ULTRASONIC MOTOR ( BY AVINASH MEENA 9703174752)

1. ULTRASONIC MOTOR
(USM)
PRESENTED BY
AVINASH MEENA
ROLL NO- 132107
B.TECH- 4/4
ELECTRICAL AND
ELECTRONICS ENGINEERING
NIT WARANGAL
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2. CONTENTS
 INTRODUCTION
 WORKING PRINCIPLE
 STRUCTURE
 CONSTRUCTION
 WORKING
 TYPE OF USM
 CHARACTERISTICS
 ADVANTAGES
 DISADVANTAGES
 APPLICATIONS
 CONCLUSION
 REFERENCE
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3. INTRODUCTION
WhatisMotor?
 Motorisadevicewhichconvertelectricalenergytomechanicalenergy
 Almost all the motors work on the principle of Faraday’s Law of Electromagnetic
Induction.
 Theenergyconversioninsuchmotorsinvolvestwostages
Electricalenergytomagneticenergy
Magnetictomechanicalenergy.
 Because of two-stage electromagnetic motor suffer from several losses that lead to
energywastage
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4.  A new class of motors using high power Ultrasonic motors were
introduced.
 The ultrasonic motors also known as piezoelectric motors, which
directly convert electric energy to mechanical energy.
 The first ultrasonic motor was introduce by V.V Lavrinko in 1965
INTRODUCTION OF USM 4

5. 5
It has very good torque-speed characteristics.
These characteristics of USM makes them attractive for robotic
applications where small motions are required.
Conversion of electric energy into motion by piezoelectric effect.
USMs replaced not only the EM motors, but also the servomotors,
stepper motors and synchronous motors.
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6. The Disadvantages Of Electromagnetic motors 6
 Noisy operations
 Magnetic losses
 High power consumption
 Low power factor
 Comparatively lesser efficiency

7. WORKING PRINCIPLE
PIEZOELECTRIC EFFECT
Before learning about USMs it is required to know about piezoelectric effect.
 In figure given below, a compressive force is applied across the crystal and we obtain
a potential difference as shown but if the compressive force is replaced by an
elongation force, the polarity reverses.
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 Converse of this phenomenon is also possible.
When a potential difference is applied across the pair of opposite faces, compressions or
elongations are obtained across the other pair of opposite faces depending upon the polarity of the
applied PD.
Further, the application of AC voltage across these faces resulted in alternating compressions and
elongations (mechanical vibrations) across the other pair of faces. This is the driving force behind the
USMs.
Crystals that exhibit the above phenomenon are called piezoelectric materials.
In short, the Ultrasonic Motors works on the principle of converse piezoelectric effect.
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9. PIEZOELECTRIC MATERIAL USED
 Quartz(SiO2).
 Barium titanate (BaTiO3).
 Lead zirconate titanate(PbZrTiO3).
 Lithium niobate titanate(LiNbO3).
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10. BASIC STRUCTURE
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11. C O N S T R U C T I O N
The Ultrasonic Motors constitutes mainly four parts
 Actuator
 Stator
 Rotor
 Casing
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12. ACTUATOR
 It is the driving unit.
 Made up of piezoelectric material (Quartz,
Barium Titanate, Tourmaline, Rochelle salt, etc).
 Fixed on the stator using thin metal sheets
and bearings.
 Directly connected to the supply mains.
`
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13. STATOR
 Stator is the stationary but vibrating part.
 It is constructed using a malleable material,
usually steel.
 It can be of ring, cylindrical or rod shaped.`
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14. ROTOR
 It is the rotating part, which acquires the energy conversion
 Produces the desired torque on the shaft.
 It is made of the same material as that of the
stator and does have the same shape.
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15. CASING
 To provide protection against abrasive forces, external interferences
and extreme environmental conditions.
 They are made of non- corrosive
alloys or fiber.
 Cylindrical, disc or box shaped.
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16. FUNDAMENTAL CONSTRUCTION OF USM 16
Fig:-7

17.  Consist of a high-frequency power supply, Connected to Vibrator.
 Vibrator is composed of a piezoelectric driving component and an
elastic vibratory part.
 The slider is composed of an elastic moving part and a friction
coat.
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18. WORKING OF USM
 When the supply is switched ON, the actuator starts vibrating owing to
converse piezoelectric effect.
 The particles of the stator receive energy from the actuator and starts
vibrating in the plane.Results in the formation of a surface wave.
 The stator and rotor are placed so close to each other that their surfaces
almost grazes upon each other.
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19.  The surface waves so produced ultrasonic frequency range.
 Not visible by our bare eyes.
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21.  Wave propagates the rotor is pulled back in the opposite direction of
movement of the wave
 Surface wave is propagating in the anti-clockwise direction
Rotor is pulled to rotate in the clockwise direction.
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22.  The shaft is mounted upon the rotor.
 Rotor rotates and the output torque is obtain.
 The stator and rotor always possess the same shape.`
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23. 23
ULTRASONIC
MOTOR
STANDING
WAVE TYPE
LINEAR
MOTOR
ROTARY
MOTOR
TRAVELLING
WAVE TYPE
LINEAR
MOTOR
ROTARY
MOTOR
TYPES OF ULTRASONIC MOTOR 23

