Engine oil recirculation system for extended maintenance interval

Abstract

An oil recirculation system for an internal combustion engine includes an oil sump for storage of engine oil, a supplemental oil tank configured for storage of supplemental engine oil therein, and a conduit configured to fluidly couple the supplemental oil tank and the oil sump such that supplemental engine oil from the supplemental oil tank is selectively delivered to the oil sump and engine oil is selectively extracted from the oil sump and delivered to the supplemental oil tank. The system is configured to deliver supplemental engine oil to the oil sump from the supplemental oil tank and extract engine oil from the oil sump to the supplemental oil tank during a predetermined time period.

What is claimed is: 
     
         1 . An oil recirculation system for an internal combustion engine, the system comprising:
 an oil sump for storage of engine oil;   a supplemental oil tank configured for storage of supplemental engine oil therein;   a conduit configured to fluidly couple the supplemental oil tank and the oil sump such that supplemental engine oil from the supplemental oil tank is selectively delivered to the oil sump and engine oil is selectively extracted from the oil sump and delivered to the supplemental oil tank;   wherein the system is configured to deliver supplemental engine oil to the oil sump from the supplemental oil tank and extract engine oil from the oil sump to the supplemental oil tank during a predetermined time period.   
     
     
         2 . The oil recirculation system of  claim 1 , wherein the supplemental engine oil is delivered to the oil sump only when the internal combustion engine is in a nonoperational state for a predetermined period of time. 
     
     
         3 . The oil recirculation system of  claim 1  further comprising a controller to control the delivery and extraction of engine oil when the internal combustion engine is in a nonoperational state. 
     
     
         4 . The oil recirculation system of  claim 1  further comprising an electric gear pump placed in-line with the conduit to pump supplemental oil from the supplemental oil tank into the oil sump and to pump engine oil out of the oil sump and into the supplemental oil tank. 
     
     
         5 . The oil recirculation system of  claim 1  further comprising a positive displacement pump placed in-line with the conduit to pump supplemental oil from the supplemental oil tank into the oil sump and to pump engine oil out of the oil sump and into the supplemental oil tank. 
     
     
         6 . The oil recirculation system of  claim 1  further comprising an anti-siphon chamber placed in-line with the conduit to prevent unwanted extraction of oil from the supplemental oil tank. 
     
     
         7 . The oil recirculation system of  claim 1  further comprising an oil tube within the oil sump and fluidly coupled to the conduit, wherein the oil tube has an open end not coupled to the conduit that is positioned within the sump at or near a desired oil level within the sump. 
     
     
         8 . The oil recirculation system of  claim 7  wherein the oil tube enters the oil sump through an engine oil drain port. 
     
     
         9 . The oil recirculation system of  claim 7  wherein the open end of the oil tube is positioned near a central point in an oil volume of the oil sump. 
     
     
         10 . An oil recirculation system for an engine having an oil sump that contains a first quantity of oil, the system comprising:
 a supplemental oil tank operable to contain a second quantity of oil;   a conduit arranged to fluidly connect the supplemental oil tank and the oil sump; and   a pump operable to at least one of pump oil from the supplemental oil tank to the oil sump and pump oil from the oil tank to the supplemental oil tank.   
     
     
         11 . The oil recirculation system of  claim 10 , wherein the supplemental oil tank includes a polymer container. 
     
     
         12 . The oil recirculation system of  claim 10 , wherein the supplemental oil tank is positioned above the oil sump. 
     
     
         13 . The oil recirculation system of  claim 12 , wherein the supplemental oil tank is operable to deliver oil to the oil sump via a gravity feed. 
     
     
         14 . The oil recirculation system of  claim 12 , wherein the pump is operable to pump oil from the oil sump to the supplemental oil tank. 
     
     
         15 . The oil recirculation system of  claim 10 , wherein the supplemental engine oil is delivered to the engine only after the engine is in a nonoperational state for a predetermined period of time. 
     
     
         16 . The oil recirculation system of  claim 10  further comprising a controller to control the delivery and extraction of engine oil when the engine is in a nonoperational state. 
     
     
         17 . The oil recirculation system of  claim 10  wherein the pump includes an electric gear pump placed in-line with the conduit to pump supplemental oil from the supplemental oil tank into the oil sump and to pump engine oil out of the oil sump and into the supplemental oil tank. 
     
     
         18 . A method of extending the life of an oil supply for an engine, the method comprising:
 providing a first quantity of oil in an oil sump;   drawing oil from the oil sump during engine operation to cool and lubricate the engine;   periodically adding a second quantity of oil from a supplemental oil tank when the engine is not running; and   pumping about the second quantity of oil from the sump in conjunction with the addition of oil from the supplemental oil tank to return the amount of oil in the sump to about the first quantity.   
     
     
         19 . The method of  claim 18 , wherein the adding a second quantity of oil occurs only when the engine is in a nonoperational state for a predetermined period of time. 
     
     
         20 . The method of  claim 18 , wherein the adding a second quantity of oil step occurs under the force of gravity alone.