MX2013001280A - System for dynamically balancing a cycloidal gears transmission. - Google Patents

Abstract

The present invention refers to a conventional gear transmission or magnetic gear transmission, with a cycloidal configuration. 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

SYSTEM FOR DYNAMICALLY BALANCING OR TRANSMISSION CYCLOID OF ENGRANES Field of the Invention The present invention relates generally to transmissions, and more specifically to cycloidal transmissions with tooth gears or magnetic cycloidal transmissions, which use a balancing wheel.

Background of the Invention In cycloidal transmissions generally used as speed reducers, a mobile gear with external teeth is driven in a circular orbit by a crank of a high-speed input shaft. Said mobile gear is linked to a fixed annular gear with internal teeth. The radius of the crank equals the eccentricity between the two gears.

Usually a coupling is used between the mobile gear and the low speed output arrow, capable of mechanically transmitting the rotational movement of said mobile gear, but not the orbital translation thereof. In such coupling, the torque transmission is made by means of a number of axial bolts evenly distributed in a disc integrated to the low speed shaft, which penetrate an equal number of circular holes in the movable gear.

Instead of using conventional tooth gears in a cycloidal transmission, it is possible to use magnetic gears with magnets, as it is in the case of the transmission described in the Mexican patent application No. MX / a / 2012/001596 of the same applicant and entitled Cycloidal Magnetic Transmission with Gears of Permanent Magnets for Power Transmission and of which the present patent application claims priority. The use of magnetic gears is also described in other publications, for example, U.S. Patent Nos. 5,013,949 and 5,569.11.

The problem encountered in the prior art cycloidal transmissions, whether with tooth gears or magnetic gears, is the imbalance of the two gear system.

A disadvantage of the cycloidal transmissions is the vibration caused by the orbital movement of the mobile gear, since its center of mass moves in a circular path that gives rise to a centrifugal force of magnitude m lr, where m represents the mass of the gear, ? the angular velocity of the crank; and r the radius of the circular path, said force represented by a vector that also rotates at the velocity co. One way to reduce this vibration is by incorporating a second mobile gear driven by a crank 180 ° from the first. The vectors that represent the centrifugal forces of both gears are of the same magnitude but of opposite direction, nevertheless they are not collinear to occur in different planes, giving rise to a moment in a rotating plane, which is why the vibration is not completely suppressed.

Brief Description of the Invention The present invention describes modalities with teeth gears and modalities with magnets, in which a balancing wheel is used whose center of mass moves in a circular path in the same plane of the trajectory of the center of the mobile gear, but at 180 ° of this, generating a centrifugal force equal, opposite and collinear with that of the mobile gear. The systems of such gears are described herein.

An object of the present invention is to realize a transmission of conventional gears of teeth of cycloidal configuration, incorporating a balancing wheel that generates an opposite and collinear centrifugal force to the centrifugal force associated with the mobile gear, the opposite and collinear centrifugal force being of equal magnitude and in the same plane as the centrifugal force associated with the mobile gear, thus totally eliminating the imbalance of the system and gear mechanism.

Another object of the present invention is to realize a transmission of magnetic gears of cycloidal configuration, incorporating a balancing wheel that generates an opposite and collinear centrifugal force to the centrifugal force associated with the mobile gear, the opposite and collinear centrifugal force being of equal magnitude and in the same plane as the centrifugal force associated with the mobile gear, thus completely eliminating the imbalance of the system and gear mechanism.

