This invention relates to the field of motors for converting energy from ocean waves, tides or other moving bodies of water or other fluids to mechanical work, and in particular to converting the energy found in such moving fluid masses to rotational energy so as to drive a transmission which in turn may drive a generator or the like.
As stated by Solell in U.S. Pat. No. 4,145,885 which issued Mar. 27, 1979 for a Wave Motor, it is known that the energy in the sea constitutes a vast reservoir of energy which has remained largely untapped to the present time. In that patent Solell proposes a wave motor which includes a float, a displaceable member coupled to the float so as to be displaceable by the ascent and descent of the float, a pair of shafts, and a transmission including a pair of one-way clutches coupling the displaceable member to the shafts to rotate one in one direction during the ascent of the float and to rotate the other in the opposite direction during the descent of the float. In particular, Solell discloses that the displaceable member is a wheel that is rotated in opposite directions by the ascent and descent of the float, or that may be a rack which is moved upwardly by the ascent of the float and downwardly by its descent.
In the Solell patent, the floats float on the exposed surface of the ocean waves and in applicant's view are therefore exposed to the waves' action. In the embodiment depicted in
In the prior art applicant is also aware of U.S. Pat. No. 5,889,336 which issued to Tateishi on Mar. 30, 1999 for a Power Generating Installation. Tateishi discloses a shallow water power generating installation for utilizing shallow water waves to generate power. The mechanical part of a power generating installation is mounted in the bottom of a hollow float. Access is via a manhole in the float to provide maintenance to the power generating equipment in the float. The float and manhole is sealed to prevent penetration of sea water into the float. Sprocket wheels for driving the power generating equipment are mounted in an open bottom central rectangular portion formed in the underside of the float. A length of chain is engaged with the sprocket wheels. Kinetic energy of an up-and-down motion of a wave turns to rotary power of the sprocket wheels. A plurality of floats form a web inter-connected by connecting members which are adapted to allow independent vertical movement of each float.
One problem applicant perceives in the prior art of Tateishi is due to horizontal movement of the web of floats. It is applicant's opinion that such horizontal movement due to waves and swells may cause the normally vertical moorage and weighted lines and chains to move and thus possibly tangle with one another. The solution according to one aspect of the present invention is to position the anchor weights on the seabed a laterally outwardly spaced distance away from a position directly under the floating structure to minimize the chance of entanglement of the line/chains with the suspended weight chains, and to arrange the anchor weights on the seabed spaced laterally outwardly and radially about the floating structure to resist and dampen horizontal movement of the floating structure, and so as to urge the floating structure to return to its at rest position.
Such a radially spaced array of weights, lines/chains and corresponding power units, radially spaced around the entire perimeter or circumference of the floating structure, also conveniently lends itself to mounting the sprockets, etc on the exterior side walls of the floating structure up out of the sea water. This improves access for maintenance and repair of the power unit, and reduces the effects on the power unit of being submerged in sea water.
In the present invention, three bodies interact to drive a transmission having a pair of one-way clutches coupling a single length of drive chain or other elongate flexible member to an intermeshed pair of counter rotatable gears so as to drive a primary shaft in a single rotational direction. A first gear of the pair of gears is mounted on the primary shaft, and a second gear of the pair of the intermeshed gears is mounted on a secondary shaft adjacent and parallel to the primary shaft. The pair of one-way clutches are mounted on each of the ends of the two shafts.
The three bodies required for the operation of the present invention are a fixed body, a floating body, and a suspended and usually submerged weighted body. The three bodies are interconnected by the single length of the elongate flexible member and are spaced apart there along. The weighted body, which may simply be a weight, however could be a spring or other device, is mounted at one end of the elongate flexible member. The elongate flexible member extends upwardly from the weight and follows the shape of an inverted “u” as it extends over, so as to be coupled with, the pair of one-way clutches which are mounted on the ends of the primary and secondary shafts. The pair of clutches are spaced apart in a planar arrangement in the vertex of the inverted u-shaped flexible member. The primary and secondary shafts are mounted to a second body above the surface of the moving fluid mass, and the end of the flexible member opposite to the weight is mounted to a third body disposed underneath the second body.
