Heat sink for air flow generation and heat dissipation

Abstract

The present invention relates to a heat sink 1 for arrangement in a rotational component 2. The heat sink 1 rotates by way of a radial movement of the rotational component 2 and thereby generates an air flow for heat dissipation. Furthermore, the heat sink 1 is designed as a sleeve 3 with cooling ribs 4 and a support unit 5. The sleeve 3 has an elongate recess 6, and the heat sink is formed in a single piece and cylindrically. In a positioned state, the heat sink 1 presses at least in a planar manner against the inner wall of the rotational component 2, which ensures a torque transfer from the rotational component 2 to the heat sink 1. This invention is used in a vehicle which has a rotational component 2, and also contains a method for cooling, in which the heat sink 1 is introduced into the rotational component 2 and the rotational component is then set into a radial movement.

Description

[0001] Heat sink for airflow generation and heat dissipation

[0002] The present invention relates to a heat sink, in particular for arrangement in a rotary component, a vehicle comprising a rotary component with a heat sink, and a method for cooling with a heat sink.

[0003] Technological background

[0004] Cooling rotating components such as axles or shafts in a vehicle, and the components attached to them such as tires, brakes, etc., is critical, as these can generate significant heat during operation. Efficient cooling is desirable to maintain temperatures within an optimal range for the performance, durability, and safety of these components. Overheating can lead to premature wear, impaired functionality, and even serious damage. Furthermore, varying temperatures among vehicle tires result in impaired vehicle control. Therefore, developing cooling systems for this component is an essential step toward optimizing vehicle performance and reliability.

[0005] There are known publications from the state of the art that deal with cooling systems.

[0006] EP0763676B1 relates to a drive axle assembly equipped with a gearbox housing and two axle tubes extending from opposite sides of the gearbox housing. This assembly houses a differential gear, which is rotatably mounted and connected to an engine-driven propeller shaft via a yoke. This differential gear assembly efficiently transmits power to a pair of vehicle wheels via drive shafts extending through the axle tubes. An interesting feature is the inclusion of a specially designed radiator cover, typically made of lightweight materials. This radiator cover plays a crucial role in creating a lubricant reservoir within the gearbox housing when in place. This reservoir is partially filled with lubricant. A highlight of this system is the lubricant cooling, which is seamlessly integrated into the radiator cap.This cooling system features a T-shaped lubricant channel with a vertical inlet channel that flows into a horizontal channel with two outlet branches leading to the respective axle tubes. The rotation of the differential ring gear forces lubricant into this channel, effectively cooling the lubricant in the axle tubes during vehicle operation. Furthermore, a throttling mechanism within the lubricant channel ensures that the lubricant flow remains relatively constant at higher ring gear speeds.

[0007] DE102020206868A1 discloses a temperature-controlled axle cooling and filtration system that can be used in vehicles, particularly articulated dump trucks. This system is designed to cool the axles during braking and high-speed transport operations to prevent overheating. Temperature sensors monitor the temperature of the axle oil in the axles or along the axle oil line and activate the axle cooling system as soon as a predetermined temperature threshold is reached. The axle cooling system consists of various components, including motors, pumps, filters, and a control system. It can have multiple motor pumps that circulate the axle oil in closed hydraulic circuits to cool and filter the axles. The control system allows the flow rate of the axle oil to be controlled independently in each hydraulic circuit to ensure that the axle oil is properly cooled.

[0008] The cooling structure according to JPH11208300A is applied to a vehicle traveling at low speeds and features a hydraulically driven axle with a unitary structure in which a hydraulic pump and a hydraulic motor are installed in an axle housing. This cooling structure uses a cooling fan that rotates with the input rotation of the hydraulically driven axle to cool the axle. This cooling structure allows the cooling fan to continue operating while transmitting the rotational drive force to the hydraulically driven axle, effectively reducing the thermal expansion of the hydraulic oil. This enables reliable operation of the hydraulically driven axle, especially in industrial vehicles that cannot rely on the cooling effect of the airflow due to their predominantly low speed.The hydraulically driven axle can be efficiently cooled even at low speeds to prevent overheating. This cooling structure is useful for vehicles such as forklifts and other industrial vehicles. Furthermore, the cooling structure can be implemented with various configurations, including the placement of the hydraulically driven axle and the integration of the cooling fan with the drive shaft. Additionally, a cooling plate can be attached to the housing of the hydraulically driven axle to further improve cooling.

[0009] CN109367329A discloses a cooling system for axles designed to optimize heat dissipation and improve axle lifespan. It consists of a closed chamber with evaporation and condensation surfaces, filled with a heat transfer medium (e.g., ethyl alcohol) under vacuum. A liquid absorption core distributes the medium evenly. During vehicle operation, the axle transfers heat generated to the evaporation surface, which evaporates the medium. The vapor condenses on the condensation surfaces, releasing heat. Cooling fins on the surface maximize heat dissipation.

[0010] The disclosure described in US2458231 A relates to a water circulation system for cooling the wheel axles of railway carriages. The main objective is to reduce the risk of overheating and the formation of hot spots, thus increasing safety and minimizing accidents. The system uses hollow axles with water pipes running through them and utilizes the principle of heat exchange to effectively and evenly cool the entire axle, thus achieving the desired results simply and efficiently. The system consists of a network of water pipes connected to a radiator on the tender and driven by an electric pump. The system ensures that each axle is supplied with cool water. It is suitable for various types of rail vehicles, including passenger coaches, dining cars, and sleeping cars.

