NONMETALLIC CLEAN SIDE SPIN-ON FILTER

Abstract: Spin-on filters are useful, for example, in cleaning impurities from fluid being circulated through a mechanism. Failure to properly clean the metal components on the clean side of the commercially available filters results in metal particles being dislodged and carried directly into the mechanism receiving the clean fluid. The subject spin-on filter (10) uses only nonmetallic components on the clean side of the filter so that the cleaned fluid does not come in contact with any metal components of the filter. The nonmetallic particles generated by the manufacturing of the nonmetallic components are readily removed from the nonmetallic components and any such particles not removed by cleaning and carried into the mechanism by the clean fluid are soft enough that they will not damage the mechanism receiving the filtered fluid.

Description: Description Nonmetallic Clean Side Spin-On Filter Technical Field This invention relates to spin-on fluid filters and more particularly to spin-on fluid filters having an outside/in flow pattern and only nonmetallic components on the clean side of the filter element. 10 Background Art The commercially available industrial type spin-on fluid filters generally have a metal end plate or a filter element having a metal center tube or ] _5 both. The center tube commonly has a multiplicity of holes punched therein while the end plate commonly has a thread machined therein for receiving the threaded tubular mounting stud. One of the problems encountered with those filters is the presence of minute metal 2o particles resulting from the process of making the metal components. Such minute metal particles tend to adhere to the metal components and if the metal components are not cleaned properly, some of the metal particles remain attached thereto even after the metal 25 components are assembled into a completed spin-on filter. The metal particles that remain attached to the metal components are then frequently dislodged therefrom when the filter is screwed onto the threaded mounting stud or are flushed therefrom by the fluid 30 passing through the filter after the filter is put in use. In the outside/in type of filter, the metal components are on the clean side of the filter element such that the fluid carries the metal particles directly into the mechanism that the filter is supposed 35 to protect. The presence of metal particles in the fluid going to the mechanism generally results in early failure of the mechanism due to damaged bearings, valves, blocked orifices, and so forth. The present invention is directed to overcoming one or more of the problems as set forth above. Disclosure of the Invention In one aspect of the present invention, a spin-on filter of the outside/in type includes a generally cylindrical housing having an open end and a closed end. A generally cylindrical filter element disposed within the housing has a closed end at the closed end of the housing and an open end adjacent the open end of the housing. A nonmetallic perforated center tube is included as an integral part of the filter element. A cover means closes the open end of the housing and includes a cylindrical portion which sealingly extends into the open end of the filter element and has a bore extending therethrough with a portion of the bore being threaded. The cylindrical portion of the cover means is a nonmetallic material. The problem of flushing metal particles from a new filter directly into the mechanism that the filter is supposed to protect is solved by replacing the metal center tube with a nonmetallic center tube and modifying the end plate so that the cleaned fluid does not contact any metal components of the filter. The manufacturing of the nonmetallic components generate less minute particles than the manufacturing process performed on the comparable metal components and any particles that are generated do not have a tendency to adhere to the nonmetallic component. Moreover, even if the minute nonmetallic particles are not properly cleaned from the nonmetallic components, such nonmetallic particles are relatively soft and are washed through the mechanism without causing damage. Brief Description of the Drawings Fig. 1 is an end view of an embodiment of the present invention; Fig. 2 is a cross-sectional view taken along line II-II of Fig. 1; and Fig. 3 is a fragmentary sectional view taken along line III-III of Fig. 2. Best Mode for Carrying Out the Invention Referring now to the drawings, a spin-on filter 10 includes a generally cylindrical housing 11 having an open end 12 and a closed end 13. The housing 10 is generally of thin wall construction and is typically formed by stamping or drawing. A filter element 14 is disposed within the housing 11 and has an open end 16 adjacent the open end of the housing 10 and a closed end 17 seated on the closed end of the housing. The filter element 14 includes a perforated center tube 18, a corrugated or pleated paper filter media wrapped around the center tube 18 and upper and lower end caps 21,22. A fiberglass roving 23 covered with hot melt is spirally wrapped around the filter media 19 such that the hot melt adheres to the tips of the corrugations to prevent distortion and displacement thereof. The lower end cap 22 extends across and closes the bottom end of the filter media 19 and center tube 18 while the upper end cap 21 has a central opening 24 therein. The end caps are made of plastic such as urethane and are typically potted in place to become integrally, sealingly bonded to the axial ends of the pleated filter media. The center tube 18 is made from any suitable nonmetallic material and in the present embodiment is made of cellulose impregnated with phenolic resin. A rigid end plate 26 is disposed in and closes the open end 12 of the housing 11. The end plate has a central hub portion 27 and a flat outwardly facing annular surface 28 spaced radially outwardly from the hub portion 12. The inwardly facing side of the end plate 26 has a plurality of radially outwardly extending reinforcing ribs 29. The end plate 26 has a plurality of inlet ports 31 generally circumferentially spaced about the hub portion 27 and between the ribs 29. A pocket 32 in the end plate has a noncircular cross-sectional shape and opens toward the inside of the filter 10. The pocket 32 in this embodiment has a polygonal shape and terminates at a radially inwardly extending flange 33 which defines a central opening 34 in the end plate. The end plate in this embodiment is made from powdered metal. A nonmetallic insert 36 is confined between the end plate 26 and the filter element 14- The insert 36 has a cylindrical portion 37 sealingly extending into the opening 24 of the end cap 21 at the open end 16 of the filter element 14. A polygonal or noncircular shaped portion 38 of the insert 36 is intimately sealingly seated in the pocket 32 of the end plate 26 so that the insert is nonrotatably fixed relative to the end plate 26. The polygonal shaped portion 38 has an end 39 in abutment with the flange 33 of the end plate 26. A bore 41 extends axially through the insert and opens into the center tube 18. At least a portion 42 of the bore 41 is threaded. The insert also has a radially outwardly extending flange 43 in sealing and axially restraining engagement with the end cap 21 of the filter element 14. The insert 36 of this embodiment is made from phenolic plastic such as Plenco 500. An annular seal plate 44 is connected to the annular surface 28 of the end plate 26 as by spot welding or the like and is sealingly secured to the housing 11 by means of a roll type seam 45 or the like. The seal plate 44 has an annular groove 46 formed therein. A fluid seal 47 is disposed within the annular groove. The above-noted construction defines an annular chamber 48 at the outside of the filter element 14 between the filter element 14 and the housing 11 and a central inner chamber 49 at the inside of the filter element with the chambers being separated by the filter media 19. The inlet ports 31 of the end plate 26 communicate the outside of the filter with the annular chamber 48 while the bore 41 of the insert 36 communicates the outside of the filter with the inner chamber 49. The end plate 26 and the insert 36 constitute a cover means 50 for closing the open end 12 of the housing 11. Industrial Applicability In use, the spin-on filter 10 is screwed onto a mounting stud of a mechanism, not shown, with the fluid seal 47 in sealing engagement with a suitable portion of the mechanism through which fluid is circulated. The unfiltered fluid from the mechanism passes through the inlet ports 31 in the end plate 26, into the annular chamber 48, through the filter media 19 and into the inner chamber 49. The filter media 19 traps any impurities in the fluid so that the fluid entering the inner chamber is cleaned. The clean fluid then passes through the bore 41 of the insert 36 and is returned to the mechanism through a passage in the mounting stud. If the mechanism is an engine, transmission and so forth, the fluid is normally a lubricant with the clean lubricant normally going directly to bearings, valves, and so forth. If the mechanism is a fuel system, the fluid being filtered is normally a fuel with the clean fuel from the filter going directly to the fuel injection pump, fuel injectors, and so forth. The primary feature of the present invention is that the filtered fluid contacts only nonmetallic components of the filter. For example, the center tube 18 is made from cellulose impregnated with a phenolic resin and the insert 36 is made from plastic. Thus, even if minute particles of the base material of the center tube or insert adheres thereto during the manufacturing process and breaks loose therefrom after the filter is in use, the relatively soft nonmetallic particles simply wash through the mechanism and do not cause any damage thereto. Other aspects, objects and advantages of this invention can be obtained from a study of the drawings, the disclosure and the appended claims.

