DE102018104131A1 - Cooling arrangement for a rotor, rotor with the cooling arrangement and electrical axis with the rotor and / or the cooling arrangement - Google Patents

Abstract

The performance and efficiency of an electric machine depends to a large extent on thermal boundary conditions. This results in the need to provide sufficient cooling for electrical machines.
For this purpose, a cooling arrangement 1 for a rotor 9 of an electric motor of a vehicle, with a rotor shaft 10, wherein the rotor shaft 10 is formed as a hollow shaft and defines a rotation axis D, with a cooling pipe 2 for coolant supply, wherein the cooling tube 2 coaxial with respect to the Rotary axis D is disposed in the rotor shaft 10, wherein between an outer periphery of the cooling tube 2 and an inner periphery of the rotor shaft 10, a gap 11 is formed for receiving a coolant, proposed, wherein the cooling tube 2 has at least one inlet channel 13 and at least one return channel 14, wherein the inlet channel 13 and the return channel 14 are fluidically connected to the intermediate space 11, wherein a flow path S of the coolant from the inlet channel 13 via the intermediate space 11 to the return channel 14 extends.

Description

The invention relates to a cooling arrangement for a rotor of an electric motor of a vehicle with the features of the preamble of claim 1. Furthermore, the invention relates to a rotor with the cooling arrangement and an electrical axis for a vehicle with the rotor and / or the cooling arrangement.

The performance and efficiency of an electric machine depends i.a. highly dependent on thermal boundary conditions. This results in the need to provide sufficient cooling for electrical machines. For this purpose, the resulting waste heat must be dissipated as best as possible, with the removal of the resulting waste heat is usually done with cooling concepts that dissipate the heat generated at the stator and on the winding heads. However, part of the heat also flows into the rotor laminations and the rotor shaft. It is therefore known to dissipate the heat generated at the rotor by means of an active liquid cooling.

The publication DE 10 2014 204 133 A1 , which probably describes the closest prior art, discloses an electric machine having a rotor, a stator and a speed sensor. The rotor comprises a hollow shaft. On the rotor, a tube is mounted co-rotating, which projects into an interior of the hollow shaft, so that a cooling fluid can be flowed through the tube into the interior. At a projecting over the hollow shaft portion of the tube, a speed sensor is mounted. In the proposed electric machine, which may be configured, for example, as an asynchronous, heat generated in the rotor can be dissipated efficiently via a cooling of the hollow shaft.

It is an object of the present invention to provide a cooling arrangement for a rotor, which is characterized by an improved cooling performance. Furthermore, it is an object of the invention to propose a corresponding rotor and an electrical axis with the cooling arrangement.

This object is achieved by a cooling arrangement having the features of claim 1, a rotor having the features of claim 9 and an electrical axis having the features of claim 10. Preferred or advantageous embodiments of the invention will become apparent from the dependent claims, the following description and the accompanying drawings.

The invention relates to a cooling arrangement which is designed and / or suitable for a rotor of an electric motor of a vehicle. In particular, the cooling arrangement serves to cool the rotor. For this purpose, the cooling arrangement is preferably in thermal contact with the rotor. Optionally, the cooling arrangement forms part of the electric motor. Preferably, the electric motor has a stator as a fixed part of the electric motor. In particular, the electric motor, in particular the rotor, is designed as an internal rotor, wherein the rotor is arranged in the stator.

The cooling arrangement has a rotor shaft, wherein the rotor shaft is formed as a hollow shaft. The rotor shaft is used in particular for receiving a rotor core. The rotor shaft preferably defines an axis of rotation with its axis of rotation and / or axis of symmetry. During operation of the electric motor, the rotor shaft preferably rotates about the axis of rotation, the stator remaining stationary.

The cooling arrangement has a cooling tube, which is designed and / or suitable for supplying coolant. The cooling tube is preferably made in one piece, in particular in a continuous production process. Specifically, the cooling tube is manufactured by an extrusion process or an extrusion process. Preferably, the cooling tube is made of aluminum or plastic.

The cooling tube is arranged coaxially in the rotor shaft with respect to the axis of rotation. In principle, the cooling tube can be arranged at least in sections in the rotor shaft. Particularly preferably, however, the cooling tube is arranged completely within the rotor shaft. The cooling tube preferably extends in the axial direction with respect to the axis of rotation over at least the entire axial length of the rotor core.

