Actuator and heat accumulator for an actuator

Abstract

The invention relates to an actuator for an orthopedic device, having an actuator housing (10) and a heat accumulator (2) for storing operating heat generated by the actuator (1), wherein the heat accumulator (2) has a heat accumulator housing (20) with a cavity (25) and a heat storage medium (26) in or consisting of the cavity, wherein the heat accumulator (2) is configured to be able to be fixed on or in the actuator housing (10) and has a receiving area (21) configured corresponding to an actuator housing section (11), which in the assembled state of the heat accumulator (2) is in heat-conducting contact with the actuator housing (10).

Description

TECHNICAL FIELD

[0001] The invention relates to an actuator for an orthopedic device, having an actuator housing and a heat accumulator for storing operating heat generated by the actuator, wherein the heat accumulator has a heat accumulator housing having a cavity and a heat storage medium located in the cavity. The invention likewise relates to a heat accumulator for fastening on the actuator. BACKGROUND

[0002] A plurality of actuators, for example passive actuators such as hydraulic dampers or pneumatic dampers or active actuators such as electric motor drives, pumps or the like, are used in orthopedic devices, for example prostheses, orthoses or exoskeletons. Active actuators, for example electric motors, can also be used together with passive actuators, for example in order to adjust a valve inside a pneumatic damper or a hydraulic damper for changing the damper characteristics depending on sensor data.

[0003] In all orthopedic devices, the space requirement and the weight of the technical components are decisive factors. The basic aim is to keep all additional devices mounted on the patient's body as small and as light as possible in order to set as little additional weight for the user and to cause as little visual negative impact as possible. Since the actuators, hydraulic dampers or motors are constructed as small and light as possible. This in turn means that the heat storage capacity of the components is relatively small.

[0004] Just when the orthopedic technical components are operated in their extreme range, the components heat up very strongly, since the heat storage capacity is small due to the desired lightweight construction and mechanical or electrical energy is dissipated as heat.

[0005] DE 10 2017 131195 A1 discloses an actuator for an orthopedic device, having an actuator housing.

[0006] From DE 10 2014 011373 A1 a kind of interface for arranging between a prosthesis or an orthosis and a prosthesis user or an orthosis user and a system consisting of the interface and the prosthesis or the orthosis are known.

[0007] EP 2 568 935 A2 discloses a device consisting of a PCM and an actively cooled heat exchange system. SUMMARY

[0008] It is therefore the task of the invention to provide an actuator with which a longer duration of use at higher loads or in the extreme range can be achieved without neglecting the aim of lightweight construction and small space requirement.

[0009] According to the application, this task is solved by an actuator having the features of the main claim and by a heat accumulator having the features of the dependent claim. Advantageous configurations and further developments of the application are disclosed in the dependent claims, the description and the drawings.

