WO2014044308A1

WO2014044308A1 - Electric actuating drive

Info

Publication number: WO2014044308A1
Application number: PCT/EP2012/068523
Authority: WO
Inventors: Martin Hoffmann; Markus Reinhard
Original assignee: Siemens Aktiengesellschaft
Priority date: 2012-09-20
Filing date: 2012-09-20
Publication date: 2014-03-27

Abstract

The invention relates to an electric actuating drive (10) comprising a first active part (12) and a second active part (14) which can be displaced relative to the first active part (12) along a pre-defined displacement path (b), one of the active parts (12, 14) having at least one magnetic element (20) and the other active part (12, 14) having at least one coil element (16) which surrounds the magnetic element (20) in at least some regions, characterised in that a movement of the second active part (14) is restricted between two end positions and the actuating drive (10) comprises a control device (26) which is designed to displace the second active part (14) between two pre-defined end positions by determining an electrical current flowing through the at least one coil element (16).

Description

description

Electric actuator The present invention relates to an electrical Stel ^¬ lantrieb. Moreover, the present invention relates to a method for operating an electric actuator.

Electrical actuators are required in a large number of applications. For example, turnout drives are used in BriefSortieranlagen that direct the letters in the corre ^¬ sponding subjects. Furthermore, electrical actuators are used as valve or damper actuators. In addition, electric actuators are used on steered wheels or for similar applications.

For highly dynamic applications, permanent-magnet synchronous motors, servomotors or servomotors are mainly used. These are usually fed via a servo inverter or control electronics. The cost of operating such machines is typically high because the machines are designed for rotary operation. Furthermore, there are high costs for rare-earth magnets, winding copper and the complex control electronics. In addition, the converters usually have corresponding bridge circuits and evaluation devices for the encoders and are therefore of complex construction.

EP 1 858 142 A1 discloses a linear motor having a secondary part with permanent magnets and a movable primary part with current-carrying multiphase windings. To increase the achievable driving forces, the permanent magnets ^{¬ are} arranged such that their north and south poles are arranged in the same direction in the direction of one behind the other. In addition, the coils of the polyphase windings are designed such that they surround the permanent magnets of the secondary part at least partially. The principle of the linear motor described in EP 1 858 142 A1 can likewise be transferred to a rotary motor. In this case, the rotor has a plurality of Permanentmag ^¬ Neten, which are arranged in the circumferential direction. The stator has a winding arrangement which surrounds the permanent magnets at least in regions. For this purpose, the stator has, for example, U-shaped bent coils.

It is an object of the present invention to provide an electric actuator that is simpler in construction and that can be operated more cost-effectively.

This object is achieved by an electric actuator with the features of claim 1 and by a method having the features of claim 10. Advantageous developments of the present invention are specified in the subclaims.

The electric actuator according to the invention comprises a first active part and a second active part, which is movable relative to the first active part along a predetermined movement path, wherein one of the active parts has at least one magnet ^¬ element and the other of the active part has at least one coil element, the at least be the magnetic element surrounds richly and wherein a movement of the second active ^¬ part is limited between two end positions. In addition, the actuator comprises a control device which is designed to move the second active part between the two predetermined end positions by setting an electrical current flowing through the at least one coil element.

The electric actuator has two active parts. The first active part is fixed - for example, on a Ge ^¬ housing - arranged. The second active part can be moved in a predetermined manner relative to the first active part. In this case, the second active part can perform a rotational movement. The actuator can also be designed so that the second active part performs a linear movement. One of the active le has a magnetic element, which may comprise, for example, one or more permanent magnets. All permanent magnets in a magnetic element have the same Magnetisie ^¬ tion. The other of the active parts has a coil element, which may have one or more coils with corresponding windings. The coil element is so ausgebil ^¬ det that it is the magnetic element at least partially around ^¬ is. The basic arrangement or design of the coil element and the magnetic element corresponds to that which is described in EP 1 858 142 AI for an electrical machine.

The movement of the second active part of the electric actuator along its trajectory is now limited. In other words, the second active part can only be moved back and forth between two predetermined end positions. A control device controls the electric current through the coil element, whereby a movement of the second active part is effected to the first active part. The electric actuator is thus a bistable tilting can be found ^¬ riding. In the electric actuator, for example, no rotating rotational movement of the second Ak ^¬ tivteils is provided. The end positions of the second active portion are determined by the spatial extents of the coil member and the magnet element and / or the interaction of the coil element with the Mag ^¬ netelement along the movement path of the second active portion. Thus, the dimension of the coil element and the magnetic element can be chosen to correspond to a range of movement of the electric actuator ^¬ . In this case, the number of coils in the coil element and the number of permanent magnet may be selected accordingly entspre ^¬ in the magnetic element in order to predetermine the two end positions for the second active part. Thus, the electric Stel ^¬ lantrieb be used, for example, where only a limited angle of rotation is needed. Examples of this are the BriefSortieranlagen, valve actuators, damper actuators or applications on steered wheels mentioned above.

