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.

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.

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.

Computerized Design and FE Simulation of Meshing of Involute Spiral Bevel Gears with Alignment Errors

2011 ◽  
Vol 199-200 ◽  
pp. 386-391 ◽  
Author(s):  
Ben Wang ◽  
Lin Hua
Keyword(s):  
Fe Simulation ◽  
Transmission Error ◽  
Load Carrying Capacity ◽  
Spiral Bevel Gears ◽  
Bevel Gears ◽  
Load Carrying ◽  
Contact Models ◽  
Stress Transmission ◽  
Spiral Bevel ◽  
Alignment Errors

Influence of alignment errors on the meshing of involute spiral bevel gears using FEM is investigated in this paper. 3D geometrical models of involute spiral bevel gear drive are computationally designed and the reliable non-linear finite element contact models are also developed. Furthermore, based on the valid 3D FE models, simulations of meshing of loaded spiral bevel gears with four types of alignment errors are performed. The influence of four types of alignment errors on contact stress, transmission error and shift of path of contact has been discussed in detail. The results demonstrate that the alignment errors have different degrees of adverse effects on the load-carrying capacity and the smoothness of transmission. Therefore, the study provides useful reference for the modification design and the assembling of spiral bevel gears in practice.

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.

Study on Tribological Performances for Textured Bearing of ICE

2013 ◽  
Vol 690-693 ◽  
pp. 1999-2002
Author(s):  
Fan Ming Meng ◽  
Tao Yang ◽  
Tao Long
Keyword(s):  
Friction Coefficient ◽  
Internal Combustion Engine ◽  
Carrying Capacity ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Load Carrying Capacity ◽  
Oil Film ◽  
Load Carrying ◽  
Inner Surface ◽  
Coupling Algorithm

The influence of dimples on the inner surface of big end bearing in internal combustion engine (ICE) on tribological performances of the bearing was investigated based on Navier-Strokes equation and other associated equations. In doing so, the CFD modulus in the software ANSYS12 version is used to analyze the dimple effect on the tribological performances of the bearing using two-way fluid-solid coupling algorithm. Some mechanisms are revealed about the dimple effect on the load-carrying capacity and friction coefficient of oil film, and the deformation and stress for the textured big end bearing.

Performance analysis of rough surface hybrid thrust bearing with elliptical dimples

2020 ◽  
pp. 135065012093198
Author(s):  
Vivek Kumar ◽  
Satish C Sharma
Keyword(s):  
Surface Roughness ◽  
Carrying Capacity ◽  
Machining Process ◽  
Fluid Film ◽  
Textured Surface ◽  
Stiffness Coefficient ◽  
Load Carrying Capacity ◽  
Power Losses ◽  
Load Carrying ◽  
Film Stiffness

Surface roughness is inherent to all machining processes. Therefore, even a high precision machining process renders micro-roughness to some extent on the surface of conventional materials. The asperities height of many rough engineering surfaces follows Gaussian distribution. The surface roughness on the bearing surface may significantly affect the bearing performance. Surface texturing is emerging as a new technique to improve the tribological behavior of the mating surfaces. Usually dimensions/height of micro-roughness is of order of the depth of surface textures in fluid film bearings. Neglecting micro-roughness while numerically simulating a textured surface bearing may generate inaccurate bearing performance data. In presented work, finite element simulation of textured surface hybrid thrust bearings has been performed. Surface texture is provided over thrust pad in the form of regular arrays of elliptical dimples. A parametric optimization is carried out to determine optimum attributes of elliptical dimple (axis, depth, texture length and orientation) so that the load-carrying capacity and fluid film stiffness should be maximized and film frictional power losses should be minimized. Use of textured surface (with optimum elliptical dimple attributes) results into a significant enhancement in load-carrying capacity (91.3%), film stiffness coefficient (+98.8%) and reduction in frictional power losses (−48.3%). It is also observed that elliptical dimple and micro-roughness (transverse orientation) generate synergistic effects in further enhancing the load-carrying capacity (+101.4%) and film stiffness coefficient (+112%) of the bearing.

