CN113509772B

CN113509772B - Filter base pipe with standpipes and flow fins

Info

Publication number: CN113509772B
Application number: CN202110907686.2A
Authority: CN
Inventors: J·R·里斯; B·A·莫里斯; S·D·欧尼斯
Original assignee: Caterpillar Inc
Current assignee: Caterpillar Inc
Priority date: 2016-06-17
Filing date: 2017-06-14
Publication date: 2023-07-28
Anticipated expiration: 2037-06-14
Also published as: DE102017113258A1; CN113509772A

Abstract

The present invention relates to a filter base pipe having a standpipe and flow fins, in particular a base pipe for use with a filter element, the base pipe comprising a unitary body having a standpipe defining a length along a longitudinal axis and a central flow passage, and a plurality of radially extending flow fins attached to the standpipe, the flow fins being axially spaced from one another along the standpipe to define radial flow passages, wherein each fin further defines a first aperture between the fin and the standpipe, the apertures together defining a first outer axial flow passage and the standpipe defining a rectangular shape.

Description

Filter base pipe with standpipes and flow fins

The present application is a divisional application of chinese invention patent application with application date 2017, 6, 14, 201710446313.3, and the inventive name "filter center tube with standpipe and flow fins".

Technical Field

The present invention relates to a filter element for filtering fluids using a filter medium wrapped around a center tube or the like. More precisely, the invention relates to a central tube for a filter, which central tube limits the risk of air entrapment during start-up of the filter.

Background

Filter elements and filter systems for filtering fluids such as fuel are well known in all areas of use of combustion engines, including earthmoving, construction and mining equipment. A filter system is typically provided that separates water or contaminants from the fuel prior to entering the engine. The filter element is typically provided as part of the system, which includes filter media wrapped around a center tube. The tube and filter media arrangement is typically substantially circular or cylindrical.

For example, fig. 1 illustrates a filter system 100 having a base 102, a filter cartridge 104, and a filter element 106. The general configuration and use of cartridge filter systems is understood by one of ordinary skill in the art. Accordingly, all details of the configuration and use of cartridge filter system 100 need not be explained herein. Cartridge filter system 100 may be used to filter fluids such as diesel or gasoline or other liquid fuels, lubricating oils, hydraulic fluids for hydraulic power systems, transmission fluids, or possibly even intake air for engines. The cartridge filter system 100 may also be used as a filter for a fuel/water separator. Cartridge filter system 100 having the features described herein may be used by one of ordinary skill in the art to serve a variety of different purposes and to adapt to a variety of other applications.

The base 102 includes an inlet channel 108 for fluid to enter the filter system 100 and an outlet channel 110 for fluid to exit the filter system 100. The base 102 also includes base threads 112. Other attachment structures other than threads may be used.

The filter cartridge 104 includes an open end 114 and a closed end 116. Adjacent to the open end 114 is cartridge threads 118 that are engageable with the base threads 112 to retain the cartridge 104 to the base 102. Threads are one example of engagement structures that may be included on the base 102 and the filter cartridge 104 to form a releasable engagement. One of ordinary skill in the art will recognize that other engagement structures may be used.

The filter element 106 may take a variety of different forms to suit a particular application. In the illustrated embodiment, the filter element 106 is well suited for use in filtering fuel or lubricating oil. The filter element 106 may include an annularly disposed filter media 120 circumferentially surrounding a central reservoir defined by a central tube 122. The axial ends of the filter media 120 are sealed by end plates or caps. The open end cap 124 defines an axial open end of the filter element 106. The open end cap 124 is referred to as an "opening" because it includes an opening 126 for allowing fluid to pass from the central reservoir defined by the central tube 122 to the outlet channel 110. The closed end cap 128 defines an axial closed end of the filter element 106 at a bottom portion thereof. The closed end cap 128 is referred to as "closed" because it prevents any fluid at the axial end of the filter element 106 adjacent to the filter media 120 from flowing unfiltered into the center tube 122. Open end cap 124 and closed end cap 128 may each be joined to center tube 122 via welding, adhesives, or the like. Alternatively, some or all of the central tube 122, open end cap 124, and closed end cap 128 may be constructed as a unitary component. Alternatively, they may be composed of multiple components. In other embodiments, the top cover may be closed and the bottom cover may be open.

Fluid to be filtered (indicated by arrows 134) enters from the inlet passage 108 and flows to the annular cavity 130 between the filter cartridge 104 and the filter media 120. The fluid then enters and passes through the filter media 120 and then enters the center tube 122 through perforations 132 shown here in fig. 1. Fluid exits the center tube 122 through the open end cap 124 and the opening 126 into the outlet passage 110. Open end cap 124 and closed end cap 128 help define fluid passages into and out of filter media 120 to prevent any fluid from flowing directly to outlet passage 110 and bypassing filter media 120.

First and second annular seals 136 and 138 may advantageously be included on the filter element 106 and also help define and seal fluid passages into and out of the filter element 106. A first annular seal 136 may be included on the open end cap 124 around the opening 126 and adjacent the axially open end of the filter element 106 to help seal the inlet passage 108 from the outlet passage 110. A second annular seal 138, which is larger in diameter than the first annular seal 136, may be formed circumferentially around the open end cap 124 to provide a seal between the filter cartridge 104 and the base 102, or in other words to prevent fluid in the inlet passage 108 from leaking out of the joint between the filter cartridge 104 and the base 102. The first and second annular seals 136, 138 may be integrally formed with the open end cap 124 or attached using adhesives or other methods known in the art. When the first and second annular seals 136, 138 are integrally formed on or included with the open end cap 124, proper replacement of these seals may be ensured when the filter element is replaced at proper intervals. Otherwise, the technician may not be able to properly replace the seals at the proper intervals, which may result in leakage out of or within the system, allowing unfiltered fluid to bypass the filter element 106 and result in contamination.

