Cooling system of a wound internal rotor of an electrically excited synchronous machine

Abstract

Rotor (1) of an electrically excited synchronous machine (2) having a rotor body (4) that is rotatable about a rotor axis (3) and has multiple salient poles (5) arranged in the circumferential direction, each of the salient poles having a pole shaft (5.1). A single coil (6) of the winding (7) is placed around each pole shaft. A star disc (10) is provided on each of the two end faces of the rotor body (4), said star disc consisting of a ring portion (11), multiple tooth portions (12) protruding radially therefrom and winding receptacles (13) formed thereon for receiving a winding head of the single coil (6). In addition, connecting channels (15), which each run within the tooth portion (12) in the radial direction and are part of a cooling path (16) formed in the rotor (1), are formed in a star disc (10) and a pole cooling channel (17), which extends in the axial direction through the salient pole (5) and is fluidically connected to one of the connecting channels (15) in a star disc (10), is provided in each of the salient poles (5).

Description

[0001] Description

[0002] title

[0003] COOLING OF A WOUND INNER ROTOR OF AN ELECTRICALLY EXCITED SYNCHRONOUS MACHINE

[0004] State of the art

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

[0006] A rotor of an electrically excited synchronous machine is already known from WO23062322 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 having a pole shaft. The pole shafts of the salient poles are each enclosed by an individual coil of an excitation winding, wherein a star disk is provided on each of the two end faces of the rotor body, each star disk having an annular portion, a plurality of tooth portions projecting radially from the annular portion, and winding receptacles formed on the tooth portions for receiving a respective winding head of the respective individual coil. Connecting channels are formed in at least one of the star disks, each of which runs in one of the tooth portions in the radial direction relative to the rotor axis and is part of a cooling path formed in the rotor.

[0007] Advantages of the invention

[0008] The rotor of an electrically excited synchronous machine according to the invention, with the characterizing features of the main claim, has the advantage that rotor cooling is improved by providing, at least in one of the salient poles, a pole cooling channel extending axially through the salient pole relative to the rotor axis and fluidly connected to one of the connecting channels of one of the star disks. The measures listed in the subclaims enable advantageous refinements and improvements of the rotor of an electrically excited synchronous machine specified in the main claim.

[0009] The respective connecting channel of the star disk can, according to an advantageous first type of channel connection, flow-connect the pole cooling channel of the salient pole to a shaft cooling channel of a rotor shaft and thus form an inlet connection into the pole cooling channel. Alternatively, according to an advantageous second type of channel connection, the respective connecting channel of the star disk can have an outlet opening at its end facing away from the pole cooling channel and form an outlet connection from the pole cooling channel, which extends radially inward from the pole cooling channel with respect to the rotor axis, wherein the outlet opening in the tooth section is arranged radially inside the winding receptacle. By extending the outlet connection radially inward, it can be achieved that the pole cooling channel is pressurized and completely filled with cooling fluid.

[0010] It is particularly advantageous if, in the case of the first type of channel connection, an annular distribution channel is formed in the star disk, from which the connecting channels branch off and which is fluidly connected to the shaft cooling channel of the rotor shaft. This allows the cooling fluid to be distributed evenly among the pole cooling channels of the salient poles in a simple manner.

[0011] According to an advantageous first embodiment, every second tooth section in each of the two star disks has a connecting channel provided as an input connection, and each remaining tooth section of the respective star disk has a connecting channel provided as an output connection. In this way, an opposite flow direction is achieved in the pole cooling channels of adjacent salient poles.

[0012] According to an advantageous second embodiment, in each tooth section of one star disk there is a connecting channel provided as an inlet connection, and in each tooth section of the other star disk there is a connecting channel provided as an outlet connection. In this way, the same flow direction is set in all pole cooling channels of the rotor. According to an advantageous third embodiment, the channel inlets into the pole cooling channels are formed in the rotor body, in particular in the center of a stack between two end plates of the rotor body, with a connecting channel provided as an outlet connection being formed in each tooth section of the two star disks. In this way, two opposite flow directions are set in all pole cooling channels of the rotor, each starting from the channel inlet into the respective pole cooling channel.

[0013] It is also advantageous if the ring section and the tooth sections of the respective star disk form a one-piece central component, which is made in particular from plastic, and if the winding receptacles of the star disk are each attached, in particular molded or plugged on, as a separate individual part to one of the tooth sections of the central component. In this way, the winding receptacles are mechanically decoupled from the central component. At high rotor speeds, the winding receptacles experience high centrifugal forces due to the mass of the wound individual coil. Without the mechanical decoupling, cracks or fractures could occur in the central component, which would result in leaks in the connecting channel or in the distribution channel of the star disk. Such leaks in the cooling path of the rotor are thus avoided.

[0014] It is also advantageous if the star disks are each clamped against one end of the rotor body by a clamping sleeve firmly connected to the rotor shaft. This ensures that the star disk fits snugly against the end of the rotor body, allowing for a good seal.

