Vibrating Actuator
20190143371 · 2019-05-16
Assignee
Inventors
Cpc classification
H02K33/00
ELECTRICITY
H02K7/1876
ELECTRICITY
B06B1/045
PERFORMING OPERATIONS; TRANSPORTING
H02K1/34
ELECTRICITY
International classification
Abstract
A vibrating actuator is disclosed, comprising: a magnet arrangement including at least one magnet (1); a hollow member (4) comprising at least one coil member (2) with a coil transversally surrounding a cavity (5) forming a longitudinal passageway for receiving the magnet arrangement and permitting a longitudinal relative movement between the hollow member (4) and the magnet arrangement; and elastic means (6) interconnecting the magnet arrangement and the hollow member (4). In one aspect, the elastic means (6) are thin membranes having an oblong shape with transversal indentations (10) on their opposite long sides. In another aspect, at least two magnets (1) are arranged with same polarities facing each other inside a magnet frame (8) at least partially surrounding the magnets (1). Furthermore, methods for assembling the magnet arrangement of a vibrating actuator, the hollow member of a vibrating actuator, and the overall vibrating actuator are disclosed.
Claims
1. A vibrating actuator, comprising: a magnet arrangement including at least one magnet; a hollow member comprising at least one coil member with a coil transversally surrounding a cavity forming a longitudinal passageway for receiving the magnet arrangement and permitting a longitudinal relative movement between the hollow member and the magnet arrangement; and elastic elements interconnecting the magnet arrangement and the hollow member; wherein the elastic elements are thin membranes having an oblong shape with transversal indentations on their opposite long sides.
2. The actuator of claim 1, wherein the indentations have a concave or polygonal shape.
3. The actuator of claim 1, wherein the elastic elements are made of copper beryllium.
4. The actuator of claim 1, wherein the magnet arrangement comprises two magnets arranged with same polarities facing each other and wherein the hollow member comprises one coil member.
5. The actuator of claim 1, wherein the magnet arrangement comprises three magnets arranged with same polarities facing each other and wherein the hollow member comprises two coil members and a spacer.
6. The actuator of claim 5, wherein coil membrane interfaces are provided at the longitudinal outer ends of the coil members.
7. The actuator of claim 1, wherein the magnet arrangement further comprises a magnet frame at least partially enclosing the at least one magnet.
8. The actuator of claim 1, wherein the hollow member is fixed to a chassis and stationary and the magnet arrangement performs a linear longitudinal vibratory movement.
9. The actuator of claim 1, wherein the magnet arrangement is fixed to a chassis and stationary and the hollow member performs a linear longitudinal vibratory movement.
10. The actuator of claim 1, wherein the magnet arrangement and the hollow member are flat and rectangular.
11-20. (canceled)
21. A method for assembling the hollow member of the vibrating actuator of claim 5, the method comprising the following steps: providing at least first and second coil members, each having a coil transversally surrounding a cavity forming a longitudinal passageway and at least one spacer having a cavity with the same shape as the cavity of the at least first and second coil members; providing a hollow member assembly rod dimensioned to engage the cavities of the at least first and second coil members and the at least one spacer in several areas such that the at least first and second coil members and the at least one spacer cannot move transversally to the rod; providing first and second hollow member assembly end pieces, each having a cavity for receiving the hollow member assembly rod such that the first and second hollow member assembly end pieces cannot move transversally to the rod; consecutively putting the first hollow member assembly end piece, the first coil member, the at least one spacer, the second coil member, and the second hollow member assembly end piece on the hollow member assembly rod with glue (i) between the first coil member and the at least one spacer and (ii) between the at least one spacer and the second coil member; compressing the first and second hollow member assembly end pieces; removing the second hollow member assembly end piece from the hollow member assembly rod; and removing the hollow member comprising the at least one spacer and the first and second coil members from the hollow member assembly rod.
22. The method of claim 21, further comprising the step of: providing first and second coil membrane interfaces, each having a cavity with the same shape as the cavity of the at least first and second coil members and the at least one spacer; the step of putting the hollow member assembly end piece on the hollow member assembly rod is followed by the step of putting the first coil membrane interface on the hollow member assembly rod; and the step of putting the second coil member on the hollow member assembly rod is followed by the step of putting the second coil membrane interface on the hollow member assembly rod.
