WO2007144330A1

WO2007144330A1 - Solid-state actuator drive apparatus

Info

Publication number: WO2007144330A1
Application number: PCT/EP2007/055730
Authority: WO
Inventors: Joachim Heinzl; Helmar Liess; Bernhard Gottlieb; Andreas Kappel; Tim Schwebel; Carsten Wallenhauer
Original assignee: Siemens Aktiengesellschaft
Priority date: 2006-06-13
Filing date: 2007-06-12
Publication date: 2007-12-21
Also published as: DE102006027406A1; EP2027614A1

Abstract

The invention relates to a solid-state actuator drive apparatus comprising a drive body (3; 3°; 3*; 3°*), comprising a circular drive body opening (5) in the drive body, comprising a shaft (4) at least leading into the drive body opening, wherein a shaft diameter of the shaft (4) is smaller than an opening diameter of the drive body opening (5), and wherein the shaft (4) bears against a wall of the drive body opening (5) in a frictionally locking and/or positively locking manner during operation, and comprising at least two solid-state actuators (1, 2) which can be driven for expansion and/or for contraction along their longitudinal axis (1), wherein the at least two solid-state actuators are coupled or fixed to the drive body, to drive the latter relative to a housing (6), such that the shaft (4) can be caused to rotate by means of a displacement movement of the drive body, wherein the longitudinal axis (1) of at least one of the at least two solid-state actuators (1, 2) is oriented at an angle (α) of between 44° and 135° with respect to a radial direction (r) of the drive body opening (5) at the drive body (3; 3°; 3*, 3°*).

Description

description

Solid-state drive device

The invention relates to a solid-state actuator ^¬ device with the Oberbegriffliehen features according to claim 1.

EP 1098429 B1 describes a solid-state actuator drive device in the manner of a rotary drive, in which a ring ^¬ shaped drive body 3 is actuated by means of electromechanical solid state actuators 1, 2, as shown in Fig. 5 Darge ^¬ is. A shaft 4 passes through a Antriebskörperöff ^¬ tion 5, wherein the shaft 4 frictionally applied to a wall of the circular drive body opening 5. The solid state ^¬ raktoren 1, 2 enable the drive body 3 in a circumferential movement, which causes a rotation of the shaft 4.

For solid-state actuators 1, 2, in particular, it is possible to use piezoelectric multilayer actuators manufactured in large series for injection technology and therefore at low cost. In the illustrated embodiment, the two solid-state actuators 1, 2 are based on a housing 6 as linear drive elements with their end facing away from the drive body 3. At the opposite end of the solid state actuators 1, 2 are mechanically rigidly connected with their end faces with the mechanically rigidly manufactured drive body 3. The shaft 4 is axially rotatable about its axis of symmetry, which is perpendicular to the plane of the drawing, but slidably mounted in the housing 6 in any spatial direction. With appropriate electrical control of the solid state actuators 1, 2, the drive body 3 is excited by the solid state actuators 1, 2 to a circular displacement movement about the shaft 4, wherein the surface of the drive body opening 5 or circular bore on the cylindrical outer surface of the shaft 4th unwinds and generates a rotation of the shaft 4. An attacking on the shaft 4 load torque is transmitted through the almost linear contact zone of the shaft 4 acting on the ring tangential to the shaft circumference force and through the mediation of the mechanically rigid drive body 3 on the solid state actuators 1, 2 at the ring distal end of the solid state actuators 1, 2 from only hinted sketched housing 6 added. In the case of high-torque rotary drives, therefore, considerable torques must be imparted to the housing 6 by the solid-state actuators 1, 2. In particular PMA (Piezoelectric Multilayer Actuator / Piezoelectric multilayer actuators) are constructed of brittle ceramic materials and therefore only to a very limited extent capable of imparting torques, ie bending forces, between the drive body 3 and the housing 6.

