Angular contact ball bearings

Transcription

1 Angulr contct bll berings Contents Angulr contct bll berings 11 Four ifferent esigns 11 Stnr high-precision ngulr contct bll berings 114 High spee high-precision ngulr contct bll berings 114 Hybri high-precision ngulr contct bll berings 115 Hybri high spee high-precision ngulr contct bll berings 115 Universlly mtchble berings 116 Mtche bering sets 117 Generl bering t 1 Fctors ffecting the prelo 17 Cges 135 Spee rtings 136 Equivlent ynmic bering lo 137 Equivlent sttic bering lo 137 Clcultion of equivlent bering lo for preloengulr contct bll berings 139 esigntion systems of single berings n mtche sets 139 Prouct tbles 141 Stnr high-precision ngulr contct bll berings 14 High spee high-precision ngulr contct bll berings 156 Hybri high-precision ngulr contct bll berings 16 Hybri high spee high-precision ngulr contct bll berings

2 Angulr contct bll berings Angulr contct bll berings Four ifferent esigns SKF high-precision ngulr contct bll berings ( fig 1 ) re vilble in three imension series: bering series 719, 70 n 7 with contct ngle of 15 (esigntion suffix C or CX n CE) or 5 (esigntion suffix AC or ACX n ACE) ( fig 3 ). erings with the greter contct ngle re recoene fopplictions where high xil stiffness n high xil lo crrying cpcity re require. The CX n ACX suffixes ientify the smll bering sizes belonging to the C n AC esign n stn for revise internl geometry. The CE n ACE esign berings hve lrger number of smll imetells compre with the stnr C or CX n AC or ACX esigns. Suing up, SKF high-precision ngulr contct bll berings re vilble in four ifferent esigns n three imension series ( fig ). Clerly the spce requirements re ifferent nrrngements cn be more or less rilly compct. Ech bering series hs chrcteristic fetures tht mkes it suitble for prticulpplictions. For higher spees, or where little ril spce is vilble, berings of series 719 or 70 shoul be chosen. For hevy los t reltively moerte spees, berings of series 7 re more pproprite. Where stiffness requirements re prmount, berings of series 719 incorporte lrge number of blls n hve the vntge tht lrge spinle imeters cn be use. oth these fctors contribute to high stiffness of the spinle system: spinle rigiity increses with incresing spinle imeten bering stiffness is more strongly influence by the number thn by the size of the blls. In fct, the rigiity of these light series berings is greter thn tht, of comprble berings from the hevier series A cross section of the three imension series Fig Single row high-precision ngulr contct bll bering ifferent esigns of SKF high-precision ngulr contct bll berings series 70 Fig 1 Fig AC, ACX C, CX ACE CE esign esign esign esign

3 Angulr contct bll berings Stnr high-precision ngulr contct bll berings SKF stnr high-precision ngulr contct bll berings re non-seprble, hving one reuce height flnge on the outer ring, in orer to llow the introuction of lrge number of blls, using onepiece cge nn optimise internl esign. Thnks to this, they represent the best solution in terms of lo crrying cpcity, rigiity n spee. The berings re mnufcture ccoring to 719, 70 n 7 series, with choice of two ifferent contct ngles: 15 egrees (CX n C) or 5 egrees (ACX n AC). The bsic esign is the sme for CX (ACX) n C (AC) series. The CX n ACX series covering the smll bering sizes hve recently been reviewe, offering improve ynmic n sttic lo rtings, which hve been increse by pprox. 15 % n 30 % respectively. An enhnce level of ril nxil rigiity hs lso been obtine without compromising the spee rtings. The rnge of stnr high-precision ngulr contct bll berings covers bore imeters from 8 to 40. imensions n technicl t cn be foun in the relevnt prouct tbles. High-spee high-precision ngulr contct bll berings In ition to the stnr series, SKF offers series of high-spee berings to meet the highest emns in respect of spee cpbility n running ccurcy. These berings belong to the series 70 CE (ACE) n 719 CE (ACE) nre chrcterise by following fetures: smllells contct ngle of 15 (CE suffixes) or 5 (ACE suffix) both outen inner ring shoulers of reuce height foetter lubriction conitions n outer ring centre cge optimise internl esign for enhnce spee cpbility n extremely high running ccurcy. The CE n ACE esign berings hve lrger number of smll imetells compre with the stnr C, CX, AC n ACX esigns. Centrifugl forces from contct between the blls n the outer ring rcewy re therefore further reuce, s is lso the contct pressure. ecuse of the smllells of the CE n ACE esigns, they occupy less of the bering crosssection. The rings re therefore corresponingly thicker. This mens tht ny form errors of shft or housing bore hve less influence on the rounness of the bering rings. As result the running ccurcy is enhnce. The rnge of very high-spee berings covers bore imeters from 0 to 10. Technicl t n imensions cn be foun in the tbles. etils concerning technicl t nvilbility of other sizes will be supplie on request. Hybri high-precision ngulr contct bll berings If the performnce require is close to the limits foll-steel berings, or if higher rigiity or longer life re neee, n lterntive my be to select SKF hybri berings. These berings hve steel rings n cermic blls. The vntges offere by cermic mteril versus steel re shown in chpter 1: Principles of bering selection nppliction, section mteril for highprecision berings. Hybri high-precision ngulr contct bll berings offer the following vntges versus ll-steel berings: lsting up to four to six times longer chieving up to 0 % higher spee lower temperture rise in the system obtining higher rigiity fewer problems with lubriction n vibrtion. less sensible to speeccelertions n ecelertions. Hybri high-precision ngulr contct bll berings re offere in the sme execution s ll-steel high-precision ngulr contct bll berings, series 719, 70 n 7 with either 15 (C n CX) or 5 (AC n ACX) egrees contct ngle. Hybri highprecision ngulr contct bll berings re ientifie by the suffix HC in the esigntion, e.g CGA/HCP4A. Hybri high-spee high-precision ngulr contct bll berings These berings hve smller cermic blls, innen outer ring shoulers of reuce height, outer ring centre cge, optimise internl esign, nre suitble for even more emning pplictions thn those covere by hybri precision ngulr contct bll berings. With proper lubriction conitions n with moerte loing rottionl spees cn go up to 3 million n m. y using specilly esigne hybri berings, the spinle spee cn be further increse. The SKF rnge comprises two series of hybri high-spee high-precision ngulr contct bll berings of series 719 (CE n ACE) n 70 (CE n ACE). The berings re ientifie by the suffix HC in the esigntions, e.g CEGA/HCP4A

