GOVERNMENT COLLEGE OF ENGINEERING , AURANGABAD

Ultrasonic Motor

Presented By:Rahul Bibave (ME16F15F011)

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.

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

Construction of USM

Types of USM

Ultrasonic motor

Standing wave

bidirectional

unidirectional

Traveling wave

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.

Travelling 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

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.