In one embodiment, the control device is designed to adapt the current flowing through the coil element electrical current so that the second active part performs a periodi ^¬ cal movement between the two end positions. With the control device, an electric current can be impressed into the coil element or a winding of the coil element. Due to the current flow, the movement of the second active part can be controlled. The feed force with which the second active part is moved relative to the first active part results from the amplitude of the electrical current. It may be desired for any applications that the second active part performs a pendulum movement from the first to the second end position of the two end positions. For this purpose, the control device can impress a substantially periodically changing current in the coil element. In particular, the coil element can be supplied with a sinusoidal current. This can be provided in a simple manner, a job drive that performs a periodic movement.

In a further embodiment, the control device is designed to hold the second active part in one of the end positions by adjusting the electrical current flowing through the coil element. If the second active part is to remain in a defined position, the current flow through the coil element can be interrupted. Thus, the second active part remains ste ^¬ hen in one of the end positions. It is also conceivable that the second active part remains in one or more intermediate positions between the end positions. If, for example, a force is to be generated with the second active part which acts against a stop, the coil element can continue to be energized. Thus, the second active part can be easily held in one of the end positions. In one embodiment, the control means is adapted to reduce a current flowing through the coils of the element ^¬ sequent electric current to a predetermined value if the second active part of one of the end positions approaches. The electric actuator can have a sensor with which it can be detected whether the second active part is approaching an area assigned to the first or second end position. At the two end positions can be provided a mechanical stop. It can also be provided that the current in the coil element is reduced when the second active part is in one of the end positions. It is also conceivable that the current flow through the coil is switched off when the second active part approaches one of the end positions. Thus can be changed prevent that I heated the coil element as a result of current flow ^¬.

Preferably, the actuator includes a switching element with which the second active part in each of the two end positions together menwirkt, wherein said control means is adapted to the current flowing through the coil element electric current in response to a switching signal of the switching element ^¬ fit. In a region of the respective end positions, a switching element may be provided which is triggered by the second tivteil AK- when this occurs because the switching element be ^¬. The switching element can be formed as a mechanical switch ^¬ , which is actuated by the second active part when this is in the end position. If that

Switching element is actuated, the current flow through the coil element can be switched off. On a switching signal of the

Switching element also the current flow through the coil ^¬ element can be reduced with the control device. Thus, the current flowing through the coil element current can be limited in a simple manner, when the second active part is in one of the end positions.

Furthermore, it is advantageous if the actuator has a Hal ^¬ teelement for respectively holding the second active part in the includes two end positions. By the holding element, the second active part can be mechanically held in the end position. Thus, the second active part in the holding element einras ^¬ th or snap. The second active part can also be released again from the holding element to allow movement of the second active part.

In one embodiment, the coil element includes two single coil ^¬. The individual coils can each have a frame-shaped form. The individual coils may consist of a wire winding and are in particular formed as flat coils. As a carrier material for the individual coils also (flexible) printed circuit boards can be used, on which the Wick ^¬ lungs of the coils are printed. The individual coils can be arranged on opposite sides of the magnetic element. The individual coils may be arranged so that their winding axes are arranged perpendicular to the movement path of the second active part. In one embodiment, the second active part comprises the magnetic element. Since the permanent magnets of the magnetic element do not require electrical connections, it may be useful for reasons of reliability to equip the second active part, ie the movable part of the actuator, with the magnetic element. In this case, the coil element is arranged in the first Ak ^¬ tivteil. Thus, a reliable actuator can be provided.

Alternatively, the second active part may comprise the coil element. Since the coil element is significantly lighter than the magnetic element, the coil element can be placed on the movable Ak ^¬ tivteil. In order to supply the coil element with electrical ^¬ tricity, slip rings, inductive transducer or trailing wires can be used. Since a two-th active part comprises a coil element less Träg ^¬ moment of inertia, the dynamics of the actuator can be increased noticeably. The inventive method for operating an electric actuator having a first active part and a second active part, which is movable relative to the first active part along a predetermined movement path, wherein one of the active parts has at least one magnetic element and the other of the active parts has at least one coil element, the the magnetic element surrounds at least in regions, comprises limiting a movement of the second active part between two end positions, setting a by the at least one coil element electric current flowing and thus moving the second active part between the two pre give ^¬ NEN end positions.

The advantages and developments described above in connection with the electric actuator according to the invention can be transferred in the same way to the method according to the invention.

The present invention will now be explained in more detail with reference to the accompanying drawings. Showing:

1 shows a perspective view of an electric Stellan ^¬ drive;

2 shows a perspective view of the electrical Stellan ^¬ drive and a control device;

3 shows a time course of an electrical current through a coil element of the actuator;

4 shows an arrangement of the coil element to a magnetic element;

5 shows an arrangement of the coil element to the magnetic ^¬ element in a further embodiment;

6 shows an arrangement of the coil element to the magnetic ^¬ element in a further embodiment; and 7 shows an arrangement of a plurality of coil elements and

Magnetic elements. The embodiments described in more detail below represent preferred embodiments of the present invention.

FIG. 1 shows an electric actuator 10. The electric actuator 10 has a first active part 12 and a second active part 14. The second active part 14 is movable ^¬ Lich to the first active part 12 is formed. The second Ak ^¬ tivteil 14 b may be moved along a movement path. Of the first active part 12, in the present case only one coil element 16 is shown. The coil element 16 has a winding, which is made of several layers of electrical conductors. The electrical conductors may be formed by a copper wire, an aluminum wire or an aluminum foil. In the present case, only one turn 24 is shown by way of example. The second active part 14 has a magnetic element 20 with a plurality of permanent magnets 18, which are glued or fixed on a magnetic carrier 22. All Per ^¬ manentmagnete 18 in a magnetic element 20 have the same magnetization. The permanent magnets 18 are cylindrical in the present example. The magnetic elements 20 are arranged so that their respective Magneti ^¬ sierungsrichtung extends along the path b. In addition, the magnetic elements 20 are arranged so that in adjacent magnetic elements 20 are the same poles.

The coil element 16 is formed so that it surrounds the Perma ^¬ nentmagneten 18 regions. When an electric current flows through the coil member 16, the second Ak ^¬ tivteil 14 is moved relative to the first active part 12th The movement path b of the second active part 14 is partially circular. In the exemplary embodiment shown, the electric actuator 10 has only one coil element 16. Due to the spatial extent of the coil element 16 and the Number and dimensions of the magnetic elements 20, the movement of the second active part 14 along the movement path b is limited between two end positions. The second active part 14 can only be moved back and forth between end positions. To the second active part 14 between the end positions to bewe ^¬ gene, an electric current is impressed into the coil member sixteenth For this purpose, the electric actuator 10 has a control device 26 which is electrically connected to the winding 24 of the coil element 16. With the control device 26, the current flowing through the coil element 16 can be adjusted. The control device 26 is shown in FIG.

3 shows the various curves 28, 30 and 32 of the electrical current that can be impressed into the coil element 16 with the control device 26. The current ^intensity I is plotted over time. The electric current must be impressed so that the desired Drehbewe ^¬ tion of the second active part 14 results. Ie. It must be a feed force generated in the desired direction.

It is conceivable a supply with an alternating current or sinusoidal current, such as the course 28 of the electrical

Current I shows. If a roller ^¬ selstrom is applied to the coil member 16, the second active part 14 executes a pendulum motion between the two end position. When the second active component should remain in a certain position 14, the current flow through the coil member 16 un ^¬ must be interrupted. The electric actuator 10 can also be operated with a ^{DC ¬} stream. This is shown by the curve 30 of the electrical current I. The Spulenele ^¬ ment is operated with a bipolar direct current. By the change of sign of the electric current, the direction of movement of the second active part 14 along the movement path b can be reversed. The electrical current can also be impressed into the coil element 16 according to the profile 32. In this case, the second active part 14, which is located in one of the end positions, becomes lungs is, first with an electric current having a high amplitude applied to overcome the Massenträgheitsmo ^¬ ment of the second active part fourteenth When the second active part 14 of the other end position is approaching, the amplitude of the electric current flowing through the Spulenele ^¬ ment 16 is again reduced. To change direction then again an electric current with a high amplitude is necessary.

