Cooling control system for working machine and the working machine

A cooling control system for a working machine, comprising:

• a prime mover having an output shaft;
• a fan to be rotated under rotational power of the output shaft;
• a housing to which the fan is attached;
• a rotor to be rotated under rotational power of the output shaft, the rotor and the housing, under the agency of a fluid introduced into a gap formed between the rotor and the housing, rotating together;
• a fluid setting circuit to determine an injection quantity of the fluid to be introduced into the gap;
• a fan rotation detection device to detect an actual rotation speed of the fan;
• a target rotation obtaining circuit to obtain a target rotation speed of the fan;
• a proportional controlling circuit to execute proportional control with respect to a difference between the actual rotation speed and the target rotation speed;
• an integral controlling circuit to execute integral control with respect to the difference;
• and
• a differential controlling circuit to execute differential control with respect to the difference,
• wherein the integral controlling circuit does not execute the integral control with the difference being greater than or equal to a threshold, and executes the integral control with the difference being less than the threshold.