1、_SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising theref
2、rom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions.Copyright 2014 SAE International All rights reserved. No part of this pub
3、lication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970
4、(outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AS8942AEROSPACESTANDARDAS8942Issued 2014-03 Bearings, Plain and PTFE Lined, Self - A
5、ligning RATIONALEThis procurement document and its corresponding parts sheets are being updated and re-formatted from MIL-B-8942 to the SAE standard. NOTICEThis document has been taken directly from U.S. Military Specification MIL-B-8942 (Rev A including amendments) and contains editorial and format
6、 changes required to bring it into conformance with the publishing requirements of SAE technical standards. The initial SAE publication of this document is intended to replace MIL-B-8942. This SAE Standard may retain the same part numbers established by the original military document.The original Mi
7、litary Specification was adopted as an SAE standard under the provisions of the SAE Technical Standards Board (TSB) Rules and Regulations (TSB 001) pertaining to accelerated adoption of government specifications and standards. TSB rules provide for (a) the publication of portions of unrevised govern
8、ment specifications and standards without consensus voting at the SAE Committee level, and (b) the use of the existing government specification or standard format. Under Department of Defense policies and procedures, any requirements associated with Qualified Products List may continue to be mandato
9、ry for DoD contracts. Requirements relating to QPLs have not been adopted by SAE for this standard and are not part of this SAE document. 1. SCOPE This SAE Aerospace Standard (AS) establishes the requirements for self-aligning, self-lubricating plain spherical bearings incorporating polytetrafluoroe
10、thylene (PTFE) in a liner between the ball and the outer race for use in a temperature range of -65 to +250 F (-54 to +121 C). 2. APPLICABLE DOCUMENTS The following publications form a part of this document to the extent specified herein. The latest issue of SAE publications shall apply. The applica
11、ble issue of other publications shall be the issue in effect on the date of the purchase order. In the event of conflict between the text of this document and references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regula
12、tions unless a specific exemption has been obtained. FOR US DEPARTMENT OF DEFENSE CONTRACTS AS8942 SHALL NOT BE USED. SEE AS81820 AS A SUGGESTED REPLACEMENT FOR AS8942 AT THE POINT OF DESIGN. DESIGNERS ARE CAUTIONED TO EVALUATE AS81820 FOR THEIR PARTICULAR APPLICATION. SAE INTERNATIONAL AS8942 Page
13、2 of 13 2.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org.AMS1424 Deicing/Anti-Icing Fluid, Aircraft, SAE Type I AMS2460 Plating, Chromium AS21230 Bearing, Pla
14、in, Self-Aligning, Grooved Outer Ring, PTFE Lined, Wide AS21231 Bearing, Plain, Self-Aligning, PTFE Lined, Wide AS21232 Bearing, Plain, Self-Aligning, Grooved Outer Ring, PTFE Lined, Narrow AS21233 Bearing, Plain, Self-Aligning, PTFE Lined, Narrow 2.2 ANSI/ASME Publications Available from American N
15、ational Standards Institute, 25 West 43rd Street, 4th Floor, New York, NY 10036-8002, Tel: 212-642-4900, www.ansi.org.ASME B46.1 Surface Texture (Surface Roughness, Waviness and Lay) ANSI/ASME Y14.100 Engineering Drawing Practices ANSI/ASQ Z1.4 Sampling Procedures and Tables for Inspection by Attrib
16、utes 2.3 U.S. Government Publications Available from DLA Document Services, Building 4/D, 700 Robbins Avenue, Philadelphia, PA 19111-5094, Tel: 215-697-6396, http:/quicksearch.dla.mil/.MIL-STD-2073-1 Standard Practice for Military Packaging MIL-DTL-197 Packaging of Bearings, Associated Parts and Sub
17、assemblies MIL-PRF-5606 Hydraulic Fluid, Petroleum Base, Aircraft, Missile, and Ordnance MIL-DTL-5624 Turbine Fuel, Aviation, Grades JP-4, JP-5 and JP-5/JP-8ST MIL-PRF-7808 Lubricating Oil, Aircraft Turbine Engine, Synthetic Base MIL-STD-129 Standard Practice Military Marking for Shipment and Storag
18、e MIL-STD-810 Environmental Engineering Considerations and Laboratory Tests Method 507.5 Humidity resistance3. REQUIREMENTS 3.1 Aerospace Standard (AS) Sheets The individual item requirements shall be as specified herein and in accordance with the applicable AS product standards. In the event of any
19、 conflict between the requirements of this specification and the AS product standard, the latter shall govern. SAE INTERNATIONAL AS8942 Page 3 of 13 3.2 Qualification The bearings furnished under this specification shall be a product which is in accordance with the applicable Aerospace Standard (AS)
