ROTOR FOR ROTARY ELECTRIC MACHINE, MANUFACTURING METHOD AND CORRESPONDING ROTARY ELECTRIC MACHINES

Abstract

The present invention relates to a rotor (100) for a rotary electric machine, in which each package of plates (300) of the rotor (100) comprises, at both ends or end sections thereof, at least one first inverted plate (311) and at least one last inverted plate (312), said plates being inverted in relation to the other plates (310) of the package of plates (300).

Claims

1. A rotor for rotary electric machine, comprising: a package of plates, wherein each package of plates of the rotor comprises, at both ends or end sections thereof, at least one first inverted plate and at least one last inverted plate, said plates being inverted in relation to other plates of the package of plates.

2. The rotor according to claim 1, characterized in that the plates have lower holes and upper holes, in which the upper holes of the plates are arranged in an off-centered manner, preferably offset or mirrored in relation to the central radial shafts of the lower holes.

3. The rotor according to claim 1, characterized in that the inverted plates cover the channels formed by the upper holes of the plates arranged between said inverted plates.

4. The rotor according to claim 1, characterized in that the lower holes of the plates remain aligned over the same package of plates.

5. The rotor according to claim 1, characterized in that the inverted plates are preferably the same as the other plates.

6. The rotor according to claim 1, characterized in that the inverted plates can be arranged, alone or together with one or more of the other plates, at points other than the ends or end sections of the same package of plates.

7. The rotor according to claim 1, characterized in that a package of plates can have more than one inverted plate at each end or end section thereof.

8. The rotor according to claim 1, characterized in that the holes of the rotor are filled with different materials, the upper hole being filled with an insulating material and the lower hole filled with a conductive material.

9. A method of manufacturing a rotor of claim 1, the method comprising: i. stamping the plates with a central hole, lower holes and upper holes; ii. grouping and concurrently aligning a plurality of plates with the holes aligned with each other forming at least one package of plates; iii. arranging one or more inverted plates in each end or end section of the package of plates, inverted or mirrored in relation to the other plates; iv. arranging the package of plates in an appropriate injection tool provided with cavities to receive the package of plates and cavities to allow filling the channels formed by aligning the lower holes of the lower cage; v. injecting injectable material to fill the channels formed by the lower holes; and vi. pressing the shaft into one or more package of plates by inserting the shaft through the center hole.

10. The method according to claim 9, characterized in that step iii. comprises arranging one or more inverted plates, alone or together with one or more of the other plates, at points other than the ends or end sections of the same package of plates.

11. A rotary electric machine comprising a rotor of claim 1.

12. A rotary electric machine manufactured by the method of claim 9.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] For a better understanding and visualization of the object, the present invention will now be described with reference to the appended figures, representing the obtained technical effect through an example embodiment without limiting the scope of the present invention, in which, schematically:

[0031] FIG. 1 shows a perspective view of a rotor according to the invention, with the package of plates assembled on the shaft;

[0032] FIG. 2 shows a front view of a plate of the rotor package of plates from FIG. 1;

[0033] FIG. 3 shows an enlarged view of detail A from FIG. 2;

[0034] FIG. 4 shows a front view of a package of plates according to the invention; and

[0035] FIG. 5 shows an enlarged view of detail B from FIG. 4, highlighting the cover of the upper holes of the package of plates by the inverted plate surface.

DETAILED DESCRIPTION OF THE INVENTION

[0036] The present invention relates to a rotor (100) comprising a shaft (200) and one or more package of plates (300).

[0037] The shaft (200) of the rotor (100) according to the invention is a shaft (200) known from the state of the art and of the type commonly used for application in rotary electric machines.

[0038] The package of plates (300) of the rotor (100) according to the invention is formed by a plurality of plates (310) made from material suitable for electric motors of the nature addressed herein, each plate (310) provided with a central hole (320), lower holes (330), which are through-holes, and upper holes (340), also through-holes, and there may be one or more package of plates (300), equal or different from each other, arranged on the same shaft (200) of the rotor (100).

[0039] The central hole (320) allows inserting the shaft (200) and may eventually be equipped with additional openings for passage over keys and other elements.

