Cooling apparatus of hybrid vehicle, including serially-connected cooling systems for electric devices which have different heat resisting allowable temperatures

A cooling apparatus built into a hybrid vehicle, comprising:

• an engine radiator connected to an engine cooling system which cools an engine by circulating a refrigerant, wherein the engine outputs a driving force of the vehicle;
• a radiator cooling fan which faces the engine radiator;
• a cooling circuit including a plurality of serially-connected cooling systems for cooling a plurality of electric devices by circulating a refrigerant, wherein the electric devices include at least a motor for outputting driving force according to a driving state of the vehicle, a battery system, and an inverter for supplying electric power to the motor;
• a circulating pump for circulating the refrigerant through the cooling circuit;
• and
• an electric device radiator which is serially connected to the cooling systems in the cooling circuit and has a refrigerant outlet from which a refrigerant is supplied, wherein:
• the serially-connected cooling systems are arranged in a manner such that heat resisting allowable temperatures, assigned to the electric devices which respectively correspond to the cooling systems, increase from the cooling system closest to the refrigerant outlet to the cooling system farthest from the refrigerant outlet in the cooling circuit, wherein each heat resisting allowable temperature is the maximum temperature at which the relevant electric device can operate.