Deformation unit, fluid conveying apparatus and method
Patent Information
- Application Number
- EP2023727248
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-05-13
- Filing Date
- 2023-05-10
- Publication Date
- 2025-03-19
AI Technical Summary
Existing fluid conveying devices, particularly micropumps, face challenges in achieving uniform deformation and peristaltic pumping movements due to limitations in deformability and stability of magnetic shape memory elements.
A deformation unit with a magnetic shape memory element held in a permanently bent state by a holding device, allowing for controlled shape changes and optimal twin structure formation for uniform traveling wave movements, which enhances micropump performance by preventing abrupt volume changes and maintaining stability.
This configuration enables uniform peristaltic pumping movements and stable fluid delivery with reduced risk of cavitation, ensuring reliable operation and efficient fluid handling in micropump applications.
Smart Images
Figure 1.1
Abstract
Description
[0001] Deformation unit, fluid conveying device and method
[0002] State of the art
[0003] The invention relates to a deformation unit according to the preamble of claim 1, a fluid conveying device according to claim 12 and a method according to the preamble of claim 16.
[0004] A deformation unit for a fluid conveying device has already been proposed, comprising at least one magnetic shape memory element which is at least intended to carry out an operating function of the fluid conveying device by means of a controllable change in shape, and comprising a holding device at least for holding the magnetic shape memory element in the fluid conveying device.
[0005] The object of the invention is, in particular, to provide a generic device with advantageous properties regarding deformability, particularly with regard to use in micropumps. This object is achieved according to the invention by the features of patent claims 1, 12, and 16, while advantageous embodiments and further developments of the invention can be found in the subclaims.
[0006] Advantages of the invention
[0007] The invention is based on a deformation unit for a fluid conveying device and / or for a mechanical actuator device, with at least one magnetic shape memory element, which is at least intended to carry out an operating function of the fluid conveying device and / or the mechanical actuator device by means of a controllable change in shape, and with a holding device at least for holding the magnetic shape memory element in the fluid conveying device and / or the mechanical actuator device.
[0008] It is proposed that the holding device permanently holds the magnetic shape memory element in a state that is bent at least in some areas, at least in sections, and / or at least partially, in particular in an arcuate manner. This allows advantageous deformation properties of the shape memory element to be achieved. This advantageously enables particularly uniform traveling wave movements of the shape memory element, which can be used particularly advantageously for micropump applications. In micropump applications of the shape memory element, a particularly uniform peristaltic pumping movement can be achieved.
[0009] In particular, the fluid conveying device is designed as a positive displacement pump. A "positive displacement pump" should be understood in particular as a pump, in particular an electrically operated pump, which uses a displacement mechanism to convey at least one medium. The positive displacement pump in particular has at least one closed conveying volume which conveys the medium and which is preferably intended to prevent an unwanted backflow of the medium against the conveying direction. The positive displacement pump is particularly advantageously self-priming and intended to independently build up a negative pressure in order to convey the medium into it, whereby in particular further negative pressure components, such as an additional vacuum pump, can be dispensed with. "Provided" should be understood in particular as specially programmed, designed and / or equipped.The fact that an object is intended for a specific function should be understood in particular to mean that the object fulfills and / or performs this specific function in at least one application and / or operating state. In particular, the positive displacement pump is designed as a micropump. A "micropump" should be understood in particular to mean a positive displacement pump with a maximum installation space of 25 cm. 3 , preferably no more than 15 cm 3 and particularly preferably of no more than 5 cm 3The micropump is preferably intended for conveying particularly small, adjustable delivery volumes. The displacement pump device is intended in particular for conveying a medium which comprises at least one liquid, at least one gas, at least one solid, in particular a powdered solid, and / or a mixture thereof. For example, the medium can comprise at least one liquid with a solid dissolved therein, such as an active ingredient, a medicament or the like. An actuator device is to be understood in particular as a drive unit which converts a signal, for example an electrical signal or a magnetic signal, into a mechanical movement and / or into a change in physical quantities such as pressure or temperature.
