Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
WAVE POWER GENERATING DEVICE
Fie1d of the Invention
The invention relates to a power generation device which utilizes water
wave motion as its driving source and, in particular, to a wave power generating device
5 which converts potential and kinetic energy of the waves to rotational energy which
may be more readily converted to alternate forms of energy.
Bacl~x~ (~und of the Invention
Various devices have heretofore been proposed which extract potential
or kinetic energy from waves for the subsequent conversion to more usable forms of
10 energy such as electricity. Typical arrangements provide that transverse waves act on
a floating mechanism to produce a linearly reciprocating motion thereof or waves
impact a paddle-wheel or similar mechanism to impart a rotational motion thereto.
Many contrivances have been devised to convert these motions into intermediary or
ultimate forms of energy.
.
SUMMARY OF THE INVENTION
; The present invention provides a wave power generation device of the
linear reciprocating type which is capable of not only extracting potential energy from
waves but also kinetic energy. The present invention also provides a simple
arrangement for conversion of this linear reciprocating motion to a rotary motion
20 which can be readily converted to alternate forms of energy. Accordingly, there is
provided a wave power generating device which comprises a main floatation section
having a ]eading end; means for anchoring the main flotation section with its leading
~7~
end into the direction of oncoming waves; a pair of parallel, spaced-apart guides
mounted at or near the leading end of the main flotation section at an angle with
respect to the horizontal; frame means constrained for sliding movement within the
guides; float means associated with the frame means, the float means being responsive
to wave action for reciprocating said frame within the guides, a shaft rotatablymounted transversely across the guides and above the main float; a pair of one-way
drive mechanisms disposed on the shaft; a pair of racks movable with the frame
means, each of said racks being engaged with a respective one-way drive mechanism
whereby said shaft is driven uni-directionally during both strokes of the frame means;
and energy conversion means operatively associated with said shaft for converting the
rotational energy of the shaft to an alternate form of energy.
Further features and advantages will become apparent from the
following description and drawings.
BRIEF DESCRIPTION OF T~IE DRAWINGS
Fig. 1 is a plan view of the wave power generating device;
Fig. 2 is a cross-section of the wave power generating device shown
along lines A-A in Fig. l;
Fig. 3 is a cross-section of the wave power generating device shown
along lines B-B in Fig. 1;
Fig. 4 is a plan view showing in detail a one-way drive mechanism usable
in connection with the invention;
Figs. 5 and 6 are the same cross-sectional views illustrated in Figs. 2 and
3, respectively, but with the wave power generating device shown in operation.
I~ETAILEI~ DESCRIPTION OF THE INVENTION
Referring now to Figs. 1 to 3, there is shown one embodiment of the
invention only in suff;cient detail to permit a thorough understanding thereo~ The
wave power generating device is denoted generally by the reference numeral 10 and
S partially comprises a main flotation section 12 upon which the remainder of the
apparatus is supported. Preferably, the main flotation section 12 consists of a pair of
floats or pontoons 14 catamaranned by a structure comprising a pair of longitudinal
beams 16 separated by a pair of cross-pieces 18, thus providing a longitudinallyextending channel 19 between the pontoons 14. ~lternatively, the main flotation
section 12 might comprise a barge or scow which is divided below the floor to form
; a similar longitudinal channel. The channel 19 permits incoming waves to flow
therethrough with minimal deleterious effects.
The main flotation section 12 is anchored in such a manner so as to
align automatically the device 10 in the direction of oncoming waves. Chains 20 are
attached at both sides of the main flotation section 12 and are pivotably anchored at
a common anchorage (not shown) so as to permit the device 10 to freely align itself.
To facilitate this alignment, a transverse keel 22 may be provided generally below the
surface of the water (see Figs. S and 6) which is attached through the pontoons 14 to
the longitudinal beams 16 by means of support braces 24. The leading ends 15 of
pontoons 14 may also be suitably configured such as depicted in Figs. 1, 2 and 3 to aid
in alignment.
A pair o~ parallel guides 26 are mounted at the leading end of the main
flotation section 12 in an upwardly transverse relationship with respect to the
longitudinal beams 16 and, hence, with respect to the horizontal. As shown, the guides
26 are preferably disposed at an oblique angle with respect to the vertical, the purpose
of which wi]l be explained hereinbelow. The guides 26 are, in essence, a pair of C-
channels which are disposed with their openings inwardly opposed and which are
spaced-apart structurally at their upper ends by a cross-bar 28 and near their lower
erlds indirectly through the longitudinal beams 16 by cross-pieces 18. Preferably, the
5 guides 26 extend downwardly below the water line of the main flotation section 12 to
take full advantage of the amplitude of the wave.
