Rotor of an electric machine

Abstract

The invention relates to a rotor of an electric machine (2), the rotor comprising: a rotor shaft (4) which is rotatable about a rotor axis (3); a rotor body (5), in particular a laminated rotor core comprising a multiplicity of laminations (9), which is arranged on the rotor shaft (4) and has magnet pockets (6) in which magnets (7), in particular permanent magnets, are accommodated, the magnets being fastened in the magnet pockets (6) by means of a potting compound (8); and at least one end disk arrangement (10) which is arranged on one of the two end faces of the rotor body (5) and comprises a balancing disk (11), in particular made of metal; characterised in that each end disk arrangement (10) additionally comprises a plastics disk (12) which faces the rotor body (5) and in which there is at least one injection channel (15), in particular a plurality of injection channels (15) arranged along the circumferential direction, through which the potting compound (8) can be injected into the magnet pockets (6).

Description

[0001] Description

[0002] title

[0003] Rotor of an electrical machine

[0004] State of the art

[0005] The invention is based on a rotor of an electrical machine according to the preamble of the main claim.

[0006] A rotor for an electric machine is already known from DE102022107435 A1. The rotor comprises a rotor shaft rotatable about a rotor axis and a rotor body arranged on the rotor shaft, which is designed as a rotor core consisting of a plurality of laminations. The rotor body has magnetic pockets in which magnets, in particular permanent magnets, are accommodated. The magnets are secured in the magnetic pockets by means of a potting compound. In addition, the rotor has at least one end plate arrangement arranged on one of the two end faces of the rotor body, which end plate arrangement comprises a balancing disc.

[0007] Advantages of the invention

[0008] The rotor of an electrical machine according to the invention with the characterizing features of the main claim has the advantage that the potting compound can be used not only to secure the magnets but also to seal a cooling channel system of the rotor in the area between the plastic disc and the rotor body. The potting compound can also be used according to the invention to secure the plastic disc to the rotor body, which can also improve the sealing of the cooling channel system. High speeds can create high pressures in the cooling channel system of the rotor, which act on the respective plastic disc and can create or increase leakage in the cooling channel system. By securing the plastic disc to the rotor body, leakage in the cooling channel system at the interface between the rotor body and the plastic disc can be avoided or minimized.

[0009] By arranging a plastic disc between the balancing disc and the rotor body, losses in the rotor are avoided. This is achieved according to the invention in that the respective end disc arrangement additionally comprises a plastic disc facing the rotor body, in which at least one injection channel, in particular several injection channels arranged along the circumferential direction, is provided, through which the casting compound can be injected into the magnetic pockets.

[0010] The measures listed in the subclaims enable advantageous further developments and improvements of the rotor of an electrical machine specified in the main claim.

[0011] It is very advantageous if the potting compound forms undercuts on the plastic disc that anchor the plastic disc to the rotor body, especially in the axial direction. This allows the potting compound to be used particularly effectively to secure the plastic disc to the rotor body, which can also improve the sealing of the cooling channel system.

[0012] It is particularly advantageous if the respective injection channel is a through-channel that runs continuously from a front side of the respective plastic disc facing away from the rotor body to a rear side of the plastic disc and opens into at least one of the magnetic pockets. In this way, the potting compound can be injected through the respective plastic disc into the magnetic pockets.

[0013] Furthermore, it is advantageous if, according to a first variant, the casting compound extends towards the front of the respective plastic pane to the outside of the injection channels and forms the undercuts there.

[0014] According to the first variant, recesses can be formed on the front side of the respective plastic disc to accommodate the potting compound located outside the injection channels, wherein the recesses each comprise one or more injection channels with respect to the inlets into the injection channels. In the case of multiple injection channels per recess, several injection channels are supplied with potting compound via a single sprue. The multiple injection channels per recess can fill several magnetic layers of a rotor pole with potting compound. Alternatively, according to a second variant, the undercuts can be formed by injection channels that widen in a stepped or conical shape in the axial direction.

[0015] According to a third variant, the undercuts can also be formed by form-fitting elements formed in the injection channels, in particular projections, depressions, webs or ribs.

