The present invention relates to a magnetic motion transmission assembly, suitable for transmission along different axes and also for the variation of the rotational parameters (angular velocity and transmitted torque).

Motion transmission is generally performed by means of toothed transmission elements (pinions, ring gears, plain gears and the like), which are mutually coupled in order to provide a kinematic continuity.

Toothed couplings ensure perfect synchronization and allow to transfer high power levels; however, they are heavily subject to wear and to mechanical losses by friction, are noisy, require lubrication and, in case of accidental overloads, they can be damaged even irreparably.

In some simple transmission cases it is known to use coupling joints of the magnetic type which utilize the interaction between permanent magnets in order to transfer motion from a motor shaft to a driven shaft.

Most of the problems mentioned above, which are typical of toothed couplings, are overcome with the use of these magnetic joints, but their field of application is heavily limited, substantially confined to the coupling of coaxial shafts (at most parallel) in synchronous rotation.

The aim of the present invention is to solve the problems mentioned above, proposing a magnetic motion transmission assembly that can be applied for each specific motion transmission and/or reduction requirement from a motor shaft to a driven shaft.

Within this aim, an object of the invention is to propose a magnetic motion transmission assembly that is quiet.

Another object of the invention is to propose a magnetic motion transmission assembly that does not require lubrication.

Another object of the invention is to propose a magnetic motion transmission assembly that is inherently protected against overloads.

Another object of the invention is to propose a magnetic motion transmission assembly that is not subject to intense heating during operation.

Another object of the invention is to propose a magnetic motion transmission assembly with high transmission efficiencies, i.e. affected by limited energy losses.

Another object of the present invention is to provide a magnetic motion transmission assembly that has low costs, is relatively easy to provide and is safe in use.

This aim and these and other objects that will become better apparent hereinafter are achieved by a magnetic motion transmission assembly of the type comprising a driving shaft, rigidly coupled to a respective motor drive unit, and a driven shaft, associated with a mechanical load, means for mutual connection being interposed between said driving shaft and said driven shaft, characterized in that said connection means comprise at least one first disk, which is coupled on said driving shaft, and at least one second disk, which is coupled on said driven shaft, said at least one first disk and said at least one second disk comprising, on corresponding annular regions thereof, a plurality of permanent magnets arranged side-by-side and with alternating polarities in succession, the magnets of said first disk interacting, optionally with the interposition of additional transmission elements provided with respective magnets, with the magnets of said second disk.

Further characteristics and advantages of the invention will become better apparent from the description of a preferred but not exclusive embodiment of the magnetic motion transmission assembly according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a perspective view of a possible embodiment of the assembly according to the invention;

Figure 2 is a transverse sectional view of the assembly of Figure 1; Figure 3 is a longitudinal sectional view of the assembly of Figure 1;

Figure 4 is a perspective view of a further embodiment of the assembly according to the invention;

Figure 5 is a transverse sectional view of the assembly of Figure 4;

Figure 6 is a perspective view of a part of internal components of the assembly of Figure 1.

With reference to the figures, a magnetic motion transmission assembly is generally designated by the reference numeral 1.

The magnetic assembly 1 according to the invention comprises a driving shaft 2, rigidly coupled to a respective motor drive unit, and a driven shaft 3, associated with a mechanical load.

Means for mutual connection are interposed advantageously between the driving shaft 2 and the driven shaft 3.

The connection means comprise at least one first disk 4, which is coupled on the driving shaft 2, and at least one second disk 5, which is coupled on the driven shaft 3.

The at least one first disk 4 and the at least one second disk 5 comprise, on corresponding annular regions thereof, a plurality of permanent magnets 6 arranged side-by-side and with alternating polarities in succession.

The magnets 6 of the first disk 4 interact, optionally with the interposition of additional transmission elements provided with respective magnets 6, with the magnets 6 of the second disk 5.

The magnetic interaction between the magnets 6 of the first disk 4 and those of the second disk 5 (optionally obtained by virtue of the interposition of the additional transmission elements provided with magnets 6) allows the transmission of motion from the driving shaft 2 to the driven shaft 3.

It is specified that the annular regions of the at least one first disk 4 and of the at least one second disk 5 comprise advantageously a plurality of contiguous seats whose shape and dimensions are complementary to those of respective permanent magnets 6 designed to be accommodated inside them.

With particular reference to a first constructive solution of unquestionable interest in practice and in application, the assembly 1 may conveniently comprise a boxlike body 7, provided with at least one first passage hole 8 for the driving shaft 2 and a second passage hole 9 for the driven shaft 3.

In this constructive solution the first hole 8 and the second hole 9 are coaxial.

This structure ensures that the driving shaft 2 and the driven shaft 3 are rigidly coupled alternately and separately to at least one component chosen from at least one first disk 4, which has a diameter that is close to and smaller than the inside diameter of the boxlike body 7 and is provided with a region 11 comprising the seats for the permanent magnets 6, and at least one second disk 5, which has a reduced diameter and is provided, on an annular region thereof, with the seats for the respective permanent magnets 6.

