JPH04145871A - Ultrasonic motor - Google Patents
Ultrasonic motorInfo
- Publication number
- JPH04145871A JPH04145871A JP2262986A JP26298690A JPH04145871A JP H04145871 A JPH04145871 A JP H04145871A JP 2262986 A JP2262986 A JP 2262986A JP 26298690 A JP26298690 A JP 26298690A JP H04145871 A JPH04145871 A JP H04145871A
- Authority
- JP
- Japan
- Prior art keywords
- ultrasonic motor
- piezoelectric
- torsional
- vibrator
- vibration
- Prior art date
- Legal status (The legal status 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 status listed.)
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- General Electrical Machinery Utilizing Piezoelectricity, Electrostriction Or Magnetostriction (AREA)
Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明はＯＡ機器や玩具などに用いられる小型モータに
関し、特にローター直径の小さい小型の超音波モータに
関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a small motor used in office automation equipment, toys, etc., and particularly relates to a small ultrasonic motor with a small rotor diameter.
（従来の技術） 超音波モータは従来の電磁モータと比較して。(Conventional technology) Ultrasonic motor is compared with traditional electromagnetic motor.
低回転で高いトルクが得られること、停止保持力を有す
ること、電磁ノイズが小さいことなどの特徴を有してお
り、カメラのオートフォーカス用や自動重用パワーモー
タなどに使用されている。第４図は従来の超音波モータ
の構造例を示す概略図である。この例において、圧電捩
り振動子５１と圧電縦振動子５２を含む縦−捩り複合振
動子５３を一方の端部に設けられた軸５６に回転自在に
支持されたローター５４を圧接して構成している。It has the characteristics of being able to obtain high torque at low rotation speeds, having stopping power, and having low electromagnetic noise, and is used for camera autofocus and automatic heavy duty power motors. FIG. 4 is a schematic diagram showing an example of the structure of a conventional ultrasonic motor. In this example, a vertical-torsion composite vibrator 53 including a piezoelectric torsional vibrator 51 and a piezoelectric longitudinal vibrator 52 is configured by pressing a rotor 54 rotatably supported on a shaft 56 provided at one end. ing.
第５図は従来の縦−捩り型超音波モータに用いられてい
る圧電捩り振動子５１の構造を示す斜視図である。この
例において１弦の方向に分極された複数個の扇形の圧電
セラミック板５５が円板あるいは円環状に、矢印で示さ
れる各々の分極の向きか閉しるように端面を合わせて接
合されている。FIG. 5 is a perspective view showing the structure of a piezoelectric torsional vibrator 51 used in a conventional vertical-torsional ultrasonic motor. In this example, a plurality of fan-shaped piezoelectric ceramic plates 55 polarized in the direction of one chord are joined together in a disc or annular shape with their end faces aligned in the direction of polarization shown by the arrow. There is.
第６図（ａ） 、 （ｂ）は第４図の縦−捩り型超音波
モタの動作原理の説明図である。これらの図において、
縦−捩り複合振動子５３の長さを横軸とした円周方向の
捩り変位と長さ方向の伸縮変位の状態か夫々示されてい
る。各々の変位の向きは第６図（ａ）に示されるように
、捩り変位においては。FIGS. 6(a) and 6(b) are explanatory diagrams of the operating principle of the vertical-torsion type ultrasonic motor of FIG. 4. In these figures,
The states of torsional displacement in the circumferential direction and expansion/contraction displacement in the longitudinal direction with the length of the longitudinal-torsional composite vibrator 53 as the horizontal axis are shown, respectively. The direction of each displacement is as shown in FIG. 6(a) in the case of torsional displacement.
圧電縦−捩り振動子の一端が右回りとなると他端はその
逆の左回りとなり、その変位の大きさは。When one end of the piezoelectric longitudinal-torsional vibrator rotates clockwise, the other end rotates counterclockwise, and the magnitude of the displacement is:
振動の中心から離れるに従って大きくなる。It increases as you move away from the center of vibration.
一方、第６図（ｂ）中に示すように、長さ方向の伸び変
位は、中心から一定で、さらに離れるに従って次第に大
きくなる。On the other hand, as shown in FIG. 6(b), the elongation displacement in the longitudinal direction is constant from the center and gradually increases as the distance from the center increases.
