Rotor of an electric machine

Abstract

Rotor (1) of an electrically excited synchronous machine (2) with a rotor body (4) rotatable about a rotor axis (3), the rotor body having several salient poles (5) arranged along a circumferential direction of the rotor (1), each pole pole comprising a pole shaft (6) and a pole shoe (7) arranged at the end of the pole shaft (6), the pole shafts (6) each being enclosed by a single coil (9) of an excitation winding (10) of the rotor (1), the pole shoes (7) each projecting into the adjacent pole slots (12), the pole shoe (7) of each salient pole (5) having a coil support surface (13) towards both pole slots (12) for supporting the respective single coil (9), a closing element (20) being arranged in each of the pole slots (12), which is provided for closing the respective pole slot (12) and is supported on two pole shoe support ramps (17) which are attached to mutually facing pole shoe ends (7e) of adjacent pole shoes (7) are formed, characterized by the fact that The pole shoe support slopes (17) of the respective pole shoe (7) each have an oblique angle (α) to the coil support surface (13), which is in the range between one degree and 45 degrees, in particular between two degrees and 25 degrees.

Description

State of the art

[0001] The invention is based on a rotor of an electrically excited synchronous machine according to the preamble of the main claim.

[0002] A rotor of an electrically excited synchronous machine is already known from DE102020200429 A1, comprising a rotor body rotatable about a rotor axis, in particular a rotor core, which has a plurality of salient poles arranged along a circumferential direction of the rotor, each comprising a pole shaft, a pole shoe arranged at the end of the pole shaft, and a pole center axis extending radially with respect to the rotor axis, wherein the pole shafts are each enclosed by an individual coil of an excitation winding of the rotor, wherein pole slots are formed between the salient poles, in each of which the coil sides of two individual coils are located, wherein the pole shoes each protrude into the adjacent pole slots, wherein the pole shoe of the respective salient pole has a coil support surface towards both pole slots for supporting the respective individual coil, wherein a closure element is arranged in each of the pole slots,which is intended to close the respective pole slot and is supported by two pole shoe support slopes. The pole shoe support slopes are formed at the mutually facing pole shoe ends of adjacent pole shoes. The pole shoe support slopes of the salient poles are comparatively steep and short, so that only a comparatively small support surface can be achieved on the pole shoe. This places high mechanical stress on the closure elements, necessitating the use of expensive plastics to manufacture the closure elements and limiting the maximum possible operating speed. In addition, comparatively steep pole shoe support slopes lead to greater radial deformation of the closure elements and, consequently, the excitation winding, which results in a larger air gap and a lower torque density. Advantages of the invention

[0003] The rotor of an electrically excited synchronous machine according to the invention, with the characterizing features of the main claim, has the advantage that the mechanical stress and / or deformation of the closure elements is reduced, thus enabling a higher rotor speed. Furthermore, more cost-effective plastics can be used to manufacture the closure elements. Furthermore, the deformation of the closure elements and the excitation winding under speed load is reduced, thus enabling a smaller air gap.

[0004] This is achieved according to the invention in that the pole shoe support slopes of the respective pole shoe each have an oblique angle to the coil support surface which lies in the range between one degree and 45 degrees, in particular between two degrees and 25 degrees.

[0005] The measures listed in the subclaims enable advantageous further developments and improvements of the rotor of an electrically excited synchronous machine specified in the main claim.

[0006] It is particularly advantageous if the respective closure element has a head section for support on two pole shoes and a foot section extending toward the rotor axis, with the flanks of the head section facing the pole slot running, in particular, parallel to a flank of the respective pole shaft. In this way, the coil sides of the individual coils can be designed as an orthocyclic winding, so that a high fill factor can be achieved in the respective pole slot. The coil sides of the individual coils are partially mechanically supported by the closure elements.

[0007] It is further advantageous if the head section of the respective closure element has two support slopes for support on the pole shoe support slopes of adjacent pole shoes, wherein each support slope of the closure element is supported on the associated pole shoe support slope without any overhang, particularly in the radial direction. In this way, the closure elements are only subjected to compressive and not shear stress, resulting in lower maximum stresses on the closure elements and thus enabling higher speeds.

[0008] Furthermore, it is advantageous if the base section of the respective closure element has wall surfaces for supporting the coil sides of the respective pole slot, wherein the wall surfaces extend in particular parallel to one another. In this way, the respective closure element can support not only the wires radially outer with respect to the rotor axis, but also the wires and layers located radially further inward. The base section of the respective closure element can extend close to or up to a slot base of the respective pole slot.