4 Angulr contct bll berings Universlly mtchble berings Universlly mtchble ngulr contct bll berings re juste uring mnufcture so tht they my be mounte ieitely jcent to ech other in bck-to-bck, fce-to-fce or tnem rrngement, s esire. When rrnge bck-to-bck or fce-to-fce the berings will hve light, meium or hevy prelo epening on the requirements. sic fetures such s ccurcy, prelo clss, spee cpbility etc. of universlly mtchble ngulr contct bll berings re the sme s those of the pre-mtche sets. Universlly mtchble berings my be useful in reucing stock holing n improving vilbility. Severl specific mtche sets my be obtine by stocking the correct universl berings. esigntion of single universl high-precision ngulr contct bll berings C G A / P4A Universl berings cn be supplie in two bsic executions: single universl berings for mounting in ny combintion, or uplex sets with mtche bore n outsie imeters. The esigntions for single universl berings re expline in Tble 1. Customers nee to orer the sme number of single universl berings s the number of berings in set, e.g. to replce set 7014 C/P4ATTA, three berings 7014 CGA/P4A re require. Alterntively, uplex sets of universlly mtchble berings cn be chosen. uplex universl berings cn eithee uses sets, or ech bering use to form other groups of berings, with the only limittion being the contct ngle n the prelo clss. Universl berings with light prelo must not be pireginst berings with ifferent contct ngle or prelo clss. For such specil cses, plese consult the SKF ppliction engineering service. Tble 1 Tble shows some possible combintions n the corresponing number of mtche sets, single berings or uplex sets to be orere. Mtche bering sets Mrking of universlly mtchble berings The bering rings hve severl mrkings for ientifiction purposes. Ech bering is mrke with the complete esigntion on the outer ring fce. To fcilitte the selection of the ctul bore n outsie imeters in orer to obtin the esire fits fter mounting, the ctul evition of the inner bore imeten outsie imeter from nominl, re mrke on the inner ring/outer ring respectively. An sterisk mrks the position of the gretest out-of-roun on the innen outer ring sie-fces. This is where the gretest wll thickness between the bse of the rcewy n the bore or the outsie imeter surfce cn be foun. A chevron V is mrke on the outer ring outsie imeter inicting the contct ngle irection. This llows the users to check tht universlly mtchble berings, once fitte on the shft, re correctly positioneccoring to the esire combintion, i.e. bck-to-bck, fce-to-fce, etc. ( fig 8 pge 11). SKF high-precision ngulr contct bll berings re lso supplies complete sets of two, three or fouerings. They re mtche uring mnufcturing so tht when the berings re mounte ieitely next to ech other, the preetermine vlue of the prelo will be obtine, or the lo will be evenly istribute. The bore n outsie imeters o not iffey more thn one thir of the permissible imeter tolernce. There is even less ifference between the imeters of mtche berings mnufcture to tolernce clss PA9A. The most populr set rrngements re shown in figs 4, 5, 6 n 7 pges The lo lines of berings rrnge bckto-bck iverge towrs the bering xis. Axil lo cn be ccoote in both irections, lthough only by one bering (or berings in tnem) t time. The bck-tobck rrngement is reltively stiff n cn lso tke up tilting moments. Tolernce clss P4A or PA9A Prelo clss A: light, : meium, C: hevy Universlly mtchble execution Contct ngle n internl esign C, CE, CX = 15 egrees AC, ACE, ACX = 5 egrees ore imeter ering series Originl Qty Single universl Qty uplex universl Qty mtche set bering bering sets 7010 C/P4ATTA 7010 CGA/P4A C/P4AGA C/P4AQCA 7010 CGA/P4A C/P4AGA C/P4AT CGA/P4A C/P4AGA C/P4AA CGA/P4A C/P4AGA C/P4AFA CGA/P4A C/P4AGA 4 Tble See Tble 17 for more etils