（発明が解決しようとする課題）
第５図かられかるように従来の圧電捩り振動子５１は、
扇形の圧電セラミック板５５をその端面を合わせて複数
個接着して構成しているため１組立工程が複雑になる上
に接着による特性のばらつきが大きいという欠点がある
。また、一般に円筒を含む円柱状の振動子においては、
捩り振動の共振周波数と縦振動の共振周波数が一致しな
いため。(Problems to be Solved by the Invention) As can be seen from FIG. 5, the conventional piezoelectric torsional vibrator 51 has
Since a plurality of fan-shaped piezoelectric ceramic plates 55 are bonded together with their end surfaces aligned, one assembly process is complicated and there is a large variation in characteristics due to bonding. In general, in a cylindrical vibrator including a cylinder,
This is because the resonant frequency of torsional vibration and the resonant frequency of longitudinal vibration do not match.
捩り振動の共振周波数で駆動し、縦振動は非共振の状態
で駆動されることになる。従って、縦振動の振動振幅が
小さくなり超音波モータのトルクを大きくすることが難
しいという欠点がある。It is driven at the resonant frequency of torsional vibration, and the longitudinal vibration is driven in a non-resonant state. Therefore, there is a drawback that the vibration amplitude of the longitudinal vibration becomes small and it is difficult to increase the torque of the ultrasonic motor.
そこで１本発明の技術的課題はローターの直径を小さく
した小型で、特性が一定しており、且つトルクの大きい
超音波モータを提供することにある。Therefore, one technical problem of the present invention is to provide a small ultrasonic motor with a small rotor diameter, constant characteristics, and large torque.
また１本発明の別の技術的課題は構成部品の少なく、製
造が容易で製造コストが低く、安価な超音波モータを提
供することにある。Another technical object of the present invention is to provide an inexpensive ultrasonic motor that has fewer components, is easy to manufacture, and has low manufacturing costs.
（課題を解決するための手段）
本発明によれば、圧電セラミック中空円柱の外周面の長
さ方向と４５°の方向に交差指電極を形成し、該交差指
電極を用いて分極及び駆動を行い。(Means for Solving the Problems) According to the present invention, interdigital electrodes are formed in a direction 45° to the length direction of the outer peripheral surface of a piezoelectric ceramic hollow cylinder, and polarization and driving are performed using the interdigital electrodes. conduct.
前記中空円柱に捩り振動を励振可能とし、前記圧電セラ
ミック中空円柱捩り振動子側端部を圧電積層アクチュエ
ータに固定し、前記捩り振動子のもう一方の端部に回転
自在に支持されたローターを圧接して構成したことを特
徴とする超音波モータが得られる。A torsional vibration can be excited in the hollow cylinder, a side end of the piezoelectric ceramic hollow cylinder torsion vibrator is fixed to a piezoelectric laminated actuator, and a rotatably supported rotor is pressure-welded to the other end of the torsion vibrator. An ultrasonic motor characterized by having the following configuration is obtained.
（作 用）
本発明においては、捩り振動子の一端面と、圧電アクチ
ュエータの一端面とが接合されている。(Function) In the present invention, one end surface of the torsional vibrator and one end surface of the piezoelectric actuator are joined.
圧電積層アクチュエータは軸方向に伸縮振動を行う。捩
り振動子は周方向に捩り振動を行う。The piezoelectric laminated actuator performs expansion and contraction vibration in the axial direction. The torsional vibrator performs torsional vibration in the circumferential direction.
圧電積層アクチュエータと捩り振動子との共振周波数を
一致させることで、捩り振動の他端に圧接されたロータ
は予め定められた軸回りに回転する。By matching the resonance frequencies of the piezoelectric laminated actuator and the torsional vibrator, the rotor, which is pressed against the other end of the torsional vibration, rotates around a predetermined axis.
（実施例）
以下本発明の超音波モータについて図面を用いて詳しく
説明する。(Example) The ultrasonic motor of the present invention will be described in detail below with reference to the drawings.
第１図は本発明の縦−捩り型超音波モータの一構成例を
示す斜視図である。この例において、超音波モータ１は
圧電セラミック中空円柱の捩り振動子−７の一端部を圧
電積層アクチュエータ９の一端面に固定し１回転自在に
支持されたローター１０を前記捩り振動子７のもう一方
の端面に圧接して構成されている。FIG. 1 is a perspective view showing an example of the configuration of a vertical-torsion type ultrasonic motor according to the present invention. In this example, an ultrasonic motor 1 has one end of a piezoelectric ceramic hollow cylindrical torsional oscillator 7 fixed to one end surface of a piezoelectric laminated actuator 9, and a rotor 10 supported so as to be able to rotate once. It is configured to be in pressure contact with one end surface.
