1、SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefro
2、m, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.TO PLACE A DOCUMENT ORDER: (724) 776-4970 FAX: (724) 776-0790SAE WEB ADDRESS http:/www.s
3、ae.orgCopyright 2001 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.A.SURFACEVEHICLE400 Commonwealth Drive, Warrendale, PA 15096-0001RECOMMENDEDPRACTICESubmitted for recognition as an American National StandardJ1266REV.APR2001Issued 1979-06Revised 2001-04Superseding J1266 A
4、PR1995Axle Efficiency Test Procedure1. Scope1.1 Data from this SAE Recommended Practice permit mapping axle efficiency and/or waste energy over theoperating range of trucks, busses, and other highway vehicles based on truck chasses.1.2 The procedure can be applied to single axles, tandem axles as a
5、system, or other systems, by combiningseparate tests, such as tests of the front axle and power divider and rear axle of tandem or tri-drive type.2. ReferencesThere are no referenced publications specified herein.3. Objectives3.1 To provide a means for measuring and comparing axle efficiency and the
6、 influence of materials, lubricants,and design factors on axle efficiency.3.2 To outline a series of tests which encompass the typical range of axle operation in terms of load, speed, andlubricant temperature.3.3 To result in data which are comparable from one test to another and between laboratorie
7、s.4. Equipment Requirement4.1 An axle dynamometer with torque and speed capabilities consistent with the size axle being tested. Separateabsorbers for each output are preferred.4.2 A separate test stand without absorbers for the no-load portion of the test is optional.4.3 Capability of measuring inp
8、ut speed with an accuracy of 1% of the actual speed.4.4 Capability of measuring all torques specified with an accuracy of 0.5% of the actual torque.4.5 Means for measuring and controlling sump lubricant temperatures to 6.0 C for steady-state temperature testsequences.4.6 Means for cold soaking the a
9、xle assembly to 35 C when efficiency at low temperature is to be measured.SAE J1266 Revised APR2001-2-5. Test Preparation5.1 The test axle is to be representative of the particular axle design. Setting of bearing preloads, backlash, etc.,outside of design specification limits is permissible only if
10、that is the purpose of the test. This applies toproduction and experimental designs.5.2 To preclude differential gear rotation as a source of inefficiency, all differentials are to be locked ormechanically blocked from rotating.NOTE Some dynamometers with automatic feedback systems to control relati
11、ve speeds of absorbers mayrequire deactivation of the feedback system.5.3 The axle is to be equipped to measure sump temperature.5.4 The axle assembly is to be tested at the attitude in which it would be installed in a vehicle, unless otherwisespecified.5.5 The axle is to be filled with lubricant re
12、commended for in-vehicle use or the specific lubricant being evaluated.5.6 Lubricant quantity is to be the axle manufacturers recommendation by mass or volume, unless lubricantquantity is a variable under test.5.7 Calculate output speeds and output torque for the break-in and test sequence. See Figu
13、re 1 and 7.3.5.8 Calculate power requirements and determine whether break-in or test sequence must be modified as outlinedin 6.1 and 7.3.NOTE If a tandem front axle is to be tested separately, the rated test torque for each axle would be one-halfthe tandem rating.6. Break-inAn axle is considered to
14、have passed through the break-in period when the efficiency of the axlehas stabilized. To minimize the running time required for axles to achieve efficiency stabilization, select theappropriate schedule from 6.1 and 6.2. Previously-run axles and axles in which the lubricant has beenchanged may not b
15、e completely stabilized. Therefore, all test axles are to be stabilized in the selected break-in schedule before final testing.6.1 If 125% of rated torque at 65 km/h does not exceed realistic in-service horsepower for the axles, run new axlesfor break-in to the following sequence at 65 km/h:a. 50% o
16、f rated output torque for 90 minb. 100% of rated output torque for 120 minc. 125% of rated output torque for 90 min6.2 To determine friction stability, measure the efficiency at the start, middle, and end of each break-in load settingrun. If friction has not stabilized during the highest load run, r
17、epeat the total break-in schedule.SAE J1266 Revised APR2001-3-FIGURE 1CALCULATIONS6.3 Control total output torque and speed to 5% of target values established in 5.7.6.4 Cool lubricant as required to maintain 90 C 5 C sump temperature.7. Efficiency TestsFour conditions of operation are recognized. T
18、hese are listed in Table 1 in order ofimportance relative to energy use and durability:TABLE 1CONDITIONS OF OPERATIONCorrelation Power Flow RotationForward drive Engine to axle Primary designForward coast Wheels to axle Primary designReverse drive Engine to axle Opposite to primary designReverse coa
19、st Wheels to axle Opposite to primary designSAE J1266 Revised APR2001-4-The procedure has been developed for the forward driving mode only because that is by far the dominantcondition of operation in the typical over-the-road application. As a guide to extending the procedure to theforward coasting
20、mode, the suggested approach is to: Run break-in at 25% of rated output torque (entered online 2 of Figure 1) and 65 km/h until stabilized, then follow the test schedule in 7.3, but limit the maximum drivegear torque to 25% of the rated output torque. For this coast test, the axle shaft is the drivi