Damaging bending stresses on the solid state actuators can be reduced by the solid state actuators are moved radially outward and thus the distance to the shaft axis is increased, the connection of the ring facing the end of the solid state with the actuator body by mechanically rigid connecting pieces sicherge ^¬ is. The torque load is calculated as a tangential force x lever arm length. Therefore, to halve the bending stress of the solid state actuators, their distance to the shaft axis would have to be approximately doubled. A demand for a compact design can not be fulfilled in this way. Another solution for reducing the bending stresses is the use of n> 2 in the circumferential direction uniformly arranged solid state actuators. The bending stress of each solid-state actuator decreases at constant ge ^{¬ held} load torque on the shaft proportional to l / n. Ei ^¬ ne significant reduction of bending stress is achievable in this way only by many linear actuators, making this solution virtually eliminated for cost reasons.

In one embodiment, which is sketched with reference to FIG. 6, damaging bending stresses on the solid state acto ren 1, 2 reduced. In this embodiment, in each case two mutually associated solid-state actuators 1, 2 engage with mutually parallel longitudinal axes 1 instead of only one solid-state actuator 1, 2 on each side of the drive body 3. The associated solid-state actuators 1, 2 are laterally moved apart from a radial direction r to the outside. In this arrangement, a total of four solid-state actuators 1, 2 as the drive elements frontally connected to the drive body 3, this arrangement has the same symmetry properties, as the arrangement of Fig. 5. By the transverse distance d of the pairwise and symmetrically arranged solid state actuators 1, 2, is transmitted from the shaft 4 to the actuator body 3 load ^¬ torque mainly by innocuous PMA in pairs longitudinal forces in the PMA of the drive member 3 to the housing 6 transmitted, can be lowered whereby the bending stress and hence higher torques are achievable. Load changes on the shaft 4 cause proportional longitudinal force changes in the PMA, which are generated by the direct piezoelectric effect charges that can be detected in an electronic circuit and used as torque information.

The object of the invention is to propose a solid-state actuator drive device which requires less installation space and in which lower bending stresses act on its solid-state actuators. The solid-state actuators should preferably be designed as solid-state linear actuators for use as linear actuators in PMA design.

This object is achieved by a solid-state actuator ^¬ device with the features of claim 1. Advantageous embodiments are the subject of dependent claims.

Preferably, a solid-state actuator drive device is accordingly ^¬ with a driving body, with a circular drive body opening in the actuator body, with a in the check- Drive shaft opening at least in leading shaft, wherein a shaft diameter of the shaft is smaller than an opening diameter of the drive body opening and wherein the shaft is frictional and / or positive fit against a wall fertilg the drive body opening in operation, and with at least two solid-state actuators which are controllable to expand and / or for contraction along its longitudinal axis, wherein the at least two solid-state actuators are coupled or attached to the drive body to drive this drive body in particular relative to a housing, so that by a sliding movement of the drive body, the shaft is set in rotation, and wherein the longitudinal axis of at least one of at least two solid-state actuators are aligned at an angle between 45 ° and 135 ° to a radial direction of the drive body opening on the drive body.

In particular, a solid-state actuator drive ^¬ is preferred apparatus in which the longitudinal axis of the solid-state actuator in a plane perpendicular to the shaft axis and / or the drive body opening axis of the drive body opening is ^¬ is arranged vertically. In principle, any reactions in the large ^¬ SEN angular range of 45 ° to 135 ° advantageous to implement. However, angular ranges with egg ^¬ nem angle of approximately 90 ° to the radial direction of the Antriebskör- perÖffnung are thus particularly preferred. As far as this angular range is given, of course, effective components of the forces and directional components of the orientations of the longitudinal axis are to be understood, which have in the plane perpendicular to the drive body and / or shaft axis. Regardless, theoretically, additional force components and orientations may exist at an angle to the plane.

In particular, a solid-state actuator drive device ^¬, at least one of a voltage in a radial direction to Antriebskörperöff ^¬ circumferential outer wall of the drive body is arranged in the solid-state actuators on the outside is preferred. This allows a flat in the axial direction Bauwei ^¬ se. In particular, a solid-state actuator drive ^¬ device, one of the solid-state actuators is disposed adjacent to a side wall of the drive body at the at least is preferred, wherein the side wall is clamped in a pierced by the shaft or a parallel thereto drive body opening axis E- bene. This allows a construction which is particularly space-saving in the radial ^direction .

