Fluid system with filter connection system between housing components

Abstract

A filter cartridge (32) includes a filter housing component (32) defining a filter axis (34) extending between a first axial end (36) and a second axial end (38), and including a peripheral surface (46) having a plurality of thread sets (48) and a plurality of slots (50). The first axial end includes an axial end surface (40) axially outwardly spaced from the plurality of thread sets (48) and the plurality of slots (50), and a ramp element (84) for aligning thread sets and slots of a second filter component (52) with the plurality of thread sets and the plurality of slots of the filter component. The ramp element extends circumferentially about the filter axis and slopes in the axial direction from a raised ramp end (88) to a shortened ramp end (90).

Description

Technical Field

[0001] This disclosure generally relates to a maintainable fluid system, and more specifically to a connection system having a threaded connection interface forming a discharge channel therethrough. Background Technology

[0002] Various machines and vehicles worldwide utilize filters for a variety of purposes. For example, most (if not all) machines and vehicles equipped with diesel engines filter diesel fuel to remove impurities that could interfere with engine operation or the combustion process itself. As particles are collected in the filter media, the filter's effectiveness can decrease over time, potentially leading to obstructed fuel flow, reduced filter performance, or other problems. For these reasons, it is generally standard practice to replace the fuel filter during regular maintenance intervals or when diagnostic equipment or operator observation indicates that the filter needs to be replaced.

[0003] The removal, disassembly, and reinstallation of filters are ideally simple and easy tasks. However, for various reasons, replacing filters in the field is often more time-consuming, labor-intensive, and cumbersome than theoretically required. Filters and related equipment typically employ some type of mechanism to securely lock or position components. A common example of filter mounting and securing and / or locking mechanisms includes threaded interfaces. Threaded interfaces between filter components are common and have a long history of use. However, certain disadvantages are inherent to threaded designs. The force required to connect two components may require engaging a large number of threads. Installation and removal may require multiple rotations of the inserted parts, including filters or related components. Threaded components can also be susceptible to misalignment (i.e., mis-threading), which can cause one or more parts to become stuck and / or permanently damaged. Threaded components can also be formed from relatively soft materials such as plastic or aluminum and may be unintentionally tightened beyond the material's yield strength. These and other problems can be amplified when the threaded components are large, as is often the case in off-highway machinery environments. An example of a replaceable filter configuration in a liquid filter environment is known from U.S. Patent No. 6,814,243B2 to Amstutz et al. Summary of the Invention

[0004] In one aspect, the fluid system includes a filter canister, a filter medium located within the filter canister, and a first housing component. The first housing component defines a filter axis and forms a filter medium cavity. The first housing component also includes a first plurality of threaded sets and a first plurality of grooves. The fluid system further includes a second housing component that forms a collection cavity and includes a second plurality of threaded sets and a second plurality of grooves. The fluid system also includes a stop member comprising a first stop member formed on the first housing component and a second stop member formed on the second housing component. The first stop member contacts the second stop member at an mounting orientation of the first housing component, wherein the first plurality of threaded sets are aligned with the second plurality of threaded sets. The first and second housing components are rotatable from the mounting orientation to a maintenance orientation, in which the first and second plurality of threaded sets engage to form a connection interface, and a discharge passage extends through the connection interface and fluidly connects the filter medium cavity to the collection cavity.

[0005] In another aspect, a connection system for a fluid system includes a first component defining an axis and having a first peripheral surface having a first plurality of threaded sets and a first plurality of grooves. The connection system also includes a second component having a second peripheral surface having a second plurality of threaded sets and a second plurality of grooves, the second plurality of threaded sets and the second plurality of grooves being configured to align with and engage with the first plurality of threaded sets and the first plurality of grooves to form a connection interface defining a discharge passage. The filter connection system also includes a stop member comprising a first stop member and a second stop member partially formed on the first component and partially formed on the second component. The first stop member is configured to contact the second stop member at an angular mounting orientation of the first component relative to the second component about an axis, in which the first plurality of threaded sets and the second plurality of threaded sets are axially aligned for engagement.

