1. A
Seminar
on
ULTRASONIC MOTORS
By
Y.CHAKRI VENKATA DINESH
(13HM1A0217)
Department of Electrical And Electronics Engineering
Annamacharya Institute of Technology and Sciences
19/01/17 1Dept.of EEE,AITS-KADAPA
2. Contents
Introduction
Drawbacks of Electro Magnetic Motors
Principle of operation
Construction
Working
Characteristic features
Advantages & Disadvantages
Applications
Conclusion
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3. Introduction
A motor is a machine which converts electrical
energy into mechanical energy.
UltraSonic Motors (USMs) are next generation
motors.
The first USM was developed by Russian scientist in
1965
USMs are characterized by the absence of noise
during operation , high accurate speed and position
control etc.,
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4. Drawbacks of Electro Magnetic Motors
Noisy operation
Less efficiency
High motor temperatures
High cost
Increased size with increase in rating of motor
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5. Principle of operation
USM works on the principle of Converse Piezoelectric
Effect.
(a)When applied DC voltage has same polarity
(b) When applied DC voltage has opposite polarity
(c) When AC voltage is applied
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8. Working
When high frequency voltage (>20KHz) is applied
piezoelectric material vibrates.
There are two power transformations involved in
running of USM.
(a)Conversion of Electrical energy into
mechanical vibrational energy by Inverse
Piezoelectric Effect.
(b)Vibrational energy of stator is
transformed into continuous moving
energy of rotor due to frictional interaction
between stator and rotor.
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9. Characteristics of USM
Simple construction
Absence of magnetic action
Low Speed
High Torque
Quick response
Noiseless
Compact
Lightweight
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10. Advantages of USM
Low AC voltage excitation
High torque at low speeds
Short time response
Ultra small size can be easily miniaturized
Dust free
Noiseless operation
High efficiency
High torque/weight ratio
No magnetic interference
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11. Disadvantages of USM
Piezoelectric materials are expensive
Requires high frequency power supply (>20 KHz)
Ultrasonic noise occurs
Due to friction life of motor reduces
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12. Applications
Auto focusing & optical zooming in digital cameras
Automatic wrist watches
Power windows
Roll screen motor for automatic open & close actions
Actuators for VCRs & CD players
Robotics
Wall clocks
Ultrasonic welding
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13. Conclusion
The above mentioned
advantages and applications concludes scope
of USMs in day - to -day life.
However disadvantages
brings up need for further researches in fields.
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