Hydraulic driving device of suction car

A hydraulic driving device of a suction car, comprising:

• a first HST circuit including a first traveling motor, a first traveling drive pump, a first connection channel that connects between the first traveling drive pump and the first traveling motor, and a second connection channel that connects between the first traveling drive pump and the first traveling motor via a different route from the first connection channel and cooperates with the first connection channel to connect between the first traveling drive pump and the first traveling motor in a closed circuit;
• a suction actuator configured to suction drive a suction device by being actuated by a hydraulic pressure;
• a supply channel that supplies oil to the suction actuator;
• and
• a switching valve switchable to a first operation state and a second operation state, the switching valve allowing oil discharged from the first traveling drive pump to the first connection channel to be supplied to the first traveling motor in the first operation state and allowing oil discharged from the first traveling drive pump to the first connection channel to flow into the supply channel and be supplied to the suction actuator in the second operation state.