[0006] In another aspect, a filter element includes a filter housing component defining a filter axis extending between a first axial end and a second axial end, and including a peripheral surface having a plurality of threaded sets and a plurality of grooves. The first axial end includes an axial end surface axially spaced outward from the plurality of threaded sets and grooves, and a ramp element for aligning the threaded sets and grooves of a second filter component with the plurality of threaded sets and grooves of the filter housing component. The ramp element extends circumferentially about the filter axis and slopes from a raised ramp end to a shortened ramp end. Attached Figure Description

[0007] Figure 1 This is a perspective view of a fluid system according to one embodiment;

[0008] Figure 2This is a cross-sectional side view of a filter assembly for a fluid system according to one embodiment;

[0009] Figure 3 This is a perspective view of a filter element according to one embodiment;

[0010] Figure 4 This is a perspective view of a portion of a filter connection system according to one embodiment;

[0011] Figure 5 This is another perspective view of a part of a filter connection system according to one embodiment;

[0012] Figure 6 This is an axial view of a filter component according to one embodiment;

[0013] Figure 7 This is a side view of a filter connection system in an installation orientation according to one embodiment; and

[0014] Figure 8 This is a side view of a filter connection system according to one embodiment, in a positioning and maintenance orientation in two cross-sectional planes. Detailed Implementation

[0015] refer to Figure 1 and Figure 2 A fluid system 10 according to one embodiment is illustrated. The fluid system 10 includes a filter housing or filter canister 12 having an inlet port 14 and an outlet port 16. An input flow 18 of the fluid to be filtered enters the inlet port 14, the dirty fluid is filtered through a filter medium 20 within the filter canister 12, and an output flow 22 of the filtered fluid exits through the outlet port 16. The fluid system 10 may include a fluid system for an internal combustion engine, such as a fuel system in a compression-ignition diesel engine. However, other applications are contemplated, such as in engine oil systems, or even fluid systems outside the engine environment. The discussion and description of “fluid” or “fuel” herein are for descriptive purposes only and are not intended to be limiting.

[0016] In one implementation, the filter medium 20 may utilize gravity to separate liquids (such as fuel and water), as discussed further herein. The fluid system 10 may also include a filter mount or bracket 24 designed to attach to the filter canister 12 and for mounting on an engine housing or other engine hardware. For this purpose, the filter canister 12 may include a corresponding mounting attachment 26, such as mounting threads 28, to selectively secure the filter canister 12 to the filter mount 24. The mounting attachment 26 may be positioned on the filter canister 12 or may be configured to accommodate subsequent additions, such as clamps, fasteners, or others. While this specification discusses the use of mounting threads 28 configured to engage the filter canister 12 to the filter mount 24, it should be understood that the mounting attachment 26 may have various forms or other methods and strategies for engaging the filter canister 12 to the filter mount 24.

[0017] Fluid system 10 is used to remove impurities from liquid fuels such as diesel fraction fuels, gasoline, naphtha, or various mixtures, and to prevent water and other contaminants from reaching the engine. Water can be present in diesel fuel for various reasons, such as condensation formed on metal parts within various systems, as a contaminant in the fuel supply, etc. Furthermore, over time, particles such as metal fragments, carbonized material, or other debris can accumulate in filter media 20. For these reasons, it is generally desirable to maintain fluid system 10 at defined maintenance intervals, or, where further maintenance is determined, to remove accumulated water and / or replace the filter media. When filter media 20 needs replacement, a maintenance technician can remove mounting attachment 26 and replace the depleted or otherwise contaminated filter media 20 in filter canister 12, and reinstall filter canister 12 by reattaching mounting attachment 26 to filter mounting piece 24. Simultaneously, or possibly at different intervals, water can be drained from filter canister 12, as discussed further herein. It should be understood that this disclosure is not limited to any particular maintenance interval or maintenance time, and alternative methods for removing, maintaining and reinstalling the filter tank 12 are within the scope of this disclosure.

[0018] Still referencing Figure 3Additional details of the fluid system 10 are shown. The fluid system 10 also includes a filter assembly 30 having a first housing component or "first component" 32, which defines a filter axis extending between a first axial end 36 and a second axial end 38. The first component 32 may include an axial end surface 40 positioned at the first axial end 36. The first component 32 also includes an axially extending filter container 42 forming a filter media chamber 44 for receiving filter media 20. During filtration, unfiltered fluid passes through the filter media 20, separating impurities such as particles including metal fragments, carbonized deposits, dirt, etc., and producing filtered fluid. Figure 3 As shown, the first component 32 includes a filter medium 20 attached to the filter container 42. Various filter media are known and commercially available, such as paper, polyester, activated carbon, etc. The first component 32 also includes a first peripheral surface 46 that spans around and is positioned radially outward of the filter axis 34. Additionally, the first peripheral surface 46 may include a first plurality of threaded groups 48 and a first plurality of grooves 50 arranged in an alternating pattern, positioned toward a first axial end 36.

