S222型浆纱机两单元传动改造实践

<正>我公司有一台20世纪80年代生产的S222型单浆槽浆纱机。经过长期运行,该机无级变速器由于正常磨损和传动链条国产化,链条经常磨损断裂,最终导致无级变速器摩擦盘损坏,造成浆纱卷绕张力不稳定,电控部分由于调节动作频繁也经常损坏,设备故障率高。由于无级变速器价格昂贵,我们将该浆纱机卷绕张力调节部分由一单元传动改成两单元传动。具体做法如下。首先去掉无级变速器机构及它与速度分配器相连的输入轴。在原位置处安装一台变频调速三相异步电动机(22 k W,转速     

ZW系列喷水织机送经无级变速器的失效分析与修复

一、概述ＺＷ系列喷水织机为了保证连续式全自动积极送经 ,采用Ｚｅｒｏ—Ｍａｘ式送经机构—机械无级变速器。无级变速器通过自动调节系统在运转中自动变速来精密调节送经量和织造张力 ,使它们在织造过程中始终满足工艺要求。无级变速器一旦失效 ,织物质量就无法保证。　　二、无级变速器的机构分析无级变速器由超越离合器和七杆机构两部分组成 ,机构简图见图 1。图 1　无级变速器机构简图七杆机构由曲柄ＯＡ(实物是铜偏心块 )、摇杆ＡＢ、连杆ＢＣ(实物呈曲折形 )、调节杆ＢＦ(实物圆弧形 )、调节框架ＥＦ杆、摆杆ＣＤ(即超越离合器的外环…     

FUX4型无级变速器在ASGA363型浆机上的应用

ASGA363型浆机采用的是一单元传动结构.由15kW主电机经齿轮箱、传动轴分为两路,一路传给边轴传动,另一路经电磁离合器传人无级变速器入轴,然后经 UG3-Wi型无级变速器输出传给强轴, 然后经 UG3-Wi型无级变速器输出传给织轴卷绕动.     

现代无级变速器的理论研究

文章首先基于端面摩擦传动的理论对无级变速器进行了结构设计,为了更好地将端面摩擦传动的形式应用在变速器上,设计出了一款新型的小轮,可以减小变速所需推动力。文章验证了基于端面摩擦传动原理的无级变速器应用的可行性,为适用于汽车等无级变速器研制的进一步完善和端面摩擦传动的研究提供了支持。     

浆纱机卷绕机构GZX-3的应用探讨

浆纱机的卷绕机构与浆轴质量和织机效率密切相关。目前,浆纱机卷绕机构使用形式较多,有行星齿轮差动轮系、摩擦夹盘式、电磁滑差式,力矩电机式、直流电动可调式,GZB-2无级变速器、GZX-3无级变速器等多种形式。其中重锤式张力自动调整无级变速器GZX—3(常德纺织机械厂生产)是一种新颖的机械式卷绕机构,它是在GZB-2型无级变     

超九卷接机组料斗驱动系统的改进

超九卷接机组的后身驱动系统由主传动器、无级变速器、电磁离合器、细刺辊和粗刺辊等组成。其工作原理为：主传动器经传动皮带带动无级变速器,无级变速器的输出经电磁离合器带动细出辊和粗出辊,最后通过粗出辊等将烟丝输送到烟枪。改进后身调速系统原理因无级变速器输出速度的大小决定着回丝量,回丝量的大小将影响烟支的多项质量指标,因此,保证无级变速器输出速度的稳定性和可调性十分重要。在实际生产中,我们经常遇到自动状态下回丝量不稳定,手动状态下回丝量不可调等故障。自动状态下回丝量不稳定的主要原因是从动机构式无级变速器…     