The guides 26 serve to constrain a frame 30 in sliding reciprocating
motion therebetween. 7'he generally rectangular frame 30 consists of a pair of lateral
slides 32 separated by a pair of transverse members 34 and a cross-bar 36. The slides
10 32 are constrained for sliding movement within the C-channel guides 26 whereby the
ends of cross-bar 36 provide a bearing surface to facilitate sliding. A pair of racks
38,40 are attached to and movable with the frame 30. A smaller float 42 is attached
to the frame 30 by means of supports 44 which are affixed to slides 32 and which
extend forwardly of the main flotation section 12 so as to dispose the float 42 forward
15 of the main flotation section 12 and generally between pontoons 14. As will be
described in greater detail hereinbelow, the float 42 is responsive to the undulating
motion of incoming waves (see Figs. 5 and 6) which in turn causes reciprocating
motion of the frame 30 within guides 26. Stops 45 are provided at or near the lower
ends of guides 26 for limiting the extent to which the frame 30 slides and to prevent
20 derailing of the frame 30 from the guides 26.
A power shaft 46 is rotatably mounted transversely across the upper
ends of the guides 30 by means of mounting brackets 47 and suitable bearings. A pair
of one-way drive mechanisms 48,50 are disposed on the shaft 46 for engagement with
racks 38,40, respectively, and in such a manner as to permit only uni-directional
rotation of the shaft. As can be seen in Figs. 2 and 3, racks 38,40 are arranged such
that they engage their respective one-way drive mechanisms 48,50 on radially opposed
sides. In particular, rack 38 lies generally in the plane of frame 30 while rack 40
extends outwardly from but parallel to the plane of the frame 30. This arrangement
permits the uni-directional driving of the shaft 46 during both the upstroke anddownstroke of the frame 30. One or more flywheels 52 are disposed on shaft 46 inorder to smooth-out power transients and to conserve the shaft's angular momentum.
Although not shown, it may be necessary to provide additional supporting membersbetween the guides 26 and the beams 16 to prevent excessive stresses from occurring
: at the joints 53.
The rotational energy of the shaft 46 can be converted into more usable
forms of energy using conventional technology. The rotating shaft may be used todrive one or more electric generators (not shown) to produce electricity which is then
transferred to shore by transmission lines. An electric generator may be situated on
the main floatation section 12, collpled to the shaft 46 through a gear or pulley
arrangement, or a pair of generators may be disposed outwardly of the flywheels 52
at either end of the shaft 46, supported by suitable supporting structure. Alternately,
the shaft 46 may drive a compressor (not shown) for pressurizing a gas which can be
stored in a tank for later use or may be used to do a myriad of other forms of work
using known techniques.
While the one-way drive mechanisms illustrated in the drawings are
ratchet mech~ni~mc, it will be understood that the invention is not necessarily
restricted to the use thereof and that other one-way drive mechanisms, for example
overrunning clutches, might likewise be employed. The ratchet mechanisms 48,50
shown in Fig. 1 and in more detail in Fig. 4, each include a pinion 54,54' which is
freely rotatable on the shaft 46; a ratchet having a driving section 56a,56a' and a
;~ '
. .,
- :
~7~
driven section 56b,56b'; a spring 58,58' for biasing the driving and driven ratchet
sections together; and a coupling mechanism such as key 60,60' for coupling the
driven ratchet section 56b,56b' to the shaft 46 by means of keyway 61,61'.
