The article discusses the features of the process of interaction of the blades of the teeth of the disk working body with the cultivated soil. If we take into account the fact that the parameters of the intensity of the impact exerted on the soil by the toothed working body will depend on the speed of movement, it will be possible to determine the values of the speed of an arbitrary point of the blade of the teeth. As a result of mathematical transformations and the application of the method of differentiation of the equation of their displacement, a formula was obtained for calculating the cutting speed for an arbitrary point of the blade of the teeth of a disk working body. Also, the acceleration of the points under consideration is determined and the dependences obtained as a result of theoretical studies are analyzed. The dependences demonstrate that the parameters of the impact speed and the trajectory of the blade movement directly depend on the shape of the cutting edge. They are also influenced by the angle of attack, the value of the inclination in relation to the vertical, as well as the speed of the planter movement. After analyzing the results obtained, it can be concluded that there is a noticeable decrease in the throwing of the upper soil layer to the side and the removal of the lower layer to the open surface of the field when exposed to a disk working body with teeth around the perimeter.

One of the promising working units for pre-sowing soil preparation, in particular, for pre-sowing soil cultivation for potatoes, are still the disk tillage. Studies of a number of authors determined, that the disc units with continuous cutting edge are more energy intensive, less resistant to running and sensitive to changes in the load and working units with a serrated cutting edge has significant advantages. However, not all gear working units are able to perform advanced agronomic requirements. The rational parameters of developed by the working units, can only be determined on the basis of a study of the process of its interaction with the soil, but in relation to working units with a serrated cutting edge, this question is poorly understood. Working unit movement with respect to the adopted reference system, can be regarded as fully qualified only, when we know the movement of its each points in the same frame of reference. Therefore, the disk working unit is considered a with the teeth, the cutting edge of which is made by a logarithmic spiral curve, providing moving cutting of soil and plant remains in motion, and the back edge is in a straight line, connecting the toe of each tooth with the center of the disk. As a result of calculations, based and the equations of motion for an arbitrary point of the cutting edge of a tooth of a flat disk of the working unit, which allows to build a trajectory in space, determine the velocity and acceleration of the blade points at any given time.