[0016] It is further advantageous if the rotor body is provided with a plurality of cooling channels extending axially relative to the rotor axis and arranged along the circumferential direction, which can be supplied with cooling fluid, in particular oil, via the hollow rotor shaft to cool the rotor. In this way, the cooling of the rotor can be improved.

[0017] It is also advantageous if connecting channels are formed in the respective plastic disc to guide the flow of the cooling fluid into or out of the cooling channels. The connecting channels can be formed cost-effectively in the plastic disc.

[0018] It is very advantageous if the injection channels of the respective plastic disc are connected via a groove-shaped distribution channel which is arranged on a rear side of the respective plastic disc facing the rotor body and in particular radially outside the cooling channels.

[0019] In this way, the distribution channel according to a first embodiment can be used to seal the cooling channels, in that the potting compound cured in the distribution channel forms an annular seal which seals or quasi-seals the cooling channels radially outwards at an interface between the rotor body and the plastic disc.

[0020] According to the advantageous first embodiment, the cooling channels are formed directly by recesses in the sheet metal lamellas.

[0021] According to an advantageous second embodiment, the cooling channels can be formed in the potting compound of the magnetic pockets and also extend through the potting compound of the injection channels. The cooling channels according to the second embodiment can be produced, for example, by axial demolding or by withdrawing a rod-shaped tool from the potting compound.

[0022] The invention further relates to an electrical machine with a rotor according to the invention.

[0023] drawing

[0024] Embodiments of the invention are shown in simplified form in the drawing and explained in more detail in the following description.

[0025] They show:

[0026] Fig.1 is a sectional view of a rotor of an electrical machine with an end plate arrangement according to the invention according to a first embodiment,

[0027] Fig.2 a three-dimensional side view of the rotor according to Fig.1,

[0028] Fig.3 is a partial view of the rotor according to Fig.2 in the state before the injection of the casting compound and before mounting the balancing disc,

[0029] Fig.4 a sectional view of the rotor through an injection channel in the

[0030] Plastic disc of the end disc arrangement according to Fig.1 to Fig.3,

[0031] Fig.5 a back side of the plastic disc of the end disc arrangement according to Fig.1 to Fig.4,

[0032] Fig.6 is a partial view of the rotor according to the invention

[0033] Casting system,

[0034] Fig.7 a rotor of an electrical machine with an inventive

[0035] End plate arrangement according to a second embodiment,

[0036] Fig.8 is a partial view of the rotor according to Fig.7.

[0037] Description of the embodiments

[0038] Fig.1 shows a sectional view of a rotor of an electrical machine with an end plate arrangement according to the invention according to a first embodiment.

[0039] Fig. 2 shows a three-dimensional side view of the rotor according to Fig. 1 . The rotor 1 of an electrical machine 2 has a rotor shaft 4 rotatable about a rotor axis 3 and a rotor body 5 arranged on the rotor shaft 4, which is in particular a rotor laminated core formed from a plurality of laminated laminations 9. The rotor body 5 has magnetic pockets 6 in which magnets 7, in particular permanent magnets, are received. The magnets 7 are fastened in the magnetic pockets 6 by means of a curable potting compound 8.

[0040] The rotor 1 further comprises at least one end disk arrangement 10 arranged on one of the two end faces of the rotor body 5, which end disk arrangement comprises a balancing disk 11, in particular a metallic one.

[0041] According to the invention, the respective end disk arrangement 10 comprises, in addition to the balancing disk 11, a plastic disk 12 facing the rotor body 5. The plastic disk 12 extends in the radial direction relative to the rotor axis 3, for example, from an inner circumference to an outer circumference of the rotor body 5.

[0042] A receptacle 14 for receiving the metallic balancing disc 11 can be formed on the plastic disc 12. In this way, the balancing disc 11, which is pressed onto the rotor shaft 4, for example, can be used to align the plastic disc 12.

[0043] Fig.3 shows a partial view of the rotor according to Fig.2 in the state before the injection of the casting compound and before mounting the balancing disc.

[0044] Furthermore, the invention provides that at least one injection channel 15, in particular a plurality of injection channels 15 arranged along the circumferential direction, is provided in the plastic disc 12, through which the potting compound 8 can be injected into the magnetic pockets 6. The potting compound 8 can be a so-called molding compound, for example.