[0010] A "magnetic shape memory element" is understood, in particular, to be an element designed to utilize at least one shape memory effect to convey the medium. The shape memory effect utilized by the shape memory element to convey the medium is, in particular, a magnetic shape memory effect. To convey a medium, it is conceivable for the displacement pump device to comprise more than one shape memory element. For example, such shape memory units could be fluidically connected to one another in parallel and / or in series. Most preferably, the displacement pump device has only a single, one-piece, preferably monolithic shape memory element.In particular, the shape memory element consists at least partially, preferably at least largely, of a shape memory material which comprises at least one structural anisotropy resulting in a shape transformation, such as through a change in the length and / or thickness of the element, and / or at least one magnetic anisotropy resulting in a reorientation of a magnetic orientation. In particular, the structural anisotropy and the magnetic anisotropy are interdependent and / or mutually dependent. In particular, if the shape memory element is designed as a magnetic shape memory element, the transformation of the anisotropy is at least magnetic field-dependent, in particular on an orientation of a magnetic field flowing through the shape memory element.The shape memory element preferably comprises at least one, in particular magnetically effective and / or active, shape memory material, and particularly preferably a magnetic shape memory alloy (also known as MSM material = Magnetic Shape Memory). The magnetic shape memory material preferably contains nickel, manganese, and gallium, which preferably form the magnetic shape memory alloy.
[0011] In particular, the shape memory element can be changed in a controlled manner, at least locally, by applying an external magnetic field. For example, the shape change caused by the external magnetic field reversibly generates a deformation on a surface of the shape memory element in the form of a hollow or groove or the like. In particular, by changing, in particular moving, the magnetic field, the deformation can be moved along the surface of the shape memory element. In particular, the operating function constitutes a main operating function of the respective device. In particular, pumping a fluid corresponds to the operating function of the fluid conveying device. In particular, a mechanical movement of a switching element corresponds to an operating function of the actuator device.In particular, the holding device is provided to hold the magnetic shape memory element in a tensioned, prestressed, and / or elastically deformed state. In particular, the holding device is provided to maintain the bent state of the shape memory element, thereby preferably creating a geometric constraint that stabilizes a microstructure / twin structure within the shape memory element. The holding device can be designed in multiple parts. Furthermore, the shape memory element in particular has at least one casing. At least the shape memory element is at least partially, preferably at least largely, and particularly preferably completely arranged in the casing and / or surrounded by it. The casing is provided to seal the shape memory element. The casing is in particular plastically and preferably elastically deformable.Preferably, the casing consists at least partially of a plastic, particularly a plastic and preferably elastic, material. However, alternative designs without a casing are also conceivable.
[0012] The shape memory element is in particular at least partially, preferably at least largely, and particularly preferably completely formed as an elongated object. An "elongated object" is understood in particular to mean an object having a dimension perpendicular to the main extension of the object that is smaller than its main extension by at least a factor of 2, preferably at least a factor of 5, and particularly preferably at least a factor of 10. A "main extension" of an object is understood in particular to mean an extension of an object along a main extension direction of the object, which advantageously runs through a geometric center and / or center of mass of the object.A "main extension direction" of an object is understood to mean, in particular, a direction oriented parallel to the longest edge of the smallest imaginary cuboid that just completely encloses the object. The shape memory element preferably has the shape of a rod. Viewed in particular in the conveying direction, the shape memory element has a quadrangular cross-section. The cross-section has, in particular, four side surfaces that define the sides of the shape memory unit. A conveying direction of the deformation unit is, in particular, at least substantially parallel to the main extension direction of the shape memory element.The fact that the holding device holds the shape memory element "permanently" in the bent state should be understood in particular to mean that the holding device holds the shape memory element in the ready-to-use state of the fluid conveying device and / or the mechanical actuator device, in the switched-off state of the fluid conveying device and / or the mechanical actuator device, and in the switched-on state of the fluid conveying device and / or the mechanical actuator device. Alternatively, however, it is also conceivable for the shape memory element to be transferred from a relaxed state to the bent state only upon activation of the respective device. In particular, the shape memory element is under internal tension in the bent state. In particular, the shape memory element is unbent and / or straight in the force-free state (e.g. when it is removed).The shape memory element can be bent, particularly along its longitudinal extension, only in sections, only in regions, or even completely. In a longitudinal element that is bent only in sections or in regions, several bent and unbent regions can be arranged in a row.
