Ball screw pair

Introduction

Whenmovinganobject,itisgenerallynecessarytotransmitthemotiongeneratedbythepowerdirectlyorindirectlythroughothermechanismstothefinalmovingpart.Taketheengineasanexample.Intheengine,thepistonmovesupanddownduetothecombustionofgasoline,anditisfinallytransmittedtothewheelsthroughanintermediatemechanismtocauseittorotate.

Intoday'sworld,devicesthatcanrepresentmachineryandhavevariousmotionmechanisms,itcanbesaidthatalldeviceshavesomeformofmotiontransmissionmechanism.Ballscrewpairisthemostreasonableproductthatconvertsrotarymotionintolinearmotion,orconvertslinearmotionintorotarymotion.

Theballscrewpairisaspiraltransmissionelementwithsteelballsasrollingelementsbetweenthescrewandthenut.Itcantransformrotarymotionintolinearmotion,ortransformlinearmotionintorotarymotion.Therefore,theballscrewpairisnotonlyatransmissionelement,butalsoaconversionelementbetweenlinearmotionandrotarymotion.

Features

Comparedwiththeslidingscrewpair,thedrivingtorqueis1/3,becausetherearemanyballsrollingbetweenthescrewshaftandthescrewnutofthePRTTballscrewpairExercise,soyoucangethigherexerciseefficiency.Comparedwiththepreviousslidingscrewpair,thedrivingtorqueislessthan1/3,thatis,thepowerrequiredtoachievethesamemotionresultis1/3oftheuseoftheslidingscrewpair.Itisveryhelpfulinthepowersavingenvironment.

Guaranteeofhighprecision

Theballscrewpairisproducedcontinuouslywiththeworld'shighestlevelofmachineryandequipmentmadeinJapan,especiallyinthefactoryforgrinding,assembling,andinspectingeachprocessIntermsofenvironment,thetemperatureandhumidityarestrictlycontrolled,andtheaccuracyisfullyguaranteedduetotheperfectqualitymanagementsystem.

Thepossibilityofmicro-feeding

Becausetheballscrewpairusesballmotion,thestartingtorqueisverysmall,andtherewillbenocrawlingphenomenonsuchasslidingmotion,whichcanensuretherealizationofprecisemicro-feeding.Feed.

Nobacklash,highrigidity

Theballscrewpaircanbepreloaded,becausethepreloadcanmaketheaxialclearancereachanegativevalue,andthenobtainhigherrigidity(ballscrewByaddingpressuretotheballsinthelever,whenactuallyusedinmechanicaldevices,therigidityofthescrewnutcanbeenhancedduetotherepulsiveforceoftheballs).

High-speedfeedispossible

Becauseofthehighmotionefficiencyandlowheatgeneration,theballscrewpaircanachievehigh-speedfeed(motion).

Loopmode

Therearetwocommonlyusedloopmodes:outerloopandinnerloop.

Theballthatsometimesdisengagesfromtheleadscrewduringthecycleiscalledtheouterloop;theballthatalwayskeepsincontactwiththeleadscrewiscalledtheinnerloop.Eachclosedloopoftheballiscalledarow,andthenumberofleadscontainedineachclosedloopoftheballiscalledthenumberofturns.Eachnutoftheinnercirculationballscrewpairhas2rows,3rows,4rows,5rows,etc.,eachrowhasonlyoneturn;eachrowoftheouterloophas1.5turns,2.5turnsand3.5turns.

(1)Outercirculation:Theoutercirculationmeansthattheballreturnstothescrewnutthroughthespiralgrooveorintubationontheoutersurfaceofthenutafterthecirculationprocessisover.Thereturnmethodsoftheoutercirculationballscrewnutpairaccordingtotheballcirculationmainlyincludeendcaptype,intubationtypeandspiralgroovetype.

Intheendcaptype,alongitudinalholeismachinedinthenuttoserveasthereturnpassageoftheballs.Thecoverplatesatbothendsofthenuthavereturnportsfortheballs,andtheballsenterthereturnpipetoformacycle.Intubationtype,itusestheelbowasthereturnpipe.Thisstructurehasgoodmanufacturability,butbecausethepipeprotrudesfromthenutbody,theradialdimensionisrelativelylarge.Spiralgroovetype,itisaspiralgroovemilledontheoutercircleofthenut,throughholesaredrilledatbothendsofthegrooveandtangenttothethreadedracewaytoformareturnchannel.Thisstructurehasasmallerradialsizethanthecannulastructure,butManufacturingismorecomplicated.Theoutercirculationballscrewhassimpleoutercirculationstructureandmanufacturingprocessandiswidelyused.Thedisadvantageisthatitisdifficulttosmooththejointsoftheraceways,whichaffectsthestabilityoftheballraceways.

(2)Innercirculation:Innercirculationadoptsreversertorealizeballcirculation.Therearetwotypesofreverser.Cylindricalconvexkeyreverser,itscylindricalpartisembeddedinthenut,andtheendisprovidedwithareversegroove.Thereversegrooveispositionedbythecylindricaloutersurfaceandtheroundkeyontheupperendtoensurethealignmentofthethreadracewaydirection.Oblateinsertreverser,thereverserisageneralroundheadflatkeyinsert,theinsertisembeddedintheslotofthenut,andtheendisopenedwithareversegroove,whichispositionedbytheoutercontouroftheinsert.Comparingthetwoinverters,thelatterhasasmallersize,whichreducestheradialsizeofthenutandshortenstheaxialsize.However,theoutercontourofthiskindofreverserandthedimensionalaccuracyoftheslotonthenutarerequiredtobehigh.

Structure

Theballscrewpairhasitsownuniquenessinthestructureofthenut.Accordingtothecirculationmodeoftheball,itcanbedividedinto

①Thereisaballrotatingchannelbetweentheelbowscrewpairandthenut.Theballgeneratesanaxialloadonthechannel,andtheballisformedaroundthescrewshaft.Aftertherollingmotion,itentersintotheelbowportinlaidinsidethenut,andcirculatesalongtheelbowtotheloadareaagain,therebyperforminginfiniterollingmotion.Thisproductisapopularproductwiththewidestvarietyofballscrewpairs,andcanbewidelyusedforvariouspurposes.

②Returnertype.

③Endenvironmenttype.

Precautionsforuse

Whenusingtheballscrewpair,payattentiontothefollowing:

1.Therollingnutshouldmovewithintheeffectivestroke,ifnecessaryLimitsarearrangedatbothendsofthestroketopreventthenutfromovertravelingawayfromthescrewshaftandcausingtheballtofalloff.

2.Duetothehightransmissionefficiencyoftheballscrewpair,itcannotbeself-locking.Whenusedforverticaltransmission,iftheweightofthecomponentisnotbalanced,itmustbepreventedthatthetransmissionstopsorthemotorlosespower.Self-weightreversetransmission,anti-reversetransmissionmethodcanbeusedturbinescrewdrive,hydraulicelectricbrakeandoverrunningclutch,etc.