© ISO 2017 Rolling bearings — Linear motion rolling bearings — Part 1 Dynamic load ratings and rating life Roulements — Roulements à mouvement linéaire — Partie 1 Charges dynamiques de base et durée n[.]
INTERNATIONAL STANDARD ISO 14728-1 Second edition 2017-02 Rolling bearings — Linear motion rolling bearings — Part 1: Dynamic load ratings and rating life Roulements — Roulements mouvement linéaire — Partie 1: Charges dynamiques de base et durée nominale Reference number ISO 14728-1:2017(E) © ISO 2017 ISO 14728-1:2017(E) COPYRIGHT PROTECTED DOCUMENT © ISO 2017, Published in Switzerland All rights reserved Unless otherwise specified, no part o f this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission Permission can be requested from either ISO at the address below or ISO’s member body in the country o f the requester ISO copyright o ffice Ch de Blandonnet • CP 401 CH-1214 Vernier, Geneva, Switzerland Tel +41 22 749 01 11 Fax +41 22 749 09 47 copyright@iso.org www.iso.org ii © ISO 2017 – All rights reserved ISO 14728-1:2017(E) Contents Page Foreword iv Introduction v Scope Normative references Terms and definitions Symbols Basic dynamic load ratings 5.1 5.2 Linear ball bearings 10 f Linear roller bearings 11 11 crossed rolle 11 1 Recirculating linear b all b earings , s leeve typ e with raceway gro oves Recirculating linear b all b earings , s leeve typ e witho ut raceway gro oves Recirculating linear b all b earings , linear guideway, carriage typ e N o n- recirculating linear b all b earings , linear guideway, deep gro ove and o ur- p o int- co ntact typ es Recirculating linear ro ller b earings , linear guideway, carriage typ e 2 N o n- recirculating linear ro ller b earings , linear guideway, flat, V- angle and r typ es Dynamic equivalent load 12 Basic rating life 12 Bibliography 14 © ISO 2017 – All rights reserved iii ISO 14728-1:2017(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies) The work o f preparing International Standards is normally carried out through ISO technical committees Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters o f electrotechnical standardization The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part In particular the different approval criteria needed for the di fferent types o f ISO documents should be noted This document was dra fted in accordance with the editorial rules of the ISO/IEC Directives, Part (see www.iso org/directives) Attention is drawn to the possibility that some o f the elements o f this document may be the subject o f patent rights ISO shall not be held responsible for identi fying any or all such patent rights Details o f any patent rights identified during the development o f the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso org/patents) Any trade name used in this document is in formation given for the convenience o f users and does not constitute an endorsement For an explanation on the meaning o f ISO specific terms and expressions related to formity assessment, as well as information about ISO’s adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html This document was prepared by Technical Committee ISO/TC 4, Rolling bearings, Subcommittee SC 8, Load ratings and life This second edition cancels and replaces the first edition (ISO 14728-1:2004), o f which it constitutes a minor revision with the following changes: — improvement of Figures 2, 4, and 9; — correction o f terms and definitions (change o f ball/roller guide systems to linear ball/roller bearings); — correction of font (ϕ changed to φ); — alignment with the latest drafting rules A list of parts in the ISO 14728 series can be found on the ISO website iv © ISO 2017 – All rights reserved ISO 14728-1:2017(E) Introduction I t i s o ften i mprac tic a l to e s tabl i sh the s uitabi l ity o f a l i ne ar mo tion rol l i ng