DE102019206269A1 - Cooling device for cooling a rotor of a wheel hub motor of a vehicle, vehicle wheel and method for cooling a rotor of a wheel hub motor of a vehicle wheel - Google Patents

Abstract

A cooling device (10) for cooling a rotor (29) of a wheel hub motor (13) of a vehicle wheel (11) is proposed, the rotor (29) being arranged completely within a rim interior (17c) of a rim (17) and wherein the cooling device (10) has at least one cooling channel (20) for guiding a coolant, which is formed in the rim (17).

Description

The invention relates to a cooling device for cooling a rotor of a wheel hub motor of a vehicle, a vehicle wheel and a method for cooling a rotor of a wheel hub motor of a vehicle wheel.

Wheel hub drives as a variant of a decentralized vehicle drive have long been known from the prior art. The integration of a wheel hub drive into a vehicle wheel, in particular into the rim of a vehicle wheel, is also known. For example, the DE 10 2010 033 852 A1 a drive unit for a vehicle wheel, in which both the stator and the rotor of a wheel hub motor are integrated in a rim. However, with the solutions known from the prior art, there is potential for improvement with regard to the performance and the cooling of the wheel hub motor.

The object of the present invention is to improve a cooling device for cooling a rotor of a wheel hub motor of a vehicle in such a way that the rotor is cooled as efficiently as possible so that the wheel hub motor can achieve the best possible performance.

The above-mentioned object is achieved by a cooling device for cooling a rotor of a wheel hub motor of a vehicle, the rotor being arranged completely within a rim interior of a rim, the device having at least one cooling channel for guiding a coolant, and the at least one cooling channel in the Rim is formed. The term “coolant” is to be understood in particular as cooling water. In particular, the cooling device comprises the rim.

By integrating the rotor of the wheel hub motor in the rim or in the rim interior, the largest possible air gap diameter, that is to say the diameter at the boundary between the rotor and stator of the wheel hub motor, is achieved. This has a positive effect on the maximum achievable torque. By forming the at least one cooling channel in the rim, the rim also serves as a heat sink for the rotor, so that the rotor is cooled as effectively as possible, so that the performance of the wheel hub motor can be optimized. This applies in particular to a continuous output of the wheel hub motor.

The formation in the rim means that the cooling channel is formed by the rim in at least one direction.

In particular, the at least one cooling channel has a first section and a second section, at least the first section being delimited in a radially outward direction by the rim. The term “radially outward direction” means the radial, outward-facing direction. The first section is arranged primarily in the area of a rim well of the rim. The first section of the cooling channel preferably runs essentially in the axial direction of the rim. Furthermore, the first section is preferably delimited by the rim in all directions except for a radially inner direction (and the axial direction in which it runs). The first section can thus be designed as a channel, in other words a recess, in an inner wall of the rim. The term “radially inner direction” is to be understood as the radial inward direction.

The second section of the at least one cooling channel preferably runs essentially in the radial direction, the second section being delimited by the rim in both directions which are perpendicular to the radial direction. The second section thus runs entirely within the rim. The second section is arranged primarily in an axially outer region of the rim.

The first section and / or the second section of the cooling channel preferably run in a straight line. Furthermore, the first section and / or the second section can be curved. The first section goes directly into the second section. In particular, the cooling channel consists of the first and the second section.

The wheel hub motor is preferably driven electrically. The rotor also preferably has magnets. In particular, the stator of the wheel hub motor is also arranged in the rim interior.

The rim is in particular formed in one piece with the exception of a possible cover. The first section of the at least one cooling channel is advantageously delimited by the rotor of the wheel hub motor, in particular by a laminated rotor core of the rotor. This is used to make the rim as simple as possible. Otherwise it would hardly be possible to manufacture the rim comprising the first section of the at least one cooling channel from one piece. Furthermore, the heat transfer from the rotor to the coolant is designed to be particularly short and efficient. The cooling channel thus runs on the outside of the rotor. Above all, the cooling device does not have a cooling channel within the laminated rotor core.

