Power flow configuration for dual clutch transmission mechanism

摘要

A transmission mechanism with a pair of selectively engageable clutch systems that has an upstream gear ratio and a downstream gear ratio that combine to provide an effective gear ratio. A different clutch drive member is associated with an input side of each of the pair of clutch systems. The clutch drive members are driven for rotation by an engine input member. The upstream gear ratio is determined by the gear ratio between the engine input member and one of the clutch drive members. Output sides of each of the clutch systems drive an associated one of a pair of non-coaxial layshafts. Pinions are located on and selectively driven by the layshafts. A countershaft is spaced from both of the layshafts, and has a plurality of gears. Each of the gears is driven for rotation by one of the pinions of the layshafts. The downstream gear ratio is determined by the gear ratio between the selected pinion and the intermeshed gear.

主权项

1. A product comprising:
an input shaft of an engine having an engine input member in simultaneous driving relation with a first clutch drive member and a second clutch drive member, the first clutch drive member configured to transfer torque from the engine input member to an input side of a first clutch at first gear ratio and the second clutch drive member configured to transfer torque from the engine input member to an input side of a second clutch at a second gear ratio, the second gear ratio different from the first gear ratio; a first layshaft rotatable about a first layshaft axis and selectively engagable to be driven by the first clutch and to receive torque transferred from the engine input member at the first gear ratio; a second layshaft rotatable about a second layshaft axis that is spaced from the first layshaft axis and selectively engagable to be driven by the second clutch and to receive torque transferred from the engine input member at the second gear ratio; and the first layshaft having a first set of a plurality of coaxial pinions, the second layshaft having a second set of a plurality of coaxial pinions; a countershaft rotatable about a countershaft axis that is spaced from the first layshaft axis and the second layshaft axis, the countershaft having a first set of gears and a second set of gears mounted coaxially thereon, each gear from the first set of the gears in intermeshing, driven relation with a pinion from the first set of pinions with a gear ratio therebetween, and each gear from the second set of the gears in intermeshing, driven relation with a pinion from the second set of pinions with a gear ratio therebetween, the gear ratio of each pair of pinions and gears differing from the gear ratios of other pairs of pinions and gears; and each of the first set of pinions independently engagable with the first layshaft when the first clutch is engaged to transfer torque to the countershaft at an effective gear ratio that is a product of the gear ratio between the engaged pinion and the gear pair and the first gear ratio between the engine input member and the first clutch drive member, and each of the second set of pinions independently engagable with the second layshaft when the second clutch is engaged to transfer torque to the countershaft at an effective gear ratio that is a product of the gear ratio between the engaged pinion and gear pair and the second gear ratio between the engine input member and the second clutch drive member, each of the effective gear ratios provided thereby differing from the other effective gear ratios.