[0040] The lower holes (330), when aligned in the package of plates (300), form through-channels which will be filled with conductive material by a suitable process, joining fusion and injection under pressure, preferably by means of injection, forming through-bars of conductive material which have their ends joined by a short-circuit ring, forming the lower cage or working cage. The material used to inject the bars that will fill the through-channels of the lower holes (330) of the working cage must be an injectable material, preferably but not limited to aluminum and/or one or more alloys thereof.

[0041] The shape of the lower holes (330) of the plates (310) will preferably depend on the design specifications of the electric machine to which they are intended.

[0042] The upper holes (340), when aligned in the package of plates (300), form through-channels that will be filled with insulating material. The material that will fill the through-channels of the upper holes (340) should be a suitable material, preferably but not limited to air.

[0043] The shape of the upper holes (340) of the plates (310) will preferably depend on the design specifications of the electric machine to which they are intended.

[0044] The plates (310) are manufactured by means and processes known from the state of the art and usual for rotary electric machines of the nature addressed herein, which may be, for example, and not limited to stamping, mechanical cutting, laser cutting, injection, casting, sintering, and other related processes, provided they are appropriate.

[0045] The package of plates (300) is formed by grouping and parallel aligning a plurality of plates (310) with the holes (320, 330, 340) aligned with each other forming a package of plates (300).

[0046] In the rotor (100) according to the invention, at least one plate (310) at each of the ends of the package of plates (300) will be assembled as an inverted plate (311, 312), in an inverted manner in relation to the other plate (310), which means that the package of plates (300) will have, at both ends thereof, along the longitudinal shaft (200) of the rotor (100), at least one first inverted plate (311) and at least a last inverted plate (312), both inverted in relation to the other plates (310) arranged therebetween, delimiting the package of plates (300) at both ends.

[0047] In the context of the present invention, one end of the package of plates (300) should be understood as equivalent to a longitudinal end stretch of up to 20%, preferably up to 15%, preferably up to 10% of the total length of the package of plates (300), measured along the longitudinal shaft (200) of the rotor (100) from the end towards the inside of the package of plates (300). This means that the inverted plates (311, 312) can be arranged both at the ends and along an end section as defined above, and there may even be more than one inverted plate (311, 312) along the same end section. Thus, each package of plates (300) will have at least two end sections, one at each end thereof. Anyway, for the purposes of clarity of the present description, the plates that will undergo inversion will be called simply the first inverted plate (311) and the last inverted plate (312).

[0048] It should be noted that the first and last inverted plate(s) (311, 312) are preferably the same as the other plates (310), differing from these only by the assembly position on the shaft (200) of the rotor (100) which, as described above, is an inverted mounting position in relation to the assembly position of the others.

[0049] The package of plates (300) may have more than one inverted plate (311, 312) at each end thereof or end sections, depending on the electric machine design, dimensions, injection pressure and other related parameters.

[0050] If the rotor (100) is provided with more than one package of plates (300), each of the package of plates (300) may also be delimited at both ends or end sections by at least one first inverted plate (311) and by at least one last inverted plate (312).

[0051] The upper holes (340) are arranged in the plates (310) in an off-centered manner, preferably offset or mirrored in relation to the central radial shafts of the lower holes (330), so that the lower holes (330) are aligned over the same package of plates (300), but the sheet of an inverted plate (311, 312), assembled upside down, covers the upper holes (340) of the subsequent plate(s) (310). As such, the upper holes (340) of the inverted plates (311, 312) of the ends or end sections will not be aligned with the upper holes (340) of the other plates (310). The inverted plates (311, 312) at the ends will serve as caps or physical restrictors for the channels formed by the upper holes (340) of the internal plates (310) and/or arranged therebetween and/or therebefore and/or thereafter.

[0052] As such, it should be noted that one or more inverted plates (311, 312) may also be arranged, alone or together with one or more of the other plates (310), at other points in addition to the ends or end sections of the same package of plates (300), and the inverted plates (311, 312) will also serve as caps or physical limits for the channels formed by the upper holes (340) of the plates (310) arranged therebetween and/or therebefore and/or thereafter.

[0053] Once assembled, the package of plates (300) is arranged in an appropriate injection tool, provided with cavities to receive the package of plates (300) and cavities to allow filling the channels formed by aligning the lower holes (330) of the lower cage, said channels being physically separated from the channels formed by aligning the upper holes (340), increasing the dimensional stability and reliability of the process.

