1、 Reference number ISO 23848-2:2009(E) ISO 2009INTERNATIONAL STANDARD ISO 23848-2 First edition 2009-11-15 Machine tools Ball splines Part 2: Dynamic and static load ratings and rating life Machines-outils Guidages cannels billes Partie 2: Charges dynamiques et statiques de base et dure de vie de bas
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5、ss given below. COPYRIGHT PROTECTED DOCUMENT ISO 2009 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO
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7、ll rights reserved iiiContents Page Foreword iv Introduction.v 1 Scope1 2 Normative references1 3 Terms and definitions .1 4 Symbols3 5 Type AI and type AII (angular type) .4 5.1 Basic dynamic load rating4 5.2 Basic static load rating .5 5.3 Basic dynamic torque rating 5 5.4 Basic static torque rati
8、ng .5 6 Type R (radial type) .5 6.1 Basic dynamic load rating6 6.2 Basic static load rating .6 7 Rating life .7 Bibliography8 ISO 23848-2:2009(E) iv ISO 2009 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (I
9、SO member bodies). The work of 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, gov
10、ernmental 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 of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC
11、 Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the membe
12、r bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 23848-2 was prepared by Technical Committee ISO/TC 39, Machine tools. IS
13、O 23848 consists of the following parts, under the general title Machine tools Ball splines: Part 1: General characteristics and requirements Part 2: Dynamic and static load ratings and rating life ISO 23848-2:2009(E) ISO 2009 All rights reserved vIntroduction The ball spline is a power transmission
14、 component based on recirculating balls, which is designed to translate axially while transmitting torque by an anti-friction means. The ball spline is selected for its smooth operation, high-speed capability, low friction and high radial and high torsional load capacity. This part of ISO 23848 spec
15、ifies and standardizes the basic dynamic load rating and torque rating, the basic static load rating and torque rating and the 90 % rating life for ball splines of type AI, type AII and type R. INTERNATIONAL STANDARD ISO 23848-2:2009(E) ISO 2009 All rights reserved 1Machine tools Ball splines Part 2
16、: Dynamic and static load ratings and rating life 1 Scope This part of ISO 23848 specifies the calculation method of basic dynamic load rating, basic static load rating and basic rating life prediction for the design and use of ball splines of type AI, type AII and type R. It also establishes the ba
17、sic static and dynamic torque ratings for these ball splines. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document
18、(including any amendments) applies. ISO 23848-1, Machine tools Ball splines Part 1: Characteristics, shapes, and dimensions 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 23848-1 and the following apply. 3.1 basic dynamic load rating C constant stat
19、ionary radial load, having direction and magnitude which do not vary with time and which a ball spline assembly theoretically endures for a basic rating life of 50 km 3.2 basic dynamic torque rating C Tconstant torque, having direction and magnitude which do not vary with time and which a ball splin
20、e assembly theoretically endures for a basic rating life of 50 km 3.3 basic rating life L 10fatigue life that of a group of ball splines have a 90 % probability of enduring 3.4 basic static load rating C 0static radial load which corresponds to a calculated Hertzian contact stress at the centre of t
21、he contacting surfaces of the maximum ball load position See Table 1. ISO 23848-2:2009(E) 2 ISO 2009 All rights reservedTable 1 Maximum contact stress, max , corresponds to basic static load rating r g/D wu 0,52 0,53 0,54 0,55 0,56 0,57 0,58 0,59 W 0,6 maxMPa 4 200 4 250 4 300 4 350 4 400 4 450 4 50
22、0 4 550 4 600 3.5 basic static torque rating C 0Tstatic torque which corresponds to a calculated Hertzian contact stress at the centre of the contacting surfaces of the maximum ball load position, as shown in Table 1 3.6 dynamic equivalent load P constant radial load under the influence of which a b
23、all spline has the same life as it attains under the actual applied load conditions 3.7 dynamic equivalent torque T constant torque under which a ball spline has the same life as it attains under the actual applied torque conditions 3.8 life total running distance of a ball spline before the first e
