scholarly journals Design of Spur Gears for Improved Efficiency

1982 ◽  
Vol 104 (4) ◽  
pp. 767-774 ◽  
Author(s):  
N. E. Anderson ◽  
S. H. Loewenthal
Keyword(s):  
Power Loss ◽  
Spur Gear ◽  
Operating Conditions ◽  
Gear System ◽  
Spur Gears ◽  
Wide Range ◽  
Pitch Ratio ◽  
Design Requirements ◽  
System Power

A method to calculate spur gear system power loss for a wide range of gear geometries and operating conditions is used to determine design requirements for an efficient gearset. The effects of spur gear size, pitch, ratio, pitch-line-velocity, and load on efficiency are shown. A design example is given to illustrate how the method is to be applied. In general, peak efficiencies were found to be greater for larger diameter and fine pitched gears and tare (no-load) losses were found to be significant.

scholarly journals Effect of Geometry and Operating Conditions on Spur Gear System Power Loss

1981 ◽  
Vol 103 (1) ◽  
pp. 151-159 ◽  
Author(s):  
N. E. Anderson ◽  
S. H. Loewenthal
Keyword(s):  
Power Loss ◽  
Ball Bearing ◽  
Large Diameter ◽  
Spur Gear ◽  
Operating Conditions ◽  
Published Data ◽  
Wide Range ◽  
Low Torque ◽  
System Power ◽  
Good Agreement

The results of an analysis of the effects of spur gear size, pitch, width and ratio on total mesh power loss for a wide range of speeds, torques and oil viscosities are presented. The analysis uses simple algebraic expressions to determine gear sliding, rolling and windage losses and also incorporates an approximate ball bearing power loss expression. The analysis shows good agreement with published data. Large diameter and fine-pitched gears had higher peak efficiencies but lower part-load efficiency. Gear efficiencies were generally greater than 98 percent except at very low torque levels. Tare (no-load) losses are generally a significant percentage of the full-load loss except at low speeds.

scholarly journals Baseline Experimental Results on the Effect of Oil Temperature on Shrouded Meshed Spur Gear Windage Power Loss

2017 ◽  
Author(s):  
Irebert R. Delgado ◽  
Michael J. Hurrell
Keyword(s):  
Experimental Test ◽  
Power Loss ◽  
Spur Gear ◽  
Spur Gears ◽  
Test Results ◽  
Oil Viscosity ◽  
Gear Teeth ◽  
Temperature Load ◽  
Loss Efficiency

Rotorcraft gearbox efficiencies are reduced at increased surface speeds due to viscous and impingement drag on the gear teeth. This windage power loss can affect overall mission range, payload, and frequency of transmission maintenance. Experimental and analytical studies on shrouding for single gears have shown it to be potentially effective in mitigating windage power loss. Efficiency studies on unshrouded meshed gears have shown the effect of speed, oil viscosity, temperature, load, lubrication scheme, etc. on gear windage power loss. The open literature does not contain experimental test data on shrouded meshed spur gears. Gear windage power loss test results are presented on shrouded meshed spur gears at elevated oil inlet temperatures and constant oil pressure both with and without shrouding. Shroud effectiveness is compared at four oil inlet temperatures. The results are compared to the available literature and follow-up work is outlined.

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.

Frictional dynamic model predictions of FZG-A10 spur gear pairs considering profile errors

2020 ◽  
pp. 135065012096297
Author(s):  
Nabih Feki ◽  
Maroua Hammami ◽  
Olfa Ksentini ◽  
Mohamed Slim Abbes ◽  
Mohamed Haddar
Keyword(s):  
Dynamic Model ◽  
Coefficient Of Friction ◽  
Power Loss ◽  
Spur Gear ◽  
Operating Conditions ◽  
Time Dependent ◽  
Nonlinear Dynamic Model ◽  
Gear Mesh ◽  
Proposed Model ◽  
Profile Errors

In this work, a nonlinear dynamic model of an FZG-A10 spur gear was investigated by taking into account for the actual time-varying gear mesh stiffness and the frictional effects between meshing gear teeth to evaluate the influence of the dynamic effects on frictional gear power loss predictions. The equations of motion of the generalized translational-torsional coupled dynamic system derived from Lagrange principle was extended compared to authors’ previous work in order to account for time dependent coefficient of friction and profile errors. The dynamic response of spur gears, computed by an iterative implicit scheme of Newmark, is changed due to the presence of coefficient of friction and profile errors. A dynamic analysis was performed and the influence of frictional effect including tooth shape deviations, in particular, was scrutinized since a time-dependent coefficient of friction is deeply related to the gear surface roughness and all parameters dependent on gears error profiles are introduced in the proposed model. The predicted meshing gear power losses with constant and local friction coefficient were compared. The influence of constant and variable profile errors considered in the local coefficient of friction formulation was also studied and their corresponding root mean square (RMS) power loss was compared to the experimental results. The results using FZG A10 spur gear pairs running under several operating conditions (different loads and speeds) validate the superiority of the proposed model against previous similar models.

