Clamping device for an elastocaloric machine and elastocaloric machine

Abstract

The invention relates to a clamping device for an elastocaloric machine, which is configured to be operated as a heat pump and / or refrigeration machine, wherein the clamping device comprises: at least one clamping device with at least two corresponding clamps, which are configured to hold an elastocaloric element within a fluid-carrying channel of the elastocaloric machine, the channel being designed in the form of a cylindrical shell, and to bring the elastocaloric element into a first state in which the elastocaloric element releases heat energy to the fluid due to the elastocaloric effect, and into a second state in which the elastocaloric element absorbs heat energy from the fluid due to the elastocaloric effect, wherein the corresponding clamps are configured to hold the part of the elastocaloric element held between them in such a way thatthat the part of the elastocaloric element forms a curved surface in the shape of a cylindrical surface segment. Furthermore, the invention relates to an elastocaloric machine with such a clamping device.

Description

The invention relates to a clamping device for an elastocaloric machine. The invention furthermore relates to an elastocaloric machine with such a clamping device.Elastocaloric machines are conventionally operated as heat pumps and / or cooling machines, for example in the form of air conditioners, in motor vehicles.Conventionally, such elastocaloric machines use elastocaloric elements formed from elastocaloric materials, in particular so-called shape memory alloys (SMA). In such pseudoelastic alloys, a strong deformation can be induced by the introduction of heat by a heat source. When the alloy recovers heat by removing the heat source, the metal recovers its original shape. This effect is absolutely reversible. The reverse effect, the so-called elastocaloric effect, is used as a result.By changing the shape of the elastocaloric material, conversion heat of the elastocaloric material is exchanged with the environment, so that the elastocaloric material can assume an energy-lower state after heat energy exchange with the environment, i.e. before the heat energy exchange. Specifically, the elastocaloric material for application and utilization of the elastocaloric effect is stretched, which corresponds to a first state explained below, to thereby release thermal energy, and relaxed, which corresponds to a second state explained below, to thereby absorb thermal energy.In particular, the elastocaloric material is subjected to a mechanical stress, for example, as mentioned above, so that a crystalline phase transformation occurs in the material and is thereby heated. This heat that arises is dissipated again via a heat sink, for example, so that the material cools down again to the starting temperature. If the mechanical stress is now removed, i.e. the material is relaxed, the order is reduced and the material cools down even to a value below the starting temperature, so that it can now absorb thermal energy from the environment.By cyclically relieving the load and relief or expanding and releasing the elastocaloric material, a corresponding heat supply and removal can thus be realized in the sense of an elastocaloric heat pump. By suitable control of the cyclic loading or expansion and relief or expansion combined with corresponding control of a fluid circuit, which can have a coolant such as water, for example, a heat pump or refrigerating machine can thus be realized on the basis of the elastocaloric machine.The introduction of mechanical forces onto the elastocaloric elements made of elastocaloric material in order to correspondingly load or expand them is conventionally effected via respective clamping devices of the clamping device, which each have two corresponding and mutually opposite clampings, via which tensile stresses of up to 1000 MPa can be applied.Such two corresponding clamps hold and move an elastocaloric element within a channel of the elastocaloric machine that conducts a fluid and is usually designed in the form of a cylinder shell or a hollow cylinder, and put the elastocaloric element into said first state, in which the elastocaloric element emits thermal energy to the fluid on account of the elastocaloric effect, and into a second state, in which the elastocaloric element absorbs thermal energy from the fluid on account of the elastocaloric effect.In particular, the corresponding restraint devices hold and move a respective elastocaloric element made of elastocaloric material or the bundle or bundles of elastocaloric material between them within the channel, for example the restraint devices move a respective elastocaloric element or one or more bundles of elastocaloric material along the channel, in particular in the circumferential direction in the case of an annular channel as seen in cross section, while said restraint devices load and relieve the respective elastocaloric element in a direction which runs perpendicularly with respect to the direction of movement of the respective elastocaloric element, i.e. runs parallel to a rotational axis or rotational axis of the elastocaloric machine. The bundle / bundles held between the respective clamps is / are thereby loaded (stretched) and unloaded (relaxed).FIG. 1A shows a perspective view of an elastocaloric machine 1 in longitudinal section. As can be seen in particular in FIG. 1A, the elastocaloric machine 1 holds a plurality of elastocaloric elements 110 in a cylinder-jacket-shaped channel 11 via corresponding clamps 100 of a clamping device 10, wherein the plurality of elastocaloric elements 110 are moved about an axis of rotation A within the channel 11 and are thereby stretched (loaded) and relaxed (relieved) in a conventional manner and in a manner not described in more detail. This is effected via respective two corresponding clamps 100, between which a respective elastocaloric element 110 made of elastocaloric material or the bundle or bundles of elastocaloric material is held within the channel 11. FIG. 3 illustrates a conventional clamping device 10 having a plurality of clamps 100 in a perspective view.Conventionally, the channel 11 is defined by an inner cylindrical lateral surface 13 and an outer cylindrical lateral surface 14 of a housing of the elastocaloric machine 1, wherein the respective corresponding clamps 