Plastic Plain Bearings Technology And Applications In The Automotive Industry
Plastic bearings from the working principle can be divided into plastic rolling bearings and plastic plain bearings, rolling bearing occurs when the work is rolling friction, occurs when the work is bearing sliding friction, which determines Rolling and plain bearings work at least ten different coefficients of friction magnitude above; and at a certain speed and load conditions without lubrication, the size of the rolling bearing friction coefficient depends basically on the ball, the manufacture of precision bearing rings and with the gap between them, the size of its friction with the bearing material itself not directly related to the rolling bearing generally require regular external lubricant; and at the same speed and load conditions without lubrication, the sliding bearing size mainly depends on the coefficient of friction self-lubricating properties of the bearing material itself, since the material itself has a good sliding bearing self-lubricating properties, can not refuel less fuel to long-term work; since the slide bearing technology to achieve a self-lubricating sliding bearings can be achieved self-lubricating maintenance-free plain bearings determine the characteristics of more and more are engineering personnel use.
Bearing lubrication mechanism and limit PV value
Sliding bearing surface can be formed at the time of initial operation due to the contact surface of the shaft and the bearing, that bearing face in sliding friction lubricating film of the sub-surface move apart, after a short run-sliding friction can be greatly reduced, then the deputy surface movement no direct contact, thus avoiding wear. Carrying capacity of plain bearings, high precision rotation, the lubricating film having a shock effect, therefore, widely used in engineering. Forming a sliding bearing lubricant film is the basic condition to work properly, the impact of factors lubricating film lubrication mode, deputy campaign relative velocity, internal lubricant physical properties and the surface roughness of the sport vice-like. Maximum limit PV value bearing performance is an important measure of the bearing can be achieved, where P is the load bearing means, and V is representative of bearing operating line speed; bearing PV limit values have larger bearing using the better the performance longer life; influence bearing limit PV value is the size of the main factors bearing material itself is self-lubricating properties and bearing properties and temperature; bearing external factors affect the actual PV value bear the main load bearing , speed, ambient temperature and with precision. Usually sliding bearing manufacturing designs limit PV value the bigger the better, and the sliding bearings designed for the requirements of PV value bearings as small as possible, which will help extend bearing life. Bearing design is generally based on the working conditions of the bearing, determine the type of structure bearing, select the appropriate bearing material and to determine the geometric parameters of the bearing.
Bearing Type: metal bearing, non-metallic sliding bearings
Sliding bearing materials can be divided according to type of metal and non-metallic sliding bearings sliding bearings; metal plain bearings is usually divided into composite plain bearings, metallic group sliding bearings; non-metallic sliding bearings are usually divided into plastic plain bearings, filament-wound bearings;
Composite bearings generally consists of three layers: a substrate layer + copper layer + anti-friction layer; wherein the carrier substrate layer plays the role of copper layer is enhanced as the binding force of the substrate surface and reducing friction between the material existence, and Save friction layer sintering and rolling technology commonly used in the surface of the bearing layer that is sintered face specialty lubricants (CSB-50 or DU bearing) or modified plastics as the self-lubricating anti-friction material (CSB-20 or DX bearings), working part-lubricating materials will gradually be transferred to the surface of the shaft, this time on the realization of bearing friction layer between the ground and the establishment of the shaft surface friction of the lubricating film, reducing the coefficient of friction and wear rate while also bearing with the decrease; generally used for anti-friction bearing surface composite material Teflon PTFE, molybdenum disulfide MoS2, graphite graphite, modified high-performance engineering plastics and so on special lubricating material; and a substrate material for the load-bearing ships low carbon steel, stainless steel, copper and the like; composite bearing materials class structure determines the workplace these bearings are generally used for medium load medium speed.