The drain 140 is typically provided at the bottom of the filter housing and opens via some sort of threaded connection. However, in other cases, the filter assembly and the filter lines connected to the filter assembly are typically closed systems. The vent is not used to replace the exiting fluid and contaminants which do not flow out of the housing or if they can flow out, they can only be intermittent and inefficient as they leave the exhaust. A drain reservoir 142 is provided at the bottom of the filter cartridge 104 that allows water or other contaminants to deposit there over time. Eventually, these substances are discharged from the reservoir via the discharge portion 140. Any exhaust known or contemplated in the art may be used for any of the contaminants discussed herein.

The filter element 106 may have a generally cylindrical configuration defining a longitudinal axis L and a radial direction R. Other configurations are also possible. Prior to attaching the filter element 106 to the filter system 100, the filter element 106 is typically primed by pouring some of the fluid, such as fuel, into the filter element 106. A fill jacket 144 is shown disposed in fig. 1 to help prevent unfiltered fluid from entering the center tube 122, which may allow unfiltered fluid to enter the engine after the filter element 106 has been attached to the filter system 100. Because of the absence of a standpipe, air may penetrate the filter media and exit the filter before any desired fluid, such as fuel, has had an opportunity to pass through the filter media. The air bubbles may reach the pump or the engine, causing problems in starting the engine.

Fig. 2 shows another design of a center tube 122' with a standpipe 146. The standpipe eliminates the problem of poor priming caused by air bubbles, as air bubbles can reside near the top of the annular flow passage 148 near the standpipe 146. A disadvantage of the design of the center tube 122' shown in fig. 2 is that the bottom of the tube needs to be opened when the mandrel expands and contracts from the bottom to form the outer annular flow channel 148. Similarly, when the center tube 122' is manufactured using an injection molding process, another mandrel is retracted from the top to form the internal tapered flow channel 150 of the standpipe 146. This limits the versatility of the structure that may be formed at the end of the center tube and may increase molding complexity and increase costs beyond expectations.

Disclosure of Invention

A filter element is provided having a generally cylindrical configuration and defining a longitudinal axis and a radial direction. The filter element includes a center tube having a length along a longitudinal axis, and the center tube includes a standpipe defining a length along the longitudinal axis and a central flow passage extending a majority of the length of the center tube along the longitudinal axis, a plurality of radially extending flow fins attached to and extending from the standpipe and axially spaced from each other to define radial flow channels, wherein each fin further defines a hole between the fin and the standpipe that together define an outer axial flow passage extending along the standpipe, wherein the standpipe further defines at least one radial flow passage in fluid communication with the outer axial flow passage and the central flow passage, wherein the standpipe and the outer axial flow passage are not in fluid communication with each other along a majority of the length of the standpipe. The annular filter media surrounds the center tube and the central flow passage and contacts the flow fins. The first open end is coupled to a center tube disposed along the longitudinal axis, the center tube including an opening to allow fluid flow from the central flow passage to an exterior of the filter element, and the second end is coupled to the center tube opposite the open end disposed along the longitudinal axis, the second end including a first end cap.

A center tube for a filter element is provided. The center tube includes a unitary body having a generally cylindrical outer configuration defining a longitudinal axis, a radial direction, and a length along the longitudinal axis from a first end to a second end, a standpipe defining a length along the longitudinal axis and a central flow passage extending a majority of the length of the center tube along the longitudinal axis, a plurality of radially extending flow fins attached to the standpipe and axially spaced from one another along the standpipe to define a radial flow passage, wherein each fin further defines an aperture between the fins and the standpipe that together define a first outer axial flow passage extending along a majority of the length of the standpipe without being in fluid communication with the central flow passage of the standpipe, and wherein the standpipe defines a cross section perpendicular to the longitudinal axis that includes a rectangular shape to define an inner perimeter defining a flow area of the central flow passage.

A filter system is provided that includes a filter cartridge including an open end and a closed end, a base including an inlet passage for allowing fluid into the filter cartridge and an outlet passage for allowing fluid out of the filter cartridge, and an attachment structure for allowing attachment of the filter cartridge, a drain penetrating through the closed end of the filter cartridge and including an attachment structure, and a filter element including a generally cylindrical configuration and defining a longitudinal axis and a radial direction. The filter element includes a center tube having a length along a longitudinal axis, and the center tube includes a standpipe defining a length along the longitudinal axis and a central flow passage extending a majority of the length of the center tube along the longitudinal axis, and a plurality of radially extending flow fins attached to and extending from the standpipe, the flow fins being axially spaced from one another along the standpipe to define radial flow passages, wherein each fin further defines first and second apertures between the fin and the standpipe that together define first and second outer axial flow passages extending along the standpipe, wherein the standpipe further defines at least one radial flow passage in fluid communication with the outer axial flow passages and the central flow passage. The annular filter media surrounds the center tube and the central flow passage and contacts the flow fins. A closed end is coupled to the center tube opposite the open end disposed along the longitudinal axis, the closed end including an end cap, wherein the fins define a flow area perpendicular to the longitudinal axis for the first and second outer axial flow channels, and the standpipe defines a flow area perpendicular to the longitudinal axis for the center flow channel, wherein the combined flow area of the first and second outer axial flow channels is approximately the same as the flow area of the center flow channel.

Drawings

FIG. 1 is a perspective cross-sectional view of a filter system known in the art using a center tube without a standpipe.

