Heat exchanger

Abstract

The invention relates to a heat exchanger (1) for transferring heat between two components (2) which can be moved relative to one another, having two contact elements (3) which are arranged at a distance from one another and can be moved relative to one another and each have a contact surface (4), by means of which a respective one of the moving components (2) can be extensively contacted, in order to exchange heat between the respective contact element (3) and the respectively contacted component (2) via the contact surface (4), and a heat transfer fluid (5) enclosed between the contact elements (3, 3'), wherein the heat exchanger (1) is designed as a prefabricated machine element. In this way, an efficient heat transfer between two components (2) moved relative to one another is made possible by means of a separately operated machine element, without a cooling fluid having to be directed onto a moving part.

Description

[0001] Heat exchanger

[0002] The invention relates to a heat exchanger for transferring heat between two components that can move relative to each other.

[0003] The transfer of heat between moving components presents a technical challenge that often requires considerable effort and high costs to overcome. A common example is the cooling of a spindle shaft, where cooling is achieved by transferring a cooling fluid to the rotating shaft, as described in EP 2058085 Bl. This document describes a cooler with a rotating shaft, a stationary lance, and a cooling circuit with a coolant inlet and outlet. The shaft is cooled by a coolant through cooling bores, with the cooler designed such that the coolant is introduced into the lance from the inside out into the shaft via the cooling bores. The lance is supplied with coolant, which can withstand centrifugal force. Lip seals are symmetrically arranged on the lance that supplies the coolant.Sealing and guiding the fluid flow presents a significant challenge and can only be achieved with considerable additional effort. The fluid transfer unit for spindle shaft cooling consists of numerous components, all of which must interact to ensure the cooling process. The spindle shaft must be bored to channel the coolant, requiring additional work steps and precision. Furthermore, the installation space at the spindle end is occupied by the transfer unit, thus reducing the available space for other functional units, such as clamping systems. Although this system is fundamentally functional, the high complexity and associated costs are reasons why it is rarely used in practice.

[0004] Another example of the challenge of cooling moving parts can be found in linear motors. Here, the moving primary part is also cooled by coolant. This coolant is fed into one or more cooling circuits via moving lines and then drawn off again. Precision coolers, primary and secondary coolers are connected to a cooling unit by hoses or pipes. Since the primary and precision coolers are located on the moving carriage, they must be connected to the cooling system via cable chains and correspondingly flexible coolant lines.

[0005] The central problem with these known solutions is the transfer of coolant to the moving components. The special sealing systems and flexible hose guides required for this are complex to implement, lead to intricate designs, and increase the required installation space. This complexity not only makes the manufacturing and maintenance of the systems more difficult but also increases their susceptibility to malfunctions and failures, ultimately increasing operating costs.

[0006] Another aspect is cooling efficiency. The moving parts and the multitude of components used for cooling lead to heat loss and less efficient heat dissipation. Furthermore, the moving cooling lines are subject to greater wear, which shortens their lifespan and necessitates more frequent maintenance and component replacements. These factors also contribute to the high operating costs and reduced reliability of the systems.

[0007] In addition to the technical challenges, there are also economic and environmental aspects that must be considered. The manufacturing and maintenance of complex cooling and sealing systems are costly, and the increased material and energy consumption also negatively impacts the environmental footprint of the systems. Therefore, there is an urgent need for alternative solutions that are more advantageous technically, economically, and environmentally.

[0008] In summary, current methods for cooling moving components present significant technical and economic challenges. The need for specialized sealing systems and flexible hose routing leads to complex designs and increased installation space requirements, making the implementation of such systems both costly and time-consuming. Furthermore, these factors negatively impact the efficiency and reliability of cooling systems, which in turn increases operating costs and worsens the environmental footprint. Therefore, there is an urgent need for new, innovative solutions that address these problems and enable efficient, reliable, and cost-effective cooling of moving components.

[0009] Based on this, the object of the invention is to enable a high-performance heat transfer between two components moving relative to each other in a simple and efficient manner, without the need to direct a cooling fluid onto a moving part.

[0010] This problem is solved by the subject matter of claim 1. Preferred embodiments are found in the dependent claims.

