scholarly journals Design and Analysis of a Novel Speed-Changing Wheel Hub with an Integrated Electric Motor for Electric Bicycles

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yi-Chang Wu ◽  
Zi-Heng Sun

The aim of this paper is to present an innovative electromechanical device which integrates a brushless DC (BLDC) hub motor with a speed-changing wheel hub stored on the rear wheel of an electric bicycle. It combines a power source and a speed-changing mechanism to simultaneously provide functions of power generation and transmission for electric bicycles. As part of the proposed integrated device, the wheel hub consists of a basic planetary gear train providing three forward speeds including a low-speed gear, a direct drive, and a high-speed gear. Each gear is manually controlled by the shift control sleeve to selectively engage or disengage four pawl-and-ratchet clutches based on its clutching sequence table. The number of gear teeth of each gear element of the wheel hub is synthesized. The BLDC hub motor is an exterior-rotor-type permanent-magnet synchronous motor. Two-dimensional finite-element analysis (FEA) software is employed to facilitate the motor design and performance analysis. An analysis of the power transmission path at each gear is provided to verify the validity of the proposed design. The results of this work are beneficial to the embodiment, design, and development of novel electromechanical devices for the power and transmission systems of electric bicycles.

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.


Author(s):  
Tomoki Fukuda ◽  
Masao Nakagawa ◽  
Syota Matsui ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama

Planetary gear trains (PGTs) are widely applied in various machines owing to their advantages, such as compactness, low weight, and high torque capacity. However, they experience the problems of vibration due to the structural and motional complexities caused by planet gears. In a previous study, it was shown that high speed monitoring is effective for evaluating the motion of planet gears under steady conditions and transient conditions including the influence of backrush. However graphical investigation was conducted manually, and improvement in accuracy is required. In this report, an improved method is proposed, which includes lighting conditions and measurement conditions. Throughout these improvement processes, instant center of rotation is calculated automatically with detected coordinates using software. This makes it possible to estimate the transient response of PGTs with planet gear motion.


2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Kaoutar Daoudi ◽  
El Mosthapha Boudi ◽  
Mohsine Abdellah

The determination of optimal design of the planetary gear train with a lightweight, a short center distance, and a high efficiency is an important issue in the preliminary design of power transmission systems. Conventional and traditional methods have been widely used in optimization. They are deterministic and limited to solve some mechanical problems with several variables and constraints. Therefore, some optimization methods have been developed, such as the nonconventional method, the genetic algorithm (GA). This paper describes a multiobjective optimization for the epicyclical gear train system using the GA. It is aimed to obtain the optimal dimensions for epicyclical gear components like a module, number of teeth, the tooth width, the shaft diameter of the gears, and a performed efficiency under the variation of operating mode of PGT system. The problem is formulated under the satisfaction of assembly and balance constraints, bending strength, contact strength of teeth, and other dimension conditions. The mathematical model and all steps of the GA are presented in detail.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Ying Fan ◽  
Lingling Gu ◽  
Yong Luo ◽  
Xuedong Han ◽  
Ming Cheng

This paper presents a flux-modulated direct drive (FMDD) motor. The key is to integrate the magnetic gear with the PM motor while removing the gear inner-rotor. Hence, the proposed FMDD motor can achieve the low-speed high-torque output and high-speed compact design requirements as well as high-torque density with a simple structure. The output power equation is analytically derived. By using finite element analysis (FEA), the static characteristics of the proposed motor are obtained. Based on these characteristics, the system mathematical model can be established. Hence, the evaluation of system performances is conducted by computer simulation using the Matlab/Simulink. A prototype is designed and built for experimentation. Experimental results are given to verify the theoretical analysis and simulation.


