Identification and Minimization of Deviations of Real Gear Tooth Surfaces

1989 ◽  
Author(s):  
F. L. Litvin ◽  
Y. Zhang ◽  
J. Kieffer ◽  
R. F. Handschuh
Keyword(s):  
Machine Tool ◽  
Gear Tooth ◽  
Real Surface ◽  
The Real ◽  
Tooth Surfaces ◽  
Coordinate Measurements

Abstract The authors propose an approach that uses coordinate measurements of the real surface to: (i) determine the real applied machine-tool settings, (ii) determine the deviations of the real surface from the theoretical one, (iii) minimize the deviations by correction of the machine-tool settings, and (iv) represent the real surface analytically in the same Gaussian coordinates as the theoretical one.

Identification and Minimization of Deviations of Real Gear Tooth Surfaces

1991 ◽  
Vol 113 (1) ◽  
pp. 55-62 ◽  
Author(s):  
F. L. Litvin ◽  
Yi Zhang ◽  
J. Kieffer ◽  
R. F. Handschuh
Keyword(s):  
Machine Tool ◽  
Gear Tooth ◽  
Real Surface ◽  
The Real ◽  
Tooth Surfaces ◽  
Coordinate Measurements

The authors propose an approach that uses coordinate measurements of the real surface to: (a) determine the real applied machine-tool settings, (b) determine the deviations of the real surface from the theoretical one, (c) minimize the deviations by correction of the machine-tool settings, and (d) represent the real surface analytically in the same Gaussian coordinates as the theoretical one.

scholarly journals Elastohydrodynamic Lubrication Analysis of Gear Tooth Surfaces From Micropitting Tests

2003 ◽  
Vol 125 (2) ◽  
pp. 267-274 ◽  
Author(s):  
J. Tao ◽  
T. G. Hughes ◽  
H. P. Evans ◽  
R. W. Snidle ◽  
N. A. Hopkinson ◽  
...  
Keyword(s):  
Film Thickness ◽  
Gear Tooth ◽  
Testing Machine ◽  
Elastohydrodynamic Lubrication ◽  
Real Surface ◽  
Test Protocol ◽  
Contact Phase ◽  
Gear Teeth ◽  
Pressure Cycling ◽  
Tooth Surfaces

The paper presents numerical results for the elastohydrodynamic lubrication of gear teeth using real surface roughness data taken from micropitting tests carried out on an FZG gear testing machine. Profiles and load conditions corresponding to four load stages in the micropitting test protocol are considered. Elastohydrodynamic film thickness and pressure analyses are presented for conditions having a slide/roll ratio of 0.3 during the single tooth contact phase of the meshing cycle. Comparisons are also included showing the elastohydrodynamic response of the tooth contacts at different times in the meshing cycle for one of the load stages. The rheological model adopted is based on Ree-Eyring non-Newtonian shear thinning, and comparisons are also included of models having constant and different pressure-dependent specifications of the Eyring shear stress parameter τ0. Parameters obtained from the micro EHL analyses are presented that quantify the degree of adversity experienced by the surfaces in elastohydrodynamic contact. These quantify extreme pressure behavior, extreme proximity of surfaces, and pressure cycling within the overall contact and indicate that the different fluid models considered lead to significantly different pressure and film thickness behavior within the contact.

Computerized Analysis of Meshing and Contact of Gear Real Tooth Surfaces

1994 ◽  
Vol 116 (3) ◽  
pp. 677-682 ◽  
Author(s):  
Y. Zhang ◽  
F. L. Litvin ◽  
N. Maruyama ◽  
R. Takeda ◽  
M. Sugimoto
Keyword(s):  
Vector Function ◽  
Tooth Surface ◽  
Real Surface ◽  
Small Deviations ◽  
The Real ◽  
Surface Deviations ◽  
Tooth Surfaces ◽  
Computerized Simulation ◽  
Gaussian Surface ◽  
Main Ideas

The authors propose a technique for computerized simulation and tangency of gears provided with real tooth surfaces. The deviations of real tooth surfaces from the theoretical ones are caused by the distortion of surfaces during the heat treatment and lapping. The main ideas of the proposed technique are as follows: (i) The gear real tooth surface is represented by a sum of two vector functions that determine the theoretical tooth surface and the deviations of the real surface from the theoretical one, respectively. (ii) Both vector functions mentioned above are represented in terms of the same Gaussian surface coordinates (the Gaussian coordinates of the theoretical surface). (iii) The deviations of the real surface are initially determined numerically using the data of surface coordinate measurements. The analytical representation of the vector function of deviations is based on the interpolation of a numerically given vector function by a bi-cubic spline. The interpolation provides a relatively high precision because it is accomplished for the surface of small deviations but not for the whole real surface. (iv) The computerized simulation of meshing and tangency of gears with real tooth surfaces is based on the algorithm that describes the conditions of continuous tangency of real tooth surfaces. The proposed approach is illustrated with application to the hypoid gear drive with real tooth surfaces. The data of surface deviations have been determined experimentally at the Nissan Motor Co.

