An Approach for Analysis of Load Sharing in Planetary Gear Drives With a Floating Sun Gear

2011 ◽  
Author(s):  
Shyi-Jeng Tsai ◽  
Siang-Yu Ye ◽  
Guan-Lin Huang
Keyword(s):  
Planetary Gear ◽  
Load Sharing ◽  
The Sun ◽  
Mesh Stiffness ◽  
Stiffness Model ◽  
Manufacturing Errors ◽  
Tooth Stiffness ◽  
Gear Geometry ◽  
Gear Drives ◽  
Acceptable Agreement

The goal of the paper is to propose an approach for analysis of load sharing in the planetary gear drives with a floating sun gear based on a stiffness model for multiple gear-pair contact under consideration of the mesh stiffness of the engaged teeth, as well as the tooth gaps due to manufacturing errors and deviated position of the sun gear. The tooth stiffness of gears is expressed analytically considering the bending deflection and the contact deformation. The relations for tooth gaps due to various errors are derived from the mesh relations of gears based on the exact involute gear geometry. The balanced position of the floating sun gear is solved iteratively by using the load equilibrium conditions and the shared loads at the corresponding position of the sun gear. Finally some numerical examples are illustrated. The results calculated by the proposed approach have, an acceptable agreement with those by using FEM.

A Three-Dimensional Load Sharing Model of Planetary Gear Sets Having Manufacturing Errors

2015 ◽  
Author(s):  
Nicholas D. Leque ◽  
Ahmet Kahraman
Keyword(s):  
Three Dimensional ◽  
Planetary Gear ◽  
Load Sharing ◽  
Distribution Model ◽  
Gear Mesh ◽  
Position Errors ◽  
Proposed Model ◽  
Manufacturing Errors ◽  
Manufacturing Tolerancing ◽  
Planetary Gear Sets

Planet-to-planet load sharing is a major design and manufacturing tolerancing issue in planetary gear sets. Planetary gear sets are advantageous over their countershaft alternatives in many aspects, provided that each planet branch carries a reasonable, preferably equal, share of the torque transmitted. In practice, the load shared among the planets is typically not equal due to the presence of various manufacturing errors. This study aims at enhancing the models for planet load sharing through a three-dimensional formulation of N-planet helical planetary gear sets. Apart from previous models, the proposed model employs a gear mesh load distribution model to capture load and time dependency of the gear meshes iteratively. It includes all three types of manufacturing errors, namely constant errors such as planet pinhole position errors and pinhole diameter errors, constant but assembly dependent errors such as nominal planet tooth thickness errors, planet bore diameter errors, and rotation and assembly dependent errors such as gear eccentricities and run-outs. At the end, the model is used to show combined influence of these errors on planet load sharing to aid designers on how to account for manufacturing tolerances in the design of the gears of a planetary gear set.

Prediction of Spur Gear Mesh Stiffness Associated with the Tooth Corrosion

2015 ◽  
Vol 799-800 ◽  
pp. 570-575
Author(s):  
Zheng Min Qing Li ◽  
Qing Bin Zhao ◽  
Xiao Zhen Li
Keyword(s):  
Spur Gear ◽  
Mesh Stiffness ◽  
Gear Mesh ◽  
Gear Drive ◽  
Corrosion Effect ◽  
Proposed Model ◽  
Stiffness Model ◽  
The Stability ◽  
Gear Drives ◽  
Gear Mesh Stiffness

In this study, a mesh stiffness model of spur gear drives considering the tooth corrosion effect, which is based on Ishikawa model, is proposed. The fidelity of mesh stiffness based on the proposed model is checked by comparing the result with a benchmark result from the reference and the effect of the tooth corrosion on mesh stiffness is analyzed. The prediction indicates mesh stiffness is insensitive to the tooth corrosion, but this conclusion has a signification for assessing the stability of inherent properties of a spur gear drive when the tooth corrosion is produced.

