Cover for rotor, rotor and rotary electric machine

Abstract

The present invention relates to a protective cover (8, 9) for the coil head region of a rotor (1) of a rotary electric machine, the cover comprising a cover wall (10) and a peripheral wall (11) extending axially from an edge region (10a) of the cover wall (10), wherein the cover wall (10) has a central region (12) configured to engage with a shaft (2) of the rotary electric machine, a region for receiving rotor balancing elements, and a plurality of through-openings (14).

Description

"COVER FOR ROTOR, ROTOR AND ROTATING ELECTRIC MACHINE" FIELD OF THE INVENTION

[0001] The present invention relates to the field of rotating electrical machines with wound rotors. FUNDAMENTALS OF THE INVENTION

[0001] Rotating electrical machines are equipment used to transform electrical energy into mechanical energy, in the case of motors, and vice versa, in the case of generators. They are generally made up of four basic structures: the rotor, which is the rotating energized component, a static element called the stator, also energized, bearings responsible for joining the static and rotating parts, and finally, the casing, which acts as an enclosure and promotes integration with other auxiliary systems.

[0002] The rotor generally comprises a stack of plates containing grooves or housings arranged at the ends of the plates, into which conductive elements, called coils, are inserted. These coils are energized, that is, electric current flows through these components.

[0003] Each coil typically comprises a stack of insulated conductive wires, with the wires filling the slot almost entirely. The coils arranged inside the slots form the groups, and these groupings form the poles of the rotating electrical machine. The portion of the coils not contained within the slots of the sheet metal stack is called the coil head.

[0004] During the operation of the electric machine, it is possible that the coil head may expand as a result of the temperature rise of the assembly, and excessive expansion can cause the coil assemblies to collapse.

[0005] Furthermore, during the operation of the electric machine, rotation can also cause displacement of the coil groups in the coil head, resulting in collapse.

[0006] Another challenge associated with the coil head region is related to temperature control. The machine's operation causes heat generation by the... conductive elements, which can be particularly relevant in machines that operate at high speeds.

[0007] Thus, there is a constant search for technical solutions that promote the protection of the coil head and that promote temperature control in that region. OBJECTIVES OF THE INVENTION

[0008] One of the objectives of the invention is to provide a solution for protecting the coil head of a rotor in a rotating electrical machine.

[0009] Another objective of the invention is to provide a protection solution for the coil head region of a rotor in a rotating electrical machine that is also capable of promoting temperature control in that region.

[0010] Another objective of the present invention is to provide a protective solution for the coil head region of a rotor in a rotating electrical machine that also assists in the assembly and securing (locking) of the rotor.

[0011] Another objective of the present invention is to provide a protection solution for the coil head region of a rotor in a rotating electrical machine that also aids in balancing the rotor. BRIEF DESCRIPTION OF THE INVENTION

[0012] The present invention achieves the above objectives by means of a protective cover for the coil head region of a rotor of a rotating electrical machine, the cover comprising a cover wall and a peripheral wall extending axially from an edge region of the cover wall, wherein the cover wall has a central region configured for fitting with a shaft of the rotating electrical machine, a region for receiving rotor balancing elements and a plurality of openings.

[0013] It should be noted that, in alternative embodiments of the invention, the rotor balancing region may be a region of added material (such as balancing mass) or removed material.

[0014] In one embodiment of the invention, the perimeter wall further comprises an edge region configured for fitting with a rotor insulating element.

[0015] In embodiments of the invention, the receiving region for rotor balancing elements comprises a plurality of receiving holes for balancing screws arranged in a circular row near an edge region of the cover wall.

[0016] In one embodiment of the present invention, the protective cover further comprises a plurality of helical walls extending from an inner surface of the cover wall to the outer wall.

[0017] Preferably, each helix wall of the plurality of helix walls projects from a region between two adjacent through openings of the plurality of through openings, and, in embodiments of the invention, each helix wall increases in thickness in a region close to the peripheral wall.

[0018] The present invention also encompasses a rotor for a rotating electric machine comprising a rotor package pressed onto a shaft, wherein said rotor package comprises a grooved region in which coils are housed and at least one coil head region in which the ends of the coils are external to the rotor package, wherein the rotor further comprises a protective cover for at least one coil head region, wherein the protective cover comprises a cover wall and a peripheral wall extending axially from an edge region of the cover wall, wherein the cover wall of the protective cover has a central region configured for fitting with the shaft, a region for receiving rotor balancing elements and a plurality of through openings.

[0019] In one embodiment of the invention, the rotor protective cover further comprises a plurality of propeller walls extending from an inner surface of the cover wall to the outer wall.