[0019] Still referencing Figure 4 The fluid system 10 also includes a second housing component or "second component" 52, which is configured to thread the first component 32 into place. Each of the first component 32 and the second component 52 may be arranged coaxially about the filter axis 34, and each of these parts may be independently understood to define the filter axis 34. It can be noted that each of the first component 32 and the second component 52 may be formed as a single-piece body, such as a molded plastic body or a machined or cast aluminum body, or a part formed by additive manufacturing, to name just a few examples.

[0020] The second component 52 includes a second outer surface 54 and a second inner surface 56 forming a collection chamber 58. As described above, the collection chamber 58 is configured to collect water as it is discharged under gravity during the filtration process and the circulation of fuel through the fluid system 10. For this purpose, the collection chamber 58 may also include a removable drain plug 60 for emptying the collection chamber 58 after water accumulation. In one embodiment, mounting threads 28 may be integrated into the second component 52 and positioned toward a second axial end 38. The second component 52 also includes a second peripheral surface 62 positioned radially outward and spanning around a filter axis 34. The second peripheral surface 62 may also include a second plurality of threaded sets 64 and a second plurality of grooves 66. The first peripheral surface 46 may be an outer peripheral surface, and the second peripheral surface 62 may be an inner peripheral surface. An embodiment with the opposite relationship is contemplated, and thus the first peripheral surface 46 may be an inner peripheral surface, and the second peripheral surface 62 may be an outer peripheral surface. The second plurality of threaded sets 64 and the second plurality of grooves 66 may also be in an alternating pattern similar to the first plurality of threaded sets 48 and the first plurality of grooves 50.

[0021] It should be understood that, considering the second plurality of thread sets 64 and the second plurality of slots 66 are designed with reference to the first plurality of thread sets 48 and the first plurality of slots 50, alternative arrangements and / or numbers of thread sets and slots are contemplated within the scope of this disclosure. In an example embodiment, each plurality of thread sets and plurality of slots may include a total of two thread sets and a total of two slots. Furthermore, as Figure 5 As shown, in the improved scheme, each plurality of thread sets and plurality of grooves can be arranged such that the first diameter line 68 intersecting the two thread sets is arranged perpendicular to the second diameter line 70 intersecting the two grooves.

[0022] Figure 5 The illustration shows a filter connection system 72 between a first component 32 and a second component 52, which includes certain elements of the fluid system 10 already described. The first component 32 and the second component 52 can be rotated from an installation orientation or arrangement to a locking maintenance orientation or arrangement, wherein the filter assembly 30 may also include locking elements as discussed later for secure placement and positioning. However, embodiments excluding locking features and configured for positioning in maintenance arrangements that are not locking maintenance arrangements are within the scope of this disclosure.

[0023] For further reference Figures 6 to 8When arranged in a snap-fit ​​maintenance orientation, the first plurality of threaded sets 48 and the second plurality of threaded sets 64 engage, and the first plurality of slots 50 and the second plurality of slots 66 align to form a connection interface 74, in which a discharge passage 76 is defined. The discharge passage 76 is configured to extend through the connection interface 74 when the filter assembly 30 is in the snap-fit ​​maintenance orientation, thereby fluidly connecting the filter media chamber 44 to the collection chamber 58 to facilitate water discharge. It should be understood that when in the snap-fit ​​maintenance orientation, the discharge passage 76 extends through the aligned first plurality of slots 50 and the second plurality of slots 66, although some discharge may also occur through the engaging threads depending on the thread design and application. As implied, variations in the number and / or geometry of the first plurality of slots 50 and the second plurality of slots 66 may result in variations in the number and / or configuration of the discharge passage 76. For example, the discharge passage 76 may be one of a plurality of discharge passages 76, each defined through an aligned pair of first plurality of slots 50 and second plurality of slots 66. The total of two slots in each of the corresponding components 32 and 52 can provide a total of two discharge channels, the total of three slots can provide a total of three discharge channels, and so on.

