Six, seven, and eight speed layshaft automatic transmission

摘要

A transmission includes a housing, an input member connectable to an engine output member, and a launch clutch assembly connected to the input member. A first and a second countershaft are rotatably supported within the transmission housing. A plurality of co-planar gear sets are connected to the input member and the first and second countershafts. A plurality of torque transmitting mechanisms are provided for coupling various components of the co-planar gear sets to the input member and countershafts. The selective engagement of the launch clutch assembly and the torque transmitting mechanisms establishes at least one of six forward speed ratios and a reverse speed ratio.

主权项

1. A transmission comprising:
a transmission housing; an input member connectable to a prime mover output member; a first drive gear selectively connectable for common rotation with the input member; a second drive gear rotatably fixed for common rotation with the input member; a launch device connected to the input member and to the first drive gear, wherein the launch device is selectively engageable to transmit torque from the input member to the first drive gear; a first countershaft rotatably supported within the transmission housing and spaced apart from and parallel with the input member; a second countershaft rotatably supported within the transmission housing and spaced apart from and parallel with the input member; a first driven gear in mesh with the first drive gear; a second driven gear selectively connectable for common rotation with the first countershaft and in mesh with the second drive gear; a transfer gear rotatably fixed for common rotation with the first countershaft; a third driven gear selectively connectable for common rotation with the second countershaft and in mesh with the second drive gear; a fourth driven gear selectively connectable for common rotation with the second countershaft and in mesh with the transfer gear; a first output gear selectively connectable for common rotation with the first countershaft; a second output gear selectively connectable for common rotation with the first countershaft; a third output gear selectively connectable for common rotation with the second countershaft; a fourth output gear selectively connectable for common rotation with the second countershaft; two torque transmitting assemblies each for selectively coupling one of the second and third driven gears with one of the first countershaft and the second countershaft; and three synchronizer assemblies each for selectively coupling one of the fourth driven gear, the first output gear, the second output gear, the third output gear, and the fourth output gear with at least one of the first countershaft and the second countershaft, and wherein the selective engagement of the launch device, the two torque transmitting assemblies, and the three synchronizer assemblies establishes at least one of six forward speed ratios and a reverse speed ratio.