Design Improvement of the Forestry Chain Saws

Abstract

At the present time cutting of trees, delimbing, and crosscutting with gasoline-powered saws and logging machines are carried out in the forestry cutting area operations with the help of chain saws. Therefore, the efficiency of forestry work depends on the reliability and performance of the chain saw machine. The problem of increasing the reliability of sawing machines, increasing their service life becomes particularly relevant due to a sharp decrease in the volume of logging with the use of multi-operator logging machines. In this regard, the wide use of efficient motor tools, improvement of their design, especially the chain saw machine, with regard to reducing the harmful effect on the operator is of great importance. Poor quality and performance of domestic machinery has led to the fact that mainly imported tools are used in Russia, while their price and maintenance costs are constantly increasing and, consequently, the cost of harvested wood increases too. In this regard, it is important to develop and introduce new, more perfect tool designs that are not only as good as the reliability and performance of the imported equipment, but even much better. Taking it into account, we can consider that the issue of chain saw research with regard to the specifics of its design, as well as its science-based improvement will increase the operational performance and reliability of machines, which is important for the logging industry. One of the main causes of saw unit failures is the increased wear of its components accompanied by the improper saw chain tensioning. Currently, the proposed devices for regulating the tension of the saw chain require periodic stopping of the saw, as none of the devices provides its automatic tensioning. Thus, the purpose of the research is to improve the reliability and service life of chain saws of forestry machinery on the basis of improving the design that provides automatic tensioning of the saw chain. The paper describes the design solutions to improve the saw machine, that is the design of the device that provides automatic tensioning of the saw chain when the saw bar is fixed, allowing to increase the reliability and service life of chain saws, to reduce the chain slipping during the work, which will increase the safety of work and reduce the risk of injury to the operator.