Shape-Memory Actuator Assembly And Assembly Method

Abstract

A shape-memory actuator assembly, comprising a shape memory wire element; a first deflection body and a second deflection body, spaced apart from each other, wherein the shape memory wire element is wound around the first deflection body and the second deflection body several times and provides an actuator arrangement located between them. At least one wire holder on the respective deflection body and sections of the shape memory wire element, contacting the wire holder, are embedded in a casting compound.

Claims

1-20. (canceled)

21. A shape-memory actuator assembly, comprising: a shape memory wire element; a first deflection body and a second deflection body, spaced apart from each other, wherein the shape memory wire element is wound around the first deflection body and the second deflection body several times and provides an actuator arrangement located between them; wherein at least one wire holder on the respective deflection body, and sections of the shape memory wire element contacting the wire holder, are embedded in a casting compound.

22. The shape-memory actuator assembly of claim 21, wherein a casting pot is assigned to each one of the first deflection body and the second deflection body, and wherein the casting compound mechanically couples the respective deflection body with the respective casting pot to transmit actuator forces.

23. The shape-memory actuator assembly of claim 22, wherein the casting pot comprises a fastening element for transmitting actuator forces.

24. The shape-memory actuator assembly of claim 21, wherein the casting compound is electrically insulating.

25. The shape-memory actuator assembly of claim 21, wherein the casting compound comprises a composite resin, a two-component adhesive or a UV-curable polymer.

26. The shape-memory actuator assembly of claim 21, wherein the casting compound completely encloses the respective deflection body.

27. The shape-memory actuator assembly of claim 21, wherein the wire holder is an electrical insulator.

28. The shape-memory actuator of claim 27, wherein the wire holder comprises groove-shaped wire receptacles.

29. The shape-memory actuator of claim 21, wherein a clamping piece embedded in the casting compound is arranged at each one of the first deflection body and the second deflection body, and wherein the clamping piece is designed for fixation of the sections of the shape memory wire element contacting the wire holder.

30. The shape-memory actuator assembly of claim 29, wherein the clamping piece is an electrical insulator.

31. The shape-memory actuator assembly of claim 21, wherein an end piece of the shape memory wire element is connected to the first deflection body or the second deflection body by a frictional connection, a form fit and/or an adhesive bond.

32. The shape-memory actuator assembly of claim 21, wherein at least a portion of the actuator arrangement between the first deflection body and the second deflection body is embedded in an actuator casting element.

33. The shape-memory actuator assembly of claim 32, wherein the actuator casting element and the casting compound are joined by a material bond.

34. An assembly method for manufacturing a shape-memory actuator assembly, comprising the steps of: multiple wrapping of an arrangement comprising a first deflection body and a second deflection body, which are spaced apart from each other, with a shape memory wire element to form an actuator arrangement; and embedding at least one wire holder on the respective deflection body, and sections of the shape memory wire element contacting the wire holder, in a casting compound.

35. The assembly method of claim 34, wherein the embedding in the casting compound is conducted such that the deflection body is completely enclosed by the casting compound.

36. The assembly method of claim 34, wherein the first deflection body and the second deflection body, after being wrapped with the shape memory wire element, are each introduced into an associated casting pot, which is filled with the casting compound, and wherein the casting compound mechanically couples the deflection body to the associated casting pot for transmitting actuator forces.

37. The assembly method of claim 34, wherein a clamping piece for fixation of the sections of the shape memory wire element contacting the wire holder is placed on the first deflection body and the second deflection body after the shape memory wire element has been wrapped around them and before they are embedded in the casting compound.

38. The assembly method of claim 34, wherein at least a part of the actuator arrangement between the first deflection body and the second deflection body is embedded in an actuator casting element.

39. The assembly method of claim 38, wherein the actuator casting element and the casting compound are joined by a material bond.

40. The assembly method of claim 39, wherein the actuator casting element and the casting compound are produced in an integral casting step, wherein a combined mold is filled with a uniform material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The following description is provided with reference to embodiments and in connection with the accompanying figures, wherein:

[0021] FIG. 1 shows a perspective view of a shape memory actuator assembly according to the present disclosure.

[0022] FIG. 2 shows an exploded view of the shape memory actuator assembly of FIG. 1.

[0023] FIG. 3 shows a side view of the shape memory actuator assembly of FIG. 1.

[0024] FIG. 4 shows the sectional view B-B of the shape memory actuator shape memory actuator assembly of FIG. 3.

[0025] FIG. 5 shows a flow chart of the assembly method according to the present disclosure for manufacturing a shape memory actuator assembly.

DETAILED DESCRIPTION

[0026] FIG. 1 shows a schematically simplified perspective external view for a preferred embodiment of the shape-memory actuator assembly 1 according to the present disclosure. Depicted is an actuator casting element 12 made of silicone which, as illustrated by the exploded view in FIG. 2, encloses an actuator arrangement 5. As shown in FIG. 2, the actuator arrangement 5 is formed by wrapping a shape memory wire element 2 around an arrangement comprising a first deflection body 3 and a second deflection body 4, which are spaced apart from each other.

[0027] The deflection bodies 3, 4, which can be seen in particular in FIG. 4, transmit the actuating forces of the actuator arrangement 5, generated by heating the shape memory wire element 2 above the phase transition temperature by means of an electric current.

