Abstract:
The present invention refers to a conventional spur gear transmission or magnetic gear transmission, with a cycloidal configuration. The magnetic gears include contact points such that the mobile gear rolls on the fixed gear. Alternatively, a balance wheel is incorporated, which generates a centrifugal force opposite to the one associated with the mobile gear, of equal magnitude and on the same plane as this latter one, thereby completely eliminating the unbalancing of the mechanism. The balance wheel is mounted on the high-speed shaft in a manner similar to the mobile gear, and has the freedom to displace itself radially through centrifugal effect in the opposite direction to the eccentric position of the center of the mobile gear until it presses against a fixed track over which it rolls, concentric with the fixed gear with an equal force, opposite and collinear with that produced by the mobile gear.

Description:
FIELD OF INVENTION 
       [0001]    The present invention refers generally to transmissions, and more specifically to cycloidal transmissions with spur gears or magnetic gears, which function as speed reducers and amplifiers. 
       BACKGROUND OF THE INVENTION 
       [0002]    In the cycloidal drives/transmissions generally used as speed reducers, a mobile gear with external teeth is propelled in a circular orbit by means of a crank of a high-speed input shaft. Said mobile gear is meshed with a fixed annular gear with internal teeth. The crank radius is equal to the eccentricity between the two gears. 
         [0003]    Typically, a coupling is used between the mobile gear and the low-speed output shaft, capable of mechanically transmitting the rotational movement of said mobile gear, but not the orbital translation of the same. In said coupling the torque transmission is accomplished by means of a number of axial rods uniformly distributed on a disc integrated to the low-speed shaft, which penetrate into an equal number of circular holes in the mobile gear. 
         [0004]    Instead of using conventional spur gears in a cyclodial transmission, it is possible to use magnetic gears with magnets, such as is the case in the transmission described in Mexican patent application number MX/a/2012/001596 by the same applicant and titled Magnetic Cyclodial Transmission with Permanent Magnetic Gears for power transmission, and from which the present application claims priority. The use of magnetic gear is also described in other publications, such as U.S. Pat. Nos. 4,808,869, 4,850,821, 5,013,949 and 5,569,111. In some transmissions, permeable iron elements are used to guide a magnetic field of alternating direction resulting from the rotation of a central wheel with permanent magnets of alternating polarities causing a slow rotation of an exterior ring having a larger number of permanent magnets. Such is the case in the transmissions described in U.S. Pat. No. 3,378,710 and in U.S. publication 2011/0127869 A1, and also in the transmission analysed by P. O. Rasmussen et al in the article “Development of a high performance magnetic gear”, IEEE Transactions on Industry Applications, vol. 41, no. 3, 2005. In the paper “The cycloidal permanent magnetic gear”, IEEE Transactions on Industry Applications, vol. 44, no. 6, 2008, by F. T. Jorgensen et al, a magnetic cycloidal transmission with a topology similar to that of the present invention is analysed. 
         [0005]    In the transmissions treated in all the previously mentioned references, the magnetic forces of attraction act across small gaps between the elements of the mechanism with no contact between them. In contrast with this characteristic, the magnetic gears of one of the embodiments of the present invention contact one another due to the fact that the mobile gear is free to move outwardly under the action of the magnetic attraction and the centrifugal force, thus exerting pressure against the internal surface of the fixed one as it rolls on it. In order for rolling to occur, the magnets of each gear must be assembled in such a way that they do not protrude from the contacting gear surfaces. In this way, the following advantages result: (1) the transmission&#39;s torque capacity is increased because, in addition to the magnetic force between the gears, a frictional force associated with the normal contact force, is developed; (2) the radial load on the bearing supporting the mobile gear is eliminated; (3) the need to accurately control the separation between the gears is eliminated. 
         [0006]    In conventional cycloidal transmissions, a coupling is used between the mobile gear and the low-speed shaft (the output shaft in the case of a speed reducer) that transmits only the rotational movement of that gear but filters out the circular translational movement resulting from its eccentric mounting. In such coupling, torque is transmitted by means of a number of axial pins uniformly distributed in a circular array in a disk integral with the low-speed shaft, said pins penetrating in an equal number of circular holes in the orbiting gear, the radii of these holes being equal to the sum of the pin radii and the gear&#39;s axis eccentricity. In the present invention, roller bearings mounted on said pins are additionally incorporated to reduce the power loss due to friction between the pins and the surfaces of the holes of the orbiting gear. In this case, the outside radius of the bearings, instead of the pin radius, must be considered in calculating the radius of the holes. The incorporation of these bearings may not be feasible for large eccentricities. 