PUX4型无级变速器在ASGA363型浆纱机上的应用

ASGA363型浆纱机采用的是一单元传动结构。由15kW主电机经齿轮箱、传动轴分为两路,一路传给边轴传动,另一路经电磁离合器传人无级变速器人轴,然后经UG3-Wi型无级变速器输出传给织轴卷绕传动。经过几年的运转使用发现,ASGA363型浆纱机在生产中经常出现设备故障,主要机件锥形盘、齿轮、压力凸轮严重磨损、变形,造成原机所配置的UG3-Wi型无级变速器输出速度差异过大,织轴卷绕张力失调,严重影响了浆纱机正常的运转和生产,同时造成大量浆料和回丝的浪费。     

介绍一种机械式无级变速齿轮箱

我厂引进一条由瑞士摩拉公司设计制造的玻璃纸机，其中湿部由于各个槽子内的辊子转速要求不同，因此需进行无级调速，所以槽子内的棍子的传动均采用机械式无级变速齿轮箱。机械式无级变速齿轮箱由无级变速器和齿轮箱两部分组成（如图1），传动通过齿轮箱的输入轴、齿轮箱内的齿轮哨合传入无级变速器，由无级变速器带动固定有行星轮的大齿轮，使充当介轮的行星轮回转的转速改变而使输出轴的转速变化，达到输出轴变速的目的。图1齿轮箱结构简图转动调速手轮（如图2），由无级变速器内的两个龄轮（类似齿轮）带动调节套上的齿条，改变两对锥形…     

七连杆无级变速器的应用

本文对日本津田驹ZA202喷气织机的送经机构中采用的七连杆无级变速器的工作原理进行了详细的分析,探讨了该无级变速器在织机上的一些应用,以便能为织机使用者和机械结构的设计人员提供参考。     

基于ADAMS软件的WWB型脉动式无级变速器速度分析

脉动式无级变速器属机械式无级变速器一类,具有传动可靠、操作方便、价格低廉等优点,在纺织、塑料、食品、电子等行业有着广泛的应用。WWB型脉动式无级变速器是新研制的一种变速器。通过调整机架Ⅰ和机架Ⅱ之间的夹角θ进行调速。因而具有调速平稳的特点。用ADAMS软件对该变速器在机架变动范围内取5个位置分别进行了建模和运动仿真分析,得出各位置的输出速度和速度波动系数,分析结果表明,随θ的增大,变速器的输出速度减小,同时输出的速度波动系数也减小,当增到36&#176;时机构的输出速度为零,实现了零转速的输出。     

Growth energetics of Lactococcus lactis subsp. lactis biovar diacetylactis in cometabolism of citrate and glucose

Certain strains of lactic acid bacteria present in commercial cheese starters, characterized by faint transparent colonies on an agar plate containing 1 mg kg ⁻¹ crystal violet (CVT), were identified as Lactococcus lactis subsp. (ssp) lactis biovar diacetylactis. The effect of citrate on the growth of these strains (CVT strains) in the presence of glucose was studied, in comparison with L. lactis strains. Molar growth yield from glucose (Y_G, g dry weight/mole of glucose consumed) for CVT strains grown on glucose plus citrate was significantly higher than the control (i.e. without citrate), but not for other L. lactis strains tested. Enhanced Y_G was also observed at a pH-controlled experiment, indicating that enhanced Y_G did not result from a buffering effect of citrate. CVT strains, in contrast to other strains of the same species, were shown to obtain enough energy to enhance Y_G on glucose–citrate mixtures.     

