Elastocaloric device, clamping element, and corresponding method for producing such a device

Abstract

The invention relates to an elastocaloric device (200; 300; 400) that is designed to assume a first state, in which an elastocaloric material emits thermal energy on the basis of the elastocaloric effect, and a second state, in which the elastocaloric material absorbs thermal energy on the basis of the elastocaloric effect. The elastocaloric device (200; 300; 400) has: a plurality of elements (210; 310, 410), which are made of an elastocaloric material, and at least two clamping elements (220; 320; 420), which lie opposite each other and each of which clamps a respective end section (211; 211; 411) of each element (210; 310; 410) such that only a central section (212; 312; 412) of each element (210; 310; 410), said central section lying between the clamping elements (220; 320; 420) lying opposite each other, can be set to the first state and the second state for absorbing and emitting thermal energy. The invention additionally relates to a clamping element and to a corresponding production method.

Description

[0001] Description

[0002] Elastocaloric device, clamping and corresponding method for producing such a device

[0003] The invention relates to an elastocaloric device for heat exchange, i.e., for thermal energy absorption and release, using an elastocaloric material. Furthermore, the invention relates to a clamping device for clamping elastocaloric material and a method for producing such an elastocaloric device.

[0004] Traditionally, one or more such elastocaloric devices are installed or incorporated into an elastocaloric machine. Such devices use elastocaloric materials, also known as shape memory alloys (SMA). In such pseudoelastic alloys, a significant shape change can be induced by the introduction of heat from a heat source. If the heat source is removed, the metal returns to its original shape. This effect is completely reversible. Along with this, the reverse effect, the so-called elastocaloric effect, is utilized. Through a change in the shape of the elastocaloric material, the transformation heat of the elastocaloric material is exchanged with the environment, so that the elastocaloric material can assume a lower energy state after exchanging heat energy with the environment, i.e., the state it was in before the heat energy exchange.

[0005] Specifically, the elastocaloric material is subjected to mechanical stress, causing it to undergo a crystalline phase transformation and heat up in the process. This generated heat is dissipated, for example, via a heat sink, so that the material cools back down to its original temperature. If the mechanical stress is then removed, i.e. the material relaxes, the order decreases and the material cools down to a value below its original temperature, so that it can now absorb thermal energy or heat energy from the environment. By cyclical loading and unloading of the elastocaloric material, appropriate heat supply and removal can be achieved in the sense of an elastocaloric heat pump.

[0006] By appropriate control of the cyclic loading and unloading or relaxation combined with appropriate control of a fluid circuit, which may, for example, contain a coolant such as water, a heat pump or refrigeration machine can be realized.

[0007] The introduction of mechanical forces onto the elastocaloric material is conventionally carried out via a clamping device, through which tensile forces of up to 1000 MPa can be applied.

[0008] In Fig. 1, a clamping device 100 known from the prior art is shown as an example in a perspective view.

[0009] In the illustrated case, a roll 120 is wound with an element or wire 110 made of elastocaloric material. The roll 120 has clamping sections 121 at its end portions, by means of which the roll 120 can be clamped and loaded. By applying mechanical forces, the wire 110 can be mechanically loaded and released again by removing these mechanical forces.

[0010] Furthermore, the roll 120 has a winding surface 122, which is intended to be wound with the wire 110 made of elastocaloric material. For this purpose, the wire 110 made of elastocaloric material is first mechanically locked at one end of the winding surface 122 and wound several times around the winding surface 122 of the roll 120.

[0011] The wire 110 is then guided from the roll 120 to a counter-bearing of the elastocaloric device 100, deflected, returned to the roll 120, and wound again around the winding surface 122 of the roll 120. The counter-bearing can be formed, for example, by another roll 120. This process is repeated until the winding surface 122 of the roll 120 is completely wound. The wires 110 are thus, as shown, clamped in two planes E between the roll 120 and the counter-bearing. However, this type of clamping, known from the prior art, entails a number of problems.

[0012] Loading / unloading or tensioning / relaxing the wire by applying and releasing mechanical forces to the reel leads to relative movement of the wire relative to the reel at the sections where the wire is in contact with the reel, i.e., at the winding surface. This causes friction between the wire and the reel, thus leading to increased wear. Furthermore, the design of the reel clamping system results in the wire being stressed at the bending radius, thus exposing it to unfavorable deformation. The friction and unfavorable mechanical loading thus reduce the service life of the elastocaloric device.

[0013] Furthermore, the elastocaloric device requires a defined prestress for operation. If the wire is deformed plastically rather than elastically as intended as a result of loading / tensioning, the prestress within the elastocaloric device is reduced and may no longer be sufficient. Plastic deformation therefore has a negative impact on the cooling / heating performance of the elastocaloric device.

