Synthesis method for compact dual-clutch transmission with four DOFs gear mechanism

Author(s):  
Xueliang Li ◽  
Jibin Hu ◽  
Zengxiong Peng

The design of dual-clutch transmission with multi-degrees-of-freedom (DOFs) is a good solution to increase in number of gears and a wider range of gear ratio in the limited space and weight. This article proposes a novel synthesis method for scheme design of the dual-clutch transmission with four degrees-of-freedoms gear mechanism. First, the shift sequences considering the path of power flow and shift logics are analyzed based on the degrees-of-freedom model, abstracted from the degrees-of-freedom of the schemes. Second, the schemes of gear-pair and shaft, defined as the scheme that ignores the arrangement of synchronizers, are derived from the basic configurations, defined as the schemes of gear-pair and shaft that contains only one of each type of the variable connections, and the numbers of each type of the variable connections. Finally, multi-parameter, including synchronizers arrangement and gear ratios, is optimally designed for the results of synthesis. The seven-speed dual-clutch transmission schemes with four degrees-of-freedom and two shaft systems are taken as an example to explain this synthesis method. In addition, this article helps to obtain a deeper understanding of the systematic design of other fixed gear transmission schemes, such as automated mechanical transmission, automated mechanical transmissions with electric torque supporting, and even some novel multi-input transmissions.

2012 ◽  
Vol 479-481 ◽  
pp. 921-924
Author(s):  
Zhao Lin Han ◽  
Feng Liu

Abstract. Hydro-Mechanical Transmission (HMT) is a dual-power flow transmission system in which power is transferred parallel by mechanical transmission and hydraulic transmission. There are four types of HMT: torque-diffluence and torque-conflux, torque-diffluence and speed-conflux, speed-diffluence and speed-conflux, speed-diffluence and torque-conflux, when gear pair and planetary train are used as power diffluence or conflux mechanism respectively. And the result of kinematics characteristics analysis indicates that only torque-diffluence and speed-conflux type of HMT can be used as the vehicle transmission system because its output speed characteristics and pump speed characteristics can meet the requirements of the vehicle drive.


2012 ◽  
Vol 472-475 ◽  
pp. 753-756
Author(s):  
Fu Yi Cao ◽  
Zhi Li Zhou ◽  
Hong Jie Zhao

The hydro-mechanical differential turning mechanism is the new type of double power flow turning mechanism of tracked vehicle. The hydraulic stepless speed regulation and the high efficiency of mechanical transmission are integrated into the turning mechanism. The stepless turning of tracked vehicle can be achieved. Basing on hydro-mechanical differential turning theory, the scheme design of steering wheel control system of tracked vehicle of hydro-mechanical differential turning is finished. By establishing model of steering wheel control system, its working stability and following characteristic is simulated and analyzed in this paper. The demand of hydro-mechanical differential turning of tracked vehicle can be realized by the steering wheel control system designed through the simulation results.


2016 ◽  
Vol 40 (4) ◽  
pp. 597-606
Author(s):  
Yi-Chang Wu ◽  
Li-An Chen

A multi-speed bicycle transmission hub includes a geared speed-changing mechanism for providing different speed ratios and a gear-shifting mechanism for controlling the gear stage. This paper focuses on the embodiment design of a mechanical gear-shifting mechanism with a rotary configuration used in a 16-speed transmission hub for bicycles. A 16-link, five-degrees of freedom (DOF) split-power epicyclic gear mechanism, which consists of a gear differential and four sets of parallel-connected basic planetary gear trains, is introduced. Based on the clutching sequence table, a systematic design process is developed to come up with the embodiment design of the gear-shifting mechanism. A feasible and compact 16-speed rear transmission hub for bicycles is presented.


