Abstract:
An hydroelectric generator for generating an electrical current from moving water comprises two endless belts arranged parallel to each other with adjacent runs running in the same direction. A plurality of paddles are mounted on one of the belts and arranged to engage the other belt over substantially the run of the belts where the belts are running adjacently and means are provided for directing the moving water between the two belts An electrical generator is driven by one or both belts.

Description:
FIELD OF THE INVENTION 
     This invention relates to an hydro electrical generator and more particularly to an hydro-electrical generator for generating electricity from energy to be found either from flowing water such as found in a river or a stream or tidal or wave motion of water as can, for example, be found in the sea. 
     BACKGROUND OF THE INVENTION 
     There is a problem today in the generation of electricity by many of the standard methods which use up natural resources, are dangerous and/or require very expensive apparatus and installation. These include coal fired power stations which use up the worlds coal resources and produce carbon dioxide adding to the green house effect, nuclear power stations which while using up the world&#39;s supply of radioactive material require sizeable structures to contain the radiation and suffer from the disadvantage of leaving radio active waste to be disposed of as a by product. A third type is the hydro electric power stations. These are the most environmentally friendly type but require there to be a large head of water and a considerable drop to provide the necessary kinetic energy to drive the electric generator turbines. 
     It is therefore desirable to find some other means of generating electricity in which can use much more readily available sources of energy such as the running water of rivers or the wave energy to be found in the sea. There have been many proposals for harnessing such sources of energy but, generally speaking, these proposals have met with little success due to either the complexity of the apparatus needed to harness it or to the difficulty in converting the energy. 
     The present invention seeks to provide an hydroelectric generator which is of a relatively simple construction and provides an efficient cost effective system. 
     SUMMARY OF THE INVENTION 
     According o the invention, there is provided an hydro-electric generator for generating an electrical current from moving water comprising two endless belts arranged parallel to each other with adjacent runs running in the same direction, a plurality of paddles mounted on one of the belts and arranged to engage the other belt over substantially the run of the belts where the belts are running adjacently, means for directing the moving water between the two belts and an electrical generator driven by one or both belts. 
     Preferably the belts are arranged one above the other, and the paddles may be carried by the upper belt and cooperate with engagement means on the lower belt. 
     The paddles may be hinged to the belt which carries them so that they can fold against the carrying belt on the return run of the belt. 
     The paddles may have a generally flat front face pointing in a direction reverse to the direction of movement of the belts and have a rear face opposite to the front face shaped to provide a minimum of resistance of the blade through water. 
     However, for wave use, for maximising utilisation wave motion, the paddles have generally flat front face pointing in a direction reverse to the direction of movement of the belts and have a rear face opposite to the front face and defining a hollow portion within the paddle into which water can flow providing stabilisation of the paddle , means being provided for allowing water to exit from the paddle so as to provide a water throughput through the paddle and reduce the resistance to movement of the paddle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described in greater detail, by way of example, with reference to the drawings, in which: 
         FIG. 1  is a schematic side view of one embodiment of the invention; 
         FIG. 2  is a schematic end view of the embodiment shown in  FIG. 1  taken from the left hand end of this figure; 
         FIG. 3  is a schematic isometric view of a paddle suitable for use with constant flow water; 
         FIG. 4  is a schematic isometric view of a paddle suitable for use with wave motion, and 
         FIG. 5  is an enlarged side view of a suitable drive between the belts and the electric generator. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring firstly to  FIGS. 1 and 2  of the drawings, there is shown an hydroelectric generator  1  comprising a pair of parallel endless belts  3  and  5  with adjacent runs  7  and  9  of the belts  3  and  5  running in the same direction. The upper belt  3  carries a number of paddles  11 , in the instance shown, three. With three paddles  11 , it ensures that there will always be one paddle  11  in the runs  7  and  9  at any one time. However, more paddles  11  could be used but with the set up as shown, it is believed that this will be the most efficient . the lower belt  5  is provided with cooperating engagement means (not shown) which will engage the free ends of the paddles  11  when they are in the run  7  position. The paddles  11  are pivoted to the belt  3  at  13  so that they can move from an extended position between the runs  7  and  9  to a retracted position against the belt  3  during the return run. It will be appreciated that the design of the paddles will depend on whether the water flow with which they are intended to be used is of a constant flow or wave type and this will be discussed hereafter. 
     The belts are arranged so as to provide a channel  15  to receive water between the runs  7  and  9 . To this end there is provided a guiding apparatus  17  in the form of a venturi  19  which guides incoming water (from the right in  FIG. 1 ). The narrow end of the venturi  19  is provided with guide flaps  21  which can be adjusted as necessary to suit the prevailing conditions. 
