bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of Spur Gears for Improved Efficiency
Authors: Anderson N. E. , Loewenthal S. H.
Published: January 2010

A method to calculate spur gear system power loss for a wide range of gear geometries and operating conditions is used to determine design requirements for an efficient gearset. The effects of spur gear size, pitch, ratio, pitch-line-velocity, and load on efficiency are shown. A design example is given to illustrate how the method is to be applied. In general, peak efficiencies were found to be greater for larger diameter and fine pitched gears and tare (no-load) losses were found to be significant.
Determination of Gear Ratios
Authors: Orthwein W. C.
Published: January 2010

Finding the number of teeth for each gear in a gear train required to provide a specified noninteger ratio (or its inverse) of angular velocity between input and output shafts has been a troublesome problem throughout the history of gearing. A direct method for finding the required number of teeth is presented, along with a program for its implementation on a programmable pocket calculator.
The “Weighted Composite Life” Problem
Authors: Townsend M. A.
Published: January 2010

A problem class is identified and characterized: The problem is to optimally select variables of a multi-segment activity or design where there is an overall limiting constraint. A number of problems have been individually solved, but it is shown that a wide variety of practical problems can be formulated thusly and that a general solution technique is effective.
Rational Approximants in Structural Design Reanalysis
Authors: Whitesell J. E.
Published: January 2010

The design of mechanical structures often involves the analysis of several candidate designs before a final selection is made. To avoid the high cost of repetitive analysis, rapid reanalysis methods based on power series expansions have been proposed. While these methods can be effective for small design changes, for larger changes poor convergence or divergence can occur. In this paper a reanalysis method based on rational approximants is presented. The method exploits the superior convergence behavior of rational approximants to gain a substantial improvement in convergence and accuracy. The method is applied to reanalysis problems involving linear equations and eigenproblems and is illustrated through representative examples.
Automated Vehicle Dynamic Analysis With Flexible Components
Authors: Kim S. S. , Shabana A. A. , Haug E. J.
Published: January 2010

A method is presented for nonlinear, transient dynamic analysis of vehicle systems that are composed of interconnected rigid and flexible bodies. The finite element method is used to characterize deformation of each elastic body and a component mode technique is employed to reduce the number of elastic generalized coordinates. Equations of motion and constraints of the coupled system are formulated in terms of a minimal set of modal and reference generalized coordinates. A Lagrange multiplier technique is used to account for kinematic constraints between bodies and a generalized coordinate partitioning technique is employed to eliminate dependent coordinates. The method is applied to a planar truck model with a flexible chassis and nonlinear suspension components. Simulation results for transient dynamic response as the vehicle traverses a bump, including the effect of bump-stops, and random terrain show that flexibility of the chassis can be routinely accounted for and predicts significant effects on vibratory motion of the vehicle. Compared with a rigid body model, flexibility of the chassis increases peak acceleration of the chassis and induces high-frequency vertical acceleration in the range of human resonance, measured in this paper as driver absorbed power, which deteriorates ride quality of off-road vehicles.
Reliability Based Optimum Design of Gear Trains
Authors: Rao S. S. , Das G.
Published: January 2010

A reliability based approach is presented for the minimum mass design of gear trains. The gear train is idealized as a weakest link kinematic chain and the optimum design is sought for a specified value of the reliability of the gear train with respect to bending strength and surface wear resistance. The design parameters such as the power transmitted, the geometric dimensions, and the material properties are treated as normally distributed random variables. A linear combination of the mean value and standard deviations of the mass of the gear train is considered as the objective function while treating the mean values of the face widths of the gears as design variables. The reliability based optimization results are compared with those obtained by the deterministic procedure. The effects of variation of parameters like the reliability of the gear train and the coefficients of variation of the random variables are also studied. The minimum mass of the gear trains is found to increase as the specified value of the reliability is increased.
A Generalized Approach to the Replication of Cylindrical Bodies With Compound Curvature
Authors: Saunders C. G. , Vickers G. W.
Published: January 2010

A generalized method of surface definition and replication for cylindrical type objects of compound curvature is presented. The interactive approach is suited to mini-computer installations used in conjunction with standard three-axis NC machines. The compound curvature surface is defined by a new form of central perspective shadow moire contourography called pericontourography. The resulting digital data are treated in such a way that a quasi-helical cutter path is generated which may be applied directly to an NC milling machine (mill turning) or an NC lathe. Specifying the surface in terms of the subsequent machining process avoids the use of complex surface fitting and reformating routines. Interference with the spherical ended tool and the object surface is automatically tested and corrections to the cutter path are made.
Optimal Design of Compact Spur Gear Sets
Authors: Carroll R. K. , Johnson G. E.
Published: January 2010