第２図は第１図の超音波モータに用いられる圧電捩り振
動子７の構造例を示す概略図である。この例において、
プレス成形された圧電セラミック中空円柱の外周面の長
さ方向と４５°の方向に延在するように導電ペーストを
印刷することにより指電極６ａ、６ｂが形成され、さら
にこれらの指電極６ａ、６ｂを一つおきに互いに反対の
端部を共通電極６ｃ、６ｄに接続して交差指電極６が形
成され二端子とされてる。この交差指電極６を用いて分
極処理を施すと分極方向は交差指電極の各指電極６ａ、
６ｂの長さ方向と直角な方向となる。FIG. 2 is a schematic diagram showing an example of the structure of the piezoelectric torsional vibrator 7 used in the ultrasonic motor shown in FIG. In this example,
Finger electrodes 6a, 6b are formed by printing a conductive paste so as to extend in a direction 45 degrees from the length direction of the outer circumferential surface of a press-molded piezoelectric ceramic hollow cylinder, and these finger electrodes 6a, 6b are The opposite ends of every other electrode are connected to the common electrodes 6c and 6d to form interdigital electrodes 6 to form two terminals. When polarization processing is performed using this interdigital electrode 6, the polarization direction is changed to each finger electrode 6a of the interdigital electrode,
The direction is perpendicular to the length direction of 6b.
この状態で前記交差指電極６に共通電極６ｃ。In this state, the common electrode 6c is attached to the interdigital electrode 6.
６ｄから交流電圧を印加すると、電圧の極性が分極時の
電圧の極性と同じ場合は分極の方向の伸び歪が発生し、
電圧の極性が分極時の極性と逆の場合は分極の方向に縮
み歪が発生する。分極方向に伸びあるいは縮み歪が発生
した場合１分極方向と直角な方向にはこれらと反対に縮
みあるいは伸び歪が発生する。以上の結果として前記圧
電セラミック中空円柱８に捩り変位が発生する。When an AC voltage is applied from 6d, if the polarity of the voltage is the same as the polarity of the voltage at the time of polarization, an elongation strain will occur in the direction of polarization.
If the polarity of the voltage is opposite to the polarity during polarization, shrinkage distortion occurs in the direction of polarization. When an elongation or contraction strain occurs in the polarization direction, an opposite contraction or expansion strain occurs in a direction perpendicular to the polarization direction. As a result of the above, torsional displacement occurs in the piezoelectric ceramic hollow cylinder 8.
また、第３図は第１図の超音波モータに用いられる圧電
積層アクチュエータ９の概略図である。Moreover, FIG. 3 is a schematic diagram of the piezoelectric laminated actuator 9 used in the ultrasonic motor of FIG. 1.
この場合１時定数の関係上振動子の静電容量は予め小さ
く設計しである。この圧電積層アクチュエタ９には予め
長さ方向に分極処理が施しである。In this case, the capacitance of the vibrator is designed to be small in advance due to the time constant. This piezoelectric laminated actuator 9 has been subjected to polarization treatment in the length direction in advance.
この状態で前記圧電積層アクチュエータ９に直流電圧を
印加すると、駆動電圧の極性が分極時の極性と一致し１
分極の方向に伸び歪が発生する。以上の結果として前記
圧電積層アクチュエータ９に白抜きの矢印５で示すよう
な縦変位が発生する。When a DC voltage is applied to the piezoelectric laminated actuator 9 in this state, the polarity of the drive voltage matches the polarity at the time of polarization.
Elongation strain occurs in the direction of polarization. As a result of the above, a vertical displacement as shown by the white arrow 5 occurs in the piezoelectric laminated actuator 9.