Between an outer periphery of the cooling tube and an inner periphery of the rotor shaft, a space for receiving a coolant is formed. In particular, the outer diameter of the cooling tube is smaller than an inner diameter of the rotor shaft, so that an annular space is formed as the gap. Preferably, the cooling tube is used to supply and / or discharge of the coolant in the intermediate space. In particular, the gap in the circumferential direction and / or in the axial direction with respect to the axis of rotation on a constant gap. For example, the gap dimension is more than 0.1 mm, preferably more than 1 mm, in particular more than 3 mm. Particularly preferably, the coolant is designed as a cooling liquid.

In the context of the invention it is proposed that the cooling tube has at least or exactly one inlet channel and at least or exactly one return channel. In particular, the inlet channel and / or the return channel extend in the axial direction with respect to the axis of rotation within the tube wall of the cooling tube. Preferred are the Inlet channel and / or the return channel formed by the continuous manufacturing process. In particular, the inlet channel and / or the return channel extend over the entire axial length of the cooling tube, so that the cooling tube is completely penetrated by the inlet channel and the return channel. In particular, the cooling tube can have more than two, in particular more than four of the inlet channels and / or the return channels. Particularly preferably, the cooling tube has exactly two of the inlet channels and exactly two of the return channels.

The inlet channel and the return channel are fluidically connected to the intermediate space, wherein a flow path of the coolant extends from the inlet channel via the intermediate space to the return channel. In particular, the coolant flows along the flow path, whereby a heat dissipation of the heat emitted to the rotor shaft heat takes place. Particularly preferably, a closed cooling circuit is formed by the flow path. Preferably, the gap, in particular during operation of the electric motor, completely filled with coolant. Thus, the coolant is permanently in direct contact with the rotor shaft.

Optionally, in addition, the cooling arrangement may have a conveying device, wherein the inlet channel and / or the return channel are connected to the conveying device, in particular fluidically. Preferably, an active cooling circuit is formed by the conveying device, wherein the coolant circulates along the flow path.

The advantage of the invention is that an improved coolant flow is made possible by the flow path according to the invention. In particular, can be cooled over a large area by the complete filling of the gap with the coolant, the rotor shaft, in particular in the region of the rotor core. Thus, a particularly simple and at the same time efficient cooling of the rotor shaft can be implemented. By the cooling tube according to the invention a particularly easy to produce coolant guide is implemented, which is also inexpensive to manufacture. The arrangement of the cooling tube within the rotor shaft, a space-saving design of the cooling arrangement is also proposed, whereby the space requirement of the cooling tube is very low.

In a preferred embodiment of the invention, the cooling tube has at least or exactly one inlet inlet and one inlet outlet, wherein the inlet inlet and the inlet outlet are connected to one another via the inlet channel. In particular, therefore, a first flow path section extends from the inlet inlet via the inlet channel to the inlet outlet. In particular, a separate inlet inlet and / or inlet outlet is assigned to each of the inlet channels. Alternatively, a common inlet inlet and / or inlet outlet is assigned to all inlet channels.

Alternatively or optionally additionally, the cooling tube has at least or exactly a return inlet and a return outlet, the return inlet and the return outlet being connected to one another via the return channel. In particular, therefore, a second flow path section extends from the return inlet via the return channel to the return outlet. In particular, each of the return channels is associated with a separate return inlet and / or return outlet. Alternatively, all return channels are assigned a common return inlet and / or return outlet. Preferably, a unidirectional flow pattern is defined by the two flow path sections.

The inlet channel and the return channel run fluidically separated from each other within the cooling tube. In particular, the cooling tube has an inner shell section and an outer shell section. In this case, the inner shell portion carries an inner surface of the cooling tube and the outer shell portion an outer surface of the cooling tube. Optionally additionally, the cooling tube has a plurality of wall sections, wherein the wall sections are preferably arranged in the radial direction with respect to the axis of rotation between the inner shell section and the outer shell section. Particularly preferably, the wall sections extend in the axial direction with respect to the axis of rotation parallel to each other.

The interaction of the wall sections, the inner shell section and the outer shell section, the inlet channel and the return channel are formed, wherein the or the inlet channels and the or the return channels are fluidly separated from each other by the wall sections. Particularly preferably, the inlet channel is arranged in a first half of the cooling tube and the return channel in a second half of the cooling tube. In particular, all the inlet channels in the first half and all return channels in the second half of the cooling tube are arranged.

In a specific embodiment, it is provided that the inlet inlet and the return outlet are arranged with respect to the axis of rotation on an axial end face of the cooling tube. In particular, each of the channels is designed as a passage opening, wherein the inlet inlet and / or the outlet outlet is defined by the inlet areas or the outlet area of the passage opening.