[0013] In this context, it is proposed that the magnetic shape memory element be deformed in the bent state relative to an original manufacturing state of the magnetic shape memory element. This allows advantageous deformation properties of the magnetic shape memory element to be achieved. Advantageously, an optimal internal structure for generating traveling wave motions, in particular a particularly fine twin structure, of the shape memory element can be achieved. In particular, the magnetic shape memory element is held by the holding device in a state deflected from the original manufacturing state. In particular, the shape memory element is unbent and / or straight in the original manufacturing state.Furthermore, it is proposed that the magnetic shape memory element, in the bent state, be compressed at least in some regions and stretched at least in some regions relative to an original manufacturing state. This makes it possible to achieve advantageous deformation properties of the magnetic shape memory element. Advantageously, an optimal internal structure for generating traveling wave movements, in particular a particularly fine twin structure, of the shape memory element can be achieved. In particular, the magnetic shape memory element is compressed on one longitudinal side in the bent state. In particular, the magnetic shape memory element is stretched on a further longitudinal side opposite the longitudinal side in the bent state. In particular, longitudinal surfaces of the magnetic shape memory element each form an arcuate shape.In particular, the longitudinal surfaces of the magnetic shape memory element run parallel to each other.
[0014] It is further proposed that the magnetic shape memory element be bent in such a way that at least substantially wedge-shaped twin structures are formed in the magnetic shape memory material of the magnetic shape memory element. This allows advantageous deformation properties of the magnetic shape memory element to be achieved. Advantageously, an optimal internal structure for generating traveling wave motions, in particular a particularly fine twin structure, can be achieved in the shape memory element. In particular, tips of the wedge-shaped twin structures each point toward one of the longitudinal surfaces of the magnetic shape memory element. Tips of the wedge-shaped twin structures can be substantially rounded. The wedge-shaped twin structures can assume acute-angled circular segment shapes or trapezoidal shapes, wherein at least some of the edges of these shapes can be substantially rounded.The twin structures are martensitic twin structures of the magnetic shape memory element, in particular of the magnetic shape memory alloy. The twin structures of the magnetic shape memory element, in particular of the magnetic shape memory alloy, are at least substantially uniform. The twin structures of the magnetic shape memory element, in particular of the magnetic shape memory alloy, are at least substantially equally distributed over at least a large portion of the magnetic shape memory element, in particular at least over a large portion of a bent region of the magnetic shape memory element. In particular, the wedge-shaped twin structures are held stable by the internal tension of the bent magnetic shape memory element.
[0015] If the magnetic shape memory element is bent in such a way that the resulting wedge-shaped twin structures remain at least partially mobile, in particular at least on at least one surface of the magnetic shape memory element, an optimal internal structure for generating traveling wave movements, in particular a particularly fine twin structure, of the shape memory element can advantageously be achieved. Advantageously, a particularly uniform pumping behavior of a fluid conveying device can be achieved, in particular by preventing abrupt volume changes of a conveyed volume. Advantageously, the risk of cavitation during fluid conveyance can be minimized, in particular by preventing abrupt volume changes of the conveyed volume.In particular, the twin structures of the magnetic shape memory element, in particular of the magnetic shape memory alloy, remain mobile along the surface parallel to the longitudinal direction of the shape memory element. In particular, the twin structures of the magnetic shape memory element, in particular of the magnetic shape memory alloy, remain mobile along a curved circumference / along the arc of the magnetic shape memory element. Additionally, it is proposed that the magnetic shape memory element be bent such that, at least in a resting state of the magnetic shape memory element, an elongation of the magnetic shape memory element at any point on the magnetic shape memory element remains significantly below a maximum possible and non-destructively reversible elongation of the magnetic shape memory element.This advantageously allows sufficient mobility of the twin structures and, in particular, of the conveying volume generated by the magnetic shape memory element to be achieved. In this context, "significantly below" is understood to mean, in particular, at least 5% below, preferably at least 10% below, advantageously at least 20% below, preferably at least 30% below, and particularly preferably at most 95% below. Alternatively or additionally, the magnetic shape memory element is bent such that, at least in a resting state of the magnetic shape memory element, compression of the magnetic shape memory element at any point on the magnetic shape memory element remains significantly above a maximum possible and non-destructively reversible compression of the magnetic shape memory element.In this context, "significantly above" is understood to mean, in particular, at least 5% above, preferably at least 10% above, advantageously at least 20% above, preferably at least 30% above, and particularly preferably at most 95% above. A "resting state" of the magnetic shape memory element is understood to mean, in particular, a state in which the magnetic shape memory element is at least free of a dynamically changing magnetic field, preferably completely free of a magnetic field. Preferably, the magnetic shape memory element is free of a conveying volume in the resting state.
