The Selection of a Most Efficient Clutching Sequence Associated With Automatic Transmission Mechanisms

1998 ◽  
Vol 120 (4) ◽  
pp. 514-519 ◽  
Author(s):  
H.-I. Hsieh ◽  
L.-W. Tsai

This paper presents a methodology for the identification of a most promising clutching sequence associated with an epicyclic-type automatic transmission mechanism. First, a methodology for the analysis of torque distribution on the links of an epicyclic gear mechanism is described. Then, the power loss relations associated with various clutching sequences of an epicyclic gear mechanism are derived. Finally, a procedure for the selection of a most efficient clutching sequence associated with a transmission mechanism is developed.

Author(s):  
Hsin-I Hsieh ◽  
Lung-Wen Tsai

Abstract This paper presents a methodology for the identification of a most promising clutching sequence associated with an epicyclic-type automatic transmission mechanism. First, a methodology for the analysis of torque distribution on the links of an epicyclic gear mechanism is described. Then, the power loss relations associated with various clutching sequences of an epicyclic gear mechanism are derived. Finally, a procedure for the selection of a most efficient clutching sequence associated with a transmission mechanism is developed.


Author(s):  
Essam L. Esmail

A new methodology for the enumeration of feasible clutching sequences for a given epicyclic gear mechanism (EGM) is presented using the kinematic nomographs of epicyclic-type transmission mechanisms. From such nomographs, the kinematic characteristics of an epicyclic gear mechanism can be expressed in terms of the gear ratios of its gear pairs. From a single nomograph, the angular velocities for all of the coaxial links can be estimated and compared directly without specifying the exact size of each gear. In addition, the angular velocities can be arranged in a descending sequence without using complicated artificial intelligence or algorithmic techniques. Then, a procedure for the enumeration of feasible clutching sequences associated with a transmission mechanism composed of two or more fundamental gear entities (FGEs) is developed. The reliability of the methodology is established by applying it to two transmission gear trains for which solutions are either fully or partially available in the literature. In the process, an incomplete in the results reported in previous literature is brought to light. And the root cause of this incompleteness is explored. The present methodology is judged to be more efficient for enumeration of all feasible clutching sequences of an EGM.


1996 ◽  
Vol 118 (2) ◽  
pp. 294-299 ◽  
Author(s):  
Hsin-I Hsieh ◽  
Lung-Wen Tsai

A new methodology for the speed ratio analysis of epicyclic-type transmission mechanisms is presented. First, the kinematic characteristics associated with various operation modes of fundamental geared entities are investigated. Then, it is shown that the overall speed ratio of an epicyclic gear mechanism can be expressed in terms of its fundamental geared entities. This method leads to an automated derivation of the speed ratio of an epicyclic-type transmission mechanism without the need of a symbolic manipulation software.


Author(s):  
Hsin-I Hsieh ◽  
Lung-Wen Tsai

Abstract The kinematic characteristics associated with fundamental geared entities are investigated. By decomposing an epicyclic gear mechanism into two subsystems and each subsystem into two subsystems until the lowest level subsystem contains only one fundamental geared entity, the overall speed ratio of an epicyclic gear mechanism can be conveniently expressed in terms of the speed ratios of the fundamental geared entities. The result can be applied for the identification of feasible clutching sequences of a transmission mechanism.


2010 ◽  
Vol 132 (7) ◽  
Author(s):  
Shaker S. Hassan

A new methodology for enumeration of feasible clutching sequences of epicyclic gear mechanism (EGM) composed of two or more fundamental gear entities is presented. The method relies on previous work on algorithmic technique. It improves on existing techniques used for automatic transmission mechanisms in its ability to accurately solve the kinematics of geared mechanisms and estimating their velocity ratios and arranging them in a descending order in a simpler manner without depending on certain gear sizes. Twelve velocity-ratio-relations are derived for any four coaxial links of an epicyclic gear train. These velocity-ratio-relations are three more than the nine relations given in literature. In addition, the velocity ratios can be arranged in a descending sequence without using complicated artificial intelligence technique or complicated computer algorithm. The present methodology is judged to be more efficient for enumeration of all feasible clutching sequences of an EGM.