In principle, the inlet inlet at one axial end face and the return outlet at the be arranged on the other axial end side. Preferably, however, the inlet inlet, in particular all inlet openings, and the return outlet, in particular all return outlets, are arranged on a common axial end face of the cooling tube.

Alternatively or optionally in addition, the inlet outlet and the return inlet are arranged on the outer circumference of the cooling tube. In particular, the inlet outlet and / or the return outlet are formed as an opening made in the cooling tube, in particular an opening and / or a bore. Particularly preferably, the inlet outlet and the return inlet are introduced into the outer shell section. In principle, the inlet outlet and the return inlet can be arranged diametrically opposite one another in the axial direction with respect to the axis of rotation. Particularly preferably, however, the inlet outlet and the return inlet in the axial direction with respect to the axis of rotation are offset from one another.

In a further embodiment, the cooling arrangement has a first and a second sealing device for sealing the intermediate space. In particular, the two sealing devices seal the gap fluid-tight, so that the gap is sealed from the environment. Particularly preferably, the sealing of the intermediate space takes place through the two sealing devices within the rotor shaft.

The intermediate space is limited in an axial direction with respect to the axis of rotation by the first sealing device and in an axial opposite direction by the second sealing device. In particular, the first and / or the second sealing device are designed as a shaft sealing ring, preferably a radial shaft sealing ring. In particular, the first and / or the second sealing device on the one hand with the cooling tube, preferably rotatably connected. On the other hand, the first and / or the second sealing device preferably abuts with a sealing lip in the radial direction with respect to the axis of rotation on the inner circumference of the rotor shaft.

In a further embodiment, the cooling arrangement has an end piece. Preferably, the end piece is designed as a rotationally symmetrical rotary part, wherein the axis of rotation forms an axis of symmetry of the rotary part. Particularly preferably, the end piece is arranged coaxially to the axis of rotation.

The end piece is connected at the end in the axial direction with respect to the axis of rotation with the cooling tube, in particular inserted into the cooling tube. Specifically, the end piece is formed as a stepped hollow shaft, wherein the end piece extends the cooling tube in the axial direction with respect to the axis of rotation. The tail is preferably non-rotatable, in particular non-positively and / or positively connected to the cooling tube. The tail can for example be pressed into the end of the cooling tube. Particularly preferably, the end piece has a connection section for this purpose. The connecting portion is preferably formed as a hollow cylindrical approach. In an assembled state, the connecting portion abuts with its cylinder jacket outer surface in the radial direction with respect to the axis of rotation on the inner jacket portion of the cooling tube.

The inlet channel and / or return channel are delimited by the end piece in the axial direction with respect to the axis of rotation. Preferably, the end piece on a contact portion, wherein the abutment portion abuts in the axial direction on the axial end side of the cooling tube. The abutment portion preferably connects directly to the connecting portion, wherein the abutment portion is offset from the connecting portion. Preferably, the abutment portion has a larger outer diameter than the connecting portion. In particular, the abutment portion is formed as a radially outwardly directed flange-like widening. Particular preference is given to the outer diameter of the abutment portion is greater than or equal to the outer diameter of the cooling tube. Preferably, the inlet channel and / or return channel are limited by an annular surface of the contact portion, wherein the annular surface extends in relation to the axis of rotation in a radial plane.

It is preferably provided that the cooling arrangement has at least or exactly one sealing means for sealing the flow channel and / or the return channel. Preferably, the sealing means serves to seal the flow channel and / or the return channel relative to the end piece, in particular of the contact section. The sealing means is preferably arranged in the axial direction with respect to the axis of rotation between the cooling tube and the end piece, so that the cooling tube rests against the abutment portion via the sealing means.

In a concrete implementation, the cooling arrangement has at least or exactly one bearing device for mounting the cooling tube relative to the rotor shaft. In particular, the bearing device serves for the axial and / or radial mounting of the radiator tube. Preferably, the bearing device is designed as a rolling bearing, in particular a ball bearing. Thus, the rotor shaft is rotatably mounted on the cooling tube, wherein the cooling tube preferably remains stationary.

The end piece has a bearing receptacle for receiving the bearing device, wherein the bearing device in the radial direction with respect to the axis of rotation on the one hand to the bearing seat and on the other hand supported on the inner circumference of the rotor shaft. In particular, the bearing device on the one hand a tight fit on the bearing receiver and on the other hand on the inner circumference of the rotor shaft. In particular, the bearing receptacle is formed as a further hollow cylindrical projection of the end piece opposite the connection section in the axial direction. Preferably, the bearing device is arranged outside the intermediate space.

