Engine oil recirculation system for extended maintenance interval

Abstract

An oil recirculation system includes an engine lubricated by a flow of oil through the engine, a supplemental oil tank arranged to contain a quantity of oil, an oil inlet conduit arranged to fluidly connect the supplemental oil tank and the engine, an oil outlet conduit arranged to fluidly connect the supplemental oil tank and the engine, a first pump operable to pump oil from the supplemental oil tank to the engine through the oil outlet conduit; and a second pump operable to pump oil from the engine to the supplemental oil tank through the oil inlet conduit. wherein the oil inlet conduit is coupled to the supplemental oil tank at a location above where the oil outlet conduit is coupled to the supplemental oil tank.

What is claimed is: 
     
         1 . An oil recirculation system, comprising:
 an engine lubricated by a flow of oil through the engine;   a supplemental oil tank arranged to contain a quantity of oil;   an oil inlet conduit arranged to fluidly connect the supplemental oil tank and the engine;   an oil outlet conduit arranged to fluidly connect the supplemental oil tank and the engine;   a first pump operable to pump oil from the supplemental oil tank to the engine through the oil outlet conduit; and   a second pump operable to pump oil from the engine to the supplemental oil tank through the oil inlet conduit;   wherein the oil inlet conduit is coupled to the supplemental oil tank at a location above where the oil outlet conduit is coupled to the supplemental oil tank.   
     
     
         2 . The oil recirculation system of  claim 1 , wherein the supplemental oil tank further comprises an oil drain separate from the oil outlet conduit, and wherein oil can be selectively drained from the supplemental oil tank through the oil drain. 
     
     
         3 . The oil recirculation system of  claim 2 , further comprising an oil vent conduit coupled to the engine and the supplemental oil tank and configured to equilibrate pressure between the engine and the supplemental oil tank. 
     
     
         4 . The oil recirculation system of  claim 1 , further comprising an oil filter. 
     
     
         5 . The oil recirculation system of  claim 1 , wherein the supplemental oil tank is disposed at least partially above the engine. 
     
     
         6 . The oil recirculation system of  claim 1 , wherein the engine includes an engine sump and the capacity of supplemental oil tank is larger than the capacity of the engine sump. 
     
     
         7 . The oil recirculation system of  claim 1 , wherein the first pump is positioned in-line with the oil inlet conduit, and wherein the second pump is positioned in-line with the oil outlet conduit. 
     
     
         8 . The oil recirculation system of  claim 1 , wherein the first pump and the second pump are positive displacement pumps. 
     
     
         9 . The oil recirculation system of  claim 1 , further comprising:
 a seat arranged to define a forward and a rearward direction, wherein the engine and the supplemental oil tank are located rearward of the seat.   
     
     
         10 . The oil recirculation system of  claim 1 , wherein the supplemental oil tank is made of metal. 
     
     
         11 . A ride-on mower, comprising:
 an engine lubricated by a flow of oil through the engine;   a supplemental oil tank arranged to contain a quantity of oil;   a seat arranged to define a forward and a rearward direction of the ride-on mower, wherein the engine and the supplemental oil tank are located rearward of the seat;   an oil inlet conduit arranged to fluidly connect the supplemental oil tank and the engine;   an oil outlet conduit arranged to fluidly connect the supplemental oil tank and the engine;   a first pump operable to pump oil from the supplemental oil tank to the engine through the oil outlet conduit; and   a second pump operable to pump oil from the engine to the supplemental oil tank through the oil inlet conduit;   wherein the oil inlet conduit is coupled to the supplemental oil tank at a location above where the oil outlet conduit is coupled to the supplemental oil tank.   
     
     
         12 . The engine of  claim 11 , wherein the supplemental oil tank further comprises an oil drain separate from the oil outlet conduit, and wherein oil can be selectively drained from the supplemental oil tank through the oil drain. 
     
     
         13 . The engine of  claim 12 , further comprising an oil vent conduit coupled to the engine and the supplemental oil tank and configured to equilibrate pressure between the engine and the supplemental oil tank. 
     
     
         14 . The engine of  claim 11 , further comprising an oil filter. 
     
     
         15 . The engine of  claim 11 , wherein the supplemental oil tank is disposed at least partially above the engine. 
     
     
         16 . The engine of  claim 11 , wherein the engine includes an engine sump and the capacity of supplemental oil tank is larger than the capacity of the engine sump. 
     
     
         17 . The engine of  claim 11 , wherein the first pump is positioned in-line with the oil inlet conduit, and wherein the second pump is positioned in-line with the oil outlet conduit. 
     
     
         18 . The engine of  claim 11 , wherein the first pump and the second pump are positive displacement pumps. 
     
     
         19 . The engine of  claim 11 , wherein the supplemental oil tank is made of metal.