Fig. 2 is a front cross-sectional view of a filter with a center tube having a standpipe according to an embodiment known in the art.

FIG. 3 is a perspective cross-sectional view of a filter system using a filter having a center tube with standpipe and flow fins, in accordance with an embodiment of the present invention.

FIG. 4 is a top perspective view of the center tube of FIG. 3 shown removed from the filter and filter system of FIG. 3.

Fig. 5 is a bottom perspective view of the center tube shown in fig. 4.

FIG. 6 is a top view of an embodiment of the center tube of the present invention having a standpipe illustrating the downward projected flow area provided by the center tube both inside and outside of the standpipe.

FIG. 7 is a bottom perspective view of another embodiment of a base pipe of the present invention having a standpipe and differently configured flow fins.

Fig. 8 is a top perspective cross-sectional view of the center tube shown in fig. 7.

FIG. 9 is a partial plan view of a mold showing two cores as part of two mold halves forming fins, risers and holes therebetween, wherein the cores are shown using different cross-hatching, and the overlapping of these patterns shows the location of the angled cutoffs forming the holes between the two cores.

Fig. 10 is a partial plan view of the mold of fig. 9 with the mold core disengaged.

FIG. 11 is a partial perspective view of the mold cores of FIG. 10 illustrating how the protrusion of one mold core mates into the groove of the other mold core while also cutting off the surface of the other mold core, creating a hole disposed between the standpipe and the fin.

FIG. 12 is a side cross-sectional view taken along section line 12-12 of FIG. 9, more clearly showing the angled cutoffs and the fin cavities formed by the two mold cores.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. In some cases, reference numerals will be indicated in this specification and the views will show reference numerals followed by letters, for example 100a, 100b or an apostrophe indication such as 100', 100 ". It should be understood that the use of letters or prime numbers immediately following the reference numerals indicate that these features are similarly shaped and have similar functionality, such as is typically the case where the geometry is mirrored about a plane of symmetry. For ease of explanation in this specification, letters or apostrophes will not generally be included herein, but may be shown in the drawings to indicate repetition of features discussed in the written specification.

The present invention provides a center tube having a standpipe and radially extending flow fins that create a central flow passage and an outer axial flow passage that are in fluid communication only near the bottom of the center tube. A filter element comprising such a central tube would be less prone to capture air that may form during filling. Further, the standpipe may be configured rectangularly, reducing mold complexity and allowing closed end features to be formed on the center tube.

Referring to fig. 3, a filter system 200 having a base 202, a cartridge 204, and a filter element 206 is illustrated. The general configuration and use of cartridge filter systems is understood by one of ordinary skill in the art. Accordingly, all details of the configuration and use of cartridge filter system 200 need not be explained herein. Cartridge filter system 200 may be used to filter fluids such as diesel or gasoline or other liquid fuels, lubricating oils, hydraulic fluids for hydraulic power systems, transmission fluids, or possibly even intake air for engines. Cartridge filter system 200 may also be used as a filter for a fuel/water separator. Cartridge filter system 200 having the features described herein may be used by one of ordinary skill in the art to serve a variety of different purposes and to suit a variety of other applications.

The base 202 includes an inlet channel 208 for fluid to enter the filter system 200 and an outlet channel 210 for fluid to exit the filter system 200. The base 202 also includes base threads 212. Other attachment structures other than threads may be used.

Canister 204 includes an open end 214 and a closed end 216. Adjacent to the open end 214 is cartridge threads 218 that are engageable with the base threads 212 to retain the cartridge 204 to the base 202. Threads are one example of engagement structures that may be included on base 202 and filter cartridge 204 to form a releasable engagement. One of ordinary skill in the art will recognize that other engagement structures may be used.

The filter element 206 may take a number of different forms to suit a particular application. In the illustrated embodiment, the filter element 206 is well suited for use in filtering fuel or lubricating oil. The filter element 206 may include an annularly disposed filter media 220 circumferentially surrounding a central flow passage 250 defined by a center tube 222. The axial ends of the filter media 220 are sealed by end plates or caps. The open end cap 224 defines an axial open end of the filter element 206. The open end cap 224 is referred to as an "opening" because it includes an opening 226 for allowing fluid to pass from the central reservoir defined by the central tube 222 to the outlet channel 210. The closed end cap 228 defines an axial closed end of the filter element 206 at a bottom portion thereof. The closed end cap 228 is referred to as "closed" because it prevents any fluid at the axial end of the filter element 206 that is adjacent to the filter media 220 from flowing unfiltered into the center tube 222. The open end cap 224 and the closed end cap 228 may each be joined to the center tube 222 via welding, adhesives, or the like. Alternatively, some or all of the center tube 222, open end cap 224, and closed end cap 228 may be constructed as a unitary component. Alternatively, they may be composed of multiple components. In other embodiments, the top cover may be closed and the bottom cover may be open.

Fluid to be filtered (indicated by arrow 234) enters from inlet channel 208 and flows to annular cavity 230 between canister 204 and filter medium 220. The fluid then enters and passes through the filter media 220, and then enters radial flow channels 256 defined by one or more radially extending flow fins 254 attached to the standpipe 246 of the center tube 222 and contacting the filter media 220, thereby supporting the media during manufacture and when in use. The fluid then flows down the axial flow channels 248 until the fluid bottoms out and passes through the radially extending flow channels 252 of the standpipe 246 and into the central flow channel 250 of the standpipe 246. The fluid then flows upward from the central flow passage 250 and exits the center tube 222 through the open end cap 224 and the opening 226 into the outlet passage 210. Open end cap 224 and closed end cap 228 help define fluid passages into and out of filter media 220 to prevent any fluid from flowing directly to outlet passage 210 and bypassing filter media 220.