In a recent article [3], Savage, Coy, and Townsend presented a method for the optimal design of compact standard spur gear sets. They gave figures and design rules based on a design model that considered scoring, pitting, bending fatigue, and involute interference. The work reported here expands the Savage, Coy, and Townsend model to include the AGMA geometry and dynamic factors. The extension was possible, in part, due to the appearance of an article by Mitchiner and Mabie [7] which provided a computationally simple means to determine geometry factors. A design strategy is presented and illustrated by examples. The method is available from the second author in the form of a short Fortran program. The code is applicable to spur gear tooth systems where the addenda and dedenda are inversely proportional to diametral pitch (e.g., the standard tooth system). Other developments of the paper include a new derivation of the expression for pinion roll angles and an observation regarding the method of Mitchiner and Mabie [7] which allows a general form to be used in the determination of the geometry factor for any point during the contact cycle.
Synthesis of Pareto Optimal Four-Bar Function Generators With Optimum Structural Error and Optimum Transmission Angles
Authors: Pugh J. T.
Published: January 2010

The four-bar function generator solution domain is systematically searched-for mechanisms which exhibit at the same time minimum structural error and the best transmission angles. First, synthesis equations are developed. Then the boundary of the solution domain is defined in terms of the permissible angular changes of the coupler link. The concept of Pareto minima is used to identify potential optimal solutions from a representative sample generated over the solution domain. The procedure is illustrated with an example.
Optimal Design of Semisubmersible’s Form Based on Systems Analysis
Authors: Akagi S. , Yokoyama R. , Ito K.
Published: January 2010

With the objective of developing a computer-aided design method to seek the optimal semisubmersible’s form, hierarchical relationships among many design objectives and conditions are investigated first based on the interpretive structural modeling method. Then, an optimal design method is formulated as a nonlinear multiobjective optimization problem by adopting three mutually conflicting design objectives. A set of Pareto optimal solutions is derived numerically by adopting the generalized reduced gradient algorithm, and it is ascertained that the designer can determine the optimal form more rationally by investigating the trade-off relationships among design objectives.
Trip Response of Overload Release Clutches
Authors: Anderson C. V.
Published: January 2010

Some torque limiting clutches can release hundreds of revolutions after an overload while others respond almost instantly. A static analysis and kinematic explanation leads to an understanding of the delayed-release phenomenon and it’s relation to clutch design. Laboratory measurements are compared to theoretical predictions for “fast-blow” and “slow-blow” clutch designs.
Optimal Actuator Sizing for Robotic Manipulators Based on Local Dynamic Criteria
Authors: Thomas M. , Yuan-Chou H. C. , Tesar D.
Published: January 2010

Robotic manipulators provide general, programmable motion paths and force functions to carry out processes of a high level of dexterity and flexibility. These systems are characterized by several degrees of freedom of controllable motion. As a consequence the resulting mechanical structure contains a very large number of design values including geometric, mass, compliance, strength, and prime mover parameters [1]. The analysis on which to base the design methods involves the multivariable mathematical relations between these design parameters and the manipulator’s force and motion states which are extraordinarily complex, nonlinear, and highly coupled. Computer-aided procedures for systems of this class become an imperative in order to establish the dynamic formulation, select rational design specifications, and to evaluate the system’s operating characteristics both locally and globally. This paper suggests some applications of optimization techniques to augment the existing analysis formulation in the literature and to create a more powerful foundation for the design of manipulator structures. This enhanced computational capability is based on position-dependent kinematic and modeling coefficients [6] which explicitly demonstrate the role of significant physical parameters in the design process. Specific examples dealing with optimal distribution of actuator load capacity are given in the paper which improves the system’s load capacity or enhances its speed and acceleration capability within the local neighborhood of a given configuration of the manipulator.
Probabilistic Modeling in Design
Authors: Siddall J. N.
Published: January 2010

A general procedure is proposed for evolving the form of a density function that is consistent with the concept of subjective probability. The procedure directly applies new data information to the updating of the form of a density function without imposing on it any theoretical distribution that could restrict its shape, and permits the direct use of judgment arising from real world experience. It is based on the simple concept that sample size is a measure of confidence in the shape of a density function. Two possible algorithms are given, and the concept is extended for simple “true” or “false” events. The importance of probability in artificial intelligence is also dicusssed, and its essentially subjective nature is described. Procedures are briefly suggested.
Branching Analysis of Spherical RRRR and Spatial RCCC Mechanisms
Authors: Reinholtz Charles F. , Sandor George N. , Duffy Joseph
Published: January 2010