Other objects of the invention are the following: 1. A force / torque transmission apparatus comprising: a first arrow with a first angular velocity; a fixed wheel; a mobile wheel with a center with a receiving means a connecting means, the first arrow being in connection with the center of the moving wheel to drive said center in a circular path creating a centrifugal force associated with the moving wheel, the moving wheel interacts with the fixed wheel; a disk with a connection means, the connection means being in connection with the receiving means and a second arrow with a second angular velocity; the apparatus characterized by a roll wheel with a center, the roll wheel driven by the first arrow being in connection with the center of the roll wheel, where the impulse of the first arrow generates a centrifugal force of the roll wheel opposite to the centrifugal force associated with the mobile wheel. 2. The apparatus of claim 1, wherein the centrifugal forces of the balancing wheel and the movable wheel have equal magnitude and have the same plane. 3. The apparatus according to claim 1, wherein the center of the roll wheel is a substantially quadrangular hole into which an elbow of the first arrow penetrates, to allow an annular extension of the roll wheel to press, by centrifugal action , on an inner surface of said annular extension of said balancing wheel on a fixed concentric cylindrical track of the fixed wheel, while allowing said inner surface of said annular extension to roll on the fixed concentric cylindrical track of the fixed wheel. 4. The apparatus according to claim 3, wherein the elbow of the first arrow has a 180 ° orientation of an elbow in connection with the movable wheel. 5. The apparatus according to claim 1, wherein a mass of the balancing wheel mb, a mass of the moving wheel I, an eccentricity of the rolling wheel e¿ and an eccentricity of the mobile wheel ee, satisfy the ratio m ¿E¿ = me ee, and where the centers of mass of both move in the same transversal plane. 6. The apparatus according to claim 1, wherein the center of the movable wheel and / or the center of the roll wheel, has a substantially quadrangular hole whose center is at a distance from the center of the respective bearing so that the latter has Eccentric movement. 7. The apparatus of claim 1, wherein the elbow of the first arrow forms a crank, and wherein the at least one hole of the movable wheel has a radius equal to the sum of the radius of the at least one bolt and the radius of the crank. 8. The apparatus of claim 1, wherein the first and second arrows are mounted on bearings where the balancing wheel is mounted on bearings, and wherein the apparatus is mounted on a transmission base plate. 9. The apparatus of claim 1, wherein the center of the roll wheel has a central hole with at least one curved end with which the first arrow is in connection with, such that when said first arrow is in connection with said central hole, between said at least one curved end and the first arrow there is a clearing that allows the radial displacement of said rolling wheel under said centrifugal force of said rolling wheel. 10. The apparatus of claim 1, wherein the center of the movable wheel and the center of the balancing wheel is an eccentric hole, and wherein the movable wheel has a diameter 5 other than a diameter of the fixed wheel, wherein the The difference between diameters depends on the desired rate reduction ratio and can be less than 20% and more preferably less than 10%. 11. A dynamic balancing system of cycloidal wheels comprising a roll wheel with a center, the roll wheel driven by a first arrow being in connection with the center of the balancing wheel, wherein the impulse of the first arrow generates a centrifugal force of the balancing wheel opposite a centrifugal force associated with the moving wheel. 12. The system of claim 1, wherein the movable wheel is a movable toothed gear, and the system comprises a fixed toothed gear, and a disk with at least one pin and a second arrow with a second angular speed, the movable toothed gear has a center and at least one opening, the first arrow being in connection with the center of the movable toothed gear to drive said center in a circular path by creating the centrifugal force associated with the mobile toothed gear, the movable toothed gear interacts with the gear fixed toothing, and the at least one pin is inserted into the at least one hole in the movable jagged gear. 13. The system of claim 1 1 wherein the impeller is a moving magnetic engagement, the system comprises a fixed magnetic gear, the fixed magnetic gear has a ring of non-magnetic material and the movable gear on an inner periphery has a ring nonmagnetic material at its outer periphery, wherein the ring fixed magnetic gear housing an even number of permanent magnets and wherein the ring mobile gear housing an even number of permanent magnets, wherein the even number of permanent magnets fixed gear is greater than the even number of permanent magnets of the mobile gear.

Brief Description of the Figures The particular features and advantages of this invention, as well as other objects of the invention, will be apparent from the following description, taken in connection with the accompanying figures, which: Fig. 1 is a middle sectional view of a cycloidal transmission of conventional tooth gears incorporating a roll wheel.

Fig. 2 is a front view of the cycloidal transmission of conventional tooth gears according to the section of the lines A-A of Fig. 1.

Fig. 3 is a front view according to the section of lines B-B of Fig. 1.

Fig. 4 is a middle section view of a cycloidal transmission of magnetic gears incorporating a roll wheel.

Fig. 5 is a front view of the cycloidal transmission of magnetic gears according to section A-A of Fig. 4.

