Hub drive system

Abstract

The invention relates to a hub driving system. The hub driving system comprises a rim, a wheel shaft and a driving motor which are coaxially arranged, the rim is rotatably supported on the radial outer side of the wheel shaft, the driving motor comprises a stator and a rotor which are coaxially arranged, and the rotor is rotatably arranged on the radial outer side of the stator. Wherein the rotor is fixed on the radial inner surface of the rim, and the stators are fixed on the radial outer side of the axle in a radial interval mode. The wheel hub driving system provided by the invention has improved spatial layout.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and more particularly to a wheel hub drive system for a motor vehicle. Background Art

[0002] With the widespread application of motor drive mode in new energy vehicles, wheel hub drive technology is becoming more and more mature. Wheel hub drive vehicles install the drive motor inside the wheel hub of the vehicle, so as to drive the wheel to rotate through the wheel hub motor. The chassis layout of this wheel hub drive vehicle is more flexible and has broad application prospects.

[0003] In the prior art, for example, in the wheel hub drive system disclosed in CN 205610442 U, the stator of the drive motor is directly mounted on the wheel axle, and the rotor is mounted close to the stator and spaced apart from the rim, so that the annular space formed between the support structure of the rotor and the rim can cool the drive motor through the airflow generated when the wheel rotates. However, this design has high space requirements and cannot provide sufficient space on the inner side of the rim to integrate other components, such as the braking mechanism. In this case, the braking mechanism needs to be installed using the space on the axial outside of the wheel, which leads to an increase in the axial size. At the same time, this design also limits the radial size of the drive motor, which is not conducive to the drive motor generating greater torque. In addition, this design cannot provide a separate sealing cavity for components such as the hub bearing. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to provide a wheel hub drive system capable of improving the spatial layout.

[0005] The above technical problems are solved by a wheel hub drive system according to the present invention. The wheel hub drive system includes a coaxially arranged rim, a wheel axle and a drive motor, the rim is rotatably supported on the radially outer side of the wheel axle, and the drive motor includes a coaxially arranged stator and a rotor, and the rotor is rotatably arranged on the radially outer side of the stator. The rotor is fixed on the radially inner surface of the rim, and the stator is fixed on the radially outer side of the wheel axle in a radially spaced manner. The drive motor is thus arranged close to the radially outer rim and spaced from the radially inner wheel axle, and the radial space between the drive motor and the wheel axle can be used to arrange components such as a brake mechanism, thereby improving space utilization. At the same time, the radial size of the drive motor is larger, so that the drive motor can generate a larger driving torque.

[0006] According to a preferred embodiment of the present invention, the wheel hub drive system may include a stator support, a support plate, a spoke and a wheel hub; wherein the stator is fixed on the radial outer side of the stator support, the support plate is connected between the axial ends of the stator support and the wheel axle facing the frame, so that the stator support is fixed on the radial outer side of the wheel axle in a radially spaced manner; wherein the wheel hub is rotatably supported on the radial outer side of the wheel axle, the spoke is connected between the axial ends of the rim and the wheel hub facing away from the frame, so that the rim is fixed on the radial outer side of the wheel hub in a radially spaced manner; wherein the stator support is located on the radial outer side of the wheel hub and is radially spaced from the wheel hub. Thus, a cavity defined by the stator support, the wheel hub, the support plate and the spoke is formed, and components such as a brake mechanism can be integrated in the cavity.

[0007] According to another preferred embodiment of the present invention, the wheel hub drive system may include a brake mechanism located radially between the stator support and the wheel axle and axially between the wheel spoke and the support plate, the brake mechanism including a brake disc fixed relative to the wheel hub and a brake caliper mounted torsionally relative to the wheel axle, the brake caliper being able to move axially relative to the brake disc to engage or release the brake disc. The brake mechanism can thereby be integrated inside the wheel without increasing the size of the wheel.

[0008] According to another preferred embodiment of the present invention, the brake disc can be clamped between the wheel spoke and the wheel hub in the axial direction and fixed together by fasteners. Thus, the relative fixation of the brake disc, the wheel spoke and the wheel hub is achieved in a simple manner.

[0009] According to another preferred embodiment of the present invention, the wheel hub drive system may include a rotary transformer, the rotary transformer including a stator part and a rotor part, the rotor part is fixed to the radial outer side of the axial end of the wheel hub facing the support plate, and the stator part is fixed to the wheel axle radially outside the rotor part. The rotational position of the wheel or the drive motor can be detected by the rotary transformer integrated inside the wheel.

