The driving force behind any type of electric motor or engine is a tightly wound, well-engineered, coil. These simple devices are designed to create a magnetic field that is used to direct power or energy to produce mechanical force. The reliable performance of these components is normally ignored since we seldom think about what makes a motor run and depend on them when needed.
What is a Motor Coil?
Any form of wire produces a magnetic field when current passes through it. To enhance the energy of the magnetic field the wires are coiled to create a field coil or electromagnet. Wound coils magnify the magnetic field with each winding and increase its force. This factor is what drives a motor and is the essential element in a motor coil.
The basic design of any motor begins with a stator and rotor that transmit the electrical current. The interchange between the stator and rotor creates a magnetic field that turns the rotor and produces mechanical energy. They are the basic elements of an electric motor coil.
In an electric motor, the current sent into the motor coil has a magnetic field that experiences force to make the rotor turn. The force, energy, and power are what makes the motor run.
Electric motors have a winding for the stator and one for the rotor, with the current for the stator being higher than that for the rotor. The motor coil is mounted on either the stator or rotor depending on the design of the motor and cost effectiveness.
Motor Coil Materials
As with any form of electrical product, the center of the manufacture of a motor coil is copper wire that has been lacquered or enameled. The main purpose of the coating is to reduce the amount of heat produced, which is the main cause of winding failures. In some cases, aluminum is used since it has a lower cost than copper.
Factors for Motor Coil Performance
One of the things that needs to be avoided when producing any form of coil is dead space, which is caused by the style of winding and insulation. The best types of coils have a high fill factor where the coils are wound in such a manner that there is a limited amount of dead space.
To have a highly efficient and productive coil, it should be wound in such a way that each layer fits neatly into the slot between the wires below. Wire gauge and bundle size have to be monitored closely with the bundle size referring to the number of turns in the coil. The gauge or diameter of the wire is critical in determining how easily the wire can be wound and its number of turns.