Mechanisms for creating undulating motion, such as for propulsion, and for harnessing the energy of moving fluid

Mechanisms are described which receive and transfer forces via transducers having one or more persistent deformations in changeable locations. Actuator or propulsion embodiments are powered by elastic or variable length transducers that exert forces on the deformed members which in turn exert forces onto ambient fluid such as air or water. Generator embodiments receive forces from ambient moving fluid via deformed members which transfer those forces to elastic or variable length transducers which convert those forces into electrical energy.

All of the aforementioned applications are expressly incorporated herein by reference.

TECHNICAL FIELD

Disclosed are apparatuses, methods and systems which, in various embodiments, facilitate the conversion of mechanical energy into electrical energy and/or facilitate the conversion of electrical energy into mechanical energy.

BACKGROUND

Mechanical devices actuated to perform prescribed motions for a variety of purposes are ubiquitous. Less common are actuated devices that create a prescribed, repetitive undulating motion, or effect. A variety of mechanical and/or electrical devices have come about to either harness the kinetic energy of moving fluids, or to create the movement of the fluids themselves. For example, seafaring vessels may employ a propeller, powered by a mechanical engine, to move through the water. There are also devices developed to harness the power of moving fluid, whereby an electromagnetic generator is coupled to the fluid, such as by a turbine wheel, to produce electrical energy for distribution and consumption by all manner of electrical-energy-powered devices.

SUMMARY

Embodiments of the disclosed apparatuses, methods and systems may be directed to devices which create repetitive and/or undulating motion, or effect, to produce useful work, such as for a propulsion system or other system. These and alternative embodiments may further be directed to devices which exhibit this same undulating motion when external forces are applied, and where this undulating motion is coupled to electricity generating components. Such uses are a consequence of a functional symmetry between actuation and energy harnessing, as between an electromagnetic motor and an electromagnetic generator.

In some embodiments, flexible sheet-like members are deformed with applied force and the resulting deformation or deformations are maintained through restraining components.

In one embodiment the restraining components are vertebra plates to which the deformed, flexible sheet-like members are attached in such a manner that they are unable to return to their relaxed state. In some implementations, the vertebrae plates may be elastically or variably-coupled to a central rigid tube or member. The elastic or variable coupled components may, in various implementations, be comprised of electroactive polymer material, a magnetostrictive material, a metal coil passing through a magnetic field, hydraulic pistons, pneumatic pistons, shape memory alloy elements, and/or the like.

For propulsion embodiments, when the elastic or variable coupling components are actuated with an input of energy, such as an excitation, they will change length and impart forces onto the deformed, flexible sheet-like members, causing their deformations to shift position. In this manner the elastic or variably-coupled actuators create undulation motion along the flexible sheet-like members which may impart force onto ambient fluid to create thrust.

For generator embodiments secured in the directional flow of fluid, the kinetic energy of the fluid imparts force onto the flexible sheet-like member, causing the positions of the deformations to shift in the direction of the fluid flow. Back and forth fluid flow may cause the deformations to move back and forth. Unidirectional fluid flow may cause the deformations to travel in one direction until they move off the downstream end of the flexible sheet-like member.

Because these deformations result from the internal energy state of the flexible sheet-like member created during fabrication, these deformations cannot be eliminated so long as the restraints remain. Therefore, when a deformation moves off the downstream end of the flexible sheet-like member, another one must come into existence at the upstream end. When the mechanism is anchored in a fluid stream, a series of undulating deformations may travel continuously along the flexible sheet-like member in the direction of the fluid stream. In one generator embodiment, the flexible sheet-like members may be coupled to vertebra plates so that movement of the deformations of the flexible sheet-like members powers the movement of the vertebra plates. The movement of the vertebra plates imparts force onto the elastic or variable coupling components. The elastic or variable coupling component may incorporate transducing components which convert this force into electrical energy. The elastic coupling components may, in some implementations, be constructed of and/or incorporate an electroactive polymer or other electroactive material able to convert mechanical strain into electrical energy. The elastic coupling component may also, in some implementations, be constructed of a magnetostrictive material, a metal coil passing through a magnetic field, hydraulic pistons, pneumatic pistons, shape memory alloy elements, and/or the like.