b e ari ng s ele c te d appl ic ation b y te s ti ng T he substitute for testing: fol lowi ng — l i fe c a lc u lation with dynam ic lo ad (I S O 147 -1) ; — s tatic lo ad s a fe ty fac tor for a s p e ci fic pro ce dure s have prove d to b e a n appropriate and convenient c a lc u l ation with s tatic lo ad (I S O 147 -2 ) T he l i fe o f a l i ne ar mo tion b e ari ng i s given b y the d i s ta nce wh ich one o f the raceways move s , i n relation to the o ther raceway, b e fore the fi rs t evidence o f or one of the rolling elements T he formu l ae for and Palmgren[8] fatigue develop s i n the materia l o f one o f the raceways c a lc u lati ng the b a s ic dyna m ic lo ad rati ngs are derive d © ISO 2017 – All rights reserved from the the or y o f Lu ndb erg [7] v INTERNATIONAL STANDARD ISO 14728-1:2017(E) Rolling bearings — Linear motion rolling bearings — Part 1: Dynamic load ratings and rating life Scope T h i s c u ment s p e ci fie s me tho d s o f c a lc u lati ng the b as ic dynam ic lo ad rati ng a nd b as ic rati ng l i fe for l i ne a r mo tion rol l i ng b e a ri ngs ma nu fac ture d from contemp ora r y, com mon ly u s e d, h igh qua l ity, hardene d b e a ri ng s te el i n accorda nce with go o d ma nu fac turi ng prac tice and b a s ica l ly o f conventiona l design as regards the shape of the rolling contact surfaces The life of linear motion rolling bearings is defi ne d a nd the cond ition s a re e s tabl i she d for rel i able l i fe c a lc u lation s T h i s c u ment i s no t app l ic able to de s ign s where the rol l i ng elements op erate d i re c tly on the s l ide s ur face o f the mach i ne e qu ipment, un le s s that s ur face i s e qu iva lent i n a l l re s p e c ts to the raceway o f the linear motion rolling bearing component it replaces Normative references There are no normative references in this document Terms and definitions For the pu r p o s e s o f th i s c u ment, the term s and defi n ition s given i n I S O 81 and I S O 5 , and the fol lowi ng apply ISO and IEC maintain terminological databases for use in standardization at the following addresses: — IEC Electropedia: available at http://www.electropedia org/ — ISO Online browsing platform: available at http://www.iso org/obp 3.1 recirculating linear ball bearing, sleeve type, with or without raceway grooves b a s ic a l ly c yl i nd ric a l s le eve provide d with a nu mb er o f clo s e d lo op s o f re ci rc u l ati ng b a l l s de s igne d to ach ieve l i ne ar rol l i ng mo tion a long rdene d c yl i nd ric a l sh a ft N o te to entr y: S e e Figure N o te to entr y: T he raceways i n the s le e ve c a n b e de s igne d c yl i nd ric a l a s wel l a s s te el i n s er ts with raceway grooves parallel to the axis © ISO 2017 – All rights reserved ISO 14728-1:2017(E) Figure — Recirculating linear ball bearing, sleeve type 3.2 recirculating linear ball (or roller) bearing, linear guideway, carriage type l i ne a r b a l l (or rol ler) b e ari ng provide d with a nu mb er o f s ym me tric a l ly arrange d , clo s e d lo op s of re ci rc u l ati ng b a l l s (or rol lers) de s igne d to ach ieve l i ne a r rol l i ng mo tion a long a h ardene d gu ideway fu rn i s he d with ade quate raceways N o te to entr y: S e e Figure Figure — Recirculating linear ball (or roller) bearing, linear guideway, carriage type © ISO 2017 – All rights reserved ISO 14728-1:2017(E) 3.3 non-recirculating linear ball bearing, linear guideway, deep groove type linear bearing with balls as rolling elements, each ball having two points of contact N o te to entr y: S e e Figure N o te to entr y: T he c ro s s - s e c tion a l rad i i o f the raceway gro ove s i n the two gu ideways a re e qu a l a nd m ay l ie between 0,52 D w a nd i n fi n ity Figure — Non-recirculating linear ball bearing, linear