[0011] The conventional approaches used in the axle cooling solutions presented, such as external cooling by airflow or passive cooling systems, have several disadvantages. External cooling can be insufficient at low speeds or when stationary, leading to uneven cooling. Passive cooling systems are often less efficient and can reach their limits in extreme operating conditions. They also offer less flexibility in adapting to different vehicle types and require additional maintenance. Furthermore, they can significantly increase the overall vehicle mass. There also appear to be no current solutions that address the compensation of varying temperatures among vehicle tires. Finally, such cooling systems often require an additional power supply and their design is complex, which increases both manufacturing and operating costs.

[0012] Description of the invention

[0013] An object of the invention is to avoid at least some of the disadvantages of the prior art.

[0014] This problem is solved by the features of independent patent claim 1.

[0015] The solution according to the invention comprises a heat sink for arrangement in a rotating component, wherein the heat sink rotates due to a radial movement of the rotating component and thereby generates an air flow.

[0016] One advantage of this solution is that effective heat dissipation occurs through the rotation of the heat sink. The generated heat is dissipated naturally, effectively preventing overheating. Heat buildup can be caused by various components, such as a brake disc mounted on a shaft. This is particularly relevant if the brake disc is not located in the center of the shaft but closer to a vehicle tire, e.g., on a kart or go-kart. Such an arrangement can lead to significant temperature differences between the tires, which can then be compensated for by cooling via the heat sink.

[0017] If tires are not heated to the same temperature, significant problems can arise for a vehicle's performance and handling stability. Different tire temperatures mean different grip characteristics, which can lead to uneven traction, poor cornering stability, and compromised braking performance. This imbalance can also accelerate tire wear and cause unpredictable handling, particularly during high-speed driving or motorsport applications where precise control is critical. Therefore, it is important to ensure all tires are heated to the same optimal operating temperature to ensure consistent performance and safety on the track. Another key benefit of the solution is its energy efficiency.Unlike conventional cooling mechanisms, which often require external power sources such as electricity or fuel, the solution relies on self-sufficient operation. The movement of the heat sink is driven by the rotating component itself, meaning no additional power supply is required.

[0018] The self-sufficient power supply reduces the risk of interruptions or failures caused by disturbances in the external power supply, thus increasing the reliability of the cooling system, especially in safety-critical applications. Furthermore, the reduction in energy consumption leads to lower operating costs, as there are no additional energy costs, increasing the overall operating cost efficiency and extending the service life of the system. Last but not least, the environmental friendliness of the solution is worth highlighting, as lower energy consumption generally leads to a lower environmental impact and a lower carbon footprint, thus contributing to a reduction in the ecological footprint.

[0019] Last but not least, the integration of the heat sink into the rotating component enables a compact overall design. This not only significantly reduces space requirements but also expands the possibilities for optimizing the overall design. This means the system takes up less space overall, which is valuable in applications where space is limited.

[0020] Furthermore, the integrated design eliminates the need to install additional external cooling devices or systems. This eliminates the need to integrate any additional components or equipment into the overall system, significantly reducing installation effort and complexity. This simplifies and accelerates system integration and minimizes the time and resources required for commissioning and maintenance.

[0021] In addition, the integration of the heat sink into the rotating component contributes to improved overall performance, as cooling occurs directly at the point of heat generation. This leads to more efficient heat dissipation and overall better temperature control. The inventive solution can be supplemented and further improved by the following additional, individually advantageous embodiments.

[0022] According to one embodiment, it is provided that the air flow generated by the heat sink causes heat dissipation.

[0023] Another important advantage is that the airflow generated by the rotation of the heatsink affects not only the heatsink itself but also other components located within this airflow. This enables comprehensive cooling and can reduce or regulate the temperature of various parts of the system.

[0024] The generated airflow also supports the efficient temperature regulation of the tires, which can be achieved, for example, by cooling the rotating component.

[0025] The braking systems also benefit from the proposed concept, especially during braking, which generates a lot of heat. The generated airflow helps cool the brakes and maintain their effectiveness. Cooling is especially important for extreme applications, such as racing cars, where the brakes must deliver peak performance.

[0026] In addition, modern vehicles can be equipped with a multitude of electronic components such as sensors and control units located near the rotating component. Electronic components are temperature-sensitive, and targeted cooling by the generated airflow helps ensure their performance and service life.

[0027] According to one embodiment, the heat sink is designed as a sleeve in its outer shape.

[0028] This design allows for easy integration of the heat sink into various assemblies or systems. It can be easily embedded into existing components or integrated into new design concepts, increasing the adaptability and flexibility of the solution. Furthermore, the sleeve serves as a protective shield for the inner part of the heat sink. This protects the internal components from external influences such as dirt, dust, or mechanical damage. The sleeve-shaped design of the heat sink also allows for a larger surface area over which the heat sink can be in contact with the rotating component. This feature ensures that the heat sink does not experience undesirable axial displacement. This is achieved by the fact that the sleeve is fixed inside the rotating component and expands at elevated temperatures.This expansion of the sleeve ensures that the heatsink stays firmly in place, even under demanding operating conditions.

[0029] Finally, the larger shared surface area between the heat sink and the rotating component leads to more efficient heat dissipation, as a larger surface area allows for better heat transfer. Thus, the sleeve helps prevent overheating by effectively regulating the temperature of the rotating component.

[0030] One way to achieve greater design flexibility could be to create a modular sleeve structure. This would allow multiple sleeves to be connected together to increase cooling capacity as needed. This would allow the solution to be adapted to different requirements and further increase flexibility.

[0031] Additionally, the sleeve could be designed to be an easily replaceable unit. This would facilitate maintenance and repair, as damaged or worn sleeves could simply be replaced with new ones without replacing the entire system.

