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Effectsofmisalignmenterror,toothmodificationsand

transmittedtorqueontoothengagementsofapairofspurgears

ShutingLi⁎

DepartmentofMechanical,ElectricalandElectronicEngineering,InterdisciplinaryFacultyofScienceandEngineering,ShimaneUniversity,Matsue690-8504,Japan

articleinfoabstract

Articlehistory:Received11November2013Receivedinrevisedform3September2014Accepted16September2014Availableonline7October2014Inthelastresearch[S.Li,Effectsofmachiningerrors,assemblyerrorsandtoothmodificationsonload-carryingcapacity,load-sharingrateandtransmissionerrorofapairofspurgear,Mech.Mach.Theory42(2007)698–726],effectsofmachiningerrors,assemblyerrorsandleadcrowningontoothsurfacecontactstresses(CS),rootbendingstresses,load-sharingratios(LSR)andtransmis-sionerrorsofapairofspurgearswereinvestigatedthroughperformingloadedtoothcontactanal-ysis(LTCA)withdevelopedfiniteelementmethod(FEM)programs.Butthisresearchcouldn'tinvestigatetheeffectsoftoothprofilemodificationandleadrelievingontoothengagements.Also,theeffectsofmachiningerrors,assemblyerrorsandtoothmodificationsontoothmeshstiff-ness(MS)couldn'tbeinvestigated.So,asacontinuousstudyofthelastresearch,thispaperinves-tigatestheeffectsoftoothprofilemodificationandleadrelievingontoothengagementsofapairofspurgearsandtheeffectsofmisalignmenterrorofgearshaftsontheplaneofaction,toothleadcrowingandtransmittedtorqueontoothMS.Anarccurveisusedtomodifytoothprofilesofapairofspurgearsinthispaper.Thisisbecausethismethodisusedverypopularlyforthespurgears.Methodsusedinthelastresearcharealsousedheretoinvestigatetheeffectsofthetoothprofilemodification,leadrelievingandtransmittedtorqueontoothengagements.Basedontheresults,itisfoundthatthetoothprofilemodificationandleadrelievinghavesignificanteffectsontoothCS,LSRandMS.ItisalsofoundthattransmittedtorquehasalittleeffectontoothMS,buthasnoeffectonLSRofthegears.Forthelead-relievedgears,calculationresultsshowthatedge-loadshappenedatthejointpartsoftherelievedpartandthenon-relievedpartoftoothleadwhentheleadisre-lievedwithstraightlines.Sincetheedge-loadsresultedingreatercontactstressesatthejointpartsandweakenedtoothcontactstrength,attentionmustbepaidtotheleadrelieving.Itisnec-essarytoreducetheedge-loadsassmallaspossiblethroughmakingthejointpartsmoothwhentheleadrelievingismade.©2014ElsevierLtd.Allrightsreserved.Keywords:SpurgearsAssemblyerrorsToothmodificationsMeshstiffnessLoad-sharingratiosContactstresses

1.Introduction

Itiswell-knownthatmachiningerrors,assemblyerrorsandtoothmodificationsofapairofgearshavesignificanteffectson

vibration,noiseandstrengthofthepairofgears.Thoughthisproblemhasbeenwellinvestigatedbymanyresearchers[1–20],

manyproblems,suchashowtoestimatevibration,noiseandstrengthlevelsofapairofgearswiththemachiningerrors,assembly

errorsandtoothmodificationsexactlyintheory,havenotbeensolvedcompletely.

Umezawaetal.[3–6]conductedresearchesontoothMScalculationsofapairofgearswithtoothsurfacedeviationsusingan

analyticalmethod.InUmezawa'sresearch,toothdeformationwasdividedintotoothdeflectionandtoothapproach(resulted

fromMechanismandMachineTheory83(2015)125–136

⁎Tel./fax:+810852328908.E-mailaddress:shutingli@ecs.shimane-u.ac.jp

.

http://dx.doi.org/10.1016/j.mechmachtheory.2014.09.0110094-114X/©2014ElsevierLtd.Allrights

reserved.ContentslistsavailableatScienceDirect

MechanismandMachineTheory

journalhomepage:www.elsevier.com/locate/mechmttheHertziancontactofcontactteeth).Thetoothdeflectionwascalculatedbyacantilevertheoryandthetoothapproachwas

calculatedbytheSneddonequation.Effectofthetoothsurfacedeviationsonrotationalvibrationofapairofhelicalgearswasalso

investigated[7].

