Rotor device for externally excited electric machine

Abstract

To provide a rotor device that is light and compact and is at the same time particularly powerful.SOLUTION: A rotor device 1 for an externally excited electric machine 10 includes a rotor 2 with a rotor base body 3 with a plurality of rotor teeth 4. Axially extending receiving grooves 13 are arranged for receiving at least one winding portion 15 of a rotor winding 5 wound on the rotor teeth between the rotor teeth 4. A filling 6 for fixing the rotor winding is arranged in the receiving grooves. The rotor teeth each include a collar portion 14 at its radially outer end, which reliably secures the filling in the receiving groove.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a rotor device for an externally excited electric machine having at least one rotor with a rotor base body having a plurality of rotor teeth. [Background technology]

[0002] Axially extending receiving grooves are disposed between the rotor tines to receive at least one winding portion of a rotor winding wound on the rotor tines.

[0003] Such rotor devices are typically used in externally excited synchronous motors. A particular advantage of such motors is that expensive permanent magnets may be eliminated.

[0004] In the manufacture of such rotor devices, the receiving groove is typically provided with additional parts for fixing the winding portion received therein. The receiving groove is then typically closed with a cover slide. Finally, the rotor winding and the receiving groove are impregnated or sealed with resin.

[0005] An externally excited motor configured as a universal motor is known, for example, from WO 2004 / 008603 (A2), in which a rotor is shown in which the coil windings, the commutator and the rotor shaft are at least partially overmolded with a plastic material. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2004 / 008603 Summary of the Invention [Problem to be solved by the invention]

[0007] In contrast, the problem addressed by the present invention is to provide an improved rotor device compared to conventional rotor devices, in particular the rotor device should be particularly powerful while at the same time being as light and compact as possible, in addition the rotor device should be simple in construction and economical to manufacture. [Means for solving the problem]

[0008] This problem is solved by a rotor device having the features of claim 1. Preferred embodiments of the invention are the subject of the dependent claims. Further advantages and features of the invention become apparent from the general description and the description of the exemplary embodiments.

[0009] A rotor device according to the invention is provided for an externally excited electric machine, in particular for an externally excited synchronous motor. The rotor device may also be provided for an asynchronous motor. The rotor device comprises at least one (externally excited) rotor with a rotor base body, the rotor base body having a plurality of rotor teeth (distributed on the circumference and extending radially and axially). Between the rotor teeth, receiving grooves are arranged for receiving at least one winding portion. The winding portion is a part of a rotor winding wound on the rotor teeth. A filler for fixing the rotor winding is arranged in the receiving groove. Each rotor tooth comprises at least one collar portion at its radially outer end. The collar portion securely fixes the hardened filler in the at least one receiving groove (associated with the rotor tooth of the collar portion).

[0010] The rotor device according to the invention offers many advantages. The combination of the filling placed in the receiving groove and the secure fixation by the collar part of the rotor tooth leads to great advantages. This means, for example, that customary additional parts and cover slides can be omitted. Thus, parts, weight and installation space can be saved. In addition, the manufacture of the rotor device is significantly simplified. For example, the assembly of additional parts for winding fixation and the assembly of the cover slides are replaced by a filling insertion or molding process. Overall, the rotor device can therefore be made lighter and more compact and at the same time can be implemented in a structurally simple manner and economically manufactured.

[0011] Preferably, the collar portion of the rotor tooth securely fixes the filler against centrifugal forces occurring during the intended operation. In particular, the filler is suitably configured to withstand these centrifugal forces. In particular, the collar portion is configured to be suitable for absorbing the centrifugal forces and in particular for diverting them radially inwards via the support portion. In particular, the collar portion extends over at least a portion of the receiving groove and / or the support portion, preferably over the entire axial length.

[0012] In particular, the filler also extends into at least a radially lower portion of the collar part. In particular, the filler is configured to be suitable for replacing a cover slide arranged between the rotor teeth and / or a part that is positively inserted between the rotor teeth to cover the receiving groove.

[0013] Preferably, each rotor tooth comprises at least one support portion defining a receiving groove in the circumferential direction of the rotor. In particular, the winding portion received in the receiving groove extends along the support portion. In particular, the collar portion adjoins the support portion radially outward. In particular, the collar portion protrudes beyond the support portion in the circumferential direction. In particular, the collar portion protrudes partially beyond the receiving groove in the circumferential direction. In particular, the collar portion partially closes the receiving groove radially outward.

