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

Author(s):  
Vilmos Simon

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.

Author(s):  
Vilmos V. Simon

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.


Author(s):  
Vilmos V. Simon

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.


2014 ◽  
Vol 136 (7) ◽  
Author(s):  
Vilmos V. Simon

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.


Author(s):  
Vilmos Simon

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.


Author(s):  
Vilmos V. Simon

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.


1997 ◽  
Vol 119 (1) ◽  
pp. 101-107 ◽  
Author(s):  
V. Simon

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.


1988 ◽  
Vol 110 (4) ◽  
pp. 699-703 ◽  
Author(s):  
Awny Y. Attia ◽  
Ahmed M. M. El-Bahloul

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.


2013 ◽  
Vol 690-693 ◽  
pp. 1999-2002
Author(s):  
Fan Ming Meng ◽  
Tao Yang ◽  
Tao Long

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.


Author(s):  
J. K. Patrick ◽  
N. N. S. Chen

This paper presents the results of an extensive experimental investigation into the performance of a short multi-grooved bearing subjected to a range of static and alternating loads. Lubricating oil was supplied, at pressures of up to 2000 lb/in2, to capillary type restrictors connected to 10 closed-end axial grooves in the bearing. The bearing had a length/diameter ratio of 1/3 and operated with a journal speed and load frequency of 327 c/min. Measured load capacity, stiffness, and flow characteristics indicate that bearings of this type have a significant load-carrying capacity at zero journal speed and that the load capacity is increased by journal rotation. A feature of the journal behaviour under alternating loads is the movement of the journal centre along a straight line coincident with the load plane. The extensive oil film pressure surveys indicate for the first time the pressure distribution within narrow hydrostatic bearings and provide a basis for a realistic theoretical analysis of this type of bearing.


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