24、vidence of rolling contact fatigue failure or flaking occurs at the raceways of either the spline outer race, the spline shaft or the re-circulating balls 3.9 static equivalent load P 0static radial load which causes the same constant stress at the centre of the contacting surfaces as occurs under t
25、he actual applied load conditions 3.10 static equivalent torque T 0static torque which causes the same constant stress at the centre of the contacting surfaces as occurs under the actual applied torque conditions 3.11 reliability R probability that the ball spline assembly will not fail by rolling c
26、ontact fatigue under a specified load and/or torque NOTE This term is the same as the probability of survival. ISO 23848-2:2009(E) ISO 2009 All rights reserved 34 Symbols Symbol Description Unit b mRating factor for contemporary used high quality hardened steel and product quality C Basic dynamic lo
27、ad rating N C TBasic dynamic torque rating Nm C 0Basic static load rating N C 0TBasic static torque rating Nm D pwBall pitch circle diameter mm D wBall diameter mm f cFactor determined by geometrical shape, working accuracy and material for each part of ball spline f 0Factor determined by geometrica
28、l shape and working stress for each part of ball spline i Number of spline grooves i tNumber of spline grooves applied to calculation of load rating k iBall row arrangement factor applied to calculation of dynamic load rating k 0iBall row arrangement factor applied to calculation of static load rati
29、ng L 10Basic rating life with 90 % reliability 50 km l tOuter race spline groove length applied to calculation of load rating mm P Dynamic equivalent load N P 0Static equivalent load N R Reliability r gSpline groove radius mm T Dynamic equivalent torque Nm T 0Static equivalent torque Nm Z tNumber of
30、 effective balls for one spline groove applied to calculation of load rating Contact angle for radial load Contact angle for torque direction Adjustment factor for dynamic load rating and torque rating maxMaximum contact stress MPa ISO 23848-2:2009(E) 4 ISO 2009 All rights reserved5 Type AI and type
31、 AII (angular type) The load ratings, torque ratings and contact angles corresponding to the applied radial load and torque for the three types of ball spline are shown in Figure 1. The load and torque ratings are defined in 5.1 to 5.4. a) Type AI b) Type AII Figure 1 Load ratings, torque ratings an
32、d contact angles for ball splines of type AI and AII 5.1 Basic dynamic load rating The basic dynamic load rating, C, is found using Equations (1) and (2): 1/30 0,7 2/3 2,1 mct t w t cos Cb fl i Z D = (1) 0,41 g c gw 2 30,9 2 r f rD = (2) where b m = 1,3; = 0,9. ISO 23848-2:2009(E) ISO 2009 All right
33、s reserved 55.2 Basic static load rating The basic static load rating, C 0 , is found using Equation (3): 2 00ttw cos CfiZD = (3) 5.3 Basic dynamic torque rating The basic dynamic torque rating, C T , is found using Equations (4) and (5): pw 1/30 0,7 2/3 2,1 mct t w t T sin 2 1000 D bfliZD C =(4) 0,
34、41 g c gw 2 30,9 2 r f rD = (5) where b m = 1,3; = 0,9. 5.4 Basic static torque rating The basic static torque rating, C 0T , is found using Equation (6): pw 2 0ttw 0T sin 2 1000 D fiZD C =(6) Table 2 f cfactor and f 0factor r g /D w0,52 0,53 0,54 0,55 0,56 0,57 0,58 0,59 0,6 f c105,8 90,3 80,8 74,3
35、 69,5 65,7 62,7 60,1 58,0 f 094,6 76,3 66,1 59,5 54,9 51,5 49,0 47,1 45,6 6 Type R (radial type) The load ratings corresponding to the applied radial load and torque are shown in Figure 2 for the radial type (type R) ball spline. The load ratings are defined in 6.1 and 6.2. ISO 23848-2:2009(E) 6 ISO
36、 2009 All rights reservedNOTE Without definition for C Tand C 0T . Figure 2 Load ratings and contact angles for ball splines of type R 6.1 Basic dynamic load rating The basic dynamic load rating, C, is found using Equations (7) and (8): 1/30 2/3 2,1 mc t t w i Cb fkl Z D = (7) 0,41 g c gw 2 30,9 2 r
37、 f rD = (8) where b m = 1,3; = 0,9. 6.2 Basic static load rating The basic static load rating, C 0 , is found using Equation (9): 2 000tw i CfkZD = (9) Table 3 k ifactor and k 0ifactor i 3 4 5 6 7 8 9 10 k i1 1 1,104 1,329 1,531 1,681 1,807 1,948 k 0i1 1 1,106 1,354 1,614 1,841 2,052 2,284 ISO 23848
38、-2:2009(E) ISO 2009 All rights reserved 77 Rating life The basic rating life, L 10 , for applied radial load is given as Equation (10): 3 10 C L P = (10) The basic rating life, L 10 , for applied torque is given as Equation (11): 3 T 10 C L T = (11) ISO 23848-2:2009(E) 8 ISO 2009 All rights reservedBibliography 1 ISO 14728-1, Rolling bearings Linear motion rolling bearings Part 1: Dynamic load ratings and rating life 2 ISO 14728-2, Rolling bearings Linear motion rolling bearings Part 2: Static load ratings ISO 23848-2:2009(E) ICS 25.060.99 Price based on 8 pages ISO 2009 All rights reserved
