Gyrostabilizer with active precession control and energy recovery system

Abstract

The present disclosure provides a system for precession control of a gyroscopic stabilizer and / or a system for recovering energy from a gyroscopic stabilizer. The system includes a gyroscopic stabilizer and a precession control device. The gyroscopic stabilizer includes a flywheel mounted for rotation about a spin axis within a gimbal frame attached to a marine vessel. The gimbal frame includes a precession shaft on which the gyroscopic stabilizer rotates about an axis to stabilize the marine vessel. The precession control device is operably coupled to the precession shaft to recover or convert kinetic energy or rotational motion of the precession shaft.

Description

[Technical Field]

[0001] The present disclosure relates to gyrostabilizers with active precession control and energy recovery systems, and more particularly to systems for recovering energy and / or converting kinetic energy or motion of a gyrostabilizer into electrical energy.

[0002] The gyrostabilizer systems of the present disclosure are typically designed for use on marine vessels and will be conveniently described in this exemplary context. However, the systems of the present disclosure are not limited to that particular application and may be designed for other applications, such as use on other fixed or floating structures, other vehicles, and / or camera mounts. [Background technology]

[0003] The discussion of background art in this specification, including any document references, should not be taken in any way as an acknowledgement that such background art is well known art or forms part of the general general knowledge in the art in Australia or anywhere else.

[0004] The structure and operation of marine gyrostabilizer assemblies are generally very well understood, and these devices are increasingly being adopted on commercial and recreational vessels. A gyrostabilizer assembly typically consists of a rotating flywheel mounted on a gimbal frame that allows two of three possible rotational degrees of freedom, with the frame rigidly mounted within the vessel. Depending on the specific manner in which the flywheel is constrained in its rotational motion, the angular momentum of the rotating flywheel can combine with the precession of the flywheel to generate a large, time-varying torque to directly counteract the vessel's dynamic rolling motion caused by wind and / or waves. Without any intervention, the vessel's rolling motion combines with the angular momentum of the flywheel to cause precession. This, combined with the angular momentum, produces a stabilizing torque that directly counteracts the vessel's undesired rotational motion (e.g., wave-induced rolling). By arranging the gimbal in a specific manner, a roll-stabilizing device is created that utilizes the naturally occurring physics of gyrodynamics and requires no further intervention to function. An example of a marine gyrostabilizer assembly is described in the applicant's Australian patent application published as AU2017-216483A1 and its international patent application published as WO2021 / 174315A1, the contents of both of which are incorporated herein by direct reference in their entirety.

[0005] As noted above, because the structure and operation of marine gyrostabilizers are generally very well understood, this specification does not aim to provide a detailed description of all of the components of a gyrostabilizer assembly, such as the flywheel, flywheel shaft, gimbal bearing, etc. Rather, this specification directs those skilled in the art to other publications for descriptions or explanations of those components. Summary of the Invention [Problem to be solved by the invention]

[0006] While seeking to optimize the energy efficiency and operation of gyrostabilizers, it has been found desirable to provide new methods and means for generating electricity from the motion of the gyrostabilizer. [Means for solving the problem]

[0007] According to one broad aspect, the present disclosure provides a system for precession control of a gyroscopic stabilizer and / or a system for recovering energy from a gyroscopic stabilizer. The system includes a gyroscopic stabilizer and a precession control device. The gyroscopic stabilizer includes a flywheel mounted for rotation about a spin axis within a gimbal frame attached to a marine vessel. The gimbal frame includes a precession shaft on which the gyroscopic stabilizer rotates about an axis to stabilize the marine vessel. The precession control device is operably coupled to the precession shaft to recover or convert kinetic energy or rotational motion of the precession shaft.

[0008] In this manner, the gyrostabilizer is forced to precess. The induced precession torque is used to drive a precession control system and / or an energy recovery or energy conversion system. In a typical case where a gyrostabilizer is deployed on a vessel, waves exciting or moving the vessel form an energy source that rotates the gyrostabilizer on the precession shaft, and this precession torque produces useful work over a range of precession angles. According to the present disclosure, this work performed on the precession shaft can be converted into electrical energy by an appropriate conversion arrangement. At the same time, the recovery of energy from the precession of the gyrostabilizer can be used to actively control or regulate the degree or range of precession.

