Development Status of Rotary Shaft Lip Seals

The rotary shaft lip seal (abbreviation: oil seal) is a high-tech precision rubber part, which prevents the leakage of lubricating oil or other media through the contact between the flexible rubber (or leather, plastic, etc.) seal and the shaft. As shown in Figure 1. In the early days, oil seals were made of leather. After the Second World War, the use of oil seals produced by synthetic rubber gradually increased. Especially in the past two or three decades, due to the rapid development of machinery manufacturing, vehicles, aviation, aerospace and other industries, oil seals have been proposed. It meets a series of harsh requirements such as high and low temperature resistance, high pressure resistance, special medium resistance, high speed, vibration and extended service life, thus promoting extensive and in-depth research on oil seal materials, structures, performance tests, quality control methods and sealing mechanisms. Research has greatly improved the sealing performance and service life of the oil seal. In the early 1960s, hydrodynamic oil seals with backflow effect were successfully developed abroad, which made a great leap in oil seal technology and solved some very difficult sealing problems of sealing parts. In the 1980s, the United States made a PTFE oil seal, which is not only suitable for ultra-high speed, but also resistant to high and low temperature, various corrosive media, and is suitable for occasions with dry friction. In the 1980s, the implementation of international standards for oil seals made oil seals more applicable and interchangeable in the world. Various countries have re-established new national standards with reference to international standards. my country started late in oil seal research. Although there has been considerable progress in the past ten years, compared with the international level, it still has problems in product structure design, rubber compounding technology, production technology, production equipment, mold processing, and quality control methods. There is a big gap. At present, the production of oil seals in my country is mostly distributed in small enterprises with relatively simple conditions. The backward production technology and equipment, coupled with the lack of sufficient understanding of the high-tech content and high-precision of oil seals in thought, insufficient technical estimation of the complexity of performance requirements and the strictness of process processing, coupled with the investment of the capital. Insufficient, resulting in poor oil seal quality, unreliable sealing performance and short service life in my country. The production level of most manufacturers only stays at the level of the 1950s and 1960s abroad. Most of my country's high-performance oil seals mainly rely on imports. On the other hand, due to the low quality of oil seals, it also affects the competitiveness of my country's mechanical products in the international market. Therefore, although the oil seal accounts for a small proportion in the entire machinery industry, it is a type of precision rubber product in the rubber industry with a wide range of services, wide influence, huge social and economic benefits, and an important role in the development of the national economy. Development should be given high priority. Company website: https://www.orksealing.com/