In a further concretization of the invention it is provided that the cooling arrangement has a bearing plate, wherein the bearing plate is connected to the cooling tube. In particular, the bearing plate is arranged in the axial direction with respect to the axis of rotation opposite to the end piece on the other axial end side of the cooling tube. Optionally, the rotor shaft can be mounted on the bearing plate via a further bearing device. Preferably, the end shield is attached to the end of the cooling tube, in particular sealing. Particularly preferably, the bearing plate is arranged coaxially to the axis of rotation. The bearing plate can be positively and / or non-positively connected to the cooling tube.

Particularly preferably, the cooling arrangement has a further sealing means, wherein the further sealing means is designed and / or suitable for sealing the cooling tube relative to the end shield. The further sealing means is preferably arranged in the axial direction with respect to the axis of rotation between the bearing plate and the cooling tube, so that the cooling tube rests on the bearing plate via the further sealing means. In particular, the sealing means and / or the further sealing means are formed as a flat gasket, preferably as a head gasket.

The end shield has a further inlet channel and a further return channel. In particular, the further inflow channel and the further return channel can each be formed by at least one bore. Preferably, the further inlet channel and the further return channel run continuously within the bearing plate. Particularly preferably, the further inlet channel and the further return channel within the bearing plate are fluidly separated from each other. The further inlet channel and / or the further return channel can be connected to the conveying device.

The further inlet channel of the bearing plate is fluidically with the inlet channel of the cooling tube and the further return channel of the bearing plate is connected to the return channel of the cooling tube. Particularly preferably, the further inlet channel is connected to the inlet inlet and / or the further return channel to the return outlet. Preferably, the further sealing means has a plurality of free areas, so that preferably the inflow channel or the return channel is in each case fluidically connected via at least one of the free areas to the further inflow channel or the further return channel. In particular, the free areas have the same cross-sectional shape as the associated inlet inlet or return outlet.

Particularly preferably, the bearing plate has a flange portion and a cylinder portion, wherein the cylinder portion in the axial direction with respect to the axis of rotation directly adjoins the flange portion. The cylinder section preferably has an insertion region for the cooling tube on the front side, wherein the cooling tube is partially inserted in the insertion region. In particular, the insertion region can be formed by an annular groove which preferably extends in the direction of rotation with respect to the axis of rotation or is introduced into the cylinder portion. The further inlet channel and / or the further return channel terminate in particular in the groove, wherein the further inlet channel communicates via the insertion region with the inlet channel and / or the further return channel via the insertion region with the return channel.

In a constructive implementation, the end piece has a sealing receptacle for receiving the first sealing device. In particular, the sealing receptacle is arranged in the axial direction with respect to the axis of rotation between the abutment portion and the bearing receptacle. The sealing receptacle is preferably offset from the contact section and / or the bearing receptacle. The first sealing device is supported in the radial direction with respect to the axis of rotation on the one hand on the sealing seat and on the other hand on the inner circumference of the rotor shaft. The first sealing device preferably has a tight fit on the sealing receptacle.

Alternatively or optionally additionally, the bearing plate has a further sealing receptacle for receiving the second sealing device. In particular, the further sealing receptacle is formed by a cylinder jacket outer surface of the cylinder section. The second sealing device is supported in the radial direction with respect to the axis of rotation on the one hand on the other sealing seat and on the other hand on the inner circumference of the rotor shaft. The second sealing device preferably has a tight fit on the further sealing receptacle.

Another object of the invention relates to a rotor with the cooling arrangement according to one of the preceding claims or as previously described. The rotor has the rotor core, wherein the rotor core is arranged on the rotor shaft. The rotor core can for example consist of a plurality of rotor laminations be formed. In particular, the rotor core is rotatably connected to the rotor shaft.

The gap extends in the axial direction with respect to the axis of rotation in the region of the rotor core, so that the rotor core is cooled by the cooling arrangement. In particular, the gap extends in the axial direction with respect to the axis of rotation over at least or just the entire axial length of the rotor core. Particularly preferably, the axial length is defined by the axial distance between the two sealing devices.

Another object of the invention relates to an electrical axis, which is designed and / or suitable for a vehicle. The axle preferably has the rotor with the cooling arrangement or the cooling arrangement, as already described above. Preferably, the vehicle is designed as an electric vehicle or a hybrid vehicle.

