The technology of manufacturing self-lubricating bearings originated in England. In the 1950s, PTFE (polytetrafluoroethylene) began to be tested as a bearing material in the UK, and at the same time a breakthrough was made in the copper powder sintering process. In 1956, the world's first self-lubricating DU bearing, lined with PTFE and supported by steel plates, was introduced to the market. In the late 1960s, self-lubricating bearings began to be used in the most advanced technologies such as the aerospace industry. Since the 1970s, British manufacturers of self-lubricating bearings have licensed their technology to French, German, Japanese and American companies. This move contributed to the rapid development of the global self-lubricating bearing industry, and self-lubricating bearings gradually entered into all machines. production fields.(2) Classification of self-lubricating bearings
With the development of self-lubricating bearing production, self-lubricating bearing production technology and materials are constantly improved, and product types are gradually enriched. According to the product structure and production materials, self-lubricating bearings are divided into multi-layer, single-layer and other three categories, which are divided into several sub-categories. The details are as follows:
Self-lubricating "layer type" bearing products consist of two or more different types of bearing materials, laminated and blended, in which the pad material acts as the self-lubricating effect and the base material acts as the support, and the other materials act as the joint transition effect. "Multi-layer" products have excellent lubricating properties, and their load-bearing capacity is determined by the compressive strength of the surface material. According to the type of substrate and cladding material, it can be divided into metal substrate and metal cladding, metal substrate and non-metal cladding, and non-metallic substrate and non-metal cladding.
"Single layer type" self-lubricating bearings are made from one type of bearing material, and the product is based on the self-lubricating materials contained in the bearing material, such as graphite, molybdenum disulfide, polytetrafluoroethylene, lead, etc. Lubricants according to the type of bearing material can be divided into metal and non-metal. Non-metallic single-layer self-lubricating bearings mainly include embedded non-metallic bearings, non-metallic rolling bearings, etc. Metal single-layer bearings mainly include solid mosaic products and oil-impregnated products. Self-lubricating “solid mosaic type” bearings pre-machin some holes or grooves in a metal substrate in a specific pattern and then embed a solidlubricant; it protrudes slightly on the sliding surface, and forms a transfer film on the metal substrate and counter surface by friction, thereby reducing friction and wear. An "oil-containing" self-lubricating bearing is a porous material formed by pressing and sintering metal powder in a powder metallurgy process, followed by filling the pores with lubricating oil; Deposition forming a film of lubricating oil on the metal substrate and contact surface, thereby reducing friction and wear.(3) Characteristics of self-lubricating bearings
Self-lubricating bearings are suitable for places where lubrication is not possible or difficult. Due to the requirements of special production processes, some key equipment in the automotive and machinery industries must operate under extreme conditions. Due to various factors such as heavy equipment, high ambient temperature, large amounts of dust or corrosive acid gases in the air, lubricant oil, so the friction and wear of rolling bearings or ordinary plain bearings is severe, and the bearings are prone to sticking or biting, which leads to wear and damage to parts, resulting in equipment shutdown. In order to ensure continuous operation, in addition to the installation of multiple rotational repair of equipment in the original design, it is necessary to invest a large number of maintenance personnel, which requires a lot of spare parts and energy. Therefore, automotive, machine building, molds and other industries need special lubricants for difficult working conditions. Oil-free can greatly simplify the design and structure of the bearing, reduce the cost, save design time, and can use the bearing without maintenance or less maintenance, and avoid the risk caused by insufficient oil supply.
Since the self-lubricating bearing does not need an oil supply device, there is no need to add oil during the working process, so it can save a lot of installation and operation costs, improve mechanical performance, and increase the service life and reliability. Oil-free processing does not require regeneration and processing of waste oil, and also contributes to environmental protection. Self-lubricating bearings place lower demands on the hardness of the grinding shaft, which reduces the complexity of machining associated parts. In a self-lubricating composite carrier structure, the surface can be plated with various metals and can be used in harsh environments. In addition, since there is no problem of oil evaporation with oil-free lubrication, self-lubricating bearings can be used in high temperature and high pressure environments.
