On Rolling Resistance in Gear Transmission

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
S. S. Ghosh ◽  
G. Chakraborty
Keyword(s):  
Experimental Data ◽  
Friction Force ◽  
Contact Force ◽  
Power Loss ◽  
Degrees Of Freedom ◽  
Rolling Resistance ◽  
Spur Gear ◽  
Gear Transmission ◽  
Gear Pair ◽  
Six Degrees Of Freedom

The effect of rolling resistance on the power loss during gear transmission has been studied. The resistance has been modeled by a lateral shift of the line of action of the contact force. The effect of this shift on the equivalent friction force has been predicted with the help of a six degrees of freedom (DOF) model of a spur gear pair. The predicted results agree closely with the experimental data available in literature.

The Engineering Design of Helical Spur Gear Transmission with Single Gear Pair for Electric Scooter

2015 ◽  
Vol 764-765 ◽  
pp. 374-378 ◽  
Author(s):  
Long Chang Hsieh ◽  
Tzu Hsia Chen ◽  
Hsiu Chen Tang
Keyword(s):  
Engineering Design ◽  
Spur Gear ◽  
Gear Transmission ◽  
Reduction Ratio ◽  
Gear Pair ◽  
Engineering Drawing ◽  
Electric Scooter ◽  
High Reduction ◽  
Cost Of Production ◽  
The Cost

Traditionally, the reduction ratio of a spur gear pair is limited to 4 ~ 7. For a spur gear transmission with reduction ratio more than 7, it is necessary to have more than two gear pairs. Consider the cost of production, this paper proposes a helical spur gear reducer with one gear pair having reduction ratio 19.25 to substitute the gear reducer with two gear pairs. Based on the involute theorem, the gear data of helical spur gear pair is obtained. According to the gear data, its corresponding engineering drawing is accomplished. This manuscript verify that one spur gear pair also can have high reduction ratio (20 ~ 30).

An Experimental Methodology to Determine Components of Power Losses of a Gearbox

2021 ◽  
Vol 143 (11) ◽  
Author(s):  
A. Dindar ◽  
K. Chaudhury ◽  
I. Hong ◽  
A. Kahraman ◽  
C. Wink
Keyword(s):  
Power Loss ◽  
Spur Gear ◽  
Rolling Element Bearing ◽  
Experimental Methodology ◽  
Total Power ◽  
Gear Pair ◽  
Rolling Element Bearings ◽  
Power Losses ◽  
Rolling Element ◽  
The One

Abstract In this study, an experimental methodology is presented to separate various components of the power loss of a gearbox. The methodology relies on two separate measurements. One is designed to measure total power loss of a gearbox housing a single spur gear pair under both loaded and unloaded conditions such that load-independent (spin) and load-dependent (mechanical) components can be separated. With the assumption that gear pair and rolling element bearings constitute the bulk of the gearbox power loss, a second measurement system designed to quantify rolling element bearing losses is proposed. With this setup, spin and mechanical power losses of rolling element bearings used in the gearbox experiments are measured. Combining the sets of gearbox and bearing data, power loss components attributable to the gear pair and rolling element bearings are quantified as a function of speed and torque. The results indicate that all gear and bearing related components are significant and a methodology such as the one proposed in this study is warranted.

scholarly journals Nonlinear Dynamic Characteristic Analysis of a Coated Gear Transmission System

Coatings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 39
Author(s):  
Yangyi Xiao ◽  
Liyang Fu ◽  
Jing Luo ◽  
Wankai Shi ◽  
Minglin Kang
Keyword(s):  
Dynamic Characteristic ◽  
Time History ◽  
Spur Gear ◽  
Transmission System ◽  
Gear Transmission ◽  
Phase Curve ◽  
Gear Pair ◽  
Characteristic Analysis ◽  
Mesh Stiffness ◽  
Gear Transmission System

Coatings can significantly improve the load-carrying performance of a gear surface, but how they affect the vibration characteristic of the system is an urgent issue to be solved. Taking into account the nonlinear factors like the variable mesh stiffness, friction, backlash, and transmission error, a six-degree-of-freedom spur gear transmission system with coatings is presented. Meanwhile, the finite element method is applied to acquire the time-varying mesh stiffness of the coated gear pair in the engagement process. With the support of the time-history curve, phase curve, Poincare map, and fast Fourier transform spectrum, the dynamic characteristics and the effects of the coating elastic modulus on vibration behaviors of a gear transmission system are minutely dissected by using a numerical integration approach. Numerical cases illustrate that the dynamic characteristic of a gear transmission system tends toward a one-period state under the given operating condition. They also indicate that, compared with softer coatings, stiffer ones can properly enhance the transmission performance of the coated gear pair. Numerical results are also compared with previous studies, and can establish a theoretical basis for dynamic design and vibration control of the coated gear transmission system.