Scanning electron microscopy of human iliac bone by a simple preparation method

1990 ◽  
Vol 48 (3) ◽  
pp. 226-227
Author(s):  
Toshihiko Takita ◽  
Tomonori Naguro ◽  
Toshio Kameie ◽  
Akihiro Iino ◽  
Kichizo Yamamoto
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Real Surface ◽  
Public Attention ◽  
Preparation Methods ◽  
The Real ◽  
Simple Preparation ◽  
Scanning Electron

Recently with the increase in advanced age population, the osteoporosis becomes the object of public attention in the field of orthopedics. The surface topography of the bone by scanning electron microscopy (SEM) is one of the most useful means to study the bone metabolism, that is considered to make clear the mechanism of the osteoporosis. Until today many specimen preparation methods for SEM have been reported. They are roughly classified into two; the anorganic preparation and the simple preparation. The former is suitable for observing mineralization, but has the demerit that the real surface of the bone can not be observed and, moreover, the samples prepared by this method are extremely fragile especially in the case of osteoporosis. On the other hand, the latter has the merit that the real information of the bone surface can be obtained, though it is difficult to recognize the functional situation of the bone.

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.

Estimation of Gear Friction Coefficient using Directional Parameter of Tooth Surface

2021 ◽  
pp. 1-27
Author(s):  
Junichi Hongu ◽  
Ryohei Horita ◽  
Takao Koide
Keyword(s):  
Friction Coefficient ◽  
Contact Surface ◽  
Gear Tooth ◽  
Correction Term ◽  
Tooth Surface ◽  
Oil Film ◽  
Tooth Surfaces ◽  
Frictional Coefficients ◽  
Finishing Processes ◽  
The Relationship

Abstract This study proposes a modification of the Matsumoto equation using a directional parameter of tooth surfaces to adapt various gear finishing processes. The directional parameters of a contact surface, which affect oil film formations, have been discussed in the field of tribology; but this effect has been undetermined on the meshing gear tooth surfaces having directional machining marks. Thus, this paper investigates the relationship between the gear frictional coefficients and the directional parameters (based on ISO25178) of their tooth surfaces with the various finishing processes; and modifies the Matsumoto equation by introducing a new directional parameter to augment the various gear finishing processes. Our findings indicate that through optimizing the coefficient of the correction term the include the new directional parameter, the calculated friction values using the modified Matsumoto equation correlate more highly to the experimental friction values than that using the unmodified Matsumoto equation.

Limitation of gear tooth surfaces by envelopes to contact lines and edge of regression

1999 ◽  
Vol 34 (6) ◽  
pp. 889-902 ◽  
Author(s):  
F.L. Litvin ◽  
Aoyong Peng ◽  
Anngwo Wang
Keyword(s):  
Gear Tooth ◽  
Contact Lines ◽  
Tooth Surfaces

Manufacturing Process for Circular-Arc Curvilinear Cylindrical Gears with Predesigned Fourth Order Transmission Error

2010 ◽  
Vol 37-38 ◽  
pp. 623-627 ◽  
Author(s):  
Jin Zhan Su ◽  
Zong De Fang
Keyword(s):  
Fourth Order ◽  
Gear Tooth ◽  
Transmission Error ◽  
Circular Arc ◽  
Cylindrical Gears ◽  
Polynomial Curve ◽  
Order Polynomial ◽  
Tooth Surfaces ◽  
The Stability ◽  
Fourth Order Polynomial

A fourth order transmission error was employed to improve the stability and tooth strength of circular-arc curvilinear cylindrical gears. The coefficient of fourth order polynomial curve was determined, the imaginary rack cutter which formed by the rotation of a head cutter and the imaginary pinion were introduced to determine the pinion and gear tooth surfaces, respectively. The numerical simulation of meshing shows: 1) the fourth order transmission error can be achieved by the proposed method; 2) the stability transmission can be performed by increasing the angle of the transfer point of the cycle of meshing; 3) the tooth fillet strength can be enhanced.

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