5 Angulr contct bll berings The lo lines of berings rrnge fceto-fce converge towrs the bering xis. Axil los cn be ccoote in both irections, lthough gin only by one bering (oerings in tnem) t time. The rrngement is not so stiff s the bck-to-bck rrngement n is less suitble for tilting moments. In tnem rrngement the lo lines of the berings re prllel. Ril n xil los re eqully istribute over the berings but xil los cn only be crrie in one irection. A set of berings in tnem is therefore generlly justeginst notheering tht cn tke the xil los cting in the opposite irection. Combintions of tnem n bck-tobck, or tnem n fce-to-fce re normlly use when the esign mkes it impossible to just furtheering, oering set ginst the tnem set. ck-to-bck rrngement foxil lo in both irections ck-to-bck rrngement esigntion suffix Fig 4 Combintion of tnem n bck-to-bck rrngement esigntion suffix TT Combintion of tnem n bck-to-bck rrngement esigntion suffix QC Combintion of tnem n fce-to-fce rrngement esigntion suffix TFT Combintion of tnem n fce-to-fce rrngement esigntion suffix QFC Fig 7 Fig 5 Fig 6 Combintion of tnem n bck-to-bck rrngement esigntion suffix QT Combintion of tnem n fce-to-fce rrngement esigntion suffix QFT Fce-to-fce rrngement foxil lo in both irections Tnem rrngement foxil lo in one irection Fce-to-fce rrngement esigntion suffix F Tnem rrngement esigntion suffix T Tnem rrngement esigntion suffix TT Tnem rrngement esigntion suffix QT

6 Angulr contct bll berings Mrking of bering sets ering sets not only hve the mrkings of single berings; but lso hve itionl mrkings for ientifiction purposes n to inicte how the berings of mtche set shoul be correctly mounte. A V -shpe mrking is to be foun on the outsie imeter of the berings. The berings nee to be mounte in the orer shown by this mrking to obtin the correct prelo. It lso inictes how the set shoul be mounte compre with the xil lo. The point of the V gives the irection in which the xil lo shoulct on the inner ring(s). Where xil los ct in both irections, the V point gives the irection of the gretexil lo. Ech bering of mtche set is mrke with the complete esigntion of the bering set. The sme seril number is shown on the fce of the outer ring ( figs 9 n 10 ). Fig 8 Fig 9 V shpe mrking on outsie imeter of universlly mtchble berings for pire mounting Exmple of set of three universlly mtchble berings combine in TT rrngement V shpe mrking on outsie imeter of high precision ngulr contct bll bering sets Mrking of bering sets Fig 10 Seril number (for sets only): 916 ore imeter evition from nominl: 5; n position of the point of mximun eccentricity of the inner ring: * Mnufcturing te: W41Y Chevron V Complete bering esigntion: ACE/HCP4AA Outsie imeter evition from nominl: 4; n position of the point of mximun eccentricity of the outer ring: * Country of origin: Itly V 10 11

7 Angulr contct bll berings Generl bering t imensions SKF high-precision ngulr contct bll berings conform to ISO 15:1998, imeter Series 9, 0 n. Tolernces SKF high-precision ngulr contct bll berings re mnufcture to tolernce clss P4A specifictions s stnr. On request, berings cn be me ccoring to clss PA9A or other specifictions. The vlues for P4A n PA9A tolernce clsses re given in Tbles 3 n 4. Hybri berings re me to the sme tolernces s the corresponing ll-steel berings. Prelo To meet vrying customer nees in terms of spee, het genertion n rigiity, SKF offers stnr high-precision ngulr contct bll berings (ientifie by suffixes CX, C, ACX n AC), universlly mtchble n mtche bck-to-bck or fce-to-fce in groups of two or more berings per set, with three ifferent prelo clsses s stnr: Clss A: light prelo Clss : meium prelo Clss C: hevy prelo Hybri high-precision ngulr contct bll berings (ientifie by the suffix HC) re normlly supplie either with prelo clss A or since the hevy prelo is not recoene for high-spee opertions. For the sme reson prelo clsses A n re usully pplie to the high-spee high-precision ngulr contct bll berings (ientifie by suffixes CE n ACE), fitte either with steel or cermic blls. Tbles 5 pge 14, 6 pge 15 n 7 pge 16 show prelo vlues foering pirs rrnge eitheck-to-bck or fceto-fce prior to mounting. Clss P4A tolernces for ril berings Clss PA9A tolernces for ril berings Tble 3 Tble 4 Inner ring mp s V p V mp s 1s V s K i S S i over incl. high low high low mx mx high low high low mx mx mx mx µm µm µm µm µm µm µm µm µm µm Inner ring s V p V mp s 1s V s K i S S i over incl. high low mx mx high low high low mx mx mx mx µm µm µm µm µm µm µm µm µm, , ,3 1,3 1,3 1, , ,3 1,3 1,3 1, , ,3,5 1,3, , ,3,5 1,3, , ,3,5 1,3, ,5 1, ,5,5,5, ,5 10 0,5 1, ,3 1,3 1,3 1, ,5 1, ,3 1,3 1,3 1, ,5 1, ,3,5 1,3, ,5 1, ,3,5 1,3, ,8 1, ,3,5 1,3, ,5 1, ,5,5,5, , ,5,5,5, , ,8 5 3, ,5 4, ,8 5 3,8 5 Outer ring mp s V p V mp Cs, C1s V Cs K e S S e over incl. high low high low mx mx mx mx mx mx µm µm µm µm µm µm µm µm Outer ring s V p V mp Cs, C1s V Cs K e S S e over incl. high low mx mx mx mx mx mx µm µm µm µm µm µm µm µm ,3 Vlues re 1,3,5 1,3, ,3 ienticl to 1,3,5 1,3, ,3 those for 1,3 3,8 1,3 3,8 inner ring ,5 1,3 of sme,5 5, ,5 1,5 bering,5 5, ,8 1,3 Vlues re 1,3,5 1,3, ,8 1,3 ienticl to 1,3,5 1,3, ,8 1,3 those for 1,3 3,8 1,3 3,8 inner ring ,5 1,3 of sme,5 5, ,5 1,5 bering,5 5, ,5 3 ( s, 1s ),5 5, ,5 4,5 3,8 6,5 3,8 6, ,5 4 3,5 3,8 6,5 3,8 6, ,5 7,5 6,5 7,5 1 13

