1、Designation: D 4693 03An American National StandardStandard Test Method forLow-Temperature Torque of Grease-Lubricated WheelBearings1This standard is issued under the fixed designation D 4693; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method determines the extent to which a testgrease retards the rotation of a special
3、ly-manufactured, spring-loaded, automotive-type wheel bearing assembly when sub-jected to low temperatures. Torque values, calculated fromrestraining-force determinations, are a measure of the viscousresistance of the grease. This test method was developed withgreases giving torques of less than 35
4、Nm at 40C.1.2 The values stated in SI units are to be regarded as thestandard. The values in parentheses are for information only.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 establis
5、h appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 217 Test Methods for Cone Penetration of LubricatingGreaseD 1403 Test Method for Cone Penetration of LubricatingGrease Using One-Quarter and
6、 One-Half Scale ConeEquipmentD 3527 Test Method for Life Performance of AutomotiveWheel Bearing GreaseD 4175 Terminology Relating to Petroleum, PetroleumProducts, and LubricantsE 1 Specification for ASTM ThermometersE 77 Test Method for Inspection and Verification of Ther-mometersE 220 Test Method f
7、or Calibration of Thermocouples byComparison TechniquesE 230 Specification and Temperature-Electromotive Force(EMF) Tables for Standardized ThermocouplesE 563 Practice for Preparation and Use of Freezing PointReference BathsE 585/E 585M Specification for Compacted Mineral-Insulated, Metal-Sheathed,
8、Base-Metal ThermocoupleCableE 608/E 608M Specification for Metal-Sheathed Base-Metal Thermocouples2.2 Military Standard:3MIL-G-10924F Specification for Automotive and Artillery2.3 Other Standard:Anti-Friction Bearing Manufacturer Assoc. (AFBMA) Stan-dard 19, 1974 (ANSI B. 3.19-1975)3. Terminology3.1
9、 Definitions:3.1.1 automotive wheel bearing grease, na lubricatinggrease specifically formulated to lubricate automotive wheelbearings at relatively high grease temperatures and bearingspeeds. D 35273.1.2 lubricant, nany material interposed between twosurfaces that reduces the friction or wear betwe
10、en them.D 41753.1.3 lubricating grease, na semi-fluid to solid product ofa dispersion of a thickener in a liquid lubricant.3.1.3.1 DiscussionThe dispersion of the thickener forms atwo-phase system and immobilizes the liquid lubricant bysurface tension and other physical forces. Other ingredients are
11、commonly included to impact special properties. D 2173.1.4 thickener, nin lubricating grease, a substance com-posed of finely-divided particles dispersed in a liquid lubricantto form the products structure.3.1.4.1 DiscussionThe solid thickener can be fibers (suchas various metallic soaps) or plates
12、or spheres (such as certainnon-soap thickeners) which are insoluble or, at the most, onlyvery slightly soluble in the liquid lubricant. The generalrequirements are that the solid particles be extremely small,1This test method is under the jurisdiction of Committee D02 on PetroleumProducts and Lubric
13、ants and is the direct responsibility of Subcommittee D02.G0 onLubricating Grease.Current edition approved Dec. 1, 2003. Published January 2004. Originallyapproved in 1987. Last previous edition approved in 2002 as D 469397 (2002)e1.2For referenced ASTM standards, visit the ASTM website, www.astm.or
14、g, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPO
15、DS.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.uniformly dispered, and capable of forming a relatively stable,gel-like structure with the liquid lubricant. D 2174.
