Self-propelled off-road vehicle with extreme pressure hydraulic propel circuit protection

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;
• and
• a 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, and
• attenuate 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.

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;
• and
• at 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.