[0011] According to the invention, a heat exchanger is provided for transferring heat between two components that can move relative to each other, with two contact elements arranged at a distance from each other and movable relative to each other, each having a contact surface with which one of the moving components can be contacted over a surface in order to exchange heat between the respective contact element and the respective contacted component via the contact surface, and a heat transfer fluid enclosed between the contact elements, wherein the heat exchanger is designed as a prefabricated machine element.

[0012] According to the invention, heat is transferred between the two components by means of an easy-to-handle and compact heat exchanger, e.g., from a moving component to a stationary component or vice versa. From there, the heat can be dissipated using known techniques, such as liquid cooling. The heat exchanger is provided as a prefabricated machine element parallel to conventional bearing elements, such as rolling bearings, and must dissipate heat exclusively and not forces. Preferably, the heat exchanger is therefore not designed to dissipate forces. The heat exchanger according to the invention is thus a machine element whose primary, or even sole, function is heat transfer.In the technical field of mechanical engineering, the term "machine element" refers, from a design perspective, to a component of a structure that cannot be meaningfully divided, performs a specific function (in this case, heat conduction), and whose properties can be determined in advance, i.e., during prefabrication. The invention thus provides a machine element that enables efficient heat transfer between two components moving relative to each other and is supplied as a ready-to-install, self-contained system.This machine element can fulfill the function of heat transfer between moving parts in different machines and devices and can therefore be used repeatedly in the design in the same or similar form with adapted dimensions and geometries, analogous to machine elements (such as rolling bearings, only with different functions) with previously known heat transfer properties.

[0013] The heat exchanger according to the invention thus represents a self-contained unit that can be provided in various embodiments and then used in different designs. The heat exchanger according to the invention is easy to assemble and disassemble and can be easily replaced for maintenance purposes. Due to prefabrication, the heat exchanger, which can be realized in various embodiments according to the invention, therefore possesses defined, known properties, such as those relating to heat transfer, geometry, tolerances, and possibly other parameters that can be taken into account during prefabrication.

[0014] One embodiment of the invention provides that the heat transfer fluid enclosed between the contact elements makes direct contact with them. This direct contact allows the heat transfer fluid to ensure highly efficient heat transfer. This is particularly advantageous when large amounts of heat need to be transferred. The direct contact of the fluid with the contact elements minimizes thermal resistance, which improves thermal conductivity and enables rapid heat dissipation. This direct contact also allows the fluid to compensate for minor irregularities or deformations of the contact surfaces, increasing the overall efficiency of the heat exchanger. The need for additional heat-conducting structures is minimized, resulting in simpler design and lower production costs.The heat exchanger can be used in parallel with conventional bearing elements without affecting their function, making it flexible to integrate into various machines and systems.

[0015] In another embodiment, the heat exchanger is combined with a bearing element in a self-contained unit that can be manufactured, supplied, and used as a machine element. By combining these two functions—heat transfer and mechanical support—in a single element with two functional areas, a particularly compact design and simplified assembly are achieved. The fluid absorbs heat directly from the warmer contact element and transfers it directly to the cooler contact element without any intermediate stages, thus increasing efficiency.

[0016] The heat transfer fluid contributes to a homogenized temperature distribution by compensating for temperature differences between the contact elements. By reducing thermal stresses and ensuring even heat distribution, the service life of the components involved, including the drive and bearing components, can be extended. Thanks to its compact design and the ability to be used in parallel with conventional bearing elements, the heat exchanger can be easily integrated into existing systems. This heat exchanger design thus offers a range of advantages and features that can contribute to increased efficiency and improved reliability and service life of machines and systems.

[0017] According to one embodiment of the invention, the open areas between the contact elements are sealed by means of seals fixed to both contact elements, which allow relative movement of the two contact elements to each other. The seals can be designed to be flexible. The flexible design of the seals allows for a high degree of freedom of movement of the contact elements without impairing the seal. This is particularly advantageous in applications where relative movement of the components is necessary, such as in oscillating linear movements, possibly in combination with a rotary movement. The flexible seal ensures that the heat transfer fluid is reliably retained within the system, which increases the efficiency of the heat transfer and minimizes the risk of leakage. This ensures the continued function of the heat exchanger even with continuous movement of the contact elements.Another advantage of this design lies in the longevity of the seals, as they are flexible enough to absorb the mechanical stresses caused by relative movement without losing functionality. This results in less wear and tear and reduced maintenance, which lowers operating costs and extends the service life of the entire system. The flexible seals also allow for a more compact heat exchanger design, as they require less space than complex sealing systems. This facilitates the integration of the heat exchanger into existing machines and systems without the need for major modifications.

