Bearings from working principle can be divided into rolling bearings and plain bearings, Rolling occurs when the rolling friction of the sliding friction and plain bearings work Vice, which determines the the work friction coefficient of rolling bearings and plain bearings differ by at least ten of magnitude or more; lubrication conditions and at a certain load and speed, the magnitude of the coefficient of friction of rolling bearings substantially vary depending on the ball, the manufacturing precision of the bearing inner ring and with the gap between, and the size of its friction with the bearing material itself no direct relationship Rolling ships require periodic external lubricant; lubrication conditions and at the same load and speed, the sliding bearing friction coefficient depends mainly on the size of the self-lubricating properties of the bearing material itself, due to the sliding bearing material having a good self-lubricating properties, without refueling or less fuel to long-term work; plain bearings bearing self-lubricating plain bearings can be maintenance-free self-lubricating characteristics determine the plain bearings are increasingly being engineering staff adopted.
Sliding bearing lubrication mechanism and limit PV value
Sliding bearing sliding friction occurs due to the contact surface of the shaft and bearing, bearing the face in the initial work surface to form a lubricating film separated from the surface of the deputy campaign, after a short-term run-sliding friction can be greatly reduced, the deputy campaign surface not in direct contact, and thus also avoids wear and tear. Sliding bearing capacity, high precision turning, lubricating film with shock effect, so access to a wide range of applications in engineering. The formation of the lubricating film is plain bearings the basic conditions for normal work, the factors that affect the formation of lubricating film lubrication, deputy campaign relative velocity, the internal lubricant physical properties, and the joint surface roughness. The maximum limit of the sliding bearing an important measure of performance is the bearing can be achieved, where P is the load bearing, and V is representative of the line of bearing operating speed; sliding bearing limit PV value larger bearing performance better life longer; affect plain bearings PV limit the size of the main factors is the bearing material itself self-lubricating properties and bearing temperature performance; external factors affect the actual PV value of plain bearings bearings to withstand load, running speed, ambient temperature, and with precision. The general design of the sliding bearing manufacturing PV limit the bigger the better, and the requirements for the design of sliding bearings bearing PV value as small as possible, which will help to extend the life of the slide bearing. Sliding bearing design is generally based on the working conditions of the bearing, determine the type of bearing structure, select the appropriate bearing material and to determine the geometric parameters of the bearing.
Sliding bearing type: metal plain bearings, non-metallic plain bearings
Plain bearings in accordance with metal sliding bearing and non-metallic materials can be divided into plain bearings. Metal sliding bearing is usually divided into a composite sliding bearings, sliding bearings, etc. of the metal base. Non-metallic sliding bearings are usually divided into> engineering plastics plain bearings, bearing filament winding.
Composite bearings generally consists of three layers: a substrate layer + layer of copper powder + antifriction layer; bearing wherein the substrate layer plays a role, the copper layer is, as the binding force between the enhanced substrate and the surface of the antifriction material exist, and Save friction layer sintering and rolling technology commonly used in the inner surface of the bearing face that sintering a layer of special lubricants (CSB-10> or DU bearings) or as a self-lubricating modified engineering plastics, anti-friction material (CSB-20 or DX bearings) jobs> part of the lubricating material will be slowly transferred to the surface of the shaft, bearing friction layer and vice create friction between the grinding surface of the shaft lubrication film, the friction coefficient at the same time reduce the rate of wear of the bearings is to achieve also decreases; generally used for the working surface of the composite bearing antifriction material Teflon PTFE, disulfide of molybdenum MoS2, graphite Graphite, modified engineering plastics, high-performance special lubricating materials; while for the loads substrate materials are generally low carbon steel, stainless steel, copper, etc.; the composite class bearing material structure determines these bearings are generally used for medium load medium speed in the workplace.
