Measurement of Oil Film Thickness Between W-N Helical Gear Tooth Profiles Using Laser Transmission Method

1990 ◽  
Vol 112 (4) ◽  
pp. 708-711 ◽  
Author(s):  
Yang Ji-Bin ◽  
Qi Yu-Lin ◽  
Chen Chen-Wen
Keyword(s):  
Film Thickness ◽  
Gear Tooth ◽  
Helical Gear ◽  
Spur Gears ◽  
Measuring Apparatus ◽  
Transmission Method ◽  
Helical Gears ◽  
Oil Film ◽  
Measurement Results ◽  
First Time

In this experiment, it was the first time that the center oil film thickness between W-N helical gear tooth profiles has been measured indirectly through measuring the change of gaps of a pair of unloaded involute spur gears mounted on the extended shafts of W-N gear box by means of laser transmission method. During the measurement of every time, it was calibrated separately, so that all errors could be eliminated completely except ones of measuring apparatus. The accuracy of this method has reached 0.1 μm (dynamic) and 0.01 μm (static), respectively. Measurement results were identical with theoretical ones. This method is also suitable for the measurement of center oil film thickness between tooth profiles and deformation of any cylindrical spur and helical gears.

Optimal Design of Modified Cylindrical Gear Based on Minimum Flash Temperature of Tooth Surfaces

2013 ◽  
Vol 655-657 ◽  
pp. 573-577
Author(s):  
Jin Ke Jiang ◽  
Zong De Fang ◽  
Xian Long Peng
Keyword(s):  
Friction Coefficient ◽  
Film Thickness ◽  
Contact Line ◽  
Gear Tooth ◽  
Tooth Surface ◽  
Uniform Grid ◽  
Normal Vector ◽  
Flash Temperature ◽  
Oil Film ◽  
Tooth Surfaces

Considering the gap of the contact line of modified involute cylindrical gears influencing on loads, oil film thickness, the friction coefficient was determined on the basis theory of TCA、 LTCA and EHL. so oil film thickness and friction coefficient corresponded with loads on contact line were dispersed, which was used to computed discrete temperature according to the Blok flash temperature formula. and an approach of modified tooth surface optimum design based on the minimum flash temperature was proposed: the modified tooth surfaces was defined as a sum of theoretical tooth and cubic B-spline fit surface based on the uniform grid points created by double parabolas and a straight line and whose normal vector was deduced, besides, used genetic algorithm to optimize the parameter of curve, and get the best modified gear tooth surfaces. the results shows that oil film is thicker in engaging-out, coefficient of friction is contrary, which is responsible for lower flash temperature in engaging-in, besides the flash temperature has little changes in the single tooth meshing zone, and helical gear has a lower flash temperature than spur gear due to higher overlap ratio.

Design and Static Analysis of an Addendum Modified Helical Gear Tooth

2013 ◽  
Vol 391 ◽  
pp. 132-138 ◽  
Author(s):  
V. Balambica ◽  
T.J. Prabhu ◽  
R. Venkateshbabu ◽  
Er Vishwa Deepak
Keyword(s):  
Gear Tooth ◽  
Helical Gear ◽  
Spur Gears ◽  
Output File ◽  
Analysis Software ◽  
C Language ◽  
Analysis Techniques ◽  
Rotating Machine ◽  
Modeling Software ◽  
C Program

A gear is a rotating machine part having cut teeth, or cogs, which mesh with another toothed part in order to transmit torque. We have several types of gears among which spur gears are used as pinion and gear between parallel shafts.. When the involute portion of the tooth mates with the non-involute portion of the other tooth an undercut is formed. Due to this the mating gear will try to scoop out metal from the interfering portion. In order to avoid undercutting and interference, addendum modification of the gear tooth is carried out. This paper describes about the modeling meshing and the analysis techniques. Effort has been taken to develop the tooth profile involute as well as the fillet region by calculating the co-ordinates using C-language. The output file of the C-program is converted to modeling software PRO/E for 3-D modeling with the help of a coupler software DXF file converter. Those PRO/E models are imported to an analysis software ANSYS for the proposed stress analysis.

Calculation of Wobble From Lead Inspection Data of Gear Teeth With Modifications

1998 ◽  
Author(s):  
Xiaogen Su ◽  
Donald R. Houser
Keyword(s):  
Satisfactory Result ◽  
Spur Gear ◽  
Helical Gear ◽  
Spur Gears ◽  
Helical Gears ◽  
Gear Teeth ◽  
Inspection Data

Abstract The effect of the reference misalignment including eccentricity and wobble on profile and lead inspection traces is discussed. The relative slopes of the lead traces induced by wobble are used to calculate the magnitude of the wobble. The deviation caused by the wobble is removed from the lead inspection results. This method is theoretically ‘exact’ for spur gears and is approximate for helical gears. Real measurement examples show this method produces a good result with a spur gear and a satisfactory result with a helical gear.

