scholarly journals On the Design of Continuously Variable Transmissions with Bidirectional Bridge Structures for Hybrid Vehicles

2021 ◽  
Vol 11 (6) ◽  
pp. 2500
Author(s):  
Hsien-Yu Kuo ◽  
Tyng Liu
Keyword(s):  
Design Method ◽  
Mechanical Efficiency ◽  
Hybrid Powertrain ◽  
Path Diagram ◽  
Continuously Variable Transmissions ◽  
Bridge Structures ◽  
Power Inputs ◽  
Torque Capacity ◽  
Coupling Pattern ◽  
System Configurations

To increase the energy efficiency of road vehicles, an ideal transmission system should have a wide ratio coverage, a high torque capacity, and a high mechanical efficiency. Continuously variable units (CVUs) have been successfully implemented due to the smooth ratio variation, sufficient torque capacity, and ratio coverage. Hence, it will be beneficial to develop a hybrid powertrain comprising a CVU. In this paper, a design method called the “basic path diagram” (BPD) is proposed. It provides a simplified schematic of the system and represents the generic connections among the mechanical components. The system configurations synthesized by the BPD can be sorted according to three characteristics: Direction of power flows through the CVU, coupling pattern of the power inputs, and number of transmission paths parallel to the CVU. The first characteristic determines the number of times the CVU ratio coverage can be exploited, the second characteristic determines whether the torque of the power inputs can be independently controlled, and the third characteristic can help reduce the torque loading of the CVU. With the aid of a BPD, one of the possible system configurations is provided as an example. The result shows that the system can exploit twice the ratio coverage of the CVU and reduce the torque and power transmitted by the CVU in combination with planetary gearsets.

Strategic selection of assembly systems under viable demands

2006 ◽  
Vol 26 (4) ◽  
pp. 335-342 ◽  
Author(s):  
Tetsuo Yamada ◽  
Kakefuda Satomi ◽  
Masayuki Matsui
Keyword(s):  
Design Method ◽  
Cell System ◽  
Comparative Approach ◽  
Lead Times ◽  
Assembly Systems ◽  
Lot Size ◽  
Content Type ◽  
Demand Fluctuations ◽  
System Configurations ◽  
Assembly Models

PurposeAims to strategically compare assembly lines to cell production including flexible cell system (FCS) under viable demands using the pair matrix table by the lot size and the number of stations and select the efficient assembly systems on demand fluctuations.Design/methodology/approachThis paper sets an assembly problem of the respective models for assembly line systems, autonomous cell system and FCS, and presents a comparative approach by the pair matrix table for the strategic selection. The simulators were constructed for the respective models, and the pair matrix tables with the profit and lead time were drawn and shown.FindingsFinds that the pair matrix table by the lot size and the number of stations are applicable in the strategic selection for comparative assembly systems, and FCS, consisting of multiple self‐completion stations connected by conveyors, is stable when there are viable changes in the demand quantity and the number of stations.Research limitations/implicationsProvides an economic comparative approach for a strategic selection in assembly models with different system configurations by simulation.Practical implicationsThe approach proposed in this paper will provide a strategic selection quantitatively with system managers to achieve higher profit and shorter lead times under viable demands.Originality/valueIntroduces the pair matrix table by the lot size and the number of stations, and compares strategically and quantitatively the respective assembly models based on an optimal design by the two‐stage design method in view of profits and lead times under viable demands.

scholarly journals Investigation of Mechanical Differentials as Continuously Variable Transmissions

2011 ◽  
Author(s):  
Dax B. Wells ◽  
Benjamin C. Groen ◽  
Robert H. Todd
Keyword(s):  
Hybrid Electric Vehicle ◽  
Power Transmission ◽  
Power Sources ◽  
Single Output ◽  
Multiple Input ◽  
Continuously Variable Transmissions ◽  
Power Inputs ◽  
Variable Transmission ◽  
Reduce Emissions ◽  
Increasing Demand

In recent years the increasing demand for fuel efficient and less pollutant vehicles has stimulated the development of hybrid and electric vehicles. These vehicle platforms often incorporate drivetrains which utilize multiple power sources for vehicle propulsion to increase fuel mileage and reduce emissions. Understanding the torque and RPM relationship within the power transmission device used to combine power sources is fundamental to overcoming the design challenges associated with hybrid/electric vehicle platforms. Results from this research include the fundamental torque and RPM relationships that exist in a multiple-input, single-output power transmission device. Results were deduced from a test incorporating two separate power inputs into a mechanical differential, which produced a single output. Testing showed that a mechanical differential has the ability to function as an infinitely variable transmission (IVT). Additionally, recommendations for overcoming some of the challenges associated with using a mechanical differential as a multiple-input, single-output device were identified.

