Power Loss Analysis and the Selection of a Most Efficient Clutching Sequence Associated With an Automatic Transmission Mechanism

1997 ◽  
Author(s):  
Hsin-I Hsieh ◽  
Lung-Wen Tsai
Keyword(s):  
Power Loss ◽  
Automatic Transmission ◽  
Transmission Mechanism ◽  
Torque Distribution ◽  
Loss Analysis ◽  
Epicyclic Gear ◽  
Gear Mechanism ◽  
Selection Of

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.

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
Keyword(s):  
Power Loss ◽  
Automatic Transmission ◽  
Transmission Mechanism ◽  
Torque Distribution ◽  
Transmission Mechanisms ◽  
Epicyclic Gear ◽  
Gear Mechanism ◽  
Selection Of

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.

Nomographs for Enumeration of Clutching Sequences Associated With Epicyclic-Type Automatic Transmission Mechanisms

2008 ◽  
Author(s):  
Essam L. Esmail
Keyword(s):  
Automatic Transmission ◽  
Root Cause ◽  
Transmission Mechanisms ◽  
Epicyclic Gear ◽  
Angular Velocities ◽  
Gear Mechanism ◽  
Gear Trains ◽  
Exact Size ◽  
Algorithmic Techniques ◽  
Transmission Gear

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.

Computing the power flow and mechanical efficiency of in-hub bicycle transmissions

2014 ◽  
Vol 31 (2) ◽  
pp. 267-282
Author(s):  
Yi-Chang Wu ◽  
Chia-Ho Cheng
Keyword(s):  
Power Flow ◽  
Automatic Transmission ◽  
Mechanical Efficiency ◽  
Efficiency Analysis ◽  
Transmission Mechanism ◽  
Design Stage ◽  
Content Type ◽  
Gear Mesh ◽  
Embodiment Design ◽  
Gear Mechanism

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.

scholarly journals Computer-Aided Sketching of Epicyclic-Type Automatic Transmission Gear Trains

1994 ◽  
Author(s):  
Goutam Chatterjee ◽  
Lung-Wen Tsai
Keyword(s):  
Automatic Transmission ◽  
Reverse Transformation ◽  
Epicyclic Gear ◽  
Computer Aided ◽  
Planet Gear ◽  
Gear Mechanism ◽  
Gear Trains ◽  
Transmission Gear

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.

scholarly journals Optimal Design of a Flyback Microinverter Operating under Discontinuous-Boundary Conduction Mode (DBCM)

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7480
Author(s):  
Georgios Christidis ◽  
Anastasios Nanakos ◽  
Emmanuel Tatakis
Keyword(s):  
Power Loss ◽  
Design Procedure ◽  
Sinusoidal Wave ◽  
Flyback Converter ◽  
Loss Analysis ◽  
Discontinuous Boundary ◽  
Loss Models ◽  
Optimization Methodology ◽  
Conduction Mode ◽  
Selection Of

The flyback converter has been widely used in Photovoltaic microinverters, operating either in Discontinuous, Boundary, or Continuous Conduction Mode (DCM, BCM, CCM). The recently proposed hybrid DBCM operation inherits the merits of both DCM and BCM. In this work, the necessary analytical equations describing the converter operation for any given condition under DBCM are derived, and are needed due to the hybrid nature of the modulation strategy during each sinusoidal wave. Based on this analysis, a design optimization sequence used to maximize the weighted efficiency of the inverter under DBCM is then applied. The design procedure is based on a power loss analysis for each converter component and focuses on the appropriate selection of the converter parameters. To achieve this, accurate, fully parameterized loss models of the converter components are implemented. The power loss analysis is then validated by applying the optimization methodology to build an experimental prototype operating in DBCM.

scholarly journals Computer-Aided Sketching of Epicyclic-Type Automatic Transmission Gear Trains

1996 ◽  
Vol 118 (3) ◽  
pp. 405-411 ◽  
Author(s):  
G. Chatterjee ◽  
Lung-Wen Tsai
Keyword(s):  
Automatic Transmission ◽  
Reverse Transformation ◽  
Epicyclic Gear ◽  
Computer Aided ◽  
Planet Gear ◽  
Gear Mechanism ◽  
Gear Trains ◽  
Transmission Gear

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.

scholarly journals Kinematic Analysis of Epicyclic-Type Transmission Mechanisms Using the Concept of Fundamental Geared Entities

1996 ◽  
Vol 118 (2) ◽  
pp. 294-299 ◽  
Author(s):  
Hsin-I Hsieh ◽  
Lung-Wen Tsai
Keyword(s):  
Kinematic Analysis ◽  
Transmission Mechanism ◽  
Speed Ratio ◽  
Ratio Analysis ◽  
Symbolic Manipulation ◽  
Transmission Mechanisms ◽  
Operation Modes ◽  
Kinematic Characteristics ◽  
Epicyclic Gear ◽  
Gear Mechanism

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.

scholarly journals Kinematic Analysis of Epicyclic-Type Transmission Mechanisms Using the Concept of Fundamental Geared Entities

1995 ◽  
Author(s):  
Hsin-I Hsieh ◽  
Lung-Wen Tsai
Keyword(s):  
Kinematic Analysis ◽  
Transmission Mechanism ◽  
Speed Ratio ◽  
Transmission Mechanisms ◽  
Kinematic Characteristics ◽  
Epicyclic Gear ◽  
Gear Mechanism

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.

scholarly journals Investigation of the Influences of Thrust Loads Resulted by Helix Angle Directions of Planetary Gear Sets on Bearing Power Losses in Automotive Planetary Gear Trains

2021 ◽  
Vol 11 (19) ◽  
pp. 8827
Author(s):  
Hyun Sik Kwon
Keyword(s):  
Power Loss ◽  
Fuel Efficiency ◽  
Automatic Transmission ◽  
Reducing Power ◽  
Planetary Gear ◽  
Helix Angle ◽  
Transmission Model ◽  
Power Losses ◽  
Loss Analysis ◽  
Planetary Gear Sets

In the recent automotive industries, automotive technologies for improving fuel efficiency have focused on the developments of reducing power losses in a transmission. As a well-developed and conventional power transmitting system, an automatic transmission is still widely used in many automotive vehicles. The automatic transmission is co-axially designed with several planetary gear sets and other mechanical parts. The co-axial arrangements and gear helix angles make the transmission necessarily include bearings for supporting loads and allowing relative rotations. In this study, the influences of thrust loads yielded by helix angle directions of planetary gear sets on bearing power losses are presented by performing the structural and power loss analysis. Bearing power losses consist of mechanical and spin power losses. For calculating thrust loads and bearing rotations, a complete transmission model is constructed by using an example structure, and structural analysis is performed for the combinations of helix angle directions of the gear sets. Finally, bearing power losses are computed by using the bearing power loss model, and the results of the entire combinations of helix angle directions are discussed.

Enumeration of Feasible Clutching Sequences of Epicyclic Gear Mechanisms

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
Shaker S. Hassan
Keyword(s):  
Artificial Intelligence ◽  
Velocity Ratio ◽  
Automatic Transmission ◽  
Gear Train ◽  
Artificial Intelligence Technique ◽  
Transmission Mechanisms ◽  
Epicyclic Gear ◽  
Gear Mechanism ◽  
Algorithmic Technique ◽  
Intelligence Technique

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.

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