[0010] Actuator for an orthopedic device, having an actuator housing and a heat accumulator for storing operating heat generated by the actuator, wherein the heat accumulator has a heat accumulator housing having a cavity and a heat storage medium located in the cavity or consisting of the heat storage medium, the actuator being designed such that the heat accumulator or the heat accumulator housing is configured to be fixed on or in the actuator and has a receiving area configured to correspond to a section of the actuator housing, the receiving area being in heat transfer contact with the actuator housing in the assembled state of the heat accumulator. The heat accumulator is in particular configured independently of the actuator housing and can be repeatedly fixed on the actuator housing and removed from the actuator housing. By means of the heat accumulator arranged on the actuator housing, the thermal capacity of the actuator can be increased. The increased thermal capacity delays an increase in the operating temperature to a limit value or slows down the heat generation of the hydraulic system. Conversely, the increased thermal capacity slows down the cooling, and the peaks of the power consumption of the actuator are flattened. The increase in the thermal capacity does not reduce the static temperature of the actuator, for which a cooling system is required. However, the increase in the thermal capacity by means of the heat accumulator has the advantage, in contrast thereto, that the device can influence the functional behavior with respect to external framework conditions that can be influenced by the user, such as the clothing of the user or the skin of the orthopedic device. By means of the configuration of the heat accumulator housing as a hollow body with a filling of the heat storage medium, it is possible to match the respective properties with respect to the heat to be stored and the weight to the respective structure or the respective use case. It is thereby possible, for example, to inject a heat storage medium having a very good specific heat capacity into the cavity, wherein the heat storage medium requires less mass and volume than the materials used for the rest of the actuator in order to achieve the same heat generation properties as in the case of using materials requiring more mass and volume. It is likewise possible and provided in addition or as an alternative that the heat accumulator consists at least partially of the heat storage medium. The heat accumulator is then at least partially solid, or the walls of the heat accumulator housing consist of the heat storage medium. The actuator thereby becomes lighter and it is possible to optimally design the actual actuator having a housing, for example, consisting of metal, a hydraulic cylinder and a mechanical device arranged on the hydraulic cylinder, and a drive device with respect to its strength and its operating properties without having to take into account the required thermal capacity. The respective required thermal capacity is provided by means of the heat accumulator having the heat storage medium and / or the heat accumulator housing of the heat storage medium arranged therein, which can be minimized with respect to the weight and maximized with respect to the thermal capacity. By means of the functional separation of the actuator and the heat accumulator and the allocation of the mechanical and dynamic requirements of the actuator and the thermal requirements of the heat accumulator, it is possible to optimize the separate components individually and thereby to provide an overall system that is optimized not only with respect to the mechanical structure but also with respect to the thermal capacity.

[0011] It is a further aspect of the application that the heat accumulator, in particular the heat accumulator housing, is positively and / or form-fittingly fixed on the actuator housing. The heat accumulator, in particular the heat accumulator housing, is in particular releasably and exchangeably arranged and fixed on the actuator housing, so that a subsequent fixing and an increase or adjustment of the heat storage capacity according to the respective use conditions is possible. The heat accumulator or the heat accumulator housing can be removed and exchanged or replaced by a heat accumulator of another size, in particular with a housing, or by a heat accumulator consisting of a heat storage material, if necessary.

[0012] On the heat accumulator, in particular the heat accumulator housing, and the actuator housing, a fixing device can be arranged or configured, by means of which the heat accumulator, in particular the heat accumulator housing, can be connected with the actuator housing. The fixing device is in particular configured as a screw receptacle, a side recess, a clamp, a clamping element, a plug, a plug receptacle, a magnet, a ferromagnetic element and / or a nylon webbing element. The heat accumulator or the heat accumulator housing can also be arranged in the actuator housing, for example clamped or pushed into a recess. A conventional screw connection enables a repeated, technically proven and reliable fixing of the heat accumulator or the heat accumulator housing on the actuator housing. It is also possible to reversibly fix on the actuator housing by means of a clamp and a side recess or other form-fitting elements which are also elastically supportable or configured. Plug connections can be provided alone or in combination with force-fitting fixing devices, such as magnets, ferromagnetic elements or vacuum devices. In addition, a nylon webbing element, for example a hook region and a pile region or a similar hooking system, makes it possible to fix and preload the heat accumulator housing in the direction towards the actuator housing by means of a flexible and, if necessary, elastic device. Ferromagnetic and / or magnetic components can constitute functional parts of the respective housing or be configured as separate devices fixed on the respective housing. It is also possible to integrate the heat accumulator into the actuator housing, for example to push it into a dovetail groove, to insert it into a surrounding receptacle or to configure it as a preferably removable part of the actuator housing.

[0013] It is a further aspect of the application that on the side of the receiving region facing the actuator, a form-fitting element is arranged or configured, which is correspondingly configured to a form-fitting element on the outside of the actuator, in order to enable a durable, releasable and reliable locking and fixing of the two housings or the heat accumulator and the actuator housing on one another.