2015 ◽  
Vol 39 (3) ◽  
pp. 407-418 ◽  
Author(s):  
Yi-Chang Wu ◽  
Che-Wei Chang

Rear hub bicycle transmissions require less maintenance and are more reliable than rear derailleurs. This study proposes a systematic design process for the conceptual design of 3-speed rear hub bicycle transmissions. By analyzing the kinematics of a basic epicyclic gear mechanism using the fundamental circuit method, the gear sequence and clutching sequence arrangements for 3-speed rear hub transmissions can be obtained. The numbers of gear-teeth for all gear elements resulting in a minimum installation space and satisfying the required speed ratio at each gear stage are determined. A gear-shifting mechanism is constructed to sequentially control the power-flow path within the epicyclic gear mechanism so as to provide three forward gears. An atlas of 3-speed rear hub bicycle transmissions is listed, where three devices are new design concepts and are suitable for further embodiment design. The results of this study will lead to the creation of new multi-speed rear hub bicycle transmissions.


2008 ◽  
Vol 15 (1) ◽  
pp. 51-60 ◽  
Author(s):  
C.Q. Liu

In this paper, an improved FRF-based substructure synthesis method combined with power flow analysis is presented and is used for performing a vehicle axle noise analysis. The major transfer paths of axle noise transmitted from chassis to vehicle body are identified and ranked based on power flows transmitted through bushings between the chassis and body. To calculate the power flows, it is necessary to know the reaction forces and the vibrations at the bushing locations on the body side. To this end, the body is represented in terms of experimentally derived frequency response functions (FRF's) at the bushing locations, and the FRF's are coupled with the FEA model of the chassis for performing a total system dynamic analysis. This paper also describes how the FRF's of the vehicle body and the frequency dependent stiffness data of the bushings can be combined together with a simple formulation to better represent the dynamic characteristics of a full vehicle. A classical example is used to illustrates the concept of the method, and the method is then applied to a vehicle axle noise analysis with detailed procedure. The theoretical predictions are compared with experimentally measured results. Good correlation has been obtained.


2015 ◽  
Vol 39 (3) ◽  
pp. 431-441 ◽  
Author(s):  
Yi-Chang Wu ◽  
Tze-Cheng Wu

This paper presents embodiment design of 5-speed rear drive hubs for bicycles. A 7-link, 2-degrees of freedom (DOF) compound planetary gear train as the main body of a rear drive hub is introduced. The relationship between the number of coaxial links of a planetary gear train and the number of gear stages that a drive hub can provide with is discussed. By means of kinematic analysis, four speed ratios of the planetary gear train are derived, which represents four forward gears of the rear drive hub. By adding a direct-drive gear, five forward gears can be provided and two feasible clutching sequence tables are synthesized. Manual translational-type gear-shifting mechanisms are further designed to incorporate with the planetary gear train for appropriately controlling the gear stage. The power-flow path at each gear stage is checked to verify the feasibility of the proposed design. Finally, two novel 5-speed bicycle rear drive hubs are presented.


2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Chao Chen ◽  
Teck Teh Liang

Epicyclic gear train is a fundamental form of mechanical transmission with broad applications. Efficiency study of these trains is critical to design, optimization, and operation. It is known that the efficiencies of these systems are highly related to the internal power flows. We apply the concept of virtual power to find analytical expression of the efficiency of a two degrees of freedom train, with associated applicable ranges. The results are verified by an example.


2013 ◽  
Vol 353-356 ◽  
pp. 2008-2014
Author(s):  
Pan Tian ◽  
Zhang Wei Chen

Acceleration iterative control is generally used in multi-degrees-of-freedom earthquake simulation test. To overcome the shortcoming of poor displacement amplitude accuracy in this control, a multi-degrees-of-freedom earthquake simulation control strategy based on multi-movement parameters iterative control is proposed. This control divide the frequency range of earthquake simulation test into displacement control area, the synthetic control area and acceleration control area from the low frequency to the high frequency, and correct the acceleration errors spectrum and displacement error spectrum by iterative control method, and produce shaker driver signal by synthesis method, and realize the displacement replication and acceleration replication at the same time. The experimental results which are got in multi-degrees-of-freedom earthquake simulation facility indicate that this control can achieve high accuracy multi-degrees-of-freedom earthquake simulation test after several times iterative.


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