[0009] In one embodiment, the gyrostabilizer precession control system and / or the system for recovering energy from the gyrostabilizer operates in an energy generating mode when the gyrostabilizer precession rate is relatively high, e.g., during large wave conditions.

[0010] In one embodiment, the precession control system of the gyrostabilizer and / or the system for recovering energy from the gyrostabilizer is in an energy recovery / energy generation mode that generates electrical energy from the rotational motion of the precession shaft; or (ii) operate in a drive mode that applies a torque to the precession shaft, i.e., actively drives the gyrostabilizer. This latter mode is beneficial in small waves, as the gyrostabilizer can provide better stability in low waves.

[0011] Previous research in this field has shown that gyroscopes used to harvest energy in this way are not suitable as stabilizing devices (e.g., on a vessel's roll axis). In this regard, gyroscopic stabilizers are typically subjected to high induced precession torques and must precess rapidly to generate enough energy to overcome losses (bearing torque) in the flywheel rotation axis. However, high precession torques are only generated or induced when the vessel's roll rate is high, resulting in low stabilization effectiveness. As a result, when the system harvests wave energy, the vessel tends to roll more than desired. Therefore, there is an inherent tension and trade-off to be resolved between stabilization on the one hand and energy recovery or energy generation on the other. This tension can result in two operating modes: stabilization mode and energy generation mode. For example, when passengers are on board the vessel, the gyroscopic stabilizer can be switched to stabilization mode, and when the vessel is unmanned, it can be switched to energy generation mode. This can be achieved by varying the rotational speed of the gyroscopic stabilizer's flywheel to suit the user's preferences. Adjusting the rotational speed (rpm) of the flywheel to switch between stabilization and energy harvesting is a novel approach. Designing a control system that enables this is not trivial. Traditionally, research in this area has focused on either maximizing stabilization or maximizing energy generation. However, the disclosed system, which can switch between either mode, offers a new approach.

[0012] In one embodiment, the energy conversion arrangement includes an electric motor (i.e., operable as a generator) having a motor shaft operably coupled to the precession shaft so as to be driven by the rotational motion of the precession shaft. That is, the electric motor is mechanically coupled to the precession shaft. A reduction gear is provided between the motor shaft and the precession shaft to convert the high precession torque and relatively slow precession speed into a high motor shaft rotational speed and low motor shaft torque. For example, a gyroscopic stabilizer may precess at a peak speed of 35 rpm, but the optimum rotational speed of the motor may be 3500 rpm. In this example, a 100:1 reduction gear is required. A smaller gyroscopic stabilizer may require a higher speed motor and a higher gear reduction ratio. A larger gyroscopic stabilizer may use a motor with more poles and rotate at a slower speed with a smaller gear reduction ratio. The reduction gear may consist of, for example, a pair of simple spur gears of different diameters or a planetary gear system.

[0013] In one embodiment, the electric motor is efficient and capable of providing torque in either direction of shaft rotation (i.e., clockwise and counterclockwise) and regenerating energy from the shaft rotation in either direction. The electric motor may be a permanent magnet alternating current (PMAC) motor (also known as a brushless DC motor). Alternatively, it may be an induction motor or a switched reluctance motor. Motor geometries may utilize axial or radial flux.

[0014] The use of electric motors offers several new advantages. First, the precession range of the gyrostabilizer can be extended to approximately ±90° (compared to hydraulic systems, which are typically limited to a range of approximately ±70°). This allows for a larger stabilizing torque to be generated for a given angular momentum. Second, electric motors and motor drives (i.e., speed controllers, variable speed drives, and variable frequency drives) are capable of four-quadrant operation (i.e., braking / generating or driving operation for both clockwise and counterclockwise shaft rotation). Therefore, torque can be provided to the precessing shaft, actively driving the gyrostabilizer for better stabilization in small waves.