DETAILED DESCRIPTION OF THE INVENTION Definitions Approximately. The term approximately confers a rank additional to that described. The term is defined as follows. The additional range provided by the term is approximately ± 10%. Exemplary, but not limiting, if it says "approximately 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%, O well between 5.5% and 8.55%. Any possibility described above is covered by the term "approximately".

The present invention relates to a cycloidal transmission or a cycloidal transmission system, in which a rolling wheel is used to eliminate the imbalance caused by the orbital movement of a mobile gear. The center of the balancing wheel moves in a circular path, and is driven by a crank in which said balancing wheel is mounted by means of a bearing. The crank wheel balancing with his elbow and crank mobile engagement with elbow are part of an arrow high speed and are diametrically opposed, that is, the crank wheel balancing with his elbow is diametrically opposed to the crank of the mobile gear with its elbow, being thus the cranks to 180 ° of yes.

The roll wheel has an extension having a ring shape, wherein an inner surface of the extension makes contact with a cylindrical track constituted 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, where the balancing wheel creates a centrifugal force opposite to the centrifugal force associated with the mobile gear, since the assembly of the balancing wheel on the crank does not restrict its radial displacement. Said opposite centrifugal force is preferably a opposite force co-linear. Thus, the roll wheel rolls on the cylindrical track of the outer surface of the fixed gear, with which the roll wheel makes contact in view that the bearing on which said roll wheel is mounted, allows it to rotate freely.

Gears with Teeth Referring to the figures, specifically to figure 1, in said figure there is shown an apparatus or system with a fixed gear 1 and the mobile gear 2. As can be seen, said gears 1, 2 have at least one point of contact , wherein at least one tooth of the movable gear 2 meshes with at least one tooth of the fixed gear 1 in zones on both sides of the contact point. Said contact point travels along the inner circumference of the fixed gear 1 giving a complete revolution for each revolution of the high-speed arrow 3, and consequently of the center of the mobile gear 2, mounted on the crank 4. While the gear mobile 2 rotates on its axis, moves with a particular eccentricity to elbows 4, 7 of the cranks 5, so when rotating on its axis, the different teeth of the mobile gear 2 tend to engage with the different teeth of the fixed gear 1. The movable gear 2 has at least one, preferably a plurality of holes 15, and even more preferably at least three holes 15, wherein the holes 15 are equidistant from the center of said movable gear 2. It is preferred that said plurality of holes 15 is at a distance equidistant from each other. In Figure 1, the high speed arrow 3 is also shown, which may have a radius less than the radius of a low speed arrow. The high speed arrow 3 has the first bend 4 at an end distant from the input / output end, where the first bend 4 forms the crank 5 on which the mobile gear 2 is mounted by means of bearings 6. However, the mounted of the mobile gear 2 can be any known in the art that allows to transmit the rotation movement between the crank 5 and the mobile gear 2. A second wheel 7, which is 180 ° from the bend 4, is mounted on the wheel swinging 8 through bearings 9 and centerpiece 10. Rolling wheel 8 has an annular extension 1 1, wherein the extension has an internal part. A disc 12 is integral with the low speed shaft 13 and with at least one axial bolt 14, preferably a plurality of axial bolts 14, and even more preferably at least three axial bolts 14. The plurality of axial bolts 14 is preferably the same in number to the holes 15 of the movable gear 2. At least one axial bolt 14 of the disc 12 penetrates at least one hole 15 of the movable gear. The radius of the holes 15 of the movable gear can be equal to the sum of the radius of the bolts 14 and the radius of the crank 5. The high-speed arrow 3 is mounted on bearings 16; however, the assembly of the high-speed arrow 3 can be any known in the art that allows to transmit the rotation movement between the mobile gear 2 and the low speed arrow 13 excluding the circular translation movement of the mobile gear 2. Likewise the low speed arrow 13 is Mounts on bearings 17; however, the assembly of the low speed arrow 13 can be any known in the art that allows to transmit the rotation movement between the mobile gear 2 and the low speed arrow 13.

