Press-in filter spud that is free to spin

A filter element, filter head, a filter system and methods of assembling or mounting a filter element to a filter head are provided. The filter element and filter head have cooperating axially undulating sealing regions. The filter head has a spud that has a non-cylindrical region that extends through a non-circular opening in the filter element to communicate a central bore of the spud with a central cavity defined by filter media of the filter element. The method includes angularly aligning the undulating sealing regions by inserting the non-cylindrical region of the spud through the non-circular opening of the filter element.

FIELD OF THE INVENTION

This invention generally relates to filter elements, filter systems, the interface between the filter element and a filter head of a filter system as well as methods of mounting filter elements to a filter head.

BACKGROUND OF THE INVENTION

Filter systems are used to filter fluids to prevent damage or reduction in performance of downstream systems. Many filter systems include a filter head to which one or more replaceable filter elements are mounted. Once the filter element is spent (e.g. a filter media thereof is full of impurities), the filter element can be removed and replaced without having to replace the entire filter system.

One particular type of filter system uses filter elements that are referred to as spin-on filters. The filter system includes a filter head to which the replaceable filter element threadedly attaches. Thus, the filter element must be spun on to be attached to the filter head during replacement intervals.

The filter head will typically include inlet and outlet ports which direct fluid into and out of the filter element. The fluid passes through the filter element, which separates particles and other contaminants from the fluid which is then sent to a downstream operating system. In order for the filter element to properly function and not leak, a positive seal must be maintained with the filter head. Typically, liquid filter elements use an O-ring supported along a plane in a straight cut or radial seal gland design. A sloped or angled seal gland design has been used, for example as shown in U.S. Pat. No. 7,494,017 for “Filter Element With Off-Axis End Cap”, issued to the assignee of the present invention. Recently, a sealing interface that utilizes an undulating geometry has been developed by the assignee of the present application and is illustrated in U.S. Pat. No. 8,916,044 for “Filter Element Wave Gland Seal.”

The invention provides improvements over the current state of the art and particularly the current state of the art as it relates to the inclusion of a sealing interface that includes an undulating geometry.

BRIEF SUMMARY OF THE INVENTION

Embodiments of the present invention provide new and improved filter elements, filter heads, filter systems and methods of assembling filter systems or mounting a filter element to a filter head.

In a particular embodiment, a spin-on filter element including an outer housing and an element sub assembly is provided. The filter housing includes an outer shell and a threaded attachment member. The threaded attachment member is secured to the outer shell. The threaded attachment member includes a mounting thread that defines a rotational axis. The threaded attachment member and outer shell define an internal shell cavity. The element subassembly is secured within the internal shell cavity. The element subassembly includes a tubular ring of filter media and a first end cap. The tubular ring of filter media extends between first and second ends and surrounds an internal media cavity. A central opening extends through the first end cap in fluid communication with the internal media cavity. The central opening defines a non-circular periphery. A seal member is attached to the first end cap and surrounds the central opening of the first end cap. The seal member has an axially undulating and radially facing sealing region.

In one embodiment, the threaded attachment member is angularly fixed to the outer shell to a greater degree than the element subassembly. Thus, the subassembly will rotate under less torque than the threaded attachment member.

In one embodiment, the element subassembly is rotatable within the outer housing.

In one embodiment, a greater torque is required to rotate the threaded attachment member relative to the outer shell about the rotational axis than is required to rotate the element subassembly relative to the threaded attachment member.

In one embodiment, the periphery of the central opening has a length that is greater than a width thereof. The length is perpendicular to the width.

In one embodiment, the seal member defines the central opening.

In one embodiment, the end cap defines the central opening.

In one embodiment, the central opening is recessed axially into the outer shell farther than the axially undulating and radially facing sealing region.

In a further embodiment, a filter system is provided. The filter system includes a filter head and a spin-on filter element. The filter element may be one as described above. The filter head includes a first port and a second port. The filter head includes a threaded filter mounting interface that includes a mounting thread. The filter head includes an axially extending spud. The spud has a bore therethrough in operable fluid communication with the first port. The spud has a first axially extending portion defining a non-cylindrical outer surface. The spud has a second axially extending portion defining a first axially undulating and radially facing sealing region. The second axially extending portion is axially offset from the first axially extending portion. The first axially undulating and radially facing sealing region of the filter head engages the axially undulating and radially facing sealing region of the spin-on filter element. The threaded attachment member threadedly engages the threaded filter mounting interface. The first axially extending portion of the spud extends through the central opening of the element subassembly with the bore of the spud in fluid communication with the internal media cavity. Thus, the port is operably in fluid communication with the cavity of the filter media.