Performance comparison of self-lubricated bearings and general purpose bearings
Self-lubricating bearings do not require oil supply and maintenance, wear resistance, heat resistance and other characteristics greatly expand the application range of the product. Many areas where conventional bearings are not suitable can use self-lubricating bearings, so self-lubricating bearings Lubricated bearings have a wider range than conventional bearings.(4) Relations between the industry and the mining and processing industries
The raw materials for self-lubricating bearings mainly include copper and steel, while the auxiliary materials are polymer materials (PTFE), graphite, etc. The applications in the subsequent steps are very extensive, and almost all mechanical equipment must use the appropriate materials. bearing products. The main application areas can be divided into mechanical engineering industries, such as automotive, machinery, mold and hydraulic equipment, home office automation equipment, construction, energy, aerospace and railway, etc.
Since the processing of steel, copper and polymer materials is directly related to product quality and the cost of purchasing raw materials for the production of self-lubricating bearings, the development of processing industries such as automotive, construction machinery, mold production and hydraulic equipment will stimulate the development of self-lubricating bearings .(5) Application examples for self-lubricating bearings
Self-lubricating bearings are widely used in various industries. The following table shows some typical applications for self-lubricating bearings:
Application typical of the industry
Automotive steering system: transmission, differential, clutch, balance bridge, lifting eye, etc.; engine: connecting rod bushing, throttle body, tensioner, turbocharger, injection pump, idler pulley, oil pump, rocker bushing, starter. etc.; steering system: suspension shock absorber, steering gear, steering resistance pump, steering damper, etc.; brake system: pedal assembly, brake shoe, etc.; bodywork: door hinge, trunk hinges, wipers, etc. /p>
Construction machinery crank bushings, idler wheel bushings, brake wheels, oil cylinders, operating mechanisms, gear oil pumps, driven wheels, driven wheels, rotary tables, grapple joints, industrial robot arms, etc.; lifting machines, loading and unloading mechanisms, stackers and other connecting parts; hydraulic cylinders, crane rods, transmission parts, etc.; plastic machines and other parts
Mold making Mold guides, chamfers, positioning, guides and other parts, pressc-shapes for tires, etc.
Hydraulic equipment Gear pumps, plunger pumps, vane pumps, metering pumps, fire pumps, compressors, submersible pumps, etc., cylinders, hydraulic cylinders, ball valves, butterfly valves, control valves, etc.< /p>
Light industry Food equipment, medical equipment, plastics equipment and other parts requiring transmission
Construction machinery Cushioning and impact protection products for buildings such as homes and factories, anti-expansion products for bridges, cable cables and other civil engineering structures
Household and office automation equipment such as fax machines, copiers, paper shredders, scanners, printers and other mechanical connections and reciprocating parts; fitness equipment, door and window openings and hinges; washing machines, air conditioners, refrigerators, microwave ovens. and sewing machines, etc. Transmission part
Power generators, motors, wind farms, dam systems, etc.
Aerospace and rail transport and other high-tech objects rocket launchers, oxygen supply rods to space suits, aircraft components, magnetic levitation current collectors, high-speed rail car connections, artificial satellite rod antennas, solar panel sail panel hinges and torsion spring mechanisms, Telescopic gravity balance rod mechanism for satellite attitude control, louver temperature control bearing, infrared camera self-lubricating bearing, optical instrument drive mechanism, liquid oxygen supply pump sleeve bearing
The following are examples of individual parts of self-lubricating bearings in some mechanical products(1) High demand for self-lubricating bearings
Self-lubricating bearings are a new product in the field of bearings. The production of self-lubricating bearings in my country is still in the growth stage. The production technology and product quality of self-lubricating bearings are still being improved, and the application fields of products are still expanding greatly. The industry is expected to maintain rapid growth in the future. The main factors behind the growth of the self-lubricating bearing industry are the natural growth of the industry, the replacement of self-lubricated bearings with other types of bearings, the expansion and expansion of new applications, and the growth of export markets. The steady growth of the industry application market plays a key role in the natural growth of the self-lubricating bearing industry. The total production value of self-lubricating bearings in my country rose from 1.641 billion yuan in 2009 to 7.905 billion yuan in 2017, with a cumulative growth rate of 21.72%. With the growth of applications in the bearing industry such asboth machinery and automotive industries, regardless of the influence of factors such as self-lubricating bearings replacing conventional plain bearings, the growth of the export market and the expansion of new applications, the self-lubricating bearing industry in my country is expected to remain stable in the next few years, and the rate of natural growth will be higher.
