Optimization of the parameters of the tensioning and releasing mechanism of the rubber-rope track belt of an agricultural tractor

The article considers the current problem of developing domestic tracked agricultural tractors with a capacity of over 350 hp, in particular, the creation of an effective hydraulic eccentric mechanism for tensioning and releasing the rubberrope track belt. It is noted that in domestic tractor manufacturing there are no analogues of foreign models, such as Challenger, Fendt and John Deere, which use a hydraulic eccentric mechanism that ensures ease of tensioning, pressure control and ease of maintenance. The considered tensioningreleasing mechanism consists of an eccentric lever, a hydraulic cylinder, a hydropneumatic accumulator and a switching unit. This mechanism is designed to operate at a pressure of 190–210 bar, which corresponds to the nominal pressure in the hydraulic system of agricultural tractors. The switching unit equipped with a pressure sensor allows you to monitor the state of the track tension and promptly inform the operator about the need for adjustment. The paper proposes a calculation method for the mechanism based on solving a system of triangles describing the geometry of the device taking into account the eccentric installation angle β. The dependences of the tension and release force on the angle β, as well as the parameters of the hydraulic cylinder and the hydropneumatic accumulator providing shock absorption, are calculated. A complete description of the mechanism operation is obtained, reflecting the nonlinearity of the forces depending on the installation angle and stretching of the track. The conclusions emphasize that the forces in the mechanism are nonlinear functions, and the optimization problem is reduced to solving a transcendental system of equations. The proposed calculation method allows to simplify and speed up the selection of optimal design solutions, improve the reliability and performance characteristics of the chassis of domestic tracked tractors, which is important for ensuring food security of the country.