[0032] According to a further embodiment, it is provided that a torque can be transmitted from the rotation component to the heat sink.

[0033] The ability to transfer torque from the rotating component to the heat sink efficiently utilizes the available rotational energy. This allows the heat sink to be set in motion without the need for additional energy input. This results in a resource-efficient solution. One possible extension is the introduction of sensors and control systems that monitor the rotational movement and temperature of the rotating component. Based on this data, the torque transmission system could be automatically optimized to ensure precise and efficient cooling. This would help further improve the system's performance and reliability.

[0034] According to a further embodiment, it is provided that the heat sink is axially supported by a support unit.

[0035] The axial support of the heat sink ensures stable and reliable positioning within the rotating component. Furthermore, the use of a support unit contributes to the overall stability of the system, especially in applications subject to vibration or other mechanical stress. This ensures that the heat sink can effectively perform its function even under demanding operating conditions.

[0036] Furthermore, the support unit can be designed to offer additional functions, such as the integration of sensors to monitor operating conditions. This would improve system monitoring and control and increase efficiency.

[0037] According to a further embodiment, it is provided that the heat sink consists of a heat-conducting material, preferably of an aluminum alloy.

[0038] It is advantageous to use aluminum as the material of the heat sink because it is characterized by its excellent thermal conductivity, which enables efficient heat transfer between the rotating component and the heat sink.

[0039] Aluminum alloys can be produced in various forms. These typically consist of the base material aluminum (Al) and other alloying elements, such as magnesium (Mg), silicon (Si), manganese (Mn), copper (Cu), and zinc (Zn). By alloying with other elements, desired physical and mechanical properties can be achieved and influenced.

[0040] Another significant advantage is the low weight of aluminum. This lightweight construction minimizes the overall weight of the heat sink and the entire system, which is particularly important in applications where weight savings are required, such as vehicle or automotive engineering.

[0041] In addition, aluminum is also characterized by its high corrosion resistance. This ensures the long-term integrity of the heat sink, even under demanding environmental conditions, and contributes to extending the service life of the overall solution.

[0042] A possible alternative to aluminum alloy as a heat sink material could be copper. Copper exhibits similarly good thermal conductivity to aluminum, making it an efficient option for transferring heat from the rotating component to the heat sink. It is also corrosion-resistant, ensuring the long-term reliability of the heat sink under various environmental conditions.

[0043] According to a further embodiment, it is provided that the heat sink is formed with cooling fins, wherein the cooling fins have an angle by which the air flow can be influenced.

[0044] By using cooling fins, heat can be dissipated effectively because the airflow is generated efficiently. The cooling fins are designed to increase the surface area of ​​the heatsink. This allows for better heat dissipation, as the larger surface area provides more space for the heat to be dissipated into the surrounding air.

[0045] Additionally, the cooling fins are arranged to influence airflow. This can help direct airflow across the surface of the heatsink, further improving heat dissipation. Targeted airflow ensures that heated air is quickly dissipated and replaced with cooler air, optimizing cooling performance.

[0046] In addition, this feature enables an increase in the airflow, which can then be used to effectively cool the components located in the airflow along the rotating component.

[0047] Finally, this design allows the dimensions of the heatsink to be minimized so that it can be installed in smaller rotating components while still providing the necessary airflow and ensuring heat dissipation.

[0048] According to a further embodiment, the cooling fins have a spiral shape.

[0049] This special design enables even more efficient cooling and heat dissipation, optimizing the entire cooling process. The spiral arrangement of the fins further increases the surface area of ​​the heat sink. This leads to improved heat dissipation, as there is a larger surface area to effectively dissipate the generated heat into the surrounding air. This keeps the component being cooled at a lower temperature, increasing its service life.

[0050] Another significant advantage is the optimized airflow. The spirals generate a consistent and powerful airflow along the entire length of the spiral. This ensures efficient cooling over a significant length of the rotating component.

[0051] The spiral shape also helps reduce turbulence in the airflow, resulting in smoother and more efficient heat exchange between the fins and the surrounding air. This is especially important for optimizing thermal performance.

[0052] Finally, the adaptability of spiral fins offers an additional advantage. Depending on the specific requirements of an application, the coils can be wound tighter or looser to optimize cooling performance and control airflow.

[0053] According to a further embodiment, the sleeve has an elongated recess.

[0054] This recess allows the sleeve to expand when heated and optimally adapt to the interior of the rotating component. This has several positive effects. The improved conformability allows the sleeve to absorb and transfer heat from the rotating component more efficiently, which is particularly beneficial in applications where heat dissipation is important. In addition, the elongated recess results in the sleeve being better fixed both axially and radially. This significantly improves the stability of the system. The increased fixation helps reduce vibration and unwanted movement, which in turn increases the overall performance and reliability of the system.

[0055] In addition, the elongated recess allows the heat sink to be compressed during installation into a rotating component, allowing it to be precisely inserted and positioned inside the rotating component. The elongated recess can be designed as a groove or slot.

[0056] According to a further embodiment, the heat sink is designed as a single piece. This means that the heat sink is either a single piece or consists of a single part.

[0057] This design significantly simplifies the manufacturing process. Furthermore, such individual parts reduce both manufacturing costs and production time.

[0058] The manufacturing process can be carried out, for example, using LPBF (laser powder bed melting). This process allows the heat sink to be built up layer by layer from metal powder while simultaneously controlling the process to create a precise and homogeneous structure.

[0059] There are alternative additive manufacturing technologies that can be considered to replace LPBF (laser powder bed melting). One such option is electron beam melting (EBM), which uses a focused electron beam to melt the metal powder. EBM offers the advantage of being able to process materials with higher melting points.