In figure 2, which is a view along the lines AA of figure 1, the coupling between the mobile gear 2 and the fixed gear 1 is shown. As mentioned above, the contact or coupling between the gears 1, 2 can be in at least one determined point of contact, wherein as the mobile gear 2 rotates, the at least one contact point between the gears 1, 2 has a circumferential displacement. The elbow 4 surrounded by the bearing 6 is also shown. The axial bolts 14 of the disk 12 and the holes 15 of the mobile gear 2 are also shown in section. At the beginning of its rotation, the mobile gear 2 also rotates its center with eccentricity in view of the elbows 4, 7 and the crank 5; as a consequence, the holes 15 of the mobile gear 2 rotate with the same eccentricity as the center, thus displacing the bolts 14 of the disk 12. This displacement of bolts 14 causes that, in turn, the disk 12 rotates with speed less than the fast speed of the high speed arrow 3. Said lower speed of rotation of the disk 12 is transmitted to the low speed arrow 13 which is directly mounted with said low speed arrow 13. In order to eliminate the unbalance, it is preferred that the system is mounted on a base plate of the transmission 37. Finally, the figure shows the extension 1 1 of the balancing wheel 8. As mentioned above, extension 11 has preferably a ring shape, however, the extension 11 can take any form that fulfills the same function. The extension has an internal part. Said internal part of the extension 1 1 has at least one point of contact with the fixed gear 1.

In Figure 3 is shown the balancing wheel 8 and its extension 1 1, as well as the elbow 7, the bearing 9 and the central part 10. Said central part 10 carries a central hole in the form of eyelet 18 through which transmits the rotation of the high-speed arrow 3 by interaction with the flat ends 19 of the buttonhole. Between the curved ends of the eye 18 and the high speed arrow 3, specifically between the curved ends of the eye 18 and the corresponding ends of the elbow 7, there is at least one clear, and preferably at least two clearings that prevent the high arrow speed 3 restrict the radial displacement of the balancing wheel 8.

As shown, Figures 1, 2 and 3 correspond to a cycloidal transmission of conventional teeth with the balancing wheel. With reference to said cycloidal transmission and said figures, the mobile gear 2 and its bearing 6 are driven by the high-speed arrow 3 by the crank 5. The link of the mobile gear 2 with the fixed gear 1 at the point of contact 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 arrow 3, simultaneous with the orbital movement of its center. In turn, the balancing wheel 8 is also driven by the high-speed arrow 3 through the elbow 7 to 180 ° of the elbow 4 corresponding to the crank 5. Due to the gap between the curved ends of the eye 18 and the high speed arrow 3, the balancing wheel 8 is free to move radially under centrifugal force until it is stopped by the contact between the inner surface of its extension 1 1 and the outer surface of the fixed gear 1 at a point diametrically opposite the crank 5 and at a point close to the point of contact between said mobile gear 2 and said fixed gear 1. It is preferable that, in order to achieve a roll, the mass of the wheel of rolling 8, mh, the mass of the moving gear 2, me, and their respective eccentricities eh and ec satisfy the relation mbeb = meee. Likewise, in order to achieve a balancing, it is preferred that the center of the balancing wheel 8 and the center of the mobile gear 2, that is, the center of mass of both be in the same transverse plane.

Magnetic Gears Figures 4 and 5 show an embodiment of the present invention, wherein the cycloidal transmission corresponds to a transmission of magnetic gears. Specifically, in Figure 4 is shown a middle section of the cycloidal transmission of magnetic gears in which the fixed gear 20, the mobile gear 21, the high speed arrow 22, which has at its left end a segment with fixed gear, is shown. flat ends 23, similar to the flat ends 19 of the reduction transmission of Fig. 3. Also shown is the balancing wheel 24 and its extension 25, its bearing 26, the center piece of the sway wheel 27, the part central of the mobile gear 28 and its bearing 29, the disc 30, integral with the low speed arrow 31 and with the plurality of axial bolts 32, which preferably bear bearings 33 and whose outer tracks make a rolling contact with the surfaces of a preferably equal number of holes 34 of the movable gear 21. The radius of the holes 34 is preferred to be equal to the sum of the outer radius of the bearings 33 and the eccentricity of the movable gear 21. The high speed arrow 22 is mounted on bearings 35; however, the assembly of the high-speed arrow 3 can be any known in the art that allows to transmit the rotation movement between the mobile gear 2 and the low speed arrow 13 excluding the circular translation movement of the mobile gear 2. low speed arrow 31 on bearings 36; however, the assembly of the low speed arrow 13 can be any known in the art that allows to transmit the rotation movement between the mobile gear 2 and the low speed arrow 13.

