Combination filter arrangment and method

Abstract

A cartridge type filter is mounted in a housing and is serviced through the top of the housing. The cartridge includes first and second media packs axially stacked. The second media pack is in series behind the first media pack, and filters a portion of the liquid therethrough. The second media pack has a higher efficiency than the first media pack. The overall design has a drain system which allows liquid to drain from the interior of the filter housing and back to the sump before the filter cartridge is completely removed from the housing. Other optional features include an oil cooler, various valving, and a filter cartridge lockout mechanism.

1 . A filter cartridge having first and second tubular filter media packs; the cartridge comprising:
 (a) the first tubular filter media pack configured to remove particulate from a first liquid stream by radial flow of the first liquid stream from outside the first tubular media pack to inside the first tubular media pack;   (b) the filter cartridge defining a flow passage axially between the first tubular media pack and the second tubular media pack; the flow passage configured to direct no more than 20% of the volume of the first liquid stream from the inside of the first tubular media pack to a region outside of the second tubular media pack; and   (c) the second tubular filter media pack configured to remove particulate from the no more than 20% of the volume of the first liquid stream from the by radial flow from outside the second tubular media pack to inside the second tubular media pack.   
     
     
         2 . A filter cartridge according to  claim 1  wherein:
 (a) the flow passage is defined by an endcap joining the first tubular filter media pack and the second tubular filter media pack. 
 
     
     
         3 . A filter cartridge according to  claim 1  wherein:
 (a) the second tubular filter media pack has a higher efficiency than the first tubular filter media pack. 
 
     
     
         4 . A filter cartridge according to  claim 1  wherein:
 (a) the first and second tubular filter media packs are cylindrical in shape; and 
 (b) the first tubular filter media pack has a larger diameter than the second tubular filter media pack. 
 
     
     
         5 . A filter cartridge according to  claim 1  wherein:
 (a) the first tubular filter media pack has an axial length greater than an axial length of the second tubular filter media pack. 
 
     
     
         6 . A filter cartridge according to  claim 1  wherein:
 (a) the first and second tubular filter media packs comprise pleated media. 
 
     
     
         7 . A filter cartridge according to  claim 1  wherein:
 (a) the first and second tubular filter media packs are co-axially aligned. 
 
     
     
         8 . A filter assembly comprising the filter cartridge according to  claim 1  and:
 (a) a base assembly including a base housing defining an interior; the filter cartridge being operably and removably mounted in the interior of the base housing; and
 (i) the base assembly including a port assembly in communication with the base housing; 
 (ii) the base assembly including a lube cooler assembly operably connected to the port assembly; 
 
 (b) a cover removably oriented on the base housing; the cover being selectively removable to allow access to the interior of the base housing and access to the removable filter cartridge. 
 
     
     
         9 . A filter assembly according to  claim 8  further comprising:
 (a) a housing insert operably oriented in the interior of the base housing; the insert including an insert surrounding wall defining an insert interior, an open mouth providing access to the insert interior, an insert bottom defining a first opening and a valve-receiving opening; and
 (i) wherein the filter cartridge is operably installed in the housing insert such that the second tubular filter media pack is located within the insert interior while the first tubular filter media pack is located outside of the insert interior; and 
 
 (b) a combination valve within the valve-receiving opening of the insert;
 (i) the combination valve controlling the amount of fluid being allowed to flow through the second media pack and also preventing fluid to drain from the base housing when there is no flow of fluid through the filter assembly. 
 
 
     
     
         10 . A filter assembly according to  claim 8  wherein:
 (a) the port assembly includes:
 (i) a first lube chamber downstream from a lube pump; 
 (ii) a second lube chamber downstream of the first lube chamber and upstream of and in communication with the lube cooler assembly; 
 (iii) a cooled lube inlet chamber downstream of and in communication with the lube cooler assembly;
 (A) the cooled lube inlet chamber being immediately upstream of the filter cartridge assembly; 
 
 (iv) a lube sump chamber downstream of the filter cartridge assembly and upstream of the lube sump; 
 (v) a first coolant chamber upstream of the lube cooler and in communication with the lube cooler; and 
 (vi) a second coolant chamber downstream of the lube cooler and in communication with the lube cooler. 
 
 
     
     
         11 . A filter assembly according to  claim 10  further including:
 (a) an anti-drain valve assembly operably oriented within the port assembly and controlling the flow of lube between the first lube chamber and the second lube chamber; and 
 (b) a lube cooler bypass valve assembly controlling the flow of lube between the first lube chamber and the cooled lube inlet chamber. 
 
     
     
         12 . A filter assembly according to  claim 8  further comprising:
 (a) a drain mechanism to drain the base housing of liquid before the filter cartridge assembly is removed from the base housing.