Is preferred in this case if at least one of the Festkörpe ^¬ raktoren on the side wall side is arranged and at least one further solid-state actuator of the drive body is arranged laterally at the opposite side to the drive body is ^¬.

It is additionally or alternatively preferred if the two solid state actuators are arranged adjacent to one another on the same side wall on the drive body.

In particular, a solid-state actuator drive device ^¬ is preferred, wherein the second solid-state actuator is arranged to the adjacent the solid side wall opposite side wall adjacent.

In particular, a solid-state actuator drive ^¬ device to at least one of the two solid-state actuators, a running with to substantially parallel the longitudinal axis of the second solid-state actuator is arranged at a distance at which it is preferred, with each of parallel arranged solid-state actuators are arranged on opposite sides from view of the drive body opening ,

In particular, a solid-state actuator drive device ^¬, is coupled or wherein at least one of the solid-state actuators in the direction of its longitudinal axis for force and / or movement transmission to a projecting from the actuator body portion attached is preferred. In particular, a solid-state actuator drive device ^¬, at least one of the solid-state actuators is disposed in a plane parallel to a wall of the drive body opening in which a longitudinal axis is preferred.

Such a solution allows to minimize the bending stress on the PMA development particularly advantageous TORQUE ^¬ ment strong rotation drive means of PMA. An advantageously implementable arrangement of the solid-state actuators in the form of solid-state linear actuators with a line of action parallel to the drive body outer surfaces and at a large transverse distance to the shaft axis enables the realization of high-torque solid-state rotary actuators and improves the capability of torque detection. Furthermore, the drive receives a compact radial design or a compact axial design due to the different arrangement options, especially under or over the drive body.

Higher torques can be achieved by the tangential arrangement of the drive elements designed as solid-state actuators. On the drive elements act by attacking rotational ^¬ moments no or hardly any bending loads. The drive elements are advantageously loaded with an attacking torque only with train or pressure. This enables simplified and even direction-dependent torque evaluation. Depending on the length of the solid-state actuators so that the shaft can be dimensioned larger and thus a ^{¬ on} drive with very high torque at low speed reali ^¬ Siert. A radially more compact design of the drive is thus made possible. The arrangement of the solid state actuators above or below the drive body results in a smaller radial dimension. By various arrangements, the axial and radial dimensions of the drive can be changed depending on the application.

The preferred embodiments develop the principle of the increased transverse distance of the line of action of the linear actuators or solid-state actuators from a shaft axis of the Wave to reduce the bending stress of the solid state actuators on. By means of the circumferentially or laterally arranged solid-state actuators, the transverse distance of the line of action of the individual solid-state actuator to the shaft axis or to the drive body opening axis of the drive body is maximized. The line of action of the solid state actuators runs parallel to the adjacent drive body outer surfaces.

As a result, considerably higher torques can be transmitted in contrast to the known arrangements. By an additionally possible enlargement of the shaft diameter to a smaller building gauge ^¬ reason for not more radially projecting from the actuator body solid-state actuators is created an actuator with a very high torque at the same time nied- engined speed.

By increasing the transverse distance of the line of action to the shaft axis, the harmful bending loads occurring in the solid-state actuators are also greatly increased in favor of tensile / compressive forces which are harmless for the solid-state actuators.

Reduced loads. This has advantages in terms of their service life and in the utilization of the direct piezoelectric effect of the piezoceramic. This effect makes it possible to infer the occurring loads of the ceramic during operation. A signal that goes through a pure

Pull / pressure load in the piezoceramic arises, this can be much easier and more accurate evaluation. In addition, the effective direction of the load torque can be determined ^¬ the.

In addition to solid-state actuators in PMA design, embodiments with other types of solid-state actuators can be used, for example, magnetostrictive, electrostrictive or magnetically acting electro ^¬ solid-state actuators.