8 Angulr contct bll berings Tble 5 Tble 6 ering Axil prelo Series 719 AC Series 719 C Series 719 ACE Series 719 CE 719 AC/HC 719 C/HC n 719 ACE/HC n 719 CE/HC 719 ACX 719 CX n 719 ACX/HC n 719 CX/HC Clss Clss Clss Clss ore Size A C 1) A C 1) A A imeter ering Axil prelo Series 70 AC Series 70 C Series 70 ACE Series 70 CE 70 AC/HC 70 C/HC n 70 ACE/HC n 70 CE/HC 70 ACX 70 CX n 70 ACX/HC n 70 CX/HC Clss Clss ore Size A C 1) A C 1) A A imeter N N ) All-steel berings only Series 719 Prelo in berings for universl piring n bering sets rrnge bck-to-bck or fce-to-fce Series 70 Prelo in berings for universl piring n bering sets rrnge bck-to-bck or fce-to-fce 1) All-steel berings only 14 15

9 Angulr contct bll berings Sets of three or more berings hve higher prelo thn sets of two berings. The relevnt prelo vlue cn be clculte by multiplying the prelo vlues of pirs reporte in the tbles by the following fctors: 1,35 for TT n TFT sets 1,60 for QT n QFT sets,00 for QC n QFC sets. Series 7 Prelo in berings for universl piring n bering sets rrnge bck-to-bck or fce-to-fce ering Axil prelo Series 7 AC Series 7 C 7 AC/HC 7 C/HC 7 ACX 7 CX n 7 ACX/HC n 7 CX/HC ore Size Clss Clss imeter A C 1) A C 1) N To clculte prelo for sets of berings involving more thn fouerings, or for sets incorporting berings of ifferent esigns, size n contct ngle, plese contct SKF ppliction engineering service. Tble 7 Fctors ffecting the prelo Prelo on bering systems is influence by severl fctors uner sttic n ynmic conitions. The ctul prelo vlue on the berings fitte in system iffers from the preetermine prelo vlue in the mnufcturing process, epening on: the ctul fits between the bering inner rings n the shft, n between the bering outer rings n the housing the system spee for constnt position rrngements. Other effects my influence the ctul prelo of ngulr contct bll berings systems while operting such s: temperture ifferences in opertion between the bering inner ring n outer rings n the rolling elements the shft n housing mterils (i.e. ifferent mterils my show vrying therml expnsion coefficients, resulting in ifferentil eformtion of the mting prt while the system is operting). geometric errors (e.g. impose mislignment, cylinricity n conicity errors, coxility errors between front n rer housing). In cse of pplictions where the bove points my be importnt plese contct the SKF ppliction engineering service fovice. Influence of the fit on the prelo When bering is mounte with n interference fit on the shft, the inner ring will expn, incresing the rcewy imeter. Conversely, n interference fit in the housing will compress the outer ring, reucing the rcewy imeter. One of these conitions lone ooth together, will reuce the spce for the rolling elements n thus increse the prelo of the bering set. The prelo chnge thus epens on the rel fit between berings n mting prts. When mting prts re me to tolernces ccoring to the recoentions given in Tbles 1 n pges 4 43 (e.g. js4 for shfts n JS5 for housings foerings of P4A precision clss) the prelo increse cn then be clculte from the following eqution with resonble ccurcy. G m = f f 1 f f HC G A,, C where G m = prelo of the mounte bering sets, N G A,, C = prelo of bering sets prior to mounting, see Tbles 5, 6 n 7 pges f = bering fctor, see igrm pge 19 1 f 1 = correction fctor epening on contct ngle, see Tble 8 pge 18 f = correction fctor epening on prelo clss, see Tble 8 f HC = correction fctor for hybri berings where pplicble, see Tble ) All-steel berings only 16 17

10 Angulr contct bll berings Exmple Wht will be the prelo of the bering pir 7194 C/P4AC when mounte? From Tble 5 pge 14, the vlue of G C is N. The vlue of the bering fctor f =, ccoring to igrm 1. The correction fctors obtine from Tble 8 re f 1 = 1 n f = 1,4. Therefore, G m = f f 1 f G C G m =, 1 1, N = N In other cses the fits my hve to be significntly higher, for instnce in very high-spee spinles, to voi the bering inner ring from loosening its contct with the shft s result of the centrifugl force. The effect of fits must then be clculte in more etil. For specil cses such s these, plese consult the SKF ppliction engineering service. The reltionship between bering fits, shfts, housing proportions n prelo increses cn be stuieccoring to igrm 1. Influence of spee on prelo A rstic increse in prelo my lso occur when pproching very high-spees. The increse is mostly ue to the centrifugl loffecting the position of the rolling elements. Thus, option of cermic blls llows much higher rottionl spees, while mintining low het genertion n ering fctor f igrm 1 List of correction fctors for prelo clcultion ering fctor f,4 ering f 1) HC f ) 1 f 3) f 3) f 3) series Prelo A Prelo Prelo C 719 C n CX ,1 1,4 719 AC n ACX 1 0,9 1 1,1 1,1 719 CE , ACE 1 0,9 1 1, C/HC n CX/HC 1, ,1 719 AC/HC n ACX/HC 1,08 0,9 1 1,1 719 CE/HC 1, , ACE/HC 1,05 0,9 1 1,14 70 C n CX ,1 1, 70 AC n ACX 1 0,9 1 1,09 1,18 70 CE ,08 70 ACE 1 0,96 1 1,08 70 C/HC n CX/HC 1, ,1 70 AC/HC n ACX/HC 1,06 0,9 1 1,09 70 CE/HC 1, ,09 70 ACE/HC 1,03 0,96 1 1,07 7 C n CX ,04 1,1 7 AC n ACX 1 0,95 1 1,05 1,1 7 C/HC n CX/HC 1, ,04 7 AC/HC n ACX/HC 1,0 0,95 1 1,04 1) f HC = correction fctor for cermic blls ) f 1 = correction fctor for contct ngle 3) f = correction fctor epenent on prelo Tble 8, 1,8 1,6 1,4 1, C, AC CX n ACX CE 719 C, AC CX n ACX 719 CE 7 C, AC CX n ACX 80 ore imeter, 18 19

