A New Method to Measure Planet Load Sharing and Sun Gear Radial Orbit of Planetary Gear Sets

2011 ◽  
Author(s):  
B. Boguski ◽  
A. Kahraman ◽  
T. Nishino
Keyword(s):  
Measurement Method ◽  
Planetary Gear ◽  
Load Sharing ◽  
Measurement Methods ◽  
New Method ◽  
Strain Gauges ◽  
Position Errors ◽  
Radial Orbit ◽  
Planetary Gear Sets ◽  
Planet Gear

A new method of measuring planet load sharing of planetary gear sets is proposed in this paper. The method uses strain gauges mounted directly on the planet pins to measure continuously the loads carried by the planets assembled in a fixed carrier. Example 4-planet gear sets of different planet phasing conditions are procured and tested with a family of planet carriers having various levels and combinations of planet pinhole position errors to demonstrate the measurement method. As the radial floating capability of the central members is critical to planet-to-planet load sharing, a companion proximity-based measurement system is also implemented to measure the radial motions of the floating sun gear under various planet phasing and carrier pinhole error conditions. It is shown that both measurement methods are effective in characterizing the loads carried by planets.

A New Method to Measure Planet Load Sharing and Sun Gear Radial Orbit of Planetary Gear Sets

2012 ◽  
Vol 134 (7) ◽  
Author(s):  
B. Boguski ◽  
A. Kahraman ◽  
T. Nishino
Keyword(s):  
Measurement Method ◽  
Planetary Gear ◽  
Load Sharing ◽  
Measurement Methods ◽  
New Method ◽  
Strain Gauges ◽  
Position Errors ◽  
Radial Orbit ◽  
Planetary Gear Sets ◽  
Planet Gear

A new method of measuring planet load sharing of planetary gear sets is proposed in this paper. The method uses strain gauges mounted directly on the planet pins to measure continuously the loads carried by the planets assembled in a fixed carrier. Example 4-planet gear sets of different planet phasing conditions are procured and tested with a family of planet carriers having various levels and combinations of planet pinhole position errors to demonstrate the measurement method. As the radial floating capability of the central members is critical to planet-to-planet load sharing, a companion proximity-probe based measurement system is also implemented to measure the radial motions of the floating sun gear under various planet phasing and carrier pinhole error conditions. It is shown that both measurement methods are effective in characterizing the loads carried by planets.

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.

Influence of Gear Rim Deflections on Planetary Gear Set Behavior

2009 ◽  
Author(s):  
H. Ligata ◽  
A. Kahraman ◽  
A. Singh
Keyword(s):  
Deformable Body ◽  
Planetary Gear ◽  
Load Sharing ◽  
Ring Gear ◽  
Hoop Strain ◽  
Position Errors ◽  
Study Results ◽  
Planetary Gear Sets ◽  
Support Conditions ◽  
Major Factors

In this study, results of an experimental and theoretical study on the influence of rim thickness of the ring gear on rim deflections and stresses, and planet load sharing of a planetary gear set are presented. Experimental study consists of measurement of ring gear deflections and strains for gear sets having various numbers of planets, different ring gear rim thicknesses as well as various carrier pin hole position errors. Root and hoop strain gauges and displacement probes are placed at various locations so that the variations due to external splines of the stationary ring gear can also be quantified. A family of quasi-static deformable-body models of the test gear planetary gear sets is developed to simulate the experiments. The predictions and the measurements are compared to assess the accuracy of the models within wide ranges of parameters. Influence of rim thickness on ring gear stresses and deflections and planet load sharing are quantified together with the interactions between the rim flexibility and the spline conditions. The results from this study confirm that the ring gear deflections and the ring gear support conditions must be included in the design process as one of the major factors.

A Closed-Form Planet Load Sharing Formulation for Planetary Gear Sets Using a Translational Analogy

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
H. Ligata ◽  
A. Kahraman ◽  
A. Singh
Keyword(s):  
Closed Form ◽  
Discrete Model ◽  
Deformable Body ◽  
Planetary Gear ◽  
Load Sharing ◽  
Position Errors ◽  
Model Predictions ◽  
Planetary Gear Sets ◽  
Torsional System

A simplified discrete model to predict load sharing among the planets of a planetary gear set having carrier planet position errors is presented in this study. The model proposes a translational representation of the torsional system and includes any number of planets positioned at any spacing configuration. The discrete model predictions are validated by comparing them to (i) the predictions of a deformable-body planetary gear set model and (ii) planet load sharing measurements from planetary gear sets having three to six planets. A set of closed-form planet load sharing formulas are derived from the discrete model for gear sets having equally-spaced planets for conditions when all of the planets are loaded. These formulas allow, in an accurate and direct way, calculation of planet loads as a function of position errors associated with each planet.

Influence of Ring Gear Rim Thickness on Planetary Gear Set Behavior

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
A. Kahraman ◽  
H. Ligata ◽  
A. Singh
Keyword(s):  
Deformable Body ◽  
Planetary Gear ◽  
Load Sharing ◽  
Ring Gear ◽  
Hoop Strain ◽  
Position Errors ◽  
Study Results ◽  
Planetary Gear Sets ◽  
Support Conditions ◽  
Major Factors

In this study, results of an experimental and theoretical study on the influence of rim thickness of the ring gear on rim deflections and stresses and planet load sharing of a planetary gear set are presented. The experimental study consists of measurement of ring gear deflections and strains for gear sets having various numbers of planets, different ring gear rim thicknesses, as well as various carrier pinhole position errors. Root and hoop strain gauges and displacement probes are placed at various locations so that the variations due to external splines of the stationary ring gear can also be quantified. A family of quasistatic deformable-body models of the test planetary gear sets is developed to simulate the experiments. The predictions and measurements are compared with the assessment of the accuracy of the models within wide ranges of parameters. The influence of rim thickness on ring gear stresses and deflections and planet load sharing are quantified together with the interactions between the rim flexibility and the spline conditions. The results from this study confirm that the ring gear deflections and the ring gear support conditions must be included in the design process as one of the major factors.

