JPS63181677A - Centroid rotary type ultrasonic motor - Google Patents

Abstract

PURPOSE:To rotate a press-bonded rotor through a static frictional force by securing the center of a centroid rotary vibrator to eccentrically rotate its centroid. CONSTITUTION:In a centroid rotary type ultrasonic motor, a piezoelectric ceramic disk 1 is polarized along a thicknesswise direction 9, front and rear surface electrodes are equally divided quadrantly, the front and rear surface opposite electrodes are short-circuited, a sine wave voltage is then applied. An urethane spring 8 is engaged with the central hole of the disk 1, a cap bolt 7 is penetrated through the center, and a supporting plate is clamped. A predetermined frequency voltage is applied to the disk 1 to generate a resonant state, and the outer periphery of the disk 1 is deformed as designated by broken lines 15, 16. As a result, the centroid of the disk 1 is moved out of a center 17 to a point 18 to sequentially move (the centroid rotates), thereby rotating a rotor 2.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は超音波モータに係わり、さらに詳しくはその動
作原理の改良に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ultrasonic motor, and more particularly to an improvement in its operating principle.

〔従来の技術〕[Conventional technology]

本発明者は、超音波楕円振動をするステータに圧着され
たロータが摩擦力を介して受ける回転トルクを利用した
モータを種々開発して来た。摩擦力を介してトルクを伝
達するため、ステータ／ロータ間の圧着面の摩耗が問題
となり、静止摩擦を利用する方法で解決して来た。しか
し、このためには超音波振動によってロータが受ける浮
力を利用せねばならず、製造するにも、運転するにも高
度の技術を要した。その根本原因は、超音波楕円振動子
は実質的には回転していないという欠点にあった。なお
超音波楕円振動子は薄く構成できないので、モータも厚
くなり薄型化できないという欠点があった。The present inventor has developed various motors that utilize rotational torque received through frictional force by a rotor that is pressed against a stator that generates ultrasonic elliptical vibration. Since torque is transmitted through frictional force, wear of the crimp surface between the stator and rotor becomes a problem, which has been solved by methods that utilize static friction. However, this required the use of the buoyant force exerted on the rotor by ultrasonic vibrations, which required sophisticated technology to manufacture and operate. The root cause of this is that the ultrasonic elliptical transducer does not substantially rotate. It should be noted that since the ultrasonic elliptical vibrator cannot be made thin, the motor also becomes thick and cannot be made thin.

さらに超音波モータのトルク及び出力はステータの振動
に伴う運動量ｍｖに依って決まるが、従来の超音波モー
タはステータの実効運動には全質量の何分の−しか関与
しない。これはステータに発生する振動が振幅分布を持
っためであり、通常全質量のＩ／π又はＩ／４程度であ
る。このようにステータの振動に伴う運動が１００％利
用できず、したがってトルクも出力もｌ／πあるいは１
八になってしまうという欠点があった。Furthermore, the torque and output of an ultrasonic motor are determined by the momentum mv associated with the vibration of the stator, but in conventional ultrasonic motors, only a fraction of the total mass is involved in the effective movement of the stator. This is because the vibrations generated in the stator have an amplitude distribution, which is usually about I/π or I/4 of the total mass. In this way, the motion accompanying the stator vibration cannot be used 100%, and therefore the torque and output are limited to l/π or 1.
There was a drawback that it ended up being eight.

