초록 ▼

A self-propelled off-road agricultural vehicle is provided with a hydraulic propel circuit protection system. The hydraulic propel circuit protection system reduces extreme pressure buildup from the motors when the pumps and/or motors are rapidly deactivated. The hydraulic propel circuit protection

A self-propelled off-road agricultural vehicle is provided with a hydraulic propel circuit protection system. The hydraulic propel circuit protection system reduces extreme pressure buildup from the motors when the pumps and/or motors are rapidly deactivated. The hydraulic propel circuit protection system may include a propel manifold with integral valving and an accumulator to protect a propel circuit of the self-propelled off-road agricultural vehicle. External relief valves which may be integrated into the propel manifold may limit the high pressure condition on the outlet of the motors to a level that prevents damage to the hydraulic motors and the accumulator provides supplemental flow and thus prevents the extremely low pressure condition from occurring at either side of the motors.

대표청구항 ▼

1. A self-propelled off-road agricultural vehicle with a hydraulic propel circuit protection system reducing pressure buildup, the self-propelled off-road agricultural vehicle comprising: a chassis having wheels for moving the self-propelled off-mad agricultural vehicle and planetary gear sets arran

1. A self-propelled off-road agricultural vehicle with a hydraulic propel circuit protection system reducing pressure buildup, the self-propelled off-road agricultural vehicle comprising: a chassis having wheels for moving the self-propelled off-mad agricultural vehicle and planetary gear sets arranged for rotating the wheels;an application system supported by the chassis and including at least one storage container storing a volume of product for delivery on to an agricultural field;a hydrostatic drivetrain system for delivering power to the wheels and including, an internal combustion engine supported by the chassis,a hydrostatic pump system receiving torque from the internal combustion engine and converting the torque from the internal combustion engine into hydraulic power for use by the hydrostatic drivetrain system;hydraulic motors receiving hydraulic power from the hydrostatic pump system and arranged for delivering power to the planetary gear sets for rotating the wheels, wherein each hydraulic motor has an inlet side receiving hydraulic fluid into the hydraulic motor from the hydrostatic pump system for driving rotation of the wheels and an outlet side releasing hydraulic fluid out of the hydraulic motor toward the hydrostatic pump system; anda hydraulic propel circuit protection system operably connected to each of the hydraulic motors with the hydraulic propel circuit protection system configured toattenuate pressure increases at the outlet side of each hydraulic motor, andattenuate pressure decreases at the inlet side of each hydraulic motor. 2. The self-propelled off-road agricultural vehicle of claim 1 wherein the hydraulic propel circuit protection system is arranged between the hydrostatic pump system and each of the hydraulic motors. 3. The self-propelled off-road agricultural vehicle of claim 2 further comprising a hydraulic distribution manifold defining a propel manifold operably interconnecting the hydrostatic pump system to each of the hydraulic motors and wherein the hydraulic propel circuit protection system is arranged at least partially in the propel manifold. 4. The self-propelled off-road agricultural vehicle of claim 3 wherein during inertial motor driving events that correspond to rapid deactivation of the hydraulic pumps and/or motors, rotational inertia of the wheels and the planetary gear sets inertially drive the hydraulic motors establishing pressure differentials between the inlet and outlet sides of the hydraulic motors; and wherein the hydraulic propel circuit protection system is configured to attenuate the pressure differentials across the inlet and outlet sides of each hydraulic motor by decreasing pressures at the outlet sides of the hydraulic motors and increasing pressures at the inlet sides of the hydraulic motors during the inertial motor driving events. 5. The self-propelled off-road agricultural vehicle of claim 4 wherein the hydraulic propel circuit protection system includes at least one pressure relief valve fluidly connected to the outlet sides of the hydraulic motors and wherein the at least one pressure relief valve is configured to limit pressure of the outlet sides of the hydraulic motors below an upper threshold pressure value in response to pressure increases at the outlet sides of the hydraulic motors during the inertial motor driving events. 6. The self-propelled off-road agricultural vehicle of claim 5 wherein the upper threshold pressure value is 4,500 PSI (pound per square inch). 7. The self-propelled off-road agricultural vehicle of claim 4 wherein the hydraulic propel circuit protection system includes at least one accumulator fluidly connected to the inlet sides of the hydraulic motors and wherein the at least one accumulator is configured to provide supplemental hydraulic fluid flow to the hydraulic motors to maintain minimum pressures on the inlet sides of the hydraulic motors in response to pressure drops at the inlet sides of the hydraulic motors during the inertial motor driving events. 8. The self-propelled off-road agricultural vehicle of claim 4, wherein the hydrostatic pump system includes a tandem pair of variable displacement hydrostatic pumps. 9. The self-propelled off-road agricultural vehicle of claim 8, wherein each of the hydraulic motors is a variable displacement hydraulic motor. 10. The self-propelled off-road agricultural vehicle of claim 1, further comprising a brake system including a brake pedal and service brakes at each of the wheels, wherein depressing the brake pedal sends a deceleration command to the hydrostatic pump system. 