[0018] In principle, sealing can also be achieved using other known sealing technologies. These include both non-contact seals, such as gap seals, labyrinth seals, baffle plates, seals based on the sealing air principle, spray edges or centrifugal discs, and contact seals, such as mechanical seals, metallic sealing discs, elastomer seals in various designs and lip seals.

[0019] According to one embodiment of the invention, the contact elements are designed as rotationally symmetrical rings and arranged relative to each other in such a way that they can rotate about one another. In this context, according to one embodiment of the invention, the open areas between the rings are sealed on both sides by a sealing arrangement comprising either a seal fixed to one ring and able to slide on the other ring in a sealing manner, or two seals, each fixed to a ring and able to slide on top of each other in a sealing manner. This offers several advantages and functions: The rotationally symmetrical design of the rings ensures a uniform distribution of forces and a constant contact area between rotating elements, which improves the efficiency of heat transfer.The double-sided sealing of the open areas between the rings by a sealing arrangement, which either comprises a seal fixed to one ring and able to slide over the other ring in a sealing manner, or comprises two seals, each fixed to a ring and able to slide over each other in a sealing manner, ensures a reliable seal. This prevents the escape of the heat transfer fluid and ensures that heat transfer can occur unimpeded.

[0020] A further advantage of this design lies in the increased durability and reliability of the seals, as they are specifically designed to seal rotational movements without any loss of effectiveness. Fixing the seals directly to the rings ensures a stable and permanent seal that functions reliably even under prolonged operating conditions. Furthermore, the ring design allows for easy integration into existing systems and adaptation to various applications, as the rings can be manufactured in different sizes and materials to meet specific requirements. This also results in a uniform heat distribution across the entire contact surface, contributing to more effective cooling and thermal regulation. This is particularly advantageous in applications requiring continuous and uniform heat transfer.Overall, this design offers high efficiency and reliability in heat transfer, very good sealing and durability, as well as flexible adaptability to various applications.

[0021] One embodiment of the invention provides that the open areas between the rings are sealed on both sides by two sealing arrangements, each comprising a seal fixed to one ring and able to slide on the other ring in a sealing manner, or comprising two seals, each fixed to a ring and able to slide on top of each other in a sealing manner, wherein a fluid other than the heat transfer fluid is arranged between each of the two sealing arrangements and the heat transfer fluid is arranged between the two pairs of the two sealing arrangements. According to one embodiment of the invention, the fluid other than the heat transfer fluid is selected such that it provides a seal against atmospheric oxygen, thus preventing or reducing oxidation of the heat transfer fluid.This design ensures increased durability and stability of the heat transfer fluid, as it effectively prevents the ingress of oxygen, which could cause oxidation-related damage. This leads to a longer system lifespan and reduces maintenance requirements, since the heat transfer fluid does not need to be replaced or treated as frequently. Furthermore, the efficiency of the heat transfer system is increased because the fluid remains in optimal condition and maintains its thermal properties over a longer period.

[0022] A further advantage of this design lies in the improved sealing performance achieved through the double sealing arrangement. This creates a reliable barrier against the ingress of contaminants and the escape of heat transfer fluid. This ensures consistent and effective heat transfer and minimizes the risk of leaks. By selectively choosing a different fluid than the heat transfer fluid, other beneficial properties can also be utilized, such as high resistance to chemical influences or low viscosity to minimize friction between the seals. This contributes to reducing mechanical wear and extends the service life of the seals and the entire system.Overall, this design offers high efficiency and reliability in heat transfer, effective sealing and protection of the heat transfer fluid against oxidation, extended service life of the system components, and reduced maintenance and fluid replacement requirements. The complex sealing structure and the specific selection of the sealing fluid contribute to increased operational reliability and maximize the heat exchanger's performance.