• 1 in einer Explosionsdarstellung eine Kühlanordnung für einen Rotor eines Elektromotors als ein Ausführungsbeispiel der Erfindung;
• 2 in einer Schnittdarstellung den Rotor mit der Kühlanordnung aus der 1;
• 3 in gleicher Darstellung wie 2 die Kühlanordnung mit einem schematisch angedeuteten Strömungsweg für ein Kühlmittel;
• 4 in einer dreidimensionalen Darstellung die Kühlanordnung mit dem Strömungsweg aus 3.

Further features, advantages and effects of the invention will become apparent from the following description of preferred embodiments of the invention. Showing:

• 1 in an exploded view, a cooling arrangement for a rotor of an electric motor as an embodiment of the invention;
• 2 in a sectional view of the rotor with the cooling arrangement of the 1 ;
• 3 in the same representation as 2 the cooling arrangement with a schematically indicated flow path for a coolant;
• 4 in a three-dimensional representation of the cooling arrangement with the flow path 3 ,

1 shows an exploded view of a cooling arrangement 1 , which is designed and / or suitable for cooling an electric motor. For example, the cooling arrangement 1 arranged in an electrical axis of a vehicle. The cooling arrangement 1 has a cooling tube 2 on, with the cooling tube 2 one end with an end piece 3 and on the other hand with a bearing plate 4 connected is. The cooling tube 2 is designed for example as a double-walled tube, wherein the cooling tube 2 in particular serves to guide the coolant. The cooling tube 2 extends in the axial direction with respect to a rotation axis D , where the tail 3 and the bearing plate 4 coaxial with the axis of rotation D are arranged.

Furthermore, the cooling arrangement 1 a first and a second sealing device 5a . b , a first and a second sealant 6a . b , as a sealant and another sealant, and a bearing device 7 on. The two sealing devices 5a . b , the two sealants 6a . b as well as the storage facility 7 are coaxial with the axis of rotation D arranged. The two sealants 6a . b are each formed as a flat gasket, in particular a head gasket. The two sealing devices 5a . b are each formed as a radial shaft seal. The tail 3 is formed as a hollow cylindrical rotary member, wherein the tail 3 the cooling tube 3 in the axial direction with respect to the axis of rotation D extended.

The tail 3 has a connection section 3a on, with the tail 3 over the connecting section 3a end into the cooling tube 2 is inserted. The connecting section 3a is designed as a hollow cylindrical approach. The tail 3 has a plant section 3b on, with the investment section 3b directly to the connecting section 3a followed. The connecting section 3a is to the investment section 3b discontinued, with the abutment section 3b as one in the radial direction with respect to the axis of rotation D flange-like widening is formed.

Furthermore, the tail has 3 a seal 3c for receiving the first sealing device 5a as well as a bearing receiver 3d for receiving the storage facility 7 on. The sealing intake 3c is between the plant section 3b and the camp admission 3d arranged, with the sealing receptacle 3c in the axial direction with respect to the axis of rotation D directly to the plant section 3c connects and deducted to this. The camp recording 3d forms together with the sealing receptacle 3c a hollow cylindrical approach, the bearing support 3d to the sealing intake 3c is discontinued.

During assembly, the first sealant 6a on the one hand in the axial direction with respect to the axis of rotation D on the connecting section 3a and on the other hand, the first sealing device 5a on the sealing seat 3c as well as the storage facility 7 on the bearing receiver 3d postponed. Subsequently, the tail is 3 with its connecting section 3a together with the first sealant 6a so far into the cooling tube 3 pushed in until the abutment section 3a frontally on the cooling tube 3 is applied. This is the first sealant 6a in the axial direction with respect to the axis of rotation D between the cooling tube 3 and the investment section 3b arranged so that the cooling tube 2 in the axial direction with respect to the axis of rotation D about the first sealant 6a at the plant section 3b is applied. Thus, the first sealant is used 6a for sealing the cooling pipe 2 opposite the tail 3 , in particular its contact section 3b ,

The bearing plate 4 has a flange portion 4a and a cylinder section 4b on, with the cylinder section 4b in the axial direction in Reference to the axis of rotation D to the flange section 4a followed. The cooling tube 2 For example, in the cylinder section 4b be plugged in. The flange section 4a is opposite the cylinder section 4b as one with respect to the axis of rotation D formed radially outwardly directed flange. The bearing plate 4 has a central bore which is coaxial with the axis of rotation D is arranged and the bearing plate 4 interspersed in the axial direction.

