The theory of oscillating movement in the soil of a toothed disc colter of a direct seeding grain seeder

Abstract

Purpose. Establishing theoretical regularities of oscillatory movements of the disc colter assembly of a direct seeding planter to justify its rational modes, which ensures high-quality sowing of seeds in the soil. Methods. During the research, methods of the theory of agricultural machines and modeling of technological processes performed by them, methods of higher mathematics, theoretical mechanics, as well as numerical calculations using a personal computer were used. Results. Compiled differential equations of translational and angular oscillations of the colter unit of the direct seeding planter, which arise under the action of reactions from the soil surface during the movement of the seeding unit along the unevenness of the field surface. The analytical solution of the specified differential equations made it possible to obtain expressions for calculating the frequencies and amplitudes of the studied oscillations depending on the structural and kinematic parameters of the colter unit and the parameters of the soil surface irregularities. On the basis of the obtained analytical expressions, graphical dependences of the amplitude of oscillations of the colter unit of the direct seeding planter on the speed of its translational movement with different stiffness of the springs of the double-spring suspension were constructed. Conclusions 1. A rational combination of the design parameters of the seeding unit, the speed of its translational movement, and the parameters of the unevenness of the soil surface, which achieve the necessary quality of seed sowing, is ensured by their determination using the obtained new analytical dependencies. 2. The obtained expressions for determining the amplitudes and frequencies of vertical oscillations of the colter assembly make it possible to minimize the magnitude of these oscillations and their impact on the quality of seed sowing. 3. Resonance values of the amplitude of oscillations are obtained when the frequency of disturbances of the colter assembly coincides with the natural frequency at speeds of translational movement of the seeder from 0.6 m s–1 to 1.0 m s–1. In the case of an increase in the speed of movement from 1.2 m s–1 to 4 m s–1 with the stiffness of the springs = 16815–67270 N∙m–1, = 17150–68600 N∙m–1, the indicators of the amplitude of vertical oscillations stabilize and acquire values, which are within 0.01–0.0004 m, respectively. Keywords: seeder, colter unit, toothed discs, soil surface irregularities, oscillations, differential equations, amplitude, frequency.