The influence of the platform leveling system on the stresses of the power plant of a feller-buncher during the pulling process

The article considers the dynamic loading of the power plant of a feller-buncher machine with a platform leveling system during its pulling by the manipulator handle during timber harvesting on slopes. A mathematical model has been developed that allows determining the value of the additional dynamic torque acting on the machine’s power plant and the crankshaft rotation frequency at the design stage of the fellerbuncher. The mathematical description is written in the form of the Lagrange equation of the second kind. An example of calculating the mathematical model for the LP-19A feller-buncher is given. Graphs of changes in the additional dynamic torque at a pulling speed of 0.1, 0.2 and 0.3 s^–1, as well as depending on the slope angle (15, 30 and 45º) are presented. A graph of changes in the crankshaft rotation frequency reduction depending on the slope angle is presented. The analysis of the research results shows that the pulling of the feller-buncher machine equipped with the platform leveling system by the manipulator handle during timber harvesting on slopes is accompanied by a significantly less significant dynamic moment on the power plant than that of a machine with a “classic” layout. Thus, when pulling the feller-buncher machine on a slope with an angle of γ = 15º, the maximum value of the additional dynamic load on the power plant will be only 4.4 Nm. The level of dynamic loading of the power plant significantly depends on the angular velocities of the machine pulling used by the operator, as well as the value of the slope angle on which the work is carried out. The developed mathematical model allows us to study the loading of the feller-buncher machine power plants equipped with platform leveling systems during pulling during timber harvesting on slopes, both at the design stage of new machines and when improving the designs of serially produced models.

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