[0014] The heat accumulator or the heat accumulator housing can be at least partially flexibly configured on the side of the receiving region facing the actuator, whereby it is possible to provide the receiving region as comprehensively as possible against the outside of the actuator housing. Thereby, the housing faces or contact faces are ensured to be as large as possible and the contact as strong as possible, in order to enable as fast a heat exchange as possible.

[0015] In a further refinement of the application, the heat accumulator or the heat accumulator housing is at least partially rigid on the side facing away from the actuator in order to achieve sufficient stability and mechanical rigidity. In this way, the heat accumulator or the heat accumulator housing also fulfils a protective function for the actuator housing. Furthermore, the form-stable outer shell of the heat accumulator housing or the heat accumulator can thus provide sufficient mechanical stability for fixing the heat accumulator housing or the heat accumulator on the actuator housing.

[0016] The heat accumulator and / or the heat accumulator housing can be composed of different materials, wherein the material in the receiving region has a thermal conductivity which is greater than the thermal conductivity of a second material outside the receiving region. Heat can thus be conducted quickly from the actuator into the heat accumulator and vice versa, whereas heat is only released from the heat accumulator to the surroundings at a reduced rate, so that, for example, the heating of the actuator of an orthosis is only slowly manifested in a perceptible heating on the outside of the heat accumulator.

[0017] The outer contour and the surface can be obtained in such a way that an optimum heat release to the surroundings is achieved. The outer contour of the side of the heat accumulator or the heat accumulator housing facing away from the actuator and / or the contour of the receiving region can have a contour which is configured correspondingly to the contour of the outside of the actuator. The inside or the receiving region thus has a contour which is configured correspondingly to the contour of the outside of the actuator housing, so that the heat accumulator lies as completely as possible against the outside of the actuator housing. By the configuration of the outside of the heat accumulator housing corresponding to the outside of the actuator housing, a form-fitting and optically continuous part of the actuator housing can be achieved by the heat accumulator or the heat accumulator housing, so that an improved overall impression of the aesthetics is achieved here. The configuration of the inside of the receiving region corresponding to the outside of the actuator housing is functionally important for good heat conduction.

[0018] Preferably, the actuator is configured as a hydraulic actuator, in particular as a hydraulic damper, further configurations of the actuator, such as a starting actuator or an electric motor, are possible.

[0019] The heat accumulator or the heat accumulator housing can encompass the actuator housing extensively, in particular completely. If the actuator housing has a cylindrical or substantially cylindrical outer contour, the heat accumulator or the heat accumulator housing is advantageously equipped with a receiving region which is configured cylindrically or at least partially cylindrically.

[0020] The heat accumulator or the heat accumulator housing can be configured in multiple parts, so that a modular structure of the heat accumulator or the heat accumulator housing can be achieved, so that the heat storage capacity can be matched to the respective requirements. The basic module of the heat accumulator or the heat accumulator housing can be configured expandably in such a way that further parts of the heat accumulator housing are fixed on the basic module, for example form-fittingly or releasably by being latched into a lateral recess. Further fixing possibilities are likewise achieved.

[0021] The heat storage medium can have a specific heat capacity of at least 1 J / (g*K) and / or a specific melting enthalpy of 100 kJ / kg at a temperature of 25°C. The heat storage medium can preferably have a smaller density than the material of the heat storage housing, in particular than the actuator, in the configuration as a filling. When the heat storage medium has a large density, then a large heat storage capacity is provided in the case of a small construction space, so that a compact construction can be achieved with the same amount of heat that can be stored in the heat storage medium. Preferably, the heat storage medium is designed as a wax, in particular beeswax, paraffin or another medium with corresponding properties. The heat storage medium and thus also the heat storage can also be designed as a salt, a salt hydrate, a sub-salt hydrate, in particular sodium acetate trihydrate or a shape-stable silica gel.

[0022] The heat storage medium is configured to be able to be triggered actively, for example by a mechanical pulse or a pressure wave that triggers recrystallization, so that the stored heat can be released at a freely selectable point in time.