[0060] Another alternative is binder jetting, in which a print head applies a binder to powder particles and solidifies them layer by layer. Compared to the intense energy sources of lasers or electron beams, this process is less heat-intensive and allows for the processing of a wide range of materials, including ceramics and metals.

[0061] Depending on the specific design of the heat sink, injection molding may also be a suitable manufacturing technology. During injection molding, the material is heated and injected into a mold, where it cools and assumes its final shape. For optimal heat dissipation, highly conductive materials such as aluminum and certain thermally conductive plastics are preferred. The manufacturing process begins with the design and manufacture of a precision mold that reproduces the exact geometry of the heat sink. The selected material is fed into the injection molding machine and heated to the required temperature. The heated material is then injected under high pressure into the mold, where it is evenly distributed. After injection, the material cools and hardens, assuming the desired shape of the heat sink.The finished heat sink is then removed from the mold and any burrs or protrusions are removed.

[0062] The heat sink can be manufactured in the form of a honeycomb structure. A honeycomb structure is a special geometric arrangement in which the internal structure of the heat sink consists of a regular arrangement of hexagonal or hexagonal cells. This structure resembles a honeycomb pattern and provides the heat sink with high mechanical strength, which is particularly important in demanding applications.

[0063] In addition, the one-piece construction offers increased stability. The heatsink can better withstand vibrations and mechanical stress, ensuring more reliable operation over a longer period of time.

[0064] Another important advantage is efficient heat dissipation. The one-piece construction allows the heatsink to more effectively dissipate heat from the components underneath.

[0065] According to a further embodiment, the heat sink has a cylindrical shape.

[0066] The cylindrical shape allows for even heat distribution along its surface, ensuring efficient heat dissipation.

[0067] Furthermore, the cylindrical shape saves space, as it requires less room than other shapes, such as fin-shaped heat sinks. This is particularly advantageous in applications where space is limited. Finally, the cylindrical shape of the heat sink allows for easy integration with rotating components that also have the same or similar shape, such as traditional axles, shafts, or hubs found in various types of vehicles.

[0068] Axles and shafts are used to support rotating machine parts such as wheels or rollers. Axles transmit force but not torque. In contrast, shafts are used to transmit torque. The hub is the part of a component that is connected to a shaft, axle, or journal. This part can be incorporated into a gear, lever, or wheel, for example.

[0069] According to a further embodiment, it is provided that the heat sink, in a positioned state inside the rotary component, presses at least flatly in one area against an inner wall of the rotary component.

[0070] This arrangement enables efficient heat dissipation from the rotating component to the heat sink. The close contact ensures maximum heat transfer surface area, significantly increasing cooling performance and preventing overheating.

[0071] Furthermore, it's worth mentioning that this configuration allows for torque transfer from the rotating component to the heatsink, causing the heatsink to rotate during rotation. The rotation of the heatsink creates an airflow, which then effectively serves to dissipate heat from the heatsink along this airflow.

[0072] The solution according to the invention also comprises a vehicle comprising a rotating component with a heat sink.

[0073] The application area of ​​this concept is broad and encompasses various types of vehicles. These include, for example, cars, trucks, Formula 1 racing cars, karts, and go-karts. The rotating component in this context can be an axle, shaft, or hub. When the vehicle is set in motion, for example, by its drive, the rotating component also begins to rotate. Due to the coupling between the heat sink and the rotating component, the heat sink rotates, creating an airflow within the rotating component. This airflow not only enables efficient heat dissipation but also cools components located in the airflow or in the surrounding area.

[0074] Such components can include various parts, including tires, which are typically located at the end of a shaft. These tires are subjected to high loads during vehicle operation and generate heat. Thanks to the airflow generated by the rotation of the heat sink, the heat from the shaft connected to the tires can be efficiently dissipated, contributing to cooling and extending the life of the tires.

[0075] In addition, other components located near the tires may also benefit from this airflow. These could include brakes, hubs, suspension components, or other mechanical parts. Targeted cooling of these components helps improve their performance and reliability and prevents potential problems due to overheating.

[0076] Additionally, electronic components may be located near the rotating component, such as sensors for monitoring wheel rotation or vehicle control electronics. Electronic components are sensitive to heat, and efficient cooling is crucial to maintaining their performance and longevity. The generated airflow can help stabilize the temperatures of these electronic components, thus ensuring their reliability and functionality.

[0077] The inventive solution also includes a method for cooling with a heat sink, which comprises at least two method steps. First, the heat sink is inserted into a rotating component. Second, the rotating component is then set in radial motion.

[0078] The heat sink can be inserted into the rotating component by slightly compressing the heat sink, which has an elongated recess, and thus inserting it precisely into the interior of the shaft.

[0079] First, integrating the heat sink into the rotating component enables efficient heat dissipation. Heat is dissipated precisely where it is generated. This can be the case, for example, on a shaft, where heat is generated by the use of a brake or brake disc.

[0080] Another advantage of this solution is its compact design. Since no external cooling device is required, space is saved and integration into existing systems is easier.

[0081] Finally, one of the remarkable features of this solution is that the airflow generated by the rotation of the rotating component, and therefore also of the heat sink, can be used not only for cooling the area where the heat sink is located, but can also cool neighboring components around the rotating component or at its end. In other words, cooling is not limited locally and also allows for comprehensive cooling of other parts of the system.

