1、Designation: D6121 12aStandard Test Method forEvaluation of Load-Carrying Capacity of Lubricants UnderConditions of Low Speed and High Torque Used for FinalHypoid Drive Axles1This standard is issued under the fixed designation D6121; the number immediately following the designation indicates the yea
2、r oforiginal adoption or, in the case 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 is commonly referred to as the L-37te
3、st.2This test method covers a test procedure for evaluatingthe load-carrying, wear, and extreme pressure properties of agear lubricant in a hypoid axle under conditions of low-speed,high-torque operation.1.2 This test method also provides for the running of the lowaxle temperature (Canadian) L-37 te
4、st. The procedure for thelow axle temperature (Canadian) L-37 test is identical to thestandard L-37 test with the exceptions of the items specificallylisted in Annex A6. The procedure modifications listed inAnnex A6 refer to the corresponding section of the standardL-37 test method.1.3 The values st
5、ated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3.1 ExceptionsIn Table A9.1, the values stated in SIunits are to be regarded as standard. Also, no S
6、I unit isprovided where there is not a direct SI equivalent.1.4 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 and health practices and determine the applica-b
7、ility of regulatory limitations prior to use. Specific warninginformation is given in Sections 4 and 7.2. Referenced Documents2.1 ASTM Standards:3D235 Specification for Mineral Spirits (Petroleum Spirits)(Hydrocarbon Dry Cleaning Solvent)E29 Practice for Using Significant Digits in Test Data toDeter
8、mine Conformance with Specifications2.2 Military Specification:4MIL-PRF-2105E Lubricating Oil, Gear, Multipurpose2.3 AGMA National Standard:5Nomenclature of Gear Tooth Failure Modes2.4 SAE Standard:6SAE J308 Information Report on Axle and Manual Trans-mission LubricantsSAE J2360 Lubricating Oil, Gea
9、r Multipurpose (Metric)Military Use3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 abrasive wear, non ring and pinion gears, removalof material from the operating surface of the gear caused bylapping of mating surfaces by fine particles suspended inlubricant, fuel, or air or i
10、mbedded in a surface. ASTM DistressRating Manual No. 2173.1.2 adhesive wear, non ring and pinion gears, removalof material from the operating surface of the gear caused byshearing of junctions formed between operating surfaces in1This test method is under the jurisdiction of ASTM Committee D02 onPet
11、roleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.B0.03 on Automotive Gear Lubricants sheared-off particles either re-main affixed to the harder of the mating surfaces or act as wearparticles between the surfaces. ASTM Distress RatingManual No. 213.1.3 broken gear to
12、oth, na gear tooth where a portion ofthe tooth face is missing and the missing material includessome part of the top land, toe, heel, or coast side of the tooth.3.1.3.1 DiscussionThis condition is distinct from andmore extensive than “chipping,” which is defined in 3.1.5.3.1.4 burnish, non ring and
13、pinion gears, an alteration ofthe original manufactured surface to a dull or brightly polishedcondition. ASTM Distress Rating Manual No. 213.1.5 chipping, non ring and pinion gears, a conditioncaused in the manufacturing process in which a small irregularcavity is present only at the face/crown edge
14、 interface. Theedge-chipping phenomenon occurs when sufficient fatiguecycles accumulate after tooth surface wear relieves the com-pressive residual stress on the tooth profile side of theprofile-to-topland interface. Chipping within 1 mm of theface/crown edge interface is to be called chipping, notp
15、itting/spalling. ASTM Distress Rating Manual No. 213.1.6 corrosion, nin final drive axles, a general alterationof the finished surfaces of bearings or gears by discoloration,accompanied by roughening not attributable to mechanicalaction. ASTM Distress Rating Manual No. 213.1.7 deposits, nin final dr
16、ive axles, material of pasty,gummy, or brittle nature adhering to or collecting around anyof the working parts. ASTM Distress Rating Manual No. 213.1.8 discoloration, non ring and pinion gears, any al-teration in the normal color of finished steel surfaces. ASTMDistress Rating Manual No. 213.1.9 pit
17、ting, non ring and pinion gears, small irregularcavities in the tooth surface, resulting from the breaking out ofsmall areas of surface metal. ASTM Distress Rating ManualNo. 213.1.10 ridging, non ring and pinion gears, an alteration ofthe tooth surface to give a series of parallel raised and polishe
18、dridges running diagonally in the direction of sliding motion,either partially or completely across the tooth surfaces of gears.ASTM Distress Rating Manual No. 213.1.11 rippling, non ring and pinion gears, an alterationof the tooth surface to give an appearance of a more or lessregular pattern resem
19、bling ripples on water or fish scales.ASTM Distress Rating Manual No. 213.1.12 scoring, non ring and pinion gears, the rapidremoval of metal from the tooth surfaces caused by the tearingout of small contacting particles that have welded together asa result of metal-to-metal contact. The scored surfa
