rotor of an electrical machine

Abstract

A rotor for an electric machine, in particular a permanent magnet excited synchronous machine, comprising: a rotor shaft (3) rotatable about a rotor axis (2); and a rotor body (4) arranged on the rotor shaft (3), in particular configured as a rotor lamination stack including a number of laminated laminations (5), in which a shaft cooling passage (13) extends through the rotor shaft (3); the rotor body (4) has a plurality of rotor poles (6), each having a pole center (7); a plurality of the rotor poles have a plurality of magnets (9), in particular permanent magnets, each having at least one The magnet pockets (10) are provided in a V-shaped, C-shaped, or arc-shaped configuration, each of which has a central region (11) without magnets between two magnets (9) and two edge regions (12) without magnets on the short sides (9s) of the magnets (9) facing away from the central region (11), and each of which has at least one pocket cooling passage (15) formed in fluid communication with the shaft cooling passage (13) and intended for cooling at least one magnet (9) of the magnet pocket (10).

Description

[Technical Field]

[0001] The present invention relates to a rotor for an electric machine, which falls within the field of the independent claims. [Background technology]

[0002] From WO 2021 / 225902 A1, a rotor for an electric machine is already known, which has a rotor shaft rotatable about a rotor axis and a rotor body arranged on the rotor shaft, in particular configured as a rotor lamination stack including a number of laminated laminations, through which shaft cooling passages extend, and the rotor body has a plurality of rotor poles, each having a pole center, and a plurality of these rotor poles are provided with at least one V-shaped, C-shaped or arc-shaped magnet pocket each having a plurality of magnets, each magnet pocket having a magnet-free central area between two magnets and two magnet-free edge areas on the short sides of the magnet facing away from the central area.

[0003] The rotor is cooled by air directed through axial passages in the rotor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2021 / 225902 Summary of the Invention [Effects of the Invention]

[0005] In contrast, a rotor of an electric machine according to the invention, having the features of the characterizing part of the independent claim, has the advantage that direct oil cooling of the magnets is provided in the rotor, thereby improving the cooling of the rotor, which is achieved according to the invention in that at least one pocket cooling passage is formed in each magnet pocket, which is fluidly connected to the shaft cooling passage and intended for cooling at least one magnet of the magnet pocket.

[0006] The measures set out in the dependent claims allow advantageous developments and improvements of the rotor of the electric machine set out in the independent claims.

[0007] Each pocket cooling passage may be formed in the central region of the respective magnet pocket or in one of the edge regions of the respective magnet pocket, based on the first and second embodiments, or in a notch in one of the magnets or between two notches in two magnets, based on the third embodiment.

[0008] In a first preferred embodiment, each magnet pocket may be filled with a hardening filler material, particularly a sealing compound or molding material, for mounting the magnets, and each pocket cooling passage is a hollow space formed within the filler material, at the edge of the filler material, or directly bounded by the wall of each magnet pocket outside the filler material. In this way, even less filler material is required. Furthermore, filler material can be used for mounting the magnets and for embedding or forming each pocket cooling passage. Furthermore, each pocket cooling passage is formed directly on or near one of the short sides of each magnet, thereby even further improving magnet cooling.

[0009] In a first example of the first embodiment, each pocket cooling passage may be formed by subsequent demolding of a particularly tapered demolding tool from the respective magnet pocket, particularly from the fill material of the respective magnet pocket. In this way, each pocket cooling passage is molded into or at the edge of the fill material of the respective magnet pocket without any additional components.

[0010] In a second implementation of the first embodiment, each pocket cooling passage may be formed by a separate cooling tube embedded in the fill material. In this way, it is possible to create particularly long and narrow cooling passages that would otherwise be precluded by the need for elaborate molds.

[0011] In a third example of the first embodiment, each pocket cooling passage may be formed between one of the short sides of each magnet and a tube half-shell embedded in the fill material that abuts the short side of the magnet. In this way, the pocket cooling passage is formed directly adjacent to the magnet, thereby achieving very good cooling of the magnet.

[0012] Preferably, two tube half-shells are provided on opposite short sides of each magnet, and the magnet and both tube half-shells are surrounded by an outer sheath to form a magnet unit. In this way, two pocket cooling passages are formed directly adjacent to both short sides of each magnet, which further improves cooling of the magnet and ensures that it is cooled evenly from both short sides.

