Actuator for arrangement in a hub of a vehicle wheel having movable aero elements, and vehicle wheel

Abstract

The invention relates to an actuator for arrangement in a hub (43) of a vehicle wheel (45) having movable aero elements (511, 513), the actuator comprising electrical and electronic components for adjusting the aero elements (511, 513) which are movably mounted on the vehicle wheel (45). In the case of an actuator in which cooling of the components arranged in and / or behind the wheel is improved, the electrical and / or electronic components (5, 17) are arranged on or in a housing (23) which is made of a thermally conductive material and which is connected to an external cooling element (31).

Description

[0001] Mercedes-Benz Group AG Frank Thoms

[0002] October 1, 2025

[0003] Actuator for arrangement in a hub of a vehicle wheel with movable aerodynamic elements and a vehicle wheel

[0004] The invention relates to an actuator for arrangement in a hub of a vehicle wheel with movable aerodynamic elements, comprising electrical and electronic components for adjusting the aerodynamic elements movably mounted on the vehicle wheel, and to a vehicle wheel.

[0005] EP 3 530482 A1 discloses a wheel with a hub having a cylindrical cavity in which an actuator that converts electrical energy into mechanical energy is arranged. The actuator is part of a modular unit that is arranged in place of a hub cap and is rotationally fixed to the hub. In addition to the actuator, the modular unit includes an energy storage device and a wireless controller for controlling a load, for example, the actuator.

[0006] From DE 102022 001 651 A1, a wheel for a motor vehicle is known, which has a wheel hub arranged centrally in the wheel and a wheel rim arranged radially around the circumference of the wheel. A wheel disc is arranged in an intermediate area between the wheel hub and the wheel rim, which is divided into several separate, movable disc segments. The angular position of the movable disc segments is changed by an actuator integrated into the wheel hub. Two different operating states can be set, in which the disc segments are either completely closed in a disengaged position of the actuator or, in a retracted position of the actuator, assume an angular position to form an air gap in order to allow an airflow to reach the rear of the wheel, for example, to cool the brake discs of the motor vehicle.The air gap is formed between the edge of the disc segments adjacent to the wheel rim and the wheel rim itself. Such aerodynamic optimization of the wheel reduces, among other things, the function of brake cooling, as the airflow required for cooling, which flows through the wheel between the spokes, is restricted.

[0007] The object of the invention is to provide an actuator and a wheel for a vehicle with movable disc segments, in which the cooling of the components arranged in and / or behind the wheel is improved.

[0008] The invention is defined by the features of the independent claims. Advantageous further developments and embodiments are the subject of the dependent claims. Further features, applications, and advantages of the invention will become apparent from the following description and the explanation of exemplary embodiments of the invention illustrated in the figures.

[0009] The problem is solved by the subject matter of claims 1 and 10 respectively.

[0010] In the actuator described above, designed for installation in the hub of a vehicle wheel with movable aerodynamic elements, which includes electrical and / or electronic components for adjusting the aerodynamic elements mounted on the vehicle wheel, the electrical and / or electronic components are arranged on or within a housing made of a thermally conductive material, which is connected to an external cooling element. This has the advantage that the heat generated by the electrical and / or electronic components is dissipated from the large-area housing directly to the environment via the cooling element. This ensures overheating protection, which contributes to the thermal stability of the electrical and / or electronic components. By reducing the thermal load on the components, the service life of the electrical and / or electronic components and thus the operational reliability of the actuator is increased.

[0011] In one embodiment, the housing is at least two-part and comprises an inner housing surrounding the electrical and / or electronic components, which is made of a thermally conductive material. The inner housing is mounted in an outer housing made of a thermally non-conductive material. The inner housing with the electrical and / or electronic components can be pre-assembled together with the cooling element as a single unit, which then only needs to be inserted into the outer housing, thus simplifying the assembly of the actuator.

[0012] In another embodiment, a metallic connection exists between the cooling element and the thermally conductive inner housing. This ensures that the heat dissipation from the inner housing to the outer cooling element is not interrupted.

