What is the insulation structure conducive to the stability of micro motor performance?

For micro motor products, the winding is the heart of the motor, the winding should maintain an insulating relationship with the iron core and other parts, and the winding is the main part of the micro motor that transmits electrical energy. The electrical energy comes from the external power supply, passes through the wires in the winding, and is transmitted to the motor chip of the micro motor. The wire of the winding is covered with insulation material, which can protect the wire from external factors such as moisture, rain, etc., and prevent short circuit between the wires. Next is the content of the insulation structure of the motor coil.
The insulation structure of the coil refers to the coating and protection of the internal and external insulating materials of the coil. It is one of the most important structures in electronic equipment such as motors and transformers, which directly affects the reliability, safety and service life of the equipment. The insulation structure of mini dc motor coil is one of the key factors to ensure its stable operation and prolong its service life. The principle is to use the electrical characteristics of different materials to form a certain electric field distribution between the conductor and the conductor of the coil and between the conductor and the shell, so that there will be no charge interaction between different parts of the coil, so as to achieve the purpose of insulation.

Coil insulation structure design and quality directly affect the performance and life of the motor. Excellent coil insulation structure can effectively improve the performance, the stability and reliability of the motor. The specific performance is as follows:
1. Improve the electrical insulation strength of the motor. Careful design and selection of suitable coil insulation materials can improve the electrical insulation strength of the motor, reduce the leakage current, and effectively prevent the short circuit and damage of the motor.
2. Improve the high temperature resistance of the motor. Reasonable design and selection of high temperature and heat resistant insulation materials can effectively improve the high temperature resistance and service life of the motor, and reduce the damage and failure caused by the motor overheating.
3. Improve the mechanical strength and vibration resistance of the motor. The use of precision winding process and high-strength insulating materials can improve the mechanical strength and vibration resistance of the motor, so that the motor is more stable and reliable during operation.
4. Reduce motor loss and noise. Reasonable coil insulation structure can effectively reduce the loss and noise of the motor, improve the efficiency and operation stability of the motor. The use of high-quality insulation materials and winding process can reduce the eddy current loss and hysteresis loss of the coil, and reduce the heat and noise of the motor.

According to different working environment and requirements, the design of micromotor coil insulation structure can adopt different materials and methods, such as coated winding, full impregnation, local impregnation and organic coating. Among them, thermoplastic, thermosetting resin, insulating paper, insulating cotton and other materials have good insulation properties, and are widely used in the insulation structure of micromotor coils. The core relates to interturn insulation, ground insulation and external insulation.

Interturn insulation
The effect of interturn insulation is to insulate adjacent components in the same coil and only withstand inter-chip voltage. The insulation between turns of large DC motors generally adopts a layer of 0.1mm mica tape on the outer half of bare copper wire, or directly adopts a high-strength enamelled double glass wire. Medium and small motors generally use double glass wire. In class F film edge large motors can be made of 0.05 mm film half-stacked and the film "sintered" on the conductor, or coated with a layer of glass ribbon. Medium and small motor half pack a layer of 0.05 mm film or "sintered" the film on the conductor. Under normal circumstances, the insulation between turns depends only on the insulation carried by the electromagnetic wire itself, such as enamelled wire, single glass wire or double glass wire. Glass wire enamelled wire, polyimide film sintered wire and other self-contained insulation. Interturn insulation is the most important and usually weak insulation in the motor insulation structure, so in the design of interturn insulation should pay attention to the selection of materials, in the manufacturing process must pay attention to, the wire should be smooth, no flash, burr, etc., can not be due to mechanical strain between turns insulation.

Insulation to ground
Ground insulation refers to the main insulation outside the coil. Ground insulation Main insulation, withstand the full voltage between the coil and the core. 1000 volt class large motor: 0.14 mm alkyd mica tape half folded around three layers. 660 volt class medium motor: 0.14 mm alkyd mica tape half folded two layers (continuous insulation) or 0.2 mm mica foil roll wrapped two layers (sleeve insulation). F class film large motor: 0.05 mm polyimide film half folded around four layers. Medium and small grade F or H motor: 0.05 mm polyimide film half folded around 2 ~ 3 layers. It is mainly subjected to the rated voltage of the motor or possible overvoltage, and its working voltage is higher, so its electrical, mechanical and thermal properties must meet the requirements of the motor operating state. The thickness of insulation to the ground generally depends on the rated working voltage of the motor and the electrical and mechanical properties of the insulation material, the higher the rated voltage of the motor, the more layers of insulation to the ground, or the thicker the thickness of the paint film. The increase of insulation thickness will reduce the heat dissipation effect and increase the temperature rise. For motors with low voltage, the consideration of the mechanical properties of the insulation is even more than the consideration of the electrical insulation properties. For high-voltage motors, if the insulation wrapping is not standardized, it will lead to the dipping effect, and serious discharge problems will occur because of the bubbles in the insulation layer.

External insulation
The insulation wrapped outside the ground insulation is mainly to protect the ground insulation from mechanical damage and make the whole coil strong and flat, and also plays a reinforcing role in the ground insulation. The coil external insulation includes the coil packaging, sheath and insulation layer. These insulation materials can be selected according to the need for different grades and functions. Commonly used materials include polyimide film, coated plastic insulation, silicone rubber and heat shrink tubes. Its role is mainly to protect the landlord insulation from mechanical equipment bruising and make all coils firm and irregular, the main insulation has a strengthening effect, and most of the outsourcing insulation uses glass fiber ribbon.

In the production process of the insulation structure, various process parameters should be controlled in strict accordance with the design requirements to ensure the stability and reliability of the insulation structure. For example, when winding, it is necessary to ensure that the winding tension is uniform, the winding density is consistent, and the air gap and foreign matter existing inside the coil are excluded. During the impregnation process, it is necessary to control the concentration and temperature of the impregnation agent, ensure that the insulation material is fully integrated with the conductor, and dry it after impregnation to avoid the influence of moisture and volatiles on the insulation performance.

The above are some professional knowledges on insulation structure to maintain the stability of micromotor performance by VSD Motors. For more relevant information, please contact us.