23. The method of claim 21 further comprising the following steps: positioning a magnet frame on a support surface; inserting two longitudinal outer magnets in the magnet frame and gluing them to the magnet frame at their longitudinal outer ends; inserting a third central magnet in the magnet frame between the two longitudinal outer magnets and gluing the central magnet to the longitudinal outer magnets; inserting the magnet arrangement into the hollow member; and attaching elastic elements interconnecting the magnet arrangement and the hollow member on both longitudinal outer ends via attachment means.
24. The method of claim 23, wherein the elastic elements are thin membranes having an oblong shape with transversal indentations on their opposite long sides.
25. The method of claim 24, wherein the membranes are made from copper beryllium.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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SUMMARY OF THE INVENTION
[0035] An object of this invention is to provide a flat vibrating actuator which permits an enhanced guidance of the moving part, a better stress distribution along the membrane and an improved, i.e., easier and cheaper, assembly which results in a device less prone to breakage when exposed to an impact force while maintaining acceleration and resonance frequency.
[0036] The present invention provides a vibrating actuator, comprising: a magnet arrangement including at least one magnet; a hollow member comprising at least one coil member with a coil transversally surrounding a cavity forming a longitudinal passageway for receiving the magnet arrangement and permitting a longitudinal relative movement between the hollow member (4) and the magnet arrangement; and elastic means interconnecting the magnet arrangement and the hollow member; wherein the elastic means are thin membranes having an oblong shape with transversal indentations on their opposite long sides.
[0037] In another aspect, the present invention provides a vibrating actuator, comprising: a magnet arrangement including at least two magnets; a hollow member comprising at least one coil member with a coil transversally surrounding a cavity forming a longitudinal passageway for receiving the magnet arrangement and permitting a longitudinal relative movement between the hollow member (4) and the magnet arrangement; and elastic means interconnecting the magnet arrangement and the hollow member; wherein the at least two magnets are arranged with same polarities facing each other inside a magnet frame at least partially surrounding the magnets.
[0038] The present invention also provides a method for assembling the magnet arrangement of a vibrating actuator, comprising the following steps: [0039] positioning a magnet frame on a support surface; [0040] inserting at least two magnets in the magnet frame and gluing the magnets to the magnet frame and to each other.
[0041] The present invention furthermore provides a method for assembling the hollow member of a vibrating actuator, comprising the following steps: [0042] providing at least two coil members each having a coil transversally surrounding a cavity forming a longitudinal passageway and at least one spacer having a cavity with the same shape as the cavity of the at least two coil members; [0043] providing a hollow member assembly rod dimensioned to engage the cavities of the at least two coil members and the at least one spacer in several areas such that the at least two coil members and the at least one spacer cannot move transversally to the rod; [0044] providing two hollow member assembly end pieces having a cavity for receiving the hollow member assembly rod such that the hollow member assembly end pieces cannot move transversally to the rod; [0045] consecutively putting [0046] the first hollow member assembly end piece, [0047] the first of the at least two coil members, [0048] the at least one spacer, [0049] the second of the at least two coil members, and [0050] the second hollow member assembly end piece [0051] on the hollow member assembly rod with glue between the members being enclosed by the two hollow member assembly end pieces; [0052] compressing the first and second hollow member assembly end pieces; [0053] removing the second hollow member assembly end piece from the hollow member assembly rod; and [0054] removing the hollow member comprising the at least one spacer and the first and second coil members from the hollow member assembly rod.
[0055] The present invention also provides a method for assembling a vibrating actuator, comprising the following steps: [0056] inserting the magnet arrangement assembled according to the above into the hollow member 4 assembled according to the above; [0057] attaching elastic means interconnecting the magnet arrangement and the hollow member on both longitudinal outer ends via attachment means.
[0058] Further advantageous features can be obtained from the specification and the claims.
