Robust tolerance design for function generation mechanisms with joint clearances

2010 ◽  
Vol 45 (9) ◽  
pp. 1286-1297 ◽  
Author(s):  
Xianzhen Huang ◽  
Yimin Zhang
Keyword(s):  
Tolerance Design ◽  
Function Generation ◽  
Joint Clearances ◽  
Generation Mechanisms

Tolerance Design for Four-Bar Function Generating Mechanisms with Joint Clearances Using Taguchi Method

2010 ◽  
Vol 118-120 ◽  
pp. 517-521 ◽  
Author(s):  
Xian Zhen Huang ◽  
Yi Min Zhang ◽  
Hao Lu ◽  
Le Tang ◽  
He Li
Keyword(s):  
Taguchi Method ◽  
Design Parameters ◽  
Tolerance Design ◽  
Function Generator ◽  
Function Generation ◽  
Joint Clearances ◽  
Generation Mechanisms ◽  
Sensitivity Maps

This paper presents a method for tolerance design of four-bar function generating mechanisms with joint clearances using Taguchi method. Based on previous studies made by other researchers, we propose a model to quantify the effects of uncertain factors on the accuracy of four-bar function generating mechanisms. Taguchi’s approach is applied to select the optimal tolerance ranges for the design parameters of function generation mechanisms. Sensitivity maps are plotted to provide an insight to the effects of parameter errors on the performance variances of four-bar function generating mechanisms. To illustrate the efficiency of the proposed methodology, the tolerance design of a four-bar function generator with joint clearances is discussed.

Application of Taguchi Method on the Tolerance Design of a Four-Bar Function Generation Mechanism

2005 ◽  
Author(s):  
Fu-Chen Chen ◽  
Hsing-Hui Huang
Keyword(s):  
Taguchi Method ◽  
Control Factor ◽  
Tolerance Design ◽  
Initial Value ◽  
Function Generator ◽  
Function Generation ◽  
Manufacturing Tolerance ◽  
Structural Error ◽  
Experimental Errors ◽  
The Mean

The purpose of this paper is to use the Taguchi method on the tolerance design of a four-bar function generator in order to obtain the structural error that is insensitive to variations in manufacturing tolerance and joint clearance. The contribution of each control factor to the variations was also examined to further determine if the tolerance of the factor should be tightened to improve the precision of the mechanism. From the study of the four-bar function generator, it was revealed that the control factor B had the most significant effect on the variation of the structural errors. These were closely followed by factors E, C and D. On the whole, experimental errors contributed only 2.69% to the structural errors, much smaller than the contribution by individual factors, indicating that the design of the experiments was appropriate and the results were highly reliable. By tightening the tolerance, it is apparent that the mean of structural errors is reduced by 0.227 and the change in variance is 69.81% of the initial value, i.e. a reduction of 30.19%.

scholarly journals Kinematic Accuracy Method of Mechanisms Based on Tolerance Theories

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Li Zhang ◽  
Hong Nie ◽  
Xiaohui Wei
Keyword(s):  
Tolerance Analysis ◽  
Functional Element ◽  
Physical Models ◽  
Small Displacement ◽  
Tolerance Design ◽  
Dimensional Chain ◽  
Movement Accuracy ◽  
Kinematic Accuracy ◽  
Tolerance Model ◽  
Joint Clearances

Traditional tolerance analysis is mostly restricted to static analysis. However, tolerances of different components also affect the movement accuracy in a mechanism. In this paper, the idea of kinematic tolerance analysis is advanced. In the interest of achieving movement precision considering tolerance, a kinematic Jacobian model is established on the basis of a traditional dimensional chain and an original Jacobian model. The tolerances of functional element (FE) pairs are expressed as small-displacement screws. In addition, joint clearances resulting from tolerance design also influence the kinematic accuracy, and they are modeled by FE pairs. Two examples are presented to illustrate the rationality and the validity of the kinematic tolerance model. The results of the two examples are shown, and the discussion is presented. A physical model of the 2D example is also built up in 3DCS software. Based on the discussion, a comparison between the statistical and physical models is carried out, and the merits and demerits of both are listed.

scholarly journals Tolerance Design and Robust Study for The Joint Clearances of Landing Gear Retraction Mechanisms

2020 ◽  
Vol 10 (14) ◽  
pp. 4856 ◽  
Author(s):  
Li Zhang ◽  
Hong Nie ◽  
Xiaohui Wei
Keyword(s):  
Landing Gear ◽  
Tolerance Design ◽  
Robust Analysis ◽  
Kinematic Accuracy ◽  
Landing Gears ◽  
Joint Clearances ◽  
Tolerance Theory

Joint clearances inevitably affect the kinematic accuracy and robustness of landing gear retraction mechanisms. However, the complexity and uncertainty of the clearances lead to difficulty in establishing mathematic models and analyzing effects. In the interest of assessing the clearance effects on the kinematic accuracy of landing gears, an integrated tolerance theory is proposed in this paper. In the theory proposed, Jacobian–Torsor model is combined with robust analysis to establish the kinematic accuracy model and predict the influences of clearances. The overall steps to apply the theory presented in practice are given. A typical landing gear retraction mechanism is chosen for the case study and the results show that the tendencies of clearances can be observed. Through the process of tolerance design, robust study, and tolerance redesign, the kinematic accuracy is significantly improved. The integrated tolerance theory proposed and the study conducted will provide designers new insights for the clearance analysis of landing gear mechanisms.

Synthesis and Dynamic Analysis of a Quick-Return Mechanism Using MATLAB and SIMULINK

2007 ◽  
Author(s):  
Ali Mohammadzadeh ◽  
Nael Barakat ◽  
Salim Haidar
Keyword(s):  
Mechanical Engineering ◽  
Equations Of Motion ◽  
Angular Position ◽  
Graphical Analysis ◽  
Kinematics And Dynamics ◽  
Dimensional Synthesis ◽  
Positive Feedbacks ◽  
Function Generation ◽  
Design Specifications ◽  
Generation Mechanisms

The approach adopted in this work is an attempt to introduce students, in kinematics and dynamics of machinery course, to a complete design and analysis of function generation mechanisms via analytical methods. Although the approach implemented in this work is for function generation type of mechanisms, the concept is indeed extendable to the other types of mechanisms as well. As a project in the kinematics and dynamics of machinery class, students designed, and analyzed a four bar quick-return mechanism using MATLAB and SIMULINK as the primary software tools. One of the aims of this project was to abandon the traditional graphical synthesis and graphical analysis, covered in all the mechanisms textbooks, and to use the powerful combination of MATLAB and SIMULINK to implement the entire design and analysis process. The project, given to an undergraduate class, serves also as a prologue to future advanced courses in mechanical engineering, such as multi-body dynamics. In implementing the dimensional synthesis portion of the project, students employed complex number arithmetic to realize the design specifications. Once the design specifications were met, a known motor torque was applied to the crank to drive the mechanism. With the known geometric and inertial properties of each link, Lagrange’s equations for constraint motion were then utilized to arrive at the second order differential equations of motion. SIMULINK, as a user friendly graphical interface, was used to carry out the integration to obtain angular position, velocity, and acceleration of the designed mechanism. The project also calculates the reaction loads on the mechanism using the concepts of Newtonian mechanics. The project, though rigorous, is an excellent way to force students to practice their knowledge of dynamics and numerical methods. The project, certainly, meets the ABET criteria for implementing design in mechanical engineering curriculum. The author received positive feedbacks from his students with regard to this project.

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