scholarly journals Worm addendum thickness and gear curvature interference for enveloping cylindrical worm drive with arc-toothed worm

2021 ◽  
Author(s):  
Xinyue Zhu ◽  
Yaping Zhao ◽  
Yifei Chi ◽  
Gongfa Li ◽  
Xinyuan Chen
Keyword(s):  
Nonlinear Equation ◽  
Geometric Analysis ◽  
Boundary Line ◽  
Initial Value ◽  
Axial Section ◽  
Value Range ◽  
Vector Rotation ◽  
Curvature Interference ◽  
In Virtue Of ◽  
Worm Drive

The purpose of this paper is to provide the calculation methods on worm addendum thickness and curvature interference limit line, and find the feasible value range of the technological crossing angle to avoiding addendum sharpening and curvature interference for enveloping cylindrical worm drive with arc-toothed worm. In accordance with the features of the proposed worm, the mathematical models of cutting and working are established. Based on this, the tooth profile geometry of the worm in its axial section and the worm addendum thickness are obtained by geometric analysis and calculation, and then, the feasible value range of the technological crossing angle is given. In virtue of vector rotation and elimination method, the nonlinear equation with one variable for solving the interference limit line is determined. In the process of solving nonlinear equation, the method of geometric construction is used to judge the existence of solutions and provide an initial value for the subsequent iterative calculation. The numerical example results show that with the increases of the technological crossing angle, the interference limit line is close to the boundary line of the conjugate region of the worm pair, and the hazard of curvature interference evident increases. Generally, a smaller value of the technological crossing angle within its available value range can completely avoid the occurrence of the curvature interference.

Ecology and the Ethics of Environmental Restoration

1994 ◽  
Vol 36 ◽  
pp. 31-43
Author(s):  
Robert Elliot
Keyword(s):  
Intrinsic Value ◽  
Environmental Restoration ◽  
Initial Value ◽  
Value Judgment ◽  
Human Interference ◽  
Rational Debate ◽  
To Come ◽  
In Virtue Of

Some people think that nature has intrinsic value, that it has value in itself quite apart from its present and future economic, intellectual, recreational and aesthetic uses. Some people think that nature's intrinsic value grounds an obligation to preserve it and to minimise human interference with it. I agree. It is important, however, to try to say exactly why nature has intrinsic value, to go beyond merely stating some idiosyncratic attitude and to provide some justification of that attitude with which others might engage. Presumably there are properties that wild nature exemplifies in virtue of which it is intrinsically valued. Only when these are indicated is rational debate as to whether wild nature has intrinsic value possible. Only when these are indicated is it possible to begin to persuade dissenters to change their views. Indeed, unless one can at least begin to say what these properties are it is not clear that the attitude could have any meaningful content. While it is perhaps possible to value something without immediately understanding what it is about the thing that makes it valuable, the failure to come up with any candidate value-adding property after some reflection suggests that the initial value-judgment is vacuous.

scholarly journals Positioning of Wireless Sensor Network under Emergency Communication Environment

2020 ◽  
Vol 19 (4) ◽  
pp. 273-279
Author(s):  
Ruilin Yuan
Keyword(s):  
Kalman Filter ◽  
Wireless Sensor Network ◽  
Embedded System ◽  
Sensor Network ◽  
Wireless Sensor ◽  
Initial Value ◽  
Emergency Communication ◽  
Positioning Accuracy ◽  
Communication Environment ◽  
Value Range

With the development of microelectromechanical system (MEMS), embedded system, and wireless communication, it is now feasible to implement and deploy wireless sensor network (WSN) in emergency communication environment. However, the positioning accuracy of WSN nodes needs to be further improved. To solve the problem, this paper improves the initial value calculation method of multi-hop positioning algorithms, which are suitable for emergency communication environment, and puts forward a WSN node positioning algorithm that narrows the initial values of Kalman filter. By narrowing the initial value range of Kalman filter, the specially deployed sensors could accurately derive its position from the known positions of anchor nodes. To prevent error accumulation in the network, distributed computing was performed to solve the global nonlinear optimization problem, and calculate the position of the nodes. Simulation results show that the proposed algorithm can improve the WSN positioning accuracy under emergency communication environment, while greatly saving computing and communication costs. The research further improves the practicability and efficiency of multi-hop positioning algorithms in emergency communication environment.

Determination of the Most Dangerous Meshing Point for Modified Hourglass Worm Drives

2011 ◽  
Author(s):  
Yaping Zhao ◽  
Tianchao Wu
Keyword(s):  
Nonlinear Equations ◽  
Slight Modification ◽  
Second Step ◽  
System Of Nonlinear Equations ◽  
Type Ii ◽  
Severe Condition ◽  
Worm Gearing ◽  
Curvature Interference ◽  
Worm Drive

A kind of modified hourglass worm drives, which is frequently called the type II worm gearing for short, has various favorable meshing features. Nevertheless, its sole shortcoming is the undercutting of the worm wheel. In the condition of adopting slight modification, this problem can be overcome due to the removal of a part of one sub-conjugate area containing the curvature interference limit line. In order to measure the effect of the avoidance of undercutting, a strategy to determine the meshing point in the most severe condition is proposed for a type II worm drive. The presented strategy can be divided into two steps. The first step is to establish a system of nonlinear equations in five variables in accordance with the theory of gearing. The second step is to solve the procured nonlinear equations by numerical iterative method to ascertain the meshing point required. A numerical example is presented to verify the validity and feasibility of the proposed scheme.