guideway, deep groove type 3.4 non-recirculating linear ball bearing, linear guideway, four-point-contact type linear bearing with balls as rolling elements, each ball having four points of contact N o te to entr y: S e e N o te to entr y: Figure T he c ro s s - s e c tio n a l rad i i o f the race way gro ove s gu ideways a re e qu a l a nd m ay l ie b e twe en , Dw for the fou r p o i nts o f co ntac t i n the two a nd i n fi n ity Figure — Non-recirculating linear ball bearing, linear guideway, four-point-contact type © ISO 2017 – All rights reserved ISO 14728-1:2017(E) 3.5 n o n - r e c i r c u l a t i n g l i n e a r r o l l e r b e a r i n g , l i n e a r g u i d e w a y , f l a t t y p e l i ne a r b e a ri ng with ne e d le rol lers or c yl i nd ric a l rol lers a s rol l i ng elements N o te to entr y: S e e F i g u r e Figure 5 — N o n - r e c i r c u l a t i n g l i n e a r r o l l e r b e a r i n g , l i n e a r g u i d e w a y , f l a t t y p e 3.6 non-recirculating linear roller bearing, linear guideway, V-angle type l i ne a r b e a ri ng with gu ideways de s igne d as p ar ts o f a V with a ° a ngle N o te to entr y: S e e Figure N o te to entr y: N e e d le rol lers o r c yl i nd r ic a l rol lers a re u s e d a s rol l i ng elements Figure — Non-recirculating linear roller bearing, linear guideway, V-angle type © ISO 2017 – All rights reserved ISO 14728-1:2017(E) 3.7 non-recirculating linear roller bearing, linear guideway, crossed roller type l i ne ar b e ari ng with c yl i nd ric a l rol lers arra nge d i n a c ro s s e d rol ler s truc tion N o te to entr y: S e e Figure Figure — Non-recirculating linear roller bearing, linear guideway, crossed roller type 3.8 life < for an i nd ividua l l i ne a r mo tion rol l i ng b e a ri ng> d i s tance one o f the raceways move s i n relation to the o ther raceway b e fore the fi rs t evidence o f of the rolling elements fatigue develop s i n the materia l o f one o f the raceways or one 3.9 reliability < for a group o f app a rently identic a l l i ne ar mo tion rol l i ng b e a ri ngs op erati ng u nder the s a me cond ition s > p ercentage o f the group that i s exp e c te d to attai n or exce e d a s p e ci fie d l i fe N o te to entr y: T he rel i ab i l ity o f a n i nd ividu a l l i ne a r mo tion rol l i n g b e a r i ng i s the p rob ab i l ity th at the b e a r i ng wi l l atta i n o r e xce e d a s p e c i fie d l i fe 3.10 basic rating life < for an i nd ividua l l i ne a r mo tion rol l i ng b e a ri ng or a group o f app a rently identic a l l i ne a r mo tion rol l i ng b e ari ngs op erati ng u nder the s ame cond ition s > l i fe a s s o ci ate d with % rel iabi l ity, with contemp ora r y, com mon ly u s e d materi a l a nd manu fac tu ri ng qua l ity and u nder conventiona l op erati ng cond ition s 3.11 basic dynamic load rating of a linear motion rolling bearing s ta nt s tationar y lo ad th at a l i ne ar mo tion rol l i ng b e ari ng cou ld the ore tic a l ly endu re rating life of 10 m N o te to entr y: I f a b a s ic rati n g l i fe o f × 10 factor should be used as shown below: — for for a b as ic m i s u s e d to de fi ne the b a s ic dyn a m ic lo ad rati n g , then a co nvers ion b a s ic dyn a m ic lo ad rati ng o f l i ne a r b a l l b e a r i ngs: C100 B = — for C50 B 1, 26 b a s ic dyn a m ic lo ad rati ng o f l i ne a r ro l ler b e a r i ngs : C100 R = C50 R 1, 23 © ISO 2017 – All rights reserved ISO 14728-1:2017(E) 3.12 dynamic equivalent load s tant s tationar y lo ad u nder the i n fluence o f wh ich a l i ne a r mo tion rol l i ng b e ari ng wou ld have the same life as it would attain under the actual load conditions 3.13 direction of load direction of load applied for load rating calculation N o te to entr y: For c a lc u l ation o f b a s ic dyn a m ic lo ad rati ngs , the d