Most mechanisms can be assembled in two or more distinct configurations for a given position of the input link. Each distinct configuration is called a branch. When the prescribed positions of a synthesized mechanism lie on more than one branch, the mechanism is said to have branching problems or to suffer from “branch defect.” Usually, branching problems will render a mechanism unsuitable for the design task because the mechanism must be moved to the other branch during the course of motion. In most cases, this would require disassembly and reassembly of the mechanism. In this paper, conditions are developed for avoiding the branching problem in the spherical RRRR and spatial RCCC mechanisms. These conditions are ideally suited for incorporation into an optimization scheme as constraints because they do not require iterative calculations or a position analysis of the mechanism.
Dynamics of an Overconstrained Shaft Coupling
Authors: Liu Tyng , Lee Ting W.
Published: January 2010

This paper presents a method for complete force analysis, including both statics and dynamics, of overconstrained, statically indeterminate spatial mechanisms. Of primary concern is the development of a method which is realistic and has general applicability. The usual tacit assumption of the vanishing of certain force and torque components in the analysis, such as zero axial forces at joints, is removed. The method combines an analytical technique—using the [3 × 3] screw matrix method—coupled with an experimental method to completely specify the dynamic state of an overconstrained mechanism. The indeterminate force is modeled using a characteristic equation simulated experimentally. The method is illustrated in the case of the UNI-LAT coupling which is a modified Hooke-type joint. Based on the analytical results, some physical insights are interpreted. It was found that overclosure affects mechanism performance and plays an important role in the dynamics of the UNI-LAT coupling. General guidelines on the design of the UNI-LAT coupling are also presented.
The Development of a Predictive Model for the Optimization of High-Speed Cam-Follower Systems with Coulomb Damping Internal Friction and Elastic and Fluidic Elements
Authors: Hanachi Shervin , Freudenstein Ferdinand
Published: January 2010

A highly accurate and predictive dynamic model of a high-speed cam-follower system has been developed and verified. In view of the predominance of Coulomb damping in high-speed cam-follower systems, this form of damping has been used as the chief mode of energy dissipation. This has resulted in a significant improvement in the predictive capability of the dynamic model. The accuracy of the model can also be attributed to careful modeling of system components such as the distributed-parameter modeling of the valve spring, the modeling of the hydraulic lifter, and modeling of the damping due to a nested-valve spring. The latter two represent the first such modeling in the area of cam-follower systems.
Dynamic Collision Detection Using Swept Solids
Authors: Ganter M. A. , Uicker J. J.
Published: January 2010

The detection of collisions in an environment composed of two three-dimensional bodies traversing independent general three-dimensional trajectories is accomplished through the use of swept solids and solid modeling techniques. A swept solid represents the space volumetrically swept out by the motion of a given body along a given trajectory. A swept solid is created for each of the bodies in the given environment. Using the swept solids created for each body, calculations (solid modeling boolean intersections) can be performed to determine if these swept solids intersect. If the original bodies will collide while traversing their given trajectories, then their swept solids will statically interfere. Further, an object comprising the volume of the intersection can be created if the bodies do, in fact, interfere. This object can be thought of as the “volume of interference.” Enhancements to this technique provide for the formation of swept solids using relative motion. Through these enhancements, only one swept solid need be created since the absolute motions can be converted to motion of one body relative to another body. Therefore, intersection calculations may be performed between one relative swept solid and the original body.
On the Scalar and Dual Formulations of the Curvature Theory of Line Trajectories
Authors: McCarthy J. M.
Published: January 2010

The curvature theory of ruled surfaces has been studied in two different ways. The scalar formulation proceeds by defining a seqeunce of ruled surfaces associated with the trajectory ruled surface. The relative positions of these surfaces and their distribution parameters characterize the local properties of the original ruled surface. The other formulation uses dual vector algebra to transform the differential geometry of ruled surfaces into that of spherical curves. In each theory functions are obtained which characterize the shape of the ruled surface. This paper unites these formulations by deriving formulas relating the scalar and dual curvature functions. This provides the ability to compute either set of curvature properties from either the scalar or dual vector representation of the ruled surface. The ruled surface generated by a line fixed in a body undergoing a screw displacement is examined in detail.
On the Numerical Inverse Kinematics of Robotic Manipulators
Authors: Kazerounian Kazem
Published: January 2010

Based on the sequential motion of joints, a method is developed for the numerical inverse kinematics of serial manipulators. This algorithm is stable and computationally efficient and uses the zero position analysis method for robotic manipulators.
An Application of the Linkage Characteristic Polynomial to the Topological Synthesis of Epicyclic Gear Trains
Authors: Tsai Lung-Wen
Published: January 2010