In operation, the wave power generating device 10 is suitably anchored
5 by means of chains 2~ in a body of water in which surface waves are prevalent. A
plurality of such devices 10 might be installed in banks along a shoreline to take full
advantage of the entire breadth of the incoming waves. Incoming waves 62 acting on
the device 10 cause the main flotation section 12 to align in the direction of the
incoming waves. Any incoming wave 62 will, therefore, contact the small float 42 first
(see Figs. 5 and 6). Since the float 42 is extremely buoyant in water, the float 42 and
attached frame 30 will be forced in an upward direction, thus extracting some of the
potential energy of the wave 62. The effect shown in Figs. 5 and 6 that the wave 62
has on the float 42 has been exaggerated for illustrative purposes and it will be
appreciated that a portion of float 42 will be submerged. As mentioned above, the
15 guides 26 are preferably disposed at an oblique angle with respect to the vertical
(essentially inclined rearwardly) while the float 42 is supported generally
perpendicularly and forwardly therefrom. Such an arrangement permits, upon impact
of the wave 62 with the float 42, at least a portion of the kinetic energy of the wave
to be transferred to the frame 30 in the form of an initial upward velocity, which
20 facilitates overcoming of inertia and permits more of the total energy of the wave to
be extracted. This function may likewise be provided simply by disposing the float 42
at such an angle to take advantage of the kinetic energy of the wave, i.e. by making
the angle 13 (see Fig. 2) at which the support 44 extends relative to the guides 26
acute, even if the guides are substantially vertical. The shape of the float 42 might
2S also provide additional kinetic energy extracting capability, for example by providing
-
:-
'
7 ~'~
the float 42 with an angled face 43 as shown in Figs. 2,3,5 and 6. As far as themagnitude of angle ~ is concerned, in general, more kinetic energy is extracted from
a wave with increasing angle ~, while more potential energy is extracted from the wave
when angle ~ approaches 0 (zero). It is also thought that waves of different shapes
S might be swited for harnessing more or less kinetic energy therefrom, i.e wind-driven
s~lrface waves versus ocean swells, respectively, and therefore it might be
advantageous, depending upon the specific app]ication of the device 10, to provide
guides 26 which are angularly adjustable. In this regard, the guide 26 could be
pivotably mounted at joints 53 to the longitudinal beams 16 with the aforementioned
non-illustrated additional supporting members being extendable to provide the
necessary support. It is also conceivable that sensing means be provided in
conjunction with an automatic angle adjustment mechanism to optimize the angle
for maximum rotational speed of the shaft 46.
As mentioned, both kinetic and potential energy from the wave may be
transferred to the frame 30 by means of the float 42, thus causing the frame 30 to be
lifted in an upstroke. As the wave 62 passes, the float 42 and attached frame 30 will
fall under the influence of gravity in a downstroke. Preferably, the mass of thetranslating components, i.e. the frame 30, racks 38,40, float 42 and supports 44, is
relatively small compared to that of the more stationary components, i.e. the main
flotation section 12, guides 26, shaft 46, ratchets 48,50 and fly~vheels 52, and the float
42 is disposed sufficiently forward of the main flotation section 12, such that the
incoming wave 62 essentially acts on the float 42 and attached *ame 30 as if the main
flotation section was fixed in place. The longitudinal channel 19 and keel 22 also help
to keep the main flotation section 12 in a relatively fixed attitude.
As mentioned above, the ratchet mechanisms 48,50, as can be seen in
~ ~14~
Fig. 1, permit the shaft 46 to be driven only in one direction while permitting slip in
the opposite direction. In particular, on the upstroke of the frame 30, both theupstroke rack 38 and downstroke rack 40 cause their respective pinions 54,54' torotate in the same direction. However, due to the manner in which the ratchet
mechanisms 48,50 are arranged, driving section 56a drives driven section 56b causing
shaft 46 to be rotated, while driving section 56a' slips against driven section 56b' due
both to the rotation of pinion 54' and the rotation of the shaft 46 in the opposite
direction. At top dead centre of the cycle, neither of the racks 38,40 are in movement,
however the shaft 46, carried by the angular momentum of flywheels 52, continues to
rotate, thereby causing both driven sections 56b,56b' to slip against their respective
driving sections 56a,56b'. On the downstroke of the frame 30, both the upstroke rack
38 and the downstroke rack 40 cause their respective pinions 54,54' to rotate in the
same direction, which direction is opposite to the direction they are rotated during the
upstroke of frame 30. This callses driven section 56a' to drive driven section 56b'
adding to the shaft's rotational velocity while driving section 56a slips against driven
section 56b. The operation of the device at bottom dead centre is the same as that
at top dead centre.
While there has been described and shown herein a particular
embodiment of the invention including some variations, it will be understood by those
skilled in the art that various modifications and/or substitutions can be made thereto
without departing from the spirit and scope of the invention as defined in the
appended claims.
' '
