A Kinematics and Power Flow Analysis Methodology for Automatic Transmission Planetary Gear Trains

2004 ◽  
Vol 126 (6) ◽  
pp. 1071-1081 ◽  
Author(s):  
A. Kahraman ◽  
H. Ligata ◽  
K. Kienzle ◽  
D. M. Zini

A generalized formulation for analyzing speeds and forces of the gear components of planetary automatic transmissions is proposed. The formulation is capable of analyzing any typical one-degree-of-freedom automatic transmission gear train containing any number of simple, compound or complex-compound planetary gear sets. The formulation consists of three components: a kinematic analysis formulation to compute rotational speeds of gears and carriers, a gear ratio and kinematic configuration search algorithm, and a power flow analysis formulation. The kinematics component computes rotational speeds of gears and carriers. Given the type and number of planetary gear sets, the search algorithm determines all possible kinematic configurations and gear tooth count combinations that result in a required set of gear ratios while eliminating all kinematic redundancies and unfavorable clutching sequences. The third component, the power-flow analysis formulation, performs a complete static force (power-flow) analysis to determine all gear and bearing forces and moments, and clutch and connection torque values. A five-speed transmission example is considered to highlight the capabilities of the proposed formulation.

Author(s):  
A. Kahraman ◽  
K. Kienzle ◽  
D. M. Zini

A generalized formulation for analyzing speeds and forces of the gear components of planetary automatic transmissions is proposed. The formulation is capable of analyzing any typical one-degree-of-freedom automatic transmission gear train containing any number of simple, compound or complex-compound planetary gear sets. It consists of three components: a kinematic analysis formulation, a gear ratio and kinematic configuration search algorithm, and a power flow analysis formulation. The kinematics module computes rotational speeds of gears and carriers. Given the type and number of planetary gear sets, the search module determines all possible kinematic configurations and gear tooth count combinations that result in a required set of gear ratios while eliminating all kinematic redundancies and unfavorable clutching sequences. The third component, the power-flow analysis formulation, performs a complete static force (power flow) analysis to determine all gear and bearing forces, and clutch and connection torque values. A five-speed transmission example is considered to highlight the capabilities of the proposed formulation.


2018 ◽  
Vol 10 (8) ◽  
pp. 168781401879410 ◽  
Author(s):  
Yahui Cui ◽  
Jing Gao ◽  
Xiaomin Ji ◽  
Xintao Zhou ◽  
Haitao Yan

The concept of multi-attribute topological graph is proposed in this article to represent the characteristics of both structure and state for typical one-degree-of-freedom planar spur closed planetary gear trains. This method is well applied in power flow analysis and provides a graphical view for the types, values, directions, and transmission relationship of power flow, especially for the recirculation power representation. Furthermore, a template model of multi-attribute topological graph for closed planetary gear trains is also presented, which would be helpful to the multi-attribute topological graph generation for some certain types of closed planetary gear trains just by changing symbols in the template model. A corresponding software is also developed to make the analysis process more convenient. By inputting different parameters, the different visual results can be obtained automatically, thus benefiting engineers in conceptual design.


Author(s):  
Essam L. Esmail ◽  
Hamed A. Hussen

A new methodology for constructing multi-axes nomographs is developed. Using this methodology, a unified general formulation for computing velocities and torques of any epicyclic-type transmission train is presented. To demonstrate and apply the new technique, Ravigneaux automatic transmission is used to show how the velocities, the torques and the power flow through the train can be simultaneously visualized on a single nomograph. The present methodology is judged to be more efficient than other methods and than the three-ax nomograph methodology. Using this methodology an innovative design of two-input transmission with only one electric motor/generator (MG) and without any rotating clutches is presented. The proposed design provides some of the benefits and flexibility of a power-split design by using the conventionally available Ravigneaux gear train in a simpler mechanical layout which makes the design compact, mechanically simple, and operationally flexible.


Author(s):  
L. Saggere ◽  
D. G. Olson

Abstract After conceptual design and dimensional synthesis of a compound epicyclic gear train (EGT), its performance evaluation involves kinematic analysis, force analysis, torque analysis, and power-flow analysis. In recent years, graph theory has proven to be a powerful symbolic representation for design of mechanisms. Application of graph theory for the topological representation and kinematic analysis of EGTs is quite well established. However, graph theory based methods for power-flow and force analysis lack certain features, making them unsuitable or difficult to implement in a general purpose program for automatic design of EGTs. The traditional approach has been to perform force and torque analysis first, and then use the results to perform power-flow analysis. This paper presents a novel, systematic approach in which power-flow analysis is performed first, and then the results are used to determine the inter-link forces in epicyclic spur-gear trains. This method is based only on the graph of the gear-train and the angular velocities of the elements, and hence, is more suitable for automatic computation, simpler to implement in a program, and also avoids requiring the formulation of tedious torque equilibrium equations. A numerical example is presented to illustrate the simplicity and generality of the method.


2015 ◽  
Vol 137 (9) ◽  
Author(s):  
Zeng-Xiong Peng ◽  
Ji-Bin Hu ◽  
Tian-Li Xie ◽  
Chun-Wang Liu

To obtain multiple speed ratios, a synthesis methodology of planetary gear trains (PGTs) with multiple operating degrees-of-freedom (DOFs) is proposed based on the variable structure method. Variable structure of PGT is accomplished by changing the fixed interconnection edge. First, PGTs with two operating DOFs are synthesized with a deduction method based on the relationship between the number of planetary gear sets (PGSs) and number of fixed interconnection edges. Next, connection characteristics of fixed interconnection edges are defined as frequency of utilization to construct original speed ratios of the two operating DOFs schemes. The connection characteristics are then obtained based on the power flow analysis. PGT graph model with connection characteristic is built to provide guidance in the design of varying structure. Finally, multispeed PGTs with multiple operating DOFs are synthesized based on the graph model and lever analogy. A design example for three-PGS PGTs is considered to highlight capabilities of the variable structure method.


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