[0013] In a fourth example of the first embodiment, each pocket cooling passage is formed by a hollow space in the central region of each magnet pocket, and the hollow space is directly bounded by the wall of each magnet pocket. In this case, the central region of each magnet pocket is created without a bridge web. The pocket cooling passage thus formed must additionally be sealed against the rotor lamination stack.

[0014] In a fifth implementation of the first embodiment, each pocket cooling passage is formed by a hollow space in a central region of each magnet pocket, the hollow space being created in a filler material disposed in the central region, and the pocket cooling passage thus formed is surrounded by the filler material and thereby sealed against the rotor lamination stack.

[0015] In the first embodiment, the central region of each magnet pocket may have a bridge web or may be configured without a bridge web. When a bridge web is present, each V-shaped, C-shaped, or arc-shaped magnet pocket is formed by two magnet pockets separated from each other by a bridge web and collectively forming a V-shaped magnet layer.

[0016] When a bridge web is present, the pocket cooling passages formed in the central region are located to the sides of the bridge web. When a bridge web is not present, the pocket cooling passages formed in the central region without a bridge web can be located pole-centered. A central region without a bridge web significantly reduces leakage flux at the rotor and allows for much larger cooling passages with lower pressure drop than two-part cooling passages separated by a bridge web.

[0017] In the second embodiment, it is preferred that the central regions of each magnet pocket are configured without bridge webs, the pocket cooling passages formed in the central regions are formed by hollow central regions, and the pocket cooling passages formed in the edge regions are formed by hollow edge regions. In this way, the pocket cooling passages can be formed without a hardening filler material, thereby reducing manufacturing costs.

[0018] Furthermore, thermal resistance is reduced because hardenable filling materials often have relatively low thermal conductivity.

[0019] It is particularly preferred that magnetically impermeable rod-shaped pocket bodies, particularly made of plastic or elastomer, are arranged in the hollow central region and / or hollow edge region of each magnet pocket to narrow the cross section of the pocket cooling passage formed in the central region or edge region. In this way, a high flow velocity, particularly for achieving turbulent flow, can be achieved in each pocket cooling passage, and thus improved cooling of the rotor magnets. Furthermore, leakage flux cannot flow through the magnetically impermeable pocket bodies.

[0020] In a preferred embodiment, each pocket body is configured as a round or square bar, in particular of solid material, and may be made of plastic or elastomer, and is configured to abut against a respective pole outer segment and a respective pole inner segment in a respective magnet pocket, in particular to be sandwiched between both pole segments.

[0021] Furthermore, the rotor body is preferably surrounded by a rotor sleeve, in particular a composite fiber sleeve, in order to preload the pole outer segments of the rotor body, in particular towards the magnets of the respective magnet pockets. In this way, in the case of the second embodiment, the pole outer segments are preloaded via the magnets and via the pockets towards one of the pole inner segments, respectively. For this purpose, each pocket has, for example, a lower stiffness than the magnets. This ensures that the magnets of the respective magnet pockets are clamped and thus fixed.

[0022] Furthermore, it is preferred if the rotor sleeve extends axially beyond the rotor body to annularly surround two cover disks of the rotor that are respectively arranged at the end faces in their joint regions, with each cover disk running flush with the outer diameter of the rotor body and the joint regions of the cover disks being covered by the rotor sleeve, so that the cover disks and thus the cooling circuits of the rotor are sealed off from the outside.

[0023] Each pocket cooling passage preferably has a pocket passage inlet for supplying cooling fluid from the shaft cooling passage and a pocket passage outlet for discharging the cooling fluid, with the pocket passage inlets of the first group of pocket cooling passages formed on one of the rotor's end faces and the pocket passage inlets of the second group of pocket cooling passages formed on the other rotor end face to generate opposite flow directions through the pocket cooling passages of both groups. In the first grouping, the pocket cooling passages of the first group may be arranged, for example, on the rotor poles of the first group, and the pocket cooling passages of the second group may be arranged, for example, on the rotor poles of the second group. In an alternative second grouping, the pocket cooling passages of the first group may be formed by pocket cooling passages located in the central region, and the pocket cooling passages of the second group may be formed by pocket cooling passages located in the edge region. In this way, the pocket cooling passages are flowed through in opposite directions during rotor operation. For example, the first group and the second group may include the same number of pocket cooling passages or have the same total flow cross-sectional area. This results in uniform cooling of the rotor, especially when viewed in the axial direction.