[0024] The filter assembly 30 may also include a stop 78 that helps prevent thread misalignment and mis-threading. The stop 78 may be partially formed on the first component 32 and partially formed on the second component 52, and includes a first stop 80 and a second stop 82. When the first component 32 and the second component 52 are engaged, the stop 78 can be used to axially align the threaded sets in the respective first component 32 and second component 52. In an embodiment, the first stop 80 may include a ramp element 84 formed on an axial end surface 40 and including a ramp surface 86. A plurality of threaded sets and a plurality of grooves are axially positioned between the ramp element 84 and the filter medium 20. The second stop 82 may include a ramp follower 100.

[0025] See Figure 6 The ramp element 84 may extend circumferentially less than 360° around the filter axis 34, and the ramp surface 86 is inclined axially from the raised ramp end 88 to the shortened ramp end 90. The ramp element 84 may extend approximately 90°, provided that it ensures guided engagement of the ramp follower 100, but this disclosure is not limited thereto. It should be understood that the term "raised" refers to the portion of the ramp element 84 that extends relatively further from the axial end surface 40 in the axial direction, and the term "shortened" refers to the portion of the ramp element 84 that extends relatively less in the axial direction than the raised ramp end 88. The ramp element 84 may also include a descending surface 92 positioned at the raised ramp end 88, which extends from the ramp surface 86 to the axial end surface 40.

[0026] The ramp element 84 can be configured to align the second plurality of threaded sets 64 and the second plurality of slots 66 of the second component 52 with the first plurality of threaded sets 48 and the first plurality of slots 50 of the first component 32. As the first component 32 and the second component 52 advance toward each other in the axial direction, the stop 78 provides a positive contact stop at the orientation where the threaded sets 48 and 64 are axially aligned for threaded engagement.

[0027] As described above, the first component 32 may also include a locking feature 94 formed on the axial end surface 40. The locking feature 94 may be positioned adjacent to the raised ramp end 88, thereby defining a locking recess 96 extending circumferentially between the locking feature 94 and the raised ramp end 88. Various configurations of the locking feature 94 are within the scope of this disclosure. In one example, the locking feature 94 may include a locking protrusion 98. In other examples, the locking feature 94 may include a clip, slot, hook, or any of various other shapes, forms, and alternative positioning, as long as it releasably secures the second stop component 82 in a locking maintenance orientation and provides some resistance to prevent the first component 32 and the second component 52 from being twisted apart. By providing a locking arrangement, the filter assembly 30 can maintain the connection between the first component 32 and the second component 52 during disassembly of the first component 32 and the second component 52, when the threads 28 disengage during removal from the filter mount 24. It should also be understood that a plurality of ramp elements 84 and a plurality of locking features 94 may be formed on the axial end surface 40, each locking feature 94 being positioned adjacent to a raised ramp end 88, and potentially each locking feature 94 being positioned adjacent to a shortened ramp end 90. Thus, the plurality of ramp elements 84 and the plurality of locking features 94 may be arranged in an alternating pattern around the filter axis 34 and may be positioned adjacent to the first peripheral surface 46 in the radial direction.

[0028] The second stop member 82 may further include a ramp follower 100 formed on the second peripheral surface 62, adjacent to the second plurality of threaded sets 64 and extending toward the second axial end 38. The ramp follower 100 may be configured to travel along the ramp element 84 when the first member 32 is rotated relative to the second member 52. It can be noted that when the first member 32 rotates, the ramp follower 100 contacts and follows the ramp element 84. Although the ramp follower 100 extending in the axial direction is discussed in this specification, alternative placements and forms of the ramp follower 100 are contemplated. For example, considering that the ramp element 84 and the locking feature 94 are positioned radially adjacent to the first peripheral surface 46, the ramp follower 100 may be positioned radially adjacent to the second peripheral surface 62. A plurality of ramp followers 100 corresponding to the number of ramp elements 84 may be present.

