Rotor for an electric machine

Abstract

The invention relates to a rotor (2) for an electric machine, said rotor comprising a plurality of pole sections (1) which point away from a rotational axis in the radial direction and have winding sections (4) on which windings are arranged or can be arranged, wherein the pole sections (1) of the rotor (2) are in the form of independent individual segments (3) that, when the rotor (2) is assembled, are arranged circumferentially adjacent to one another.

Description

[0001] Rotor for an electric machine

[0002] The invention relates to a rotor for an electrical machine, comprising a plurality of pole sections which are radially directed away from an axis of rotation and which have winding sections on which windings are arranged or can be arranged.

[0003] Electrical machines, for example as traction drives for motor vehicles, which have rotors rotatably mounted relative to a stator of the electrical machine, are generally known from the prior art. Depending on the design of the electrical machine, the rotor has pole sections that point radially away from the rotor's axis of rotation. Winding sections, on which windings of electrical conductors are or can be arranged, are in turn arranged at the pole sections. The geometry of the pole sections, in particular their winding sections, is limited in such a way that it must be ensured that the windings can be applied to the winding sections. Various winding methods are known for this purpose. For example, in a needle winding method, the winding device engages a space between two winding sections adjacent in the circumferential direction and winds one of the winding sections.

[0004] For this to happen, the space between the two winding sections must be large enough to accommodate the winding process, even if adjacent winding sections have already been wound. This makes it necessary to reserve space in the circumferential direction for the winding process, so that the winding density is reduced and the rotor is enlarged accordingly, without the increase in rotor size being able to be utilized. The individual sheet metal laminations that form the rotor, which are arranged next to one another in the axial direction and thus form the base body of the rotor, must also be punched out of a single piece of sheet metal. This increases the influence of possible irregularities in the material, since these are always aligned in the same way. Furthermore, the waste of unused material that remains unused from the sheet metal used for punching increases.The invention is based on the object of providing an improved rotor for an electrical machine.

[0005] The object is achieved by a rotor having the features of claim 1. Advantageous embodiments are the subject of the subclaims.

[0006] As described, the invention relates to a rotor for an electrical machine, which rotor has a plurality of pole sections extending radially from the axis of rotation. Winding sections are provided or formed on the pole sections, on which the windings are or can be arranged. The invention is based on the finding that the pole sections of the rotor are designed as independent individual segments that are arranged circumferentially adjacent to one another when the rotor is assembled.

[0007] In other words, the invention proposes, instead of using continuous segments in the circumferential direction that can be arranged axially adjacent to one another, so-called "laminations" forming a laminated core, to form separate individual segments in the circumferential direction. The individual segments can also consist of or have sub-segments arranged axially adjacent to one another. In any case, the individual segments can be provided separately from one another and wound separately from one another.

[0008] Only when the individual segments are wound can the individual segments be arranged next to one another in the circumferential direction to form an assembly for the rotor. Advantageously, this means that it is not necessary to limit the production of the windings on the winding sections to individual suitable winding processes. Consequently, it is also not necessary to unnecessarily restrict the boundary conditions for individual winding processes. For example, the space between two pole sections in the assembled state can be made much smaller because the individual segments are arranged next to one another already wound and it is therefore not necessary, for example in a needle winding process, to intervene in the spaces to produce the winding. This makes it possible to make the rotor more compact with the same winding or to produce a rotor of a certain size with an increased copper fill factor orincreased winding density.

[0009] As described, the individual segments, which may have sub-segments arranged axially adjacent to one another, for example in the form of "laminations," can be provided and wound separately. At least one winding section of an individual segment can be designed as a circumferential recess located between a radial inner section and a radial outer section of the individual segment. In other words, the winding section can be designed as a constriction or taper of the pole section in the radial direction, such that the "recess" creates space in which the windings can be accommodated. For example, the geometry, viewed in cross-section, can represent a double-T shape. Each of the winding sections facing in the circumferential direction can have a U-shape.In other words, the pole section can be designed to be wider in the circumferential direction on the inside and outside relative to the winding section, so that the winding section arranged between the inner section and the outer section is designed to be narrower in comparison.

