In order to solve the lubrication problems of high temperature, low speed, heavy load, large dust, water shower and impact vibration in mechanical equipment, composite sliding bearings can be selected. The following is an introduction to the selection and characteristics of the composite sliding bearing.
1. Structure of the bearing The composite sliding bearing is developed by arranging the holes of appropriate order and size on the metal friction surface of the bearing base, and embedding molybdenum disulfide and graphite to form a composite self-lubricating slider mounted on the metal sleeve. Composite bearings, solid lubricant friction area of 25-65%. The solid self-lubricating block can work normally at a high temperature of 280 °C. However, due to its low mechanical strength, weak bearing capacity and easy deformation, it can be suppressed by inserting it in the metal hole groove, forming a metal part to bear the bearing function and lubricating the self-lubricating block. The lubrication mechanism of the composite sliding bearing is that during the sliding friction between the shaft and the sleeve, a part of the self-lubricating material molecules is transferred to the metal surface of the shaft to fill the micro-non-planar surface, and a stable solid lubricating film is formed. , causing the grinding between the solid lubricating film to prevent the adhesion of the shaft and the sleeve. This combination of rationality combines the complementary advantages of copper alloys and non-metal wear-reducing materials, and is particularly suitable for motion-free environments in oil-free, high-temperature, high-load, low-speed, anti-fouling, anti-corrosive, and strong radiation environments, and Use under special conditions that are infiltrated in water or other solutions and cannot be greased at all.
2. The area occupied by self-lubricating block is related to the running speed and bearing strength, and the running speed is low; the bearing strength is large, and the area occupied by metal should be larger. For example, the area occupied by the self-lubricating block of the traveling wheel bearing of the ingot car is about 25%, the lubrication of the shaft bearing of the pulling mechanism is sufficient, the bearing strength is not large, and the area occupied by the self-lubricating block is about 65%.
3, the technical requirements for the bushing material bushing should be made of alloy copper, the bushing should have a higher hardness, generally heat treatment, its hardness is not lower than HRC45.
4. Geometry and setting requirements of self-lubricating blocks. The self-lubricating block has two shapes of a column shape and a rectangular shape, and the self-lubrication can adopt a column shape according to the occupied area, and a rectangle can be used instead. No matter what shape must be set in order to prevent it from falling off during operation.
5. The clearance value of the bushing and the shaft The linear expansion coefficient of the self-lubricating block is about 10 times that of steel. In order to adapt to the bearing temperature change, the gap between the shaft and the bushing is increased from the original four-stage dynamic matching (D4/DC4) 0.032~0.15MM to 0.45~0.5MM. The self-lubricating block protrudes from the side of the friction pair by 0.2 to 0.4 mm of the bushing metal. This will be fully lubricated during the initial run-in period of the bearing operation, reducing the power consumption of the power drag.
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