[0023] The application likewise relates to an orthopedic device having an actuator and a heat storage as described above. The application likewise relates to a heat storage having a heat storage housing as described above. The heat storage is intended to be fastened to an actuator of an orthopedic device as described above. The design of the heat storage medium as a wax has the advantage, in addition to the relatively large specific heat capacity and the small melting point of, for example, beeswax at approximately 55°C, that the wax does not corrode, is electrically non-conductive and is cyclically stable and furthermore has good sound-insulating properties. The usual temperature range in which the actuator is operable does not lead to either evaporation or freezing of the wax, which leads to a high operating safety. Furthermore, the melting point of 55°C of beeswax has the advantage that, as the temperature of the wax continues to increase, the wax is necessarily melted, for which a melting enthalpy of 176 kJ / kg is required, so that an increase in the specific heat capacity overall results. The generally large specific heat capacity of the wax, in particular of beeswax, is further increased by the use of phase changes and the melting enthalpy required therefor, so that the thermal capacity of a usual hydraulic actuator can be achieved by only one eighth to one ninth of the mass of the beeswax. BRIEF DESCRIPTION OF DRAWINGS

[0024] One embodiment of the application is explained in detail below with the aid of the drawings. The drawings show:

[0025] Figure 1 - a perspective view of a hydraulic actuator having a heat storage housing arranged thereon;

[0026] Figure 2 - a front view of a hydraulic actuator having an open heat storage housing according to Figure 1 - a variant of the application;

[0027] Figures 3-2 - a variant of the application;

[0028] Figure 4 - sectional view with two different thermal storage media;

[0029] Figure 5 - schematic representation of the use of the application;

[0030] Figure 6 - perspective view of the thermal store;

[0031] Figure 7 - thermal store according to Figure 6 without receiving area;

[0032] Figures 8-6 - view of the outer wall with partial cutaway according to

[0033] Figures 9-8 - view without outer wall according to

[0034] Figures 10-9 - side view according to

[0035] Figures 11-10 - front view according to

[0036] Figures 12-11 - top view according to DETAILED DESCRIPTION

[0037] In Figure 1 a perspective view is shown an actuator 1 in the form of a hydraulic damper with an actuator housing 10 in which a cylinder is constructed in which a not visible piston can be coupled with an orthopedic device via a piston rod 12. The hydraulic actuator 1 can be constructed as a hydraulic damper or as an actively driven device. An accessory 15 is arranged on the actuator housing 10 in which a motor drive for driving a pump or for adjusting one or more valves or similar devices can be arranged. Furthermore a sensor, a microprocessor as part of a control device and similar devices can be arranged in the accessory 15, alternatively the drive and all further components can be arranged in the actuator housing 10.

[0038] The heat accumulator 2 with the heat accumulator housing 20, in which the heat storage medium is located, is arranged outside the actuator housing 10. The heat accumulator housing 20 has an outer wall 22, which is composed of a rigid, dimensionally stable material, for example a light metal. On the inner side of the heat accumulator housing 20 facing the actuator housing 10, a receiving area 21 is configured, which is configured to correspond to the actuator housing section 11 on the outer side of the actuator housing 10. On the receiving area 21 of the actuator housing 10, the part of the heat accumulator 2 is arranged, which should receive the heat and, if necessary, continue to transmit the heat to the heat storage medium 26. In the embodiment shown, the actuator housing section 11 extends from the end side of the actuator housing 10 over the total length of the outer side of the actuator housing 10 up to the attachment 15. The piston rod 12 protrudes from the visible end side of the actuator housing 10. The opposite end side is provided, for example, with a fixing device for fixing on an orthopedic technical device, for example a prosthesis, an orthosis or an exoskeleton.

[0039] In Figure 2 the receiving area 21 can be seen in a front view with the partially cut heat accumulator housing 20, which is shown in dashed lines. The receiving area 21 lies against the outer side of the actuator housing 10 on the actuator housing section 11. Thereby, the heat released by the actuator housing 10 can be released via the receiving area 21 to the cavity 25 with the heat storage medium 26. The heat storage medium 26, for example wax, stores the heat and enables a smoothing of the energy dissipation peak and enables, with the relatively small weight due to the hollow construction of the heat accumulator 20 and the functionally matched material selection of the heat storage medium 26, an extended operating duration of the actuator 1 under high loads.