In one embodiment, the second body is a floating structure and the third body is an anchor resting in a fixed position underneath the floating structure such that movement of the moving fluid mass, which may for example be the ocean, causes the floating structure to translate in a direction having a predominately vertical direction. As the floating structure oscillates predominately vertically, during its ascent the length of the flexible member extending between the floating structure and the anchor lengthens, thereby shortening the length of the flexible member between the floating structure and the weight, it being understood that the elongate flexible member is substantially inelastic and therefore of a substantially fixed length. In this embodiment then the transmission, and in particular its exposed pair of one-way clutches, are mounted high enough up on the floating structure to minimize battering by the waves, and the weight and the anchor remain submerged, again, to minimize the battering effect of waves travelling on the surface of the moving fluid mass. On the ascent of the floating structure, the flexible member drives one of the one-way clutches to rotate its corresponding shaft in one direction and rotates the other one-way clutch and corresponding shaft in the opposite direction during the descent.
In a second embodiment, the second body is a fixed structure mounted above the surface of the moving fluid mass, and the third body is a float riding on the surface of the moving fluid mass. The transmission is mounted onto the fixed structure, that is, the second body, so as to once again be mounted high enough to be up out of the way of interference by the waves. The transmission operates in the same fashion as described for the first embodiment, and differs from the teaching of Solell in his U.S. Pat. No. 4,145,885 described above, in at least that the use of the suspended weight allows the operation of the transmission no matter which direction the waves are moving relative to the fixed structure and float.
Thus as may be seen by an understanding of the first and second embodiments of the present invention, it is the use of the weight, or other suspended weighted body, that enables the relative movement between the first, second and third bodies as the fluid mass moves or swells (or is otherwise elevated, rises and falls or such other hydraulic actuation) to drive the drive chain or other flexible member riding over the pair of one-way clutches, the weight tensions the chain while suspended either above-surface or subsurface, and enables the drive chain to continuously drive the primary and secondary shafts via the clutches resulting in a continuous rotation of the primary shaft in a useful rotational direction so as to for example drive an electrical generator or otherwise to provide work.
The relative movement between the first, second and third bodies provides for an upward stroke of the weight as the distance between the second and third bodies lengthens and provides for a downward stroke of the weight as the distance between the second and third bodies shortens as the moving body of fluid swells and subsides respectively. The hydraulic energy in the swelling or otherwise elevation of the surface of the fluid mass provides the energy to raise the weight, and then as the surface of the fluid mass falls, the weight falls correspondingly thereby tensioning the flexible member over the one-way clutches as the change in relative position between the three bodies causes the rotation of the one-way clutches and the corresponding rotation of either the primary shaft directly with the secondary shaft being free running or of the primary shaft indirectly as driven by the driven rotation of the secondary shaft driving the pair of intermeshed gears which thereby drive the primary shaft in its useful rotational direction.
a is a perspective diagrammatic view of a large scale pontoon having a multiplicity of the power generation units of
a is the system of
b is the system of
c is the system of
d is the system of
a illustrates the variables associated with the design of the power unit of
As seen in
As is known in the art, in the one form of one-way clutch which is illustrated, and which is not intended to be limiting, each clutch includes an outer body in the form of a ring 20a and 22a which may be a sprocket usually having teeth or the like (not shown) for mating with an elongate flexible member such as drive chain 26. An inner ratchet mechanism 20b and 22b are respectively mounted rotatably within rings 20a and 22a. The ratchets are each mounted rigidly to the ends of the corresponding shafts 12 and 14 and are coupled to the corresponding outer rings 20a and 22a by a radially spaced apart array of balls 20c and 22c radially spaced apart around and between rings 20a and 22a, and inner ratchet mechanisms 20b and 22b. As would be known to one skilled in the art, rotation of the outer rings relative to the inner ratchet mechanisms tend to wedge the corresponding balls between the outer ring and inner ratchet thereby effecting a coupling between the outer ring and the corresponding inner ratchet as the outer ring rotates first in a direction which compresses the balls into engagement with the ratchet mechanism and decouples the ring from the ratchet mechanism when the outer ring rotates in the opposite direction leaving thereby the outer ring to be free running with respect to the ratchet.