Figure 5 shows the magnetic gears 20 and 21, the sectioned high-speed arrow 22 showing its flat sides 23. Also shown are the balancing wheel 24, the central part of the mobile gear 28 and its bearing 29 Fig. 5 also shows in section, the axial bolts 32, the bearings 33, and the holes 34 of the mobile gear 21, as well as a base plate of the transmission 37.

As described in the patent application No. X / 2012/001596 filed in Mexico, corresponding to the same inventor, the same owner and the priority of the present patent application, the force transmission between the magnetic gears has to be it achieves by means of the attraction in tangential direction between magnets of different polarity when a slight relative displacement occurs between both and, in addition, by the friction associated to the normal force of contact between the gears. In the view of the middle section of the transmission of Fig. 4, the fixed magnetic gear 20 and the mobile gear 21 are shown. The inner periphery of the first and the outer periphery of the second, may consist respectively of rings of non-magnetic material . In Fig. 5 the point of contact between the gears 20, 21 is observed. Said contact point moves along the inner circumference of the fixed gear 20 giving a complete turn for each revolution of the high-speed arrow 22, and consequently of the center of the mobile gear 21. At the point of contact between the gears a normal force resulting from the attraction between the magnets of the fixed gear 20 and the magnets of the mobile gear 21, as well as the centrifugal force due to the movement is transmitted. circular of the center of mass of the mobile gear 21. The above occurs because the mobile gear 21 can move freely in the radial direction thanks to the sliding coupling between the center piece 27 and the high-speed arrow 22. It is preferred that the exposed poles of the magnets permanent, alternate between N and S along the periphery of each gear 20, 21. Equivalent to a transmission of mechanical gears conventionally, the ratio of speeds between the high-speed arrow 22 and the low-speed arrow 31- is n and ri2), where n and n2 respectively represent the number of pairs of magnets in the gears 20, 21. The movable gear 21 has a movement characterized by a circular translation of the same magnitude and direction as the angular velocity? of the high-speed arrow 22, and a counter-clockwise rotation, of magnitude [(?? -? 2) /? 2]? 3, same as the angular velocity of the low-speed arrow 31. As can be seen, the relative movement of the movable gear 21 with respect to the assembly of the disk 30, the bolts 32, and the low speed arrow 31, is a circular translation of magnitude 3 3. Thus, each bolt 32 executes a revolution inside a hole 34 of the movable gear 21, for each revolution of the high speed arrow 22.

Unlike the invention described by the same inventor and owner of the present invention, in the patent application No. MX / a / 2012/001596 to which priority is claimed, the present invention contains the improvement of having incorporated the balancing wheel 24 with its respective extension 25, which counteracts the imbalance of the centrifugal force of the mobile gear 21 in the same way as in the previously described case of the gear transmission of teeth. In figures 4 and 5 another mode is illustrated, specifically the case of a difference in the diameters of the gears 21, 22, corresponding to a high speed reduction. The difference between the diameters can be less than about 20%, preferably less than about 10%, and even more preferable between approximately 5% to 9.5%. Because of this, it is possible to obtain the eccentric movement of the movable gear 21 and of the balancing wheel 24 without resorting to bends in the high-speed arrow 22, but by means of eccentric eyelets in the respective central parts 28 and 27, as shown in FIG. it is appreciated in Figures 4 and 5. It is preferred that balancing requires that the same conditions as stated above be met in the case of the transmission of tooth gears.

In all the modes, when the transmission operates as a speed reducer, power is transmitted from the high-speed arrow 3, 22 to the low-speed arrow 13, 31 and inversely, to operate as a speed amplifier, power is transmitted from the arrow low speed 13, 31 to high speed arrow 3, 22. Likewise, in all modes, the system of holes and bolts can be substituted when the eccentricity is small by methods known in the prior art, such as flexible copies.

While this invention has been described in terms of various embodiments, there are alterations, permutations and equivalents that fall within the scope of this invention. It should also be noted that there are many alternative ways to implement the apparatuses and methods of the present invention. Accordingly, it is intended that the following appended claims be construed as including all such alterations, permutations and equivalents as they fall within the true spirit and scope of the present invention.

