The led panel lights is generally composed of a DC moto […]
The led panel lights is generally composed of a DC motor, a transmission mechanism and an electromagnetic switch.
1. DC motor construction
The DC motor is composed of an armature, a magnetic pole, a casing, a brush and a brush holder.
(1) Armature assembly The armature is used to generate electromagnetic torque, which is composed of a core, an armature winding, an armature shaft and a commutator. The armature core is formed by stacking a plurality of mutually insulated silicon steel sheets; the armature winding is wound by a thick copper flat wire by a wave winding method; the copper of the commutator is thick, and mica is used between adjacent copper sheets. Sheet insulation.
2. Magnetic pole
The magnetic pole is composed of a core and an exciting winding, and its function is to generate a magnetic field in the motor. The pole core is generally made of low carbon steel and fixed to the motor casing by screws. The magnetic poles are generally four, and two pairs of magnetic poles form two pairs of magnetic poles, which are opposite to each other. A common excitation winding is generally connected in series with the armature winding, so it is called a series-excited direct current motor.
3. Brush and brush holder
The function of the brush and the brush holder is to introduce current into the armature to cause the armature to rotate continuously. Brushes are generally pressed with copper and graphite to help reduce electrical resistance and increase wear resistance. The brush is mounted in the brush holder and pressed against the commutator by the spring pressure. Directly connected to the outer casing to form a circuit ground, called a grounding brush, connected to the excitation winding and the armature winding, and insulated from the outer casing, called an insulated brush.
The outer casing is rolled from low carbon steel or cast from cast iron. The starting time of the starter is very short, so sliding bearings are generally used. The deceleration starter uses a rolling bearing because of the high rotational speed of its armature.