International Scholarly Research Network (I S R N)
ISRN Tribology vol:2013
When the clutch is in disengaged condition, ideally no torque should be transmitted. However, in reality, the relative motion between the disks causes viscous shearing of fluids in the gap. This results in a drag torque which is considered as a loss. The objective of the present study is to formulate a drag torque model as well as to experimentally evaluate the effect of several parameters on the drag torque.A model based on continuity and Navier-Stokes equations, considering laminar flow, is deduced. The drag torque estimated by the model is the sum of drag torque due to shearing of the ATF and mist (suspension of ATF in air) film. In order to validate the model and characterize the drag torque experiments are performed using SAE# 2 test setup under real conditions of variable ATF flow rate, and disks rotation state for higher clutch speed range. The drag torque predicted by the model is in good agreement with the experimental results obtained by varying the flow properties and disks rotation state. By analyzing the experimental results, factor by which, the variation in parameters like ATF flow rate, ATF temperature, disk size, and disk rotation state influences the drag torque are determined.