CA2049990A1 - Ultrasound motor having two rotors - Google Patents
Ultrasound motor having two rotorsInfo
- Publication number
- CA2049990A1 CA2049990A1 CA002049990A CA2049990A CA2049990A1 CA 2049990 A1 CA2049990 A1 CA 2049990A1 CA 002049990 A CA002049990 A CA 002049990A CA 2049990 A CA2049990 A CA 2049990A CA 2049990 A1 CA2049990 A1 CA 2049990A1
- Authority
- CA
- Canada
- Prior art keywords
- stator
- ultrasound
- ultrasound motor
- contact
- motor according
- 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.)
- Abandoned
Links
- 238000002604 ultrasonography Methods 0.000 title claims abstract description 34
- 239000013013 elastic material Substances 0.000 claims abstract description 3
- 239000000919 ceramic Substances 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 239000002783 friction material Substances 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- 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
- H02N2/163—Motors with ring stator
Landscapes
- General Electrical Machinery Utilizing Piezoelectricity, Electrostriction Or Magnetostriction (AREA)
Abstract
FBP 89/5 January 18, 1990 ULTRASOUND MOTOR HAVING TWO ROTORS
Abstract In an ultrasound motor composed of a stator made of an elastic material and equipped with one or a plurality of ultrasound oscillators for exciting traveling waves in a stator and a movable component which is in contact, under pressure, with a surface region of the stator, a second movable component is provided which is in contact, under pressure, with a second surface region of the stator in which traveling waves are excited.
Abstract In an ultrasound motor composed of a stator made of an elastic material and equipped with one or a plurality of ultrasound oscillators for exciting traveling waves in a stator and a movable component which is in contact, under pressure, with a surface region of the stator, a second movable component is provided which is in contact, under pressure, with a second surface region of the stator in which traveling waves are excited.
Description
2~99~
Translation: -FBP 89/S January 24, 1990 ULTRASOUND MOTOR HAVING TWO ROTORS
Specification The present invention relates to an ultrasound motor in which a driving moment is generated with the aid o~ ultra-sound oscillators r for example electros~riction or mag-netostriction elements.
Such an ultrasound motor, as it is disclosed, for example, in U.S~ Patent No. 4,562,374, is composed of a rotor and a stator of elastic material, with mechanical waves being excited in the latter by means of a piezoelectric ceramic element. Rotor and stator are in contact with one another under axial pressure, with the contact surface being provided with a 6uitable friction coating. The advantages of such motors are, among others, the possibility of generating high torques without gear assemblies and at user friendly low numbers of revolution, their small structural volume with low weight and high ~nergy density as well as a high holding moment in the passive state.
,' ~ :' ' ' `' , . . .
,: : , ,, ' ' ' ` ' 2~9~
PCT/EPsl/00133 The driving of a motor of this type is effected by the rotor generating traveling waves in the stator. Since the respective surface elements of the stator then move on approximately ellip-tical paths, the friction between the surfaces of stator and rotor generate tangential forces in the contact zone between the two surfaces, leading to the development of rotor movement. Starting torque, idling speed, efficiency and service life of the motor are here essentially a function of the contact and pressure conditions between stator and rotor. For example, an increased axial force between rotor and stator results in a greater driving force and a greater torque. However, this increase en-counters a barrier at the point at which the customary friction material reaches its flow limit. Similarly, although an increase in the contact surface area as a result of the use of a vibrating stator having a larger diameter leads to a greater torque, it simultaneously reduces the resonant frequency of the stator down to the audible range.
Prior attempts at improvinq the contact and pressure conditions in ultrasound motors of this type were directed primarily toward the optimum configuration of the stator surface (Laid-Open Patent Application 3,626,389) and the ' .
, 2 ~ o PCT/EPgl/00133 development of specially adapted friction materials for stator and rotor (EP-A 0,222,394).
It is an object of the present invention to improve the prior art and particularly to provide an ultrasound motor which has improved contact characteristics between stator and rotor, a higher torque and a better quality of synchron-sm.
This is accomplished by the invention with the features of claim 1. In an ultrasound motor equipped with a stator and two rotors, the stator excites traveling waves, for example by means of piezoelectric ceramic components. The two rotors are in respective contact, under pressure, with the upper and underside of the stator. With this motor configuration, the contact surface between stator and rotor is enlarged without creating the above-mentioned drawback of reducing the resonant frequency. Further advantages of the motor according to the invention are its increased quality of synchronism and better heat dissipation and distribution due to the use of two moving components. The invention further enables operation of the motor at a lower axial pressure between stator and rotor. Other advantageous embodiments of the invention are disclosed in dependent claims 2 to 6.