Acoustic Emission and Elastohydrodynamic Film Thickness for Meshing of Spur and Helical Gear

2007 ◽  
Author(s):  
R. I. Raja Hamzah ◽  
D. Mba
Keyword(s):  
Acoustic Emission ◽  
Film Thickness ◽  
Experimental Evidence ◽  
Liquid Nitrogen ◽  
Gear Wheel ◽  
Helical Gear ◽  
Operating Conditions ◽  
Asperity Contact ◽  
Helical Gears ◽  
Test Conditions

This paper presents experimental evidence of the correlation between Acoustic Emission (AE) activity and the specific film thickness (λ) for operational spur and helical gears. Whilst recording AE activity for a range of test conditions the specific film thickness was varied during operation by spraying liquid nitrogen onto the rotating gear wheel. It was noted that the AE activity reduced significantly as the theoretically estimated specific film thickness increased. It is concluded that the measurements of AE activity may offer an opportunity to quantify the level of asperity contact for meshing gears under a range of operating conditions.

Laser Holographic Measurement of Tooth Flank Form of Cylindrical Involute Gear: Part 2 — For Helical Gear Tooth

1992 ◽  
Author(s):  
H. Fujio ◽  
A. Kubo ◽  
S. Tochimoto ◽  
H. Hanaki ◽  
S. Saitoh ◽  
...  
Keyword(s):  
Gear Tooth ◽  
Measuring Method ◽  
Helix Angle ◽  
Helical Gear ◽  
Helical Gears ◽  
Error Surface ◽  
Tooth Flank ◽  
Form Deviation ◽  
Laser Holography ◽  
Holographic Measurement

Abstract The interferometry using laser holography is applied to measure the form deviation of tooth flank of involute helical gears. One problem of this method is that the increase of helix angle reduces the region of the flank to which the laser beam can irradiate at a same time. To solve this problem, following method is developed: The objective tooth flank is divided into some regions, and the interferometry measurement is worked out for each region. The measured values for the form deviation of each region of the tooth flank are transformed to the values on the plane of action of this gear. These values for each region of the tooth flank are then concatenated successively until they result the curved surface for the form deviation of the whole tooth flank of the helical gear. The error surface of the tooth flank of helical gear obtained by this procedure is compared with that of conventional measuring method using contacting stylus.

Study of Transient Elastohydrodynamic Lubrication of Spur Gears under Impact Load

2011 ◽  
Vol 121-126 ◽  
pp. 3506-3509
Author(s):  
You Qiang Wang ◽  
Zhi Cheng He ◽  
Wei Su
Keyword(s):  
Film Thickness ◽  
Impact Load ◽  
Gear Tooth ◽  
Elastohydrodynamic Lubrication ◽  
Spur Gear ◽  
Time Varying ◽  
Spur Gears ◽  
Lubrication Film ◽  
The Impact ◽  
Contact Parameters

Spur gear contacts experience a number of time-varying contact parameters including the load, surface velocities, radii of curvature, and slide-to-roll ratio. It is very hard to obtain transient elastohydrodynamic lubrication (EHL) solution of spur gears. In this study, a transient EHL model of involute spur gear tooth contacts is proposed. A full transient EHL solution of involute spur gear under impact load is obtained by utilizing the multigrid technique. The influences of impact load on the EHL of spur gear are analyzed in the paper. The numerical results show that the approach impact load has strong transient influence on the oil film thickness and pressure distribution between contact zones. The impact load may lead to instantaneous lubrication film deterioration between contact teeth of involute spur gears.

Analytical Model for the Heat Transfer in Impingement Cooled Spur Gears

2020 ◽  
Author(s):  
Christian Kromer ◽  
Felix C. von Plehwe ◽  
Marc C. Keller ◽  
Corina Schwitzke ◽  
Hans-Jörg Bauer
Keyword(s):  
Heat Transfer ◽  
Analytical Model ◽  
Gear Tooth ◽  
Gear Train ◽  
Spur Gears ◽  
Impingement Cooling ◽  
Oil Film ◽  
Low Pressure Turbine ◽  
Tooth Flank ◽  
Oil Jet

Abstract The geared turbofan is a promising concept for civil aircraft jet engines. With the introduction of a gearbox between the low-pressure turbine and the fan, both components can rotate at their respective optimum speed. The geared turbofan enables a lower specific fuel consumption as well as jet engine noise reductions. A planetary gear train is usually chosen for the transmission with the sun gear connected to the low-pressure turbine. This high-speed reduction gear train needs to transmit high loads with a high efficiency in limited installation space. To ensure a safe operation of the gear train, the thermal behavior of the gears needs to be understood. The heat generated by the meshing processes is dissipated by oil impingement cooling. While the field of Elastohydrodynamic lubrication yields good results for the heat generation, no validated model for the impingement cooling process is available in literature. In this study, an analytical model is developed and validated against experimental data. First, the surface area of the oil film on the gear tooth flank formed by the impinging oil jet is calculated. Second, the heat transfer from the gear tooth flank to the oil film is determined. The fluid motion is modeled as an oil film that is flung off the gear tooth flank by centrifugal forces. In addition to the film flow, the presented model takes into account the temperature dependence of the viscosity of the oil and the initial oil film height. The effect of a lubrication oil film on the gear tooth flank before the oil jet impinges is included and its effect on the heat transfer is assessed. The analytical model agrees well with experimental results over the entire range of investigated operating conditions. Finally, a discussion on the effect of several assumptions in the derivation of the analytical model is presented. The validated analytical model can be used as an efficient tool for the design of gear trains with impingement cooled spur gears.

Sign in / Sign up

Export Citation Format

Share Document