[0010] According to another preferred embodiment of the present invention, the wheel hub drive system may include a bearing and a center cover, wherein the wheel hub is supported on the radially outer side of the wheel axle through the bearing, the center cover is installed on the radially inner side of the wheel hub to close the axial end of the wheel hub facing the spoke, and the bearing is encapsulated in a sealed cavity defined by the center cover, the wheel hub and the wheel axle. The center cover realizes the sealing of the bearing and facilitates the alignment of the wheel hub and the wheel axle during installation.

[0011] According to another preferred embodiment of the present invention, the stator and the rotor can be encapsulated in a sealed cavity defined by the rim and the stator bracket, thereby preventing external pollutants from invading the drive motor.

[0012] According to another preferred embodiment of the present invention, the wheel hub drive system may include a coolant channel formed between the stator and the stator bracket. The drive motor may be efficiently cooled by the coolant circulating in the coolant channel.

[0013] According to another preferred embodiment of the present invention, the wheel hub drive system may include a coolant inlet and a coolant outlet respectively connected to the coolant channel, and the coolant inlet and the coolant outlet are located at the axial end of the stator bracket facing the support plate. The coolant inlet and the coolant outlet facing the support plate are also facing the frame, so it is convenient to connect with the coolant supply source and the drive pump in the frame.

[0014] According to another preferred embodiment of the present invention, the stator support may include a groove formed on the radial outer surface, and the stator closes the groove from the radial outer side to form a coolant channel; wherein the groove includes an axial segment extending in the axial direction and a plurality of circumferential segments extending in the circumferential direction and spaced in the axial direction, and the circumferential ends of each circumferential segment are separated by a separation area extending in the axial direction on the radial outer surface of the stator support, the axial segment is formed in the separation area and connects one of the coolant inlet and the coolant outlet with one of the plurality of circumferential segments axially closest to the spoke, the other of the coolant inlet and the coolant outlet is connected with one of the plurality of circumferential segments axially closest to the support plate, and each of the remaining plurality of circumferential segments is connected with the adjacent circumferential segments on the opposite side at both circumferential ends. Thus, a groove extending in a serpentine shape along the radial outer surface of the stator support is formed, so that the coolant can fully cool the entire drive motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention is further described below in conjunction with the accompanying drawings. The same reference numerals in the drawings represent elements with the same functions.

[0016] Figure 1 A cross-sectional view showing a wheel hub drive system according to an exemplary embodiment of the present invention;

[0017] Figure 2 A plan view showing a wheel hub drive system according to an exemplary embodiment of the present invention;

[0018] Figure 3 Another plan view showing a wheel hub drive system according to an exemplary embodiment of the present invention;

[0019] Figure 4 A perspective view showing a wheel hub drive system according to an exemplary embodiment of the present invention; and

[0020] Figure 5 A perspective view showing a stator support of a wheel hub drive system according to an exemplary embodiment of the present invention is shown. DETAILED DESCRIPTION

[0021] The following detailed description and drawings are used to illustrate the principle of the present invention. The present invention is not limited to the preferred embodiments described. The protection scope of the present invention is defined by the claims.

[0022] According to an embodiment of the present invention, a wheel hub drive system for a motor vehicle is provided, which integrates components such as a wheel support structure and a drive motor. Figures 1 to 5 An exemplary embodiment of a wheel hub drive system according to the invention is shown.