         [0007]    One of the problems encountered in prior art cycloidal transmissions, whether it be with spur gears or with magnetic gears, is the unbalancing of the two gear system. 
         [0008]    A disadvantage of cycloidal transmissions is the vibration due to the orbital movement of the mobile gear, given that its mass center is displaced in a circular trajectory which causes a centrifugal force of mw 2 r magnitude, where m represents the gear mass, w the angular speed of the crank, and r the radius of the circular trajectory, said force represented by a vector which also rotates at a speed w. A way to lower this vibration is by incorporating a second mobile gear propelled by a crank at 180° to the first. The vectors which the centrifugal forces of both gears represent are of the same magnitude but in opposite direction, however they are not collinear as they occur in different planes, giving rise to a moment on a rotating plane, reason by which the vibration is not completely suppressed. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0009]    Initially, a magnetic gear cycloidal transmission is disclosed, either for speed reduction or speed amplification, such that each gear has an even number of permanent magnets in its periphery, said magnets inserted in radial holes with alternating N and S exposed poles and without protruding from the corresponding gear surfaces, and such that the gears maintain contact with one another, the mobile gear rolling on the interior surface of the fixed gear. 
         [0010]    Furthermore, it is disclosed that the mobile gear which is mounted on the high-speed shaft, is free to move in a radially outwardly direction, ensuring its contact with the fixed gear&#39;s internal surface and allowing it to roll on said surface while its center moves on a circular trajectory imposed by the shaft on which it is eccentrically mounted. 
         [0011]    It is also disclosed that the incorporation of a coupling between the mobile gear and the low-speed shaft (the output shaft in the case of a speed reducer) transmits the gear&#39;s rotational movement but not its translational orbiting movement, the coupling consisting of a number of pins rigidly attached to a disk rigidly assembled to the low-speed shaft, said pins penetrating in an equal number of holes in the mobile gear and each pin having a roller bearing providing a rolling contact with the inner surface of the holes which has a radius equal to the sum of the outer radius of the bearings and the mobile gear&#39;s eccentricity. 
         [0012]    In order to provide an adequate path for the permanent magnets&#39; field, both gears be made of a material with high magnetic permeability, except for the annular portion containing the magnets, which must be made of a non-magnetic material. 
         [0013]    The present invention also describes embodiments with spur gears and embodiments with magnets, in which a balance wheel is used, whose mass center is displaced in a circular trajectory on the same plane as the trajectory of the center of the mobile gear, but at 180° of it, generating an equal centrifugal force, opposite and collinear to that of the mobile gear. The systems of such gears are described in the present description. 
         [0014]    Therefore, an objective of the present invention is providing a magnetic cycloidal gear transmission with permanent magnet gears, which have a magnetic gear equivalent to a gear with external teeth and another one equivalent to a gear with internal teeth, the first one being eccentrically mounted on a shaft, which in the case of a speed reducer corresponds to the input of power, and the second one being fixed. Furthermore, the embodiment incorporates an element which, in the case of a speed reducer, is driven by the first gear through a coupling that only transmits the rotation of said gear but not its translational movement resulting from its eccentric mounting. The input and output shafts in these transmissions are collinear. 
         [0015]    Another objective of the present invention is to accomplish a conventional spur gear transmission with a cyclodial configuration, incorporating a balance wheel which generates a centrifugal force opposite and collinear to the centrifugal force associated with the mobile gear, the opposite and collinear centrifugal force being of equal magnitude and on the same plane as the centrifugal force associated with the mobile gear, thereby completely eliminating the unbalancing of the system and the gear mechanism. 
         [0016]    Another objective of the present invention is to accomplish a magnetic gear transmission with a cyclodial configuration, incorporating a balance wheel which shall generate a centrifugal and collinear force opposite to the centrifugal force associated with the mobile gear, the opposite and collinear centrifugal force being of equal magnitude and on the same plane as the centrifugal force associated with the mobile gear, thereby completely eliminating the unbalancing of the system. 