[0040] Between the actuator housing section 11 and the receiving area 21, a heat conductor 40, for example a heat-conducting paste, a heat-conducting pad and / or a heat-conducting plate composed of a particularly well heat-conducting material, can be arranged. Via the heat conductor 40, the free space between the outer side of the actuator housing 10 and the receiving area 21 can be compensated.

[0041] The heat accumulator housing 20 can have an inwardly directed protrusion at the transition to the attachment 15, which cooperates with a gap or slot between the attachment 15 and the actuator housing 10, so that a form-fit locking on the actuator housing 10 can be achieved thereby. For this purpose, only the protrusion or the entire heat accumulator housing 20 can be configured elastically extensible, so that the actuator housing 10 can be placed, pushed into a receiving area and fixed on the receiving area by a form-fit, springy locking. Alternatively, form-fit elements, for example dowels, spigots or screw connections can be provided and arranged or configured on the actuator housing 10 and the heat accumulator housing 20, so that the heat accumulator 2 can be fixed releasably and advantageously reusable on the actuator housing 10. A permanent connection can be achieved, for example, by adhesive, for example by adhesive thermal conductors. Alternatively or additionally, a force-fit connection can be established by magnetic coupling.

[0042] Figure 3 A variant of the application according to Figure 2 is shown, in which the heat accumulator 2 is composed of the heat storage medium 26 instead of a hollow body filled with the heat storage medium 26. Preferably, the heat storage medium 26 of the heat accumulator 2 is a material with a very large heat absorption capacity, for example silica gel, which is placed directly on the actuator housing 10 and fixed on the actuator housing. The heat accumulator 2 then does not have a separate heat accumulator housing 20, on which the fixing can be carried out here releasably and repeatable mounted on the actuator housing 10.

[0043] A further variant of the embodiment is shown in Figure 4 , in which only the actuator housing 10 with the actuator housing section 11 is shown, on which the respective variant of the heat accumulator 2', 2" is placed. The respective heat accumulator 2', 2" is arranged in the shown embodiment on the outside of the actuator housing 10. In Figure 4Two variants of the heat accumulator 2 are shown in the middle, the first variant having a heat accumulator 2' composed of a salt or a material predominantly comprising a salt, in particular a sub-salt. The second variant of the heat accumulator 2" is composed of a paraffin and has a greater thickness D2 than the first variant of the heat accumulator 2' having a first thickness D1. The reason for this is that the enthalpy of the salt and its density are greater than that of the paraffin and thus require a smaller volume of the heat storage medium 26 in comparison. The two heat accumulators 2', 2" are applied against the actuator housing section 11, which is provided for heat exchange or heat transfer from the actuator housing 10 to the heat accumulator 2', 2". If the respective heat storage medium 26 of the heat accumulator 2', 2" is not shape-stable, instead of the configuration of the heat accumulator 2', 2" composed of the respective heat storage medium 26, a respective shell can be arranged around the heat storage medium, which shell serves as a heat accumulator housing and constitutes a cavity in which the respective heat storage medium is arranged. It is possible, in particular in an arrangement having a flexible heat accumulator housing, at least one partially flexible heat accumulator housing, to use a deformable heat storage medium, which in the deformable state is applied against the actuator housing 10 and is then solidified or crystallized. Thereby it becomes easy to apply closely and comprehensively against the area of the outside of the actuator housing 10, which is provided for heat transfer.