[0020] In embodiments of the invention, the rotor further comprises an insulating element disposed in at least one coil head region, wherein the shaft comprises a stop portion (or a keyway portion) whose shape corresponds to that of a central opening in the central fitting region and in that the insulating element has extended elements whose shape corresponds to the shape of a portion of the inner surface of the peripheral wall.

[0021] In alternative embodiments of the invention, the central fitting region of the protective cover comprises a split cylindrical wall extending coaxially with the peripheral wall, and the shaft comprises a receiving portion for the central fitting region.

[0022] The rotor of the present invention may further comprise a plurality of styluses, the ends of which also have a flat wall whose shape corresponds to a portion of the inner surface of the peripheral wall.

[0023] The present invention also encompasses a rotating electrical machine comprising a rotor according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be described in more detail below, with reference to the accompanying drawings, in which:

[0025] Figure 1 - is a perspective view of a rotating electric machine rotor according to an embodiment of the present invention, showing the rotor with the coil head region exposed;

[0026] Figure 2 - is a perspective view of a rotating electric machine rotor according to an embodiment of the present invention, showing the rotor with protective covers in the coil head regions;

[0027] Figure 3 - is a perspective view of a protective cover according to a first embodiment of the present invention;

[0028] Figure 4 - is a second perspective view of the protective cover according to the first embodiment of the present invention;

[0029] Figure 5 - is a perspective view of the rotor end that receives the protective cover according to the first embodiment of the present invention;

[0030] Figure 6 - is a perspective view of the rotor end shown in Figure 5 with the cover according to the first embodiment of the present invention assembled;

[0031] Figure 7 - is a perspective view of a protective cover according to with a second embodiment of the present invention;

[0032] Figure 8 - is a second perspective view of the protective cover according to the second embodiment of the present invention;

[0033] Figure 9 - is a perspective view of the rotor end that receives the protective cover according to the second embodiment of the present invention; and

[0034] Figure 10 - is a perspective view of the rotor end shown in Figure 9 with the cover according to the second embodiment of the present invention assembled. DETAILED DESCRIPTION OF THE INVENTION

[0035] The present invention will be described below based on an exemplary embodiment of the present invention shown in Figures 1 to 6 and an alternative embodiment shown in Figures 7 to 10.

[0036] Figure 1 shows a rotor 1 applied in rotating electrical machines. The rotor comprises, in simplified terms, a shaft 2, a rotor package 3, also known as a lamination package, and a coil head region 4. A person skilled in the art would have no difficulty understanding that the rotor may include other components not described herein, so only the elements relevant to the understanding of the present invention will be described and presented.

[0037] The coil head region 4 comprises the portion of the coils 5 not contained within the slots of the lamination bundle 3. The region may further comprise an insulating element 6 disposed at the axial end of the rotor bundle 3.

[0038] In this sense, it should be understood that insulator 6 holds the coils in the rotor, with the insulator being held by the cover 8 (see figure 2).

[0039] As can be seen in Figure 1, the rotor may comprise two coil heads, each formed at a respective axial end of the rotor package 3.

[0040] In the construction of the rotor, a plurality of 7 shims can also be foreseen, extending longitudinally along the rotor package and along the longitudinal dimension of the coil heads. By "longitudinal extension," As defined here, it should be understood as a dimension of length or extension parallel to the axis of rotation of the electrical machine.

[0041] Figure 2 shows rotor 1 with two protective covers 8, 9, each arranged over a respective coil head region. Naturally, in other embodiments of the present invention, the rotor could comprise only one protective cover, with the other rotor end being closed by another element.

[0042] The protective cover 8, 9 according to the present invention is configured to protect the coil head region, but is also capable of assisting in rotor mounting and locking, rotor balancing and rotor cooling.

[0043] Figures 3 and 4 show a first embodiment of the lid 8 according to the present invention.

[0044] As can be seen in these figures, the cover 8 comprises a cover wall 10 and a perimeter wall 11 that extends axially from an edge region 10a of the cover wall 10. “Axially” is used here with reference to the rotor axis. In the preferred, but not limiting, embodiment of the invention, the perimeter wall 11 is a cylindrical wall coaxial to the rotor axis.

[0045] In the illustrated embodiment, the cover wall 10 is a substantially flat circular wall having a central interlocking region 12 with the axis 2 and a receiving region for balancing elements. In alternative embodiments of the present invention, the cover wall 10 could have another shape suitable for the application.