[0059] In this application, the term longitudinal means in the direction of the linear movement of the moving part of the actuator; accordingly, the term transversal means in a direction in the plane orthogonal to the longitudinal direction. The term long in connection with the oblong membranes, on the other hand, denominates the longer sides of the membranes in contrast to their shorter sides.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0060] The present invention is directed to a vibrating actuator for a variety of applications. In an exemplary application, a vibrotactile voice-coil or moving magnet-type actuator for high-definition haptic feedback to create immersive experiences for video, gaming and music and other immersive experiences is connected to an audio device via an amplifier like a loudspeaker and via an additional low pass filter to limit the audio frequency range to the tactile perceptible range of the skin. The actuator can be worn, for example, around the user's wrist or other body part like a bracelet.
[0061] The general arrangement of a preferred embodiment of the actuator is shown in
[0062] The three magnets 1 of the magnet arrangement are positioned inside the magnet frame 8, wherein the magnets 1 are each arranged with same polarities facing each other, i.e., north facing north or south facing south, to create a highly concentrated magnetic field in the plane between them. The magnet frame 8 will be described in more detail below.
[0063] The hollow member 4 is shaped depending on the shape of the magnet arrangement such that the gap between the coils and the magnets 1 is relatively small in order to reduce the loss of magnetic force. For example, the inner cavity 5 of each element 2, 3 and 7 of the hollow member 4 as well as the outer contour of the hollow member 4 should be flat and oblong if the magnet arrangement comprising the magnets 1 and the frame 8 is flat and oblong, or the internal cavities 5 and the outer contour of the hollow member 4 should be cylindrical and oblong if the magnet arrangement is cylindrical and oblongof course, there has to be certain spacing between the magnet arrangement and the inner surfaces defining the internal cavities 5 of the elements 2, 3 and 7 of the hollow member 4 to enable the magnet arrangement to move within the cavities 5. The hollow member 4 is attached to the chassis which can be a bracelet worn by a user or at least a casing containing both the actuator and further electronics. The attachment can be, for example, a clip-in type attachment and ensure that the hollow member 4 remains stationary (by being attached to the chassis) and maintains the position of the coils. Accordingly, the stationary part comprises the coil members 2, the spacer 3 and the coil membrane interfaces 7. In the resting position of the actuator, the two coil members 2 transversally surround at least the two areas where the same polarities of the magnets 1 face each other (see above) but not the whole length of the arrangement of magnets 1 which is achieved by the spacer 3 between the coil members 2. It is preferred to provide one coil member 2 per area where two magnets 1 face each other with same polarity, i.e., in the embodiment acc. to
[0064] The linear movement of the moving part occurs along the longitudinal axis of the actuator (i.e., the longitudinal axis of the magnet arrangement comprising magnet frame 8 with the magnets 1 inserted therein and the hollow member 4 comprising the coil members 2). Each end of the oblong hollow member 4 is open (such that the elements 2, 3 and 7 forming the hollow member 4 form a tube) to allow attachment of two elastic elements 6 to both the coil membrane interfaces 7 and the longitudinally outer ends of the magnet frame 8 on both longitudinal outer ends of the actuator. The attachment of the elastic elements 6 can be obtained by using glue, rivets or screws 9, and if the coil membrane interfaces 7 are omitted the elastic elements 6 are attached directly to the coil members 2. The elastic elements 6 allow the moving magnet part to perform its longitudinal movement back and forth without hitting the stationary part, i.e., the hollow member 4 and the chassis.