[0024] The rotor body has a cover disk on each of its two end faces, with the first cover disk having first connecting passages to the pocket passage inlets of the first group of pocket cooling passages, and the second cover disk having second connecting passages to the pocket passage inlets of the second group of pocket cooling passages.

[0025] In the first piping configuration, the first and second connecting passages of both cover disks are fluidly connected to the shaft cooling passages, respectively, thereby realizing a parallel circuit of all pocket cooling passages of the rotor.

[0026] In the second piping configuration, the first connecting passage is fluidly connected to the shaft cooling passage, and the second connecting passage is fluidly connected to the pocket passage outlets of the first group of pocket cooling passages. In particular, each of the second connecting passages is fluidly connected to at least one of the pocket passage outlets of the first group of pocket cooling passages. In an alternative second grouping configuration, each of the second connecting passages can connect the pocket cooling passages located within the same rotor pole to each other. In this way, a series circuit of the first group of pocket cooling passages and the second group of pocket cooling passages is realized.

[0027] Furthermore, the pocket passage outlets are preferably each fluidly connected to an outlet passage in one of the two cover disks, the cover disk outlet passages each having an outlet opening for cooling one of the stator winding heads, the outlet opening being located in particular on the end face or on the periphery of the respective cover disk or opening into the return flow area of the shaft cooling passage, thus forming a cooling circuit.

[0028] In addition, each collecting passage is preferably fluidly connected with a plurality of pocket cooling passage outlets of rotor poles, in particular those having pocket cooling passages at different radial positions, and the collecting passages of the cover disk each extend radially inward relative to the rotor axis from the respective pocket passage outlet toward the outlet opening, so that a uniform flow through the pocket cooling passages connected to the same collecting passage is achieved by static pressure recovery.

[0029] The invention further relates to an electric machine comprising a rotor according to the invention. [Brief explanation of the drawings]

[0030] An embodiment of the invention is shown in a simplified form in the drawing and is explained in more detail in the following description.

[0031] The drawings show: [Figure 1]1 shows a rotor of an electric machine having a parallel circuit of pocket cooling passages according to the present invention. [Figure 2] 2 shows a cross-sectional view of the rotor of FIG. 1 taken along line II-II of FIG. [Figure 3] 2 illustrates one of the rotor poles of the rotor of FIG. 1 according to a first example of the first embodiment; [Figure 4] 2 shows one of the rotor poles of the rotor of FIG. 1 according to a second example of the first embodiment; [Figure 5] 2 shows one of the rotor poles of the rotor of FIG. 1 according to a third example of the first embodiment; [Figure 6] 2 shows one of the rotor poles of the rotor of FIG. 1 according to a first example of the second embodiment; [Figure 7] 2 shows one of the rotor poles of the rotor of FIG. 1 according to a third embodiment; [Figure 8] 1 shows a rotor of an electric machine having a series circuit of pocket cooling passages according to the present invention. [Figure 9] 6 shows a partial cross-sectional view of the cover disk of the rotor along line IX-IX in FIG. 2 for a first example of the second embodiment. [Figure 10] 2 shows one of the rotor poles of the rotor of FIG. 1 according to a second example of the second embodiment; [Figure 11] 11 shows a cross-sectional view of the rotor of FIG. 10. [Figure 12] 2 illustrates one of the rotor poles of the rotor of FIG. 1 according to a fourth example of the first embodiment; [Figure 13] 10 illustrates one of the rotor poles of the rotor of FIG. 1 according to a fifth example of the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0032] FIG. 1 shows a rotor of an electric machine having a parallel circuit of pocket cooling passages according to the invention.

[0033] A rotor 1 of an electric machine, in particular of a permanent magnet excited synchronous machine, comprises a rotor shaft 3 rotatable about a rotor axis 2 and a rotor body 4 arranged on the rotor shaft 3. The rotor body 4 is configured as a rotor lamella stack, for example comprising a number of laminated lamellas 5.