行星锥盘无级变速器滑动率的数值计算

推导了行星锥盘无级变速器几何滑动率的计算公式,提出了一种求解其滑动率的数值计算方法,在此基础上编制了自动求解程序,并给出了计算实例。     

清梳联合机落棉试验及控制方法

为了合理控制特吕茨施勒尔清梳联合机的落棉率,提高落棉含杂率和除杂效率,对清梳联进行了落棉试验。系统落棉试验表明,该清梳联的落棉排杂主要集中在ＤＫ７６０型梳棉机、ＣＶ１３型清棉机和ＡＦＣ型双轴流开棉机上。通过对此三种设备进行落棉试验和工艺分析,从中找出了合理的落棉工艺方案。     

THE INFLUENCE OF LACTIC CULTURES ON GROUND BEEF QUALITY

SUMMARY– The effects of adding 5 and 10% lactic culture (Streptococcus lactis and Leuconostoc citrovorum) grown in skim milk; 2.5, 5, 10, and 20% lactic cultures grown in 20% milk solids; 1 and 2% frozen concentrated lactic cultures; lactic acid to pH 5.0 and 4.5; and 2.5, 5, and 10% skim milk to ground beef stored at refrigeration temperature (7°C) were studied in the 6 preliminary trials. Results obtained were used to formulate the principal investigation. The influence of 10% lactic culture and 10% lactic culture plus 450 ppm of ascorbic acid were tested in 5 replicate trials for the principal investigation. Cultures used in the replicate trials were grown in 20% milk solids. CVT (crystal violet tetrazolium) counts for gram-negative bacteria, pH, VNC (volatile nitrogen content), and organoleptic observations were evaluated. Data from the preliminary study indicated a profound inhibitory action of the lactic cultures on the growth of the inherent gram-negative bacteria in ground beef. The addition of 10% lactic culture grown in 20% milk solids was effective in preventing aerobic growth. The addition of pure lactic acid inhibited microbial growth, but caused an undesirable color and aroma. Frozen concentrated cultures required 1% lactose to inhibit the growth. The CVT count in the uncultured meat significantly increased (P < .01) as the storage time progressed. Cultured meat did not exhibit a significant increase in CVT count until 7 days of storage. The pH of the cultured meat significantly declined (P <.01) whereas the uncultured meat indicated a significant increase in pH (P < .01) during storage. VNC in the uncultured meat was significantly higher (P <.01) than in the cultured meat. Cultured meat with 450 ppm of ascorbic acid was consistently preferred for flavor, aroma, and when color was compared with the uncultured meat and the meat with culture alone.     

A quantum mechanical study on the formation of PCDD/Fs from 2-chlorophenol as precursor

The most direct route to the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in combustion and thermal processes is the gas-phase reaction of chemical precursors such as chlorinated phenols. Detailed insight into the mechanism and kinetics properties is a prerequisite for understanding the formation of PCDD/Fs. In this paper, we carried out molecular orbital theory calculations for the homogeneous gas-phase formation of PCDD/Fs from 2-chlorophenol (2-CP). The profiles of the potential energy surface were constructed, and the possible formation pathways are discussed. The single-point energy calculation was carried out at the MPWB1K/ 6-311+G(3f,2p) level. Several energetically favorable formation pathways were revealed for the first time. The rate constants of crucial elementary steps were deduced over a wide temperature range of 600 approximately 1200 K using canonical variational transition-state theory (CVT) with small curvature tunneling contribution (SCT). The rate-temperature formulas were fitted. The ratio of PCDD to PCDF formed shows strong dependency on the reaction temperature and chlorophenoxy radicals (CPRs) concentration.     

Gram Negative Bacteria Inhibition by Lactic Acid Culture and Food Preservatives on Catfish Fillets during Refrigerated Storage

Treating catfish fillets with sodium acetate (SA) and/or potassium sorbate (PS), with or without lactic culture (Lactococcus lactic spp. cremoris ATCC 19257 grown in 20% milk solids) was studied at 4°C. Gram negative bacterial (CVT) counts on crystal violet tetrazolium chloride agar, pH, and sensory evaluation of fillets were assessed over time. Treatment with the combination of 0.50% SA, 0.25% PS with 2.50% lactic acid culture (LC) and, also, 0.50 to 1.00% SA alone completely inhibited growth for 6 days at 4°C. After 12 days, counts with this treatment and the 1.00% SA increased ～1.3 and 1.2 log cycles, respectively. The antimicrobial effects did not appear to be due to pH values. The combination of 0.50% SA and 0.25% PS with 2.50% LC, or 1.00% SA, alone, improved catfish odor and appearance during 13 days storage.     