〔発明が解決しようとする問題点〕[Problem that the invention seeks to solve]

この発明は、上記従来の超音波モータが持っていた回転
しないステータに圧着されたロータだけを回転させねば
ならぬという欠点と、さらに、ステータを構成する超音
波楕円振動子は構造上厚くなってしまい、従ってモータ
が薄型化できないという欠点を解決し、実効的な回転運
動をする重心回転振動子という薄型が可能なステータを
用い、動作の安定性、寿命の優れた使い易く特性の優し
た薄型が可能なモータの提供を目的とする。This invention overcomes the drawbacks of the above-mentioned conventional ultrasonic motor in that only the rotor, which is crimped to the non-rotating stator, must be rotated, and furthermore, the ultrasonic elliptical vibrator that constitutes the stator is thick due to its structure. This solves the drawback that the motor cannot be made thinner, and uses a stator that can be made thinner, such as a center-of-gravity rotating oscillator that performs effective rotational motion, and has a thinner design that is easy to use and has excellent characteristics with excellent operational stability and longevity. The purpose is to provide a motor that is capable of

〔問題点を解決するための手段〕[Means for solving problems]

本発明は、重心が回転運動をする重心回転振動子をステ
ータとし、フラフープあるいはハーモニックドライブの
原理を利用した超音波モータである。超音波モータには
振動片型、進行波型、定在波型などがあるが、これらは
いづれも振動を回転運動に変えたモータであり、ステー
タの重心は動かない。これに反し、本発明の重心回転振
動子は、中心が固定されているにもかかわらず重心が偏
心回転をするので、このステータの偏心回転トルクを、
圧着されているロータに静止摩擦力を介して伝達する動
作原理にもとづいて回転する超音波モータを提案するも
のである。The present invention is an ultrasonic motor that uses a center-of-gravity rotating vibrator as a stator and utilizes the principle of hula hoop or harmonic drive. There are three types of ultrasonic motors: a vibrating piece type, a traveling wave type, and a standing wave type, but all of these are motors that convert vibration into rotational motion, and the center of gravity of the stator does not move. On the other hand, in the center-of-gravity rotation vibrator of the present invention, the center of gravity rotates eccentrically even though the center is fixed, so the eccentric rotation torque of the stator is
The present invention proposes an ultrasonic motor that rotates based on the operating principle of transmitting static friction force to a rotor that is crimped.

本発明の超音波モータでは重心の移動を利用しており、
したがってステータの全質量がモータのトルク及び出力
を作り出すのに利用されトルクも出力も極めて大きい理
想的モータである。The ultrasonic motor of the present invention utilizes the movement of the center of gravity,
Therefore, the entire mass of the stator is used to create the torque and output of the motor, making it an ideal motor with extremely large torque and output.

超音波振動を回転運動に変える原理を創造するのにフラ
フープを原点としたのは本発明者に限らず、例えば日経
メカニカル１９８６．１２．１号９６頁に紹介されてい
る。このものは同じフラフープを原点としながら進行波
型モータを開発し、本発明者は重心回転振動子及びこれ
を用いた超音波モータを開発した。両者が開発した超音
波モータが全く異なる物になったことば興味深い。両者
の差異は進行波型は重心が１すＪかないモータであり、
本発明のモータは重心が回転運動をすることからも明ら
かである。重心の移動を利用するとトルクも出力も極め
て大きくなることは前述した通りである。The inventor is not the only one who used the hula hoop as a starting point for creating the principle of converting ultrasonic vibrations into rotational motion; for example, the invention is introduced in Nikkei Mechanical, December 1, 1986, page 96. This device developed a traveling wave motor using the same hula hoop as its origin, and the present inventor developed a center-of-gravity rotating vibrator and an ultrasonic motor using the same. It is interesting to hear that the ultrasonic motors developed by both parties are completely different. The difference between the two is that the traveling wave type motor has a center of gravity of only 1 J.
This is also clear from the fact that the center of gravity of the motor of the present invention rotates. As mentioned above, if the center of gravity is moved, the torque and output will be extremely large.

〔実施例〕〔Example〕

（実施例１） 第１図及び第２図は本発明に係る重心回転型超音波モー
タの最も単純な実施例を示す図である。(Embodiment 1) FIGS. 1 and 2 are diagrams showing the simplest embodiment of the centroid rotation type ultrasonic motor according to the present invention.