First and second annular seals 236 and 238 may be advantageously included on the filter element 206 and also help define and seal fluid passages into and out of the filter element 206. A first annular seal 236 may be included on the open end cap 224 around the opening 226 and adjacent the axially open end of the filter element 206 to help seal the inlet passage 208 from the outlet passage 210. A second annular seal 238, larger in diameter than the first annular seal 236, may be formed circumferentially around the open end cap 224 to provide a seal between the filter cartridge 204 and the base 202, or in other words to prevent fluid in the inlet channel 208 from leaking out of the joint between the filter cartridge 204 and the base 202. The first and second annular seals 236, 238 may be integrally formed with the open end cap 224 or attached using adhesives or other methods known in the art. When the first and second annular seals 236, 238 are integrally formed or included on the open end cap 224, proper replacement of these seals may be ensured when the filter element is replaced at proper intervals. Otherwise, the technician may not be able to properly replace the seals at the proper intervals, which may result in leakage out of or within the system, allowing unfiltered fluid to bypass the filter element 206 and result in contamination.

The drain 240 is typically provided at the bottom of the filter housing and opens via some type of threaded connection. However, the filter assembly and the filter lines connected to the filter assembly are typically otherwise closed systems. The vent is not utilized to replace the exiting fluid and contaminants with air, which would not flow out of the housing, or if they do so, they would leave the exhaust inefficiently upon ejection. A drain reservoir 242 is provided at the bottom of the filter cartridge 104 that allows water or other contaminants to deposit there over time. Eventually, these substances are discharged from the reservoir via the discharge portion 240. Any drain known or contemplated in the art may be used with any of the embodiments described herein. For reasons set forth earlier herein, a fill sheath 244 is shown to help prevent unfiltered fluid from entering the central flow passage 250.

Referring now to FIG. 3, a filter system 200, 300 according to an embodiment of the invention may be described below. The filter system 200, 300 may include a filter cartridge 204 including an open end 214 and a closed end 216, a drain 240 penetrating through the closed end 216 of the filter cartridge 204 and including an attachment structure 258, and a filter element 206 including a generally cylindrical configuration and defining a longitudinal axis L and a radial direction R.

As best seen in fig. 4 and 7, for example, in conjunction with fig. 3, the filter element 206 may include a center tube 222, 322 defining a length L222, L322 along a longitudinal axis L (see fig. 4 and 7) and including a standpipe 246 defining a length L246 along the longitudinal axis L and a central flow passage 250 extending a majority of the length L222, L322 along the longitudinal axis L to define a radial flow passage 256, a plurality of radially extending flow fins 254, 354 attached to the standpipe 246, wherein each of the fins 254, 354 further define first and second apertures 260, 360, 262, 362 defining first and second outer axial flow passages 248, 348 extending along a majority of the length L246 of the standpipe 246 without being in fluid communication with the central flow passage 250. The standpipe 246 further defines at least one radial flow passage 252 in fluid communication with the outer axial flow passages 248, 348 and the central flow passage 250.

Focusing only on fig. 3, the annular filter media 220 surrounds the center tubes 222, 322 and the center flow channels 250 and contacts the flow fins 254, 354. Opposite the open end disposed along the longitudinal axis L, a closed end is coupled to the center tubes 222, 322, which includes the end cap 216. That is, the first end cap is closed to prevent fluid from exiting through the second end of the filter element. The fins 254, 354 define a flow area 264, 364 (shown by cross hatching in fig. 6) for the first and second outer axial flow channels 248, 348 that is perpendicular to the longitudinal axis L, and the standpipes 222, 322 define a flow area 266 (shown by cross hatching in fig. 6) for the central flow channel 250 that is perpendicular to the longitudinal axis L, wherein the combined flow area 264, 364 of the first and second outer axial flow channels is substantially the same as the flow area 266 of the central flow channel. The ratio of flow areas will be discussed in more detail herein after with reference to fig. 6. It is contemplated that the ratio of flow areas may vary depending on the response or desire so that they may not be about the same, etc.

The filter system 200, 300 of fig. 3 further includes a base 202 including an inlet channel 208 for allowing fluid to enter the cartridge filter system and an outlet channel 210 for allowing fluid to exit the cartridge filter system, and attachment structures 212, 218 for allowing attachment of the cartridge 204. The filter element 206 may further include a second end cap 224 coupled to the center tubes 222, 322 and configured to allow flow from the center flow channel 250 to the exterior of the filter element 206.

For the particular embodiment shown in fig. 3, 4 and 7, the standpipe 246 includes a rectangular configuration, but the shape can vary as desired or required, as will be discussed later herein. Further, the length L268 of the standpipe 246, measured along the longitudinal axis L, that is not in fluid communication with the axial flow passages 248, 348 may be 60-80% and may be approximately 70% of the length L246 of the standpipe. Similarly, the length L246 of the standpipe can be 60-90% and can be nearly 80% as compared to the overall length L222, L322 of the base pipe. In other embodiments, any of these lengths or ratios may be varied as needed or desired.

Turning now to fig. 4, 5, 7 and 8, the filter element 206 of fig. 3 may include a center tube 222, 322 having the following features. The radial flow channels 252 defined by the standpipe 246 may be in fluid communication with radial flow channels 256 defined at least in part by the flow fins 254, 354 (see, for example, the radial flow channels illustrated in fig. 4, 5, 7, and 8) and with the outer axial flow channels 248, 348.