         [0017]    Other objectives of the invention are the following: 
         [0018]    1. An apparatus for the transmission of torque/force comprising: 
         [0019]    a first shaft with a first angular speed; 
         [0020]    a fixed wheel; 
         [0021]    a mobile wheel with a center with a receiving means, the first shaft being connected with the center of the mobile wheel to propel said center in a circular trajectory creating a centrifugal force associated with the mobile wheel, the mobile wheel interacts with the fixed wheel; 
         [0022]    a disc with connecting means, the connecting means being in connection with the receiving means and a second shaft with a second angular speed; 
         [0023]    a balance wheel with a center, the balance wheel is propelled by the first shaft being connected with the center of the balance wheel, wherein the propelling of the first shaft generates a centrifugal force of the balance wheel opposite to the centrifugal force associated with the mobile wheel. 
         [0024]    2. The apparatus of claim 1 wherein the centrifugal forces of the balance wheel and of the mobile wheel have the same magnitude and are on the same plane. 
         [0025]    3. The apparatus of claim 1 wherein the center of the balance wheel is a hole into which an elbow of the first shaft penetrates, to allow an annular extension of the balance wheel to pressure, through centrifugal action, on an inner surface of said annular extension of said balance wheel on a fixed cylindrical concentric track of the fixed wheel, allowing in turn that said inner surface of said annular extension roll on the fixed cylindrical concentric track of the fixed wheel. 
         [0026]    4. The apparatus of claim 3 wherein the elbow of the first shaft has a 180° orientation to an elbow in connection with the mobile wheel. 
         [0027]    5. The apparatus of claim 1 wherein a mass of the balance wheel m b , a mass of the mobile wheel m e , an eccentricity of the balance wheel e b  and an eccentricity of the mobile wheel e e , satisfy the relationship M b  e b =m e  e e , and wherein the mass centers of both are displaced on a same transversal plane. 
         [0028]    6. The apparatus according to claim 1 wherein the center of the mobile wheel and/or the center of the balance wheel, has a substantially rectangular hole whose center is set at a distance from the center of the respective bearing, so that the latter has eccentric movement. 
         [0029]    7. The apparatus of claim 1, wherein the receiving means is a plurality of holes and the connecting means is a plurality of rods, wherein the plurality of rods are inserted in the plurality of holes providing the connection between the disc and the mobile gear. 
         [0030]    8. The apparatus of claim 7, wherein the elbow of the first shaft forms a crank, and wherein at least one radial hole of the mobile wheel has a radius equal to the sum of the radius of the at least one rod and the radius of the crank. 
         [0031]    9. The apparatus of claim 1, wherein the first and the second shafts are mounted on bearings wherein the balance wheel is mounted on bearings, and wherein the apparatus is mounted on a base plate of the transmission. 
         [0032]    10. The apparatus of claim 1, wherein the center of the balance wheel has a central hole with at least one end curved with which the first shaft is found in connection with, in such a way that when said first shaft is in connection with said central hole, between said at least one curved end and the first shaft a clearance is found which allows the radial displacement of said balance wheel under said centrifugal force of said balance wheel. 
         [0033]    11. The apparatus of claim 1, wherein the mobile wheel and the balance wheel are mounted by means of bearings in central pieces with eccentric holes, and wherein the mobile wheel has a diameter different than the fixed wheel, wherein the difference in diameters depends on the desired speed reduction relation and wherein the difference in diameters is less than about 20% and more preferably, less than about 10%. 
         [0034]    12. A dynamic balancing system of cyclodial wheels comprising a balance wheel with a center, the balance wheel propelled by a first shaft which is in connection with the center of the balance wheel, wherein the propelling of the first shaft generates a centrifugal force of the balance wheel opposite to a centrifugal force associated with the mobile wheel. 
         [0035]    13. The system of claim 12, wherein the mobile wheel is a mobile spur gear, and the system comprises a fixed spur gear, with a connecting means and a disc with at least one rod and a second shaft with a second angular speed, the spur mobile gear has a center and a receiving means for the connecting means, the first shaft is in connection with the center of the mobile spur gear to create the centrifugal force associated with the mobile spur gear, the mobile spur gear interacts with the fixed spur gear, and the at least one rod is inserted in the at least one radial hole of the mobile spur gear. 
         [0036]    14. The system of claim 13, wherein the mobile wheel is a mobile magnetic gear, the system comprises a fixed magnetic gear. 
         [0037]    15. The system of claim 14, wherein the fixed magnetic gear has in an inner periphery a non-magnetic material ring and the mobile gear has a non-magnetic material ring in its outer periphery. 
         [0038]    16. The system of claim 14, wherein the fixed magnetic gear ring houses an even number of permanent magnets and wherein the mobile gear ring houses an even number of permanent magnets, wherein the even number of permanent magnets of the fixed gear is greater than the even number of permanent magnets of the mobile gear. 