16、 Summary of Test Method4.1 A freshly stirred and worked sample of test grease ispacked into the bearings of a specially-manufactured,automotive-type spindle-bearings-hub assembly. The assemblyis heated and then cold soaked at 40C, unless another testtemperature is specified by the grease specificati
17、on. Thespindle is rotated at 1 rpm and the torque required to preventrotation of the hub is measured at 60 s.5. Significance and Use5.1 This test method differentiates among greases havingdistinctly different low-temperature characteristics. This test isused for specification purposes and correlates
18、 with its precursorwhich has been used to predict the performance of greases inautomotive wheel bearings in low-temperature service.4It isthe responsibility of the user to determine the correlation withother types of service.6. Apparatus6.1 Low-Temperature Wheel Bearing Torque Apparatus,5illustrated
19、 in Fig. 1.NOTE 1Several apparatus configurations are available, differingmainly in the drive system. For example, with large cold chambers, aunitized apparatus (see Fig. 1) can be used totally within the cold chamber.With small cold chambers, the drive system can be mounted externallyand only the t
20、est unit subjected to low temperature. Regardless of theexact configuration, the essential apparatus consists of a 1/3 hp electricmotor connected to a gear reducer by means of a timing belt and pulleys,which drive a specially-manufactured spindle-bearings-hub assemblyequipped with a spring-loading m
21、echanism. For apparatus containedtotally within the cold chamber, the drive system should be prepared byreplacing the grease in the motor bearings with a suitable low-temperaturegrease (1 Nm torque at 40C), such as one meeting the requirements ofSpecification MIL-G-10924F or similar, and the lubrica
22、nt in the gearreducer should be replaced with a suitable low-temperature ( 50C pourpoint) worm-gear lubricant.6In addition, if not already so-equipped,large-diameter (152 mm), narrow-width (13 mm) timing pulleys and asuitable timing belt should be used.6.2 Torque Measuring System, consisting of a st
23、rain-gageload cell with a matching bridge-balance unit,7a suitablestrip-chart recorder to record the load-cell output, and a seriesof weights (up to 20 kg, at least) suitable for load-cellcalibration.NOTE 2In order to calculate torque from force measurements, theload cell should be located a known d
24、istance from the test-unit centerline;100 mm is convenient. A convenient way to do this is to centrally drill a1.78-mm diameter hole (No. 50 drill) in the torque arm, 100 mm from thespindle centerline; temporarily replace the load cell contact with a secondcontact having a 1.59-mm diameter pin (sold
25、ered in place) extendingabout 5 mm above the contact point; position the load cell to permitinsertion of the pin in the torque-arm hole; secure the position of the loadcell by tightening the clamping screws; replace pin contact with originalcontact before running test.6.3 Temperature Measuring Syste
26、m, consisting of Type T(preferred) or Type J (acceptable), 3.18-mm diameter metal-sheathed, grounded thermocouples meeting SpecificationsE 585/E 585M and E 608/E 608M and conforming to thespecial limits of error defined in Table 1 of Specification E 230;a suitable potentiometer, satisfying the requi
27、rements forGroups B or C as described in Test Method E 220; an ASTM4Verdura, T. M., “Performance of Service Station Wheel Bearing Greases in aNew Low-Temperature Test,” NLGI Spokesman 35 10-21 (1971).5Available from Koehler Instrument Co., 1595 Sycamore Avenue, Bohemia,L.I., NY 11716.6Mobil SHC 624
28、(or similar), available from Mobil Oil Corporation, 3225Gallows Rd., Fairfax, VA 22037.7A Model 3167-50 load cell and matching electronic circuitry are available fromLebow Associates, Inc., 1728 Maplelawn, Troy, MI 48062.FIG. 1 Low-Temperature Torque ApparatusD 4693 03273C precision thermometer meet
29、ing Specification E 1, certified(traceable to National Institute of Standards and Technologycertification) or verified and calibrated according to TestMethod E 77; a suitable comparator as described in TestMethod E 77; and an ice bath prepared according to PracticeE 563.NOTE 3Other temperature-measu
30、ring instrumentation, such as a pre-cision platinum resistance thermometer, may be used instead of thermo-couples, providing the limits of error are within those defined inSpecification E 230.6.4 Test BearingUse LM67010-LM67048 and LM11910-LM11949 (AFBMA Standard 19) inboard and outboard ta-pered ro
31、ller bearings, respectively.86.5 Low-Temperature Test Chamber, equipped with internalfan, and capable of maintaining the spindle at 40 6 0.5C,and with sufficient capacity to cool the spindle at the rateshown in Fig. 2(A) and Fig. 2(B).6.6 Laboratory Oven, forced air, capable of maintaining 706 3C.6.