Moreover, at least one third disk 10 is advantageously provided and must be rotatable with respect to an axis that is parallel to the axis of the holes 8 and 9; this axis of the at least one third disk 10 is validly arranged substantially at the centerline between the seats for the permanent magnets 6 of the first disk 4 and the seats for the permanent magnets 6 of the second disk 5.

The at least one third disk 10, in this case, comprises, along an annular portion thereof, respective seats for permanent magnets 6 which at least partially face and are proximate to the seats of the first disk 4 and of the second disk 5.

Again with reference to the constructive solution shown previously, it is noted that the first disk 4 can advantageously comprise at least one auxiliary annular element 12, which is coupled to a respective perimetric edge of the first disk 4 and is provided with respective seats for respective permanent magnets 6, which are aligned with the seats of the region 11 of the first disk 4.

The third disks 10 may conveniently be at least two, each comprising respective seats which are substantially aligned and proximate, in the assembly configuration, to the corresponding seats of the first disk 4 and of the at least one auxiliary annular element 12.

By increasing the number of the third disks 10 and inserting the auxiliary annular elements 12 it is possible to increase the magnetic interaction between the driving shaft 2 and the driven shaft 3, thus ensuring the possibility to deliver even considerable torques.

Within the scope of this possible version, it is specified that the second disks 5 may advantageously be at least two, arranged at a mutual axial distance, along the respective shaft 3, which is slightly greater than the thickness of the at least one third disk 10.

In this manner, in the assembly configuration, at least one portion of the at least one third disk 10 is interposed between the second contiguous disks 5.

In this manner it is thus possible to provide a reduction unit of the epicyclic type in which the planetary gears (i.e., the third disks 10) have a fixed arrangement of their rotation axes and in which the so-called sun pinion (constituted by the driven shaft 3) is rotated by the annular element (i.e., the first disk 4 associated with the driving shaft 2), utilizing only magnetic interactions among the components, among which no mechanical interference will occur.

The absence of toothed couplings is advantageous since it eliminates the risk of failures if a sudden increase in torque occurs (for example an unexpected jamming of the driven shaft 3), it greatly reduces noise and makes lubrication unnecessary. Maintenance operations, by virtue of the minimization of the wear of the components with respect to an epicyclic reduction unit that uses toothed couplings, also are drastically reduced and this also entails considerably lower operating costs than those of a traditional reduction unit.

With particular reference to a further and different constructive solution of particular interest for numerous industrial applications, the assembly 1 may conveniently comprise a boxlike body 13, provided with at least one first passage hole 14 for the driving shaft 2 and a second passage hole 15 for the driven shaft 3.

In this particular constructive solution the first hole 14 and the second hole 15 lie on incident and mutually inclined axes.

The driving shaft 2 and the driven shaft 3 are thus separately and rigidly coupled to a respective disk (the first disk 4 and the second disk 5) provided with a substantially perimetric region which comprises respective seats for the permanent magnets 6.

The boxlike body 13 furthermore comprises (freely pivoted inside it) at least one third disk 16, which is able to rotate with respect to the axis on which the bisecting line of the angle defined between the axes of the first hole 14 and of the second hole 15 lies.

The at least one third disk 16 comprises, along an annular portion thereof, respective seats for permanent magnets 6 which at least partially face and are proximate to the seats of the first disk 4 and of the second disk 5.

With particular reference to the constructive solution shown by way of non-limiting example in the accompanying figures, the first disk 4 and the second disk 5 can validly have same shape and dimensions.

Said disks 4 and 5 have an inclined terminal edge 17 which defines the region affected by the seats for the permanent magnets 6.

The annular portion of the at least one third disk 16 in turn has an orientation that is oppositely inclined and complementary to the one of the terminal edge 17 of the first disk 4 and of the second disk 5.

With particular reference to the constructive solution exemplified in the accompanying figures (without this causing any limitation to the possible constructive variations of the assembly 1 according to the invention), the third disk 16 may comprise an annular region affected by an annular slot 18 whose shape and dimensions are complementary to those of the inclined terminal edge 17 of the disks 4 and 5.

The seats designed to contain the permanent magnets 6 are provided along the mutually opposite and facing surfaces that delimit the annular slot 18 of the third disk 16.

In this manner, each magnet 6 present on the seats of the inclined terminal edge 17 is (in the assembly configuration) interposed between two magnets 6 (conveniently arranged with the correct magnetic polarity for correct interaction) which are present on the surfaces that delimit the annular slot 18: the magnetic interaction that can be obtained with this particular configuration allows to increase the maximum torque that can be transmitted with the assembly 1 thus provided.

With particular reference to an alternative constructive solution (not shown in the accompanying figures), the third disks 16 might also be two, aligned and mutually opposite.

In this case, each disk 16 would comprise, along an annular portion thereof, respective seats for permanent magnets 6 which at least partially face and are proximate to the seats of the first disk 4 and of the second disk 5.

In other words, the two disks 16 would interact on substantially opposite portions of the disks 4 and 5, further increasing the magnetic interactions that are present (and are used to transfer the torque).

This further constructive solution necessarily entails larger dimensions of the boxlike body 13 with respect to the ones that can be envisioned for providing the assembly 1 which constitutes an angular joint shown in the accompanying figures.

