Vibration motor is a compact size coreless DC motor used toinforms the users of receiving the signal by vibrating, no sound. Vibration motors are widely used in a variety of applications including cell phones, handsets, pagers, and so on. The main features of vibration motor is the magnet coreless DC motor are permanent, which means it will always have its magnetic properties (unlike an electromagnet, which only behaves like a magnet when an electric current runs through it); another main feature is the size of the motor itself is small, and thus light weight. Moreover, the noise and the power consumption that the motor produce while using are low. Based on those features, the performance of the motor is highly reliable.
The vibration motors are configured in two basic varieties: coin (or flat) and cylinder (or bar). There are some components in both of their internal constructions.
Rotor:
The rotor is the non-stationary part of a rotary electric motor. The wires and magnetic field of the motor are arranged so that a torque is developed about the rotor’s axis. In some designs, the rotor can act to serve as the motor’s armature, across which the input voltage is supplied.
Stator:
The stator is the stationary part of a rotary electric motor. It could be worked as the magnet field and interact with the armature to create motion. Another function of the stator is it could act as the armature, which receives its influence from moving field coils on the rotor.
Commutator:
A commutator is a rotary electrical switch in certain types of electric motors or electrical generators that periodically reverses the current direction between the rotor and the external circuit. In a motor, it applies power to the best location on the rotor, and in a generator, picks off power similarly. As a switch, it has exceptionally long life, considering the number of circuit makes and breaks that occur in normal operation.
Armature:
The armature in this motor is a set of thin metal plates stacked together, with thin copper wire coiled around each of the three poles of the armature. (How the electric motor works) The main function of the armature is to convert the magnetic energy into the kinetic energy.
Windings:
Windings are consisted with some turns of coils. These coils are assembled to generate a magnetic field once electricity goes through them.
Weight:
In order to make a vibrating alert, a weight mass need to be attached to the shaft. Through the high speed displacement of weight, the vibration can be achieved. Moreover, the magnitude of the force can be controlled and adjusted, and the factors that could affect it will be discussed below.
Brushes:
In motor’s shaft, the brushes conduct the current between stator and coils. The life of the motor depends on when the brushes will be worn out. Based on this factor, brushless dc motor, which is also called BLDC, is used to extend the life of motors.