scholarly journals Experimental investigations and analysis on churning losses of splash lubricated spiral bevel gears

2017 ◽  
Vol 18 (4) ◽  
pp. 412 ◽  
Author(s):  
S. Laruelle ◽  
C. Fossier ◽  
C. Changenet ◽  
F. Ville ◽  
S. Koechlin
Keyword(s):  
Experimental Tests ◽  
Operating Conditions ◽  
Experimental Investigations ◽  
Spiral Bevel Gear ◽  
Power Losses ◽  
Test Rig ◽  
Specific Test ◽  
Spiral Bevel Gears ◽  
Bevel Gears ◽  
Spiral Bevel

Churning losses are a complex phenomenon which generates significant power losses when considering splash lubrication of gear units. However, only few works deal with bevel gears dipped lubrication losses. The objective of this study is to provide a wide variety of experimental tests on churning losses, especially getting interested in geometry of spiral bevel gears influence. A specific test rig was used in order to study a single spiral bevel gear partially immersed in an oil bath. Experiments have been conducted for several operating conditions in terms of speeds, lubricants, temperatures and gear geometries to study their impact on splash lubrication power losses. These experimental results are compared with the predictions from various literature sources. As the results did not agree well with the predictions for all operating conditions, an extended equation derived from previous works is introduced to estimate churning losses of bevel gears.

Matching the relationship between rotational speed and load-carrying capacity on high-speed and heavy-load hydrostatic thrust bearing

2018 ◽  
Vol 70 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Xiao-dong Yu ◽  
Lei Geng ◽  
Xiao-jun Zheng ◽  
Zi-xuan Wang ◽  
Xiao-gang Wu
Keyword(s):  
Carrying Capacity ◽  
Rotational Speed ◽  
Thrust Bearing ◽  
Lubricating Oil ◽  
Load Carrying Capacity ◽  
Average Pressure ◽  
Content Type ◽  
Oil Film ◽  
Hydrostatic Bearing ◽  
Load Carrying

Purpose Rotational speed and load-carrying capacity are two mutual coupling factors which affect high precision and stable operation of a hydrostatic thrust bearing. The purpose of this paper is to study reasonable matching relationship between the rotational speed and the load-carrying capacity. Design/methodology/approach A mathematical model of relationship between the rotational speed and the load-carrying capacity of the hydrostatic bearing with double-rectangle recess is set up on the basis of the tribology theory and the lubrication theory, and the load and rotational speed characteristics of an oil film temperature field and a pressure field in the hydrostatic bearing are analyzed, reasonable matching relationship between the rotational speed and the load-carrying capacity is deduced and a verification experiment is conducted. Findings By increasing the rotational speed, the oil film temperature increases, the average pressure decreases and the load-carrying capacity decreases. By increasing the load-carrying capacity, the oil film temperature and the average pressure increases and the rotational speed decreases; corresponding certain reasonable matching values are available. Originality/value The load-carrying capacity can be increased and the rotational speed improved by means of reducing the friction area of the oil recess by using low-viscosity lubricating oil and adding more oil film clearance; but, the stiffness of the hydrostatic bearing decreases.

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.

Thermo-EHD Analysis of Lubrication of Helical Gears

1988 ◽  
Vol 110 (3) ◽  
pp. 330-336 ◽  
Author(s):  
V. Simon
Keyword(s):  
Regression Analysis ◽  
Carrying Capacity ◽  
Power Loss ◽  
Operating Conditions ◽  
Load Carrying Capacity ◽  
Helical Gears ◽  
Oil Film ◽  
Gear Teeth ◽  
Temperature Distributions ◽  
Load Carrying

The full thermal elastohydrodynamic analysis of lubrication of helical gears is presented. A numerical solution of the coupled Reynolds, elasticity, energy, and Laplace’s equations for the oil film shape, pressure and temperature distributions in the oil film, and temperature distribution in gear teeth is obtained. The effects of gear parameters and operating conditions on EHD performance characteristics is discussed. Based on the obtained results, by regression analysis, equations are derived to calculate the EHD load carrying capacity, maximum oil temperature, and power loss.

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