Use of the Integrated Flexpin Bearing for Improving the Performance of Epicyclical Gear Systems

2003 ◽  
Author(s):  
Gerald P. Fox ◽  
Eric Jallat
Keyword(s):  
Power Density ◽  
Planetary Gear ◽  
Load Sharing ◽  
Contact Patterns ◽  
Length Direction ◽  
Gear Systems ◽  
Planetary Gear System ◽  
Gear Contact ◽  
Gear Drives ◽  
Deflected State

Epicyclical gear systems have typically been equipped with straddle-mounted planetary idlers having pins supported on the input and output sides of the carrier. Torsional wind-up of the carrier, position accuracy of the pins, machining tolerances of the planetary gear system components and bearings clearances can all contribute to a poor load sharing among the planetary idlers as well as misaligned gear contacts in the deflected state. Use of the double-cantilevered flexible pin concept to achieve better load sharing and gear contact patterns among a multiplicity of planetary idlers, has been used to improve reliability in advanced gear drives for many years. The consequence of this practice is to build a compliant epicyclical system that improves power density in the gear length direction because the probability of achieving a properly centered gear contact is increased. The Integrated Flexpin Bearing, the subject of this paper, is capable of achieving additional power density in the gear diameter direction through integration of bearing components, gearing and shafting. This paper presents one designer’s approach to optimizing an Integrated Flexpin Bearing to improve the reliability of an epicyclical gearbox.

Investigation of the Noise and Vibration of Planetary Gear Drives

2003 ◽  
Author(s):  
Yong Chen ◽  
Akira Ishibashi
Keyword(s):  
Phase Difference ◽  
Planetary Gear ◽  
Experimental Results ◽  
The Sun ◽  
Noise And Vibration ◽  
Helical Gears ◽  
Automatic Transmissions ◽  
Gear Drives

With the aim of reducing the operating noise and vibration of the planetary gearsets used in automotive automatic transmissions, a meshing phase difference was applied to the planet gears that mesh with the sun and ring gears. Shaved and hardened helical gears with and without grinding were used as the component gears that were tested under varying rotational speeds and tooth loads. The experimental results clearly showed that planetary gearset noise and vibration were reduced when a meshing phase difference was applied.

An Experimental Study of the Influence of Manufacturing Errors on the Planetary Gear Stresses and Planet Load Sharing

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
H. Ligata ◽  
A. Kahraman ◽  
A. Singh
Keyword(s):  
Experimental Study ◽  
Planetary Gear ◽  
Load Sharing ◽  
Position Errors ◽  
Manufacturing Errors ◽  
Time Histories ◽  
Analysis System ◽  
The Individual ◽  
Torque Values ◽  
The Impact

In this paper, results of an experimental study are presented to describe the impact of certain types of manufacturing errors on gear stresses and the individual planet loads of an n-planet planetary gear set (n=3–6). The experimental setup includes a specialized test apparatus to operate a planetary gear set under typical speed and load conditions and gear sets having tightly controlled intentional manufacturing errors. The instrumentation system consists of multiple strain gauges mounted on the ring gear and a multichannel data collection and analysis system. A method for computing the planet load-sharing factors from root strain-time histories is proposed. Influence of carrier pinhole position errors on gear root stresses is quantified for various error and torque values applied to gear sets having three to six planets. The results clearly indicate that manufacturing errors influence gear stresses and planet load sharing significantly. Gear sets having larger number of planets are more sensitive to manufacturing errors in terms of planet load-sharing behavior.

scholarly journals Load Sharing Behavior of Double-Pinion Planetary Gear Sets Considering Manufacturing Errors

2019 ◽  
Vol 677 ◽  
pp. 052068 ◽  
Author(s):  
Weiqiang Liu ◽  
Junqing Li ◽  
Yanlong Kang ◽  
Yanfang Liu ◽  
Xiangyang Xu ◽  
...  
Keyword(s):  
Planetary Gear ◽  
Load Sharing ◽  
Manufacturing Errors ◽  
Planetary Gear Sets ◽  
Sharing Behavior

scholarly journals Investigation of Dynamic Load Sharing Behavior for Herringbone Planetary Gears considering Multicoupling Manufacturing Errors

