scholarly journals Corrigendum: About the Gear Efficiency to a Simple Planetary Train

2019 ◽  
Vol 16 (3) ◽  
pp. 115-115
Author(s):  
Florian Ion T. Petrescu ◽  
Antonio Apicella ◽  
Raffaella Aversa ◽  
Relly Victoria V. Petrescu
Keyword(s):  
Gear Efficiency

scholarly journals Worm gear efficiency model considering misalignment in electric power steering systems

2018 ◽  
Vol 9 (1) ◽  
pp. 201-210 ◽  
Author(s):  
Seong Han Kim
Keyword(s):  
Electric Power ◽  
Normal Load ◽  
Contact Point ◽  
Normal Pressure ◽  
Worm Gear ◽  
Electric Power Steering ◽  
Friction Coefficients ◽  
Power Steering ◽  
Worm Wheel ◽  
Gear Efficiency

Abstract. This study proposes a worm gear efficiency model considering misalignment in electric power steering systems. A worm gear is used in Column type Electric Power Steering (C-EPS) systems and an Anti-Rattle Spring (ARS) is employed in C-EPS systems in order to prevent rattling when the vehicle goes on a bumpy road. This ARS plays a role of preventing rattling by applying preload to one end of the worm shaft but it also generates undesirable friction by causing misalignment of the worm shaft. In order to propose the worm gear efficiency model considering misalignment, geometrical and tribological analyses were performed in this study. For geometrical analysis, normal load on gear teeth was calculated using output torque, pitch diameter of worm wheel, lead angle and normal pressure angle and this normal load was converted to normal pressure at the contact point. Contact points between the tooth flanks of the worm and worm wheel were obtained by mathematically analyzing the geometry, and Hertz's theory was employed in order to calculate contact area at the contact point. Finally, misalignment by an ARS was also considered into the geometry. Friction coefficients between the tooth flanks were also researched in this study. A pin-on-disk type tribometer was set up to measure friction coefficients and friction coefficients at all conditions were measured by the tribometer. In order to validate the worm gear efficiency model, a worm gear was prepared and the efficiency of the worm gear was predicted by the model. As the final procedure of the study, a worm gear efficiency measurement system was set and the efficiency of the worm gear was measured and the results were compared with the predicted results. The efficiency considering misalignment gives more accurate results than the efficiency without misalignment.

Effect of assembly errors in back-to-back gear efficiency testing

2014 ◽  
pp. 784-793 ◽  
Author(s):  
M. Andersson ◽  
M. Sosa ◽  
S. Sjöberg ◽  
U. Olofsson
Keyword(s):  
Gear Efficiency

scholarly journals Bearing Power Losses with Water-Containing Gear Fluids

Lubricants ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 5 ◽  
Author(s):  
Mustafa Yilmaz ◽  
Thomas Lohner ◽  
Klaus Michaelis ◽  
Karsten Stahl
Keyword(s):  
Power Loss ◽  
Stribeck Curve ◽  
Detailed Knowledge ◽  
Power Losses ◽  
Test Rig ◽  
Load Bearing ◽  
Gear Efficiency ◽  
Efficiency Test ◽  
Typical Calculation ◽  
Calculation Procedures

Lubricants have a large influence on gearbox power losses. Recent investigations at a gear efficiency test rig have shown the high potential of water-containing gear fluids in drastically reducing load-dependent gear losses and temperatures. In this study, the bearing power losses with water-containing gear fluids were evaluated at a specific bearing power loss test rig explicitly and compared with mineral and polyalphaolefine oils. For all investigated lubricants, a Stribeck curve behavior of the load-dependent losses is observed. The water-containing gear fluids demonstrate lower no-load bearing losses and higher load-dependent bearing losses at higher rotational speeds. The comparison of measured bearing losses with typical calculation procedures showe partially large differences. The results underline the importance of having detailed knowledge of bearing losses when evaluating gear losses in gearboxes.

Two-Stage Precession Type Gear: Design, Geometric and Kinematic Analysis

2017 ◽  
Author(s):  
Łukasz Macyszyn ◽  
Adam Myszkowski ◽  
Roman Staniek ◽  
Stanisław Pabiszczak
Keyword(s):  
Gear Ratio ◽  
Original Method ◽  
Two Stage ◽  
Precession Angle ◽  
Gear Design ◽  
The Face ◽  
Gear Efficiency ◽  
Rotary Speed ◽  
Gear Wheels ◽  
Neodymium Magnets

The paper presents the theoretical bases, design and the principle of operation of two-stage precession type transmission with face meshing. Description and the principle of forming the face meshing which is modified by the original method have been shown as well. Dimensional relations between particular components of the gears are established and the analysis of optimal gear ratio, depending on the number of teeth or magnets on the circumferences of meshing gear wheels is also provided in the paper. For further analysis four prototypes of mechanical precession transmission with face meshing were designed, built and investigated. Those prototypes present different sizes, reduction ratio and precession angle. Investigations, described in the paper, helped to determine the gear efficiency rate as well as the maximal torque that could be transferred for the given rotary speed. This paper presents also the conception of the design of a novel double stage precession magnetic gear with face neodymium magnets. The results of the initial studies are the background of the further research in the field of magnetic precession type transmission.

