Pressurized fluid supply system for an agricultural vehicle

A pressurized fluid supply system for an agricultural vehicle, the system comprising:

• a main supply pump configured to provide a first source of pressurized fluid to a steering system of the vehicle through a steering circuit and to other consumers through a main circuit;
• a cooling fan pump configured to provide a source of a pressurized fluid to a cooling fan motor driving a cooling fan through a cooling fan circuit;
• a prioritization valve configured to regulate flow of fluid from the cooling fan pump to the cooling fan motor, the prioritization valve having at least two operative configurations and movable between the at least two operative configurations in dependence on a fluid pressure in the steering circuit;
• and
• an emergency steering pump fluidly connectable with a fluid reservoir through an emergency steering pump circuit;
• wherein the cooling fan pump is fluidly connectable with the steering circuit to provide a second a source of pressurized fluid to the steering system;
• wherein the prioritization valve is configured to adopt a first operative configuration in which fluid flow from the cooling fan pump to the cooling fan motor through the prioritization valve is substantially unrestricted when the fluid pressure in the steering circuit is at or above a first threshold value and to adopt a second operative configuration in which fluid flow from the cooling fan pump to the cooling fan motor through the prioritization valve is at least partially restricted when the fluid pressure in the steering circuit is below the first threshold value;
• and
• wherein the prioritization valve is operative to regulate the flow of fluid through the emergency steering pump circuit to the fluid reservoir, wherein the emergency steering pump circuit is fluidly connectable with the steering circuit at a position upstream of the prioritization valve, and wherein the flow of fluid from the emergency steering pump through the prioritization valve to the reservoir is substantially unrestricted when the prioritization valve is in either of its first and second operative configurations.

A pressurized fluid supply system for an agricultural vehicle, the system comprising:

• a main supply pump configured to provide a first source of pressurized fluid to a steering system of the vehicle through a steering circuit and to other consumers through a main circuit;
• a cooling fan pump configured to provide a source of pressurized fluid to a cooling fan motor driving a cooling fan through a cooling fan circuit;
• and
• a prioritization valve configured to regulate flow of fluid from the cooling fan pump to the cooling fan motor, the prioritization valve having at least two operative configurations and movable between the at least two operative configurations in dependence on a fluid pressure in the steering circuit;
• wherein the cooling fan pump is fluidly connectable with the steering circuit to provide a second a source of pressurized fluid to the steering system;
• wherein the prioritization valve is configured to adopt a first operative configuration in which fluid flow from the cooling fan pump to the cooling fan motor through the prioritization valve is substantially unrestricted when the fluid pressure in the steering circuit is at or above a first threshold value and to adopt a second operative configuration in which fluid flow from the cooling fan pump to the cooling fan motor through the prioritization valve is at least partially restricted when the fluid pressure in the steering circuit is below the first threshold value;
• wherein one of the cooling fan pump and the cooling fan motor is variable displacement machine, and wherein the fluid supply system further comprises a control system operative to adjust a displacement of the variable displacement machine;
• and
• wherein the control system is operative to adjust the displacement of the variable displacement machine to maintain an input drive power provided by the cooling fan motor to the cooling fan substantially constant.