20、 and which has been subjected to and which have passed the qualification tests specified herein, and which also have been listed on or approved for listing on the applicable Qualified Products List (QPL). 3.2.1 Product Change Any change in product design, description, materials, processing, procedur
21、es or plant location shall be reported to the qualifying activity and may require requalification of the product to an extent determined by the qualifying activity. Any other specific changes, which must be brought to the qualifying activities attention, shall be identified in the qualification noti
22、fication letter. 3.2.2 Product Manufacture Except for the bonding operations, the manufacturer is permitted to subcontract manufacturing operations without violating the requirements of 3.2.1. The bonding operations shall be performed in the plant listed on the Qualified Products List. Manufacture o
23、f the self-lubricating liner material may also be subcontracted. Any change in (1) the liner manufacturer, (2) the liner manufacturing procedures, or (3) the materials used in manufacture of the liner will require requalification to an extent determined by the qualifying activity. The manufacturer i
24、s responsible for meeting all requirements of the standard and for the quality of the end product, whether it is manufactured totally in-house or some of the operations are performed by a subcontractor. Inherent in the responsibility for the end product it is the responsibility ofthe manufacturer to
25、 verify that the subcontractors processes meet standard requirements. 3.3 Materials Material for the ball, outer race and liner shall be in accordance with the applicable AS product standard. PTFE shall be included in the liner in such a manner that the bearing will conform to all requirements of th
26、is specification. 3.3.1 Plating Plating of the ball will be permitted, at the option of the manufacturer, and shall be per AMS2460.3.4 Design, Bearing design shall conform to that shown on AS21230, AS21231, AS21232, and AS21233. 3.5 Construction The liner shall be so secured that all relative motion
27、 shall be between the wear surface of the liner and the ball. The bearing shall not have loading slots. Except as otherwise specified on the applicable AS product standard, the details of the design shall be optional. 3.5.1 Dimensions and Tolerances Dimensions and tolerances shall be as specified on
28、 the applicable AS product standard. Dimensions not shown shall be at the option of the manufacturer. 3.5.2 Surface Texture The surface texture shall be in accordance with the applicable AS product standard and ASME B46.1. Bearings shall be free of any surface defects, which may be detrimental to sa
29、tisfactory installation, performance or bearing life as defined in this specification. Unless otherwise specified, liner surfaces are exempt from surface texture measurements. 3.5.3 Lubrication Initial lubrication by the manufacturer will be permitted. Relubrication will not be permitted.SAE INTERNA
30、TIONAL AS8942 Page 4 of 13 3.6 Performance 3.6.1 Radial Static Limit Load After the radial load listed on the applicable AS product standard has been applied as specified in 4.6.1, the total deflection of the bearing and fixture shall be less than 0.010 inch for bearings with a bore of 0.3750 inch o
31、r less, 0.015 for 0.4375 and 0.5000 inch, 0.017 for 0.5625 and 0.6250 inch and 0.020 for 0.7500 inch and up. The permanent set shall be less than 0.003 inch. 3.6.2 Axial Static Limit Load After the axial load listed on the applicable AS product standard has been applied as specified in 4.6.2, the pe
32、rmanent set shall be less than 0.005 inch. 3.6.3 Ultimate Load No fracture of the race or ball, or push-out of the ball shall occur when 1.5 times the radial or axial limit load is applied asspecified in 4.6.1 or 4.6.2. 3.6.4 Oscillation under Radial Load The total liner wear of the bearing shall no
33、t exceed 0.006 inch when tested in accordance with 4.6.3 with the radial unidirectional load listed on the applicable AS product standard. Visual examination of the liner after test shall indicate no loss of bonding to the metal substrate in the loaded area. 3.6.5 Self-Alignment The bearing shall be
34、 self-aligning and permit the angular displacement specified in the applicable AS product standard 3.6.6 No-Load Breakaway Torque When tested in accordance with 4.6.4, the no-load breakaway torque shall be within the limits of the values specified on the applicable AS product standard. 3.6.7 Fluid C