The Design and Development of a Single-Axle Parallel Hybrid Powertrain Test Platform

2014 ◽  
Vol 937 ◽  
pp. 346-350
Author(s):  
Qiang Sun ◽  
Cheng Cheng Ma ◽  
Qiang Miao ◽  
Guo Xiang Li
Keyword(s):  
Software Design ◽  
Modular Design ◽  
Design Method ◽  
Hybrid Powertrain ◽  
Function Design ◽  
Test Platform ◽  
Parallel Hybrid ◽  
Design Software ◽  
Run Test ◽  
Test Result

Based on the structure analysis of a hybrid truck, design a single-axle parallel hybrid powertrain test platform. Modular design method is used to realize this platform and this platform is divided into four modules. Function design, software design and realization of the four modules are respectively discussed. Finally, a cycle run test was taken and the test result indicates that effectiveness and accurateness of the test platform are realized well.

Behavior of Bridge Outrigger Knee Joint Systems

1995 ◽  
Vol 11 (3) ◽  
pp. 477-509 ◽  
Author(s):  
Christopher R. Thewalt ◽  
Božidar Stojadinović
Keyword(s):  
Knee Joint ◽  
Design Method ◽  
Knee Joints ◽  
Loma Prieta Earthquake ◽  
Longitudinal Loading ◽  
Bridge Structures ◽  
Primary Focus ◽  
Upgrading Strategies ◽  
Analytical Tools ◽  
Repair Techniques

The catastrophic collapse of the Cypress Street Viaduct during the 1989 Loma Prieta earthquake emphasized the vulnerability of older elevated freeway bridge structures. One part of a joint Caltrans/University of California at Berkeley research project is the investigation of outrigger knee joints found in elevated freeway bents. This project has two principal goals: to evaluate the behavior of the existing outrigger knee joint systems under a combined transverse and longitudinal loading, and to design and experimentally verify upgrading strategies and repair techniques suitable for application on the existing elevated freeways. The primary focus of this paper will be to present the behavior of the as-built and upgraded systems, but an overview of the design method and the analytical tools used in the upgrade will also be presented.

On the Mechanical Efficiency of Differential Gearing

1985 ◽  
Vol 107 (1) ◽  
pp. 61-67 ◽  
Author(s):  
D. Yu ◽  
N. Beachley
Keyword(s):  
Analytical Methods ◽  
Degrees Of Freedom ◽  
Computer Programming ◽  
Mechanical Efficiency ◽  
Input Power ◽  
Degree Of Freedom ◽  
Two Degrees Of Freedom ◽  
Power Coupling ◽  
Continuously Variable Transmissions ◽  
Full Utilization

Although much work has been done on the efficiency of epicyclic gearing, emphasis has usually been given to the planetary that has only one degree of freedom. In this paper, a thorough study of the efficiency of differential gearing that has two degrees of freedom is presented. New analytical methods and programs are designed to calculate differential efficiencies and to plot useful curves. Examples are given for split-path differential, continuously variable transmissions (CVT) with input power coupling. It is pointed out that there are six different ways of using a given differential design in such a split-path CVT, providing the opportunity for full utilization of its potential. With the help of computer programming, optimum designs can be obtained.

