Cluta Fundamentals

     An automotive clutch is used to connect and disconnect the engine and manualtransmission or transaxle. The clutch is located between the engine and the transmission.

    Only vehicles with manual transmission require a clutch. Vehicles with automatictransmissions do not need one.  They have a torque converter, which automaticallydisengages the engine and transmission at low engine speeds.

    Power flow from one unit to another can be controlled with a drive disc and a drivendisc. Relating to an automotive clutch, one disc is fastened to the rear of the enginecrankshaft. The other disc is attached to the input shaft of the transmission.

    When the discs do not tough，the crankshaft can rotate while the transmission inputshaft remains stationary. However, when the transmission disc is forced into the spinningdisc on the crankshaft, both spin together. Power flow is then transferred out of theengine and into the transmissions.

    Fig. 9.2 shows a simplified，exploded view of a clutch.