Showing papers in "Journal of Mechanisms Transmissions and Automation in Design in 1987"

Hertzian damping, tooth friction and bending elasticity in gear impact dynamics

Abstract: Etude de la dynamique des chocs dans une transmission a engrenages en tenant compte du frottement entre les dents, de l'elasticite en flexion et de l'amortissement du contact hertzien

Kinematic and Dynamic Analysis of Parallel Manipulators by Means of Motor Algebra

Abstract: Analyse cinematique et dynamique des manipulateurs ayant une chaine cinematique partiellement fermee (mecanisme parallele)

An Application of the Linkage Characteristic Polynomial to the Topological Synthesis of Epicyclic Gear Trains

Abstract: Utilisation des polynomes caracteristiques des mecanismes pour la synthese topologique des trains d'engrenages epicycloidaux

Offset Surface Generation and Contouring in Computer-Aided Design

Abstract: Two computational techniques are presented for Computer-Aided Design (CAD) and Machining (CAM) of parametrically defined surfaces. One technique deals with construction of offset surfaces. An algorithm is presented that would allow detection and removal of the closed loop on the offset surface due to its self-intersection. The second computational technique presented deals with contouring of parametric surfaces. The technique presented allows for optimal generation of planar contour lines. The results are applied to Numerical Control (NC) machining of surfaces.

A Compliance Number Concept for Compliant Mechanisms, and Type Synthesis

Abstract: Introduction du concept de nombre de complaisance pour le calcul des mecanismes elastiques. Application a la synthese typologique

Dynamic Analysis of Three-Dimensional Mechanisms in “Natural” Coordinates

Abstract: Analyse dynamique d'un mecanisme spatial utilisant un nouveau systeme de coordonnees dites naturelles (utilisation des coordonnees et des composantes de points et de vecteurs rigides attaches a chaque element du mecanisme)

A New Concept in Semi-Active Vibration Isolation

Abstract: Nouvelle conception pour des amortisseurs de vibrations semi-actifs (c'est-a-dire sans apport d'energie exterieur)

The Dynamic Modeling of Flexible Spatial Machine Systems With Clearance Connections

Abstract: Modele dynamique d'un systeme mecanique spatial flexible tenant compte du jeu dans les articulations

Surface Geometry of Straight and Spiral Bevel Gears

Abstract: The fundamental geometrical characteristics of bevel gears have been discussed in this study. The mathematical modeling of the tooth surface geometry of bevel gears can be developed based on the basic gearing kinematics and involute geometry along with the tangent planes geometry. The parametric representations of the spherical involute and the involute spiraloid, which are the tooth surface geometry of straight bevels and spiral bevels, respectively, have been derived in this paper. This study may provide some fundamentals for computer numerical controlled manufacturing of bevel gears.

Implementation of Design Sensitivity Analysis with Existing Finite Element Codes

Abstract: A numerical method is presented to implement structural design sensitivity analysis theory, using the versatility and convenience of existing finite element structural analysis programs. Design variables such as thickness and cross-sectional areas of components of individual members and built-up structures are considered. Structural performance functionals considered include displacement and stress. The method is also applicable for eigenvalue problem design sensitivity analysis. It is shown that calculations can be carried out outside existing finite element codes, using postprocessing data only. Thus, design sensitivity analysis software does not have to be embedded in an existing finite element code. Feasability of the method is shown through analysis of several problems, including a built-up structure. Accurate design sensitivity results are obtained without the uncertainty of numerical accuracy associated with selection of finite difference perturbations.

Robot Kinematics—A Compact Analytic Inverse Solution for Velocities

Abstract: Calcul de la cinematique inverse des robots. Methode analytique compacte pour le calcul des vitesses

Rigid Body Location and Robot Workspaces: Some Alternative Manipulator Forms

Abstract: Using an enumeration procedure for connectivity, the theoretically minimum number of actuators is identified for each of six types of point workspace. Robot dexterity is described using the omnidirectional, primary, and dexterous workspaces of a point. It is shown that only two plane workspaces are sufficient to provide all the mechanically achievable workspaces that are dual to the six point workspaces. Several manipulator structures are identified, and these provide equivalent dexterity to that achieved by a spherical wrist with three concurrent, sequentially orthogonal, and fully-rotatable hinge joints.

Development and Testing of Hypotheses in Engineering Design Research

Abstract: Engineering Design Research (EDR) has yet to be fully established as a legit- imate field of inquiry. Design Researchers don't often cast their efforts into the scientific paradigm of hypothesis creation and testing, resulting in the present sit- uation where analysts and Scientists find little justification for EDR. The apparent lack of scholarly or intellectual content appears to be related to a number of factors: Rigor and scholarship in the technical arena have become associated with skillful analysis.

Lateral Stability Behavior of Railway Freight Car System With Elasto-Damper Coupled Wheelset: Part 2—Truck Model

Abstract: A general model of single rail vehicle wheelset with elasto-damper coupling between the wheels, has been developed as a first step in developing a railway freight truck model with elasto-damper coupled wheelset (EDCW). By choosing different coupler parameters, various stiffness-damper combinations, as well as rigid axle (conventional wheelset) could be simulated. The mathematical model of EDCW has been validated by comparing the model under limiting cases with those of published results for conventional system. In this paper, the results of linearized stability analysis of EDCW model on tangent track are presented and discussed. The investigation showed that wheelset coupler parameters have significant influence on the stability behavior of the wheelset, and there is an optimal coupler parameter which can improve the wheelset critical speed over the conventional system.

Computer Aided Concept Design for Structural Configuration of Machine Tools: Variant Design Using Directed Graph

Abstract: The modular design system has recently become important, not only to rationalize the design and manufacturing procedures of the machine tool, but also to evolve the flexible manufacturing system. In this paper, therefore, to establish a design methodology for the modular construction system of machine tools, a generating method for structural configuration, i.e., a procedure of computer aided concept design has been proposed. The proposed method is of variant design type, in which a machine tool as a whole and modular complex are represented with the directed graph, it being suitable for the information processing and storage of data. When generating a structural configuration, at first, possible modular complexes in the data memory are referred to, and then through simple mathematical treatment they are integrated so as to form structural configurations. By this method, all possible structural configurations of the machine tool can be generated systematically and rationally, according to the machining requirement.

Dynamic Model of a Fluctuating Rocker-Arm Ratio Cam System

Abstract: Modele dynamique d'un systeme arbre a cames-culbuteurs dans lequel la longueur du bras de levier correspondant au culbuteur varie au cours d'un cycle

Method for Generation of Spiral Bevel Gears With Conjugate Gear Tooth Surfaces

Abstract: A method for generation of spiral bevel gears is proposed that provides conjugate gear tooth surfaces. This method is based on a new principle for the performance of parallel motion of a straight line that slides along two mating ellipses with related dimensions and parameters of orientation. The parallel motion of the straight line, that is, the contact normal, is performed parallel to the line which passes through the foci of symmetry of the related ellipses. The manufacturing of gears can be performed with the existing Gleason's equipment.