[0009] It is very advantageous if the layers of the respective coil sides of each individual coil are orthocyclically superimposed in the respective pole slot. This allows a high fill factor to be achieved in the respective pole slot.

[0010] It is also advantageous if the respective pole shoe support slope of the respective salient pole is provided in direct connection with the coil support surface of the pole shoe of the salient pole. This allows a high fill factor to be achieved in the respective pole slot.

[0011] It is further advantageous if the respective coil support surface of the respective salient pole comprises a straight support section toward the pole shoe support slope, which runs in particular perpendicular to the pole center axis, and a bent support section toward the pole shaft. In this way, a high degree of strength of the salient pole can be achieved. The bent support section can comprise at least one slope or at least one rounded portion, in particular a radius or spline.

[0012] Furthermore, it is advantageous if the bent support section includes a transition slope that has an angle to the straight support section in the range between 25 degrees and 35 degrees, in particular between 29 and 31 degrees. This allows the strength of the salient pole to be further increased. Furthermore, a high fill factor in the respective pole slot can be achieved.

[0013] It is advantageous if the bent support section toward the pole shaft includes a further transition bevel, which has an oblique angle to the transition bevel that lies in the range between 25 degrees and 35 degrees, in particular between 29 and 31 degrees. In this way, the strength of the salient pole can be further increased.

[0014] It is also advantageous if a star disk is arranged on each of the two end faces of the rotor body. Each star disk has a ring section and several tooth sections projecting radially from the ring section relative to the rotor axis to accommodate a winding head of the respective individual coil. The star disk is designed to be electrically insulating. A rotor sleeve, for example, made of fiber-reinforced plastics, can be applied around the star disk.

[0015] It is further advantageous if the tooth sections of the respective star disk each have two opposing round edges for the transition into the adjacent pole slots, wherein at the radially outer end of the respective tooth section a step contour is formed at least on the two round edges to form a layer step, on which the last turn of the first layer is provided in a lower step level and the first turn of the second layer is provided in an upper step level, wherein the first turn of the second layer is located at least one turn further radially outward than the last turn of the first layer, wherein the layer step comprises a ramp-shaped recess which forms a ramp for guiding the wire into the higher step level. In this way, a wire crossing can be achieved for a layer jump which produces no or only slight curvature or bulging in the upper layers of the individual coil.

[0016] According to an advantageous embodiment, the winding heads of the excitation winding are each enclosed by a rotor sleeve, which in particular also encloses the respective star disk. In this way, the centrifugal forces of the respective winding heads of the excitation winding can be directed into the rotor sleeve and absorbed without mechanically overloading or damaging the star disk. The rotor sleeve can be made of fiber-reinforced plastics, for example. This enables higher speeds. drawing

[0017] An embodiment of the invention is shown in simplified form in the drawing and explained in more detail in the following description.

[0018] They show: Fig. 1 shows a section through a rotor of an electrically excited synchronous machine according to the invention, Fig. 2 a section along the line II-II in Fig. 1, Fig. 3 a detail A after Fig. 1 according to a first embodiment, Fig. 4 the detail A after Fig. 1 according to a second embodiment, Fig. 5 one of the star discs Fig. 1 and Fig. 6 a tooth section of the star disk according to Fig. 5 Description of the embodiment

[0019] Fig. 1 shows a section through a rotor of an electrically excited synchronous machine according to the invention.

[0020] The rotor 1 of the electrically excited synchronous machine 2 comprises a rotor body 4, in particular a rotor core, rotatable about a rotor axis 3. The synchronous machine 2 comprises the rotor 1 and a stator. An air gap is formed between the stator and the rotor 1 in the radial direction relative to the rotor axis 3.

[0021] Fig. 2 shows a section along the line II-II in Fig. 1.

[0022] The rotor body 4 has a plurality of salient poles 5 arranged along a circumferential direction of the rotor 1. The salient poles 5 each have a pole shaft 6, a pole shoe 7 arranged at the end of the pole shaft 6, and a pole center axis 8 running radially with respect to the rotor axis 3. The pole shafts 6 are each enclosed by an individual coil 9 of an excitation winding 10 of the rotor 1. Between the salient poles 5, pole slots 12 are formed, in which the coil sides 9s of two individual coils 9 are located. The pole shoes 7 of the salient poles 5 each protrude on both sides into the adjacent pole slots 12.

[0023] The flanks 6f of the respective pole shaft 6 run, for example, parallel to the pole center axis 8. Alternatively, the flanks 6f of the respective pole shaft 6 could also run at an oblique angle to the pole center axis 8.