SinceitisadifficultthingtouseUmezawa'smethodtosolvetoothcontactproblemsofapairofgearswithcomplicatedmachining

errors,assemblyerrors,toothprofilemodificationsandthinrims,Li[11,12]developedFEMsoftwaretodoLTCAofapairofgearswith

machiningerrors,assemblyerrorsandtoothmodificationsbasedontheprincipleofthemathematicalprogrammingmethodpresent-

edbyConryandSeireg[13,14].Inthelastresearchoftheauthor[12],effectsofmachiningerrors,assemblyerrorsandleadcrowning

ontoothsurfaceCS,rootbendingstresses,LSRandtransmissionerrorsofapairofspurgearswereinvestigatedusingthedeveloped

FEMsoftware.Butthisresearchcouldn'tinvestigatetheeffectsoftoothprofilemodificationandleadrelievingontoothengagements.

Also,theeffectsofthemachiningerrors,assemblyerrorsandtoothmodificationsontoothMSofapairofspurgearscouldn'tbein-

vestigated.So,asacontinuousstudyofthelastresearch,thispaperinvestigatestheproblemsthathavenotbeensolvedinthelast

research.ThesamemethodsandFEMprogramsareusedtodoLTCAofapairofspurgearswithtoothprofilemodificationandlead

relieving.Theeffectsofmisalignmenterrorontheplaneofaction,toothleadcrowingandtransmittedtorqueontoothMSofthe

pairofspurgearsarealsoinvestigated.

Basedoncalculationresults,itisfoundthattoothprofilemodificationandleadrelievinghavesignificanteffectsontoothCS,LSR

andMS.ItisalsofoundthattransmittedtorquehasalittleeffectontoothMS,buthasnoeffectonLSRofthegears.Forthelead-

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1-s2.0-S0960894X10004464-main

1-s2.0-S0960894X10004464-main

Chitooligosaccharidesprotectratcorticalneuronsagainstcopperinduced

damagebyattenuatingintracellularlevelofreactiveoxygenspecies

WeiXu,Han-changHuang,Chang-junLin,Zhao-FengJiang*

CollegeofArtsandScience,BeijingUnionUniversity,Beijing100191,ChinaBeijingKeyLaboratoryofBioactiveSubstancesandFunctionalFoods,BeijingUnionUniversity,Beijing100191,China

articleinfo

Articlehistory:Received26December2009Revised3March2010Accepted27March2010Availableonline2April2010

Keywords:CopperNeurotoxicityCOSsNeuroprotectiveeffectsOxidativedamageCorticalneuronsabstract

Alargenumberofevidencehassuggeststhatdyshomeostasisoftheredox-activebiometalssuchascop-perandothermetalionscanleadtooxidativestressinneurons,whichplaysakeyroleinthepathologyofneurodegenerativedisorders.Chitooligosaccharides(COSs)arebiodegradationproductofchitosananddemonstrateddiversebiologicalactivities,HerewefirstreportthatprotectiveeffectsofCOSs(M.W.1500,DD.90%)againstCu(II)inducedneurotoxicityinprimaryculturedratcorticalneurons.ThetoxicityofCu(II)tocorticalneuronswasobviouslyattenuatedinaconcentration-dependentmannerbyCOSspre-treated.Thedataderivedfromlactatedehydrogenase(LDH)releaseandtheHoechst33342assaysupporttheresultsfromMTTassay.AfterDCFHassay,COSswerefoundtodepressCu(II)inducedelevationinintracellularreactiveoxygenspecies(ROS),ThesefindingssuggestthatCOSsprotectagainstCu(II)inducedneurotoxicityinprimarycorticalneuronsbyinterferingwithanincreaseinintracellularreactiveoxygenspecies(ROS).Ó2010ElsevierLtd.Allrightsreserved.

Moxa UPort 1200 1400 1600系列USB-to-Serial转换器快速安装指南说

Moxa UPort 1200 1400 1600系列USB-to-Serial转换器快速安装指南说

P/N: 180201400001A

*180201400001A* UPort 1200/1400/1600 Series Quick Installation Guide

USB-to-Serial Converter

Version 9.2, May 2021

Technical Support Contact Information

/support

 2021 Moxa Inc. All rights reserved.

Overview

Moxa’s USB-to-serial product provides a wide range of easy-to-use

solutions for adding Windows COM ports and Linux tty ports through a

PC’s USB port.