[0014] In particular, the collar portion protrudes beyond the support portion on both circumferential sides, i.e., the collar portion protrudes beyond the support portion in a clockwise and counterclockwise circumferential direction, in particular, the support portion and the collar portion together form a T-shaped cross-sectional shape of the rotor tooth (when cut transversely to the axial direction).

[0015] It is preferred and advantageous that the filling has bridge surfaces. In particular, the bridge surfaces each extend between collar portions of adjacent rotor teeth in the circumferential direction. In particular, the bridge surfaces do not contact the collar portions. In particular, the bridge surfaces are configured to be exposed. In particular, the bridge surfaces do not positively contact the collar portions.

[0016] Preferably, each bridge surface is (radially inwardly) concave. In particular, each bridge surface is suitably configured to enable targeted transfer of forces from the packing to the rotor base body.

[0017] Preferably and advantageously, each bridge surface is recessed (radially inwards) with respect to the maximum (radial) diameter of the packing, the recess being in particular related to the circumference of the packing, although the bridge surface may also be flush with the circumference.

[0018] Preferably, the bridge surfaces each comprise at least one radially inwardly curved trough. In particular, the trough is concave. In particular, the trough reaches its maximum height at the collar portions. In particular, the trough reaches its maximum depth between (in the middle of) the collar portions. In particular, the trough extends axially or parallel to the longitudinal axis of the drain.

[0019] In a further advantageous embodiment, the bridge surfaces are each curved radially inwards in a parabolic shape, in particular the troughs are curved radially inwards in a parabolic shape.

[0020] Advantageously, the bridge surfaces may each extend radially inwards in a V-shape. In particular, the troughs extend radially inwards in a V-shape. In particular, the troughs have sides that meet at an acute or obtuse angle at the deepest point of the trough. In particular, the sides are planar (flat). The sides may also be at least partially curved.

[0021] In an advantageous embodiment, it is provided that the bridge surfaces each comprise a biomechanically optimized geometry. In particular, each bridge surface recedes with a biomechanically optimized geometry. In particular, the troughs have a biomechanically optimized geometry. For example, the above-mentioned geometries serve as the basis for such a biomechanical optimization. In particular, the geometry of the bridge surfaces (preferably their cross-sectional structure) is biomechanically calculated.

[0022] In particular, the design paradigm for supporting bio-natural structures is applied to large body structures for biomechanical optimization. In particular, fillers are placed in locations where the expected loads during operation of the rotor device are higher. In particular, fillers are omitted in locations where the expected loads are lower. In particular, the geometry of the bridge surfaces is optimized for weight and stability.

[0023] Advantageously and preferably, the bridge surfaces partially project at a distance from the opposing collar parts. In particular, each bridge surface extends at a distance below the collar parts. However, it is also possible that the bridge surfaces are formed only between the opposing collar parts. In this case, the bridge surfaces do not project at a distance from the collar parts. In particular, in this case, the bridge surfaces do not extend below the collar parts.

[0024] In a further particularly preferred advantageous embodiment, at least one cooling channel for cooling the rotor is formed in the packing. The at least one cooling channel preferably passes through the packing of at least some of the receiving grooves. For example, at least one cooling channel is formed in each receiving groove, or every third, third or fourth receiving groove in the packing. Each receiving groove may comprise at least two, three or more cooling channels.

[0025] In particular, the cooling channel extends in the axial direction or in the longitudinal direction of the receiving groove. The cooling channel is in particular used for cooling the winding parts. The cooling channel is in particular located between the support parts and radially inward from the collar parts. In particular, the cooling channel passes between adjacent winding parts. In particular, the cooling channel is configured for a liquid cooling fluid.

[0026] The filling and the at least one cooling channel may be molded simultaneously using the same molding method. In particular, the at least one cooling channel is produced by cutting out with a suitable tool during the molding of the filling. In particular, the filling and the cooling channel are produced by transfer molding or a similar primary molding process. However, it is also possible to produce the cooling channel after the filling has been molded. For example, the filling is locally removed so that the cooling channel is cut out.

[0027] In particular, the rotor device comprises at least one rotor shaft. Preferably, the at least one cooling channel can be supplied with a (liquid) cooling fluid via a supply channel passing through the rotor shaft. In particular, the rotor shaft is connected to the rotor in a rotationally fixed manner. In particular, the rotor shaft is rotatably mounted relative to the stator. In particular, at least one fluid connection extends between the supply channel and the at least one cooling channel.