In this paper, a random number technique for computing the value of a linkage characteristic polynomial is shown to be an effective method for identifying isomorphic graphs. The technique has been applied to the topological synthesis of one-degree-of-freedon, epicyclic gear trains with up to six links. All the permissible graphs of epicyclic gear trains were generated by a systematic procedure, and the isomorphic graphs were identified by comparing the values of their corresponding linkage characteristic polynomials. It is shown that there are 26 nonisomorphic rotation graphs and 80 displacement nonisomorphic graphs from which all the six-link, one-degree-of-freedom, epicyclic gear trains can be derived.
Integrated Kinematic and Dynamic Optimal Design of Flexible Planar Mechanisms
Authors: Kakatsios A. J. , Tricamo S. J.
Published: January 2010

The following describes a new integrated approach to the problem of designing high speed mechanisms. Employing a nonlinear programming formulation, it allows both the kinematic parameters and the link cross sections to vary while simultaneously bounding trajectory accuracy and minimizing the disturbing force on the ground. Furthermore, link stresses are bounded to limits imposed by the designer. The technique is capable of taking into account the complex coupling which exists between kinematic and dynamic characteristics in flexible mechanisms to determine linkage parameters which best satisfy a given set of design requirements. A path synthesis problem is used to illustrate the technique.
Design of a Synthesized Helical Gear Set
Authors: Eggeman G. W.
Published: January 2010

Three interrelated mathematical models are developed to determine the size and shape of a helical gear tooth. These models are combined into a design procedure to produce a compact high load capacity helical gear set. The profile geometry is based on synthesis and consists of two differential equations concerning conjugate profiles and the Hertz contact pressure. This is merged with a bending strength model based on the moment image method. This merger is accomplished by adjusting the pitch line tooth thickness and the profile curvature. A balanced design is reached where the three load capacities are equal or where the weakest tooth in bending is made as wide as possible. This makes the most efficient use of the given pitch line space. A third model, consisting of a search routine, is placed around the capacity models. Its purpose is to select values for the variables describing the tooth contact area which provides the maximum capacity for the gear set. These variables are needed in the boundary conditions for the profile model and to determine the tooth height for bending strength calculations. A comparison is made with the 20 deg involute system. The synthesized gears show twice the load capacity of an equivalent sized involute gear set for softer materials. This is reduced to a 50 percent improvement for the harder steels.
A Method for Calculating the Steady-State Dynamic Response of Rigid-Body Machine Systems
Authors: Zadoks R. I. , Midha A.
Published: January 2010

The rigid-body equations of motion for conservative rotating machine systems with position-dependent moments of inertia are found to reduce to a single, second-order, inhomogeneous, nonlinear, ordinary differential equation with variable coefficients. Upon linearization this equation is reduced to first-order form. A rational proportionality between the periods of the variable coefficient and the in-homogeneous term implies that the steady-state rigid-body response will also be periodic. To solve for the steady-state rigid-body response the least common period of the system is divided into an appropriate number of sub-intervals, and the solution over each sub-interval is derived by assuming a constant value of the coefficient during that sub-interval. The final solution is computed by applying appropriate compatiblity and periodicity constraints. The solution algorithm is extended to systems for which the linearization assumptions do not apply through the application of a recursion scheme. Examples are included to illustrate the utility of the algorithm.
Design of Spherical Drag-Links Between Positions of Unity Velocity Ratio
Authors: Chiang C. H.
Published: January 2010

While synthesizing a planar drag-link between positions of unity velocity can be reduced to a problem of synthesizing a planar crank-rocker, this is not the case with a spherical drag-link. Synthesis equations for designing spherical drag-links between positions of unit velocity ratio are derived from equations previously obtained for matching two prescribed velocity ratios. It has been shown that the loci of both crank pins are spherical ellipses and great circles. An example is given.
Effect of Eccentricity on the Speed Fluctuation of Cam Mechanisms With Translating Followers
Authors: Tas¸can S.
Published: January 2010

In this article, disc cams with translating followers are studied and the speed fluctuation of the input shaft is minimized with respect to eccentricity. First, the equations of motion for the cam mechanisms with roller follower and flat-faced follower are determined. Then, by solving these equations for steady-state motion, the coefficient of speed fluctuation is calculated. The optimum eccentricity that would minimize the coefficient of speed fluctuation is determined.
Thermoelastic Analysis of Flexible Multibody Machine-Tool Mechanisms
Authors: Ukani S. S. , Chang C. W. , Shabana A. A.
Published: January 2010