11. A self-propelled off-road agricultural vehicle with a hydraulic propel circuit protection system reducing pressure buildup, the self-propelled off-road agricultural vehicle comprising: a chassis having wheels for moving the self-propelled off-road agricultural vehicle;a cab supported by the chassis;planetary gear sets arranged for rotating the wheels;a brake system including a brake pedal provided in the cab and service brakes at each of the wheels;an application system supported by the chassis and including at least one storage container storing a volume of product for delivery on to an agricultural field;a hydrostatic drivetrain system for delivering power to the wheels and including, an internal combustion engine supported by the chassis,a hydrostatic pump system receiving torque from the internal combustion engine and converting the torque from the internal combustion engine into hydraulic power for use by the hydrostatic drivetrain system;hydraulic motors receiving hydraulic power from the hydrostatic pump system and arranged for delivering power to the planetary gear sets for rotating the wheels, wherein each hydraulic motor has an inlet side receiving hydraulic fluid into the hydraulic motor from the hydrostatic pump system for driving rotation of the wheels and an outlet side releasing hydraulic fluid out of the hydraulic motor toward the hydrostatic pump system; anda hydraulic propel circuit protection system operably connected to each of the hydraulic motors with the hydraulic propel circuit protection system configured to,attenuate pressure increases at the outlet side of each hydraulic motor, andattenuate pressure decreases at the inlet side of each hydraulic motor,wherein the hydraulic propel circuit protection system includes at least one pressure relief valve fluidly connected to the outlet sides of the hydraulic motors and wherein the at least one pressure relief valve is configured to limit pressure of the outlet sides of the hydraulic motors below an upper threshold pressure value in response to pressure increases at the outlet sides of the hydraulic motors during an inertial motor driving event. 12. The self-propelled off-road agricultural vehicle of claim 11 wherein the hydraulic propel circuit protection system is arranged between the hydrostatic pump system and each of the hydraulic motors. 13. The self-propelled off-road agricultural vehicle of claim 12 further comprising a hydraulic distribution manifold defining a propel manifold operably interconnecting the hydrostatic pump system to each of the hydraulic motors and wherein the hydraulic propel circuit protection system is arranged at least partially in the propel manifold. 14. The self-propelled off-road agricultural vehicle of claim 13 wherein during the inertial motor driving event that corresponds to rapid deactivation of the hydraulic pumps and/or motors, rotational inertia of the wheels and the planetary gear sets inertially drive the hydraulic motors establishing pressure differentials between the inlet and outlet sides of the hydraulic motors; and wherein the hydraulic propel circuit protection system is configured to attenuate the pressure differentials across the inlet and outlet sides of each hydraulic motor by decreasing pressures at the outlet sides of the hydraulic motors and increasing pressures at the inlet sides of the hydraulic motors during the inertial motor driving events. 15. The self-propelled off-road agricultural vehicle of claim 14 wherein the hydraulic propel circuit protection system includes at least one accumulator fluidly connected to the inlet sides of the hydraulic motors and wherein the at least one accumulator is configured to provide supplemental hydraulic fluid flow to the hydraulic motors to maintain minimum pressures on the inlet sides of the hydraulic motors in response to pressure drops at the inlet sides of the hydraulic motors during the inertial motor driving events. 16. The self-propelled off-road agricultural vehicle of claim 14, wherein the hydrostatic pump system includes a tandem pair of variable displacement hydrostatic pumps. 17. The self-propelled off-road agricultural vehicle of claim 16, wherein each of the hydraulic motors is a variable displacement hydraulic motor. 18. The self-propelled off-road agricultural vehicle of claim 11, wherein depressing the brake pedal sends a deceleration command to the hydrostatic pump system. 19. A method for reducing pressure buildup in self-propelled off-road agricultural vehicle having a chassis including wheels for moving the self-propelled off-road agricultural vehicle, planetary gear sets arranged for rotating the wheels, and an application system supported by the chassis and including at least one storage container storing a volume of product for delivery on to an agricultural field, the method comprising: receiving torque from an internal combustion engine supported by the chassis and converting the torque from the internal combustion engine into hydraulic power for use by a hydrostatic drivetrain system;delivering the hydraulic power from the hydrostatic drivetrain system to hydraulic motors, and delivering power from the hydraulic motors to the planetary gear sets for rotating the wheels, wherein each hydraulic motor has an inlet side receiving hydraulic fluid into the hydraulic motor from the hydrostatic pump system for driving rotation of the wheels and an outlet side releasing hydraulic fluid out of the hydraulic motor toward the hydrostatic pump system; andat least one of attenuating pressure increases at the outlet side of each hydraulic motor and attenuating pressure decreases at the inlet side of each hydraulic motor using a hydraulic propel circuit protection system operably connected to each of the hydraulic motors. 20. The method of claim 19, further comprising limiting pressure of the outlet sides of the hydraulic motors below an upper threshold pressure value in response to pressure increases at the outlet sides of the hydraulic motors during an inertial motor driving event.