An embodiment will be explained in more detail with reference to the drawing. Show it: 1 components of a first preferred solid-state drive device in sectional view,

2 components of an alternative embodiment in sectional view,

3 components of a further alternative embodiment in perspective view,

4 shows components of a still further alternative embodiment,

Fig. 5 components of an embodiment according to the prior art and

Fig. 6 components of another embodiment according to the prior art.

As can be seen from the sectional illustration according to FIG. 1, in a first preferred embodiment the principle of the increased transverse distance of the line of action of a solid-state actuator 1, 2 to a shaft axis z 4 or to a drive body opening axis z to a rotary drive with two solid-state actuators 1 designed as linear actuators 1, 2 applied.

The central component is a drive body 3, through which a drive body opening 5 leads. Particularly preferred is a drive body 3 with a cuboid or square-shaped cross section perpendicular to the drive body opening axis z, which leads as a central axis through the drive body opening 5. In the drive body opening 5, a shaft 4 at least into it. Preferably, the shaft 4 passes completely through the drive body opening 5, so that it can be mounted in the direction of its shaft axis z4 on both sides of the drive body 3. The shaft axis z4 is guided in a Be ^¬ operating position parallel to the drive body opening axis z ^¬ , that is laterally offset to this. The offset is chosen type that the shaft 4 with its outer circumference ^¬ form-fitting and / or frictionally applied to an inner side wall of the drive body opening.

The solid state actuators 1, 2, which serve to put the drive body 3 relative to a housing 6 in a plane x, y perpendicular to the drive body opening axis z in a translatori ^¬ cal movement, thereby the shaft 4 in a rotation about the shaft axis z4 is offset, are arranged laterally outside of the actual drive body 3 in the first embodiment. A respective longitudinal axis 1 of the solid-state actuators 1, 2, along which the solid-state actuators 1, 2 expand or contract, is preferably arranged parallel to the profile of an adjacent drive-body outer wall 7.

In the direction of the longitudinal axis 1, the solid-state actuators 1, 2 are coupled or fastened in a first end-side section 9 on a section 9 protruding from the drive body 3, in order to force or move the front-side section 9 of the solid-state actuator 1, 2 onto the front side Drive ^¬ body 3 projecting section 8 to transfer. Such a movement is transmitted to the drive body 3 via the section 8 projecting from the drive body 3. In the region of the front end portion 9 opposite end of the solid state actuators 1, 2 are connected to the housing 6, wherein in the drawing only schematically wall portions of such a housing 6 are outlined. Characterized that the solid-state actuators 1, 2 se at an angle of 90 ° vorzugswei- are arranged relative to each other on the actuator body 3 in ^¬, it can be displaced in translational motion.

Compared with known embodiments, the longitudinal axis 1 of the solid-state actuators 1, 2 thus not in a radial direction r from the viewpoint of the drive body opening axis z or at an angle of less than 45 ° to the radial direction r, but in the ideal case vertically, ie under a Angle α of 90 ° to the radial direction r of the drive body opening axis z or possibly also at an angle between 45 ° and 135 ° to the radial direction r of the drive body opening axis z.

Compared to such an embodiment, various modifications are possible. For example, the drive body 3 does not necessarily have a square or cuboid cross-section. In principle, other shapes, game as examples annular arrays of the driving body mög ^¬ Lich. In such a case, the sections projecting from the drive body would, if appropriate, protrude correspondingly far in the lateral direction, in particular tangentially, from an annular outer circumferential surface of the drive body. Preferred, however, is an embodiment in which such protruding from the drive body 3 sections 8 are designed as a ei ^¬ ner drive body outer wall 7 substantially perpendicular ab ^¬ standing short walls. In each case, who particularly preferably ^¬ the embodiments in which the longitudinal axis 1 of the solid-state actuators 1, 2 are parallel to the circular surface of the drive body opening 5, so that the transverse distance between the line of action of the Festkörpe ^¬ raktors 1, 2 to the shaft axis z4 or to Drive body opening axis z is advantageously maximized.

