Electric machine for a motor vehicle

Abstract

An electric machine (1) for a motor vehicle, comprising a temperature control device (2) designed for temperature control, in particular for cooling, at least one section of the electric machine (1), wherein the electric machine (1) has a laminate pack (4) with a plurality of laminations arranged one another in the axial direction of the electric machine (1), wherein the temperature control device (2) has at least one temperature control channel (3) extending at least sectionally through the laminate pack (4) in the axial direction, wherein a feed ring (7) defining a feed chamber (6) is provided in the axial direction adjacent to the laminate pack (4), which feed chamber (6) is connected to the temperature control channel (3) through which a temperature control medium can be conveyed, wherein the feed ring (7) has at least one opening on the side facing away from the laminate pack (4).

Description

[0001] The invention relates to an electric machine for a motor vehicle, comprising a temperature control device designed for temperature control, in particular for cooling, at least one section of the electric machine, wherein the electric machine has a laminate pack with a plurality of laminations arranged one another in the axial direction of the electric machine, wherein the temperature control device has at least one temperature control channel extending at least partially through the laminate pack in the axial direction, wherein a supply ring defining a supply chamber is provided in the axial direction adjacent to the laminate pack, which supply chamber is connected to the temperature control channel through which a temperature control medium can be conveyed.

[0002] Electrical machines of the type mentioned above, which have a temperature control device designed for temperature control, specifically cooling, of the electrical machine, are generally known from the prior art. A temperature control channel is typically routed through the stator's laminated core to dissipate heat from the laminations. To supply the temperature control fluid, which is guided in the temperature control channel, to the laminated core, at least one supply ring is usually provided at an axial end of the laminated core, i.e., at an end face of the stator. This supply ring defines a supply chamber from which the temperature control fluid is introduced into the temperature control channel. In other words, the supply chamber typically forms an annular space into which the temperature control fluid is fed. Within the supply chamber, the temperature control fluid is pressurized relative to the surroundings and is sealed off from the surroundings by the supply ring.

[0003] From the supply chamber, the cooling fluid enters the cooling channel through one or more inlet openings, allowing it to flow through the stator or the laminated core and exit, typically at the axial end faces. In this area, the cooling fluid is guided over the so-called "winding heads," i.e., the conductors exiting the laminated core, to cool them as well. After leaving the laminated core and flowing over the winding heads, the cooling fluid usually collects in a base area of ​​the housing, where a drain opening is provided. Since the supply ring or two supply rings are located at the axial end faces of the laminated core, there is usually no space for the drain opening there. Therefore, it is located on a radially extending wall of the housing or further away from the laminated core.

[0004] This can lead to a certain amount of the cooling fluid accumulating inside the housing until the drain opening is reached. Furthermore, during cornering or driving at an angle, the accelerations acting on the cooling fluid can cause its surface to tilt relative to the housing base or the normal. In an unfavorable scenario, this can lead to the cooling fluid being drawn into the gap between the stator and rotor, or it can wet rotating parts within the electric machine.

[0005] The invention is based on the objective of providing an improved electrical machine in which, in particular, the guidance of the temperature control medium is improved, and specifically, the penetration of temperature control medium into the gap space is better prevented.

[0006] The problem is solved by an electric machine with the features of claim 1. Advantageous embodiments are the subject of the dependent claims.

[0007] As described at the outset, the invention relates to an electric machine for a motor vehicle, which includes a temperature control device designed for temperature control, for example, cooling, of at least one section of the electric machine. The electric machine can specifically be configured as a traction drive, in particular an axle drive, of the motor vehicle. The electric machine has a laminated core in which a plurality of axially arranged laminations are accommodated. For the purposes of this application, the terms "axial direction," "radial direction," and "circumferential direction" are generally used with reference to a longitudinal axis of the electric machine, in particular an axis of rotation of the rotor of the electric machine.

[0008] The at least one temperature control channel of the temperature control device extends axially, at least partially, through the laminated core. Temperature control fluid is supplied to the channel via the supply ring, which defines the supply chamber from which the fluid can flow into the channel. In other words, the supply ring is arranged on the laminated core such that a supply chamber is formed between the laminated core, the supply ring, and optionally at least one wall of the housing. The supply ring seals the supply chamber from the remaining interior space of the electrical machine housing, particularly by means of at least one, and preferably two, seals. This allows the temperature control fluid to be pressurized within the supply chamber and, after exiting the temperature control channel, for example, after flowing over the winding heads, to be discharged without pressure.

