This disclosure concerns filter cartridges useful in a variety of systems including, for example, hydraulic tanks. In particular, this disclosure concerns filter cartridges with anti-drain back valves and methods of use.
Many hydraulic systems have tanks with filters in the tanks. In such systems, the filters are periodically changed out. During filter change out, it is helpful to keep contamination from getting into the clean hydraulic circuit. Anti-drain back valves are meant to close flow and prevent sediment and dirt captured by the filter from cross contamination.
A filter cartridge is provided to improve the prior art.
In an example, a filter cartridge is provided comprising: filter media arranged in a tubular shape defining an open filter interior, the filter media having first and second opposite ends; a first end cap secured to the first end of the filter media; the first end cap having an opening in communication within the open filter interior; a second end cap secured to the second end of the filter media; a central structure in the open filter interior extending away from the first end cap at least partially toward the second end cap; and an unbiased valve member within the open filter interior; the valve member being movable between a first position and a second position; the first position including the valve member covering the opening of the first end cap; and the second position including the valve member being spaced from the first end cap to expose the opening of the first end cap.
In various examples and/or embodiments:
In some examples or embodiments, there further includes:
In various examples and/or embodiments:
In various examples and/or embodiments:
In various examples and/or embodiments:
In another aspect, an in-tank filter assembly is provided including a tank; and a filter cartridge according to a various aspects above removably sealed within the tank.
A variety of examples of desirable product features or methods are set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practicing various aspects of the disclosure. The aspects of the disclosure may relate to individual features as well as combinations of features. It is to be understood that both the foregoing general description and the following detailed description are explanatory only and are not restrictive of the claimed invention.
In general, a filter cartridge with flow travelling from inside to outside with a flow path in a bottom end cap to enter the cartridge is provided with an anti-drain back valve to prevent cross-contamination to the clean side of the system during filter change-out. The anti-drain back valve moves away from the bottom end cap to allow inlet flow into the cartridge during filtering operation, and when flow ceases, the valve settles to the bottom of the cartridge to plug the flow path during service.
Still in reference to
In some example embodiments, the filter cartridge 100 further includes an optional layer of secondary media 113 circumscribing the filter media 110.
A first end cap 114 is secured to a first end 116 of the media 110. First end cap 114 includes an opening 118 to permit access to the filter interior 112, which corresponds to, in the arrangement shown, an unfiltered liquid volume 120. The unfiltered liquid volume 120 is defined, at least in part, by an inner diameter of the filter media 110.
A first seal member 124 can be oriented adjacent to the first end cap 114. Many variations of mounting the first seal member 124 are possible.
In the example shown, the first end cap 114 includes a seal holder 121 in the form of a rigid seal mount 122 projecting axially outwardly from an exterior portion. The term “outwardly” in this context, is meant to refer to a direction of projection away from the media 110. The mount 122 can be formed (for example molded) integral with a remainder of end cap 114. Although alternatives are possible, the example mount 122 shown includes a groove defined by spaced flanges that operate as a mounting space for the seal member 124. Although variants are possible, in the particular example shown, the mount 122 is configured such that the seal 124 is a radially, outwardly, directed form of seal. The particular seal member 124 depicted is an o-ring 124a, although alternatives are possible. The seal member 124 can form a seal with other filter structure, such as an additional filter cartridge or a housing piece.
In
A second end cap 140 is secured to a second end 142 of the filter media 110. The second end cap 140 can be closed or have an opening. In the example shown, the second end cap has an opening 144. In this embodiment, the opening 144 accommodates a central structure 170 (discussed further below). In this example, the second end cap 140 has a plurality of gussets 146 projecting axially outwardly from an exterior portion to the opening 144.
The second end cap 140 depicted has an optional handle 148. The handle 148 is secured to the exterior and can be pivoted from the illustrated position of flat against the exterior to a position 90° away from it.
The second end cap 140 is shaped as a tray 150 (
In this example, the second end cap 140 has an outer rim 155. In this particular example, the outer rim 155 is radially spaced radially outwardly from the outer tray wall 154.
The second end cap 140 holds a second end cap seal member 156. Many variations are possible. In the example shown, the outer rim 155 has a radial groove 158 holding the second end cap seal member 156 therein. The radial groove 158 is depicted as outwardly extending, but could be inwardly extending. The seal member 156 can form a seal with a cover or a filter head.
The filter cartridge 100 has a central longitudinal axis 101 (
The filter cartridge 100 further includes central structure 170 in the open filter interior 112 extending away from the first end cap 114 at least partially in extension toward the second end cap 140.
While many embodiments are possible, in the embodiment of
In reference now to
The flow tube 172 is provided to convey fluid, such as bypass flow, within the conduit 178. Alternatives are possible.
In this example, the flow tube 172 has a first end 184 adjacent the first end cap 114. The first end 184 of the flow tube 172 has a flow tube seal member 186. Many variations are possible, and in the example shown, the flow tube seal member 186 projects radially therefrom, but it could also be an axial seal or other methods, such as potting. In one example, the seal member 186 projects radially outward from the flow tube 172. The seal member 186 can form a seal with other structure, such as additional filter cartridges or housings. In embodiments that do not have flow tube 172, there is no seal member 186.
As can be seen in
The flow tube 172 has a second end 188 adjacent the second end cap 140. The second end 188 is shown extending axially outwardly from the second end cap 140, but it could be even with, or extending axially inwardly from the second end cap 140. The second end 188 of the flow tube 172 has a flow tube seal member 190. While there can be many alternatives, including radially inward or axial, in the example shown, the flow tube seal member 190 projects radially therefrom. In the example shown, the seal member 190 projects radially outward from the flow tube 172. The seal member 190 can form a seal with a filter head or housing structure.
