Influence of Lubricant and Operating Parameters on EHD Lubrication in Hypoid Gears

2005 ◽  
Author(s):  
Vilmos V. Simon
Keyword(s):  
Elastohydrodynamic Lubrication ◽  
Density Variation ◽  
Operating Parameters ◽  
Power Losses ◽  
Oil Viscosity ◽  
Hypoid Gears ◽  
Oil Film ◽  
Ehd Lubrication ◽  
Load Carrying ◽  
Oil Film Pressure

The influence of lubricant characteristics and operating parameters on the elastohydrodynamic lubrication in hypoid gears is investigated. The full thermal elastohydrodynamic analysis of lubrication is applied, based on the simultaneous solution of the Reynolds, elasticity, energy, and Laplace’s equations. The oil viscosity variation with respect to pressure and temperature and the density variation with respect to pressure are included. Using a computer algorithm, the influence of oil viscosity, pressure-viscosity and temperature-viscosity exponents, supplied oil temperature, speed and minimum oil film thickness on maximum oil film pressure and temperature, EHD load carrying capacity, and power losses in the oil film is investigated. The obtained results are presented and discussed.

Influence of Lubricant and Operating Characteristics on EHD Lubrication in Hypoid Gears

2008 ◽  
Author(s):  
Vilmos Simon
Keyword(s):  
Density Variation ◽  
Load Carrying Capacity ◽  
Power Losses ◽  
Operating Characteristics ◽  
Oil Viscosity ◽  
Hypoid Gears ◽  
Oil Film ◽  
Ehd Lubrication ◽  
Load Carrying ◽  
Oil Film Pressure

The full thermal EHD lubrication analysis is applied, therefore, the oil viscosity variation with respect to pressure and temperature and the density variation with respect to pressure are included. By using the corresponding computer program, the influence of oil viscosity, pressure-viscosity and temperature-viscosity exponents, supplied oil temperature, speed and minimum oil film thickness on maximum oil film pressure and temperature, EHD load carrying capacity, and on power losses in the oil film is investigated. Small part of the obtained results is presented and discussed.

Influence of Misalignments on EHD Lubrication in Hypoid Gears

2007 ◽  
Author(s):  
Vilmos V. Simon
Keyword(s):  
Angular Position ◽  
Density Variation ◽  
Oil Viscosity ◽  
Hypoid Gears ◽  
Oil Film ◽  
Gear Teeth ◽  
Ehd Lubrication ◽  
Load Carrying ◽  
Tooth Surfaces ◽  
Oil Film Pressure

The thermal elastohydrodynamic analysis of lubrication is applied to investigate the influence of misalignments of the meshing members on EHD lubrication in hypoid gears. The calculation is based on the simultaneous solution of the Reynolds, elasticity, energy, and Laplace’s equations. The full thermal EHD lubrication analysis is applied, therefore, the oil viscosity variation with respect to pressure and temperature and the density variation with respect to pressure are included. The real shape of the gap existing between the contacting tooth surfaces is treated, based on gear teeth geometry defined by the gear processing method and including the misalignments of mating members. By using the corresponding computer program, the influence of pinion’s running offset and axial adjustment errors, and angular position error of pinion axis on maximum oil film pressure and temperature, EHD load carrying capacity, and on power losses in the oil film is investigated. The obtained results are presented and discussed.

Optimal Tooth Modifications in Face-Hobbed Spiral Bevel Gears to Reduce the Influence of Misalignments on Elastohydrodynamic Lubrication

2014 ◽  
Vol 136 (7) ◽  
Author(s):  
Vilmos V. Simon
Keyword(s):  
Carrying Capacity ◽  
Optimization Procedure ◽  
Load Carrying Capacity ◽  
Power Losses ◽  
Spiral Bevel Gears ◽  
Oil Film ◽  
Bevel Gears ◽  
Ehd Lubrication ◽  
Load Carrying ◽  
Spiral Bevel

In this study, an optimization methodology is proposed to systematically define the optimal tooth modifications introduced by head-cutter geometry and machine-tool settings to minimize the influence of misalignments on the elastohydrodynamic (EHD) lubrication characteristics in face-hobbed spiral bevel gears. The goal is to simultaneously maximize the EHD load-carrying capacity of the oil film and to minimize power losses in the oil film when different misalignments are inherent in the gear pair. The proposed optimization procedure relies heavily on the EHD lubrication analysis developed in this paper. The core algorithm of the proposed nonlinear programming procedure is based on a direct search method. Effectiveness of this optimization was demonstrated on a face-hobbed spiral bevel gear example. A drastic increase in the EHD load-carrying capacity of the oil film and a reduction in the power losses in the oil film were obtained.