When passing through the first section of the cooling channel, heat from the laminated rotor core is absorbed by the coolant. When the coolant passes through the second section, heat can be given off via an end face of the rim. In particular, the cooling device can comprise cooling elements on an end face of the rim for the best possible heat dissipation to the ambient air. The cooling elements are preferably cooling ribs and / or turbulators which are formed on the end face. In particular, the end face is designed to be completely closed. As a result of the rotation of the vehicle wheel and thus the rim and the resulting vehicle speed, there will always be a comparatively strong and turbulent air flow at the end face of the rim, which promotes heat transfer to the ambient air. This effect can be optimized at this point with the cooling elements.

In particular, the cooling device has a coolant pump integrated into the rim interior for pumping the coolant through the at least one cooling channel, the coolant pump comprising a pump wheel. In particular, the coolant pump is arranged at the end of the second section of the at least one cooling channel.

Furthermore, the cooling device preferably has two collecting areas, a first collecting area for the flow and a second collecting area for the return. Both collecting areas are designed primarily in a ring shape.

In particular, the cooling device comprises a multiplicity of cooling channels, each of which is designed as described above. At least one first cooling channel is used for the flow and at least one second cooling channel for the return flow of the coolant. Each cooling channel has a first section described above and a second section described above.

In particular, a first section of a first cooling channel and a first section of a second cooling channel are each connected to one another by a U-shaped connecting channel in an axially inner region of the rim.

In particular, the device comprises a plurality of first cooling channels which are arranged at a distance from one another in the circumferential direction and whose second sections end in the first collecting area. The second sections of the first cooling channels preferably extend radially from the first collecting area. The first cooling channels are thus connected to one another via the first collecting area.

Furthermore, the device preferably comprises a multiplicity of second cooling channels which are arranged at a distance from one another in the circumferential direction and whose first sections end in the second collecting area. The first sections of the first cooling channels preferably extend radially from the first collecting area. The second cooling channels are thus connected to one another via the second collecting area.

The cooling device is designed in particular to transport the coolant from the second collecting area through the second section of at least one second cooling channel, wherein it then flows through the first section of the second cooling channel, specifically along the outside of the rotor in an axially inner direction. The coolant flow is reversed in an axially inner region of the rim, the coolant then flowing through the first section of a first cooling channel and then through the second section of the first cooling channel into the corresponding first collecting region. The collecting areas can be connected to one another. The pump wheel, which conveys coolant from the first to the second collecting area, is located between these. The cycle can thus begin again.

In particular, the first sections of the at least one first and second cooling channel are arranged offset from one another in the circumferential direction of the rim or of the vehicle wheel. The second sections of the at least one first and second cooling channel are also arranged offset from one another in the circumferential direction and also preferably in the axial direction. The collecting areas are also advantageously arranged offset in the axial direction. This ensures the best possible flow from or to the collecting areas of the coolant pump. The first collecting area is preferably arranged further out in the axial direction than the second collecting area.

In particular, the coolant pump does not have a shaft seal for the pump wheel. Alternatively, the coolant pump can have a shaft seal for the pump wheel. The pump wheel can be mounted in different ways, for example by a plain bearing or a roller bearing. The pump wheel is primarily arranged in such a way that it can deliver coolant from the second collecting area into at least one second cooling channel.

The pump wheel is advantageously firmly locked so that it does not rotate with the rotor or with the vehicle wheel. In particular, a pump output of the coolant pump results essentially from a rotation of the vehicle wheel. In particular, the rim represents a pump housing for the coolant pump. The coolant pump therefore does not have a separate housing. As a result of a rotation of the vehicle wheel and thus a rotation of the rim, the pump housing rotates, while the pump wheel, as described above, is preferably firmly locked. In particular, the cooling circuit of the cooling device is thus at a standstill of the vehicle a stationary vehicle wheel inactive, the coolant being conveyed when the vehicle wheel rotates. In particular, no further drive for the coolant pump is used.

In particular, the impeller of the coolant pump is locked by means of a magnetic coupling. For this purpose, a wheel carrier of the vehicle wheel has magnets, the pump wheel also including magnets which interact to lock it. Alternatively, the pump wheel can be driven by an additional electric motor. The magnetic coupling is also used for the drive.

In particular, the impeller of the coolant pump has blades, the blades comprising two metals with different coefficients of thermal expansion, so that the blades adjust themselves independently as a function of a rotor temperature to regulate a coolant flow. In other words, the blades are bimetallic.

