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SAE No. 2 Friction Test Machine µPVT Test
- Ground Vehicle Standard
- J2490_201208
- Revised
Downloadable datasets available
Annotation ability available
Sector:
Issuing Committee:
Language:
English
Scope
This SAE Recommended Practice is intended as the definition of a standard test, which may be subject to frequent change to keep pace with experience and technical advances. This should be kept in mind when considering its use.
The SAE No. 2 Friction Test Machine is used to evaluate the friction characteristics of automatic transmission plate clutches with automotive transmission fluids. It can also be used to conduct durability tests on wet friction systems.
The specific purpose of this document is to define a µPVT Test for the evaluation of the variation of wet friction system performance as a function of speed, temperature, and pressure. This procedure is intended as a standard for both suppliers and end users.
The only variables selected by the supplier or user of the friction system are:
-
a
Friction Material
-
b
Fluid
-
c
Reaction Plates
These three variables must be clearly identified when reporting the results of this test. If any of the test parameters or system hardware as described in this document are changed, other than the friction material, test fluid, or reaction plates, the data may not be reported as having been obtained using this document.
This procedure is intended to evaluate the endpoint/midpoint ratios, midpoint and breakaway coefficients. The procedure can be used to demonstrate changes that occur between the different levels of engagement speed, sump temperature and apply pressure. Refer to SAE J2487, SAE J2488, or SAE J2489 for coefficient variations due to changes in power level.
The procedure, as described in detail in Table 1, consists of four 50 cycle break-in levels at 3500 r/min with increasing steps of apply pressure, followed by 16 levels consisting of 25 dynamic engagements and one breakaway following completion of the 25th dynamic cycle. The 16 levels are achieved by varying initial engagement speed, apply pressure and oil sump temperature while the inertia is kept constant at 0.701 kg-m2.
Rationale
The standard as written allowed too large a tolerance stack as far as energy and did not require reporting of critical performance factors. These revisions came about as a result of a subcommittee discussion on October 26, 2006. Removal of North America OEM designations in keeping with revisions to other standards and their general unavailability and/or obsolescence. Removal of 3 plate option is in line with the philosophy of standards in general. The original balloting of these changes resulted in a need for correction on figure numbers.
Recommended Content
| Ground Vehicle Standard | SAE No. 2 Friction Test Machine 3600 rpm Stepped Power Test |
| Ground Vehicle Standard | SAE No. 2 Friction Test Machine 6000 rpm Stepped Power Test |
| Technical Paper | Control of Band/Drum Interface Temperature in Automatic Transmissions and the Impact Upon Friction System Durability |
Data Sets - Support Documents
| Title | Description | Download |
|---|---|---|
| Unnamed Dataset 1 | ||
| Unnamed Dataset 2 | ||
| TABLE 1A | REQUIRED PARAMETERS µPVT TEST | |
| TABLE A1 | TEST COMPONENTS AND ASSEMBLY LAYOUT |
Issuing Committee
Automatic Transmission and Transaxle Committee
The Automatic Transmission and Transaxle Standards Committee reports to the Powertrain Systems Group of the Motor Vehicle Council. The Committee is responsible for developing and maintaining SAE Standards, Recommended Practices, and Information Reports related to all systems, subsystems, and components of automatic transmissions, including both step ration and CVT designs. This committee will direct its attention to passenger cars and light trucks. Participants in the SAE Automatic Transmission Transaxle Standards Committee include OEMs, suppliers, consulting firms, government, and other interested parties.
Reference
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