1、Designation:D352721Standard Test Method forLife Performance of Automotive Wheel Bearing Grease1This standard is issued under the fixed designation D3527;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A numb
2、er in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONThis standard is based on a test rig that was originally designed in the 1960s.Since the standard wasfirst published,there have been several a
3、ttempts to revise the equipment and test procedure to improvethe precision of the test.Since the first publication,there have been many advances in the quality ofthe hardware and automated control systems have superseded manual and analogue controls.Several generations of test rig are still in comme
4、rcial use,each potentially having their own issuesrelating to certification and contributing to the overall poor precision of this test.The Subcommitteeresponsible for this standard is aware of these issues,but has been unable to obtain sufficient interestto conduct an ILS program required to evalua
5、te possible revisions and establish updated precision andbias data for comparison to the current test.A 2017 ballot to withdraw this standard was unsuccessful and the standard will be re-approved tomeet the needs of users and its inclusion in other industry and military standards,even though the hub
6、design is obsolete.Work is underway to develop a replacement test that will better representcontemporary bearing designs and offer a selection of test conditions.1.Scope*1.1 This test method covers a laboratory procedure forevaluating the high-temperature life performance of wheelbearing greases whe
7、n tested under prescribed conditions.NOTE1Changes to this test method in the 1985 revision increased testseverity.Results will not be comparable with data from earlier procedures.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandar
8、d.1.2.1 ExceptionApparatus dimensions in inches are to beregarded as the standard.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental prac
9、tices and deter-mine the applicability of regulatory limitations prior to use.For specific warning statements,see 8.1 8.4.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevel
10、opment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 AFBMA Standard:AFBMA Standard 19,1974(ANSI B.3.19-1975)23.Terminology3.1 Definitions:3.1.1 lubricant,nany material interposed betwee
11、n twosurfaces that reduces the friction or wear between them.3.1.2 lubricating grease,na semi-fluid to solid product ofa dispersion of a thickener in a liquid lubricant.3.1.2.1 DiscussionThe dispersion of the thickener forms atwo-phase system and immobilizes the liquid lubricant bysurface tension an
12、d other physical forces.Other ingredients arecommonly included to impart special properties.3.1.3 thickener,nin lubricating grease,a substance com-posed of finely-divided particles dispersed in a liquid lubricantto form the products structure.3.1.3.1 DiscussionThe solid thickener can be fibers(sucha
13、s various metallic soaps)or plates or spheres(such as certainnon-soap thickeners)which are insoluble or,at the most,onlyvery slightly soluble in the liquid lubricant.The general1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is t
14、he direct responsibility ofSubcommittee D02.G0.05 on Functional Tests-Temperature.Current edition approved Nov.1,2021.Published November 2021.Originallyapproved in 1976.Last previous edition approved in 2018 as D3527 18.DOI:10.1520/D3527-21.2Available from American National Standards Institute(ANSI)
15、,25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with inte
16、rnationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1requirements are that the solid particles be extremely small,uniformly dispersed,and capable of forming a relatively stable,gel-like structure with the liquid lubricant.3.2 Definitions of Terms Specific to This Standard:3.2.1 automotive wheel bearing
