A Novel Design of Cylindrical Hob for Machining of Precision Involute Gears

2006 ◽  
Vol 129 (3) ◽  
pp. 334-345 ◽  
Author(s):  
Stephen P. Radzevich
Keyword(s):  
Analytical Methods ◽  
Tooth Profile ◽  
Surface Generation ◽  
Design Parameters ◽  
Analytical Mechanics ◽  
Straight Line ◽  
Vector Algebra ◽  
Involute Gears ◽  
Design Yield ◽  
Novel Design

This paper aims at development of a novel design of precision gear hob for machining involute gear on a conventional gear-hobbing machine. The reported research is based on use of fundamental results obtained in analytical mechanics of gearing. For solving the problem, both the descriptive-geometry-based (DGB) methods together with pure analytical methods have been employed. The use of DGB methods is insightful for solving most of the principal problems, which consequently were analytically solved. The analytical methods used provide an example of application of the DG∕K-method of surface generation developed earlier by the author. For interpretation of the results of research, several computer codes in the commercial software MathCAD∕Scientific were composed. Ultimately, a method of computation of parameters of design of a hob with straight-line lateral cutting edges for machining of precision involute gears is developed in the paper. Coincidence of the straight-line lateral cutting edges of the hob with the straight-line characteristics of it generating surface eliminates the major source of deviations of the hobbed involute gears. The relationships between major principal design parameters that affect the gear hob performance are investigated with the use of vector algebra, matrix calculus, and elements of differential geometry. Gear hobs of the proposed design yield elimination of the principal and major source of deviation of the desired hob tooth profile from the actual hob tooth profile. The reported results of this research are ready to put in practice.

On Satisfaction of the Fifth Necessary Condition of Proper Part Surface Generation in Design of Plunge Shaving Cutter for Finishing of Precision Involute Gears

2006 ◽  
Vol 129 (9) ◽  
pp. 969-980 ◽  
Author(s):  
Stephen P. Radzevich
Keyword(s):  
Gear Tooth ◽  
Numerical Control ◽  
Proper Part ◽  
Surface Generation ◽  
Tooth Surface ◽  
Necessary Condition ◽  
Analytical Mechanics ◽  
Part Surface ◽  
Involute Gears ◽  
Novel Design

In this paper, a novel modified scheme and effective computer representation for design of a plunge shaving cutter is presented. The paper aims to develop a novel design of shaving cutter for plunge shaving of precision involute gears. The study is carried out on the premise of satisfaction of the fifth necessary condition of proper part surface generation (PSG) when designing the plunge shaving cutter. In the current study, the author’s earlier developed DG/K method of surface generation is used together with the principal elements of analytical mechanics of gears. (The DG/K method is based on fundamental results obtained in differential geometry of surfaces, and on kinematics of multi-parametric motion of a rigid body in the E3 space. The interested reader may wish to go for details to the monograph: Radzevich, S.P., Fundamentals of Surface Generation, Monograph, Kiev, Rastan, 2001, 592 pp., and to: Radzevich, S.P., Sculptured Surface Machining on Multi-Axis NC Machine, Monograph, Kiev, Vishcha Schola, 1991, 192 pp.) In the particular case under consideration, the method employs (a) an analytical description of the gear tooth surface to be machined, (b) configuration of the plunge shaving cutter relative to the involute gear, (c) analytical representation of the coordinate systems transformations, and (d) the fifth condition of proper PSG that is adapted to finishing of precision involute gears. The fifth condition of proper PSG is investigated in the paper. On the premise of the obtained results of the investigation, a novel design of plunge shaving cutter for finishing of precision involute gears is proposed. The developed novel design of plunge shaving cutter can be used on shaving machines available on the market, e.g. on Gleason’s new Genesis™ 130SV computer numerical control (CNC) shaving machine.

A Novel Design Procedure for Reducing Vibration and Noise in Gears

1993 ◽  
Author(s):  
K. Y. Yoon ◽  
S. S. Rao
Keyword(s):  
Gear Tooth ◽  
Design Procedure ◽  
Transmission Error ◽  
Tooth Profile ◽  
Profile Modification ◽  
Noise Characteristics ◽  
Spline Curves ◽  
Involute Gears ◽  
Static Transmission Error ◽  
Novel Design

Abstract A new method is proposed for reducing vibration and noise of involute gears. The method is based on the use of cubic spline curves for gear tooth profile modification. The tooth profile is constrained to assume an involute shape during the loaded operation. Thus the new gear profile assures conjugate motion at all points along the line of action. The new profile is found to result in a more uniform static transmission error compared to standard involute profile thereby contributing to the improvement of vibration and noise characteristics of the gear.

scholarly journals Modeling Airtanker Flight Distance between Concurrent Fires: The Development and Use of Statistical Distribution Parameters