[0015] In one embodiment, the energy conversion section comprises a hydraulic circuit operatively coupled to the precession shaft for transferring energy from the rotational motion of the precession shaft to hydraulic energy. The hydraulic circuit includes at least one hydraulic cylinder coupled to the precession shaft for converting the rotational motion of the precession shaft into axial motion of a piston in the hydraulic cylinder to generate hydraulic pressure. Preferably, the hydraulic circuit includes at least two hydraulic cylinders coupled to the precession shaft for converting motion of the precession shaft in either direction about the precession shaft. The hydraulic cylinders are preferably connected to the hydraulic circuit via four check valve rectifiers. In this version of the energy conversion arrangement, the hydraulic cylinders are used to control the precession motion.

[0016] The term "gyrostabilizer" as used throughout this document refers to a gyrostabilizer device or gyrostabilizer unit or "gyrostabilizer assembly" that may be incorporated into or installed on a vehicle, such as a watercraft, or other device that is subject to undesirable rotational motion (such as wave-induced rolling motion) to counteract and / or reduce such undesirable motion. [Brief explanation of the drawings]

[0017] For a more complete understanding of the present invention and its advantages, exemplary embodiments thereof will be described in more detail in the following description taken in conjunction with the accompanying drawings, in which: [Figure 1] FIG. 2 is a schematic partial cross-sectional view of a vacuum chamber assembly in the gyrostabilizer assembly. [Figure 2] FIG. 10 is a schematic diagram of a gyrostabilizer precession shaft mechanically coupled to a motor / generator shaft in one embodiment of the system of the present disclosure. [Figure 3] FIG. 1 is a schematic diagram illustrating four quadrants of operation of the disclosed system in accordance with an embodiment of the disclosure. [Figure 4] FIG. 1 is a schematic diagram illustrating the variation of stabilizing effect and energy production with variation of flywheel rotation speed of a gyrostabilizer. [Figure 5] FIG. 1 is a schematic diagram illustrating the variation in energy production with variation in the precession angle and rate of a gyrostabilizer. [Figure 6] FIG. 1 is a schematic diagram of a hydraulic circuit in one embodiment of an energy conversion system of the present disclosure.

[0018] The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate certain embodiments of the invention and, together with the description, serve to explain the principles of the invention. Other embodiments and many of the attendant advantages of the invention will be readily appreciated as the same become better understood by reference to the following detailed description.

[0019] It will be understood that common and / or well-understood elements that may be useful or necessary in commercially feasible embodiments have not necessarily been depicted in order to facilitate a more abstract view of the embodiments. Additionally, it should be noted that elements in the figures are not necessarily drawn to scale relative to each other. Also, while certain acts or steps in method embodiments may be described or depicted in a particular order of occurrence, those skilled in the art will understand that such specificity with respect to order is not actually required. DETAILED DESCRIPTION OF THE INVENTION

[0020] Referring to FIG. 1, a gyrostabilizer assembly including a vacuum chamber assembly 10 is illustrated schematically. The gyrostabilizer assembly includes a housing 13 enclosing a flywheel chamber 12 for supporting a partial vacuum V (e.g., in the range of approximately 1 to 100 mbar) as an operating pressure. A flywheel 11 is housed within the flywheel or vacuum chamber 12 within the housing 13. The flywheel 11 is attached to, fixed to, or (as shown) integrally formed with a flywheel shaft 19. The flywheel shaft 19 is positioned relative to the housing 13 by an upper spin bearing 21 and a lower spin bearing 31 so that the flywheel 11 can rotate relative to the housing 13 about a spin axis 20 driven by a spin motor. The housing itself is rotatably mounted on a precessing stub shaft or stub axle 14, which is fixed to the housing 13. A precessing bearing 15 is shown attached to the stub shaft or stub axle 14 to define the precessing shaft. Rotation of the vacuum chamber assembly 10 about the precession shaft is controlled by a precession control system 1, which will be described below.

[0021] 2 through 5, a first embodiment of a precession control and / or energy regeneration system 1 includes a shaft S of an electric motor / generator M mechanically coupled to a precession output shaft (e.g., stub shaft) 14 of a gyrostabilizer assembly. The high precession torque and slow precession speed require a reduction gear G between the two shafts S, 14. This allows for low torque and high rotation of the electric motor M, as shown schematically in FIG.