i re c tio n o f the lo ad i s de fi ne d mo tion b e a r i ngs a s s hown b y the a r rows i n Figure for a l l l i ne a r Rol l i n g b e a r i ng de fi ne d i n 3.1 3.2 3.4 3.7 Figure — Direction of load 3.14 pitch diameter < o f re ci rc u l ati ng l i ne a r b a l l b e ari ng, sle eve typ e> d ia me ter o f the ci rcle conta i n i ng the centre s o f the b a l l s i n contac t with the raceways , i n a pl ane p er p end ic u la r to the b e ari ng a xi s 3.15 nominal contact angle angle between the direction of load on the linear bearing and the nominal line of action of the resultant o f the force s tra n s m itte d b y a b e ari ng raceway memb er to a rol l i ng element N o te to entr y: S e e Figure Figure — Nominal contact angle © ISO 2017 – All rights reserved ISO 14728-1:2017(E) Symbols For the purposes o f this document, the symbols given in ISO 281, ISO 15241 and Table apply Table — Symbols, terms and units Symbol b m C C Term Rating factor for contemporary, commonly used, high quality, hardened bearing steel in accordance with good manu facturing practice, the value o f which varies with bearing type and design Basic dynamic load rating Basic static load rating Basic dynamic load rating for linear ball bearings calculated for a basic rating li fe o f × 10 m Basic dynamic load rating for linear roller bearings calculated for a basic rating li fe o f C50R × 10 m C100B Basic dynamic load rating for linear ball bearings calculated for a basic rating li fe o f 10 m C100R Basic dynamic load rating for linear roller bearings calculated for a basic rating li fe o f 10 m Adjustment factor for recirculating linear ball bearings, sleeve type, with or without race cL way grooves, applicable in the calculation o f load ratings D pw Pitch diameter of ball rows Dw Ball diameter D we Roller diameter applicable in the calculation of load ratings 50B C F c f s f i i Load on bearing Factor that depends on the geometry o f the bearing components, the accuracy to which the various components are made, and on the material Correction factor for short stroke application, applicable for recirculating linear ball bear- F k i k we 10 ls L L t l P p g tw r Z t Z N N N N N N mm mm mm N ings, sleeve type with or without grooves, specified by the manu facturer NOTE In the case o f recirculating linear bearings, sleeve type, it is the total number o f Number o f load-carrying rows o f balls in loaded zone −90° < φ < +90° o f recirculating line ar ball bearings, sleeve type, with or without raceway grooves, applicable in the calculation Number of rows of balls or rollers applicable in the calculation of load ratings rows of balls t Unit j of load ratings Dynamic load factor Factor for recirculating linear ball bearings, sleeve type, with or without raceway grooves, applicable in the calculation of load ratings Roller length applicable in the calculation of load ratings Basic rating li fe associated with 90 % reliability Travel length of linear bearings Raceway length applicable in the calculation o f load ratings For recirculating linear bearings, that o f sleeve or carriage, determined by the manu facturer, and for non-recirculating linear bearings, that o f guideway, equal to the centre distance between the load-carrying balls or rollers at both ends of one row Dynamic equivalent load Exponent Cross-sectional radius o f the raceway groove on guideway Centre distance between two neighbouring balls or rollers Number of balls or rollers in one row Number o f load-carrying balls or rollers in one row applicable in the calculation o f load ratings © ISO 2017 – All rights reserved 1 mm 10 m mm mm N mm mm 1 ISO 14728-1:2017(E) Table (continued) Symbol α φj λ Term Unit Nominal contact angle Angle between the direction of load and the ball row j Reduction factor ° ° Basic dynamic load ratings 