The document presents information about magnetic bearings by Biswajit Swain, a mechanical engineering student at Radhakrishna Institute of Engineering and Technology. It discusses the basic operation of magnetic bearings, including how they levitate rotating shafts and moving machinery without physical contact using electromagnetic attraction. It also covers the classification, advantages, and applications of magnetic bearings, such as their use in compressors, turbines, pumps, motors and generators where high speeds are possible without lubrication or wear.

1. PRESENTED BY : BISWAJIT
SWAIN
MECHANICAL
ENGINEERING
REGD. NO. : 1121367047
7th SEMESTER
RADHAKRISHNA INSTITUTE OF ENGINEERING AND
TECHNOLOGY,BHUBANESWAR.

2. CONTENTS:
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BEARING
MAGNETIC BEARING
DESCRIPTION
BASIC OPERATION
CLASSIFICATION
MAGNETIC BEARING PERFORM
ADVANTAGES
DISADVANTAGES
APPLICATION
CONCLUSION
REFERENCE

3. BEARING
 A Bearing is a machine
element which support
another moving
element.
 It permits relative
motion between the
contact surfaces of the
members while carrying
a load.
 Most bearings support
rotating shafts against
either radial or axial

4. MAGNETIC BEARING
 A Magnetic bearing is a
bearing which supports
a load a load using
magnetic levitation.
 A Magnetic bearing
support moving
machinery without
physical contact,for
example,they can
levitate a rotating shaft

5. and linear moving
machinery
elements,without contact
with rotor,this is
accomplished by electro
magnet(bearing) which
attracts a ferromagnetic
material(rotor),using this
principle rotor can be
suspended in magnetic
field which is generated
by bearing.

6. DESCRIPTION
 It is difficult to build a
magnetic bearing using
permanent magnets due
to the limitation imposed
and techniques using
diamagnetic materials
are relatively
undeveloped.
 As a result, most
magnetic bearing require
continuous power input
and an active control
system to hold the load
stable. Because of this

7. BASIC OPERATION
 An active magnetic
bearing (AMB) works on
the principle
of electromagnetic
suspension and consists
of
an electromagnet assembl
y, a set of power
amplifiers which supply
current to the
electromagnets, a controll
er, and gap sensors with

8. •The power amplifier supplies equal bias
current to two pairs of electromagnets on
opposite sides of a rotor. This constant
tug-of-war is mediated by the controller
which offsets the bias current by equal and
opposite perturbations of current as the
•The gap sensors are usually inductive in
rotor deviates from a differential mode.
nature and sense in its center position.
The power amplifiers in a modern
commercial application are solid state
devices which operate in a pulse width
modulation (PWM) configuration. The

9. Classification
 According to Control action
– Active
– Passive
– Hybrid
 According to Forcing action
– Repulsive
– Attractive
 According to Sensing action
– Sensor sensing
– Self sensing

10. •According to Load support
– Axial or Thrust
– Radial or Journal
– Conical
•According to Magnetic effect
– Electro magnetic
– Electro dynamic

11. MAGNETIC BEARING PERFORM
 Lubrication Free
 Clean & Contamination Free
 Reliability
 High Surface Speed
 Low Vibration
 Low Energy Consumption
 Non-Contacting
 Submerged Operation

12. aDVANTAGES
Highest speeds are possible even till the
ultimate strength of the rotor.
 Absence of lubrication seals allows the
larger and stiffer rotor shafts.
 Absence of mechanical wear results in
lower maintenance costs and longer life
of the system.
 Adaptable stiffness can be used in
vibration isolation,passing critical
speeds, robust to external disturbances


13. DISADVANTAGES
 Include High Cost.
 Large in Size.

14. APPLICATIONS
 Magnetic bearings are increasingly
used in industrial machines such as
compressors, turbines, pumps, motors
and generators.
 Magnetic bearings are commonly used
in watt-hour meters by electric utilities
to measure home power consumption.
 A new application of magnetic bearings
is their use in artificial hearts.

15. CONCLUSION
 Magnetic bearings advantages and
applications have been discussed .
 Electromagnetism and Control system
technologies have been introduced .
 Design of thrust and radial magnetic
bearings have been studied .
 Control of a rotor by rigid rotor and
flexible rotor models have been studied
.

16. REFERENCES
 Schweitzer, G., Bleuler, H. and
Traxler, “Basic Properties and
Applications of Active Magnetic
Bearings.
 Chiba, A., Fukao, T., Ichikawa, O., Oshi
ma, M., Takemoto, “Magnetic Bearings
& Bearingless Drives.
 Maslen, E., “Magnetic
Bearings”, University of Virginia.