Patent Publication Number: US-2012031207-A1

Title: Wave energy converter

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a wave energy converter (WEC). 
     WECs are known in the art and disclosed, for example, in the U.S. Pat. No. 1,567,470. This WEC has an above water horizontal platform and floats connected to the latter by crossed links and toothed bars pivoted to the floats. However, it is non-operable because the distance between ends  30  and  32  of the crossed links must, but cannot change during supposed vertical movement of the float, and because the bars  7  must, but cannot tilt during its undulating movement. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a wave energy converter which avoids the disadvantages of the prior art. 
     In keeping with this object and with others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in a WEC which has a plurality of vertical frames between which a plurality of floats are mounted, and means for transmitting vertical reciprocating movement of each float into unidirectional rotation of an electric generator provided with a flywheel which is mounted on an overrunning clutch installed on a drive shaft. 
     The novel features of the invention are set forth in the appended claims. The invention itself, however, will be best understood from the following description and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1 ,  2  and  3  are schematic views showing floats on waves. 
         FIGS. 4 and 5  are mechanical diagrams of a gearing. 
         FIGS. 6 and 7  show rows of the floats transverse and parallel to the wave front. 
         FIG. 8  shows the contour of a frame transverse to the wave front. 
         FIGS. 9 ,  10 ,  13  and  14  are fragmentary sectional views of the WEC in different scales. 
         FIG. 11  is a mounting scheme of the WEC. 
         FIG. 12  shows the shape of the WEC. 
         FIG. 15  is a plan view of the WEC. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     A float  1  ( FIG. 1 ) intended for utilizing in the inventive WEC is filled up with surrounding water because of openings  2  and  2 ′ for increasing its weight (instead of a ballast), i.e. for its partial submerging. The opening  2  may be closed by a check valve  3 . 
     Suspended between pillars (or pales)  4  ( FIG. 2 ) on a beam  5  by a chain (or rope)  6  engaged with upper and lower sprockets (or pulleys)  7 , the float is submerging and pushing upward by an incoming wave W with a force F (proportional to resistance of a generator to rotate) which rotate the sprockets clockwise (and pushes pillars upward). After the crest of the wave W passes the float  1  ( FIG. 3 ), the latter rotates the sprockets  7  counterclockwise (and pulls the pillars downward). Thus, the chain  6  and sprockets  7  fixed on a shaft  8  ( FIG. 4 ), represent a means which converts the vertical reciprocating movement of the float  1  into rotation of the shaft  8 . The known in the art gearing  9  is installed for converting alternate rotation of its input shaft  8 , into unidirectional rotation of an output shaft  10 . 
     A pinion  11  fixed on the input shaft  8  of the gearing  9  is engaged with bevel gears  12  mounted on overrunning clutches  13  which are seizing in the opposite direction on the shaft  10 . Therefore the rotation of the sprocket  7  in the opposite directions is converted into unidirectional rotation of the output shaft  10 . An overrunning clutch  14  may be mounted between the shaft  10  and a shaft  15  of a generator  16 . A flywheel  17  fixed on the shaft  15 , stabilizes the rotation of the latter when the crests or throats pass the float, i.e. when the sprocket  7  turns slowly, and lets the float to sink on the throat to initial depth ( FIG. 1 ). 
     Another mechanical diagram of the gearing is shown in  FIG. 5 . The bevel gears  12  mounted on the overrunning clutches  13 , are engaged with a bevel gear  12 ′ fixed on the output shaft  10 . The overrunning clutch  14  may be mounted between the shaft  10  and the flywheel  17  fixed on the generator shaft  15 . 
     The waves spend energy for lifting the float, i.e. for turning the shaft of the generator, which signifies that their height lessens. Their height lessens also when the float emerges ( FIG. 3 ), because surrounding water has to fill the freeing volume up. If the inventive WEC has a plurality of the floats  1  placed in rows between frames  18  ( FIG. 6 ) transverse to the wave front, the waves W will take the contour shown in  FIG. 8 , while the contour of the frames  18  may be trapezoidal. Just several floats and pillars are conditionally shown for clarity. The frames  18  ( FIG. 7 ) may be parallel to the wave front and have therefore the rectangular contour the height of which decreases in the direction, shown by the arrow W. The frames are connected with one another by cross-bars  19  forming the space truss. 
     Although the friction between the float  1  and pillars  4  is overcoming by some additional submerging of the float, rollers  20  and  21  ( FIG. 9 ) may be utilized to diminish the friction. They may be mounted on posts  22  increasing the resistance of the float to cocking. Instead of rollers, bolls  23  ( FIG. 10 ) may be installed. 
     The mounting of the WEC near shore may be started with the highest rectangular (or square) front and flank sections  24  ( FIG. 11 ) of suitable dimensions collected on the beach. They can generate electric energy immediately. Each next row of attaching sections ( 25 ,  26  etc) has lessened (comparatively to the previous row) height so as the WEC will obtain the shape of broadened amphitheater the contours of which are shown in  FIG. 12 . The WEC mounted in the open sea may have the shape of elongated or circular stadium. It may be mounted around an island. The WEC mounted around towers of wind energy converters will make electrical energy up during a swell, i.e. when the wind converter does not function, or vice versa, which diminishes irregularity of the provision of energy. 
     The inventive WEC collected from light (hollow, plastic) parts of the space truss, may be made floatable, moored by any suitable conventional means and may be provided with propeller units. The heavy generators  16  ( FIG. 13 ) and gearing  9  are installed in the floats  1  for guaranteeing of stability of the WEC. The vertical reciprocating movement of the float is transmitted to the gearing  9  by a gear  27  engaged with a rack  28  provided on the pillar  4 . The electric current is transmitted to the beach by conductors and contacts hermetically closed in swinging links  29  ( FIG. 14 ) which working life is many times longer than the life of fast rotating corresponding parts of the generator. 
     There is some disparity between forces F which the highest wave applies to the first floats in the row which is transverse to the wave front, and forces F of the lowered passed wave. This disparity is balanced by some additional submerging of the rest of the floats so as heeling of the WEC is insignificant. Pontoons (not shown) fixed to the rear portions of the space truss may diminish heeling. 
     The floating WEC mounted around towers  30  ( FIG. 15 ) of the wind energy converters, may be provided with means for their turning, e.g. propeller units. 
     The main advantages of the described WEC are: almost complete capture energy of the incoming waves; a short period of construction and provision energy from the very beginning of construction; it may be mounted almost everywhere or towed to a place of utilization; a low cost of parts each producing in huge amount, especially for long (for example 1 km) and several WEC. 
     The invention is not limited to the details shown since various modifications and structural changes are possible without departing in any way from the spirit of the present invention.