[0013] In another embodiment, the cooling element is mounted on the outer surface of the actuator that seals off the wheel hub. During vehicle travel, the cooling element is continuously exposed to the airflow, which contributes to the rapid dissipation of heat transported from the inside to the outside.

[0014] In another embodiment, the cooling element is designed as a metallic decorative element. Such a cooling element contributes to the attractive design of the vehicle's wheel.

[0015] In a further embodiment, the electrical components comprise an electric motor which is operatively connected, via a transmission element that transmits the motor's rotational motion, to a coupling element that generates a linear motion from the motor's rotational motion. The coupling element is connected to a drive element designed to actuate the movable aerodynamic elements. Such an actuator can be centrally mounted on the wheel, thereby increasing the service life of the components used and improving their insensitivity to centrifugal forces and vibrations occurring in the vehicle, as well as to thermal loads. Such an actuator is suitable for use in various vehicle wheels, which is why large quantities can be manufactured in series production.

[0016] In a further embodiment, the transmission element is designed as a hollow spindle shaft that encloses the electric motor. The outer wall of the hollow spindle shaft engages positively with the coupling element for the linear displacement of the drive element. This results in a particularly compact unit that requires very little axial installation space and can therefore be conveniently installed in the hub of the vehicle wheel. The integration of signal and power transmission within the actuator also contributes to this compactness. In another embodiment, a rotor positioned on the coupling element engages, in a retractable and extendable manner, with a spindle thread in the outer wall of the hollow spindle shaft along its longitudinal axis to execute axial movement. Because the coupling element is arranged around the hollow spindle shaft, only a small amount of axial installation space is required to convert the motor's rotary motion into the linear motion of the drive element.

[0017] In a further embodiment, the disc-shaped drive element extends beyond the housing and features a channel designed as a central air passage opening in the area of ​​the electrical and / or electronic components for their cooling. This central air passage opening allows cooling air to flow to the actuator from the outside, further increasing the cooling effect.

[0018] Another aspect of the invention relates to a wheel for a vehicle, comprising a wheel hub arranged centrally in the wheel, a wheel rim arranged radially in the circumferential region of the wheel, and a wheel disc arranged in the intermediate region between the wheel rim and the wheel hub, which is divided into at least two separate movable disc segments, the angular position of which can be changed when controlled by an actuator integrated in the wheel hub, wherein the actuator is designed according to at least one feature described in this patent application.By means of such a vehicle wheel, the brake discs of the vehicle can preferably be cooled in case of overheating by means of different angular positions of the disc segments, which are set by the movement mechanism housed in the actuator, since the angular position sets an air gap between the disc segments through which a convective flow reaches the back of the vehicle wheel.

[0019] Further advantages, features, and details will become apparent from the following description, in which at least one exemplary embodiment is described in detail. The described features can, individually or in any meaningful combination, constitute the subject matter of the invention, optionally also independently of the claims, and can, in particular, also be the subject matter of one or more separate applications. The following are shown:

[0020] Fig. 1 shows a perspective view of an external view of an embodiment of the actuator according to the invention in its assembled state.

[0021] Fig. 2 shows a schematic representation of the actuator housing,

[0022] Fig. 3 shows a schematic representation of an embodiment of the vehicle wheel according to the invention with the actuator in a disengaged position in section, and

[0023] Fig. 4 shows a schematic representation of the vehicle wheel according to the invention with the actuator according to Figure 3 in a recessed position in section.

