FILTER ASSEMBLY

Abstract

A filter assembly (1) for use in a vehicle, the filter assembly (1) including a filter (2) having a first end with a valve seat, a housing cover (3) and a valve assembly (4) including a valve member and biasing structure, wherein the filter (2) is configured to be received, in use, within a filter housing with the housing cover (3) secured to the filter housing and over the first end of the filter such that an inner surface of the housing cover engages the biasing structure and urges the valve member into sealing engagement with the valve seat of the first end of the filter (2).

Claims

1. A filter assembly (1) for use in a vehicle, the filter assembly (1) comprising a filter (2) having a first end with a valve seat (25c), a housing cover (3) and a valve assembly (4) including a valve member (41) and biasing means, wherein the filter (2) is configured to be received, in use, within a filter housing with the housing cover (3) secured to the filter housing and over the first end of the filter such that an inner surface of the housing cover engages the biasing means and urges the valve member (41) into sealing engagement with the valve seat (25c) of the first end of the filter (2).

2. A filter assembly according to claim 1, wherein the housing cover (3) is connected to the filter (2) by a connector (29, 35) with the biasing means and valve member (41) captivated therebetween.

3. A filter according to claim 1, wherein the housing cover (3) comprising a locator (34) which locates and engages the biasing means.

4. A filter assembly according to claim 3, wherein the connector (29, 35) at least partially surrounds the locator (34) and includes one or more apertures describing a bypass flow passage.

5. A filter assembly according to claim 4, wherein the connector (29, 35) comprises a first annular connector, which includes an external radial flange and is received within a second annular connector that includes an internal radial flange, the biasing means urging the housing cover away from the filter (2) such that the flanges engage one another.

6. A filter assembly according to claim 5, wherein one of the annular connectors (29, 35) comprises an interrupted annular wall including a plurality of spaced annular wall segments and the apertures describing the bypass flow passage are described between the spaced annular wall segments.

7. A filter assembly according to claim 1, wherein the biasing means comprise a spring.

8. A filter assembly according to claim 1, wherein the biasing means comprise resilient material.

9. A filter assembly according to claim 1, wherein the filter (2) comprises a bypass end cap (22) which comprises a first hollow spigot (25), the valve member (41) and the biasing means being inserted into the first hollow spigot (25).

10. A filter assembly according to claim 1, wherein the filter (2) comprises a inlet end cap (21) which comprises a second hollow spigot (23).

11. A filter assembly according to claim 1, wherein the filter (2) comprises a tubular filter element.

12. A lubrication circuit comprising the filter assembly (1) of claim 1.

Description

DESCRIPTION OF THE DRAWINGS

[0054] Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:

[0055] FIG. 1 is a section view through a filter assembly according to an embodiment of the invention;

[0056] FIG. 2 is a partial perspective section view of the filter assembly of FIG. 1 shown prior to assembly of the housing cover onto the filter; and

[0057] FIG. 3 is a similar view to that of FIG. 2, illustrating the filter assembly in the assembled condition.

DETAILED DESCRIPTION

[0058] Referring now to FIG. 1, there is shown a filter assembly 1 for use in a lubrication circuit for a vehicle (not shown), which includes a filter 2, a housing cover 3 and a valve assembly 4 captivated between the filter 2 and the housing cover 3.

[0059] The filter 2 includes a pleated filter element 20, a lower, inlet end cap 21 and an upper, bypass end cap 22. The inlet end cap 21 is circular in plan and includes a central spigot 23 projecting into the filter element 20, which is circumscribed by an annular pad 24. The spigot 23 is hollow and open at each of its ends with an opening 23a at the end received within the filter element 20, which corresponds to an inlet 23a of the filter 2.

[0060] The bypass end cap 22 is also circular in plan and includes a central spigot 25 projecting into the filter element 20, which is also circumscribed by an annular pad 26. The spigot 25 of the bypass end cap 22 is also hollow and open at each of its ends, with an opening 25a at the end received within the filter element 20, which corresponds to a bypass inlet 25a of the filter 20. The spigot 25 includes a radial lip 25b, which circumscribes the bypass inlet 25a and describes a valve seat 25c. The spigot 25 also includes a plurality of axial ribs 25d spaced about its internal surface.

[0061] In this example, the pleated filter element 20 is partially embedded within the annular pads 24, 26, thereby to secure the end caps 21, 22 to the filter element 20. This is achieved by heating the surface of the annular pads 24, 26 using infrared or a hot mirror, and pushing the pleated filter element 20 into the melted surface layer. However, it is also envisaged that the annular pads 24, 26 may be omitted, with the filter element 20 being secured to the end caps 24, 26 using hot melt. In other examples, mechanical fixings are used, for example wherein the filter element 20 bears against the annular pads 24, 26, which retain the filter element 20 in compression.

[0062] The bypass end cap 22 also includes a continuous annular wall 27 (shown more clearly in FIG. 2) projecting from the opposite side to the spigot 25 and annular pad 26. The annular wall 27 includes a radial flange 28 projecting outwardly from its free end. The radial flange 28 is in the form of a barb, with a radial surface parallel to the circular body of the bypass end cap 22 and a lead-in opposite the radial surface. Together, the annular wall 27 and radial flange 28 describe an annular connector 29.