2014 ◽  
Vol 701-702 ◽  
pp. 853-857
Author(s):  
Yuan Zhang ◽  
Kun Li ◽  
Qiang Wei ◽  
Bo Yang Meng

According to the three-wheeled high clearance sprayer on the current market, the traditional empirical design method can hardly be used for effective stress distribution calculation and structural optimization, so it leads to the unreasonable structural design. Based on the overall structure of the sprayer design, a new-type high clearance sprayer designed, It is mainly composed of the engine-powered diaphragm pump power transmission parts, the power steering of scalable universal joint, the rear wheel steering mechanism and other components. Meanwhile, the finite element analysis and structural optimization on the sprayer frame have been finished. Therefore, the results showed that the frame realized the lightweight on the premise of the demand of performance and stiffness, each mechanism’s matching performance of sprayer meets the design requirements, and this approach provides a beneficial investigation into the future sprayer design.


2022 ◽  
pp. 1-13
Author(s):  
Jiangang Liu ◽  
Zhipeng Tong ◽  
Yu Gao-hong ◽  
Xiong Zhao ◽  
Haili Zhou

Abstract This study proposes a new non–circular gear transmission mechanism with an involute–cycloid composite tooth profile to realize the twice unequal amplitude transmission (In a complete rotation cycle of gear transmission, instantaneous transmission ratio has twice fluctuations obvious with unequal amplitude) of non–circular gears. The twice unequal amplitude transmission ratio curve was designed based on Fourier and polynomial functions, the change law of the Fourier coefficient on the instantaneous transmission ratio(In non-circular gear transmission, the transmission ratio changes with time, and the transmission ratio of non-circular gear should be instantaneous transmission ratio) was analyzed, and the pressure angle and contact ratio of the involute–cycloid composite tooth profile was calculated. The involute–cycloid composite tooth profile non–circular gear was machined by WEDM technology, while its meshing experiment was performed using high-speed camera technology. The results demonstrate that the instantaneous transmission ratio curve value obtained via the high-speed camera experiment was consistent with the simulation value of virtual software. Furthermore, the involute–cycloid composite tooth profile was applied in the seedling pickup mechanism of non–circular gear planetary gear train. The possibility of the application of the involute–cycloid composite tooth profile in the seedling pickup mechanism was verified by comparing the consistency of the theoretical and simulated seedling picking trajectory.


2018 ◽  
Vol 10 (7) ◽  
pp. 168781401878482 ◽  
Author(s):  
Yi-Chang Wu ◽  
Chin-Tsung Chan

This article proposes a new magnetic rear hub transmission for bicycles, which consists of a coaxial magnetic gear mechanism to serve as the speed-changing device and a speed control mechanism to govern the gear stage. A 3-speed magnetic hub transmission, including a low-speed gear, a direct-drive gear, and a high-speed gear, is designed and installed in the rear hub of a bicycle, which allows the rider to select different gears to adjust the pedaling force. For a new kind of rear hub transmission, kinematic analysis and power-flow path analysis are essential to validate the speed ratio and the power-flow path at each gear stage. They are also the fundamentals for the mechanical efficiency analysis. Here, a system’s kinematic equation, which is an analytical approach and analogous to the kinematics of a basic planetary gear train, for the presented coaxial magnetic gear mechanism is derived without considering the complex space harmonics of the magnetic flux density distribution presented in previous studies. Hence, the speed ratio at each gear stage of the magnetic hub transmission can be easily calculated.


2007 ◽  
Vol 10-12 ◽  
pp. 900-904 ◽  
Author(s):  
Y. Lu ◽  
Ying Xue Yao ◽  
W.Z. Xie

High speed machining is a promising technology for significantly increasing productivity and reducing production costs. Development of high-speed spindle technology is strategically critical to the implementation of high speed machining. Compared to conventional spindles, and motorized spindles are equipped with built-in motors for better power transmission and balance to achieve high-speed operation. However, the built-in motor introduces additional mass to the spindle shaft, besides, since its very high working speed, some high-speed rotational effects, including centrifugal forces and gyroscopic moments on the spindle shaft can not be neglected in the analysis as is done in conventional spindle, thus complicating its mechanical-dynamic behaviors. In this paper, the FEM model of motorized spindle is set up to research on its dynamic characteristics in theory with an eye to high-speed rotational effects, including centrifugal forces and gyroscopic moments on the motorized spindle shaft. The motorized spindle’s natural frequencies and corresponding vibration shapes are got through the modal analysis, and the effect of the axial preload on the natural frequency is programmed to be seen clearly.


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