[0024] The pole piece 7 of the respective salient pole 5 has a coil support surface 13 facing both pole slots 12 for supporting the respective individual coil 9. A closure element 20 is arranged in each of the pole slots 12, which closure element is provided for closing the respective pole slot 12 and is supported on two pole piece support slopes 17 formed on mutually facing pole piece ends 7e of two adjacent pole pieces 7. The pole piece support slopes 17 are each formed on an inner side of the respective pole piece 7 facing the respective pole slot 12.

[0025] The respective closure element 20 has a head section 21 supported on two pole shoes 7 and a foot section 22 extending towards the rotor axis 3. The flanks 21f of the head section 21 facing the pole groove 12 run, for example, parallel to a flank 6f of the respective pole shaft 6.

[0026] The foot section 22 of the respective closure element 20 has wall surfaces 22w for supporting the coil sides 9s of the respective pole groove 12, wherein the wall surfaces 22w run in particular parallel to one another.

[0027] The winding heads of the excitation winding 10 can be Fig. 1 each be enclosed by a rotor sleeve 35, which in particular also encloses the respective star disk 24.

[0028] Fig. 3 shows a detail A after Fig. 1 according to a first embodiment.

[0029] According to the invention, it is provided that the pole shoe support slopes 17 of the respective pole shoe 7 each have an oblique angle α to the coil support surface 13, which lies in the range between one degree and 45 degrees, in particular between two degrees and 25 degrees.

[0030] The respective pole shoe support slope 17 of the respective salient pole 5 is provided, for example, in direct connection to the coil support surface 13 of the pole shoe 7 of the salient pole 5.

[0031] The respective coil support surface 13 of the respective salient pole 5 comprises a straight support section 13L, which is provided towards the pole shoe support slope 17 and runs in particular perpendicular to the pole center axis 8, and a bent support section 13B, which is provided towards the pole shaft 6 and bends towards the pole shaft 6. The bent support section 13B can Fig. 3 and Fig. 4 have at least one bevel or alternatively at least one rounding, in particular radius or spline.

[0032] The bending support section 13B has Fig. 3, for example, a transition bevel 14, which has an oblique angle β to the rectilinear support section 13L in the range between 25 degrees and 35 degrees, in particular between 29 and 31 degrees. The respective transition bevel 14 can each transition with a rounded portion into the pole shaft 6 and / or with a rounded portion into the coil support surface 13 of the pole shoe 7.

[0033] After Fig. 4, the bending support section 13B has a further transition bevel 15 towards the pole shaft 6, which has an oblique angle γ to the transition bevel 14, which lies in the range between 25 degrees and 35 degrees, in particular between 29 and 31 degrees.

[0034] The head section 21 of the respective closure element 20 has two support slopes 21s for support on the pole shoe support slopes 17 of adjacent pole shoes 7, wherein each support slope 21s of the closure element 20 is supported on the associated pole shoe support slope 17 without protrusion, particularly with respect to the radial direction. Thus, each support slope 21s of the closure element 20 does not protrude beyond the associated pole shoe support slope 17 in the radial direction with respect to the rotor axis 3.

[0035] In the respective pole slot 12, the layers of the respective coil side 9s of the respective individual coil 9 lie orthocyclically one above the other.

[0036] A slot insulation 16 can be provided in each pole slot 12, also between the pole shoe support slope 17 and the support slope 21s of the closure element 20.

[0037] Fig. 5 shows one of the star discs Fig. 1.

[0038] On both end faces of the rotor body 4, Fig. 1 each have a star disk 24 arranged, which Fig. 5 each has a ring section 25, a plurality of tooth sections 26 projecting from the ring section 25 in the radial direction with respect to the rotor axis 3 for receiving a winding head of the respective individual coil 9 and is designed to be electrically insulating at least in sections, in particular with regard to an electrical connection to be excluded between the excitation winding 10 and the rotor body 4.

[0039] Fig. 6 shows a tooth section of the star disk according to Fig. 5.

[0040] The tooth sections 26 of the respective star disk 24 each have two opposing round edges 27 for transition into the adjacent pole slots 12. The round edges 27 of the tooth sections 26 can be grooved for wire guidance.