In one embodiment, the non-cylindrical outer surface of the first axially extending portion has an outer profile that corresponds to the non-circular periphery of the central opening such that the spud angularly engages the element subassembly and a torque is transferred between the spud and the element subassembly as the spin-on filter element is threadedly mounted to the threaded filter mounting interface.

In one embodiment, the spud is rotatably mounted to rotate with the spin-on filter element as the threaded attachment member is rotatably mounted to the threaded filter mounting interface with the spud extending into the central opening.

In one embodiment, the element subassembly is rotatably carried within the outer housing. As such, with the spud engaged with the central opening, the element subassembly is rotated within the outer housing as the spin-on filter element is mounted to the threaded filter mounting interface.

In one embodiment, the mounting thread of the threaded filter mounting interface is axially spaced relative to the first axially extending portion of the spud a first distance and the mounting thread of the threaded attachment member is axially spaced relative to the central opening of the element subassembly a second distance less than the first distance such that the first axially extending portion of the spud extends into the central opening before the mounting thread of the filter head engages the mounting thread of the spin-on filter element during installation.

In one embodiment, the non-cylindrical outer surface of the spud cooperates with the non-circular periphery of the central opening such that insertion of the first axially extending portion of the spud into the central opening angularly aligns the first axially undulating and radially facing sealing region of the filter head with the axially undulating and radially facing sealing region of the spin-on filter element.

In one embodiment, the mounting thread of the threaded filter mounting interface is axially spaced relative to the first axially extending portion of the spud and the mounting thread of the threaded attachment member is axially spaced relative to the central opening of the element subassembly such that the first axially extending portion of the spud extends into the central opening before the mounting thread of the filter head engages the mounting thread of the spin-on filter element.

In an embodiment, a method of mounting a spin-on filter element to a filter head is provided. The filter head and the filter element may be according to those outlined above. The method includes angularly aligning the first axially undulating and radially facing sealing region of the filter head with the axially undulating and radially facing sealing region of the spin-on filter element by inserting the first axially extending portion of the spud into the central opening with the non-cylindrical outer periphery angularly oriented with the non-circular periphery of the central opening. The method includes engaging the mounting thread of the spin-on filter element with the mounting thread of the filter head.

In one method, engaging the mounting thread of the spin-on filter element with the mounting thread of the filter head includes rotating the outer housing of the spin-on filter element relative to the threaded filter mounting interface. Additionally, rotating the outer housing rotates the spud relative to the threaded filter mounting interface.

In one method, engaging the mounting thread of the spin-on filter element with the mounting thread of the filter head includes rotating the outer housing of the spin-on filter element relative to the threaded filter mounting interface. Additionally, the method includes preventing rotation of the element subassembly relative to the threaded filter mounting interface during the step of engaging by angularly engaging the spud with the central opening. The spud is angularly fixed relative to the threaded filter mounting interface.

In one method, the spud is axially inserted into the central opening prior to the step of engaging the mounting thread of the spin-on filter element with the mounting thread of the filter head.

In one method, the method includes radially engaging the first axially undulating and radially facing sealing region of the filter head with the axially undulating and radially facing sealing region of the spin-on filter element to prevent fluid bypass between the spud and the seal member.

In one embodiment, a filter head is provided for use with a replaceable filter element. The filter head includes a body member, a threaded filter mounting interface and an axially extending spud. The body member includes a first port and a second port. The threaded filter mounting interface includes a mounting thread. The spud has a bore therethrough in operable fluid communication with the first port. The spud has a first axially extending portion defining a non-cylindrical outer surface. The spud has a second axially extending portion defining a first axially undulating and radially facing sealing region. The second axially extending portion is axially offset from the first axially extending portion.