EHD Lubrication Characteristics of a New Type of Ground Cylindrical Worm Gearing

1997 ◽  
Vol 119 (1) ◽  
pp. 101-107 ◽  
Author(s):  
V. Simon
Keyword(s):  
Density Variation ◽  
Grinding Wheel ◽  
Oil Viscosity ◽  
Circular Arcs ◽  
Ehd Lubrication ◽  
Highly Nonlinear ◽  
Load Carrying ◽  
Worm Gearing ◽  
New Type ◽  
Lubrication Characteristics

A full thermal elastohydrodynamic analysis of lubrication of a new type of cylindrical worm gearing with concave worm profile, ground by a grinding wheel whose profile consists of two circular arcs, is presented. The EHD lubrication analysis is based on the simultaneous solution of the Reynolds, elasticity, energy, and Laplace’s equations. The oil viscosity variation with respect to pressure and temperature and the density variation with respect to pressure are included. The finite difference method and numerical integration have been used to get the solution of the highly nonlinear integrodifferential system of governing equations. By using a computer program, the influence of design and operating parameters of the new type of worm gearing on EHD lubrication characteristics has been investigated. Also, the comparison of the EHD load carrying capacity and of the power losses in the oil film of the new type and of the commonly used cylindrical worm gearings has been carried out.

Influence of Position Errors on EHD Lubrication in Spiral Bevel Gears

2010 ◽  
Author(s):  
Vilmos Simon
Keyword(s):  
Friction Factor ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Oil Viscosity ◽  
Spiral Bevel Gears ◽  
Oil Film ◽  
Bevel Gears ◽  
Ehd Lubrication ◽  
Load Carrying ◽  
Spiral Bevel

The thermal elastohydrodynamic analysis of lubrication is applied to investigate the influence of misalignments of the meshing members on lubrication in spiral bevel gears. The calculation is based on the simultaneous solution of the Reynolds, elasticity, energy, and Laplace’s equations. The full thermal EHD lubrication analysis is applied, therefore, the oil viscosity variation with respect to pressure and temperature and the density variation with respect to pressure are included. By using the corresponding computer program, the influence of pinion’s running offset and axial adjustment errors, and angular position error of pinion axis on maximum oil film pressure and temperature, EHD load carrying capacity, and on power losses in the oil film is investigated. On the basis of the obtained results it can be concluded that the EHD load carrying capacity and the friction factor are very sensitive to misalignments of the mating members in the spiral bevel gear pair, the friction factor is reduced by the increase of EHD load carrying capacity and vise versa, and the maximum inlet oil temperature is almost insensitive to the misalignments.

Minimization of the Influence of Misalignments on EHD Lubrication in Face-Hobbed Spiral Bevel Gears

2013 ◽  
Author(s):  
Vilmos V. Simon
Keyword(s):  
Carrying Capacity ◽  
Optimization Procedure ◽  
Load Carrying Capacity ◽  
Power Losses ◽  
Spiral Bevel Gears ◽  
Oil Film ◽  
Bevel Gears ◽  
Ehd Lubrication ◽  
Load Carrying ◽  
Spiral Bevel

In this study, an optimization methodology is proposed to systematically define optimal tooth modifications introduced by head-cutter geometry and machine tool settings to minimize the influence of misalignments on EHD lubrication characteristics in face-hobbed spiral bevel gears. The goal is to simultaneously maximize the EHD load carrying capacity of the oil film and to minimize power losses in the oil film when different misalignments are inherent in the gear pair. The proposed optimization procedure relies heavily on the EHD lubrication analysis developed by the author of this paper. The core algorithm of the proposed nonlinear programming procedure is based on a direct search method. Effectiveness of this optimization was demonstrated on a face-hobbed spiral bevel gear example. Drastic increase in the EHD load carrying capacity of the oil film and reduction in the power losses in the oil film were obtained.

