Coolant-circulating system for electric machines and the like

Claim 1

A COOLING SYSTEM FOR CIRCULATING LIQUID COOLANT TO AND FROM AN INLET AND AN OUTLET OF A CASING OF AN EDDY-CURRENT ELECTRIC COUPLING HAVING AN EXCITER COIL AND ROTATING PARTS THEREIN, COMPRISING A LIQUID SUMP, A PUMP HAVING A SUPPLY CONNECTION WITH SAID SUMP AND AN OUTLET PRESSURE CONNECTION WITH SAID INLET, RETURN MEANS FROM SAID OUTLET TO SAID SUMP, A CROSS CONNECTION BETWEEN SAID PRESSURE CONNECTION AND SAID RETURN MEANS, SAID CROSS CONNECTION AND THE CASING WHICH HAS SAID ROTATING PARTS THEREIN FORMING PARALLEL-CONNECTED FLOW PATHS BETWEEN THE PUMP AND THE SUMP, A THERMOSTATICALLY CONTROLLED PROPORTIONING VALVE IN SAID CROSS CONNECTION INCLUDING A TEMPERATURE-SENSITIVE ELEMENT RESPONDING TO TEMPERATURE OF THE COOLANT AT THE OUTLET OF THE CASING AND ADAPTED TO CONTROL THE POSITION OF SAID VALVE SUCH THAT FLOW THERETHROUGH IS INCREASED UPON COOLANT TEMPERATURE REDUCTION IN THE CASING, WHEREBY FLOW THROUGH THE CASING IS DECREASED AND WHEREBY FLOW THROUGH SAID CROSS CONNECTION IS DECREASED UPON COOLANT TEMPERATURE INCREASE IN THE CASING WITH INCREASED FLOW THROUGH SAID CASING, AND A MINIMUM-FLOW-RESPONSIVE SWITCH LOCATED IN THE CONNECTION BETWEEN SAID CROSS CONNECTION AND THE INLET ADAPTED TO BE CONNECTED TO DEPRIVE SAID EXCITER COIL OF EXCITATION IN RESPONSE TO LIQUID FLOW BELOW A MINIMUM.