第１図に戻って、超音波モータ１の圧電セラミック中空
円柱に捩り振動の変位と同期して縦振動か励振されると
、ローター１０は捩り変位の方向に回転する。この場合
の回転数及びトルクは駆動周波数が一定の場合、圧電捩
り振動子による捩り振動及び圧電積層アクチュエータに
よる縦振動の振動振幅の大きさによって定まる。Returning to FIG. 1, when longitudinal vibration is excited in the piezoelectric ceramic hollow cylinder of the ultrasonic motor 1 in synchronization with the displacement of torsional vibration, the rotor 10 rotates in the direction of the torsional displacement. When the drive frequency is constant, the rotational speed and torque in this case are determined by the vibration amplitudes of torsional vibration caused by the piezoelectric torsional vibrator and longitudinal vibration caused by the piezoelectric laminated actuator.
本発明の実施例に係る超音波モータにおいては。In an ultrasonic motor according to an embodiment of the present invention.
圧電積層アクチュエ−９を用いており、低電圧で大きな
縦振幅を得ることが出来る。また、前記捩り振動子７は
形状が薄肉パ１イブ状であるのに対して前記積層アクチ
ュエータの形状は円柱状あるいは角柱状であるので単位
長さ当りの質量が１桁程度大きいため、前記捩り振動子
は前記圧電積層アクチュエータをベースに片側固定型の
振動を行う。A piezoelectric laminated actuator 9 is used, and a large longitudinal amplitude can be obtained with low voltage. Furthermore, while the torsional vibrator 7 has a thin tube-like shape, the laminated actuator has a cylindrical or prismatic shape, so the mass per unit length is about an order of magnitude larger. The vibrator performs one-sided fixed vibration based on the piezoelectric laminated actuator.
従って、捩り振動子７の捩り振動の振動振幅と圧電積層
アクチュエータ９の縦振動の振動振幅を共に大きくする
ことが可能となる。この時の駆動電圧の周波数は捩り振
動の共振周波数に合わせてあり、前記圧電積層アクチュ
エータ９の駆動電圧の周波数は、この周波数に合わせて
あり、それぞれの駆動電圧の位相は９０°である。また
、捩り振動子の端面に圧接されるローター１０の回転方
向は捩り振動駆動電圧と縦振動駆動電圧の位相の何れか
を一方を１８０°変化させることにより可能である。Therefore, it is possible to increase both the vibration amplitude of the torsional vibration of the torsional vibrator 7 and the vibration amplitude of the longitudinal vibration of the piezoelectric laminated actuator 9. The frequency of the drive voltage at this time is matched to the resonance frequency of torsional vibration, the frequency of the drive voltage of the piezoelectric laminated actuator 9 is matched to this frequency, and the phase of each drive voltage is 90°. Further, the rotational direction of the rotor 10 that is pressed against the end face of the torsional vibrator can be changed by changing the phase of either the torsional vibration drive voltage or the longitudinal vibration drive voltage by 180 degrees.
（発明の効果）
以上説明したように本発明の超音波モータにおいては、
駆動力を発生させるための圧電捩り振動子の形状が単純
で１通常一般的に適用されているプレス成形技術に：よ
り容易に製造することが可能：１
な圧電セラミック中空円柱を用いて、この外周面にこれ
も一般的な技術である電極印刷を施すことにより圧電捩
り振動子が得られるため、製造が容易で複雑な加工工程
による特性のばらつきの少ない超音波モータか得られる
。(Effects of the Invention) As explained above, in the ultrasonic motor of the present invention,
The shape of the piezoelectric torsional vibrator for generating the driving force is simple and can be manufactured more easily than the commonly used press molding technology. Since a piezoelectric torsional vibrator is obtained by printing electrodes on the outer circumferential surface, which is also a common technique, an ultrasonic motor that is easy to manufacture and has less variation in characteristics due to complicated processing steps can be obtained.
更に９本発明の超音波モータにおいては、縦振動を得る
ために圧電積層アクチュエータを用いており、低電圧で
大きな縦振幅を得ることか出来る。Furthermore, in the ultrasonic motor of the present invention, a piezoelectric laminated actuator is used to obtain longitudinal vibration, and a large longitudinal amplitude can be obtained with a low voltage.
従って、トルクが大きく小径で小型の超音波モータが得
られる。Therefore, a compact ultrasonic motor with large torque and small diameter can be obtained.
