Hydraulic system with smart relief valve and valve control method
AssigneeDana Italia S.R.L.
InventorsMario Gelmini, Lorenzo Dalla Palma
Life of this patent
Estimating the term…
Abstract
Methods and systems for a transmission are provided herein. In one example, a hydraulic system is provided that includes a boost pump, a relief valve in fluidic communication with the boost pump and a reservoir, and a plurality of control valves in fluidic communication with the boost pump, positioned downstream of the relief valve, and in fluidic communication with a plurality of hydraulic devices. The hydraulic system further includes a controller designed to actively adjust a position of the relief valve based on an aggregate hydraulic pressure demand of the plurality of hydraulic devices to alter a boost pressure of a hydraulic fluid supplied to the plurality of control valves.
Claims20
A transmission system, comprising:
- a boost pump;
- a relief valve in fluidic communication with the boost pump and a reservoir;
- a plurality of control valves in fluidic communication with the boost pump, positioned downstream of the relief valve, and in fluidic communication with a plurality of hydraulic devices;
- and
- a controller including:
- instructions that when executed, during transmission operation, cause the controller to:
- actively adjust a position of the relief valve based on an aggregate hydraulic pressure demand of the plurality of hydraulic devices to alter a boost pressure of a hydraulic fluid supplied to the plurality of control valves;
- and
- instructions that when executed, during an engine cranking event, cause the controller to:
- operate the relief valve to decrease the boost pressure to a lower pressure.
A method for operation of a transmission system, comprising:
- actively adjusting a position of a relief valve based on an aggregate hydraulic pressure demand of a plurality of hydraulic devices to alter a boost pressure of a hydraulic fluid supplied to a plurality of control valves;
- and
- during an engine cranking event, operating the relief valve to decrease the boost pressure to a lower pressure;
- wherein the transmission system includes:
- a boost pump;
- the relief valve in fluidic communication with the boost pump and a reservoir;
- and
- the plurality of control valves in fluidic communication with the boost pump, positioned downstream of the relief valve, and in fluidic communication with the plurality of hydraulic devices.
A hydromechanical variable transmission (HVT) system, comprising:
- a hydraulic pump;
- a relief valve in fluidic communication with the hydraulic pump and a reservoir;
- a plurality of control valves in fluidic communication with the hydraulic pump, positioned downstream of the relief valve, and in fluidic communication with a hydraulic clutch and a hydrostatic pump;
- and
- a controller including instructions that when executed, during transmission operation, cause the controller to:
- determine an aggregate hydraulic pressure demand of the hydraulic clutch and the hydrostatic pump;
- and
- actively adjust a position of the relief valve based on the aggregate hydraulic pressure demand to augment a boost pressure of a hydraulic fluid supplied to the plurality of control valves.
Dependencies are inferred from the claim text.