[0023] Figure 1 1 shows a cross-sectional view through the central axis of a wheel hub drive system according to an exemplary embodiment of the present invention. Figure 1 As shown, the wheel hub drive system mainly includes a wheel rim 1, a wheel axle 2, a wheel spoke 3, a wheel hub 4 and a drive motor. Figure 2 and Figure 3 The two sides of the axis are shown respectively. Figure 1 A plan view of the wheel hub drive system. Figures 1 to 3 As shown in FIG. 1 , the wheel rim 1 and the wheel hub 4 are respectively substantially cylindrical components, and the wheel axle 2 is substantially cylindrical. The wheel axle 2 is connected to the frame (located at one side of the wheel hub drive system) Figure 1 The wheel hub 4 is coaxially arranged on the radial outside of the wheel axle 2 and can rotate around the central axis relative to the wheel axle 2. The rotatable support of the wheel hub 4 relative to the wheel axle 2 can be achieved, for example, by one or more bearings 13 installed radially between the wheel hub 4 and the wheel axle 2. The rim 1 is coaxially arranged on the radial outside of the wheel hub 4 and is radially spaced apart from the wheel hub 4. The axial extension range of the wheel hub 4 and the wheel axle 2 basically falls within the axial extension range of the rim 1. Figure 4 As shown in the perspective view of FIG. 1 , the radial outer surface of the rim 1 has a concave shape for mounting a tire (not shown). The spokes 3 extend substantially radially between the rim 1 and the hub 4 and are fixedly connected to both, thereby fixing the rim 1 to the hub 4. The rim 1, the spokes 3 and the hub 4 can rotate relative to the wheel axle 2 as a whole.

[0024] The drive motor includes a stator 6 and a rotor 7. Both the stator 6 and the rotor 7 are substantially cylindrical structures around the central axis. The rotor 7 is coaxially arranged radially outside the stator 6. The rotor 7 includes a rotor magnet 7a and a rotor yoke 7b fixed radially outside the rotor magnet 7a. The rotor 7 (especially through the radially outer rotor yoke 7b) is fixed to the radial inner surface of the rim 1. The stator 6 includes a stator core 6a and a coil winding 6b wound on the stator core 6a. The coil winding 6b can be connected to a power source (not shown) through a connection 16. The stator 6 is fixed radially outside the axle 2 in a radially spaced manner, and is also located radially outside the hub 4 and radially spaced from the hub 4. When the coil winding 6b in the stator 6 is connected to current, the generated electromagnetic field can drive the rotor 7 to rotate relative to the stator 6 around the central axis, and at this time the rim 1, the spoke 3 and the hub 4 rotate relative to the axle 2 together with the rotor 7.

[0025] like Figure 1 and Figure 3 As shown, in order to support the stator 6 on the wheel axle 2 in a radially spaced manner, the wheel hub drive system may further include a stator bracket 8 and a support plate 5. The stator bracket 8 is a substantially cylindrical structure, which is coaxially arranged on the radial inner side of the rim 1 and the radial outer side of the wheel axle 2 and the wheel hub 4, and is radially spaced from the wheel axle 2 and the wheel hub 4. The stator 6 is directly fixed (for example, by interference fit or bonding) on ​​the radial outer side of the stator bracket 8. The support plate 5 is a plate-like structure extending in a plane substantially perpendicular to the central axis, which is connected to the axial ends ( Figure 1 The support plate 5 is fixed to the vehicle frame (for example, the right end in the middle) and is fixed to both of them (for example, by screws or other fasteners), so that the stator bracket 8 is fixed to the radial outside of the wheel axle 2 in a radially spaced manner. The support plate 5 can be fixed to the vehicle frame at the same time (for example, by screws or other fasteners), and the wheel axle 2 can also be fixedly connected to the vehicle frame via the support plate 5.

[0026] The spokes 3 are connected to the axial ends of the rim 1 and the hub 4 that are used to face away from the frame. Figure 1 The wheel rim 1 is fixed to the radial outer side of the wheel hub 4 in a radially spaced manner. Figure 2As shown, the wheel spoke 3 may include a substantially disc-shaped wheel spoke flange 3b located radially inward and a plurality of wheel spokes 3a connected between the wheel spoke flange 3b and the wheel rim 1. The plurality of wheel spokes 3a extend substantially in the radial direction and are spaced apart in the circumferential direction. The plurality of wheel spokes 3a are fixedly connected to the wheel rim 1 and the wheel spoke flange 3b, respectively. The wheel spokes 3a and the wheel spoke flange 3b are fixed together, for example, by welding or integral forming. The wheel spoke flange 3b is used to be fixedly connected to the wheel hub 4 (for example, by fasteners such as screws).