Metal matrix sliding bearing technology
Metal-based sliding bearings generally can be divided into the mosaic of the solid lubricant sliding bearing (CSB650 series), bi-metal sliding bearing (CSB800 series) and overall sliding bearings; the solid lubricant mosaic sliding bearings generally use special copper material as the matrix, then in accordance with the horizontal and vertical projection no blind through holes in the bearing substrate thickness on the hole in the solid lubricant inlaid copper substrate; work both as a carrier material as a friction material, while the solid lubricant embedded in the hole slowly distributed in the bearing bore friction surface, and will run slowly as the work part of the transfer to the surface of the shaft to form a lubricating film; double metal sliding bearing by the steel sheet substrate layer and the surface friction-reducing layer, The substrate steel sheet and the composite sliding bearing similar ships such as low carbon steel, friction reducing layer on the surface as compared to copper alloy containing a solid lubricant powder sintering; the overall sliding bearings is generally used copper alloy containing a solid lubricant powder sintering into, and then through the vacuum suction processing, so that the tiny pores in the bearing material containing lubricant, lubricant or oil will work in a thin layer of a lubricating film is formed on the grinding surface of the shaft; metal base class sliding bearings due to its material property determines applicable to the work load is relatively large and low speed applications.
Non-metallic sliding bearing technology
Non-metallic plain bearings engineering polymers bearing (CSB-EP series) and filament-wound bearings (CSB-CR series); plastic plain bearings due to material modified polymer-based, while the domestic polymer polymer modification technology development relatively late, earlier studies only at the theoretical or laboratory tests mainly the industrialization of time lags behind the developed countries in Europe and the United States for nearly 20 years; formation of industrial production only Zhejiang Changsheng Sliding Bearing Co., Ltd. (CSB), China CSB not only in polymers plain bearings ahead of the domestic market, its metal plain bearings have been leading in the international market; China CSB has become a global sliding bearing industry one of the frontrunners.
Technology development of polymer plastic bearings including almost all polymer modification technology; molded sintered plastic plain bearings and injection molded plastic plain bearings can be divided into up points from the manufacturing process.
Molded sintering plain bearings are generally constrained by the low efficiency and high manufacturing precision, so the space is relatively small, not suitable for mass production; molded sintering technology made of a plastic polymer plain bearings applications relatively There are two types: one is filled with modified Teflon PTFE made plain bearings, while another is filled with modified polyimide plain bearings; modified PTFE molded sintered manufacturing plain bearings technical content relatively low, so the higher number of domestic manufacturers began early application of the production and application of these bearings, the advantage of relatively low friction coefficient of about 0.11 or so strong, corrosion resistant to almost all industrial chemical liquids, high temperature up to 260 ° C, but is not widely used due to poor abrasion resistance but also by the factors of production and price. Filled modified polyimide manufacture of plain bearings due to its material modified relatively high technical requirements, specialized mass production only in Europe, USA and Japan, DuPont Vespel material both strength and temperature from the wear respects superior; continuous use temperature up to 288 ° C, short-term can reach 480 ° C, by adding graphite Graphite or molybdenum disulphide MoS2 modified so that the friction coefficient is reduced to between 0.08 to 0.12, has excellent wear resistance; very expensive because of the prices of raw materials, mainly used in aircraft, spacecraft, military parts, with the continuous improvement of the technical requirements of the automotive, OA machinery gradually Vespel products.