[0024] In the embodiment of the actuator 1 according to the invention shown in the figures, the actuator comprises a motor cage 3 into which an electric motor and a gearbox can be inserted. A hollow spindle shaft is inserted into the motor cage 3 from the opposite side and encompasses the electric motor. A coupling element 11, designed as a spider, engages the outside of the hollow spindle shaft by means of a rotor. A drive element 15 is connected to the coupling element 11 and is driven by the coupling element 11 into a linear back-and-forth movement. Accumulators are placed in the motor cage 3 and surround the hollow spindle shaft. A generator holder serves as a support for an unbalanced generator, which charges the accumulators while the vehicle is in motion. The generator holder also carries a power electronics unit (not shown).A housing 23 covers and seals a rotating unbalanced weight and the motor cage 3 with the components arranged therein. The housing 23 is sealed with a membrane that also allows moisture to escape from the housing 23. The electric motor, including the gearbox, is inserted into the motor cage 3 and is covered with an electronics cover. This cover serves to seal control electronics (not shown) and to house other electronic components. The electronics cover also has a membrane on its outer surface to allow moisture to escape. A wheel cover 31 forms the outer, visible part of the actuator 1. In an advantageous embodiment, the motor cage 3 has various recesses along its radial length to facilitate the sequential assembly of the electric motor, the hollow spindle shaft, the coupling element, and the batteries.The centrally arranged electric motor is operatively connected to the surrounding hollow spindle shaft via its motor shaft, thereby transmitting the rotary motion of the electric motor to the hollow spindle shaft. The hollow spindle shaft has a spindle thread on its outer circumference into which the rotor of the coupling element 11 engages positively and is guided back and forth in a linear motion in the axial direction, depending on the direction of rotation of the electric motor. This causes the drive element 15, which is connected to the coupling element 11, to move back and forth. The drive element 15 has drive pockets 36 along its circumference that project beyond the housing 23. The opening created by the drive element 15 is sealed by an overlap between the coupling element 11 and the housing 23.

[0025] An external view of the actuator 1 according to the invention in its assembled state is shown in Figure 1. The housing 23 with the integrated linear guide is shown, which is only visible externally through the coupling element 11 and the drive element 15, with the drive pockets 36 projecting radially from the housing 23. The wheel cover 31 serves to cover the mounting screws of the actuator 1 on the vehicle wheel. Figure 1a shows the drive element 15 and the coupling element 11 in a first position A of the linear movement L with a stop against the wheel cover 31. According to Figure 1b, the coupling element 11 and the drive element 15 have moved linearly towards the end of the housing 23 into a position B of the linear movement, covering a travel distance of approximately 20 mm.

[0026] Figure 2 shows a schematic representation of the housing 23 of the actuator 1, which is constructed in two parts: an outer housing 37 and an inner housing 39 that is positively inserted into it. The inner housing 39 is made of a thermally conductive material, for example, a metal such as aluminum, and is connected to the wheel cover 31 via a metallic connecting element 41. This wheel cover 31 is also made of a thermally conductive metal and serves as a heat sink for the actuator 1, as it is exposed to the airflow while the vehicle is in motion. Inside the inner housing 39 are the motor cage 3 with the electric motor, hollow spindle shaft, rotor of the coupling element 11, and other thermally sensitive components (not shown).The outer housing 37, which serves as a support for the inner housing 39, is made of a thermally non-conductive material, such as plastic, and protects the actuator 1 from vibrations, shocks, and mechanical damage. The drive element 15 is disc-shaped and has a circumferential channel 43.

[0027] Figure 3 shows an embodiment of the wheel according to the invention with the actuator 1 disengaged. A wheel hub 47 is centrally formed in the wheel 45 and is connected to an axle of the vehicle (not shown). A wheel rim 49 is arranged circumferentially around the wheel 45, on which a tire (not shown) can be mounted. A wheel disc 51 is located between the wheel hub 47 and the wheel rim 49, which is, for example, divided into four equally sized, separate, movable disc segments. For clarity, only two disc segments 511 and 513 are shown in the figures. The electromagnetic actuator 1, which extends axially within the wheel hub 47, is integrated therein. It is terminated with the wheel trim element 31 and is connected to all four disc segments 511 and 513 of the wheel disc 51 via connecting elements 53, which are designed as rocker arms.The ends 65 of the disc segments 511, 513 pointing towards the center are coupled to the outer drive element 15 of the actuator 1 via the connecting elements 53. Each disc segment 511, 513 is coupled to a wheel spoke 57 via a support element 55, the support element 55 being fixedly mounted to the disc segment 511, 513 and to a bearing point 59 on the wheel spoke 57, allowing it to rotate or pivot.

