Seals made of construction machinery technology application and development prospects

The current Chinese construction machinery industry has introduced a large number of host countries design and manufacturing technology, and gradually adopted the international advanced sealing system seals the design concept and application technology. But because the level of sealing the constraints of industrial manufacturing, engineering, mechanical seal technology level is still lagging behind the international advanced level of about 20-25 years. Host no leakage around 400h normal working hours only, less than the international advanced level of 1 / 10.
Application Status: domestic seal product variety and quality are still unable to meet the introduction of advanced manufacturing technology, mechanical engineering and supporting the development needs of
In fact, in China's construction machinery industry services for the rubber seals manufacturer with nearly a thousand, but with better production conditions and technological capabilities of more than 40 companies only, which has strong technical capabilities, the company has complete sets of advanced equipment only There are 7-8 at home (in the production of military products, the professional institute seal is not the column). Nevertheless, these companies production of sealing products in quality and service life is still there with more or less advanced level of gap. Construction machinery and in industry, the introduction of high-pressure hydraulic components such as Linde, Caterpillar, Komatsu, ZF words, the world's leading manufacturers such as Rexroth's manufacturing technology, the domestic seal product variety and quality can not meet the introduction of advanced manufacturing technology products and supporting the development needs of a case in point. Second, demand considerable dump truck lifting device with a small U-shaped cross-section ring (AU), because of poor quality sealing products made, both OEMs and users of foreign companies to purchase.
Problems: the quality of seals and sealing systems product design and application of standards to be improved http://www.prmindustry.com/
Abstract...Articles section 1 seal quality
20 years, the national research and technical staff work together to create a complete integration with ISO/TC131/SC7 various seals installed cavity national standards. Also established with various international standards sealing size series of seals, seal performance and appearance quality seals, seal packaging, storage, transportation and other seals national standards. Thus, to facilitate the construction machinery and other medium and high pressure hydraulic mechanical seal system with seal product design and selection. But the reality is there are still many shortcomings exist. The main reason is too weak industrial base, the quality and variety of raw materials is not satisfactory, management is not standardized, and so on. Especially the gap between the hydraulic pump, hydraulic motor and gearbox oil seals and hydraulic rotary cylinder reciprocating dynamic sealing of the product quality is the worst. For ZL50C wheel loader axle seal life, I have done a comparison test installed by the band developed a domestic unit within the Vice-lip seal, installed after the road test after only 50km began leaking, and installed while the assessment of a company BABSL foreign oil seal, use the last three years has not leaked. Another example: construction machinery hydraulic cylinder dynamic seal element of quality, to meet the 5000 standards for foreign hours without leakage, and seal life is generally made for 1 / 10, some even less than 100 hours of work.
(2) sealing system design and application level
Sealing system design and application level depends on the ability to develop sealing products, mainly in three aspects.
(1) rotary dynamic sealing systems
Extensive use of the current standard is still common seal, the pressure required for the rotation can only provide a pressure seal for the l-3MPa of pressure-type oil seal, and the international advanced level of 10MPa. Acting hydraulic return oil seal applications in mechanical engineering in rotating seal has not been universal.
(2) hydraulic cylinder reciprocating dynamic sealing system
Most domestic construction machinery hydraulic cylinder dynamic seal system design is still used as the main U-shaped ring seal. The mid-1990s design and production of construction machinery hydraulic cylinder dynamic seal system, began to adopt coaxial components and U-shaped sealing ring of the composite design. Widely used internationally in season 5 components (or 3 components) with a hydraulic cylinder piston seal with support ring combination of components, manufacturing process more complex, currently still stuck in the stage of small batch production, the quality is less stable.