第１図は本発明の超音波モータの一構成例を示す斜視図
、第２図は第１図の超音波モータに用いられる圧電捩り
振動子の構造を示す概略図、第３図は第１図の超音波モ
ータに用いられる圧電積層アクチュエータ９の概略図、
第４図は従来の超音波モータの一構造例を示す斜視図、
第５図は第４図の超音波モータに用いられる圧電捩り振
動子５の構造を示す斜視図、第６図は縦−捩り型超音波
モータの動作原理の説明図である。
図中、１は超音波モータ、５は縦振動の方向を示す矢印
、６は交差指電極、７は圧電捩り振動子。
９は圧電積層アクチュエータ、１０はロータ。
５１は圧電捩り振動子、５２は圧電縦振動子。
５３は超音波モータ、５４はロータ、５６は軸。
范３図
第４図FIG. 1 is a perspective view showing an example of the configuration of the ultrasonic motor of the present invention, FIG. 2 is a schematic diagram showing the structure of a piezoelectric torsional vibrator used in the ultrasonic motor of FIG. A schematic diagram of a piezoelectric laminated actuator 9 used in the ultrasonic motor shown in the figure,
FIG. 4 is a perspective view showing an example of the structure of a conventional ultrasonic motor.
FIG. 5 is a perspective view showing the structure of the piezoelectric torsional vibrator 5 used in the ultrasonic motor of FIG. 4, and FIG. 6 is an explanatory diagram of the operating principle of the vertical-torsion type ultrasonic motor. In the figure, 1 is an ultrasonic motor, 5 is an arrow indicating the direction of longitudinal vibration, 6 is an interdigital electrode, and 7 is a piezoelectric torsional vibrator. 9 is a piezoelectric laminated actuator, and 10 is a rotor. 51 is a piezoelectric torsional vibrator, and 52 is a piezoelectric longitudinal vibrator. 53 is an ultrasonic motor, 54 is a rotor, and 56 is a shaft. Fan 3 Figure 4
Claims (1)
５゜の方向に交差指電極を形成し，該交差指電極を用い
て分極及び駆動を行い，前記中空円柱に捩り振動を励振
可能とし，前記圧電セラミック中空円柱捩り振動子の一
側端部を圧電積層アクチュエータに固定し，前記捩り振
動子のもう一方の端部に回転自在に支持されたローター
を圧接して構成したことを特徴とする超音波モータ。1. The length direction of the outer peripheral surface of the piezoelectric ceramic hollow cylinder and 4
Interdigital electrodes are formed in the 5° direction, and polarization and driving are performed using the interdigital electrodes to enable torsional vibration to be excited in the hollow cylinder, and one end of the piezoelectric ceramic hollow cylinder torsional vibrator is 1. An ultrasonic motor comprising a rotor fixed to a piezoelectric laminated actuator and rotatably supported at the other end of the torsional vibrator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2262986A JP2995665B2 (en) | 1990-10-02 | 1990-10-02 | Ultrasonic motor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2262986A JP2995665B2 (en) | 1990-10-02 | 1990-10-02 | Ultrasonic motor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04145871A true JPH04145871A (en) | 1992-05-19 |
| JP2995665B2 JP2995665B2 (en) | 1999-12-27 |
Family
ID=17383312
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2262986A Expired - Fee Related JP2995665B2 (en) | 1990-10-02 | 1990-10-02 | Ultrasonic motor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2995665B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20170054385A1 (en) * | 2015-08-19 | 2017-02-23 | Lawrence Livermore National Security, Llc | Electrostatic generator/motor rotor electrode system suitable for installation on the outer surface of an emb rotor |
-
1990
- 1990-10-02 JP JP2262986A patent/JP2995665B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20170054385A1 (en) * | 2015-08-19 | 2017-02-23 | Lawrence Livermore National Security, Llc | Electrostatic generator/motor rotor electrode system suitable for installation on the outer surface of an emb rotor |
| WO2017030797A1 (en) * | 2015-08-19 | 2017-02-23 | Lawrence Livermore National Security, Llc | Electrostatic generator/motor rotor electrode system suitable for installation on the outer surface of an emb rotor |
| US10312830B2 (en) | 2015-08-19 | 2019-06-04 | Lawrence Livermore National Security, Llc | Electrostatic generator/motor rotor electrode system suitable for installation on the outer surface of an EMB rotor |
| US10727763B2 (en) | 2015-08-19 | 2020-07-28 | Lawrence Livermore National Security, Llc | Method using a electrostatic generator/motor rotor electrode system suitable for installation on the outer surface of an EMB rotor |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2995665B2 (en) | 1999-12-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |