Honda's innovative Rincon boasts the only true automotive-style automatic transmission in the entire ATV world. Though it features several innovations that cater specifically to ATV application, the Rincon's torque converter operates in principle much like other torque converters. Basically, it links the engine to the automatic transmission much like a manual clutch connects an engine to a manual gearbox. Both systems drive the vehicle and they also come into play when the vehicle stops.
With a manual transmission, manual actuation of the clutch temporarily disengages the engine from the transmission when coming to a stop. In similar fashion, a torque converter performs this connect/disconnect function but automatically, as needed. Moreover, with a torque converter and automatic transmission, the rider need only release the throttle and operate the brake when stopping the vehicle.
A torque converter can accomplish this because it is a fluid coupling, rather than a solid coupling. At low engine speeds, the torque converter slips internally, which allows the engine to spin independently of the transmission. As a result, the engine of the stopped vehicle is allowed to run at idle while the transmission is in gear. When it's time to roll, the rider simply opens the throttle to increase engine speed, and the torque converter then transfers power to the transmission to make the vehicle move.
In the Rincon, the engine output shaft drives the torque converter's impeller, which uses fins to pump fluid--in this case, engine oil. As this fluid drives the vanes of the torque converter's turbine, the spinning turbine then powers the automatic transmission to propel the vehicle. The Rincon's automatic transmission employs three hydraulic clutches and an ECU that automatically selects one of three forward gears or reverse.