11 Angulr contct bll berings equte stiffness. In igrm the prelo vrition versus spee for ifferent executions of bsic bering type 7014 is shown. Fopplictions where spee is in excess of 1 1, million n m n constnt position prelo is necessry, plese consult the SKF Appliction Engineering Service for more etils. For high-speepplictions like internl grining spinles n high-frequency milling spinles, the prelo is often given through set of elstic clibrte springs ( fig 11 ), olterntively hyrulic prelo is use. Tble 9 gives guieline vlues for the spring force to be pplie on berings in constnt lorrngements. The vlues refer to single berings with 15 egrees contct ngle (suffixes CX, C n CE), both ll-steel n hybri, of the most populr sizes use with spring prelo systems. If berings re pire in tnem, the vlue in the tble nees to be multiplie by the number of single berings in the set. The bove vlues re clculte to minimise the ifference in contct ngle between outen inner rcewy contcts, n to retin certin xil rigiity of the bering t high spee. However, it shoul be note tht itionl prelo is etrimentl to performnce becuse of het genertion. Fig 11 Prelo increse fctor for ifferent bering esigns Reference bse type 7014 igrm Fopplictions where extremely high spee is require preloing shoul be one through clibrte springs cting ginst bering ring Prelo increse fctor C (ll-steel) CE (ll-steel) 15 ering Spee fctor size (n m 10 6 ),5,0 1,75 1,5 1,5 Prelo N Tble 9 Guieline vlues for the spring force in constnt lo bering rrngements Constnt lo C/HC (hybri) CE/HC (hybri) ,45 0,9 1,35 1,8 Spee fctor, n m ( 10 6 )

12 Angulr contct bll berings Prelo for customise nees Most often, intermeite rings (spcers) re inserte between the berings of set ( fig 1 pge 135). When specil prelo my be require to chieve the best performnce, it is possible to chnge prelo by fce grining the inner or outer spcer. It is not visble to moify the berings in ny wy. Tbles 10 n 11 show which spcer(s) shoul be groun to increse or ecrese the prelo. Tbles 1 n 13, pge 134 show the necessry with reuction to be chieve by fce grining. Spcers re not only use to customise the prelo but to improve the system rigiity, n sometimes to bring the oil pipes s close s possible to the rcewys. In Spcer with reuction for chnging prelos in mtche sets, C, CX n CE esigns Tble 1 ering Spcejustment size Series 719 C Series 70 C Series 7 C Series 719 CE Series 70 CE 719 C/HC 70 C/HC 7 C/HC n 719 CE/HC n 70 CE/HC 719 CX 70 CX 7 CX n 719 CX/HC n 70 CX/HC n 7 CX/HC ore Size imete b b b ering The prt to be Amount to be groun off rrngement fce groun to increse prelo from A up to up to C A up to C ck-to-bck Inner spce b + b Fce-to-fce Outer spce b + b Tble 10 Spcer(s) to be groun to increse prelo µm ering The prt to be Amount to be groun off rrngement fce groun to ecrese prelo from own to A C own to C own to A ck-to-bck Outer spce b + b Fce-to-fce Inner spce b + b Tble 11 Spcer(s) to be groun to ecrese prelo

13 Angulr contct bll berings Spcer with reuction for chnging prelos in mtche sets, AC, ACX n ACE esigns ering Spcejustment size Series 719 AC Series 70 AC Series 7 AC Series 719 ACE Series 70 ACE 719 AC/HC 70 AC/HC 7 AC/HC n 719 ACE/HC n 70 ACE/HC 719 ACX 70 ACX 7 ACX n 719 ACX/HC n 70 ACX/HC n 7 ACX/HC ore Size imete b b b µm Tble 13 other cses, especilly in grese-lubricte spinles, it is necessry to hve spcers to llow grese to escpe from the contct zone to reuce running temperture. In orer to get the best performnce from the berings, spcers shoul not eform uner lo, n form errors shoul not be introuce, s these woulffect the prelo of the bering sets. In generl, the guielines given in the form tolernce requirements for shft n housing cn be followe. For spcers in prticulr, the mteril shoul be hr enough to resist mge uring hnling, preferbly the sme hrness s bering rings (i.e. roun 60 HRC), but mterils with HRC woul be equte. The most importnt point concerns the prllelism of the fces n the with ifference between the outen inner spcer, in the sme set of berings. The prllelism shoul be kept within 1 µm. To obtin the lowest possible ifference in with of the innen outer spcer, the two spcers shoul be fce groun together (one plce insie the other). Cges High-precision ngulr contct bll berings re s stnr equippe with outer ring ln riing fbric-reinforce phenolic resin cges. The cges re lightweight n esigne to minimise centrifugl force, while ensuring n optimum lubricnt flow throughout the bll-rcewy contct. They re not ientifie in the bering esigntion. New, better performnce cges now being introucere me of PEEK (polyether ether ketone) nre ientifie in the bering esigntion by the suffix TNH. Fbric-reinforce phenolic resin bll guie cges n metllic mchine cges re lso vilble on request Fig 1 Exmple of spcers in between group of two high-precision ngulr contct bll berings mtche bck-to-bck