5.1 Linear ball bearings 5.1.1 Recirculating linear ball bearings, sleeve type with raceway grooves T he b as ic dynam ic lo ad rati ng for th i s b e ari ng , i n ver tic a l lo ad i ng p o s ition, i s given i n Formula (1): (1) C100 B = b m × fc × k i × l t1 / 30 × Z t2 / × D w 2, where D fc = λ × c L × 29, 2, 18 × − w D pw j =it ki = ∑ ( cos ϕ ) −4, 67 × rg + × rg − D w −1 , 37 −0 , 2,5 j j =1 j =i t cos ϕ j j =1 ∑( = 1,3 λ = 0,9 cL = to 1,2 ) 0, bm I n the nu mb er o f lo ad- ca rr yi ng rows o f b a l l s i n the lo ade d a re a, an angu lar are a o f − ° < account The values of bm and λ manufacturer The value of cL The values for ki f given in Table φj it , those rows which are arranged in Figure 8) shall be taken into < + ° to the d i re c tion o f norma l lo ad (s e e given ab ove are the ma xi mum va lue s , s ma l ler va lue s may b e u s e d b y the i s de term i ne d by the ma nu fac turer i n the nge given ab ove o re ci rc u l ati ng l i ne ar b a l l b e ari ng , s le eve typ e, with e qua l ly s p ace d b a l l rows , a re © ISO 2017 – All rights reserved ISO 14728-1:2017(E) 5.1.2 Recirculating linear ball bearings, sleeve type without raceway grooves T he b a s ic dynam ic lo ad rati ng for th i s b e ari ng , i n ver tic a l lo ad i ng p o s ition, i s given i n Formula (2): (2) C100 B = b m × fc × k i × l t1 / 30 × Z t2 / × D w 2, where D fc = λ × c L × 22, 0, 91 × − w D pw j =i t ki = ∑ ( cos ϕ ) = −4, 67 D + 1+ w D pw −1 , 67 −0 , 2, j j j =i t cos ϕ j j =1 ∑( b m = 1,3 ) 0,3 λ = 0,9 L = to 1,2 c t, those rows which are arranged in I n the numb er o f lo ad- c arr yi ng rows o f b a l l s i n the lo ade d are a, i φ an a ngu la r are a o f − ° < account The values of m and λ manufacturer The value of L The values for i f given in Table b c i k Figure 8) shall be taken into gi ven ab ove a re the ma xi mu m va lue s , s ma l ler va lue s may b e u s e d b y the i s de term i ne d b y the manu fac tu rer i n the range given ab ove k o i j < + ° to the d i re c tion o f norma l lo ad (s e e 1,000 re c i rc u lati ng l i ne ar b a l l b e a ri ng , s le eve typ e, with e qua l ly s p ace d b a l l rows , are Table — Values of ki 1,000 1,104 1,329 1,531 1,681 1,807 10 1,948 5.1.3 Recirculating linear ball bearings, linear guideway, carriage type T he b a s ic dynam ic lo ad rati ng for th i s b e ari ng i s given i n C100 B = b m × fc × l t1 / 30 × i 0, × Z t2 / × D w 2, × cos α Formula (3): (3) where × rg fc = λ × 24, × × rg − D w © ISO 2017 – All rights reserved , 41 ISO 14728-1:2017(E) b m = 1,3 = 0,9 The values of m and λ manufacturer The values of c calculated with λ = 0,9 are given in Table λ b given ab ove are the ma xi mum va lue s , s ma l ler va lue s may b e u s e d b y the f T he lo ad- ca rr yi ng abi l ity o f a b e ari ng i s no t ne ce s s ari ly i nc re a s e d b y the u s e o f s ma l ler raceway gro ove rad i i, but it i s re duce d b y the u s e o f la rger raceway gro ove rad i i tha n tho s e i nd ic ate d i n Table Table — Values of fc g c r 0,52 0,53 0,54 0,55 0,56 0,57 0,58 0,59 0,60 f 83,9 71,6 64,1 58,9 55,1 52,1 49,7 47,7 46,0 w w Dw Dw Dw Dw Dw Dw Dw D D 5.1.4 Non-recirculating linear ball bearings, linear guideway, deep groove and four-pointcontact types T he b as ic dynam ic lo ad rati ng for the s e b e ari ngs i s given i n Formula (4): (4) C100 B = b m × fc × l t1 / 30 × i 0, × Z t2 / × D w 2, × cos α where × rg fc = λ × 24, × × rg − D w t = (Zt l b , 41 w − 1) × t m = 1,3 = 0,9 The values of m and λ manufacturer The values of and t are given in Table λ b i given ab ove are the ma xi mum va lue s , s ma l ler va lue s may b e u s e d b y the Z Table — Values of i and Zt Bearing D e ep gro o ve typ e Fo u r-p oi nt- contac t typ e 10 i t Z Z Z © ISO 2017 – All rights reserved ISO 14728-1:2017(E) The values of c calculated