Air Dryer Cartridge with Integrated Check Valve
An air dryer cartridge having an outer shell, an inner shell positioned within the outer shell, and a check valve positioned at least partially between the inner and outer shells. The inner and outer shells each have an inlet and an outlet. The outer shell is preferably operable to removably engage an air dryer. The check valve is operable to regulate the rate of flow of fluid through the outlet of the inner shell. Preferably, the check valve also seals between portions of the inner and outer shells and/or is operable to sealingly engage an air dryer.
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BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention is directed to an air dryer cartridge, and more specifically to an air dryer cartridge having an integrated check valve.
2. Description of Related Art
The pneumatic braking system of a commercial vehicle typically has an air compressor, a governor for controlling the operating cycle of the air compressor, an air dryer and a reservoir for holding pressurized air for delivery to the pneumatic components, such as the brakes. The air compressor operates successively in a loading (compressing) mode and an unloading (non-compressing) mode.
When the pressure in the air reservoir falls below a predetermined minimum pressure, typically about 100 psig, the governor causes the air compressor to operate in the loading mode to compress air for storage in the air reservoir. Before storing the air in the air reservoir, the compressed air from the air compressor passes through an air dryer which removes moisture and contaminants therefrom. When the air reservoir reaches the desired pressure, typically about 120 psig, the governor causes the air compressor to operate in the unloading mode and causes the purge valve in the air dryer to open to atmosphere.
One type of air dryer includes a removable cartridge that dries the compressed air as it flows through the cartridge during the loading mode. During the unloading mode, when the governor causes the purge valve in the air dryer to open the inlet of the cartridge to exhaust to atmosphere, the air flow direction is reversed and previously dried compressed air is sent through the cartridge to remove moisture and contaminants from the cartridge.
A check valve is commonly used to reduce the rate of flow of air through the cartridge during the unloading mode in order to more efficiently remove moisture and contaminants from the desiccant. The check valve is frequently positioned within a housing of the air dryer, but it may also be a part of the air dryer cartridge. One type of air dryer cartridge has outer and inner shells with a seal positioned between the two to direct air flow through a preferable passage within the cartridge. The seal is not integrated with a check valve. Typically, air dryer cartridges also have two separate gaskets or seals for sealing between a base of the cartridge and an air dryer. These seals are also not integrated with a check valve.
BRIEF SUMMARY OF THE INVENTIONThe present invention is directed toward an air dryer cartridge having an outer shell, an inner shell positioned within the outer shell, and a check valve positioned at least partially between the inner and outer shells. The inner and outer shells each have an inlet and an outlet. The outer shell is preferably operable to removably engage an air dryer. The check valve is operable to regulate the rate of flow of fluid through the outlet of the inner shell. Incorporating the check valve into the air dryer cartridge permits an operator to replace the check valve by replacing the entire cartridge without accessing the interior of an air dryer on which the cartridge is installed.
Preferably, the check valve also seals between portions of the inner and outer shells and/or is operable to sealingly engage an air dryer. The check valve is preferably positioned to seal between the inner and outer shells and/or sealingly engage an air dryer on which the cartridge is installed to reduce complexity of the cartridge and the number of seals and serviceable items within the cartridge.
The outlet of the inner shell preferably includes a plurality of holes and the check valve preferably has a flap that is moveable between a low flow rate position, in which it blocks a majority of the holes, and a high flow rate position, in which fluid can flow through each of the holes. Preferably, the check valve has a first seal portion coupled with and extending from the flap that seals between portions of the inner and outer shells. The check valve also preferably has a second seal portion coupled with and extending from the first seal portion that is operable to sealingly engage an air dryer removably engaged by the outer shell. The inlets of the outer and inner shells may be spaced either radially inward or radially outward from the outlets of the outer and inner shells.