14 Angulr contct bll berings Spee rtings The limiting spees quote in the bering tbles re guieline vlues nre vli provie tht the berings re lightly loe (P 0,06 C), tht they re lightly preloe by mens of springs, n tht the trnsport of het wy from the bering position is goo. The vlues for oil spot lubriction re mximum vlues n shoul be reuce for certin other methos of oil lubriction s mentione in the chpter Spee ( pge 3). The vlues for grese lubriction re lso mximum vlues. oth pply to single berings. When single berings re juste ginst ech other to greter egree, e.g. to increse spinle stiffness, or if mtche sets of two, three or fouerings re to be use, the spee rting vlues given in the tbles must be reuce. Reuction fctors to obtin guieline vlues for the pproprite conitions re given in Tble 14. For specil prelos plese contct SKF. If the spee rting obtine from the bove for mtche bering sets is inequte, simple esign chnge, such s the inclusion of intermeite rings between the berings will llow pprecible increses to be me ( fig 1 pge 135). For sets of three berings, for exmple, it shoul then be possible to run t the spee rting for pire berings. Springs to prelo the berings my be beneficil. This type of prelo is generlly use for high-spee opertion in orer to obtin n even prelo over the whole operting rnge of the mchine. Equivlent ynmic bering lo Foerings rrnge singly or pire in tnem P = F r P = XF r + YF when F /F r e when F /F r > e Fctor vlues re given in Tble pge 138. When clculting bering pirs, F n F represent the forces cting on the bering pir. Foerings pire bck-to-bck or fce-to-fce P = F r + Y 1 F P = XF r + Y F when F /F r e when F /F r > e Fctor vlues re given in Tble 16 pge 138. When clculting bering pirs, F n F represent the forces cting on the bering pir. 15 Equivlent sttic bering lo Foerings rrnge singly or pire in tnem P 0 = 0,5 F r + Y 0 F when P 0 < F r, P 0 = F r shoul be use. Foerings pire bck-to-bck or fce-to-fce P 0 = F r + Y 0 F The vlue of fctor Y 0 epens on the contct ngle n cn be obtine from Tbles 15 n 16. When clculting bering pirs, F n F re the forces cting on the bering pir. Spee reuction fctors for preloe bering sets of ngulr contct bll berings Tble 14 ering ering esign rrngement C, C/HC, AC All CE, CE/HC, ACE AC/HC n ACE/HC CX, CX/HC, ACX n ACX/HC Prelo Specil Prelo prelo A C A Set of berings pire in tnem 0,90 0,80 0,65 0,90 0,70 Set of berings pire bck-to-bck or fce-to-fce 0,80 0,70 0,55 Cll SKF 0,75 0,60 Set of 3 berings 0,70 0,55 0,35 0,65 0,40 Set of 4 berings 0,65 0,45 0,5 0,55 0,

15 Angulr contct bll berings Vibrtion from other mchinery, trffic or uring trnsporttion my cuse mge to berings. In such cses, bering life is not limite by the mteril ftigue, but by the permnent eformtion prouce in the contct between blls n rcewys. A bll my be riven into the surfce of the rings by the pplie lo. The sme my hppen foerings sustining hevy shock los uring frction of revolution. As emns re high for running properties n life, permnent eformtion of the bering prts shoul be voiet ll times. The mximum lo shoul therefore not excee the equivlent sttic lo obtine from the eqution: P 0 = C 0 /s 0 where P 0 = equivlent sttic bering lo, N C 0 = bsic sttic lo rting, N s 0 = sttic sfety fctor. Foll-steel high-precision ngulr contct bll berings, minimum sfety fctor s 0 of 3 is recoene. For hybri berings, sfety fctor s 0 of 3,4 cn be use. Clcultion of equivlent bering lo for preloe ngulr contct bll berings When clculting the equivlent bering lo for preloe berings, it is necessry to tke the prelo into ccount. The xil component of the lo (F ) is neee for the equivlent lo clcultion. It is obtine using the following equtions when ctul operting conitions re consiere (the vlues obtine will be pproximte). Foering pirs uner ril lo nxilly secure F = G m Foering pirs uner ril lo n preloe by springs esigntion systems of single berings n mtche sets The complete esigntion of single bering ientifies the series, bore imeter, contct ngle, n esign, s well s the suffix inicting the tolernce clss e.g C/P4A. The esigntion of bering sets lso inclues suffixes inicting the number of berings in the set, their rrngement n prelo. Aitionl suffixes my be e to ientify berings incorporting specil fetures, such s greses, specil tolernces, etc. Plese consult SKF for precise informtion. The esigntion scheme of SKF high-precision ngulr contct bll berings is shown in Tble 17 pge 140. F = G A, Clcultion fctors for single berings n berings pire in tnem Clcultion fctors foerings pire bck-to-bck or fce-to-fce Foering pirs unexil lo nxilly secure Tble 15 Tble 16 F = G m + 0,67 K F = K when K 3 G m when K > 3 G m f 0 F /C 0 e X Y Y 0 f 0 F /C 0 e X Y 1 Y Y 0 Contct ngle 15 egrees (suffix C, CX n CE) < 0,178 0,38 0,44 1,47 0,46 0,357 0,4 0,44 1,40 0,46 0,714 0,43 0,44 1,30 0,46 1,07 0,46 0,44 1,3 0,46 1,43 0,47 0,44 1,19 0,46,14 0,5 0,44 1,1 0,46 3,57 0,55 0,44 1,0 0,46 5,35 0,56 0,44 1,00 0,46 > 7,14 0,56 0,44 1,00 0,46 Contct ngle 5 egrees (suffix AC, ACX n ACE) 0,68 0,41 0,87 0,38 Contct ngle 15 egrees (suffix C, CX n CE) < 0,178 0,38 0,7 1,65,39 0,9 0,357 0,4 0,7 1,57,8 0,9 0,714 0,43 0,7 1,46,11 0,9 1,07 0,46 0,7 1,38,00 0,9 1,43 0,47 0,7 1,34 1,93 0,9,14 0,5 0,7 1,6 1,8 0,9 3,57 0,55 0,7 1,14 1,66 0,9 5,35 0,56 0,7 1,1 1,63 0,9 > 7,14 0,56 0,7 1,1 1,63 0,9 Contct ngle 5 egrees (suffix AC, ACX n ACE) 0,68 0,67 0,9 1,41 0,76 Foering pirs unexil lo n preloe by springs F = G A, + K where F = xil component of bering lo, N G A, = prelo of bering pir, N G m = prelo on mounte bering pir, N K = externl xil force cting on single bering, N Vlues of f 0 re given in the bering tbles Vlues of f 0 re given in the bering tbles

