SAE J2490:2019 pdf free

SAE J2490:2019 pdf free.SAE No. 2 Friction Test Machine μPVT Test
Install a reaction plate to contact the pressure plate. Follow with a friction assembly, reaction plate, and so on until all the required components have been installed. The last plate to be installed must be a reaction plate. Spacer thickness must be selected to ensure that the pack clearance is as defined in 4.11. The pack configuration is PRFRFRFRFRSC, where P is the piston, R is a reaction plate, F a friction plate, S the spacer plate (as required), and C the cover. Reaction plates may be used as the spacer. To verify axial alignment of hub oil holes and friction plates, see Appendix A.
For digital data acquisition systems the data is to be recorded at 1000 samples per second per channel using a 15 ms time constant RC filter. (Filtering will slew data. Preferred method is to record all raw data and manipulate later.)
Data is to be averaged at the specified location in either the time or speed domain as specified in 6.1 with midpoint coefficient average values calculated using data points +80 ms on both sides of the required calculation point. Endpoint coefficient average values are calculated from non-filtered peak torque data measured in the last 100 ms of the engagement. For the 1000 Hz sampling rate the averages are based on 161 data points.
If the system does not successfully complete both the 25 dynamic engagements and the breakaway test, there is no data reported for that level. Alternatively, only data for the successful completion of a level are to be reported. Failure is defined as complete destruction of the friction material/system. (Report number of cycles into level at which failure occurred.)
A change bar (I) located in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only.SAE J2490 pdf free download.