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An investigation into the vibration of harmonic drive systems
M. Masoumi, H. Alimohammadi
《机械工程前沿（英文）》 2013年 第8卷 第4期 页码 409-419 doi: 10.1007/s11465-013-0275-5
Harmonic drive systems are precise and specific transmission gear systems which are beneficial in terms of the high transmission ratio and almost zero backlash. These inherent and spectacular properties result in using this mechanism in robotic and space sciences where the precision and lightwieght play an important role. This paper presents a vibration analysis of harmonic drive systems using the shell theory. Equations of vibration for the flexspline and the circular spline of the system are derived and used to find the natural frequencies for both parts and, moreover, vibration response of the system under the operating condition is calculated. Also, obtained vibration equations are utilized to study the effects of different involved parameters such as the geometry of the flexspline and its gear tooth, eccentricity, and unbalancing on the vibrational behavior of the system.
关键词： harmonic drive system strain wave gearing mechanism vibration analysis natural frequencies
《机械工程前沿（英文）》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0674-6
关键词： harmonic drive meshing flexibility matrix meshing force loading backlash flexspline contact analysis
Hierarchical parameter estimation of DFIG and drive train system in a wind turbine generator
Xueping PAN, Ping JU, Feng WU, Yuqing JIN
《机械工程前沿（英文）》 2017年 第12卷 第3期 页码 367-376 doi: 10.1007/s11465-017-0429-y
A new hierarchical parameter estimation method for doubly fed induction generator (DFIG) and drive train system in a wind turbine generator (WTG) is proposed in this paper. Firstly, the parameters of the DFIG and the drive train are estimated locally under different types of disturbances. Secondly, a coordination estimation method is further applied to identify the parameters of the DFIG and the drive train simultaneously with the purpose of attaining the global optimal estimation results. The main benefit of the proposed scheme is the improved estimation accuracy. Estimation results confirm the applicability of the proposed estimation technique.
关键词： wind turbine generator DFIG drive train system hierarchical parameter estimation method trajectory sensitivity technique
Evaluation of the harmonic scalpel in open surgery for abdominal aortic aneurysm
null
《医学前沿（英文）》 2012年 第6卷 第1期 页码 85-88 doi: 10.1007/s11684-012-0174-x
The harmonic scalpel is a hemostatic device primarily designed for use in laparoscopic surgery. During the last few years, many surgeons have begun to use the harmonic scalpel in open surgery. Several papers have cited the benefits of the device compared with conventional knot-tying techniques; however, no evidence showing the advantages of using the harmonic scalpel in complicated abdominal aortic aneurysm (AAA) surgery has been presented. The aim of the present study is to determine the value of the harmonic scalpel in open operation for AAA. A total of 153 patients who underwent open surgery for AAA at the Department of Vascular Surgery of Guangdong General Hospital, China between January 2001 and December 2010, were retrospectively analyzed. Open surgery performed with the harmonic scalpel on 105 patients was compared with open operation using conventional knot-tying techniques on 48 patients. The operative time, intraoperative blood loss, total postoperative drainage fluid volumes, hospital stay, and postoperative complications between the two groups were compared. The harmonic scalpel group was associated with a shorter operation time (113.2±23.6 min vs. 232.1±39.2 min, P<0.01) and lower intraoperative blood loss (126.1±96.6 ml vs. 592.1±207.2 ml, P<0.01). Postoperative drainage fluid volumes were greater in the conventional surgery group than in the harmonic scalpel group (702.1±192.8 ml vs. 198.5±97.4 ml, P<0.01). The hospital stay was shorter for the harmonic scalpel group than for the conventional surgery group (10.7±3.3 d vs. 16.5±4.7 d, P<0.05). No differences between the postoperative complications or hospital mortality of the two groups were found. The harmonic scalpel is a safe and minimally invasive tool in open surgery for AAA and is associated with shorter operative time, shorter hospital stay, and lower intraoperative blood loss and postoperative drainage fluid volumes compared with conventional knot-tying techniques.