[0028] For a preferred embodiment, the actuator arrangement 5 is energized serially so that the windings of the shape memory wire element 2 are not allowed to contact each other. This is ensured in the section between the deflection bodies 3, 4 by the actuator casting element 12, wherein it additionally dissipates heat from the actuator arrangement 5, thereby enabling fast cyclic operation of the shape-memory actuator assembly 1.

[0029] Furthermore, for a preferred embodiment, at least the wire holder 6 on the deflection bodies 3, 4 is designed as an electrical insulator. A ceramic hollow cylinder with groove-shaped wire receptacles 10.1, 10.2 on the outer surface is used, which serve to place the shape memory wire element 2 with defined lateral distances on the deflection bodies 3, 4 during the manufacture of the winding arrangement. Inside the ceramic hollow cylinder there is a metal pin as structural reinforcement, or the ceramic component forms a coating on a load-bearing metal component. Possible alternatives are an all-ceramic design of the deflection body 3, 4 or a design made of an insulating plastic, for example PEEK.

[0030] As shown in FIG. 2 and by the sectional view B-B shown in FIG. 4, in the assembled state of the shape-memory actuator assembly 1, a clamping piece 11.1, 11.2 is fitted on the wire holder 6 after the wrapping, which provides a fixation of the sections of the shape memory wire element 2 guided around the deflection bodies 3, 4. By this measure, the winding arrangement can be handled as a unit during assembly, which has to be placed in a mold for the casting step. According to the present disclosure, an embedding of at least the wire holder 6 on the respective deflection body 3, 4 and of the portions of the shape memory wire element 2, contacting the wire holder 6, in a casting compound 7.1, 7.2 is carried out. For the preferred embodiment shown in FIGS. 1-4, the casting pots 8.1, 8.2 associated with the deflection bodies 3, 4 serve as lost formwork of the casting step.

[0031] In particular FIGS. 2 and 4 depict that after the casting, the deflection bodies 3, 4 with the clamping pieces 11.1, 11.2 fitted thereon are completely enclosed by the casting compound 7.1, 7.2, preferably an electrically insulating composite resin or a two-component adhesive or a UV-curable polymer. This ensures that the sections of the shape memory wire element 2, contacting the wire holder 6, are positionally fixed. In addition, a mechanical coupling is created between the deflection bodies 3, 4 and the respective associated casting pot 8.1, 8.2, on which fastening elements 9.1-9.4 in the form of internal threads are arranged to transmit the actuator forces.

[0032] To ensure a sufficiently long electrical insulating distance, lateral recesses 15.1, 15.2 are arranged on the casting pots 8.1, 8.2 in the vicinity of the mounting position of the deflection bodies 3, 4, which are filled with the casting compound 7.1, 7.2. The millings 16.1, 16.2 at the edges of the casting pots 8.1, 8.2 serve the same purpose.

[0033] The electrical contacts 13.1, 13.2, which are formed by the sections of the shape memory wire element 2, covered with heat shrink tubing 14.1, 14.2 and extending out of the winding arrangement, supply electric current. Preferably, the electrical contacts 13.1, 13.2 extend from the casting pot 8.1, 8.2 into the actuator arrangement 5, so that even under the effect of the actuator forces, crushing against the walls of the casting pot 8.1, 8.2 can be reliably prevented. For a preferred embodiment, the force generated by the actuator arrangement 5 in the activated state is completely transmitted via the casting compound 7.1, 7.2 to the casting pot 8.1, 8.2. Furthermore, it is preferred to design the casting compound 7.1, 7.2 and the actuator casting element 12, enclosing the actuator arrangement 5, as being joined by a material bond.

[0034] FIG. 5 shows a flow chart of the assembly method according to the present disclosure for manufacturing a shape memory actuator assembly. Step A refers to the multiple wrapping of an arrangement comprising a first deflection body 3 and a second deflection body 4 with a shape memory wire element to form an actuator arrangement 5. Step B refers to the fitting of a clamping piece 11.1, 11.2 for the fixation of the sections of the shape memory wire element 2, contacting the wire holder 6 on the deflection bodies 3, 4. For step C, the winding arrangement thus secured in the vicinity of the deflector bodies 3, 4 is introduced into assigned casting pots 8.1, 8.2, which are filled with a casting compound 7.1, 7.2. Step D denotes the actuator embedding by transferring it into a second mold and the manufacturing of the actuator casting element 12 for the section providing the actuator arrangement 5.

[0035] Further modifications and embodiments according to the present disclosure will be apparent to those skilled in the art and from the following set of claims, without having to describe or show same herein and without departing the scope of the claims.

LIST OF REFERENCE NUMERALS

[0036] 1 shape-memory actuator assembly

[0037] 2 shape-memory wire element

[0038] 3 first deflection body

[0039] 4 second deflection body

[0040] 5 actuator arrangement

[0041] 6 wire holder

[0042] 7.1, 7.2 casting compound

[0043] 8.1, 8.2 casting pot

[0044] 9.1, 9.2

[0045] 9.3, 9.4 fastening element

[0046] 10.1-10.n groove-shaped wire receptacle

[0047] 11.1, 11.2 clamping piece

[0048] 12 actuator casting element

[0049] 13.1, 13.2 electrical contacting

[0050] 14.1, 14.2 heat shrink tubing

[0051] 15.1, 15.2 lateral recess

[0052] 16.1, 16.2 milling