Recent Research and Progress in Food,Feed and Nutrition with Advanced Synchrotron-based SR-IMS and DRIFT Molecular Spectroscopy

Ultraspatially resolved synchrotron radiation based infrared microspectroscopy is able to detect the structure features of a food or feed tissue at cellular and molecular levels. However, to date, this advanced synchrotron-based technique is almost unknown to food and feed scientists. The objective of this article was to introduce this novel analytical technology, ultra-spatially resolved synchrotron radiation based infrared microspectroscopy (SR-IMS) to food, feed, conventional nutrition, and molecular nutrition scientists. The emphasis of this review focused on the following areas: (1) Principles of molecular spectroscopy for food and feed structure research, such as protein molecular structure, carbohydrate conformation, heating induced protein structure changes, and effect of gene-transformation on food and feed structure; (2) Molecular spectral analysis methodology; (3) Biological applications of synchrotron SR-IMS and DRIFT spectroscopy; and (4) Recent progress in food, feed and nutrition research program. The information described in this article gives better insight in food structure research progress and update.     

Mechanism and direct kinetics study on the homogeneous gas-phase formation of PBDD/Fs from 2-BP, 2,4-DBP, and 2,4,6-TBP as precursors

This study investigated the homogeneous gas-phase formation of polybrominated dibenzo-p-dioxin/dibenzofurans (PBDD/Fs) from 2-BP, 2,4-DBP, and 2,4,6-TBP as precursors. First, density functional theory (DFT) calculations were carried out for the formation mechanism. The geometries and frequencies of the stationary points were calculated at the MPWB1K/6-31+G(d,p) level, and the energetic parameters were further refined by the MPWB1K/6-311+G(3df,2p) method. Then, the formation mechanism of PBDD/Fs was compared and contrasted with the PCDD/F formation mechanism from 2-CP, 2,4-DCP, and 2,4,6-TCP as precursors. Finally, the rate constants of the crucial elementary reactions were evaluated by the canonical variational transition-state (CVT) theory with the small curvature tunneling (SCT) correction over a wide temperature range of 600-1200 K. Present results indicate that only BPs with bromine at the ortho position are capable of forming PBDDs. The study, together with works already published from our group, clearly shows an increased propensity for the dioxin formations from BPs over the analogous CPs. Multibromine substitutions suppress the PBDD/F formations.     

LNG 罐式集装箱框架结构的强度分析

通过有限元法计算分析LNG罐式集装箱在常温环境下,考虑动态惯性力影响后结构的应力水平,直观地分析出其框架在受载情况下的应力情况;对框架的结构设计提出了改进意见,使框架结构设计更加合理,以提高罐式集装箱的安全可靠性。     

Drought‐proofing barley (Hordeum vulgare) and its impact on grain quality: A review

Barley starch research is currently focused on the biosynthesis (enzymatic pathways), structure and the properties of barley grown under optimal conditions. With only limited information available on the effects of abiotic stress (drought) on starch structure, the need arises to determine the effects of genetic expression, inferring drought tolerance and its impact on starch biosynthesis and structure under terminal drought stress. Using size‐exclusion chromatography for the first time can bring an understanding of how starch molecular structure is influenced by drought tolerance trait expression; this has the potential to improve our current knowledge of starch biosynthesis, structure and properties. This understanding may aid plant breeders in producing varieties that are drought‐tolerant whilst maintaining the desired starch quality characteristics required by industry. In this review, starch hierarchical structure and molecular structural characterization methods are summarized. This is followed by an overview of our current knowledge of abiotic stress, stress tolerance and its impact on grain quality. Copyright © 2015 The Institute of Brewing & Distilling