[0027] Thus, a cavity defined by the stator support 8, the wheel hub 4, the support plate 5 and the spoke 3 is formed inside the wheel hub drive system, and the space in the cavity can be used to integrate other components. Preferably, the cavity can be used to install the brake mechanism of the wheel hub drive system. Figure 1 As shown, the brake mechanism is located between the stator support 8 and the wheel axle 2 in the radial direction and between the spoke 3 and the support plate 5 in the axial direction. Specifically, the brake mechanism includes a brake disc 9 fixed relative to the wheel hub 4 and a brake caliper 10 mounted torsionally relative to the wheel axle 2. Figure 1 and Figure 2 As shown, the brake disc 9 is an annular disc extending substantially in a plane perpendicular to the central axis and is coaxially arranged with the wheel hub 4. Preferably, the radially inner portion of the brake disc 9 can be clamped axially between the spoke flange 3b of the wheel spoke 3 and the axial end of the wheel hub 4 facing away from the frame, and a fastener 11 (such as a screw, etc.) can axially pass through the wheel hub 4, the brake disc 9 and the spoke flange 3a, thereby fixing the three together. The radially outer portion of the brake disc 9 extends radially outward of the wheel hub 4. The brake caliper 10 is substantially arc-shaped in a plane perpendicular to the central axis, and is radially located between the stator support 8 and the wheel hub 4. The brake caliper 10 includes two caliper bodies located on opposite sides of the brake disc 9 in the axial direction. The two caliper bodies of the brake caliper 10 are mounted to the support plate 5 in an axially movable manner and are torsionally connected relative to the support plate 5 and the wheel axle 2. The brake caliper 10 can be driven to move axially relative to the support plate 5 and the brake disc 9 by an actuating mechanism (such as a mechanical actuating mechanism or a hydraulic actuating mechanism, etc., not shown), so as to engage or release the brake disc 9 as required. When the brake caliper 10 engages the brake disc 9, the braking mechanism is activated and the vehicle enters a braking state; when the brake caliper 10 releases the brake disc 9, the braking mechanism is deactivated and the vehicle can travel normally.

[0028] In order to detect the rotational position of the wheel and the drive motor, the wheel hub drive system may also preferably include a rotary transformer 12. Figure 1As shown, the rotary transformer 12 includes a stator portion 12a and a rotor portion 12b. The rotor portion 12b is fixed to the radial outer side of the axial end of the hub 4 facing the support plate 5. The stator portion 12a is fixed to the axle 2 (for example, fixed to the flange of the axial end of the axle 2 facing the support plate 5) at the radial outer side of the rotor portion 12b, so that the axial positions of the stator portion 12a and the rotor portion 12b are roughly aligned. The rotary transformer 12 can detect the relative rotational position between the axle 2 and the hub 4.

[0029] Preferably, the wheel hub drive system may further include a center cover 14 for encapsulating the bearing 13 in the wheel hub 4. Figure 1 and Figure 2 As shown, the center cover 14 is installed on the radial inner side of the axial end of the hub 4 facing the spoke 3, thereby closing the inner cavity of the hub 4. The axial end of the hub 4 facing the support plate 5 can be closed by the flange of the axle 2. The bearing 13 is thus encapsulated in the sealed cavity defined by the center cover 14, the hub 4 and the axle 2. In addition, in order to position the bearing 13 in the axial direction, a nut 18 can also be installed on the radial outer side of the axial end of the axle 2 facing the spoke 3. The nut 18 abuts against the bearing 13 axially toward the support plate 5, thereby constraining the axial position of the bearing 13.

[0030] Preferably, the stator 6 and the rotor 7 can be enclosed in a sealed cavity defined by the rim 1 and the stator support 8. Figure 1 As shown, the radial inner side of the rim 1 may be formed with a flange extending toward the stator support 8, which is sealed relative to the stator support 8 by a sealing ring 17. The radial outer side of the stator support 8 may also be formed with a flange extending toward the rim 1, which is also sealed relative to the rim 1 by another sealing ring 17. The stator 6 and the rotor 7 are located between the two flanges in the axial direction. Thus, the stator 6 and the rotor 7 are encapsulated in a closed sealed cavity.

[0031] In order to cool the drive motor, the wheel hub drive system may also preferably include a coolant channel 15 formed between the stator 6 and the stator bracket 8. The coolant flowing in the coolant channel 15 can cool the drive motor. The coolant channel 15 is connected to a coolant inlet 15a and a coolant outlet 15b respectively. The coolant inlet 15a and the coolant outlet 15b are located at the axial end of the stator bracket 8 facing the support plate 5. The coolant inlet 15a can be connected to a coolant supply source and / or a drive pump in the frame, for example, to supply coolant to the coolant channel 15. The coolant outlet 15b is used to communicate with a coolant recovery path to recover and circulate the coolant flowing out of the coolant channel 15. Preferably, the coolant inlet 15a and the coolant outlet 15b can be staggered with the brake caliper 10 in the circumferential direction.