[0022] While the gyroscopic stabilizer may rotate at a peak speed of 35 rpm, the optimum rotational speed of motor M may be 3500 rpm. In this case, a 100:1 reduction gear is required. Smaller gyroscopic stabilizers require a motor with a higher rotational speed, which may require a gear with a higher reduction ratio. Larger gyroscopic stabilizers can use motors with more poles, allowing them to rotate at a slower speed with a smaller reduction gear ratio. The gearing can be a simple pair of unequal diameter spur gears or a planetary gear system. Various gear configurations are possible. The electric motor M is efficient and can provide torque in both directions of rotation (clockwise and counterclockwise) while also providing regenerative energy in both directions through the output shaft. It can be a permanent magnet alternating current (PMAC) motor (also known as a brushless DC motor). Alternatively, it can be an induction motor or a switched reluctance motor. The motor geometry can utilize axial or radial flux.

[0023] The use of an electric motor offers several advantages. Its precession range can be extended to ±90°, allowing for a more stable torque to be generated for a given angular momentum. Furthermore, the electric motor and motor drive (also known as a speed controller / variable speed drive / variable frequency drive) are capable of four-quadrant operation, as shown in Figure 3, allowing it to provide torque to the precession shaft 14 and actively drive the gyrostabilizer in small waves. This is beneficial because it allows the gyrostabilizer to generate better stability in low waves. As mentioned above, there is an inherent tension and trade-off between stabilization and energy generation that must be resolved. This tension results in two operating modes in the present disclosure: a stabilization mode and an energy recovery / energy generation mode. For example, when passengers are on board the vessel, the gyrostabilizer can be switched to stabilization mode, and when the vessel is unmanned, it can be switched to energy generation mode. This can be achieved by varying the rotational speed of the gyrostabilizer flywheel to suit the user's preferences.

[0024] At low precession rates, the ability to harvest / generate electrical energy is low, and therefore the regenerative braking torque applied is low. To maintain effective control of the gyrostabilizer and prevent unwanted shocks, the precession control system may need to consume energy by generating a high counter torque. Therefore, the system can be configured to change from generating energy to consuming energy. When the gyrostabilizer is precessing at its fastest speed, the greatest amount of work done on the precession shaft (due to the induced precession torque) occurs in the middle of the precession range. This is a desirable result because it means that regenerative braking works well in this region, as shown in Figure 5. Alternative methods of controlling the precession of the gyrostabilizer are needed at low (and zero) precession rates, where the impact of the regenerative braking system is limited. For example, mechanical brakes or locking pins may be employed.

[0025] Referring to FIG. 6, a second embodiment of a precession control and / or energy regeneration system 1 is illustrated. In this embodiment, a hydraulic circuit 2 includes two hydraulic cylinders 3 connected by a mechanical linkage L, which is used to control the precession. Piston movement within the hydraulic cylinders 3 causes fluid to flow out of the cylinders 3 and into a main or primary manifold 4. The manifold 4 uses four check valves to rectify the unidirectional flow as shown (i.e., despite the oscillating and alternating direction of precession in the precession shaft 14). The flow exiting the rectification circuit 4 first passes through a control valve 5 for normal braking operation. Downstream of the control valve 5 is a hydraulic motor 6 (whose pump head is coupled to an electric motor M). The electric motor I drive combination is capable of four-quadrant operation, as in the previous embodiment (see FIG. 3). The hydraulic motor 6 can absorb / regenerate energy from the hydraulic fluid flow by regeneratively braking the hydraulic fluid flow. Alternatively, the hydraulic motor 6 can be used to increase the flow rate to assist the gyrostabilizer in moving forward in small waves. A series of accumulators 7 can be arranged to assist in reducing flow / pressure pulses that may result from rectifying the sinusoidal fluid flow generated by oscillations or alternating precession.

[0026] In this embodiment, the system 1 must have several operating modes. In small waves, where the induced precession torque is small, the hydraulic motor 6 may need to be constantly driven and consume energy to increase the precession of the gyrostabilizer (and therefore the stabilizing effect). In this mode, the control valve V is fully open to minimize pressure losses in the circuit. In medium waves, the system's hydraulic motor 6 alternates between supplying and recovering energy to the gyrostabilizer. In the middle of the precession, the precession speed is highest and the motor 6 brakes and generates electrical energy. At both ends of the precession, the hydraulic motor 6 consumes electrical energy to accelerate the precession. In large waves, the hydraulic motor 6 constantly counteracts the precession of the gyrostabilizer and therefore constantly regenerates energy. The control valve V begins to intervene in this mode, i.e., when the braking pressure generated by the hydraulic motor 6 is saturated.

