It will help to know about the how the magnetic bearing will work

1. B.L.D.E.A's V.P. Dr. P.G.HALAKATTI COLLEGE OF
ENGINEERING AND TECHNOLOGY
VIJAYAPUR - 586103
Department of Mechanical Engineering
2018-19
A Seminar on
“STUDY OF MAGNETIC BEARING”
PRESENTED BY : GUIDED BY:
BASAVARAJ KALLIGUDD (2BL16ME408) Dr. R.G.TIKOTKAR.

2. INTRODUCTION
 A magnetic bearing is a bearing which supports a load using
magnetic levitation.
 A magnetic bearing support the moving machinery without
physical contact.
 Magnetic bearing support the highest speed of any kind of
shaft.
 By monitoring the position of the shaft, the magnetic
bearing keeps the rotor in a desired position.

3. Elements of the System
 Electromagnets
 Rotor
 Sensor
 Controller
 amplifier

4. Working principle

5.  The working of magnetic bearings is based upon the principle that
an electromagnet will attract ferromagnetic material.
 A ferromagnetic rotor can be supported in a magnetic field
generated in the bearing electromagnet stator.
 Since the nature tendency of the stator is to attract the rotor until it
makes contact, some control action is required to modulate the
magnetic field and maintain the rotor in the desired position.
 The most common type of control involves the feedback of shaft
position.
 This information is then used by the control system to modulate the
magnetic field through power amplifiers, so that the desired rotor
position is maintained even under changing shaft load conditions.

6. There are two types
 Active magnetic bearing (AMB)
 Passive magnetic bearing (PMB)
Active magnetic bearing :
 Require a specialized control and software.
 They are comprised of three distinct parts : the bearing
itself, the electronic control system, and the auxiliary
bearings.
 The purpose of the electronic control system is to control
the position of the rotor by varying the current in the
electro magnets.
 The auxiliary bearings are used to support the rotor
when the machine is stationary.

7. Passive magnetic bearing
Passive magnetic bearings (PMB) do not require control hardware or
software for operation.
They have lower stiffness and damping characteristics than similar size
active bearings.
Passive bearings can be constructed with permanent magnets.

8. Advantages:
 Low wear rate and low vibration.
 Possibility of adjust position between the shaft and the
bearing.
 Absence of mechanical contact between shaft and
bearing.
 High rotational speeds.
 No lubrication is required.
Disadvantages :
 Magnetic bearing have a specific load capacity lower than
other bearing.
 Magnetic bearing require power to drive the control
system, sensor and electromagnets.
 High initial cost.

9. Applications
Flywheel :
 To reduce the rotational loss
 Increase the life of the shaft
 It detect the overload condition and
instantly shut down the machining operation
Maglev trains :
 It provide the typical speed of 350kmh
 150 mm levitation over the guideway track
 Stator : track, rotor : magnets on trains

10. Other Applications:
 These bearings are also commonly used watt-hour meters by electric
utilities to measure home power consumption.
 Magnetic bearings can be used in the grinding machine to improve
the grinding performance.
 Magnetic bearings are also used in the high precision instrument
and support the equipment in vacuum.
 These are also used in the turbo-compressor rotor.

11. THANK YOU