The cylinder section 4b has another seal 8th for receiving the second sealing device 5b on, wherein during assembly, the second sealing device 5b on the further sealing recording 8th is postponed. For example, during assembly of the cooling arrangement 1 first the second sealing device 5b on the further sealing recording 8th postponed and then the bearing plate 4 with the cooling pipe 2 connected. The second sealant 6b is in the axial direction with respect to the axis of rotation D between the cylinder section 4b and the cooling tube 2 arranged so that the cooling tube 2 in the axial direction with respect to the axis of rotation D over the second sealant 6b at the cylinder portion 4b is present or recorded in this.

2 shows in a sectional view along the axis of rotation D a rotor 9 the electric motor with the cooling arrangement 1 out 1 , The rotor 9 has a rotor shaft 10 on, with the rotor shaft 10 another component of the cooling arrangement 1 forms. Furthermore, the rotor has 9 a rotor core 12 on, with the rotor core 12 coaxial with the axis of rotation D on the rotor shaft 10 is arranged. For example, the rotor core 12 be formed by a plurality of laminated cores or windings.

The rotor shaft 10 is formed as a hollow shaft, wherein the rotor shaft 10 with its axis of rotation, the axis of rotation D Are defined. The cooling tube 2 is coaxial with the axis of rotation D within the rotor shaft 10 disposed between an outer periphery of the cooling tube 2 and an inner circumference of the rotor shaft 10 a gap 11 is formed. The rotor shaft 10 and the cooling tube 2 are spaced apart in the radial direction, so that the gap 11 is formed. In particular, the gap 11 designed as an annulus.

In the axial direction with respect to the axis of rotation D is the gap 11 on both sides by the first and the second sealing device 5a . b limited. Here is the first sealing device 5a on the one hand rotatably on the sealing seat 3c arranged and on the other hand in the radial direction with respect to the axis of rotation D with a sealing lip on the inner circumference of the rotor shaft 10 on. The second sealing device 5b on the one hand rotatably on the other sealing receptacle 8th arranged and on the other hand in the radial direction with respect to the axis of rotation D with a sealing lip on the inner circumference of the rotor shaft 10 on. Thus, the gap 11 through the two sealing devices 5a . b sealed against the environment fluid-tight. The gap 11 extends in axial seal with respect to the axis of rotation D over the entire axial width of the rotor core 12 , where the rotor core 12 in the axial direction with respect to the axis of rotation D seen between the two sealing devices 5a , b on the rotor shaft 10 is arranged.

The cooling tube 2 has an outer shell portion 2a and an inner wall portion 2 B on, wherein the outer shell portion 2a a radial outer surface of the cooling tube 2 and the inner shell portion 2 B a radial inner surface of the cooling tube 2 forms. The cooling tube 2 has at least one inlet channel 13 and a return channel 14 on, with the inlet channel 13 and the return channel 14 in the axial direction with respect to the axis of rotation D between the two jacket sections 2a . b extends. For example, the inlet channel 13 and the return channel 14 formed as through holes, so that the cooling tube 2 in the axial direction with respect to the axis of rotation D through the channels 13 . 14 is interspersed. The inlet channel 13 and the return channel 14 are inside the cooling tube 2 fluidically separated from each other.

The cooling tube 2 has a inlet inlet 13a and an inlet outlet 13b and a return entry 14a and a return outlet 14b on. The inlet inlet 13a is via the inlet channel 13 with the inlet outlet 13b and the return entry 14a is via the return channel 14 with the return outlet 14b fluidically connected. The inlet outlet 13b and the return entry 14b are with the gap 11 fluidically connected. These are the inlet outlet 13b and the return entry 14b within the space 11 in the outer shell section 2a brought in. Thus, the inlet outlet 13b and the return entry 14a or the inlet channel 13 and the return channel 14 fluidically over the gap 11 connected with each other.

For example, the inlet channel 13 and the return channel 14 arranged diametrically opposite each other, wherein the inlet channel 13 in a first half and the return channel 14 in a second half of the cooling tube 2 are arranged. The inlet outlet 13b and the return entry 14a are arranged offset in the axial direction to each other, wherein the distance between the inlet inlet 13a and the inlet outlet 13b is greater than the distance between the return inlet 14a and the return outlet 14b ,

The inlet inlet 13a and the return outlet 14b are together on an axial end face of the cooling tube 2 arranged, wherein the inlet inlet 13a through the inlet region of the inlet channel 13 and the return outlet 14b through the exit region of the return channel 14 are defined. The cylinder section 4b of the end shield 4 has a plug-in area 15 on, with the cooling tube 2 in the plug-in area 15 is included. For example, the insertion area 15 as one with respect to the axis of rotation D circumferential groove formed, wherein the cooling tube 2 at least in sections accurately fitting in the insertion area 15 is arranged. The bearing plate 4 For example, a further inlet channel and a further return channel, not shown, have, wherein the further inlet channel via the insertion region 15 with the inlet inlet 13a and the further return channel via the insertion area 15 with the return outlet 14b fluidically connected.

