Standard range of wheeled tractors

The article proposes a variant of the formation of a standard range of wheeled tractors based on the classification system used in Russia, since it should take into account the results of their evolution and development trends towards a significant expansion of traction-speed ranges of use in tillage operations of different energy intensity due to a significant change in the operating weight by installing dual wheels and removable ballast. As the main operational parameters, the developed operational power of the engine indicated in the technical specification and the adjustable weight of the tractor, which determines the traction class, are proposed. In order to optimize it by ballasting we used an indicator of manufacturability - specific weight characterizing the ratio of mass and energy parameters of a tractor in the nominal traction-speed mode. The basic value of the specific weight of 67.3 kg/kW corresponds to the nominal speed of 2.50 m/s for the main tillage operations of the first group (moldboard plowing) and characterizes the maximum level of operational mass at full ballasting and the main traction class of the tractor. The minimum values of the specific weight of 45-56 kg/kW and, accordingly, the operating weight in the speed range of 3.33 ± 0.33 m/s for tillage operations of the second and third groups characterize the tractor use in the adjacent lower traction class with the least ballasting. The proposed two-parameter standard range of energy-saturated wheeled tractors is represented by a growing sequence of ten power classes from 21 to 410 kW containing (except for the first and tenth) two adjacent traction classes at the minimum and maximum ballasting for use in operations of different energy-intensive groups.