[0016] It is also proposed that the holding device contains the magnetic
[0017] The shape memory element is permanently held in an arcuate state, in particular uniformly and continuously over at least a large part of the longitudinal extent of the magnetic shape memory element. This advantageously stabilizes the deformation properties of the magnetic shape memory element. Advantageously, an internal structure optimal for generating traveling wave motions can be permanently and stably maintained. Alternatively, however, it is also conceivable for the arcuate shape to be regenerated each time the deformation unit is activated, and for the magnetic shape memory element to be temporarily relaxed in the resting state.
[0018] If the arcuate shape of the magnetic shape memory element has a bending angle that is below a maximum bending angle at which the arcuate bend generates a maximum possible and non-destructively reversible elongation of the magnetic shape memory element at at least one point on the magnetic shape memory element, high mobility can advantageously be achieved while simultaneously providing a sufficient delivery volume for a fluid delivery device. In particular, the bending angle of the magnetic shape memory element is at least 10%, preferably at least 20%, advantageously at least 30%, preferably at least 40%, and particularly preferably at least 50% below the maximum bending angle at which the arcuate bend generates a maximum possible and non-destructively reversible elongation of the magnetic shape memory element at at least one point on the magnetic shape memory element.In particular, the maximum bending angle results from a maximum achievable elongation of the magnetic shape memory element, a thickness of the magnetic shape memory element, and a length of the magnetic shape memory element. In particular, the bending angle of the magnetic shape memory element is spanned by extending surface planes of opposite longitudinal ends of the magnetic shape memory element at the intersection point of the extended surface planes. In particular, the maximum bending angle of a magnetic shape memory element is limited not only by the external geometry of the magnetic shape memory element but also by an internal lattice structure of the magnetic shape memory element. If the magnetic shape memory element is bent to its maximum without irreversible damage, then the twin structure of the magnetic shape memory element is oriented towards an external contour of the magnetic shape memory element for maximum elongation (e = 1; e.g.Strain = 6%), while the twin structure on the opposite outer contour is fully compressed (E = 0; e.g., strain = 0%). If the bending angle is greater than a minimum bending angle and at the same time smaller than a maximum bending angle, the magnetic shape memory element can advantageously exhibit a partial magnetic shape memory effect, i.e., in contrast to full stretching or compression, the twin boundaries remain limitedly mobile and allow the formation of a traveling wave motion at least along the partially stretched outer surface of the magnetic shape memory element. At the same time, the internal microstructure / twin structure is advantageously stabilized by the geometric constraint (stretching / compression).
[0019] If, in addition, the arcuate shape of the magnetic shape memory element has a bending angle which is above a minimum bending angle at which a twin structure of the magnetic shape memory element is stabilized by the bending in such a way that, in particular at least at typical operating temperatures of the magnetic shape memory element, permanent changes in the twin structures due to regular fluid conveying operation and / or due to regular actuator operation are at least substantially excluded, a high reliability of the deformation unit can advantageously be achieved over its entire service life.
[0020] Furthermore, it is proposed that the arcuate shape of the magnetic shape memory element has a bending angle that is approximately half the maximum bending angle of the magnetic shape memory material, at which the arcuate bend generates a maximum possible and non-destructively reversible elongation of the magnetic shape memory element at at least one point on the magnetic shape memory element. This advantageously makes it possible to achieve high mobility of the twin boundaries while simultaneously ensuring sufficient stability of the twin structures, e.g., during conveying operation. For example, a maximum bending angle for a 15 mm long and 1 mm wide magnetic shape memory element with a maximum elongation of 6% can be approximately 55° or approximately 60°. In this case, the optimal bending angle of the magnetic shape memory element is approximately 30°.
[0021] Furthermore, it is proposed that the magnetic shape memory element have a surface free of post-stabilization treatment, in particular an unblasted surface. This advantageously allows for a simple and / or cost-effective design. Surface treatment for twin boundary stabilization, which could potentially negatively influence the magneto-mechanical behavior of the magnetic shape memory element, can be omitted. Advantageously, a magnetic shape memory element particularly suitable for fluid conveying tasks can be obtained.
[0022] Furthermore, a fluid conveying device, in particular a positive displacement pump, preferably a micropump, with at least one deformation unit is proposed, which further comprises at least one magnetic field generation unit, and wherein the magnetic shape memory element is provided to be excited by the magnetic fields generated by the magnetic field generation unit to a peristaltic deformation movement and / or a traveling wave movement, whereby conveying volumes are temporarily created that are at least partially limited by the magnetic shape memory element and move between a fluid inlet and a fluid outlet along the magnetic shape memory element. This advantageously enables advantageous, precise, and in particular particularly compact fluid conveyance. In particular, the magnetic field generation unit can comprise one or more, in particular rotatable and / or translatable, permanent magnets.Alternatively, the magnetic field generating unit may comprise one or more controllable electromagnets for generating the magnetic fields.