[0023] One embodiment of the invention provides that the heat transfer fluid has a thermal conductivity of at least 1 W / (m K) or more in the temperature range between -10 and +200 °C. According to one embodiment of the invention, the heat transfer fluid comprises a liquid metal that is liquid at a temperature of 20 °C. The liquid metal can be selected from the group consisting of sodium-potassium alloys, a gallium-containing alloy, such as Gallinstan (gallium, indium, and tin), EGa-In-Sn, and EGa-In, and a mercury-containing alloy, such as a eutectic mercury-thallium alloy. A significant advantage of this embodiment is the high thermal conductivity of the liquid metals used, which significantly increases the efficiency of the heat exchanger.Liquid metals such as Gallinstan or E-Ga-In-Sn offer thermal conductivity far exceeding that of conventional liquids, enabling rapid and uniform heat distribution. This maximizes the system's thermal efficiency, which is crucial in many industrial applications. Furthermore, these liquid metals remain liquid over a wide temperature range, increasing their versatility. Their operating range of -10 to +200 °C makes them suitable for applications where large temperature fluctuations are possible. This is particularly beneficial in high-performance environments where the system is subjected to high thermal stresses.

[0024] The specific selection of liquid metals also offers chemical and physical stability, thus extending the service life of the heat transfer fluid. Liquid metals such as Gallinstan are non-toxic and have low vapor pressure, which improves the safety and environmental friendliness of the system. Furthermore, the high density and specific heat capacity of these metals enable efficient storage and transport of thermal energy. Another advantage of this design is the low viscosity of the liquid metals at operating temperature, resulting in low-friction fluid movement and reduced mechanical stress on the seals. This reduces wear and maintenance requirements of the entire system, which in turn lowers operating costs. Additionally, the low viscosity ensures low friction-related heat loss.Overall, this embodiment offers outstanding thermal conductivity, a wide operating temperature range, chemical stability, high safety standards and an extended system lifespan.

[0025] According to one embodiment of the invention, at least one of the contact elements has a surface in contact with the heat transfer fluid, which is geometrically designed such that, during operation of the heat exchanger, a flow is generated within the heat transfer fluid to support heat transfer. The efficiency of the heat exchanger can therefore be significantly increased if pressure-generating structures are incorporated into one or both surfaces in contact with the heat transfer fluid, generating flows that additionally transport heat by convection. For example, a herringbone pattern can be incorporated into one or both surfaces to generate such a flow.The invention also relates to an arrangement with a first component, a second component arranged at a distance from the first component and movable relative to it, and a heat exchanger as described above, wherein the contact surfaces of the contact elements each contact a component over a surface area in order to exchange heat between the respective contact element and the respective contacted component via the contact surfaces.

[0026] One embodiment of the invention provides that both contact surfaces are fixed to the respective component with which they make surface contact. Alternatively, another embodiment provides that one contact surface is fixed to the component with which it makes surface contact, and the other contact surface is movable relative to the component with which it makes surface contact. The other contact surface, which is movable relative to the component with which it makes surface contact, thus constitutes a sliding surface. The embodiment of the invention in which both contact surfaces are fixed to the respective component with which they make surface contact offers high stability and reliability in heat transfer. By fixing both contact surfaces, a firm and unchanging connection between the components and the contact surfaces is ensured, resulting in uniform and constant heat transfer.This design minimizes mechanical stresses and reduces the risk of wear or damage to the contact surfaces, thus extending the system's lifespan and reducing maintenance requirements.

[0027] Alternatively, one embodiment of the invention provides that one contact surface is fixed to the component to which it makes area contact, while the other contact surface is movable relative to the component to which it makes area contact, thus forming a sliding surface. This configuration offers increased flexibility and adaptability of the heat exchanger. The movable contact surface allows for different forms of relative movement between the components, which is particularly advantageous in applications with dynamic or oscillating movements. The sliding surface ensures that continuous heat transfer is maintained despite movement of the components. This is especially important in systems where mechanical movements and thermal requirements must be met simultaneously.The mobility of one contact surface also reduces the risk of mechanical stresses and thermal expansion, thus improving the structural integrity of the heat exchanger. Furthermore, the sliding surface helps ensure a uniform distribution of heat across the entire contact area, increasing heat transfer efficiency. This flexibility also allows for easier integration of the heat exchanger into existing systems, as it can better adapt to varying mechanical requirements.

