Dalian Lubricant R&D Center Installs a Low-Speed Friction Test Machine

In order to better develop a new generation of automatic transmission fluids, the Dalian R&D Center recently introduced a low-speed friction test machine from the Japanese company Automax. The test machine can evaluate the low-speed anti-shudder performance of automatic transmission fluids very well and effectively raise the center's level of friction performance evaluation for automatic transmission fluids. The low-speed friction test machine has now been installed and commissioned.
In recent years, because continuous-slip torque converters and electronically controlled torque converters offer good fuel economy and can effectively improve NVH performance, they have been widely used in the field of passenger car automatic transmissions. However, continuous-slip torque converters are prone to self-excited vibration, or to shudder caused by a decline in friction performance as rotational speed increases. Many institutions have carried out a great deal of research work to change this situation. The results show that rationally controlling the μ-v relationship between the friction coefficient of automatic transmission fluid and sliding speed is more effective than improving the friction material of the clutch plates.
The ILSAC ATF subcommittee once studied the correlation among various test methods and concluded that the JASO M349 test procedure can evaluate the anti-shudder durability of automatic transmission fluids very well. This method was developed by the Japan Automobile Manufacturers Association; it uses a low-speed friction test machine and, through longitudinal loading, brings the clutch plate immersed in oil into engagement with the reaction steel plate, measures the friction force generated during engagement and calculates the friction coefficient, and finally evaluates the anti-shudder and durability performance of the oil by analysing the relationship between the friction coefficient and sliding speed.