100 for holding and moving a respective elastocaloric element 110 are provided at respective front ends of the cylindrical lateral surfaces and hold and move the elastocaloric elements 110 made of elastocaloric material, for example bundles in the form of wires or wire bundles.FIG. 1B shows, by way of example, a clamping device 100 known from the prior art in a perspective view, which holds an elastocaloric element 110, which is only partially illustrated, made of elastocaloric material or bundle made of elastocaloric material in the form of a wire bundle. An associated further corresponding clamping of the elastocaloric element 110 or wire bundle, which serves as a counter bearing, is not shown in this case, but is designed identically to the clamping 100. In the case shown, the clamping device 100 has a roller 120 which is multiply wound with wire of elastocaloric material and thereby forms the wire bundle of elastocaloric material.The roller 120 has clamping sections 121, in the case shown square clamping sections, at end sections, by means of which the roller 120 can be clamped and loaded. By introducing mechanical forces onto the roller 120, the wire bundle can be mechanically loaded or stretched and relieved or relaxed again by cancelling these mechanical forces.Furthermore, the roll 120 has a winding surface 122, which is wound with the wire of elastocaloric material. To accomplish this, the wire of elastocaloric material is first mechanically locked to one end of the winding surface 122, for example, by inserting and securing a wire end into a bore in the winding surface 122, and is wound multiple times around the winding surface 122 of the roll 120. Subsequently, the wire is guided from the roller 120 to the counter bearing, which is formed by the further identical clamping, not shown, is deflected there, is returned to the roller 120 and is again wound around the winding surface 122 of the roller 120. This process is preferably repeated until the winding surface 122 of the roll 120 is fully wound and thus the wire bundle 110 is formed from elastocaloric material. In this case, these are therefore clamps 100, which function as bearings and counter bearings, for a single wire bundle.The wires made of elastocaloric material are thus, as shown in FIG. 1B, clamped in two planes E between the respective clamps 100 and thus form the individual wire bundle made of elastocaloric material or the elastocaloric element 110, which in cross section, hereinafter usually referred to as bundle cross section, has the shape of two parallel and flush lines or rectangles, i.e. lines or rectangles terminating at the same height.A conventional measure for increasing the cooling capacity of the elastocaloric machine consists, according to the prior art, for example, in providing as many constraints as possible in the narrowest space and / or combining such constraints described above quasi into a one-piece common constraint, as is shown in FIG. 2. Two conventional clamps functioning as bearings and counter bearings thus hold a wire bundle of elastocaloric material according to FIG. 1B or a plurality of wire bundles of elastocaloric material according to FIG. 2 described below.FIG. 2 shows, by way of example, a restraint 100 known from the prior art in a view from above, which corresponds to a combination of two restraint 100 from FIG. 1B and is therefore designed for holding two wire bundles made of elastocaloric material.As shown, in addition to the previously described roller 120, another smaller diameter roller 130 is used which is wrapped with wire of elastocaloric material. By using a corresponding identical clamping as counter bearing, the wires made of elastocaloric material can thus be further nested one inside the other via the respective rollers 120 and 130 and ultimately two wire bundles can be held.The elastocaloric elements 110 made of elastocaloric material are usually designed in the form of wires, as described above, but can alternatively also be embodied as thin strips or tubes. As a result, the elastocaloric volume formed by the elastocaloric elements 110 can be configured with the largest possible surface for heat emission and heat absorption.In order to generate as much latent heat as possible, the elastic material wires are conventionally stretched up to 7%. When the elastic material wires are stretched, stresses of up to 1000 MPa and beyond can occur in the material. Thus, in order to generate more latent heat, as is possible in the example of FIG. 1B, the number of wires made of elastocaloric material or the number of held wire bundles is increased according to the prior art, as is shown in FIG. 2.According to the cross section of the material, high tensile forces must be applied. This, in turn, requires a corresponding dimensioning of the holding clamps in the case of a large number of wires or in the case of a plurality of held wire bundles.Along with the increase in the number of wire bundles or corresponding dimensioning of the clamps due to the increased number of wire bundles, the negative impairment of the cooling / heating efficiency of the elastocaloric machine is. This is because the rotation of the wire bundles results in a thorough mixing of the cooling / heating medium or of the fluid. The wire bundles practically push the cooling / heating medium forward of them due to the rotational movement, so that this part of the cooling / heating medium reaches the warm or cold side of the channel and thus leads to a reduced cooling / heating efficiency.The document DE 10 2016 118 776 A1 discloses a thermoelastic energy converter having a thermoelastic arrangement with at least one thermoelastic element made of a thermoelastic material; two retaining elements; a fastening element for retaining an end of the at least one thermoelastic element; a guide device which is coupled to the fastening element of the at least one thermoelastic element in order to bring about a change in length of the at least one thermoelastic element in the longitudinal direction in the event of synchronous rotation of the retaining elements relative to the guide device, such that cyclic elastic deformation and relaxation of the at least one thermoelastic element is achieved.The post-published document DE 10 2022 206 212 A1 discloses a thermoelastic energy conversion system having an energy conversion unit with thermoelastic elements and a loading