[0032] Preferably, the volume of the coolant channel 15 can be provided by a groove formed on the stator support 8. Specifically, Figure 5 As shown, the stator support 8 may include a groove formed on the radial outer surface, and the stator 6 closes the groove from the radial outer side to form a coolant channel 15. The groove includes a plurality of sections that are sequentially connected along the flow path of the coolant, including an axial section 8a and a plurality of circumferential sections 8b. The axial section 8a extends generally in the axial direction, while each circumferential section 8b extends generally in the circumferential direction and is distributed at intervals in the axial direction. The number of circumferential sections 8b is preferably greater than or equal to three. The separation area 8c extending generally in the axial direction on the radial outer surface of the stator support 8 separates the circumferential ends of each circumferential section 8b. The axial section 8a is formed in the separation area 8c and connects one of the coolant inlet 15a and the coolant outlet 15b (for example, the coolant inlet 15a is shown in the figure) with the circumferential section 8b closest to the spoke 3 in the axial direction. At the same time, the other of the coolant inlet 15a and the coolant outlet 15b (for example, the coolant outlet 15b is shown in the figure) is connected to the circumferential segment 8b closest to the support plate 5 in the axial direction. If the number of the circumferential segments 8b is greater than or equal to three, the circumferential ends of the remaining circumferential segments 8b are respectively connected to the adjacent circumferential segments 8b on the opposite side, that is, one end is connected to the adjacent circumferential segment 8b close to the spoke 3, and the other end is connected to the circumferential segment 8b close to the support plate 5. If there are only two circumferential segments 8b, the circumferential ends of the two that are not directly connected to the coolant inlet 15a or the coolant outlet 15b are aligned with each other and connected. Thereby, a groove extending serpentinely along the radial outer surface of the stator bracket 8 is formed, so that the coolant can fully cool the entire drive motor.

[0033] The wheel hub drive system according to the present invention improves the arrangement of the drive motor, and forms a cavity between the drive motor and the wheel hub and the wheel axle for arranging components such as a brake mechanism or a rotary transformer, thereby improving the compactness and integration of the wheel hub drive system. At the same time, the radial size of the drive motor is increased, thereby improving the driving capacity of the drive motor.

[0034] Although possible embodiments are described by way of example in the above description, it should be understood that there are still a large number of variations of embodiments through the combination of all known and other technical features and embodiments that are easily conceivable to the skilled person. It should also be understood that the exemplary embodiment is only an example and that such an embodiment in no way limits the scope of protection, application and configuration of the present invention. The above description is more to provide the skilled person with a technical guide for converting at least one exemplary embodiment, wherein various changes can be made, especially changes in the functions and structures of the components, as long as they do not depart from the scope of protection of the claims.

[0035] Reference numerals list

[0036] 1 Rim

[0037] 2 Axles

[0038] 3 spokes

[0039] 3a Spoke

[0040] 3b Spoke flange

[0041] 4 Hubs

[0042] 5 Support plate

[0043] 6 Stator

[0044] 6a Stator core

[0045] 6b Coil winding

[0046] 7 Rotor

[0047] 7a Rotor magnet

[0048] 7b Rotor yoke

[0049] 8 Stator bracket

[0050] 8a Axial section

[0051] 8b Circumferential section

[0052] 8c Separation Area

[0053] 9 Brake disc

[0054] 10 Brake caliper

[0055] 11 Fasteners

[0056] 12. Resolver

[0057] 12a Stator part

[0058] 12b Rotor section

[0059] 13 Bearings

[0060] 14 Center Cap

[0061] 15 Coolant channel

[0062] 15a Coolant inlet

[0063] 15b Coolant outlet

[0064] 16 Wiring

[0065] 17 Sealing ring

[0066] 18 Nut

Claims

1. A wheel hub drive system, comprising a coaxially arranged wheel rim (1), a wheel axle (2) and a drive motor, wherein the wheel rim (1) is rotatably supported on the radially outer side of the wheel axle (2), and the drive motor comprises a coaxially arranged stator (6) and a rotor (7), wherein the rotor (7) is rotatably arranged on the radially outer side of the stator (6). It is characterized in that The rotor (7) is fixed on the radial inner surface of the rim (1), and the stator (6) is fixed on the radial outer side of the axle (2) in a radially spaced manner.