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 Investigations on Oil Flow Rates Projected on the Casing Walls by Splashed Lubricated Gears

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
G. Leprince ◽  
C. Changenet ◽  
F. Ville ◽  
P. Velex
Keyword(s):  
Spur Gear ◽  
Operating Conditions ◽  
Test Rig ◽  
Variable Size ◽  
Flow Measurements ◽  
Flow Rates ◽  
Lubricant Flow ◽  
Wide Range ◽  
Oil Flow ◽  
Set Up

In order to investigate the oil projected by gears rotating in an oil bath, a test rig has been set up in which the quantity of lubricant splashed at several locations on the casing walls can be measured. An oblong-shaped window of variable size is connected to a tank for flow measurements, and the system can be placed at several locations. A series of formulae have been deduced using dimensional analysis which can predict the lubricant flow rate generated by one spur gear or one disk at various places on the casing. These results have been experimentally validated over a wide range of operating conditions (rotational speed, geometry, immersion depth, etc.).

scholarly journals Generalized Behavioral Modelling Methodology of Switch-Diode Cell for Power Loss Prediction in Electromagnetic Transient Simulation

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1500
Author(s):  
Yanming Xu ◽  
Carl Ngai Man Ho ◽  
Avishek Ghosh ◽  
Dharshana Muthumuni
Keyword(s):  
Power Loss ◽  
Process Analysis ◽  
Operating Conditions ◽  
Transient Simulation ◽  
Oxide Semiconductor ◽  
Model Parameters ◽  
Electromagnetic Transient ◽  
Proposed Model ◽  
Wide Range ◽  
Electromagnetic Transient Simulation

Modern wide-bandgap (WBG) devices, such as silicon carbide (SiC) or gallium nitride (GaN) based devices, have emerged and been increasingly used in power electronics (PE) applications due to their superior switching feature. The power losses of these devices become the key of system efficiency improvement, especially for high-frequency applications. In this paper, a generalized behavioral model of a switch-diode cell (SDC) is proposed for power loss estimation in the electromagnetic transient simulation. The proposed model is developed based on the circuit level switching process analysis, which considers the effects of parasitics, the operating temperature, and the interaction of diode and switch. In addition, the transient waveforms of the SDC are simulated by the proposed model using dependent voltage and current sources with passive components. Besides, the approaches of obtaining model parameters from the datasheets are given and the modelling method is applicable to various semiconductors such Si insulated-gate bipolar transistor (IGBT), Si/SiC metal–oxide–semiconductor field-effect transistor (MOSFET), and GaN devices. Further, a multi-dimensional power loss table in a wide range of operating conditions can be obtained with fast speed and reasonable accuracy. The proposed approach is implemented in PSCAD/ Electromagnetic Transients including DC, EMTDC, (v4.6, Winnipeg, MB, Canada) and further verified by the hardware setups including different daughter boards for different devices.

Forced Aeration Composting

1983 ◽  
Vol 15 (1) ◽  
pp. 169-180 ◽  
Author(s):  
George B Willson
Keyword(s):  
Agricultural Research ◽  
Land Application ◽  
Operating Conditions ◽  
Moisture Removal ◽  
Simple Method ◽  
Wide Range ◽  
Design Requirements ◽  
Forced Aeration ◽  
Density Population ◽  
Pilot Tests

Composting enhances the acceptability of sewage sludge for land application especially in high density population areas. A relatively simple method of forced-aeration pile composting was developed at the Beltsville Agricultural Research Center. Pilot tests of full scale composting were conducted to determine process control and facility design requirements. The amount of bulking materials needed to condition the sludge for composting is related to the percentage of sludge solids. Aeration is discussed as it relates to oxygen consumption, temperature control and moisture removal. The process is readily adaptable to many operating conditions, to a variety of materials, and to a wide range of levels of compost production.

scholarly journals An Analytical Method to Predict Efficiency of Aircraft Gearboxes

1986 ◽  
Vol 108 (3) ◽  
pp. 424-432 ◽  
Author(s):  
N. E. Anderson ◽  
S. H. Loewenthal ◽  
J. D. Black
Keyword(s):  
Friction Coefficient ◽  
Test Data ◽  
Analytical Method ◽  
Power Loss ◽  
Large Scale ◽  
Prediction Method ◽  
Computer Programs ◽  
Spur Gear ◽  
Spur Gears ◽  
Gear Efficiency

A spur gear efficiency prediction method previously developed by the authors was extended to include power loss of planetary gearsets. A friction coefficient model was developed for MIL-L-7808 oill based on disk machine data. This, combined with the recent capability of predicting losses in spur gears of nonstandard proportions, allows the calculation of power loss for complete aircraft gearboxes that utilize spur gears. The method was applied to the T56/501 turboprop gearbox and compared with measured test data. Bearing losses were calculated with large-scale computer programs. Breakdowns of the gearbox losses point out areas for possible improvement.

An Experimental Study of Influence of Lubrication Methods on Efficiency and Contact Fatigue Life of Spur Gears

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
J. Moss ◽  
A. Kahraman ◽  
C. Wink
Keyword(s):  
Experimental Study ◽  
Power Loss ◽  
Contact Fatigue ◽  
Spur Gear ◽  
Spur Gears ◽  
Power Losses ◽  
Contact Fatigue Life ◽  
The Impact ◽  
Jet Velocities ◽  
Lubrication Conditions

An experimental investigation of spur gear behavior was conducted with the aim of quantifying the impact of lubrication methods and conditions on the power losses and contact fatigue lives. Variations of dip and jet-lubrication are defined, and these behaviors were observed as a function of the lubrication conditions. Both types of measurements were performed using the same type of back-to-back test machines and the same spur gear test articles such that their evaluations can be correlated. Power loss experiments were performed under both loaded and unloaded conditions to determine both load-independent (spin) and load-dependent (mechanical) losses. Sets of long-cycle contact fatigue experiments were performed under the same lubrication conditions to determine macropitting lives in a statistically meaningful manner. Results indicate that the spin power losses are impacted by the lubrication method significantly while the mechanical losses are not influenced. Contact fatigue lives from jet-lubricated tests are comparable to those under dip-lubricated conditions ones as long as jet velocities are sufficient.

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