1、Designation: D6121 12Standard 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 year
2、 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-37tes
3、t.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 tes
4、t. 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 sta
5、ted 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 SI
6、 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-bi
7、lity 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 toDeterm
8、ine 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, Gear
9、 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 im
10、bedded in a surface.ASTM Distress Rating 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 onPetr
11、oleum 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 Rating Manual No. 213.1.3 burnish, non ri
12、ng and pinion gears, an alteration ofthe original manufactured surface to a dull or brightly polishedcondition. ASTM Distress Rating Manual No. 213.1.4 chipping, non ring and pinion gears, a conditioncaused in the manufacturing process in which a small irregularcavity is present only at the face/cro
13、wn edge 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 chippin
14、g, not pitting/spalling. ASTM Distress Rating Manual No. 213.1.5 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. 213.1.6 deposits, nin
15、final drive axles, material of pasty,gummy, or brittle nature adhering to or collecting around anyof the working parts.ASTM Distress Rating Manual No. 213.1.7 discoloration, non ring and pinion gears, any al-teration in the normal color of finished steel surfaces.ASTM Distress Rating Manual No. 213.
16、1.8 pitting, non ring and pinion gears, small irregularcavities in the tooth surface, resulting from the breaking out ofsmall areas of surface metal.ASTM Distress Rating Manual No. 213.1.9 ridging, non ring and pinion gears, an alteration ofthe tooth surface to give a series of parallel raised and p
17、olishedridges running diagonally in the direction of sliding motion,either partially or completely across the tooth surfaces of gears.ASTM Distress Rating Manual No. 213.1.10 rippling, non ring and pinion gears, an alterationof the tooth surface to give an appearance of a more or lessregular pattern
18、 resembling ripples on water or fish scales.ASTM Distress Rating Manual No. 213.1.11 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
19、 surface ischaracterized by a matte or dull finish.ASTM Distress Rating Manual No. 213.1.12 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 Distres
20、s Rating Manual No. 213.1.13 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 Manual No. 213.1.14 surface fatigue, non ring and pinion gears, thefailure of the ring gear and pinion mater
21、ial as 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.AGMA National Standard3.1.15 wear, non ring and pinion gears, the removal ofmetal, without evidence of surface fatigu
22、e or adhesive 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 Distress Rating Manual No. 214. Summary of
23、 Test 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 uni
24、t for100 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
25、N-m) torque 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 ringge
26、ar and 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 prote
27、ction 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 J308.5.2.4 Military Specification MIL-PRF-2105E.5.2.5 SAE J2360.8“Lubricant Servic
28、e Designations for Automotive Manual Transmissions,Manual Transaxles, 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 1226. Apparatus6.1 Test UnitThe test uni
29、t is 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 through-out the entire test and arrange the vent so that no water entersthe housing.6.2
30、.2 Axle 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 a thermo-couple, as described in 6.2.4.1.6.2.3 Test Stand ConfigurationMount
31、the complete 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 ther
32、mocouple, 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 pl
33、ate lip by 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 o
34、f the test 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 a
35、ny combination of thefollowing part numbers depending on how the system isplumbed: Straight Male NPT (Part No. 3/8GG-SS22), 90Male 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 waters
36、upply. 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.
37、2 forL-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 lo
38、cating 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 ma
39、intaining 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 Dy
40、namometer 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 transmis
41、sion andtest 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 Coupli
42、ngCouple 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 Mater
43、ials7.1 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 Scal
44、e).(WarningCombustible. Health hazard.) Obtain a Certificateof Analysis for each batch of solvent from the supplier.8. Preparation of Apparatus8.1 Cleaning of Reusable HardwareClean as necessaryall reusable parts including axle shafts, thermocouples axlehousing cover, and all associated drain pans a
45、nd funnels usedfor the addition of and collection of test oil.8.2 Preparation of Axle:8.2.1 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
46、 adjustments that are10The 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 International Headquarters.Your comments will receive careful con
47、sideration 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.Pfaff Company, 3443 Edwards Road, Suite D, Cincinnati, OH 4
48、5208. 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.D6121 123made to the axle prior to testing shall be noted in
49、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 the torques required to break and to turn the pinionshaft of the completely assembled test unit.8.2.3 Backlash MeasurementsRecord the backlash on thetest axle reported from the manufacturer. To be acceptable, thebacklash reported by the manufacturer shall be between 0.004to 0.012 in. (0.102 to 0.