[0034] A shaft cooling passage 13 extends through the rotor shaft 3. The rotor body 4 has a plurality of rotor poles 6, each having a pole center 7.

[0035] At least one V-shaped, C-shaped or arc-shaped magnet pocket 10 is provided at a plurality of the rotor poles 6, for example at each rotor pole 6, for accommodating a plurality of magnets 9, in particular permanent magnets.

[0036] A magnet layer 8 of a plurality of magnets 9 is formed in each magnet pocket 10. For example, each magnet layer 8 includes two magnets 9 arranged in a V-shape as an example in FIG. 1 . The magnet layers 8 are arranged symmetrically with respect to the respective pole centers 7. Each rotor pole 6 is subdivided by each magnet layer 8 into a pole inner segment 6i and a pole outer segment 6a in the radial direction with respect to the rotor axis 2.

[0037] Each magnet pocket 10 may be a magnet layer 8 that includes two magnet pockets separated from each other by a bridge web.

[0038] Each magnet pocket 10 has a magnet-free central region 11 between two magnets 9 and two magnet-free edge regions 12 on the short sides 9s of the magnets 9 facing away from the central region 11. The central regions 11 are formed in the region of the pole center 7 and extend, as viewed in the circumferential direction, between the two short sides 9s of the two magnets 9 of the magnet pocket 10 facing toward the pole center 7. The magnet layer 8 includes two angled legs, and the edge regions 12 are provided at the ends of the legs facing away from each other of the magnet layer 8, in particular on or near the short sides 9s facing away from the central region 11. Each edge region 12 of each magnet pocket 10 may have a bridge web toward the outer periphery of the rotor body 4, or may be formed without a bridge web.

[0039] FIG. 2 shows a cross-sectional view of the rotor of FIG. 1 taken along line II-II of FIG.

[0040] According to the present invention, it is intended that in each magnet pocket 10 at least one pocket cooling passage 15 is formed which is fluidly connected to the shaft cooling passage 13 and is intended for cooling at least one magnet 9 of the magnet pocket 10. For example, in each magnet pocket 10, multiple pocket cooling passages 15 may be created.

[0041] In the first and second embodiments, each pocket cooling passage 15 may be formed in the central region 11 of each magnet pocket 10 or in one of the edge regions 12 of each magnet pocket 10.

[0042] In the first and second embodiments, the central region 11 of each magnet pocket 10 may have a bridge web 22 for connecting the pole outer segment 6a and the pole inner segment 6i, or may be configured without a bridge web.

[0043] Each pocket cooling passage 15 has a pocket passage inlet 15e for supplying cooling fluid from the shaft cooling passage 13 and a pocket passage outlet 15a for discharging the cooling fluid. The pocket passage inlets 15e of the pocket cooling passages 15 of the first group 14.1 may be formed on one of the two end faces of the rotor 1, and the pocket passage inlets 15e of the pocket cooling passages 15 of the second group 14.2 may be formed on the other end face, so that the pocket cooling passages 15 of both groups 14.1, 14.2 flow through the pocket cooling passages 15 in opposite directions. In the first grouping, the pocket cooling passages 15 of the first group 14.1 may be arranged specifically on the rotor poles 6 of the first group, and the pocket cooling passages 15 of the second group 14.2 may be arranged specifically on the rotor poles 6 of the second group. The pocket cooling passages 15 of the first group 14.1 may be formed, for example, by the pocket cooling passages 15 of every other rotor pole 6 in the circumferential direction. The pocket cooling passages 15 of the second group 14.2 are formed, for example, by the pocket cooling passages 15 of every other rotor pole 6 in the circumferential direction.

[0044] In all embodiments, the rotor body 4 has one cover disk 25 on each of its two end faces, with the first cover disk 25.1 having first connecting passages 26.1 to the pocket passage inlets 15e of the pocket cooling passages 15 of the first group 14.1, and the second cover disk 25.2 having second connecting passages 26.2 to the pocket passage inlets 15e of the pocket cooling passages 15 of the second group 14.2. The first and second connecting passages 26.1, 26.2 of both cover disks 25 are fluidly connected to the shaft cooling passages 13, thereby realizing a parallel circuit of all the pocket cooling passages 15.

