WO2023157372A1 - Moteur à ultrasons - Google Patents

Moteur à ultrasons Download PDF

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Publication number
WO2023157372A1
WO2023157372A1 PCT/JP2022/037656 JP2022037656W WO2023157372A1 WO 2023157372 A1 WO2023157372 A1 WO 2023157372A1 JP 2022037656 W JP2022037656 W JP 2022037656W WO 2023157372 A1 WO2023157372 A1 WO 2023157372A1
Authority
WO
WIPO (PCT)
Prior art keywords
vibrating body
flexible wiring
ultrasonic motor
piezoelectric elements
rotor
Prior art date
Application number
PCT/JP2022/037656
Other languages
English (en)
Japanese (ja)
Inventor
俊明 山下
宏志 浅野
Original Assignee
株式会社村田製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社村田製作所 filed Critical 株式会社村田製作所
Publication of WO2023157372A1 publication Critical patent/WO2023157372A1/fr

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
    • H02N2/00—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction
    • H02N2/10—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing rotary motion, e.g. rotary motors
    • H02N2/12—Constructional details
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
    • H02N2/00—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction
    • H02N2/10—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing rotary motion, e.g. rotary motors
    • H02N2/16—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing rotary motion, e.g. rotary motors using travelling waves, i.e. Rayleigh surface waves