[0044] Figure 5One variant of the application is shown, wherein the actuator 1 is configured as part of an orthopedic technical device. On the actuator housing 10 on the upper end a pyramid adapter 13 is arranged in order to connect the actuator 1 with an upper part of a leg orthosis or a leg prosthesis, for example. The piston rod 12 protrudes from the actuator housing 10 and extends up to a lower part 15 of the orthopedic technical device. The heat accumulator 2 with the heat accumulator housing 20 is arranged on the outside of the actuator housing 10. In the left-hand view the heat storage medium 26 inside the heat accumulator housing 2 is arranged in the receiving area 21 of the actuator housing 10 in the solid state. If by operating the actuator 1, for example, frictional energy is converted into heat or electrical energy is dissipated into heat, the thermal energy is not only stored in the actuator 1 but also in the heat accumulator 2. Thereby the maximum duration of use of the actuator 1 and thereby also of the orthopedic technical device is prolonged, because the actuator has a maximum operating temperature which must not be exceeded. If the actuator temperature, for example, reaches 80°C, the user must wait until the thermal energy is released to the surroundings and the joint or the orthopedic technical device is sufficiently cooled. By means of the heat accumulator 2 arranged on the receiving area 21 the thermal energy can be absorbed and stored in the heat storage medium 26 in order to then release the absorbed energy at a further, defined point in time, for example during a standstill phase. The user must therefore no longer wait so long until the joint can be used again or the user can use the joint or the orthopedic technical device longer within the same cooling duration. The heat accumulator can preferably be easily removed and again easily fixed on the actuator. In particular the heat accumulator can be fixed on the actuator and removed from the actuator tool-free, so that the user can change, in particular increase, the heat storage capacity of the actuator and thereby the duration of use. The removed heat accumulator can be cooled, while a newly arranged replacement heat accumulator can absorb the heat of the actuator housing.

[0045] The state in which the heat accumulator 2 is occupied when heat is stored in the heat accumulator 2 is shown in the right-hand view. The heat storage medium 26 melts and is accordingly liquid or low-viscous. The thermal energy from the actuator 1 is absorbed in the heat storage medium 26 of the heat accumulator 2. At a later point in time, the heat accumulator 2 and, if necessary, also the actuator 1 is cooled, which is shown in the lower middle view. The heat storage medium 26 inside the heat accumulator 2 can be freely selected on the one hand and, if necessary, initiated manually by means of a trigger signal triggered event. If, for example, a salt hydrate is used, there is the possibility of determining the point in time at which the thermal energy should be released again. If the orthopedic technology or joint, or the actuator 1, is overheated, it is no longer mandatory to wait until the entire thermal energy is released to the surroundings, whereby the actuator can be used again. Precisely the energy is stored in a chemical reaction and can be released at any point in time. The waiting duration until the joint or orthopedic technology is again available after overheating is shortened thereby. In the case of a heat accumulator 2 which can be quickly exchanged, in particular, the service life can be greatly extended thereby. By means of the salt or salt hydrate as heat storage medium, the energy of the entropy is not released automatically, precisely the energy of the specific heat capacity of the actuator 1 must be released. The cooling time is significantly shortened thereby. The remaining energy of the entropy can be released at any determinable point in time. Until the recrystallization is triggered, the joint can always release energy in the size of the specific heat capacity of the orthopedic technology or actuator 1. If the thermal energy from the heat accumulator 2 is released, the state in the left-hand middle appears Figure 5 .

[0046] The recrystallization of the salt can be triggered, for example, by a pressure wave, for example by the operation of a small metal sheet or by a vibrating motor or by switching on a further trigger or trigger mechanism 30. The trigger mechanism 30 is shown schematically in Figure 5 and can be arranged directly on the heat accumulator 2, which can be reached from the outside. For example, a key, a switch or a flexible point can be configured on the heat accumulator housing, by means of which a metal sheet or a further actuator can be activated to trigger a pressure wave by means of which the crystallization of the heat storage medium 26 can take place at the respective desired point in time. By using a latent heat accumulator in the form of a salt, a relatively light heat accumulator with small volume can be provided. The enthalpy of the salt is greater compared to paraffin, while the heat capacity is smaller.