Effect of Design Parameters on Lubrication Behavior of Spur Gear Pairs

2017 ◽  
Author(s):  
Yanfang Liu ◽  
Qiang Liu ◽  
Peng Dong
Keyword(s):  
Power Loss ◽  
Elastohydrodynamic Lubrication ◽  
Spur Gear ◽  
Design Parameters ◽  
Curvature Radius ◽  
Gear Pair ◽  
Sliding Velocity ◽  
Rolling Velocity ◽  
Lubrication Performance ◽  
Meshing Process

An involute spur gear pair meshing model is firstly provided in this study to achieve relevant data such as rolling velocity, sliding velocity, curvature radius etc. These data are needed in a transient, Newtonian elastohydrodynamic lubrication (EHL) model which is provided later. Based on these two models, the behavior of an engaged spur gear pair during the meshing process is investigated under dynamic conditions, film thickness, pressure, friction coefficient etc. could be achieved through the models. Then, power loss under certain operating condition is calculated. Relationship between power loss and lubrication performance is also analyzed.

Numerical and experimental investigation of a spur gear pair with unloaded static transmission error

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Duncai Lei ◽  
Xiannian Kong ◽  
Siyu Chen ◽  
Jinyuan Tang ◽  
Zehua Hu
Keyword(s):  
Transmission Error ◽  
Spur Gear ◽  
Gear Transmission ◽  
Dynamic Responses ◽  
Gear Pair ◽  
Mesh Stiffness ◽  
Content Type ◽  
High Order Harmonic ◽  
Static Transmission Error ◽  
Harmonic Components

Purpose The purpose of this paper is to investigate the dynamic responses of a spur gear pair with unloaded static transmission error (STE) excitation numerically and experimentally and the influences of the system factors including mesh stiffness, error excitation and torque on the dynamic transmission error (DTE). Design/methodology/approach A simple lumped parameters dynamic model of a gear pair considering time-varying mesh stiffness, backlash and unloaded STE excitation is developed. The STE is calculated from the measured tooth profile deviation under the unloaded condition. A four-square gear test rig is designed to measure and analyze the DTE and vibration responses of the gear pair. The dynamic responses of the gear transmission are studied numerically and experimentally. Findings The predicted numerical DTE matches well with the experimental results. When the real unloaded STE excitation without any approximation is used, the dynamic response is dominated by the mesh frequency and its high order harmonic components, which may not be result caused by the assembling error. The sub-harmonic and super-harmonic resonant behaviors are excited because of the high order harmonic components of STE. It will not certainly prevent the separations of mesh teeth when the gear pair is under the condition of high speed and heavy load. Originality/value This study helps to improve the modeling method of the dynamic analysis of spur gear transmission and provide some reference for the understanding of the influence of mesh stiffness, STE excitation and system torque on the vibration behaviors.

Oil Churning Power Losses of a Gear Pair: Experiments and Model Validation

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
S. Seetharaman ◽  
A. Kahraman ◽  
M. D. Moorhead ◽  
T. T. Petry-Johnson
Keyword(s):  
Power Loss ◽  
Spur Gear ◽  
Companion Paper ◽  
Design Parameters ◽  
Measured Parameter ◽  
Gear Pair ◽  
Power Losses ◽  
Gear Design ◽  
Face Width ◽  
Wide Range

This paper presents the results of an experimental study on load-independent (spin) power losses of spur gear pairs operating under dip-lubricated conditions. The experiments were performed over a wide range of operating speed, temperature, oil levels, and key gear design parameters to quantify their influence on spin power losses. The measurements indicate that the static oil level, rotational speed, and face width of gears have a significant impact on spin power losses compared with other parameters such as oil temperature, gear module, and the direction of gear rotation. A physics-based gear pair spin power loss formulation that was proposed in a companion paper (Seetharaman and Kahraman, 2009, “Load-Independent Spin Power Losses of a Spur Gear Pair: Model Formulation,” ASME J. Tribol., 131, p. 022201) was used to simulate these experiments. Direct comparisons between the model predictions and measurements are provided at the end to demonstrate that the model is capable of predicting the measured spin power loss values as well as the measured parameter sensitivities reasonably well.