         [0039]    17. An apparatus for the transmission of torque/force comprising: 
         [0040]    a first shaft with a first angular speed; 
         [0041]    a magnetic fixed wheel gear with an inner periphery, the inner periphery having a non-magnetic material ring; 
         [0042]    a magnetic mobile wheel gear with a center with a receiving means and an outer periphery, the first shaft being connected with the center of the mobile wheel to propel said center in a circular trajectory creating a centrifugal force associated with the mobile wheel, the mobile wheel interacts with the fixed wheel, wherein the outer periphery of the magnetic mobile gear has a non-magnetic material ring; 
         [0043]    a disc with connecting means, the connecting means being in connection with the receiving means and a second shaft with a second angular speed; 
         [0044]    wherein the fixed magnetic gear ring houses an even number of permanent magnets and wherein the mobile gear ring houses an even number of permanent magnets, wherein the even number of permanent magnets of the fixed gear is greater than the even number of permanent magnets of the mobile gear. 
         [0045]    18. A cycloidal magnetic transmission with permanent magnet gears for power transmission, having each gear in its periphery an even number of permanent magnets with alternating N and S poles facing outwardly, said magnets permanently inserted in radial holes without protruding therefrom, there being contact between the gears allowing the moving gear to roll on the inner surface of the fixed gear. 
         [0046]    19. The cycloidal magnetic transmission with permanent magnet gears for power transmission in conformity with claim 1 in which the moving gear mounted on the high-speed shaft is free to move radially out insuring its contact with the internal surface of the fixed gear and allowing it to roll on that surface as its center moves in a circular orbit mandated by the high-speed shaft on which it is mounted. 
         [0047]    20. The cycloidal magnetic transmission with permanent magnet gears for power transmission in conformity with claim 1 incorporating a coupling between the moving gear and the low-speed shaft (the output shaft in the case of speed reduction mode) to mechanically transmit the rotational motion of said gear but not the orbital translatory motion, said coupling consisting of a plurality of axial pins rigidly attached to a disk rigidly assembled the low-speed shaft, with said pins penetrating in an equal number of holes in the moving gear and each pin having a roller bearing providing rolling contact with the interior surface of the holes which have a radius equal to the sum of the outside radius of the bearings and the moving gear&#39;s eccentricity. 
         [0048]    21. The cycloidal magnetic transmission with permanent magnet gears for power transmission in conformity with claim 1 in which the material of the fixed and moving gears is of high magnetic permeability except for non magnetic rings holding the permanent magnets. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0049]    The particular characteristics and advantages of this invention, as well as other objectives of the invention, will become apparent from the following description, taken along with the attached figures, which: 
           [0050]      FIG. 1  is a view of the mid section of a first embodiment of the magnetic transmission of the present invention. 
           [0051]      FIG. 2  is a front view of the transmission according to section A-A in  FIG. 1 . 
           [0052]      FIG. 3  is a mid-section view of a second embodiment, specifically a cyclodial gear transmission with conventional teeth incorporating a balance wheel. 
           [0053]      FIG. 4  is a front view of the cyclodial gear transmission with conventional teeth according to the section of lines A-A of  FIG. 3 . 
           [0054]      FIG. 5  is a front view according to the section of lines B-B of  FIG. 3 . 
           [0055]      FIG. 6  is a mid-section view of a cyclodial magnetic gear transmission incorporating a balance wheel, according to the second embodiment. 
           [0056]      FIG. 7  is a front view of the cyclodial magnetic gear transmission according to section A-A of  FIG. 6 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Definitions 
       [0057]    About. The term about confers an additional range to the one disclosed. The term is defined in the following manner. The additional range provided is about ±10%. By way of example, but not in a limitative manner, if the following is disclosed “about between 5% and 9.5%” the exact range is between 4.5% and 10.45%, or between 5.5% and 10.45%, or between 4.5% and 8.55%, or between 5.5% and 8.55%. Any of the possibilities previously described is covered with the term “about”. 