This investigation is concerned with the thermoelastic analysis of flexible multibody machine-tool mechanisms using the finite-element method. Thermoelastic response of the machine tool is obtained by discretizing the machine tool into a number of simple elements and calculating the thermal stress and strain of each element under the average temperature rise. The generalized thermoelastic forces associated with the generalized elastic coordinates are then determined using the virtual work. The nonlinear dynamic behavior of the machine-tool mechanism due to the application of a constant cutting force as well as a chattering (dynamic) force, with and without thermal effects, is analyzed. The chattering force is obtained by considering the cutting force variations due to the variation of undeformed chip thickness and the rate of penetration of the tool, as a result of tool deformation. In this investigation, the machine-tool mechanism is considered as a multibody system consisting of interconnected rigid and flexible bodies that undergo large angular rotations. Bending and axial deformation of the elastic bodies in the system are considered. Component mode synthesis techniques are employed in order to reduce the number of elastic coordinates and the system differential equations of motion and nonlinear algebraic constraint equations are written in terms of a coupled set of reference and modal elastic coordinates. The formulation is exemplified using a crank-shaper mechanism wherein the flexibility of the tool as well as the flexibility of the mechanism links are considered.
An Automated Procedure for Intelligent Mechanism Selection and Dimensional Synthesis
Authors: Soni A. H. , Dado Mohammad H. F. , Weng Yicheng
Published: January 2010

This paper describes the fundamentals for the development of the intelligent selection system for the mechanism configuration and the development of an automated dimensional synthesis procedure. The selection system is a rule-based system. Using an interactive dialogue with a designer; the system converges to an appropriate mechanism configuration satisfying a prescribed synthesis requirements including type of synthesis problems, number of precision positions, and number of independent inputs. The user has an option to inquire the selection system to give reasons for the mechanism configuration selection. The automated synthesis procedure uses the data supplied by the selection system to generate the design equations. A powerful numerical algorithm solves the design equations giving all possible solutions without the need of supplying initial guesses. The complete system provides a valuable tool that performs a comprehensive design procedure with minimal user interaction and background knowledge in mechanism design.
Simulation and Optimization of an Anaerobic Digestion System
Authors: Durand J. H. , Miles J. B. , Iannotti E. L.
Published: January 2010

An automated procedure for the design of an optimized (for both configuration and operating point) anaerobic digestion system is presented. The procedure is based on modern nonlinear programming algorithms and numerical models of the various system components (biological, thermal, and economic). The model simulates yearly digester system operation, and uses this to calculate the after-tax net present value for a particular system design. The optimal design is found using BIAS, a method of multipliers code. Substantial improvements in the net present value were found when the optimized design was compared to the designs in current use. A sensitivity analysis revealed that the price of energy and the energy conversion efficiency were the parameters which influenced system economics most strongly for the best system configuration at the optimal operating point.
Life and Reliability Modeling of Bevel Gear Reductions
Authors: Savage M. , Brikmanis C. , Lewicki D. G. , Coy J. J.
Published: January 2010

A reliability model is presented for bevel gear reductions with either a single input pinion or dual input pinions of equal size. The dual pinions may or may not have the same power applied for the analysis. The gears may be straddle mounted or supported in a bearing quill. The reliability model is based on the Weibull distribution. The reduction’s basic dynamic capacity is defined as the output torque which may be applied for one million output rotations of the bevel gear with a 90 percent probability of reduction survival. The components on which the reduction’s life and reliability are based are the bevel gears and their radial and thrust bearings.
A Technique to Predict the Effects of Wear in Keyed Connections
Authors: Service T. H. , Nyden I. J. , Ritter J. E. , Motherway J. E.
Published: January 2010

A methodology for predicting the effects of wear on the rotation of a keyed connection subjected to reversing loads is presented. The approach couples an empirical relationship for wear with a finite-element analysis of the connection. Predictions of overall connection rotations as a function of the number of load cycles agreed well with the results obtained from experiments.
Optimal Solutions for Nonhomogeneous Multiply-Connected Torsional Sections
Authors: Mioduchowski A. , Faulkner M. G. , Kim B.
Published: January 2010

Optimization of a second-order multiply-connected inhomogeneous boundary-value problem was considered in terms of elastic torsion. External boundary and material proportions are the applied constraints in finding optimal internal configurations of the cross section. The optimization procedure is based on the numerical simulation of the membrane analogy and the results obtained indicate that the procedure is usable as an engineering tool. Optimal solutions are obtained for some representative cases of the torsion problem and they are presented in the form of tables and figures.
Approximate Circular and Straight-Line Path Generation With High-Performance Function-Generating Linkages
Authors: Mahyuddin A. I. , Nahvi H. , Farhang K. , Midha A.
Published: January 2010

