Abilash C A

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Seminar onSeminar on

ULTRASONIC MOTORSULTRASONIC MOTORSByBy

ABILASH C AABILASH C A

ELECTRICALELECTRICAL

MTI THRISSURMTI THRISSUR


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ContentsContents

Introduction

Working of USM

Principle of operation

Mechanism

Types of USM

Applications

Conclusion


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INTRODUCTIONINTRODUCTION

An Ultrasonic motor is a type of electric motorformed from the ultrasonic vibration of a

component, the stator being placed against

another, the rotor depending on the scheme of

operation.

These motors offer high torque density at low

speed, high holding torque, simple constructionand have a quick response.


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To obtain the levels of torque speed

characteristics of USM using conventional

motors we require to add a gear system to

reduce the speed.

USMs are fundamentally designed to

have high holding force,providing zero

backlash.

These characteristics of USM makes them

attractive for robotic applications wheresmall motions are required.


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ULTRASONIC MOTORULTRASONIC MOTOR


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WORKING OF USMWORKING OF USM

A travelling wave is established over thestator surface,which behaves as an elasticring and produces elliptical motion at theinter face with the rotor.

This elliptical motion of the contact surfacepropels the rotor and the drive shaftconnected to it.

The teeth which are attached to the statorare intended to increase the moment armto amplify the speed.


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TRAVELLING WAVE IN USMTRAVELLING WAVE IN USM
http://images.google.co.in/imgres?imgurl=http://ndeaa.jpl.nasa.gov/nasa-nde/usm/usm-sim.gif&imgrefurl=http://ndeaa.jpl.nasa.gov/nasa-nde/usm/usm-hp.htm&usg=__tFB1tAKj_th2opYghoB6mcVCl18=&h=259&w=260&sz=52&hl=en&start=13&tbnid=3kJITakhSER2aM:&tbnh=112&tbnw=112&prev=/images%3Fq%3DWORKING%2BOF%2BULTRASONIC%2BMOTORS%26gbv%3D2%26hl%3Den%26sa%3DG


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Principle of operationPrinciple of operation

The general principle of operation of theultrasonic motors is to generate gross

mechanical motion through the

amplification and repetition of microdeformations of the active material.

The active material, induces an orbital

motion of the stator of the stator at therotor contact points to produce macro

motion of the stator.


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The active material which is a peizo

electric material excites a traveling flexuralwave within the stator that leads to the

elliptical motion of the stator.

Teeth are used to enhance the speed thatis associated with the propelling effect of

these particles.

The frictional force between the stator androtor causes the rotor to spin.


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MechanismMechanism

Dry friction is often used in contact and thethe ultra sonic vibration induced in thestator is used both to impart motion to therotor and to modulate the frictional force

present at the interface. An exceptionally high torque hybrid

transducer ultrasonic motor usescircumferentially poled and axially poledpiezoelectric elements to combine axialand torsional vibration.


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TYPES OF USM

Bi-directional linear standing wave USM

Rotary Ultrasonic Motor

Spherical ultrasonic motor


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ApplicationsApplications

Canon was one of the pioneers of the

ultrasonic motors and made it famous for

the manufacture of the autofocus lenses.

USMs are also used in watch motors and

compact paper handling,in spacecraft

instruments and subsystems.


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ULTRASONIC MOTORS IN ROBOTICSULTRASONIC MOTORS IN ROBOTICS


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ConclusionConclusion

Hence the ultrasonic motors, which is a

new step in the miniaturized electrical

technology has got many applications in

small appliances because of its hightorque at low density.


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QUERIES?


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THANK UTHANK U

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