       First Embodiment 
     Cycloidal Magnetic Transmission with Permanent Magnet Gears 
       [0058]      FIG. 1  is a view of the mid section of the transmission showing the fixed magnetic gear  41 , the mobile magnetic gear  42 , the high-speed shaft  43 , having a throw at its end, forming a crank  44  with two flat parallel surfaces  45 , that allow the central piece  46  on which gear  42  is mounted by means of bearing  47 , to slide freely. Gear  41  has an internal ring of non-magnetic material  48  and gear  42  an external ring of non-magnetic material  49 . Inserted permanently in ring  48  are an even number of permanent magnets  50 , and a smaller even number of permanent magnets  51  in ring  49 . With the exception of rings  48  and  49 , gears  41  and  42  are made of a high magnetic permeability material. Disk  52  is rigidly attached to the low-speed shaft  53  and has rigidly attached to it a plurality of axial pins  54 , each having a roller bearing  55 . Each bearing  55  makes rolling contact with the surface of a hole  56  in gear  42 . The number of holes  56  is equal to the number of pins  54 . The radius of the holes  56  is equal to the sum of the outside radius of the bearings  55  and the eccentricity of the moving gear  42 . The high-speed shaft is mounted on bearings  57 , and the low-speed shaft on bearings  58 . 
         [0059]      FIG. 2  is a front view of the transmission according to section A-A in  FIG. 1 , which shows magnetic gears  41  and  42 , their respective rings  48  and  49  and crank  44  in section allowing a view of its flat sides  45 . Also shown in  FIG. 2  are the central piece  46 , the bearing  47  and the permanent magnets  50  of gear  41  and  51  of gear  42 . Also shown in  FIG. 2  are pins  54 , bearings  55 , holes  56  in gear  42 , and a base plate  59  for the transmission. 
         [0060]    The magnetic gear cycloidal transmission has gears that are disks with permanent magnets distributed on the periphery, that may be used as a speed reducer or speed amplifier and being kinematically equivalent to a conventional gear cycloidal transmission. Gear  41  is equivalent to a gear with internal teeth, and gear  42  to a gear with external teeth. Transmission of force between the magnetic gears is effected by the attraction in a tangential direction between magnets of opposite polarities arising from a small relative displacement and also by friction associated to a normal contact force between the gears. 
         [0061]    In the view of the mid-section of the transmission,  FIG. 1 , the fixed magnetic gear  41  and the mobile magnetic gear  42  are shown. The internal periphery of gear  41  and the external periphery of gear  42 , consist of non-magnetic rings  48  and  49  respectively.  FIG. 2  shows the contact point between gears  41  and  42 . This contact point moves along the internal circumference of gear  41  making one complete turn in each revolution of the high-speed shaft  43  and consequently also of the center of gear  42  which is mounted on the crank  44 . At the contact point between the gears, a normal force results from the attraction between magnets  50  of gear  41  and  51  of gear  42  and also from the centrifugal force due to the circular motion of the center of mass of gear  42 . This action takes place because gear  42  is free to move in a radially outwardly orientation in view of the slidable cooperation between center piece  46  and the crank throw  44 . The contact point between gears helps the transmission of the power with friction, as well as the force between the magnets is greater than without a contact point, since said force between magnets in the prior art, having a clearance between said gears, that is, gears which have no contact point, decreases rapidly with the gap size between magnets. The exposed poles of the permanent magnets alternate from N to S along the periphery of each gear. As in a conventional mechanical cycloidal gear transmission, the speed ratio between shafts  43  and  53  is n 2 /(n 1 −n 2 ), where n 1  and n 2  represent the number of magnet pairs in gears  41  and  42  respectively. Gear  42  has a movement characterized by a circular translational speed of the same magnitude and sense as the angular speed ω 3  of shaft  43 , and a rotational speed of opposite sense of magnitude 
         [0000]    
       
         
           
             
               
                 
                   ( 
                   
                     
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                       1 
                     
                     - 
                     
                       n 
                       2 
                     
                   
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                   n 
                   2 
                 
               
                
               
                 ω 
                 3 
               
             
             , 
           
         
       
     
         [0000]    the same as that of shaft  53 . As may be appreciated, the motion of gear  42  relative to disk  52  is a circular translation of magnitude ω 3 . Thus, each pin  54  executes one revolution inside a hole  56  of gear  42  for each revolution of shaft  43 . 
         [0062]    Power flows from shaft  43  to shaft  53  in the speed reducer mode of the transmission, and from shaft  53  to shaft  43  in the speed amplifier mode. 
       Second Embodiment 
       [0063]    This embodiment refers to a cyclodial transmission or to a cyclodial transmission system, in which a balance wheel is used to eliminate the unbalancing caused by the orbital movement of a mobile gear. The center of the balance wheel is displaced in a circular trajectory, and is propelled by a crank unto which said balance wheel is mounted by means of a bearing. The crank of the balance wheel with its elbow and the crank of the mobile gear with its elbow are part of a high-speed shaft and are diametrically opposed, that is, the crank of the balance wheel with its elbow is diametrically opposed to the crank of the mobile gear with its elbow, and thus the cranks are 180° from each other. 