[0014] If a wire is excessively plastically deformed and subsequently breaks, this leads to the failure of the entire wire bundle or of the wires spanned in the same plane E.

[0015] Furthermore, the manufacture of the elastocaloric device with a roll-type clamping system is complex. The prestress of the applied wire must be maintained throughout joining, winding, and assembly, right up to its use. Furthermore, these manufacturing steps cannot be performed in a single clamping device, making maintaining the prestress even more difficult. The cooling / heat conduction achieved by the elastocaloric device depends particularly on the surface of the elastocaloric wire, which comes into contact with a coolant intended for heat exchange.

[0016] According to the state of the art, one measure to increase the cooling capacity of a device is to combine several clampings and / or several bundles in one clamping.

[0017] Fig. 2 shows an example of a combination of clamps known from the prior art in a view from above. In the elastocaloric device shown, in addition to the previously described roller 120, another roller 130 with a smaller diameter is provided. In this way, the corresponding elastocaloric devices 100 can be nested within one another. However, this combination is disadvantageous in that the maximum elongation is always determined by the roller pair with the smaller diameter. This is due to the fact that, due to the nesting, this roller pair spans a shorter distance and can therefore experience a smaller elongation path. The maximum elongation is therefore not achieved in the outer roller pair with the larger diameter, so that the full efficiency of this roller pair cannot be exploited.

[0018] Against this background, it is the object of the present invention to provide an elastocaloric device, a clamping device and a method for producing an elastocaloric device, by means of which a more efficient cooling performance and / or a higher failure protection can be achieved.

[0019] This object is achieved by an elastocaloric device according to claim 1, a clamping device according to claim 13 and a method according to claim 14.

[0020] Advantageous embodiments and further developments of the invention emerge from the dependent claims.

[0021] The elastocaloric device according to the invention is configured or designed to assume a first state in which an elastocaloric material releases heat energy on the basis of the elastocaloric effect, and to assume a second state in which the elastocaloric material absorbs heat energy on the basis of the elastocaloric effect, and the elastocaloric device comprises: a plurality of elements formed from an elastocaloric material, and at least two mutually opposing clamps which clamp respective end sections of each element in such a way that only a central section of each element lying between the opposing clamps can be placed in the first state and the second state for absorbing and releasing heat energy.

[0022] Preferably, one or more of the elastocaloric devices according to the invention are installed or accommodated in an elastocaloric machine.

[0023] The respective end sections of each element are thus advantageously firmly clamped or clamped between sections / clamping parts of each clamping fixture. The respective end sections are preferably clamped via linear or surface pressure using the clamping parts.

[0024] The elastocaloric effect describes the property of certain elastocaloric materials to respond to changes in a mechanical load exerted on the material by cooling or heating.

[0025] Preferably, the clamping devices are configured to bring about the first and second states of the plurality of elements by bringing about the first state by exerting force, e.g. by loading or tensioning, on the plurality of elements via the clamping devices and bringing about the second state by relaxing the plurality of elements while removing the force exerted.

[0026] Preferably, two opposing clamps and the plurality of elements can form an elastocaloric cell, wherein several such cells can be provided in the elastocaloric device. If a mechanical load is applied to an elastocaloric material, a crystalline phase transformation occurs, whereby the elastocaloric material heats up. In this first state, the resulting heat energy can be dissipated to the environment, so that the material cools back down to its original temperature. If the mechanical load acting on the elastocaloric material is subsequently removed, the crystalline phase transformation occurs in the reverse manner, whereby the elastocaloric material cools down. Accordingly, in this second state, the elastocaloric material can absorb heat energy from the environment.By cyclical loading and unloading of the material and the corresponding supply and removal of heat energy, a cyclic process can be created that can be used for heating as well as cooling. Examples of elastocaloric materials are shape memory alloys such as nickel titanium, which undergo a crystalline phase transformation from a cubic austenite structure to a metastable martensite structure under mechanical stress.

[0027] The elements made of elastocaloric material are preferably designed as thin strips, tubes or wires so that the volume of the element has as large a surface as possible for heat dissipation and heat absorption.

[0028] Mechanical stress can preferably be caused by stretching, compression, bending, shearing or torsion, whereby the deformation of the material by the mechanical stress should occur within the elastic range of the material.

[0029] Furthermore, the elastocaloric device according to the invention can be designed such that the middle sections of the plurality of elements have a uniform length and / or the respective end sections of the elements are fixedly clamped in the clamping devices.