16 Angulr contct bll berings ering series 719 Single row ngulr contct bll bering, ISO imension Series Single row ngulr contct bll bering, ISO imension Series 10 7 Single row ngulr contct bll bering, ISO imension Series 0 ore imeter 8 8 bore imeter 9 9 bore imeter bore imeter 01 1 bore imeter 0 15 bore imeter bore imeter 04 ( 5) 0 bore imeter I 48 ( 5) 40 bore imeter Contct ngle n internl esign AC, ACX 5 C,CX 15 ACE 5 CE 15 Tble ACE TNH / HC P4A Q C A Prouct tbles Cge esign n mteril Outer ring ln riing, fbric reinforce phenolic resin TNH Rolling element riing, glss fibre reinforce PEEK Rolling element mteril Steel HC Silicon nitrie (cermic) Tolernce clss P4A imensionl ccurcy to ISO clss 4, running ccurcy better thn ISO clss 4 PA9A Accurcy to AMA clss AEC 9 Number of berings in set berings in mtche set T 3 berings in mtche set Q 4 berings in mtche set ering rrngement in mtche set ck-to-bck F Fce-to-fce T Tnem T ck-to-bck/tnem FT Fce-to-fce/tnem C ck-to-bck of pirs in tnem FC Fce-to-fce of pirs in tnem G For universl piring Prelo A C G.. Light prelo Meium prelo Hevy prelo Specil prelo, vlue in N, e.g. G

17 Stnr high-precision ngulr contct bll berings 8 17 r r4 r 1 r3 r1 r r r b C, AC, CX n ACX Principl sic lo rtings Ftigue Clcultion Spee rtings Mss esigntion imensions ynmic sttic lo fctor Lubriction limit grese oil spot C C 0 P u f 0 imensions Abutment n fillet imensions 1 1 r 1, r 3, 4 b min min min mx mx mx mx N N r/min kg , , CX , , CX , , CX , ACX , , CX , ACX , , CX , ACX , , CX , ACX , , CX , ACX , , CX , ACX , , CX , ACX , , CX , ACX , , CX , ACX , , CX , ACX , , CX , ACX , , CX , ACX 8 11,8 17,6 0,3 0, ,1 0,3 0,1 9 13,5 19,9 0,3 0,1 6 11,1 0,3 0, ,6 17,8 0,3 0, ,5 0,3 0,1 13,6 17,8 0,3 0, ,5 0,3 0,1 15,1 1,3 0,3 0, ,1 0,3 0,1 15,1 1 0,3 0, ,1 0,3 0,1 16,8 3,3 0,6 0, ,1 0,6 0,3 16,8 3,3 0,6 0, ,1 0,6 0,3 1 15,9 0,1 0,3 0,1 5 14,5 0,3 0,1 15,9 0,1 0,3 0,1 7 14,5 0,3 0,1 17,1 3,3 0,3 0, ,1 0,3 0,1 17,1 3,3 0,3 0, ,1 0,3 0,1 18, 5,8 0,6 0, ,1 0,6 0,3 18, 5,8 0,6 0, ,1 0,6 0, ,1 3,9 0,3 0, ,5 0,3 0,1 19,1 3,9 0,3 0, ,5 0,3 0,1 0,6 6,8 0,3 0, ,1 0,3 0,1 0,6 6,5 0,3 0, ,1 0,3 0,1 1,5 9,1 0,6 0, ,6 0,3 1,5 9,1 0,6 0, ,6 0,3 17 1,1 5,9 0,3 0, ,5 0,3 0,1 1,1 5,9 0,3 0, ,5 0,3 0,1,9 9,6 0,3 0, ,4 0,3 0,1,9 9, 0,3 0, ,4 0,3 0,1 4, 3,8 0,6 0, ,6 0,3 4, 3,8 0,6 0, ,6 0,