21、ng member and thepropeller shaft (or equivalent) is the driven member. Because fuel economy is influenced to a minor degree byforward coasting, and to an insignificant degree by the reverse modes in typical over-the-road use, theseprocedures have not been developed. The committee welcomes comments f
22、rom users regarding theprocedures outlined and the need to extend the procedures.7.1 Efficiency is calculated by the formula in Figure 1, item 5. Use the precise ratio computed from toothcombinations rather than a nominal ratio.7.2 Measured output torque and speed are to be controlled within 5% of t
23、he target value and temperature within5 C of the target value.7.3 Axle efficiency for a given lubricant and axle may vary with torque, speed, and temperature. Completedetermination at 6 torques, 6 speeds, and 5 temperatures would require 180 data points. For some purposes,mapping efficiency with loa
24、d and speed variations at one steady-state temperature will be adequate. Thisstandard test is to be at 90 C with output torque and speed sequences as in Table 2.7.4 Other evaluations may require similar testing over a broader range of steady-state temperatures. If so, it isrecommended that the previ
25、ous sequence be repeated at the temperatures of interest or in 30 C incrementsfrom the standard 90 C temperature.7.5 For cold start, short duration trip evaluations, an optional transient temperature test is recommended.Standard speed for this test is 80 km/h, and standard output torque is 25% of ra
26、ting. Additional speeds andtorques are optional. The procedure for this optional test is as follows.7.5.1 Thoroughly cold soak the test axle to approximately 35 C.7.5.2 Accelerate and stabilize at test speed and torque.7.5.3 Determine input and output torque as soon as stabilization is achieved, wit
27、h 20 C as a target for the firstreadings.7.5.4 Record torques at 15 C increments as the axle warms up from the friction being generated.7.5.5 Continue the test through 120 C or the maximum anticipated operating temperature (whichever is lower).Auxiliary heating may be required for low-load, high-tem
28、perature testing.TABLE 2OUTPUT TORQUE AND SPEED SEQUENCESOutput Torque% of RatingOutput SpeedIncrements(km/h)Output SpeedIncrements(km/h)Output SpeedIncrements(km/h)Output SpeedIncrements(km/h)Output SpeedIncrements(km/h)100% 20.0 40.0 60.0 80.0 100.050% 20.0 40.0 60.0 80.0 100.025% 20.0 40.0 60.0 8
29、0.0 100.015% 20.0 40.0 60.0 80.0 100.010% 20.0 40.0 60.0 80.0 100.00% 20.0 40.0 60.0 80.0 100.0SAE J1266 Revised APR2001-5-8. Test Presentation(See Figures 2 through 5.)8.1 Specific end uses of this procedure and the forms in which data may be best presented for specific purposesare so varied that a
30、 standardized recommended data sheet is not provided. Figures 2 to 5 illustrate typicalreduction of data to performance curves.8.1.1 No-load drive pinion torque versus speed (Figure 2).8.1.2 Family of efficiency versus torque curves at each output speed for each steady-state temperature test(Figure
31、3).8.1.3 Efficiency versus temperature for optional transient temperature tests (Figure 4).8.1.4 Parasitic losses and efficiency converted to waste energy per kilometer (Figure 5).8.2 Detail information to be included in data presentation when pertinent to the purpose of the test includestestagency,
32、 test date, test identification number, axle model and part number, axle ratio, axle rating, geargeometry detail, bearing detail, lubricant identification, lubricant detail specifications, lubricant quantity, angleof inclination of axis of input shaft, test torques and speeds, lubricant temperatures
33、, test purpose, axle orlubricant application, numerical values for test results, conversion of data to preferred form, statisticalsignificance of results, and prior use of axle or lubricant. Users of the procedure can choose data mostappropriate for specific purposes.FIGURE 2TYPICAL REDUCTION OF DAT
34、A TO PERFORMANCE CURVENO-LOAD DRIVE PINION TORQUE VERSUS SPEEDSAE J1266 Revised APR2001-6-FIGURE 3TYPICAL REDUCTION OF DATA TO PERFORMANCE CURVEFAMILY OF EFFICIENCY VERSUS TORQUE CURVES AT EACH OUTPUT SPEEDFOR EACH STEADY-STATE TEMPERATURE TESTFIGURE 4TYPICAL REDUCTION OF DATA TO PERFORMANCE CURVEEF
35、FICIENCYVERSUS TEMPERATURE FOR OPTIONAL TRANSIENT TEMPERATURE TESTSSAE J1266 Revised APR2001-7-FIGURE 5TYPICAL REDUCTION OF DATA TO PERFORMANCE CURVEPARASITIC LOSSES AND EFFICIENCY CONVERTED TO WASTE ENERGY PER KILOMETER9. Notes9.1 Marginal IndiciaThe change bar (l) located in the left margin is for
36、 the convenience of the user in locatingareas where technical revisions have been made to the previous issue of the report. An (R) symbol to the leftof the document title indicates a complete revision of the report.PREPARED BY THE SAE TRUCK AND BUS AXLE SUBCOMMITTEEOF THE SAE TRUCK AND BUS POWERTRAI
37、N COMMITTEESAE J1266 Revised APR2001RationaleNot applicable.Relationship of SAE Standard to ISO StandardNot applicable.ApplicationData from this SAE Recommended Practice permit mapping axle efficiency and/or wasteenergy over the operating range of trucks, busses, and other highway vehicles based on
38、truck chasses.The procedure can be applied to single axles, tandem axles as a system, or other systems, bycombining separate tests, such as tests of the front axle and power divider and rear axle of tandem or tri-drive type.Reference SectionThere are no referenced publications specified herein.Developed by the SAE Truck and Bus Axle SubommitteeSponsored by the SAE Truck and Bus Powertrain Committee