2008 ◽  
Vol 54 (1) ◽  
pp. 47-57
Author(s):  
Francis E. Greulich
Keyword(s):  
System Design ◽  
Analytical Methods ◽  
Statistical Distribution ◽  
Flight Distance ◽  
Design Parameters ◽  
Initial Attack ◽  
System Planning ◽  
Protection Zone ◽  
Transfer Activity ◽  
Distribution Parameters

Abstract Airtankers, while actively engaging in initial attack, are sometimes reassigned and flown directly to another randomly occurring initial attack fire. Airtanker system planning that means to incorporate this fire-to-fire transfer activity needs information about the flight distance between these randomly located fires. Moments of the distance distribution, derived in this article, can be used to characterize and evaluate fire-to-fire airtanker dispatch within and between protection areas. A hypothetical example illustrates how a proposed change in an airtanker protection zone can affect not only airbase-to-fire flight distance but also fire-to-fire flight distance. In this example, the expected airbase-to-fire distance and the expected total transfer-flight distance are both significantly reduced, but at the same time, somewhat unexpectedly, the average fire-to-fire flight distance actually increases. The discovery and quantification of such unanticipated results can potentially influence airtanker system design. These key system design parameters can now be obtained through the exceedingly fast and accurate analytical methods presented here.

Phoretic self-propulsion of helical active particles

2021 ◽  
Vol 927 ◽  
Author(s):  
Ruben Poehnl ◽  
William Uspal
Keyword(s):  
Particle Surface ◽  
Design Parameters ◽  
Strong Impact ◽  
Directed Motion ◽  
Concentration Gradients ◽  
Slender Body Theory ◽  
Active Particles ◽  
Straight Line ◽  
Judicious Choice ◽  
Body Theory

Chemically active colloids self-propel by catalysing the decomposition of molecular ‘fuel’ available in the surrounding solution. If the various molecular species involved in the reaction have distinct interactions with the colloid surface, and if the colloid has some intrinsic asymmetry in its surface chemistry or geometry, there will be phoretic flows in an interfacial layer surrounding the particle, leading to directed motion. Most studies of chemically active colloids have focused on spherical, axisymmetric ‘Janus’ particles, which (in the bulk, and in absence of fluctuations) simply move in a straight line. For particles with a complex (non-spherical and non-axisymmetric) geometry, the dynamics can be much richer. Here, we consider chemically active helices. Via numerical calculations and slender body theory, we study how the translational and rotational velocities of the particle depend on geometry and the distribution of catalytic activity over the particle surface. We confirm the recent finding of Katsamba et al. (J. Fluid Mech., vol. 898, 2020, p. A24) that both tangential and circumferential concentration gradients contribute to the particle velocity. The relative importance of these contributions has a strong impact on the motion of the particle. We show that, by a judicious choice of the particle design parameters, one can suppress components of angular velocity that are perpendicular to the screw axis, or even select for purely ‘sideways’ translation of the helix.

scholarly journals Effect of a dual tire pressure on the design parameters of thick asphalt pavements using finite element freeware

DYNA ◽  
2016 ◽  
Vol 83 (196) ◽  
pp. 194-203
Author(s):  
Myriam Rocío Pallares Muñoz ◽  
Julián Andrés Pulecio-Díaz
Keyword(s):  
Finite Element ◽  
Analytical Methods ◽  
Asphalt Pavement ◽  
Field Tests ◽  
Asphalt Pavements ◽  
Design Parameters ◽  
Future Research ◽  
Tire Pressure ◽  
The Cost ◽  
Cost Of Construction

<p>The effect of a dual tire pressure on the design parameters of thick asphalt pavements using finite element freeware EverStressFE©1.0 is evaluated. This is trying to represent more adjusted the footprint shape and intensity of stress generated by the tires of vehicles. To validate the elastic multilayer EverStress©5.0 software was used. The results of the deformations can be concluded that the asphalt pavement designs made with analytical methods may be slightly oversized and consequently increase the cost of construction of pavements. This study marks a route to analyze the sensitivity of various factors that may affect the design of asphalt pavements. Future research is expected to integrate dynamic conditions by introducing results of field tests to full scale.</p>

The Research of Linear Rotation-Axis Control Machining CNC Rotary Cam Surface Transformation

2012 ◽  
Vol 163 ◽  
pp. 138-142
Author(s):  
Feng Qin Ding ◽  
Yi Yu ◽  
Zhi Yi Miao
Keyword(s):  
Control System ◽  
Numerical Control ◽  
Data Conversion ◽  
Design Parameters ◽  
Milling Machine ◽  
Numerical Control System ◽  
Cnc Milling ◽  
Cnc Milling Machine ◽  
Straight Line ◽  
Linear Movement

General CNC milling machine for special transformation in the middle and low numerical control system of internal control software does not change under the premise of achieving the original system does not have the linear movement and rotary movement of the operating linkage function. The numerical control system of linear movement into rotary movement of the operation, and expansion of two straight line linkage CNC system functions, cleverly converted to a straight line movement control of a rotary movement of the linkage, thereby achieving the surface of the cylinder rotating cam track surface CNC machining. CNC Milling through the difficult parts of the application examples to explain the design principles of transformation CNC milling machine, design approach,As well as the design parameters in the programming of data conversion. And data conversion processing errors resulting from the measures and the elimination of error analysis.

