Substantiation of working parts parameters of the vineyard rotary earth auger for firm soils

BACKGROUND: The study is focused on improvement of basic machines and development of new machines for digging of holes for young fruit trees in firm soils.

AIMS: Expansion of technological abilities and decrease of energy resource intensity of an earth auger with the rotary working body for the sake of replacement of technically obsolete pothole diggers.

METHODS: For working bodies parameters substantiation, the vineyard rotary earth auger, which design includes a bulk, a frame, a rod and a beam, forming the hinged forebody mechanism, whereas the bulk and the frame are linked to the attachment system of the power source, is investigated.

RESULTS: The most widespread actuators of working bodies of universal hole diggers are analyzed. Principles of shock-and-vibrational digging of a drill tool make it possible to obtain significant improvement of digging performance. The design and technological layout of an earth auger and the theoretical substantiation of working bodies parameters under the vibration effect are proposed. The amplitude of the bar reciprocating motion along the splines is not less than washer teeth height in order to transform the rotation into the reciprocating motion in the vibrational operation mode of an auger. For the vibrational operation mode of an earth auger, the simulation model, considering physical and mechanical properties of soils, geometry parameters of the working body for the sake of substantiation the number of teeth of working body drive washers are proposed. It is found that for the auger diameter increases from 0.15 to 0.35 m the number of teeth of working body vibratory drive washers, ensuring demanded vibration frequency for soil layer breaking-off by auger shares, increase from 7 to 16 pieces in accordance to technical properties of the auger and physical and mechanical properties of considered firm soils. The proposed design parameters for reducing gear box fixed to the frame and auger offset from the tractor longitudinal axis corresponding to frame rotation angle β = 33°20’ is ensured by a hydraulic cylinder, the beam length L₁ is 800 mm, for pivot fixing of the frame with the length L₂ of 1300 mm, the offset value up to 1500 mm.

CONCLUSIONS: The obtained results of the earth auger simulation for operation at firm soils in the case of planting perennials are given. The study is targeted to the expansion of technological abilities, the substantiation of design and technological parameters of an earth auger and the decrease of energy resource intensity of hole digging.