Looking now at fig. 6, the standpipe 246 defines a cross-section 270 that is perpendicular to the longitudinal axis L and is non-circular. The cross-section 270 is rectangular in shape with an inner perimeter 272 that defines the flow area 266 of the central flow channel 250. The plurality of fins define a flow area 264, 364 of the outer axial flow channels 248, 348 that is perpendicular to the longitudinal axis L and is created by projecting all edges of the holes 260, 262, 360, 362 defining the flow channels 248, 348 onto a radial plane. This area 264 on each side of the standpipe is at least half of the flow area 266 of the central flow passage 250. In other words, each of the fins 254, 354 defines a second aperture 262, 362 defining a second outer axial flow channel 248', 348' configured similarly to the first outer axial flow channel 248, 348 and having the same flow area, wherein the total flow area 264, 364 of the outer axial flow channels 248, 348 is substantially the same as the flow area 266 of the central flow channel 250. In some embodiments, the flow areas 264, 364 may be 175mm2 and the flow area may be 185mm2. Thus, approximately equal means that they fall within 10% of each other. These areas and their ratios may be varied as needed or desired.

Turning to fig. 4, 5, 7, and 8, in certain embodiments, the center tube 222, 322 may include a unitary body 274, 374 defining a generally cylindrical outer configuration defining a longitudinal axis L, a radial direction R, and a length L222, L322 along the longitudinal axis L from the first end 276 to the second end 278. The standpipe 246 further defines at least one radial flow passage 252 in fluid communication with the outer axial flow passages 248, 348 and the central flow passage 250. For the particular embodiment shown in these figures, the radial flow channels 252 of the standpipe 246 are in direct communication with radial flow channels 256 defined at least in part by the flow fins 254, 354 and in fluid communication with the outer axial flow channels 248, 348. In other embodiments, the radial flow passage of the standpipe may be in direct fluid communication with an external axial flow passage. That is, the radial flow passage of the standpipe can be rotated 90 ° about the longitudinal axis L.

Each of the plurality of fins 254, 354 includes, at least in part, a generally annular shape, and the standpipe 246 includes first, second, third, and fourth sides 280, 282, 284, 286 defined by the rectangular shape of the standpipe 246, and a plurality of fins 288, 388 of the fins 254, 354, such as every other fin along the longitudinal axis L, may extend from the first side 280 of the standpipe 246 and be spaced apart from the second side 282 of the standpipe 246 to define first apertures 260, 360 defining the external axial flow channels 248, 348. The plurality of fins 288, 388 may be spaced apart from the third side 284 of the standpipe 246 on an opposite side of the standpipe 246 from the second side 282 to define second apertures 262, 362 defining second external axial flow passages 248', 348'.

Referring to fig. 4 and 5, a plurality 288 of fins are attached to a fourth side 286 of the standpipe 246 opposite the first side 280 to close the perimeter of the holes 260, 262 forming the first and second external axial flow passages 248, 248'. In contrast in fig. 7 and 8, the plurality of fins 388 have portions 390 of the fins that are not connected to the remainder of the fins. Thus, the apertures 360, 362 have an open perimeter.

Referring back to fig. 4 and 5, each of the plurality 288 of fins 254 includes a first level 290 and a second level 292 (best seen on the second uppermost example of the fins in fig. 4 and 5), wherein the first level 290 extends from the first side 280 of the standpipe 246 and the second level 292 extends from the fourth side 286 of the standpipe 246 about the second and third sides 282, 284 to join the first level 290 to create a first step 294 between the first and second levels 290, 292. Each of the plurality 288 of fins 254 includes a third level 296 extending from the first side 280 of the standpipe 246 to divide the first level 290 into two portions and create a second step 298 between the first and third levels 294, 296. This third level 296 is an optional design choice and may be omitted in other embodiments. The first step 294 defines a planar surface that is coplanar with the first side 280 of the standpipe 246. Thus, each fin is similarly configured except that the configuration of one fin is rotated 180 ° about the longitudinal axis L as compared to an adjacent fin along the longitudinal axis L. This is an alternative arrangement of fins that also exist in the embodiment of the center tube 322 shown in fig. 7 and 8.

Referring to the two embodiments in fig. 4, 5, 7, and 8, the center tube 222, 322 can further include a first barrel portion 299, 399 attached to the standpipe 246 at the first end 276 and a second barrel portion 299', 399' attached to the standpipe 246 at the second end 278, wherein at least one barrel portion 299, 399, 299', 399' defines a void 297, 397 in fluid communication with the central flow channel 250.

In some, but not all embodiments, such as the one shown in fig. 7 and 8, the other barrel portion 399 'defines a void 397' that is not in fluid communication with the central flow passage 250. It is observed that the bowl portion 399', which is not in fluid communication with the central flow passage 250, includes an annular wall 395 that is disposed within a void 397' of the bowl that includes internal threads 393. An air pocket 391 is defined between the annular wall 395 and the remainder of the barrel, with a threaded interior of the annular wall defining an attachment pocket 389. It is contemplated that the attachment pockets and air pockets may be defined by the end caps in other embodiments.

Industrial applicability

Specifically, the machine may be sold or retrofitted with the filter systems 200, 300, filter elements 206, or center tubes 222, 322 described herein.

The center tubes 222, 322 may be injection molded as a single or unitary piece. Due to the alternative arrangement and orientation of the fins 254, 354, a similarly configured mold core may form fins that are arranged in an alternating pattern, oriented toward each other and interlocked with each other in a direction perpendicular to the first side 280 or the fourth side 286 of the standpipe 246. The use of a rectangular configuration for the standpipe eliminates undercuts that would be extremely difficult to strip, and the fact that the first step 294 is coplanar with the first side 280 of the standpipe 246 allows for the use of straight core drawing to strip the fins 254, 354 without the use of complex parting lines or the like. It is contemplated that other non-circular configurations may be used as long as they do not create an undercut.