[0045] Each connecting passage 26.1 opens into a plurality of pocket passage inlets 15e, respectively, and can thus function as a distribution passage.

[0046] The cover discs 25.1, 25.2 are made radially with respect to the rotor axis 2, for example flush with the rotor body 4.

[0047] FIG. 3 shows one of the rotor poles of the rotor of FIG. 1 according to a first example of the first embodiment.

[0048] In the first embodiment, each magnet pocket 10 may be filled with a hardenable filling material 17, in particular a sealing compound or molding material, for mounting the magnets 9, and each pocket cooling passage 15 is a hollow space embedded in the filling material 17 or a hollow space formed between the edge of each magnet pocket 10 and the edge of the filling material 17.

[0049] In a first example of the first embodiment shown in Figure 3, each pocket cooling passage 15 may be formed by, for example, subsequent demolding or extraction of a tapered demolding tool from each magnet pocket 10, in particular from the filler material 17 of each magnet pocket 10. In Figure 3, two pocket cooling passages 15 are illustratively formed in the central region 11, and one pocket cooling passage 15 is formed in each of both edge regions 12. Instead of the two pocket cooling passages 15 in the central region 11, only one pocket cooling passage 15 may be formed in the central region 11. Of course, fewer than four pocket cooling passages 15 may be provided in each magnet pocket 10, for example, only in the central region 11 or only in the edge regions 12.

[0050] FIG. 4 shows one of the rotor poles of the rotor of FIG. 1 according to a second example of the first embodiment.

[0051] In a second implementation of the first embodiment, each pocket cooling passage 15 is formed by a separate cooling tube 18 embedded in the fill material 17. In Figure 4, one cooling tube 18 is illustratively created in the central region 11, and one cooling tube 18 each in both edge regions 12.

[0052] Of course, fewer than three pocket cooling passages 15 may be provided within each magnet pocket 10, for example only in the central region 11 or only in the edge regions 12.

[0053] FIG. 5 shows one of the rotor poles of the rotor of FIG. 1 according to a third example of the first embodiment.

[0054] In a third example of the first embodiment, each pocket cooling passage 15 may be formed between one of the short sides 9s of each magnet 9 and a tube half-shell 19 embedded in the filling material 17 that abuts the short side 9s of the magnet 9. A tube shell that includes a cross section that is slightly larger or smaller than half the cross section of the tube is also understood as a tube half-shell 19.

[0055] In the third embodiment, two tube half-shells 19 are provided on both opposite short sides 9s of each magnet 9, and the magnet 9 and both tube half-shells 19 are surrounded by an outer sheath 20 to form a magnet unit.

[0056] FIG. 6 shows one of the rotor poles of the rotor of FIG. 1 according to a first example of the second embodiment.

[0057] In a first example of the second embodiment, the central region 11 of each magnet pocket 10 is configured without a bridge web, the pocket cooling passages 15 formed in the central region 11 are defined by the hollow central region 11, and the pocket cooling passages 15 formed in the edge regions 12 are defined by the hollow edge regions 12. Here, the hollow central region 11 is bounded in the circumferential direction by the short sides 9s of the two magnets 9 facing toward the pole center 7, and in the radial direction with respect to the rotor shaft 2 by the magnet pockets 10. The hollow edge regions 12 are bounded by the short sides 9s of each magnet 9 facing away from the central region 11 and by the sides of the magnet pockets 10 in the leg end regions.

[0058] A magnetically impermeable rod-shaped pocket body 23, particularly made of plastic or elastomer, may be arranged in the hollow central region 11 and / or hollow edge region 12 of each magnet pocket 10 to narrow the cross section of the pocket cooling passage 15 formed in the central region 11 or edge region 12. In this case, the pocket cooling passage 15 is formed between the pocket body 23 and the short side 9s of each magnet 9.

[0059] However, the pocket body 23 shown in FIG. 6 can obviously be omitted.

[0060] 6, one pocket body 23 is exemplarily created in the central region 11, and one pocket body 23 is created in each of the edge regions 12. Of course, fewer than three pocket bodies 23 may be provided in each magnet pocket 10, for example, only one pocket body 23 located in the central region 11. The pocket bodies 23 located in the central region 11 are, for example, arranged symmetrically with respect to the pole center 7.