[0028] The actuator 1 can adjust the disc segments 511, 513 to two different angular positions. For this purpose, the actuator 1 is moved axially. In normal driving conditions, the actuator 1 is in a disengaged position, as shown in Figure 3. The disc segments 511, 513 form a fully enclosed cover for the wheel 45, with an outer edge 61 of the disc segments 511, 513 resting on the wheel rim 49. The channel 43 of the drive element 15 is closed by the wheel trim element 31, as this extends radially beyond the disc-shaped drive element 15. The connecting elements 53, designed as rocker arms, extend radially around the circumference of the drive element 15 and are coupled to the narrow side of the respective direct ends 65 of the disc segments 511, 513. The disc segments 511, 513 thus form a fully enclosed cover of the wheel 45.

[0029] Figure 4 shows an embodiment of the wheel according to the invention with the actuator 1 engaged. The engagement movement of the actuator 1 pulls the drive element 15 downwards, creating a gap to the wheel trim element 31. This gap generates an air gap 67 through which air (arrow P1) is drawn in from the surroundings, passes through the channel 43, and is released back to the outside via the air gap 69. The air gap 69 is created because the connecting elements 53 press the disc segments 511, 513 downwards, causing the disc segments 511, 513 to open against the wheel rim 49.

Claims

Mercedes-Benz Group AG Frank Thoms October 1, 2025 Patent claims 1. Actuator for arrangement in a hub (43) of a vehicle wheel (45) with movable aero elements (511, 513), comprising electrical and / or electronic components for adjusting the aero elements (511, 513) movably mounted on the vehicle wheel (45), characterized in that the electrical and / or electronic components are arranged in a housing (23) made of a thermally conductive material, which is connected to an external cooling element (31).

2. Actuator according to claim 1, characterized in that the housing (23) is formed in at least two parts and comprises an inner housing (39) comprising the electrical and / or electronic components made of the thermally conductive material, wherein the inner housing (39) is mounted in an outer housing (37) which is made of a thermally non-conductive material.

3. Actuator according to claim 1 or 2, characterized in that a metallic connection (41) exists between the cooling element (31) and the thermally conductive inner housing (39).

4. Actuator according to one of the preceding claims, characterized in that the cooling element (31) is placed on the outer surface of the actuator (1) which closes off the wheel hub (47).

5. Actuator according to one of the preceding claims, characterized in that the cooling element is designed as a metallic decorative element (31).

6. Actuator according to one of the preceding claims, characterized in that the electrical components comprise an electric motor which is operatively connected via a transmission element transmitting the motor rotational movement to a coupling element (11) generating a linear movement from the motor rotational movement, wherein the coupling element (11) is connected to a drive element (15) designed for actuating the movable aero elements (511, 513).

7. Actuator according to claim 6, characterized in that the transmission element is designed as a hollow spindle shaft which encloses the electric motor, wherein the outer wall of the hollow spindle shaft is in a positive engagement with the coupling element (11) for linear displacement of the drive element (15).

8. Actuator according to claim 7, characterized in that a runner positioned on the coupling element (11) is capable of moving up and down to perform an axial movement and engages in a spindle thread (35) of the outer wall of the spindle hollow shaft along its longitudinal extent.

9. Actuator according to one of the preceding claims, characterized in that the disc-shaped drive element (15) extends beyond the housing (23) and has a channel (43) designed as a central air passage opening in the area of ​​the electrical and / or electronic elements for cooling them.

10. Wheel for a vehicle, comprising a wheel hub (47) arranged centrally in the wheel (45), a wheel rim (49) arranged radially in the circumferential region of the wheel (45) and a wheel disc (51) arranged in the intermediate region between the wheel rim (49) and the wheel hub (47), which is divided into at least two separate movable disc segments (511, 513) whose angular position can be changed when actuated by an actuator (1) integrated in the wheel hub (47), characterized in that the actuator (1) is designed according to at least one of the preceding claims.

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