[0082] In kart racing, a lack of grip and what's known as "smearing" of the rear tires, especially the left rear tire, can occur. The brake is mounted on a steel axle as a rotating component and, depending on the track, can heat up to 350-400°C under high loads, depending on the track. This also heats the rear left wheel hub and tire. With a heat sink built into the rotating component, a temperature reduction of approximately 30% can be achieved. The heat sink is integrated into the rotating component and dissipates heat efficiently. This effect is enhanced by the large surface area of ​​the cooling fins. Torsion calculated using CFD airflow models accelerates the hot air and directs it out of the steel axle or rotating component to the right. A cooler brake results in more consistent performance and the effect of the rear left and right tire temperatures being virtually identical, remaining within ± 2-3°C, while increasing performance.

[0083] It is also possible to arrange the heat sink into the axle or shaft of a turbine, such as a water or wind turbine. The integration of a cooler into the axle of a turbine, as in a water or wind turbine, aims to dissipate heat effectively. By absorbing and dissipating the generated heat directly at the source, the cooler can minimize thermal expansion and shrinkage of the axle. These physical processes are usually a direct result of the temperature fluctuations caused by the operating load of the turbine. The axle of a turbine is supported by bearings to enable smooth rotation. However, thermal expansion and shrinkage can affect the alignment and clearance between the axle and bearing, which can lead to increased wear and potential malfunction.By reducing these thermal fluctuations, the heat sink ensures that the axle maintains its more stable and precise bearings. This leads to less mechanical stress on the bearings, thus increasing their service life and reliability.

[0084] The solutions according to the present disclosure can be combined in any way and further improved by the following embodiments, each of which is advantageous in its own right. Unless otherwise stated, the embodiments can be readily combined with one another.

[0085] Character description

[0086] Embodiments of the invention are described with reference to the following figures.

[0087] Fig. 1 : shows a schematic plan view of a kart;

[0088] Fig. 2: a schematic view of a rotary component with a heat sink;

[0089] Fig. 3: an enlarged schematic cross-section of a rotary component with a heat sink;

[0090] Fig. 4: a schematic perspective view of a heat sink;

[0091] Fig. 5: a sectional view of a heat sink;

[0092] Fig. 6: a perspective view of a heat sink arranged in a rotating component;

[0093] Fig. 7: a perspective view of a partial heat sink;

[0094] Fig. 8: a schematic perspective view of a heat sink without a support unit; Fig. 9: a perspective view of a heat sink arranged in the rotating component without a support unit;

[0095] Fig. 10: a schematic perspective view of a heat sink without a support unit;

[0096] Fig. 11: a one-piece heat sink; and Fig. 12A-C: a heat sink and a rotating component, wherein the heat sink is arranged in the rotating component.

[0097] In the following, the invention is described using exemplary embodiments relating to karts or go-karts. These karts are usually single-seater, open vehicles powered by an internal combustion engine or electric motor. However, the invention is not limited to karts or go-karts and can be used in

[0098] Machines, devices, vehicles, hubs or other applications where efficient cooling of a heated shaft is required.

[0099] Implementation of the invention

[0100] Figure 1 shows a schematic top view of a kart or go-kart 20. The kart vehicle 20 has a rotating component 2, which functions or is designed as a shaft. Within this shaft is a heat sink 1, which cools both the shaft and surrounding components. The kart 20 also includes an accelerator pedal 11, a brake pedal 12, a brake 9, and other components such as a driver's seat, a steering wheel, an engine, a transmission, wheel suspensions, etc., which are arranged on or at a chassis or frame. Alternatively, several heat sinks 1 can be arranged in the shaft. These heat sinks 1 can also have the same or different lengths.

[0101] When the kart is set in motion, the shaft begins to rotate, causing the heat sink 1 to move radially. If the driver wants to accelerate the kart, they press the accelerator pedal 11. If the driver wants to decelerate or stop the kart, they press the brake pedal 12, which activates the brake 9 or brake disc arranged around the shaft, causing the shaft and thus the kart 20 to decelerate.

[0102] This generates heat W (see Figure 2). The brake 9 or brake disc heats the rear axle 2.

[0103] The rotating component 2 and also the tire 7A are heated more than the tire 7B because the brake 9 is located closer to the tire 7A than to the tire 7B. To compensate for the different temperatures of the tires 7A-B, the heat sink 1 is provided, which achieves this through an air flow S generated by the rotation (see Figure 2). The air flow S helps to reduce the temperatures of the rotating component 2 and equalize the temperatures of the tires 7A-B to maintain an optimal operating temperature.

[0104] Furthermore, the effective cooling of the brake 9 and the tire(s) 7A-B by the heat sink 1 and the generated airflow S not only contributes to improved driving stability but also extends the service life of the tires 7A-B. Overheated tires 7A-B tend to wear faster. Their grip properties may be compromised. High temperatures can cause the rotating component 2 or shaft to lose its strength or expand unevenly, which in turn can compromise the structural integrity of the shaft. A cool shaft remains stiffer and more stable.

[0105] During a race, the rotating component 2, also known as the shaft or axle, is subjected to torsional forces, especially during cornering. A cooler rotating component 2, or rear axle 2, minimizes metal expansion, improving torsional strength. This enables more precise steering in challenging cornering.

[0106] By reducing the temperature at the rotational component 2, or rear axle, the stability of the kart 20 is increased. This results in improved grip of the tires 7A-B and better vehicle dynamics, helping to stabilize the kart 20 during fast corners and abrupt changes of direction.

[0107] A consistently cool rear axle 2 reduces the thermal stress on the wheel spiders, hubs, tires 7A-B, and brake 9. Overheating can impair the performance of brake 9 and tires 7A-B. The heat sink 1 significantly improves the performance of the components. A reduction in the core temperature of brake 9 or brake disc by over 30% can be achieved.