device which is coupled to ends of the thermoelastic elements and is designed to rotate the thermoelastic elements about this axis of rotation during rotation about an axis of rotation and in the process to clamp and expand them in such a way that latent heat is released during clamping and latent heat is absorbed during expansion, wherein the clamping takes place in a first range of angles of rotation and the expansion takes place in a second range of angles of rotation.Post-published documents DE 10 2022 207 885 B3 and DE 10 2022 207 886 B3 further disclose an elastocaloric machine for exchanging thermal energy with a fluid, comprising: a first channel configured to conduct a first fluid to absorb thermal energy through the first fluid conducted in the first channel, a second channel configured to conduct a second fluid to emit thermal energy through the second fluid conducted in the second channel, and a lock device configured to couple the first channel and the second channel to each other such that the first channel and the second channel can be connected to each other or separated from each other in a lock-like manner.Against this background, it is the object of the present invention to provide an elastocaloric machine with which the heating and / or cooling efficiency can be increased compared to the prior art, preferably without necessarily increasing the costs for an elastocaloric machine and / or without increasing the required installation space.This object is achieved by a clamping device according to claim 1 and an elastocaloric machine according to claim 8. Advantageous embodiments and further developments of the invention are evident from the dependent claims.The clamping device according to the invention is provided for an elastocaloric machine which is configured to be operated as a heat pump and / or refrigerating machine. The clamping device according to the invention comprises: at least one clamping device having at least two corresponding clamps which are configured to hold, in particular also to move, an elastocaloric element within a channel of the elastocaloric machine which conducts a fluid and is designed in the form of a cylinder shell or hollow cylinder, and to put the elastocaloric element into a first state in which the elastocaloric element emits thermal energy to the fluid on account of the elastocaloric effect, and into a second state in which the elastocaloric element absorbs thermal energy from the fluid on account of the elastocaloric effect, wherein the corresponding clamps are designed in such a way, in order to hold the part of the elastocaloric element or the wire bundle held between them in such a way that the part of the elastocaloric element or the wire bundle / wire bundles forms a curved surface in the form of a lateral surface segment of a cylinder. The part of the elastocaloric element or of the wire bundle held between the corresponding clamps is preferably circular-arc-shaped in cross section or in bundle cross section, formed by individual wires in the form of round wires, strips, tubes, etc. In this case, the clamping device preferably has a multiplicity of corresponding clamps which are distributed over the entire channel or in the cylinder shell at a predetermined distance.By holding the part of the elastocaloric element in the form of a lateral surface segment, it is possible to seal the channel between the cold and warm sides more efficiently, for example by means of a simple gap seal, the gap of which can be traversed by the elastocaloric elements held in this way. Similarly, a transport of heating / cooling medium is reduced due to the rotational movement of the elastocaloric elements or the wire bundles from the warm side to the cold side or vice versa; in particular due to the low flow resistance of the elastocaloric element or the wire bundle or the wire bundles in the form of the lateral surface segment of a cylinder.On the basis of the clamping arrangements configured in this way, for example, the wires or wire bundles of the elastocaloric element can be clamped or mechanically held in such a way that the failure of a wire does not lead to the failure of all the wires of a bundle of the elastocaloric element. Also, on the basis of the thus configured constraints, the "active" portion of the elastocaloric element or of the wire, which actively serves for heat absorption and heat emission, is not exposed to loads other than predetermined loads, whereby the service life can be increased. The embodiment of the clamping device according to the invention also results in a process that is easy to install, so that a certain automation is ensured.According to the invention, a respective clamping device has at least two clamping plates, between which another part of the elastocaloric element or of the wire bundle is clamped, in particular fixed immovably between the clamping plates. In particular, on the basis of the thus configured constraints, the "inactive" portion of the elastocaloric element or of the wire, which does not actively serve for heat absorption and heat emission, is fixed.According to the invention, the at least two clamping plates of a clamping device each have sealing surfaces which are opposite the sealing surfaces of the corresponding clamping device and seal the channel in the form of the cylinder shell or hollow cylinder at the end face. They are thus preferably outer radial sealing surfaces and inner radial sealing surfaces with respect to the channel in the form of the cylinder shell.Moreover, the clamping device according to the invention can be implemented in such a way that one of the clamping plates is designed as a carrier plate which has a plurality of pins to which the other part of the elastocaloric element can be fastened.Furthermore, the clamping device according to the invention can be designed in such a way that a respective clamping device has at least one base plate and a pull rod which is connected to the base plate, in particular rotatably or fixedly connected, and by means of which the one part of the elastocaloric element can be set into the first and second state.Moreover, the clamping device according to the invention can be further developed in such a way that a respective clamping device forms a link of a chain of links of respective clamping devices, wherein each link is in each case connected in an articulated manner to adjacent links