[0065] It should be noted, however, that the actuator can also have an inverted arrangement as disclosed in Applicant's DE 10 2015 111 527.1, wherein the hollow member 4 comprising the coils is the moving part and the magnet arrangement is the stationary part fixed to the chassis, for example, via attachment members extending through slots in the hollow member 4. The novel inventive membrane 6, the magnet arrangement comprising the magnet frame 8 and the manufacturing process for (parts of) the actuator as well as the advantageous effects resulting therefromall of which will be discussed in more detail beloware not affected by the choice of the moving and stationary parts, i.e., whether the magnet arrangement moves and the hollow member comprising the coils is stationary or vice versa. Neither is the number of magnets 1 or the order of their polarity or the presence of the spacer 3 and/or the coil membrane interfaces 7 essential for the novel inventive membrane 6 and its advantageous effectseven the minimum arrangement with the membranes 6 interconnecting only one magnet 1 and one coil member 2 with a coil at least partially surrounding the magnet 1 is possible. In view of the inventive magnet frame 8 and the manufacturing process for (parts of) the actuator as well as the advantageous effects resulting therefrom, the magnet arrangement should comprise at least two magnets 1 with same polarities facing each other and the hollow member should comprise at least two coil members 2 and a spacer 3. In the following, the preferred embodiment of the actuator of
Membrane
[0066] In order to allow sufficient movement of the moving part (i.e., in the embodiment shown in
[0067] Longer performance tests have shown that copper beryllium as the membrane material has the further advantages of high yield strength and high dynamic fatigue resistance. The performance tests have also shown, however, that even these membranes tend to deteriorate and even break due to the stress imposed on them resulting from the strong vibratory movement of the moving part. Thus, the present invention takes the design of the membranes further by providing novel specially shaped membranes 6 interconnecting the moving and stationary parts of the actuator. The membranes 6 according to the present invention are shown in more detail in
[0068] The inventive membrane is ideal, in particular, for flat rectangular actuators which are preferred for applications where small size matters such as when the actuator is used around the user's wrist or other body part like a bracelet. In the case of a rectangular magnet arrangement it is challenging to guide the moving magnet arrangement comprising the magnets 1 inside the hollow member 4 comprising the coils without friction. Friction creates noise and is, thus, particularly undesirable for devices designed to enhance musical experience or the like. A minor rotation of the magnet arrangement around its longitudinal axis will result in friction between the moving magnet arrangement and the hollow member 4. Due to its even stress distribution, the inventive membrane allows a high displacement and at the same time a precise longitudinal guiding of the moving part.
Magnet Frame
[0069] In another aspect, the present invention provides a magnet frame 8 at least partially surrounding the magnets 1. As indicated above, in vibrating magnet-type actuators several magnets 1 can be arranged facing each other with the same polarity to allow a high concentration of magnetic field to be generated inside the at least one coil and coil member 2, resp. However, assembling strong magnets with same polarities facing each other is very difficult due to the high repelling force created by the magnetic poles. In the embodiment shown in
[0070] Assembling the magnet arrangement, i.e., consecutively inserting the magnets 1 in the frame 8, will be described in further detail below. The magnet frame 8 reduces the material/spare part costs and makes the assembly easier and cheaper because instead of having to use an expensive adhesive and custom shaped magnets, the inventive frame 8 permits the use of a common adhesive and standard, i.e., readily available (standard shape), magnets. After gluing, the metallic frame holds the magnets together and also acts as an interface between the magnets 1 and the membranes 6 as already described in connection with the membrane 6 above. Gluing the magnets 1 together without the frame 8 would leave the joints between the magnets 1 under tensionsince adhesives are typically weak under tension loads there is a high risk of joint breakage after a shock or collision. Accordingly, providing the magnet frame 8 significantly reduces the risk of breakage when the assembly is exposed to an impact force. In case the magnet arrangement comprising the magnets 1 and the frame 8 is the moving part, the frame 8 adds to its mass and, thus, can be used to adjust the resonance frequency of the actuator.
Manufacturing Method
[0071] The manufacturing of the inventive actuator can be divided into three separate parts, namely assembling (i) the magnet arrangement comprising the magnets 1, (ii) the hollow member 4 comprising the coils and (iii) the overall actuator.
(i) Assembling the Magnet Arrangement
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[0075] In the case of the preferred embodiment acc. to
(ii) Assembling the Hollow Member
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[0092] In the case of the preferred embodiment acc. to
the step of putting the hollow member assembly end piece 12 on the hollow member assembly rod 11 is followed by the step: [0094] putting the first coil membrane interface 7 on the hollow member assembly rod 11; and
the step of putting the second of the at least two coil members 2 on the hollow member assembly rod 11 is followed by the step: [0095] putting the second coil membrane interface 7 on the hollow member assembly rod 11.
(iii) Assembly Overall Actuator
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[0099] As mentioned above, the inventive vibrating actuator can be used in a variety of applications including, but not limited to, high-definition haptic feedback to create immersive experiences for video, gaming and music and other immersive experiences. Generally, the vibrator can be used in all applications where a vibratory feedback is desirable, wherein this feedback is not limited to an input to a human user but can also be addressed to a device.