Certain manufacturing industries, including the semiconductor industry, are now moving toward very high-speed machinery requiring very small yet precise motions. The total path of a coupler point on harmonic motion-generating linkages, with relatively small input cranks, has been shown to be an approximate ellipse. Such linkages have been described to possess superior performance qualities for high speed machine application. Two special cases of the elliptical path are circular and linear paths. An investigation of the kinematic equations, which govern the motion of a coupler point, reveal the nonexistence of such exact paths, prompting the two theorems with proofs forwarded herein. Linkages are synthesized in an effort to find coupler points which trace “near-circle” and “near-straight-line” entire paths. Some interesting results are obtained in studying the motion behavior of coupler points on such linkages.
Actively Coordinated Vehicle Systems
Authors: Kumar V. , Waldron K. J.
Published: January 2010

The use of independent actuation of suspension and locomotion degrees of freedom offers significant potential for improved performance vehicles. In this paper, the mathematics of active coordination of such systems is explored. Two different, actively coordinated mobility system configurations are used as examples to elucidate the principles involved.
A Separating Channel Decomposition Algorithm for Nonconvex Polygons With Application in Interference Detection
Authors: Ku T. S. , Ravani B.
Published: January 2010

An algorithm for efficient decomposition of interface channels between nonconvex polygons in a Computer-Aided Design (CAD) environment is presented. This algorithm forms the computational basis for the solution of several design automation problems. In this paper, the channel decomposition algorithm is presented and applied to the problem of interference detection between nonconvex polygons. The resulting interference detection algorithm does not require preprocessing of the data and uses a simple data structure. In a companion paper (Ku and Ravani, 1989), the rigid channel decomposition algorithm is applied to the problem of model-based rigid-body guidance in presence of geometric constraints.
Some Further Results on Monotonicity in Globally Optimal Design
Authors: Hansen P. , Jaumard B. , Lu S. H.
Published: January 2010

Many problems of globally optimal design have been solved by using monotonicity analysis. Extended monotonicity principles are obtained by exploiting nonstrict monotonicity of the objective function and of the constraints. Ways to detect monotonicity and branching rules using monotonicity results are also discussed. Several illustrative examples from the literature are solved in an easier way than previously.
Minimum Fuel Consumption Design of a Turbo-Charged V-6 Engine
Authors: Woodard J. K. , Johnson G. E. , Lott R. L.
Published: January 2010

The design of a turbocharged, gasoline fueled, four-stroke engine is considered with the goal of selecting design and operating variables to minimize fuel consumption. The development of the engine simulation code and the effect of model assumptions on the results are presented. The optimization includes constraints on detonation, exhaust emissions, and torque. Variables are bounded to assure the validity of the simulation. A number of observations about the interaction between the thermo-fluid model and the nonlinear programming algorithm are made and general strategies to enhance the optimization under such circumstances are discussed. The method is illustrated by exploring the design of a turbocharged Buick V-6 engine on an IBM PC/AT personal computer. Stock design variables, and operating variables that provided a design away from the constraints imposed by torque, emission, and detonation were chosen as the starting point for the optimization. Application of the optimization strategy resulted in an 18 percent reduction in predicted fuel consumption at 50 miles per hour. Significant specific recommendations included a reduction in combustion chamber volume, an increase in intake manifold pressure, an increase in intake duration, a decrease in exhaust duration, and relatively small changes in valve geometry. The paper clearly demonstrates that it is feasible to do relatively sophisticated engineering design and optimization on personal computers, and it sets the stage for further work in this area.
The Generalized Transmission Error of Parallel-Axis Gears
Authors: Mark W. D.
Published: January 2010

The traditional one-component transmission error of parallel-axis helical gears is generalized to a three-component transmission error which characterizes the composite displacement in the plane-of-contact resulting from arbitrary small deviations in the positions of both gears of a meshing pair from the positions of their rigid perfect involute counterparts. A set of linear algebraic equations is derived for the contribution to the three generalized transmission error components arising from elastic deformations of the teeth and gear bodies and deviations of the tooth running surfaces from equispaced perfect involute surfaces. It is shown how to combine this set of equations with the generalized transmission error definition and the equations of motion of a gear system to predict the dynamic response of gear elements in the system. For the case of negligible gearbody and bearing/bearing support inertial forces, an additional set of algebraic equations that includes the effects of bearing flexibility and misalignment is derived. Combining the solution of this set of equations with the above-mentioned generalized transmission error equations yields the three-component generalized static transmission error.
Kinematic Calibration of Robotic Manipulators
Authors: Kazerounian K. , Qian G. Z.
Published: January 2010