of the chain.Furthermore, the clamping device according to the invention can be designed such that a respective clamping device forms a link of a chain of links of respective clamping devices, wherein each link is connected in each case via a tongue-and-groove connection to adjacent links of the chain in such a way that the links of the chain can be moved, in particular translationally moved, in each case in the transverse direction to the direction of extent of the chain relative to a respective adjacent link.In addition, the clamping device according to the invention can be realized in such a way that the corresponding clamping devices are designed in such a way that they hold the one part of the elastocaloric element held between them in such a way that the one part of the elastocaloric element is formed in a circular arc shape in cross section, preferably formed from individual wires of a wire bundle of the elastocaloric element.Furthermore, the clamping device according to the invention can be configured such that the corresponding clamping devices are configured such that they hold the one part of the elastocaloric element held between them such that the cross section of the one part of the elastocaloric element is formed exclusively by wires, tubes or strips of elastocaloric material of the elastocaloric element arranged in the circular arc direction or arranged next to one another.The elastocaloric machine according to the invention is configured to be operated as a heat pump and / or cooling machine and comprises: a duct which is designed in the form of a cylinder shell or hollow cylinder and is configured to guide a fluid in a flow direction predefined by the duct, a clamping device according to the invention, and a gap seal which is arranged in the duct and seals a warm and cold side of the duct with respect to one another, wherein the gap seal is configured such that it defines a gap which surrounds the one part of the elastocaloric element in a bearing manner when passing through the gap and is otherwise sealed in a sealing manner.This results in the properties and advantages explained in connection with the clamping device according to the invention being obtained in the same or similar manner, for which reason, in order to avoid repetitions, reference is made to the above explanations with respect to the clamping device according to the invention.Preferred embodiments of the invention are explained below by way of example with reference to the figures.The following are shown: FIG. 4 ashows a schematic representation of an elastocaloric machine according to the invention with a clamping device according to the invention in a cross-sectional view; FIG. 4 b is a schematic illustration of an enlarged portion of the elastocaloric machine of FIG. 4 a according to the invention; FIG. 5 ashows a schematic representation of a section of the clamping device according to the invention according to a first embodiment in a perspective view from above; FIG. 5 bshows a schematic representation of the clamping device according to the invention from FIG. 5 ain a perspective view for further explanation and partially in section; FIG. 5 cshows a schematic representation of the clamping device according to the invention from FIG. 5 ain a perspective view for further explanation and partially in section; FIG. 6 ashows a schematic representation of the clamping device according to the invention from FIG. 5 ain a first assembly step; FIG. 6 bshows a schematic illustration of the clamping device according to the invention from FIG. 5 ain a second mounting step; FIG. 6 cshows a schematic representation of the clamping device according to the invention from FIG. 5 ain a third assembly step; FIG. 6 dis a schematic illustration of the clamping device according to the invention from FIG. 5 ain a fourth mounting step; FIG. 6e shows a schematic illustration of the clamping device according to the invention from FIG. 5a in a fifth mounting step; FIG. 6 f shows a schematic illustration of the clamping device according to the invention from FIG. 5 a in a sixth mounting step; FIG. 6 g shows a schematic illustration of the clamping device according to the invention from FIG. 5 ain a seventh mounting step; FIG. 6 h shows a schematic illustration of the clamping device according to the invention from FIG. 5 a in an eighth mounting step; FIG. 6 i shows a schematic illustration of the clamping device according to the invention from FIG. 5 a in a ninth mounting step; FIG. 6j shows a schematic illustration of the clamping device according to the invention from FIG. 5a in a tenth mounting step; FIG. 6 k shows a schematic illustration of the clamping device according to the invention from FIG. 5 a in an eleventh mounting step; FIG. 6 lis a schematic illustration of the clamping device according to the invention from FIG. 5 ain a twelfth mounting step; FIG. 7 ashows a schematic representation of a section of the clamping device according to the invention according to a second embodiment in a perspective view from above; FIG. 7 bshows a schematic representation of the clamping device according to the invention from FIG. 7 ain a perspective view and with an enlarged section for further explanation; FIG. 7 cshows a schematic representation of the clamping device according to the invention from FIG. 7 ain a perspective view for further explanation; FIG. 8 ashows a schematic representation of the clamping device according to the invention from FIG. 7 ain a first assembly step; FIG. 8 bshows a schematic illustration of the clamping device according to the invention from FIG. 7 ain a second mounting step; FIG. 8 cshows a schematic representation of the clamping device according to the invention from FIG. 7 ain a third assembly step; FIG. 8 dis a schematic illustration of the clamping device according to the invention from FIG. 7 ain a fourth mounting step; FIG. 8 e shows a schematic illustration of the clamping device according to the invention from FIG. 7 a in a fifth mounting step; and FIG. 8 f shows a schematic illustration of the clamping device according to the invention from FIG. 7 a in a sixth mounting step.FIG. 4 ashows a schematic representation of an elastocaloric machine 1 according to the invention with a clamping device 1000 according to the invention in a cross-sectional view which corresponds with regard to the basic structure of the elastocaloric machine 