INFLUENCE OF TRACTOR HITCH LINKAGE SYSTEM ON PLOWING UNIT PERFORMANCE.

The quality indicators of the ploughing unit largely depend on the joining diagram of the mounted plough with the tractor. Most often, this joining, performed according to a two-point or three-point diagram, is asymmetric. As a result, momentum arises that tries to turn the tractor in a horizontal plane. Depending on the chosen diagram for joining the tractor with a mounted plough, this momentum will be greater or less, and the performance of the ploughing unit will be worse or better. This paper evaluates the dependence of the momentum value on the plough rotation angle and the asymmetry of its joining to the tractor with two-point and three-point diagrams for adjusting the rear hitch linkage system. Calculations have established that the increase in the specified momentum occurs more intensively with a two-point diagram for joining the plough to the tractor. In this regard, its use is advisable only for specific ratios between the plough width and the parameters of the tractor running system. At the same time, with a certain adjustment of the tractor's rear hitch linkage system according to the three-point diagram, it is possible to achieve such a position when its centre of mass practically coincides with the point of the plough traction resistance application. Ultimately, this ensures the momentum value is reduced to a minimum (almost zero) value. Experimental studies have established, when setting the convergence angle of the lower links of the tractor hitch linkage system according to the three-point diagram at the level of 0.49 rad, the null hypothesis about the equality of the plough operating width variances in comparison with the option of its joining according to the two-point diagram does not deviate. The frequency distributions of the plough rotation angle oscillations (β) are also almost identical. The maxima of the normalized spectral densities of the parameter β oscillations fall on the same frequency equal to 0.1 s-1. The oscillation variances of the angle β for both plough joining diagrams are concentrated in the same range of rather low frequencies: 0-1.0 s-1, i.e. 0-0.16 Hz. [ABSTRACT FROM AUTHOR]