:: , , , ~ : , ,5 ' :` ~ .
2 ~ o The ultrasound motor according to the invention will now be described in greater detail with reference to drawing figures. Individually, it is shown in:
- Figure 1, a schematic cross-sectional view of a prior art ultrasound motor;
- Figure la, an illustration of the stator configura-tion of a prlor art ultrasound motor.
- Figure 2, a schematic cross-sectional view of an ultrasound motor according to the invention.
- Figure 3, a schematic cross-sectional view of another embodiment of the invention.
The prior art ultrasound rotation motor shown in Figures 1 and la is composed of a stator 1 and a rotor 2. The stator 1 includes as ultra50und oscillators pie~oceramic elements 3 which are arranged in a circular ring, are provided with electrodes and are ylued to the actual oscillating body.
Stator and rotor are in contact with one another under axial pressure: the contact surface is provided with a thin coating of a suitable plastic. By way of the electrodes, the piezo-ceramic element is excited with a high-frequency alternating voltage so that mechanical traveling waves are generated in .
~ ' ' ``'``' `
2 ~
the stator. The actual oscillating body employed is a metal ring or a circular metal disc.
Figure 2 is a schematic representation of an ultrasound rotation motor according to the invention. Here the circular disc shaped stator 4 is in contact, under axial pressure and at two respectively oppositely disposed surface regions 4a and 4b, with two rotors 5a and 5b that are seated on a common shaft. In the stator, traveling waves are generated by each ultrasound element 6a and 6b and lead by way of friction to tangential forces and to the development of a rotary movement and a torque at rotors 5a and 5b. The oppositely directed axial pressure of the rotors on stator 4 is symbolized in Figure 2 by spring elements 7a and 7b, respectively. In another embodiment of the motor, ultrasound elements are disposed only on one stator surface.
It is possible to effect the excitation in any desired region of khe stator surface. In principle, the oscillators may be attached anywhere, but not at the center plane of the stator, with the center plane being understood to mean the plane which cuts the stator plate in half at every point. As an alternative to the arrangement of the ultrasound oscil-lators at the stator surfaces, their arrangement is also - , , ,, : .
' ' ' ' ~ , 2 0 !~ ~ 9 9 0 possible in the stator. Figure 3 shows an embodiment of the invention in which the traveling waves are excited by oscil-lators 8 that are embedded in the stator body.
Although the above described motor embodiments all employ circular rotors, it must be emphasized that the invention also relates to linear ultrasound motors.
~ .
-' ,-
Translation: -FBP 89/S January 24, 1990 ULTRASOUND MOTOR HAVING TWO ROTORS
Specification The present invention relates to an ultrasound motor in which a driving moment is generated with the aid o~ ultra-sound oscillators r for example electros~riction or mag-netostriction elements.
Such an ultrasound motor, as it is disclosed, for example, in U.S~ Patent No. 4,562,374, is composed of a rotor and a stator of elastic material, with mechanical waves being excited in the latter by means of a piezoelectric ceramic element. Rotor and stator are in contact with one another under axial pressure, with the contact surface being provided with a 6uitable friction coating. The advantages of such motors are, among others, the possibility of generating high torques without gear assemblies and at user friendly low numbers of revolution, their small structural volume with low weight and high ~nergy density as well as a high holding moment in the passive state.
,' ~ :' ' ' `' , . . .
,: : , ,, ' ' ' ` ' 2~9~
PCT/EPsl/00133 The driving of a motor of this type is effected by the rotor generating traveling waves in the stator. Since the respective surface elements of the stator then move on approximately ellip-tical paths, the friction between the surfaces of stator and rotor generate tangential forces in the contact zone between the two surfaces, leading to the development of rotor movement. Starting torque, idling speed, efficiency and service life of the motor are here essentially a function of the contact and pressure conditions between stator and rotor. For example, an increased axial force between rotor and stator results in a greater driving force and a greater torque. However, this increase en-counters a barrier at the point at which the customary friction material reaches its flow limit. Similarly, although an increase in the contact surface area as a result of the use of a vibrating stator having a larger diameter leads to a greater torque, it simultaneously reduces the resonant frequency of the stator down to the audible range.
Prior attempts at improvinq the contact and pressure conditions in ultrasound motors of this type were directed primarily toward the optimum configuration of the stator surface (Laid-Open Patent Application 3,626,389) and the ' .
, 2 ~ o PCT/EPgl/00133 development of specially adapted friction materials for stator and rotor (EP-A 0,222,394).
It is an object of the present invention to improve the prior art and particularly to provide an ultrasound motor which has improved contact characteristics between stator and rotor, a higher torque and a better quality of synchron-sm.