[0061] In a second embodiment, the rotor body 4 is surrounded by a rotor sleeve 24, in particular a composite fiber sleeve, which is fabricated or assembled with a preload to preload the pole outer segments 6a towards the magnets 9 of the magnet layer 8.

[0062] Each pocket body 23 abuts against a respective pole outer segment 6a and a respective pole inner segment 6i in each magnet pocket 10 and is sandwiched between both pole segments 6a, 6i, for example, by a preloaded rotor sleeve 24.

[0063] The long sides of the magnet 9 may be provided with a sealing compound (not shown), in particular an epoxy resin, for fixing or sealing the magnet, respectively.

[0064] FIG. 7 shows one of the rotor poles of the rotor of FIG. 1 according to a third embodiment. In the third embodiment, the pocket cooling passage 15 is formed in the notch 16 of one of the magnets 9 or between two notches 16 of two magnets 9 .

[0065] FIG. 8 shows a rotor of an electric machine having an alternative series circuit of pocket cooling passages according to the present invention.

[0066] As an alternative to the parallel circuit of the pocket cooling passages 15 shown in FIG. 1 , in all embodiments 8, the first connecting passage 16.1 of the first cover disk 25.1 can be fluidly connected to the shaft cooling passage 13, and the second connecting passage 16.2 of the second cover disk 25.2 can be fluidly connected to the pocket passage outlets 15a of the pocket cooling passages 15 of the first group 14.1, thereby realizing a series circuit of the pocket cooling passages 15 of the first group 14.1 and the pocket cooling passages 15 of the second group 14.2. In particular, the second connecting passages 16.2 are each fluidly connected to one of the pocket passage outlets 15a of the pocket cooling passages 15 of the first group 14.1. In an alternative second grouping, the second connecting passages 16.2 can connect the pocket cooling passages 15 located inside the same rotor pole 6 to each other.

[0067] FIG. 9 shows a partial cross-sectional view of the cover disk of the rotor along line IX-IX in FIG. 2 for the first example of the second embodiment in FIG.

[0068] In all embodiments, each pocket passage outlet 15a is fluidly connected to a collecting passage 27 of one of the cover discs 25.1, 25.2, the collecting passages 27 of the cover discs 25.1, 25.2 each having an outlet opening 28 which may be located on the end face or on the outer periphery of the respective cover disc 25.1, 25.2 or which opens into the return zone of the shaft cooling passage 13. A plurality of collecting passages 27 may be configured in each cover disc 25.1, 25.2.

[0069] Each collecting passage 27 may be fluidly connected with a plurality of pocket passage outlets 15a of rotor poles 6, in particular those in which the pocket cooling passages 15 have different radial positions relative to the rotor shaft 2, and the collecting passages 27 of the cover disks 25.1, 25.2 extend radially inward relative to the rotor shaft 2 from the respective pocket passage outlets 15a towards the outlet openings 28.

[0070] FIG. 10 shows one of the rotor poles of the rotor of FIG. 1 according to a second example of the second embodiment.

[0071] The second example of the second embodiment shown in Figure 10 differs from the first example shown in Figure 6 only in that it has two magnet layers 8 with pocket bodies 23 according to the present invention.

[0072] FIG. 11 shows a cross-sectional view of the rotor of FIG.

[0073] The rotor sleeve 24 may extend beyond the rotor body 4 in the axial direction relative to the rotor shaft 2 in order to annularly surround two cover disks 25.1, 25.2 of the rotor 1, which are arranged on their end faces at the respective joining regions 24.1. A joining connection is provided between each joining region 24.1 of the rotor sleeve 24 and each cover disk 25.1, 25.2, which may be made, for example, particularly liquid-tight.

[0074] 11, the collecting passages 27 of the cover disks 25.1, 25.2 also extend radially inward with respect to the rotor shaft 2 from the respective pocket passage outlets 15a toward the outlet openings .

[0075] FIG. 12 shows one of the rotor poles of the rotor of FIG. 1 according to a fourth example of the first embodiment.