[0108] A brake that's approximately 30% cooler is less prone to overheating and allows for more consistent braking performance throughout a race. This allows drivers to use their brakes more aggressively without worrying about a potential drop in braking performance.

[0109] This also contributes to safety. Overheated brakes can lead to brake failure, which can create dangerous situations on the racetrack. Cooler brakes significantly reduce the risk of brake failure, thus contributing to the safety of the driver and others on the racetrack.

[0110] More consistent braking performance allows drivers to better plan their lap times and drive more precisely. They can more accurately estimate deceleration and braking points, resulting in better overall vehicle handling. In a competitive environment, improved braking performance can provide a decisive advantage. A driver who can use their brakes more effectively and is less affected by overheating has a better chance of beating the competition.

[0111] Figure 2 shows a schematic side view in cross-section of a rotating component 2 with a heat sink 1. In this figure, the rotating component 2 is designed as a hollow shaft containing the heat sink 1 inside. As soon as the shaft is set in motion, the heat sink 1 also begins to rotate. The clever placement of the heat sink 1 is at a location that is characteristic for the generation of heat W, for example, near the brake 9 with a brake disc attached to the shaft of the kart.

[0112] The brake 9, or the kart's braking system, slows the rotation of the shaft through a combination of components, specifically a brake disc and a brake shoe. The brake disc, which is directly connected to the kart's shaft, rotates with it. When the driver depresses the brake pedal 12, a mechanism comes into play that exerts a force on the brake shoes. In a disc brake system, this force is transferred to the brake pads in the brake caliper. This force exerted by the brake shoes or blocks creates friction between them and the rotating brake disc. As a result, the shaft begins to slow down and eventually comes to a stop. Furthermore, the friction generates heat, which warms the shaft and the components attached to it, such as the wheels 10A-B and tires 7A-B.

[0113] The generated heat can be dissipated by the rotating heat sink 1 by transferring this heat to the incoming or sucked-in input air EL. The input air EL is consequently heated, passed through the heat sink 1 via cooling fins 4 or louvers, and output as warm output air AL. This cooling and the generated air flow are important for several reasons. Primarily, they serve to dissipate the generated heat in such a way that components in the vicinity of the heat sink 1, such as the shaft or tires, do not further increase their temperature. In addition, overheating of the brake 9 is avoided. An overheated braking system can impair its effectiveness and negatively impact braking performance.

[0114] Furthermore, the brake 9 or brake disc mounted on the axle of a kart is typically not positioned in the center, but closer to a wheel 10A or tire 7A. This enables effective braking, which can lead to improved stability, traction, and controllability of the vehicle, especially in curves or during rapid deceleration.

[0115] Since the brake 9, as shown in Figure 1, is closer to the rear wheel 10A and therefore also to a tire 7A, this wheel heats up more during braking than the other 7B. This can lead to a different temperature distribution between the two tires 7A, 7B, which can result in different behavior or handling.

[0116] A warmer tire (7A) typically has more grip, while a cooler tire (7B) has less grip. Therefore, if the brake (9) is positioned closer to one of the rear wheels and that wheel (10A) heats up more, this can affect the kart's handling and lead to an uneven distribution of forces between the wheels (10A and 10B), which can affect driving stability and steering response.

[0117] To avoid or improve this behavior, the heat sink 1 is arranged inside the shaft.

[0118] Figure 3 illustrates an enlarged schematic cross-section of a rotating component 2 with a heat sink 1. It can be seen that a sleeve 3 of the heat sink 1 is in contact with the inner surface of the rotating component 2. Heat W is transferred from the rotating component 2 to the heat sink 1 and dissipated by an air flow S generated by the rotation of the cooling fins 4 of the heat sink 1. Finally, the cooling fins 4 are arranged on a support unit 5, which can be designed in the form of a hollow tube.

[0119] In a further embodiment, the support unit 5 is omitted, so that the area of ​​the cooling fins 4 is enlarged, since they can be formed up to the central axis.

[0120] Figure 4 shows the individual components of the heat sink 1. In this embodiment, the heat sink 1 consists of several independent parts, including a sleeve 3 having an elongated recess 6, a support unit 5, and cooling fins 4 arranged spirally on the support unit 5. The material used for the entire heat sink 1 is preferably aluminum or an aluminum alloy. This material is characterized by very good thermal conductivity, meaning it can dissipate heat efficiently. At the same time, aluminum is cost-effective and, due to its formability and machinability, is well suited for the production of the heat sink 1.

[0121] The sleeve 3 fulfills a dual function. On the one hand, it serves to protect the cooling fins and maintain their integrity. On the other hand, the sleeve 3 increases the adaptability of the heat sink 1 to the rotating component 2, thereby ensuring efficient transmission of torque and heat. The surface of the sleeve 3 is preferably smooth or provided with a finish. In a particular embodiment, the sleeve 3 is designed by a surface treatment such that the sleeve surface adapts particularly well to the inner surface of the rotating component 2. This ensures optimized heat transfer.

[0122] The elongated recess 6 in the sleeve 3 fulfills an equally important function. The recess 6 allows the sleeve 3 to expand or contract depending on the temperature conditions to which it is exposed. This thermal expansion capability is important because it ensures that the sleeve retains its shape and fit even when it expands or contracts due to heating or cooling. In this way, the structural integrity of the heat sink and efficient heat dissipation are maintained even during temperature fluctuations. Alternatively, a locking mechanism, e.g., with a locking slot, can be incorporated into the sleeve 3.

