Hydraulic braking energy utilization for emergency steering, braking, charging accumulator(s), and/or work functions to reduce or prevent engine from overspeed, assist acceleration and/or unlimited towing

A method of controlling a hydraulic drive of a machine;

• said hydraulic drive includes a) a pump adapted to be driven by a prime motor of said machine, b) a secondary motor that is fluidly coupled to said pump by a supply line and a return line;
• said secondary motor includes a high-pressure port side, and c) a first work function circuit that is fluidly coupled to said supply line and said return line;
• said method comprising:
• directing at least a portion of a pressurized fluid output from said high-pressure port side of said secondary motor to a heat control circuit;
• returning said pressurized fluid back to said high-pressure port side of said secondary motor when said secondary motor is running as a secondary pump;
• activating first and second pressure valves after a predetermined pressure is sensed to facilitate in redirecting said pressurized fluid to said heat control circuit;
• and
• providing a signal from a pressure transducer to activate said first and second pressure valves;
• wherein said directing and returning inhibits overspeeding in said secondary motor.

A hydrostatic propulsion system in a machine;

• said system comprising:
• a hydraulic circuit;
• said hydraulic circuit includes:
• a pump that is configured to be driven by a prime motor;
• a secondary motor that is fluidly coupled to said pump by a supply line and a return line;
• said secondary motor includes a high-pressure port side;
• said secondary motor is configured to run as a secondary pump;
• a fluid output from said secondary motor;
• a first work function circuit that is fluidly coupled with said supply line and said return line;
• said first work function circuit includes a prime motor control circuit that is configured to a) minimize overspeeding in said prime motor, b) assist in acceleration, and/or c) permit towing;
• said first work function circuit includes i) a first pressure transducer, ii) first and second pressure valves, and iii) a pressure reducing valve;
• said first and second pressure valves are configured to be activated at a predetermined pressure and to at least partially redirect fluid from said secondary motor to a heat control circuit;
• said pressure reducing valve includes a preset setting;
• said pressure reducing valve is configured to allow fluid to be directed to a fluid accumulator when a pressure of said fluid is at said preset setting or exceeds said preset setting;
• said first pressure transducer is configured to cause at least one of said first and second pressure valves to be activated when said fluid accumulator is charged at a certain level to thereby direct at least a portion of said fluid to said heat control circuit;
• said heat control circuit is configured to reduce heat generation;
• said heat control circuit includes one or more of a fan pump and a fan motor, and
• a valving arrangement that is operative for directing at least a portion of said fluid output from said secondary motor during braking operations to said heat control circuit.