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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%3DG7/29/2019 Abilash C A
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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