The UPort 1200/1400/1600 series are the following models:

• UPort 1250: 2-port RS-232/422/485 USB-to-serial converter

• UPort 1250I: 2-port RS-232/422/485 USB-to-serial converter w/

isolation protection

• UPort 1410: 4-port RS-232 USB-to-serial converter

• UPort 1450: 4-port RS-232/422/485 USB-to-serial converter

• UPort 1450I: 4-port RS-232/422/485 USB-to-serial converter w/

isolation protection

• UPort 1610-8: 8-port RS-232 USB-to-serial converter

不锈钢行业标准汇总

不锈钢行业标准汇总

K1+478～K1+5888段左侧片石混凝土挡土墙第1部分1页脚内容不锈钢行业标准汇总

目录

● 俄罗斯及欧洲废钢标准

● 美国废钢铁标准介绍（1991年）

● 日本废钢铁分类标准（Jis G2401）

● 中国新《废钢铁》国家标准介绍

● 世界各国不锈钢标准钢号对照表（新版）

● 锅炉用钢管及钢材料标准与安全

● 薄壁不锈钢水管行业标准

● 钢管标准中的常用术语

● 钢管的分类及标准

● 不锈钢小直径钢管标准号对照表

● 中国与亚洲、北美诸国以及澳大利亚的不锈钢钢号近似对照表

● 各国不锈钢团体标准对照表

● 美国ASTM标准中200系列（Cr－Mn系）奥氏体不锈钢

薄壁不锈钢水管行业标准

目前，建设部给水排水产品标准化委员会已组织专家审查通过了薄壁不锈钢水管及不锈钢卡压式管件二项行业标准，且报批稿已上交建设部。现将上述二项标准的要点介绍如下： 1《薄壁不锈钢水管》 1.1 本标准是参照采用了国家标准GB/T12771-2000《流体输送用不锈钢焊接钢管》、欧洲标准DINEN10312-1999《液体（包括饮用水）输送用不锈钢管及管件》、英国标准BS4127-1994《主要输送水用薄K1+478～K1+5888段左侧片石混凝土挡土墙第1部分2页脚内容壁不锈钢管》和日本标准JISG3448-1997《一般管道用不锈钢管》，并根据国情制定的。 1.2 范围：DN≯150mm，工作压力≯1.6MPa可输送饮用净水、生活饮用水、热水和温度≯135℃的高温水。 1.3 管材及适用场所见表1。 1.4 管材的化学成分见表2。

表1管材及适用场所

牌号 用 途

0Cr18Ni9(304) 饮用净水、生活饮用水、空气、医用气体、热水等管道用

0Cr17N12Mo2(316) 耐腐蚀性比0Cr18Ni9更高的场合

00Cr17N14Mo2(316L) 海水

s7200常见问题

s7200常见问题

1：Step7 Micro/WIN V4.0安装在什么环境下才能正常工作？

Step7 Micro/WIN V4.0的安装、运行环境为：

Windows 2000 SP3以上

Windows XP Home

Windows XP Professional

西门子没有在其他操作系统下测试，不保证能够使用。

2：Step7 Micro/WIN V4.0和其他的版本兼容性如何？

Micro/WIN V4.0生成的项目文件，旧版本的Micro/WIN不能打开或上载。

3：siemens200 PLC硬件版本有什么区别？

二代S7-200（CPU22x）系列也分几个主要的硬件版本。

6ES721x-xxx21-xxxx是21版；6ES721x-xxx22-xxxx是22版。

22版与21版相比，硬件、软件都有改进。22版向下兼容21版的功能。

22版与21的主要区别是：

21版CPU的自由口通讯速率300、600被22版的57600、115200所取代，22版不再支持300和600波特率 ，22版不再有智能模块位置的限制

4：plc的电源改如何连接？

在给CPU进行供电接线时，一定要特别小心分清是哪一种供电方式，如果把220VAC接到24VDC供电的CPU上，或者不小心接到24VDC传感器输出电源上，都会造成CPU的损坏。

5：200PLC的处理器是多少位的？

S7-200 CPU的中央处理芯片数据长度为32位。从CPU累加器AC0/AC1/AC2/AC3的数据长度也可以看出。

6：如何进行S7-200的电源需求与计算？

S7-200 CPU模块提供5VDC和24VDC电源：

当有扩展模块时CPU通过I/O总线为其提供5V电源，所有扩展模块的5V电源消耗之和不能超过该CPU提供的电源额定。若不够用不能外接5V电源。