Base metal sliding bearing technology
Base metal plain bearings can generally be divided solid lubricant inlaid bearing (CSB650 Series), bi-metal sliding bearings (CSB800 series) and integral sliding bearings; solid lubricants inlaid sliding bearing material is generally made of special copper base, There was no blind in accordance with horizontal and vertical projection through pores and then mounted on the bearing wall thickness of the substrate in the wells of the solid lubricant; at work, both as a carrier matrix material and copper as a friction material and embedded in the hole will be the solid lubricant slowly distributed in the bearing bore and the friction surface will be run as part of the work gradually transferred to the shaft, the lubricating film formed on the surface; and double-metal sliding bearings by a steel sheet substrate layer and the surface layers of friction-reducing work, matrix composite sliding bearing steel and ships similar to low carbon steel, antifriction surface layer was copper alloy contains a solid lubricant powder sintering; overall sliding bearings are generally used copper alloy powder contains a solid lubricant and sintering into, and then through the vacuum suction process, so that the bearing material containing tiny pores oil, lubricants or lubricants which will be at work in the shaft, the surface of a thin layer of lubricating film; a metal base class since the plain bearings which determine the characteristics of the material itself is suitable for relatively large work load and lower speed applications.
Non-metallic sliding bearing technology
Non-metallic sliding bearings are mainly polymer plastic plain bearings (CSB-EPB series) and filament wound bearings (CSB-CRb series); plastic plain bearings due to modification of polymer-based materials, and domestic polymer polymer modification technology is relatively late, early research is only stay in the theory or in the main laboratory tests, which industrialization time lag in American and European countries for nearly 20 years; currently the formation of industrial production only Zhejiang Changsheng bearing Co., Ltd. (CSB), CSB Chinese companies not only in polymer plain bearings ahead of the domestic market, its metal slide bearings has been ahead of the international market; China has become a global company CSB bearing industry one leader.
Development of polymer plastic bearing technology almost all polymer modification technology; up points from the manufacturing process can be divided into sintered plastic molded and injection molded plastic plain bearings sliding bearings;
Molded by sintering sliding bearings are generally low efficiency and high precision manufacturing constraints, so the development space is relatively small, not suitable for mass production; sintering technology currently used in molding made of a plastic polymer plain bearing applications relatively more there are two types: one is to use a sliding bearing filled Teflon PTFE made, while another is filled using a modified polyimide sliding bearings; die manufacturing plain bearings sintering technique with the modified PTFE content relatively low, so the earlier domestic manufacturers began to use more production and application of these bearings, the advantage of a relatively low coefficient of friction of about 0.11, and strong corrosion resistant to almost all industrial chemical liquid, high temperature up to 260 ℃, but due to poor abrasion resistance and restricted production and price factors, so applications are not widespread. Manufactured using modified polyimide filled sliding bearing material modification due to its relatively high technical requirements, currently only professional production of DuPont in Europe, USA and Japan, VESPEL material either from the strength or temperature from wear excellent Comparative aspects; continuous use temperatures up to 288 deg.] C, short-term up to 480 deg.] C, by adding graphite or molybdenum disulfide MoS2 graphite modified so that the coefficient of friction is reduced to between 0.08 and 0.12, has excellent abrasion resistance; but because raw material prices are very expensive, mainly used in aircraft, space, military products, parts, with the rising automobile, OA machinery and technical requirements are gradually adopting VESPEL products.
