THE IMPACT FORCED FLUID COOLING OF FRICTION PAIRS IN AUTOMOTIVE CLUTCHES ON ITS THERMAL LOAD

Abstract

The article is describe the results of experimental investigations of forced fluid cooling of friction pairs in wet clutches on their thermal load. It is found that forced fluid cooling of the friction clutch can significantly increase the time of engagement and slipping in comparison with the time of operation similar couplings presently used on tractors and automobiles. It is found that at steady clutch disc temperature greatest influence parameters such as the pressure on the friction surface, the amount of cooling oil and its temperature in the inlet area of friction and has a much smaller effect change in the relative sliding speed of the rubbing surfaces. With increasing pressure on the disc friction surfaces with 0,501 to 2,82 MPa at specific consumption of oil 6,810-3 m3/(m2s) and the constant rotation frequency of 1000 min-1 a steady-state temperature is reduced by 15 % (from 143 to 125 °C). Therefore, by increasing the friction power 165 % (from 24,92 to 9,39 kW) temperature of clutch disc increases only by 75 %. With the increasing of specific oil consumption on the friction surface by 20 % (from 5,65 10-3 to 6,8 10-3 m3/(m2s)) at a pressure of 2,06 MPa and a constant speed of 1000 min-1 a steady-state temperature is reduced by 15 % (from 143 to 125 °C). The increasing in the at a speed of 100 % (from 500 to 1000 min-1) and, respectively, and friction power by 52 % (from 16,33 to 24,92 kW) at the pressure of 2,82 MPa and a permanent specific consumption of oil increases steady disk temperature by 19 % (from 122 to 145 °C). Based on the results of experimental studies found that increasing friction power per 1 kW due to the gain of a pressure on the friction surface leads to growing of friction disc temperature at the average of 4 °C, but due to the gain of disk rotation speed - at the average of 2,5 °C.