35、ompatibility When tested in accordance with 4.6.5, the bearings shall be compatible with the fluids listed in 4.6.5 and the total liner wear shall not exceed 0.006 inch.3.6.7.1 Corrosion Resistance Corrosion resistance shall be determined in accordance with Method 507.5 (Humidity resistance) of MIL-
36、STD-810. Superficial tarnish which can be removed with a damp cloth shall not be cause for rejection. 3.6.8 High Temperature When tested in accordance with 4.6.7, under the oscillating load specified in the applicable AS product standard, the total liner wear shall not exceed 0.006 inch.3.6.9 Low Te
37、mperature When tested in accordance with 4.6.8, the no-load breakaway torque shall not be more than twice the maximum value specified on the applicable AS product standard. SAE INTERNATIONAL AS8942 Page 5 of 13 3.7 Interchangeability All parts having the same manufacturers part number shall be direc
38、tly and completely interchangeable with each other and with respect to installation and performance. The drawing number requirements of ANSI/ASME Y14.100 shall govern changes in the manufacturers part numbers and also how the part numbers are to be called out. 3.8 Identification of Product Each bear
39、ing shall be permanently and legibly marked with the manufacturers CAGE code, manufacturers lot number, and Aerospace Standard part number as a minimum. Where feasible, identification shall appear on the side face of the outer race; otherwise identification shall appear on the periphery of the beari
40、ng outer race. Metal impression stamping is prohibited.3.9 Workmanship The bearings shall be free of toolmarks, chatter waves, rust, grinding scratches, pits, or other defects that may adversely affect their serviceability. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for Inspection Unless oth
41、erwise specified in the contract or purchase order, the manufacturer is responsible for the performance of all inspection requirements as specified herein. Except as otherwise specified, the manufacturer, may utilize his/her own facilities or any other commercial laboratory acceptable to the Governm
42、ent. The Government reserves the right to perform any of the inspections set forth in the standard where such inspection are deemed necessary to assure supplies and services conform to prescribed requirements. 4.1.1 Qualification Test Records The manufacturer shall maintain a record showing quantita
43、tive results for all tests required by this specification. This record shall be available to the purchaser and shall be signed by an authorized representative of the manufacturer or the testing laboratory, as applicable. 4.2 Classification of Tests The inspection and testing of the bearings shall be
44、 classified as: a. Qualification tests (4.3) b. Quality conformance tests (4.4) 4.3 Qualification Tests 4.3.1 Sampling Instructions Qualification test samples shall consist of 30 bearings conforming to MS21232-8 and 9 each of all other sizes upon which qualification is desired. All bearings necessar
45、y for tests specified herein shall be furnished by the manufacturer. Samples shall be identified as required and forwarded to the activity designated in the letter of authorization (see 6.3). 4.3.2 Certified Test Report The manufacturer shall furnish a certified test report showing that the manufact
46、urers product satisfactorily conforms to the part standard and this specification. The test report shall include, as a minimum, actual results of the tests specified herein. When the report is submitted, it shall be accompanied by a dated drawing which completely describes the manufacturers products
47、 by specifying all dimensions and tolerances, outer race and ball material, coating or plating, and heat treatment. The manufacturers part number for each size shall be included on the drawing. SAE INTERNATIONAL AS8942 Page 6 of 13 4.3.3 Tests Qualification tests shall include all the examinations a
48、nd tests specified in Table 1 of this standard. The minimum number of samples per test shall be in accordance with Table 1. TABLE 1 - QUALIFICATION TEST SAMPLES Examination and Tests Requirement Paragraph Samples to be tested Examination of product 4.5.1 5 Preparation for delivery 4.5.2 5 Axial stat
49、ic limit load 4.6.2 3 Radial static limit load 4.6.1 3 Oscillating radial load 4.6.3 3 No-load breakaway torque 4.6.4 3 Fluid compatibility 4.6.5 1/ 3 Corrosion resistance 4.6.6 1/ 3High temperature 4.6.7 1/ 3Low temperature 4.6.8 1/ 31/ Nominal size 8 only 4.4 Quality Conformance Tests The quality conformance testing of the bearings shall consist of the following examinations and tests to determine conformance of the