[0123] The support unit 5 is designed in the form of a hollow tube or core tube and primarily serves the function of supporting the cooling fins mounted on this component. The cooling fins are attached to the support unit 5 at an angle of approximately 30° to efficiently influence the airflow in the rotating component 1 and generate a powerful airflow, which leads to better heat dissipation. The outer diameter of the support unit 5 can be selected according to an optimized airflow.

[0124] In another embodiment, the heat sink 1 is manufactured as a single component. This monoblock construction offers several advantages. First, it ensures high structural integrity and stability of the heat sink, as there are no joints or gaps that could be weak. This is particularly important because the heat sink operates in a rotating system and is therefore subject to strong mechanical stress.

[0125] The heat sink 1 can be manufactured using laser powder bed fusion technology. This additive manufacturing process enables a precise and complex design of the heat sink 1. During the process, aluminum powder is applied layer by layer and melted using a laser or electron beam to form the heat sink 1. The structure can be honeycomb-shaped, which ensures particularly high stability of the heat sink 1.

[0126] Figure 5 shows a sectional view of the heat sink 1, in which in particular the positioning of the cooling fins on the support unit 5 with respect to the fin angle is highlighted.

[0127] The fin angle changes the airflow direction. This influences the speed and pressure of the air flowing over the surface of the cooling fins 4. A larger fin angle results in a greater drop in pressure on the front side of the cooling fins 4 and a greater increase on the back side. This pressure difference leads to an acceleration of the airflow S over the cooling fins 4, which improves heat dissipation.

[0128] Because the air or ambient air in front of the fins is at lower pressure, it is essentially sucked in, accelerating the airflow over the fins. This increases convection, as the air can absorb more heat from the fins. At the back of the fins, the air is expelled to the outside, which promotes the dissipation of the absorbed heat.

[0129] Selecting the correct fin angle is crucial, as it significantly influences the efficiency of the cooling process. When designing a heat sink, careful consideration should be given to which fin angle is best suited for the specific application.

[0130] A fin angle that is too small can result in insufficient air acceleration, making heat dissipation inefficient. A fin angle that is too large can lead to flow problems and insufficient heat transfer. Engineers and designers must therefore consider several factors, including the specific cooling requirements, the geometry of the heat sink, and the type of medium to be cooled—i.e., the air.

[0131] In addition to choosing the optimal fin angle, other factors such as fin height, spacing between fins, and the thermal conductivity of the material must also be considered to achieve maximum cooling performance. A typical fin angle is usually between 10 and 45 degrees.

[0132] Figure 6 shows a perspective view of the heat sink 1 arranged in the rotating component 2. The rotating component 2 functions here as the shaft of a vehicle and houses a brake 9 or brake disc that influences the rotational movement of the shaft. This shaft is closely connected to a wheel 10A carrying a tire 7A.

[0133] The heat sink 1 is strategically positioned within the shaft to effectively dissipate the heat generated during braking operations, in which the brake 9 is applied with the brake disc, by drawing in an inlet air EL and expelling an outlet air AL. The heat sink 1 plays a significant role in ensuring that temperatures remain within an acceptable range during braking, thus ensuring braking performance and efficiency. Furthermore, the heat dissipation also prevents the temperature of the tire 7A from increasing further, resulting in better vehicle control.

[0134] Figure 6 also shows that heat sink 1 requires no external power supply and rotates along with the shaft. This unique property demonstrates the efficiency of heat sink 1 in passive operation. Since it is mounted directly within the shaft, heat sink 1 utilizes the kinetic energy and airflow generated by the rotation to dissipate heat.

[0135] Figure 7 shows a perspective view of the heat sink 1. The heat sink is intentionally depicted without a sleeve 3 to allow a clear representation of the cooling fins 4 attached to the sleeve 3.

[0136] Furthermore, the cooling fins 4 have a rectangular shape and are arranged spirally within the sleeve 3. This spiral arrangement allows a large number of cooling fins 4 to be placed in a limited space, which in this case is inside the shaft. This solution optimizes the use of available space.

[0137] Furthermore, it should be noted that other cooling fin shapes are also possible depending on specific requirements and design considerations. Computational Fluid Dynamics (CFD) simulations help determine the optimal shape and arrangement of the cooling fins 4 for a specific application, such as heat dissipation from a brake or brake disc 9.

[0138] Figure 8 shows a schematic perspective view of a heat sink 1 without a support unit 5. It is advantageous if the heat sink 1 is manufactured without the support unit 5. Above all, the manufacturing costs and time can be reduced because one less component has to be manufactured. If the heat sink 1 is manufactured using a 3D printing process, this means reduced material consumption, shorter printing time and fewer complex post-processing steps. The sleeve 3 with recess 6 and the cooling fins 4 can be produced in one manufacturing process as one part, i.e. heat sink 1. In Figure 8, however, the cooling fins 4 and the sleeve 3 are shown separately for clarity.

[0139] The spiral shape of the cooling fins 4 enables efficient heat dissipation, as they offer a larger surface area for heat dissipation. Furthermore, the absence of a support unit 5 leads to a weight reduction of the heat sink 1. This is important because, in one embodiment, the heat sink 1 is arranged in a rotating component 2, for example, a shaft of a kart 20. In such applications, every additional gram of weight is significant, as it increases the rotating mass and can thus impair performance. Therefore, the proposed design solution is particularly well suited for a kart 20, as it accelerates quickly, corners efficiently, and has better maneuverability overall.

[0140] In addition, the reduced weight of the heatsink 1 can result in savings in operating costs, as less energy is required to move the kart 20.