A kinematic calibration model for serial robotic manipulators is presented. This model is based on the zero position analysis method, and is not prone to the difficulties encountered in case of parallel or near parallel joints when using joint coordinate system notations. The convergence and effectiveness of the model are demonstrated by numerical simulations.
On the Derivation of Grashof-Type Movability Conditions With Transmission Angle Limitations for Spatial Mechanisms
Authors: Rastegar J.
Published: January 2010

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.
The Creation of Nonfractionated, Two-Degree-of-Freedom Epicyclic Gear Trains
Authors: Tsai Lung-Wen , Lin Chen-Chou
Published: January 2010

To date, most of the multi-DOF (degree-of-freedom) epicyclic gear trains have been used as a series of one-DOF devices. Comparatively little is known with regard to the existence and synthesis of nonfractionated, epicyclic gear trains. This paper presents a systematic methodology for the identification and enumeration of the kinematic structure of nonfractionated, two-DOF epicyclic gear trains. It has been shown that there exists no such gear trains with five or less links. It has also been shown that there exist two nonisomorphic rotation graphs of six vertices and twenty nonisomorphic rotation graphs of seven vertices. An atlas of nonisomorphic displacement graphs which can be used to construct nonfractionated, two-DOF epicyclic gear trains with six and seven links has been developed. It is hoped that this atlas will lead to more optimum and efficient designs of machines with multiple actuating requirements such as robotic wrists, grippers, and walking machines.
Planetary-Gear-Type Second-Harmonic Balancers
Authors: Tsai L. W. , Maki E. R.
Published: January 2010

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.
Design of Machine Tool Spindles Based on Transient Analysis
Authors: Reddy V. R. , Sharan A. M.
Published: January 2010

This investigation is concerned with the design of machine tool spindles based on transient analysis. The dynamic equation of motion of a lathe spindle has been obtained using finite element analysis along with modal analysis. These equations are solved to obtain the displacement distribution along the spindle-workpiece system and thus the maximum dynamic displacement response. The system design parameters should be chosen in such a way that a combination of these would minimize the maximum dynamic displacement response. The global system matrices are replaced by condensed matrices of lower order, which preserve the lower modes with reasonable accuracy. This is done to economize on the computer memory storage and computation time. The system design parameters used are: (a) bearing spacing, (b) bearing stiffness, (c) location of an external damper, and (d) the workpiece diameter. The optimum design variables are selected based on single-parameter variation. The objective of this investigation is the minimization of the maximum dynamic response by a suitable choice of design variables.
Mobility Conditions for Planar Linkages Using Triangle Inequality and Graphical Interpretation
Authors: Midha A. , Zhao Zhen-Lu , Her I.
Published: January 2010

The triangle inequality concept is utilized in formulating the mobility conditions for a planar four-bar linkage. These conditions are used to investigate crank existence and mobility region for the linkage. More significantly, a manifest graphical interpretation is offered, enabling an expeditious mobility determination. A computer-aided graphics approach lends itself to relevant computations with greater speed and accuracy. The concept is further exemplified by means of a more complex planar linkage.
On the Global Convergence of Nonlinear Programming Algorithms
Authors: Schittkowski K.
Published: January 2010

In a previous paper a unified outline of some of the most successful nonlinear programming methods was presented by the author, i.e. of penalty, multiplier, sequential quadratic programming, and generalized reduced gradient algorithms, to illustrate their common mathematical features and to explain the different numerical performance observed in practice. By defining a general algorithmic frame for all these approaches, a global convergence result can be achieved in the sense that starting from an arbitrary initial point, a stationary solution will be approximated.
Effect of MoS2 Films on Scoring Resistance of Gears
Authors: Terauchi Y. , Nadano H. , Kohno M.
Published: January 2010

In trying to clarify the effect of molybdenum disulfide film on the scoring resistance and the wear characteristics of gears, various tests on balls and gears coated with MoS2 film have been run. From the test results obtained with a four-ball machine and a power-circulating gear machine it was found that the effect of the MoS2 film was small on the seizure load of the balls. In contrast, the effect of the MoS2 film on the scoring resistance of the gears was significant, and the development of the gears of which the load-carrying capacity against scoring is considerably large could be made.
Application of Group Technology to Design Optimization of Machine Structural Systems
Authors: Yoshimura M. , Hitomi K.
Published: January 2010

