1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-22860-6 SANS 10341:2009Edition 1.2SOUTH AFRICAN NATIONAL STANDARD Installation and maintenance of bearings General guidelines Published by
4、 SABS Standards Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001Tel: +27 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS SANS 10341:2009 Edition 1.2 Table of changes Change No. Date Scope Amdt 1 2003 Amended to update reference standards to align with international standards
5、. Amdt 2 2009 Amended to update referenced standards. Acknowledgement The SABS Standards Division wishes to acknowledge the valuable assistance derived from publications of the following organizations: SKF South Africa (Pty) Ltd; LBA Transmissions (Pty) Ltd; and Timken SA (Pty) Ltd. Foreword This So
6、uth African standard was approved by National Committee SABS TC 4, Bearings, in accordance with procedures of the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This document was published in August 2009. This document supersedes SANS 10341:2003 (edition 1.1). A vertic
7、al line in the margin shows where the text has been technically modified by amendment No. 2. SANS 10341:2009 Edition 1.2 1 Contents Page Acknowledgement Foreword 1 Scope 3 2 Normative reference . 3 3 Bearing types 3 4 Storage and handling 9 5 Maintenance . 16 6 Mounting and dismounting of bearings .
8、 21 7 Failure analysis . 30 8 Housings . 30 9 Selecting the correct type of grease lubrication 40 10 Selecting the correct type of oil lubrication . 43 11 Inspection 44 Bibliography 46 SANS 10341:2009 Edition 1.2 2 This page is intentionally left blank SANS 10341:2009 Edition 1.2 3 Installation and
9、maintenance of bearings General guidelines 1 Scope 1.1 This standard gives guidelines for the installation and maintenance of the most common types of roller bearing. 1.2 This standard recommends the tools and lubricants to be used and also suitable methods of storage and handling bearings. 2 Normat
10、ive reference The following standard contains provisions which, through reference in this text, constitute provisions of this standard. All standards are subject to revision and, since any reference to a standard is deemed to be a reference to the latest edition of that standard, parties to agreemen
11、ts based on this standard are encouraged to take steps to ensure the use of the most recent edition of the standard indicated below. Information on currently valid national and international standards can be obtained from the SABS Standards Division. SANS 355/ISO 355, Rolling bearings Metric tapered
12、 roller bearings Boundary dimensions and series designations. Amdt 1; amdt 2 3 Bearing types 3.1 Radial bearings 3.1.1 Deep-groove ball bearing Deep-groove ball bearings (see figure 1) are single-row bearings, open on both sides, have a filling slot in both the outer and the inner ring, and, for man
13、ufacturing reasons, have recesses in the outer ring shoulders to take shields. Bearings with shields are filled with lithium-based grease, are lubricated for life and are maintnance free. Bearings for the automotive industry are supplied with a snap ring groove in the outer ring and a snap ring. A r
14、adial bearing can be a bearing that consists of a) a single row of balls, with filling slots, or b) filling slots and shields, or c) filling slots and snap rings. SANS 10341:2009 Edition 1.2 4 Figure 1 Deep-groove ball bearing 3.1.2 Self-aligning ball bearing Self-aligning ball bearings (see figure
15、2) have two rows of balls. A common sphered raceway in the outer ring gives it the self-aligning property. The bore can either be cylindrical or tapered. A self-aligning bearing can be a bearing a) with adaptor sleeves, or b) with seals, or c) with sleeves and adaptor sleeves, or d) with extended in
16、ner rings. Figure 2 Self-aligning ball bearing 3.1.3 Angular contact ball bearing Angular contact ball bearings (see figure 3) come in three variations, i.e. single-row, double-row and four-point contact ball bearings. Angular contact bearings have raceways in the inner and outer rings which are dis
17、placed with respect to each other in the direction of the bearing axis. SANS 10341:2009 Edition 1.2 5 Figure 3 Angular ball bearing 3.1.4 Thrust ball bearing Thrust ball bearings (see figure 4) can be a) single direction, or b) single direction with sphered housing washer, or c) double direction, or
18、 d) double direction with sphered housing washers. Single-direction thrust ball bearings can accommodate axial loads in one direction and shall not be subjected to any radial load. Single-direction thrust ball bearings with a sphered housing washer can compensate for initial misalignment if they are
