Motor
A Electrical Machine which changes the electrical energy into mechanical energy is called Motor.
On the basis of electrical supply .They are of two types:
- AC Motor
- Dc Motor
Dc Motor
- Dc Motor is run by Dc Source and covert Dc electrical energy into mechanical energy.
- When a current carrying conductor is placed on a magnetic field, it will experience a force which can be determined by Fleming's Left Hand Rule.
- Dc Motor are subdivided into different category by changing the connection of armature winding and fielding winding.
Construction:
Yoke:
- The Outer Frame/Yoke is a hollow cylinder of cast iron or unlaminated ferromagnetic material and protecting cover to the machine.
- Yoke is stationary and no flux variation take place ,hence no iron loses. So, no need of lamination required.
- It provides mechanical support and path for the pole flux and carry half of the magnetic field flux and other half by the armature core.
- Field core consist of pole core and pole shoe and made up sheet steel lamination's that are insulated from each other to reduce eddy-current losses.
- Pole shoe are fixed to the pole core appropriately having a curved surface towards center.It supports the field coils and increase the cross section area of the magnetic circuit and reduces its reluctance.
- Each pole has one or more field coil to produce magnetic field.
Armature:
- It consists of a shaft upon which a laminated cylinder is mounted.The armature core has grooves or slots on its outer surface.
- Armature conductor is located on this slots.The connected arrangement of conductors is armature winding.
- Armature core provides the low reluctance path for the magnetic field.It is made up of thick lamination of silicon steel to reduce the eddy-current losses.