Improvements in the mixed elastohydrodynamic lubrication and in the efficiency of hypoid gears

2019 ◽  
Vol 234 (6) ◽  
pp. 795-810 ◽  
Author(s):  
Vilmos V Simon
Keyword(s):  
Gear Tooth ◽  
Numerical Procedure ◽  
Elastohydrodynamic Lubrication ◽  
Equation System ◽  
Density Variation ◽  
Asperity Contact ◽  
Oil Viscosity ◽  
Hypoid Gears ◽  
The Real ◽  
Transient Nature

In this paper, the influence of the manufacturing parameters on the conditions of mixed elastohydrodynamic lubrication is investigated. On the basis of the obtained results, recommendations are formulated to improve the mixed EHL and the efficiency of face-milled hypoid gears. A full numerical analysis of the mixed EHL in hypoid gears is applied. The equation system and the numerical procedure are unified for a full coverage of all the lubrication regions, including the full film, mixed, and boundary lubrication. In the hydrodynamically lubricated areas, the calculation method employed is based on the simultaneous solution of the Reynolds, elasticity, energy, and Laplace's equations. In the asperity contact areas, the Reynolds equation is reduced to an expression equivalent to the mathematical description of dry contact problem. The real geometry and kinematics of the gear pair based on the manufacturing procedure are applied; thus, the exact geometrical separation of the mating tooth surfaces is included in the oil film shape, and the real velocities of these surfaces are used in the Reynolds and energy equations. The transient nature of gear tooth mesh is included. The oil viscosity variation with respect to pressure and temperature and the density variation with respect to pressure are included. The non-Newtonian behaviour of the lubricant is considered. Using this model, the pressures, film thickness, temperatures, and power losses in the mixed lubrication regime are predicted. The effectiveness of the presented method is demonstrated by using hypoid gear examples.

Influence of Surface Waviness on the Thermal Elastohydrodynamic Lubrication of an Eccentric-Tappet Pair

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
J. Wang ◽  
C. H. Venner ◽  
A. A. Lubrecht
Keyword(s):  
Film Thickness ◽  
Elastohydrodynamic Lubrication ◽  
Surface Waviness ◽  
Film Pressure ◽  
Oil Film ◽  
Working Cycle ◽  
Temperature Oscillations ◽  
Minimum Film Thickness ◽  
Traction Coefficient ◽  
Oil Film Pressure

The effect of single-sided and double-sided harmonic surface waviness on the film thickness, pressure, and temperature oscillations in an elastohydrodynamically lubricated eccentric-tappet pair has been investigated in relation to the eccentricity and the waviness wavelength. The results show that, during one working cycle, the waviness causes significant fluctuations of the oil film, pressure, and temperature, as well as a reduction in minimum film thickness. Smaller wavelength causes more dramatic variations in oil film. The fluctuations of the pressure, film thickness, temperature, and traction coefficient caused by double-sided waviness are nearly the same compared with the single-sided waviness, but the variations are less intense.

scholarly journals Effects of Oil Viscosity and Anti-wear Agent on Load Carrying Characteristics of Hypoid Gears : Mainly on Limiting Load for Scoring and Power Loss

1982 ◽  
Vol 25 (205) ◽  
pp. 1164-1172
Author(s):  
Shoji HAIZUKA ◽  
Chotaro NARUSE ◽  
Ryozo NEMOTO ◽  
Satoshi SAKURAI
Keyword(s):  
Power Loss ◽  
Oil Viscosity ◽  
Hypoid Gears ◽  
Limiting Load ◽  
Load Carrying

Lubrication Capacity of Gears of Circular-Arc Tooth-Profile

1988 ◽  
Vol 110 (4) ◽  
pp. 699-703 ◽  
Author(s):  
Awny Y. Attia ◽  
Ahmed M. M. El-Bahloul
Keyword(s):  
Film Thickness ◽  
Carrying Capacity ◽  
Helix Angle ◽  
Load Carrying Capacity ◽  
Test Rig ◽  
Oil Viscosity ◽  
Oil Film ◽  
Lubricant Oil ◽  
Linear Dimensions ◽  
Load Carrying

The paper presents the results of an experimental investigation carried out at Mansoura University Laboratories aiming at studying the effect of change of speed, oil viscosity, and helix angle on the load carrying capacity of the oil film. A three pairs of test gears of 6 DP, 91.5 mm pitch diameter with 22.3, 33.6 and 42.25 deg helix angles were run in power circulating test rig at 100 to 3000 r.p.m. speeds and transmitting tooth load ranging from 185 to 1090 Kp. The test gears were lubricated with oils of 200, 462, and 653 cSt at 40°C kinematic viscosities. The oil film thicknesses between contacting teeth were measured by measuring the changes in capacitance between test gears and transferred to linear dimensions by calibration curves drawn by knowing the changes in capacitance through the gaps between teeth of values known through the amount of backlash. The experimental results show that; Oil film thickness decreases with tooth load, while increases with speed and viscosity of the lubricant. Oil film thickness versus helix angle give an inversed parabola for the smallest and medium tooth loads, while oil film thickness decreases with increasing the helix angle under increased tooth loads. Load carrying capacity increases with speeds and viscosity of the lubricant while decreases with increasing the helix angle.

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