In fact, it would be necessary to provide for the free pivoting of the additional third disk 16 at the comer 19 of said boxlike body.

It is specified that the permanent magnets 6 can preferably have a maximum operating temperature of no less than 80 °C.

In this manner they can efficiently tolerate temporary overheatings that might occur during operation.

For some specific cases, the use of magnets with maximum operating temperature even greater than 300°C may be suitable.

The permanent magnets 6 used in the assembly 1 according to the invention are of the type constituted by at least one material chosen from ferrite, magnetite, alloys of iron oxide and carbonates, aluminum-nickel- cobalt alloys, titanium-cobalt-nickel-aluminum alloys, lanthanide alloys, molecular magnets, organic magnets, alloys of iron with at least one substance chosen from cobalt, nickel, rare earths, boron, and combinations of such materials and constituents.

The possibility is provided to use permanent magnets 6 of the commercial type (for non-demanding applications and for providing assemblies 1 with low costs).

For example, cylindrical commercial magnets 6 having a diameter of 10 mm and a height of 10 mm have a force of attraction measured by“pull- away” (i.e., the traction force at which the separation of a magnet 6 from another identical fixed magnet 6 occurs) of about 6-7 kg.

In the case of magnets 6 having a diameter of 10 mm and a height of 10 mm, the value of this force of attraction measured by“pull-away” may be even 9 or more kg.

Likewise, the possibility is also provided to use permanent magnets 6 of a type optimized for some specific applications in order to maximize, for example, the maximum operating torque.

In cases of magnets 6 produced specifically for specific applications, the force of attraction measured by“pull-away” will have very high values even with reduced dimensions of the components involved.

In the assembly configuration, the maximum distance between the magnets 6 of one disk (first disk 4, second disk 5, third disk 10 or 16) and those of the contiguous disk will be no more than a few millimeters.

In particular, it is specified that the best results that can be obtained, if it is necessary to overcome a high negative torque, entail that the maximum distance between magnets of contiguous disks (first disk 4, second disk 5, third disk 10 or 16) is at most 1 millimeter, obtaining increasingly better performance when it is possible to minimize said distance.

Advantageously, the present invention solves the problems mentioned above by proposing a magnetic motion transmission assembly 1 that can be applied for each specific requirement of motion transmission and/or reduction from a motor shaft (the driving shaft 2) to a driven shaft 3.

The assembly 1 according to the invention in fact does not have limitations in application, since it can be adapted easily to any technical requirement.

Conveniently, the assembly 1 according to the invention is extremely quiet with respect to those of a known type provided with toothed meshing couplings and thus can be used in any type of application, without requiring the use of additional means for noise mitigation.

Advantageously, the magnetic assembly 1 according to the invention does not require lubrication and this leads to a reduction of operating costs (routine maintenance operations will be certainly significantly far less frequent with respect to a gear-based transmission assembly) and a greater overall cleanliness of the assembly 1 and of the area near it (in the case of gear transmission assemblies it is not always possible to exclude some leakage of lubricant).

Usefully, the assembly 1 according to the invention is inherently protected against overloads. In fact, at an excessively high negative torque the magnets of disks (4, 5, 10 and 16) will slip with respect to each other (overcoming the force of mutual magnetic attraction that would keep them facing each other), without causing any damage to the assembly. In the case of gear-based transmission assemblies, instead, an excessively high negative torque might cause damage of the mutually meshing teeth (and thus the failure of said assembly).

Advantageously, the assembly 1 according to the invention is not subject to intense heating during operation.

In fact, since there is no friction between components in mutual motion, no heating occurs which can be attributed to this phenomenon (which instead is a major problem for gear-based transmission assemblies).

Any heating of the components of the assembly 1 according to the invention can occur due to eddy currents induced by the movement of the permanent magnets 6: this phenomenon, however, can be limited easily by using specific materials (for example by making the boxlike bodies 7 and 13 or the disks 4, 5, 10 and 16 of paramagnetic material or, if they are made of ferromagnetic material, by providing for their lamination).

It is specified in any case that the intensity of said eddy currents is linked to the frequency of variation of the magnetic field (which is due to the movement of the permanent magnets 6).

Positively, the assembly 1 according to the invention ensures high transmission efficiencies, since it is affected by limited energy losses.

The elimination of the frictions and of the rubbing actions between the teeth that affect traditional gear-based motion transmission assemblies ensures that the assembly 1 according to the invention achieves very high transmission efficiencies.

Validly, the magnetic motion transmission assembly 1 is a device that is relatively simple to provide in practice and can be produced at substantially low costs: these characteristics make the assembly 1 according to the invention an innovation of assured application.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the accompanying claims; all the details may furthermore be replaced with other technically equivalent elements.

In the examples of embodiment shown, individual characteristics, given in relation to specific examples, may actually be interchanged with other different characteristics that exist in other examples of embodiment.

In practice, the materials used, as well as the dimensions, may be any according to the requirements and the state of the art.

The disclosures in Italian Patent Application No. 102019000001619, from which this application claims priority, are incorporated by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.