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STANDING WAVE TYPE USM
The first ultrasonic standing wave motor was
proposed by H.V. Barth in 1973.
The standing-wave type is sometimes referred
to as a vibratory-coupler type or a woodpecker
type.
A vibratory piece is connected to a
piezoelectric driver and the tip portion generates
flat elliptical movement.
the vibratory piece generates bending because
of restriction by the rotor,
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1. LINEAR TYPE STANDING WAVE USM
K Uchino et al invented a π-shaped linear
motor.
 This linear motor is equipped with a
multilayer piezoelectric actuator and fork-
shaped metallic legs.
 Since there is a slight difference in the
mechanical resonance frequency between the
two legs, the phase difference between the
bending vibrations of both legs can be
controlled by changing the drive frequency.
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ROTATING TYPE STANDING WAVE USM
The torsion coupler consisting of two legs
which transform longitudinal vibration.
Extruder is aligned with a certain cant angle
to the legs, which transforms the bending to a
torsion vibration.
This transverse moment coupled with the
bending up–down motion leads to an elliptical
rotation on the tip portion.
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The standing-wave type is
• Low in cost (one vibration source)
and
• High efficiency (up to 98%
theoretically)
• But lack of control in both
clockwise and counterclockwise
directions.
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TRAVELLING WAVE USM
The propagating-wave type combines two
standing waves with a 90 degree phase
difference both in time and in space.
A surface particle of the elastic body draws an
elliptical locus due to the coupling of
longitudinal and transverse waves.
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LINEAR TYPE TRAVELLING WAVE USM
Linear motor using bending vibration.
The two piezoelectric vibrators installed at
both ends of a transmittance steel rod excite
and receive the traveling transverse wave.
Adjusting a load resistance in the
receiving vibrator leads to a perfect
traveling wave.
Exchanging the role of exciting and receiving
piezo-components provided a reverse moving
direction.
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ROTARY TYPE TRAVELLING USM
Two voltage sources are used
to produce travelling wave.
Vibrations of the piezoelectric
material is amplified by the
stator teeth.
Due to frictional forces rotor
rotates.
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THE TRAVELLING-WAVE TYPE-
• Requires two vibrating source.
• Controllable in both direction.
• Silent operation, so suitable to video
cameras with microphone.
• Thinner design, leading to space saving.
• Low efficiency(not more than 50%)
• Energy saving.
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32. The other methods of classifications of USM
Type of motion
1. Rotary
2.Linear
3.Spherical
Shape of implementation
1. Beam
2. Rod
3.Disk
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LINEAR USM
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ROTARY USM 34

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CHARACTERISTICS 35

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37. ADVANTAGES 37
 High output torque & efficiency
 Good positioning accuracy
 Capable of working in extreme environmental conditions.
 Simple construction
 Compact size.
 Energy saving

38. 38DISADVANTAGE
 High frequency supply range
 Cost of Piezoelectric crystal
 Large field application is not possible now.

39. 39APPLICATIONS
 Auto focusing & optical zooming in digital cameras
 Surveillance cameras.
 The disk heads of hard disks
 CD drives Controlling
 Wrist watches & Clocks
 Robotics
 Aerospace

40. 40Auto focusing& optical zooming

41. 41Disk heads of hard disks
Fig:-14
Fig:-15

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Surveillance cameras
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43. Wrist watches & Clocks
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Robotics
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CONCLUSIONS
 The USM which is a new step in the miniaturized electrical
technology
 Many applications in small appliances because of its high torque at
low density.
 USMs are not widely used for heavy motoring activities.
 World might be expected in the near future that replaces the futile
electromagnetic motors by the proficient ultrasonic motors.
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46. 46REFERENCES
[1] Shi Jingzhuo,You Dongmei.“Characteristic model of travelling wave ultrasonic motor”.
School of Electrical Engineering, Henan University of Science and Technology, Luoyang
471023, China. 0041-621X-(2013)
[2] Yingxiang Liu, Weishan Chen, Junkao Liu, Shengjun Shi.“A cylindrical standing wave
ultrasonic motor using bending vibration transducer”. State Key Laboratory of Robotics and
System, Harbin Institute of Technology, Harbin 150001, Heilongjiang Province, China,
0041-62MX2010) Elsevier B.V.
[3] Xiang Li , Zhiyuan Yao, Shengli Zhou, Qibao Lv, Zhen Liu.“Dynamic modeling and
characteristics analysis of a modal-independent linear ultrasonic motor”.State Key
Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of
Aeronautics and Astronautics, Nanjing 210016, China
0041-624YAX/( 2016) Elsevier B.V.

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QUESTIONS ?
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