20、ce ischaracterized by a matte or dull finish. ASTM Distress RatingManual No. 213.1.13 scratching, non ring and pinion gears, an altera-tion of the tooth surface in the form of irregular scratches, ofrandom length, across the tooth surface in the direction ofsliding of the surfaces. ASTM Distress Rat
21、ing Manual No.213.1.14 spalling, non ring and pinion gears, the breakingout of flakes of irregular area of the tooth surface, a conditionmore extensive than pitting. ASTM Distress Rating ManualNo. 213.1.15 surface fatigue, non ring and pinion gears, thefailure of the ring gear and pinion material as
22、 a result ofrepeated surface or subsurface stresses that are beyond theendurance limit of the material. It is characterized by theremoval of metal and the formation of cavities. AGMANational Standard3.1.16 wear, non ring and pinion gears, the removal ofmetal, without evidence of surface fatigue or a
23、dhesive wear,resulting in partial or complete elimination of tool or grindingmarks or development of a discernible shoulder ridge at thebottom of the contact area near the root or at the toe or heel endof pinion tooth contact area (abrasive wear). ASTM DistressRating Manual No. 214. Summary of Test
24、Method4.1 Prior to each test run, inspect the test unit (final axleassembly) and measure and record confirming manufacturingspecifications.4.2 Begin the test when the axle assembly is installed on thetest stand and charged with test lubricant.4.3 Gear Conditioning PhaseRun the charged test unit for1
25、00 min at 440 wheel r/min and 395 lbf-ft (535 N-m) torqueper wheel, maintaining an axle sump temperature of 297F(147C). (WarningHigh-speed rotating equipment, electri-cal shock, high-temperature surfaces.)4.4 Gear Test PhaseNext, run the test unit for 24 h at 80wheel r/min, 1740 lbf-ft. (2359 N-m) t
26、orque per wheel and anaxle sump temperature of 275F (135C). (WarningSee4.3.)4.5 The test is completed at the end of the gear test phase.Visually inspect the test parts.4.5.1 Remove the ring gear, pinion, and pinion bearing, andrate for various forms of distress. Use the condition of the ringgear and
27、 pinion to evaluate the performance of the test oil.5. Significance and Use5.1 This test method measures a lubricants ability to protectfinal drive axles from abrasive wear, adhesive wear, plasticdeformation, and surface fatigue when subjected to low-speed,high-torque conditions. Lack of protection
28、can lead to prema-ture gear or bearing failure, or both.5.2 This test method is used, or referred to, in the followingdocuments:5.2.1 American Petroleum Institute (API) Publication1560.85.2.2 STP-512A.95.2.3 SAE J308.8“Lubricant Service Designations for Automotive Manual Transmissions,Manual Transax
29、les, and Axles,” available from American Petroleum Institute, 1220L St. NW, Washington, DC 20005.9“Laboratory Performance Tests for Automotive Gear Lubricants Intended forAPI GL-5 Service.”D6121 12a25.2.4 Military Specification MIL-PRF-2105E.5.2.5 SAE J2360.6. Apparatus6.1 Test UnitThe test unit is
30、a new complete hypoid truckaxle assembly less axle shafts, Dana Model 60, 5.86 to 1ratio.10See Annex A6 for part numbers.6.2 Test Stand and Laboratory Equipment:6.2.1 Axle VentVent the axle to the atmosphere throughoutthe entire test and arrange the vent so that no water enters thehousing.6.2.2 Axle
31、 CoverThe axle cover has a 3.5-in. (8.9-cm)inspection port installed, as shown in Fig. A2.1. This allowsfilling the axle and provides a means for inspecting the axleafter the gear condition phase (see 10.1). Install athermocouple, as described in 6.2.4.1.6.2.3 Test Stand ConfigurationMount the compl
32、ete as-sembly in a rigid fixture as shown in Fig. A3.1. Mount the testunit in the test stand with pinion and axle shaft centerlineshorizontal.6.2.4 Temperature ControlThe test axle housing shallinclude a means of maintaining the lubricant at a specifiedtemperature. This shall include a thermocouple,
33、 a temperaturerecording system, and a cooling method.6.2.4.1 ThermocoupleDetermine the thermocouple loca-tion on the rear cover using the cover plate temperature sensorlocating device as shown in Fig. A4.1.(1) Install the thermocouple such that the thermocoupletip is flush with the cover plate lip b
34、y placing the cover plateface on a flat surface and inserting the thermocouple into thecover plate until the thermocouple tip is flush with the flatsurface.(2) Lock the thermocouple into place.6.2.4.2 Temperature Recording SystemThe temperaturerecording system shall record the temperature of the tes
35、t oilthroughout the test.6.2.4.3 Axle CoolingUse three spray nozzles to distributewater over the cover plate and axle housing as shown in Fig.A5.1. Actuate the water control valve by the temperature PIDcontrol system. See A6.3.2.1 for L-37 Canadian Version test.(1) Spray nozzles11shall be any combin
36、ation of the fol-lowing part numbers depending on how the system is plumbed:Straight Male NPT (Part No. 3/8GG-SS22), 90 Male NPT(Part No. 3/8GGA-SS22), Straight Female NPT (Part No.3/8G-SS22), and 90 Female NPT (Part No. 3/8GA-SS22).(2) Use a single control valve to control the cooling watersupply.