32、7 Grease Packer, as described in Test Method D 3527 orequivalent.6.8 Ultrasonic Cleaner.97. Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee
33、 on Analytical Reagents of the American Chemical Societywhere such specifications are available.10Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.7.2 Ethylene Glycol, commerc
34、ial automotive antifreeze.(WarningModerately toxic. Can be harmful if inhaled,swallowed or absorbed through skin. Contact can irritate eyes,or mucosa.)7.3 Chloroform, reagent grade. (WarningHealth hazard.)7.4 1,1,1-Trichloroethane, reagent grade. (WarningHealth hazard.)7.4.1 For routine testing, a f
35、unctionally equivalent solventmay be substituted throughout this test method wherever1,1,1-trichloroethane is specified. However, in referee situa-tions, 1,1,1-trichloroethane or chloroform shall be used unlesscontractual parties agree on the acceptability of the function-ally equivalent solvent.7.4
36、.1.1 To be functionally equivalent, the solvent must notaffect test results, must clean as effectively as 1,1,1-trichloroethane, have similar volatility characteristics, leave noresidue on evaporation, and contain no water or additives.NOTE 4This test method (and the precision values) was originally
37、developed using chloroform. This was subsequently replaced by 1,1,1-trichloroethane which was declared an ozone depleting substance by theU.S. Environmental Protection Agency (EPA). Federal regulations ban theproduction of this material after December 31, 1995, but existing stocksmay continue to be
38、used. Currently there are no EPA restrictions on the useof chloroform, but the user should be aware of its health hazards, if it isused. No other solvent intended as a substitute for 1,1,1-trichloroethane inthis test method has been cooperatively evaluated. (WarningIf thefunctionally equivalent solv
39、ent is flammable or a health hazard, properprecautions should be taken.)8. Calibration8.1 Torque Calibration:8.1.1 Place the load cell in the cold chamber at 40C andallow it to come to temperature equilibrium. Electrically nullthe load cell and recording potentiometer using the adjustingpotentiomete
40、r of the matching network. Adjust or standardizethe range potentiometer as needed to achieve the desiredzero-point and full-scale calibration. Select a millivolt range onthe recording potentiometer, and record pen displacement as aknown force is applied to the load cell. (It may be necessary tofabri
41、cate a platform to attach to the load cell to support thecalibrating weights.) Apply several forces (up to about 200 Nor more) in stepwise fashion while recording pen displacementas a function of applied force. Calibrate the other millivoltranges in similar fashion until limited by either maximumdis
42、placement or maximum load. Remove forces stepwise todetermine possible hysteresis.8.1.2 Construct a plot of pen displacement as a function offorce for each millivolt range. Use these plots for the subse-quent determination of torque for the test greases. Ordinarily,the plots will be linear, and simp
43、le conversion factors can becalculated.NOTE 5Data logging software may be uesd to collect this data.8.1.3 This calibration need be done only at the time of initialsetup and when occasional checks indicate that it is required.However, the torque measuring system is to be standardizedbefore each test.
44、8.2 Temperature Calibration:8.2.1 In order to obtain precise torque measurements, anaccurate temperature calibration is essential. Meticulous at-tention to the details described in the several ASTM methods oftemperature calibration is of paramount importance.8.2.2 Calibrate the temperature-measuring
45、 system, includ-ing both the potentiometer and the spindle thermocouple, at0C and 40C by comparing the observed temperature withthat of the certified thermometer as described in Test MethodE 220. Alternatively, both thermometer and thermocouple can8Timken or Bower bearings are suitable.9A Bransonic
46、220 (Branson Cleaning Equipment Co., Shelton CN 06484),having a capacity of about 4 L operating at an output frequency of about 55 kHz,with a power input of about 125 W, has been found satisfactory.10Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, D
47、C. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.TABLE 1 Torque Tes
48、t Results at 40C with NLGI ReferenceSystem A (Batch 3)Mean value 3.7 NmStandard deviation 0.67 NmConfidence limits, 95 %:Lower 3.2Upper 4.1D 4693 033be calibrated using the freezing point of mercury as describedin Test Method E 77. The reference ice bath is to be made inaccordance with Practice E 56
49、3.NOTE 6A suitable low-temperature liquid bath can be made with a 65volume per volume percent commercial, automotive-type, ethylene glycolantifreeze (7.2) in water.8.2.3 The temperature correction determined by the thermo-couple calibration shall be applied when measuring the tem-perature of the spindle.8.3 Spring Calibration:8.3.1 Remove the spring (Part 8, Fig. 3), and outer and innercompression plates (Parts 9 and 11, Fig. 3) from the test unit.8.3.2 Reassemble spring and compression plates in correctorder. Apply a force of 400 N and measu
