LD COLLEGE OF ENGINEERING AHMEDABAD DC MOTOR

Present By; NAME ENROLLMENT NO. RONIT PATEL 140280109084 SACHIN PATEL 140280109085 SAGAR PATEL 140280109086 SHREYA PATEL 140280109087 VIDHIN PATEL 140280109088

INDEX HISTORY & INTRODUCTION OF THE DC MOTOR WORKING OF DC MOTOR CONSTRUCTION OF DC MOTOR TYPES OF DC MOTOR MERITS & DEMERITS OF DC MOTOR

Brief History of DC Motor The history of DC Motor can be traced back to the 1830s,when Michael Faraday did extensive works on disc type of machine

INTRODUCTION OF DC MOTOR A DC Motor is a machine which converts electrical energy into mechanical energy. It depends for its operation on the force which is known to exist on conductor carrying a current while situated in a magnetic field.

Working Principle Of DC MOTOR Whenever a current carrying conductor is placed in a magnetic field, it experienced a force whose direction is given by Fleming’s Left Hand Rule. It shows the field set up by the poles It shows the conductor field due to flow of current in the conductor

Construction of DC MOTOR FIELD POLES- The pole shoe acts as a support to the field coils and spread out the flux in the air gap and reduce the reluctance of magnetic field. FRAME- The Frame is the stationary part of a machine in which poles, and rotor are stationed. ARMATURE- The armature consist of core and winding. It is built up of thin lamination of low loss silicon steel(0.4 to 0.5)

Cont. COMMUTATOR- A commutator converts alternating voltage to direct voltage. It is a cylindrical structure built up of segment made drawn copper. BRUSHES- The use of brushes is made for machines designed for large current at low voltage. ARMATURE WINDING- The winding must be designated with the most advantages utilization of the material in respect to weight and efficiency

Types of dc motors The D.C motors are classified depending upon the way of connecting the field winding with the armature winding. D.C motor D.C compound motor Long shunt Short shunt D.C series motor D.C shunt motor

D.C series motor  

D.C shunt motor  

D.C compound motor Long shunt motor Short shunt motor    

Characteristics of a DC Motor Torque-Armature current(electrical) characteristic(T Vs Ia) Speed-Armature current characteristic(N Vs Ia)

Characteristics of a DC Shunt Motor

Characteristics of a DC Series Motor

Characteristics of a DC Compound Motor The compound motors are of two types namely the cumulative compound of differential compound motors.

DC Motor Applications: Shunt motor application printing machinery Paper machines Centrifugal and reciprocating pumps Series motor application Electric trains Cranes Hoists Conveyers Compound motor application Elevators Punches Shears planers

MERITS DEMERITS High starting torque Speed control over a wide range, both below and above normal speed Accurate seedless speed control Quick starting, stopping High initial cost Increased operating and maintenance cost because of the commutator and brush gear

APPLICATIONS OF DC MOTORS D.C. SHUNT MOTOR LATHES , FANS, PUMPS DISC AND BAND SAW DRIVE REQUIRING MODERATE TORQUES. D.C. SERIES MOTOR ELECTRIC TRACTION, HIGH SPEED TOOLS D.C. COMPOUND MOTOR ROLLING MILLS AND OTHER LOADS REQUIRING LARGE MOMENTARY TORQUES.