Hydro-mechanical transmission and valve assembly
AssigneeDeere & Company
InventorDouglas R. Johnson
Life of this patent
Estimating the term…
Abstract
A hydro-mechanical transmission for an agriculture vehicle, such as a tractor. The transmission includes an input shaft, a hydrostatic unit driven by the input shaft, a mechanical transmission driven by the hydrostatic unit and/or the input shaft, and a valve assembly having a pressure control valve assembly to control an output speed of the hydrostatic unit. A mechanical shift control valve assembly is coupled with the mechanical transmission to selectively engage one of the gear sets of the mechanical transmission and adjust the hydrostatic unit speed.
Claims4
A valve assembly for a hydro-mechanical transmission, the valve assembly comprising:
- a housing at least partially defining a valve support cavity, a first fluid path, and a second fluid path, and a pressure control cavity;
- first and second actuating valves supported by the housing;
- a first control valve movable within the valve support cavity between a first position, where the valve support cavity is fluidly connected with the first actuating valve, and a second position, where the valve support cavity is fluidly connected with the second actuating valve;
- and
- controller movable within the valve support cavity between a first position, where the pressure control cavity has a first volume, and a second position, where the pressure control cavity has a second volume.
Dependencies are inferred from the claim text.