Fig. 9-11 illustrate one example of fins 254, standpipe portion 246, and holes 260, 262 therebetween to best explain the unique utility of the geometry of center tube 222 illustrated in fig. 4 and 5. It will be appreciated that the mould constituting the alternating pattern of fins and holes of figures 4 and 5 will in fact comprise groups of mould cores which will now be described and which alternate in their direction along the longitudinal axis of the standpipe.

Fig. 9 illustrates a first or bottom mold core 400 that includes two thin tabs 402 that help form the holes 260, 262 disposed between the fins 254 and the standpipes 246. The extent of the bottom mold core 400 shown using the first cross hatching extends from bottom right to top left in fig. 9. The second or bottom mold core 404 includes two thicker projections 406, a portion of which facilitates forming the holes 260, 262 disposed between the fins 254 and the standpipe 246. The extent of the top mold core 404 shown using the second cross hatching extends from upper right to lower left. The areas where these patterns overlap indicate the angled cutoffs 408 formed by the protrusions 404, 406 of the cores 400, 404, creating the apertures 260, 262 disposed on either side of the standpipe 246. A third cross-hatched pattern is also provided that indicates the area 412 where an undercut would result if a circular profile 410 were used for standpipe 246.

It should be noted that the mold core forming the interior of the standpipe 246, which would be a negative image of the central flow passage 250, has been omitted for clarity. The core is removed using a shrink structure such as a sliding action. If internal threads 393 and air pockets 391 are formed on the other end of center tube 222, these features may similarly be created using a non-threaded mechanism, a sliding action, or other mechanism to eliminate undercuts before the part is ejected from the mold.

Turning to fig. 9, when the mold is closed or when the mold cores 400, 404 are otherwise proximate to one another, as indicated by arrow 414, the desired geometry of the center tube 222 is established by the cavity formed in the mold cores and the angled interruptions 408 between the projections 402, 406 of the mold cores 400, 404. The plastic is then injected into the cavity until it cools and the part solidifies sufficiently to allow the part to be ejected from the mold. The mold is then opened or the mold cores 400, 404 are otherwise disengaged from each other, as indicated by arrow 416. If there is an undercut in the disengagement direction, the mold core will have to pull apart or otherwise damage the standpipe 246, which is undesirable. For example, if the upper undercut 412 is formed by the bottom mold core 400, as would be the case if the angled cutoffs 408 were desired to be created to form the holes 260, 262, that area would be damaged when the mold is opened. If the undercut 412' were to be formed by the top mold core 404 as would be the case if the angled cutoffs 408 were to be created to form the holes 260, 262, this area would be damaged when the mold is opened.

In contrast, as best seen in, for example, FIGS. 9 and 10, if the semi-circular portion 412' is formed by a portion of the mold core that is located on the bottom mold core 400, a feathered edge 424 on the bottom mold core 400 may be required to intercept the opposing mold core 406. These feathered edges 424 can inherently weaken and can quickly fracture during molding, and damage such as tearing and scratching can occur to the plastic part due to any deformation of the feathered edges 424 when the mold is opened, which can result in mold downtime and mold repair and possible scrap of the plastic part.

Since the standpipe 246 additionally has a rectangular profile, these undercut or feathered edges are not formed, allowing for flat drawing of the mold cores 400, 404 without damaging the standpipe 246, while still forming the holes 260, 262 between the fins 254 and the standpipe 246 during the injection stage of the process without risking frequent mold repairs. Fig. 10 also shows the location where an undercut region 412 would be formed by the tabs 402, 406 if a rounded profile 410 were used.

Fig. 10 and 11 show the mold cores 400, 404 or halves in a disengaged configuration. As best seen in fig. 11, for example, the top surface 418 of the thin tab 402 of the bottom mold core 400 will intercept onto the top surface 420 of the complementarily shaped recess 422 of the top mold core 404, thereby creating the apertures 260, 262 disposed between the standpipe 246 and the fins 254.

Fig. 12 more clearly shows the angular cutoff 408 between the tabs 402, 406 of the cores 400, 404. As shown, the angled cut 408 between the mold cores 400, 404 is at a five degree angle that allows the mold cores 400, 404 to be easily and properly aligned with and disengaged from each other (directions 414, 416). The angled undercut 408 allows molding the aperture 260 (best seen in fig. 4 and 5) of the fin 254 without forming an undercut. The cavities forming the first and second levels 290, 292 and the first step 294 of the fin 254 are also clearly visible.

For example, it is conceivable that the shape of the various features formed by the mold core may differ from any known pure geometry. For example, the rectangular configuration of the standpipe may actually comprise an alternating series of trapezoidal shapes that approximate a rectangular shape due to draft angles that oppose demolding from one side of the mold to the other. Thus, any shape that is within 10% of a pure geometric shape should be considered to have that shape when viewed in any embodiment discussed herein, including the claims. In the case of rectangular, any combination of trapezoidal configurations that deviate from the purely rectangular configuration by less than 10 degrees should be considered rectangular.

Once the center tubes 222, 322 are formed, the filter media 230 may be wrapped around the center tubes and the filter element 206 may be assembled in a manner known in the art. The general configuration of fins 254, 354 and center tubes 222, 322 provides the desired structural integrity and fluid management requirements of the filter element.