[0063] The housing cover 3 is substantially circular in plan and includes an end wall 30, a peripheral wall 31 depending from the end wall 30 and joined thereto by a transition portion 32. The housing cover 3 also includes an external locator 33 projecting from an outer surface of the end wall 30, an internal locator 34 depending from an inner surface of the end wall 30 and an annular connector 35 also depending from the inner surface of the end wall 30 and surrounding or circumscribing the internal locator 34.

[0064] The peripheral wall 31 has a threaded external surface 31a and a radial flange 31b between the threaded external surface 31a and the transition portion 32. The transition portion 32 is in the form of a part-spherical ring 32, which provides a gradual transition from the end wall 30 to the peripheral wall 31. The external locator 33 is in the form of a hollow cylinder, with a blind bore extending into the internal locator 34. The internal locator 34 is hollow and includes a cylindrical, root portion 34a projecting from the end wall 30 and an end portion 34b in the form of a truncated dome, which is joined to the root portion 34a by a step 34c.

[0065] The annular connector 35 includes an interrupted annular wall provided by a plurality of annular wall segments 36, six in this example, spaced from one another by a gap G. Each annular wall segment 36 includes a radial flange 37 projecting inwardly from its free end. The radial flange 37 is in the form of a barb, with a radial surface parallel to the end wall 30 and a lead-in opposite the radial surface. Together, the annular wall segments 36 and radial flanges 37 describe the annular connector 35.

[0066] The valve assembly 4 includes a biasing member 40, which is a coil spring 40 formed of stainless steel in this example, and a valve member 41. The valve member 41 includes a flat, circular disc 42, which engages the valve seat 25c on a first side, and an annular wall 43 projecting from side opposite the valve seat 25c.

[0067] In order to assemble the filter assembly, the valve member 41 is inserted into the central spigot 25 of the bypass end cap 22 and brought into abutment with the valve seat 25c. The biasing member 40 is then inserted into the central spigot 25, such that it engages the circular disc 42 of the valve member 41, and surrounds the annular wall 43. The axial ribs 25d ensure that the biasing member 40 is centralised within the spigot 25.

[0068] The housing cover 3 is then placed over the bypass end cap 22 and lowered thereon until the biasing member 40 receives the end portion 34b of the internal locator 34, and comes to rest against the step 34c. The housing cover 3 is then urged toward the bypass end cap 22, thereby compressing the biasing member 40, until the annular connector 29 of the bypass end cap 22 engages the annular connector 35 of the housing cover 3. Further axial force causes the lead-ins of each of the annular connectors 29, 35 to engage one another. This forces the free ends of the annular wall segments 36 of the housing cover annular connector 35 apart until the flanges 37 pass over those of the bypass end cap annular connector 29, at which point the annular wall segments 36 snap back into their original state.

[0069] Once the annular connectors 29, 35 are engaged, the biasing member 40 urges the housing cover 3 away from the bypass end cap 22 of the filter 2, thereby urging the flanges 28, 37 of the annular connectors 29, 35 toward one another and locking the housing cover 3 to the bypass end cap 22. As a result, the filter assembly 1 is a self-contained assembly, ready to be assembled to a filter housing (not shown) of the vehicle (not shown).

[0070] Specifically, the filter assembly 1 would be mounted to the filter housing (not shown) by inserting the filter 2 therein through a threaded opening (not show), and rotating the housing cover 3 to engage the threaded external surface 31a of the peripheral wall 31 with the threaded opening (not shown) of the filter housing (not shown).

[0071] The skilled person will appreciate that rotation of the housing cover 3 to secure it to the filter housing (not shown) may result in relative rotation between the housing cover 3 and the filter 2. The skilled person will also appreciate that the configuration of the annular connectors 29, 35 is such that this relative rotation can be accommodated without distorting the filter element 20.

[0072] In use, fluid flows from a port in the filter housing (not shown) into the inlet 23a of the filter 2. Under normal conditions, the fluid flows along a first fluid path P1 from the inlet 23a, along the inside and through the filter element 20 to the outside thereof. If the pressure exceeds a predetermined threshold, for example if the fluid is too cold, the valve member 41 unseats from the valve seat 25c, thereby opening the bypass inlet 25a.

[0073] When the bypass inlet 25a is open, a second fluid path P2 is described from the bypass inlet 25a, into the spigot 25 and through the openings described by the gaps G between the annular wall segments 36, the end wall 30 of the housing cover 3 and the upper edge of the annular connector 29 of the bypass end cap 22. The flow through the second fluid path P2 is then redirected by the inner surface of the transition portion 32 and out between the filter element 20 and the peripheral wall 31.

[0074] The skilled person will appreciate that the annular wall segments 36 and the gaps G therebetween may be sized and configured to inhibit any flow restrictions through the second fluid path P2. Their size and configuration must, however, balance the requirement for a sufficient aggregate flow area, with that of their structural rigidity, to ensure a reliable connection between the housing cover 3 and the end cap 22 of the filter 2.

[0075] It will be appreciated by those skilled in the art that several variations to the aforementioned embodiments are envisaged without departing from the scope of the invention. For example, the housing cover 3 need not include a peripheral wall 31 with a threaded external surface 31a. It may instead include mounting lugs with holes, for receiving threaded fasteners to secure the housing cover 3 to the filter housing (not shown). The filter 2 need not incorporate end caps 21, 22, at least not as illustrated.

[0076] It will also be appreciated by those skilled in the art that any number of combinations of the aforementioned features and/or those shown in the appended drawings provide clear advantages over the prior art and are therefore within the scope of the invention described herein.