[0047] In Figure 6The diagram illustrates another variation of the invention, showing a heat accumulator 2 with an outer wall 22 and a receiving area 21. The actual actuator is not shown and can be configured as a damper or a motor drive. The receiving area 21, together with the outer wall 22, forms a cavity and thus integrally constitutes the heat accumulator housing 20, which advantageously contains and is filled with a heat storage medium. The heat storage medium is, for example, wax or another heat storage material, through which heat energy can be transferred from the actuator through the receiving area 21 and absorbed. Protrusions or form-fitting elements are arranged or constructed on the receiving area 21 as fixing devices 3 for attachment to the actuator (not shown). Correspondingly formed form-fitting elements are arranged or constructed in the actuator. Other forms of form-fitting elements, such as nylon chains, clamps, side recesses, bolts, or similar elements, can be used as fixing devices 3. Instead of form-fitting elements, fixing devices 3 can also be constructed as magnets or clamping elements to achieve force-fit fixation.

[0048] exist Figure 7 The diagram shows a heat accumulator 2 without a receiving area 21, which can be constructed, for example, as a thermally conductive metal. A heat conductor or thermally conductive coating can be constructed or arranged on the underside of the receiving area 21 or on the side facing the actuator to facilitate or achieve heat transfer from the actuator to the heat accumulator 2. A cavity is constructed inside the heat accumulator housing 20, which can be bonded to or otherwise fixed to the receiving area 21, the cavity being constructed by means of... Figure 8 Specifically described. The accumulator housing 20, having an outer wall 22, is constructed to be closed toward the receiving area 21, such that the accumulator housing 20 can be constructed as a separate module, which is subsequently fixed to the receiving area 21.

[0049] A partially cut-out view of the accumulator housing 20 already assembled on the receiving area 21. Figure 8 As shown in the diagram, the outer wall 22 and the inner wall 22' together form a cavity 25 in which the heat storage medium 24 can be disposed. In the illustrated embodiment, three separating elements 24 extend from the inner wall 22' toward the outer wall 22, and in the illustrated embodiment, extend parallel upward away from the receiving section 21, thereby forming a total of four small cavities inside the cavity 25. These small cavities are interconnected, thereby allowing heat exchange and, if necessary, material exchange in the case of a liquid heat storage medium.

[0050] Figure 9The diagram shows an arrangement of a heat accumulator housing 20 having a receiving area 21 and no outer wall, the heat accumulator housing having an inner wall 22' and a partition wall 24 projecting upward from the inner wall. The partition wall 24 may be integrally constructed with the inner wall 22', or alternatively, the partition wall 24 may be subsequently arranged on and fixed to the inner wall 22'.

[0051] Figure 10 Shown in side view according to Figure 9 The view. By Figure 10 It can be seen that the inner wall 22' does not extend over the entire receiving area 21; more precisely, it exposes sections not covered by the heat accumulator 2. In principle, it is possible that said area is also fully covered and shielded by the heat accumulator 2.

[0052] according to Figure 11 The view shows the parallel orientation of the three partition walls 24 and their substantially vertical upward orientation.

[0053] exist Figure 12 In the top view, a section in the front region of the accumulator housing 20 can be seen, wherein the receiving area 21 is not covered by the accumulator housing 20 and the inner wall 22'.

[0054] In addition to separating and isolating the various cavities, the partition element 24 also serves the functions of stabilizing the heat accumulator 2 and facilitating heat conduction from the receiving area 21 and the inner wall 22' into the inner cavity of the heat accumulator 2. Compared to when heat conduction occurs only through the walls, the heat storage medium arranged in the cavity 25 is heated more uniformly through the partition element 24 extending into the cavity 25. The partition element 24 can be made of a material with good thermal conductivity for this purpose, for example, a material with the thermal conductivity of the receiving area 21. Heat is conducted through the partition element 24, resulting in more uniform heating of the heat storage medium in the cavity 25. In addition to the edge regions, heat is also applied to the center of the cavity 25, thereby achieving improved heat output from the actuator.