[0076] In a fourth example of the first embodiment, the central region 11 of each magnet pocket 10 is configured without a bridge web. A single pocket cooling passage 15 is formed in the central region 11 by the hollow central region 11 outside the filler material 17. This is because the magnet pocket 10 is filled with the filler material 17 via a sprue outside the central region 11, for example, in at least one of the edge regions 12, and the central region 11 is kept completely free of the filler material 17, for example, by a removable demolding tool or by pressureless filling of the filler material. The central region 11 of the magnet pocket 10 is formed, for example, in a triangular or trapezoidal shape. The short sides 9s of each magnet 9 facing the central region 11 are kept free of the filler material 17, for example, by sealing with the rotor body 4 or the demolding tool. Each magnet pocket 10 can have notches on the inside facing the long sides of each magnet 9, particularly near the positioning lugs for positioning the magnet 9, to improve ventilation during filling of the filler material 17.

[0077] FIG. 13 shows one of the rotor poles of the rotor of FIG. 1 according to a fifth example of the first embodiment.

[0078] In a fifth example of the first embodiment, the central region 11 of each magnet pocket 10 is configured without a bridge web. A single pocket cooling passage 15 is formed in the central region 11 of each magnet pocket 10 by filling the magnet pocket 10 with filler material 17 via a sprue external to the central region 11, e.g., in at least one of the edge regions 12, and keeping the central region 11 completely free of filler material 17 in a partial cross-section smaller than the cross-section of the central region 11, e.g., by a subsequently removable demolding tool.

[0079] The pocket cooling passage 15 thus formed is surrounded by and sealed with the filling material 17. The central region 11 of the magnet pocket 10 is made, for example, triangular or trapezoidal.

Claims

1. 1. A rotor for an electric machine, in particular a permanent magnet excited synchronous machine, comprising: a rotor shaft (3) rotatable about a rotor axis (2); and a rotor body (4) arranged on the rotor shaft (3), in particular configured as a rotor lamination stack including a number of laminated laminations (5), in which a shaft cooling passage (13) extends through the rotor shaft (3), the rotor body (4) has a plurality of rotor poles (6), each having a pole center (7), in a plurality of the rotor poles (6) at least one V-shaped, C-shaped or arc-shaped magnet pocket (10) containing a plurality of magnets (9), in particular permanent magnets, each of the magnet pockets (10) having a magnet-free central region (11) between two of the magnets (9) and two magnet-free edge regions (12) on the short sides (9s) of the magnets (9) facing away from the central region (11), in each magnet pocket (10) at least one pocket cooling passage (15) is formed which is fluidly connected to the shaft cooling passage (13) and is intended for cooling at least one of the magnets (9) of the magnet pocket (10), Rotor.

2. Each of the pocket cooling passages (15) comprises: a. in the central region (11) of each of the magnet pockets (10), or in one of the edge regions (12) of each of the magnet pockets (10), or b) formed in one notch (16) of the magnet (9) or between two notches (16) of two of the magnets (9); The rotor of claim 1 .

3. Each of said magnet pockets (10) is filled with a hardenable filling substance (17), in particular a sealing compound or molding material, for the attachment of said magnets (9); Each of the pocket cooling passages (15) is a hollow space formed within the packing material (17), at the edge of the packing material (17), or directly bounded by the wall of each of the magnet pockets (10) outside the packing material (17).

3. A rotor according to claim 1 or 2, characterized in that:

4. 4. A rotor according to claim 3, characterized in that each pocket cooling passage (15) is formed by subsequent demolding of a particularly tapered demolding tool from each magnet pocket (10), in particular from the filling material (17) of each magnet pocket (10).

5. A rotor according to claim 3, characterized in that each of said pocket cooling passages (15) is formed by a separate cooling tube (18) embedded in said fill material (17).

6. 4. A rotor according to claim 3, characterized in that each of the pocket cooling passages (15) is formed between one of the short sides (9s) of each of the magnets (9) and a tube half-shell (19) embedded in the filling material (17) abutting the short side (9s) of the magnet (9).

7. Two tube half-shells (19) are provided on the opposite short sides (9s) of each of the magnets (9), The magnet (9) and both of the tube half-shells (19) are surrounded by an outer sheath (20) to form a magnet unit. A rotor according to claim 6, characterized in that it comprises:

8. 4. A rotor according to claim 2 or 3, characterized in that the central region (11) of each magnet pocket (10) is configured with or without a bridge web (22).