直径４０１．内径１５耶、厚さ２鰭のＰｂ（ＺｒＴ　ｒ
　）　０３系圧電セラミック円板１を厚さ方向９に沿っ
て分極し、表裏両面の電極を４等分割し、これら電極１
１，１゜、１３，１．及び裏面対向電極１５゜１６．１
□、１８（図面には表示されていない）の中、電極１．
と１□、電極１□と１８．電極１３と１３．電極１４と
１６とをそれぞれ短絡した後、電極１１と１．の間に正
弦波電圧１００■を印加し、電極１□と１４の間にも同
一周波数、同一電圧で位相が９０°異なる正弦波電圧を
印加した。Diameter 401. Pb (ZrT r
) The 03 series piezoelectric ceramic disc 1 is polarized along the thickness direction 9, and the electrodes on both the front and back surfaces are divided into four equal parts.
1,1°, 13,1. and back facing electrode 15°16.1
□, 18 (not shown in the drawing), electrode 1.
and 1□, electrodes 1□ and 18. Electrodes 13 and 13. After short-circuiting electrodes 14 and 16, respectively, electrodes 11 and 1. A sine wave voltage of 100 square meters was applied between electrodes 1 and 14, and a sine wave voltage of the same frequency and voltage but with a phase difference of 90 degrees was also applied between electrodes 1 and 14.

圧電円板１は内径１５ｍｍの中心孔に外径１５關。The piezoelectric disk 1 has a center hole with an inner diameter of 15 mm and an outer diameter of 15 mm.

内径６ＩＩｌ＋１．長さ１０鰭のウレタンスプリング８
を嵌め、その中心に径６＋１１１のキャップボルト７を
通し、支持板（図示せず）へ締め付けた。ボルト７を締
め付けるとスプリング８の外径が太くなるので、圧電円
板１を強く支持できる。圧電円板１に加える電圧の周波
数を変えて行くと、共振状態が生じ大振動が生じる。こ
の振動の仕方は第３図に示したように、領域１４０面積
が広がったとき、領域１２０面積が縮み、その瞬間は領
域１１および１３は伸縮していないので、圧電円板１の
外周は点線１６及び１５のように変形する。その結果円
板１の重心は中心１７から外れ点１８に移る。Inner diameter 6IIl+1. Urethane spring 8 with length 10 fins
A cap bolt 7 with a diameter of 6+111 was passed through the center of the cap bolt, and the cap bolt 7 was tightened to a support plate (not shown). When the bolt 7 is tightened, the outer diameter of the spring 8 becomes thicker, so that the piezoelectric disk 1 can be strongly supported. When the frequency of the voltage applied to the piezoelectric disk 1 is changed, a resonance state occurs and large vibrations occur. The way this vibration occurs is as shown in Figure 3, when the area of area 140 expands, the area of area 120 contracts, and at that moment, areas 11 and 13 are not expanding or contracting, so the outer periphery of piezoelectric disk 1 is indicated by the dotted line. 16 and 15. As a result, the center of gravity of the disk 1 moves from the center 17 to the off point 18.

次のπ／４サイクルでは領域１１の外周がふくらみ、領
域１３の外周がへこむので重心は点１９の位置へ移り、
′八　πのとき点２ｏへ３／４　πのとき点２１へ移る
。結局、圧電円板１の重心は共振周波数の１サイクルの
間に中心から約数μｍはずれた円周上を−まわすする。In the next π/4 cycle, the outer circumference of area 11 bulges and the outer circumference of area 13 is depressed, so the center of gravity moves to the position of point 19,
When '8 π, move to point 2o; when 3/4 π, move to point 21. As a result, the center of gravity of the piezoelectric disk 1 rotates on the circumference about several micrometers away from the center during one cycle of the resonance frequency.

なお図中の１７は中心を示ず十マークである。Note that 17 in the figure does not indicate the center and is a ten mark.