[0029] Now for reference Figure 7 and Figure 8 The diagram illustrates filter connection systems 72 in both mounting and locking / maintenance orientations. As discussed in this specification, a first component 32 can be positioned about filter axis 34 in a mounting orientation where first plurality of threaded sets 48 can be inserted into second plurality of slots 66, and then rotated to a locking / maintenance orientation via engagement of the first plurality of threaded sets 48 and the second plurality of threaded sets 64. As the first component 32 rotates relative to the second component 52, a ramp follower 100 can continuously contact the ramp element 84 within a certain angular mounting orientation range of the first component 32 relative to the second component 52. During rotation, the ramp follower 100 can travel circumferentially between a shortened ramp end 90 and a raised ramp end 88. In a practical embodiment, the first component 32 can rotate approximately one-quarter of a turn clockwise relative to the second component 52, but this specification is not limited thereto.

[0030] Just before reaching the positioning maintenance orientation, the ramp follower 100 can cross the positioning protrusion 96 to enter the positioning recess 96 and be captured between the positioning protrusion 96 and the descending surface 92. In this configuration, the slot 50 can be aligned with the slot 66, and the discharge channel 76 allows for the discharge of water received in the collection chamber 58. Industrial applicability

[0031] Referring generally to the accompanying drawings, one may recall the common desire to replace used filters with new ones at predetermined intervals or periodically as needed. The user can remove the second component 52 manually or with the aid of tools from the filter mount 24. In one embodiment, the user unloads the mounting threads 28 on the second component 52 by rotating it in a first direction and slides the second component 52 out of the filter mount 24. If the filter media 20 is to be replaced, the replacement filter media or the first component 32 with attached filter media can be installed by first removing the depleted filter. To install the replacement, the new first component 32 (“filter cartridge”) with attached filter media can be positioned in the mounting orientation and rotated to engage the second component 52. As discussed herein, the first stop component 80 can contact the second stop component 82 at the mounting orientation of the first component 32 and the second component 52 to align the thread set 48 with the thread set 64. As the first component 32 rotates relative to the second component 52, the first stop component 80 and the second stop component 82 are in continuous contact within an angular orientation ranging from the mounting orientation to the locking maintenance orientation. With the first component 32 and the second component 52 connected together, their components can be reinstalled in the filter mounting 24, and the fluid system 10 can be put back into use.

[0032] As will be apparent, this disclosure envisions threaded connections between parts in a fluid system, where fluid can be discharged through the threaded interface itself. This strategy differs from some earlier designs in which O-rings or the like were involved in positioning the threads for engagement, but subsequently provided with a fluid seal that would prevent any discharge through the threaded interface. While the field of engine fuel systems is envisioned as a practical implementation strategy, it should be understood that various other environments can also benefit from applying the teachings herein, and various other fluid connections for filters between two fluid conduits, between a fluid conduit and another structure such as a fuel tank, or other structures are also considered herein. Filter system 10 or its components may be sold as original equipment or as one or more aftermarket products, including as replacement filter elements comprising a first component 32 and an attached filter medium 20.

[0033] This specification is for illustrative purposes only and should not be construed as limiting the scope of this disclosure in any way. Therefore, those skilled in the art will understand that various modifications can be made to the embodiments currently disclosed without departing from the full and fair scope and spirit of this disclosure. Other aspects, features, and advantages will be readily apparent upon examination of the accompanying drawings and appended claims. As used herein, the articles “a” and “an” are intended to include one or more items and are interchangeable with “one or more”. The term “an” or similar language is used where only one item is intended. Furthermore, as used herein, the terms “has,” “have,” “having,” etc., are intended to be open-ended terms. Additionally, the phrase “based on” is intended to mean “at least partially based on” unless otherwise expressly stated.

Claims

1. A fluid system (10), comprising: Filter canister (12); Filter medium (20), the filter medium (20) is located inside the filter canister; as well as A first housing component (32) defines a filter axis (34) and forms a filter media cavity (44). The first housing component includes a first plurality of threaded groups (48) and a first plurality of grooves (50). The second housing component (52) forms a collection cavity (58) and includes a second plurality of threaded groups (64) and a second plurality of grooves (66). Stop (78), the stop (78) includes a first stop (80) formed on the first housing component and a second stop (82) formed on the second housing component; The first stop member contacts the second stop member at the mounting orientation of the first housing member and the second housing member, aligning the first plurality of threaded sets with the second plurality of threaded sets; and The first housing component and the second housing component are rotatable from the mounting orientation to the maintenance orientation, in which the first plurality of threaded sets and the second plurality of threaded sets engage to form a connection interface (74) and a discharge channel (60) that extends through the connection interface and fluidly connects the filter media chamber to the collection chamber.