[0015] It is also advantageous to provide a seal between the respective star disk and the end face of the rotor body to seal the distribution channel and the connecting channels. This seals off the cooling path formed in the star disk.

[0016] The invention further relates to an electrically excited synchronous machine with a rotor according to the invention. Drawing

[0017] Embodiments of the invention are shown in simplified form in the drawing and explained in more detail in the following description

[0018] They show:

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

[0020] Fig.2 is a front view of one of the two star discs according to Fig.1, Fig.3 is a rear view of the star disc according to Fig.2 and Fig.4 is a view of a section along the line IV-IV in Fig.1.

[0021] Description of the embodiments

[0022] Fig.1 shows in section a rotor according to the invention of an electrically excited synchronous machine according to a first embodiment.

[0023] The rotor 1 according to the invention is a rotor of an electrically excited synchronous machine 2 and comprises a rotor body 4, in particular a rotor laminated core, which is rotatable about a rotor axis 3. The rotor body 4 has a plurality of salient poles 5 arranged along a circumferential direction of the rotor, each having a pole shaft 5.1. The pole shafts 5.1 of the salient poles 5 are each enclosed by an individual coil 6 of an excitation winding 7. A star disk 10 is provided on each of the two end faces of the rotor body 4, each of which has an annular portion 11, a plurality of tooth portions 12 projecting radially from the annular portion 11, and winding receptacles 13 formed on the tooth portions 12 for receiving a respective winding head of the respective individual coil 6.In at least one of the star disks 10, in particular in both star disks 10, connecting channels 15 are formed, each of which runs in one of the tooth sections 12 in the radial direction with respect to the rotor axis 3 and is part of a cooling path 16 formed in the rotor 1. The cooling path 16 is provided for the flow of a cooling fluid, in particular oil. The connecting channels 15 are designed, for example, in the shape of a groove. According to the invention, at least in one of the salient poles 5, in particular in all salient poles 5, a pole cooling channel 17 is provided which extends in the axial direction with respect to the rotor axis 3 through the salient pole 5 and is fluidly connected to one of the connecting channels 15 of at least one of the star disks 10, in particular both star disks 10.

[0024] According to a first type of channel connection, the respective connecting channel 15 of the respective star disk 10 can fluidly connect the pole cooling channel 17 of the respective salient pole 5 with a shaft cooling channel 19 of a rotor shaft 20 of the rotor 1, thus forming an inlet connection 21 into the pole cooling channel 17. For this purpose, at least one shaft opening 18 is provided in the rotor shaft 20, which is fluidly connected to the respective connecting channel 15, in particular via a distribution channel 25.

[0025] The respective connecting channel 15 of the respective star disk 10 can also have, according to a second type of channel connection, an outlet opening 22 at its end facing away from the pole cooling channel 17, thus forming an output connection 23 from the pole cooling channel 17, which extends radially inward from the pole cooling channel 17 relative to the rotor axis 3, wherein the outlet opening 22 is arranged in the tooth section 12 radially inside the winding receptacle 13. From the respective outlet opening 22, the cooling fluid is directed to the winding head of the respective individual coil 6 for cooling.

[0026] According to Fig. 1 to Fig. 4, several of the connecting channels 15 of the two star disks 10 are designed according to the first type of channel connection, while the remaining connecting channels 15 of the two star disks 10 are designed according to the second type of channel connection. The number of connecting channels 15 per star disk 10 corresponds, for example, to the number of salient poles 5 of the rotor 1.

[0027] In the case of the first type of channel connection, an annular distribution channel 25 can be formed in the star disk 10, from which the connecting channels 15 branch off and which is fluidly connected to the shaft cooling channel 19 of the rotor shaft 20.

[0028] The distribution channel 25 is, for example, an annular recess in the star disk 10, which is open, for example, toward the rotor shaft 20. According to the first exemplary embodiment illustrated in the figures, each second tooth section 12 in each of the two star disks 10, viewed in the circumferential direction, has a connecting channel 15 provided as an input connection 21, and each remaining tooth section 12 of the respective star disk 10 has a connecting channel 15 provided as an output connection 23.

[0029] Alternatively, according to a second exemplary embodiment (not shown), a connecting channel provided as an input connection can be provided in each tooth section 12 in one star disk 10 and a connecting channel provided as an output connection can be provided in each tooth section 12 in the other star disk 10.

[0030] Further alternatively, according to a third exemplary embodiment shown in dashed lines in Fig. 1, the channel inlets 24 into the pole cooling channels 17 can be formed in the rotor body 4, in particular in a stack center between two end laminations of the rotor body 4. In this case, a connecting channel 15 provided as an output connection 23 is formed in each of the tooth sections 12 of the two star disks 10. As a result, two flow directions running in opposite directions, shown in dashed lines, are set in all pole cooling channels 17 of the rotor 1, each starting from the channel inlet 24 into the respective pole cooling channel 17.