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

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
N. Leque ◽  
A. 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 (3D) 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 the three types of manufacturing errors, namely, constant errors such as carrier 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.

Pinion Assembly Strategies for Planetary Gear Sets

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Pei-en Feng ◽  
Yuxuan Qi ◽  
Qingying Qiu
Keyword(s):  
Mathematical Model ◽  
Planetary Gear ◽  
Load Sharing ◽  
Assembly Sequence ◽  
Statistical Calculation ◽  
Phase Rule ◽  
Position Errors ◽  
Planetary Gear Sets ◽  
Sharing Behavior ◽  
Sequence Rules

Previous works illustrate that the orientation of pinion run-out errors has strong effect on the load sharing behavior of floating planetary gear sets. To minimize the inequality of load sharing, an in-phase rule for assembling pinions is recommended by other researchers, while a theoretical proof is still lacking. In this paper, not only the orientation but also the assembly sequence of the pinions is under scrutiny. A generalized mathematical model is developed in order to study the best load sharing conditions and floating gear sets with 4-6 pinions are specially treated. Through statistical calculation, several pinion sequence rules and orientation rules are extracted. By numerical simulation, four different pinion assembly strategies, which originate from the combinations of the existing rules and methods, are compared with each other. The most effective assembly strategies for systems with 4-6 pinions are proposed. The statistical analysis indicates that the proposed strategies significantly improve the load sharing behavior if only pinion run-out errors are considered and retain their effectiveness when pinhole position errors and tooth thickness errors are introduced as interference factors.

Dynamical load sharing behaviors of heavy load planetary gear system with multi-floating components

2018 ◽  
Vol 09 (01) ◽  
pp. 1850005 ◽  
Author(s):  
Xiangyang Xu ◽  
Tianhong Luo ◽  
Jiayuan Luo ◽  
Xia Hua ◽  
Reza Langari
Keyword(s):  
Planetary Gear ◽  
Load Sharing ◽  
External Input ◽  
Gear System ◽  
Central Component ◽  
Heavy Load ◽  
Position Errors ◽  
Planet Gear ◽  
Planetary Gear System ◽  
Input Load

To investigate the dynamical load sharing behaviors of multi-floating components in the heavy load planetary gear system, a multi-floating planetary gear system that includes a floating central component and a quasi-floating planet flexible supporting pin is employed. Then a 21 degree of freedom lumped parameters dynamical model of this system is presented to study the dynamical load sharing behaviors. Some influencing factors, such as supporting stiffness, positions error of sun or carrier, and external input load are analyzed on the dynamical load sharing of the planetary gear system with multi-floating components. The results demonstrate that the load sharing condition of the system is best when both the sun gear and planet gears are multi-floating at the same time. When the planet gear position errors remain constant, reducing the flexible pin stiffness of planet gear or increasing external input load can effectively improve the load sharing. These conclusions are verified by the relevant experiments.

Cross Calibration by FFT Equalization

1997 ◽  
Vol 119 (2) ◽  
pp. 236-242 ◽  
Author(s):  
K. Peleg
Keyword(s):  
Measurement Method ◽  
Functional Relationship ◽  
Measurement Methods ◽  
New Method ◽  
Measurement Systems ◽  
True Value ◽  
Calibration Problem ◽  
Regression Techniques ◽  
The Cross ◽  
Cross Calibration

The classical calibration problem is primarily concerned with comparing an approximate measurement method with a very precise one. Frequently, both measurement methods are very noisy, so we cannot regard either method as giving the true value of the quantity being measured. Sometimes, it is desired to replace a destructive or slow measurement method, by a noninvasive, faster or less expensive one. The simplest solution is to cross calibrate one measurement method in terms of the other. The common practice is to use regression models, as cross calibration formulas. However, such models do not attempt to discriminate between the clutter and the true functional relationship between the cross calibrated measurement methods. A new approach is proposed, based on minimizing the sum of squares of the differences between the absolute values of the Fast Fourier Transform (FFT) series, derived from the readings of the cross calibrated measurement methods. The line taken is illustrated by cross calibration examples of simulated linear and nonlinear measurement systems, with various levels of additive noise, wherein the new method is compared to the classical regression techniques. It is shown, that the new method can discover better the true functional relationship between two measurement systems, which is occluded by the noise.

The Research on Natural Characteristic and Eigensensitivity of Ravingneaux Compound Planetary Gear Sets

2013 ◽  
Vol 446-447 ◽  
pp. 590-596
Author(s):  
Bo Qian ◽  
Shi Jing Wu
Keyword(s):  
Natural Frequency ◽  
Planetary Gear ◽  
Torsional Stiffness ◽  
Ring Gear ◽  
Vibration Model ◽  
Planetary Gear Sets ◽  
Planet Gear ◽  
Natural Characteristic ◽  
Gear Ring ◽  
The Moment

The dynamic model of Ravingneaux compound planetary gear sets has been built. Then the Natural frequency and vibration model have been solved in the Ravingneaux compound planetary gear sets. The eigensensitivity to parameters have been researched based on the dynamical model. The varying trend of natural frequency according to the varying of parameters have been researched, which include gear mass (sun gear, ring gear , or planet gear), the moment of inertia of gears, the support stiffness , the torsional stiffness.

Sign in / Sign up

Export Citation Format

Share Document