Котки різних конструкцій. Інженерний аналіз

Abstract

Comparative field tests of similar in design ring-spur and gear-spur rollers for soil rolling provide their developers and users with information on the understanding of the design and technological features. The Goal of research – engineering analysis of structures of ring-spur and gear-spur rollers according to the criteria of weight, shape of working surfaces, soil pressure, completeness of compaction, penetrating ability in the range of depth of pre-sowing and surface tillage. Methods and Materials. Engineering analysis involved the study of three types of rollers. The research hypothesis assumed that the combination of weight characteristics of rollers and their geometric shapes of working surfaces in contact with the soil, in statics will provide the inherent properties of each cat (the first stage of research), which will potentially focus on choosing the most acceptable criteria for comparing functional features of rollers. necessary for field research in dynamics (the second stage of research). According to the criteria of static research were selected: penetrating ability (1); soil pressure (2); completeness of compaction of the area (3); direction of clamping forces (4); features of working surfaces (5); the nature of the mounting of solid disks on the shaft (6). Methodologically, the first three criteria required special adaptations (capacities) with the ability to change the height of the soil layer in the range of depths of pre-sowing and sowing tillage. Other criteria were supposed to be carried out by organoleptic evaluation. The study was supposed to be carried out on soil characteristic of the Forest-Steppe zone and homogeneous in fractional composition, to exclude the influence of soil inclusions of different sizes. Evaluation of soil characteristics was performed by thermostatic-weight method, according to the generally accepted method of "cutting ring" [Kaczynski, 1947] with a cylinder volume of 100 cm3. To determine the area of one elementary working surface of the annular disk, the application of a marking grid on its imprint on the surface left in the soil layers hmin, hmid, hmax was used. When determining the pressure on the soil, depending on the height of the treated layer, the marking grid was superimposed on the imprint of several areas of elementary working surfaces, which were fixed on the chord of immersion in the soil of the annular segment. Statistical analysis of experimental data was performed by the method of analysis of variance according to [Dospekhov, 1985] and interpreted by standard computer programs Excel and graphs. Results. According to the physical characteristics (weight and geometric parameters) of the roller combines the proximity of the diameter of the disks, the width of the working surfaces on the edge of the generator, the presence of spurs. The difference lies in the dimensional characteristics that fall on the width of the grip, the presence of aggressive protruding shapes (teeth) in the gear-spur structure. Each roller has an individual layout of elementary work surfaces. This allowed the conditional marking of rollers as "classic", "modernized" and "specialized". The working surfaces of the classic and specialized rollers provide vertical and lateral action of the clamping forces, while the modernized forms them in the vertical direction. These forces for each of the rollers are derived from the orientation of the working surfaces of different configurations (flat narrow, flat wide; a combination of point-focused with trapezoidal). In addition, work surfaces can have a one- or two-level sequence of contact with the soil at a variable depth. It is established that the nature of the attachment of adjacent disks on the shaft can be rigid or movable. Definitions of concepts and their estimation on indicators of pressure, completeness of consolidation, penetrating ability are resulted. Conclusions. According to the indicators of engineering analysis, each of the three rollers is predicted to have its inherent dominant feature for the most effective use in milling, pre-sowing and post-sowing tillage operations. It is determined that the most acceptable criteria for further research in the dynamics of variable speed should be the intensity of crushing lumps, the degree of soil compaction, the intensity of soil compaction, sticking of the working surface of the roller in high humidity, self-cleaning ability. The criteria of further research in dynamics are determined.