The architecture of the system may be the same or similar for certain propulsion and pump embodiments. For example, the difference between some pump and propulsion embodiments is that the elastic or variable coupling components of the propulsion and pump embodiments are actuators rather than generators. In other words, in propulsion embodiments the elastic or variable coupling components convert electrical energy into mechanical actionFIG. 1whereas in the generator embodiments the elastic or variable coupling components convert mechanical action into electrical energy,FIG. 2.

The mechanisms, including apparatuses, methods and systems, discussed herein are not dependent on any particular actuator technology nor on any particular generator technology.

DETAILED DESCRIPTION

In some embodiments, flexible sheet-like members1are deformed with at least one applied force2in such a manner as to create one or more deformationsFIG. 3to form a crenated strip3. The deformation(s) of the crenated strip3may be maintained via one or more restraining components. In one embodiment, this restraining component is at least one vertebra plate4coupled in at least one location to the crenated strip3. The restrained crenated strip is referred to as the crenated strip fin, or CS fin5,FIG. 4.

The CS fin5may be coupled, in some implementations, to a rigid or semi rigid central member6, such as via one or more variable length or elastic tendons7. Directional forces between the tendon7and central member6are balanced by equal and opposite directional forces of at least one other tendon7and one other CS fin5.FIG. 4.

FIG. 5shows an embodiment of a single vertebra plate4with multiple tendons7attached to the central member6at one end, and attached to the vertebra plate4via a bar connector8at another other end. The configuration inFIG. 5may work equally well for propulsion and generator embodiments.

For actuated embodiments, actuation of the tendons7will cause them to lengthen or shorten, thereby changing the internal energy state of the CS fins5and thereby causing the position of the deformation, or deformations, to shift position. In shifting position relative to an ambient fluid, the deformations of the CS fins5may impart forces onto the ambient fluid to create a propulsive effect in some embodiments. In one embodiment, the tendons7may be comprised of rolled or stacked electroactive polymers, a class of materials which may contract when an electric charge is applied via electrodes. Electrical energy from a power source is converted to mechanical strain in electroactive polymer tendons7. Adding charge to or removing charge from an electroactive polymer tendon7may cause the length of the tendon7to change. Therefore, by controlling charge to the tendons7, the relative lengths of the tendons may be controlled. As their lengths change, the forces they impart to the CS fins5change and therefore the internal energy states of the CS fins5change, causing the positions of the deformations to change.

For generator embodiments of the invention, forces14from ambient moving fluid may cause the deformations of the CS fins5to shift in position, imparting force onto the tendons7. This force on the tendons7may cause them to lengthen or shorten in some implementations. In one embodiment, the tendons7are comprised of electroactive polymers, which may convert mechanical energy into electrical energy through material strain and may convert electrical energy into mechanical strain,FIGS. 8-14

For generator embodiments, mechanical energy may act upon an electroactive polymer sheet with electrodes, and/or other type of transducer. In some implementations, electrical energy from the transducer passes through generator control electronics and then to power conversion circuitry, and then to an electrical output or storage device.FIG. 6. For actuator embodiments, energy from a battery or other energy source may pass through a converter and then through actuator electronics, then to electroactive polymer material via electrodes, and/or to some other transducer, which converts electrical energy into mechanical energy.FIG. 7.

FIGS. 8-11show aspects of a sequence under operation and forces of moving water14, showing how in one generator embodiment, the travel of deformations along a CS fin5correlates with rotation of vertebra plates4which in turn changes the length of the tendons7via which the CS5fins are coupled to the central member6. The deformations can, in one implementation, be thought of as protruding from either side of a neutral axis and causing partial rotation clockwise or counter clockwise.FIGS. 8-11track a single point15on a CS fin5as defined by maximum deformation and maximum rotation. The relative rotation16of a vertebra plate4may correlate with the movement of a single point15of deformation along the CS fin5.

FIGS. 12-14show aspects of a sequence under operation of a generator embodiment showing a top view of the embodiment shown inFIGS. 8-11, and tracks the travel of a single point17on one CS fin5at maximum wave amplitude, or rotation, as deformations travel along the CS fin5imparting rotation to the vertebra plates4.

FIGS. 15-18show aspects of a sequence under operation of an actuated propulsion embodiment, showing how, in one implementation, actuated tendons7may sequentially rotate vertebra plates4which impart force onto the CS fins5to create a propulsive force18.FIGS. 15-18track a single point15on a CS fin5as defined by maximum deformation and maximum rotation. The relative rotation16of a vertebra plate4may correlate with the movement of a single point15of deformation along the CS fin5.