1 of FIG. 1. The elastocaloric machine 1 is in this case configured to be operated as a heat pump and a refrigerating machine in the form of an air-conditioning system.As can be seen in FIG. 4 a, the elastocaloric machine 1 comprises a duct 11 like that of FIG. 1, which is designed in the form of a cylinder shell or hollow cylinder, and is therefore shown in the form of a circular ring in the case shown in cross section. The channel 11 conducts a fluid in a flow direction predefined by the channel 11 which, in the case shown, is directed counterclockwise according to the arrows drawn, which identify the flow direction of two inlets E and two outlets A. The channel 11 is thus divided into a sub-channel 11 1( right sub-channel in FIG. 4 a) and a sub-channel 11 2( left sub-channel in FIG. 4 a). The partial channel 11 1 connects an inlet E and an outlet A of a warm side, i.e. a warm fluid flows through it. By contrast, the partial channel 11 2 connects an inlet E and an outlet A of a cold side, i.e. a cold fluid flows through it. Furthermore, the channel 11 has two further sub-channels 11 3 which are formed between the respective outlets and inlets and connect the two sub-channels 11 1 and 11 2.Both partial channels 11 3 have at their two ends a gap seal 60 each, which is thus arranged in the channel 11 between respective outlets A and inlets E and which seal the warm and cold sides of the channel 11 against one another, in the case shown in the manner of a lock.FIG. 4 bshows a schematic representation of an enlarged section of the elastocaloric machine 1 according to the invention or of the duct 11 from FIG. 4 a. As can be seen more clearly in FIG. 4 a, the respective gap seals 60 are designed such that they define a gap 62, which can be passed by a part of elastocaloric elements or wire bundles 110 which are held by the clamping device 1000 according to the invention, which is discussed in more detail below. In this case, the elastocaloric elements or wire bundles 110 rotate in the arrow direction DR drawn in FIG. 4 a, counter to the flow direction of the fluid, i.e. in the clockwise direction.In any event, the respective gap seals 60 are adapted to define the gap 62 which is passed by the portion of elastocaloric elements or wire bundles 110 while the gap seal abuts the same and is otherwise sealed.FIG. 5 ashows a schematic representation of a section of the clamping device 1000 according to the invention in accordance with a first embodiment in a perspective view from above and FIGS. 5 band 5 cshows a schematic representation of the clamping device 1000 according to the invention from FIG. 5 ain a perspective view for further explanation and partially in section.As can be seen in FIGS. 5 a- 5 c, the clamping device 1000 according to the invention comprises a plurality of clamping devices 10 with a plurality of clamps 100, wherein the respective corresponding opposite clamps 100 are not illustrated.The clamps 100 are configured to respectively hold and move elastocaloric elements 110 in the form of a wire bundle within the fluid-conducting channel 11 formed in the form of the cylinder shell or hollow cylinder, and in the process to put them via a conventional mechanism, not described in more detail, into a first state in which the elastocaloric elements 110 emit thermal energy to the fluid due to the elastocaloric effect, and into a second state in which the elastocaloric elements 110 absorb thermal energy from the fluid due to the elastocaloric effect.The corresponding clamps 100 are configured in such a way that they hold the part of the elastocaloric element 110 or wire bundle held between them in such a way that this part forms a curved surface in the form of a lateral surface segment of a cylinder, as can be clearly seen in particular in FIGS. 4 aand 4 b. In particular, the respective parts of the elastocaloric elements 110 or wire bundles are held such that all wires are arranged individually in a curved surface in the form of a cylindrical surface which corresponds to a circular arc in FIGS. 4 aand 4 b.This reduces the effect that heating / cooling medium is transported or pushed from the cold side to the warm side and vice versa due to the rotational movement of the wire bundles 110. This allows, on the one hand, a minimized aerodynamic end face of the wire bundles and, on the other hand, this wire arrangement allows the use of the aforementioned gap seal 60.Referring again to FIGS. 5 a- c, the concrete structure of a clamping device 100 is described below.In the case shown, a respective clamping device 100 comprises two clamping plates 12, 14, between which another part of the elastocaloric element 110 or of the wire bundle is clamped, in particular fixed immovably between the clamping plates 12, 14. In particular, the part of the wire bundle 110 is fixed which is not set between the first and second states and is therefore not in heat exchange with the fluid. The two clamping plates 12, 14 of a clamping device 100 each have sealing surfaces 12 1, 141 an outer radial sealing surface 12 1 and an inner radial sealing surface 14 1, the respective sealing surfaces 12 1, 141 are opposite the corresponding clamping device 100, not shown, and thus seal the channel 11 in the form of the cylinder shell or hollow cylinder on the end face. Since components of the clamping device 100 are themselves situated in sections in the channel 11, as can also be seen from the illustration of FIG. 1A, the clamping device 100 is surrounded by a seal, not illustrated, such as a leaf or sponge seal along the channel 11, in order to prevent the fluid from being transported via the respective clamping devices 100. Accordingly, a seal which runs circumferentially in the channel longitudinal direction, i.e. in the circumferential direction, is provided at least on the end face and on its outer and inner radial sides, said seal sealing a gap between the clamping means 100 and a housing wall, in particular a channel wall of the channel 11. The end-face section of the seal is substantially designed such that it has a constant extension circumferentially in the direction of the axis of rotation A for end-face sealing, with the exception that a greater extension is provided in the region of the elastocaloric machine in which the clamping performs a stroke movement, in order to be able to compensate the stroke movement. As is shown in FIG. 5 c, by way of