Actuator using magnetic shape memory material, coils and permanent magnets

Patent metadata

Field	Value
Publication number	US-9450170-B2
Application number	US-201214005365-A
Country	US
Kind code	B2
Filing date	Mar 15, 2012
Priority date	Mar 16, 2011
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

An actuator having a drive element made of a magnetic shape memory material is driven responsive to electrical control of a plurality of coil apparatuses and carries out an expansion movement in response to the control. The coil apparatuses are magnetically connected to the drive element via flux-concentrating apparatus having a flux-concentrating section associated with the coil apparatuses for interaction with the drive element. Each flux-concentrating apparatus has a core section and connecting section, which conducts a magnetic flux to the drive element, such that a magnetic flux-concentrating circuit for each of the coil apparatuses is formed by the common drive element. The flux-concentrating circuits are magnetically connected in parallel with one another, based on the common drive element, and/or a magnetic flux direction of a magnetic flux in the particular flux-concentrating circuit in the drive element has the same orientation.

First claim

The invention claimed is:

1. An actuator with
a drive element of a magnetic shape memory material that can be driven as a reaction to an electrical activation of a plurality of coil devices ( 10 , 12 ) and designed for purposes of executing an expansion movement as a reaction to the activation,
wherein the coil devices are magnetically connected with the drive element ( 14 ) via flux-conducting means ( 20 , 22 , 24 , 26 , 28 , 30 ), and a flux-conducting section of the flux-conducting means is assigned to the coil devices for purposes of interacting with the drive element,
the flux-conducting means for each of the plurality of coil devices have a core section ( 20 , 22 , 30 ) and also a connecting section ( 24 , 26 ), conducting a magnetic flux to the drive element such that for each of the coil devices a magnetic flux-conducting circuit is formed through the common drive element, and
with reference to the common drive element the flux-conducting circuits are connected magnetically in parallel with each other, and/or a magnetic flux direction of a magnetic flux in the respective flux-conducting circuit in the drive element is aligned in the same directional sense,
characterised in that,
the drive element is configured in terms of a rectangular and/or a polygonal cross-section, and with plane outer surfaces, and an introduction of magnetic flux into the drive element does not take place along a longest axis or dimension of extent of the drive element
wherein the magnetic shape memory alloy material is selected having Ni, Mn, Ga and also at least Co in the composition Ni a Mn b Ga c Co d Fe e Cu f , wherein
a, b, c, d, e and f are specified in atom-%, and fulfil the conditions:
44≦a≦51;
19≦b≦30;
18≦c≦24;
0.1≦d≦15;
0≦e≦14.9;
0≦f≦14.9:
d+e+f≦15;
a+b+c+d+e+f=100.

2. The actuator in accordance with claim 1 , wherein two of the plurality of coil devices are spaced apart from one another and are arranged opposite one another with reference to the drive element.

3. The actuator in accordance with claim 1 , wherein a common flux-conducting section is coupled into the flux-conducting circuits so as to interact with the drive element.

4. The actuator in accordance with claim 1 , wherein a first flux-conducting section ( 28 ) of the flux-conducting means is assigned to a first of the plurality of the coil devices so as to interact with the drive element, a second flux-conducting section ( 30 ) of the flux-conducting means is assigned to at least one other ( 12 ) of the plurality of the coil devices so as to interact with the drive element, and the first ( 28 ) and the second ( 30 ) flux-conducting sections are provided adjacent to one another, and are designed to be magnetically separated and/or decoupled from one another such that a reciprocal magnetic flux transfer and/or magnetic flux coupling between the first and the second flux-conducting sections is prevented or reduced in comparison to a common and/or one-piece flux-conducting body to be provided instead of the first and second flux-conducting sections.

5. The actuator in accordance with claim 4 , wherein the first and the second flux-conducting sections are designed in at least some sections to be extended and running parallel to one another, and are also designed to be commonly contacting the drive element for purposes of introducing a magnetic flux.

6. The actuator in accordance with one of the claim 1 , wherein the flux-conducting section and the connecting section are of one-piece design and/or are formed from of a single piece, or multiple pieces, of a magnetically conducting sheet metal material.