FIG. 19shows some aspects of a generator embodiment attached to one implementation of an anchoring mechanism19that will hold the mechanism still in a fluid stream. In the illustrated embodiment, flexible longitudinal strips20enclose the vertebra plates and tendons in a longitudinal enclosure21. For hydropower embodiments, the longitudinal strips20may provide a waterproof enclosure21,FIG. 20, such as to keep electronic components dry. This waterproofing may not be a requirement for wind power embodiments. The electronic components enclosed within the longitudinal enclosure21may include electroactive polymer tendons, wiring, printed circuit boards, and/or the like components. In one implementation, electronic components may be housed in the anchoring mechanism19and connected to the generator core by a conduit22.

FIG. 21shows some aspects of the generator embodiment ofFIG. 20without the longitudinal strips20to reveal the vertebra plates4and tendons7inside.

The number of CS fins5may vary in different embodiments for both propulsion and generation,FIGS. 22-24.FIG. 25shows a generator embodiment with 2 CS fins.

In yet another embodiment of the present inventionFIG. 26, the CS fins5may be eliminated and the longitudinal strips20are the external surface primarily interacting with the fluid instead. In such embodiments without the CS fins5, the vertebra plates4may be widenedFIG. 28. During fabrication, forces may be applied to the longitudinal strips20in their relaxed state to create deformations in the longitudinal strips20. The vertebra plates4may be coupled to the longitudinal strips20and elastically or variably coupled to the central member6via tendons7in some implementations. The longitudinal strips20are unable to return to their pre-deformed shape after being restrained via attachment to the vertebra plates4. Therefore, undulations in the longitudinal strips20persist and undulations, such as traveling undulations, are expressed as partial rotation of the vertebra plates4clockwise and counterclockwise.

Rotation of the vertebra plates causes the lengths of the tendons7to change.FIGS. 29-33illustrate aspects of a vertebra plate4undergoing a sequence of clockwise rotations and show how the tendons7change length with rotation in one implementation.FIGS. 34-38illustrate further detail from the same sequence with the vertebra plate4removed from view but with rings23that couple the vertebra plates to the tendons remaining visible.

Several of these embodiments may be attached to a vessel to propel the vessel through fluid. In one implementation, one device is attached to the vessel, and in alternative embodiments, multiple devices may be attached. The device may be attached to the vessel by, for example, connecting the central core member to the vessel. This connection may be made with screws, glue, gusset plates, or other connecting mechanism. Alternate means of connection may also be implemented.

FIG. 27illustrates an example of a free-swimming propulsion embodiment25.

In yet another implementation of the propulsion embodiment, the central member26is flexible and may be induced to bend in any direction via one or more actuated longitudinal tendons27which connect to each other end-to-end forming one or more rows of longitudinal tendon27lines that run parallel to the flexible central member26,FIGS. 39-40. Actuation of the longitudinal tendons27causes them to change in length. This change in length may occur by applying and releasing voltage, current, pressure, a magnetic field and/or the like. Three or more rows of longitudinal tendons27allow control of direction of movement of a free-swimming propulsion mechanism25. The longitudinal tendons27are fixed to the flexible central member26, such as by radial arms28and may be arranged relative to the flexible central member26so that one line is above and one line is below the flexible central member26, and one line is to one side of the flexible central member26, and one line is to the other side of the flexible central member26, such as in a cross-shaped pattern. Reducing the length of only the upper line of longitudinal tendons27will cause the central axis of the mechanism to curve upward. Reducing the length of only the lower line of longitudinal tendons27will cause the central axis of the mechanism to curve downwards. In the same way, reducing the length of the line of longitudinal tendons27on only one side causes the central axis of the mechanism to curve towards that side, and the mechanism will veer in that direction.

In one implementation, each line of longitudinal tendons27may be supplied with an actuation circuit and a sensor circuit connected electronically to a microcontroller29, which may control the length of each via actuation of the line of longitudinal tendons27. In this manner, the microcontroller may cause the direction of travel of the vessel to change by causing the longitudinal central axis of the mechanism to curve, causing the vessel to alter its course from a straight trajectory to a curved trajectory. The longitudinal tendons27may be comprised of a number of different materials, such as electroactive polymers, shape memory alloys, carbon nano-tubes, and/or any other of a variety of existing and emerging materials in which the material will change shape when actuated by electric charge, heat and/or other input. In addition, these actuated components described above may be actuated pneumatically or hydraulically using assemblies of components such as pumps and valves coupled to such final actuators as pistons, diaphragms and/or other actuators. Methods by which such components may be induced to change the shape and/or length may be applied, so that the arrangements described above will produce the desired actions described above, whichever materials/components are used.