[0046] In further embodiments of Figures 3 and 4, the receiving region for balancing elements is the edge region 10a of the cover wall 10 and preferably comprises a plurality of receiving holes 13 for balancing screws arranged in a circular row close to the edge of the cover wall 10. Naturally, in alternative embodiments of the present invention, the balancing elements could have a different configuration, such that the receiving region for balancing elements would comprise receiving means configured to receive such elements. Also, in alternative embodiments of the present invention, the receiving region for balancing elements The balancing factor could be formed in a region other than the 10a edge region.

[0047] It should be noted that, in alternative embodiments of the invention, the rotor balancing region may be a region of added material (such as balancing mass) or removed material.

[0048] As shown in figures 3 and 4, the cover wall 10 may also include a plurality of openings 14. The openings 14 assist in the ventilation of the rotor, in addition to allowing a reduction in the total weight of the cover.

[0049] As best seen in Figure 4, the surface of the cover wall 10 from which the peripheral wall 11 projects can be defined as an inner surface 15 of the cover wall 10. From this inner surface also projects a plurality of propeller walls 16, so that the cover 8 forms a fan for cooling the rotor.

[0050] In the embodiment shown in Figures 3 and 4, each of the helical walls 16 projects from a region between two adjacent openings 14 and extends to the peripheral wall 11. Also in this embodiment, the wall increases in thickness in a region close to the peripheral wall 11. The increase in thickness aids in ventilation, preventing stagnation (stagnant air) at the outlet of the helical wall.

[0051] Thus, the region (between openings) from which the propeller wall 16 projects, associated with the shape of the wall 16, increases the efficiency of the fan thus formed.

[0052] In alternative embodiments of the invention, the helix walls could have a different shape or could be present in different quantities and arrangements.

[0053] The cover 8 according to the present invention is also configured to assist in the assembly and locking of the rotor 1.

[0054] In this regard, Figure 5 shows the rotor end where the cover 8 is mounted. In the embodiment shown, the shaft 2 and the insulating element 6 are configured to fit, respectively, with the central fitting region 12 and with the peripheral wall 11 of the cover 8.

[0055] Thus, in the illustrated embodiment, shaft 2 comprises a stop portion 17 whose shape corresponds to the shape of the opening of the central fitting region 12, and the insulating element 6 has extended elements 18 whose shape corresponds to the shape of an inner surface portion of the peripheral wall 11. In the illustrated embodiment, the extended elements 18 comprise a flat face with rounded corners, fitting into the cover and providing support for the coil head.

[0056] In this way, cover 8 can be fitted onto shaft 2 and insulating element 6.

[0057] In embodiments of the invention where rotor 1 comprises a plurality of spades 7, the ends of the spades 7 also have a flat part whose shape corresponds to a portion of the inner surface of the peripheral wall 11.

[0058] After fitting, the cover 8 can be locked in the coil head region by a system of pressure washer 19 and nut 20, which ultimately allows the rotor assembly 1 to be locked. This locking system is illustrated in figure 6. It should be understood, however, that in other embodiments of the invention, another means of fixing the cover could be used, such as, for example, interference fit or adhesive fixation.

[0059] In the embodiment of the invention shown in Figures 2 to 6, the peripheral wall 11 of the lid 8 further comprises a plurality of elongated openings 21. These elongated openings on the outer radius serve as air inlet and outlet, removing hot air at the extremities due to heating. Naturally, in alternative embodiments of the invention, the openings could have other shapes. The openings 21 also help to reduce the mass of the lid 8.

[0060] Figures 7 and 8 show a second embodiment for the lid of the present invention.

[0061] As shown in the figures, in this second embodiment, lid 9 presents some characteristics identical to those described for the lid in the embodiment of figures 3 and 4. These identical characteristics are indicated in Figures 7 and 8 have the same reference numbers as Figures 3 and 4, so the description of these figures in relation to Figures 3 and 4 can be applied to the realization of Figures 7 and 8.

[0062] The implementation of figures 7 and 8 differs from the implementation of figures 3 and 4 in the configuration of the central interlocking region.

[0063] In the embodiment of figures 7 and 8, the central fitting region 120 comprises a cracked cylindrical wall 121 that extends coaxially with the peripheral wall 11.

[0064] Figure 9 shows the rotor end on which the cover 9 is mounted. In the embodiment shown, the shaft 2 and the insulating element 6 / pegs 7 are also configured to fit, respectively, with the central fitting region 120 and with the peripheral wall 11 of the cover 9.

[0065] However, in this embodiment, axis 2 comprises a receiving portion 170 for the central fitting region 120, and at least one slot in the slotted wall 121 may allow the passage of a connecting cable 122.

[0066] As shown in Figure 10, after fitting, the cover 9 can be locked in the coil head region by the pressure washer system 19 and nut 20 also used in the cover embodiment of Figures 3 and 4. It should be understood, however, that in other embodiments of the invention, another means of fixing the cover could be used, such as, for example, interference fit or adhesive fixation.

