Showing papers on "Revolute joint published in 1980"
TL;DR: In this article, the relative motion across the clearance, impact and rebound, and restoration of continuous contact in plain unlubricated revolute joints is surveyed, with a focus on motion in continuous contact.
67 citations
TL;DR: In this paper, the conditions at a general idealized revolute joint, with clearance but with no hydrodynamic lubrication present, were derived, and a series of numerical solutions of the equations were used to predict the conditions under which contact is lost, leading to impacts.
Abstract: Equations are derived that describe the conditions at a general idealized revolute joint, with clearance but with no hydrodynamic lubrication present. The equations are governed by three dimensionless parameters that depend on the nominal motion, mass distribution and influence coefficients of the linkage in which the joint appears, as well as the clearance magnitude. A series of numerical solutions of the equations is used to predict the conditions under which contact is lost, leading to impacts. The results are presented in the form of a design chart and the implications are discussed.
48 citations
01 May 1980
TL;DR: In this paper, a pin joint network consisting of straight bars which are connected frictionless at the nodes is considered at large deformations and it is shown that a general work theorem and a principle of virtual forces exist, if the lengths of the bars and the position vectors of the nodes (both in the deformed state) are introduced as kinematic variables rather than the elongations of the bar and the displacement vectors, respectively.
Abstract: A pin joint network consisting of straight bars which are connected frictionless at the nodes is considered at large deformations. Such constructions have been analyzed numerically in [1] and [2] on the basis of an equilibrium iteration process starting with kinematic admissible quantities. On the other hand in [3] a kinematic iteration process is used starting with static admissible quantities. In this paper we show that both procedures correspond to complementary variational principles. Especially there is demonstrated that — besides the principle of virtual displacements—a general work theorem and a principle of virtual forces exist, if the lengths of the bars and the position vectors of the nodes (both in the deformed state) are introduced as kinematic variables rather than the elongations of the bars and the displacement vectors of the nodes respectively. On this basis various principles of stationary potentials are derived for a (possibly nonlinear) elastic network which coincide formally with the corresponding principles of the geometric linear theory [4]. Extremum qualities are discussed also. Some numerical examples are given.
25 citations
01 Jan 1980
TL;DR: It is shown that the configuration of robots makes a considerable difference for the solvability respectively for the fast and exact solution of the coordinate transformation.
Abstract: This paper deals with the calculation of the reference input of a industrial robot controller. Treated in detail are the problems of the transformation of coordinates, particularly from “world”-coordinate systems into the joint coordinate systems. These transformations are an essential part for the calculation of reference input of industrial robots. They are necessary if using external sensors as well as teaching the robot using external coordinate systems. Hereby it is shown that the configuration of robots (number of joints, prismatic or revolute joints, arrangement of joints) makes a considerable difference for the solvability respectively for the fast and exact solution of the coordinate transformation.
10 citations
TL;DR: Several variants are considered according to various rhythms of the tracing of a point on the coupler along the traced curve, using the Rosenbrock method of optimization to synthesise a spatial 4-link mechanism with two kinematic revolute pairs.
1 citations