[0045] Fig.4 shows a sectional view of the rotor through an injection channel in the plastic disc of the end disc arrangement according to Fig.1 to Fig.3. According to Fig.4, the potting compound 8 can form undercuts 16 on the plastic disc 12, which anchor the plastic disc 12 to the rotor body 5, in particular in the axial direction.

[0046] The respective injection channel 15 is a through-channel which runs continuously from a front side 12f of the respective plastic disc 12 facing away from the rotor body 5 to a rear side 12b of the plastic disc 12 facing the rotor body 5 and opens into at least one of the magnetic pockets 6.

[0047] In the first embodiment, the potting compound 8 extends towards the front side 12f of the respective plastic disc 12 to the outside of the injection channels 15 and forms the undercuts 16 there, i.e. outside the injection channels 15.

[0048] On the front side 12f of the respective plastic disc 12, for example, recesses 17 are formed for receiving the potting compound 8 located outside the injection channels 15. The respective recess 17 can comprise one or more injection channels 15.

[0049] Alternatively, the undercuts 16 can also be formed, in a manner not shown, by injection channels 15 which widen in a step-like or conical manner in the axial direction or by form-fitting elements formed in the injection channels 15, in particular projections, depressions, webs or ribs.

[0050] A plurality of cooling channels 20 extending axially relative to the rotor axis 3 and arranged along the circumferential direction can be formed in the rotor body 5. These cooling channels can be supplied with cooling fluid, in particular oil, via the hollow rotor shaft 4 for cooling the rotor 1 and are part of a cooling channel system of the rotor 1. According to the first exemplary embodiment, the cooling channels 20 are formed, for example, directly by recesses in the sheet metal laminations 9. A flow connection 21 of the cooling channels 20 to the hollow rotor shaft 4 can be implemented, for example, in a central stack section of the rotor body 5.

[0051] Connection channels 22 for conducting the flow of cooling fluid into or out of the cooling channels 20 can be formed in the respective plastic disc 12. The connection channels 22 are also part of the cooling channel system of the rotor 1. According to the first exemplary embodiment, the connection channels 22 of the respective plastic disc 12 each lead into a pipe-socket-shaped fluid outlet 23 for cooling the winding head of a stator 30 of the electrical machine 2.

[0052] At least some of the injection channels of the respective plastic disc are connected via a groove-shaped distribution channel which is arranged on a rear side of the respective plastic disc facing the rotor body and radially outside the cooling channels.

[0053] The magnets 7 of the rotor 1 can be arranged in one or more, in particular two, magnetic layers 7L per rotor pole 1p. The magnetic layers 7L are, for example, V-shaped or C-shaped.

[0054] Fig.5 shows a back side of the plastic disc of the end disc arrangement according to Fig.1 to Fig.4.

[0055] At least some of the injection channels 15 of the respective plastic disc 12 can be connected via a groove-shaped distribution channel 25, which is arranged on a rear side 12b of the respective plastic disc 12 facing the rotor body 5 and, for example, radially outside the cooling channels 20. For example, several injection channels 15 can be connected from a single rotor pole 1p or from several, in particular all, rotor poles 1p via a groove-shaped distribution channel 25.

[0056] According to the embodiment in Fig. 5, the injection channels 15 for injecting the magnetic pockets 6 of the inner magnetic layers 7L are fluidly connected via a particularly annular distribution channel 25. Furthermore, according to Fig. 5, the injection channels 15 of an outer magnetic layer 7L of an individual rotor pole 1p are connected via, for example, a V-shaped distribution channel 25. Alternatively or additionally, the injection channels 15 for injecting the magnetic pockets 6 of the outer magnetic layers 7L can be fluidly connected via a particularly annular distribution channel 25 in a manner not shown.

[0057] According to Fig. 4 and Fig. 5, the potting compound cured in the distribution channel 25 forms an annular seal 25, which seals the cooling channels 20 radially outward at an interface between the rotor body 5 and the plastic disc 12. Fig. 6 shows a partial view of the potting compound system formed in the rotor according to the invention, which is formed by the potting compound 8 cured in the rotor 1.

