INMATEH - Agricultural Engineering

6

Authors: Meca V.A., Cârdei P.

The researches whose results are presented in this article aim to theoretically optimize the agricultural machines designed to prepare the germinating bed. For ploughing machinery, an optimization method has been known since 1970-1980. The movement resistance force of ploughing machines was expressed in relation with the forward speed by a formula known since the middle of past century. By means of this formula, the method of optimizing the working regime of ploughing machines was achieved. For the machines designed to preparing the germinating bed, the formula giving the calculation of movement resistance does not depend explicitely on speed, and the constant expressing the soil action in contact with working parts is a global one- a resistance density per machine working width. This constant should be experimentally determined. Our researches have aimed to modify this formula of calculation of movement resistance similarly with that of plowing machines and solve the optimizing problem taking into account the method already used. The researches frame within a scientific unifying current in the field of agricultural mechanics, which purpose is to reduce the diversity of expression by other procedures and generalization. Renouncing to use special formulae lead to large opportunities in conceiving, designing and testing agricultural machines, the agricultural mechanics formulae taking its roots in modern science base.

6

Authors: Ovidiu M., Muntean L. S., Drocas I., Muntean M.

The main purpose of this study was to identify seed conditioning procedures for the species Melissa officinalis L., considering the difficulties encountered due to the small size and weight. Starting from this objective and using a sieving machine one has tried to develop a sieve separation techniques of seeds from flowers. In the experimental tests, as working material seeds of two months old were used, taking into account two factors: time of sieving (5, 10 and 15 minutes) and sieving amplitude (0.2, 1 and 2.2 mm). The results from experimental investigations have shown the possibilities to use sieve conditioning of Melissa officinalis L. species seed, but also noted the need to use further procedures for seed separation from impurities using currents of air. The main result consists of identifying the sieve time and the amplitude of the sieve.

8

Authors: Constantin N., Irimia D., Persu C., Cociu A.

Multifunctional aggregate for soil tillage in agricultural fields - MATINA is based on conservative agriculture system which consists in the main soil operation without furrow overturning, the vegetal wastes being superficially incorporated and at least 30% out of their amount being maintained at soil surface. This system assures competitive productions in terms of quality and quantity similar to those classically obtained, but with reduced costs and high profit, while improving soil features and preserving environment. The aggregate laboratory-field tests have been performed within private agricultural farms in Dolj and Teleorman county for tilling the soil in unplugged lands (in spring) and in wheat and barley stubble (in summer), during April-August 2011. MATINA performs at a single passing, the following agricultural operations: soil deep loosening with loosening parts, in order to facilitate plants roots easily to penetrate into the soil in search of water and nutritive elements; preparing the germinating bed with specific working parts; soil breaking and additional leveling by means of rollers with rods. During the field-laboratory tests, procedures elaborated by INMA-DI have been used, measuring and monitoring equipment (EMM) in terms of metrology verified, have been also used and appropriate working qualitative and energetic indexes have been obtained. Productions of crops set up in spring of 2011 in soil worked with MATINA have been similar to those obtained by classical system, with expenses by about 50% less.

8

Authors: Ivan Gh., Nedelcu M.

The article presents the part four of the study of pile displacement on the straw walker of conventional grain combine harvesters, in order to determine the structural and functional characteristics of the straw walker, to increase its working capacity. The material presented in the article represents the study of functions tsalt(k,α,δ,f) and S(k,α,δ,f,), duration and size of displacement of a pile jump on the shaking element at a complete rotation of it

8

Authors: Popa Gh., Constantinescu A., Dumitru I. , Vlădut V.

The paper presents the calculation of traction of a tractor equipped with additional hydrostatic transmission of mechanical transmission. The variation of the hydraulic parameters – the working liquid pressure, the hydraulic pump delivery – modify the parameters of the hydraulic motor – the rotation speed of the motor axle, the motor torque – and, also, the traction performances of the tractor. Also, wheeled traction performance are influenced by constructive and functional parameters of tractor tire, parameters influencing the interaction between the ground and wheels.