Thus in the embodiment of
As the swell of ocean 36 subsides so that floating structure 30 descends in a direction opposite to direction A, causing weight 28 to translate in a direction opposite to direction B, chain 26 runs in direction E, again as seen in
In
Total displacement of water would be the sum of the weight of the pontoon, the weight of the mechanical components 24, 38, 40, and the weights 28 attached to the chains 26. The mechanical components are mounted to platforms 33 attached along the inner sides of the walls, and braced by braces 33a for stability. The amount of freeboard (distance from surface of water to top of structure) is calculated to allow free access to the mechanical components, yet minimize the effect of wind moving the pontoon horizontally. Sealed hatches 30b located in the top of the pontoon provide access. The amount of power produced may be varied, with variable being the number and size of generators, etcetera, the draft, beam and length of the pontoon. This embodiment may be retro-fitted to other existing floating structures, such as used barges, hulls from de-commissioned ships or other existing floating structures.
Apart from the driving of transmission 10 by the operation of ocean swells, the rise and fall of the tides may also operate to drive transmission 10 thereby provide for usable work being provided by shaft 12.
For example in an ebb tide, as the tide recedes, floating structure 30 descends and free weight 28 at end 26a of chain 26 pulling downwardly under the force of gravity urges one of the pair of one-way clutches to rotate its corresponding shaft while being free running over the other clutch. Another example would be during a flood tide so that as the tide changes and starts to flood floating structure 30 starts to ascend and anchor 32 on seabed 34 then tensions chain 26 so as to cause translation of the chain in an opposite direction thereby reversing the operation of the pair of clutches. That is, the drive clutch during the descent of the floating structure becomes the returning clutch and the clutch which was the free turning clutch during the descent of the floating structure becomes the driving clutch. Thus during both the ebb tide and flood tide as the floating structure correspondingly descends and ascends, the pair of one-way clutches operate to drive shaft 12 continuously in a single rotational direction.
With respect to floating structure 30, it may be a free floating or a tethered floating structure including such things as floating marinas or docks, barges, house boats, such examples not intending to be limiting.
Frame 104 is aligned with frame 106 mounted on the interior of the hull of floating structure 31. Shaft 108 extends from speed multiplier 102, through seals 110 in the hull side wall 31a and bearings 112 on frame 106 so as to drive output sprocket 114. Drive belt 116 on sprocket 114 drives one-way clutches and gears as hereinbefore described within gearbox 118, which turns flywheel 120 and drives electrical generating device 122, which may as depicted be a generator or alternator. Gearbox 118 may also drive other devices such as pumps, etc.
As would be know to one skilled in the art the following variables may be adjusted for conditions, required or provided load, size of vessel, for example: the gear ratio of speed multiplier 102, the size of sprocket 100, the size and weight of weight 28, the size of sprocket 114, the size or circumference dimensions of the over-running or one-way clutches 118a or gears 118b, the size of flywheel 120, and the torque and rpm specifications of electrical generating device 122.
Thus as seen in
As seen in
In terms of the potential power that may be provided by the present invention without substantially affecting vessel draft, the chart of
Thus the combination of the system described herein provides a combination of the advantages of continuously capturing energy by the rise and fall of ocean swells and waves with the advantages of a stabilized platform anchored to the seafloor, which is horizontally or laterally stabilized while resisting tangling of mooring and weight lines or chains, and providing for ease of access to sprockets, gearing, generators, pumps, drives, etc, when mounted externally above the water line of the floating structure. A further advantage of such separate externally mounted devices is that they may be retrofitted to many existing kinds of floating structures including old barges or decommissioned strips thus reducing the cost of providing power.
In some coastal areas tidal flats occur at low tide. In order to capture the full height of a tide, as seen in
As seen in
During the flood tides, as the tide floods, the float rises and the counterweight forces the chain to rotate the pair of one-way clutches 20, 22 to thereby rotate shaft 12. Once the tidal tank fills, the valve 54 from the sea to the tidal tank 44 closes, preventing further ingress of sea water. The valve 48 between the tidal tank 44 and the equalization tank 42 opens, allowing the water to flow from the tidal tank 44 into the equalization tank 42 until the level of the two tanks equalizes. This causes the float 52 to drop in the tidal tank 44 and the counterweight 28 to rise, turning the clutches 20, 22 in the opposite direction. This again causes shaft 12 to rotate.