[0030] An advantage is that the end sections of the elements are clamped in a fixed / immovable manner relative to the clamping fixture. This minimizes friction between the clamping fixture and the elements. Furthermore, when the elements are subjected to mechanical stress, there is no relative movement between the clamping fixture and the end sections of the elements. This can increase the service life of the element.

[0031] Another advantage is that the elements are clamped individually in the clamping system via their respective end sections. This means that if one element breaks, only that element fails, while the elastocaloric device with the remaining elements remains operational due to the individual clamping. Furthermore, ideally only the middle sections are loaded and unloaded, or tensioned and relaxed, in order to release or absorb thermal energy. The middle sections should preferably not be subjected to any further loads, such as friction, thus increasing the service life of the elements. The uniform length of the middle sections preferably ensures that the mechanical load is the same for all middle sections. If the mechanical load is caused by stretching, for example, all middle sections experience the same stretch due to their uniform length and therefore deliver the same thermal output.The variance between the individual elements is thus minimized.

[0032] Furthermore, the elastocaloric device according to the invention can be realized in such a way that a respective clamping has a plurality of spheroid-shaped / ellipsoid-shaped shell elements of different sizes, which are fitted into one another in such a way that the end sections of the plurality of elements are clamped between adjacent shell elements.

[0033] A spheroid of revolution (Z-ellipsoid) is a three-dimensional equivalent of a circular or elliptical surface, created by rotating it around one of its axes. Corresponding shell elements are therefore preferably created by rotating circular or oval / elliptical surfaces. Preferably, half-shell-shaped elements are formed in this way, which can be structurally joined together, for example, by varying their dimensions.

[0034] Furthermore, the elastocaloric device according to the invention can be further developed such that a first shell element and an adjacent second shell element clamp end sections of a one-piece first bundle of several elements, and the second shell element and an adjacent third shell element clamp end sections of a one-piece second bundle of several elements that is different from the first bundle.

[0035] Preferably, a bundle comprises a plurality of elements that are geometrically arranged in a predefined manner. For example, the plurality of elements are aligned in a circular or elliptical arrangement. With multiple bundles, a concentric arrangement of the bundles is thus created radially, for example, in a circular or elliptical shape, around a common longitudinal axis of the adjacent shell elements.

[0036] Furthermore, a bundle is preferably clamped between interlocking or adjacent shell elements. A bundle can also be designed as a single piece, comprising several connected or interconnected or integral elements.

[0037] Alternatively, the elastocaloric device can be further developed such that the first shell element, the adjacent second shell element, and the adjacent third shell element clamp end portions of a single, integral bundle. In other words, the single, integral bundle with its connected elements can extend over multiple shell elements.

[0038] Preferably, the bundles differ in the dimensions of the predefined geometric arrangement, for example in diameter.

[0039] The interlocking shell elements in combination with the bundles are advantageous because they allow for better use of the installation space.

[0040] Preferably, the first shell element is designed as a hemispherical shell with a smallest radius or as an ellipsoidal shell with smallest semiaxes, wherein each additional shell element, as a hemispherical or ellipsoidal shell with a larger radius or larger semiaxes, adjoins the next shell element with a smaller radius or smaller semiaxes. Furthermore, the shell elements can be designed as ellipsoidal half-shells.

[0041] Preferably, the hemispherical or ellipsoidal shells have a spheroidal / ellipsoidal section and a cylindrical section. Clamping the multiple elements in the cylindrical section ensures that the elements are loaded along their longitudinal direction, thus preventing any loading along the bending radius.

[0042] Alternatively, adjacent shell elements can be braced against each other using fasteners.

[0043] Preferably, the respective clamping devices are designed in the form of a plate which has a plurality of clamping devices distributed in the circumferential direction for clamping end sections of respective elements.

[0044] It is advantageous if the plate is designed as a circular disk with a flat surface. The clamping devices can also be arranged in a star pattern on the plate.

[0045] A corresponding clamping device can have a recess and a corresponding clamping element that can be inserted into the recess, wherein the clamping element can be inserted into the recess in such a way that the end sections of the plurality of elements are clamped between the recess and the clamping element clamped therein.

[0046] It is advantageous if the recess and the clamping element can be joined together in a form-fitting manner. The recesses and the clamping elements can, for example, be implemented in the form of a tongue-and-groove connection, with the elements being clamped between the groove and the tongue.

[0047] A bundle preferably comprises several elements that are clamped together in the clamping device. A plurality of bundles can be distributed along the circumferential direction of the plate. This allows for efficient and scalable use of installation space, as more elements can be accommodated in the available installation space.

[0048] The recess and the corresponding clamping element that can be inserted into the recess preferably clamp end sections of elements of a bundle.

[0049] The clamping can preferably be secured by crimping, gluing or welding.

