Applied Mechanics and Materials Vol. 657

Abstract: In the paper a research methodology was developed and used to determine the rigidity in the axial direction.The paper presents a the experimental results regarding the total deformation of narrow modules found in the structure of modular sets. The research conducted showed the different evolution of deformation curves in the case of modular structure composed of modules, with different shape and different sizes, in the case of similar loads

Abstract: This paper presents the general features about the stability of emulsions and modeling particle sedimentation process at the flow of water-oil emulsion (WOE) through a horizontal pipe. Are presented a plant and the methodology for determining the stability of WOE, and finally the experimental results that validates the theoretical equations and particle sedimentation model along the pipeline.

Abstract: Fixtures are used for orientation-positioning-tightening of workpieces during machining on machine tools. Multiple clamping fixtures are intended to clamp several workpieces for simultaneous or successive machining. Multiple clamping is characterized by a series of economical advantages, due to the reduction of total machining time. These advantages are more important once the number of workpieces is higher or if the machining is made with compound tools. Due to the complexity, overall size and the high number of components, the multiple clamping fixtures have diminished accuracy than simple fixture due to elastic and contact deformations of fixtures housing, of supports etc. Also, multiple clamping fixtures present diminished rigidity and dynamic stability. From the analysis of the specialized literature results that there are a few paper on the subject of multiple clamping. In the paper there are presented the causes that can lead to the diminish of the accuracy of multiple fixture. The modalities for the determination of fixtures precision are presented, also, for the parallel and serial multiple clamping fixtures.

Abstract: In this paper we will elaborate a statistic analysis on the main parameters which influence the tribologic depositions process of thin TiN layers. The deposition of tribologic layers will be executed on the axes of the supercharging turbines at the automobiles made of C120, the maximum allowed thickness being of 1÷1,5μm. The main stages of the TiN coating operation are washing and drying conditions which we relate to adhesion layer deposited titanium and titanium coating process, the process consists of important elements of the TiN coating (Electron heating time-Argon plasma, electron temperature, plasma heating argon for Bias voltage ramp., Bias voltage temperature ramp., temperature ion cleaning time for coating titanium pressure nitrogen nitrogen temperature) relative to the thickness of the deposited titanium. The operation of coating with a layer of TiN will be done on a DREVA 400 machine at S.C. “Rulmenti” S.A. Barlad. The statistical analysis of the parameters will be done using the Minitab 14 software.

Abstract: The Paper Presents a Study Conducted by the Authors for Mapping of Soil Resistance According to Depth and Space. the Determination of Penetration Resistance Pressure of the Soil was Done in Field, with a Penetrograph, and the Experimental Data were Statistically Analyzed, in Order to Assess the Loading Regimes Faced by the Active Organs of Agricultural Machinery while Working for Soil Processing, for Estimating the Influences on their Durability. A Durability Case Study on a Real Reversible Chisel Type Cultivator Blade was also Conducted, Using a 3D Finite Element Solid Model and Two Classical 2D Models in Order to Determine its Fatigue Response, Using as Loads the Determined Soil Resistance Pressure.

Abstract: The main goal of the kinematic feed chains used on numerically controlled machine tools is to ensure the relative position between the manufactured part and the cutting tool tip with a high accuracy. Therefore, the positioning precision is a major performance criterion for CNC machine tools. The guidance system of the machine table, together with the actuation system and the closed-loop control system, represents a key factor in manufacturing high precision machine tools. Mounting and alignment errors of guideways, both in vertical and horizontal directions, directly affect the table positioning precision and implicitly, the manufacturing precision of the machine tool. Guideways misalignment also generates stresses, plays and excessive run-out. The present paper contains a method of experimental analysis regarding the influence of guideways alignment errors on the positioning precision of the kinematic feed chains, which takes into account the alignment of the two guide rails, both in vertical and horizontal plans. The feed axis used in the experimental setup is closed-loop controlled, making use of an indirect position measurement system.

Abstract: A very important parameter which must be considered when designing a hydrostatic guideway of high stiffness is the pressure from the hydrostatic pockets. Modifications of this parameter during functioning are caused by variations of flow and supply pressure and also by the defective geometry of the hydrostatic pockets. The pocket pressure has a major importance for achieving the hydraulic sustentation, because it determines the load capacity, which thenceforth determines the film thickness and the flow. The latter is used for determining the hydraulic resistance of lands and also for deciding the geometry of the hydrostatic guideway as a whole. Based on these considerations, the analysis of the pocket pressure variations represents an important criterion which should be taken into account when designing a hydrostatic guideway with a very high stiffness. The present paper contains a new method for analysing the hydrostatic guideway behaviour with regard to its stiffness, for different pocket pressure values. The experimental research was carried out on a closed hydrostatic guideway, with the moving element having the dimensions of 500x260 [m and the pocket dimensions of 150x88 [m.

Abstract: High-ratio planetary gears are frequently used in robot arm articulations for the purpose of transmitting motion from the electric motors to the moving elements. Actual planetary gears used in industrial robots have a relatively large weight related to the gear ratio, which leads to a high inertia of the moving elements.Throughout this paper, a novel computation method of the dynamic momentum is presented as well as constructive methods used to improve the dynamic behaviour of the planetary gear. The optimization method regarding the dynamic behaviour is based on the reduction of all moving masses towards the motor shaft but also on new construction strategies for planetary gears that help minimizing the gyration momentum. This method has been applied for a three-stage planetary gear having a gear ratio of 175,61:1 in order to optimize the shape of the carriers that are attached to the output shafts, according to its kinematic diagram. The results obtained will be presented comparatively and in a graphical form, thus serving as a practical guide addressed to the designers or manufacturers of industrial robots.

Abstract: The purpose of the paper is to establish the stress state on the piece triangular profile of the corrugated, submissive under the influence of an equally spread pressure. The results of the analysis make an estimative model for experimental approach of the behaviour of corrugated metallic diaphragms, also allowing the comparison of the results obtained by modelling, using the finite elements method with the experimental ones.

Abstract: The paper refers to an original device, designed by the authors, which provides cleaning for shoe soles when a person enters into a home. This device resembles an ordinary scale and provides cleaning without causing pollution. It is composed of a flexible strip with a brush on the active surface. The dirt is collected by means of tabs that allow its storage in a drawer cell. The device has a simple structure, but originally, it is different from other similar products available worldwide. It is easily accomplished by using existing components (eg. a drill with helical gear). It is easy to maintain and can be powered from any AC grounded outlet 220 V.