[0010] In principle, the individual segments can be arranged one after the winding process in any desired manner, for example by means of form-fitting, welding, gluing, or other connection methods. According to one embodiment of the rotor, each individual segment may have a receiving section, particularly one that protrudes axially from a base body of the individual segment, with a common mounting element enclosing the receiving sections of the individual segments in the mounted state. In other words, the individual segments are arranged one after the other in the circumferential direction to form the closed base body of the rotor. To mount the individual segments one after the other or to secure the arrangement of the individual segments in the circumferential direction, the mounting element is placed on the receiving sections.

[0011] In the assembled state, the mounting element engages around the receiving sections of the individual segments so that, once the mounting element is installed, they can no longer be separated from one another but are held together by the mounting element. The receiving sections projecting in the axial direction can also be referred to as "axial projections." The mounting element can also be viewed as a bandage that engages around the receiving sections projecting in the axial direction. Such a mounting element and the associated receiving sections can be provided in the axial direction on both sides of the base body of the individual segments, so that the individual segments can be fixed to one another at both axial end sections of the rotor.

[0012] According to a further development of the rotor, it can be provided that the receiving sections form a lateral surface that projects in the axial direction relative to the base bodies of the individual segments and is surrounded in an assembled state by a, in particular annular, mounting element. As previously described, each of the individual segments has a receiving section, or two receiving sections at the axial ends, which protrude in the axial direction from the base body of the individual segment. Together, the receiving sections form a lateral surface, for example a cylindrical lateral surface, which can be surrounded by the mounting element. Each receiving section can, for example, be designed as a circular arc or circular segment on the receiving section and protrude in the axial direction from the base body.

[0013] In a state in which the individual segments are arranged next to one another in the circumferential direction, the receiving sections are also arranged next to one another and thus form a continuous outer surface onto which the mounting element can be arranged. The mounting element can be designed in the shape of a ring, in particular as a ring, and can be arranged in the axial direction over the projecting outer surface, for example by being inserted or pushed. It is therefore clear that the individual segments, in particular their receiving sections, together form a circumference or a geometry onto which the mounting element can be placed, for example as a bandage. The mounting element can be referred to as a ring or as a “heel bandage”. As described above, the mounting element can be used for orThe mounting element is primarily used to fix the individual segments arranged next to one another, namely via the contact of the inner surface of the mounting element with the outer surface of the receiving sections. According to a further embodiment, the mounting element can be designed as a star disk or insulator disk, or as a receiving element for a star disk or insulator disk. In other words, in addition to fixing the individual segments to one another, the mounting element can perform a further task, namely the realization of a star disk or insulator disk, or the mounting element can be designed as a receiving element for such a star disk or insulator disk.

[0014] In a further embodiment of the rotor, it can be provided that at least one, in particular each, individual segment is wound in a disassembled state. As described, the individual segments can in principle be provided separately and independently of one another. The individual segments can be formed from sub-segments arranged next to one another in the axial direction. The formed individual segments can then be wound separately from one another and thus provided wound for assembly of the rotor. Since the individual segments are wound separately from one another, different winding methods can be used than those possible for winding a rotor formed from pole sections already firmly arranged next to one another.By providing the already wound individual segments for assembly, in which the individual segments are arranged next to each other in the circumferential direction, the winding and ultimately the utilization of the space of the rotor can be significantly improved.

[0015] As described, the provision of the individual segments makes winding methods accessible that cannot normally be used for winding the rotor. As described at the beginning, a needle winding method is usually used for winding the rotor in order to be able to engage the spaces between the pole sections or the winding sections and thus to be able to wind the pole sections of the rotor. In the embodiment of the rotor described here, it can be provided that at least one, in particular each, individual segment is wound using a linear winding method. The linear winding method offers advantages, in particular with regard to space utilization, effort, cycle time, and costs, for example, compared to the needle winding method described above.

[0016] The described rotor can further be developed such that two windings are arranged in the circumferential direction of adjacent individual segments with a defined safety distance, in particular in contact with one another. In contrast to the described prior art, which requires a comparatively large safety distance to be maintained to ensure that the needle winding process can be carried out for all windings, a defined, in particular reduced, safety distance can be set. The defined safety distance can be significantly reduced compared to safety distances implemented in the prior art, so that the density of the windings in the rotor and thus the copper fill factor can be improved.

[0017] In particular, it can be provided that the safety distance is close to zero, i.e., that the windings in the circumferential direction of different winding sections can touch or almost touch each other. This is possible in particular because the individual segments are wound separately and then joined together in the circumferential direction. The safety distance can therefore also be zero. It is also possible to make the coating or insulation of the individual windings smaller or thinner, since there is no risk of them being damaged during the winding process, as the individual segments are wound separately.