Polymer engineering plastics compounding and injection molding plastic sliding bearing technology the world has been rapid development; China CSB self-lubricating modification technology has been 20 years of development history, the CSB according to various polymer materials inherent characteristics have been modified products suitable for different conditions of use; polymer plain bearing performance depends mainly on the modified bearing material itself fixed performance, CSB uses state-of-the-art polymer modification technology in high-performance polymer filled special lubricants and high functional fiber, high-performance polymer as the base material from the wear effect, special lubricants for lubrication reduces the coefficient of friction, enhancing effect from the fiber and filler; using the molding process of the injection molding process can be processed into various shapes plain bearings, polymer plastic sliding bearings in the molding characteristics in the manufacture of all sliding bearings having an absolute advantage; polymer sliding bearing material as a whole are modified-modified self-lubricating material, so that from either the friction performance or from the service life of the bearings are superior to metal composite bearing (the composite bearing friction material only the surface layer of about 0.03mm); polymer plastic bearings the relative metal composite bearing the following advantages: resistance to corrosion, low cost, quality light and suitable for OEM mass production; China CSB provides long-term use temperature of 250 ° C high-performance polymer plastic bearings CSB-EP5, and the bearings are resistant to almost all chemical media; bearing low water absorption and corrosion resistance can be long-term for underwater operation; made of high-speed operation experts CSB-EP13 linear bearing slide film has a very low coefficient of friction and allow a maximum operating speed of 10m / s; currently the most widely used in the automotive industry is the CSB- EP universal and the CSB-EP3 enhanced type polymer plastic sliding bearings.
Plain bearings application of technology in the automotive industry
Superior self-lubricating plain bearings performance in the automotive industry has been fully reflected; CSB plain bearings applied to almost every carmaker; especially the polymer plastic plain bearings in the car has become increasingly widespread , it can be applied to various parts of the car: Car Door hinge system from the most simple to the complex mechanical structure, demanding member, such as: automobile steering the steering system to shift gears in the transmission system. In addition to having excellent mechanical properties and for Free lubricating, dry running of the advantages of the very low price of engineering plastics sliding bearings. PTFE-coated metal plain bearings, CSB polymer plastic plain bearings up to 50% cheaper.
Application of the sliding bearing in the vehicle door hinge system
Car door hinge system due to the CSB-EP3 enhanced the series plastic sliding bearings, to overcome the metal sliding bearing pull up force is increased or noise phenomenon caused by rust, and opening and closing the car door or the trunk lid is not any moment stuck phenomenon.
Sliding bearing applications in the automotive damping system
Car shock absorber used in the system plain bearings from wear resistance, impact resistance ability and with the accuracy requirements are very strict; plain bearings wear resistance is poor then it will lead to the outside ring wear increased, seals failure After lead to leakage of hydraulic oil, shock absorption function failure; CSB-40 composite bearing (DP4 materials) is completely received the challenges of the harsh conditions, successfully used in a variety of automotive shock absorbers.
Plain bearings in automotive steering system
Automobile steering systems, thanks to the the CSB-RPM4 support sets, making the car running relatively stable throughout the course of turning the steering wheel, even in the case of very bad road conditions but also to ensure the normal operation of the steering system. CSB-RPM4 excellent wear and damping effect in the automotive steering system has been verified.
Application of plain bearings in the automotive braking systems
High-performance polymer the CSB-EP4 plastic bearings in the automotive braking systems makes driving relatively stable during braking, but also to achieve fast and stable braking even in case of emergency; regardless of whether the car is smooth steering or in the case of emergency steering can ensure effective braking; higher EP4 material of hardness and wear resistance for long service life, this is the most high-performance lubricants and functional fibers are added to this material .
Plain bearings in the car seat adjustment system
Since the sheet metal material used for car seat system or punching holes, as well as cold rolled steel sheet generally has great dimensional tolerance, however, in the seat system requiring minimum clearance in order to minimize noise. In order to resolve this contradiction, the production and delivery of the CSB Company CSB-EP series plastic plain bearings are now increasingly being used.
Sliding bearing applications in the automotive transmission system
The car gearshift CVT system not only required to ensure successful implementation of the stalls in the process of using the joystick shift, and requires shifting process is relatively smooth and comfortable; CSB-EP series engineering plastic bearing applications because of its excellent wear resistance and impact resistance In this system.
Conclusion
With the self-lubricating materials modification technology continues to progress, the sliding bearing applications also the rapid development of technology! Currently, plain bearings have been successfully applied in the fields of civil machinery, military machinery and aerospace; With the continuous improvement of applications continues to expand and the job requirements, sliding bearing materials technology, manufacturing and application technology has yet to be constantly in practice to explore, research and progress.



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