Technical development prospects of chain and sprocket products

How to expand the variety as soon as possible, overcome technical difficulties, improve the quality of economic growth, and enter the track of the chain drive "production power" is worthy of in-depth exploration and research. This article discusses the technology development prospects of chain drive products from a technical point of view.

1. Strengthen basic scientific research work and comprehensively improve technological innovation capabilities

In recent years, a lot of experimental research work has been done on the fatigue performance of chains at home and abroad, which undoubtedly played an important role in guiding product design and manufacturing.

At the same time, I have also noticed the research on the fatigue life distribution of the chain, but due to various reasons, these research work is not thorough and systematic, and the analysis of the fatigue fracture, especially the micro analysis of the fatigue fracture, is far from sufficient. The mechanism of crack initiation, micro-crack propagation, macro-crack propagation, fracture failure and its dynamic observation during the fracture process are poorly understood. The failure analysis of the fracture is a crucial part of the inspection and guidance of product design and manufacturing processes. Of course, the fracture analysis should not be limited to the fatigue fracture of the chain plate parts, but should also include the low energy fatigue fracture of the rollers, sleeves and the parts. In fact, domestic counterparts have begun to realize the importance of fatigue life analysis and fracture analysis, and have initiated research in this area at different levels. The establishment of a typical fatigue fracture map should be an important basic work in the industry. .

The study of wear mechanism and its failure mechanism is very important to build brand-name chain products. Wear has always been one of the most important and easily detectable key technical indicators of chain products. In recent years, domestic research on the wear failure mechanism of roller chains and toothed chains has begun. The main wear mechanisms such as abrasive wear, fatigue wear, and adhesion wear of the chain have been microscopically analyzed, and the generation, propagation and spalling of contact fatigue cracks have been discussed. The dynamic process and cyclic hardening and cyclic softening characteristics. With the continuous improvement of the market's requirements for the wear resistance of chain products (ε<1%), a comprehensive and systematic study of the wear characteristics of many products such as roller chains, bushing chains, toothed chains and chains used in special working conditions is becoming Must do. As a technological development trend, it will be of practical value to carry out research on the wear mechanism and failure mechanism under severe service conditions such as high speed, impact, speed change, variable load, dust and corrosion, and to explore important ways to improve wear resistance. Key technologies and innovative projects.

The industry has long known the importance of high-speed chain transmission noise, but the corresponding research and testing work has not progressed. The reason is that there are no relevant standards and inspection specifications in the industry, and it is necessary to propose chain transmission noise. The evaluation indicators and test methods of the above are difficult to achieve without a solid preliminary research foundation as the support; secondly, the scientific noise test environment and test conditions also limit the development of this aspect of work. At present, many chain products, such as automobile engine timing chain, oil pump chain, gearbox transmission chain, motorcycle engine timing chain, have gradually introduced noise evaluation indicators, thereby driving the industry’s demand for this market. The emergence of technical strategies. It should be pointed out that noise testing and research should not be limited to the instantaneous noise value of the chain drive system, but should conduct real-time analysis of the noise spectrum of the transient signal or unsteady state information of the chain drive system, and study the frequency of its noise over time. Dynamic characteristics, seek the source of noise and measures to reduce noise, and put forward relevant evaluation standards and inspection specifications on this basis. This research work first started with high-speed sleeve roller chain transmission and high-speed toothed chain transmission. Will have important guiding significance.

In addition, pragmatic basic technology research should be carried out on the chain transmission meshing mechanism, such as the Hy-Vo chain and the derived Hy-Vo meshing chain that are currently used in high-precision mechanical transmission in the world (in the same chain) The meshing principle and design method of new chains, such as both external and internal contact), Hy-Vo multi-pitch swing pin chain (there are two pitch sizes in the same hanging chain).