37、The control shall be a12 in. (12.7 mm) two-way, Clinear trim, air to close, Research Control valve. Use a singlePID loop to maintain the axle lubricant temperature control forboth the Standard and Canadian version test. A separate PIDloop control for each version is not permitted. See A6.3.2.2 forL-
38、37 Canadian Version test.(3) Use only38 or12 in. (9.5 or 12.7 mm) line material tothe spray nozzles.(4) Use a minimum supply water pressure of 25 psi (172kPa) to the control valve.(5) Use an axle box cover as shown in Fig. A5.2. Thepurpose is to contain water and eliminate drafts.(6) Use a locating
39、pin or stop block as an indexing deviceto ensure that all subsequent axle installations are consistentlyinstalled perpendicular with the axle housing cover to engineand transmission driveshaft centerline.6.2.5 Power SourceThe power source consists of agasoline-powered V-8 engine capable of maintaini
40、ng testconditions.6.2.6 Dynamometers and Torque Control SystemUse twoaxle dynamometers with sufficient torque absorbing capacity tomaintain axle torque and speed conditions. Suitable controlequipment with sensitivity of adjustment to permit mainte-nance of test conditions is required.6.2.7 Dynamomet
41、er Connecting ShaftsFabricate shaftsconnecting the dynamometer to the axle shafts. Shafts shall bestrong enough to handle the torques encountered and shall bedynamically (spin) balanced.6.2.8 Drive Shaft and Universal JointsFabricate a shaftwith universal joints connecting the manual transmission an
42、dtest axle. The shaft shall have a 4 6 0.2-in. (10.1 6 0.51-cm)outside diameter with a 0.095 6 0.005 in. (0.24 6 0.013 cm)wall thickness. Shaft and universal joints should be strongenough to handle the torques encountered and shall be dynami-cally (spin) balanced.6.2.9 Transmission and CouplingCoupl
43、e the engine to thetest unit through a clutch and manual transmission of sufficienttorque carrying capacity to operate normally under test condi-tions.6.3 Speed Measuring and Control System, capable of mea-suring speed of both axles and also of maintaining testconditions.7. Reagents and Materials7.1
44、 Sealing Compound, where necessary, Permatex No. 2,or equivalent.7.2 SolventUse only mineral spirits meeting the require-ments of Specification D235, Type II, Class C for AromaticContent (0-2% vol), Flash Point (142F/61C, min) and Color(not darker than +25 on Saybolt Scale or 25 on Pt-Co Scale).(War
45、ningCombustible. Health hazard.) Obtain a Certificateof Analysis for each batch of solvent from the supplier.8. Preparation of Apparatus8.1 Cleaning of Reusable HardwareClean as necessary allreusable parts including axle shafts, thermocouples axle hous-ing cover, and all associated drain pans and fu
46、nnels used for theaddition of and collection of test oil.8.2 Preparation of Axle:10The sole source of supply of the apparatus known to the committee at this timeis Dana Corp., P.O. Box 2424, Fort Wayne, IN 46801. If you are aware of alternativesuppliers, please provide this information to ASTM Inter
47、national Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical committee,1which you may attend.11The sole source of supply of the apparatus known to the committee at this timeis Spray Systems Company, and the spray nozzles can be purchased through E.I
48、.Pfaff Company, 3443 Edwards Road, Suite D, Cincinnati, OH 45208. If you areaware of alternative suppliers, please provide this information to ASTM Interna-tional Headquarters. Your comments will receive careful consideration at a meetingof the responsible technical committee,1which you may attend.D
49、6121 12a38.2.1 Record the “as received” drive side contact patternlength and flank values as noted on the axle housing from DanaCorp.10Length values of L2and L3and flank values of F1,F0,and F+1are considered acceptable. Any adjustments that aremade to the axle prior to testing shall be noted in the commentssection of the test report.Axle housings from prior gear batchesthat do not have contact pattern markings shall be patternedand reported by the test labs in the test report.8.2.2 Break and Turn Torque MeasurementsDetermineand record