19、 used together with a seating washer that has a sphered surface. Double-direction thrust ball bearings can accommodate axial loads acting in both directions, can be used to locate a shaft in both directions, and shall not be subjected to any radial load. When used with sphered housing washer(s) that
20、 has (have) a seating washer which has a sphered surface, they can compensate for initial misalignment. Figure 4 Thrust ball bearing 3.1.5 Pillar block unit (Y-bearing units) A pillar block unit (see figure 5) is a simple, economic bearing arrangement that consists of a single-row deep-groove ball b
21、earing (that is sealed on both sides and that has a sphered outside surface), SANS 10341:2009 Edition 1.2 6 and of a Y-bearing housing. The Y-bearing housing can be cast iron or pressed steel and has a sphered bore. Pillar block units can accommodate moderate initial misalignment but do not allow fo
22、r axial displacement. Figure 5 Pillar block unit 3.2 Roller bearings 3.2.1 Cylindrical roller bearing Single-row cylindrical roller bearings with cage (see figure 6) are guided between either one or two integral flanges on either the inner or outer bearing ring. The bearing ring with integral flange
23、s and the roller-and-cage assembly can be withdrawn axially. This facilitates both mounting and dismounting where both rings have to have interference fits because of load conditions. Figure 6 Cylindrical roller bearings 3.2.2 Needle-roller bearing Needle-roller bearings (see figure 7) can be used w
24、ith or without an inner ring, depending on the application required. The chromium steel rings have a low sectional height and a very high load-carrying capacity. SANS 10341:2009 Edition 1.2 7 Needle-roller bearings without inner rings are the better choice where it is possible to grind and harden th
25、e necessary raceways on the shaft, since without an inner ring, the shaft can have a larger diameter and will therefore be stronger and stiffer. Single-row needle-roller bearings are also available as sealed bearings. The seals are made of synthetic rubber which provides efficient protection against
26、 water and dust contamination. Figure 7 Needle-roller bearings, with and without an inner ring 3.2.3 Spherical roller bearing Collar-mounted spherical roller bearing units (see figure 8) are sealed, pre-lubricated and pre-adjusted for mounting. The split-outer-ring design and the threaded locating c
27、ollar used in the design allow for a range of running clearances as might be required for different applications and temperatures. Some spherical roller bearings are fitted with “H“ type floating labyrinth seals with multiple self-centring rings held securely in a steel retainer. These seals can han
28、dle a misalignment of the bearing of up to 2. The seals float 0,040 m clear of the inner ring hub, to purge grease past the seal, making the ingress of dirt almost impossible. The bearings, therefore, can be used in very dirty and hostile operating conditions. Figure 8 Spherical roller bearings SANS
29、 10341:2009 Edition 1.2 8 3.2.4 Tapered roller bearing Tapered roller bearings (see figure 9) have tapered inner and outer ring raceways between tapered rollers. If extended, the tapered surfaces converge towards a single point on the bearing axis, enabling the bearings to meet a wide range of appli
30、cation requirements. Tapered roller bearings can be a) single-row, two-row, and four-row bearings, or b) spacer assembly bearings, or c) package bearings, or d) thrust bearings, or e) sealed bearings, or f) precision bearings, or g) high-speed bearings. Figure 9 Tapered roller bearings 3.2.5 Cylindr
31、ical roller thrust bearing Cylindrical roller thrust bearings (see figure 10(a) are single-direction bearings and can only accommodate axial loads in one direction. Cylindrical roller thrust bearings are simple in design and generally consist of a shaft washer, a housing washer, and a cylindrical ro
32、ller-and-cage thrust assembly. 3.2.6 Needle-roller thrust bearing Needle-roller thrust bearings (see figure 10(b) are single-direction bearings and can only accommodate axial loads in one direction. Needle-roller thrust bearings consist of a needle-roller-and-cage thrust assembly of a form-stable ca
33、ge that guides and retains a large number of needle rollers. The cylindrical surface is slightly relieved towards the roller ends to ensure an even load distribution and to prevent detrimental edge loading at the roller ends. SANS 10341:2009 Edition 1.2 9 Figure 10(a) Cylindrical roller thrust beari
34、ng Figure 10(b) Needle-roller thrust bearing 3.2.7 Spherical roller thrust bearing Spherical roller thrust bearings (see figure 11) are of a separable design the shaft washer with roller and cage assembly and the housing washer can be mounted individually. Spherical roller thrust bearings incorporat