This is accomplished by the invention with the features of claim 1. In an ultrasound motor equipped with a stator and two rotors, the stator excites traveling waves, for example by means of piezoelectric ceramic components. The two rotors are in respective contact, under pressure, with the upper and underside of the stator. With this motor configuration, the contact surface between stator and rotor is enlarged without creating the above-mentioned drawback of reducing the resonant frequency. Further advantages of the motor according to the invention are its increased quality of synchronism and better heat dissipation and distribution due to the use of two moving components. The invention further enables operation of the motor at a lower axial pressure between stator and rotor. Other advantageous embodiments of the invention are disclosed in dependent claims 2 to 6.
:: , , , ~ : , ,5 ' :` ~ .
2 ~ o The ultrasound motor according to the invention will now be described in greater detail with reference to drawing figures. Individually, it is shown in:
- Figure 1, a schematic cross-sectional view of a prior art ultrasound motor;
- Figure la, an illustration of the stator configura-tion of a prlor art ultrasound motor.
- Figure 2, a schematic cross-sectional view of an ultrasound motor according to the invention.
- Figure 3, a schematic cross-sectional view of another embodiment of the invention.
The prior art ultrasound rotation motor shown in Figures 1 and la is composed of a stator 1 and a rotor 2. The stator 1 includes as ultra50und oscillators pie~oceramic elements 3 which are arranged in a circular ring, are provided with electrodes and are ylued to the actual oscillating body.
Stator and rotor are in contact with one another under axial pressure: the contact surface is provided with a thin coating of a suitable plastic. By way of the electrodes, the piezo-ceramic element is excited with a high-frequency alternating voltage so that mechanical traveling waves are generated in .
~ ' ' ``'``' `
2 ~
the stator. The actual oscillating body employed is a metal ring or a circular metal disc.
Figure 2 is a schematic representation of an ultrasound rotation motor according to the invention. Here the circular disc shaped stator 4 is in contact, under axial pressure and at two respectively oppositely disposed surface regions 4a and 4b, with two rotors 5a and 5b that are seated on a common shaft. In the stator, traveling waves are generated by each ultrasound element 6a and 6b and lead by way of friction to tangential forces and to the development of a rotary movement and a torque at rotors 5a and 5b. The oppositely directed axial pressure of the rotors on stator 4 is symbolized in Figure 2 by spring elements 7a and 7b, respectively. In another embodiment of the motor, ultrasound elements are disposed only on one stator surface.
It is possible to effect the excitation in any desired region of khe stator surface. In principle, the oscillators may be attached anywhere, but not at the center plane of the stator, with the center plane being understood to mean the plane which cuts the stator plate in half at every point. As an alternative to the arrangement of the ultrasound oscil-lators at the stator surfaces, their arrangement is also - , , ,, : .
' ' ' ' ~ , 2 0 !~ ~ 9 9 0 possible in the stator. Figure 3 shows an embodiment of the invention in which the traveling waves are excited by oscil-lators 8 that are embedded in the stator body.
Although the above described motor embodiments all employ circular rotors, it must be emphasized that the invention also relates to linear ultrasound motors.
~ .
-' ,-
Claims (7)
Patent Claims
1. An ultrasound motor composed of a stator made of an elastic material and provided with one or a plurality of ultrasound oscillators so as to excite traveling waves in a stator and a movable component which is in contact, under pressure, with a surface region of the stator, characterized in that a second movable component is provided which is in contact, under pressure, with a second surface region of the stator in which traveling waves are excited.
2. An ultrasound motor according to claim 1, charac-terized in that the second movable component is fixed to the first movable component.
3. An ultrasound motor according to claim 1 or 2, characterized in that the stator has a circular disc-shaped configuration and the first and second movable components are in contact with the stator on respectively oppositely disposed surface sides of the stator.
4. An ultrasound motor according to one of claims 1 to 3, characterized in that the ultrasound oscillators are arranged on the stator in the form of a circular ring.
5. An ultrasound motor according to one of claims 1 to 4, characterized in that the ultrasound oscillators are arranged on only one surface side.
6. An ultrasound motor according to one of claims 1 to 4, characterized in that the ultrasound oscillators are disposed on two oppositely disposed surface sides of the stator.