[0041] At the radially outer end of the respective tooth section 26, a step contour 30 is formed at least on the two rounded edges to form a layer step 31. At the layer step 31, the last turn of a first layer is provided in a lower step level and the first turn of a second layer of the individual coil 9 is provided in an upper step level. The first turn of the second layer is located at least one turn further radially outward than the last turn of the first layer. The layer step 31 comprises a ramp-shaped recess 32 which forms a ramp for guiding the wire into the higher step level. The ramp-shaped recess 32 runs obliquely in the direction of the wire extension in order to guide the last turn of the first layer into the first turn of the second layer. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 102020200429 A1

[0002]

Claims

[1] Rotor (1) of an electrically excited synchronous machine (2) with a rotor body (4) rotatable about a rotor axis (3), in particular a rotor core, which has a plurality of salient poles (5) arranged along a circumferential direction of the rotor (1), each comprising a pole shaft (6), a pole shoe (7) arranged at the end of the pole shaft (6) and a pole center axis (8) running in the radial direction with respect to the rotor axis (3), wherein the pole shafts (6) are each enclosed by an individual coil (9) of an excitation winding (10) of the rotor (1), wherein between the salient poles (5) pole slots (12) are formed in each case, in which the coil sides (9s) of two individual coils (9) are located, wherein the pole shoes (7) each protrude into the respectively adjacent pole slots (12), wherein the pole shoe (7) of the respective salient pole (5) has a Coil support surface (13) for supporting the respective individual coil (9),wherein a closure element (20) is arranged in each of the pole slots (12), which closure element is provided for closing the respective pole slot (12) and is supported on two pole shoe support slopes (17) which are formed on mutually facing pole shoe ends (7e) of adjacent pole shoes (7), , characterized by that the pole shoe support slopes (17) of the respective pole shoe (7) each have an oblique angle (α) to the coil support surface (13) which lies in the range between one degree and 45 degrees, in particular between two degrees and 25 degrees. [2] Rotor according to claim 1, characterized by that the respective closure element (20) has a head section (21) for support on two pole shoes (7) and a foot section (22) running towards the rotor axis, wherein the flanks (21f) of the head section (21) facing the pole groove (12) run in particular parallel to a flank (6f) of the respective pole shaft (6). [3] Rotor according to claim 2, characterized bythat the head section (21) of the respective closure element (20) has two support slopes (21s) for support on the pole shoe support slopes (17) of adjacent pole shoes (7), wherein each support slope (21s) of the closure element (20) is supported on the associated pole shoe support slope (17) without projection, in particular with respect to the radial direction. [4] Rotor according to one of claims 2 or 3, characterized by that the foot section (22) of the respective closure element (20) has wall surfaces (22w) for supporting the coil sides (9s) of the respective pole groove (12), wherein the wall surfaces (22w) run in particular parallel to one another. [5] Rotor according to one of the preceding claims, characterized by that in the respective pole slot (12) the layers of the respective coil side (9s) of the respective individual coil (9) lie orthocyclically one above the other. [6] Rotor according to one of the preceding claims, characterized bythat the respective pole shoe support slope (17) of the respective salient pole (5) is provided in direct connection to the coil support surface (13) of the pole shoe (7) of the salient pole (5). [7] Rotor according to one of the preceding claims, characterized by that the respective coil support surface (13) of the respective salient pole (5) comprises a straight support section (13L) towards the pole shoe support slope (17), which runs in particular perpendicular to the pole center axis (8), and a bent support section (13B) towards the pole shaft (6). [8] Rotor according to claim 7, characterized by in that the bent support section (13B) comprises a transition slope (14) which has an oblique angle (β) to the rectilinear support section (13L) in the range between 25 degrees and 35 degrees, in particular between 29 and 31 degrees. [9] Rotor according to claim 8, characterized bythat the bending support section (13B) towards the pole shaft (6) comprises a further transition bevel (15) which has an oblique angle (γ) to the transition bevel (14) which is in the range between 25 degrees and 35 degrees, in particular between 29 and 31 degrees. [10] Rotor according to one of the preceding claims, characterized by that a star disk (24) is arranged on each of the two end faces of the rotor body (4), each of which has a ring section (25), a plurality of tooth sections (26) projecting from the ring section (25) in the radial direction with respect to the rotor axis (3) for receiving a respective winding head of the respective individual coil (9) and is designed in particular to be electrically insulating. [11] Rotor according to claim 10, characterized byin that the tooth sections (26) of the respective star disk (24) each have two opposing round edges (27) for transitioning into the adjacent pole slots (12), wherein at the radially outer end of the respective tooth section (26) at least at the two round edges (27) a step contour (30) is formed to form a layer step (31), on which the last turn of a first layer is provided in a lower step level and the first turn of a second layer is provided in an upper step level, wherein the first turn of the second layer is located at least one turn further radially outward than the last turn of the first layer, wherein the layer step (31) comprises a ramp-shaped recess (32) which forms a ramp for guiding the wire into the higher step level. [12] Rotor according to one of the preceding claims, characterized bythat the winding heads of the excitation winding (10) are each enclosed by a rotor sleeve (35) which in particular encloses the respective star disk (24). [13] Electrical machine (2) with a rotor (1) according to one of the preceding claims.

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