The Production Geometric Analysis of the New Type, Spiroid Worm Gear Drive Having Arched Profile

2013 ◽  
Author(s):  
Illés Dudás ◽  
Sándor Bodzás
Keyword(s):  
Geometric Analysis ◽  
Research Field ◽  
Worm Gear ◽  
Axial Section ◽  
Gear Drive ◽  
New Type ◽  
Application Fields ◽  
The University ◽  
Conical Worm ◽  
Spiroid Worm

In the last few decades in Hungary, the Budapest University of Technology and Economics and the University of Miskolc have been intensively focusing on the research field of worm gear drives [2, 5]. Our results at the University of Miskolc have also been published in a book published in the USA as well [2]. A new geometric worm gear drive has been developed, that is the conical worm gear drive having arched profiled in axial section [3]. The aim of our publication is to present the advantages, the geometric questions and the possible application fields of this new type worm gear drive.

Determination of the Most Dangerous Meshing Point for Modified-Hourglass Worm Drives

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Yaping Zhao ◽  
Yimin Zhang
Keyword(s):  
Nonlinear Equations ◽  
Slight Modification ◽  
System Of Nonlinear Equations ◽  
Type Ii ◽  
Severe Condition ◽  
Numerical Iteration ◽  
Worm Gearing ◽  
Curvature Interference ◽  
Worm Drive

A type of modified-hourglass worm gear drive, frequently called type-II worm gearing for short, has various favorable meshing features. Its sole shortcoming is the undercutting of the worm wheel. By adopting a slight modification, this problem can be overcome due to the removal of a part of one subconjugate area containing the curvature interference limit line. To measure how effectively the undercutting is avoided, a strategy to determine the meshing point in the most severe condition is proposed for a type-II worm drive. The strategy presented consists of two steps. The first step is to establish a system of nonlinear equations in five variables in accordance with the theory of gearing. The second step is to solve the system of nonlinear equations by a numerical iteration method to ascertain the meshing point required. A numerical example is presented to verify the validity and feasibility of the proposed scheme.

scholarly journals The Local Stability of Solutions for a Nonlinear Equation

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Haibo Yan ◽  
Ls Yong
Keyword(s):  
Differential Equation ◽  
Partial Differential Equation ◽  
Nonlinear Equation ◽  
Local Stability ◽  
Nonlinear Partial Differential Equation ◽  
Strong Solutions ◽  
Stability Of Solutions ◽  
Initial Value ◽  
Partial Differential

The approach of Kruzkov’s device of doubling the variables is applied to establish the local stability of strong solutions for a nonlinear partial differential equation in the spaceL1(R)by assuming that the initial value only lies in the spaceL1(R)∩L∞(R).

Geometric Modeling and Meshing Characteristics of the Toroidal Drive

2004 ◽  
Vol 127 (5) ◽  
pp. 988-996 ◽  
Author(s):  
Ligang Yao ◽  
Jian S. Dai ◽  
Guowu Wei ◽  
Huamin Li
Keyword(s):  
Geometric Modeling ◽  
Geometric Analysis ◽  
Three Dimensional ◽  
Analytical Models ◽  
Design Parameters ◽  
Necessary Condition ◽  
Axial Section ◽  
Three Dimensional Modeling ◽  
Worm Gears ◽  
Meshing Characteristics

This paper investigates the geometric properties of the toroidal drive, reveals the meshing characteristics, and develops analytical models of both axial section and normal section of the toroidal tooth profile. Based on coordinate transformation, the meshing function is obtained and leads to the necessary condition of existence of the enveloping surface. The helix and helix lead angle are then proposed for meshing between the sun-worm and planet worm-gears and both undercutting curve and meshing limit curve are introduced. This further leads to the induced normal curvature for evaluating gearing properties and the selection of the best suitable meshing parameters. The geometric analysis and analytical modeling present a tool for design, leading to three tables of numerical results and design parameters. This is then demonstrated in a three-dimensional modeling of both helical sun-worm and stationary internal gear of the toroidal drive.

scholarly journals Modifications to Accelerate the Iterative Algorithm for the Single Diode Model of PV Model

2020 ◽  
Vol 18 (47) ◽  
pp. 33-43
Author(s):  
Mohammed RASHEED ◽  
Suha SHIHAB
Keyword(s):  
Solar Cell ◽  
Nonlinear Equation ◽  
Ambient Temperature ◽  
Equivalent Circuit ◽  
Iterative Algorithm ◽  
Load Resistance ◽  
New Method ◽  
Initial Value ◽  
The Absolute ◽  
Resistance Equation

This paper discussed the solution of an equivalent circuit of solar cell, where a single diode model is presented. The nonlinear equation of this model has suggested and analyzed an iterative algorithm, which work well for this equation with a suitable initial value for the iterative. The convergence of the proposed method is discussed. It is established that the algorithm has convergence of order six. The proposed algorithm is achieved with a various values of load resistance. Equation by means of equivalent circuit of a solar cell so all the determinations is achieved using Matlab in ambient temperature. The obtained results of this new method are given and the absolute errors is demonstrated.

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