In some embodiments, a filter element 206 may be provided for self-draining drain. For example, as shown in fig. 3, the filter element 206 may have a generally cylindrical configuration defining a longitudinal axis L and a radial direction R. The filter element 206 may include a center tube 222, 322 having a length along a longitudinal axis, and including a standpipe 246 defining a length along the longitudinal axis, and a central flow passage 250 extending a majority of the length of the center tube 222, 322 along the longitudinal axis L.

As shown in fig. 4, 5, 7, and 8, the center tube 222, 322 may further include a plurality of radially extending flow fins 254, 354 attached to the standpipe 246 to define a radial flow passage 256, wherein the center tube 222, 322 further defines an axial flow passage 248 and a control flow passage 250 that are in fluid communication with each other and with the radial flow passage 256. The annular filter media 230 surrounds the center tubes 222, 322 and the center flow channels 250 and contacts the flow fins 254, 354. The filter element 206 has a first open end 214 (see fig. 3) coupled to a center tube 222, 322 disposed along a longitudinal axis, the open end including an opening 226 to allow fluid to flow from the central flow passage to the exterior of the filter element. The filter element may also have a second end 216 coupled to the center tube opposite the open end disposed along the longitudinal axis, the second end including a first end cap 228 that is closed, and wherein the center tubes 222, 322 define an attachment pocket 389 and an air pocket 391 (see fig. 7 and 8).

In some embodiments, such as shown in fig. 7 and 8, the center tube 322 includes a tub portion 399 integral with the standpipe 246 to define a void 397 that is divided into air pockets and attachment pockets by an annular wall 395. The annular wall 395 may define internal threads 393 in the attachment pocket 389, or some other attachment structure may be provided. As shown in fig. 7 and 8, the barrel portion defines an axial end 278 of the center tube 322 and the annular wall 395 defines a free end (see location directed to reference numeral 395) that is coplanar with the axial end 278 of the center tube 322. In some cases, the free end of the annular wall may be further slotted or closer to the standpipe than the axial end of the center tube, or vice versa.

It should be appreciated that the foregoing description provides examples of the disclosed components and techniques. However, it is contemplated that other embodiments of the invention may differ in detail from the foregoing examples. While all references to the invention or examples thereof are intended to refer to particular examples discussed at this point in time, and are not intended to imply any limitation as to the scope of the invention more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for such features, but not to exclude such from the scope of the invention entirely unless otherwise indicated.

Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein.

It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of the apparatus and method of assembly discussed herein without departing from the scope or spirit of the invention. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the various embodiments disclosed herein. For example, some of the devices may be configured and function differently than the devices described herein, and certain steps of any method may be omitted, performed in a different order than that explicitly mentioned, or performed simultaneously or in sub-steps in some cases. Further, variations or modifications may be made to certain aspects or features of the various embodiments to produce yet further embodiments, and features and methods of the various embodiments may be added to or substituted for other features or aspects of the other embodiments to provide yet further embodiments.

Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

1. A filter element having a generally cylindrical configuration and defining a longitudinal axis and a radial direction, the filter element comprising:

a center tube having a length along the longitudinal axis, the center tube comprising:

a standpipe defining a length along the longitudinal axis and a central flow passage extending a majority of the length of the center tube along the longitudinal axis;

a plurality of radially extending flow fins attached to and extending from the standpipe, the flow fins being axially spaced apart from each other to define radial flow channels, wherein each of the flow fins further defines a first aperture between the flow fins and the standpipe, each of the first apertures together defining a first outer axial flow channel extending along the standpipe, wherein the standpipe further defines at least one radial flow channel in fluid communication with the first outer axial flow channel and the central flow channel, wherein the standpipe and the first outer axial flow channel are not in fluid communication with each other along a majority of a length of the standpipe; and

An annular filter medium surrounding the center tube and the central flow channel and contacting the flow fins;

a first open end coupled to the center tube disposed along the longitudinal axis, the first open end including an opening to allow fluid to flow from the central flow passage to an exterior of the filter element; and

a second end coupled to the center tube opposite the first open end disposed along the longitudinal axis, the second end including a first end cap,

wherein the standpipe defines a cross-section perpendicular to the longitudinal axis, the cross-section being non-circular, and the first external axial flow passage is radially disposed between the plurality of radially extending flow fins and the cross-section,

the filter element further includes a second end cap coupled to the center tube and configured to allow flow from the center flow channel to an exterior of the filter element.

2. The filter element of claim 1, wherein the first end cap is closed to prevent fluid from exiting the filter element through the second end of the filter element.

3. A filter element having a generally cylindrical configuration and defining a longitudinal axis and a radial direction, the filter element comprising:

wherein the radial flow channels defined by the standpipe are in fluid communication with radial flow channels defined at least in part by flow fins, the radial flow channels being in fluid communication with the first outer axial flow channel.

4. A filter element having a generally cylindrical configuration and defining a longitudinal axis and a radial direction, the filter element comprising:

wherein the at least one radial flow channel is disposed axially adjacent to the second end.

5. The filter element of claim 4, wherein the cross-section is rectangular in shape with an inner perimeter defining a flow area of the central flow channel.

6. The filter element of claim 5, wherein the plurality of flow fins define a flow area of the first outer axial flow channel perpendicular to the longitudinal axis that is at least half of a flow area of the central flow channel.

7. The filter element of claim 6, wherein the plurality of flow fins each define a second aperture defining a second outer axial flow channel configured similarly to the first outer axial flow channel and having the same flow area, wherein the overall flow area of the first and second outer axial flow channels is substantially the same as the flow area of the central flow channel.