7. The actuator in accordance with one of the claim 1 , wherein a closed magnetic flux-conducting circuit is assigned to each of the plurality of coil devices such that the coil device is provided around a respective core section of the flux-conducting circuit, the flux-conducting section is designed to be opposite to the core section in the flux-conducting circuit, and the plurality of the core sections ( 20 , 22 ) assigned to the coil devices, with reference to the drive element is arranged radially outwards and/or extending relative to one another with parallel axes.

8. The actuator in accordance with claim 1 , further comprising permanent magnetic means ( 36 - 54 ), which as a section of a permanent magnetic material are connected with the flux-conducting means in a magnetically flux-conducting manner, and/or are coupled into a magnetic flux-conducting circuit for at least one of the flux-conducting sections.

9. The actuator in accordance with claim 8 , wherein the permanent magnetic means ( 36 - 50 ) are coupled into the magnetic flux-conducting circuit such that in a de-energised activation state of a related coil device a permanent magnetic flux flows through a core section of the magnetic flux-conducting circuit and the permanent magnetic flux, as a reaction to the electrical activation of the coil device and a flux component thereby caused, is displaced into the related flux-conducting section and the drive element.

10. The actuator in accordance with claim 8 , wherein the permanent magnetic means ( 36 - 50 ), as a body magnetised in a magnetic flux direction, is part of the flux-conducting section or one of the flux-conducting sections, of one of the core sections assigned to the coil devices, and/or of a connecting section connecting the core section with the drive element of a relevant magnetic flux-conducting circuit.

11. The actuator in accordance with claim 8 , wherein the permanent magnetic means ( 36 , 38 ) are designed as one or a plurality of bodies of a permanent magnetic material commonly assigned to the flux-conducting section/s.

12. The actuator in accordance with claim 1 , wherein at least one of the coil devices is provided as a wire winding directly on a core section of the flux-conducting means, without an intermediate coil body.

13. The actuator in accordance with claim 1 , further comprising restoring means assigned to the drive element, which are mechanically coupled with the drive element, and are implemented as an additional counteracting actuator having a shape memory material, or by means of a permanent magnet, and/or as an energy store.

14. The actuator in accordance with claim 1 , further comprising housing means, which are designed as a shell of a magnetically conducting material and/or an insert moulding, in particular by means of a plastic material, at least partially surrounding the actuator and/or the coil means.

15. The actuator in accordance with claim 1 , wherein the parallel-permanent magnet means ( 52 , 54 ) are connected magnetically parallel to at least one of the coil devices such that a permanent magnetic flux of the permanent magnet means can occur through a related core section, a coil magnetic flux of the coil device is in a magnetically parallel manner, and/or in a rectified manner, superposed with a permanent magnetic flux of the parallel-permanent magnetic means flowing across the drive element, and an activation of at least one of the coil devices causes an at least partial magnetic flux shift of the permanent magnetic flux of the parallel-permanent magnetic means from the related core section via the drive element.

16. The actuator in accordance with claim 15 , wherein a short-circuit section of the flux-conducting means outwards of the related core section is assigned to the at least one coil device so as to form at least one magnetic flux arm with no air gap, and the parallel-permanent magnetic means are connected magnetically in parallel to the at least one coil unit such that i

Assignees

• Schiepp Thomas
• Laufenberg Markus
• Eto Magnetic Gmbh

Inventors

• Schiepp Thomas
• Laufenberg Markus

Classifications

• H01L41/12 Primary

  Electricity · mapped topic

• H02N2/005

  Mechanical details, e.g. housings (casings for dynamo-electric machines H02K5/00) · CPC title

• H02N2/00

  Electric machines in general using piezoelectric effect, electrostriction or magnetostriction (generating mechanical vibrations in general B06B; piezoelectric, electrostrictive or magnetostrictive devices in general H10N30/00) · CPC title

• H01L41/20

  Electricity · mapped topic

• H10N35/85

  Magnetostrictive active materials · CPC title