Analysis of Transmission Errors Under Load of Helical Gears With Modified Tooth Surfaces

1997 ◽  
Vol 119 (1) ◽  
pp. 120-126 ◽  
Author(s):  
Y. Zhang ◽  
Z. Fang
Keyword(s):  
Rigid Bodies ◽  
Contact Load ◽  
Tooth Contact Analysis ◽  
Helical Gears ◽  
Transmission Errors ◽  
Proposed Model ◽  
Tooth Surfaces ◽  
Simulation Results ◽  
Meshing Characteristics ◽  
Gear Contact

This paper presents a model for the analysis of transmission errors of helical gears under load. The model accommodates the modification of tooth surfaces, gear misalignments and the deformation of tooth surfaces caused by contact load. In this model, the gear contact load is assumed to be nonlinearly distributed along the direction of the relative principal curvature between the two contacting tooth surfaces. As compared with conventional tooth contact analysis (TCA) that assumes gear surfaces as rigid bodies, the model presented in this paper provides more realistic simulation results on the gear transmission errors and other gear meshing characteristics when the tooth surfaces are deformed under load. The proposed model is applied to a pair of helical gears in the numerical example included in the paper.

Application and Investigation of Modified Helical Gears With Several Types of Geometry

2007 ◽  
Author(s):  
Ignacio Gonzalez-Perez ◽  
Alfonso Fuentes ◽  
Faydor L. Litvin ◽  
Kenichi Hayasaka ◽  
Kenji Yukishima
Keyword(s):  
Gear Tooth ◽  
Tooth Surface ◽  
Contact Ratio ◽  
Tooth Contact Analysis ◽  
Helical Gears ◽  
Transmission Errors ◽  
Advantages And Disadvantages ◽  
Bearing Contact ◽  
Tooth Surfaces ◽  
Gear Drives

Involute helical gears with modified geometry for transformation of rotation between parallel axes are considered. Three types of topology of geometry are considered: (1) crowning of pinion tooth surface is provided only partially by application of a grinding disk; (2) double crowning of pinion tooth surface is obtained applying a grinding disk; (3) concave-convex pinion and gear tooth surfaces are provided (similar to Novikov-Wildhaber gears). Localization of bearing contact is provided for all three types of topology. Computerized TCA (Tooth Contact Analysis) is performed for all three types of topology to obtain: (i) path of contact on pinion and gear tooth surfaces; (ii) negative function of transmission errors for misaligned gear drives (that allows the contact ratio to be increased). Stress analysis is performed for the whole cycle of meshing. Finite element models of pinion and gear with several pairs of teeth are applied. A relative motion is imposed to the pinion model that allows friction between contact surfaces to be considered. Numerical examples have confirmed the advantages and disadvantages of the applied approaches for generation and design.

scholarly journals Computerized Design and Generation of Low-Noise Helical Gears with Modified Surface Topology

1995 ◽  
Vol 117 (2A) ◽  
pp. 254-261 ◽  
Author(s):  
F. L. Litvin ◽  
N. X. Chen ◽  
J. Lu ◽  
R. F. Handschuh
Keyword(s):  
Gear Tooth ◽  
Error Function ◽  
Transmission Error ◽  
Low Noise ◽  
Surface Topology ◽  
Helical Gears ◽  
Transmission Errors ◽  
Bearing Contact ◽  
Pinion Gear ◽  
Tooth Surfaces

An approach for the design and generation of low-noise helical gears with localized bearing contact is proposed. The approach is applied to double circular arc helical gears and modified involute helical gears. The reduction of noise and vibration is achieved by application of a predesigned parabolic function of transmission errors that is able to absorb a discontinuous linear function of transmission errors caused by misalignment. The localization of the bearing contact is achieved by the mismatch of pinion-gear tooth surfaces. Computerized simulation of meshing and contact of the designed gears demonstrated that the proposed approach will produce a pair of gears that has a parabolic transmission error function even when misalignment is present. Numerical examples for illustration of the developed approach are given.

Research on Meshing Characteristics for Face Gear with Arcuate Tooth

2011 ◽  
Vol 86 ◽  
pp. 39-42
Author(s):  
Xiang Wei Cai ◽  
Zong De Fang ◽  
Jin Zhan Su
Keyword(s):  
Contact Analysis ◽  
Tooth Surface ◽  
Face Gear ◽  
Tooth Contact Analysis ◽  
Surface Equation ◽  
Transmission Errors ◽  
Gear Drive ◽  
Parabolic Function ◽  
The Face ◽  
Meshing Characteristics

The generating of face gear with arcuate tooth has been proposed in this paper, and the meshing characteristics are investigated. Based on the concept of imaginary gear cutter, tooth surface equation has been derived, flank modification has also been considered. The transmission errors and bearing contacts of the face gear drive with arcuate tooth under different assembly conditions are investigated by applying the tooth contact analysis. The numerical results reveal that the bearing contacts are not sensitive to the errors of misalignments, and a more favorable type parabolic function of transmission errors with better symmetry and reduced amplitude may be obtained according to the modification of the face gear.

