[Introduction of Scientific and Technological Achievements] Insulating Bearings

Bearings are important core basic parts in mechanical equipment. Its main function is to support the mechanical rotating body, reduce the friction coefficient in the process of its movement, and ensure its rotation accuracy. Its performance directly affects the quality, performance and reliability of major equipment and the host, and is often known as the "heart" parts of mechanical equipment.

With the rapid development of China's bearing industry, the variety of bearings is from small to large, the product quality and technical level are from low to high, and the scale of the industry is from small to large. A professional production system with basically complete product categories and reasonable production layout has been formed.
Today's edition of "Promotion of Scientific and Technological Achievements" brought to you by Xiao Bian will be well introduced by our hospital.Research Institute of Composite Manufacturing and Intelligent Identification(hereinafter referred to as "Composite Manufacturing Institute")insulation bearing.

science and technology research and development]

The insulating bearing adopts a special spraying process, and the outer surface of the bearing is sprayed with high-quality film. The film has strong bonding force with the substrate and good insulation performance. It can avoid the electric corrosion effect of the induced current on the bearing and prevent the current from affecting the grease, rolling elements and raceways. The damage caused by the channel improves the service life of the bearing.
　　There are two measures to prevent electric corrosion of bearings. One is to install a grounding device (shunt) on the motor shaft so that the current does not pass through the bearing; the other is to make the bearing an insulator. From the perspective of reliability and other aspects, to solve the problem of electric erosion of traction motor bearings, insulation bearings are the main way.It is more cost-effective and reliable than other insulation methods, such as shaft or housing insulation. The external dimensions and basic technical characteristics of insulated bearings are the same as non-insulated bearings, so they can be 100% interchangeable. It is suitable for motors and generators, especially frequency conversion motors.

　　How to make the bearing an insulator?
Two different materials are selected for composite manufacturing, and the bearing becomes an insulator through a plasma spraying preparation process.
Method 1: Use oxide, resin and other insulating materials to spray the bearing parts to make it an insulating bearing.
Method 2: Insulating bearings are made of nitride insulating ceramics.

　
Oxide Insulated Bearings Nitride Insulated Bearings

science and technology innovation]

Advantages of insulated bearings manufactured by plasma spraying:
1. Good bonding strength
The high-speed performance of plasma spraying ensures that the bonding strength of the bearing surface is greater than 30MPa, thus ensuring the durability of the coating.
2. Work heat impact is small
Due to the use of special process parameters, the molten particles are rapidly cooled and solidified when sprayed on the surface of the ring, which can keep the bearing surface at about 100 ℃ and eliminate the deformation effect of high temperature on the bearing.
3. Professional sealing technology
After spraying, professional follow-up sealing technology can penetrate about 20% of the thickness of the spray coating.
① To prevent the abrasive particles falling from the grinding wheel during the grinding of the coating from polluting the pores in the coating;
② Ensure the insulation performance of the coating;
Improve the corrosion resistance of the coating;
④ Pore sealing to prevent oxidation;
⑤ Ensure the air tightness of the coating.

application value]

The application of insulation mode is generally determined according to the power supply state of the motor. For high-voltage large motors or motors powered by variable frequency power supply, considering the high-frequency components contained in the power supply, the motor shaft current will increase. In addition, some special working conditions, such as electric vehicles, railway locomotive traction motors, wind turbines, etc., must adopt corresponding insulation schemes.
With the rapid development of science and technology, the application fields of insulating bearings are more and more extensive, mainly including the following fields: power industry, railway industry, machinery and metallurgical industry, mining machinery industry, petrochemical industry, etc.

Research Institute of Composite Manufacturing and Intelligent Identification
With surface engineering, non-standard automation, on-line detection and intelligent identification technology as the technical core, Tsinghua University Tianjin High-end Equipment Research Institute has carried out high-end research and development projects such as surface technology of insulating bearing spraying for high-speed motors, aviation non-standard manufacturing, visual detection, and production of AGV complete vehicles and key parts of AGV steering wheels. More than 80% of the project team members have a master's degree or above in key universities. Through independent research and development and innovation, they have solved the core problems of industrialization. They have cooperated with many manufacturing companies to solve production problems, complement each other's advantages, share resources, integrate the industrial chain, and form a collection A team integrating R & D, production and sales.

Technical docking and business negotiation
Contact: Wang Rongguo
Tel: 18518677771/022-24890969
Email: wangrg@tsinghua-tj.org

Source | Composite Manufacturing and Intelligent Identification Institute
Editor | Zhang Shu
The final interpretation of the above related technologies belongs to the Institute of Composite Manufacturing and Intelligent Identification.