Colored brushes are made of copper, lead, tin, graphite and other powders, mixed with phenolic resin as binder, and processed by hot pressing. However, since they are produced by mixing metal and non-metal powders, the phenomenon of powder segregation is more serious. Brushes have poor performance uniformity, short service life, poor commutation ability, low operating temperature, low application height, and shortcomings of moisture, mildew, and salt spray "three prevention" capabilities.
The production process of black aviation brushes is completely different from non-ferrous aviation brushes. It uses non-metal powders (ie carbon materials) such as coke, carbon black, graphite, etc. and undergoes processes such as roller, grinding, pressing, roasting, dipping, graphitization , First made into semi-finished products, and then take some auxiliary measures to meet the high-altitude performance requirements of aviation motors.
Even the most wear-resistant brushes under normal temperature and pressure, once they work in the high-altitude conditions of lack of water and oxygen, once the brushes are worn out in tens of minutes or even a few minutes, it will wear out. This is because ordinary brushes are Under high-altitude conditions, a lubricating film cannot be formed, and sharp dusty wear occurs.
The new type of brush is made of ordinary copper graphite brushes by adding lead powder and tin powder. The lead and tin in the brush can form a tin-lead solid melt at a lower temperature and penetrate into the rectifier during motor operation. The sub-surface layer forms a solid melt protective film, so that the brush can work normally without water vapor and air. This is the high-altitude lubrication mechanism of the earliest colored aviation brushes.
We adopt the advanced technology imported from Europe, patented technology, specialized software to optimize the design for Dry Type Transformer. The core is made of cold-rolled grain-oriented silicon steel sheet which cut in step-lap by GEORG Germany TBA core cutting lines and laminated by the method of fifth-order step-by-step stacking technology, enabling the no-load performance of the core to improve greatly. The epoxy resin from American HUNTSMAN is adopted for the windings which casted in the vacuum resin casting machine imported from HEDRICH, Germany. The winding material ensures good permeability, no bubbles occur, which leads to minimum partial discharge. The HV and LV winding mate with each other tightly, which ensures solid strength of structure and capability to withstand short circuit and vibration. Under normal service condition, the service life of dry type transformer is 30 years. No crack will form on the surface of transformer winding due to temperature variation as long as the transformer runs under normal service condition.
Dry Type Transformer
Dry Type Transformer,High Quality Special Transformer,1600Kva Dry-Type Transformer,800Kva Dry-Type Transformer
Hangzhou Qiantang River Electric Group Co., Ltd.(QRE) , https://www.qretransformer.com