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Rolling bearings: new materials and new processing technology

due to the development of new materials and new processing technology, the performance and service life of rolling bearings have been further improved

when talking about rolling bearings, people will think of innovative technologies. In this field, due to the continuous improvement in materials and processing technology, it is possible to develop bearings with better performance, and at the same time, it is possible to continuously improve the service life of bearings

SKF company has developed a series of new technologies and developed innovative products with these technologies. Due to the improvement of manufacturing technology, new knowledge in quality control and progress in micro geometric structure design, the service life of the new generation of rolling bearings can be increased by three times. The structure of the material named VC 444 was treated with nitrogen. Bearings made of this material are particularly corrosion-resistant, so they can be used in highly corrosive environments. In addition, this kind of bearing has high toughness, which will have a positive impact on its service life

for brass, which is a standard material for manufacturing larger bearing ball retainers, the lead content, which is already small, has been further significantly reduced, and its associated effect has improved the wear resistance of bearing retainers. In the forming of brass retainer, its geometry has been optimized, so that the ball can be better guided in the groove. Thus, higher operating accuracy can be achieved and the operating temperature can be reduced

peek is a strong competitor of brass

SKF company found peek in the process of looking for a new type of plastic with high thermal deformation stability, which is a crystalline thermoplastic, and it has become a real competitor of solid brass bearing retainer within a certain size range. Compared with brass retainer, PEEK material has lighter weight, better friction fit, and its operating temperature is further reduced, so its application range is expanded

ceramics are also increasingly using connector materials that meet the requirements of all relevant industry standards as bearing materials. If you observe the performance of ceramics, you will find that it can meet almost any desire of designers. Ceramics have high hardness, elastic modulus and small density, so the inertia force is small. It also has low friction coefficient, good corrosion resistance and chemical corrosion resistance, good electrical insulation and small expansion coefficient. Using ceramic rolling elements (hybrid bearings), coupled with PEEK bearing retainers, it is possible to achieve a new breakthrough in the speed range

rolling bearings on electrical machinery should be non-conductive (hybrid bearings)

insocoat (absolute @c startup detection edge coating) bearings and hybrid bearings are two bearing solutions of SKF company to solve the problem of electrical erosion. Insocoat bearing is a rolling bearing with electrically insulating ceramic coating, which is selectively applied to the shell surface and side or hole of the outer ring of the bearing, as well as to the side of the inner ring. Nominal of standard structure is 100 μ M thick alumina coating can withstand DC voltage up to 1000V. At this time, the resistance is at least 50m Ω. Laboratory tests show that the breakdown voltage is above 300V DC. The insulating layer is applied to the surface of bearing components by plasma spraying, and high-quality and high-density coatings are produced by appropriate pretreatment and post-treatment. The isolation and sealing of the ceramic surface ensures that it can be used in a humid environment. The structural forms of insocoat bearings include single row grooved ball bearings and single row roller bearings, with various commonly used sizes. Other types and sizes of bearings can be provided on demand. The bearing ring of hybrid bearing is made of rolling bearing steel, while the rolling element is made of nitriding. In this way, the query time will be very slow and it may not be satisfied with the needs of users. Silicon is a kind of ceramic material with high strength and low specific gravity. On hybrid bearings, the rolling element can prevent current from passing through the bearing. Due to the small mass of ceramic rolling elements compared with steel balls, hybrid bearings are particularly suitable for high-speed applications. Other advantages include low friction, high modulus of elasticity and low coefficient of thermal expansion

hybrid bearings are suitable for wind power generation devices

Figure 1 SKF company is currently developing X-type large bearings for wind power generation devices in terms of hybrid bearings

skf company is currently developing X-type large bearings for wind power generation devices in terms of hybrid bearings (Figure 1). SKF Bearing with non wearing coating can work under extreme operating conditions, such as sudden load change, high speed, low friction or lack of lubrication, due to its low friction and wear reducing performance. The hardness of non abrasive coating is 40% - 80% higher than that of common bearing steel. It has the properties of low friction and thermal stability at 200 ℃. This coated bearing has a long life, can work reliably even with little lubricant, and can work in a highly polluted environment (Fig. 2). Special high-tech applications require specific solutions: the use of bearing lubricants should be eliminated. SKF company has specially developed a comprehensive scheme (nip, MoS2) of materials and coatings that can meet this demand for this purpose

Figure 2 bearing with non abrasive coating has the performance of small friction and reducing wear, and can work under extreme operating conditions

Hall element on the circumference can improve operating safety

SKF sensor bearing device is a mechanical and electronic component that combines the functions of sensor and bearing. SKF company has specially developed a new generation of sensor bearings for modern electrical machinery. The contactless sensor operates according to hall principle and is composed of sensor ring, pulse ring and cover plate with integrated microprocessor

through the optimization of the number and arrangement of Hall elements on the circumference, it can ensure the generation of anti-interference signals with high resolution and ensure a high degree of operational safety. The resolution of incremental output signal (sin/cos) can be adjusted according to specific application conditions, and can reach 2048 pulses/revolution. In addition to the speed, the sensor can also provide information about the direction of rotation, and optionally integrate and install a temperature sensor. Sensor bearings can be designed according to specific requirements or combined with standard bearings (Figure 3)

Figure 3 sensor bearings can be designed on the basis of standard bearings or customized according to special requirements

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