[0027] Thus, the hydraulic system 1 of the embodiment of Figure 6 can simultaneously generate energy and drive the motion of the precession shaft. By using an appropriate hydraulic control system assisted by accumulator 7, as shown in the circuit of Figure 6, the pulsating flow of the gyrostabilizer can be smoothed out. This allows for consistent energy generation during braking. Alternatively, if system 1 requires some excitation input to the precession shaft, this combination of hydraulic components can easily be used to actively drive the precession motion.

[0028] It has been determined that the motion of a gyrostabilizer should be controlled by specifying the allowable precession for each point within the precession range. This can be achieved hydraulically by using a pressure-compensated flow control valve. In this disclosure, a control strategy is adapted to allow for the use of an electric motor. The control utilizes a simple system in which the allowable precession rate is calculated for each time step. The torque input by the motor on the precession shaft is automatically adjusted using a PID loop to achieve the set speed. This methodology means that knowledge of the wave system is not required. As a result, at high precession speeds, useful amounts of energy can be generated. However, at lower speeds, the amount of energy consumed is likely to be low. To assist with this, a battery energy storage system can be used, with the goal being to use an operating point where net energy is produced.

[0029] While specific embodiments of the present invention have been illustrated and described herein, those skilled in the art will recognize that various alternative and / or equivalent embodiments exist. It should be understood that each exemplary embodiment is merely an example and is not intended to limit the scope, applicability, or configuration of the present invention in any way. Rather, the foregoing summary and detailed description will provide those skilled in the art with a convenient roadmap for implementing at least one exemplary embodiment, and it will be understood that various changes can be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope defined by the appended claims and their legal equivalents. In general, this application is intended to cover any adaptations or variations of the specific embodiments discussed herein.

[0030] In general, the present disclosure is intended to cover any adaptations or variations of the specific embodiments discussed herein. By way of example, those skilled in the art will readily appreciate that the gyrostabilizers and energy conversion systems of the present disclosure are not limited to being made from any particular materials described in the specific embodiments. Rather, those skilled in the art will appreciate that a range of suitable materials exists, and those skilled in the art will be able to readily select an appropriate material based on the known mechanical properties of that material suitable for use in the present disclosure. Because the present disclosure involves many fields of engineering, it is expected that the intended "persons skilled in the art" will consist of a group or team of individuals with technical expertise and / or qualifications in one or more of the following fields or disciplines: mechanical engineering, electrical engineering, marine engineering, and hydraulic engineering.

[0031] It is also understood that, as used herein, the terms “comprise,” “comprising,” “include,” “including,” “contain,” “containing,” “have,” “having,” and variations thereof, are intended to be understood in an inclusive (i.e., non-exclusive) sense unless the context indicates otherwise. Any process, method, device, apparatus, or system described herein is understood in a non-exclusive sense such that it is not limited to the described features, integers, portions, elements, or steps, but may include other features, integers, portions, elements, or steps not expressly described and / or inherent in such process, method, device, apparatus, or system. Furthermore, the indefinite articles “a” and “an,” as used herein, are intended to be understood to mean one or more unless expressly stated otherwise. Furthermore, the terms “first,” “second,” “third,” etc., are used merely as labels and are not intended to impose numerical requirements on the importance of their objects or to establish an order of importance. Additionally, references to positional terms such as "lower" and "upper" used in the above description should be taken in the context of the illustrated embodiments and should not be taken as limiting the invention to the literal interpretation of the terms, but rather as would be understood by one of ordinary skill in the art in the appropriate context.

Claims

1. A precession control system for a gyro stabilizer, comprising: A gyro stabilizer, a precession control unit; Equipped with the gyro stabilizer comprises a flywheel mounted for rotation about a spin axis within a gimbal frame attached to the vessel; the gimbal frame includes a precession shaft on which the gyro stabilizer rotates about an axis to stabilize the vessel; The system, wherein the precession control is operatively coupled to the precession shaft to recover or convert kinetic energy or rotational motion of the precession shaft.