Polymer engineering plastics modification technology and injection molded plastic sliding bearings technology the world has been a rapid growth; China CSB self-lubricating modification technology company has more than 20 years of development history, the current CSB itself according to various polymer materials the inherent characteristics of the product has been modified for different conditions of use; plastic plain bearing performance depends mainly on the modified bearing material itself fixed performance, CSB company uses advanced technology filled polymer modified high performance polymer specialty lubricants and high functional fiber, high performance polymer as the base material from the wear effect, special lubricants lubricant to reduce the friction coefficient, fiber and filler from the enhancement; injection-molding process can be processed into various shapes sliding bearing, polymer plastic plain bearings have an absolute advantage in all sliding bearing manufactured in the molding characteristics; due to the overall polymer plain bearings are self-lubricating materials modified material modification, so it either from friction performance or from the bearing life have to be superior to metal-based composite bearings (friction bearing composite material surface just about 0.03mm); relatively high polymer plastic plain bearings metal composite bearings have the following advantages: corrosion resistance, low cost, quality OEM light and suitable for mass production; currently China CSB can provide long-term use temperature of 250 ℃, high-performance plastic plain bearings CSB-EPB5, and the bearing is resistant to almost all chemical media; and CSB-EPB4 plastic plain bearing low water absorption and corrosion resistance can be used underwater long run; high speed plastic linear bearing slide film specialist CSB-EPB13 made with a very low coefficient of friction and the maximum allowable operating speed of 10m / s; currently the most widely used in the automotive industry is CSB-EPB universal and CSB-EPB3 reinforced polymer plastic plain bearings.
Plain bearings in the automotive industry Application Technology
Because self-lubricating sliding bearing superior performance in the automotive industry has been fully reflected; currently China CSB Bearing applied to almost every automotive manufacturer worldwide; in particular polymer plastic plain bearings in automotive applications has become increasingly widespread each part, it can be applied to cars: from the most simple car door hinge system to the mechanical structure is complex, demanding parts, such as: automotive steering system to the steering transmission in the gearshift and the like. In addition to having excellent mechanical properties and lubrication-free, the advantages of running dry, plastic plain bearing extremely low prices. With respect to the PTFE-coated metal sliding bearings, CSB polymer plastic plain bearings up to 50% cheaper.
Sliding bearings used in automotive door hinge system
Car door hinge system due to the CSB-EPB3 enhanced series of plastic plain bearings, sliding bearings overcome the metal caused by rust or pull force increased noise phenomenon, and the opening and closing a car door or trunk lid is not any moment stuck phenomenon.
Sliding bearings used in automotive shock absorber system
Sliding bearings used in automotive suspension systems, whether from wear resistance, impact resistance and the ability to meet the requirements of accuracy are very strict; if the slide bearing wear resistance is poor then it will lead to increased wear and tear out seals, seal failure after leading to leakage of hydraulic oil, damping function failure; CSB-40 composite bearings (DP4 material) is fully received the challenge of this harsh conditions, successfully used in a variety of automotive shock absorbers.
Bearing in Automotive Steering System
Automobile steering system due to the CSB-RPM4 support sleeve, steering makes the car throughout the course of the operation of the steering wheel is relatively stable, even in case of very bad road conditions but also to ensure the normal operation of the steering system. CSB-RPM4 excellent wear and shock absorption has been verified in the automotive steering systems.
Bearing in automobile braking system
CSB-EPB4 high performance polymer plastic plain bearings used in automotive braking system so that driving personnel during braking is relatively stable, even in emergency situations can achieve fast and stable braking; whether the car is stationary in the steering or in the case of an emergency steering can ensure effective braking; EPB4 higher material hardness and wear resistance can be obtained long service life, which most largely due to high-performance lubricants and functional fibers are added in this material .
Bearing in automobile seat adjustment system
Since the system for an automobile seat in the sheet metal material or punched holes, as well as cold rolled steel sheet generally has a great dimensional tolerance, however, requires a minimum clearance in the seat system to reduce noise as much as possible. To solve this problem, CSB produced and supplied CSB-EPB series plastic plain bearings are now increasingly being used.
Sliding bearings used in automotive transmission system
Car gearshift CVT system not only requires the use of a joystick gearshift ensure successful implementation of the process stalls, and requires shifting process is relatively smooth and comfortable; CSB-EPB series of plastic plain bearings because of its excellent wear resistance and impact resistance are applied in this system.
With the progress of self-lubricating material modification, the slide bearing application technology is the rapid development! Currently, the slide bearings has been successfully applied in the civilian machinery, military machinery and aerospace and other fields; With the rising applications continue to expand and work requirements, the slide bearing materials technology, manufacturing and application technology yet we are constantly in practice to explore, study and progress.