关键词： abdominal aortic aneurysm harmonic scalpel minimally invasive
System construction of a four-side primary permanent-magnet linear motor drive mechanical press
Jintao LIANG, Zhengfeng MING, Peida LI
《机械工程前沿（英文）》 2020年 第15卷 第4期 页码 600-609 doi: 10.1007/s11465-020-0597-z
关键词： mechanical press direct drive primary permanent-magnet linear motor (PPMLM) servo system active disturbance rejection control (ADRC) prototype experiment
丁荣军,刘侃
《中国工程科学》 2019年 第21卷 第3期 页码 56-60 doi: 10.15302/J-SSCAE-2019.03.018
本文探讨了新能源汽车电机驱动系统的关键技术及发展趋势，包括驱动控制器中的功率半导体器件及封装、智能门极驱动、基于器件的系统集成设计，以及驱动电机中的扁铜线、多相永磁电机、永磁同步磁阻电机等关键技术。其中，着重介绍了当前车用电机驱动技术的发展趋势，并指出永磁同步电机在未来10 年内将依然是新能源汽车市场的主流驱动电机。同时，通过横向比较指出当前我国在驱动电机发展道路上所面临的关键问题，可以为我国未来新能源汽车技术发展提供一定参考。
Shoudao HUANG, Xuan WU, Xiao LIU, Jian GAO, Yunze HE
《机械工程前沿（英文）》 2017年 第12卷 第3期 页码 281-302 doi: 10.1007/s11465-017-0442-1
Electric power conversion system (EPCS), which consists of a generator and power converter, is one of the most important subsystems in a direct-drive wind turbine (DD-WT). However, this component accounts for the most failures (approximately 60% of the total number) in the entire DD-WT system according to statistical data. To improve the reliability of EPCSs and reduce the operation and maintenance cost of DD-WTs, numerous researchers have studied condition monitoring (CM) and fault diagnostics (FD). Numerous CM and FD techniques, which have respective advantages and disadvantages, have emerged. This paper provides an overview of the CM, FD, and operation control of EPCSs in DD-WTs under faults. After introducing the functional principle and structure of EPCS, this survey discusses the common failures in wind generators and power converters; briefly reviewed CM and FD methods and operation control of these generators and power converters under faults; and discussed the grid voltage faults related to EPCSs in DD-WTs. These theories and their related technical concepts are systematically discussed. Finally, predicted development trends are presented. The paper provides a valuable reference for developing service quality evaluation methods and fault operation control systems to achieve high-performance and high-intelligence DD-WTs.
关键词： direct-drive wind turbine electric power conversion system condition monitoring fault diagnosis operation control under faults fault tolerance
Electromagnetic interference modeling and suppression techniques in variable-frequency drive systems
Le YANG, Shuo WANG, Jianghua FENG
《机械工程前沿（英文）》 2018年 第13卷 第3期 页码 329-353 doi: 10.1007/s11465-018-0466-1
Electromagnetic interference (EMI) causes electromechanical damage to the motors and degrades the reliability of variable-frequency drive (VFD) systems. Unlike fundamental frequency components in motor drive systems, high-frequency EMI noise, coupled with the parasitic parameters of the trough system, are difficult to analyze and reduce. In this article, EMI modeling techniques for different function units in a VFD system, including induction motors, motor bearings, and rectifier-inverters, are reviewed and evaluated in terms of applied frequency range, model parameterization, and model accuracy. The EMI models for the motors are categorized based on modeling techniques and model topologies. Motor bearing and shaft models are also reviewed, and techniques that are used to eliminate bearing current are evaluated. Modeling techniques for conventional rectifier-inverter systems are also summarized. EMI noise suppression techniques, including passive filter, Wheatstone bridge balance, active filter, and optimized modulation, are reviewed and compared based on the VFD system models.
关键词： variable-frequency drive (VFD) electromagnetic interference (EMI) motor drive modeling EMI noise suppression
Solid-state transformer-based new traction drive system and control
Jianghua FENG, Jing SHANG, Zhixue ZHANG, Huadong LIU, Zihao HUANG
《机械工程前沿（英文）》 2018年 第13卷 第3期 页码 411-426 doi: 10.1007/s11465-018-0467-0
A new type of traction drive system consisting of solid-state traction transformer (SSTT), inverter unit, auxiliary inverter, traction motor and other key components is built in order to suit the demand of developing the next-generation electric traction system which will be efficient and lightweight, with high power density. For the purpose of reducing system volume and weight and improving efficiency and grid-side power quality, an efficient SSTT optimized topology combining high-voltage cascaded rectifiers with high-power high-frequency LLC resonant converter is proposed. On this basis, an integrated control strategy built upon synchronous rotating reference frame is presented to achieve unified control over fundamental active, reactive and harmonic components. The carrier-interleaving phase shift modulation strategy is proposed to improve the harmonic performance of cascaded rectifiers. In view of the secondary pulsating existing in a single-phase system, the mathematical model of secondary power transfer is built, and the mechanism of pulsating voltage resulting in beat frequency of LLC resonant converter is revealed, so as to design optimum matching of system parameters. Simulation and experimental results have verified that the traction system and control scheme mentioned in this paper are reasonable and superior and that they meet the future application requirements for rail transit.