Some of the propulsion and generator embodiments disclosed thus far have utilized rotary reciprocating motion of the vertebral plates, with the CS fins5coupled to the vertebra plates4so that the CS fins5undulate substantially in-phase with each otherFIG. 41. The longitudinal strips20also undulate substantially in-phase with each other in such embodiments. In another implementation, the CS fins5may rotate in substantially opposite directions relative to each other to create a bilateral reciprocating actionFIG. 42.

Bilateral reciprocator30embodiments may be configured with a central member6coupled on opposite sides by tendons7that, as with embodiments utilizing rotational motion, may be actuators for propulsion embodiments or energy harnessing components for generator embodiments. The forces within the deformations of the CS fins5are transferred first to the longitudinal strips20and then onto the tendons7and then onto the central member6. Each tendon7may, in one implementation, be coupled at one end to the central member6, such as via a tension bracket31, and may be coupled at the other end to the junction point32of two longitudinal strips20, such as via a tension hanger bracket33,FIGS. 43-47.

FIG. 44illustrates some aspects of assembled details of a bilateral reciprocating embodiment.

FIG. 45illustrates some aspects of a bilateral reciprocating embodiment with its longitudinal strips20removed.

FIG. 46illustrates some aspects of a bilateral reciprocating embodiment with its CS fins5removed.

FIG. 47illustrates some aspects of a bilateral reciprocating embodiment ofFIG. 46with its CS fins5removed and its longitudinal strips20removed.

Actuator embodiments of the bilateral reciprocator30utilizing electroactive polymers may be employed to address the challenge of electroactive polymer actuation in which tension force is desired: The potential energy stored in the CS fins during the fabrication process from the force2used to create the persistent deformations of the crenated strips3that forms the CS fins5, is redistributed within the CS fin5when charge is selectively applied to tendons7. Therefore, rather than actuation of a tendon7causing it to contract and exert propulsive force onto the CS fin5, actuation of a tendon causes it to elongate, which causes deformations to shift via the elastic forces loaded as potential energy during fabrication.

Described another way, the tendons of propulsion embodiment are not actuated to exert tensile force. The tensile forces in the entire mechanism are present due to deformation forces during fabrication. Actuation of tendons may cause them to relax, thus changing the balance of forces and causing the stored potential energy to release, thereby initiating motion in the tendons7and therefore also in the CS fins5.

Some actuator and generator embodiments may also be described as follows:

Two or more crenated strips3or deformed members3elastically coupled to a rigid or semi rigid central member6via tendons7so that the deformation energy of one deformed member3is shared with every other deformed member3in dynamic equilibrium.

A rigid or semi rigid central member6symmetrically coupled via tendons7to at least two deformed members3with the potential energy of the deformations in the deformed members3held in equilibrium by the transfer of forces between the deformed members3via the tendons7.

A central rigid or semi-rigid member6elastically coupled via tendons7to at least two deformed members3whose internal energy states communicate via the tendons7and rigid or semi-rigid member6so that the internal energy states of the deformed members3are in equilibrium.

Energy from an external source such as the kinetic energy of moving water or air causes the deformations of the deformed members3to shift and in so doing impart energy onto the tendons7from which energy may be harnessed. An input of energy into the tendons7causing them to expand or contract imparts forces onto the deformed members3causing the deformations therein to shift and thereby imparting force onto ambient fluid such as air or water to create a propulsive effect.

This disclosure describes inventive aspects, including at least the following:

It is to be understood that the tendons7of propulsion and generator embodiments may be configured as transducers and may be comprised of a number of different components. Embodiments discussed herein are directed to novel mechanical components and their novel assembly which effectively transfer forces to the tendon7transducers, or transfer forces away from the tendon7transducers. Therefore, this invention may couple with other components not described explicitly. Examples include adaptations whereby the tendons7are pneumatic tubes or pistons which may pump a fluid for the purpose of pumping, and/or to drive a conventional electromagnetic generator.

It is to be understood that while the embodiments discussed herein focus on examples utilizing electroactive polymer materials for the tendons7, the mechanical principles brought to bear work equally well for embodiments in which the tendons7may be any elastic or variable length transducer. Embodiments discussed herein are directed to the design, arrangement and functioning of mechanical components acting upon tendons7, which are transducers for propulsion or energy harnessing.