4 shows an arrangement of the coil element 16 to the magnetic element 20 in a further embodiment. In this case, the permanent magnets 18 may have the shape of a hollow cylinder ^¬ segment. The permanent magnets can also be formed cuboid ^¬ shaped. The coil element 16 has two individual coils 34. The individual coils 34 are formed as a frame-shaped flat coils. A single coil 34 may be gebil ^¬ det by a single layer or a multi-layer printed circuit board, are applied to the respective windings. If the single coil 34 is a three-dimensional contour aufwei ^¬ sen to, a flexible printed circuit board with entspre ^¬ accordingly applied turns may be used. The turns can be printed, for example. Lei ^¬ terplatten can be used, which have no curved contour on ^¬ . In the embodiment according to FIG. 4, the magnetic elements 20 may be magnetized along the movement path b or perpendicularly through the movement path b.

The individual coils 34 are arranged such that the Wi ^¬ ckelachsen of the individual coils 34 are arranged perpendicular to the movement path b. The individual coils 34 are arranged along the supply track BEWE ^¬ b on the right and left edges of the permanent magnet 18th In the two individual coils 34, the current direction can be impressed against each other or rectified to each other, whereby a magnetization of the permanent magnet 18 parallel or perpendicular to the movement path b is possible. Depending on the required force action along the movement path b, the use of a single coil 34 in the first Ak is 12 is sufficient. One example is ge ^¬ shows in FIG. 5

Depending on the desired power dissipation, the coil element 16 or the individual coils 34 can be arranged on the tangential side surfaces of the permanent magnet 18. The individual coils 34 may also be arranged so that they are arranged along the movement path b above and below the permanent magnet 18 Perma ^¬ . Such an embodiment is shown in FIG.

To increase the force component, a plurality of coil elements 16 and magnetic elements 20 along the movement path b can be arranged one behind the other. Such an arrangement is shown in FIG. The coil elements 16 may be electrically connected in parallel or in series.

Reference sign list

10 actuator

12 active part

14 active part

16 coil element

18 permanent magnet

20 magnetic elements

22 magnetic carrier

24 turn

26 control device

28 History

30 course

32 course

34 single coils b trajectory

I current

Claims

claims

1. Electric actuator (10) with

- A first active part (12) and

- A second active part (14) which is movable relative to the first active part (12) along a predetermined movement path (b), wherein

- One of the active parts (12, 14) has at least one magnetic element (20) and

- the other of the active parts (12, 14) comprises at least one Spulenele ^¬ ment (16), the at least be rich ^¬ surrounds the magnetic element (20),

characterized in that

- A movement of the second active part (14) is limited between two end positions and

- That the actuator (10) comprises a control device (26) which is adapted to move by adjusting an at least one coil element (16) flowing electric current, the second active part (14) between the two predetermined end positions ,

2. Electric actuator (10) according to claim 1, characterized in that the control device (26) is designed to ^{¬ out} , by the coil element (16) flowing electric current to adjust so that the second active part (14) has a periodic movement between performs the two end positions.

3. Electric actuator (10) according to claim 1 or 2, character- ized in that the control device (26) is adapted to, by adjusting the current through the coil element (16) electrical current, the second active part (14) in one of the end positions to keep.

4. Electric actuator (10) according to any one of the preceding claims, characterized in that the Steuerein ^¬ direction (26) is adapted to a current strength (I) of the coil element (16) flowing electrical current to reduce to a predetermined value, if the second active part (14) approaches one of the end positions.

5. Electric actuator (10) according to one of the preceding claims, characterized in that the actuator

(10) comprises a switching element cooperating with the second active part (14) in each of the two end positions, wherein the control device (26) is adapted to the electrical current flowing through the coil element (16) in response to a switching signal of the switching element adapt.

6. Electric actuator (10) according to any one of the preceding claims, characterized in that the actuator (10) comprises a holding element for respectively holding the second active part (14) in the two end positions.

7. Electric actuator (10) according to one of the preceding claims, characterized in that the coil element (16) comprises two individual coils (34).

8. Electric actuator (10) according to one of the preceding claims, characterized in that the second active ^¬ part (14) comprises the magnetic element (20).

9. Electric actuator (10) according to one of claims 1 to 7, characterized in that the second active part (14) comprises the coil element (16).

10. A method for operating an electric actuator (10) having a first active part (12) and a second active part (14) relative to the first active part (12) along a predetermined movement path (b) is movable, wherein one of Active parts (12, 14) has at least one magnetic element (20) and the other of the active part (12, 14) has at least one coil element (16) surrounding the magnetic element (20) at least in regions,

marked by Limiting a movement of the second active part (14) between two end positions,

- Setting an electrical current flowing through the at least one coil element (16) and thereby

- Moving the second active part (14) between the two predetermined end positions.