The rotor shaft 10 is relative to the cooling tube 2 over the storage facility 7 around the axis of rotation D rotatably mounted. Here is the storage facility 7 For example, formed as a ball bearing, wherein an inner ring in the radial direction with respect to the axis of rotation D on the one hand at the bearing receiver 3d and an outer ring on the other hand on the inner periphery of the rotor shaft 10 supported. Optionally, the rotor shaft 10 via another bearing device, for example another ball bearing, on the bearing plate 4 be stored.

3 shows in the same representation as the 2 the cooling arrangement 1 , being a flow path S is indicated schematically for a coolant. For example, the coolant is a coolant, which via a conveying device, such as a feed pump, active along the flow path S through the cooling arrangement 1 is circulated. In particular, the flow path describes S a coolant circuit, wherein the coolant circuit is preferably formed as a closed coolant circuit. For example, the additional inlet channel and / or the further return channel may be connected to the conveying device, so that an active closed cooling circuit is implemented.

The flow path S runs through the bearing plate 4 , in particular via the further inlet channel, not shown, to the insertion region 15 and then via the inlet inlet 13a , the inlet channel 13 , the inlet outlet 13b , the gap 11 , the return entry 14a , the return channel 14 , the return outlet 14b and the insertion area 13 back through the end shield 4 , In particular, the further return channel, not shown.

For example, the gap 11 completely filled with the coolant, so that the rotor shaft 10 in the area of the gap 11 is cooled extensively on its inner circumference. Through the flow path S a unidirectional course of the coolant is defined, with the rotor shaft 10 emitted heat can be continuously removed. As a result, during an operation of the electric motor, the rotor 9 , in particular the rotor core 12 , Are cooled, whereby the reliability and the life of the electric motor is significantly increased. Due to the direct contact of the coolant to the rotor shaft 10 over the complete length of the rotor core 12 is the cooling capacity of the cooling arrangement 1 significantly improved, while also a uniform cooling over the entire range is implemented.

4 shows in a three-dimensional representation of the cooling arrangement 1 with the flow path S , where the cooling tube 2 two of the inlet channels 13 and two of the return channels 14 having. The channels 13 . 14 are through several wall sections 2c separated from each other. The wall sections 2c are between the outer shell portion 2a and the inner shell portion 2c arranged and seamlessly connected to it. For example, the cooling tube 2 designed as an aluminum extruded profile or a plastic profile. The channels 13 . 14 are through the wall sections 2c divided into four equal segments, the two inlet channels 13 in an upper half and the two return channels 14 in a lower half of the cooling tube 2 are arranged.

The two inlet channels 13 each have a separate inlet inlet 13a and a common inlet outlet 13b on. The inlet outlet 13b is as an elongated cutout in the outer surface 2a formed, with the inlet outlet 13b in the direction of rotation via the two inlet channels 13 extends. The coolant can simultaneously via the two inlet entries 13a along the flow path S in the two inlet channels 13 and about the common inlet outlet 13b in the gap 11 flow.

The two return channels 14 each have a separate return outlet 14b and a common return entry 14a on. The return entry 14a is for example identical to the inlet outlet 13b formed, wherein the return entry 14a in the direction of rotation via the two return channels 14 extends. The coolant flows from the gap 11 via the common return entry 14a along the flow path S in the two return channels 14 and via the associated return outlet 14b out.

The second sealant 6b points in the area of the inlet entries 13a and the return spill 14b several open spaces, so the flow path S over the free areas to the associated channel 13 . 14 can run. In particular, the free areas have the same cross-sectional shape as the associated inlet inlet 13a or return outlet 14b on.