35、e a large number of asymmetrical rollers and have specially designed raceways of optimum conformity. They are suitable for very heavy axial loads that permit relatively high speed operations. Figure 11 Spherical roller thrust bearing 4 Storage and handling 4.1 Storage Preservation and packing are no
36、t the only factors to be considered if corrosion of the bearings is to be avoided; humidity and temperature shall also be controlled during storage. Roller bearings are coated with a rust-inhibiting compound before packaging and can be stored in their original package for several years, thus being p
37、rotected against dirt and corrosion. SANS 10341:2009 Edition 1.2 10 4.2 Handling 4.2.1 Handling and care of bearings (see figure 12) To achieve maximum roller bearing service life, proper installation and maintenance of bearings are essential. Proper installation and maintenance include a) cleanline
38、ss, b) the accurate selection of bearings, c) the use of correct installation and maintenance tools. Bearings have to be protected from dirt and moisture and have to be correctly mounted and lubricated. For this purpose, the following essential provisions have to be added, i.e. special attention sha
39、ll be paid to d) the design of the bearing arrangement, e) the condition of seals, f) the type of lubricant, and g) regular lubrication. NOTE See the manufacturers guide for details. Figure 12 Handling and care of bearings Component protected in a plastic bag 4.2.2 Shelf life Certain types of bearin
40、g have a limited time of storage (shelf life). When, for example, bearings marked with the suffix -2Z and seals marked with the suffix -2RS1 are stored for longer periods than usual, they might be found to have a higher initial starting torque than new bearings. NOTE See the manufacturers catalogue
41、for details. The lubricating properties of grease can also deteriorate after long storage periods. 4.2.3 Seals Seals (see figure 13) protect bearings from moisture and contamination and prevent the leakage of lubricant. The efficiency of the sealing arrangement contributes to the bearings operationa
42、l life. SANS 10341:2009 Edition 1.2 11 There are two basic types of bearing seal: a) non-rubbing (gap or labyrinth) seals; and NOTE The effectiveness of non-rubbing seals depends on the sealing action at the narrow gap. b) rubbing (contact) seals. NOTE The effectiveness of rubbing seals depends on t
43、he consistency of certain pressures at the contact surface. 4.2.4 Sealing problems (see figure 13) Rubbing seals are designed to permit a small amount of lubricant leakage. This leakage serves to lubricate the seal contact area. If leakage appears to be excessive, or if moisture and dirt enter the b
44、earing, the seal needs to be replaced. Figure 13 Protection by seals 4.3 Precautions to be taken before usage WARNING Bearings should always be replaced with care. Bearings are designed to run under very specific operating conditions. Changes are often made without anticipating possible negative eff
45、ects due to, for example, a) the use of a different lubricant; b) a change in lubrication systems; c) higher machine speeds; and d) higher loads. When a bearing is replaced, no other changes which could adversely affect its operation shall be made. SANS 10341:2009 Edition 1.2 12 4.4 Fit and toleranc
46、es 4.4.1 Bearing designations and identification 4.4.1.1 The designations of a bearing usually appear on the face of the inner or outer ring. Equipment specifications and drawings can state which bearings shall be installed in specific locations. If the bearing designation is illegible, take the bea
47、ring to the local distributor for identification (see SANS 355). Amdt 1; amdt 2 4.4.1.2 Each bearing, the dimensions of which are given in SANS 355, is referred to by a dimension series. The dimension series is designated by a combination of three symbols, for example 2AC. Amdt 1; amdt 2 The first s
48、ymbol is a numeric character, which represents a range of contact angles, i.e. an angle series. The second symbol is an alphabetic character, which represents a range of numeric values for the outside diameter to bore relationship, i.e. a diameter series. The third symbol is an alphabetic character,
49、 which represents a range of numeric values for the width to section height relationship, i.e. a width series. The designations for the standardized bearings conform generally with the angle ranges and the numeric values for the relationships given in table 1 of SANS 355. In some cases an exception has been made to avoid the condition that the same designation be used for two different bearings with the same bore diameter. Amdt 1; amdt 2 4.4.2 Bearing identification by measurement 4.4.2.1 Bearings can be identified by measuring their bounda
