The technical application of domestic seals for construction machinery?

Technical application of domestic seals for construction machinery? At present, China's construction machinery industry has introduced a large number of main engine design and manufacturing technologies from developed countries, and gradually adopts internationally advanced sealing system design concepts and sealing device application technologies for mechanical seals for autoclaves. However, due to the constraints of the domestic industrial manufacturing level of seals, the application level of engineering machinery seal technology is still behind the international advanced level by about 20-25 years. The normal working hours of the host without leakage are only about 400h, which is less than 1/10 of the international advanced level. Application status: The product variety and quality of domestic seals still cannot meet the development and supporting needs of construction machinery with advanced manufacturing technology. In fact, there are nearly 1,000 rubber and plastic seal manufacturers serving the construction machinery industry in China, but there are only more than 40 companies with better production conditions and technical capabilities. Among them, the only companies with strong technical capabilities and complete sets of advanced equipment are There are 7-8 (professional research institutes engaged in the production of military seal products are not among them). Nevertheless, the quality and service life of the sealing products produced by these companies still have a more or less gap with the advanced level of foreign countries. After the construction machinery and medium and high-pressure hydraulic parts industry introduced the manufacturing technology of world-renowned manufacturers such as Linde, Carter, Komatsu, Zeai, Rexroth, etc., the product variety and quality of domestic seals could not meet the development of imported advanced manufacturing technology products. And supporting needs are examples. Secondly, the small-section U-shaped sealing ring (AU) for the lifting device of the dump truck, which is in high demand, is purchased from foreign companies due to the poor quality of domestic sealing products. Existing problems: The quality of seal products and the design and application level of seal systems need to be improved. 1. In the past 20 years, the quality of seal products has been established through the joint efforts of domestic scientific and technical personnel to establish a complete national standard system for various seal installation cavities that is in line with ISO/TC131/SC7. At the same time, a national standard system of seals size series, seal performance indicators, seal appearance quality, seal packaging, storage, and transportation that are in line with international standards for various seals has also been established. Thus, it is convenient to design and select the seals for the sealing system of construction machinery and other medium and high-pressure hydraulic machinery products. But there are still many ills in actual operation. The main reasons are that the industrial base is too weak, the quality and variety of raw materials are not satisfactory, and the management is not standardized. The gap is especially the biggest in the product quality of rotary oil seals for hydraulic pumps, hydraulic motors and gearboxes and reciprocating seals for hydraulic cylinders. Aiming at the service life of the wheel side oil seals on the drive axle of the ZL50C loader, the author has done an installed comparison test. An internal skeleton oil seal with a secondary lip developed by a domestic unit was tested after being installed on the road, and it leaked at only 50km, while the installation The assessed BABSL oil seal of a foreign company has not leaked in the past 3 years. Another example: The quality of the dynamic sealing element of the hydraulic cylinder of construction machinery can meet the foreign level of 5000 working hours without leakage, and the service life of domestic seals is generally 1/10, and some even less than 100 working hours.