The article describes the layered movement of the grain flow through the working body, which is an inclined surface with grooves located along the ramp line. The working body performs translational harmonic oscillations in a straight line, perpendicular to the flutes. The stream is conventionally divided into two layers: one (lower) in thickness is equal to the height of the flute, the second (upper), is located above the grooves. The movement of the lower flow, that is, the movement of grain between grooves, is considered. A diagram of the forces acting on a material particle, the system of differential equations of its motion is presented. As a result, the analytical dependences of the particle displacement at an arbitrary moment of the oscillation period of the supporting surface were obtained. The possibility of transporting particles of the lower layer between grooves under the action of a component of gravity along the line of the largest slope of the self-braking working surface is theoretically substantiated and proved. The experimental studies carried out confirmed the adequacy of the obtained analytical dependencies.