Studies on Seismic Demand Spectra Based on Strength Reduction Factor

2011 ◽  
Vol 243-249 ◽  
pp. 4047-4051
Author(s):  
Xiao Li Zhu ◽  
Gao Hang Cui ◽  
Xia Xin Tao
Keyword(s):  
Seismic Design ◽  
Design Method ◽  
Structural Characteristics ◽  
Reduction Factor ◽  
Strength Reduction ◽  
Seismic Demand ◽  
Capacity Design ◽  
Strength Reduction Factor ◽  
Seismic Design Code ◽  
Bridge Structures

For resolving the practical problem about bridge structures, according to the seismic damage regularity and the structural characteristics, the capacity design method of bridge structure was introduced. In order to account synthetically for the influence factors and convert the inelastic seismic design method into the pseudo-static method, which is easily accepted by engineers, the strength reduction factor was commonly used in seismic design of structures. Based on the principles of the inelastic spectrum established by using the relationship between the strength reduction factor R and ductility factor μ, the seismic demand spectra were obtained from the design spectrum of the Highway Engineering Seismic Design Code (JTJ 004-89). This will be beneficial to the earthquake-resistant capacity design in practical bridge structures.

Comparative Study of Energy Management Strategies for Hydraulic Hybrids

2014 ◽  
Vol 137 (4) ◽  
Author(s):  
Timothy O. Deppen ◽  
Andrew G. Alleyne ◽  
Jonathan J. Meyer ◽  
Kim A. Stelson
Keyword(s):  
Energy Management ◽  
Design Method ◽  
Tracking Error ◽  
Management Strategies ◽  
Stochastic Dynamic ◽  
Drive Cycle ◽  
Hybrid Powertrain ◽  
Hydraulic Hybrid ◽  
System A ◽  
Factorial Design Of Experiments

The sensitivity of energy management strategies (EMS) with respect to variations in drive cycle and system parameters is considered. The design of three strategies is presented: rule-based, stochastic dynamic programming (SDP), and model predictive control (MPC). Each strategy is applied to a series hydraulic hybrid powertrain and validated experimentally using a hardware-in-the-loop system. A full factorial design of experiments (DOE) is conducted to evaluate the performance of these controllers under different urban and highway drive cycles as well as with enforced modeling errors. Through this study, it is observed that each EMS design method represents a different level of tradeoff between optimality and robustness based on how much knowledge of the system is assumed. This tradeoff is quantified by analyzing the standard deviation of system specific fuel consumption (SSFC) and root mean square (RMS) tracking error over the different simulation cases. This insight can then be used to motivate the choice of which control strategy to use based on the application. For example, a city bus travels a repeated route and that knowledge can be leveraged in the EMS design to improve performance. Through this study, it is demonstrated that there is not one EMS design method which is best suited for all applications but rather the underlying assumptions of the system and drive cycle must be carefully considered so that the most appropriate design method is chosen.

scholarly journals The seismic design suggestions of girder bridge

2020 ◽  
Vol 165 ◽  
pp. 04034
Author(s):  
Hong Li
Keyword(s):  
Seismic Design ◽  
Design Method ◽  
Seismic Damage ◽  
Earthquake Resistance ◽  
Earthquake Response ◽  
Elastic Plastic ◽  
Bridge Structures ◽  
Girder Bridge

This article mainly analyses different representations of bridge seismic damage and their causes, discusses mostly the analytic means of bridge structures’ elastic-plastic earthquake response and the design method of ductile earthquake-resistance. In the end, the developing trends of the method in future are introduced, the suggestions of modifying the specification are given.

Reversibility of Power-Split Transmissions

2011 ◽  
Vol 133 (8) ◽  
Author(s):  
F. Bottiglione ◽  
G. Mantriota
Keyword(s):  
Kinetic Energy ◽  
Energy Recovery ◽  
Power Flow ◽  
Mechanical Efficiency ◽  
Transmission Efficiency ◽  
Short Paper ◽  
Reverse Mode ◽  
Power Split ◽  
Continuously Variable Transmissions ◽  
Ratio Spread

Recent applications of continuously variable transmissions with large ratio spread, such as mechanical Kinetic Energy Recovery Systems or recent hybrid architectures, need the transmission to be perfectly reversible. This short paper deals with the mechanical efficiency of power-split continuously variable transmissions with particular emphasis on the switching from forward to reverse power flow. Forward and reverse transmission efficiency are calculated and compared, and the conditions which make it impossible to switch to reverse mode are studied. In particular, it is suggested that, although less efficient at high transmission ratios, a forward power circulation should be preferred because it has almost the same efficiency in forward and reverse operation.

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