In one embodiment, the spud is rotatably mounted to the filter body for rotation relative to the threaded filter mounting interface about an axis defined by the mounting thread.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1illustrates a filter system100for filtering fluids and particularly liquids. In one implementation, the filter system100filters fuel. The filter system100includes a filter head102, a primary filter element104, and a secondary filter element106. While multiple filter elements are illustrated, embodiments of the invention may be practiced with more or less filter elements.

The filter head102includes a plurality of ports (dirty fluid inlet and clean fluid outlet ports108,110are illustrated inFIG. 1) for connecting to fluid supplies and downstream systems such as for example an upstream fuel tank and a downstream engine. The dirty fluid inlet port108is upstream of the primary filter element104with the clean fluid outlet port110downstream of the secondary filter106. Internal porting is provided between a clean side of the primary filter and a dirty side of the secondary filter. As such, the filter head102will typically provide a clean and a dirty port for each of the primary and secondary filter elements104,106.

The primary and secondary filter elements104,106are spin-on filter elements that threadedly attach to the filter head102.

FIG. 2illustrates a portion of the filter system100in cross section and particularly a portion of the primary filter element104. The dirty fluid inlet port108where dirty fluid enters the system and a clean fluid outlet port112where cleaned fluid that has passed through the primary filter element104are illustrated.

As noted, the primary filter element104is a spin-on filter element. As such, the filter head102includes a threaded filter mounting interface114that includes a plurality of helical mounting threads. The primary filter element104includes a corresponding threaded attachment interface in the form of a threaded attachment member116that is in the form of an attachment plate that includes a plurality of helical mounting threads. The threaded filter mounting interface114and threaded attachment member116define a rotational axis118about which the threaded attachment member116rotates as the primary filter element104is rotated to engage the cooperating threads and mount the primary filter element104to the filter head102.

To prevent leakage of fluid passing through the filter system100, a first housing seal120is provided between the filter head102and the primary filter element104. The first housing seal120is an axial seal that is axially compressed between the primary filter element104and the filter head102.

A second seal arrangement122is provided between the filter head102and the primary element104. The second seal arrangement122is a provided by radial engagement between a seal member124of the primary filter element104and an axially extending spud126of the filter head102.

With additional reference toFIG. 3, the seal member124includes a first axially undulating and radially facing sealing region128(also referred to herein as “first sealing region128”) that faces radially inward. The spud126includes a corresponding second axially undulating and radially facing sealing region130(also referred to herein as “second sealing region130”) that faces radially outward and is sized and shaped to mate with the first axially undulating and radially facing sealing region128. The first and second sealing regions radially engage one another to prevent fluid bypass between the seal member124and the spud126. The radial and axial directions are taken with respect to the rotational axis118.

Due to the various voids132,134,136,138created by the undulating geometry of the first and second sealing regions128,130, the sealing regions128,130must be properly angularly oriented relative to one another when the primary filter element104is mounted to the filter head102. The ability to properly angularly orient the sealing regions128,130will be discussed in more detail after more general discussion of the components of the filter system100are discussed.

With reference toFIG. 4, the primary filter element104is illustrated in cross-section. The primary filter element104includes an outer housing140that is formed in part by the threaded attachment member116and an outer shell142. The outer shell142is operably secured to the threaded attachment member116to angularly fix the two components to inhibit rotation of the threaded attachment member116relative to the outer shell142such that mounting and removal of the primary filter element104can be performed by operably gripping the outer shell142and applying an appropriate torque thereto. For example, a portion rim portion144of the threaded attachment member116may be crimped between a seal support plate146that supports first housing seal120and which is crimped to an end of an annular sidewall of the outer shell142. Alternatively, the threaded attachment member116could be welded, adhesively secured or mechanically interlocked with either or both of the outer shell142or seal support plate146.

The threaded attachment member116and outer shell142combine to define, at least in part, an internal shell cavity148.

An element subassembly150(also referred to herein as “subassembly150”) is secured within the internal shell cavity148. The subassembly150includes a tubular ring of filter media152(also referred to herein as “filter media152”) that extends axially between first and second ends154,156. The tubular ring of filter media152and surrounds an internal media cavity158. The tubular ring of filter media152may be provided by pleated media and may have inner and outer wrappers for support and may also include a support core within the internal media cavity158.