In particular, the pump wheel has blades on the inlet side, the blades on the inlet side and / or the blades on the outlet side being embodied as bimetallic, as described above. In particular, the blades are at least partially formed from two metals, which primarily form two different sides, a front and a rear, of the blade. As a result, the blades are designed to change their radius of curvature, in particular on an inlet side of the coolant, and thus set a different volume flow of the coolant. In particular, when the coolant heats up because the rotor temperature rises, the volume flow can be increased by changing the radius of curvature of the blades independently. As a result of this design, the cooling device is equipped for the broadest possible temperature range.

In particular, the coolant enters from a collecting area to the cooling channels or from the cooling channels to a collecting area in the radial direction. Furthermore, entry and / or exit can also take place in the axial direction, in which case the blades of the pump wheel are preferably S-shaped when viewed from the radial direction.

In particular, the invention relates to a vehicle wheel of a vehicle, the vehicle preferably being a heavy vehicle, for example a truck or a bus. The vehicle wheel comprises a rim and a wheel hub motor. A rotor of the wheel hub motor is arranged entirely in the inner space of the rim, the vehicle wheel comprising a cooling device described above. Furthermore, the vehicle wheel can have a wheel carrier including a magnetic coupling as described above. The rim and / or the wheel hub motor and / or the rotor and / or the wheel carrier are preferably designed as described above.

In particular, the rim has a removable rim flange. This can be used to change the tire, the replacement of the tire being made considerably easier and the replacement of the entire vehicle wheel superfluous.

Furthermore, the rim can be designed as a housing for the stator and possibly other components, such as power electronics. Furthermore, the rim can have an additional inner cover to protect the wheel hub motor against environmental influences, for example dirt. The inner cover can serve as a support for a brake disc of the vehicle wheel. Furthermore, the cover can have efficient heat protection so that the heat input from a brake system is kept as low as possible. The space enclosed by the rim and its cover is understood as the rim interior.

In a further aspect, the invention relates to a method for cooling a rotor of a wheel hub motor of a vehicle, the rotor being arranged completely within a rim space of a rim, the method comprising the use of a cooling device described above. In particular, the method comprises conveying coolant through the at least one cooling channel by means of a coolant pump as described above. The coolant is guided in particular through a first cooling channel and a second cooling channel, which are preferably designed as described above. The delivery rate of the coolant pump can essentially be achieved by turning the vehicle wheel.

In particular, the method further comprises the automatic adjustment of blades of an impeller of the coolant pump as a function of a rotor temperature, so that the coolant flow can be regulated automatically.

The method can also include temperature monitoring of the rotor, so that the power can be throttled when critical temperatures are reached.

The invention is explained in more detail with reference to the following purely schematic figures.

• 1 eine perspektivische Ansicht eines Fahrzeuges umfassend eine erfindungsgemäße Kühlvorrichtung und ein erfindungsgemäßes Fahrzeugrad;
• 2 einen radialen Schnitt durch eine erfindungsgemäße Kühlvorrichtung und ein erfindungsgemäßes Fahrzeugrad;
• 3 eine Draufsicht auf die Stirnseite der Felge aus der 2;
• 4 eine perspektivische Ansicht eines Pumpenrades einer Kühlmittelpumpe der erfindungsgemäßen Kühlvorrichtung;
• 5 eine axiale Draufsicht auf das Pumpenrad der 4; und
• 6 eine weitere perspektivische Ansicht des Pumpenrades der 4 und 5.

The figures show:

• 1 a perspective view of a vehicle comprising a cooling device according to the invention and a vehicle wheel according to the invention;
• 2 a radial section through a cooling device according to the invention and a vehicle wheel according to the invention;
• 3 a plan view of the end face of the rim from 2 ;
• 4th a perspective view of an impeller of a coolant pump of the cooling device according to the invention;
• 5 an axial plan view of the impeller of 4th ; and
• 6th a further perspective view of the impeller of 4th and 5 .

1 Figure 10 is a perspective view of a vehicle 100 comprising a cooling device according to the invention 10 and a vehicle wheel according to the invention 11 represents the arrangement in relation to the coordinate system also shown in the other figures 12th better to illustrate. The Y direction of the coordinate system 12th thus corresponds to the axial direction of the vehicle wheel 11 while the positive X direction is in the forward direction of the vehicle 100 shows.