8. A base pipe for use with a filter element, the base pipe comprising:

a unitary body having a generally cylindrical outer configuration defining a longitudinal axis, a radial direction, and a length along the longitudinal axis from a first end to a second end, the unitary body comprising:

a plurality of radially extending flow fins attached to the standpipe, the flow fins being axially spaced from one another along the standpipe to define radial flow passages, wherein each of the flow fins further defines a first aperture between the flow fins and the standpipe, the first apertures together defining a first outer axial flow passage extending along a majority of a length of the standpipe and not in fluid communication with the central flow passage of the standpipe; and

Wherein the standpipe defines a cross-section perpendicular to the longitudinal axis, the cross-section comprising a rectangular shape and defining an inner perimeter defining a flow area of the central flow passage, the standpipe further defining at least one radial flow passage in fluid communication with the first outer axial flow passage and the central flow passage, wherein the radial flow passage of the standpipe is in direct fluid communication with a radial flow passage defined at least in part by a flow fin, the radial flow passage being in direct fluid communication with the first outer axial flow passage.

9. A base pipe for use with a filter element, the base pipe comprising:

wherein the standpipe defines a cross-section perpendicular to the longitudinal axis, the cross-section comprising a rectangular shape, and defining an inner perimeter defining a flow area of the central flow passage, the standpipe further defining at least one radial flow passage in fluid communication with the first outer axial flow passage and the central flow passage, wherein each of the plurality of flow fins comprises at least in part a generally annular shape, the standpipe comprises first, second, third, and fourth sides defined by the rectangular shape of the standpipe, and a plurality of the flow fins extend from the first side of the standpipe and are spaced apart from the second side of the standpipe to define the first aperture, the first aperture defining the first outer axial flow passage.

10. The center tube of claim 9, wherein the plurality of flow fins are spaced apart from a third side of the standpipe on a side of the standpipe opposite the second side to define a second bore, the second bore defining a second external axial flow passage.

11. The center tube of claim 10, wherein the plurality of flow fins are attached to a fourth side of the standpipe opposite the first side to close a perimeter of the first and second holes forming the first and second outer axial flow passages, respectively.

12. The center tube of claim 11, wherein each of the plurality of flow fins comprises a first level and a second level, wherein the first level extends from a first side of the standpipe and the second level extends from a fourth side of the standpipe around the second side and a third side to join the first level to create a first step between the first level and the second level.

13. The center tube of claim 12, wherein each of the plurality of flow fins includes a third level extending from the first side of the standpipe to split the first level into two portions and create a second step between the first level and third level.

14. A base pipe for use with a filter element, the base pipe comprising:

wherein the standpipe defines a cross-section perpendicular to the longitudinal axis, the cross-section comprising a rectangular shape and defining an inner perimeter defining a flow area of the central flow passage, the standpipe further defining at least one radial flow passage in fluid communication with the first outer axial flow passage and the central flow passage, wherein the center tube further comprises a first bowl portion attached to the standpipe at the first end and a second bowl portion attached to the standpipe at the second end, wherein at least one bowl portion defines a void in fluid communication with the central flow passage.

15. The center tube of claim 14, wherein the other barrel portion defines a void that is not in fluid communication with the central flow passage.

16. The center tube of claim 15, wherein the bowl portion that is not in fluid communication with the central flow channel comprises an annular wall disposed within a void of a bowl comprising internal threads, the wall and the bowl defining an air pocket.

17. A filter system, the filter system comprising:

a filter cartridge comprising an open end and a closed end;

a base including an inlet channel for admitting fluid into the filter system and an outlet channel for admitting fluid out of the filter system and an attachment structure for permitting attachment of the filter cartridge,

a drain penetrating through the closed end of the filter cartridge and including an attachment structure, an

A filter element comprising a generally cylindrical configuration and defining a longitudinal axis and a radial direction, the filter element comprising:

a standpipe defining a length along the longitudinal axis and a central flow passage extending a majority of the length of the center tube along the longitudinal axis,

A plurality of radially extending flow fins attached to and extending from the standpipe, the flow fins axially spaced from each other along the standpipe to define radial flow passages, wherein each of the flow fins further defines first and second apertures between the flow fins and the standpipe, the first apertures together defining a first outer axial flow passage extending along the standpipe, the second apertures together defining a second outer axial flow passage extending along the standpipe, wherein the standpipe further defines at least one radial flow passage in fluid communication with the first and second outer axial flow passages and the central flow passage; and

an annular filter medium surrounding the center tube and the central flow channel and contacting the flow fins; and

a closed end coupled to the center tube opposite an open end disposed along the longitudinal axis, the closed end comprising an end cap, wherein the flow fins define a flow area perpendicular to the longitudinal axis for the first and second outer axial flow channels and the standpipe defines a flow area perpendicular to the longitudinal axis for the center flow channel, wherein the combined flow area of the first and second outer axial flow channels is substantially the same as the flow area of the center flow channel,

Wherein the standpipe defines a cross-section perpendicular to the longitudinal axis, the cross-section being non-circular, and the first and second external axial flow channels are each disposed radially between the plurality of radially extending flow fins and the cross-section.

18. A filter system, the filter system comprising:

a filter cartridge comprising an open end and a closed end;

a closed end coupled to the center tube opposite an open end disposed along the longitudinal axis, the closed end comprising an end cap, wherein the flow fins define a flow area perpendicular to the longitudinal axis for the first and second outer axial flow channels and the standpipe defines a flow area perpendicular to the longitudinal axis for the center flow channel, wherein the combined flow area of the first and second outer axial flow channels is substantially the same as the flow area of the center flow channel.