Powertrain for an automotive vehicle with multiple-ratio gearing and a dual power input clutch

A multiple-ratio power transmission for an engine-powered vehicle comprising:

• a mainshaft in a transmission housing connected drivably to a power output shaft;
• a first countershaft disposed parallel to the mainshaft and a second countershaft being a sleeve shaft mounted concentrically about the first countershaft;
• first and second power input shafts, the first power input shaft being mounted concentrically about the second power input shaft;
• a headset gear assembly including first and second headset gears connected drivably to the first and second power input shafts, respectively;
• mainshaft gears in meshing engagement with countershaft gears to establish torque flow paths between the mainshaft and the power input shafts;
• the first headset gear being in meshing engagement with a countershaft gear for the first countershaft;
• the second headset gear being in meshing engagement with a countershaft gear for the second countershaft;
• a dual clutch assembly for alternately establishing and disestablishing a torque flow path from an engine to the first and second headset gears;
• a first countershaft bearing for supporting the first countershaft at a first distal end within the housing;
• a second countershaft bearing for journaling a second distal end of first countershaft;
• and
• a third countershaft bearing for rotatably supporting the first countershaft at a location disposed intermediate the first and second countershaft bearings whereby the countershaft gear load capacity is improved,
• wherein the headset gear assembly includes a first headset bearing rotatably supporting the second power input shaft and the second headset gear in the housing, a second headset bearing rotatably supporting the first power input shaft on the housing, and a third headset bearing rotatably supporting the first power input shaft on the second power input shaft, whereby headset gearing loads are accommodated.

A multiple-ratio power transmission for an engine-powered vehicle comprising:

• a mainshaft in a transmission housing connected drivably to a power output shaft;
• a first countershaft disposed parallel to the mainshaft;
• a second countershaft mounted concentrically about the first countershaft;
• first and second power input shafts, the first power input shaft being mounted concentrically about the second power input shaft;
• a headset gear assembly including first and second headset gears connected drivably to the first and second power input shafts, respectively;
• mainshaft gears in meshing engagement with countershaft gears to establish torque flow paths between the mainshaft and the power input shafts;
• the first headset gear being in meshing engagement with a countershaft gear for the first countershaft;
• the second headset gear being in meshing engagement with a countershaft gear for the second countershaft;
• a dual clutch assembly for alternately establishing and disestablishing a torque flow path from an engine to the first and second headset gears;
• wherein the first power input shaft is journaled by a first tapered roller bearing,
• wherein the second headset gear is formed on the second power input shaft at an inboard end and is journaled by a first headset bearing,
• wherein the first headset gear is formed on the first power input shaft and is journaled by a second tapered roller bearing on the inboard end of the second power input shaft,
• wherein the mainshaft is journaled by a third tapered roller bearing;
• wherein a distal end of the mainshaft is journaled by a mainshaft bearing, and
• wherein a fourth tapered roller bearing rotatably supports the mainshaft at a location intermediate the mainshaft bearing and the third tapered roller bearing.

A multiple-ratio power transmission for an engine-powered vehicle comprising:

• a mainshaft in a transmission housing connected drivably to a power output shaft;
• a first countershaft disposed parallel to the mainshaft and a second countershaft being a sleeve shaft mounted concentrically about the first countershaft;
• first and second power input shafts, the first power input shaft being mounted concentrically about the second power input shaft;
• a headset gear assembly including first and second headset gears connected drivably to the first and second power input shafts, respectively;
• mainshaft gears in meshing engagement with countershaft gears to establish torque flow paths between the mainshaft and the power input shafts;
• the first headset gear being in meshing engagement with a countershaft gear for the first countershaft;
• the second headset gear being in meshing engagement with a countershaft gear for the second countershaft;
• a dual clutch assembly for alternately establishing and disestablishing a torque flow path from an engine to the first and second headset gears;
• a first countershaft bearing for supporting the first countershaft at a first distal end within the housing;
• a second countershaft bearing for journaling a second distal end of first countershaft;
• and
• a third countershaft bearing for rotatably supporting the first countershaft at a location disposed intermediate the first and second countershaft bearings whereby the countershaft gear load capacity is improved
• wherein first and second ratio change clutches for countershaft gears are located adjacent opposite ends of the first countershaft and first and second ratio change clutches for the mainshaft are located intermediate axial locations of the first and second ratio change clutches for the first countershaft whereby the ratio change clutches are situated at optimum locations for effecting a simplified ratio change clutch control.

A multiple-ratio power transmission for an engine-powered vehicle comprising:

• a mainshaft in a transmission housing connected drivable to a power output shaft;
• a first countershaft disposed parallel to the mainshaft and a second countershaft being a sleeve shaft mounted concentrically about the first countershaft;
• first and second power input shafts, the first power input shaft being mounted concentrically about the second power input shaft;
• a headset gear assembly including first and second headset gears connected drivably to the first and second power input shafts, respectively;
• mainshaft gears in meshing engagement with countershaft gears to establish torque flow paths between the mainshaft and the power input shafts;
• the first headset gear being in meshing engagement with a countershaft gear for the first countershaft;
• the second headset gear being in meshing engagement with a countershaft gear for the second countershaft;
• a dual clutch assembly for alternately establishing and disestablishing a torque flow path from an engine to the first and second headset gears;
• a first countershaft bearing for supporting the first countershaft at a first distal end within the housing;
• a second countershaft bearing for journaling a second distal end of first countershaft;
• a third countershaft bearing for rotatable supporting the first countershaft at a location disposed intermediate the first and second countershaft bearings whereby the countershaft gear load capacity is improved;
• and
• first and second mainshaft bearings for end supporting the mainshaft within the housing, and a third mainshaft bearing disposed intermediate the first and second mainshaft bearings wherein the third countershaft and the third mainshaft bearing are both located in a common mid-bearing support wall.