[0018] The provision of individual segments, the sub-segments of the individual segments arranged axially adjacent to one another, is also advantageous for the material used for the individual segments. These can, for example, be punched from a strip material, whereby the utilization of the strip material is significantly improved, particularly compared to circumferentially single-piece segments for a circumferentially closed rotor that is not formed from individual segments. A further advantage is that different materials can be selected for the stator and the rotor.

[0019] In addition to the described rotor, the invention relates to an electric machine comprising a previously described rotor. Furthermore, the invention relates to a motor vehicle comprising a previously described electric machine and / or a previously described rotor.

[0020] The invention further relates to a method for producing a rotor for an electrical machine, in particular a rotor as described above, comprising a plurality of pole sections radially extending from a rotational axis, said pole sections having winding sections on which windings are arranged, wherein the pole sections of the rotor are formed as independent individual segments which, in an assembled state of the rotor, are arranged adjacent to one another in the circumferential direction. In other words, for the production of the rotor, a plurality of pole sections are provided as independent individual segments which are arranged adjacent to one another in the circumferential direction. The individual segments are in particular provided wound, i.e. the individual segments can be wound independently of one another in a disassembled state.After the individual segments have been wound, they can be arranged next to one another in the circumferential direction and, if necessary, fixed with one or more mounting elements.

[0021] All advantages, details and features described with regard to the rotor are fully transferable to the electrical machine, the motor vehicle and the method.

[0022] The invention is explained below using exemplary embodiments with reference to the figures. The figures are schematic representations and show:

[0023] Fig. 1 shows a perspective view of an individual segment for a rotor for an electrical machine; Fig. 2 shows an axial view of several individual segments for a rotor for an electrical machine in an assembled state;

[0024] Fig. 3 shows a wound single segment for a rotor for an electrical machine in axial view;

[0025] Fig. 4 shows a rotor for an electrical machine in a perspective view in an assembled state;

[0026] Fig. 5 shows a rotor for an electrical machine in a perspective view in an assembled state; and

[0027] Fig. 6 a rotor for an electrical machine in axial view in an assembled state.

[0028] Fig. 1 shows a pole section 1 for a rotor 2 for an electrical machine. The pole section 1 or the plurality of pole sections 1 shown in Figs. 1-6 are designed as individual segments 3. The rotor 2 has a plurality of, for example six, pole sections 1, which are designed as individual segments 3, as can be seen, for example, in Figs. 2, 4-6. Each pole section 1 has a winding section 4 which is arranged in the radial direction relative to an axis of rotation of the rotor 2 between a radially inner inner section 5 and a radially outer outer section 6. On the winding section 4, the windings are wound onto the pole sections 1, as shown, for example, in Figs. 3, 6. The individual segments 3 are provided wound for the assembly of the rotor 2, which means that the individual segments 3 are wound independently and spatially separated from one another, in particular dismantled from one another.For the sake of clarity, the windings are hidden in some figures, particularly figures 1, 3, 4, 5.

[0029] As already described, each pole section 1 can be designed as an individual segment 3. Each individual segment 3 can in turn be segmented into subsegments that are arranged axially relative to the rotational axis of the rotor 2, for example in the form of so-called "laminations."

[0030] Each individual segment 3 further comprises at least one receiving section 7 which protrudes in the axial direction from a base body 8 of the individual segment 3. In the embodiment shown in Figs. 1, 4, 5, each individual segment 3 comprises two receiving sections 7 which are arranged in the axial direction on opposite sides of the base body 8. The receiving sections 7 serve to mount the individual segments 3 to one another in the circumferential direction.

[0031] Fig. 2 schematically illustrates how the individual pole sections 1, in the form of individual segments 3, can be brought closer together in the circumferential direction. As already described, each of the individual segments 3 can be wound prior to assembly, so that wound individual segments 3 are mounted together. Fig. 3 shows any state of one of the individual segments 3, in which the windings 3 are applied to the winding section 4.

[0032] Fig. 4 schematically shows that the individual pole sections 1, i.e., the individual segments 3, can be attached to one another in the circumferential direction. As described, this is carried out in the wound state, so that the individual segments 3 can be wound onto one another before assembly. The windings are not shown for the sake of clarity. The receiving sections 7 of the individual segments 3 adjacent in the circumferential direction form a common receiving section or a lateral surface on which mounting elements 9 can be arranged.