[0028] One embodiment of the invention provides that the arrangement includes a bearing arrangement for the component that requires movable mounting. This bearing arrangement ensures that the heat exchanger does not have to withstand any bearing forces originating from the component. Decoupling the heat exchanger from these bearing forces results in significantly higher efficiency and reliability in heat transfer. The heat exchanger can thus concentrate solely on conducting heat without having to absorb mechanical loads, leading to improved performance. A key advantage of this embodiment lies in the reduction of mechanical stresses and loads on the heat exchanger.Since it is not responsible for dissipating bearing forces, the heat exchanger components are subjected to less stress, which extends the system's service life and reduces maintenance requirements. This also contributes to reduced downtime, as the heat exchanger requires less frequent servicing or replacement. The bearing arrangement ensures that the movements and positions of the moving component are maintained precisely and stably, further increasing the efficiency and accuracy of heat transfer. This is particularly advantageous in applications requiring high precision and stability.

[0029] Furthermore, relieving the heat exchanger of mechanical forces increases flexibility in its design and placement. The heat exchanger can be installed in various positions and orientations without having to consider mechanical loads, which facilitates integration into existing systems. Another advantage of this embodiment is the potential optimization of the bearing arrangement itself. Since the bearing forces do not have to be transferred through the heat exchanger, the bearings can be specifically designed to meet the requirements of motion control and stability, thus increasing the overall efficiency of the system. The invention is explained in more detail below with reference to a preferred embodiment and the accompanying drawings.

[0030] The drawings show

[0031] Fig. 1 schematically shows an arrangement with a heat exchanger and two movable components according to a first embodiment of the invention in a sectional view.

[0032] Fig. 2 schematically shows an arrangement with a heat exchanger and two movable components according to a second embodiment of the invention in a sectional view.

[0033] Fig. 3 schematically shows an arrangement with a heat exchanger and two movable components according to a third embodiment of the invention in a sectional view.

[0034] Fig. 4 schematically shows an arrangement with a heat exchanger and two movable components according to a fourth embodiment of the invention in a sectional view and

[0035] Fig. 5 schematically shows an arrangement with a heat exchanger and a mechanical bearing combined in a machine element according to a fifth embodiment of the invention in a sectional view.

[0036] Figure 1 schematically shows an arrangement with a heat exchanger 1, which serves to transfer heat between two components 2, 2' that are movable relative to each other. For this purpose, the heat exchanger 1 has two contact elements 3, 3' arranged at a distance from each other and movable relative to each other. Each contact element 3, 3' has a contact surface 4, 4' with which one of the moving components 2, 2' is in surface contact. Heat is exchanged between the respective contact element 3, 3' and the component 2, 2' it contacts via the contact surface 4, 4'. The two contact surfaces 4, 4' are fixed to the respective component 2, 2' that they contact, e.g., by means of a form-fit, material-fit, or friction-fit connection.

[0037] A heat transfer fluid 5 is enclosed between the contact elements 3, 3', making direct contact with them. The heat transfer fluid 5 is selected to have a thermal conductivity of at least 1 W / m K in the temperature range between -10 and +200 °C, thus ensuring good heat transfer through the heat exchanger 1. Liquid metals are particularly suitable as heat transfer fluid 5. Examples of such liquid metals are sodium-potassium alloys, gallium-containing alloys, or mercury-containing alloys.

[0038] In the arrangement shown in Fig. 1, the central component 2 is a shaft that rotates about an axis of rotation, as indicated by the direction of rotation R. The contact elements 3, 3' are designed as rotationally symmetrical rings and arranged relative to each other in such a way that they can rotate about one another, practically like concentric circles that can rotate about each other around the axis of rotation. The open areas between the rings are sealed on both sides by a sealing arrangement 7, which comprises two seals, each fixed to a ring and running against each other in a sealing manner.