[0028] Preferably and advantageously, the at least one cooling channel is formed at least in a lower (in radial direction) part of the bridge surface. In particular, the longitudinal axis of the cooling channel extends at least partially parallel to the longitudinal axis of the trough. In particular, the at least one cooling channel is located at least partially on an imaginary line extending from the centre of the bridge surface to the rotor shaft. In particular, the cooling channel is close to the bridge surface. All cooling channels provided in the receiving groove can be arranged below the bridge surface.

[0029] It is advantageous and preferred that the filler embeds the winding parts and (completely) fills the space between the winding parts extending into the common receiving groove. In particular, the filler fills the space such that the winding parts extending into the receiving groove are completely embedded. In particular, the space within the winding parts is also filled by the filler. In particular, the filler also ensures contact with the rotor teeth and / or winding parts in the circumferential direction.

[0030] In particular, the rotor does not comprise permanent magnets for generating an excitation field. In particular, the rotor is excited externally. The rotor winding is in particular configured as an excitation winding. In particular, the receiving grooves extend axially (with respect to their longitudinal axis). The winding parts are in particular wound on the support parts.

[0031] The rotor device is provided in particular for a traction motor for an at least partially electrically powered vehicle, and for example for an electric vehicle and / or a hybrid vehicle. The applicant reserves the right to claim such a vehicle with a rotor device according to the invention. The applicant reserves the right to claim an (externally excited) electric machine having a rotor device according to the invention.

[0032] In particular, the filling comprises at least one electrically insulating molding compound. The filling is in particular introduced by a molding process. The filling may also be called a mold. The filling is in particular manufactured by a molding process, preferably by injection molding. In particular, the collar parts of the adjacent rotor teeth provide an undercut so that the filling cannot leave the receiving groove after the molding process. The filling is in particular used to close the receiving groove.

[0033] In particular, the collar portions of circumferentially adjacent rotor teeth at least partially close the receiving grooves extending radially below them. In particular, each filling received in the receiving groove is securely fixed by the collar portions of the rotor teeth through which the receiving groove passes. In particular, the collar portions of the rotor teeth at least partially close two adjacent receiving grooves separated from one another by a rotor tooth from the radial outside. In particular, the distance between the opposing collar portions is smaller than the distance between the opposing support portions. In particular, the width of the receiving groove in the circumferential direction is smaller between the support portions than between the collar portions. Effect of the Invention

[0034] Further advantages and features of the present invention are apparent from the following exemplary embodiments described with reference to the accompanying drawings. [Brief description of the drawings]

[0035] [Figure 1] 1 is a purely schematic cross-sectional front view of a rotor device according to the invention; [Diagram 2] 4 is a cross-sectional front view showing details of a further embodiment of a rotor device according to the present invention; FIG. [Diagram 3] 4 is a cross-sectional front view showing details of another further embodiment of a rotor device according to the present invention; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] 1 shows a rotor device 1 according to the invention for an externally excited electric machine 10 (not shown here in detail), e.g. an externally excited synchronous motor 20. The rotor device 1 comprises a rotor 2 and a rotor shaft 12, which is rotatably mounted on a stator (not shown here). The rotor 2 comprises a rotor base body 3 having a plurality of rotor teeth 4 and receiving grooves 13 extending between the rotor teeth 4.

[0037] The rotor windings 5 ​​are received on the rotor teeth 4 with their winding portions 15 extending into the receiving grooves 13. Each rotor tooth 4 includes a support portion 24 and a collar portion 14 axially outwardly adjacent the support portion 24. A groove insulation 25 is disposed between the rotor teeth 4 and the winding portions 15.

[0038] The receiving groove 13 contains a filler 6 made of an electrically insulating material (e.g. duromer or thermoplastic resin). The filler 6 serves to fix the rotor winding 5 and to close the receiving groove 13. The filler 6 is securely fixed in the receiving groove 13 by a collar portion 14.

[0039] The collar part 14 absorbs the centrifugal forces occurring during operation and transmits them radially inwards into the rotor base body 3 via the support part 24. As a result, the rotor device 1 shown here does not require any parts that are actively inserted between the rotor teeth 4 to cover the receiving grooves, e.g. cover slides. In addition, additional parts for winding fixation can also be omitted. The filling 6 and its secure fixation thus allow a functional integration of several parts.

