应用变频理论改造J2205型胶印机电路系统的工程实践

一、引言 J2205型胶印机(以下简称05机)是北京人民机器厂上世纪80年代的产品,此机的主传动电机采用JZT2-52-4型电磁调速异步电动机,又称滑差电机(11KW,120-1200r/min),其制动由制动离合器控制.     

RC4切丝机制动装置的改造

ＲＣ４切丝机主电机采用交流变频调速后，在发生故障停机时不能快速刹车（制动过程需２０ｓ左右），对设备和人身安全威胁极大，有必要进行改造。介绍了一种采用能耗制动的改造方案，使改造后的ＲＣ４切丝机在故障或紧急停机时能快速制动（制动时间在２ｓ左右），为拥有同类型机的用户提供了一种可供借鉴的改造方案。     

J2205型胶印机采用变频器电路改造方案

在印刷的微利时代,节能降耗,首当其冲地成为了印刷厂节流的重点.我厂有3台老式J2205型胶印机,主电机均为电磁滑差调速电机,能耗大,为了节能我们采用了变频技术,利用G9变频器对其进行改造,设备运转正常,效果良好.现将技改的主要内容介绍如下.     

YEJ系列电磁制动电动机吸合性能简便测试方法

1概述YEJ系列电磁制动电动机是Y系列电动机派生产品，具有制动快捷、可靠，结构紧凑、噪声低，操作简单等特点，适用于拖动运输机械、升降工作机械以及木工机械中的某些需要准确安全制动定位的场合。根据《YEJ系列电磁制动异步电动机技术条件》的要求，必须对制动电动机吸合性能的测定，以确保能否可靠、安全地满足工程使用的要求，为此在制动电机出厂或用户在使用过程中更换电磁制动器后，必须对制动电机吸合性能进行检测。本文介绍一种较简便的测试方法。2制动电机的结构和基本原理。YEJ系列电磁制动电机的结构见图1当制动电机与三相…     

气压制动在1452A（G）型整经机上的应用

气压制动在１４５２Ａ（Ｇ）型整经机上的应用１４５２Ａ（Ｇ）型整经机原制动装置为电动机能耗制动，存在一些不足：（１）刹车电流大易烧毁电机。刹车时电流高达３０Ａ，是电动机额定电流的四倍（正常运转时电流仅４Ａ），因此，当频繁刹车时，导致定子过热而烧毁。（２...     

探讨纸凹机控制系统的制动问题

纸张凹版印刷机张力控制系统分放卷、放卷牵引、收卷牵引、收卷四个部分.收放卷电机在大惯量停车或正常工作过程中,有时会处于发电状态,当放卷牵引和收卷牵引的前后张力调节失衡时也会处于发电状态,而系统的制动均采用单台变频器的能耗制动模式,即电机处于发电状态时所产生的再生能量全部消耗到制动电阻,这样个别变频器制动电阻温度会比较高,有的制动电阻甚至被烧坏.     

变频器连续再生电力的应用

在多台变频器和电机构成的化纤丝牵伸卷绕机系统中变频器之间通过直流母线连接,将卷绕丝一侧产生的连续再生电力,使用在卷绕另一侧,从而达到节能以及制动元件减少的低碳效果。     

多尼尔喷气织机单片制动离合器的调整和改造

ＤＯＲＮＩＥＲＬＷＶ 4 /Ｓ 360型喷气织机 ,主机功率 :4ｋＷ ;织造幅宽 :360 0ｍｍ ;1 6页综框 ;车速可达 70 0ｒ/ｍｉｎ。通过单片电磁离合制动器的转换使织机分别工作在三种状态 ,即运转状态、慢速调整状态和刹车制动状态 (瞬间 )。要求主离合制动器工作响应快 ,工作寿命长 ,可靠度高。特别在高速运转状态下 ,快速接合 ,机器起动或刹车的滑移角度要小 ,保证与设定的工艺角度相一致。( 1 )原理与调整图 1　制动离合器结构示意图如图 1所示 ,Ａ为起停离合作用的定盘 ,由螺栓Ｈ固定在惯性飞轮上 ,机器通电即随主驱动电机旋转 ,Ｃ为刹车制动…     

变频电机改造 年节约电费3万元

<正>20世纪90年代以后生产的一些印前、印刷及印后设备的主传动电机,陆续应用了新式节电型电机,即变频调速电磁制动三相异步电动机。但是,一些老设备还是延续应用20世纪七八十年代生产的可调速的主     

制动电阻在引风机变频控制中的应用

由于变频调速的诸多优势,变频调速技术在工业生产中得到了广泛应用。在变频调速中,当系统的惯性较大,电机的转速在迅速下降或快速停机,电机将产生再生电能回馈到变频器的直流母线上,导致直流电压升高,保护动作,造成停机,本文将对此类工业环境中制动电阻的应用做简单论述。     

变频器过电压的原因以及对策

过电压现象是变频器运行中最常见的故障之一，直流制动与再生制动功能是防止过电压产生的最主要的手段，而再生制动功能是解决因外力拖动而使电机处于再生状态所引起的变频器过电压的唯一有效措施。     

全自动胶囊充填机控制系统改进设计

本文通过对进口样机进行消化、吸收，分析了样机有触点继电器逻辑控制主轴定位不准的蔽病，提出了用无触点可编程控制器控制不但主轴定位正确，而且无惯性冲击，解决了凸轮低惯量负载主轴定位的难题。进一步完善了整机控制功能。     

台达变频器保证粗纱机多电机同步制动

为了实现变频器驱动的粗纱机事故掉电时不断线,要求传动控制系统具有同步制动功能.提出了变频器外挂电容再生同步制动原理设计和参数计算方法.     

电锭细纱机制动特性研究

为了减小细纱机纱线卷绕时的纱线张力、降低断头率,本文优化设计了电锭专用无刷直流电机速度调节曲线。同时,为了使电锭电机快速制动,针对回馈制动低速时制动力矩不足的问题,提出了能量回馈制动+反接制动的混合制动控制策略,并利用MATLAB/SIMULINK进行了仿真分析。结果表明,使用回馈制动+反接制动的控制方法,与电锭电机自由停转相比,制动时间减少了80%,蓄电池电量增加了0.007 5%的能量,制动效果良好。     

钢丝拉拔和镀锌设备安全停机装置设计

拉拔和镀锌设备原安全停机装置设计中的主要缺陷:不能单独停止其中的一个设备;操作空间较大,控制点相对较远;设备运行速度太快,反应时间不够等。针对这些缺陷进行改进:采取全方位的钢丝绳连接行程开关,配合电磁刹车装置,可以在设备周围任何操作位置实现紧急停机。介绍全方位安全停机装置的工作原理和主要设计内容,此安全停机装置覆盖面广、联动性强、停机迅速,不影响设备正常运转,降低了安全事故的发生几率。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.