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.