[0023] If the magnetic field generating unit is designed as an at least two-pole, in particular at least four-pole, preferably rotatably mounted, permanent magnet, a conveying volume can advantageously be increased, in particular without increasing the risk of generating cavities, as can occur, for example, when the magnetic field moves too quickly.
[0024] It is also proposed that the fluid conveying device have at least two fluid connections that extend outward at least substantially parallel. This advantageously allows a simple (standard) connection to be provided by the fluid conveying device. The fluid connections can be aligned in the same direction or in opposite directions. The fluid connections each form an inlet and an outlet for the fluid to be conveyed. The two fluid connections form the fluid inlet and the fluid outlet.
[0025] Furthermore, a method is proposed with a deformation unit for a fluid conveying device and / or for a mechanical actuator device, comprising at least one magnetic shape memory element that performs an operating function of the fluid conveying device and / or the mechanical actuator device through a controllable change in shape. The magnetic shape memory element is permanently held in a bent state, at least in some areas. This allows advantageous deformation properties of the shape memory element to be achieved.
[0026] This advantageously enables particularly uniform traveling wave movements of the shape memory element, which can be used particularly advantageously for micropump applications. In micropump applications of the shape memory element, a particularly uniform peristaltic pumping movement can advantageously be achieved. The deformation unit according to the invention, the fluid conveying device according to the invention, and the method according to the invention are not intended to be limited to the application and embodiment described above. In particular, the deformation unit according to the invention, the fluid conveying device according to the invention, and the method according to the invention can have a number of individual elements, components, and units that differs from the number stated herein to fulfill a function described herein.
[0027] Drawings
[0028] Further advantages will become apparent from the following description of the drawings. The drawings illustrate an exemplary embodiment of the invention. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations.
[0029] They show:
[0030] Fig. 1 is a schematic sectional view of a fluid conveying device with a deformation unit,
[0031] Fig. 2 is a schematic side view of a magnetic shape memory element of the deformation unit in a bent state with indicated twin structures,
[0032] Fig. 3a is a schematic representation of the fluid conveying device with a magnetic field generating unit designed as a two-pole permanent magnet,
[0033] Fig. 3b is a schematic representation of the fluid conveying device with a magnetic field generating unit designed as a four-pole permanent magnet, Fig. 3c is a schematic representation of the fluid conveying device with a magnetic field generating unit designed as an eight-pole permanent magnet,
[0034] Fig. 4 is a schematic side view of the magnetic shape memory element of the deformation unit in an original manufacturing state and
[0035] Fig. 5 is a schematic flow diagram for a method with the deformation unit for the fluid conveying device.
[0036] Description of the embodiment
[0037] Fig. 1 shows a schematic sectional view of a fluid conveying device 14. The fluid conveying device 14 forms, for example, part of a positive displacement pump. The fluid conveying device 14 forms, for example, part of a micropump. The fluid conveying device 14 has a deformation unit 10. The deformation unit 10 comprises a magnetic shape memory element 12. The magnetic shape memory element 12 is made of a shape memory alloy. The magnetic shape memory element 12 is provided to perform an operating function (pumping fluid) of the fluid conveying device 14 through a controllable change in shape. The fluid conveying device 14 comprises two outwardly directed fluid connections 40. A first fluid connection 40 forms a fluid inlet 36. A second fluid connection 40 forms a fluid outlet 38.When the fluid conveying device 14 performs its operating function, a fluid is conveyed from the first fluid inlet 36 to the fluid outlet 38. In Fig. 1 and Fig. 2, the magnetic shape memory element 12 is shown, by way of example, in a rest state 26. In Figs. 3a to 3c, the magnetic shape memory element 12 is shown, by way of example, when performing an operating function (during conveying operation). The fluid conveying device 14 has a magnetic field generating unit 32. The magnetic field generating unit 32 is provided for generating a dynamically changing magnetic field. In the illustrated embodiment, the magnetic field generating unit 32 comprises a permanent magnet 42. The permanent magnet 42 is rotatably mounted. The permanent magnet 42 can be bipolar (cf. Fig. 3a). However, the permanent magnet 42 can also be designed as a multi-pole diametrical magnet. The permanent magnet 42 can be four-pole (see Fig. 3b).The permanent magnet 42 can be eight-pole (cf. Fig. 3c), etc. With the number of poles, the pumpable volume increases, but the pumping pressure can also decrease. Due to the rotatable bearing, the magnetic field at the location of the