Oil filter

Abstract

An oil filter assembly is disclosed for a machine, such as an internal combustion engine, that has an oil output port and an oil input port. A mounting plate may be fixed with an outer enclosure and may be adapted for securing to the machine. The mounting plate may be further adapted to conduct oil from the machine into a peripheral portion of the outer enclosure, and then returning oil from a central portion of the outer enclosure back to the machine. Oil may pass from the peripheral portion to the central portion through a primary filter having a first porosity. A pressure-actuated valve may be fixed fluidly between the peripheral portion and central portion of the outer enclosure. Oil may pass through the pressure-actuated valve only when an oil pressure differential between the peripheral portion and the central portion of the outer enclosure exceeds a predetermined threshold pressure. A secondary filter may have a second porosity greater than the first porosity, and may be fixed fluidly between the pressure-actuated valve and the central portion of the outer enclosure.

1 .- 18 . (canceled) 
     
     
         19 . A filter assembly, comprising:
 (i) a mounting plate adapted to conduct fluid from an outlet port of an attached machine into the filter assembly via a tapered conduit,   (ii) a primary filter and a secondary filter, wherein the secondary filter is concentrically positioned within the primary filter;   (iii) a pressure-actuated valve situated in the filter assembly, wherein the pressure-actuated valve is movable into an open position in response to a pressure differential; and   (iv) an inlet port configured to receive the filtered fluid from the filter assembly and return the filtered fluid to the attached machine.   
     
     
         20 . The filter assembly of  claim 19 , wherein the primary and secondary filters are each made from titanium mesh, metallic stainless mesh, hybrid ceramic material, Nitronic 60, glass, stainless steel, micro glass, synthetic fibers, or carbon fibers, or a combination thereof. 
     
     
         21 . The filter assembly of  claim 19 , wherein the primary filter has a first porosity and the secondary filter has a secondary porosity. 
     
     
         22 . The filter assembly of  claim 19 , wherein the filter assembly comprises an outer enclosure comprising a peripheral portion and a central portion. 
     
     
         23 . The filter assembly of  claim 22 , wherein the mounting plate is secured to the outer enclosure of the filter assembly. 
     
     
         24 . The filter assembly of  claim 22 , wherein the primary filter is disposed within the outer enclosure such that a fluid in the peripheral portion passes across the primary filter into the central portion. 
     
     
         25 . The filter assembly of  claim 22 , wherein the secondary filter is disposed within the primary filter and between the pressure-actuated valve and the central portion of the outer enclosure. 
     
     
         26 . The filter of  claim 19 , wherein the pressure-actuated valve comprises a ball valve biased in a closed position with a spring. 
     
     
         27 . The filter of  claim 22 , wherein the outer enclosure comprises a plurality of cooling fins protruding radially therefrom. 
     
     
         28 . The filter of  claim 19 , wherein the primary filter comprises an end cap with a threaded aperture for mounting a secondary filter assembly that comprises the secondary filter. 
     
     
         29 . The filter assembly of  claim 28 , wherein the secondary filter assembly comprises a secondary filter housing that at least partially encloses the secondary filter and fixes the secondary filter and the pressure-actuated valve to the end cap with a ball seat and seal plate. 
     
     
         30 . The filter assembly of  claim 29 , wherein the secondary filter housing has a set of threads for engagement with the threaded aperture of the end cap. 
     
     
         31 . The filter assembly of  claim 30 , wherein the primary filter and the secondary filter are threadedly coupled to each other or the secondary filter and the pressure-actuated valve are threadedly coupled to each other. 
     
     
         32 . The filter assembly of  claim 19 , wherein the tapered conduit is at an angle, with respect to a horizontal plane of the mounting plate, of less than 90 degrees. 
     
     
         33 . The filter assembly of  claim 19 , wherein the primary filter is substantially cylindrical and includes an end cap with a threaded aperture for mounting thereto a secondary filter assembly that includes a secondary filter housing, wherein the secondary filter housing at least partially encloses the secondary filter and fixes the secondary filter and the pressure-actuated valve to the end cap with a ball seat and seal plate. 
     
     
         34 . The filter assembly of  claim 19 , wherein when the pressure-actuated valve is in an open position in response to a pressure differential, any fluid that passes through the secondary filter does not pass through the primary filter and any fluid that passes through the primary filter does not pass through the secondary filter. 
     
     
         35 . The filter assembly of  claim 19 , wherein the mounting plate comprises a seal, whereby the seal forms a fluid tight seal between the filter assembly and the attached machine. 
     
     
         36 . The oil filter assembly of  claim 19 , wherein the primary filter has a porosity of less than about 125 microns. 
     
     
         37 . The oil filter assembly of  claim 19 , wherein the secondary filter has a porosity of greater than about 125 microns. 
     
     
         38 . The oil filter assembly of  claim 19 , wherein the primary filter is sandwiched between two semi-rigid protective grids.