[0009] The invention is based on the finding that the feed ring has at least one opening on the side facing away from the lamella stack. As described, the feed ring is arranged on the lamella stack such that an inlet for the temperature control channel in the lamella stack communicates with the feed chamber, which is bounded by the feed ring. On the opposite side, i.e., the side of the feed ring that points axially away from the lamella stack, the feed ring has at least one opening. Advantageously, the opening can be arranged, or openings can be provided on the feed ring, such that they can communicate with a drain opening of the temperature control circuit.In other words, this design allows the feed ring to be positioned directly on the fin stack while still placing the drain opening as close as possible to the fin stack, thus improving the drainage of the cooling fluid in the base area of ​​the electric motor. If the feed ring were designed without the opening, it would obstruct the base area at that point, preventing the installation of a drain opening there. By including the opening, this constraint is eliminated, allowing the drain opening to be positioned significantly closer to the fin stack, thereby improving the drainage of the cooling fluid and reducing the amount of accumulated cooling fluid in this area.

[0010] The electric machine can be further developed such that the feed ring has at least one tooth projecting axially from a base body of the feed ring on the side facing away from the lamellar pack. The tooth can thus project from the base body in such a way that the latter is surrounded circumferentially by the at least one opening. For example, two radially opposing teeth or any number of teeth can be provided, with gaps formed as openings between them. This ensures that the feed ring can be held in its axial position by the at least one tooth, for example, supported against a housing wall, while the opening, namely the at least one gap, can still be designed to allow the cooling medium to drain into the drain opening.For example, teeth and gaps can alternate in the circumferential direction. The base body can be understood, in particular, as that section of the feed ring which defines the feed chamber. Receptacles for sealing elements, in particular a radial seal and an axial seal, are provided on the base body.

[0011] In the electric machine, it can further be provided that at least one tooth is shorter in the circumferential direction than a drain opening of the temperature control device. According to the described embodiment, the circumferential extent of the tooth is dimensioned such that it is smaller than the drain opening of the temperature control device. In other words, the tooth can be arranged in any circumferential orientation within the electric machine, since even when the tooth is positioned at the same circumferential location as the drain opening, it cannot completely cover the drain opening. This offers the particular advantage that the feed ring can be mounted in the electric machine without a fixed circumferential orientation. In the worst-case scenario, the at least one tooth lies within the area of ​​the drain opening and partially obscures it.However, since the drain opening is larger than the tooth, especially in the circumferential direction, the drain opening is not completely covered and the drainage of the tempering agent is not significantly impeded.

[0012] In a further embodiment of the electric machine, at least one gap formed between two teeth can be longer in the circumferential direction than the teeth themselves. Therefore, the feed ring can be positioned arbitrarily within the electric machine, since even with an unfavorable orientation, as previously described, a tooth located in the area of ​​the discharge opening cannot completely obstruct it. By making the gap longer in the circumferential direction than the teeth, it can also be achieved that the gap is positioned so that it fully communicates with the discharge opening; that is, the feed ring can be positioned so that the discharge opening fully communicates with the gap and is thus not obstructed by a tooth.

[0013] In a further embodiment of the electric machine, it can be provided that the cooling fluid collected between a drain opening and an edge defining a gap between the rotor and stator chambers of the electric machine falls below the line connecting the edge of the drain opening and the edge. Accordingly, cooling fluid that can collect in the base region of the electric machine, particularly in the area of ​​the feed ring, can always fall below the line connecting the edge of the drain opening and the described edge, especially regardless of lateral accelerations or up to a defined lateral acceleration. This means that even during inclined travel orDuring cornering, where increased lateral accelerations occur and act on the cooling fluid, only as much cooling fluid can be absorbed between the drain opening and the edge as is possible, so that it does not exceed the line connecting the drain opening and the edge. Excess cooling fluid rises above the edge of the drain opening and is thus discharged through it. In other words, the drain opening can be positioned so close to the fin stack that the amount of cooling fluid that can collect between the drain opening and the fin stack is insufficient to rise above the edge and penetrate the gap.

[0014] As previously described, the feed ring can have at least one tooth that projects axially from the base of the tooth, specifically away from the laminated core. In a further development of the described embodiment, the at least one tooth can be configured to position the feed ring axially, particularly between a housing wall of the electrical machine and the laminated core. This allows the feed ring with the tooth to be in contact with another component of the electrical machine, for example, a housing wall, and thus correctly position the feed ring axially. Specifically, by contacting the tooth with the housing wall, the feed ring can be preloaded axially against the axial end face of the stator, i.e., the end face of the laminated core. The seal, which is located on the feed ring in this area, can then be...The space provided between the feed ring and the lamellar pack can thus be pre-tensioned in a defined manner, thereby improving the sealing effect. Specifically, this allows the individual components of the electric machine to be assembled from the same side, so that the feed ring, the lamellar pack, and other components can be inserted axially into the housing of the electric machine from the same side. Advantageously, this eliminates the need for additional mounting elements to fix the feed ring in its axial position.

