A Numerical Approach to Calculation of Load Sharing in Planetary Gear Drives

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Alfred N. Montestruc
Keyword(s):  
Planetary Gear ◽  
Load Sharing ◽  
Numerical Approach ◽  
Design Tolerance ◽  
Epicyclic Gear ◽  
The Subject ◽  
Gear Drives ◽  
Relationship Of ◽  
Floating Systems ◽  
Exact Relationship

In AGMA 6123-B06 [2006, “Design Manual for Enclosed Epicyclic Gear Drives,” ANSI/AGMA Paper No. 6123-B06], a specific table is given for estimation of the planet load share factor Kγ, as it is termed in that publication; that table is vague as to the exact relationship of tolerance and load to the value of Kγ. Others have done significant works on the subject of load sharing among planets; a brief review of that work is presented. This work calculates a useful value of Kγ directly from design tolerance values and the torque applied to the carrier, and other factors showing how this can be done. This formulation is designed explicitly for nonfloating systems, but may be adaptable to floating systems. The use of flexible planet pins to improve load sharing is discussed. In addition, treating Kγ as a constant with respect to torque for a given planetary design is shown to be inaccurate.

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.

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.

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.

Numerical and Experimental Analysis of Flexible Pin Mechanisms for Load Balancing in Planetary Gear Drives

2013 ◽  
Author(s):  
Hsiang-Yu Yeh ◽  
Shyi-Jeng Tsai ◽  
Yuan-Yi Yu
Keyword(s):  
Numerical Analysis ◽  
Load Balancing ◽  
Experimental Analysis ◽  
Planetary Gear ◽  
Load Sharing ◽  
Design Parameters ◽  
Sufficient Information ◽  
Gear Drives ◽  
Important Design ◽  
Novel Design

Load balancing mechanism is an important design for planetary gear drives. Among the well-known designs the flexible pin mechanism has advantage for even load sharing among more than three planet gears. However, there is no sufficient information about how to design such mechanisms. The goal of the paper is to propose an analysis approach of flexible pin mechanisms for planetary gear drives numerically and experimentally. Two types of flexible pin mechanisms are analyzed in the study, a conventional design and a novel design. Numerical analysis is carried out by software KISSsoft and FEM to evaluate the influence of the design parameters of flexible pin mechanism on the deformation performance. An experiment was finally conducted to verify the analysis results.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Light and Sensitivity: Love in the Time of the Daguerreotype

2015 ◽  
Author(s):  
Katarzyna Czeczot
Keyword(s):  
Male Gaze ◽  
History Of Photography ◽  
Sensitive Material ◽  
History Of ◽  
The Subject ◽  
Definition Of ◽  
Relationship Of ◽  
Point Of Departure ◽  
Passive Object

The article deals with the love of Zygmunt Krasiński to Delfina Potocka. The point of departure is the poet's definition of love as looking and reads Krasiński's relationship with his beloved in the context of two phenomena that fascinated him at the time: daguerreotype and magnetism. The invention of the daguerreotype in which the history of photography and spiritism comes together becomes a pretext for the formulation of a new concept of love and the loving subject. In the era of painting the woman was treated as a passive object of the male gaze; photography reverses this scheme of power. Love ceases to be a static relationship of the subject in love and the passive object – the beloved. The philosophy of developing photographs (and invoking phantoms) allows Krasiński - the writing subject to become like a light-sensitive material that reveals the image of the beloved.

Teaching oral requests

Pragmatics ◽  
2013 ◽  
Vol 23 (3) ◽  
pp. 499-517 ◽  
Author(s):  
Eleni Petraki ◽  
Sarah Bayes
Keyword(s):  
Conversation Analysis ◽  
English Language ◽  
Language Teaching ◽  
English Language Teaching ◽  
Cultural Appropriateness ◽  
Language Classroom ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Everyday Communication

Research in English language teaching has highlighted the importance of teaching communication skills in the language classroom. Against the backdrop of extensive research in everyday communication, the goal of this research was to explore whether current discourse analytic research is reflected in the lessons and communication examples of five English language teaching textbooks, by using spoken requests as the subject of investigation. The textbooks were evaluated on five criteria deriving from research on politeness, speech act theory and conversation analysis. These included whether and the extent to which the textbooks discussed the cultural appropriateness of requests, discussed the relationship of requests and other contextual factors, explained pre-sequences and re-requests and provided adequate practice activities. This study found that none of the coursebooks covered all of the criteria and that some coursebooks actually had very inadequate lessons. The results of the textbook analysis demonstrate that teachers using these five coursebooks and designers of future coursebooks must improve their lessons on requests by using pragmatics research and authentic examples as a guide.

Dynamic Modeling of the Torsional Vibration of the Slewing Mechanism of a Hydraulic Excavator

2012 ◽  
Vol 253-255 ◽  
pp. 2102-2106 ◽  
Author(s):  
Xu Juan Yang ◽  
Zong Hua Wu ◽  
Zhao Jun Li ◽  
Gan Wei Cai
Keyword(s):  
Torsional Vibration ◽  
Natural Frequencies ◽  
Planetary Gear ◽  
Moment Of Inertia ◽  
Hydraulic Excavator ◽  
Planetary Gear Trains ◽  
Vibration Model ◽  
Gear Trains ◽  
The Moment ◽  
Relationship Of

A torsional vibration model of the slewing mechanism of a hydraulic excavator is developed to predict its free vibration characteristics with consideration of many fundamental factors, such as the mesh stiffness of gear pairs, the coupling relationship of a two stage planetary gear trains and the variety of moment of inertia of the input end caused by the motion of work equipment. The natural frequencies are solved using the corresponding eigenvalue problem. Taking the moment of inertia of the input end for example to illustrate the relationship between the natural frequencies of the slewing mechanism and its parameters, based on the simulation results, just the first order frequency varies significantly with the moment of inertia of the input end of the slewing mechanism.

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