Efficiency analysis of multi-speed automatic transmission with planetary gear trains

2017 ◽  
Vol 81 (2-3) ◽  
pp. 163-173 ◽  
Author(s):  
Fuchun Yang ◽  
Yafei Wang
Keyword(s):  
Automatic Transmission ◽  
Planetary Gear ◽  
Efficiency Analysis ◽  
Planetary Gear Trains ◽  
Gear Trains

On the Kinematic and Meshing Efficiency Analysis of Planetary Gear Reducer with Two Ring Gears

2014 ◽  
Vol 575 ◽  
pp. 395-399
Author(s):  
Long Chang Hsieh ◽  
Teu Hsia Chen ◽  
Hsiu Chen Tang
Keyword(s):  
Planetary Gear ◽  
Efficiency Analysis ◽  
Reduction Ratio ◽  
Gear Train ◽  
Planetary Gear Train ◽  
Ratio Equation ◽  
Planetary Gear Trains ◽  
Gear Trains ◽  
High Reduction

Planetary gear trains can be used as the gear reducers with high reduction ratio. This paper focused on the kinematic and meshing efficiency analysis of planetary simple gear reducer with two ring gears. First, the planetary simple gear train with two ring gears is proposed by using different shift coefficients. Then, by referring to the train value equation, the reduction-ratio equation is derived for the design the planetary gear reducer with two ring gears. According to reduction-ratio equation, the planetary gear reducers with two ring gears and having reduction ratios (20, 50, and 100) are synthesized. Then, based on the latent power theorem, the meshing efficiency equation of planetary gear train with two ring gears is derived. According to the meshing efficiency equation, the meshing efficiencies of planetary gear trains with two ring gears are analyzed. In this paper, we conclude: (1) Larger reduction ratio makes less meshing efficiency, and (2) The meshing efficiency of planetary gear reducer with two ring gears is not good.

The Research and Design on the Electric Vehicles’ Centrifugal Automatic Transmission

2014 ◽  
Vol 721 ◽  
pp. 12-15
Author(s):  
Yi Fan
Keyword(s):  
Electric Vehicles ◽  
Optimization Design ◽  
Simple Structure ◽  
Automatic Transmission ◽  
Planetary Gear ◽  
Design Concepts ◽  
Transmission Parameters ◽  
Planetary Gear Trains ◽  
Gear Trains ◽  
Research And Design

Aiming at the deficiencies of the commonly used AMT and DSG structure in the electric vehicles’ transmission, a kind of three-speed automatic transmission structured by the planetary gear trains is designed. It uses the centrifugal components to realize the gear shifting, while using the electromagnetic brake and the motor reversal to realize the reversing. Based on the design concepts proposed, we did some matching calculations on the transmission system of a three-wheel pure electric vehicle, and finally made the optimization design on the driving motor’s selection and transmission parameters. The designed electric vehicle’s centrifugal automatic transmission has the characteristics of simple structure, small size and shifting smoothness, which can not only meet the requirements of the automobile power, but also improve the efficiency of the driving motor.

Power flow and efficiency analysis of multi-flow planetary gear trains

2015 ◽  
Vol 92 ◽  
pp. 86-99 ◽  
Author(s):  
Fuchun Yang ◽  
Jianxiong Feng ◽  
Hongcai Zhang
Keyword(s):  
Power Flow ◽  
Planetary Gear ◽  
Efficiency Analysis ◽  
Planetary Gear Trains ◽  
Gear Trains

Kinematic Analysis of Planetary Gear Trains Based on Topology

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Ming-Fei Gao ◽  
Ji-Bin Hu
Keyword(s):  
Automatic Transmission ◽  
Planetary Gear ◽  
Graph Representation ◽  
Speed Ratio ◽  
Topological Graph ◽  
Planetary Gear Trains ◽  
And Topology ◽  
Conceptual Design Phase ◽  
Gear Trains ◽  
The Relationship

Planetary gear trains (PGTs) are used in automatic transmission to achieve any desired speed ratios. At present, the study on the relationship between speed ratio and topology is not significant. Therefore, this paper focuses on studying the speed ratio based on topology. For this purpose, the graph theory is used to represent PGTs, and a concept of the speed topological graph is introduced. Based on the proposed graph representation, the relationship between the speed ratio and topology is studied. Three types of topological graphs are analyzed, which includes path, tree, and unicyclic graph, and necessary results are presented. The results reveal the relationship between speed ratio and topology, which helps in understanding the PGTs further. The result can help engineers to arrange the clutches and brakes to achieve desired speed ratio during the conceptual design phase, which can greatly improve the design efficiency of PGTs. The presented kinematics analysis method can be extended to analyze multi-input and multi-output planetary transmission.

Investigation of Noise Features of Planetary Gear Trains Based on Human Aural Characteristic

2017 ◽  
Author(s):  
Masao Nakagawa ◽  
Dai Nishida ◽  
Deepak Sah ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama
Keyword(s):  
Gear Tooth ◽  
Structural Complexity ◽  
Planetary Gear ◽  
Transmission Error ◽  
Sound Level ◽  
Tooth Surface ◽  
Surface Error ◽  
Planetary Gear Trains ◽  
Tooth Stiffness ◽  
Gear Trains

Planetary gear trains (PGTs) are widely used in various machines owing to their many advantages. However, they suffer from problems of noise and vibration due to the structural complexity and giving rise to substantial noise, vibration, and harshness with respect to both structures and human users. In this report, the sound level from PGTs is measured in an anechoic chamber based on human aural characteristic, and basic features of sound are investigated. Gear noise is generated by the vibration force due to varying gear tooth stiffness and the vibration force due to tooth surface error, or transmission error (TE). Dynamic TE is considered to be increased because of internal and external meshing. The vibration force due to tooth surface error can be ignored owing to almost perfect tooth surface. A vibration force due to varying tooth stiffness could be a major factor.

A New Technique Based on Loops to Investigate Displacement Isomorphism in Planetary Gear Trains

2002 ◽  
Vol 124 (4) ◽  
pp. 662-675 ◽  
Author(s):  
V. V. N. R. Prasad Raju Pathapati ◽  
A. C. Rao
Keyword(s):  
Graph Isomorphism ◽  
Planetary Gear ◽  
Degree Of Freedom ◽  
Gear Train ◽  
Graph Representation ◽  
Kinematic Structure ◽  
Graph Representations ◽  
Planetary Gear Trains ◽  
Gear Trains ◽  
A New Technique

The most important step in the structural synthesis of planetary gear trains (PGTs) requires the identification of isomorphism (rotational as well as displacement) between the graphs which represent the kinematic structure of planetary gear train. Previously used methods for identifying graph isomorphism yielded incorrect results. Literature review in this area shows there is inconsistency in results from six link, one degree-of-freedom onwards. The purpose of this paper is to present an efficient methodology through the use of Loop concept and Hamming number concept to detect displacement and rotational isomorphism in PGTs in an unambiguous way. New invariants for rotational graphs and displacement graphs called geared chain hamming strings and geared chain loop hamming strings are developed respectively to identify rotational and displacement isomorphism. This paper also presents a procedure to redraw conventional graph representation that not only clarifies the kinematic structure of a PGT but also averts the problem of pseudo isomorphism. Finally a thorough analysis of existing methods is carried out using the proposed technique and the results in the category of six links one degree-of-freedom are established and an Atlas comprises of graph representations in conventional form as well as in new form is presented.

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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