example, on the right next to the clamping elements 100, in the case of a leaf seal, the latter fundamentally has a constant extent, i.e. a constant leaf height, with the exception of the region in the elastocaloric machine in which the respective clamping element 100 performs its stroke movement.One of the clamping plates, in this case the clamping plate 14, is designed as a carrier plate which has a plurality of pins 16 to which the other part of the elastocaloric element 110 is fastened, which will be discussed in more detail below in connection with FIG. 6.Furthermore, each clamping device 100 has a base plate 20 and a pull rod 22, which is rotatably connected to the base plate 20 via a pin 40 and via which a part of the elastocaloric element 110 can be put into the first and second state by a corresponding application of force. As will be explained in more detail below, the base plates 20 of each adjacent clamping device 100 are configured differently, as can be seen in particular in FIG. 6 c, in order that the respective clamping devices 100 can form links of a chain from a plurality of links of respective clamping devices 100, each link being connected in each case in an articulated manner to two adjacent links of the chain.In the following, in conjunction with FIGS. 6 a- l, the mounting of the above-described restraint 100 and its structure will be described in concrete terms, in particular the concatenation of the individual links G 1 and G 2 for an arrangement, also referred to as chain restraint, of individual links of respective restraint 100, as is illustrated in FIGS. 5 a- c.FIG. 6 ashows a schematic representation of the clamping device according to the invention from FIG. 5 ain a first assembly step. In the first embodiment, the individual chain links are connected to one another by means of rivets 30. By way of example, the assembly of two chain links is described, for which purpose, as can be seen in FIG. 6 a, rivets 30 are used in a first assembly step 4.FIG. 6 bshows a schematic illustration of the clamping device according to the invention from FIG. 5 ain a second mounting step. In this second assembly step, two of the 4 rivets 30 are inserted into bores 201 and 202 of the base plate 20, wherein the rivets 30 are designed such that adjacent chain links G 1, G 2 can be rotated relative to one another when these are connected to one another.FIG. 6 cshows a schematic representation of the clamping device according to the invention from FIG. 5 ain a third assembly step. In this assembly step, the adjacent link G 2 is rotatably fixed to the link G 1 via a rivet 30. As will be apparent below, the rotatable connection of the chain links G 1 and G 2 is a necessary prerequisite for a lifting movement for stretching the elastocaloric elements or wire bundles to be able to be introduced into a respective restraint 100 or chain link G 1 by means of the pull rod 22, whereby the respective held wire bundle is stretched without stretching the wire bundle of the adjacent chain link G 2.FIG. 6 d shows a schematic illustration of the clamping device according to the invention from FIG. 5 a in a fourth assembly step, in which a corresponding bearing bolt 40 is inserted into bores 203 of the respective base plates 20 of the adjacent chain links G 1 and G 2.FIG. 6 e shows a schematic illustration of the clamping device according to the invention from FIG. 5 a in a fifth assembly step, in which a corresponding tie rod 22 is then rotatably connected to the respective bearing bolts 40 of the chain links G 1 and G 2, wherein the respective tie rods 22 can be equipped with corresponding pivot bearings.FIG. 6 f shows a schematic illustration of the clamping device according to the invention from FIG. 5 a in a sixth mounting step, in which the clamping plate 12 designed as a carrier plate is connected to the rivets 30 of the chain link G 1. As can also be seen in FIG. 6 f, a plurality of pins 16 are provided arranged in a straight line on an upper side of the clamping plate 12 designed as a carrier plate. These pins 16 serve as a support for the wire bundle of elastocaloric material.FIG. 6 g shows a schematic illustration of the clamping device according to the invention from FIG. 5 ain a seventh mounting step. In this assembly step, a corresponding wire made of elastocaloric material is thus wound around the pins 16 in a meandering manner. The winding of the wire takes place on two chain links of corresponding clamps 100 lying opposite one another.FIG. 6 h shows a schematic illustration of the clamping device according to the invention from FIG. 5 ain an eighth mounting step, in which finally corresponding wires made of elastocaloric material are wound in meandering fashion around the pins 16 of the two chain links G 1 and G 2.FIG. 6 i shows a schematic illustration of the clamping device according to the invention from FIG. 5 ain a ninth assembly step, in which the further clamping plate 12 is applied from above to the clamping plate 14 at the chain link G 1, which clamps the wires after the final riveting process.The same process in connection with FIG. 6 iis also carried out with the chain link G 2, as can be seen from FIG. 6 j, which shows a schematic illustration of the clamping device according to the invention from FIG. 5 ain a tenth assembly step.As can be further seen from FIG. 6 j, the adjacent chain links G 1 and G 2 differ only in the embodiment of the base plate 20. In terms of function, i.e. in particular in terms of kinematic terms, the adjacent chain links G 1 and G 2 have the same effect.FIG. 6 k shows a schematic illustration of the clamping device according to the invention from FIG. 5 ain an eleventh mounting step, in which a plurality of chain links G 1, G 2, G 3,..., Gi are connected to one another in the manner described above.FIG. 6 l shows a schematic illustration of the clamping device according to the invention from FIG. 5 ain a twelfth assembly step, in which a plurality of chain links Gicomprise chain link segments which ultimately at least partially form the clamping device 10 are illustrated.FIG. 7 ashows a schematic representation of a section of the clamping device 1000 according to the invention according to a second embodiment in a perspective view from above. FIG. 7 bshows a schematic representation of the inventive clamping device of FIG. 7 ain a perspective view and with an enlarged section for further