Analysis of Four Periods of Application of Sealing Skills in Construction Machinery in my country

Analysis of the four periods in the use of China's construction machinery sealing technology The development of my country's construction machinery sealing technology has gone through more than 50 years of history. From the initial difficulty to the rapid development, my country's construction machinery sealing technology is the development of my country's construction machinery industry. Made an important contribution. The development process of engineering machinery sealing technology that uses rubber and plastic seals as the main body can be roughly divided into four periods. 1. The working pressure of the autoclave mechanical seals of the hydraulic system of my country's construction machinery products during the initial period (1960-1970) was roughly 12-14MPa. The selected seals for the sealing system are: 0-shaped rubber sealing ring (NBR); iron shell-cowhide rotary oil seal; corrugated steel skin, cork, and metal tension spring end face seal; asbestos packing; asbestos 10 rubber gasket; V -Shaped sealing ring (cowhide ten phenolic ten bakelite); V-shaped sealing ring (NBR ten sandwich fabric): soft will belong to the sealing gasket, etc. 2. The pioneering period (1971-1980) during this period of China's construction machinery is the most important The mechanical seal pressure of the working kettle of the product's hydraulic system is roughly 14-3.5MPa. The seals used in the seal system are mainly rubber and plastic seals, and the end seals of cowhide, asbestos fiber and corrugated steel and corrugated wood are eliminated. Type D is: 0-shaped sealing ring (NBR, FKM); Floating oil seal for crawler D chassis (metal ring dry 0-shaped diagram); D inner skeleton rotating oil seal (BR, FKM, ZACM). Hydraulic and pneumatic reciprocating seal D has 0-shaped sealing ring (NBR, FKM); U-shaped dense D shooting ring (NBR, AU, BU): V-shaped sealing ring (NBR ten-clip fabric); cup-shaped sealing ring ( NBR ten clip fabric) and so on. In the past 10 years, in order to meet the development needs of selecting medium and high pressure hydraulic skills such as construction machinery and forging machinery, the original machinery department has established 7 professional rubber and plastic seal production plants. In addition, in order to promote the development of sealing technology in my country, in 1975 and 1979, the 'National Hydraulic and Pneumatic Standardization Skills Committee No. 1 and the National Hydraulic and Pneumatic Standardization Skills Committee Rubber and Plastic Seal Standardization Subcommittee' (with the old ISO/ Corresponding to TCI3/SC7) and the Fluid Seal Technical Committee of the Society of Tribology. 3. During the period of consolidation and development (1981-1990), the working pressure of the hydraulic system of the primary product of domestic construction machinery reached 16-40MPa, and the seals used in the sealing system were still mainly rubber-plastic sealed products. The main types are: O-ring seals (NBR, FKM); floating oil seals for crawler chassis (O-shaped figure ten metal rings); seal components for smooth-seal crawler tracks (NBR+AU): internal and external frame rotating oil seals ( NBR, FKM, ACM, EPDM); combined sealing gasket (NBR+metal); hydraulic cylinder piston and piston rod dynamic seal. Coaxial seal components for sealing (PTFE+NBR); dynamic hydraulic return oil seals for rotating shafts (NBR, FKM, ACM); and pressure-resistant rotary oil seals (NBR, FKM) with a working pressure of 1 to 3 MPa; two-way media rotary oil seals (NBR, FKM), a dual-effect reciprocating D dynamic seal assembly (NBR+PTFE+POM) with a supporting ring for the piston of a hydraulic O cylinder