Construction of a Series Wound DC Motor
The Components of the series wound DC motor include
Construction of Series wound Motor
Majorly, it is divided into three main categories.
- Stator
- Armature
- Brushes
Stator
- Frame: Unlike some motor designs that utilize a solid cast iron frame, series wound DC motors often employ a lighter and more economical approach. The stator frame can be constructed from rolled steel sheets laminated together. This lamination minimizes eddy currents, which are parasitic currents induced in the solid metal by the changing magnetic field. Eddy currents create unnecessary heat loss and reduce motor efficiency.
- Field Windings: The field windings are the heart of the magnetic field generation. Traditionally, these windings are made from thick, round copper wires with high current carrying capacity. However, for some high-performance applications, alternative wire shapes like rectangular or square copper conductors might be used. These shapes can improve packing density within the limited space available for the windings, allowing for more turns and a stronger magnetic field.
Armature
- Core: Similar to the stator frame, the armature core is often laminated from steel sheets to minimize eddy currents. However, the core design can be more intricate than a simple cylinder. Some series wound DC motors, particularly those designed for high torque, might employ slotted cores with skewed slots. By a slight change of angle to the axis of rotation helps to reduce cogging torque. Due to the interaction between the permanent magnets , unequal torque experienced by the motor shaft is called cogging torque.
- Commutator: Mainly, It is used for armature windings to ensure correct current flow. Traditionally, commutator segments were made from solid copper. However, modern motors might utilize copper segments with silver brazing on the contact surfaces with the brushes. This brazing material offers superior wear resistance compared to pure copper, extending the commutator’s lifespan.
- Armature Windings: It is typically made up of round copper wire, but for high-power applications, rectangular or square copper conductors might be used for improved packing density. Based on the motors design and performance, the winding pattern can be changed. Some motors might employ lap windings, while others utilize wave windings. These winding configurations influence factors like the number of poles generated, back EMF (electromotive force) produced, and overall motor behavior.
Brushes
- Brushes are the sliding electrical contacts that transfer current to the commutator. It is made up of carbon or graphite. Brushes made from a combination of copper and graphite for high performance and for critical environments, brushes are used. Compared to pure carbon brushes, It improves current carrying capacity and reduces sparking. These brushes are also known as metal graphite brushes.
There is a another one which is responsible for rotation.
- Shaft and Bearings: To handle the torque generated by the motor and transmit it to the load, the shaft is needed. It is made up of high strength steel. The shaft also extends outwards to connect the motor to the load it needs to drive. For the shaft rotation, bearings are supported. It can be ball bearings or roller bearings.
Series Wound DC Motor or DC Series Motor
In electric motors, the series wound DC motor or DC series motor is one of the types of self-excited DC motor. The field winding of the series wound DC motor is internally connected to the armature winding and stands out for its robust starting torque and unique characteristics. Whereas in the shunt wound DC motor, the field winding is connected in parallel with the armature winding.
In this article, we will cover the topics of Construction, Voltage and current equation, Speed regulation and with the advantages, disadvantages and applications of series wound DC motor or DC Series Motor.
Table of Content
- Series Wound DC Motor or DC series Motor
- Construction
- Voltage and Current Equation
- Speed and Torque
- Speed Regulation
- Characteristics
- Advantages and Disadvantages
- Applications