7. An ultrasound motor according to one of claims 1 to 6, characterized in that the ultrasound oscillators are arranged in a circle within the stator.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP4002254.4 | 1990-01-26 | ||
| DE4002254A DE4002254A1 (en) | 1990-01-26 | 1990-01-26 | ULTRASONIC MOTOR WITH TWO ROTORS |
| PCT/EP1991/000133 WO1991011850A1 (en) | 1990-01-26 | 1991-01-24 | Ultrasonic motor with two rotors |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2049990A1 true CA2049990A1 (en) | 1991-07-27 |
Family
ID=6398816
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002049990A Abandoned CA2049990A1 (en) | 1990-01-26 | 1991-01-24 | Ultrasound motor having two rotors |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0465616A1 (en) |
| AU (1) | AU7154191A (en) |
| CA (1) | CA2049990A1 (en) |
| DE (1) | DE4002254A1 (en) |
| WO (1) | WO1991011850A1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2690018A1 (en) * | 1991-10-10 | 1993-10-15 | Mecanique Appliquee Lab | Piezoelectric modular motor with stator having two active faces - has both faces excited by transducers having two active faces insulated by coaxial element |
| DE4216050C2 (en) * | 1992-05-15 | 1995-05-24 | Daimler Benz Ag | Ultrasonic traveling wave motor with positive engagement of traveling waves |
| FR2709214B1 (en) * | 1993-08-18 | 1995-10-27 | Figest Bv | Piezoelectric traveling wave motor. |
| DE19710601C2 (en) * | 1997-03-14 | 1999-05-20 | Univ Magdeburg Tech | Motion generator |
Family Cites Families (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2438939A1 (en) * | 1978-10-09 | 1980-05-09 | France Etat | PIEZOELECTRIC BI-RESONATOR |
| JPS57170048A (en) * | 1981-04-14 | 1982-10-20 | Nippon Radiator Co Ltd | Commutator for flat motor |
| CA1208269A (en) * | 1982-02-25 | 1986-07-22 | Toshiiku Sashida | Motor device utilizing ultrasonic oscillation |
| FR2529346A1 (en) * | 1982-06-28 | 1983-12-30 | Snecma | PROXIMITY RADAR |
| JPS59117473A (en) * | 1982-12-21 | 1984-07-06 | Canon Inc | Vibration wave motor |
| DE3309239A1 (en) * | 1983-03-15 | 1984-09-20 | Siemens AG, 1000 Berlin und 8000 München | Piezo-electric motor |
| NL8303129A (en) * | 1983-09-09 | 1985-04-01 | Gist Brocades Nv | METHOD AND APPARATUS FOR ANAEROOB FERMENTATION OF SOLID WASTES IN TWO PHASES. |
| US4663556A (en) * | 1984-01-11 | 1987-05-05 | Hitachi Maxell, Ltd. | Torsional mode ultrasonic vibrator |
| US4786836A (en) * | 1984-03-01 | 1988-11-22 | Matsushita Electric Industrail Co., Ltd. | Piezoelectric motor |
| JPS6130972A (en) * | 1984-07-18 | 1986-02-13 | Taga Denki Kk | Supersonic motor device |
| CA1262471A (en) * | 1985-11-13 | 1989-10-24 | Masanori Sumihara | Ultrasonic motor having a friction material comprising a rubber-like elastic material and aromatic polyamide fiber |
| US4742260A (en) * | 1986-02-06 | 1988-05-03 | Hiroshi Shimizu | Piezoelectrically driving device |
| DE3626398A1 (en) * | 1986-08-04 | 1988-02-11 | Siemens Ag | ELECTRONIC OVERCURRENT RELEASE |
| JP2595950B2 (en) * | 1987-01-27 | 1997-04-02 | 松下電器産業株式会社 | Ultrasonic motor drive |
| CN1035213A (en) * | 1987-12-29 | 1989-08-30 | 精工电子工业株式会社 | Travelling wave motor |
| DE3904070C2 (en) * | 1988-02-12 | 1997-02-20 | Ngk Spark Plug Co | Ultrasonic motor |
| DE3833342A1 (en) * | 1988-09-30 | 1990-04-05 | Siemens Ag | Piezoelectric motor |
-
1990
- 1990-01-26 DE DE4002254A patent/DE4002254A1/en not_active Ceased
-
1991
- 1991-01-24 CA CA002049990A patent/CA2049990A1/en not_active Abandoned
- 1991-01-24 EP EP91902388A patent/EP0465616A1/en not_active Withdrawn
- 1991-01-24 WO PCT/EP1991/000133 patent/WO1991011850A1/en not_active Application Discontinuation
- 1991-01-24 AU AU71541/91A patent/AU7154191A/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| DE4002254A1 (en) | 1991-08-14 |
| EP0465616A1 (en) | 1992-01-15 |
| WO1991011850A1 (en) | 1991-08-08 |
| AU7154191A (en) | 1991-08-21 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |