To Assessment of the Value of Dynamic Load of Forestry Machines From the Installation Place of Its Safety Devices

Abstract

An integral part of the drive elements of machines in forestry are devices that ensure their protection against breakdowns during overloads. Safety devices can be installed on various parts of the kinematic chain of the machine drive elements: at the beginning, at the end or in the middle, and can also be built into the working unit (body). It is most advisable to install fuses closer to the end of the drive lines of the kinematic chain of the machine. If torque safety devices are installed at the beginning or in the middle of the drive, they are not in the overload zone (more often, overload occurs next to the working unit or directly on it). Under these conditions, the drive links of the kinematic chain are subject to overloads of various magnitudes. With distance from the place of occurrence of overload, the value of the value of the dynamic moment decreases due to elastic deformations and friction losses in the drive links of the machine. Consequently, there is a breakdown or destruction of parts and components of the drive, and the fuse itself does not work. Thus, in this article, using a calculated mathematical model of the actuation process of safety devices using a computer, calculations were carried out to determine the values of dynamic loads and an assessment was given in the case of installing a fuse at the beginning and at the end of the kinematic chain of the machine drive

Overload protection for forestry machines when using pressed wood friction material

“…It is almost impossible to take into account all factors. In [6,10], it is proposed to set the level of the protection parameter based on the consideration of the fields of the limiting torques of the machine and the safety device. When choosing the protection parameter for forestry machines, the proposed method can be taken as a basis, but with certain amendments regarding the direct operation of the machine under certain conditions and the fuse used to protect it.…”

“…The stiffness coefficient of each rubber ring representing a truncated cone can be found by the formula [6], using the average cross-sectional area A (13) 𝐶 = 𝜋𝐸𝐴 ℎ .…”