[0050] Preferably, the clamping element has a further recess into which a further corresponding clamping element insertable into the further recess can be inserted, wherein the further clamping element can be inserted into the further recess in such a way that the end sections of the plurality of elements are clamped between the further recess and the further clamping element clamped therein.

[0051] The further recess and the corresponding further clamping element that can be inserted into the further recess preferably clamp end sections of elements of another bundle.

[0052] Preferably, the clamping devices are designed as a disc, preferably as a circular disc.

[0053] The clamping device according to the invention for clamping a plurality of elements made of an elastocaloric material comprises: at least a first clamping part and a second clamping part, which are fitted into one another in such a way that end sections of the plurality of elements can be clamped in a fixed manner between the first clamping part and the second clamping part.

[0054] With regard to the clamping, the properties and advantages explained in connection with the elastocaloric device according to the invention result in the same or similar way, which is why reference is made to the above statements to avoid repetition.

[0055] The method according to the invention for producing an elastocaloric device according to the invention, which is configured to assume a first state in which an elastocaloric material absorbs heat energy on the basis of the elastocaloric effect, and to assume a second state in which the elastocaloric material releases heat energy on the basis of the elastocaloric effect, comprises the following steps:

[0056] Clamping a plurality of elements formed from an elastocaloric material in at least two mutually opposite clamping devices, which clamp respective end sections of each element in such a way that only a central section of each element lying between the opposite clamping devices can be placed in the first state and the second state for heat energy absorption and heat energy release.

[0057] It is advantageous if the clamps are pre-positioned in a fixture. This allows the entire manufacturing process to take place sequentially within the fixture. Parts of the clamps are advanced one after the other, and the elements of each bundle are applied in the immediately following sub-process. The elements are applied across the entire bundle under continuous and homogeneous pre-tensioning through a controlled element placement process (monitoring the wire tension). This provides an assembly-friendly process that also offers high automation potential.

[0058] With regard to the method, the properties and advantages explained in connection with the elastocaloric device according to the invention also arise in the same or similar way, which is why reference is made to the above statements to avoid repetition.

[0059] Preferred embodiments of the invention are explained below with reference to the accompanying drawings. Figure 1 shows a perspective view of an elastocaloric device known from the prior art.

[0060] Figure 2 shows a top view of a combination of two of the clamping devices known from the prior art.

[0061] Figure 3 shows a perspective cross-sectional view of an elastocaloric device according to a first embodiment of the invention.

[0062] Figure 4 shows a longitudinal sectional view of the elastocaloric device according to the invention of Fig. 3.

[0063] Figures 5A to 5C show a method according to the invention for producing the elastocaloric device according to the invention according to the first embodiment of the invention.

[0064] Figures 6A to 6C show the device according to the invention in a modification of the first embodiment.

[0065] Figure 7 shows a perspective cross-sectional view of an elastocaloric device according to the invention according to a second embodiment of the invention with first bundles.

[0066] Figure 8 shows a method according to the invention for producing the elastocaloric device according to the invention according to the second embodiment of the invention in a perspective exploded view.

[0067] Figure 9 shows a perspective view of the elastocaloric device according to the second embodiment of the invention with first bundles. Figures 10A and 10B show a perspective view of the elastocaloric device according to the second embodiment of the invention with first bundles in structurally modified forms.

[0068] Figure 11 shows a perspective cross-sectional view of an elastocaloric device according to the invention according to a modification of the second embodiment of the invention with first and second bundles.

[0069] Figure 12 shows a perspective view of the elastocaloric device according to the invention according to the modification of the second embodiment of the invention with first bundles and second bundles in a perspective exploded view.

[0070] Figure 13 shows a method according to the invention for producing the elastocaloric device according to the invention according to the modification of the second embodiment of the invention with first bundles and second bundles using an exploded view.

[0071] Figure 3 shows a perspective cross-sectional view of an elastocaloric device 200 according to a first embodiment of the invention. One or more of these elastocaloric devices 200 can be installed or accommodated in an elastocaloric machine. The elastocaloric device 200 comprises a plurality of elements 210 formed from an elastocaloric material. These elements 210 are clamped in two opposing clamps 220, wherein, due to the cross-sectional view, only one of the two clamps 220 is shown. The opposing clamps 220 and the associated elastocaloric elements 210 are preferably designed in the form of one or more elastocaloric cells.