2 shows a radial section of a cooling device according to the invention 10 and a vehicle wheel according to the invention 11 . The vehicle wheel 11 has an in-wheel motor 13 with an axis of rotation 14th on, with both the rotor 29 , in particular the laminated core of the rotor, as well as the stator 30th , in particular a stator core of the stator, of the wheel hub motor 13 entirely in one interior 17c the rim 17th are arranged.

The cooler 10 comprises at least one cooling channel 20th that is in the rim 17th of the vehicle wheel 11 is trained. And that is in 2 a first cooling channel 20a and a second cooling channel 20b to a coolant pump 21st to see.

Both cooling channels have a first section 20c and a second section 20d on. Both sections are in the rim 17th educated. The first sections 20c of the two cooling channels 20th run essentially in the axial direction (Y-direction in 2 ) and are moved in a radially inner direction (negative Z-direction in 2 ) through the rotor 29 limited. A first section each 20c a first cooling channel 20a and a first section 20c a second cooling channel 20b are through a U-shaped connecting channel 38 (please refer 3 ) connected with each other. The second sections 20d run in the radial direction (Z-direction in 2 ) and are through the rim in both the X and Y directions 17th limited. The first sections 20c are in the area of a rim well 17a and the second sections 20d in an axially outer area 17b the rim 17th arranged.

The first sections of the cooling channels 20th are arranged offset in the circumferential direction of the vehicle wheel. The same applies to the second sections 20d , which also work in the axial direction (Y direction in Fig 2 ) are staggered.

Furthermore, the cooling device 10 a first collection area 23 and a second collection area 24 on, which are also arranged offset in the axial direction.

The coolant pump 21st has an impeller 22nd (see the following figures), by means of a magnetic coupling, namely by means of the magnets 31 and 37 (please refer 6th ) is fixed. When the vehicle wheel rotates 11 the rim moves 17th that is the housing of the coolant pump 21st represents, and the coolant pump 21st conveys the coolant from the second collection area 24 through the second section 20d and the first section 20c of the second cooling channel 20b . In an axially inner area of the rim 17th is the coolant by means of a U-shaped connecting channel 38 reversed and flows through the first section 20c and the second section 20d of the first cooling channel 20a to the first collection area 23 .

When going through the first sections 20c the coolant takes heat from the rotor 29 on while it is going through the second sections 20d Heat to the ambient air via the front side 17d the rim 17th gives. In order to improve the heat dissipation to the ambient air, the front face 17d the rim 17th Cooling elements 25th , in particular cooling fins.

The rim 17th also includes a cover 18th to the axially inner side, which is the wheel hub motor 13 protects against environmental influences. It also serves as a carrier for other components, e.g. a brake disc of the vehicle wheel 11 . The vehicle wheel 11 includes a wheel carrier 16 who like the stator 30th is certain. The wheel carrier 16 is about rolling bearings 27 with the rim 17th connected, further seals 26th are provided.

The rim 17th has a removable rim flange 19th on, by changing the tire 28 is simplified significantly.

In 3 is a top plan view of the end face 17d the rim 17th from the 2 to see, with a view of the second sections through a drawn opening 20d of the first cooling channel 20a and the second cooling channel 20b is granted. Two sectional views in two different axial positions can be seen in the opening. In the left half, the section is arranged further to the front (ie axially further out) compared to the right half.

It's an offset of the second sections 20d of the two in 2 cooling channels shown 20th in the circumferential direction and thus the direction of rotation 15th of the wheel hub motor 13 to see. When the vehicle wheel rotates 11 and thus the rim 17th the coolant is from the annular second collection area on the right-hand side 24 in the second section 20d of the second cooling channel 20b is fed. The coolant then runs along the first section 20c of the second cooling channel 20b in the negative Y direction of the 2 , it being in an axially inner region of the rim 17th in the first section 20c of the first cooling channel 20a is reversed and then again in the second section 20d of the first cooling channel 20a arrives. In this case, the cooling device primarily has a large number of first and second cooling channels. 3 indicates another second cooling channel 20b , which is also in the second collection area 24 ends, as well as another first cooling channel 20a in the first collection area 23 ends.