[0031] According to Fig. 2 and Fig. 3, the ring section 11 and the tooth sections 12 of the respective star disk 10 form a one-piece central component 14, which is made in particular of plastic. The winding receptacles 13 of the respective star disk 10 are each attached as an individual part to one of the tooth sections 12 of the central component 14, in particular by injection molding or plugging. The winding receptacles 13 are made, for example, of plastic.

[0032] According to Fig. 1, the star disks 10 are each clamped or pressed against an end face of the rotor body 34 by a clamping sleeve 26 that is firmly connected to the rotor shaft 20. The clamping sleeve 26 has an L-shaped sleeve cross-section, with a sleeve section of the clamping sleeve 26 being firmly connected to the rotor shaft 20 on an inner circumference and centering the star disk 10 on an outer circumference. The clamping sleeve 26 presses, for example, with a shoulder section, onto the respective star disk 10. On the side of the star disk 10 facing the rotor body 4, a plurality of pin-shaped counterbearings 27 are provided in the distribution channel 25, which are arranged in the circumferential direction and support the star disk 10 on the rotor body 4.

[0033] According to Fig.4, a seal 28 for sealing the distribution channel 25 and / or the connecting channels 15 can be provided between the respective star disk 10 and the end face of the rotor body 4.

Claims

Claims 1. Rotor 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 having a pole shaft (5.1), wherein the pole shafts (5.1) of the salient poles (5) are each enclosed by an individual coil (6) of an excitation winding (7), wherein a star disk (10) is provided on each of the two end faces of the rotor body (4), each of which has an annular portion (11), a plurality of tooth portions (12) projecting radially from the annular portion (11), and winding receptacles (13) formed on the tooth portions (12) for receiving a respective winding head of the respective individual coil (6), wherein connecting channels (15) are formed in at least one of the star disks (10),which each extend in one of the tooth sections (12) in the radial direction with respect to the rotor axis (3) and are part of a cooling path (16) formed in the rotor (1), characterized in that at least in one of the salient poles (5) a pole cooling channel (17) is provided which extends in the axial direction with respect to the rotor axis (3) through the salient pole (5) and is fluidly connected to one of the connecting channels (15) of one of the star disks (10).

2. Rotor according to claim 1, characterized in that a. the respective connecting channel (15) of the star disk (10) fluidly connects the pole cooling channel (17) of the salient pole (5) with a shaft cooling channel (19) of a rotor shaft (20) and forms an inlet connection (21) into the pole cooling channel (17), or b. the respective connecting channel (15) of the star disk (10) has an outlet opening (22) at its end facing away from the pole cooling channel (17) and forms an outlet connection (23) from the pole cooling channel (17), which extends radially inwards from the pole cooling channel (17) with respect to the rotor axis (3), wherein the outlet opening (22) in the tooth section (12) is arranged radially inside the winding receptacle (13).

3. Rotor according to claim 2, characterized in that an annular distribution channel (25) is formed in the star disk (10), from which the connecting channels (15) branch off and which is fluidly connected to the shaft cooling channel (19) of the rotor shaft (20).

4. Rotor according to one of claims 2 and 3, characterized in that each second tooth section (12) in each of the two star disks (10) has a connecting channel (15) provided as an input connection (21) and each remaining tooth section (12) of the respective star disk (10) has a connecting channel (15) provided as an output connection (23).

5. Rotor according to one of claims 2 and 3, characterized in that in one star disk (10) in each tooth section (12) there is a connecting channel (15) provided as an input connection (21) and in the other star disk (10) in each tooth section (12) there is a connecting channel (15) provided as an output connection (23).

6. Rotor according to one of claims 2 and 3, characterized in that the channel inlets (24) into the pole cooling channels (17) are formed in the rotor body (4), in particular in a package center between two end plates of the rotor body (4), and in the two star disks (10) in each tooth section (12) a connecting channel (15) provided as an output connection (23) is designed.

7. Rotor according to one of the preceding claims, characterized in that the ring section (11) and the tooth sections (12) of the respective star disk (10) form a one-piece central component (14) which is made in particular of plastic, and in that the winding receptacles (13) of the star disk (10) are each fastened, in particular injection-molded or plugged, as an individual part to one of the tooth sections (12) of the central component (14).

8. Rotor according to one of the preceding claims, characterized in that the star disks (10) are each clamped against an end face of the rotor body (4) by a clamping sleeve (26) firmly connected to the rotor shaft (20).

9. Rotor according to one of the preceding claims, characterized in that a seal for sealing the connecting channels (15) and / or the distribution channel (25) is provided between the respective star disk (10) and the end face of the rotor body (4).

10. Electrically excited synchronous machine (2) with a rotor (1) according to one of the preceding claims.

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