[0072] In the specific case illustrated, the elements 210 are formed as thin wires with a circular cross-section. The elements 210 are grouped or combined into bundles, each bundle comprising a plurality of elements 210 that are connected to one another. Each bundle is thus a one-piece bundle composed of several connected elements 210. In each bundle, the individual elements 210 of a bundle are arranged radially around a longitudinal axis LA of the elastocaloric device 200 at the same radius, thus forming a grouping. Different bundles thus comprise elements 210 that are arranged at different radii around the longitudinal axis LA of the elastocaloric device 200. Within a bundle, the distance of the elements 210 from the longitudinal axis LA is thus uniform. In the first embodiment shown, the elastocaloric device 200 comprises three concentric bundles B1-B3 of elements 210.

[0073] Figure 4 shows a longitudinal sectional view of the elastocaloric device 200 according to the invention from Fig. 3. As can be seen from Fig. 4, the clamping device 220 comprises four hemispherical shell elements 221-224 of different sizes, which are fitted into one another. The first hemispherical shell element 221 has a smallest radius, and each additional shell element 222-224 borders, with a larger radius, on the next shell element with a smaller radius. End sections 211 of the elements 210 are fixedly clamped in the clamping device 220 between the adjacent surfaces of the shell elements 221-224. The elements 210 of the first bundle B1 are fixedly clamped between the first shell element 221 and an adjacent second shell element 222. The elements 210 of the second bundle B2 are fixedly clamped between the second shell element 222 and an adjacent third shell element 223.Furthermore, the elements 210 of the third bundle B3 are clamped between the third shell element 223 and an adjacent fourth shell element 224. The shell elements 221-224 form a common surface A on one side of the (first) clamping element 220, which faces the opposite second clamping element (not shown). Thus, the center sections 212 of the elements 210, which lie between the two opposite clamping elements 220, have a uniform length. The center sections 212 are exposed and thus configured for heat exchange with the environment. Furthermore, the shell elements 221-224 have a concentric bore B.

[0074] The shell elements 221 - 224 can be clamped to one another or against one another via this bore by means of a fastening means not shown.

[0075] Figures 5A to 5C show a method according to the invention for producing the elastocaloric device 200 according to the first embodiment of the invention.

[0076] Step 1 (Figure 5A)

[0077] The first shell elements 221, which have the smallest radius, are prepositioned opposite one another in a receptacle (not shown). Subsequently, the plurality of elements 210 of the first bundle B1 are applied to the first shell elements 221 such that the respective end portions 211 of the elements 210 of the first bundle B1 are in contact with the first shell elements 221 and the center portions 212 are exposed between the two opposing first shell elements 221.

[0078] Step 2 (Figure 5B)

[0079] Subsequently, the second shell elements 222 with the next larger radius are each fitted into the first shell elements 221 with the smallest radius, so that the end sections 211 of each element 210 of the first bundle are each fixedly clamped between the adjacent surfaces of the first shell elements 221 and the second shell elements 222, while the central sections 212 remain exposed.

[0080] Step 3 (Figure 5C)

[0081] Subsequently, the plurality of elements 210 of the second bundle B2 are applied to the second shell elements 222 such that the respective end portions 211 of the elements 210 of the second bundle B2 are in contact with the second shell elements 222 and the center portions 212 are exposed between the two opposing second shell elements 222. Subsequently, further shell elements (e.g., 223 in Fig. 4) and bundles (e.g., B3 in Fig. 4) can be added or attached until final shell elements (e.g., 224 in Fig. 4) are applied. Figures 6A to 6C show the device 200 according to the invention in a modification of the first embodiment, wherein the plurality of elements 210 are formed in one piece.

[0082] Figure 6A shows a first possibility of forming the plurality of elements 210 of the first bundle as a one-piece element, or as a one-piece bundle of several elements 210. For this purpose, the first shell element 221 comprises cylindrical guide elements 2211 in the form of protruding short bolts, which are arranged radially around the longitudinal axis LA on the adjacent surface of the first shell element 221.

[0083] The one-piece first bundle is first guided from a first shell element 221 to another first shell element 221. The first shell elements 221 are then rotated about the longitudinal axis LA, with the one-piece bundle initially being guided along a first cylindrical guide element 2211 of the other first shell element 221 and being placed into a groove formed in the other first shell element 221. The one-piece bundle is then guided around a second guide element 2212 on the other first shell element 221 and then returned to the one first shell element 221. This process is repeated until all cylindrical guide elements 2211 are occupied by the one-piece bundle.

[0084] Figure 6B shows a second possibility of forming the plurality of elements 210 of the first bundle as a one-piece element, or as a one-piece bundle of several elements 210. For this purpose, the first shell element 221 also comprises the cylindrical guide elements 2211, which are arranged radially around the longitudinal axis LA on the adjacent surface of the first shell element 221.