Claims

1. An actuator for an orthopaedic device, having an actuator housing (10) and a heat accumulator (2) for storing operating heat generated by the actuator (1), wherein The heat accumulator (2) has a heat accumulator housing (20) with a cavity (25) and a heat storage medium (26) in or of the cavity, characterized in that the heat accumulator (2) is configured to be fixed on or in the actuator housing (10) and has a receiving area (21) configured corresponding to the actuator housing section (11), which is in heat-conducting contact with the actuator housing section (11) in the assembled state of the heat accumulator (2), wherein the heat accumulator (2) is fixed on the actuator housing (10) releasably, and wherein the specific heat capacity of the heat storage medium (26) is greater than the specific heat capacity of the actuator housing (10).

2. The actuator of claim 1, wherein The heat accumulator (2) is fixed on the actuator housing (10) positively and / or form- fittingly.

3. The actuator according to claim 1 or 2, characterized in that A fixing device (3) is arranged or configured on the heat accumulator (2) and the actuator housing (10).

4. The actuator of claim 3, wherein The fixing device (3) is a bolt receptacle, a side recess, a clamp, a clamping element, a plug, a plug receptacle, a magnet, a ferromagnetic element and / or a nylon webbing element.

5. The actuator according to claim 1 or 2, wherein A form-fitting element is arranged or configured on the side of the receiving area (21) facing the actuator (1), which is configured correspondingly to a form-fitting element on the outside of the actuator housing (10).

6. The actuator of claim 1 or 2, wherein The heat accumulator (2) is at least partially flexible on the side of the receiving area (21) facing the actuator (1).

7. The actuator of claim 1 or 2, wherein The heat accumulator (2) is at least partially rigid on the side facing away from the actuator (1).

8. The actuator of claim 1 or 2, wherein The heat accumulator (2) is composed of different materials, and the material in the receiving area (21) has a thermal conductivity λ M1 which is greater than the thermal conductivity λ M2 of a second material outside the receiving area (21).

9. The actuator of claim 1 or 2, wherein The outer contour of the side of the heat accumulator (2) facing away from the actuator (1) and / or the contour of the receiving area (21) has a contour configured correspondingly to the contour of the outside of the actuator housing (10).

10. The actuator of claim 1 or 2, wherein At least one heat conductor (40) is arranged between the actuator housing (10) and the heat accumulator (2).

11. The actuator of claim 10, wherein, The heat conductor (40) is a heat-conducting paste, a heat-conducting pad and / or a heat-conducting plate.

12. The actuator of claim 1 or 2, wherein The actuator is configured as a hydraulic actuator.

13. The actuator of claim 1 or 2, wherein The actuator is configured as a hydraulic damper.

14. The actuator of claim 1 or 2, wherein The heat accumulator (2) broadly surrounds the actuator housing (10).

15. The actuator of claim 1 or 2, wherein, The heat accumulator (2) is configured in multiple parts.

16. The actuator of claim 1 or 2, wherein The heat storage medium (26) has a specific heat capacity of at least c p = 1 J / (g K) at a temperature of T = 25 °C.

17. The actuator of claim 1 or 2, wherein The heat storage medium (26) has a specific melting enthalpy of at least h WM = 100 kJ / kg.

18. The actuator of claim 1 or 2, wherein, The heat storage medium (26) is designed as wax, paraffin, salt, a salt hydrate, a sub-salt hydrate or a shape-stable silica gel.

19. The actuator of claim 1 or 2, wherein, The heat storage medium (26) is designed as sodium acetate trihydrate.

20. The actuator of claim 1 or 2, wherein, The heat storage medium (26) is configured to be actively triggered.

21. An orthopedic device having an actuator (1) according to any one of the preceding claims.

22. A heat accumulator (2) according to any one of claims 1 to 20, the heat accumulator being a heat accumulator of an actuator (1) according to any one of claims 1 to 20, the heat accumulator having a heat accumulator housing (20) for being fixed on an actuator (1) of an orthopedic device.

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