A General Theory for Complete Balancing of Shaking Force and Shaking Moment of Spatial Linkages Using Counterweights and Inertia-Counterweights

1994 ◽  
Author(s):  
Ting-Li Yang ◽  
Ming Zhang ◽  
Jian-Qin Zhang
Keyword(s):  
General Theory ◽  
Kinematic Equation ◽  
Force Moment ◽  
Minimum Number ◽  
Spatial Linkages ◽  
Independent Loops ◽  
Shaking Moment

Abstract The links of a spatial linkage with v independent loops can be divided into two parts — a set of v chord-links and a tree-system. Add a suitable counterweight to each chord-link for satisfying the certain conditions, under which, the v chord-links can be completely shaking force-moment-balanced by the counterweights and inertia-counterweights attached to the tree-system of the linkage; The conditions for complete balance of shaking force and shaking moment of the tree system can be written directly without extracting them from the kinematic equation of the linkage; A formula which define the minimum number of inertia-counterweights needed for a complete shaking-moment-balance and the criteria for selecting the optimum chord-link set have been presented. Two examples (a Bennett linkage and a spherical six-bar linkage) are provided.

On the Minimum Number of Counterweights for Multi-Loop Spatial Linkages

1985 ◽  
Vol 107 (4) ◽  
pp. 526-528
Author(s):  
Q.-X. Zhang ◽  
N.-X. Chen
Keyword(s):  
Minimum Number ◽  
Spatial Linkages

This paper offers extensions to the force-balancing theory and the techniques of spatial linkages given in [9-12]. It incorporates another technique for determining the minimum number of counterweights needed for a full balance and discusses the minimum number of counterweights without attachment to any common floating link of loops. Some examples are given to illustrate the application of these results.

The Optimization of Dimensions of an Adjustable Mechanism for a Packaging Machine

1989 ◽  
Vol 203 (1) ◽  
pp. 37-40 ◽  
Author(s):  
A Daadbin ◽  
K S H Sadek
Keyword(s):  
Rigid Body ◽  
Complex Mechanism ◽  
Uniform Velocity ◽  
Packaging Machine ◽  
Minimum Number ◽  
Adjustable Mechanism ◽  
Spatial Linkages ◽  
Mechanical Devices ◽  
Cam Systems

Mechanisms form the basic geometrical elements of many mechanical devices including automatic packaging machinery, typewriters, textile and printing machinery, and others. A mechanism typically is designed to create a desired motion of a rigid body relative to a reference member by the help of gears, cam systems or spatial linkages. In flow pack machines a tube of wrapper containing the products moves with a uniform velocity, while the reciprocating heads move forward and backwards sealing different products. In an existing machine, these motions are produced by a rather complex mechanism involving cams and adjustable links. The paper suggests replacing these cams by a suitable quick-return mechanism with a minimum number of adjustable links. The dimensions of this mechanism are optimized such that the motions produced are as near as possible to those obtained by the original cam mechanisms. The simplification can result in reduction in the mass of different components and existing forces in the mechanism.

A New Method for Full Shaking Force Balancing of Planar Linkages by a Few Finite Positions

1996 ◽  
Author(s):  
Ting-Li Yang ◽  
Ming Zhang ◽  
Qiong Jin
Keyword(s):  
Basic Principle ◽  
Linear Equations ◽  
New Method ◽  
System Of Linear Equations ◽  
Position Data ◽  
Minimum Number ◽  
Spatial Linkages ◽  
Planar Linkages

Abstract A new method called “Finite Position Method” is presented in this paper. By means if this method, it is easy to obtain the condition for full shaking force balancing of planar linkages (FSFBPL), to derive the counter theorem and the minimum number of counterweights. The balancing condition could be generated easily via establishing and solving a system of linear equations using a few finite position data of the linkage. The basic principle of this method could be expanded to the study for balancing theory of the spatial linkages.

A process for the step-by-step integration of differential equations in an automatic digital computing machine

1951 ◽  
Vol 47 (1) ◽  
pp. 96-108 ◽  
Author(s):  
S. Gill
Keyword(s):  
General Theory ◽  
Differential Equations ◽  
Fourth Order ◽  
Order Accuracy ◽  
Computing Machine ◽  
Minimum Number

AbstractIt is advantageous in automatic computers to employ methods of integration which do not require preceding function values to be known. From a general theory given by Kutta, one such process is chosen giving fourth-order accuracy and requiring the minimum number of storage registers. It is developed into a form which gives the highest attainable accuracy and can be carried out by comparatively few instructions. The errors are studied and a simple example is given.

Design and optimization of CAM connecting rod system in high-speed drives based on dynamic characteristics and mathematical model

2017 ◽  
Vol 232 (1) ◽  
pp. 113-128 ◽  
Author(s):  
Xin Shang ◽  
Bi-Zhong Xia ◽  
Shi-Yuan Ren
Keyword(s):  
Kinetic Model ◽  
High Speed ◽  
Parameter Method ◽  
Connecting Rod ◽  
Linkage Mechanism ◽  
Kinematic Equation ◽  
Rod System ◽  
Cam Profile ◽  
Shearing Mechanism ◽  
Shaking Moment

To explore the cause of structure vibration, this study aims to propose a kinematic equation and analyze its movement in relation to cam linkage mechanism for a jacketing machine and shearing mechanism. Finite element method is adopted to construct the kinetic model of linkage subsystem of shearing mechanism. This method can solve the inability of the shearing mechanism to accurately complete the shearing actions of the rubber hose during large vibration of the mechanism. Lumped parameter method is adopted to establish the kinetic model of the cam roller subsystem, and Newmark method is used to solve the kinetic equation of the shearing mechanism. The optimal parameters of the linking rod, cam profile, and shaking force and shaking moment of the mechanism at different rotation speeds are analyzed. Results show that rotation speed and cam profile are factors affecting the performance of the mechanism. The shaking force (shaking moment) is the main cause of the vibration of the mechanism on the rack. As such, the shaking force and shaking moment of the mechanism are selected as the objective functions of the optimization model. The node parameters of B-spline curve movement law and cross-section parameters of the linking rod are used as variables for the optimal design of the cam linkage system. Finally, the obtained optimal value is x = [0.33 0.2 0.54 0.62 8.7 3.0 7.8 16.3] T.

Design Improvement of Manipulators by Minimizing Shaking Force/Moment and Driving Torques

1992 ◽  
Author(s):  
Muqtada Husain ◽  
Akhtar K. Mallik ◽  
A. Ghosh
Keyword(s):  
Mechanical Design ◽  
Open Loop ◽  
Design Improvement ◽  
Trade Offs ◽  
Proper Mass ◽  
Force Moment ◽  
Manipulator Arm ◽  
Improved Design ◽  
The Given ◽  
Shaking Moment

Abstract In this work, an algorithm for design improvement of open loop manipulators, after allowing for the necessary trade-offs among the maximum shaking force, shaking moment and the driving torques is presented. The improved design is attempted by only proper mass distribution of the links for the given kinematic structure and link masses. A min-max optimization problem, considering the worst configuration, is formulated via closed form expressions of the dynamical quantities derived by using Newton-Euler approach. The procedure, though applicable in general, is illustrated through the design of the arm structure of a PUMA 560 manipulator. This developed procedure will also be very helpful in the mechanical design of any new manipulator arm.

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