振動による変形は円板１の１次共振モードに対応し、こ
の実施例では２相の４６．５ＫＨｚであった。すなわち
重心は毎秒４万６千５百回、半径数μｍの円を描いて回
転する。そこで圧電円板１に外径５０■、内径約４０ｍ
５．厚さ５ＩＩ１１のアルミニウムリングを外接させた
ところ、リングが勢いよく反時計まわりに廻ねった。た
だし、リングの内径は上２龍が４０，０００ｉ：ｅ、０
０２５ｍ１１゜下３１が４．０．００５±０．００２５
酊に加工されているので、圧電円板１を嵌めたとき、リ
ングが抜は落ちることはなかった。次に２相４６．５Ｋ
Ｈｚの駆動電圧の位相を一９０°に変えたところ、ロー
タは同じ回転数、同じトルクで逆回転した。The deformation due to vibration corresponds to the first-order resonance mode of the disk 1, and in this example, it was two-phase at 46.5 KHz. In other words, the center of gravity rotates 46,500 times per second in a circle with a radius of several micrometers. Therefore, the piezoelectric disk 1 has an outer diameter of 50 mm and an inner diameter of about 40 m.
5. When an aluminum ring with a thickness of 5II11 was circumscribed, the ring rotated vigorously counterclockwise. However, the inner diameter of the ring is 40,000i:e, 0 for the top two dragons.
025m11° lower 31 is 4.0.005±0.0025
Since the ring was machined carefully, when the piezoelectric disk 1 was fitted, the ring did not fall off. Next 2 phase 46.5K
When the phase of the Hz drive voltage was changed to 190 degrees, the rotor rotated in the opposite direction at the same rotation speed and the same torque.

（実施例２） 第４図及び第５図は、本発明になる重心回転型超音波モ
ータの別の実施例を示す説明図である。(Embodiment 2) FIGS. 4 and 5 are explanatory diagrams showing another embodiment of the center-of-gravity rotation type ultrasonic motor according to the present invention.

実施例１との差異は円板状の圧電素子を５ｍｍｘ１５都
×２龍の矩形板２２，２３，２４．．２５と変え、これ
らをアルミニウム円板２７および２６に嵌め込み、圧電
素子を実施例１と同様に駆動した。The difference from Example 1 is that the disc-shaped piezoelectric elements are replaced with rectangular plates 22, 23, 24, 5 mm x 15 squares x 2 dragons. ．． 25, these were fitted into aluminum disks 27 and 26, and the piezoelectric elements were driven in the same manner as in Example 1.

そうすると圧電体２３〜２５の振動がアルミニウム円板
２６の１次振動モードに共鳴増幅され、中心をヘアリン
グ２９で保持したロータ２８を約４ｏｏｒｐｍの回転数
で力強く回転させることができ、ロータ２８の出力シャ
フト３１から１　ｋｇ　−ｃｔｎのトルクが得られた。Then, the vibrations of the piezoelectric bodies 23 to 25 are resonantly amplified by the primary vibration mode of the aluminum disk 26, and the rotor 28, whose center is held by the hair ring 29, can be powerfully rotated at a rotation speed of about 4 oorpm. A torque of 1 kg-ctn was obtained from the output shaft 31.

なお、アルミニウム円板２６とロータ２８の内周面ば圧
接しやすいように約１０°のテーパーがついた円錐面と
し、ロータ２８はステータにスプリング（図示せず）に
よって強く圧着させた。この場合も互いに対向する２組
の圧電素子に印加する電圧の位相関係をスイッチするこ
とにより逆転できることはごうまでもない。尚、第４図
において３０は支持シャフトである。The inner circumferential surfaces of the aluminum disk 26 and the rotor 28 were made into conical surfaces tapered by about 10 degrees to facilitate pressure contact, and the rotor 28 was strongly pressed against the stator by a spring (not shown). In this case as well, it goes without saying that the phase relationship can be reversed by switching the phase relationship of the voltages applied to the two sets of piezoelectric elements facing each other. In addition, in FIG. 4, 30 is a support shaft.