Definitions

  • the present invention relates to ultrasonic motors.
  • Patent Document 1 discloses an example of an ultrasonic motor.
  • An annular elastic body is used in this ultrasonic motor.
  • a plurality of piezoelectric elements are arranged side by side on the end face of the elastic body.
  • the elastic body is vibrated by driving the plurality of piezoelectric elements.
  • a traveling wave is generated in the elastic body.
  • the movable body is in contact with the elastic body.
  • the moving body is rotated by the traveling wave. Power is supplied to each piezoelectric element through wiring using a flexible printed circuit board.
  • the coefficient of thermal expansion differs between the piezoelectric body of the piezoelectric element, the flexible printed circuit board, and the elastic body.
  • the coefficient of thermal expansion of the piezoelectric body is around 7, for example, and the coefficient of thermal expansion of the elastic body is 15-30, for example.
  • the thermal expansion coefficient of the piezoelectric body is much smaller than that of the elastic body.
  • the coefficient of thermal expansion of the flexible printed circuit board is also smaller than that of the elastic body.
  • thermosetting resin or an ultraviolet curable resin is used for joining the piezoelectric element, the flexible printed circuit board and the elastic body. Also, in the case of using any of them, the temperature change is accompanied. In particular, when the piezoelectric element, the flexible printed circuit board, and the elastic body are cooled after bonding, the flexible printed circuit board contracts more than the elastic body and the piezoelectric element. Therefore, the elastic body tends to be distorted due to the tension of the flexible printed circuit board.
  • An object of the present invention is to provide an ultrasonic motor in which uneven wear of the stator and rotor can be suppressed and shortening of the service life is unlikely to occur.
  • FIG. 1 is a front cross-sectional view of an ultrasonic motor according to a first embodiment of the invention.
  • FIG. 2 is a schematic perspective view of a stator and flexible wiring in the first embodiment of the invention.
  • FIG. 3 is a schematic perspective view including a cross section of flexible wiring in the first embodiment of the present invention.
  • FIG. 4 is a schematic perspective view showing an enlarged part of the flexible wiring according to the first embodiment of the present invention.
  • FIG. 5 is a front sectional view of the first piezoelectric element in the first embodiment of the invention.
  • FIG. 6 is a bottom view showing bent portions of flexible wiring in the first modification of the first embodiment of the present invention.
  • FIG. 7 is a bottom view showing bent portions of flexible wiring in a second modification of the first embodiment of the present invention.
  • FIG. 8 is a bottom view of the stator according to the second embodiment of the invention.
  • FIG. 1 is a front cross-sectional view of an ultrasonic motor according to the first embodiment of the present invention.
  • FIG. 2 is a schematic perspective view of a stator and flexible wiring in the first embodiment.
  • FIGS. 1 and 2 the up and down directions are reversed for the sake of convenience. That is, FIG. 2 is a perspective view seen from below in FIG. Note that a coverlay, which will be described later, is omitted in FIG.
  • the ultrasonic motor 1 has a stator 2, a rotor 4, and a shaft member 10.
  • the stator 2 and rotor 4 are in contact.
  • a traveling wave generated in the stator 2 causes the rotor 4 to rotate.
  • the shaft member 10 rotates.
  • FIG. 1 is a schematic view, and in practice, a felt (not shown) or the like may be placed under the stator 2 in FIG.
  • a specific configuration of the ultrasonic motor 1 will be described below.
  • the stator 2 has a plate-like vibrating body 3.
  • the vibrating body 3 has an annular shape.
  • the vibrating body 3 has a first main surface 3a and a second main surface 3b.
  • the first main surface 3a and the second main surface 3b face each other.
  • the axial direction Z is a direction connecting the first main surface 3a and the second main surface 3b and along the rotation center axis.
  • the axial direction Z is parallel to the direction in which the shaft member 10 extends.
  • the shape of the vibrating body 3 is not limited to an annular shape.
  • the shape of the vibrating body 3 may be, for example, an annular shape other than a circular ring, or may be disc-shaped.
  • the shape of the outer peripheral edge of the vibrating body 3 when viewed from the axial direction Z may be, for example, a regular polygon such as a regular hexagon, a regular octagon, or a regular decagon.
  • a polygon includes cases where the vertices are curved and chamfered.
  • the vibrating body 3 is made of an appropriate metal. However, the vibrating body 3 does not necessarily have to be made of metal.
  • the vibrating body 3 may be composed of other elastic bodies such as ceramics, silicon material, or synthetic resin, for example.
  • viewing from the axial direction Z side may be referred to as plan view or bottom view.
  • the plan view means viewing from a direction corresponding to the upper side in FIG. 1
  • the bottom view means viewing from a direction corresponding to the lower side.
  • viewing from the second main surface 3b side of the vibrating body 3 to the first main surface 3a side is a plan view
  • viewing from the first main surface 3a side to the second main surface 3b side is a bottom view. It is sight.
  • the plurality of piezoelectric elements 13 are distributed in the circumferential direction. More specifically, the plurality of piezoelectric elements 13 are dispersed along the circulating direction of the traveling wave so as to generate a traveling wave circulating around an axis parallel to the axial direction Z. As shown in FIG. A structure in which a plurality of piezoelectric elements 13 are arranged in a distributed manner in the stator 2 and driven to generate a traveling wave is disclosed, for example, in International Publication No. 2010/061508. Therefore, a detailed description of the generation of traveling waves is omitted.
  • a flexible wiring 5 is provided on the first main surface 3 a of the vibrating body 3 .
  • the flexible wiring 5 is electrically connected to the plurality of piezoelectric elements 13 .
  • the flexible wiring 5 extends along the route A. More specifically, the path A is a path that connects the piezoelectric elements 13 that are adjacent in the winding direction. In this embodiment, path A is circular.
  • the shape of the path A is not limited to a circular shape, and may be substantially the same as or substantially similar to any one of the flexible wiring 5, vibrating body 3, and stator 2.
  • the path A may be, for example, a shape in which curved lines are connected to each other, or may be a polygon.
  • the path A may be a straight line connecting the plurality of piezoelectric elements 13, or may be a line connecting the center or the center of gravity of the flexible wiring 5 in plan view.
  • the flexible wiring 5 is annular.
  • the flexible wiring 5 may have a lead portion extending to be connected to the outside.
  • another wiring may be provided for connecting the flexible wiring 5 to the outside.