(3) Static Seals Static Seals in, despite the elimination of asbestos and plant fiber sealing products, but the polymer material the use of liquid gasket not popular. At present, the use of such products are still produced by various types of Loctite sealant products. Domestic liquid sealant and hydraulic system piping connections for the anaerobic brand less, and the coating process and quality performance are still some gaps. Outlook: China seals for sealing technique of research physicians will face the engineering manufacturing industry grumble mechanical and other, high-pressure hydraulic machinery industry made serious issue
With the international advanced technology and manufacturing technology introduction and development of the economy after 2000, trends, U the introduction of advanced technology as the basis of the Chinese construction machinery industry will have a larger development. Construction machinery hydraulic system operating pressure and the system's advanced, reliable. @ Probing high stresses will promote the sealing elements sealing system design and manufacturing technology development, and therefore, China's sealing technology research and seals manufacturing industry will face in the construction machinery and other high-pressure hydraulic machinery industry made serious issue . Can be expected, when the Chinese industrial system will no longer seal is a high energy consumption, low efficiency, structure and numerous small-scale peasant-style business model, and will be a highly intensive, large-scale, low-power, high efficiency management system . By then, the main varieties of Chinese seals will have 60% of the late 1980s to meet international quality level of the early 1990s, and the other will have 15% of product variety sealing products meet international quality standards of the contemporary. Chinese construction machinery and in the high-pressure hydraulic machinery seal system design and application level will reach the mid-1990s level of technology.
Background: China Construction Machinery seal the four stages of technology
The rubber seals for the application of the main engineering mechanical seal technology development process can be divided into four stages.
1 the initial stage (1960-1970)
During this period China's construction machinery hydraulic system operating pressure is approximately 12-14MPa. The sealed system with the seal are: 0-shaped rubber seals (NBR); steel a rotating seal leather; corrugated steel skin ten cork ten metal spring seal; asbestos packing; asbestos ten rubber sealing gasket; V ring (leather ten phenolic ten bakelite); V-ring (NBR ten folders] fabric: soft, would be a gasket and so on.
(2) start-up phase (1971-1980)
During this period the production of major products, Chinese construction machinery hydraulic system operating pressure is approximately 14-3.5MPa. The sealing system used in rubber seals to seal the main, out of leather, asbestos fiber and corrugated steel skin ten cork seal. Main Type D: 0-ring (NBR, FKM); crawler chassis with floating seal D (dry 0-shaped metal ring diagram); D rotation skeleton oil seal inside the package Sichuan BR, FKM, ZACM). Hydraulic and pneumatic reciprocating seals have 0-ring D (NBR, FKM); U-shaped density D shot ring (NBR, AU, BU): V-ring (NBR ten folders fabric); cup-shaped ring ( NBR ten clip the fabric) and so on.
In the past 10 years, to meet such as engineering machinery, forging machinery, medium, high pressure hydraulic technology development needs, the former Ministry of Machinery set up seven professional rubber seals manufacturing plant. In addition, sealing technology to promote the development of China, in 1975 and 1979 formed the "National hydraulic, pneumatic and Standardization Technical Committee a 'national hydraulic, pneumatic rubber seal Standardization Technical Committee for Standardization Technical Committee" (the old ISO/TCI3 / SC7 mapping), and fluid sealing friction Society Technical Committee.
3 consolidation and development phase (1981-1990)
The main products of domestic engineering machinery hydraulic system working pressure of a 16-40MPa, the sealing system seals used in the form of rubber sealing products are still based. Main types are: O-ring (NBR, FKM); crawler chassis with floating seal (O-Figure X metal ring); lubricated sealed track with a sealed component (NBR + AU): inner frame and outer frame rotation oil raw ten (NBR, FKM, ACM, EPDM); combination gasket (NBR + metal); hydraulic cylinder piston and piston rod intensive. Seal components with coaxial seal (PTFE + NBR); action hydraulic rotary shaft seals return (NBR, FKM, ACM); and the working pressure of 1? 3MPa the pressure rotary seals (NBR, FKM); two-way medium rotating seal (NBR, FKM), fluid pressure cylinder piston O ring with a double-acting reciprocating D support dynamic sealing components (NBR + PTFE + POM) and so on.
4 high-speed development stage (after 1991)
Construction machinery and other medium and high pressure hydraulic industry, has introduced a large number of manufacturing technology, to promote the sealing of foreign businessmen to enter the Chinese market, the pace of seals. The entry of foreign capital and technology to improve the overall level of China's sealing industry.

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       Peter  Huang