explanation, and FIG. 7 cshows a schematic representation of the inventive clamping device of FIG. 7 ain a perspective view for further explanation.In describing this second embodiment, only the essential differences from the first embodiment are discussed in order to avoid repetitions, wherein identical or similar components are denoted by identical or similar reference numerals.In this exemplary embodiment, a respective restraint 200 forms a link G 1, G 2 of a chain of links of respective restraint 200, wherein each link G 1, G 2 is connected in each case via a tongue-and-groove connection 50 to adjacent links of the chain in such a way that the links of the chain are each translationally movable relative to a respective adjacent link in the transverse direction to the direction of extent of the chain. The respective chain links G 1, G 2 are thus designed to be translationally movable relative to one another.In the following, in conjunction with FIGS. 8 a- f, the mounting of the above-described restraint 200 and its structure will be described in concrete terms, in particular the concatenation of the individual links to form an arrangement, also referred to as chain restraint, of individual links of respective restraint 200, as is illustrated in FIGS. 7 a- c.FIG. 8 ashows a schematic representation of the clamping device according to the invention from FIG. 7 ain a first assembly step, in which a chain link G 1 is first used, which comprises a base plate 20 which is connected to the clamping plate 12 formed as a carrier plate with pins 16 or is formed in one piece.FIG. 8 bshows a schematic illustration of the inventive clamping device from FIG. 7 ain a second mounting step, in which-analogously to FIGS. 6 gand 6 h-the corresponding wires made of elastocaloric material are wound in meandering fashion around the pins 16.FIG. 8 cshows a schematic representation of the clamping device according to the invention from FIG. 7 ain a third assembly step, in which the clamping plate 12 is fastened onto the upper side of the clamping plate 14 acting as a carrier plate.FIG. 8 d shows a schematic illustration of the clamping device according to the invention from FIG. 7 a in a fourth assembly step, in which the clamping plates 12, 14 have been connected via the rivets 30. In particular, the clamping plate 12 is applied from above, which clamps the wires or wire bundles of the elastocaloric element 110 by means of a final riveting process.FIG. 8e shows a schematic representation of the clamping device according to the invention from FIG. 7a in a fifth assembly step, in which the pull rod 22 has been fastened via a nut 23 in a through hole 24 provided in the base plate 20.FIG. 8 f shows a schematic illustration of the clamping device according to the invention from FIG. 7 a in a sixth assembly step, in which ultimately the respective chain links G 1, G 2, G 3,..., Gi are connected to one another via the respective tongue-and-groove connections 50 and form a respective clamping means 100 of a clamping device 10.As in the first embodiment, adjacent chain links differ due to the tongue and groove connection 50 formed by the base plate 20. In terms of function, i.e. in particular in terms of kinematic terms, the adjacent chain links are equally active.In this embodiment, the pull rod 22 is screwed to the base plate 20 acting as a carrier plate, and can alternatively be welded, soldered, adhesively bonded or joined by forming (e.g. crimped) to the carrier plate.As can be seen from the above-described embodiments, all the wires are individually clamped during the riveting process. For better positioning of the wires during the winding process, grooves for the wires can preferably be made in the carrier plate. The clamping of the wires by riveting can be secured by a further process step such as crimping or application of adhesive before mounting of the clamping plate.The separate tension of each individual wire allows the so-called "active" part of the wire, which is stretched and relaxed and thus gives off and absorbs heat to the fluid or medium, to undergo only stretching and relaxation and minimizes the relative movement of the wire with respect to the tension. Minimizing the friction between the wire and the clamping leads to an increase in the service life of the wire.The aforementioned embodiments of the clamps according to the first and second embodiments make it possible to arrange all the wires one behind the other in one surface, so that only the wire diameter for the projected resistance surface is to be used fluidically.With the arrangement of wires in one surface, a favorable sealing principle can be implemented by means of the gap seal in the form of the aperture. The advantage of such a gap seal is moreover the simple construction and cost-effective construction.By configuring the clamping as a chain clamping, the interleaving or the meshing of the adjacent chain links is made possible. This achieves a closed top and bottom side of the entire chain restraint. A respectively closed upper and lower side is suitable as a sealing surface for contacting seals. The end faces of the chain links are designed such that they can also be used as sealing surface for contacting seals, as can be seen in particular in FIGS. 5 cand 7 c.The type of clamping reduces the relative movement of wire with respect to the clamping, which leads to an extension of the service life, which thus also counteracts the aging of the machine.Due to the design of the constraints, all wires experience the same percentage strain. For performance reasons, it is necessary to stretch the wire to a certain percentage. This maximum value should not be exceeded. In the chain-bindings carried out, all wires undergo the same strain. In a prior art roller design, where at least two or more pairs of rollers are necessary due to the required wire mass, the maximum elongation is always determined by the inner pair of rollers. Thus, the maximum possible extension at the outer roller pair is not achieved. Compared to the roller design belonging to the prior art, the chain clamping enables the mounting of the individual components in a clamping, which promotes the mounting and can lead to cost savings.The features of the invention disclosed in the above description, in the drawings and in the claims can be essential for the realization of the invention both individually and in any combination.

