This document summarizes an seminar presentation on ultrasonic motors. It discusses that ultrasonic motors have been known for over 30 years and are now used in small applications. Ultrasonic motors use piezoelectric materials to convert electric energy to motion via ultrasonic vibrations between a stator and rotor, achieving high speed and precision. They have advantages over electromagnetic motors such as high torque, compact size, and lack of magnetic interference. However, their use is limited by the cost of piezoelectric materials and generation of ultrasonic noise.

1. SEMINAR
ON
“ULTRASONIC MOTOR”
Prepared by,
VISHNURAJ.MR
S5 AUTOMOBILE
ROLL NUMBER.44
Dept. of
AUTOMOBILE.
ENGREGISTER
NUM
[2101051754]

3.  It has been known from more than 30 years.
 After some research work now a days it is implemented
in our small applications.
 An Ultrasonic motor is a type of electric motor formed
from the ultrasonic vibration of a component, and that
vibration is feel by the stator, the rotor depending on the
scheme of operation.
 Conversion of electric energy into motion by
piezoelectric effect.

4.  It has very good torque-speed characteristics.
 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.

6.  Piezoelectricity – generation of voltage in response of
mechanical stress.
 Deformation is only 0.1 % of the original dimension.
 Piezoelectric material:- quartz(SiO2), barium titanate (BaTiO3)
Rochelle salt and certain types of ceramics.
“The piezoelectric effect is understood as the linear
electromechanical interaction between the mechanical
and the electrical state in crystalline materials with no
inversion symmetry.”

7.  Electromagnetic motors are famous 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.
 Piezoelectric motor has High positional accuracy respect to
Electromagnetic Motor.

9.  When a voltage is applied to a piezoelectric element,
alternating expansion and contraction occur either in
the ceramic body itself or in the piezoelectric body
 And that body is connected with stator.
 So the stator is also vibrate.
 Frictional interface between the rotor and stator.
 This produce the motion in the ROTOR.
 And its Working frequency is around 20 KHz to 10
MHz.

11. Ultrasonic
motor
Standing
wave
Traveling
wave

12.  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.
 In this stator is particles vibrating only in vertical
direction.
 Low cost, and unidirectional,

14.  The active material excites a traveling wave within
the stator that leads to elliptical motion of the surface
particles.
 The stator has its particles vibrating both in the
vertical direction as well as horizontal direction.
 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.
 Controllable in both direction.

16.  Low cost
 High efficiency
 No magnetic interference
 Compact size
 High torque/weight ratio
 Energy saving

17.  Use of high frequency power supply
 Piezoelectric material is expensive.
 Ultrasonic noise occurs.
 Due to friction life of motor is become less.

18.  Auto focusing & optical zooming
in digital cameras.
 Wrist watches & Clocks.
 Robotics.
 Aerospace.
 Medical application.
 Hardware positioning (Hard
disks, Floppy & CD Drives) etc.

19.  The above mentioned advantages and applications,
concludes the scope of USMs in the day-to-day life.
 Hence the ultrasonic motors, which is a new step in
the electrical technology has got many small
applications because of its high torque at low
density.

20.  However the disadvantages brings up the need
for further researches in the field.
 Suppose if we can minimize the friction loss
between stator and rotor by implementing some
new techniques then this motor is become more
useful than conventional motor.