Modular power transmission with self-energizing clutch

Claim 1

A power transmission including a plurality of similar, sequentially arranged modules each providing both direct and reduction drive ratios, each of the modules comprising a fixed housing forming a modular portion of the housing for the complete power transmission, an input shaft, an output shaft, the output shaft of each module within the sequence being coupled with the input shaft of the next succeeding module, a planetary gear set having a sun gear, a ring gear and a plurality of planetary gears mounted upon a rotatable carrier and engaged with the ring gear and the sun gear, the input shaft being coupled for rotation with the ring gear and the output shaft being coupled for rotation with the carrier, a reduction brake for selectively locking the sun gear against rotation, a direct drive clutch selectively engageable for causing rotation of the ring gear together with the sun gear, a source of signal fluid under pressure, means for operating both the direct drive clutch and reduction clutch in response to a single fluid pressure signal, and further comprising means securing the fixed housing of the modules together to form an enclosure for the complete power transmission and to assure proper engagement between the output shaft and input shaft for adjacent power transmission modules, a common center shaft extending through the plurality of similar sequentially arranged modules and supporting the planetary gear set of each sequential module, and each of the modular housing portions being penetrated by a passage formed in the lower portion of the housing, the passages of the assembled modular housing providing a common sump for the complete transmission.