scholarly journals About the Gear Efficiency to a Simple Planetary Train

2016 ◽  
Vol 13 (12) ◽  
pp. 1428-1436 ◽  
Author(s):  
Relly Victoria V. Petrescu ◽  
Raffaella Aversa ◽  
Antonio Apicella ◽  
MirMilad Mirsayar ◽  
Florian Ion T. Petrescu
Keyword(s):  
Gear Efficiency

scholarly journals Estimating efficiency of survey and commercial trawl gears from comparisons of catch-ratios

2017 ◽  
Vol 74 (5) ◽  
pp. 1448-1457 ◽  
Author(s):  
Nicola D. Walker ◽  
David L. Maxwell ◽  
Will J. F. Le Quesne ◽  
Simon Jennings
Keyword(s):  
Monitoring Program ◽  
Data File ◽  
Species Group ◽  
Additive Models ◽  
Reference Points ◽  
Target Species ◽  
Commercial Catch ◽  
The North ◽  
Gear Efficiency ◽  
Species Groups

Abstract Assumptions about gear efficiency and catchability influence estimates of abundance, mortality, reference points and catch potential. Despite the need to better quantify fishing effects on some target species and on many non-target species taken as bycatch, there are few gear efficiency estimates for some of the most widely deployed towed fishing gears in the northeast Atlantic. Here, we develop a method that applies generalised additive models to catch-at-length data from trawl surveys and a commercial catch and discard monitoring program in the North Sea to estimate catch-ratios. We then rescale these catch-ratios and fit relationships to estimate gear efficiency. When catches of individuals by species were too low to enable species-specific estimates, gear efficiency was estimated for species-groups. Gear efficiency (and associated uncertainty) at length was ultimately estimated for 75 species, seven species-groups and for up to six types of trawl gear per species or species-group. Results are illustrated for dab (Limanda limanda), grey gurnard (Eutrigula gurnardus) and thornback ray (Raja clavata), two common non-target species and a depleted elasmobranch. All estimates of gear efficiency and uncertainty, by length, species, species-group and gear, are made available in a supplementary data file.

scholarly journals Experimental Investigation of Spur Gear Efficiency

2007 ◽  
Author(s):  
T. T. Petry-Johnson ◽  
A. Kahraman ◽  
N. E. Anderson ◽  
D. R. Chase
Keyword(s):  
Surface Roughness ◽  
High Speed ◽  
Mechanical Load ◽  
Spur Gear ◽  
Total Power ◽  
Test Machine ◽  
Gear Mesh ◽  
Test Methodology ◽  
Gear Efficiency ◽  
Accuracy And Repeatability

In this study, a test methodology was developed for measurement of spur gear efficiency under high-speed and variable torque conditions. A power-circulating test machine was designed to operate at speeds to 10,000 rpm and transmitted power levels to 700 kW. A precision torque measurement system was implemented and its accuracy and repeatability in measuring torque loss in the power loop was demonstrated. Tests were conducted on gears with two values of module, and two surface roughness levels, operating in a dry sump jet-lubrication environment with three different gear lubricants. These tests were used to quantify the influence of these parameters on load-dependent (mechanical), load-independent (spin), and total power loss. Trends in mechanical gear mesh efficiency and total gearbox efficiency were discussed in terms of rotational speed and transmitted torque. Finally, recommendations were made for the design of spur gear pairs, surface roughness, and lubricant selection for improved efficiency.

Lubricant Influence on Gear Efficiency

2009 ◽  
Author(s):  
Klaus Michaelis ◽  
Bernd-Robert Ho¨hn ◽  
Andreas Doleschel
Keyword(s):  
Power Loss ◽  
Energy Savings ◽  
Operating Conditions ◽  
Test Method ◽  
Test Results ◽  
Additive Package ◽  
Mean Values ◽  
Base Oil ◽  
Power Loss Reduction ◽  
Gear Efficiency

Power loss in a transmission is strongly related to the properties of the gear lubricant. Viscosity of the lubricant determines the no-load splash and churning losses. The losses in the EHD regime depend on the base oil type. In the boundary and mixed lubrication regime losses are mainly related to the chemical composition of the additive system. A test method was developed to evaluate the frictional properties of candidate transmission lubricants in relation to a mineral reference oil ISO VG 100 with a typical sulphur-phosphorus additive package. The test results can be expressed in simple correlation factors for no-load, EHD and boundary lubrication conditions, in comparative steady-state temperature development for given mean values of operating conditions, and in a ranking scale of different candidates. For a more detailed analysis of the expected power loss in a transmission in practice the results of the efficiency test can be introduced into an equation for the mean coefficient of gear friction for the respective oil. Thus the test results can be applied to any gear in practice at any operating conditions for any gear geometry. Examples of the influence of viscosity, base oil and additive type on the frictional behavior of gear lubricants and their effect on power loss reduction and energy savings in a gearbox are discussed.

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