THE ENGINEERING DESIGN AND TRANSMISSION EFFICIENCY VERIFICATION OF HELICAL SPUR GEAR TRANSMISSION WITH A SINGLE GEAR PAIR

2016 ◽  
Vol 40 (5) ◽  
pp. 981-993 ◽  
Author(s):  
Long-Chang Hsieh ◽  
Tzu-Hsia Chen
Keyword(s):  
Engineering Design ◽  
Spur Gear ◽  
Transmission Efficiency ◽  
Gear Transmission ◽  
Reduction Ratio ◽  
Gear Pair ◽  
High Reduction

The transmission efficiency of a gear reducer (ηT) can be expressed as ηT = ηm × ηb × ηs, where ηm is the meshing efficiency of gear pairs, ηb is the efficiency of bearings, and ηs is efficiency of oil seals. Based on the research of Hsieh, et al., the meshing efficiencies of a helical spur gear pair (4, 77) are between 96.13 and 99.20%. The purpose of this article is to analyze the theoretical transmission efficiencies of non-standard helical spur gear pair and verify the theorem. According to the gear data, the theoretical transmission efficiencies are calculated to be 90.13–97.85%. And its test values of transmission efficiencies are between 82.3 and 91.9% (acceptable values). There are only 5.39–14.14% errors between these two values. This manuscript verifies that a helical spur gear pair can have a high reduction ratio (20–30) and acceptable real transmission efficiencies.

Dynamic effects on spur gear pairs power loss lubricated with axle gear oils

2019 ◽  
Vol 234 (5) ◽  
pp. 1069-1084 ◽  
Author(s):  
Maroua Hammami ◽  
Nabih Feki ◽  
Olfa Ksentini ◽  
Taissir Hentati ◽  
Mohamed Slim Abbes ◽  
...  
Keyword(s):  
Dynamic Model ◽  
Power Loss ◽  
Degrees Of Freedom ◽  
Experimental Tests ◽  
Spur Gear ◽  
Operating Conditions ◽  
Dynamic Responses ◽  
Dynamic Effects ◽  
Nonlinear Dynamic Model ◽  
Gear Oils

The dynamic model of 12-degrees-of-freedom for spur gears pair accounting for nonlinear time-varying stiffness, damping, and coefficient of friction along the path of contact obtained from experimental tests is investigated. The Newmark's integration method is used to solve the equations and obtain the dynamic responses. Elementary mass, stiffness, and damping matrices with torsional and translational coupled effects were detailed. The lens of this work is to start from a nonlinear dynamic model to evaluate the influence of dynamic effects and lubrication on meshing gears power loss for different spur gear geometries within various operating conditions. The results reveal some useful references to vibration control, dynamic design, and efficiency improvement.

scholarly journals Effect of roughness on meshing power loss of planetary gear set considering elasto-hydrodynamic lubrication

2020 ◽  
Vol 12 (2) ◽  
pp. 168781402090842
Author(s):  
Xinlei Wang ◽  
Changle Xiang ◽  
Chunming Li ◽  
Shenlong Li ◽  
Yimin Shao ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Dynamic Model ◽  
Friction Force ◽  
Power Loss ◽  
Hydrodynamic Lubrication ◽  
Planetary Gear ◽  
Tooth Surface ◽  
Gear Pair ◽  
Surface Geometry ◽  
Loss Calculation

Meshing power loss is one of the most important parts in power loss calculation of planetary gear set. However, most of the conventional methods assumed the friction coefficient between gears as a constant value in the meshing power loss calculation, and most importantly, the influence of gear tooth surface geometry is usually ignored, for example, roughness. Therefore, a new meshing power loss calculation model for planetary gear set that considers tooth surface roughness is proposed on the basis of elasto-hydrodynamic lubrication method. With the proposed model, a planetary gear set dynamic model that considers friction force between gears is first established to study the time-varying meshing forces, sliding speeds, and curvature radii of the gear pairs. Then, an elasto-hydrodynamic lubrication model of the gear pair contact interface is constructed to investigate and modify the friction force distribution in the gear meshing process of the dynamic model iteratively until the meshing forces converge to stable values. Furthermore, the relationship between the tooth surface roughness and film thickness is studied in the elasto-hydrodynamic lubrication model. After that, the meshing power loss is calculated based on the obtained meshing forces, friction coefficients, sliding speeds, and so on. The results show that there is a sudden growth of the meshing power loss at the end of the meshing cycle, which has a good agreement with the meshing force impact. And, it is found that tooth surface roughness has a direct influence on the meshing power loss of sun–planet gear pair, which yields an increasing tendency as the surface roughness growing.

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