magnetic shape memory element 12 changes repeatedly during operation. The magnetic field(s) of the magnetic field generation unit 32 are provided to excite the magnetic shape memory element 12 to a peristaltic deformation movement. The magnetic field(s) of the magnetic field generation unit 32 are provided to excite the magnetic shape memory element 12 to a peristaltic deformation movement. The magnetic field(s) of the magnetic field generation unit 32 are provided to excite the magnetic shape memory element 12 to a traveling wave movement.The magnetic field(s) of the magnetic field generation unit 32 are intended to generate delivery volumes 34 in the magnetic shape memory element 12 (see Figures 3a to 3c). The delivery volumes 34 are formed as depressions / dents in a surface 24 of the magnetic shape memory element 12. Due to the magnetic fields of the magnetic field generation unit 32, the delivery volumes 34 move along the surface 24 of the magnetic shape memory element 12. The delivery volumes 34 move between the fluid inlet 36 and the fluid outlet 38 along the magnetic shape memory element 12. The delivery volumes 34 are temporarily formed. In the absence of the magnetic field, the delivery volumes 34 disappear. However, designs with permanently present delivery volumes 34 are also conceivable. The surface 24 of the magnetic shape memory element 12 is formed free from a stabilization post-processing.The surface 24 of the magnetic shape memory element 12 is unblasted.
[0038] The delivery volumes 34 are partially delimited by the magnetic shape memory element 12. The delivery volumes 34 are delimited on at least three sides by the magnetic shape memory element 12. The fluid delivery device 14 has a sealing element 44. The sealing element 44 delimits the magnetic shape memory element 12 at least on one side. The sealing element 44 delimits the magnetic shape memory element 12 at least on the side to which the delivery volume 34 is open. The sealing element 44 could also completely encompass or envelop the magnetic shape memory element 12. The sealing element 44 is designed as a PTFE strip. The fluid connections 40 penetrate the sealing element 44. The sealing element 44 is sealed by the fluid connections 40. The fluid connections 40 are guided outwards in parallel. The fluid connections 40 are guided outwards in identical directions.
[0039] The deformation unit 10 comprises a holding device 16. The holding device 16 is intended to hold the magnetic shape memory element 12 in the fluid conveying device 14. The holding device 16 is intended to permanently hold the magnetic shape memory element 12 in a bent, in particular arcuate, state 18. In the exemplary case shown, the holding device 16 forms two halves 46, 48, which form a curved receiving space 50 for the magnetic shape memory element 12. By connecting the two halves 46, 48, the originally straight-manufactured (see Fig. 4) magnetic shape memory element 12 is bent under force. The magnetic shape memory element 12 is deformed in the bent state 18 (see Fig. 2) relative to an original manufacturing state 20 (see Fig. 4) of the magnetic shape memory element 12.In the bent state 18, the magnetic shape memory element 12 is partially compressed relative to the original manufacturing state 20. The magnetic shape memory element 12 is compressed on a side facing the magnetic field generation unit 32 (surface 52). In the bent state 18, the magnetic shape memory element 12 is partially stretched relative to the original manufacturing state 20. The magnetic shape memory element 12 is stretched on a side facing away from the magnetic field generation unit 32 (surface 24).
[0040] The magnetic shape memory element 12 is bent in such a way that at least substantially wedge-shaped twin structures 22 are formed in the magnetic shape memory material of the magnetic shape memory element 12 (cf. Fig. 2 or Figs. 3a to 3c). The tapered ends of the wedges of the at least substantially wedge-shaped twin structures 22 are each directed toward one of the longitudinal surfaces 24, 52. The magnetic shape memory element 12 is bent in such a way that the resulting wedge-shaped twin structures 22 remain at least partially mobile up to the surfaces 24, 52 of the magnetic shape memory element 12. Twin boundaries each terminate at the longitudinal surfaces 24, 52 of the magnetic shape memory element 12. No surface is completely covered by a martensitic twin (this would mean a maximum possible (and non-destructively reversible) stretching or compression, seeSee also the twin structures 22 in the areas of the delivery volumes 34 in Figures 3a to 3c). The magnetic shape memory element 12 is bent in such a way that, at least in the rest state 26 (cf. Figure 2) of the magnetic shape memory element 12, the elongation of the magnetic shape memory element 12 at any point on the magnetic shape memory element 12 remains substantially below the maximum possible and non-destructively reversible elongation of the magnetic shape memory element 12. The magnetic shape memory element 12 is bent such that, at least in the rest state 26 (cf. Fig. 2) of the magnetic shape memory element 12, a compression of the magnetic shape memory element 12 at any point of the magnetic shape memory element 12 remains substantially below the maximum possible and non-destructively reversible compression of the magnetic shape memory element 12.
