valve is arranged to rotatably oscillate about the longitudinal axis of the output shaft between a first inlet position, in which the inlet valve is arranged to allow working fluid to enter the first sub-chamber but prevent working fluid entering the second sub-chamber, and a second inlet position, in which the inlet valve is arranged to allow working fluid to enter the second sub-chamber but prevent working fluid entering the first sub-chamber;the chamber further comprising a second end wall extending in a plane perpendicular to the longitudinal axis of the output shaft, the second end wall comprising a first outlet through which working fluid is arranged to exit the first sub-chamber, and a second outlet through which working fluid is arranged to exit the second sub-chamber; andan outlet valve connectable to the output shaft and arranged adjacent to the second end wall, wherein the outlet valve is arranged to rotatably oscillate about the longitudinal axis of the output shaft between a first outlet position, in which the outlet valve is arranged to allow working fluid to exit the first sub-chamber but prevent working fluid exiting the second sub-chamber, and a second outlet position, in which the outletvalve is arranged to allow working fluid to exit the second sub-chamber but prevent working fluid exiting the first sub-chamber;wherein the vane, inlet valve, and outlet valve are arranged to rotatably oscillate in synchrony with each other.

2. The engine of claim 1, wherein the inlet valve comprises an inlet blocking means arranged to control the flow of working fluid into the chamber, and the outlet valve comprises an outlet blocking means arranged to control the flow of working fluid out of the chamber.

3. The engine of claim 2, further comprising a valve actuation means arranged to move the respective blocking means along a predetermined portion of the vane’s angular travel, wherein the predetermined portion of the vane’s angular travel is less than the vane’s full angular travel.

4. The engine of claim 2 or claim 3, further comprising an inlet closing delay means for delaying the closing of the first or second inlet, in use.

5. The engine of claim 4, wherein the inlet closing delay means comprises a first securing means arranged to releasably secure the respective blocking means at a first predetermined angular position of the vane, in use.

6. The engine of any one of claims 3 to 5, further comprising an inlet opening delay means for delaying the opening of the first or second inlet, in use.

7. The engine of claim 6, wherein the inlet opening delay means comprises a second securing means arranged to releasably secure the blocking means at a second predetermined angular position of the vane, in use.

8. The engine of any of claims 2 to 7, wherein the inlet blocking means and the outlet blocking means each comprise a valve plate rotatable about the longitudinal axis of the output shaft, the valve plate comprising an opening, wherein, in use, the opening is arranged to align with a respective inlet or outlet, to allow working fluid to flow through the respective inlet or outlet.

9. The engine of any preceding claim, arranged such that when the inlet valve is in its first inlet position, the outlet valve is in its second outlet position, and when the inlet valve is in its second inlet position, the outlet valve is in its first outlet position.

10. The engine of any preceding claim, wherein the first and second sub-chambers comprise a fuel ignition means, and in use the engine is arranged to receive a fuel / air mix within the chamber via the first inlet or second inlet.

11. The engine of any of claims 1 to 9, wherein, in use, the engine is arranged to receive a compressed gas within the chamber via the first inlet or second inlet, wherein the compressed gas is arranged to be from a source external to the engine.

12. The engine of any preceding claim, comprising a plurality of chambers, wherein each chamber comprises a vane, and each vane is attachable to the output shaft.

13. The engine of claim 12, wherein each vane of the plurality of chambers is rigidly attachable to the output shaft, such that the rotatable oscillation of each vane in synchrony with each other vane.

14. A pump comprising:a casing having a chamber;an input shaft extending through the casing, the input shaft being rotatable about its longitudinal axis;a vane arranged to extend radially from the input shaft into the chamber, to divide the chamber into a first sub-chamber and a second sub-chamber, the vane further arranged to rotatably oscillate about the longitudinal axis of the input shaft, to increase the volume of one of the first sub-chamber and the second sub-chamber, and correspondingly decrease the volume of the other of the first sub-chamber and the second sub-chamber, in use;the chamber comprising a first end wall extending in a plane perpendicular to the longitudinal axis of the input shaft, the first end wall comprising a first inlet through which working fluid is arranged to enter the first sub-chamber, and a second inlet through which working fluid is arranged to enter the second sub-chamber;an inlet valve connectable to the input shaft and arranged adjacent to the first end wall, wherein the inlet valve is arranged to rotatably oscillate about the longitudinal axisof the input shaft between a first inlet position, in which the inlet valve is arranged to allow working fluid to enter the first sub-chamber but prevent working fluid entering the second sub-chamber, and a second inlet position, in which the inlet valve is arranged to allow working fluid to enter the second sub-chamber but prevent working fluid entering the first sub-chamber;the chamber further comprising a second end wall extending in a plane perpendicular to the longitudinal axis of the output shaft, the second end wall comprising a first outlet through which working fluid is arranged to exit the first sub-chamber, and a second outlet through which working fluid is arranged to exit the second sub-chamber; andan outlet valve connectable to the input shaft and arranged adjacent to the second end wall, wherein the outlet valve is arranged to rotatably oscillate about the longitudinal axis of the input shaft between a first outlet position, in which the outlet valve is arranged to allow working fluid to exit the first sub-chamber but prevent working fluid exiting the second sub-chamber, and a second outlet position, in which the outlet valve is arranged to allow working fluid to exit the second sub-chamber but prevent working fluid exiting the first sub-chamber;wherein the vane, inlet valve, and outlet valve are arranged to rotatably oscillate in synchrony with each other.IntellectualPropertyOfficeApplication GB2416991.4Search report under Section 17 of the Patents Act 1977Date search completed: 07 May 2025Claims searched: 1-14International classificationSubclass and subgroup Valid from F01C21 / 18 01 / 01 / 2006 F01C9 / 00 01 / 01 / 2006 F01L7 / 06 01 / 01 / 2006 F02B53 / 06 01 / 01 / 2006 F04C15 / 06 01 / 01 / 2006 F04C21 / 00 01 / 01 / 2006 F04C29 / 12 01 / 01 / 2006 F04C9 / 00 01 / 01 / 2006Field of searchWorldwide search of patent documents classified in the following areas of the IPC:F01C, F01L, F02B, F04CDatabases used in the preparation of this search report:SEARCH-PATENT26Intellectual Property Office is an operating name of the Patent Office www.gov.uk / ipoDocuments considered to be relevantPatent literatureCategory Relevant claims Document of relevance A - EP 1042591 B1 (Choi), See paragraphs 0052-0058 and figure 7 in particular. A - GB 219398 A (Day), See page 1 lines 9-33 and figures 1-5 in particular. Non-patent literature Category Relevant claims Document of relevanceCategoriesLetter or DescriptionsymbolX Document indicating lack of novelty or inventive step.Y Document indicating lack of inventive step, if combined with anotherdocument of the same category.& Member of the same patent family. A Document indicating technological background. P Document published on or after the priority date but before the fling date of the present application.Letter or symbol Description E Earlier application published on or after the filing date of the present application.

Images