At present, the applications of self-lubricating bearings mainly include automotive, machinery, mold and hydraulic equipment, and other areas of mechanical production. Self-lubricating bearings offer unique advantages such as being oil-free, wear-resistant, and heat-resistant. In some applications where other bearings are used, switching to self-lubricating bearings can improve the performance of related mechanical equipment and reduce maintenance. Mechanical requirements. Other bearings have potential replacement space. In terms of current manufacturing and application conditions, general purpose plain bearings are the biggest potential replacement for self-lubricating bearings.
With the rapid development of economic globalization, the structure of the global automotive industry has undergone some new changes. In developed countries such as Europe, America and Japan, the production and consumption of automobiles have reached a certain state of saturation, while the economic growth of developing countries is relatively fast, demand on the popularization of car consumption will continue to become an important driving force behind the growth of global production and sales of cars, and the center of gravity of the structure of the global automotive industry will continue to shift towards developing countries.
As a major link supporting and influencing the development of the automotive industry, auto parts will play an important role in building the automotive technology innovation system, promoting the transformation, upgrading and sustainable development of the automotive industry in line with the new requirements of the "Made in China 2025" automotive energy strategy . To play a more important role, bearings still have great development prospects in the automotive industry in the next few years.
Self-lubricating bearings can be used in the joints and transmission parts of construction machinery. With the rapid growth of mechanical engineering, especially in the construction industry, the demand for self-lubricating bearings in construction machinery is gradually increasing. .
According to "China's 13th Five-Year Construction Machinery Development Plan", by 2020, the main income of my country's construction machinery business is expected to reach 650 billion yuan, the proportion of exports and overseas business income will exceed 30%, and the export volume of the industry will reach 24-25 billion US dollars, and the share of the international market will be more than 20%.
The mold is an extremely important and indispensable special basic processing equipment in industrial production. With high production efficiency, high consistency, low energy consumption of materials, and high precision and complexity of using molds for mass production of parts, it is more and more appreciated by various industrial production units of the national economy and widely used. fields of machinery, electronics, automobiles, information, aviation, aerospace, light industry, military industry, transportation, building materials, medical treatment, biology, energy and other manufacturing fields, many parts need to be molded, and the molds are called " the mother of industry." The market demand is huge.
④ Hydraulic and other general mechanical engineering
The technical level and strength of the general machinery industry directly influences and determines the competitiveness of other industries and products, and is an important manifestation of a country's comprehensive national strength. The production capacities and the level of production of the main sets of equipment are a comprehensive reflection of the technological, economic and industrial level of the country.
Self-lubricating bearings can be widely used in general machinery industry, so as the market capacity in this industry continues to grow, the natural growth of the self-lubricating bearing market will be guaranteed.
In addition to the above industries, the products are also widely used in plastics machinery and other light industry equipment, office automation equipment, construction machinery, energy, aerospace and other industries with great development potential. The vigorous development of the processing and marketing industry has led to an increase in demand for related spare parts and has played an important role in promoting the development of the self-lubricating bearing market.(2) The potential for new applications for self-lubricating bearings is enormous
With new applications emerging, the future market space for self-lubricating bearings will expand. Expanding and expanding the new field of application of self-lubricating bearings involves two aspects.
One aspect is the expansion of empty areas of application, the other is the further study and in-depth application of existing application industries.
Regarding the application status of self-lubricating bearings in developed countries, self-lubricating bearings can be applied to architectural decoration, cushioning, impact resistance and expansion protection for houses and bridges. In the field of architectural decoration, self-lubricating bearings can be usedbe used for doors, windows, curtains and other objects, and the installation of self-lubricating bearings can improve the quality of these objects. Flexibility, balance, and can also greatly reduce the noise generated during use. In developed countries, self-lubricating bearings are widely used in the field of architectural decoration, but in our country, the application in this field is less, and the potential for future development is huge. In addition, self-lubricating bearings are also widely used in shock-absorbing, anti-shock and anti-expansion structures of buildings such as houses and bridges. Let's take Japan for example. Oiles Group, a well-known manufacturer of self-lubricating bearings, derives 30% of its operating income from the construction industry, such as building houses and bridges.
In addition, in the existing applications of other self-lubricating bearings, such as machinery industry, there is still a certain gap between my country and developed countries, and there are still many opportunities for earthworks at the depth of application. self-lubricating bearings in these areas.