2. The fluid system of claim 1, wherein the first plurality of threaded groups and the first plurality of grooves are in an alternating pattern, and the second plurality of threaded groups and the second plurality of grooves are in an alternating pattern, and wherein, in the mounting orientation, the first plurality of threaded groups are located within the second plurality of grooves, and the second plurality of threaded groups are located within the first plurality of grooves.

3. The fluid system of claim 2, wherein in the maintenance orientation, the first plurality of slots are aligned with the second plurality of slots, and wherein the discharge channel is one of a plurality of discharge channels, each discharge channel extending through the aligned pairs of the first plurality of slots and the second plurality of slots.

4. The fluid system according to any one of claims 1 to 3, wherein the first stop member is in continuous contact with the second stop member within an angular orientation range of the first housing member relative to the second housing member about the filter axis from the mounting orientation to the maintenance orientation.

5. A filter connection system (72), comprising: A first component (32) defines an axis (34) and includes a first peripheral surface (46) having a first plurality of threaded groups (48) and a first plurality of grooves (50). The second component (52) includes a second peripheral surface (62) having a second plurality of threaded sets (64) and a second plurality of grooves (66), the second plurality of threaded sets (64) and the second plurality of grooves (66) being configured to align with and engage with the first plurality of threaded sets and the first plurality of grooves to form a connection interface (74) defining a discharge channel (76). A stop member (78), the stop member (78) comprising a first stop member (80) partially formed on the first component and a second stop member (82) partially formed on the second component; and The first stop member is configured to contact the second stop member at an angular mounting orientation relative to the second member about the axis, wherein the first plurality of threaded sets and the second plurality of threaded sets are axially aligned for engagement.

6. The connection system of claim 5, wherein the first peripheral surface is an outer peripheral surface and the second peripheral surface is an inner peripheral surface, and the first component is rotatable relative to the second component from the angular mounting orientation to a locking orientation, and in the locking orientation, the first plurality of threaded sets and the second plurality of threaded sets engage, and the first plurality of slots and the second plurality of slots are circumferentially aligned.

7. The connection system according to claim 5 or 6 further includes a locking feature (94) adjacent to the first stop member and in fixed contact with the second stop member, wherein the first stop member includes a ramp element (84) inclined from a raised ramp end (88) to a shortened ramp end (90), the ramp element (84) extending about the axis from the raised ramp end to the shortened ramp end by less than 360°.

8. A filter element (32), comprising: A filter housing component (32) is defined with a filter axis (34) extending between a first axial end (36) and a second axial end (38), and includes a peripheral surface (46) having a plurality of threaded sets (48) and a plurality of grooves (50). The first axial end includes an axial end surface (40) spaced axially outward from the plurality of thread sets and the plurality of grooves, and a ramp element (84) for aligning the thread sets and grooves of the second filter component (34) with the plurality of thread sets and the plurality of grooves of the filter housing component; and The ramp element extends circumferentially around the filter axis and is inclined in the axial direction from the raised ramp end (88) to the shortened ramp end (90).

9. The filter element according to claim 8, wherein the first axial end further includes a locking feature (94) adjacent to the raised end.

10. The filter element according to claim 8 or 9, wherein the locking feature includes a locking protrusion (98), and the filter element further includes a locking recess (96) extending circumferentially between the locking protrusion and the raised end.

11. The filter element according to any one of claims 8 to 10, wherein the ramp element is one of a plurality of ramp elements formed on the axial end surface, and the locking feature is one of a plurality of locking features formed on the axial end surface, and the plurality of ramp elements and the plurality of locking features are arranged in an alternating pattern around the filter axis and positioned adjacent to the peripheral surface in the radial direction.

12. The filter element according to any one of claims 8 to 11, wherein the peripheral surface is an outer peripheral surface that extends circumferentially around the filter axis.

13. The filter element according to any one of claims 8 to 12, wherein the plurality of threaded groups and the plurality of grooves comprise a total of two threaded groups and a total of two grooves, and the diameter line (68) intersecting the two threaded groups is arranged perpendicular to the diameter line (70) intersecting the two grooves.

14. The filter element according to any one of claims 8 to 13, further comprising a filter medium (20) attached to the filter housing component, wherein the plurality of threaded groups and the plurality of grooves are axially positioned between the ramp element and the filter medium.

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