1、 i Load Ratings and Fatigue Life for Roller Bearings ANSI/ABMA 11:2014 (Revision of ANSI/ABMA 11:1990) Secretariat American Bearing Manufacturers Association ANSI/ABMA 11:2014 Accredited Standards Committee B3 ii AMERICAN NATIONAL STANDARD (This is not an approved part of the standard) Approval of a
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4、 preclude anyone, whether they approved the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standard. The American National Standards Institute does not develop standards and will in no circumstances give an interpretation
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6、e appears on the title page of this standard. CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National Standards Institute or online
7、at www.ANSI.org. Published by American Bearing Manufacturers Association 2025 M Street, N.W., Suite 800 Washington, DC 20036 Copyright 2014 by American Bearing Manufacturers Association All rights reserved. No part of this publication may be reproduced in any form, in an electronic retrieval system
8、or otherwise, without prior written permission of the publisher. Printed in the United States of America iii Load Ratings and Fatigue Life For Roller Bearings CONTENTS SECTION PAGE 1. Introduction 1 1.1 Purpose of Standard . 1 1.2 Life Criterion . 1 1.3 Static Load Criterion . 1 2. Symbols . 2 3. De
9、finitions . 3 3.1 Life . 3 3.2 Reliability 3 3.3 Static Load . 3 3.4 Pitch Diameter of a Roller Set, Dpw 4 3.5 Rating Life . 4 3.6 Basic Rating Life, L10 . 4 3.7 Adjusted Rating life, Lna . 4 3.8 Basic Dynamic Radial Load Rating, Cr . 4 3.9 Basic Static Radial Load Rating, C0r . . 4 3.10 Basic Dynam
10、ic Axial Load Rating, Ca . 4 3.11 Basic Static Axial Load Rating, C0a 4 3.12 Dynamic Equivalent Radial Load, Pr 4 3.13 Static Equivalent Radial Load, P0r 4 3.14 Dynamic Equivalent Axial Load, Pa 4 3.15 Static Equivalent Axial Load, P0a 5 3.16 Static Safety Factor, S0 5 3.17 Roller Diameter, Dwe . 5
11、3.18 Effective Roller Length, Lwe . 5 3.19 Nominal Contact Angle, . 5 3.20 Line Contact . 5 3.21 Point Contact . 5 3.22 Optimized Contact . 5 3.23 Conventional Operating Conditions . 5 3.24 Viscosity ratio, 5 3.25 Film Parameter, 6 3.26 Pressure-viscosity Coefficient 6 3.27 Bearing Arrangements: Pai
12、red Mounting 6 3.28 Bearing Arrangements: Back-to-back 6 3.29 Bearing Arrangements: Face-to-face 6 3.30 Bearing Arrangements: Tandem 6 4. Scope . 6 4.1 Bearing Types . 6 4.1.1 General 6 4.1.2 Basic Types. 6 4.1.3 Double Row . 6 4.2 Limitations 6 4.2.1 Truncated Contact Area 6 4.2.2 Materials 7 4.2.3
13、 Bearing Types . 7 4.2.4 Lubrication . 7 4.2.5 Ring Support and Alignment 7 4.2.6 Internal Clearance . 7 4.2.7 High Speed Effects 7 4.2.8 Interference Fits . 7 4.2.9 Residual Stress 7 4.2.10 Stress Concentrations . 8 iv 4.2.11 Tolerances 8 4.2.12 Plastic Deformation in the Contact Area 8 4.3 Operati
14、ng Parameters . 8 5 Radial Roller Bearings 9 5.1 Basic Dynamic Radial Load Rating . 9 5.1.1 Basic Dynamic Radial Load Rating for Single Bearings 9 5.1.2 Basic Dynamic Radial Load Rating for Bearing Combinations 9 5.2 Dynamic Equivalent Radial Load 11 5.2.1 Dynamic Equivalent Radial Load for Single B
15、earings 11 5.2.2 Dynamic Equivalent Radial Load for Bearing Combinations 11 5.3 Basic Rating Life . 11 5.3.1 Life Equation 11 5.3.2 Loading Restriction on the Life Equation . 12 5.4 Basic Static Radial Load Rating . 12 5.4.1 Basic Static Radial Load Rating for Single Bearings . 12 5.4.2 Basic Static
16、 Radial Load Rating for Bearing Combinations . 12 5.5 Static Equivalent Radial Load . 12 5.5.1 Static Equivalent Radial Load for Single Bearings . 12 5.5.2 Static Equivalent Radial Load for Bearing Combinations . 13 6 Thrust Roller Bearings 13 6.1 Basic Dynamic Axial Load Rating 13 6.1.1 Basic Dynam
17、ic Axial Load Rating for Single-row Bearings . 13 6.1.2 Basic Dynamic Axial Load Rating for Bearings with Two or More Rows of Rollers 14 6.1.3 Basic Dynamic Axial Load Rating for Bearing Combinations . 14 6.2 Dynamic Equivalent Axial Load . 14 6.3 Basic Rating Life 18 6.3.1 Life Equation 18 6.3.2 Lo
18、ading Restriction on the Life Equation . . 18 6.4 Basic Static Axial Load Rating 18 6.4.1 Basic Static Axial Load Rating for Single-direction and Double-direction Bearings . 18 6.4.2 Basic Static Axial Load Rating for Bearings Mounted in a Tandem Arrangement . . 19 6.5 Static Equivalent Axial Load 1
19、9 6.5.1 Static Equivalent Axial Load Rating for Single-direction and Double-direction Bearings 19 6.5.2 Static Equivalent Axial Load Rating for Bearings Mounted in a Tandem Arrangement 19 7 Static Safety Factor . 19 7.1 General 19 8 Adjusted rating Life . 20 8.1 General 20 8.2 Limitations . 20 8.3 L
20、ife Adjustment Factor for Reliability, a1 . . 20 8.4 Life Adjustment Factor for Special Bearing Properties, a2 21 8.5 Life Adjustment Factor for Operating Conditions, a3 . 21 8.5.1 General 21 8.5.2 Viscosity Ratio 22 8.5.3 Calculation of Life Under Low Load Conditions 23 v LIST OF TABLES TABLE NO. T
21、ITLE PAGE RADIAL ROLLER BEARINGS 1 Values for fcm for Radial Roller Bearings . 10 2 Values for X and Y for Radial Roller Bearings 11 3 Values for X0 and Y0 for Radial Roller Bearings with 0 . 13 THRUST ROLLER BEARINGS 4 Values of fcm for Tapered Roller Thrust Bearings . . 15 5 Values for fcm for Cyl
22、indrical Roller Thrust Bearings and Needle Roller Thrust Bearings . 16 6 Values for fcm for Spherical Roller Thrust Bearings . 17 7 Values for X and Y for Thrust Roller Bearings 18 8 Guideline Values of the Static Safety Factor S0 for Roller Bearings 20 9 Life Adjustment Factor for Reliability, a1 2