[0015] In a further embodiment, the electric machine can have only one feed ring on one side of the laminated core. As described above, concepts for electric machines are known in which a feed ring is formed on each side of the laminated core, for example, as a double-sided feed or as a feed and outlet. In the embodiment described here, the electric machine has only a single feed ring, which is arranged on one of the two axial end faces of the laminated core, i.e., one of the end faces of the stator. Accordingly, no feed ring is provided on the side of the laminated core opposite the feed ring; instead, the cooling medium can exit the laminated core in this area and, for example, be guided via the winding heads to the bottom of the housing.In this area, the drain opening can be positioned particularly close to the lamella pack, as no feed ring is required in this area.

[0016] In other words, the temperature control fluid can be fed from the single feed ring and its feed chamber into the fin stack. There, the temperature control channel can split, with a first part leading back to the axial end face of the fin stack where the feed ring is located, and a second part of the temperature control channel leading to the opposite side. This ensures that the temperature control fluid is guided through the entire fin stack and a defined portion of it is discharged from both sides of the fin stack, for example, via the winding heads to the bottom of the housing.

[0017] In addition to the described electric machine, the invention relates to an electric axle drive comprising a described electric machine. Furthermore, the invention relates to a drive train comprising such a described electric machine and / or a described electric axle drive. Finally, the invention relates to a motor vehicle comprising a described electric machine and / or a described drive train and / or a described electric axle drive.

[0018] All the advantages, details and features described in relation to the electric machine are fully transferable to the electric axle drive, the drive train and the motor vehicle.

[0019] The invention is explained below with reference to exemplary embodiments and the figures. The figures are schematic representations and show: Fig. 1. A schematic representation of a section of an electrical machine according to an exemplary embodiment; Fig. 2 a schematic representation of a section of an electrical machine in the area of ​​a feed ring; Fig. 3. A schematic representation of a section of an electric machine in the area of ​​a drain opening; and Fig. 4 an isolated schematic representation of a feed ring.

[0020] Fig. Figure 1 shows an electric machine 1, for example, the electric machine 1 of a motor vehicle (not shown in detail). The electric machine 1 can be a traction drive of the motor vehicle, for example, a component of an electric axle drive or an electric drivetrain of the motor vehicle. The electric machine 1 has a temperature control device 2, which is designed for temperature control, for example, for cooling, of the electric machine 1. The temperature control device 2 has a temperature control channel 3, which extends schematically through a laminated core 4 of a stator 5 of the electric machine 1.

[0021] The temperature control channel 3 is schematically represented by arrows, and is supplied with temperature control fluid from a supply chamber 6, which is bounded by a supply ring 7. The supply chamber 6 can, for example, be designed as an annular space, with several inlets for temperature control channels 3, or for the temperature control channel 3 itself, distributed circumferentially within the supply chamber 6. The supply chamber 6 is connected to a feed through which the temperature control fluid is introduced into the supply chamber 6.

[0022] The feed ring 7 has a base body 8, which essentially defines and seals the feed chamber 6. Two sealing elements 9 and 10 are shown schematically on the base body 8. These seal the feed chamber 6 from the rest of the interior of the housing 11 of the electric machine 1, for example, axially and radially. The feed chamber 6, in turn, has an inlet through which the temperature control fluid can be introduced. One or more inlets can be provided, for example, at an upper end of the housing 11.

[0023] The feed ring 7 has at least one tooth 12 on the side opposite the lamellar pack 4 in the axial direction, which distances the feed ring 7 from a housing wall of the housing 11. In particular, the feed ring 7 has, as for example in Fig. Figure 4 shows several teeth 12 arranged circumferentially, alternating with gaps 13. The gaps 13 form circumferential openings in the feed ring 7. As shown in Fig. As shown in Figure 1, for example, in the lower part of the housing 11 of the electric machine 1, there is such a gap 13 in communication with a drain opening 14 in the housing 11. In other words, the drain opening 14 is not covered by a tooth 12, but communicates with a gap 13, so that cooling medium leaving the cooling channel 3 can be discharged through the drain opening 14.