Claims

A clamping device (1000) for an elastocaloric machine (1) configured to be operated as a heat pump and / or a refrigerating machine, the clamping device (1000) comprising: at least one clamping device (10) having at least two corresponding clamps (100; 200) configured to hold an elastocaloric element (110) within a channel (11) of the elastocaloric machine (1) that conducts a fluid and is formed in the form of a cylinder shell and to put the elastocaloric element (110) into a first state, in which the elastocaloric element (110) gives off thermal energy to the fluid due to the elastocaloric effect, and into a second state, in which the elastocaloric element (110) absorbs thermal energy from the fluid due to the elastocaloric effect, wherein the corresponding clampings (100) are designed in such a way that they hold the part of the elastocaloric element (110) held between them in such a way that the part of the elastocaloric element (110) forms a curved surface in the form of a lateral surface segment of a cylinder, wherein a respective clamping (100) has at least two clamping plates (12, 14) between which another part of the elastocaloric element (110) is clamped, in particular is fixed immovably between the clamping plates (12, 14), and the at least two clamping plates (12, 14) of a clamping (100) each have sealing surfaces (12 1, 141) which sealing surfaces (12 1, 14_ner4_) are opposite the corresponding clamping (100) and seal the channel (11) in the form of the cylinder shell / hollow cylinder on the end face.Clamping device (1000) according to claim 1, wherein one of the clamping plates (12, 14) is formed as a carrier plate (14) comprising a plurality of pins (16) to which the other part of the elastocaloric element (110) is attachable.Clamping device (1000) according to one of claims 1 to 2, wherein a respective clamping device (100) comprises at least one base plate (20) and a pull rod (22) connected to the base plate (20), in particular rotatably or fixedly connected, by means of which pull rod the one part of the elastocaloric element (110) can be placed in the first and second state.A clamping device (1000) according to any one of claims 1 to 3, wherein a respective clamp (100) forms a link of a chain of links of respective clamps (100), each link being hinged to adjacent links of the chain, respectively.The clamping device (1000) according to any one of claims 1 to 3, wherein a respective clamping device (200) forms a link of a chain of links of respective clamping devices (200), wherein each link is respectively connected via a tongue and groove connection (50) to adjacent links of the chain such that the links of the chain are respectively movable in the transverse direction to the extension direction of the chain relative to a respective adjacent link.Clamping device (1000) according to one of the preceding claims, wherein the corresponding clamping devices (100; 200) are configured to hold the one part of the elastocaloric element (110) held between them such that the one part of the elastocaloric element (110) is configured in a circular arc shape in cross section.Clamping device (1000) according to one of the preceding claims, wherein the corresponding clamping devices (100; 200) are configured to hold the one part of the elastocaloric element (110) held between them such that the cross section of the one part of the elastocaloric element (110) is formed exclusively by wires, tubes or strips of elastocaloric material of the elastocaloric element (110) arranged in the circular arc direction or arranged next to one another.Elastocaloric machine (1) which is configured to be operated as a heat pump and / or refrigerating machine, having: a duct (11) which is designed in the form of a cylinder shell / hollow cylinder and is configured to guide a fluid in a flow direction predefined by the duct, a clamping device (1000) according to one of the preceding claims, and a gap seal (60) which is arranged in the duct (11) and seals a warm and cold side of the duct (11) with respect to one another, wherein the gap seal (60) is configured such that it defines a gap (62) which surrounds the one part of the elastocaloric element (110) in a bearing manner when passing the one part of the elastocaloric element (110) through the gap (62) and is otherwise sealed in a sealing manner.

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