〔発明の効果〕〔Effect of the invention〕

以上説明したように本発明では、重心が右まわり、又は
左まわりの回転運動をする重心回転振動子に圧着された
ロータが摩擦力を介して受ける回転トルクを利用する構
成をとった。As explained above, the present invention is configured to utilize rotational torque received through frictional force by a rotor that is crimped onto a center-of-gravity rotating oscillator whose center of gravity rotates clockwise or counterclockwise.

そのため、従来の超音波モータのように楕円振動をする
ステータに圧着されたロータが摩擦力を介して受ける回
転トルクを利用する構成と異なり、ステータそのものが
実効的に回転運動をしている。Therefore, unlike conventional ultrasonic motors, which utilize rotational torque received through frictional force from a rotor that is pressed against a stator that vibrates elliptically, the stator itself effectively rotates.

そのためころがり摩擦を利用したトルクの伝達が可能で
あり、面すべりが生じにくいので摩耗防止が簡単であり
、構造そのものも極めて簡単なうえ、薄型化に好都合で
あり、しかも発生トルクも出力も大きく、エネルギー効
率も高くできるなど実用上の顕著な効果がある。Therefore, it is possible to transmit torque using rolling friction, and since surface slip is less likely to occur, it is easy to prevent wear, the structure itself is extremely simple, it is convenient for thinning, and the generated torque and output are large. It has significant practical effects such as higher energy efficiency.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図及び第２図は本発明による重心回転型超音波モー
タの一実施例を示す平面図及び縦断面図、第３図は本発
明による重心回転型超音波モータのステークを構成する
重心回転振動子の変形に伴う重心回転の説明図、第４図
及び第５図は本発明による重心回転型超音波モータの別
の実施例を示す縦断面図と平面断面図である。 １、　２２．　２３．　２４．　２５−−−−圧電素子
、１１．１□＋　１３＋　１４　’−−−−−−電極、
１１．１２．１３゜１４−−−一領域、３．４，５．６
−−−−−リード線、７−・−ボルト、８−一−−ウレ
タンスプリング、２゜２８・−−−−ロータ、９−−一
−−−分極を示す矢印、１７−−中心を示す＋マーク、
１８，１９，２０．２１−−−−−重心を示す点、２７
−−−中心支持具、２９−−ベアリング、３〇　−支持
シャフト、３１−−−−ロータシャフト。 第１図 第２図 第３図 ２１　　　　　　　／（Ｊ1 and 2 are a plan view and a vertical sectional view showing an embodiment of the centroid rotation type ultrasonic motor according to the present invention, and FIG. An explanatory diagram of rotation of the center of gravity due to deformation of the vibrator, and FIGS. 4 and 5 are a vertical sectional view and a plan sectional view showing another embodiment of the center of gravity rotation type ultrasonic motor according to the present invention. 1, 22. 23. 24. 25----Piezoelectric element, 11.1□+13+14'----Electrode,
11.12.13゜14---One area, 3.4, 5.6
---Lead wire, 7--Volt, 8--Urethane spring, 2゜28--Rotor, 9--1--Arrow indicating polarization, 17--Pointing to center + mark,
18, 19, 20.21---Point indicating the center of gravity, 27
---Center support, 29--Bearing, 30--Support shaft, 31--Rotor shaft. Figure 1 Figure 2 Figure 3 21 /(J

Claims (1)

【特許請求の範囲】[Claims] （１）　重心が右まわり、又は左まわりの回転運動をす
る重心回転振動子に圧着されたロータが摩擦力を介して
受ける回転トルクを利用したことを特徴とする超音波モ
ータ。(1) An ultrasonic motor characterized in that it utilizes rotational torque received through frictional force by a rotor that is crimped onto a center-of-gravity rotating vibrator whose center of gravity rotates clockwise or counterclockwise.