[0085] The one-piece bundle is first guided from one first shell element 221 to the other first shell element 221. The one-piece bundle is then guided around a first cylindrical guide element 2211. Subsequently, the one-piece bundle is returned to one shell element 221 and guided around a second cylindrical guide element 2212. The one-piece bundle is thus applied to the first shell elements 221 in a meandering pattern. An exemplary result of this process is shown in Figure 6C.

[0086] Figure 7 shows a perspective cross-sectional view of an elastocaloric device 300 according to a second embodiment of the invention with first bundles B11-B14. Figure 8 shows a perspective exploded view of a method according to the invention for producing the elastocaloric device 300 according to the second embodiment of the invention. One or more of these elastocaloric devices 300 can be installed or incorporated in an elastocaloric machine.

[0087] The elastocaloric device 300 comprises a plurality of elements 310 formed from an elastocaloric material. These elements 310 are clamped in two opposing clamps 320, although due to the cross-sectional view, only one of the two clamps 320 is shown. The opposing clamps 320 and the elastocaloric elements 310 can also be provided as one or more elastocaloric cells.

[0088] In the specific case illustrated, the elements 310 are formed as thin wires with a circular cross-section. Furthermore, the elements 310 are grouped or combined into the first four bundles B11-B14.

[0089] The clamping device 320 comprises a first clamping part 321, which in the illustrated case is designed as a plate / circular disk. The first clamping part 321 / the plate has four clamping devices distributed in the circumferential direction for clamping end sections 311 of respective elements 310 of the first bundles B11-B14.

[0090] For this purpose, the first clamping part 321 / the plate comprises projections on one side that have recesses 3211-3214, with corresponding clamping elements 3221-3224 that can be inserted into the recesses 3211-3214 being provided. The insertable clamping elements 3221-3224 are connected to one another or formed integrally via a connecting part to form a second clamping part 322. The end sections 311 of the elements 310 are clamped or fixedly clamped between adjacent surfaces of the recesses 3211-3214 and the corresponding clamping elements 3221-3224.

[0091] The center sections 312 of the elements 310 of all the first bundles B11-B14, which lie between the two opposing clamps 320, have a uniform length. The center sections 312 are exposed and thus configured for heat exchange with the environment.

[0092] Furthermore, the first clamping part 321 / the plate on which the projections with the recesses 3211-3214 are formed, and the second clamping part 322, which has the clamping elements 3221-3224, have a concentric bore. Via this bore, the corresponding clamping elements 3221-3224 and the respective recesses 3211-3214 can be clamped to one another or against one another using a fastening means, in the illustrated case using a screw S.

[0093] The first clamping part 321 / the plate, which has the recesses 3211-3214, is pre-positioned in a holder not shown.

[0094] Subsequently, the recesses 3211-3214 of the first plate 321 are joined via the clamping elements 3221-3224, on which the plurality of elements 310 of the first bundles B11-B14 are already arranged, so that the respective end sections 311 of the elements 310 of the first bundles B11-B14 are fixedly clamped in contact between the recesses 3211-3214 and the clamping elements 3221-3224 and the central sections 312 are exposed.

[0095] Finally, the first clamping part 321 / the plate and the second clamping part 322, which has the clamping elements 3221-3224, are clamped against each other by inserting the screw S into the bore.

[0096] Figure 9 shows a perspective view of the elastocaloric device 300 according to the second embodiment of the invention with first bundles B11-B14. In the illustrated case, the clamping of the recesses 3211-3214 and the corresponding clamping elements 3221-3224 is additionally secured by bonding / welding 331 and / or by crimping 332 (connection by plastic deformation) of the respective corresponding pairs.

[0097] Figures 10A and 10B show a perspective view of the elastocaloric device 300 according to the second embodiment of the invention with first bundles in structurally modified shapes.

[0098] The elastocaloric device 300 shown in Figure 10A comprises five clamping devices distributed in the circumferential direction for clamping end portions 311 of respective elements 310 of first bundles B11 '-B15'.

[0099] The elastocaloric device 300 shown in Figure 10B comprises six clamping devices distributed in the circumferential direction for clamping end portions 311 of respective elements 310 of first bundles B11 "-B16".

[0100] By increasing the number of tensioning elements or the first bundles, an increase in the packing density of the elastocaloric device 310 can be achieved.

[0101] Figure 11 shows a perspective cross-sectional view of an elastocaloric device 400 according to the invention, in accordance with a modification of the second embodiment of the invention, with first bundles B11-B14 and second bundles B21-B24. One or more of these elastocaloric devices 400 can be installed or accommodated in an elastocaloric machine. The elastocaloric device 400 comprises a plurality of elements 410 formed from an elastocaloric material. These elements 410 are clamped in two opposing clamps 420, although due to the cross-sectional view, only one of the two clamps 420 is shown. The opposing clamps 420 and the elastocaloric elements 410 can also be provided as one or more elastocaloric cells. In the specific case illustrated, the elements 410 are formed as thin wires with a circular cross-section.In addition, elements 410 are divided into first bundles B11 -B14 and second bundles B21 -B24.

[0102] Figure 12 shows a perspective view of the elastocaloric device 400 according to the invention according to the modification of the second embodiment of the invention with first bundles B11 -B14 and second bundles B21 -B24 in a perspective exploded view.

[0103] The clamping device 420 comprises a first clamping part 421, in the illustrated case a plate, which is designed as a circular disk. The plate 421 forms four clamping devices distributed in the circumferential direction for clamping end sections 411 of respective elements 410 of the first bundles B11-B14.

[0104] For this purpose, the first clamping part 421 or the plate comprises projections on one side that have recesses 4211-4214, with corresponding clamping elements 4221-4224 that can be inserted into the recesses 4211-4214 being provided. The insertable clamping elements 4221-4224 are connected to one another via a connecting part to form a second clamping part 422. The end sections 411 of the elements 410 of the first bundles B11-B14 are clamped or fixedly clamped between adjacent surfaces of the recesses 4211-4214 and the corresponding clamping elements 4221-4224.

[0105] Furthermore, four further clamping devices for clamping end sections 411 of respective elements 410 of second bundles B21-B24 are formed in the clamping elements 4221-4224. For this purpose, the clamping elements 4221-4224 comprise further recesses 4221'-4224', with corresponding further clamping elements 4231-4234 being provided that can be inserted into the further recesses 4221'-4224'. The further insertable clamping elements 4231-4234 are connected to one another via a further connecting part to form a third clamping part 423. The end sections 411 of the elements 410 of the first bundles B11-B14 are fixedly clamped or clamped between adjacent surfaces of the further recesses 4221'-4224' and the corresponding further clamping elements 4231-4234. Middle sections 412 of the elements 410 of all first bundles B11 -B14 and all second bundles B21 -B24, which lie between the two opposite clampings 420, have a uniform length.The central sections 412 are exposed and are thus designed for heat exchange with the environment.

[0106] Furthermore, the first clamping part 421 / the plate on which the projections with the recesses 4211-4214 are formed, the second clamping part 422, which has the clamping elements 4221-4224, and the third clamping part 423, which has the further clamping elements 4231-4234, have a concentric bore. Via this bore, the corresponding clamping elements 4221-4224 and the respective recesses 4211-4214, as well as the corresponding further clamping elements 4231-4234 and the respective recesses 4221-4224, can be clamped together using a fastening means, in the case shown, a screw S.

[0107] Figure 13 shows a method according to the invention for producing the elastocaloric device 400 according to the invention of Figure 12 according to the modification of the second embodiment of the invention using an exploded view.

[0108] In the following, reference is made to Figure 13 in conjunction with Figure 12.

[0109] The plate or the first clamping part 421, which has the projections with the recesses 4211-4214, the second clamping part 422, which comprises the clamping elements 4221-4224 and the further recesses 4221'-4224', and the third clamping part 423, which comprises the further clamping elements 4231-4234, are pre-positioned in a receptacle (not shown).

[0110] First, the additional clamping elements 4231-4234 of the third clamping part 423 are wrapped with the plurality of elements 410 of the second bundles B21-B24. Subsequently, the second clamping part 422 is positioned by applying the additional recesses 4221'-4224' to the additional wrapped clamping elements 4231-4234, so that the respective end sections 411 of the elements 410 of the second bundles B21-B24 are clamped in a fixed manner between the recesses 4221'-4224' and the additional clamping elements 4231-4234, and the center sections 412 are exposed.

[0111] Subsequently, the clamping elements 4221-4224 of the second clamping part 422 are wrapped with the plurality of elements 410 of the first bundles B11-B14.

[0112] Thereafter, the first clamping part or the plate 421 is positioned by applying the recesses 4211-4214 to the wrapped clamping elements 4221-4224, so that the respective end sections 411 of the elements 410 of the first bundles B11-14 are fixedly clamped between the recesses 4211-4214 and the clamping elements 4221-4224 and the middle sections 412 are exposed.

[0113] Finally, the plate / first clamping part 421, the second clamping part 422, which comprises the clamping elements 4221-4224, and the third clamping part 423, which comprises the further clamping elements 4231-4234, are clamped together by inserting the screw S into the bore.

[0114] The features of the invention disclosed in the above description, in the drawings, and in the claims may be essential for the realization of the invention both individually and in any combination.

Claims

Patent claims 1. Elastocaloric device (200; 300; 400) which is configured to assume a first state in which an elastocaloric material emits heat energy based on the elastocaloric effect, and a second state in which the elastocaloric material absorbs heat energy based on the elastocaloric effect, wherein the elastocaloric device (200; 300; 400) comprises: several elements (210; 310, 410) formed from an elastocaloric material, and at least two opposing clamping points (220; 320; 420) which clamp respective end sections (211; 311; 411) of each element (210; 310; 410) such that only a gap exists between the opposing clamping points (220; 320; 420). The lying central section (212; 312; 412) of each element (210; 310; 410) can be moved into the first state and the second state for heat energy absorption and heat energy release.

2. Elastocaloric device (200; 300; 400) according to claim 1, wherein the clamping devices (220; 320; 420) are configured to bring about the first and second states of the multiple elements (210; 310; 410) by bringing about the first state by exerting force on the multiple elements (210; 310; 410) via the clamping devices (220; 320; 420) and the second state by relaxing the multiple elements (210; 310; 410) while removing the force.

3. Elastocaloric device (200; 300; 400) according to claim 1 or 2, wherein the central sections (212; 312; 412) of the multiple elements have a uniform length and / or the respective end sections (211; 311; 411) of the multiple elements (210; 310; 410) are fixedly clamped in the clamping devices (220; 320; 420).

4. Elastocaloric device (200) according to one of claims 1 to 3, wherein a respective clamping device (220) has several spheroidal shell elements (221-224) of different sizes, which are joined together in such a way that the End sections (211) of the several elements (210) are clamped between adjacent shell elements (221-224).

5. Elastocaloric device (200) according to claim 4, wherein a first shell element (221) and an adjacent second shell element (222) clamp end sections (211) from a one-piece first bundle (B1) of several elements (210), and the second shell element (222) and an adjacent third shell element (223) clamp end sections (211) from a one-piece second bundle (B2) of several elements (210) that differs from the first bundle (B1).

6. Elastocaloric device (200) according to claim 5, wherein the first shell element (221) is designed as a hemispherical shell with a smallest radius or as an ellipsoidal shell with smallest semi-axes, and each further shell element (222-224) is designed as a hemispherical or ellipsoidal shell with a larger radius or larger semi-axes adjacent to the next shell element with a smaller radius or smaller semi-axes.

7. Elastocaloric device (200) according to claim 5, wherein adjacent shell elements (221-224) can be clamped against each other via fastening means (S).

8. Elastocaloric device (300; 400) according to one of claims 1 to 3, wherein the respective clamping devices (320; 420) are formed in the form of a plate which has several clamping devices distributed in the circumferential direction for clamping end sections (311; 411) of respective elements (310; 410).

9. Elastocaloric device (300; 400) according to claim 8, wherein a corresponding clamping device has a recess (3211-3214; 4211-4214) and a corresponding clamping element (3221-3224; 4221-4224) that can be inserted into the recess, wherein the clamping element (3221-3224; 4221-4224) can be inserted into the recess (3211-3214; 4211-4214) such that the end sections (311; 411 ) of the several elements (310; 410) between the recess (3211 -3214; 4211-4214) and the clamping element (3221-3224; 4221-4224) clamped therein.

10. Elastocaloric device (400) according to claim 9, wherein the clamping element (4221-4224) has a further recess (4221 '-4224') into which a further corresponding clamping element (4231-4234) can be inserted into the further recess (4221 '-4224'), wherein the further clamping element (4231-4234) can be inserted into the further recess (4221 '-4224') such that the end sections (311 ; 411 ) of the several elements (310; 410) are clamped between the further recess (4221 '-4224') and the further clamping element (4231-4234) clamped therein.

11. Elastocaloric device (300; 400) according to one of claims 8 to 10, wherein the clamping devices (320; 420) are designed as a disk, preferably as a circular disk.

12. Method for manufacturing an elastocaloric device (200; 300; 400), preferably an elastocaloric device (200; 300; 400) according to any one of claims 1 to 11, which is configured to assume a first state in which, based on the elastocaloric effect, an elastocaloric material absorbs heat energy, and to assume a second state in which, based on the elastocaloric effect, the elastocaloric material releases heat energy, wherein the method comprises the following steps: Clamping several elements (210; 310; 410) made of an elastocaloric material into at least two opposing clamping points (220; 320; 420), which clamp respective end sections (211; 311; 411) of each element (210; 310; 410) in such a way that only a central section (212; 312; 412) of each element (210; 310; 410) located between the opposing clamping points (220; 320; 420) can be moved into the first state and the second state for heat energy absorption and heat energy release.

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