Journal of Mechanisms, Transmissions, and Automation in Design

Journal Information
ISSN : 0738-0666
Published by: ASME International (10.1115)
Total articles ≅ 668
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Latest articles in this journal

Kenneth J. Waldron
Journal of Mechanisms, Transmissions, and Automation in Design, Volume 111, pp 449-449; https://doi.org/10.1115/1.3259019

D. A. Streit, B. J. Gilmore
Journal of Mechanisms, Transmissions, and Automation in Design, Volume 111, pp 451-458; https://doi.org/10.1115/1.3259020

Abstract:
A new equilibrator design approach based on system potential energy functions is presented. This approach was used to discover a group of spring equilibrators which perfectly balance a rotatable rigid link at every orientation angle through 360 deg of link rotation. Springs are connected between a rotatable link and ground, where one end of each spring is connected to the rigid link and the other end of each spring is connected to ground. The rigid link is connected to ground by a pin joint and is free to rotate about that joint. The conditions for existence and the design equations for all equilibrators which fall into this category are developed and presented. Three designs appear to offer unique advantages over the infinite number of design options available.
R. G. Fenton, W. L. Cleghorn, Jing-Fan Fu
Journal of Mechanisms, Transmissions, and Automation in Design, Volume 111, pp 465-470; https://doi.org/10.1115/1.3259022

Abstract:
A method is presented to determine tolerance bands for the dimensions of multiple loop planar mechanisms such that output motions will be kept within specified allowable limits. The kinematic equations of mechanisms are generated by combining various link groups. A preliminary set of estimated tolerance bands is calculated using an analytical technique. An optimization and checking routine is then employed to determine the set of input parameters which satisfies the prescribed output motion requirements. Examples have been included to illustrate the method.
R. H. Crawford, S. S. Rao
Journal of Mechanisms, Transmissions, and Automation in Design, Volume 111, pp 479-481; https://doi.org/10.1115/1.3259024

Z. Wang, K. Kazerounian
Journal of Mechanisms, Transmissions, and Automation in Design, Volume 111, pp 488-493; https://doi.org/10.1115/1.3259026

Abstract:
A method is developed to resolve the redundancy of serial robotic manipulators. The main characteristics of this method are as follows: (a) The solution is conservative (unique); (b) It globally (over the task period) optimizes the objective function; (c) It is computationally very fast. In fact, it is about three orders of magnitude faster than solving for the exact boundary value problem.
E. R. Tuttle, S. W. Peterson, J. E. Titus
Journal of Mechanisms, Transmissions, and Automation in Design, Volume 111, pp 498-503; https://doi.org/10.1115/1.3259028

Abstract:
A procedure for systematically and completely enumerating all nonfractionated planar kinematic chains having N links and F degrees of freedom has been developed. This procedure employs the theory of finite symmetry groups to eliminate isomorphic chains. The analysis of 8-, 9-, and 10-link chains having 1, 2, and 3 degrees of freedom, respectively, is presented as an example.
Kwun-Lon Ting
Journal of Mechanisms, Transmissions, and Automation in Design, Volume 111, pp 504-507; https://doi.org/10.1115/1.3259029

Abstract:
Single-closed-loop N-bar mobility criteria are presented. These criteria provide a simple and effective method (1) to determine the full rotatability of any single closed-loop linkages, (2) to predict the revolvability between two adjacent links, (3) to explain and identify the existence of singular positions, (4) to classify linkages, and (5) to identify the difference of singular positions between linkages of different types. These criteria are fundamental tools toward a better understanding on the mobility of more complicated linkages.
J. Rastegar
Journal of Mechanisms, Transmissions, and Automation in Design, Volume 111, pp 519-523; https://doi.org/10.1115/1.3259032

Abstract:
Derivation of Grashof-type movability conditions for spatial mechanisms that may include transmission angle limitations is discussed. It is shown that in general, different conditions must be derived for each configuration (branch) of a mechanism. In the absence of transmission angle limitations, the conditions become identical for pairs of configurations. As an example, Grashof-type conditions that ensure crank rotatability, existence of drag link type of mechanisms, the presence of single or multiple changeover points, and the possibility of full rotation at intermediate revolute joints are derived for a spatial RRRSR mechanism. The problems involved in such derivations, the use of approximation techniques, and a number of related subjects are discussed.
L. W. Tsai, E. R. Maki
Journal of Mechanisms, Transmissions, and Automation in Design, Volume 111, pp 530-536; https://doi.org/10.1115/1.3259034

Abstract:
This paper describes several mechanical balancers, based on the planetary gear trains known as the hypotrochoid and epitrochoid trains, for reducing or eliminating second-order out-of-balance in mechanical systems. It is shown that by proper arrangement of the planetary gear trains, a balancer can be obtained for the elimination of second-order shaking forces or second-order shaking moments or a combination of both shaking forces and moments. The advantage of this type of balancer is that the carrier of the gear train needs only to run at the primary speed of the mechanical system to be balanced. Therefore, the balancer can be designed to be concentric with the primary rotating shaft of the machine using the primary shaft as the carrier. For example, for the balance of the second-order shaking force of an inline four-cylinder four-stroke internal combustion piston engine, the balancer can be placed on the third main bearing or one on each of the second and fourth main bearings.
M. Z. Huang,
Journal of Mechanisms, Transmissions, and Automation in Design, Volume 111, pp 545-554; https://doi.org/10.1115/1.3259036

Abstract:
This paper addresses a basic problem which arises in the coordination of serial chain manipulators, namely, that of decomposing a given end effector velocity state into a set of joint rates. Such a problem is indeterminate for manipulators with kinematic redundancy. A novel method of solving the rate distribution problem for the class of fully revolute-jointed, serial manipulators is developed. The technique is an extension of the axial field solution scheme developed initially for solving the force allocation problem in a statically indeterminate parallel chain system. The basis of the solution method lies in the dualities of velocity and force systems between series and parallel mechanisms. The method offers an efficient means of rate coordination and is especially useful in the control of manipulators with high degrees of redundancy. Two examples have been given for illustration. It is shown that the minimum norm solution, obtainable commonly from pseudoinverse, can also be achieved using this new efficient algorithm.
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