2014 ◽  
Vol 31 (2) ◽  
pp. 267-282
Author(s):  
Yi-Chang Wu ◽  
Chia-Ho Cheng

Purpose – The analysis of power flow and mechanical efficiency constitutes an important phase in the design and analysis of gear mechanisms. The aim of this paper is to present a systematic procedure for the determination of power flow and mechanical efficiency of epicyclic-type transmission mechanisms. Design/methodology/approach – A novel epicyclic-type in-hub bicycle transmission, which is a split-power type transmission composed of two transmission units and one differential unit, and its clutching sequence table are introduced first. By using the concept of fundamental circuits, the procedure for calculating the angular speed of each link, the ideal torque and power flow of each link, the actual torque and power flow of each link determined by considering gear-mesh losses, and the mechanical efficiency of the transmission mechanism is proposed in a simple, straightforward manner. The mechanical efficiency analysis of epicyclic-type gear mechanisms is largely simplified to overcome tedious and complicated processes of traditionally methods. Findings – An analysis of the mechanical efficiency of a four-speed automotive automatic transmission completed by Hsu and Huang is used as an example to illustrate the utility and validity of the proposed procedure. The power flow and mechanical efficiency of the presented 16-speed in-hub bicycle transmission are computed, and the power recirculation inside the transmission mechanism at each speed is detected based on the power flow diagram. When power recirculation occurs, the mechanical efficiency of the gear mechanism at the related speed reduces. The mechanical efficiency of this in-hub bicycle transmission is more than 96 percent for each speed. Such an in-hub bicycle transmission possesses reasonable kinematics and high mechanical efficiency and is therefore suitable for further embodiment design and detail design. Originality/value – The proposed approach is suitable for the mechanical efficiency analysis of all kinds of complicated epicyclic-type transmissions with any number of degrees of freedom and facilitates a less-tedious process of determining mechanical efficiency. It is a useful tool for mechanical engineering designers to evaluate the efficiency performance of the gear mechanism before actually fabricating a prototype as well as measuring the numerical data. It also helps engineering designers to cautiously select feasible gear mechanisms to avoid those configurations with power recirculation in the preliminary design stage which may significantly reduce the time for developing novel in-hub bicycle transmissions.


Author(s):  
Goutam Chatterjee ◽  
Lung-Wen Tsai

Abstract The enumeration of epicyclic gear mechanisms in the form of graphs gives rise to the need of a methodology for reverse transformation, that is, for constructing the mechanisms from graphs. This paper addresses the issue by discretizing an epicyclic gear mechanism into Fundamental Geared Entities. Further, these geared entities are shown to be a conglomeration of four primitives; namely, the carrier, sun, ring, and the planet gear. An algorithm is formulated to create the entities from a graph by using these primitives. The entities are then connected together to form a mechanism.


1996 ◽  
Vol 118 (3) ◽  
pp. 405-411 ◽  
Author(s):  
G. Chatterjee ◽  
Lung-Wen Tsai

The enumeration of epicyclic gear mechanisms in the form of graphs gives rise to the need of a methodology for reverse transformation, that is, for constructing the mechanisms from graphs. This paper addresses the issue by discretizing an epicyclic gear mechanism into Fundamental Geared Entities. Further, these geared entities are shown to be a conglomeration of four primitives; namely, the carrier, sun, ring, and the planet gear. An algorithm is formulated to create the entities from a graph by using these primitives. The entities are then connected together to form a mechanism.


2012 ◽  
Vol 605-607 ◽  
pp. 1217-1223 ◽  
Author(s):  
Ming Fu You ◽  
Qiang Wen ◽  
Ming Feng Zheng ◽  
Zhi Wei Li

The power performance and fuel economy could be improved by increasing the shift. The 01N automatic transmission was a Navgneaus planetary gear mechanism with four forward gears, and the 6-speed transmission scheme was achieved by the planetary in series with the Navgneaus planetary gear mechanism. The original lever method was expanded for its limitation, the 6-speed transmission mechanism can be analyzed perfectly by the expanded lever method. The lever method was validated accurate and feasible.


Author(s):  
Zhen Chen ◽  
Ming Zeng

In this paper, an active design method of meshing line for a spiral bevel gear mechanism with nonrelative sliding is presented. First, the general meshing line equations for a nonrelative sliding transmission mechanism between two orthogonal axes are proposed based on the active design parameters. Then, parametric equations for contact curves on the drive and driven spiral bevel gears are deduced by coordinate transformation of the meshing line equations. Further to this, parametric equations for the tooth surface of each bevel gear are derived according to the conical spiral motion of a generatrix circle along the calculated contact curves. Finally, a set of numerical examples is presented based on two types of motion equation of the meshing points. Material prototypes are fabricated and experimentally tested to validate the kinematic performance of the functionally designed spiral bevel gear set.


Sign in / Sign up

Export Citation Format

Share Document