         [0064]    The balance wheel has an extension which has a ring shape, wherein an inner surface of the extension comes into contact with a cylindrical track made up by the outer surface of the fixed gear. This contact between the inner surface of the extension and the outer surface of the fixed gear generates the reaction of opposite centrifugal forces, wherein the balance wheel creates a centrifugal force opposite to the centrifugal force associated with the mobile gear, given that the assembly of the balance wheel at the crank does not restrict its radial displacement. Said centrifugal force is preferably a co-lineal opposite force. In this way, the balance wheel rolls on the cylindrical track of the outer surface of the fixed gear, and the balance wheel comes into contact with it, in light of the bearing on which said balance wheel is mounted, allowing it to rotate freely. 
         [0000]    Spur Gears Embodiment with Balance Wheel 
         [0065]    Taking the figures into account, specifically  FIG. 3 , where said figure shows an apparatus or a system with a fixed gear  1  and the mobile gear  2 . Such as can be seen, said gears  1 ,  2  have at least one contact point, wherein at least one tooth of the mobile gear meshes with the at least one tooth of the fixed gear  1  in areas on both sides of the contact point. Said contact point displaces itself along the length of the inner circumference of the fixed gear  1  making a complete turn per each revolution of the high-speed shaft  3 , and consequently of the center of the mobile gear  2 , mounted on the crank. While the mobile gear  2  rotates on its axis, it moves with a particular eccentricity determined by elbow  4  of crank  5 , so that when rotating on its axis, the different teeth of the mobile gear, tend to mesh with the different teeth of the fixed gear  1 . The mobile gear  2  consists with at least one, but preferably a plurality of holes  15  and more preferably at least three holes  15 , wherein the holes  15  are equidistant from the center of said mobile gear  2 . It is preferred that said plurality of holes  15  be at an equidistant distance from each other. In  FIG. 3 , a high-speed shaft  3  is also shown, which has a diameter lower than the diameter of a low-speed shaft. The high-speed shaft  3  has the first elbow  4  at an end distant from the input/output end, where the first elbow  4  forms the crank  5  unto which the mobile gear  2  is mounted on by means of bearings  6 . However, the mounting of the mobile gear  2  may be according to any known mounting of the prior art that allows transmitting the rotation movement between the crank  5  and the mobile gear  2 . A second elbow  7 , which is found at 180° from the elbow  4 , is mounted with the balance wheel  8  by means of bearings  9  and the central piece  10 . The balance wheel  8  has an annular extension  11 , where the extension has an inner part. A disc  12  is integral with the low-speed shaft  13  and with at least one axial rod  14 , and preferably a plurality of axial rods  14 , and more preferably at least three axial rods  14 . The plurality of axial rods  14  is preferably a number which equals the number of holes  15  of the mobile gear  2 . At least one axial rod  14  of the disc  12  penetrates the at least one hole  15  of the mobile gear  2 . The radii of the holes  15  of the mobile gear  2  may be equal to the sum of the radii of the rods  14  and the radii of the crank  5 . The high-speed shaft  3  is mounted on bearings  16 ; however, the mounting of the high-speed shaft  3  may be any of those known in the art which allows transmitting the rotation movement between the mobile gear  2  and the low-speed shaft  13 , excluding the circular translation movement of the mobile gear  2 . Likewise the low-speed shaft  13  is mounted on bearings  17 ; however, the mounting of the low-speed shaft  13  may be any known in the art which allows the rotational movement between the mobile gear  2  and the low-speed shaft  13 . 