18 Stnr high-precision ngulr contct bll berings 0 40 r r4 r 1 r3 r1 r r r b C, AC, CX n ACX Principl sic lo rtings Ftigue Clcultion Spee rtings Mss esigntion imensions ynmic sttic lo fctor Lubriction limit grese oil spot C C 0 P u f 0 imensions Abutment n fillet imensions 1 1 r 1, r 3, 4 b min min min mx mx mx mx N N r/min kg , , CX , ACX , , CX , ACX , ,1 704 CX ,1 704 ACX , CX , ACX , , CX , ACX , , CX , ACX , CX , ACX , , CX , ACX , C , AC , C , AC , , C , AC ,8 707 C ,8 707 AC , C , AC , C , AC , C , AC 0 5,4 31,6 0,3 0, ,5 0,3 0,1 5,4 31,6 0,3 0, ,5 0,3 0,1 6,9 35,1 0,6 0, ,1 0,6 0,3 6,9 35,1 0,6 0, ,1 0,6 0,3 9,1 38,7 1 0, ,1 1 0,3 9,1 38,7 1 0, ,1 1 0,3 5 30,4 36,6 0,3 0, ,5 0,3 0,1 30,4 36,6 0,3 0, ,5 0,3 0,1 31,9 40,1 0,6 0, ,1 0,6 0,3 31,9 40,1 0,6 0, ,1 0,6 0,3 34,1 43,7 1 0, ,1 1 0,3 34,1 43,7 1 0, ,1 1 0, ,4 41,6 0,3 0, ,5 0,3 0,1 35,4 41,6 0,3 0, ,5 0,3 0,1 38,1 46,9 1 0, ,1 1 0,3 38,1 46,9 1 0, ,1 1 0,3 40,3 51,7 1 0, ,3 40,3 51,7 1 0, , , 48,8 0,6 0, ,8 0,6 0,1 41, 48,8 0,6 0, ,8 0,6 0,1 43,7 53,3 1 0, ,3 43,7 53,3 1 0, , ,1 0, , ,1 0, , ,7 55,3 0,6 0, ,8 0,6 0,1 46,7 55,3 0,6 0, ,8 0,6 0,1 49, 58,8 1 0, ,3 49, 58,8 1 0, , ,1 0, , ,1 0, ,

19 Stnr high-precision ngulr contct bll berings r r4 r 1 r3 r1 r r r b C, AC Principl sic lo rtings Ftigue Clcultion Spee rtings Mss esigntion imensions ynmic sttic lo fctor Lubriction limit grese oil spot C C 0 P u f 0 imensions Abutment n fillet imensions 1 1 r 1, r 3, 4 b min min min mx mx mx mx N N r/min kg , C , AC , C , AC , C , AC , C , AC , C , AC , C , AC , C , AC , C , AC , C , AC , C , AC ,4 701 C ,4 701 AC ,8 71 C ,8 71 AC , C , AC , C , AC C AC 45 5, 60,8 0,6 0, ,8 0,6 0,1 5, 60,8 0,6 0, ,8 0,6 0,1 54,7 65,3 1 0, ,3 54,7 65,3 1 0, ,3 57,5 7,5 1,1 0, ,6 57,5 7,5 1,1 0, , ,7 65,3 0,6 0, ,8 0,6 0,1 56,7 65,3 0,6 0, ,8 0,6 0,1 59,7 70,3 1 0, ,3 59,7 70,3 1 0, ,3 6,5 77,5 1,1 0, ,6 6,5 77,5 1,1 0, ,6 55 6,7 7,3 1 0, ,3 6,7 7,3 1 0, ,3 66,3 78,7 1,1 0, ,6 66,3 78,7 1,1 0, , ,9 1,5 0, ,5 0, ,9 1,5 0, ,5 0, ,7 77,3 1 0, ,3 67,7 77,3 1 0, ,3 71,3 83,7 1,1 0, ,6 71,3 83,7 1,1 0, ,6 75,6 94,4 1,5 0, ,5 0,6 75,6 94,4 1,5 0, ,5 0,6 65 7,7 8,3 1 0, ,3 7,7 8,3 1 0, ,3 76,3 88,7 1,1 0, ,6 76,3 88,7 1,1 0, ,6 8, ,5 0, ,5 0,6 8, ,5 0, ,5 0,

20 Stnr high-precision ngulr contct bll berings r r4 r 1 r3 r1 r r r b C, AC Principl sic lo rtings Ftigue Clcultion Spee rtings Mss esigntion imensions ynmic sttic lo fctor Lubriction limit grese oil spot C C 0 P u f 0 imensions Abutment n fillet imensions 1 1 r 1, r 3, 4 b min min min mx mx mx mx N N r/min kg , C , AC , C , AC ,1 714 C ,1 714 AC , C , AC , C , AC , 715 C , 715 AC , C , AC , C , AC , C , AC , C , AC , C , AC ,8 717 C ,8 717 AC , C , AC , C , AC ,5 718 C ,5 718 AC 70 79,3 90,7 1 0, ,3 79,3 90,7 1 0, ,3 8,9 97,1 1,1 0, ,6 8,9 97,1 1,1 0, , ,5 0, ,5 0, ,5 0, ,5 0, ,3 95,7 1 0, ,3 84,3 95,7 1 0, ,3 87, ,1 0, ,6 87, ,1 0, , ,5 0, ,5 0, ,5 0, ,5 0, , , ,3 89, , ,3 94, ,1 0, ,6 94, ,1 0, ,6 98, , , ,1 0, ,6 95, ,1 0, ,6 99, ,1 0, , ,1 0, , ,1 0, , ,1 0, , ,1 0, , ,5 0, ,5 0, ,5 0,