First and second end caps160,162are attached to first and second ends154,156. The end caps160,162that operably seal the first and second ends154,156. The first and second ends154,156may be adhesively secured to the end caps160,162, the first and second ends154,156of the filter media152may be operably embedded into the first and second end caps160,162(e.g. if the end caps are plastic or formed from a polyurethane type material), or the end caps could be molded in plate such as from an appropriate plastic or polyurethane material.

In the illustrated embodiment, the first end cap160is annular and includes an opening that provides access therethrough to the internal media cavity158. The seal member124is operably mounted in the opening in the first end cap160. The seal member124also defines a central opening164that is in fluid communication with the internal media cavity158. The seal member124is axially snap engaged to the first end cap160within the opening of the first end cap160by one or more radially extending projections that overlaps with a portion of the first end cap160. The seal member124is sealed to the first end cap160to prevent fluid bypass between the seal member124and the first end cap160.FIG. 4also illustrates the first sealing region128and the repeating undulating geometry thereof.

With reference toFIG. 4, the central opening164is recessed axially into the outer shell142along axis118farther than the first seal region128.

The threads of the threaded attachment member116are clearly illustrated inFIG. 4as well.

With reference toFIGS. 3 and 8, the central opening164of the seal member124has a non-circular periphery. The non-circular periphery includes a pair of lobes165that provide the non-circular periphery. The non-circular periphery has a length L1that is greater than a width W1which is perpendicular to length L1. Both length L1and width W1are perpendicular to axis118. This non-circular periphery corresponds to a similarly shaped portion of the spud126to angularly align the first and second seal regions128,130.

With reference toFIGS. 3 and 5, the spud126is an axially extending member that defines a bore166that extends axially therethrough. The spud126includes a first axially extending portion168, a second axially extending portion170, and a third axially extending portion172that are axially offset from one another with the second portion positioned axially between the first and third portions.

With additional reference toFIG. 6, the first axially extending portion168defines a non-cylindrical outer surface174. As used herein, non-cylindrical shall mean that it does not have a circular outer periphery when viewed in cross-section. The non-cylindrical outer surface174includes a pair of radially outward extending lobes176that extend from a generally cylindrical section178. The cross-section of the non-cylindrical outer surface has a length L2that is greater than a width W2, which is perpendicular to length L2. Both length L2and width W2are perpendicular to axis118. The non-cylindrical outer surface174is used to angularly orient the spud126relative to seal member124such that the first and second seal regions128,130align when the primary filter element104is mounted to the filter head102. The length L2generally corresponds to length L1while width W2corresponds to width W1of opening164of the seal member124such that the two cross-sections generally correspond and mate with one another to properly angularly orient one another and such that torque may be transferred therebetween. While one particular shape is illustrated it is contemplated that other shapes could be provided. Further, the non-cylindrical outer surface could be provided by a plurality of features or shapes in order to create a custom profile for a particular application. For instance, different shapes or sizes could be used for filters for different systems to prevent use of an improper filter element.

With reference toFIG. 3, the second axially extending portion170defines the second seal region130.

With reference toFIGS. 3 and 7, the third axially extending portion172defines a mounting region that includes a first annular groove178that carries a seal member180illustrated in the form of an o-ring that seals the spud126to a body portion188of the filter head102and particularly the clean fluid port112thereof. The mounting region also includes a second annular groove182that carries a mounting ring184for axially securing the spud126to the rest of the filter head102. The mounting ring184is received in another groove186formed in body portion188of the filter head102. By providing this type of mounting of the spud126, the spud126is free to rotate about axis118to assist in angularly aligning the first and second sealing regions128,130when mounting the primary filter element104to the filter head102. The spud126in this embodiment is free to rotate about axis118relative to the threaded filter mounting interface114of the filter head102.

With reference toFIG. 2, when the primary filter element104is mounted to the filter head102, the first axially extending portion168of spud126extends through central opening164. This communicates the clean port112with the internal media cavity158of the filter media152. Further, with the first axially extending portion168extending through central opening164, the corresponding peripheral shapes of the two components (illustrated inFIGS. 6 and 8) cause proper angular alignment of the seal member124and spud126such that the corresponding first and second sealing regions128,130are properly angularly aligned.