New developments in the design and generation of gear drives

2001 ◽  
Vol 215 (7) ◽  
pp. 747-757 ◽  
Author(s):  
F. L. Litvin ◽  
A Fuentes ◽  
A Demenego ◽  
D Vecchiato ◽  
Q Fan
Keyword(s):  
Point Contact ◽  
Tooth Surface ◽  
Helical Gears ◽  
Transmission Errors ◽  
Bevel Gears ◽  
Bearing Contact ◽  
Analysis And Synthesis ◽  
Tooth Surfaces ◽  
Design Generation ◽  
Gear Drives

Design, generation and simulation of the meshing and contact of gear drives with favourable bearing contact and reduced noise are considered. The proposed approach is based on replacement of the instantaneous line of contact of tooth surfaces by point contact and on application of a predesigned parabolic function of transmission errors that is able to absorb linear discontinuous functions of transmission errors caused by misalignment. Basic algorithms for analysis and synthesis of gear drives are presented. The developed theory is applied for design and generation of the following gear drives with modified geometry: (a) spur and helical gears, (b) a new version of Novikov-Wildhaber (N-W) helical gears, (c) asymmetric face gear drives with a spur pinion, (d) formate-cut spiral bevel gears. Generation of the tooth surface of a worm gear is presented as the formation of a two-branch envelope. The discussed topics are illustrated with examples.

Concave modifications of tooth surfaces of beveloid gears with crossed axes

2018 ◽  
Vol 233 (4) ◽  
pp. 1411-1425 ◽  
Author(s):  
Siyuan Liu ◽  
Chaosheng Song ◽  
Caichao Zhu ◽  
Qi Fan
Keyword(s):  
Film Thickness ◽  
Contact Ratio ◽  
Tooth Contact Analysis ◽  
Transmission Errors ◽  
Maximum Value ◽  
Contact Patterns ◽  
Beveloid Gears ◽  
Minimum Film Thickness ◽  
Tooth Surfaces ◽  
Crossed Axes

The mathematical models of the beveloid gear surfaces with different scenarios of combinations of profile concave modification and lead crowning are derived. Four schemes of modifications were proposed for beveloid gears with crossed axes. Tooth contact analysis is developed to study the influences of different schemes of concave modifications on the mesh behaviors including film thickness, transmission errors, contact ratio, root stresses, and contact patterns. Comparison of the contact characteristics of a beveloid gear drive with and without concave modifications is conducted. The results show that all the concave modification schemes can increase the area of contact patterns and decrease the maximum value of contact stresses, while the minimum film thickness can be increased. For the scheme i.e. the pinion with profile crowning modification and gear with profile concave modification, the contact ratio increases firstly then decreases to a relative lower value. Also, the root stresses are increased obviously. For the scheme for pinion without modification and gear with lead concave modification and the scheme for both pinion and gear with lead concave modification, the transmission errors are decreased slightly. The scheme for the pinion with combined crowning modification and gear with combined concave modification shows the largest improvement for the mesh behaviors in terms of the transmission errors and contact patterns where an almost contact condition can be found for the crossed beveloid gear pair.

Surface design and tooth contact analysis of an innovative modified spur gear with crowned teeth

2005 ◽  
Vol 219 (2) ◽  
pp. 193-207 ◽  
Author(s):  
J-L Li ◽  
S-T Chiou
Keyword(s):  
Gear Tooth ◽  
Point Contact ◽  
Spur Gear ◽  
Contact Analysis ◽  
Tooth Surface ◽  
Tooth Contact Analysis ◽  
Tooth Contact ◽  
Surface Design ◽  
Tooth Surfaces ◽  
Meshing Characteristics

An innovative modified spur gear with crowned teeth and its generating mechanism are proposed in this study. The main purpose of tooth surface modification is to change line contact to point contact at the middle of gear tooth surfaces in order to avoid edge contact resulting from possible unavoidable axial misalignment. Moreover, the surface of one gear tooth can be generated with just one cutting process, thereby facilitating easy manufacturing. Based on gearing theory, the model for surface design is developed. A tooth contact analysis (TCA) model for the modified gear pair is also built to investigate meshing characteristics, so that transmission errors (TEs) under assembly errors can also be studied. Examples are included to verify the correctness of the models developed and to demonstrate gear characteristics.

A Surface Wear Prediction Methodology for Parallel-Axis Gear Pairs

2004 ◽  
Vol 126 (3) ◽  
pp. 597-605 ◽  
Author(s):  
P. Bajpai ◽  
A. Kahraman ◽  
N. E. Anderson
Keyword(s):  
Numerical Procedure ◽  
Surface Wear ◽  
Wear Prediction ◽  
Helical Gears ◽  
Coordinate Measurement ◽  
Mechanics Model ◽  
Manufacturing Errors ◽  
Tooth Surfaces ◽  
Parallel Axis ◽  
Gear Contact

In this study, a surface wear prediction methodology for spur and helical gears is proposed. The methodology employs a finite elements-based gear contact mechanics model in conjunction with the Archard’s wear formulation to predict wear of contacting tooth surfaces. An iterative numerical procedure is developed to account for the changes in the gear contact as the gears wear. A methodology is developed to import gear coordinate measurement machine data into the gear contact model in order to analyze gears with actual manufactured surfaces with profile and lead modifications. Results of an experimental study are presented for validation of the methodology. A set of simulations is also included to highlight the differences between gear pairs having modified and unmodified tooth surfaces, with and without manufacturing errors in terms of their wear characteristics.

