Dual clutch transmission with multiple range gearing

A power transmission mechanism for an engine-powered vehicle comprising a multiple speed ratio gear system and planetary ratio range gearing with at least two ranges including a high range and a low range, the multiple ratio gear system having first and second torque input shafts;

• a dual clutch assembly with dual clutches for alternately connecting a vehicle engine selectively to the first and second torque input shafts;
• ratio change clutches in the gear system selectively connecting and disconnecting elements of the gear system whereby a torque flow path for the gear system is defined for each ratio as a torque flow path in an adjacent gear ratio in a ratio change sequence is preselected;
• the planetary ratio range gearing having a carrier connected to a power output member, a sun gear and a ring gear;
• and
• the ratio range gearing including a first range clutch for anchoring the ring gear to establish the low range and for connecting two elements of the planetary ratio range gearing together to establish the high range.

A power transmission mechanism for an engine-powered vehicle comprising a multiple ratio gear system and countershaft range gearing with at least two ranges including a high range and a low range, the multiple ratio gear system having first and second torque input shafts;

• a dual clutch assembly with dual clutches for alternately connecting a vehicle engine selectively to the first and second torque input shafts;
• ratio change clutches in the gear system selectively connecting and disconnecting elements of the gear system whereby a torque flow path for the gear system is defined for each ratio and a torque flow path for an adjacent gear ratio in a ratio change sequence is preselected;
• the countershaft range gearing having a countershaft gear element engaged with a first countershaft gearing low ratio gear;
• and
• a countershaft range clutch for connecting a torque transmitting member of the multiple ratio gear system to a torque output shaft to establish a high range and connecting a second countershaft gearing low ratio gear to a torque transmitting member of the multiple ratio gear system to establish low range.

A ratio range gearing assembly for use with gearing of a multiple speed ratio power transmission mechanism in a vehicle powertrain, one gear of the range gearing assembly being connected drivably to a power output shaft;

• first selectively engageable clutch means for establishing and disestablishing separate torque flow paths through the range gearing assembly to a torque output member;
• second selectively engageable clutch means for establishing and disestablishing a driving connection, respectively, between separate torque input elements of the range gearing assembly and separate gears of the transmission mechanism;
• dual clutches for the transmission mechanism;
• a first of the dual clutches, when engaged, providing torque delivery to one of the separate gears of the transmission mechanism;
• a second of the dual clutches, when engaged, providing torque delivery to another of the separate gears of the transmission mechanism;
• the dual clutches being alternately and simultaneously engaged and disengaged whereby a transition is effected from one ratio to another ratio without torque interruption.