[0041] Fig. 2 schematically shows a side view of the arcuately bent magnetic shape memory element 12. The magnetic shape memory element 12 has an arcuate shape 28. The arcuate shape 28 of the magnetic shape memory element 12 has a bending angle 30. The bending angle 30 lies below a maximum bending angle at which the arcuate bend produces the maximum possible and non-destructively reversible elongation of the magnetic shape memory element 12. The bending angle 30 lies above a minimum bending angle at which the martensitic twin structure 22 of the magnetic shape memory element 12 is stabilized by the bending in such a way that permanent changes to the twin structures 22 due to regular fluid conveying operation are excluded.The arcuate shape 28 of the magnetic shape memory element 12 has a bending angle 30 which is approximately half as large as the maximum bending angle of the magnetic shape memory material of the magnetic shape memory element 12, at which a maximum possible and non-destructively reversible elongation of the magnetic shape memory element 12 is generated by the arcuate bend at at least one point of the magnetic shape memory element 12.
[0042] Fig. 4 shows a schematic representation of the magnetic shape memory element 12 in the original manufacturing state 20. The magnetic shape memory element 12 has a first length 54 (z £ =o). The first length 54 indicates the length of the magnetic shape memory element 12 in the maximum compressed state. The magnetic shape memory element 12 has a second length 56 (z £=i). The second length 56 indicates the length of the magnetic shape memory element 12 in the maximum stretched state. In known shape memory alloys, the second length 56 is up to 6% greater than the first length 54. The magnetic shape memory element 12 has a first width 58 (x £ =i). The first width 58 indicates the width of the magnetic shape memory element 12 in the maximum compressed state. The magnetic shape memory element 12 has a second width 60 (x £=o). The second width 60 indicates the width of the magnetic shape memory element 12 in the maximally stretched state. The second width 60 is smaller than the first width 58. The bending angle 30 indicated in Figures 1 and 2 corresponds approximately to half the optimal maximum possible bending angle. The optimal bending angle 30 can be calculated depending on the geometry and the maximum extensibility of the magnetic shape memory element 12. Using the following formula, the approximate optimal bending angle for a magnetic shape memory element 12 can be calculated depending on the geometry and material:
[0043] □optimal = Qmax
[0044] Fig. 5 shows a schematic flow diagram for a method with the deformation unit 10 for the fluid conveying device 14. In at least one method step 62, the magnetic shape memory element 12 is installed in a bent state into the holding device 16 of the fluid conveying device 14. The magnetic shape memory element 12 thus installed is permanently held in the bent state 18 by the holding device 16. In at least one further method step 64, the magnetic shape memory element 12 performs the operating function of the fluid conveying device 14 through a controllable change in shape. The operating function corresponds to conveying fluids by means of fillable and emptyable movable conveying volumes 34, which are pushed along the surface 24 of the magnetic shape memory element 12 by dynamically spatially variable magnetic fields of the magnetic field generation unit 32. Reference numerals
[0045] 10 deformation unit
[0046] 12 Magnetic shape memory element
[0047] 14 Fluid conveying device
[0048] 16 Holding device
[0049] 18 Bent state
[0050] 20 Original manufacturing condition
[0051] 22 Twin structure
[0052] 24 Surface
[0053] 26 Hibernation
[0054] 28 Arch shape
[0055] 30 bending angles
[0056] 32 Magnetic field generation unit
[0057] 34 funding volumes
[0058] 36 Fluid inlet
[0059] 38 Fluid outlet
[0060] 40 Fluid connection
[0061] 42 permanent magnet
[0062] 44 Sealing element
[0063] 46 half
[0064] 48 half
[0065] 50 recording room
[0066] 52 Surface
[0067] 54 length
[0068] 56 length
[0069] 58 width
[0070] 60 width
[0071] 62 process steps
[0072] 64 process steps
Claims
Claims: Deformation unit (10) for a fluid conveying device (14) and / or for a mechanical actuator device, comprising at least one magnetic shape memory element (12) which is at least designed to perform an operating function of the fluid conveying device (14) and / or the mechanical actuator device by means of a controllable change in shape, and comprising a holding device (16) for at least one mounting of the magnetic shape memory element (12) in the fluid conveying device (14) and / or the mechanical actuator device, characterized in that the holding device (16) permanently holds the magnetic shape memory element (12) in a bent state (18) that is at least partially bent. Deformation unit (10) according to claim 1, characterized in that the magnetic shape memory element (12) is deformed in the bent state (18) relative to an original manufacturing state (20) of the magnetic shape memory element (12).Deformation unit (10) according to claim 1 or 2, characterized in that the magnetic shape memory element (12) in the bent state (18) is at least partially compressed and at least partially stretched relative to an original manufacturing state (20).