In 4th Figure 3 is a perspective view of the impeller 22nd the coolant pump 21st the 3 to see while 5 an axial plan view of the impeller 22nd shows.

The impeller 22nd has upstream blades 32 and downstream blades 33 on. The upstream blades 32 are curved about an axis that is perpendicular to an axis about which the downstream blades 33 are curved. The downstream blades 33 are essentially each curved around an axis that is parallel to the axis of rotation of the pump wheel 22nd stands. For the upstream blades 32 the respective axis of curvature is essentially radial and thus runs perpendicular to the axis of curvature of the inlet-side blades 32 .

The upstream blades 32 are made of two materials, a first material 34 and a second material 35 . Because of this bimetallic design, they can change their radius of curvature. Furthermore, the pump wheel is mounted on a plain bearing, whereby the sliding surface 36 in 4th able to see.

In 6th Figure 3 is another perspective view of the impeller 22nd the 4th and 5 to see. In 6th Magnets 37 to see the one with the magnets 31 (please refer 2 ) work together to lock the impeller.

List of reference symbols

10

Cooling device

11

Vehicle wheel

12

Coordinate system

13

Wheel hub motor

14th

Axis of rotation of the wheel hub motor

15th

Direction of rotation of the wheel hub motor

16

Wheel carrier

17th

rim

17a

Rim base

17b

axially outer area

17c

Rim interior

17d

Face

18th

cover

19th

Rim flange

20th

Cooling duct

20a

first cooling channel

20b

second cooling channel

20c

first section

20d

second part

21st

Coolant pump

22nd

Impeller

23

first collection area

24

second collection area

25th

Cooling element

26th

poetry

27

roller bearing

28

tires

29

rotor

30th

stator

31

magnet

32

inlet-side blade

33

downstream blade

34

first material

35

second material

36

Sliding surface

37

magnet

38

Connection channel

100

vehicle

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was 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.

Patent literature cited

• DE 102010033852 A1 [0002]

Claims (10)

Cooling device (10) for cooling a rotor (29) of a wheel hub motor (13) of a vehicle wheel (11), the rotor (29) being arranged completely within a rim interior (17c) of a rim (17), the cooling device (10) at least has a cooling channel (20) for guiding a coolant, characterized in that the at least one cooling channel (20) is formed in the rim (17). Cooling device (10) after Claim 1 , characterized in that at least a first section (20c) of the at least one cooling channel (20) in the region of a rim well (17a) of the rim (17) runs essentially in the axial direction of the rim (17). Cooling device (10) after Claim 2 , characterized in that the first section (20c) of the at least one cooling channel (20) is delimited in a radially inner direction by the rotor (29) of the wheel hub motor (13). Cooling device (10) according to one of the preceding claims, characterized in that a second section (20d) of the at least one cooling channel (20) in an axially outer region (17b) of the rim (17) essentially in the radial direction of the rim (17) runs. Cooling device (10) according to one of the preceding claims, characterized in that the cooling device (10) comprises cooling elements (25) on an end face (17d) of the rim (17) for dissipating heat to the ambient air. Cooling device (10) according to one of the preceding claims, characterized in that the cooling device (10) has a coolant pump (21) integrated into the rim interior (17c) for pumping the coolant through the at least one cooling channel (20) comprising a pump wheel (22) . Cooling device (10) after Claim 6 , characterized in that the rim (17) represents a pump housing for the coolant pump (21). Cooling device (10) according to one of the Claims 6 or 7th , characterized in that the pump impeller (22) has blades, the blades comprising two metals with different coefficients of thermal expansion, so that the blades adjust independently depending on a rotor temperature to regulate a coolant flow. Vehicle wheel (11) of a vehicle (100), the vehicle wheel (11) comprising at least one rim (17) and a wheel hub motor (13), wherein a rotor (29) of the wheel hub motor (13) is completely within a rim interior (17c) of the rim (17) is arranged, characterized in that the vehicle wheel (11) has a cooling device (10) according to one of the Claims 1 to 8th includes. Method for cooling a rotor (29) of a wheel hub motor (13) of a vehicle wheel (11), wherein the rotor (29) is arranged completely within a rim interior (17c) of a rim (17), characterized in that the method involves the use of a cooling device (10) according to one of the Claims 1 to 8th includes.

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