ULTRASONIC MOTOR (USM)

GUIDED BYVISHNU PRATHAPASSISTANT PROFESSORMECHANICAL DEPT.Govt. Engg. College Idukki

PRESENTED BYARJUN SIBIROLL NO- 61. SEM-7MECHANICAL DEPT.Govt. Engg. College Idukki

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CONTENTS

INTRODUCTION TYPE OF USM WORKING PRINCIPLE STRUCTURE CONSTRUCTION WORKING ADVANTAGES DISADVANTAGES APPLICATIONS CONCLUSION REFERENCE

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INTRODUCTIONWhat is Motor? Motor is a device which convert electrical energy to mechanical energy

Almost all the motors work on the principle of Faraday’s Law of Electromagnetic Induction.

The energy conversion in such motors involves two stagesElectrical energy to magnetic energy

Magnetic to mechanical energy.

Because of two-stage electromagnetic motor suffer from several losses that lead to energy wastage

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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

The Disadvantages Of Electromagnetic motors 5

Noisy operations

Magnetic losses

High power consumption

Low power factor

Comparatively lesser efficiency

TYPES OF ULTRASONIC MOTORULTRASONICMOTOR

STANDING WAVE TYPE

LINEARMOTOR

ROTARYMOTOR

TRAVELLINGWAVE TYPE

LINEARMOTOR

ROTARYMOTOR

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7LINEAR USM

Fig:-1

8ROTARY USM

Fig:-2

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.

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Fig:-3

PIEZOELECTRIC MATERIAL USED

Quartz(SiO2).

Barium titanate (BaTiO3).

Lead zirconate titanate(PbZrTiO3).

Lithium niobate titanate(LiNbO3).

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Compressing Force Potential difference`11

Fig:-4

BASIC STRUCTURE12

Fig:-5

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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Fig:-6

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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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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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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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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FUNDAMENTAL CONSTRUCTION OF USM 18

Fig:-7

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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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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The surface waves so produced ultrasonic frequency range. Not visible by our bare eyes.

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Fig:-8

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Fig:-9

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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Fig:-10

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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Fig:11

The other methods of classifications of USM

Type of motion* Rotary

* Linear * Spherical

Shape of implementation * Beam * Rod * Disk

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ADVANTAGES 26

High output torque & efficiency

Good positioning accuracy

Capable of working in extreme environmental conditions.

Simple construction

Compact size.

Energy saving

27DISADVANTAGE

High frequency supply range

Cost of Piezoelectric crystal

Large field application is not possible now.

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

29Auto focusing& optical zooming

Fig:-12 Fig:-13

30Disk heads of hard disks

Fig:-14

Fig:-15

31CASE STUDY

The case study is done in MRI robor bv ts by using PIEZO LEGS motors

ORAGNIZATIONWorcester Polytechnic Institute USA

INDUSTRYMedical Robotic Surgical Tools USA

Fig:-16

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

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

34Piezo LEGS Rotary 50

which provides positioning over 360° at micro-radian resolutions.

Fig:-18

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.

36BEFORE USING USM AFTER USING USM

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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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, China0041-624YAX/( 2016) Elsevier B.V.

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