2. 10. The system of claim 1, wherein the precession controller operates in an energy generating mode when the precession rate of the gyrostabilizer is relatively high, such as when waves are high.

3. The precession control unit is (i) an energy recovery / energy generation mode in which electrical energy is generated from the rotational motion of the precession shaft; or (ii) A driving mode in which a torque is applied to the precession shaft, i.e., the gyrostabilizer is actively driven.

3. The system according to claim 1, wherein the system operates in accordance with the

4. the precession control unit includes an electric motor operable as a generator; the electric motor includes a motor shaft; 4. The system of claim 1, wherein the motor shaft is operatively coupled to the precession shaft so as to be driven by the rotational movement of the precession shaft.

5. 5. The system of claim 4, wherein a reduction gear is provided between the motor shaft and the precession shaft to convert high precession torque and relatively slow precession speed into high motor shaft rotational speed and lower motor shaft torque.

6. 6. The system of claim 1, wherein the precession control comprises a hydraulic circuit operatively coupled to the precession shaft for transferring energy from the rotational motion of the precession shaft to hydraulic energy.

7. the hydraulic circuit includes at least one hydraulic cylinder; 7. The system of claim 6, wherein the hydraulic cylinder is coupled to the precessing shaft to convert rotational motion of the precessing shaft into axial motion of a piston in the hydraulic cylinder to generate hydraulic pressure.

8. The hydraulic circuit includes at least two hydraulic cylinders; the hydraulic cylinder is coupled to the precession shaft for translating motion of the precession shaft in either direction about the precession shaft; 8. The system of claim 7, wherein the hydraulic cylinder is connected to the hydraulic circuit through four check valve rectifiers.

9. 1. A system for recovering energy from a gyro stabilizer, comprising: A gyro stabilizer, An energy conversion unit; Equipped with the gyro stabilizer comprises a flywheel mounted for rotation about a spin axis within a gimbal frame attached to the vessel; the gimbal frame includes a precession shaft on which the gyro stabilizer rotates about an axis to stabilize the vessel; 1. The system, wherein the energy conversion unit is operatively coupled to the precession shaft to recover the rotational motion of the precession shaft, preferably to convert the rotational motion of the precession shaft into electrical energy or hydraulic energy.

10. 10. The system of claim 9, wherein the energy conversion unit operates in an energy generation mode when the precession rate of the gyrostabilizer is relatively high, for example, when waves are high.

11. The energy conversion unit is (i) an energy generation mode in which electrical energy is generated from the rotational motion of the precession shaft; or (ii) A driving mode in which a torque is applied to the precession shaft, i.e., the gyrostabilizer is actively driven.

11. The system according to claim 9 or 10, characterized in that it operates in

12. the energy conversion unit includes an electric motor operable as a generator; the electric motor includes a motor shaft; 12. The system of any of claims 9 to 11, wherein the motor shaft is operatively coupled to the precession shaft so as to be driven by the rotational movement of the precession shaft.

13. 13. The system of claim 12, wherein a reduction gear is provided between the motor shaft and the precession shaft to convert high precession torque and relatively slow precession speed into high motor shaft rotational speed and lower motor shaft torque.

14. 14. The system of any one of claims 9 to 13, wherein the energy conversion portion comprises a hydraulic circuit operatively coupled to the precession shaft for transferring energy from the rotational motion of the precession shaft to hydraulic energy.

15. the hydraulic circuit includes at least one hydraulic cylinder; 15. The system of claim 14, wherein the hydraulic cylinder is coupled to the precessing shaft to convert rotational motion of the precessing shaft into axial motion of a piston in the hydraulic cylinder to generate hydraulic pressure.

16. The hydraulic circuit includes at least two hydraulic cylinders; the hydraulic cylinder is coupled to the precession shaft for translating motion of the precession shaft in either direction about the precession shaft; 16. The system of claim 15, wherein the hydraulic cylinder is connected to the hydraulic circuit through four check valve rectifiers.

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