[0024] For example, in Fig. As shown in Figures 2-4, the circumferential extent of the gaps 13 is greater, wider, or longer than that of the teeth 12. Specifically, as for example... Fig. Since the length of the gaps 13 is longer in the circumferential direction than the drainage opening 14, each tooth 12 is shorter in the circumferential direction than the drainage opening 14. Regardless of the circumferential orientation of the feed ring 7, the drainage opening 14 is therefore not obscured by a tooth 12, even if the feed ring 7 is positioned directly above the drainage opening 14, because the drainage opening 14 extends further in the circumferential direction than the length of the tooth 12. However, since the length of the gaps 13 in the circumferential direction is longer than that of the teeth 12, as also described in Fig. As shown in Figure 3, the feed ring 7 is usually aligned so that a gap 13 is located above the drain opening 14, so that the tempering agent can drain freely in both cases.

[0025] In Fig. Figure 1 also schematically shows a connecting line 15 that connects an edge of the drain opening 14 with an edge 16 of a gap between the stator 5 and a rotor 17 of the electric machine 1. In the embodiment shown, the drain opening 14 can be positioned so close to the laminated core 4 that any cooling medium that collects in the area between the drain opening 14 and the edge 16 cannot penetrate the gap, even under lateral acceleration.

[0026] How Fig. Since the supply ring 7 can be removed from the fin stack 4, the space on the side of the fin stack 4 opposite the supply ring 7 is free of supply rings 7. This means that no supply ring 7 needs to be provided in this area, so that the drain opening 14' there can be arranged very close to the fin stack 4, allowing the temperature control fluid to drain freely there as well.

[0027] The advantages, details, and features shown in the individual embodiments with reference to the individual figures can be combined, interchanged, and transferred to one another as desired. As described, the electric machine 1 can be a component of an electric axle drive, a drive train, or a motor vehicle, so that all advantages, details, and features are also transferable to these applications. Reference sign 1 Electric Machine 2 Temperature control device 3 temperature control channels 4 slat package 5 Stator 6 Feed chamber 7 Feed ring 8 basic shapes 9, 10 Sealing element 11 cases 12 teeth 13 Gap 14, 14' Drainage opening 15 connecting line 16 edge 17 Rotor

Claims

[1] An electric machine (1) for a motor vehicle, comprising a temperature control device (2) designed for temperature control, in particular for cooling, of at least one section of the electric machine (1), wherein the electric machine (1) has a plate pack (4) with a plurality of plates arranged next to one another in the axial direction of the electric machine (1), wherein the temperature control device (2) has at least one temperature control channel (3) extending at least partially through the plate pack (4) in the axial direction, wherein a feed ring (7) delimiting a feed space (6) is provided adjacent to the plate pack (4) in the axial direction, which feed space (6) is connected to the temperature control channel (3) through which a temperature control medium can be conveyed, characterized by that the feed ring (7) has at least one opening on the side facing away from the disk pack (4). [2] Electrical machine (1) according to claim 1, characterized bythat the feed ring (7) has, on the side facing away from the disk pack (4), at least one tooth (12) projecting in the axial direction from a base body (8) of the feed ring (7). [3] Electrical machine (1) according to claim 2, characterized by that the at least one tooth (12) is shorter in the circumferential direction than a drain opening (14, 14') of the tempering device (2). [4] Electrical machine (1) according to claim 2 or 3, characterized by that at least one gap (13) formed between two teeth (12) is longer in the circumferential direction than the teeth (12). [5] Electrical machine (1) according to one of the preceding claims, characterized bythat tempering medium received between a drain opening (14, 14') and an edge (16) defining a gap between the rotor space and the stator space of the electrical machine (1) falls below a connecting line (15) between an edge of the drain opening (14, 14') and the edge (16). [6] Electrical machine (1) according to one of the preceding claims, characterized by that the at least one tooth (12) positions the feed ring (7) in the axial direction, in particular between a housing wall of the electrical machine (1) and the disk pack (4). [7] Electrical machine (1) according to one of the preceding claims, characterized by that the electrical machine (1) has only one feed ring (7) on one side of the disk pack (4). [8] Electric axle drive comprising an electric machine (1) according to one of the preceding claims. [9] Drive train comprising an electric machine (1) according to one of claims 1 to 7 and / or an electric axle drive according to the preceding claim. [10] Motor vehicle, comprising an electric machine (1) according to one of claims 1 to 7 and / or a drive train according to the preceding claim and / or an electric axle drive according to claim 8.

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