     At the end of the belts  3  and  5  away from guiding apparatus a gear set  23  is provided. This gear set  23  couples the two belts  3  and  5  together so as to ensure that they drive in synchronism with the runs  7  and  9  running in the same direction and will provide a drive for transferring power received by the belts  3  and  5  through the paddles  11  to an electric generator  25 . The whole arrangement is supported on a framework comprising a base plate  31  carried at one end  33  (to the left in  FIG. 1 ) on legs  35  and at the other end  37  (to the right in  FIG. 1 ) by the lower part  39  of the venturi  19  which may be provided with suitable weights  41  to increase the stability. 
     The operation of the hydroelectric generator will now be described: 
     The apparatus is set up in a suitable position in either a river or in the sea with the venturi  19  aligned with the direction of flow of either the river water or the waves and is adjusted, particularly using the flaps  21  to channel the water into the channel  15  between the belts  3  and  5 . The flow of the water or the waves will impinge on the paddle  11  which is extending across the channel  15  and drive it to the left in  FIG. 1 . This motion of the paddle  11  will drive both belts  3  and  5  to the left rotating the gear set  23  and drive the generator  25  to generate electricity. As the paddle  11  reaches the end of the run, the next paddle  11  will come down from the upper run of the belt  3  and will engage the engagement means on the lower belt  5  to take up a position across the channel  15  to receive the water flow or waves and continue to drive the belts  3  and  5 . In the meantime, the original paddle  11  will have reached the end of its run and will run round the end of the belt onto the return run of the upper belt  3 , having disengaged from the engagement means of the belt  5  and folded, under gravity against the belt  3 . 
     It will be appreciated that with a river flow, the movement of the belts  3  and  5  will be substantially continuous and can provide a direct drive to the generator. However, in the case of wave flow, this will be intermittent due to the wave motion and means will be required for evening out this movement between the belts and the generator. One possibility is to use an hydraulic cylinder driven in one direction by the belts and be returned in the opposite direction by a spring or similar arrangement during the period in which the belts are not being driven. The reciprocating movement of the hydraulic cylinder can then be converted into a continuous rotary movement by any known means 
     As has already been stated, the design of the paddles  11  will depend on the type of flow being encountered.  FIG. 3  shows a design of paddle suitable for use with constant flow. This paddle, referenced  51  will have a flat front or operating face  53  while the rear part comprising two converging surfaces  55  and  57  connected to the front face  53  by a straight portion  59  and a curved portion  61 . The angles concerned between the surfaces and the curvature of the curved portion  61  will be designed to provide the least resistance to movement of the paddle through the water which will remain to the rear of the paddle  51  during operation. In this figure, the pivot axis of the paddle  51  for pivoting to the belt  3  is shown at  63  while means for engagement with the engagement means on the lower belt  5  is shown at  65 . 
       FIG. 4  shows a design of paddle  11  for use in wave applications. This paddle  71  again has a flat front face  73  and a slanting rear face  75  connected to the front face  73  by a generally curved portion  77 . The rear face  75  has a rearwardly facing opening  69 . Within the paddle  71 , there is a hollow portion  79  into which water can enter through an opening  81  in the upper surface of the paddle  71 . This inflow of water results either from the water resistance behind the paddle in the forward stroke of the wave or from the return stroke of the wave. The water will exit the paddle through the opening  69 . The water in the hollow portion  79  will help to stabilise the paddle in its operative position. Some of the water will exit through a forwardly facing opening  83  at the bottom of the paddle  71  and in doing so will act to provide an additional drive to the paddle  71  in the drive direction, i.e. to the left in  FIG. 4.87  shows the pivot axis of the paddle where it is pivoted to the upper belt  3  and  89  shows means for engagement with the engagement means on the lower belt  5 . It will also be seen from  FIG. 4 , that the rear of the paddle  71  has inclinations rearwardly to reduce the resistance to travel through the water behind the paddle while the paddle is being acted on by a wave. The dimensions of the hollow portion  79  is such that the quantity of water it contains is proportional to the weight of the paddle and so keep it in balance. This will assist the paddle  71  to be positioned and maintained at the correct level in relation to the wave and will also help to reduce the load on the belts as well as keeping the paddle in the centre of the wave. 
       FIG. 5  shows an enlarged side view of a suitable generator drive for the situation of a constant water flow. Here can be seen the generator  25  having a small gear  91  which cooperates with a larger gear wheel  93  on a shaft  95  connected to the upper drive belt  3 . The upper and lower belts  3  and  5  are connected for movement together by a chain and sprocket drive  97 . 
     It will be appreciated that many modifications of or additions to the above described embodiment without departing from the scope of the invention. For example, while drive belts have been described, these could be replaced by chains, preferably at least one on each side of the paddles. The number of paddles used could be increased above the three shown if desired. Other suitable drives could be provided for the generator using other combinations of gears and chains. Also other means could be used to smooth out the intermittent drive caused in the case of wave motion. Such smoothing arrangements could make use of a flywheel which would keep the drive operating for those periods in which the belts are not driven by the wave. While the belts have been shown as horizontal, the could, if desired be inclined to the horizontal, for example, to take into account a slope of a river bed.