In accordance with principles of this disclosure, the filter cartridge 100 includes a valve member 200. The valve member 200 is positioned within the open filter interior 112. The valve member 200 is movable between a first position (
In one example, the first position (
In one example, the second position (
In an example implementation, and in reference now to
The valve member 200 is positioned to be radially constrained by the central structure 170. By “radially constrained”, it is meant that the central structure 170 prevents movement of the valve member 200 in a radial direction. By “radial direction”, it is meant a direction orthogonal to the longitudinal axis 101 (
In the example shown, the valve member 200 is positioned to be in intimate communication with the central structure 170, such that the central structure 170 rests within the through opening 204 of the valve member 200. By comparing
Still in reference to
The plate 218 has a first axial surface 222 and an opposite second axial surface 224. The first axial surface 222 faces the first valve end 208 and first end cap 114. The second axial surface 224 faces the second valve end 210 and the second end cap 140.
The first axial surface 222 forms a seal surface 226 to cover the inlet arrangement 180 and form a seal to prevent flow from the filter interior 112 and the unfiltered liquid volume 120. This will prevent cross-contamination to the clean side of the system during filter change-out. The valve 200 settles to the bottom of the cartridge 100 to substantially close the flow path 180 during service. By “substantially close”, it is meant that an intentional leak path is permitted to prevent excessive suction. In this example, and as can be seen in
Referring again to
The valve 200 optionally includes a second plurality of gussets 234 extending downward and radially away from the second valve end 210 to the second axial surface 224. The gussets 234 can provide strength to the valve 200.
The valve member 200 is constructed of a material having a specific density greater than that of the fluid (such as hydraulic oil) being filtered. This ensures that the valve member 200 sinks in the fluid when there is no filtering operation. During filtering operation, the pressure differential will push the valve member 200 away from the inlet arrangement 180. The valve member 200 is free to move along the exterior surface 175 of the flow tube 172. The valve member 200 can move to the second end cap 140 and against the plurality of gussets 146 in the opening 144 of the second end cap 140. Full flow is permitted between the valve member 200 and the opening 144 of the second end cap 140 to allow for, for example, bypass flow. During servicing, when flow through the cartridge 100 stops, the valve member 200 sinks to the bottom of the cartridge 100 to block the flow path 180.
In reference now to
In an example, the rigid post 302 extends from a first end cap 305 only partially toward the second end cap 140. For example, the rigid post 302 extends from the first end cap 305 less than 50% of a length of the filter cartridge 300 toward the second end cap 140. In other embodiments, the post 302 could extend a full length of the cartridge 300 between the first end cap 305 and second end cap 140.
The valve member 304 comprises a non-porous disk 306 having a through-opening 308. The rigid post 302 is in intimate communication with the through-opening 308. The through opening 308 is sized to allow the valve member 304 to freely move (slide) along the post 302.
In this example embodiment, the disk 306 includes an outer rim 312. The outer rim 312 is sized to be just slightly smaller than the inner diameter of the media 110. The disk 306 includes a first axial side 314 and second opposite axial side 316. The first axial side 314 faces the first end cap 114.
The first axial side 314 has a circumferential ridge 320 projecting therefrom and spaced radially inboard from the outer rim 312. The first axial side 314 has seal surface 322 between the outer rim 312 and the ridge 320. The second axial side 316 also has a circumferential ridge 321 projecting therefrom and spaced radially inboard from the outer rim 312.
In this example embodiment, the valve member 304 further includes a plurality of ribs 326 on each of the first and second axial sides 314, 316 axially projecting from the first and second axial sides 314, 316 and radially extending from the through-opening 308.
In this embodiment, the first end cap 305 includes a tray 330 holding the filter media 110 and having an inner tray wall 332. A central hub 334 is in a first end cap opening 336. A plurality of spokes 338 extends between the hub 334 and the inner tray wall 332. An inlet arrangement 340, between the spokes 338, allows for fluid to be filtered to enter the cartridge 300 and into the filter interior 112.
The seal surface 322 of the first axial side 314 covers the inlet arrangement 340 to engage a terminal end of the inner tray wall 332 and forms a seal to prevent flow from the filter interior 112 and the unfiltered liquid volume 120. This will prevent cross-contamination to the clean side of the system during filter change-out. The valve 304 settles to the bottom of the cartridge 300 to substantially close the flow path 340 during service. By “substantially close”, it is meant that an intentional leak path is permitted to prevent excessive suction.
In this example, the rigid post 302 projects from the central hub 334 into the open filter interior 112. A terminal end of the rigid post 302 includes a radial projection 344 larger than the through opening 308 of the disk 306 to trap the disk 306 on the post 302. Many alternatives are possible.
In operation, fluid to be filtered enters the cartridge 300 through the inlet arrangement 340 and moves the valve member 304 away from sealing contact with the inner tray wall 332 of the first end cap 305. This allows the fluid to flow into the filter interior 112. During servicing, when flow through the cartridge 300 stops, the valve member 304 sinks to the bottom of the cartridge 300 to block the flow path 340.
A variety of ways to provide a seal member on the valve member 200, 304 can be implemented, and the above are just examples. Further examples are shown in
A bulb seal 402 (
A wedge seal 406 (
A torus shaped (i.e., ring or donut-shaped) seal 412 (
The above represents example principles. Many embodiments can be made using these principles.
This application claims the benefit of U.S. Provisional Patent Application No. 63/223,699, filed Jul. 20, 2021, which is incorporated by reference herein in its entirety.
Number | Date | Country | |
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63223699 | Jul 2021 | US |