ULTRASONIC MOTOR(PIEZOELECTRIC MOTOR)

1. ULTRASONIC MOTOR
(USM)
GUIDED BY
VISHNU PRATHAP
ASSISTANT PROFESSOR
MECHANICAL DEPT.
Govt. Engg. College Idukki
PRESENTED BY
ARJUN SIBI
ROLL NO- 61. SEM-7
MECHANICAL DEPT.
Govt. Engg. College Idukki
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2. CONTENTS
 INTRODUCTION
 TYPE OF USM
 WORKING PRINCIPLE
 STRUCTURE
 CONSTRUCTION
 WORKING
 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. The Disadvantages Of Electromagnetic motors 5
 Noisy operations
 Magnetic losses
 High power consumption
 Low power factor
 Comparatively lesser efficiency

6. TYPES OF ULTRASONIC MOTOR
ULTRASONIC
MOTOR
STANDING
WAVE TYPE
LINEAR
MOTOR
ROTARY
MOTOR
TRAVELLING
WAVE TYPE
LINEAR
MOTOR
ROTARY
MOTOR
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7. 7LINEAR USM
Fig:-1

8. 8ROTARY USM
Fig:-2

9. WORKING PRINCIPLE
PIEZOELECTRIC EFFECT
 In certain types of crystals when a pressure is applied across a pair of
opposite faces, an equivalent potential difference is developed across
the other pair of opposite faces.
 Converse of this phenomenon is also possible.
9
Fig:-3

10. PIEZOELECTRIC MATERIAL USED
 Quartz(SiO2).
 Barium titanate (BaTiO3).
 Lead zirconate titanate(PbZrTiO3).
 Lithium niobate titanate(LiNbO3).
10

11. Compressing Force Potential difference`
11
Fig:-4

12. BASIC STRUCTURE
12
Fig:-5

13. C O N S T R U C T I O N
The Ultrasonic Motors constitutes mainly four parts
 Actuator
 Stator
 Rotor
 Casing
13
Fig:-6

14. 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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15. 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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16. 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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17. 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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18. FUNDAMENTAL CONSTRUCTION OF USM 18
Fig:-7

19.  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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20. 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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21.  The surface waves so produced ultrasonic frequency range.
 Not visible by our bare eyes.
21
Fig:-8

22. 22
Fig:-9

23.  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.
23
Fig:-10

24.  The shaft is mounted upon the rotor.
 Rotor rotates and the output torque is obtain.
 The stator and rotor always possess the same shape.`
24
Fig:11

25. The other methods of classifications of USM
Type of motion
* Rotary
* Linear
* Spherical
Shape of implementation
* Beam
* Rod
* Disk
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26. ADVANTAGES 26
 High output torque & efficiency
 Good positioning accuracy
 Capable of working in extreme environmental conditions.
 Simple construction
 Compact size.
 Energy saving

27. 27DISADVANTAGE
 High frequency supply range
 Cost of Piezoelectric crystal
 Large field application is not possible now.

28. 28APPLICATIONS
 Auto focusing & optical zooming in digital cameras
 Surveillance cameras.
 The disk heads of hard disks
 CD drives Controlling
 Wrist watches & Clocks
 Robotics
 Aerospace
 Medicine

29. 29Auto focusing& optical zooming
Fig:-12 Fig:-13

30. 30Disk heads of hard disks
Fig:-14
Fig:-15

31. 31CASE STUDY
The case study is done in MRI robor bv ts by using PIEZO LEGS motors
ORAGNIZATION
Worcester Polytechnic Institute USA
INDUSTRY
Medical Robotic Surgical Tools USA
Fig:-16

32. 32
 Surgical robot designed for use inside an MRI machine that can
operate within the high magnetic fields generated by an MRI.
 Any electrical noise generated by power supply or drive electronics
is to distort the image
 Here the MRI robot required up to about 100 mm of linear travel or
a continuous 360 degree rotation
CHALLENGES

33. 33USM SPECIFICATION
Piezo LEGS Linear 10
 It delivers micro-steps as
long as 4 μm with nano-
scale resolution.
 which moves a 100.8-mm drive rod over of 80 mm at speeds as
high as 10 mm/s.
Fig:-17

34. 34
Piezo LEGS Rotary 50
 which provides positioning over 360° at micro-radian resolutions.
Fig:-18

35. 35CASESTUDY RESULTS
 They can capture ultra-high-resolution images of the tumor
using magnetic resonance imaging.
 They can use ultra-precise surgical tools to remove the tumor.
 Can operate within the high magnetic fields generated by an
MRI unit.

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BEFORE USING USM AFTER USING USM

37. 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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38. 38REFERENCES
[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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