Abstract:
A rotation assistance device ( 1 ) is equipped with a rotating shaft body ( 11 ) and multiple rotation assistance bodies ( 20 ), which are equipped with rotating bodies ( 40 ). The rotating bodies are equipped with a rotation-promoting body ( 22 ), having a mass that maintains rotation, and with a spring shaft ( 23 ), one end of which is connected to the shaft body ( 11 ) and the other end of which is connected to the rotation-promoting body ( 22 ), and which expands and contracts in the lengthwise direction by means of an elastic body. The rotation assistance bodies also are equipped with guide rails ( 21 ), which guide the rotation-promoting bodies ( 22 ) of the rotating bodies ( 40 ) so as to rotate in an elliptical orbit. The rotating bodies ( 40 ) are attached to the shaft body ( 11 ) such that their respective attachment angles around the axis of rotation are displaced with respect to each other.

Description:
TECHNICAL FIELD 
       [0001]    Embodiments of the present invention relate to a rotation assistance device, a rotation assistance method, and a power generation device. 
       BACKGROUND ART 
       [0002]    For devices that are driven by rotation energy, such as automobiles, ships, and power generation devices, a flywheel is used to allow and maintain smooth rotation. 
         [0003]    A typical flywheel employs a metal that is formed into a disk shape. Accordingly, the weight of the flywheel itself is heavy. The heavy weight leads to a decrease in fuel efficiencies of automobiles and ships. 
         [0004]    In that respect, what is proposed is a technique for arranging a magnet on an outer periphery of the flywheel in such a way that the magnet is inclined, and fixing the magnet to an outer side of the flywheel to make use of a repulsive force of the magnet to reduce attenuation of the rotation energy. 
         [0005]    However, according to the above technique, the flywheel becomes inevitably large and heavy. 
       CITATION LIST 
     Patent Literature 
       [0006]    PLT 1: Japanese Patent Application Laid-Open No. 2007-151364 
       SUMMARY OF THE INVENTION 
     Technical Problem 
       [0007]    Therefore, a small, lightweight rotation assistance device is desired. 
       Solution to Problem 
       [0008]    To solve the above problem, an embodiment of the present invention provides a rotation assistance device including a plurality of rotation assistance bodies each of which includes: a shaft body that rotates; a rotation body that includes a rotation promotion body which has mass to keep rotation, and a spring shaft whose one end is connected to the shaft body and the other end to the rotation promotion body and which expands and contracts in a radial direction with the help of an elastic body; and a guide rail that regulates in such a way that the rotation promotion body of the rotation body is shifted in an elliptical manner, wherein the rotation bodies are mounted to the shaft body in such a way that mounting angles around a rotation axis are different from one another. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a diagram showing the configuration of a rotation assistance device. 
           [0010]      FIG. 2  is a front view of a guide rail. 
           [0011]      FIG. 3  is a cross-sectional view of the guide rail of  FIG. 2  taken along line AA. 
           [0012]      FIG. 4  is a side cross-sectional view of a first example of a rotation body. 
           [0013]      FIG. 5  is a cross-sectional view of the first example of the rotation body of  FIG. 4  taken along line BB. 
           [0014]      FIG. 6  is a side cross-sectional view of a second example of a rotation body. 
           [0015]      FIG. 7  is a cross-sectional view of the second example of the rotation body of  FIG. 6  taken along line CC. 
           [0016]      FIG. 8  is a diagram showing how a rotation body is rotated. 
           [0017]      FIG. 9  is a diagram showing how a rotation body is rotated. 
           [0018]      FIG. 10  is a diagram showing how a rotation body is rotated. 
           [0019]      FIG. 11  is a diagram showing how a rotation body is rotated. 
           [0020]      FIG. 12  is a diagram showing an example of a power generation device that uses a rotation assistance device. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0021]    Hereinafter, an embodiment of a rotation assistance device, rotation assistance method, and power generation device will be described in detail with the use of the accompanying drawings. 
         [0022]    A rotation assistance device of the present embodiment includes a plurality of rotation assistance bodies, each of which includes: a shaft body that rotates; a rotation body that includes a rotation promotion body which has mass to keep rotation, and a spring shaft whose one end is connected to the shaft body and the other end to the rotation promotion body and which expands and contracts in a radial direction with the help of an elastic body; and a guide rail that regulates in such a way that the rotation promotion body of the rotation body changes in an elliptical manner, wherein the rotation bodies are mounted to the shaft body in such a way that mounting angles around a rotation axis are different from one another. 
         [0023]      FIG. 1  is a diagram showing the configuration of a rotation assistance device  1  of the present embodiment. As shown in  FIG. 1 , the rotation assistance device  1  includes a plurality of rotation assistance bodies  20 , each of which includes: a shaft body  11  that rotates; a rotation body  40  that includes a rotation promotion body  22  which has mass to keep rotation, and a spring shaft  23  whose one end is connected to the shaft body  11  and the other end to the rotation promotion body  22  and which expands and contracts in a radial direction of a rotation circle, or in a longitudinal direction, with the help of an elastic body  33  described later; and a guide rail  21  that regulates in such a way that a rotation orbit of the rotation promotion body  22  of the rotation body  40  is elliptical, wherein the rotation bodies  40  are mounted to the shaft body  11  in such away that mounting angles around a rotation axis are different from one another. 
         [0024]    The rotation promotion body  22  is a weight that has enough mass to keep a rotation force. 
         [0025]    A portion of the guide rail  21  that regulates rotation of the rotation promotion body  22  is formed into an elliptical shape; a plurality of guide rails  21  are so disposed that long-axis directions of the ellipses are aligned with one another. 
         [0026]    Incidentally, the guide rails  21  are not limited to rails. The guide rails  21  may be mounted in such a way that the long-axis directions of the ellipses are different from each other. 
         [0027]    The spring shaft  23  includes an elastic body  33  that presses the rotation promotion body  22  in an outer peripheral direction. 
         [0028]    In this case, the spring shaft  23  is a support member that expands and contracts in a longitudinal direction with the help of the elastic body  33 . The elastic body  33  is not limited to the spring; any other member having an elastic force may be used. The elastic body  33  may be an air cylinder, a fluid cushion, or a resin having an elastic force. 
         [0029]      FIG. 2  is a front view of the guide rail  21 .  FIG. 3  is a cross-sectional view of the guide rail  21  of  FIG. 2  taken along line AA. 
         [0030]    As shown in  FIGS. 2 and 3 , the guide rail  21  is formed into an elliptical shape, and a cross section thereof is in a U-shape. Inside the guide rail  21 , a rail  24  is provided. The rail  24  may have permanent magnets  29  having an S-pole magnetized outer side and an N-pole magnetized inner side. The permanent magnets  29  may be electromagnets. 
         [0031]    The spring shaft  23  may be curved in a rotation direction of the spring shaft  23 , or in a direction opposite to the rotation direction. 
         [0032]      FIG. 4  is a side cross-sectional view of a first example of the rotation body  40 .  FIG. 5  is a cross-sectional view of the first example of the rotation body  40  of  FIG. 4  taken along line BB. 
         [0033]    As shown in  FIGS. 4 and 5 , the rotation body  40  includes the rotation promotion body  22 , the spring shaft  23 , and the elastic body  33 . 
         [0034]    The rotation promotion body  22  includes a curved section that faces a rotation direction, and includes a groove section  26 , into which a rail  24  is fitted, and rollers  27 , which come in contact with the rail  24 . 
         [0035]    If the rail  24  includes the permanent magnets, the rotation promotion body  22  further includes permanent magnets  28  that are N-pole magnetized toward a rotation-direction outer periphery and are S-pole magnetized toward an inner peripheral direction. 
         [0036]    A repulsive force of the permanent magnets reduces friction between the rotation promotion body  22  and the rail  24 . 
         [0037]    The spring shaft  23  includes an inner core  31 , whose one end is joined to the rotation promotion body  22 ; an external cylinder  32 , whose one end is joined to the shaft body  11  and into which the inner core  31  is inserted; a connection section  34 , which connects the external cylinder  32  to the shaft body  11 ; and the elastic body  33 . That is, the spring shaft  23  is so formed as to have a cylinder structure, and the elastic body  33  is provided on an outer periphery of the cylinder. It is desirable that an expansion-contraction direction of the spring shaft  23  be the same as an expansion-contraction direction of the elastic body  33 . 
         [0038]    The rotation promotion body  22  is mounted to the inner core  31  through a pin  22 A in such a way as to be able to rotate in the rotation direction of the rotation body  40 . Accordingly, the rotation promotion body  22  has play so as to rotate in the rotation direction of the rotation body  40 . 
         [0039]    The rotation promotion body  22  is mounted in such a way that the center of gravity thereof is shifted from the pin  22 A in the rotation direction of the rotation body  40  or in a direction opposite to the rotation direction. 
         [0040]    The elastic body  33  should be a helical spring, which is advantageous in terms of manufacturing costs. The elastic body  33  maybe an air cylinder or a synthetic resin having an elastic force. 
         [0041]    If the elastic body  33  is a helical spring, the elastic body  33  is so placed as to go around the outer sides of the inner core  31  and external cylinder  32 . 
         [0042]    The elastic body  33  pushes the inner core  31  toward the rotation promotion body  22 . 
         [0043]      FIG. 6  is a side cross-sectional view of a second example of the rotation body  40 .  FIG. 7  is a cross-sectional view of the second example of the rotation body  40  of  FIG. 6  taken along line CC. 
         [0044]    As shown in  FIGS. 6 and 7 , the rotation body  40  can be formed in such a way that an inner core  31  passes through a connection section  34  and a shaft body  11 . 
         [0045]    In this case, the rotation body  40  may include a spring chamber  35 , which is provided at an end portion of the inner core  31  that protrudes from the connection section  34  and which houses the end portion; and an elastic member  36 , which pushes the end portion toward the rotation promotion body  22 . 
         [0046]    The elastic member  36  helps an elastic body  33  expand and contract, and also helps to keep the rotation of the rotation body  40  for a longer time. 
         [0047]    Incidentally, on the rotation body  40  of the second example, the external cylinder  32  may not be provided. 
         [0048]    The configuration of the other portions of the rotation body  40  of the second example is the same as that of the rotation body of the first example. 
         [0049]      FIGS. 8 to 11  are diagrams showing how the rotation body  40  is rotated. As shown in  FIG. 8 , when the rotation body  40  is shifted in a direction of arrow X1 from an ellipse long axis position to a short axis position, the orbit of the rotation promotion body  22  is regulated by the guide rail  21 ; the spring shaft  23  is shortened, and the elastic body  33  is compressed toward the shaft body  11 . That is, the rotation energy is accumulated in the elastic body  33 . 
         [0050]    As shown in  FIG. 9 , when the rotation body  40  is shifted in a direction of arrow X2 from an ellipse short axis position to a long axis position, the compressed elastic body  33  expands. At this time, the energy accumulated in the elastic body  33  is released in a direction in which the rotation promotion body  22  is rotated. 
         [0051]    As shown in  FIG. 10 , when the rotation body  40  is shifted in a direction of arrow X3 from an ellipse long axis position to a short axis position, the rotation energy is accumulated in the elastic body  33  as in the case of  FIG. 6 . 
         [0052]    As shown in  FIG. 11 , when the rotation body  40  is shifted in a direction of arrow X4 from an ellipse short axis position to a long axis position, the compressed elastic body  33  expands. At this time, the energy accumulated in the elastic body  33  is released in a direction in which the rotation promotion body  22  is rotated. 
         [0053]    In this case, because of the loss of energy caused by friction or the like, the energy is not sufficient enough for the rotation body  40  to completely make one rotation. 
         [0054]    However, mounting positions of the other rotation bodies  40  on the shaft body  11  are different; the rotation body  40  therefore makes one rotation by using the energy accumulated in the elastic bodies  33  of the other rotation bodies  40 . 
         [0055]    As described above, an interchange of energy takes place between a plurality of rotation bodies  40 , so that the rotation bodies  40  continue to rotate. 
         [0056]    Accordingly, compared with a disc-shaped flywheel, it is possible to reduce the mass even when maintaining the same rotation force. 
         [0057]    According to an experiment, compared with a disc-shaped flywheel of the same mass, the rotation assistance device  1  could continue to rotate 30% longer. 
         [0058]      FIG. 12  is a diagram showing an example of a power generation device  100  that uses the rotation assistance device  1 . As shown in  FIG. 12 , the power generation device  100  includes the rotation assistance device  1  and a generator  2 . External energy  3  uses an appropriate device to give a rotation force to the rotation assistance device  1 . 
         [0059]    The external energy  3  is produced by converting the energy generated by thermal power generation, hydraulic power generation, nuclear power generation, solar cells, internal-combustion engines, or the like into rotation energy. 
         [0060]    In the case of the power generation device  100 , the advantage is that, without an increase in the mass of the generator, it is possible to generate power in a stable manner even when a load is varied. 
         [0061]    The above has described several embodiments. However, the embodiments are given for illustrative purposes, and not intended to limit the scope of the invention. The embodiments may be embodied in other various forms. Various omissions, replacements and changes may be made without departing from the subject-matter of the invention. The above embodiments and variants thereof are within the scope and subject-matter of the invention, and are similarly within the scope of the invention defined in the appended claims and the range of equivalency thereof. 
       REFERENCE SIGNS LIST 
       [0000]    
       
         
           
               11 : Shaft body 
               21 : Guide rail 
               22 : Rotation promotion body 
               23 : Spring shaft 
               33 : Elastic body