4. Deformation unit (10) according to one of the preceding claims, characterized in that the magnetic shape memory element (12) is bent such that at least substantially wedge-shaped twin structures (22) are formed in a magnetic shape memory material of the magnetic shape memory element (12).
5. Deformation unit (10) according to claim 4, characterized in that the magnetic shape memory element (12) is bent in such a way that the resulting wedge-shaped twin structures (22) remain at least partially mobile, in particular at least on at least one surface (24) of the magnetic shape memory element (12).
6. Deformation unit (10) according to one of the preceding claims, characterized in that the magnetic shape memory element (12) is bent such that at least in a rest state (26) of the magnetic shape memory element (12) the elongation of the magnetic shape memory element (12) at every point of the magnetic shape memory element (12) remains substantially below a maximum possible and non-destructively reversible elongation of the magnetic shape memory element (12).
7. Deformation unit (10) according to one of the preceding claims, characterized in that the holding device (16) permanently holds the magnetic shape memory element (12) in a state (18) that is at least partially curved. Deformation unit (10) according to claim 7, characterized in that the arc shape (28) of the magnetic shape memory element (12) has a bending angle (30) which is below a maximum bending angle at which the arc-shaped bending at at least one location of the magnetic shape memory element (12) generates a maximum possible and non-destructively reversible elongation of the magnetic shape memory element (12). Deformation unit (10) according to claim 7 or 8, characterized in that the arc shape (28) of the magnetic shape memory element (12) has a bending angle (30) which is above a minimum bending angle at which a twin structure (22) of the magnetic shape memory element (12) is stabilized by the bending in such a way that permanent changes to the twin structures (22) due to regular fluid conveying operation and / or regular actuator operation are at least substantially excluded.Deformation unit (10) according to one of claims 7 to 9, characterized in that the arc shape (28) of the magnetic shape memory element (12) has a bending angle (30) which is about half as large as a maximum bending angle of the magnetic shape memory element (12) at which the arc-shaped bending at at least one point of the magnetic shape memory element (12) generates a maximum possible and non-destructively reversible elongation of the magnetic shape memory element (12). Deformation unit (10) according to one of the preceding claims, characterized in that the magnetic shape memory element (12) has a surface (24) that is free from stabilization post-processing, in particular an unblasted surface. Fluid conveying device (14), in particular a positive displacement pump, preferably a micropump, with at least one deformation unit (10) according to one of the preceding claims.Fluid conveying device (14) according to claim 12, characterized by at least one magnetic field generating unit (32), wherein the magnetic shape memory element (12) is provided to be excited by the magnetic fields generated by the magnetic field generating unit (32) to a peristaltic deformation movement and / or to a traveling wave movement, whereby conveying volumes (34) temporarily limited at least partially by the magnetic shape memory element (12) are created, which move along the magnetic shape memory element (12) between a fluid inlet (36) and a fluid outlet (38). Fluid conveying device (14) according to claim 13, characterized in that the magnetic field generating unit (32) is designed as a permanent magnet (42) with at least two poles, preferably rotatably mounted.Fluid conveying device (14) according to one of claims 12 to 14, characterized by at least two fluid connections (40) leading at least substantially parallel to the outside. Method with a deformation unit (10) for a fluid conveying device (14) and / or for a mechanical actuator device, in particular with a deformation unit (10) according to one of claims 1 to 11, with at least one magnetic shape memory element (12) which is controlled by a shape change performs an operating function of the fluid conveying device (14) and / or the mechanical actuator device, characterized in that the magnetic shape memory element (12) is held permanently in a bent state (18) at least in certain areas.