[0058] Fig. 7 shows a rotor of an electrical machine with an end plate arrangement according to the invention according to a second embodiment. Fig. 8 shows a partial view of the rotor according to Fig. 7

[0059] In the second embodiment, the potting compound 8 is also injected into the magnetic pockets 6 through injection channels 15 of the respective plastic disc 12, whereby the potting compound 8 forms undercuts 16 on the plastic disc 12, which anchor the plastic disc 12 to the rotor body 5, particularly in the axial direction. For example, to form the undercuts 16, the potting compound 8 extends outside the injection channels 15 into the recesses 17 formed on the front side 12f of the plastic disc 12.

[0060] According to the second embodiment, the cooling channels 20 of the rotor body 5 are formed in the potting compound 8 of the magnetic pockets 6. The cooling channels 20 also extend through the potting compound 8 of the injection channels 15 formed in the plastic discs 12.

[0061] Connection channels 22 for directing the flow of the cooling fluid into or out of the cooling channels 20 are also formed in the respective plastic disc 12. According to the second embodiment, the connection channels 22 are fluidly connected, for example, to the hollow rotor shaft 4.

Claims

Claims 1. A rotor of an electrical machine (2), comprising a rotor shaft (4) rotatable about a rotor axis (3), a rotor body (5) arranged on the rotor shaft (4), in particular a rotor laminated core comprising a plurality of laminated laminations (9), which has magnetic pockets (6) in which magnets (7), in particular permanent magnets, are received, which are fastened in the magnetic pockets (6) by means of a casting compound (8), and at least one end plate arrangement (10) arranged on one of the two end faces of the rotor body (5), which end plate arrangement comprises a balancing disc (11), in particular a metallic one, characterized in that the respective end plate arrangement (10) additionally comprises a plastic disc (12) facing the rotor body (5), in which at least one injection channel (15), in particular a plurality of injection channels (15) arranged along the circumferential direction, is provided, through which the casting compound (8) can be injected into the magnetic pockets (6).

2. Rotor according to claim 1, characterized in that the casting compound (8) forms undercuts (16) on the plastic disc (12) which anchor the plastic disc (12) to the rotor body (5), in particular in the axial direction.

3. Rotor according to one of the preceding claims, characterized in that the respective injection channel (15) is a through-channel which leads from a front side (12f) of the respective plastic disc facing away from the rotor body (5) (12) runs continuously onto a rear side (12b) of the plastic disc (12) and opens into at least one of the magnetic pockets (6).

4. Rotor according to one of claims 2 or 3, characterized in that the casting compound (8) extends towards the front side (12f) of the respective plastic disc (12) to the outside of the injection channels (15) and forms the undercuts (16) there.

5. Rotor according to claim 4, characterized in that recesses (17) for receiving the casting compound (8) located outside the injection channels (15) are formed on the front side (12f) of the respective plastic disc (12). wherein the respective recess (17) comprises one or more injection channels (15).

6. Rotor according to one of claims 2 to 5, characterized in that the undercuts (16) are formed by - injection channels (15) widening in the axial direction in a step-like or conical manner, - by form-fitting elements formed in the injection channels (15), in particular projections, depressions, webs or ribs.

7. Rotor according to one of the preceding claims, characterized in that a plurality of cooling channels (20) are formed in the rotor body (5) which run in the axial direction with respect to the rotor axis (3) and are arranged along the circumferential direction and which can be supplied with cooling fluid, in particular oil, via the hollow rotor shaft (4) for cooling the rotor (1).

8. Rotor according to claim 7, characterized in that connecting channels (22) for conducting the flow of the cooling fluid into the cooling channels (20) or out of the cooling channels (20) are formed in the respective plastic disc (12).

9. Rotor according to one of the preceding claims, characterized in that at least some of the injection channels (15) of the respective plastic disc (12) are connected via a groove-shaped distribution channel (25) which is arranged on a rear side (12b) of the respective plastic disc (12) facing the rotor body (5) and in particular radially outside the cooling channels (20).

10. Rotor according to one of the preceding claims, characterized in that - the cooling channels (20) are formed directly by recesses in the sheet metal lamellas (9) or - the cooling channels (20) are formed in the potting compound (8) of the magnetic pockets (6) and also extend through the potting compound (8) of the injection channels (15).

11. Electrical machine (2) with a rotor (1) according to one of the preceding claims.

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