[0039] Two thick arrows pointing from component 2 to components 2' indicate how heat is transferred from component 2 via the contact surfaces 4, 4' of the contact elements 3, 3' and through the heat transfer fluid 5 to components 2'. From there, the heat can be transferred in the conventional manner to a further cooling device, not shown here.

[0040] Figure 2 schematically shows a sectional view of an arrangement with two heat exchangers 1 and two movable components 2, 2' according to a second embodiment of the invention. The right-hand heat exchanger 1 is essentially identical in construction to the heat exchanger in Figure 1. Here, too, the central component 2 is a shaft that rotates about an axis of rotation, as indicated by the direction of rotation R. Therefore, the contact elements 3, 3' are also designed as rotationally symmetrical rings and arranged relative to each other in such a way that they can rotate about one another. However, unlike in Figure 1, the open areas between the rings on both sides are sealed by two sealing assemblies 7, each comprising two seals that are fixed to a ring and slide against each other in a sealing manner. Thus, a pair 10 of sealing assemblies is provided on each side.Within the seals of each pair 10, a fluid 8 different from the heat transfer fluid 5 is provided, namely a fluid 8 which provides a seal against atmospheric oxygen, so that oxidation of the heat transfer fluid 5, which is arranged between the two pairs 10 of sealing arrangements, is avoided or at least reduced.

[0041] Figure 3 schematically shows a sectional view of an arrangement with a heat exchanger 1 and two movable components 2, 2' according to a third embodiment of the invention, in which components 2 and 2' perform an oscillating linear movement relative to each other. This is indicated by the double arrow marked L. Here, the focus is on heat transfer from the upper component 2' to the lower component 2, which is also represented by a thick arrow pointing downwards.

[0042] Here, only a fixed coupling of the upper contact element 3' with its contact surface 4' to the component 2' is provided, e.g., by frictional engagement, while the coupling of the lower contact element 3 with its contact surface 4 to the component 2 is movable; the contact surface 4 is therefore a sliding surface between the lower contact element 3 and the component 2. The open areas between the contact elements 3 and 3' are sealed by means of flexible seals 6 fixed to both contact elements 3 and 3', which allow relative movement of the two contact elements 3 and 3' to each other. A dynamic seal, as shown in the embodiments in Figures 1 and 2, is therefore not required here.

[0043] Finally, Fig. 4 schematically shows a sectional view of an arrangement with a heat exchanger 1 and two movable components 2, 2' according to a fourth embodiment of the invention. Here, the central component 2 is a longitudinally movable shaft that performs a rotational movement R and an oscillating linear movement L, as indicated by the corresponding arrows. In this respect, the techniques from Fig. 1 and Fig. 3 are practically combined, in that the contact elements are designed as concentric rings, but these are not rotatable around each other; rather, they are fixed to one another by means of the flexible seal. The coupling of the contact elements 3' to the components 2' via their contact surfaces 4' is fixed, while the contact surfaces 4, with which the contact elements 3 are coupled to the central component 2, are sliding surfaces; thus, there is no fixed coupling here.

[0044] Essential for all embodiments is that a bearing arrangement 9 is provided for the movable component 2, 2' in which the movable component 2, 2' is movably mounted in such a way that the heat exchanger 1 does not have to dissipate any bearing forces originating from the first component 2 and / or from the second component 2'.

[0045] Figure 5 shows a solution combining a heat exchanger with a mechanical bearing, here represented as a rolling bearing, in a machine element. The function of the heat exchanger shown on the right, with contact elements 3 and 3', contact surfaces 4 and 4', and heat transfer fluid 5, corresponds to the illustrations above. Here, the heat exchanger is physically, but not functionally, combined with a mechanical bearing with a rolling element 11' to achieve a particularly compact design and simplify assembly. Reference numerals

[0046] I Heat exchanger

[0047] 2, 2' components

[0048] 3, 3' contact elements

[0049] 4, 4' contact surfaces

[0050] 5. Heat transfer fluid.

[0051] 6 flexible seals

[0052] 7 Sealing arrangement

[0053] 8 Fluid

[0054] 9 Storage arrangement

[0055] 10 pairs of sealing arrangements

[0056] II rolling elements

Claims

Patent claims 1. Heat exchanger (1) for transferring heat between two components (2, 2') that are movable relative to each other, comprising two contact elements (3, 3') arranged at a distance from each other and movable relative to each other, each having a contact surface (4, 4') with which one of the moving components (2, 2') can be made to make contact over a surface in order to exchange heat between the respective contact element (3, 3') and the respective contacted component (2, 2') via the respective contact surface (4, 4'), and a heat transfer fluid (5) enclosed between the contact elements (3, 3'), wherein the heat exchanger (1) is designed as a prefabricated machine element.

2. Heat exchanger (1) according to claim 1, wherein the heat transfer fluid (5) enclosed between the contact elements (3, 3') directly contacts the contact elements (3, 3').

3. Heat exchanger (1) according to claim 1 or 2, wherein the open areas between the contact elements (3, 3') are sealed by means of flexible seals (6) fixed to both contact elements (3, 3') which allow a relative movement of the two contact elements (3, 3') to each other.

4. Heat exchanger (1) according to one of the preceding claims, wherein the contact elements (3, 3') are designed rotationally symmetrically as rings and are arranged relative to each other in such a way that they are rotatable about each other.

5. Heat exchanger (1) according to claim 4, wherein the open areas between the rings are sealed on both sides by a sealing arrangement (7) comprising a seal that is fixed to one ring and can run on the other ring in a sealing manner, or comprising two seals that are each fixed to a ring and can run on each other in a sealing manner.

6. Heat exchanger (1) according to claim 4, wherein the open areas between the rings are sealed on both sides by a pair of sealing arrangements (10), each sealing arrangement comprising a seal that is fixed to one ring and can run on the other ring in a sealing manner, or comprising two seals that are each fixed to a ring and can run on each other in a sealing manner, wherein a fluid (8) different from the heat transfer fluid (5) is arranged between the two pairs of sealing arrangements (10) and the heat transfer fluid (5) is arranged between the two pairs of sealing arrangements (10).

7. Heat exchanger (1) according to claim 6, wherein the fluid (8) different from the heat transfer fluid (5) is selected such that it provides a seal against atmospheric oxygen, so that oxidation of the heat transfer fluid (5) is avoided or reduced.

8. Heat exchanger (1) according to one of the preceding claims, wherein the heat transfer fluid (5) has a thermal conductivity of at least 1 W / m K in the temperature range between -10 and +200 °C.

9. Heat exchanger (1) according to claim 8, wherein the heat transfer fluid (5) comprises a liquid metal which is liquid at a temperature of 20 °C.

10. Heat exchanger (1) according to claim 9, wherein the liquid metal is selected from the group comprising alloys of sodium and potassium, a gallium-containing alloy and a mercury-containing alloy.

11. Heat exchanger (1) according to one of the preceding claims, wherein at least one of the contact elements (3, 3') has a surface in contact with the heat transfer fluid (5) which is geometrically designed such that, during operation of the heat exchanger (1), a flow is generated within the heat transfer fluid (5) to support heat transfer.

12. Arrangement comprising a first component (2), a second component (2') arranged at a distance from the first component (2) and movable relative to it, and a heat exchanger (1) according to one of the preceding claims, wherein the contact surfaces (4, 4') of the contact elements (3, 3') each make planar contact with a component (2, 2') in order to exchange heat between the respective contact element (3, 3') and the respective contacted component (2, 2') via the contact surface (4, 4').

13. Arrangement according to claim 12, wherein both contact surfaces (4, 4') are fixed to the respective component (2, 2') which they contact over a surface.

14. Arrangement according to claim 12, wherein one contact surface (4') is fixed to the component (2') to which it makes planar contact, and the other contact surface (4) is movable relative to the component (2) to which it makes planar contact.

15. Arrangement according to one of claims 11 to 13, comprising a bearing arrangement (9) for one of the components (2, 2') in which the corresponding component (2, 2') is mounted in such a way that the heat exchanger (1) does not have to dissipate any bearing forces originating from the corresponding component (2, 2').

16. Arrangement comprising a heat exchanger (1) according to one of claims 1 to 11 and a mechanical bearing, preferably an integrated rolling element (11), in a machine element

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