摘要 |
A multi-range, synchronous shifting, hydromechanical transmission for application in an automotive drivetrain. The transmission receives split power inputs from the engine; one input being geared down (28) to a lower speed for driving a continuously variable hydrostatic transmission unit (22), while the other input drives a counter shaft (46) from which mechanical outputs (34) are taken at different speed ratios. A planetary gear set (58), driven by the hydrostatic transmission unit (22), is shiftable to provide either a low continuously variable speed hydrostatic output, suitable for transmission operation in low output ranges or a high continuously variable speed hydrostatic output, suitable for transmission operation in high output ranges. A gear system (32) includes a plurality of gearsets selectively controlled by clutches and brakes to combine the hydrostatic and the mechanical outputs to produce four continuously variable forward ranges and one continuously variable reverse range. |