With the reference to FIG. 1 outlined and more simply constructed embodiment, the solid-state actuator drive ^¬ device in the circumferential direction and parallel to the drive body opening inner surfaces of the drive body opening 5 oriented lines of action of the solid-state actuators 1, 2 only two such solid-state actuators 1, 2. By compared to known embodiments larger lever arm of the drive with an L-shaped arrangement of FIG. 5 can generate a larger torque. In particular, in the case of rotary drives with a shaft diameter comparable or larger than the length of the solid-state actuators 1, 2, such a solid-state actuator drive device is produced relative to arrangements. gene according to FIG. 5 or FIG. 6 more compact, ie space-saving, since it has smaller radial dimensions.

With reference to FIGS. 2 to 4 further particularly preferred embodiment are shown. The same reference numerals refer to structurally and / or functionally identical components as described with reference to FIG. 1. With an index ver ^¬ provided reference numerals refer to in relation to the discussion of FIG. 1, various configurations.

2 shows a second embodiment of a solid-state actuator drive device with a drive body 3 °, on which four solid-state actuators 1, 2 are arranged. In the preferred embodiment, two solid-state actuators 1, 1 or 2, 2 are arranged with their longitudinal axes 1 parallel to one another. The solid-state actuators 1, 1 or 2, 2 which are oriented parallel to one another are arranged adjacent to the outer walls of the drive body 3 °.

The mutually parallel solid state actuators 1, 1 and 2, 2 are each arranged rectilinearly parallel to each other, so that a first end portion 9 ei ^¬ nes each of the parallel solid state actuators 1, 1 or 2, 2 in the same direction of the longitudinal axes. 1 has.

Accordingly, the actuator body 3 ° more projecting from ^¬ sections 8 in the extension of the outlined with reference to FIG. 1 projecting portions 8 ßenwand on the respective opposite Au 7 is arranged. At the back, the secured to the drive body 3 ° protruding from at ^¬ portion 8 end-face section 9 that the solid-state actuators 1, 2 which in turn are attached to a respective element of the housing. 6

In principle, it is also possible to provide an antiparallel arrangement of the solid-state actuators arranged with mutually parallel longitudinal axes. Fig. 3 shows a third and in the radial direction even more space-saving arrangement of a Festkörperaktor- drive device. However, this claimed a larger space in the axial direction of the drive body opening axis z. In this embodiment, the solid-state actuators 1, 2 are not arranged adjacent to a radially extending to the drive body opening 5 outer wall section 7 *, but arranged in the direction parallel to the drive body opening axis z side of the drive body 3 *. Th other Wor ^¬ are the solid-state actuators 1, 2 in parallel and adjacent to a side wall 10 of the drive body 3 * arranged which x in a plane y normal to the Antriebskörperöff- voltage axis z clamped and voltage axis by the Antriebskörperöff- is pierced z.

In the illustrated embodiment, two with their longitudinal axes parallel to each other 1 ^¬ teach te solid-state actuators 1, 1, and 2, 2 * are again reasonable to the actuator body 3 arranged respectively. As projecting from the drive body section 8 * is in the direction parallel to the drive body opening axis z in the illustrated embodiment instead of individual narrow sections from a continuous wall. In order to enable such a space-saving design, the first group of parallel solid-state actuators 1, 1 adjacent to a first in the plane x, y spanned side wall 10 of the drive body 3 * arranged, while the second group of solid state actuators 2, 2 to the in Direction of the drive body opening axis z opposite side wall is arranged adjacent.

