Magnetic bearing

Presentation on magnetic bearing

1. MAGNETIC BEARING NAME : SHEIKH SADI ID : 2015006623 MAJOR : MECHATRONICS ENGINEERING HUZHOU UNIVERSITY

2. CONTENTS:  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 and permit relative

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 complexity, the magnetic

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 andopposite perturbations of current as therotor deviates from its center position The gap sensors are usually inductive in nature and sense in a differential mode. The power amplifiers in a modern commercial application are solid state devices which operate in a pulse width modulation (PWM) configuration.

9. Classification According to Control action – Active – Passive – Hybrid According to Forcing action – Repulsive – Attractive According to Sensing action – Sensor sensing – Self sensing According to Magnetic effect – Electro magnetic – Electro dynamic According to Load support – Axial or Thrust – Radial or Journal – Conica l

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

11. 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

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

13. 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.

14. 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 .

15. REFERENCES Internet : www.google.com www.Wikipedia.org www.linkedin.com

16. Thank you