Stresses of the power plant of a feller buncher during the pulling process when harvesting wood on slopes

Abstract

The article develops the dynamic loading of the power plant of a feller buncher machine in the process of pulling it up with the handle of a manipulator when harvesting wood on slopes. A mathematical model has been developed that allows, at the design stage of a compact feller buncher machine, to determine the magnitude of a significant dynamic moment existing on the machine’s power plant, as well as the crankshaft rotation speed. The mathematical description is in the form of the Lagrange equation of the second kind. An example of calculating a mathematical model for a LP-19A feller buncher machine is given. A graph of changes in the additional dynamic moment is presented at a pull-up speed of 0.1, 0.2 and 0.3 s^–1, as well as depending on the slope angle (15, 30 and 45°). A graph of changes in the dynamic coefficient depending on the value of the additional dynamic moment is presented. Graphs of changes in the reduction in the number of crankshaft revolutions are presented depending on the load on the power plant and depending on the slope angle. Analysis of the research results showed that pulling up the feller buncher machine with the handle of a manipulator when harvesting wood on slopes is accompanied by a significant amount of additional dynamic moment on the power plant, leading to a decrease in the crankshaft rotation speed. Thus, when pulling up the feller buncher machine on a slope with an angle γ = 15º, the maximum value of the additional dynamic load on the power plant will be 74.2 Nm, and the reduction in the crankshaft speed will occur at 311 rpm.