Cooling system for a turbomachine speed reducer

In a turbomachine including at least one air intake scoop, an internal gas flow path, an exhaust nozzle, a speed reducer which is arranged to be lubricated by a lubricant, and a cooling system for said lubricant, said cooling system comprising:

• a lubricant circuit for flow of lubricant to and from said speed reducer;
• a radiator located in said lubricant circuit and configured to dissipate heat from said lubricant as said lubricant flows through said radiator;
• an air supply duct leading to said radiator;
• at least one air take-off slot having a very reduced cross-section, as compared with a cross-section of said at least one air intake scoop, and being disposed in said at least one air intake scoop of the turbomachine, said at least one air take-off slot communicating with and feeding air to said air supply duct;
• a compressed air take-off duct connected to a compressor in said internal gas flow path of the turbomachine and opening into an air discharge duct through a lobe type ejector-mixer in order to accelerate an air flow through said cooling system;
• and
• a control valve configured to control said compressed air take-off duct and controlled by a control unit of the turbomachine.