1、Designation:D429020Standard Test Method forDetermining the Leakage Tendencies of Automotive WheelBearing Grease Under Accelerated Conditions1This standard is issued under the fixed designation D4290;the number immediately following the designation indicates the year oforiginal adoption or,in the cas
2、e of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method covers a laboratory procedure forevaluating leakage tendencies of wheel bearing
3、 greases whentested under prescribed conditions.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.The exception is apparatus dimensions,in inches,which are to be regarded as the standard.1.3 This standard does not purport to ad
4、dress 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 practices and deter-mine the applicability of regulatory limitations prior to use.For specific warning statements,see Section
5、8.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers t
6、o Trade(TBT)Committee.2.Referenced Documents2.1AFBMA Standard:2AFBMA Standard 19 1974(ANSI B.3.19-1975)3.Terminology3.1 Definitions:3.1.1 lubricant,nany material interposed between twosurfaces that reduces the friction or wear between them.3.1.2 lubricating grease,na semifluid to solid product ofa d
7、ispersion 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 and other physical forces.Other ingredients arecommonly included to impart special properties.3.1.3 thickener,nin lubricatin
8、g 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(suchas various metallic soaps)or plates or spheres(such as certainnon-soap thickeners)which are insoluble or,at the most,onlyve
9、ry slightly soluble in the liquid lubricant.The generalrequirements 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 be
10、aring grease,na lubricatinggrease specifically formulated to lubricate automotive wheelbearings at relatively high grease temperatures and bearingspeeds.3.2.2 leakage,nof wheel bearing grease,separation andoverflow of grease or oil from the bulk grease charge,inducedby high temperatures and bearing
11、rotation.4.Summary of Test Method4.1 The test grease is distributed in a modified,automobilefront wheel hub-spindle-bearings assembly.While the bearingsare thrust-loaded to approximately 111 N,the hub is rotated at1000 rpm and the spindle temperature maintained at 160.0 C6 1.5 C for 20 h.Leakage of
12、grease or oil,or both,ismeasured,and the condition of the bearing surface is noted atthe end of the test.5.Significance and Use5.1 This test method differentiates among wheel bearinggreases having distinctly different high-temperature leakagecharacteristics.It is not the equivalent of longtime servi
13、ce tests.5.2 This test method has proven to be helpful in screeninggreases with respect to leakage tendencies for automotivewheel bearing applications.NOTE1It is possible for skilled operators to observe changes in greasecharacteristics that can occur during the test,such as grease condition.Leakage
14、 is reported as a quantitative value,whereas the evaluation ofgrease condition is subject to differences in personal judgment amongoperators and cannot be used effectively for quantitative measurements.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuel
15、s,and Lubricants and is the direct responsibility ofSubcommittee D02.G0.05 on Functional Tests-Temperature.Current edition approved June 1,2020.Published June 2020.Originallyapproved in 1983.Last previous edition approved in 2019 as D4290 19.DOI:10.1520/D4290-20.2Available from American National Sta
16、ndards Institute(ANSI),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 internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by
