This document discusses ultrasonic motors, which use ultrasonic vibrations from a piezoelectric transducer to generate torque. It describes how they work by establishing a traveling wave on the stator that causes elliptical motion to propel the rotor. Ultrasonic motors are classified based on their mode of operation, type of motion, and shape. Their advantages include compact size, high accuracy, and resistance to electromagnetic fields. Applications include camera autofocus systems, medical equipment, and small robotics. Future work may include using ultrasonic motors in miniature surgical robots.

1. BY:-
Saumya Ranjan Behura

2. CONTENTS
INTRODUCTION.
 WORKING.
 CLASSIFICATION.
 ADVANTAGES.
 APPLICATIONS.
 FUTURE WORK.

3. INTRODUCTION
 An Ultrasonic motor (USM) is a type of electric motor driven
by ultrasonic vibration of a piezoelectric transducer.
 The ultrasonic vibration is transformed into output torque by
friction between the stator and the rotor.
 USMs are often called solid state motors.
 Most common application is in camera lenses as a part of
autofocus system is used to move lens element.

5. WORKING
 A traveling wave is established over the stator
surface, which behaves as an elastic ring and produces
elliptical motion at the inter face with the rotor.
This elliptical motion of the contact surface propels
the rotor and the drive shaft connected to it.
The teeth which are attached to the stator are intended
to increase the moment arm to amplify the speed.

6. TRAVELLING WAVE IN USM

8. CLASSIFICATION
USMs can be classified in the following ways:
 Mode of operation:
• Static
• Resonant
 Type of motion:
• Rotary
• Linear
 Shape of implementation:
• Beam
• Rod
• Disk

9. PROTOTYPES OF USM
 Linear standing wave USM
Rotary Ultrasonic Motor
Spherical ultrasonic motor

10. SPHERICAL USM
This particular USM consists of a thin square plate,
30x30mm in area.
It can rotate in more than 4 individual directions.

11. ADVANTAGES
The major advantages of USMs are:
 Compact, lightweight, flexible and robust.
 High positioning accuracy.
 High low-speed torque and holding torque.
 Unaffected by external electric or magnetic fields.
 Quiet drive system.
 Hard brake with no backlash.
 Variable stroke.
 Quick response.

12. APPLICATIONS
Some applications where USMs have been used are:
 Camera lens autofocus.
 Spacecraft planetary instruments.
 Medical equipment (MRIs etc).
 Small robotic joints.

13. FUTURE WORK
 One very promising research area is in medical
diagnostic instruments.
 The Robotics Institute of Carnegie Mellon University and
the Division of Cardiac Surgery at the University of
Pittsburgh are teaming up to create a tiny robot called the
HeartLander.

14.  The HeartLander is a
tiny robot that surgeons
could insert into a
patient’s chest cavity
through a minimally
invasive incision which
could move along the
surface.
 The surgeon would be
able to control every
movement external to
the patients body.

15. 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.