Claims: Claims 1. In a spin-on filter (10) of the outside/in type including a generally cylindrical housing (11) having an open end (12) and a closed end (13) and a generally cylindrical filter element (14) disposed within the housing (11) and having a closed end (17) at the closed end of the housing (11) and an open end (16) adjacent the open end of the housing (11), the improvement comprising: a nonmetallic perforated center tube (18) included as an integral part of the filter element (14); and cover means (50) for closing the open end of the housing (11) and including a cylindrical portion (37) sealingly extending into the open end (16) of the filter element (14) and having a bore (41) extending therethrough with a portion (42) of the bore being threaded and wherein at least said cylindrical portion (37) of said cover means is a nonmetallic material. 2. The spin-on filter of claim 1 wherein said cover means (50) includes an end plate (26) disposed in the open end (12) of the housing (11) and a nonmetallic insert (36) nonrotatably connected to the cover means (50), said cylindrical portion (37) being an integral part of the insert. 3. In a spin-on filter (10) of the outside/in type including a generally cylindrical housing (.11.) having an open end (12) and a closed end (13), a generally cylindrical filter element (14) disposed within the housing (11) and having a closed end (17) adjacent the closed end of the housing (11) and an open end (16) adjacent the open end (12) of the housing (11), and a rigid end plate (26) disposed in the open end of the housing, the improvement comprising: a nonmetallic perforated center tube (18) included, as an integral part of. the-filter element (14) r -' ' means defining a centrally disposed noncircular shaped pocket (36) in the. end plate (26); and a nonmetallic insert (36) confined between the end plate (26) and the filter element (14), said insert having a cylindrical portion- (37) sealingly extending into the open end of the filter element (14), a noncircular shaped portion (38) intimately seated in the pocket (32) in the end plate (26), and a bore (41) extending therethrough and opening into the center tube (18), said bore (41) having at least a portion (42) thereof threaded. 4. The spin-on filter (10) of claim 3 wherein said center tube (18) is made from cellulose impregnated with a phenolic resin. 5. The spin-on filter (10) of claim 3 wherein said insert (36) is made from phenolic plastic. 6. The spin-on filter (10) of claim 3 wherein said end plate (26) includes an inwardly extending annular flange (33) defining an abutment surface, said insert (36) having an end (39) in abutment with the abutment surface. 7. The spin-on filter (10) of claim 6 wherein said insert (36) has a radially outwardly extending flange (43) in sealing engagement with the filter element (14) . 8. The spin-on filter (10) of claim 3 wherein said noncircular shaped pocket (36) and said noncircular shaped portion (38) both have a polygonal shape.

Inventors: GROEZINGER JOHN J, STREITMATTER RONALD W, GROEZINGER, JOHN, J., STREITMATTER, RONALD, W.
Applicants: CATERPILLAR INC, CATERPILLAR INC.
Application year: 1985
Main classification: B01D27
IPC codes: B01D27, F01M11