Ф2.2m×6.5m磨机大齿圈振动一例

1故障情况 2000年4月,我厂一分厂Ф2.2m×6.5m水泥磨大修后,出现大齿圈每转1周有2次振动和异响的现象.大齿圈齿型为直齿,齿数158,模数22,齿宽360mm,转速21.4r/min.我厂对可能引起大齿圈振动的各因素进行了排查,包括大小齿轮的轮齿表面、齿顶间隙、啮合接触面积、两半大齿圈连接处的相邻两齿顶面径向跳动、两半大齿圈剖分面塞尺塞入深度、连接螺栓的紧固程度等,未发现异常.     

回转窑等转筒设备传动开式齿轮的研究(Ⅴ)——渐开线齿轮传动振动原因分析与控制

从多方面对回转窑等转筒设备边缘传动齿轮振动产生的原因进行了分析和归纳,阐述了振动的控制阶段和控制方法。在设计方面分析了齿轮受力方向、重合度、滑动率差、变位系数、齿宽系数、刚度及硬度等因素;在制造方面分析了齿轮端面和径向跳动、回转筒体的同轴度、齿轮精度、硬度、挡轮和轮带接触锥角、轴承装配间隙等因素;在安装方面分析了齿轮侧隙、齿轮平行度、大齿圈的联接紧固情况、膜片联轴器同轴度和基础等因素;在使用方面分析了润滑油黏度、齿轮浸油深度、润滑方式、轴承磨损、齿轮磨损、支承零件磨损、轴瓦磨损(或烧瓦)和磨机中空轴中心标高变化等因素。得出综合分析才能对振动原因做出正确判断的结论。     

窑中大齿圈调向的处理方法

我公司于1994年建成并投产了一条2000t/d的熟料生产线,自运转以来到现在,由于大齿轮圈和窑体位置的变化以及恶劣的工作环境,致使大齿轮表面无规则性的磨损相当严重,齿轮啮合接触面远远达不到标准要求,再加上齿圈弹簧板变形,销孔由于磨损比原来扩大了7mm,两半齿圈接触面达到2mm的间隙,经测量齿圈的径向跳动(偏摆)达9mm,由此引发窑体振动急剧增大,大齿圈对口面联接螺栓频繁断裂,严重影响了窑的运转率和工艺操作的稳定性,成本大幅提高.     

边缘传动磨机大小齿轮齿隙的选择及控制

边缘传动磨机大小齿轮的齿隙(尤其是齿侧间隙)是齿轮啮合的重要指标,必须正确选择并加以控制。边缘传动磨机大小齿轮齿隙的选择,新磨机安装,要采用控制齿侧间隙的方法,并同时测量齿顶间隙作为以后检修时的参考;调校及检修,要采用控制齿顶间隙的方法。     

球磨机大小齿轮的安装

介绍了球磨机边缘传动装置的安装找正方法,通过大小齿轮的找正和齿顶隙、齿侧隙的调整,满足大小齿轮啮合面接触面积不小于齿高的40%、齿宽的50%,确保齿轮安装质量和使用寿命。     

回转窑等转筒设备传动开式齿轮的研究(Ⅴ)#br# ——渐开线齿轮传动振动原因分析与控制

从多方面对回转窑等转筒设备边缘传动齿轮振动产生的原因进行了分析和归纳,阐述了振动的控制阶段和控制方法。在设计方面分析了齿轮受力方向、重合度、滑动率差、变位系数、齿宽系数、刚度及硬度等因素;在制造方面分析了齿轮端面和径向跳动、回转筒体的同轴度、齿轮精度、硬度、挡轮和轮带接触锥角、轴承装配间隙等因素;在安装方面分析了齿轮侧隙、齿轮平行度、大齿圈的联接紧固情况、膜片联轴器同轴度和基础等因素;在使用方面分析了润滑油黏度、齿轮浸油深度、润滑方式、轴承磨损、齿轮磨损、支承零件磨损、轴瓦磨损（或烧瓦）和磨机中空轴中心标高变化等因素。得出综合分析才能对振动原因做出正确判断的结论。     

采用偏心找正解决球磨机中空轴不同心度严重超差

我厂73年安装了一台中心传动棒球磨机(φ2.4×13米),由于磨机制作质量差,在运行时传动接管法兰径向跳动量达10毫米,不能正常运转,其原因是胴体两端接口不同心及两端面不平行。因此,只得将磨机主要部件送回原制造厂返修,于78年修复安装后,运转时传动接管法兰径向跳动仍达2.6毫米,而按照磨机安装规范,只允许径向跳动量为0.2毫米。减速机要求磨机传动接管外端法兰径向跳量在0.1毫米之内。     

Φ3.6m×30m烘干机筒体窜动和传动装置振动的处理

<正>2012年12月20日本公司的Φ3.6m×30m烘干机突然出现了不正常现象,严重影响到其它设备的正常运转。具体情况如下:(1)烘干机回转筒体上下窜动,两个挡轮都受到了不同程度的损伤;同时由于烘干机回转筒体的上窜,导致炉膛的弧形圆圈塌落造成停机。(2)烘干机传动装置振动大,运行不平稳。停机后检查发现大小齿轮的啮合过紧即我们常说的齿顶间隙太小,实测只有2.5mm,理论齿顶间隙为8mm。根据存在的这些问题,制定了针对性的检修方案,具体如下。     

管磨机振动原因的查找与处理

我厂φ2.6×13米管磨机,传动小齿轮与大齿轮啮合时,发出不正常响声,振动惊人。磨机开动后,整个磨房感到抖动,因此无法生产。为解决这一问题,我们对磨机齿轮进行了检测,具体做法如下: 一、在大小齿轮制造上找原因把油箱里润滑油全部放出,将齿洗净,对齿形制造有关的数据(模数、齿厚、齿间、公法线等)作了详细测量。同时对大齿圈的不     

Ф3m×12.5m水泥磨齿轮磨损分析

某水泥厂使用的Ф3m×12.5m水泥磨的大小齿轮使用了仅3个月,齿厚磨损接近四分之一,严重影响了磨机的运行。通过检查齿轮磨损情况并结合弹性流体润滑理论进行分析,成功解决了该磨机齿轮磨损问题。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。