  • FIG. 3 is a schematic perspective view including a cross section of the flexible wiring in the first embodiment.
  • FIG. 4 is a schematic perspective view showing an enlarged part of the flexible wiring in the first embodiment.
  • the flexible wiring 5 has a base material layer 6A, a first wiring pattern 7A and a second wiring pattern 7B, and a coverlay 6B.
  • a first wiring pattern 7A and a second wiring pattern 7B are provided between the base layer 6A and the coverlay 6B.
  • the base material layer 6A and the coverlay 6B are schematically illustrated with a space therebetween.
  • the coverlay 6B is provided on the base material layer 6A without being separated by a space. More specifically, the coverlay 6B is provided on the base material layer 6A so as to cover the first wiring pattern 7A and the second wiring pattern 7B.
  • an opening is provided in the portion of the base layer 6A above the piezoelectric element 13.
  • the first wiring pattern 7A or the second wiring pattern 7B is connected to the piezoelectric element 13 in the opening.
  • the first wiring pattern 7A and the second wiring pattern 7B transmit signals of different phases.
  • a metal such as copper, for example, can be used for the first wiring pattern 7A and the second wiring pattern 7B.
  • a resin such as polyimide, for example, can be used for the base material layer 6A and the coverlay 6B.
  • the flexible wiring 5 has a plurality of bent portions 5A.
  • the bent portion 5A is bent so as to return to the route A after deviating from the route A.
  • the base layer 6A has a pair of first corners 6a at the bent portion 5A.
  • the base material layer 6A is bent so as to deviate from the path A at any of the first corner portions 6a.
  • a notch 6c is provided between the pair of first corners 6a.
  • the base layer 6A has a second corner portion 6b.
  • the base material layer 6A is bent to return to the path A at the second corner portion 6b.
  • 6 A of base materials layers are comprised so that it may reach the other 1st corner part 6a via the 2nd corner part 6b from the 1st corner part 6a of one side in 5A of bending parts.
  • the coverlay 6B also has a pair of first and second corners and a notch.
  • the first wiring pattern 7A and the second wiring pattern 7B are also bent along the base layer 6A at the bent portion 5A.
  • the flexible wiring 5 should just have at least 1 bending part 5A.
  • FIG. 5 is a front sectional view of the first piezoelectric element in the first embodiment.
  • the first electrode 15A is attached to the first main surface 3a of the vibrating body 3 with an adhesive.
  • the thickness of this adhesive is very thin. Therefore, the first electrode 15A is electrically connected to the vibrating body 3.
  • the adhesive for example, a thermosetting resin or an ultraviolet curable resin is used.
  • the rotor 4 is in contact with the second main surface 3b of the vibrating body 3.
  • the rotor 4 is disc-shaped.
  • a through hole 4 c is provided in the central portion of the rotor 4 .
  • the through hole 4c may be located in a region including the center in the axial direction.
  • the shape of the rotor 4 is not limited to the above.
  • the shape of the rotor 4 may be, for example, a regular polygon such as a regular hexagon, a regular octagon, or a regular decagon in plan view.
  • a feature of this embodiment is that the flexible wiring 5 has at least one bent portion 5A. As a result, uneven wear of the stator 2 and the rotor 4 can be suppressed, and shortening of the life of the ultrasonic motor 1 is unlikely to occur. This is explained below.
  • the coefficient of thermal expansion of the flexible wiring 5 is described as the coefficient of thermal expansion of the base layer 6A and the coverlay 6B.
  • the thermal expansion coefficient of the flexible wiring 5 is larger than the thermal expansion coefficients of the piezoelectric body 14 and the vibrating body 3 . Therefore, the flexible wiring 5 expands or contracts relatively greatly when the temperature changes.
  • the flexible wiring 5 has a bent portion 5A.
  • the tension applied to the plurality of piezoelectric elements 13 and the vibrating body 3 is absorbed in the bent portion 5A.
  • distortion of the vibrating body 3 can be suppressed. Therefore, uneven wear of the stator 2 and the rotor 4 can be suppressed, and shortening of the life of the ultrasonic motor 1 is unlikely to occur.
  • the ultrasonic motor 1 has a first case member 8 and a second case member 9.
  • the second case member 9 is cap-shaped, and the first case member 8 is lid-shaped.
  • a case is constituted by the first case member 8 and the second case member 9 .
  • a spring member 16, a rotor 4 and a stator 2 are arranged inside the case.
  • the second case member 9 has a cylindrical projecting portion 9a.
  • the cylindrical protrusion 9a protrudes outside the case.
  • a through hole 9c is provided in the cylindrical projecting portion 9a.
  • a second bearing portion 19 is provided in the through hole 9c.
  • the shaft member 10 is inserted through the through hole 9 c and the second bearing portion 19 .
  • the shaft member 10 protrudes from the through hole 9c of the second case member 9 to the outside of the case.
  • the configuration of the second case member 9 is not limited to the above.
  • sliding bearings or bearings may be used for the first bearing portion 18 and the second bearing portion 19 .
  • the rotor 4 has a pair of recesses 4a and side walls 4b.
  • the recess 4a is circular in plan view.
  • the side wall portion 4b is a portion surrounding both recesses 4a.
  • One recess 4a is located on the stator 2 side.
  • the other recessed portion 4a is positioned on the second bearing portion 19 side.
  • the rotor 4 is in contact with the stator 2 at the end face 4d of the side wall portion 4b.
  • the concave portion 4a and the side wall portion 4b may not be provided.
  • the rotor 4 and the shaft member 10 are configured separately.
  • the rotor 4 and the shaft member 10 may be integrally configured.
  • the vibrating body 33 is disc-shaped.
  • a through hole 33 c is provided in the center of the vibrating body 33 .
  • a shaft member 10 similar to that of the first embodiment shown in FIG. 1 is inserted through the through hole 33c.
  • four piezoelectric elements 13 are provided on the first main surface 33a of the vibrating body 33.
  • the shape of path B is square.
  • the flexible wiring 35 has three bent portions 35A. Bent portions 35A are positioned at three of four inter-piezoelectric element portions 33d on the first main surface 33a of the vibrating body 33, respectively.
  • the lead-out portion 35B is positioned in one inter-piezoelectric element portion 33d.
  • the lead-out portion 35B is a portion connected to the outside, and is a portion connected to the start point or the end point of the flexible wiring 35 on the vibrating body 33. As shown in FIG. Therefore, the lead-out portion 35B is different from the bent portion 35A that returns to the path B after deviating from the path B.
  • bent portion 35A is provided as described above, it is possible to suppress the distortion of the vibrating body 33 in the same manner as in the first embodiment. Therefore, uneven wear of the stator 32 and the rotor can be suppressed, and shortening of the life of the ultrasonic motor is unlikely to occur.