with λ = 0,9 are given in Table f Table — Values of fc g c r 0,52 0,53 0,54 0,55 0,56 0,57 0,58 0,59 0,60 f 82,8 70,7 63,3 58,2 54,4 51,5 49,1 47,1 45,4 21,8 w Dw Dw Dw Dw Dw Dw Dw Dw D ∞ 5.2 Linear roller bearings 5.2.1 Recirculating linear roller bearings, linear guideway, carriage type T he b a s ic dynam ic lo ad rati ng for th i s b e ari ng i s given i n Formula (5): (5) C100 B = b m × fc × l t1 / 36 × i / × Z t3 / × L we / × D we 35 / 27 × cos α where c=λ m = 1,1 λ = 0,83 The values of manufacturer f × 19 b roller types N o n - r b e and λ m c i r c u l a t i gi ven ab ove a re the ma xi mu m va lue s , s ma l ler va lue s may b e u s e d b y the n g l i n T he b a s ic dynam ic lo ad rati ng e a r for r o l l e r b e a r i n g s , l i n e a r g the s e b e ari ngs i s given i n u i d e w a y , f l f l a t , V - a n g l e a n d c r o s s e d Formula (6): C100 B = b m × fc × l t1 / 36 × i / × Z t3 / × L we / × D we 35 / 27 × cos α where c=λ t=( t m = 1,1 λ = 0,83 The values of manufacturer (6) × 19 w Z − 1) × t b b m and λ gi ven ab ove a re the ma xi mu m va lue s , s ma l ler va lue s may b e u s e d b y the © ISO 2017 – All rights reserved 11 ISO 14728-1:2017(E) The values of and t are given in Table i Z Table — Values of i and Zt Bearing t i Z 2 Flat type V-angle type Crossed roller type Z Z /2 Z Dynamic equivalent load The dynamic equivalent load for a linear motion rolling bearing is given in Formula (7): P = F×F k (7) The dynamic load factor kF is taken to be one (kF = 1) when the direction of bearing load, F, is normal (as shown in Figure 8) and bearing clearance is in the normal range For bearing load directions other than normal and/or with additional torque loads, the values of F should be specified by the bearing manufacturer k Basic rating life The basic rating life for a linear motion rolling bearing is given in Formula (8) for the two bearing types: L10 C = P p (8) The values of are given in Table p Table — Values of p Bearing type Linear ball bearing Linear roller bearing p 10/3 The conditions established for reliable life calculations are as follows: Dynamic equivalent load: P ≤ 0,5 C P ≤ C0 Applied stroke for all types o f recirculating linear ball (or roller) bearings: s ≥ lt l Applied stroke for all types o f non-recirculating linear ball (or roller) bearings: s ≤ lt l and when the balls or rollers stroke within the raceway in the rolling direction 12 © ISO 2017 – All rights reserved ISO 472 8-1 : 01 7(E) T he l i fe o f re c i rc u lati ng l i ne ar b a l l b e ari ngs , s le eve typ e i s i n fluence d b y appl ie d s hor ter s troke a s defi ne d ab ove and c an b e adap te d i n L10 where C = fs P Formula (9): p (9) l fs = f s l t The correction factor fs sh a l l b e s p e ci fie d b y the manu fac tu rer © ISO 2017 – All rights reserved 13 ISO 14728-1:2017(E) Bibliography [1] [2] [3] ISO 281, Rolling bearings — Dynamic load ratings and rating life ISO 5593, Rolling bearings — Vocabulary ISO 12090-1, Rolling bearings — Profiled rail guides for linear motion rolling bearings — Part 1: [4] ISO 12090-2, Rolling bearings — Profiled rail guides for linear motion rolling bearings — Part 2: [5] [6] [7] [8] 14 Boundary dimensions and tolerances for series 1, and Boundary dimensions and tolerances for series and ISO 10285, tolerances Rolling bearings — Sleeve type linear ball bearings — Boundary dimensions and ISO 15241, Rolling bearings — Symbols for physical quantities Lundberg G., & Palmgren A Dynamic capacity ofrolling bearings, Acta Polytechnica, Mechanical Engineering Series, Royal Swedish Academy o f Engineering Sciences, Vol 1, No (1947) Lundberg G., & Palmgren A Dynamic capacity ofroller bearings, Acta Polytechnica, Mechanical Engineering Series, Royal Swedish Academy o f Engineering Sciences, Vol 2, No (1952) © ISO 2017 – All rights reserved