LIST OF REFERENCE NUMBERS

1

cooling arrangement

2

cooling pipe

2a

Outer casing surface

2 B

Inner surface area

2c

wall sections

3

tail

3a

connecting portion

3b

contact section

3c

sealing recording

3d

bearing seat

4

end shield

4a

flange

4b

cylinder section

5a

first sealing device

5b

second sealing device

6a

first sealant

6b

second sealant

7

Storage facility

8th

further sealing intake

9

rotor

10

rotor shaft

11

gap

12

rotor core

13

inlet channel

13a

feed entry

13b

inlet outlet

14

Return channel

14a

Return entry

14b

Return outlet

15

insertion

D

axis of rotation

S

flow

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102014204133 A1 [0003]

Claims (10)

Cooling arrangement (1) for a rotor (9) of an electric motor of a vehicle, having a rotor shaft (10), wherein the rotor shaft (10) is formed as a hollow shaft and defines a rotation axis (D) with a cooling pipe (2) for coolant supply, wherein the cooling pipe (2) is arranged coaxially with respect to the rotation axis (D) in the rotor shaft (10), wherein between an outer periphery of the cooling pipe (2) and an inner periphery of the rotor shaft (10) there is a clearance (11) for receiving a coolant is formed, characterized in that the cooling tube (2) at least one inlet channel (13) and at least one return channel (14), wherein the inlet channel (13) and the return channel (14) are fluidically connected to the intermediate space (11), wherein a flow path (S) of the coolant from the inlet channel (13) via the intermediate space (11) to the return channel (14) extends. Cooling arrangement (1) after Claim 1 , characterized in that the cooling tube (2) at least one inlet inlet (13a) and at least one inlet outlet (13b), wherein the inlet channel (13) connects the inlet inlet (13a) with the inlet outlet (13b) and / or that the cooling tube ( 2) has at least one return inlet (14a) and at least one return outlet (14b), wherein the return channel (14) connects the return inlet (14a) with the return outlet (14b), and wherein the inlet channel (13) and the return channel (14) fluidly separated from each other within the cooling tube (2). Cooling arrangement (1) after Claim 2 , characterized in that the inlet inlet (13a) and the return outlet (14b) with respect to the axis of rotation (D) on an axial end face of the cooling tube (2) are arranged and / or the inlet outlet (13b) and the return inlet (14a) the outer circumference of the cooling tube (2) are arranged. Cooling arrangement (1) according to one of the preceding claims, characterized by a first and a second sealing device (5a, b) for sealing the intermediate space (11), wherein the intermediate space (11) with respect to the axis of rotation (D) by the first sealing device (11). 5a) is limited in an axial direction and by the second sealing means (5b) in an axial opposite direction. Cooling arrangement (1) according to one of the preceding claims, characterized by an end piece (3), the end piece (3) being connected to the cooling tube (2) at the end in the axial direction with respect to the axis of rotation (D), the inlet channel (13) being and / or return channel (14) are limited by the end piece (3) in the axial direction with respect to the axis of rotation (D). Cooling arrangement (1) after Claim 5 characterized by a bearing device (7) for supporting the cooling tube (2) relative to the rotor shaft (10), wherein the end piece (3) has a bearing receptacle (3 d) for receiving the bearing device (7), wherein the bearing device (7) radial direction with respect to the axis of rotation (D) on the one hand on the bearing support (3d) and on the other hand on the inner circumference of the rotor shaft (10) is supported. Cooling arrangement (1) according to one of the preceding claims, characterized by a bearing plate (4), wherein the bearing plate (4) is connected to the cooling tube (2), wherein the bearing plate (4) has a further inlet channel and a further return channel, wherein the further inlet channel of the bearing plate (4) fluidly connected to the inlet channel (13) of the cooling tube (2) and the further return channel of the bearing plate (4) with the return channel (14) of the cooling tube (2). Cooling arrangement (1) according to one of Claims 5 to 7 , characterized in that the end piece (3) has a sealing receptacle (3c) for receiving the first sealing device (5a), wherein the first sealing device (3c) in the radial direction with respect to the axis of rotation (D) on the one hand to the sealing receptacle (3c ) and on the other hand on the inner circumference of the rotor shaft (10) and / or that the bearing plate (4) has a further sealing seat (8) for receiving the second sealing means (5b), wherein the second sealing means (5b) in the radial direction with respect on the axis of rotation (D) on the one hand to the further sealing seat (8) and on the other hand on the inner circumference of the rotor shaft (10) is supported. Rotor (9) with the cooling arrangement (1) according to one of the preceding claims, characterized by a rotor core (12), wherein the rotor core (12) on the rotor shaft (10) is arranged, wherein the intermediate space (11) in the axial direction in With respect to the axis of rotation (D) extends in the region of the rotor core (12), wherein the rotor core (12) by the cooling arrangement (1) is cooled. Electric axle for a vehicle with the rotor (9) after Claim 9 and / or with the cooling arrangement (1) according to one of Claims 1 to 8th ,

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