1、AEROSPACE RECOMMENDEDPRACTICEARP5448/5Issued 2003-03Plain Bearing No-Load Rotational Breakaway Torque Measurement1. SCOPE:This test method provides a procedure for measuring no-load rotational breakaway torque of self-lubricating spherical bearings.2. APPLICABLE DOCUMENTS:The following publications
2、form a part of this document to the extent specified herein. The latest issue of SAE publications shall apply. The applicable 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 he
3、rein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained.2.1 ANSI Publications:Available from ANSI, 25 West 43rd Street, New York, NY 10036-8002.ANSI/NCSL Z540-1 Calibration Laborator
4、ies and Measuring and Test Equipment - General Requirements3. DEFINITIONS:NO-LOAD ROTATIONAL BREAKAWAY TORQUE: No-load rotational breakaway torque of a spherical bearing is the torque required to initiate rotation of the ball with respect to the race with no radial or axial loads applied.Reaffirmed
5、2010-06SAE 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
6、therefrom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2010 SAE International All rights reserved. No part of this publicat
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8、 USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedbackon this Technical Report, please visit http:/www.sae.org/technical/standards/ARP5448/5Copyright SAE International Provided by IHS under license with SAENot for ResaleNo r
9、eproduction or networking permitted without license from IHS-,-,-SAE ARP5448/5- 2 -4. GENERAL REQUIREMENTS:4.1 Test Apparatus:4.1.1 The test fixture shall provide a means of holding the outer ring of the bearing fixed while rotating the ball about the bearing axis.4.1.2 The test fixture shall provid
10、e a means of holding the outer ring in such a manner as to minimize bearing distortion and the resultant effect on bearing torque.4.1.3 The test fixture shall provide a means of rotating the ball without excessive clamping forces or otherwise distorting the ball so as to affect the bearing torque.4.
11、1.4 The test fixture shall provide a means of measuring the rotational torque at which ball rotation is initiated. The accuracy of the torque measuring device shall be 5% of the indicated value.4.1.5 Calibration of the test apparatus shall be in accordance with ANSI-NCSL Z540-1.4.2 Temperature:Unles
12、s otherwise specified, temperature of the test area shall be 75 F 10 F.4.3 Relative Humidity:Relative humidity of the test area shall not exceed 75%.5. DETAILED REQUIREMENTS:5.1 Stabilize the test bearing at the temperature and relative humidity of the test area.5.2 Place the test bearing in the tes
13、t fixture and apply the holding feature to the outer ring.5.3 Unless otherwise specified, misalign the ball in two mutually perpendicular planes and rotate through two to three revolutions immediately prior to testing. This may be accomplished by hand or with the assistance of an appropriately sized
14、 test shaft inserted in the bore of the bearing.5.4 Gradually apply torque to the ball until rotation begins.5.5 Record the torque at which ball rotation is initiated.Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without licen
15、se from IHS-,-,-SAE ARP5448/5- 3 -6. NOTES:6.1 Intended Use:This test method provides procedures for measuring no-load rotational breakaway torque of standard airframe self-lubricating spherical bearings and similar non-standard bearings.6.2 Method of Reference:This test method may be referenced in
16、general and detail specifications, standards or drawings for self-lubricating spherical bearings. Specific data requirements are given in the applicable document. The following note is suggested to reference this test method:“NOTE: Measure no-load rotational breakaway torque in accordance with ARP54
17、48/5.”6.3 Key Words:Bearing, test, torquePREPARED UNDER THE JURISDICTION OFSAE SUBCOMMITTEE ACBGREB, ROLLING ELEMENT BEARING OFCOMMITTEE ACBG, AIRFRAME CONTROL BEARING GROUPCopyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