9. 9. The rotor according to claim 8, wherein the central region (11) of each of the magnet pockets (10) is configured without a bridge web, the pocket cooling passages (15) formed in the central region (11) are formed by the hollow central region (11), and the pocket cooling passages (15) formed in the edge regions (12) are formed by the hollow edge regions (12).

10. 10. The rotor according to claim 9, characterized in that a magnetically impermeable rod-shaped pocket body (23), in particular made of plastic or elastomer, is arranged in the hollow central region (11) and / or the hollow edge region (12) of each magnet pocket (10) in order to narrow the cross section of the pocket cooling passage (15) formed in the central region (11) or the edge region (12).

11. A rotor according to any one of claims 1 to 10, characterized in that the rotor body (4) is surrounded by a rotor sleeve (24), in particular by a composite fibre sleeve, in order to preload the pole outer segments (6a) of the rotor body (4), in particular towards the magnets (9) of the respective magnet pockets (10).

12. 12. The rotor according to claim 11, wherein the rotor sleeve (24) extends axially beyond the rotor body (4) in order to annularly surround two cover disks (25.1, 25.2) of the rotor (1) arranged at their end faces at their respective joining regions (24.1), and wherein a joining connection is provided between each joining region (24.1) of the rotor sleeve (24) and each of the cover disks (25.1, 25.2).

13. Each of the pocket cooling passages (15) has a pocket passage inlet (15e) for supplying cooling fluid from the shaft cooling passage (13) and a pocket passage outlet (15a) for discharging the cooling fluid; a. the pocket passage inlets (15e) of the pocket cooling passages (15) of the first group (14.1) are formed in one of both end faces; b. the pocket cooling passage inlets (15e) of the pocket cooling passages (15) of the second group (14.2) are formed on the other end face of the rotor (1) to create opposite throughflows of the pocket cooling passages (15) of both groups (14.1, 14.2); the pocket cooling passages (15) of the first group (14.1) are arranged in particular on the rotor poles (6) of the first group, and the pocket cooling passages (15) of the second group (14.2) are arranged in particular on the rotor poles (6) of the second group, or the pocket cooling passages (15) of the first group (14.1) are formed by pocket cooling passages (15) located in the central region (11), and the pocket cooling passages (15) of the second group (14.2) are formed by pocket cooling passages (15) located in the edge region (12). A rotor according to any one of claims 1 to 12, characterized in that it comprises a rotor.

14. The rotor body (4) has one cover disk (25.1, 25.2) on each of the two end faces, the first cover disk (25.1) having first connecting passages (26.1) to the pocket passage inlets (15e) of the pocket cooling passages (15) of the first group (14.1) formed therein, and the second cover disk (25.2) having second connecting passages (26.2) to the pocket passage inlets (15e) of the pocket cooling passages (15) of the second group (14.2) formed therein; a. the first and second connecting passages (26.1, 26.2) of both cover discs (25.1, 25.2) are fluidly connected with the shaft cooling passage (13), or b. the first connecting passage (26.1) is fluidly connected to the shaft cooling passage (13), and the second connecting passage (26.2) is fluidly connected to the pocket passage outlets (15a) of the pocket cooling passages (15) of the first group (14.1); A rotor according to claim 13, characterized in that

15. 15. A rotor according to claim 13 or 14, characterized in that each of the pocket passage outlets (15a) is fluidly connected to a collecting passage (27) of one of the cover disks (25.1, 25.2), the collecting passage (27) of the cover disks (25.1, 25.2) having an outlet opening (28) which can be located in particular on an end face or on an outer periphery of the respective cover disk (25.1, 25.2) or which opens into a return flow zone of the shaft cooling passage (13).

16. 16. The rotor according to claim 15, wherein each of the collecting passages (27) is fluidly connected with a plurality of the pocket passage outlets (15 a) of rotor poles (6) in which the pocket cooling passages (15) have different radial positions with respect to the rotor shaft (2), and the collecting passages (27) of the cover disks (25.1, 25.2) extend radially inward with respect to the rotor shaft (2) from the respective pocket passage outlets (15 a) toward the outlet openings (28).

17. An electric machine comprising a rotor (81) according to any one of claims 1 to 16.

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