Study of AC and DC Motors....a Presentation for Mechanical Engg. student.

1. Industrial Summer Training
BHEL HARIDWAR
Presentation By:
Arun Kumar Gupta
Final Year ME-G
0902740026

2. Training Sections
Introductory Classroom
Sessions about BHEL.
Plant Visit and Self
Observation.
Specific Work under
Supervision.

3. Bharat Heavy Electricals Limited
• Largest power equipment manufacturer in
India and 7th Largest in the world.
• Engaged in the Design, Engineering,
Manufacture, Construction, Testing,
Commissioning and Servicing of a wide range
of products and services.
• Covers Power, Transmission, Heavy Industry,
Transportation, Renewable Energy, Oil & Gas.

4. Presence
• 15 manufacturing divisions.
• Two repair units.
• Four regional offices.
• Eight service centres.
• Eight overseas offices.
• 15 regional centres and
• Currently operates at more than 150 project
sites across India and abroad.

5. .....and.....
• Ranked ninth most
innovative company
in the world by US
business magazine
Forbes.
• The only Indian
Engineering
company on the list.

6. Summer Training 2012
Study of AC and DC Motors
BHEL HARIDWAR

7. BHEL Ranipur
• Started in 1960s with the
help of Russia and Czech.
• BHEL has two plants
here:
– HEEP: Heavy Electrical
Equipment Plant.
– CFFP: Central Foundry
Forge Plant.
• Spread in about 5000
Acres.

8. Product Profile

9. DC Motors
• A DC motor is an electric motor that runs
on direct current (DC) electricity
• Main Parts:

10. Poles of Motors
Two Pole Motor Four Pole Motor

11. Armature
Actual Image of Armature

12. Output of the DC Motors

13. Manufacturing of DC Motor
• SHAFT MACHINING:-
– It involves finishing of shaft by machining it with a central
lathe machine.
– It is done in accordance to the engineering drawing design.
Special care is taken to maintain the tolerance level.
• SLOTTING:-
– Two types of machines do slotting, air cooled and liquid
cooled.
– Slotting is done diametrically. First the shaft is made to rest
on two horizontal plates and is firmly attached to them with
the help of chains which exerts load and with the help of jack
so that it handles the vibrations produced during the slotting
process.

14. • ROTOR WINDING :-
– Rotor winding involves coiling of rotor.
– Rotor coils are made of pure copper + 0.2% silver, which has
high tensile as well as temperature bearing properties.
– The coil doesn’t deform even at high temperatures as on
adding silver the thermal stresses are eliminated.
• ROTOR SLOT WEDGES :-
– To protect the rotor windings against the effects of
centrifugal force and the secured in slots with wedges.
– Slot wedges are made of copper-nickel-silicon alloy featuring
high temperature resistance and high strength.
– There is retaining ring, which protects the rotor from the
impact of centrifugal force on end windings.

15. – Comprehensive tests such as ultrasonic examination and
liquid penetration examination are carried out in the coils.
– To ensure low contact resistance, retaining rings are coated
with nickel, aluminium and silver by three step flame-
spraying process.

16. AC Motors
• An AC motor is an electric motor driven by
an alternating current.
• Major Parts:

17. Types of AC Motors
• On the basis of types of Rotor Used:
Induction Motor. Synchronous Motor.

18. Manufacturing of AC Motors
Image of Conductor Bars and their Cuts

19. Manufacturing of Stator
• Stator Frame:
– Stator body is a totally enclosed gas tight fabricated structure
made up of high quality mild steel and austenitic steel.
– It is suitably ribbed with annular rings in inner walls to ensure
high rigidity and strength. The arrangement, location and
shape of inner walls is determined by the cooling circuit for
the flow of the gas and required mechanical strength and
stiffness.
• Stator Core:
– It consists of thin laminations. Each lamination made of
number of individual segments.
– Segments are stamped out with accurately finished die from
the sheets of cold rolled high quality silicon steel.

20. Manufacturing of Rotor
• Rotor Shaft:
– The rotor shaft is a single piece solid forging manufactured
from a vacuum casting.
• Rotor Winding:
– After preliminary turning, longitudinal slots are milled on
horizontal slot milling machine.
– The slot houses the field winding consists of several coils.
• Rotor Wedges:
– For protection against the effect of centrifugal force the
winding is secured in the slots by slot wedge.
– The wedges are made from duralumin, an alloy of copper,
magnesium and aluminium having good electrical
conductivity and high mechanical strength.

21. • Retaining Ring:
– The overhang portion of field winding is held by non-
magnetic steel forging of retaining ring against centrifugal
forces.

22. AC motor Data Plate

23. Questions.....?

24. Thank You