Design and experimental validation of a novel double ring plate gear reducer

A novel double ring plate gear reducer (DRPGR) is designed and its experimental validation is conducted. By using the closed graph method, the modification coefficients of internal gearing in DRPGR are determined. Based on this, the overall structure of the reducer is designed and its kinematics simulation is achieved. With APDL programming language of ANSYS, a 3D finite element (FE) model of DRPGR is established, and its modal analysis and loaded tooth contact analysis (LTCA) are conducted respectively. The modal analysis reveals that the lower natural frequencies of DRPGR are much higher than the input frequency and the lower modes can be classified as vertical and horizontal bending of input and output shafts. The LTCA indicates that three pairs of gear teeth contact simultaneously at rated output torque. Due to the multi teeth contacts, the maximum stress is much lower than the permissible stress of internal gearings. The experimental tests of the prototype validate that DRPGR is adapted to both single driven and dual driven work condition. When single droved, DRPGR can eliminate the kinematic uncertainty by non 180 degree phase difference design. DRPGR claims a better dynamic performance in dual driven work condition. The efficiency of DRPGR increases with the increment of output torque and the reducer has an excellent short term overloaded capacity. The experimental results validate that the proposed method can be used to guide the design of that kind of reducer.     

A gamete abortion locus detected by segregation distortion of isozyme locus Est-9 in wide crosses of rice (Oryza sativa L.)

Summary A locus for male gamete abortion in hybrids for Japonica and Indica rice was identified with the aid of marker genes Rc and Est-9 on chromosome 7. In an Indica-Japonica cross, AKAMAI 1/IR50, the Indica allele Est-9 ² was transmitted via the male gamete with a ratio of 0.29 instead of the normal 0.5, whereas no segregation distortion was observed for the Rc locus. The recombination value (p) for Est-9 and Rc was estimated to be 0.38 by a least square method after adjusting Mendelian segregation ratios with the male transmission ratios of 0.29 (Tr) for Est-9 ² and 0.71 (1-Tr) for Est-9 ¹. The recombination value (q) for the new locus for male gamete abortion, ga-11, and Est-9 was estimated to be 0.23 by using 56 F₃ lines from F₂ plants which were heterozygous for the Est-9 locus. No linkage for Rc and ga-11 was found. Therefore, the two markers and ga-11 were located in the order of ga-11-Est-9-Rc. Using the estimated recombination value (q), the male transmission rate (k) of ga-11 ^a was estimated to be 0.11 with the F₂ data and-0.07 with the F₃ line data. Thus, it was apparent that male gametes possessing ga-11 ^a were frequently aborted in the Indica-Japonica hybrid.     

基于逆系统方法的直驱式AMT换挡控制方法

为提高直驱式AMT换挡品质的稳定性,针对2自由度电磁执行器的特性引入逆系统控制方法。阐述了执行器的结构及工作原理,通过建模分析了执行器参数耦合现象,执行器静态特性测试表明其输出特性具有非线性的特点。引入逆系统方法并分析系统的可逆性,建立执行器的伪线性系统并根据线性系统理论设计状态反馈控制器。扩张状态观测器的引入提高了系统在摩擦阻力时变条件下的输出特性稳定性。仿真与试验结果表明,基于逆系统方法的换挡控制受参数变化影响小,位移控制精度较高,执行器输出特性较为稳定,基于逆系统方法的直驱式AMT换挡性能较为突出,有利于提升AMT竞争力。     

基于N:N网络和GPRS传输技术的综合供水系统

为了实现对消防和生活供水系统的自动变频控制和集中管理,设计了综合供水系统.本系统通过N:N网络现场总线技术使现场各系统之间可以进行数据交换,并利用GPRS传输实现组态王对现场的远程实时监控.该系统在太原市邮政局的成功应用既节约了大量能源,也提高了系统管理的效率.     

电控电执行器自动变速器的开发研究

从电控电执行器自动变速器的结构、工作原理及设计要点出发,对电控电执行器自动变速器的开发进行了研究,并对其执行机构电磁离合器的开发做了重点阐述。结合中国变速器的现状,对在中国进行电控电执行器自动变速器开发的可行性进行了论述。     

湿式双离合器自动变速器液压系统仿真分析

利用AMESim软件对湿式双离合器自动变速器液压系统的主要子系统进行仿真分析,根据仿真分析的结果分析模型的合理性及影响各子系统的主要参数,为湿式双离合器自动变速器液压系统的设计及改进提供依据。     

重型拖拉机异形变速箱体柔性加工工艺浅析

通过分析大型异形变速箱壳体的结构特点,进行柔性加工工艺设计,解决了大型异形变速箱壳体的定位基准选择、夹紧变形、深孔加工等问题,用两道工序即可完成大型异形变速箱壳体6个方向的加工。加工调试的实践表明,大型异形变速箱壳体的夹紧变形不容忽视。     

节水灌溉自动控制器的设计与研究

论述了一种自动化节水灌溉控制系统的硬件设计、外部连线及其使用功能。系统控制器以与8051完全兼容的GMS90L51单片机为核心，采用计算机分布式管理；系统有传感器自动闭环控制、手动／半手动控制、微机超控等多种工作方式；系统能够实现自动化灌溉，具有排水警示、实时时钟、历史数据查询、数据上传及双向通信等功能。     

大中型泵站行星变速传动装置的分析与应用

简单地分析了国内大、中型泵站传动装置的现状，讨论了泵站用变速调节装置的作用，并对现有的双速电机调速、液力耦合器和磁力耦合器调速以及变频调速装置进行了分析和讨论，指出了其适用的局限性。提出了一种用新型2X-H型行星齿轮变速箱调节泵速度的方法，给出了3种具体方案。通过对各方案的配齿进行具体计算和分析，得出第2种方案具有行星轮系的结构简单，传动效率高的特点。     

无线传输技术在农产品长势及质量监测中的应用

介绍了几种无线传输在农产品长势和质量检测中的应用,数字农业管理中引入无线传输技术后,可以对农牧业产品实时动态监控。首先,对几种传输技术进行简要概括。其次,重点介绍ZigBee技术在数字化果园中的研究,FRID技术在禽牧产品管理和可追溯性研究以及遥感技术在农作物长势监测研究。最后,对无线传输在农牧业数字化管理中的应用做出了总结及展望。