This paper proposes a design optimization method using the concept of group technology in order to reduce production cost of products. The design optimization procedures consisting of three phases, simplification, optimization, and realization, enable design optimization using group technology to be conducted effectively. With this method, identical or similar machine parts are used as often as possible in a product or series of products varying in functional requirements, within an allowable degree of degradation of performance. The method is demonstrated on structural models of manipulators and their machine elements.
Dynamic Behavior of a Hydraulically Actuated Mechanism. Part 1: Small Perturbations
Authors: Venkatraman V. , Mayne R. W.
Published: January 2010

This paper considers the dynamic behavior of a mechanism actuated by an oscillating hydraulic cylinder. The analysis is generalized by introducing nondimensional parameters. In this first portion of the paper, linearization is applied to explore the basic nature of the system transient response. A wide range of parameter values is considered to illustrate the effects of fluid capacitance, fluid inertance, load, leakage and friction on the system behavior and quantitative design guidelines are indicated. Part 2 of the paper deals with nonlinear aspects of the actuator-mechanism system.
A Method for Determining the AGMA Tooth Form Factor from Equations for the Generated Tooth Root Fillet
Authors: Lopez M. A. , Wheway R. T.
Published: January 2010

The determination of the AGMA tooth form factor requires that the dimensions of the critical tooth section, at which the maximum bending stress is deemed to occur, be found. Critical section dimensions have traditionally been measured from a scaled generated layout of the tooth profile. The layout procedure, however, requires very careful drafting, and even then it is difficult to achieve really satisfactory accuracy because of the complex operations required to produce the fillet curve, with the added difficulty of estimating the point of tangency with the Lewis iso-bending stress parabola. Although a number of analytical methods are available for computing the critical section dimensions, their solution has generally been cumbersome, or convergence on the correct solution remained a problem. This paper presents equations for the gear tooth root fillet curve which have been derived from an analysis of the relative motion between a rack cutter and gear tooth during the generating cycle. An improved iterative procedure is used to find the critical tooth section dimensions from these equations. A further application of the root fillet equations, which is also covered, is in the computer generation of tooth profiles for assessment of the final tooth shape.
Systems Analysis of a Solar Industrial Process Steam Generating Plant
Authors: Gupta G. D. , Gangadharan A. C. , Bhayana G. K.
Published: January 2010

The systems analysis of a solar steam production plant is presented. The plant is designed to generate industrial process steam at 1034 kPag (150 lb/in.2g) for Dow Chemical Company’s Latex Manufacturing Plant located in Dalton, Ga. The project is intended to develop a demonstration unit with 929 m2 (10,000 ft2) of solar collector surface area. In this paper we have described an economic model developed for use in the systems analysis of solar steam plants, and discussed the systems analysis and optimization of the Dow solar steam plant. The economic model uses the annualized cost of a unit of fossil energy displaced by the solar steam plant as the cost-effectiveness parameter. The different factors that must be taken into account in developing this cost-effectiveness parameter are discussed. The concept selected for the detailed systems analysis uses an intermediate heat-transfer fluid in the primary loop. This fluid is circulated through the solar collectors to a boiler where steam is generated. Parabolic trough collectors are used in the system.
Optimization of a Point-Focusing, Distributed Receiver Solar Thermal Electric System
Authors: Pons R. L.
Published: January 2010

This paper presents an approach to optimization of a solar concept which employs solar-to-electric power conversion at the focus of parabolic dish concentrators. Modularity is obtained through the use of multiple concentrators to achieve the desired power level (up to 10MW); the system is connected to an electric utility grid but is capable of operation in a stand-alone mode. The power conversion subsystem is packaged into a single assembly which includes (1) a cavity receiver, (2) thermal transport hardware, (3) a heat engine and (4) a synchronous a-c generator. In the example presented, the baseline heat engine is a Stirling cycle power plant and the receiver is a high temperature (∼800°C) sodium pool boiler; thermal transport is provided by a short pipe with the dual function of delivering sodium vapor to the engine heater head and returning liquid condensate to the boiler. The optimization procedure is presented through a series of trade studies, which include the results of optical/thermal analyses and individual subsystem trades. The optical/thermal analyses include the effect of concentrator rim angle, surface slope error, pointing error, geometric concentration ratio and pertinent cavity parameters including shape, temperature and inner surface radiation properties. For the concentrator, the effects pf slope error, rim angle and diameter on unit cost (dollars/m2 of aperture) are presented as part of an overall cost analysis which generates total system life-cycle energy cost as the optimization parameter. Alternate closed-cycle and open-cycle Brayton engines and organic Rankine engines are considered to show the influence of the optimization process, and various storage techniques are evaluated, including batteries, flywheels and hybrid-engine operations.