[0141] Figure 8 shows the sleeve 3 with the recess 6. It is advantageous if the recess 6 extends spirally through the sleeve 3, as the recess 6 is then longer than if it were designed as a straight line. This leads to better functionality of the recess 6 when expanding and shrinking due to temperature changes of the heat sink 1 and also increases the adaptability of the heat sink 1 to the rotating component 2. Alternatively, the recess 6 can also be designed differently, e.g., as a straight groove or with additional milled recesses.

[0142] Figure 9 illustrates a perspective view of a heat sink 1 arranged in a rotating component 2 without a support unit 5. Compared to Figure 6, the heat sink 1 is positioned inverted here, with the cooling fins 4 being provided with an angle that causes ambient or inlet air EL to be drawn in approximately centrally from the tire 7A, while the outlet air AL is discharged to the left of the heat sink 1. This illustration illustrates a general application of the heat sink 1, in which it can be placed in either direction within the rotating component 2.

[0143] In addition, the heat sink 1 serves to effectively dissipate the heat W generated by the brake 9 in order to avoid overheating of the rotation component 2 and the components connected to it, such as the tire 7A and the wheel 10A.

[0144] Figure 10 shows a schematic perspective view of a heat sink 1 without a support unit 5. As can be seen, the heat sink 1 consists only of a sleeve 3 and spiral-shaped cooling fins 4. Furthermore, the heat sink 1 is arranged in a rotating component 2, the rotation of which generates an air flow with an inlet air EL and an outlet air AL. This air flow S is used to effectively dissipate the heat W via the heat sink 1 or the cooling fins 4.

[0145] Figure 11 shows a perspective view of a one-piece heat sink 1. The manufacturing process allows for high-precision production that is efficient and cost-effective. The material should be lightweight, highly conductive, and non-metallic. The heat sink 1 in this example weighs 143 grams, measures 0.50 mm, and is 300 mm long.

[0146] Figure 12A shows (partially) a rotating component 2 for accommodating a heat sink 1. The rotating component 2 has three openings or holes 30 into which an anti-slip device can be inserted. More or fewer openings 30 can be provided. The heat sink 1 is held securely in place by a radial lock when inserted. The heat sink 1 has radial recesses 32 that serve to increase the flexibility of the cooler. Figure 12B shows a heat sink 1 being inserted into a rotating component 2. It can be seen how an elongated opening in the heat sink is positioned with the opposing holes 30. This ensures radial locking of the heat sink 1, which contributes to the heat sink 30 rotating with the rotating component 2. The radial locking can be achieved, for example, by means of a screw or by using bolts that are passed through the openings and fixed.

[0147] Figure 12C shows a heat sink 1 arranged in a rotating component 2.

[0148] The present disclosure provides a heat sink, in particular for arrangement in a rotating component. It goes without saying that a person skilled in the art can conceive numerous other areas of application in the field of rotating components based on the exemplary embodiments described.

[0149] List of reference symbols

[0150] Heatsink 1

[0151] Rotation component 2

[0152] Sleeve 3

[0153] Cooling fins 4

[0154] Carrying unit 5

[0155] Recess 6

[0156] Tires 7A, 7B

[0157] Brake 9

[0158] Wheel 10A, 10B

[0159] Accelerator pedal 11

[0160] Brake pedal 12

[0161] Kart 20

[0162] Openings or holes 30

[0163] Recesses 32

[0164] Inlet air EL

[0165] Outlet air AL

[0166] Heat W

[0167] Airflow S

Claims

AMENDED CLAIMS received by the International Bureau on 24 January 2025 1. Heat sink (1) for arrangement in a rotary component (2), wherein the heat sink (1) rotates due to a radial movement of the rotary component (2) and thereby generates an air flow (S), wherein the heat sink (1) in a positioned state inside the rotary component (2) presses at least flatly in one area against an inner wall of the rotary component (2), so that a torque transmission from the rotary component to the heat sink is possible.

2. Heat sink (1) according to at least one of the preceding claims, wherein the air flow (S) generated by the heat sink (1) causes heat dissipation.

3. Heat sink (1) according to claim 1, wherein the heat sink is designed in its outer shape as a sleeve (3).

4. Heat sink (1) according to at least one of the preceding claims, wherein a torque can be transmitted from the rotation component (2) to the heat sink (1).

5. Heat sink (1) according to at least one of the preceding claims, wherein the heat sink (1) is formed with cooling fins (4), wherein the cooling fins (4) have an angle by which the air flow (S) can be influenced.

6. Heat sink (1) according to claim 5, wherein the cooling fins (4) have a spiral shape.

7. Heat sink (1) according to at least one of the preceding claims, wherein the heat sink (1) is axially supported by a support unit (5).

8. Heat sink (1) according to at least one of the preceding claims, wherein the heat sink (1) consists of a heat-conducting material, preferably of an aluminum alloy.

9. Heat sink (1) according to at least one of the preceding claims, wherein the sleeve (3) has an elongated recess (6). AMENDED SHEET (ARTICLE 19) 10. Heat sink (1) according to at least one of the preceding claims, wherein the heat sink (1) is designed in one piece.

11. The heat sink (1) according to at least one of the preceding claims, wherein the heat sink (1) has a cylindrical shape.

12. A vehicle comprising a rotating component (2) with a heat sink (1) according to one of claims 1 to 11.

13. Device, in particular a machine, comprising a rotary component (2) with a heat sink (1) according to one of claims 1 to 11.

14. Method for cooling with a heat sink (1) according to one of claims 1 to 11 comprising at least the method steps: Inserting the heat sink (1) into a rotating component (2); and Setting the rotational component (2) into a radial movement. AMENDED SHEET (ARTICLE 19)

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