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Fei Ren ◽  
Jinchen Ji ◽  
Guofu Luo ◽  
Shaofu Zhao ◽  
Liya Zhao ◽  
...  
Keyword(s):  
Planetary Gear ◽  
Load Sharing ◽  
Gear Train ◽  
Actual Structure ◽  
Lumped Parameter ◽  
Manufacturing Errors ◽  
Main Components ◽  
Gyroscopic Effects ◽  
Profile Errors ◽  
Sharing Behavior

In this study, based on the lumped-parameter theory and the Lagrange approach, a novel and generalized bending-torsional-axial coupled dynamic model for analyzing the load sharing behavior in the herringbone planetary gear train (HPGT) is presented by taking into account the actual structure of herringbone gears, manufacturing errors, time-dependent meshing stiffness, bearing deflections, and gyroscopic effects. The model can be applied to the analysis of the vibration of the HPGT with any number of planets and different types of manufacturing errors in different floating forms. The HPGT equivalent meshing error is analyzed and derived for the tooth profile errors and manufacturing eccentric errors of all components in the HPGT system. By employing the variable-step Runge–Kutta approach to calculate the system dynamic response, in conjunction with the presented calculation approach of the HPGT load sharing coefficient, the relationships among manufacturing errors, component floating, and load sharing are numerically obtained. The effects of the combined errors and single error on the load sharing are, respectively, discussed. Meanwhile, the effects of the support stiffness of the main components in the HPGT system on load sharing behavior are analyzed. The results indicate that manufacturing errors, floating components, and system support stiffness largely influence the load sharing behavior of the HPGT system. The research has a vital guiding significance for the design of the HPGT system.

Research on the Load Sharing Technique and Experimental Validation of NGW Type Planetary Gear Train

2011 ◽  
Vol 86 ◽  
pp. 243-246
Author(s):  
Hai Feng Li ◽  
Bi Bo Fu ◽  
Dan Fu
Keyword(s):  
Experimental Validation ◽  
Planetary Gear ◽  
Load Sharing ◽  
Calculation Model ◽  
Gear Train ◽  
Flexible Structure ◽  
The Sun ◽  
Planetary Gear Train ◽  
Gear Modification ◽  
Selection Of

In order to solve the problem of load sharing in planetary gear train, the design of planetary gear train was described briefly in this paper. The calculation model of type NGW planetary gear train was established. By analyzing the variety of factors, such as selection of bearing clearance, gear modification, using of flexible structure and the sun gear floating design technology, several ways to improve the load sharing of the planetary gear train techniques were obtained, and they were verified by experiments finally.

Influence of Planet Pin Stiffness on Load Sharing in Planetary Gear Drives

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Alfred N. Montestruc
Keyword(s):  
Planetary Gear ◽  
Load Sharing ◽  
Spring Constant ◽  
Spur Gears ◽  
The Finite Element Method ◽  
Specific Design ◽  
The Subject ◽  
Gear Drives ◽  
Gear Meshes ◽  
Spring Constants

Others have done significant work on the subject of load sharing among the planets of planetary gear drives; a brief review of that work is presented. Little work has been done, however, to evaluate the utility of the Hicks type flexible planet pins in improvement of load sharing in a planetary gear stage. This work shows the potential value of the three variations of the Hicks type flexible planet pin used on cantilever carriers, and a new design of a low spring constant planet pin that can be used on straddle type carriers. This is done by the calculation of the spring constants of gear meshes, bearings, and various designs of planet pins using the finite element method for a specific design of a planetary gear stage with spur gears and eight planets. The result showed significant differences. Low spring constant flexible pins are shown to have significantly superior load sharing characteristics.

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