Abstract: A hydro-mechanical transmission assembly includes a hydrostatic pump-motor assembly having a variable displacement hydrostatic pump. The pump has a primary input shaft configured to be operatively driven by a prime mover. The hydrostatic pump-motor assembly also includes a hydraulic motor fluidly coupled to and operatively driven by the hydrostatic pump. The motor has a primary output shaft that is bi-directionally rotatable with change in displacement of the pump. The primary output shaft is coupled to a secondary input shaft of a multi-speed transmission, wherein the multi-speed transmission includes one of: a counter-shaft transmission system, a multi-stage planetary gear set, and a power-shift transmission system that includes a combination of the counter-shaft transmission system and the multi-stage planetary gear set. This way, a secondary output shaft of the multi-speed transmission is configured to operate with discrete speed ratios in relation to the primary output shaft of the hydraulic motor.

Abstract: A hydraulic piston system includes a housing that defines a piston pocket and a fluid inlet. A piston with a peripheral region and an end is movable within the piston pocket of the housing. The end of the piston has peripheral defined channels and a portion structured and arranged to engage the housing to limit travel of the piston. Further, a seal is configured to seal the peripheral region of the piston against the piston pocket. The seal is structured and arranged to receive fluid pressure when the piston is positioned with the portion of the piston is in engagement with the housing and fluid communication exists between the fluid inlet and the seal through the peripheral defined channels.