With reference toFIG. 9, the initial threads for mounting purposes of the threaded filter mounting interface114is spaced a first axial distance D1from a distal end190of the spud126proximate/forming part of the first axially extending portion168with the non-cylindrical outer surface. The initial threads for mounting purposes of the threaded attachment member116are spaced a second axial distance D2from the central opening164. This allows the distal end190and the first axially extending portion168to be inserted into the central opening before the threads of the threaded filter mounting interface114and the threaded attachment member116engage during mounting purposes. As such, the user can properly angularly align the spud126with the seal member124and, thus, the corresponding first and second sealing regions128,130prior to beginning threaded engagement between the threaded filter mounting interface114and threaded attachment member116.

While not necessary, it is desireable that a third axial distance D3between the second sealing region130and distal end190is greater than a fourth axial distance D4between an axially outer side of the first sealing region128and the central opening164. This allows the distal end190to be inserted into the central opening164prior to the first and second sealing regions128,130coming into axial abutment/radial overlap. Again, this further facilitates angularly aligning the first and second sealing regions128,130relative to axis118.

With reference toFIG. 4, in some embodiments, the element subassembly150is rotatably carried within outer housing140as compared to threaded attachment member116. More particularly, a greater amount of torque is required to rotate the threaded attachment member116relative outer shell142about axis118than is required to rotate the element subassembly150relative to the threaded attachment member142. This allows the element subassembly150to rotate and further facilitate aligning the spud126with central opening164. Further yet, if the spud126becomes fixed relative to body188of the filter head102and particularly the threaded filter mounting interface114, the primary filter element104can still be rotated to engage the threaded filter mounting interface114with the threaded attachment member116. This also provides another embodiment in which the spud126is not rotatably mounted to the body188and is fixed angularly about axis118relative to the threaded filter mounting interface114. In this embodiment, the spud126and element subassembly150will remain in a fixed angular orientation with respect to the threaded filter mounting interface of the filter head102while the outer housing104(e.g. outer shell142and threaded attachment member116) rotates about axis118when mounting or removing the primary filter element104from the threaded filter mounting interface114.

In the illustrated embodiment, where the spud126is rotatably attached to body188, the spud126will typically rotate with the primary filter element104as the primary filter element104is rotatably secured to the filter head102. The spud126will rotate during mounting due to the angular engagement and torque transfer between the non-circular/non-cylindrical peripheries of the central opening164and first axially extending portion168.

A method of mounting the primary filter element104to the filter head102will be described. First, the first axially extending portion168of the spud126will be angularly aligned with the central opening164such that the first axially extending portion168can be axially inserted into the central opening (e.g. the corresponding non-circular/non-cylindrical geometries will be angularly aligned). This will also angularly align the first and second sealing regions128,130.

Thereafter/at substantially the same time, the first axially extending portion168of the spud126will be inserted axially into the central opening164until the initial threads of the threaded filter mounting interface114and threaded attachment member116axially abut (see e.g.FIG. 10).

The threads will then be rotatably engaged to attach the primary filter element104to the filter head102by rotating the outer housing140and particularly the threaded attachment member116relative to the threaded filter mounting interface. This will axially draw the primary filter element104towards the filter head102. The primary filter element104will be rotated relative to the filter head102until it is properly axially seated relative to the filter head102. This will occur when first housing seal120is properly axially compressed against a corresponding seal region194of the body188. This will also ensure that the first and second sealing regions128,130are properly radially engaged with one another to prevent fluid bypass between the seal member124and the spud126.

Depending on the embodiment, rotating the outer housing140rotates the spud126relative to the threaded filter mounting interface114, e.g. the embodiment where the spud126is rotatably mounted to body188. Further, in some embodiments, rotating the outer housing140rotates the element subassembly150relative to the outer housing140. This can be done by inhibiting rotation of the element subassembly150by angular engagement with an angularly fixed spud126.

While the prior discussion was based on the primary filter element104, the mounting of the secondary filter element106to the filter head102is similar to that of the primary filter element104. More particularly, a similar spud, central opening and undulating seal arrangement may be included.

Further, other embodiments need not include both a primary and a secondary filter element, but only a single filter element.

Further yet, while the central opening and the non-circular geometry thereof is provided by the snap in seal member124, other embodiments could have the non-circular opening through the end cap provided directly the end cap. In such an embodiment, the seal member would need to be properly angularly aligned relative to the non-circular profile of the central opening.