[0054] As such, the material of the lower cage does not penetrate the upper holes (340), keeping the channels formed by the upper holes (340) free of material, in particular free of conductive material, reducing high frequency losses.

[0055] The differentiated arrangement of the first and last inverted plate(s) (311, 312) of the package of plates (300), or of one or more groups of inverted plates (311, 312), by inverting them in the assembly, with or without plates (310) and even package of plates (300) inverted in the middle of the pack, and together with the separation of the upper hole (340) in relation to the lower hole (330), helps in the aluminum injection process in the lower bottom cage or working cage (filled with material), preventing aluminum from entering the air-filled hole during the injection process.

[0056] The holes (330, 340) of the rotor (100) according to the invention are filled with different materials, the upper hole (340) being filled with air so as to simulate an equivalent opening of the bridge of the rotor (100), and the lower or working hole (330) filled with conductive material through an aluminum injection process. The upper hole (340) being filled with air reduces high frequency losses in motors powered by a frequency converter, an effect that would not occur if the hole (340) were filled with a conductive material.

[0057] A process for manufacturing a rotor (100) according to the invention is a process for manufacturing a rotor (100) comprising a shaft (200) and at least one or more package of plates (300), in which at least one plate (310) from each of the ends or end sections of the package of plates (300) will be assembled as an inverted plate (311, 312), inverted in relation to the other plates (310), delimiting the package of plates (300) one or more times at both ends or end sections.

[0058] This process comprises the process steps of: [0059] i. stamping the plates (310) with a central hole (320), lower holes (330) and upper holes (340); [0060] ii. grouping and concurrently aligning a plurality of plates (310) with the holes (320, 330, 340) aligned with each other forming at least one package of plates (300); [0061] iii. arranging one or more inverted plates (311, 312) in each end or end section of the package of plates (300), inverted or mirrored in relation to the other plates (310); [0062] iv. arranging the package of plates (300) in an appropriate injection tool provided with cavities to receive the package of plates (300) and cavities to allow filling the channels formed by aligning the lower holes (330) of the lower hole; [0063] v. injecting injectable material to fill the channels formed by the lower holes (330); and [0064] vi. pressing the shaft (200) into one or more package of plates (300) by inserting the shaft (200) through the center hole (320).

[0065] In a preferred non-limiting embodiment of the invention, step iii. may further comprise arranging one or more inverted plates (311, 312), alone or together with one or more plates (310), at points other than the ends or end sections of the same package of plates (300).

[0066] The manufacturing process according to the invention has important and striking differences in relation to the equivalent steps from processes for manufacturing rotors in the state of the art.

[0067] Execution times of the steps of the invention are reduced in relation to those of equivalent steps from the state of the art, given that there is no need to press or weld the package of plates (300) and, more importantly, additional tools and/or back pressure to insulate the upper hole (340) cavities during the injection process are unnecessary.

[0068] Using only one type of plates (310), the outermost ones serving as caps for the ends or end sections of the package of plates (300) are exactly the same as the other plates (310), does not require additional parts or components, reducing the number of motor items and thus improving the quality indexes in the assembly.

[0069] As such, the process according to the invention for manufacturing a rotor (100) according to the invention drastically reduces the manufacturing times for the type of rotors addressed herein, reduces material and labor costs, increases productivity, demand fewer steps and optimizes manufacturing capacity by bit requiring additional machinery or auxiliary devices. It should be noted that the process according to the invention may have other accessory steps, before and after those described above, according to the technical knowledge and manufacturing practices necessary for the construction of rotors for rotary electric machines.

[0070] A rotary electric machine according to the invention is an electric motor provided with a rotor (100) according to the invention manufactured according to a process according to the invention.

CONCLUSION

[0071] It will be easily understood by one skilled in the art that modifications may be made to the present invention without departing from the concepts set out in the description above. Such modifications should be considered as included within the scope of the present invention. Consequently, the particular embodiments previously described in detail are merely illustrative and exemplary, and not limitative in terms of the scope of the present invention, to which the full extent of the accompanying claims should be given, in addition to all and any equivalents thereof.