Once the tank levels equalize, the equalization tank valve 48 closes and the sea water valve 54 opens and water continues to flow into the tidal tank 44 until it reaches a level which is higher than the earlier level attained when valve 54 was open because of the incoming tide. Then the sea water valve closes and the equalization tank valve 48 opens allowing the water to flow into the equalization tank 42 until the two tanks once again equalize.
Each time the water rises or falls in the tidal tank 44 it causes the shaft 12 to rotate. The use of an equalization tank 42 significantly increases to total vertical movement—the larger the equalization tank—the greater the increase in vertical tide movement. An equalization tank 42 of double the surface area of the tidal tank 44 almost triples the vertical distance the water rises and falls within the tidal tank 44. By way of analogy then the tidal tank acts as a cylinder and the reciprocating motion of the float on the end-weighted chain as a piston reciprocating in the cylinder.
During the ebb tide, with both valves closed, the level of the water in the tidal tank 44 lowers to a pre-determined level. The sea valve 54 closes, then the equalization tank valve 48 opens and water from the equalization tank 42 moves into the tidal tank 44 until the water level in both tanks equalizes. Every time the water in the tidal tank 44 lowers and then rises, alternatingly ascending and descending, it causes shaft 12 to rotate.
This permits a tidal power unit to operate during times when sea ice or other severe weather conditions would make other systems difficult or impossible to continue to operate. Pure vertical tidal power (disregarding swells and waves) is predictable using this system. Time intervals between valve changes can be altered to suit the tidal profile in any chosen area. Size of equalization tank 42, if used, can be sized according to the tidal profile in order to optimize the activation of the generating device.
In some regions the size of the vertical tide may not be sufficient to provide sufficient rpm's to activate an electrical generating unit. As an example of tide differences, the tide characteristics of two locations in Canada were compared on the same day. The tidal change in the west coast location was about 6 feet per tidal cycle, while that on the east coast location was about 20 feet.
In addition to an equalization tank, a solution would be to use springs which could be wound up to a predetermined tension, after which the power could be transferred to the shaft. Using multiple gearboxes, the springs could be wound up to be released at different times. In this way a more constant delivery of electricity could be achieved.
Where multiple units are needed to ensure a more consistent source of power, for example when springs are used to store the potential energy, and sequenced to discharge at different intervals, a single float could be used to connect the multiple units as seen in
If a tank is located ashore, the weights may be suspended outside the tank so that only the float contacts the water.
In the application shown in
In the further example of
As with tidal tank 44, the cistern is sized to accept a float 52 and counterweight 28 on opposite ends of chain 26, where chain 26 drives one-way clutches 20, 22. Since locks fill and empty relatively quickly, the time for power generation may be very short. The diameter of the connecting pipe 62 may be reduced to maximize the length of time it takes to fill and empty the cistern, thereby increasing the length of time of power generation per cycle of the lock. Thus as the lock fills, the water enters the cistern and the float rises while the counterweight descends. The weight on the chain causes the shaft 12 to rotate and thereby actuate the power generating device. Conversely, as the lock empties, the float, which again, although buoyant has a dead weight greater than that of weight 28, descends while the weight ascends, causing the chain to move in the opposite direction, rotating the shaft and thereby continuously to actuate the power generating device.
As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.
This application is a continuation-in-part of application Ser. No. 12/379,578 filed Feb. 25, 2009, which claims priority from U.S. Provisional Patent Application No. 61/064,262 filed Feb. 25, 2008 and from Canadian Patent Application No. 2,622,284 filed Feb. 25, 2008, both entitled Method and Apparatus for Converting Energy in a Moving Fluid Mass to Rotational Energy Driving a Transmission.
Number | Date | Country | |
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Parent | 12379578 | Feb 2009 | US |
Child | 13633774 | US | |
Parent | 13633127 | Oct 2012 | US |
Child | 12379578 | US |