         [0066]    In  FIG. 4 , which is a view along the length of lines A-A of  FIG. 3 , the coupling between the mobile gear  2  and the fixed gear  1  is shown. Such as was previously mentioned, the contact or coupling between the gears  1 ,  2  may be at least one pre-determined contact point, where as the mobile gear  2  rotates, the at least one contact point between the gears  1 ,  2  has a circumferential displacement. It also shows the elbow  4  surrounded by the bearing  6 .  FIG. 4  also shows in section, the axial rods  14  of the disc  12 , and the holes  15  of the mobile gear  2 . Upon starting its rotation, the mobile gear  2  also rotates its center with eccentricity in light of the elbow  4  and the crank  5 ; as a consequence, the holes  15  of the mobile gear  2  rotate with the same eccentricity as the center, thereby displacing the rods  14  of the disc  12 . This displacement of the rods  14  causes the disc  12 , in turn to rotate at a lower speed than the speed of the high-speed shaft  3 . Said lower speed of the disc  12  is transmitted to the low-speed shaft  13  which is directly mounted with said low-speed shaft  13 . With the end goal of eliminating the unbalancing, it is preferred that the system be mounted on a base plate of the transmission  17 . Finally, the extension  11  of the balance wheel  8  is shown in the figure. Such as was previously mentioned, the extension  11  preferably has a ring shape, however, the extension  11  may adopt any form that complies with the same function. The extension has an inner part. Said inner part of the extension  11  has at least one contact point with the fixed gear  1 . 
         [0067]    The balance wheel  8  and its extension  11 , as well as the elbow  7 , the bearing  9  and the central piece  10  are shown in  FIG. 5  which is a view along the length of lines B-B of  FIG. 3 . Said central piece  10  is set with a central hole with a buttonhole shape  18  through which the rotation of the high-speed shaft  3  is transmitted by interaction with the plane ends  19  of the buttonhole. Between the curved ends of the buttonhole  18  and the high-speed shaft  3 , specifically between the curved ends of the buttonhole  18  and the corresponding ends of the elbow  7 , at least one clearance and preferably at least two clearances are set which avoid that the high-speed shaft  3  restrict the radial displacement of the balance wheel  8 . 
         [0068]    Such as can be seen,  FIGS. 3 ,  4  and  5  correspond to a cyclodial transmission with conventional gear teeth with the balance wheel. Referencing to said cyclodial transmission and said figures, the mobile gear  2  and its bearing  6  are propelled by the high-speed shaft  3  by means of the crank  5 . The linkage between the mobile gear  2  and the fixed gear  1  at the contact point between said mobile gear  2  and said fixed gear  1 , causes a rotation of the mobile gear  2  in the opposite direction to the rotation of the shaft  3 , simultaneous with the orbital movement of its center. In turn, the balance wheel  8  is also propelled by the high-speed shaft  3  by means of its elbow  7  at 180° from the elbow  4  corresponding to the crank  5 . Given the clearance between the curved ends of the buttonhole  18  and the high-speed shaft  3 , the balance wheel  8  remains free to displace radially under centrifugal force until it is stopped by the contact between the inner surface of its extension  11  and the outer surface of the fixed gear  1  at a diametrically opposed point to the crank  5  and at a point in near proximity to the contact point between said mobile gear  2  and said fixed gear  1 . It is preferable that to achieve balancing, the mass of the balance wheel  8 , m b , the mass of the mobile gear  2 , m e , and their respective eccentricities, e b  and e e , satisfy the relationship m b  e b =m e  e e . Similarly, to achieve balancing, it is preferred that the center of the balance wheel  8  and the center of the mobile gear  2 , that is, the mass center of both be at the same transverse plane. 
         [0000]    Magnetic Gears Embodiment with Balance Wheel 
         [0069]      FIGS. 6 and 7  show an embodiment of the present invention, where the cyclodial transmission corresponds to a magnetic gear transmission. Specifically,  FIG. 6  shows a mid-section of the cyclodial transmission with magnetic gears, in which the fixed gear  20 , the mobile gear  21 , the high-speed shaft  22 , which has on its left end a segment with plane ends  23 , similar to the plane ends  19  of the transmission of  FIG. 5 . Also shown are the balance wheel  24  and its extension  25 , its bearing  26 , the central piece of the balance wheel  27 , the central piece of the mobile gear  28  and its bearing  29 , the disc  30 , integral with the low-speed shaft  31  and with the plurality of axial rods  32 , which preferably have bearings  33  and whose outer tracks come into a rolling contact with the surfaces of an equal number of holes  34  of the mobile gear  21 . The radii of the holes  34  is preferred to be equal to the sum of the outer radii of the bearings  33  and the eccentricity of the mobile gear  21 . The high-speed shaft  22  is mounted on the bearings  35 ; however, the mounting of the high-speed shaft  22  may be any known in the art that allows transmitting rotation movement between the mobile gear  2  and the low-speed shaft  31  excluding the circular translation movement of the mobile gear  21 . The low-speed shaft  31  is also mounted on bearings  36 ; however, the mounting of the low-speed shaft  31  may be any known in the art that allows the rotational movement between the mobile gear  21  and the low-speed shaft  31 . 