[0033] For example, each receiving section 7 forms a circular arc segment or a circular segment, so that the receiving sections 7 together form a cylindrical outer surface to which a ring-shaped mounting element 9, for example in the form of a "heel bandage," can be applied. The mounting element 9 or the two mounting elements 9 hold the receiving sections 7 and thus the individual segments 3 together so that they remain arranged next to one another, as shown, for example, in Fig. 5. In addition, the mounting element 9 can form a star conductor or an insulator disk, or a holder for a star conductor or an insulator disk.

[0034] Fig. 6 shows a rotor 2 which comprises assembled pole sections 1, i.e. individual segments 3, onto whose winding sections 4 windings are applied. Since the individual segments 3 are wound separately from one another and then joined together as described, the distances or spaces between the pole sections 1 can be significantly reduced, since it is not necessary, for example in a needle winding process, to intervene in the spaces in order to wind the windings onto the winding sections 4. Instead, the individual segments 3 are wound separately from one another, for example in a linear winding process. This allows both the safety distances between the two circumferentially adjacent pole sections 1 and the insulation of the individual windings to be reduced.

[0035] As described, the rotor 2 can form a component of an electrical machine, which is not shown in detail. Such an electrical machine can be implemented, in particular, as a traction drive, for a motor vehicle. The rotor 2 shown can be manufactured, in particular, using the method described herein.

[0036] All advantages, details, and features described in relation to the individual embodiments are fully combinable, interchangeable, and transferable. The described advantages, details, and features are also transferable to the electric machine, the motor vehicle, and the method.

[0037] Reference symbol

[0038] 1 pole section

[0039] 2 rotors

[0040] 3 single segments

[0041] 4 winding section

[0042] 5 Interior section

[0043] 6 Outer section

[0044] 7 Recording section

[0045] 8 basic bodies

[0046] 9 Mounting element

Claims

Patent claims 1. Rotor (2) for an electrical machine, comprising a plurality of pole sections (1) which are radially directed away from an axis of rotation and which have winding sections (4) on which windings are arranged or can be arranged, characterized in that the pole sections (1) of the rotor (2) are designed as mutually independent individual segments (3) which, in an assembled state of the rotor (2), are arranged one against the other in the circumferential direction.

2. Rotor (2) according to claim 1, characterized in that at least one winding section (4) of an individual segment (3) is designed as a recess in the circumferential direction, which is arranged between a radial inner section (5) and a radial outer section (6) of the individual segment (3).

3. Rotor (2) according to claim 1 or 2, characterized in that each individual segment (3) has a receiving section (7) which projects in particular in the axial direction from a base body (8) of the individual segment (3), wherein a common mounting element (9) encompasses the receiving sections (7) of the individual segments (3) in an assembled state.

4. Rotor (2) according to claim 3, characterized in that the receiving sections (7) form a lateral surface projecting in the axial direction relative to the base bodies (8) of the individual segments (3), which in an assembled state are surrounded by a, in particular annular, mounting element (9).

5. Rotor (2) according to claim 3 or 4, characterized in that the mounting element (9) is designed as a star disk or insulator disk or as a receiving element for a star disk or an insulator disk.

6. Rotor (2) according to one of the preceding claims, characterized in that at least one, in particular each, individual segment (3) is wound in a disassembled state.

7. Rotor (2) according to one of the preceding claims, characterized in that at least one, in particular each, individual segment (3) is wound by means of a linear winding process 8. Rotor (2) according to one of the preceding claims, characterized in that two windings are arranged in the circumferential direction of adjacent individual segments (3) with a defined safety distance, in particular contacting each other.

9. Electrical machine comprising a rotor (2) according to one of the preceding claims.

10. Motor vehicle comprising an electric machine according to the preceding claim and / or a rotor (2) according to one of claims 1 to 8.

11. A method for producing a rotor (2) for an electrical machine, in particular a rotor (2) according to one of claims 1 to 8, comprising a plurality of pole sections (1) which are radially directed away from an axis of rotation and which have winding sections (4) on which windings are arranged, characterized in that the pole sections (1) of the rotor (2) are designed as individual segments (3) which are independent of one another and which are arranged next to one another in the circumferential direction when the rotor (2) is in the assembled state.

Images