关键词： solid-state traction transformer high-voltage cascaded rectifier LLC resonant converter synchronous rotating reference frame carrier-interleaving phase shift control secondary pulsating voltage beat frequency
Multi-harmonic forced vibration and resonance of simple beams to moving vehicles
《结构与土木工程前沿（英文）》 页码 981-993 doi: 10.1007/s11709-023-0979-5
关键词： forced vibration linear Euler beam moving load harmonic structure frequency modulation end restraints
Power control of dual-motor electric drive for tracked vehicles
Yuan ZOU, Chengning ZHANG, Fengchun SUN, Jingbo WU,
《机械工程前沿（英文）》 2010年 第5卷 第1期 页码 67-72 doi: 10.1007/s11465-009-0059-0
Hu SHI, Guofang GONG, Huayong YANG
《机械工程前沿（英文）》 2011年 第6卷 第3期 页码 369-376 doi: 10.1007/s11465-011-0223-1
Focusing on a segment erector of a shield-tunneling machine developed with 6 degrees of freedom (DOF) and controlled by electro-hydraulic proportional systems, the kinematics of the segment erection process is presented. The perturbation method in the error analysis is introduced to establish the position and attitude error model, considering a number of factors such as the hydraulic drive, control accuracy, and tolerance in manufacturing and assembly. Dynamic simulations are carried out to obtain the controlling precision of electrohydraulic drive systems. Formulas for calculating the position and attitude error of the grip hand of the segment erector are derived. The calculation results verify the practicality and effectiveness of the error analysis, providing a foundation for practical designing, manufacturing, and assembling of the segment of the erecting mechanism.
关键词： shield tunneling machine segment erector kinematics position and attitude precision
SCRaMbLE drive application of synthetic yeast genome
Jin Jin, Yuan Ma, Duo Liu
《化学科学与工程前沿（英文）》 2018年 第12卷 第4期 页码 832-834 doi: 10.1007/s11705-018-1749-0
Effects of elastic support on the dynamic behaviors of the wind turbine drive train
Shuaishuai WANG, Caichao ZHU, Chaosheng SONG, Huali HAN
《机械工程前沿（英文）》 2017年 第12卷 第3期 页码 348-356 doi: 10.1007/s11465-017-0420-7
The reliability and service life of wind turbines are influenced by the complex loading applied on the hub, especially amidst a poor external wind environment. A three-point elastic support, which includes the main bearing and two torque arms, was considered in this study. Based on the flexibilities of the planet carrier and the housing, a coupled dynamic model was developed for a wind turbine drive train. Then, the dynamic behaviors of the drive train for different elastic support parameters were computed and analyzed. Frequency response functions were used to examine how different elastic support parameters influence the dynamic behaviors of the drive train. Results showed that the elastic support parameters considerably influenced the dynamic behaviors of the wind turbine drive train. A large support stiffness of the torque arms decreased the dynamic response of the planet carrier and the main bearing, whereas a large support stiffness of the main bearing decreased the dynamic response of planet carrier while increasing that of the main bearing. The findings of this study provide the foundation for optimizing the elastic support stiffness of the wind turbine drive train.
关键词： wind turbine drive train elastic support dynamic behavior frequency response function
Design and analysis of a new high frequency double-servo direct drive rotary valve
Muzhi ZHU,Shengdun ZHAO,Jingxiang LI
《机械工程前沿（英文）》 2016年 第11卷 第4期 页码 344-350 doi: 10.1007/s11465-016-0406-x
Researchers have investigated direct drive valve for many years to solve problems, such as fluid force imbalance and switching frequency. The structure of the rotary valve has received considerable research interest because of its favorable dynamic properties and simple structure. This paper studied the high frequency double-servo direct drive rotary valve (DDRV), and proposed a novel structure and drive method satisfying high reversing frequency and adequate quantity of flow. Servo motors are integrated into the valve by the innovative structure, which is designed to equilibrate the unbalanced radial fluid force with the symmetric distributed oil ports. Aside from the fast reversing function of the valve, the DDRV presented high performance in linearity of the flow quantity and valve opening as a result of the fan-shaped flow ports. In addition, a computational fluid dynamics (CFD) method based on Fluent was conducted to verify the flux regulation effect of the height change of the adjustable boss.
关键词： direct drive rotary valve computational fluid dynamics (CFD) flow regulation
标题 作者 时间 类型 操作
Meshing stiffness property and meshing status simulation of harmonic drive under transmission loading
期刊论文
Hierarchical parameter estimation of DFIG and drive train system in a wind turbine generator
Xueping PAN, Ping JU, Feng WU, Yuqing JIN
期刊论文
System construction of a four-side primary permanent-magnet linear motor drive mechanical press
Jintao LIANG, Zhengfeng MING, Peida LI
期刊论文
Overview of condition monitoring and operation control of electric power conversion systems in direct-drive
Shoudao HUANG, Xuan WU, Xiao LIU, Jian GAO, Yunze HE
期刊论文
Electromagnetic interference modeling and suppression techniques in variable-frequency drive systems
Le YANG, Shuo WANG, Jianghua FENG
期刊论文
Solid-state transformer-based new traction drive system and control
Jianghua FENG, Jing SHANG, Zhixue ZHANG, Huadong LIU, Zihao HUANG
期刊论文
Power control of dual-motor electric drive for tracked vehicles
Yuan ZOU, Chengning ZHANG, Fengchun SUN, Jingbo WU,
期刊论文
Drive system design and error analysis of the 6 degrees of freedom segment erector of shield tunneling
Hu SHI, Guofang GONG, Huayong YANG
期刊论文
Effects of elastic support on the dynamic behaviors of the wind turbine drive train
Shuaishuai WANG, Caichao ZHU, Chaosheng SONG, Huali HAN
期刊论文
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