23、1 LIST OF FIGURES FIGURE NO. TITLE PAGE 1 Reference Kinematic Viscosity, 1 . . 23 1 Load Ratings and Fatigue Life for Roller Bearings 1. INTRODUCTION 1.1 Purpose of Standard Roller bearing performance is a function of many variables. These include the bearing design, the characteristics of the mater
24、ial from which the bearings are made, the way in which they are manufactured, as well as many variables associated with their application. The only sure way to establish the satisfactory operation of a bearing selected for a specific application is by actual performance in the application. As this i
25、s often impractical, another basis is required to estimate the suitability of a particular bearing for a given application. This is the purpose of this standard. This standard specifies the method of calculating the basic dynamic load rating of rolling bearings within the size ranges shown in the re
26、levant ANSI/ABMA standards, manufactured from contemporary, commonly used, good quality hardened bearing steel in accordance with good manufacturing practice and basically of conventional design as regards the shape of rolling contact surfaces. This standard also specifies the method of calculating
27、the basic rating life, which is the life associated with 90% reliability, with commonly used high quality material, good manufacturing quality and with conventional operating conditions. In addition, it specifies the method of calculating adjusted rating life, in which various reliabilities, special
28、 bearing properties and specific operating conditions are taken into account by means of life adjustment factors. Furthermore, this standard specifies the method of calculating the basic static load rating and the static equivalent load for roller bearings within the size ranges shown in the relevan
29、t ANSI/ABMA Standards, manufactured from good quality hardened bearing steel, in accordance with good manufacturing practice and basically of conventional design as regards the shape of rolling contact surfaces. 1.2 Life Criterion Even if roller bearings are properly mounted, adequately lubricated,
30、protected from foreign matter, and are not subjected to extreme operating conditions, they can ultimately fatigue. Under ideal conditions, the repeated stresses developed in the contact areas between the roller and the raceways eventually can result in fatigue of the material which manifests itself
31、as spalling of the load carrying surfaces. In most applications the fatigue life is the maximum useful life of a bearing. This fatigue is the criterion of life used as the basis for the first part of this standard. Fatigue life calculated in accordance with this standard does not represent the maxim
32、um that can be attained by applying all known technology to roller bearing design and application. Neither does it represent the minimum that should be expected of a bearing made by a producer lacking skill and experience in the design and manufacture of roller bearings, even though the bearing meet
33、s the geometric parameters given below. The calculated fatigue life represents the performance normally expected from high quality bearings made by reputable manufacturers. Manufacturers can supply longer lived bearings by the application of advanced materials and manufacturing processes. The presen
34、t standard has evolved as a means for bearing users to specify a reasonable standard of performance for the bearing they wish to purchase. 1.3 Static Load Criterion A static load is a load acting on a non-rotating bearing. Permanent deformations appear in rollers and raceways under a static load of
35、moderate magnitude and increase gradually with increasing load. It is often impractical to establish whether the deformations appearing in a bearing in a specific application are permissible by testing the bearing in that application. Other methods are therefore required to establish the suitability
36、 of the bearing selected. 2 Experience shows that a total permanent deformation of 0.0001 of the rolling element diameter, at the center of the most heavily loaded roIIer/raceway contact, can be tolerated in most bearing applications without the subsequent bearing operation being impaired. The basic
37、 static load rating is, therefore, given a magnitude such that approximately this deformation occurs when the static equivalent load is equal to the load rating. Tests indicate that a load of the magnitude in question may be considered to correspond to a calculated contact stress of; 4,000 MPa (580,
38、000 psi) for all roller bearings at the center of the most heavily loaded rolling element/raceway contact. The formulae and factors for the calculation of the basic static load ratings are based on these contact stresses. The permissible static equivalent load may be smaller than, equal to or greate
39、r than the basic static load rating, depending on the requirements for smoothness of operation and friction, as well as on actual contact surface geometry. Bearing users without previous experience of these conditions should consult the bearing manufacturers. 2. SYMBOLS a1 life adjustment factor for
40、 reliability a2 life adjustment factor for special bearing properties a3 life adjustment factor for operating conditions Ca basic dynamic axial load rating, in newtons (pounds) Cr basic dynamic radial load rating, in newtons (pounds) C0a basic static axial load rating, in newtons (pounds) C0r basic static radial load rating,