Effect of tooth waist order parameters of double involute gears on lubrication performance of gear drive

2016 ◽  
Vol 68 (6) ◽  
pp. 671-675 ◽  
Author(s):  
Zhimin Fan ◽  
Wanfeng Zhou ◽  
Ruixue Wang ◽  
Na Wang
Keyword(s):  
Elastohydrodynamic Lubrication ◽  
Reference Value ◽  
Tooth Profile ◽  
Order Parameters ◽  
Content Type ◽  
Oil Film ◽  
Gear Drive ◽  
Involute Gear ◽  
Lubrication Performance ◽  
Involute Gears

Purpose The purpose of this paper is to derive a new lubrication model of double involute gears drive and study the effect of the tooth waist order parameters of double involute gears on lubrication performance. Design/methodology/approach The new lubrication model of double involute gears drive was established according to the meshing characteristics of double involute gears drive and the finite length line contact elastohydrodynamic lubrication theory. Numerical calculation of the lubrication model of gear drive was conducted using the multigrid method. Findings The results show that the oil film necking phenomenon and the oil film pressure peak emerged at the tooth waist order area and the tooth profile ends, and when compared with involute gear, the lubrication performance at the tooth waist order area is better than that at the tooth profile ends. The effect of tooth waist order parameters on lubrication performance at the tooth waist order area was greater than that at other areas. Originality/value This research will promote the application of the double involute gear as soon as possible, and it has the reference value for other types of gears.

An Intelligent System for Spur Gear Design and Analysis

2001 ◽  
Author(s):  
El-Sayed Aziz ◽  
C. Chassapis
Keyword(s):  
Finite Element ◽  
Closed Form ◽  
Intelligent System ◽  
Tooth Profile ◽  
Hertzian Contact ◽  
Design Parameters ◽  
Analysis Model ◽  
Closed Form Solutions ◽  
Gear Teeth ◽  
Gear Design

Abstract A methodology for the analysis of load distribution and contact stress on gear teeth, which utilizes a combination of closed form solutions and two-dimensional finite element methods, within a constraint-based knowledge-based environment, is presented. Once the design parameters are specified, the complete process of generating the analysis model, starting from the determination of the coordinates of the tooth profile, the creation of a sector of the mating gear teeth, automatic mesh generation, boundary conditions and loading, is totally automated and transparent to the designer. The effects of non-standard geometry, load sharing on the contact zone, friction and root stresses are easily included in the model. The Finite Element Method (FEM) based results compare favorably with those obtained from closed form solutions (AGMA equations and classical Hertzian contact solution). The advantage of the approach rests in the ability to modify any of the gear design parameters such as diametral pitch, tooth profile modification etc., in an automated manner along with obtaining a better estimation of the risks of failure of the gear design on hand. The procedure may be easily extended to other types of gearing systems.

Study on the effects of tooth profile design parameters of rotor to performance of vacuum pump

2020 ◽  
Vol 34 (22n24) ◽  
pp. 2040141
Author(s):  
Van-The Tran ◽  
Bui Trung Thanh ◽  
Banh Tien Long ◽  
Hoang Quoc Tuan ◽  
Duc Toan Nguyen
Keyword(s):  
Vacuum Pump ◽  
Tooth Profile ◽  
Design Parameters ◽  
Tooth Root ◽  
Performance Indices ◽  
Circular Arc ◽  
Numerical Example ◽  
Design Flexibility ◽  
Profile Design ◽  
Rotor Tooth

The vacuum pump usually used traditional curves such as the circular, cycloidal curves and their combinations to construct tooth profile. However, to increase efficiency and design flexibility for the vacuum pump, a novel rotor tooth profile for Roots rotor of vacuum pumps is proposed. Which is named “CEIEC” tooth profile and orderly composed of five significant segments, a circular arc for tooth tip, an epicycloid curve with variable extension, an involute, an enveloped epicycloid curve and a conjugated circular arc for tooth root. A numerical example is presented to evaluate the performance indices for proposed vacuum pump, including the hermeticity coefficients of the rotor mesh gap and tip gap.

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