         [0070]      FIG. 7  shows the magnetic gears  20  and  21 , the high-speed shaft sectioned  22 , where its plane sides  23  can be appreciated. Also shown, are the balance wheel  24 , the central piece of the mobile gear  28  and its bearing  29 .  FIG. 7  also shows in section, the axial rods  32 , the bearings  33 , and the holes  34  of the mobile gear  21 , as well as a base plate for the transmission  37 . 
         [0071]    Such as was described in patent application number MX/2012/001596 filed in Mexico, corresponding to the same applicant and the priority of the present patent application, the force transmission between the magnetic gears is accomplished by means of the attraction in tangential direction between magnets with different polarities, when a slight relative displacement occurs between each other and, additionally, by the friction associated with the normal contact force between the gears. In the mid-section view of the transmission in  FIG. 6 , the fixed magnetic gear  20  and the mobile gear  21  are shown. The inner periphery of the first and the outer of the second, may consist respectively of rings of non-magnetic material. In  FIG. 7 , the point of contact between the gears  20 ,  21  can be seen. Said point of contact displaces itself along the length of the inner circumference of the fixed gear  20  making a complete turn per every revolution of the high-speed shaft  22 , and consequently of the center of the mobile gear  21 . At the point of contact of the gears a normal force is transmitted resulting from the attraction between the fixed gear magnets  20  and the mobile gear magnets  21 , as well as the centrifugal force given by the circular movement of the mass center of the mobile gear  21 . The above occurs because the mobile gear  21  is able to freely displace itself in a radial direction thanks to the sliding coupling between the central piece  27  and the high-speed shaft  22 . It is preferred that the exposed poles of the permanent magnets alternate between N and S along the length of the periphery of each gear  20 ,  21 . In an equal manner to a conventional transmission with mechanical gears, the relation of velocities between the high-speed shaft  22  and the low-speed shaft  31  is n 2 /(n 1 −n 2 ), where n 1  and n 2  represent respectively, the number of magnet pairs in the gears  20 ,  21 . The mobile gear  21  has a movement characterized by a circular translation of the same magnitude and direction as the angular speed ω 3  of the high-speed shaft  22 , and a rotation in the opposite direction, of magnitude [(n 1 −n 2 )/n 2 ]ω 3 , same as the angular speed of the low-speed shaft  31 . As can be appreciated, the relative movement of the mobile gear  21  in relation to the ensemble of the disk  30 , the rods  21  and the low-speed shaft  31 , is a circular translation with ω 3  magnitude. In this way, each rod  32  executes one revolution within a hole  34  of the mobile gear  21 , per each revolution of the high-speed shaft  22 . 
         [0072]    As opposed to the invention described by the same applicant of the present invention, in Mexican patent application number MX/a/2012/001596 to which priority is claimed, the present invention contains an improvement by having incorporated the balance wheel  24  with its respective extension  25 , which counter-arrests the unbalancing of the centrifugal force of the mobile gear  21  in the same manner as in the previously described transmission with spur gears case. In  FIGS. 6 and 7  yet another embodiment is shown, specifically the case of a difference in gear diameters  21 ,  22 , corresponding to a high-speed ratio. The difference between the diameters can be lesser than about 20%, preferably lesser than about 10% and even more preferably, between about 5% and 9.5%. Given this, it is possible to obtain the eccentric movement of the mobile gear  21  and of the balance wheel  24  without having to resort to elbows on the high-speed shaft  22 , but rather by means of eccentric buttonholes in the respective central pieces  28  and  27 , as can be seen in  FIGS. 6 and 7 . It is preferred that the balancing requires that the same conditions previously described for the transmission with spur gear case be met. 
         [0073]    In all the embodiments, when the transmission acts as a speed reducer, the power from the high-speed shafts  3 ,  22  is transmitted to the low-speed shafts  13 ,  31 , and inversely, to operate as a speed amplifier, power is transmitted from the low-speed shafts  13 ,  31  to the high-speed shafts  3 ,  22 . Likewise, in all the embodiments, the hole and rod system may be substituted when the eccentricity is small for methods known in the prior art, such as flexible couplings. 
         [0074]    In so far as this invention has been described in terms of various embodiments, there are alterations, permutations and the like which fall within this invention&#39;s reach. It should also be noted, that there are many alternatives to implement the apparatus and methods of the present invention. Therefore, it is intended that the following claims be interpreted including all the alterations, permutations and the like which fall within the true spirit and reach of the present invention.