[0067] It should be noted that while Figure 2 shows a rotor in which a first end receives cap 8 and a second end receives cap 9, alternative embodiments of the invention could use different cap combinations, including a cap 8 or 9 on only one end, two identical cap 8s, or two identical cap 9s.

[0068] Having described examples of preferred embodiments of the present invention, it should be understood that the scope of the present invention encompasses other possible variations of the inventive concept described, being limited only by the content of the appended claims, including possible equivalents.

Claims

CLAIMS 1. Protective cover (8, 9) for the coil head region of a rotor (1) of a rotating electric machine, characterized in that it comprises: a cover wall (10) and a peripheral wall (11) extending axially from an edge region (10a) of the cover wall (10), wherein the cover wall (10) has a central region (12) configured for fitting with a shaft (2) of the rotating electric machine, a region for receiving rotor balancing elements and a plurality of through openings (14).

2. Protective cover (8, 9), according to claim 1, characterized in that the peripheral wall (11) further comprises an edge region configured for fitting with an insulating element (6) of the rotor (1).

3. Protective cover (8, 9), according to claim 1 or 2, characterized in that the receiving region for rotor balancing elements comprises a plurality of receiving holes (13) for balancing screws arranged in a circular row close to an edge region of the cover wall (10).

4. Protective cover (8, 9), according to any one of claims 1 to 3, wherein the protective cover (8, 9) comprises a plurality of helical walls (16) extending from an inner surface (15) of the cover wall (10) to the perimeter wall (11).

5. Protective cover (8, 9), according to claim 4, characterized in that each helix wall (16) of the plurality of helix walls projects from a region between two adjacent through openings (14) of the plurality of through openings (14).

6. Protective cover (8, 9), according to claim 4 or 5, characterized in that each helix wall (16) increases in thickness in a region close to the peripheral wall (11).

7. Rotor (1) for a rotating electric machine comprising a rotor pack (3) mounted on a shaft (2), wherein said rotor pack (3) comprises a region with grooves in which coils are housed and at least one coil head region (4) in which the ends of the coils (5) are external to the rotor package (3), the rotor being characterized in that it further comprises: a protective cover (8,9) for at least one coil head region (4), wherein the protective cover (8,9) comprises a cover wall (10) and a peripheral wall (11) extending axially from an edge region (10a) of the cover wall (10), wherein the cover wall (10) of the protective cover (8,9) has a central region (12) configured for fitting with the shaft (2), a region for receiving rotor balancing elements and a plurality of through openings (14).

8. Rotor (1), according to claim 7, characterized in that it further comprises an insulating element (6) disposed in at least one coil head region (4) and wherein: the shaft (2) comprises a stop portion (17) whose shape corresponds to the shape of a central opening of the central fitting region (12); and the insulating element (6) has extended elements (18) whose shape corresponds to the shape of an inner surface portion of the peripheral wall. (11).

9. Rotor (1), according to claim 7, characterized in that it further comprises an insulating element (6) disposed in at least one coil head region (4) and wherein: the central fitting region (120) of the protective cover (9) comprises a slotted cylindrical wall (121) extending coaxially with the peripheral wall (11); the shaft (2) comprises a receiving portion (170) for the central fitting region (120); and the insulating element (6) has chamfered elements (18) whose chamfer shape corresponds to the shape of an inner surface portion of the wall. peripheral (11).

10. Rotor (1), according to claim 8 or 9, characterized in that it further comprises a plurality of styli (7) and wherein the ends of the styli have a flat wall whose shape corresponds to a portion of the inner surface of the peripheral wall (11).

11. Rotor (1), according to any one of claims 7 to 10, characterized in that the receiving region of rotor balancing elements of the protective cover (8,9) comprises a plurality of receiving holes (13) for balancing screws arranged in a circular row close to an edge region of the cover wall (10).

12. Rotor (1), according to any one of claims 7 to 11, wherein the protective cover (8,9) further comprises a plurality of helical walls (16) extending from an inner surface (15) of the cover wall (10) to the peripheral wall (11).

13. Rotor (1), according to claim 12, characterized in that each propeller wall (16) of the plurality of propeller walls of the protective cover (8,9) projects from a region between two adjacent through openings (14) of the plurality of through openings (14).

14. Rotor (1), according to claim 12 or 13, wherein the protective cover (8, 9), characterized in that each propeller wall (16) increases in thickness in a region close to the peripheral wall (11).

15. Rotating electric machine characterized in that it comprises a rotor as defined in any one of claims 7 to 14.

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