The deformed member3or CS5fins described herein may also, in some implementations, be comprised of a segmented sheet-like material, such as one having portions which are stiffer coupled to each other by portions or joints which are less stiff.

FIG. 48illustrates some aspects of a generator embodiment in which the transducer of at least one vertebra is an electromagnetic generator34rotationally coupled to the vertebra plate4and fixed to the central member6. Traveling undulations of the CS fins5cause rotational movement of the vertebra plates4as described above, generating electricity in the ring generators34which may be fixed in position relative to the central member6.

FIG. 48also illustrates some aspects of a propulsion embodiment in which the transducer of at least one vertebra is an electric motor35rotationally coupled to the vertebra plate4and fixed to the central member6. Actuation of the electric motor35causes the vertebra plates4to rotate which imparts force to the CS fins5which impart force onto ambient fluid

Some propulsion embodiments may also be described as follows:

Two or more deformed flexible members3symmetrically coupled to a fixed central member6so that the potential energy in the deformations of each flexible member3are in equilibrium with the potential energy in the deformations of every other flexible member3, and where the coupling mechanism is a transducer, and whereby an external energy source14causes the distribution of potential energy in the flexible members3to change and transfer energy to the transducers which harness the transferred energy. The transducer may be electroactive polymers, electromagnetic generator, etc.

Two or more deformed flexible members3symmetrically coupled to a fixed central member6so that the potential energy in the deformations of each flexible member6are in equilibrium with the potential energy in the deformations of every other flexible member6, and where the coupling mechanism is a transducer, and where actuation of the transducer imparts force onto the flexible members3causing the distribution of potential energy in the deformed flexible members3to change and to transfer force onto the deformed flexible members3thereby creating a propulsive action18. The transducer may be electroactive polymers, electromagnetic motor, etc.

FIG. 49shows an exemplary embodiment of transducer excitation. A plurality of transducers may be affixed in sequence in a direction of desired wave propagation, wherein the plurality of transducers are each affixed at a first end to a first restraining component4901. The second end of the plurality of transducers may be affixed to a second restraining component, wherein the plurality of transducers are maintained in ma state of excited equilibrium by connections to the first and second restraining components4905. In some embodiments, the maintained state of excited equilibrium may be caused by an elongation of tendons, an applied pressure, and/or the like. An excitation signal may be applied to a first group of transducers, wherein the excitation signal causes a release in the transducer of mechanical resistance to forces imparted by the first and second restraining components4910. The excitation signal may, in various embodiments, be a voltage, current, pressure, magnetic field, and/or the like. In some implementations, the strength of the excitation signal may be determined based on, for example, wave length, wave speed, wave frequency, historical values, sensor data wherein the sensors may track factors such as stress or displacement, and/or the like. Conditions may be monitored via a processor, CPU, microcontroller, and/or the like to determine the next excitation4915and a determination of whether the next excitation condition is satisfied4920. The processor, CPU, microcontroller, etc., may also determine how much, where, and when excitation should be applied. The conditions may be based on, for example, whether sensor data such as a force or displacement exceeds or drops below a certain value. For example, the sensors may measure force in the tendons or displacement in the CS fins relative to a certain threshold. In an alternative embodiment, the condition may be based on a set passage of time and/or a model that indicates a signal should be sent to a certain part at a certain time. For example, in some implementations, sequence programming in the memory or data structures may include time, place, and the amount and/or type of excitation to apply as it relates to the propagation of a wave. If the condition is not met, the system may wait for a predetermined period of time4925or, in an alternative embodiment, continually loop to monitor for the next excitation4915. When the next excitation condition is satisfied4920, an excitation may be applied to the next group of transducers4930. In some embodiments, as the wave propagates, the amount of excitation applied may decrease; that is, as motion propagates through the CS fins, the tendons may require less excitation. In some implementations, sensors may measure a restraining force, which may then be compared to a threshold value to determine the amount of excitation to apply. Further embodiments may show that when the excitation occurs in one group of transducers, the force on the second group of transducers is increased. In alternative embodiments, the force on the second group of transducers may be decreased after excitation occurs in the first group of transducers. If there is another group of transducers4935, the system may monitor for the condition for the next excitation4915; if there are no more groups, the loop terminates4940.