[0040] The elimination of metal cover slides also has the advantage that it does not adversely affect the electromagnetic properties of the machine 10. Due to the high insulating properties of the filling 6, the overall structure is also particularly compact (thinner layer thicknesses). In addition, the design of the rotor device 1 shown here allows an optimized thermal connection of the entire rotor winding 5.

[0041] Between the opposing collar parts, the filler 6 has an exposed bridge surface 26 which is not securely fixed by the collar part 14. To be able to dissipate the forces acting on the winding parts 15 and on the filler 6 during operation in a targeted manner, the bridge surface 26 is, for example, provided with a radially inwardly curved (concave) trough 36.

[0042] An example of such a trough 36 is shown in FIG.

[0043] In an advantageous embodiment, the bridge surface 26 or trough 36 may be provided with a biomechanically optimized geometry 46. Such geometry provides an ideal tactile path.

[0044] Additionally or alternatively, the bridge surface 26 can partially protrude away from the collar portion 14. Such an embodiment can also be seen, for example, in Figures 2 and 3, where the bridge surface 26 protrudes from each end portion 34 of the collar portion 14.

[0045] 3, bridge surfaces 26 are shown swept radially inward in a V-shape. In the embodiment shown, the sides meet at an acute angle at the deepest point of trough 36.

[0046] In the rotor device 1 shown in Fig. 1, cooling channels 7 are formed in the filling 6. Two parallel cooling channels 7 run through each receiving groove 13. The cooling channels 7 are supplied with a cooling fluid, for example a liquid, via a supply channel 17 running through the rotor shaft 12. The cooling channels 7 are arranged radially next to each other below the respective bridge surface 26. The winding parts 15 are thus cooled particularly reliably and effectively. Due to the increased heat dissipation, a higher power output of the machine 10 is possible.

Claims

1. A rotor device (1) for an externally excited electric machine (10), in particular for an externally excited synchronous motor (20), comprising: The rotor (2) has at least one rotor (2) with a rotor base body (3) having a plurality of rotor teeth (4), Axial extending receiving grooves (13) are arranged between the rotor teeth (4) to receive at least one winding portion (15) of the rotor winding (5) wound on the rotor teeth (4); A filler (6) for fixing the rotor winding (5) is disposed in the receiving groove (13), the rotor tooth (4) is provided at its radially outer end with at least one collar portion (14) for securely fixing the filler (6) in the receiving groove (13); Each of the rotor teeth (4) comprises at least one support portion (24) that defines the receiving groove (13) in the circumferential direction; The winding portion (15) extends along the support portion (24), and the collar portion (14) is adjacent to the support portion (24) radially outward; the collar portion (14) projects beyond the support portion (24) in the circumferential direction and partially closes the receiving groove (13) radially outward; The filler (6) is in contact with the collar portion (14) of the circumferentially adjacent rotor tooth (4) and has a bridge surface (26); the collar portion (14) projects partially beyond the bridge surface (26); the bridge surface (26) extends between the collar portions (14) of circumferentially adjacent rotor teeth (4) and extends below the collar portions (5) at a distance from end portions (34) of the collar portions (14); the bridge surfaces (26) each include a radially inwardly curved trough (36); Rotor device (1).

2. the collar portion (14) of the rotor tooth (4) securely fixes the filler (6) against centrifugal forces occurring during intended operation, the filler (6) being particularly suitably configured to withstand these centrifugal forces; A rotor device (1) according to claim 1.

3. the bridge surfaces (26) are each configured to be concave; A rotor device (1) according to claim 1.

4. the bridge surface (26) is curved radially inward in a parabolic shape; A rotor device (1) according to claim 1.

5. the bridge surface (26) extends radially inward in a V-shape; A rotor device (1) according to claim 1.

6. At least one cooling channel (7) for cooling the rotor (2) is formed in the packing (6), and preferably the at least one cooling channel (7) in the packing (6) extends axially in at least some of the receiving grooves (13). A rotor device (1) according to claim 1 or 2.

7. at least one rotor shaft (12), wherein the at least one cooling channel (7) can be supplied with a cooling fluid via a supply channel (17) passing through the rotor shaft (12); A rotor device (1) according to claim 6.

8. At least one cooling channel (7) is formed at least partially below said bridge surface (26). A rotor device (1) according to claim 1.

9. The filler (6) embeds the winding portions (15) and fills the spaces between the winding portions (15) that extend into the receiving grooves (13). A rotor device (1) according to claim 1 or 2.

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