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  • General Electrical Machinery Utilizing Piezoelectricity, Electrostriction Or Magnetostriction (AREA)

Abstract

Est prévu un moteur à ultrasons qui est apte à empêcher un stator et un rotor de s'user différemment et dans lequel la réduction de durée de vie a à peine lieu.　Le moteur à ultrasons selon la présente invention comprend : un stator 2 possédant un corps vibrant en forme de plaque 3 et une pluralité d'éléments piézoélectriques 13, ledit corps vibrant 3 comprenant une première surface principale 3a et une seconde surface principale 3b qui se font face, ladite pluralité d'éléments piézoélectriques 13 étant disposée sur la première surface principale 3a du corps vibrant 3 et disposée de manière distribuée dans une direction orbitale sur une vue en plan ; un fil flexible 5 disposé sur la première surface principale 3a du corps vibrant 3 et connecté à la pluralité d'éléments piézoélectriques 13 en s'étendant le long d'un itinéraire A qui relie les éléments piézoélectriques 13 adjacents les uns aux autres dans la direction orbitale ; et un rotor qui est en contact avec la seconde surface principale 3b du corps vibrant 3. Le fil flexible 5 possède au moins une partie courbée 5A qui se courbe de façon à s'écarter de l'itinéraire A puis à revenir à l'itinéraire A lorsqu'il est vu dans la direction orbitale.
PCT/JP2022/037656 2022-02-21 2022-10-07 Moteur à ultrasons WO2023157372A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022024492 2022-02-21
JP2022-024492 2022-02-21

Publications (1)

Publication Number Publication Date
WO2023157372A1 true WO2023157372A1 (fr) 2023-08-24

Family

ID=87577904

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2022/037656 WO2023157372A1 (fr) 2022-02-21 2022-10-07 Moteur à ultrasons

Country Status (1)

Country Link
WO (1) WO2023157372A1 (fr)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11187677A (ja) * 1997-12-19 1999-07-09 Canon Inc 振動装置、振動型駆動装置およびこれを用いた装置
JP2006269721A (ja) * 2005-03-24 2006-10-05 Yamaha Corp 熱電モジュール及びその製造方法

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11187677A (ja) * 1997-12-19 1999-07-09 Canon Inc 振動装置、振動型駆動装置およびこれを用いた装置
JP2006269721A (ja) * 2005-03-24 2006-10-05 Yamaha Corp 熱電モジュール及びその製造方法

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