An approach of calculation on sliding friction power losses in involute helical gears with modification

2015 ◽  
Vol 230 (9) ◽  
pp. 1521-1531 ◽  
Author(s):  
Cheng Wang ◽  
Huan Yong Cui ◽  
Qing Ping Zhang ◽  
Wen Ming Wang
Keyword(s):  
Sliding Friction ◽  
Tooth Surface ◽  
Surface Load ◽  
Power Losses ◽  
Tooth Contact Analysis ◽  
Helical Gears ◽  
Friction Power ◽  
Transmission Errors ◽  
Normal Forces ◽  
Load Distributions

Sliding friction between the teeth is recognized as one of the main reasons of power losses in transmission as well as a potential reason of vibration and noise. A new approach is proposed to accurately calculate the sliding friction power losses in involute helical gears considered modification and geometric deviations resulting from the manufacturing processes, assembly errors, and deflections of support structures based on the simulation of gear mesh under light and significant load. Firstly, the paths of contact points on the pinion tooth surface are obtained from tooth contact analysis. Tooth surface load distributions and loaded transmission errors in one mesh period are obtained from loaded tooth contact analysis. Secondly, tooth surface load distributions are converted into the normal forces of tooth surface points of contact, loaded transmission errors are brought to the calculation formulas of sliding velocity, and the sliding friction coefficients of tooth surface points of contact are calculated by a non-Newtonian thermal elastohydrodynamic lubrication model. Substituting the sliding velocities, the normal forces, and the sliding friction coefficients into the power calculation formulas gives the sliding friction power losses of tooth surface points of contact. By the soft MATLAB, the values of the sliding friction power losses are integrated and the sliding friction power loss in helical gears from engagement to disengagement is obtained. Finally, an example of this approach is shown in the end. The results indicate that it is very necessary to consider the influence of loaded transmission errors for calculation of sliding friction power losses.

scholarly journals Computerized Design and Generation of Low-Noise Helical Gears With Modified Surface Topology

1994 ◽  
Author(s):  
F. L. Litvin ◽  
N. X. Chen ◽  
J. Lu ◽  
R. F. Handschuh
Keyword(s):  
Gear Tooth ◽  
Low Noise ◽  
Surface Topology ◽  
Helical Gears ◽  
Transmission Errors ◽  
Bearing Contact ◽  
Pinion Gear ◽  
Tooth Surfaces ◽  
Modified Surface ◽  
Computerized Simulation

Abstract An approach for design and generation of low-noise helical gears with localized bearing contact is proposed. The approach is applied to double circular arc helical gears and modified involute helical gears. The reduction of noise and vibration is achieved by application of a predesigned parabolic function of transmission errors that is able to absorb a discontinuous linear function of transmission errors caused by misalignment. The localization of the bearing contact is achieved by the mismatch of pinion-gear tooth surfaces. Computerized simulation of meshing and contact of the designed gears demonstrated that the proposed approach will produce a parabolic transmission errors function when misalignment is present. Numerical examples for illustration of the developed approach are given.

Simulation of Elastic Gears with Non-Standard Flank Profiles

2013 ◽  
Vol 60 (1) ◽  
pp. 55-73
Author(s):  
Trong Phu Do ◽  
Pascal Ziegler ◽  
Peter Eberhard
Keyword(s):  
Multibody System ◽  
Rigid Bodies ◽  
Contact Forces ◽  
Reference Formulation ◽  
Elastic Deformations ◽  
Beveloid Gears ◽  
Elastic Multibody System ◽  
Floating Frame ◽  
Simulation Results ◽  
Gear Contact

There exist cases where precise simulations of contact forces do not allow modeling the gears as rigid bodies but a fully elastic description is needed. In this paper, a modally reduced elastic multibody system including gear contact based on a floating frame of reference formulation is proposed that allows very precise simulations of fully elastic gears with appropriately meshed gears in reasonable time even for many rotations. One advantage of this approach is that there is no assumption about the geometry of the gears and, therefore, it allows precise investigations of contacts between gears with almost arbitrary non-standard tooth geometries including flank profile corrections. This study presents simulation results that show how this modal approach can be used to efficiently investigate the interaction between elastic deformations and flank profile corrections as well as their influence on the contact forces. It is shown that the elastic approach is able to describe important phenomena like early addendum contact for insufficiently corrected profiles in dependence of the transmitted load. Furthermore, it is shown how this approach can be used for precise and efficient simulations of beveloid gears.

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