FIG. 4 shows a fourth embodiment in which four solid-state actuators 1, 2 are likewise arranged adjacent to the two side walls 10 of the drive body, which are at a distance from each other in the axial direction of the drive body opening axis z. In this embodiment, two arranged with mutually perpendicular longitudinal axes 1 Festkörpe ^¬ are raktoren 1, 2 disposed on the one side, while the two further with likewise mutually perpendicular longitudinal axes 1 arranged solid state actuators 1, 2 are arranged on the opposite side of the drive body 3 ° *. On each side of the drive body 3 ° * in this embodiment, a drive pair of solid state actuators 1, 2 is arranged in each case. Each of the solid-state actuators 1, 2 is assigned a projecting from the drive body portion 8 ° *, which are of the drive body 3 ° * protruding portions 8 ° * preferably only small dimensions and laterally from the side wall 10 of the drive body 3 ° * abste ^¬ hen , In addition to this embodiment, various other embodiments are possible in which, for example, all four solid state actuators 1, 1, 2, 2 are arranged on only one side of the drive body 3 ° *.

Claims

claims

1. Solid-state actuator drive device with

a drive body (3, 3 °, 3 *, 3 ° *), a circular drive body opening (5) in the drive body,

- One in the drive body opening (5) leading shaft (4), wherein a shaft diameter of the shaft (4) is smaller than an opening diameter of the drive body opening (5) and wherein the shaft (4) in operation frictionally and / or form ^¬ conclusively on a Wall of the drive body opening (5) is applied, and

- At least two solid state actuators (1, 2), which are controllable to expand and / or contraction along its longitudinal axis, wherein the at least two solid-state actuators on

Drive body (5) are coupled or fixed, the drive ^¬ body (5) to drive so that by a displacement movement of the drive body, the shaft (4) is set in rotation, characterized in that

- the longitudinal axis (1) of at least one of the at least two solid state actuators (1, 2) at an angle (α) between 44 ° and 135 ° to a radial direction (r) of the drive body opening (5) on the drive body (3; *, 3 ° *).

2. Solid-state actuator drive device according to claim 1, wherein the longitudinal axis (1) of the solid-state actuator (1, 2) in a plane (x, y) perpendicular to the shaft axis (z4) and / or perpendicular to the drive body opening axis (z) of the drive body ^¬ opening is arranged.

3. Solid-state actuator drive device according to claim 1 or 2, wherein at least one of the solid-state actuators (1, 2) outside of a radially in the radial direction (r) to the drive body opening (5) encircling outer wall (7) of the drive body (3) is arranged.

4. Solid-state actuator drive device according to any preceding claim, wherein at least one of the solid state actuators

(1, 2) is arranged adjacent to a side wall (10) of the drive body (3 *, 3 ° *), wherein the side wall in a plane pierced by a drive body opening axis (z) plane (x, y) is clamped.

5. Solid-state actuator drive device according to claim 4, in which at least one of the solid state actuators (1) is arranged adjacent to the side wall (10) adjacent to the drive body (3 *, 3 ° *) and at least one further solid state actuator (1, 2) on the opposite side of the drive body (3 *, 3 ° *) is arranged.

6. Solid-state actuator drive device according to claim 4 or

5, in which the two solid state actuators (1, 2) to each other next to the same side wall (10) on the drive body (3 ° *) are arranged.

7. solid-state actuator drive device according to claim 4 or 5, wherein the second solid-state actuator (2) to the solid (1) adjacent side wall (10) opposite side wall is arranged adjacent.

8. Solid-state actuator drive device according to any preceding claim, wherein at at least one of the two solid-state actuators (1, 2) a parallel longitudinal axis (1) extending second solid-state actuator (1 or 2) is arranged spaced, wherein the mutually parallel solid state actuators ( 1, 1 or 2, 2) are arranged on opposite sides of the drive body opening (5).

10. Solid-state actuator drive device according to any preceding claim, wherein at least one of the solid-state actuators (1, 2) in the direction of its longitudinal axis (1) for force and / or motion transmission to one of the drive body (3; 3 °, 3 *, 3 ° *) projecting portion (8, 8 *, 8 ° *) coupled or be ^¬ consolidates.

11. Solid-state actuator drive device according to any preceding claim, wherein a longitudinal axis (1) of at least one of the solid state actuators (1, 2) is arranged in a plane parallel to a wall of the drive body opening (5).