ultrasonic motor

1. 1
Department of Electrical and Electronics Engineering
15-08-2022
ULTRASONIC
MOTOR
Name: VIJAY S HIREMATH
USN : 4NM19EE077

2. 2
Department of Electrical and Electronics Engineering
15-08-2022
Content
• Introduction
• Piezoelectric Effect
• Advantages of USM
• Basic Principle
• Fundamental Construction
• Types of USM
• Working Mechanism
• Application
• Conclusion

3. 3
Department of Electrical and Electronics Engineering
15-08-2022
Introduction
• It has been known for more than 30 years
• The first ultrasonic motor was introduce by v.v lavrinko in 1965
• An Ultrasonic motor is a type of electric motor formed from the ultrasonic vibration of a
component, the stator being placed against another, the rotor depending on the scheme of
operation
• Conversion of electric energy into motion by inverse piezoelectric effect
• To obtain the levels of torque speed characteristics of USM using conventional motors we
require to add a gear system to reduce the speed
• These characteristics of USM makes them attractive for robotic applications where small motions
are required
• This motor achieves high speed and drive forces, while still permitting the moving part to be
positioned with high accuracy

4. 4
Department of Electrical and Electronics Engineering
15-08-2022
What is Piezoelectric effect?
The piezoelectric effect is understood as the linear electromechanical interaction between the
mechanical and the electrical state in crystalline materials with no inversion symmetry
• Piezoelectricity – generation of voltage in response of mechanical stress
• The word is derived from the Greek piezein, which means to squeeze or press
• This effect is also reversible
• Deformation is only 0.1 % of the original dimension.
• Piezoelectric material- quartz(SiO2), barium titanate (BaTiO3) lead zirconate titanate and
occasionally lithium niobate

5. 5
Department of Electrical and Electronics Engineering
15-08-2022
Advantages
• Electromagnetic motors are notorious for consuming high amount of power and creating high
ambient motor temperatures respect to USM
• The electromagnetic motors produce strong magnetic fields which cause interference. Ultrasonic
motors use piezoelectric effect and hence no magnetic interference
• Electromagnetic motor has high input to output energy loss ratios
• USM High positional accuracy respect to Electromagnetic Motor
vs

6. 6
Department of Electrical and Electronics Engineering
15-08-2022
Basic Principle
• Generation of gross mechanical motion through the amplification and repetition of micro-
deformations of active material
• The active material induces an orbital motion of the stator at the rotor contact points
• Frictional interface between the rotor and stator rectifies the micro-motion to produce macro-
motion of the ROTOR
• Working frequency-20 KHz to 10 MHz
• Amplitude of the actuator motion – 20 to 200nm

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Department of Electrical and Electronics Engineering
15-08-2022
How it looks

8. 8
Department of Electrical and Electronics Engineering
15-08-2022
Construction

9. 9
Department of Electrical and Electronics Engineering
15-08-2022
Types of USM
Ultrasonic
Motors
Standing Wave
Bidirectional
Unidirectional
Traveling
Wave

10. 10
Department of Electrical and Electronics Engineering
15-08-2022
Standing Wave USM
• This type of motors use three groups of crystals: two
of which are Locking and one Motive.
• First, one group of locking crystals is activated — this
gives one locked side and one unlocked side of the
'sandwich'
• Next, the motive crystal group is triggered and held —
the expansion of this group moves the unlocked
locking group along the motor path. This is the only
stage where motor movement takes place
• This type of motor commonly known under the
names of Inchworm, Piezo LEGS or PiezoWalk
motors

11. 11
Department of Electrical and Electronics Engineering
15-08-2022
Traveling Wave USM
• Superposition of multiple standing wave create a traveling wave
• Representation of travelling wave
U(x ,p)= A cos(k x) cos(wt) + A cos(k x - 90) cos (wt-90)
• Phase difference is 90 degree
• The active material excites a traveling flexural wave within the stator that leads to elliptical motion of the surface
particles
• Teeth are used to enhance the speed that is associated with the propelling effect of these particles
• The rectification of the micro-motion an interface is provided by pressing the rotor on top of the stator and the
frictional force between the two causes the rotor to spin

12. 12
Department of Electrical and Electronics Engineering
15-08-2022
Applications
• Camera auto focus lenses
• Driving fluid
• Watch motors and compact paper handling
• Optoelectronics area
• In micro surgery and sensor scanning

13. 13
Department of Electrical and Electronics Engineering
15-08-2022
Conclusion
Hence the ultrasonic motors, which is a new step in the miniaturized
electrical technology has got many applications in small appliances because
of its high torque at low density

14. 14
Department of Electrical and Electronics Engineering
15-08-2022
Reference
• M. Kuribayashi, S. Ueha and E. Mori, "Excitation conditions of flexural traveling
waves for a reversible ultrasonic linear motor", J. Acoust. Soc. Am., vol. 77, no. 4, pp.
1431-1435, Apr. 1985
• T. Sashida, "Trial construction of an ultrasonic vibration driven motor", Oyo
Butsuri, vol. 51, no. 6, pp. 713-720, 1982
• S. Takahashi, "Multilayer piezoelectric ceramic actuators and their
applications", Jpn. J. Appl. Phys., vol. 24, no. Suppl.24-2, pp. 41-45, 1985

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Department of Electrical and Electronics Engineering
15-08-2022
Thank You