Claims (16)

1. A force / torque transmission apparatus comprising: a first arrow with a first angular velocity; a fixed wheel; a mobile wheel with a center with a receiving means to a connecting means, the first arrow being in connection with the center of the mobile wheel to drive said center in a circular path creating a centrifugal force associated with the moving wheel, the wheel mobile interacts with the fixed wheel; a disk with a connection means, the connection means being in connection with the receiving means and a second arrow with a second angular velocity; the apparatus characterized by a roll wheel with a center, the roll wheel driven by the first arrow being in connection with the center of the roll wheel, where the impulse of the first arrow generates a centrifugal force of the roll wheel opposite to the centrifugal force associated with the mobile wheel.

2. The apparatus of claim 1, wherein the centrifugal forces of the balancing wheel and the movable wheel have equal magnitude and have the same plane.

3. The apparatus according to claim 1, wherein the center of the roll wheel is a hole into which an elbow of the first arrow penetrates to allow an annular extension of the roll wheel to press, by centrifugal action, into a inner surface of said annular extension of said balancing wheel on a concentric fixed cylindrical track of the fixed wheel, while allowing said inner surface of said annular extension to roll on the fixed concentric cylindrical track of the fixed wheel.

4. The apparatus according to claim 3, wherein the elbow of the first arrow has a 180 ° orientation of an elbow in connection with the movable wheel.

5. The apparatus according to claim 1, wherein a mass of the balancing wheel mb, a mass of the movable wheel I, an eccentricity of the balancing wheel eb and an eccentricity of the movable wheel ee, satisfy the relation w¿ ei, - me ee, and where the centers of mass of both move in the same transversal plane.

6. The apparatus according to claim 1, wherein the center of the movable wheel and / or the center of the balancing wheel has a hole whose center is at a distance from the center of the respective bearing so that the latter has eccentric movement .

7. The apparatus of claim 1, wherein the receiving means is a plurality of holes and the connecting means is a plurality of pins, wherein the plurality of bolts is insertable in the plurality of holes providing the connection between the disk and the movable wheel.

8. The apparatus of claim 7, wherein the elbow of the first arrow forms a crank, and wherein the at least one hole of the movable wheel has a radius equal to the sum of the radius of the at least one bolt and the radius of the crank.

9. The apparatus of claim 1, wherein the apparatus is mounted on a base plate of the transmission.

10. The apparatus of claim 1, wherein the center of the roll wheel has a central hole with at least one curved end with which the first arrow is in connection with, such that when said first arrow is in connection with said central hole, between said at least one curved end and the first arrow there is a clearing that allows the radial displacement of said rolling wheel under said centrifugal force of said rolling wheel.

The apparatus of claim 1, wherein the movable wheel and the balancing wheel are mounted on center pieces with eccentric holes, and wherein the movable wheel has a diameter other than a diameter of the fixed wheel, wherein the The difference between diameters depends on the desired rate reduction ratio and wherein the difference between diameters is less than about 20% and, more preferably, less than about 10%.

12. A dynamic balancing system of cycloidal wheels comprising a roll wheel with a center, the roll wheel driven by a first arrow being in connection with the center of the roll wheel, where the impulse of the first arrow generates a force centrifugal of the balancing wheel opposite a centrifugal force associated with the moving wheel.

13. The system of claim 12, wherein the movable wheel is a movable jagged gear, and the system comprises a fixed cogged gear with a connecting means and a second arrow with a second angular speed, the movable jagged gear has a center and a half receiver of the connecting means, the first arrow being in connection with the center of the movable toothed gear to create the centrifugal force associated with the movable toothed gear, the movable toothed gear interacts with the fixed toothed gear.

14. The system of claim 12, wherein the movable wheel is a movable magnetic gear, the system comprises a fixed magnetic gear.

15. The system of claim 14, wherein the fixed magnetic gear has a ring of non-magnetic material at an internal periphery and the movable gear has a ring of non-magnetic material at its outer periphery.

16. The system of claim 14, wherein the fixed magnetic gear ring houses an even number of permanent magnets and wherein the movable 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 magnets permanent of the mobile gear.