Cooling system for machine having radiator assembly and method

Abstract

A cooling system for a machine includes a radiator assembly having a tank access port, and an overflow port formed in a radiator tank. A solid cap is coupled with the radiator tank to seal the tank access port, and a valve mechanism is coupled with the radiator tank. The valve mechanism includes a pressure relief valve and a coolant return valve operable to fluidly connect the radiator tank with a recovery bottle responsive to a pressurized or a vacuum state of the radiator tank, respectively.

1 . A cooling system for a machine comprising:
 a radiator assembly including a radiator tank having formed therein a tank access port, an overflow port, and a plurality of coolant circulation ports, for connecting with a coolant circulation loop;   a recovery bottle;   a vent line fluidly connected with the recovery bottle;   the radiator assembly further including a cap coupled with the radiator tank to seal the tank access port, and a valve mechanism;   the valve mechanism including a valve body attached to the radiator tank and having formed therein an inlet fluidly connected with the overflow port, and an outlet fluidly connected with the recovery bottle by way of the vent line;   the valve mechanism further including a pressure relief valve positioned fluidly between the inlet and the outlet and having a first valve opening surface, and a coolant return valve positioned fluidly between the inlet and the outlet and having a second valve opening surface;   the first valve opening surface being exposed to a fluid pressure of the inlet, such that the pressure relief valve opens in response to a pressure drop from the inlet to the outlet, to convey coolant from the radiator tank to the recovery bottle;   the second valve opening surface being exposed to a fluid pressure of the outlet, such that the coolant return valve opens in response to a pressure drop from the outlet to the inlet, to convey coolant from the recovery bottle to the radiator tank; and   the valve mechanism further including a first biaser contacting the pressure relief valve and holding the pressure relief valve in a closed position, and a second biaser contacting the coolant return valve and holding the coolant return valve in a closed position.   
     
     
         2 . The system of  claim 1  further comprising a thermostat assembly including a recirculation valve, and a recirculation line extending between the recirculation valve and one of the plurality of coolant circulation ports. 
     
     
         3 . The system of  claim 1  wherein the radiator tank defines a vertical axis, and wherein a first one of the plurality of coolant circulation ports is positioned vertically higher than a second one of the plurality of coolant circulation ports, and the recovery bottle includes a bottle inlet positioned vertically lower than the overflow port. 
     
     
         4 . The system of  claim 3  wherein the overflow port is positioned vertically lower than the tank access port. 
     
     
         5 . The system of  claim 1  wherein the cap includes a solid cap having an unperforated metallic body with a pressure side, and an ambient side, and a non-metallic sealing member sandwiched between the pressure side and the radiator tank. 
     
     
         6 . (canceled) 
     
     
         7 . The system of  claim 1  wherein the valve body defines a longitudinal axis, and each of the pressure relief valve and the coolant return valve has a fixed angular orientation about the longitudinal axis. 
     
     
         8 . The system of  claim 7  wherein the pressure relief valve has a first valve opening pressure based at least in part upon a size of the first valve opening surface and a stiffness of the first biaser, and the coolant return valve has a second valve opening pressure based at least in part upon a size of the second valve opening surface and a stiffness of the second biaser, and wherein the first valve opening pressure is greater than the second valve opening pressure. 
     
     
         9 . The system of  claim 8  wherein the pressure relief valve is movable in a first opening direction within the valve body and the coolant return valve is movable in a second opening direction within the valve body that is opposite to the first opening direction. 
     
     
         10 . A radiator assembly comprising:
 a radiator tank including an inner surface defining an internal fluid space, and an outer surface, and having formed therein a plurality of coolant circulation ports, a tank access port, and an overflow port;   a cap coupled with the radiator tank at the tank access port and blocking fluid flow through the tank access port;   a vent line;   a valve mechanism coupled with the radiator tank at the overflow port, and including a valve body having formed therein an inlet fluidly connected with the overflow port, and an outlet fluidly connected to the vent line to fluidly connect with a recovery bottle;   the valve mechanism further including a pressure relief valve having a first valve opening surface, and a coolant return valve having a second valve opening surface;   the valve mechanism being in a first state where the first valve opening surface is exposed to a fluid pressure of the inlet, the second valve opening surface is exposed to a fluid pressure of the outlet and the valve mechanism inhibits fluid flow through the overflow port; and   the valve mechanism being adjustable to a second state to permit fluid flow through the overflow port by way of opening the pressure relief valve responsive to a pressure drop from the inlet to the outlet or to a third state to permit fluid flow through the overflow port by way of opening the coolant return valve in response to a pressure drop from the outlet to the inlet;   the radiator tank defining a vertical axis, and wherein a first one of the plurality of coolant circulation ports is positioned vertically higher than a second one of the plurality of coolant circulation ports; and   the overflow port being positioned vertically lower than the tank access port, and wherein the cap is attached to a top of the radiator tank and the valve body is attached to a side of the radiator tank such that the valve mechanism conveys coolant between the radiator tank and the vent line at the location that is vertically lower than the tank access port.   
     
     
         11 . The assembly of  claim 10  wherein the pressure relief valve is movable in a first opening direction within the valve body and the coolant return valve is movable in a second opening direction within the valve body that is opposite to the first opening direction. 
     
     
         12 . The assembly of  claim 11  wherein the pressure relief valve is nested with the coolant return valve. 
     
     
         13 . The assembly of  claim 12  further comprising a first biaser biasing the pressure relief valve toward a closed position, and a second biaser biasing the coolant return valve toward a closed position. 
     
     
         14 . The assembly of  claim 13  wherein the first biaser is held in compression between the pressure relief valve and the valve body, and the second biaser is held in compression between the coolant return valve and the pressure relief valve. 
     
     
         15 . The assembly of  claim 10  wherein the valve body defines a longitudinal axis extending between a first axial end and a second axial end, and wherein the inlet is formed in the first axial end and the outlet is formed in the second axial end. 
     
     
         16 . The assembly of  claim 15  wherein the valve body includes a connector located at the first axial end and including a first set of threads, and the radiator tank includes a second set of threads extending circumferentially around the overflow port and mated with the first set of threads, and wherein the valve body further includes a second connector located at the second axial end and having the outlet formed therein. 
     
     
         17 . The assembly of  claim 16  wherein the first set of threads include external threads, and wherein the connector has a tapered shape such that the first set of threads forms a tapered profile. 
     
     
         18 . (canceled) 
     
     
         19 . The assembly of  claim 10  wherein the cap includes a solid cap having an unperforated metallic body with a pressure side, and an ambient side, and a non-metallic sealing member sandwiched between the pressure side and the radiator tank. 
     
     
         20 . A method of operating a cooling system for a machine comprising:
 conveying a coolant between a radiator and a coolant circulation loop structured to exchange heat with a machine;   increasing a temperature and a pressure of the coolant within the cooling system by way of the exchange of heat;   opening a pressure relief valve in a valve mechanism attached to a side of the radiator at an overflow port in response to the increase in pressure;   venting an excess volume of the coolant produced in response to the increase in temperature to a recovery bottle by way of the pressure relief valve;   decreasing the temperature and the pressure of the coolant such that a volume of the coolant is reduced;   opening a coolant return valve in the valve mechanism in response to the decrease in pressure;   returning coolant to the radiator by way of the coolant return valve; and   inhibiting leakage of coolant and air through a tank access port during the venting of the excess volume of coolant and the returning of the coolant to the radiator by way of a solid cap attached to a top of the radiator and fluidly sealing the tank access port.