Electro-hydraulic system for fan driving and brake charging
AssigneeCaterpillar Inc.
InventorsXiaodong Huang, Rabie E. Khalil, John James Krone
Life of this patent
Estimating the term…
Abstract
An electro-hydraulic system for a machine may include a brake charging system including at least one accumulator. A fan drive system may include a fan and a fan motor. A fluid source may be in communication with the brake charging system and the fan drive system. The fluid source may be configured to provide pressurized fluid to the brake charging system and the fan drive system to charge at least one accumulator and to drive a fan motor. A priority valve may be configured to provide pressure from the fluid source to the brake charging system, such that the fluid pressure at the accumulator is maintained at a substantially constant level during normal operating conditions.
Claims25
An electro-hydraulic system for a machine comprising:
- a brake charging system including at least one accumulator configured to store fluid pressure for brake control;
- a fan drive system including a fan and a fan motor, the fan motor being configured to turn the fan;
- a fluid source in communication with the brake charging system and the fan drive system, the fluid source being configured to provide pressurized fluid to the brake charging system and the fan drive system to charge the at least one accumulator and to drive the fan motor;
- and
- a priority valve configured to provide pressure from the fluid source to the brake charging system, such that the fluid pressure at the accumulator is maintained at a substantially constant level during normal operating conditions, wherein the priority valve is a three-position, pressure driven valve.
An electro-hydraulic system for a machine comprising:
- a brake charging system including at least one accumulator configured to store fluid pressure for brake control;
- a fan drive system including a fan and a fan motor, the fan motor being configured to turn the fan;
- a fluid source in communication with the brake charging system and the fan drive system, the fluid source being configured to provide pressurized fluid to the brake charging system and the fan drive system to charge the at least one accumulator and to drive the fan motor;
- and
- a priority valve configured to provide pressure from the fluid source to the brake charging system, such that the fluid pressure at the accumulator is maintained at a substantially constant level during normal operating conditions, wherein the priority valve includes a fan-only position and a shared-flow position, the priority valve being configured to shift between the fan-only position and the shared-flow position.
An electro-hydraulic system for a machine comprising:
- a brake charging system including at least one accumulator configured to store fluid pressure for brake control;
- a fan drive system including a fan and a fan motor, the fan motor being configured to turn the fan;
- a fluid source in communication with the brake charging system and the fan drive system, the fluid source being configured to provide pressurized fluid to the brake charging system and the fan drive system to charge the at least one accumulator and to drive the fan motor;
- and
- a priority valve configured to provide pressure from the fluid source to the brake charging system, such that the fluid pressure at the accumulator is maintained at a substantially constant level during normal operating conditions, wherein the fan drive system includes a reversing valve operable to reverse the flow of fluid through the fan motor to change a rotational direction of the fan.
An electro-hydraulic system for a machine comprising:
- a brake charging system including at least one accumulator configured to store fluid pressure for brake control;
- a fan drive system including a fan and a fan motor, the fan motor being configured to turn the fan;
- a fluid source in communication with the brake charging system and the fan drive system, the fluid source being configured to provide pressurized fluid to the brake charging system and the fan drive system to charge the brake system and to drive the fan motor;
- and
- a priority valve disposed between the fluid source and the brake charging system and also disposed between the fluid source and the fan drive system, the priority valve being configured to permit flow sharing between the brake charging system and the fan drive system.
The electro-hydraulic system of 11, wherein the fan drive system includes a reversing valve operable to reverse the flow of fluid through the fan motor to change a rotation direction of the fan.
A method of operating an electro-hydraulic system for a machine, comprising:
- directing fluid to a brake charging system including at least one accumulator configured to store fluid pressure for brake control;
- directing fluid to a fan drive system including a fan motor the fan motor being configured to turn the fan;
- providing pressurized fluid to the brake charging system and the fan drive system with a fluid source to charge the least one accumulator and to the fan motor;
- maintaining the fluid pressure at the accumulator at a substantially constant level during normal operating conditions;
- and
- providing flow sharing between the brake charging system and the fan drive system.
A method of operating an electro-hydraulic system for a machine, comprising:
- directing fluid to a fan drive system including a fan and a fan motor, the fan motor being configured to turn the fan;
- providing pressurized fluid to the fan drive system with a fluid source to drive the fan motor;
- reducing a rotational speed of the fan below a pre-established threshold;
- and
- activating a reversing valve configured to reverse the rotational direction of the fan.
Dependencies are inferred from the claim text.