The figure shows the vacuum clutch system. This sort of clutch makes use of the existing vacuum inside the engine manifold to operate the clutch. The vacuum clutch consists of a reservoir, non-return valve, vacuum cylinder with piston, and solenoid valve.  This prevents the transmission shaft and clutch plate from https://clutch-kereta98642.aboutyoublog.com/36157690/the-fact-about-clutch-plate-that-no-one-is-suggesting