2. The wheel hub drive system according to claim 1, characterized in that: The wheel hub drive system comprises a stator bracket (8), a support plate (5), a wheel spoke (3) and a wheel hub (4). The stator (6) is fixed on the radial outer side of the stator bracket (8), and the support plate (5) is connected between the axial ends of the stator bracket (8) and the wheel axle (2) facing the vehicle frame, so that the stator bracket (8) is fixed on the radial outer side of the wheel axle (2) in a radially spaced manner; The wheel hub (4) is rotatably supported on the radial outer side of the wheel axle (2), and the wheel spokes (3) are connected between the axial ends of the wheel rim (1) and the wheel hub (4) which are used to face away from the frame, so that the wheel rim (1) is fixed on the radial outer side of the wheel hub (4) in a radially spaced manner; The stator support (8) is located radially outside the wheel hub (4) and is spaced apart from the wheel hub (4) in the radial direction.

3. The wheel hub drive system according to claim 2, characterized in that: The wheel hub drive system comprises a brake mechanism located radially between the stator support (8) and the wheel axle (2) and axially between the spokes (3) and the support plate (5), the brake mechanism comprising a brake disc (9) fixed relative to the wheel hub (4) and a brake caliper (10) mounted torsionally relative to the wheel axle (2), the brake caliper (10) being capable of axially moving relative to the brake disc (9) to engage or release the brake disc (9).

4. The wheel hub drive system according to claim 3, characterized in that: The brake disc (9) is clamped between the wheel spoke (3) and the wheel hub (4) in the axial direction and fixed together by a fastener (11).

5. The wheel hub drive system according to claim 2, characterized in that: The wheel hub drive system comprises a rotary transformer (12), wherein the rotary transformer (12) comprises a stator part (12a) and a rotor part (12b), wherein the rotor part (12b) is fixed to the radial outer side of the axial end of the wheel hub (4) facing the support plate (5), and the stator part (12a) is fixed to the wheel axle (2) at the radial outer side of the rotor part (12b).

6. The wheel hub drive system according to claim 2, characterized in that: The wheel hub drive system comprises a bearing (13) and a center cover (14); the wheel hub (4) is supported on the radial outer side of the wheel axle (2) through the bearing (13); the center cover (14) is installed on the radial inner side of the wheel hub (4) so ​​as to close the axial end of the wheel hub (4) facing the spoke (3); the bearing (13) is encapsulated in a sealed cavity defined by the center cover (14), the wheel hub (4) and the wheel axle (2).

7. The wheel hub drive system according to claim 2, characterized in that: The stator (6) and the rotor (7) are enclosed in a sealed cavity defined by the rim (1) and the stator bracket (8).

8. The wheel hub drive system according to any one of claims 2 to 7, characterized in that: The wheel hub drive system includes a coolant channel (15) formed between the stator (6) and the stator bracket (8).

9. The wheel hub drive system according to claim 8, characterized in that: The wheel hub drive system comprises a coolant inlet (15a) and a coolant outlet (15b) respectively connected to the coolant channel (15); the coolant inlet (15a) and the coolant outlet (15b) are located at the axial end of the stator bracket (8) facing the support plate (5).

10. The wheel hub drive system according to claim 9, characterized in that: The stator support (8) comprises a groove formed on a radial outer surface, and the stator (6) closes the groove from the radial outer side to form the coolant channel (15); The groove comprises an axial section (8a) extending in the axial direction and a plurality of circumferential sections (8b) extending in the circumferential direction and spaced apart in the axial direction, the circumferential ends of each circumferential section (8b) being separated by a separation area (8c) extending in the axial direction on the radial outer surface of the stator support (8), the axial section (8a) being formed in the separation area (8c) and connecting one of the coolant inlet (15a) and the coolant outlet (15b) to one of the plurality of circumferential sections (8b) which is axially closest to the spoke (3), the other of the coolant inlet (15a) and the coolant outlet (15b) being connected to one of the plurality of circumferential sections (8b) which is axially closest to the support plate (5), and each of the remaining plurality of circumferential sections (8b) being connected at both circumferential ends to the adjacent circumferential sections (8b) on the opposite side.

Images