Additional aspects of the invention, together with the advantages and novel features appurtenant thereto, will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned from the practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
An air dryer cartridge in accordance with one embodiment of the present invention is generally shown as 10 in
Referring to
The outer shell 22 includes a cylindrical housing 28 having an open end 30 that is partially enclosed by a gasket retainer 32 and base plate 34. The housing 28 includes a side wall 36 integrally joined with a top wall 38. A lower end of the side wall 36 adjacent open end 30 is rolled with a peripheral edge of gasket retainer 32 to join the housing 28 and gasket retainer 32. A seal (not shown) may be positioned between the side wall 36 and gasket retainer 32 to prevent air flow between them. The gasket retainer 32 includes a groove 40 in its lower surface that receives a gasket 42, which seals between the gasket retainer 32 and air dryer 16, as shown in
Base plate 34 is positioned on top of gasket retainer 32. The base plate 34 is disk shaped and is sized so that its peripheral edge closely fits within the inner surface of side wall 36. The base plate includes eight concentric holes, two of which are shown as 48a and 48b in
Inner shell 24 includes a cylindrical side wall 54 that is joined with an integral bottom wall 56 at one end and has an open end 58 opposite bottom wall 56. A cylindrical inner wall 60 is integral with and extends upward from bottom wall 56. Inner wall 60 is concentric with and has a smaller diameter than side wall 54. Bottom wall 56 includes a plurality of holes 62 positioned between the side wall 54 and inner wall 60 that in combination form an inlet of the inner shell 24. Bottom wall 56 also includes a plurality of holes 64 surrounded by the inner wall 60 that in combination form an outlet of the inner shell 24. The holes 64 include a central hole 64a and a plurality of holes 64b spaced radially outward from the central hole 64a. The inlets of outer shell 22 and inner shell 24 are spaced radially outward from the outlets of outer shell 22 and inner shell 24. Bottom wall 56 is spaced a distance from base plate 34 to create a ring-shaped chamber 65 between them.
A ring-shaped pre-filter 66 is supported by bottom wall 56 and is positioned between side wall 54 and inner wall 60. Although pre-filter 66 occupies the entire space between bottom wall 56 and the coalescing filter 68 described below, only a portion of pre-filter 66 is shown in
A load plate 76 and spring 78 are positioned between the desiccant beads 72 and top wall 38 of housing 28 to reduce gaps between the desiccant beads 72 and improve the performance of the beads 72. The load plate 76 includes a cylindrical side wall 80 that is slidably received by the side wall 54 of inner shell 24 and a top wall 82 integral with side wall 80 and spaced a distance from top wall 38 of housing 28. A spring retainer 84 is integral with and extends upward from top wall 82 toward the top wall 38 of housing 28. The spring retainer 84 includes concentric circular walls spaced a distance to define a groove for receiving a portion of spring 78 therebetween. Spring 78 is a coil spring positioned between the top wall 38 of housing 28 and top wall 82 of load plate 76 that forces load plate 76 downward to exert pressure on desiccant beads 72.
Check valve 26 includes a generally circular base 86 with a periphery forming a first seal portion 88 that seals between the base plate 34 of outer shell 22 and bottom wall 56 of inner shell 24. The base 86 includes a middle portion 90 integral with and extending radially inward from first seal portion 88. The middle portion 90 is slightly thinner than the first seal portion 88 to create a groove between the first seal portion 88 and a second seal portion 92 that is integral with and extends downward from middle portion 90. Five flaps 94a-e (shown in
The flaps 94a-e of check valve 26 are operable to regulate the rate of flow of fluid through the holes 64 comprising the outlet of the inner shell 24. Referring to
Referring now to
Referring to
The outer shell 102 includes a cylindrical housing 108 having an open end 110 that is partially enclosed by a gasket retainer 112 and base plate 114. The housing 108 includes a side wall 116 integrally joined with a top wall (not shown) in a similar manner as the housing 28 shown in
Base plate 114 is positioned on top of gasket retainer 112. The base plate 114 is disk shaped and is sized so that its peripheral edge closely fits within the inner surface of side wall 116. The base plate 114 includes eight concentric holes, one of which is shown as 126, each aligned with the holes 122 of gasket retainer 112 and surrounding a larger central hole 128 that is smaller than and aligned with the central hole 124 of gasket retainer 112. The aligned holes 122 and 126 of gasket retainer 112 and base plate 114, respectively, in combination form an outlet of the outer shell 102. The aligned holes 124 and 128 of the gasket retainer 112 and base plate 114, respectively, form an inlet of the outer shell 102. Base plate 114 has a cylindrical, threaded surface 130 that surrounds opening 128 and engages a threaded surface 53 on air dryer 16 when the cartridge 100 is installed on the air dryer 16 as shown in
Inner shell 104 includes a cylindrical side wall 132 that is joined with an integral bottom wall 134 at one end and has an open end (not shown) opposite bottom wall 134 similar to inner shell 24 shown in
A circular pre-filter 148 is supported by bottom wall 134 and is surrounded by inner wall 138. Pre-filter 148 preferably performs the same functions as the pre-filter 66 shown in
The cartridge 100 preferably has a load plate (not shown) and spring (not shown) that are similar to the load plate 76 and spring 78 of cartridge 10 described above and shown in
Check valve 106 includes a generally circular base 158 that forms a first seal portion sealing between the base plate 114 of outer shell 102 and bottom wall 134 of inner shell 104. The peripheral edge of the base 158 forms a flap 160 extending radially outward from the first seal portion. A groove 162 in the base 158 receives a corresponding protrusion of bottom wall 134 for aligning the check valve 106. A second seal portion 164 is integral with and extends downward from base 158. The second seal portion 164 includes a cylindrical section extending generally perpendicular downward from the base 158 and a tapered end 166 with a triangular cross-section extending downward from the cylindrical section. The tapered end 166 extends outward from the cylindrical section and is operable to fit tightly against an inner cylindrical surface 96 of dryer 16, as shown in
The flap 160 of check valve 106 is operable to regulate the rate of flow of fluid through the holes 140 comprising a portion of the outlet of the inner shell 104. Referring to
In operation, referring to
From the foregoing it will be seen that this invention is one well adapted to attain all ends and objectives herein-above set forth, together with the other advantages which are obvious and which are inherent to the invention.
Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matters herein set forth or shown in the accompanying drawings are to be interpreted as illustrative, and not in a limiting sense.
While specific embodiments have been shown and discussed, various modifications may of course be made, and the invention is not limited to the specific forms or arrangement of parts and steps described herein, except insofar as such limitations are included in the following claims. Further, it will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.
Claims
1. An air dryer cartridge, comprising:
- an outer shell comprising an inlet and an outlet;
- an inner shell positioned within said outer shell and comprising an inlet and an outlet; and
- a check valve positioned at least partially between said outer shell and said inner shell and sealing between a portion of said outer shell and a portion of said inner shell, wherein said check valve is operable to regulate the rate of flow of fluid through said outlet of said inner shell.
2. The air dryer cartridge of claim 1, wherein said outlet of said inner shell comprises a plurality of holes, wherein said check valve comprises at least one flap moveable between a low flow rate position, in which said flap restricts the rate of flow of fluid through at least a portion of said holes, and a high flow rate position.
3. The air dryer cartridge of claim 2, wherein said check valve comprises a plurality of flaps moveable between said low flow rate position, in which said flaps block fluid from flowing through a majority of said holes, and said high flow rate position, in which fluid can flow through each of said holes.
4. The air dryer cartridge of claim 3, wherein said check valve comprises a first seal portion coupled with and extending radially outward from said flaps, wherein said first seal portion seals between a portion of said outer shell and a portion of said inner shell.
5. The air dryer cartridge of claim 4, wherein said outer shell is operable to removably engage an air dryer, wherein said check valve comprises a second seal portion coupled with and extending from said first seal portion, wherein said second seal portion is operable to sealingly engage said air dryer.
6. The air dryer cartridge of claim 5, wherein said inlet of said outer shell and said inlet of said inner shell are spaced radially outward from said outlet of said outer shell and said outlet of said inner shell.
7. The air dryer cartridge of claim 2, wherein said flap blocks fluid from flowing through a majority of said holes when in said low flow rate position, and wherein fluid can flow through each of said holes when said flap is in said high flow rate position.
8. The air dryer cartridge of claim 2, wherein said check valve comprises a first seal portion coupled with and extending radially inward from said flap, wherein said first seal portion seals between a portion of said outer shell and a portion of said inner shell.
9. The air dryer cartridge of claim 8, wherein said outer shell is operable to removably engage an air dryer, wherein said check valve comprises a second seal portion coupled with said first seal portion and extending from said first seal portion, wherein said second seal portion is operable to sealingly engage said air dryer.
10. The air dryer cartridge of claim 9, wherein said inlet of said outer shell and said inlet of said inner shell are spaced radially inward from said outlet of said outer shell and said outlet of said inner shell.
11. The air dryer cartridge of claim 1, further comprising desiccant positioned within said inner shell.
12. An air dryer cartridge, comprising:
- an outer shell comprising an inlet and an outlet, wherein said outer shell is operable to removably engage an air dryer;
- an inner shell positioned within said outer shell and comprising an inlet and an outlet; and
- a check valve positioned at least partially between said outer shell and said inner shell, wherein said check valve is operable to regulate the rate of flow of fluid through said outlet of said inner shell, and wherein said check valve is operable to sealingly engage said air dryer.
13. The air dryer cartridge of claim 12, wherein said outlet of said inner shell comprises a plurality of holes, wherein said check valve comprises at least one flap moveable between a low flow rate position, in which said flap restricts the rate of flow of fluid through at least a portion of said holes, and a high flow rate position.
14. The air dryer cartridge of claim 13, wherein said check valve comprises a seal portion coupled with and extending from said flap, wherein said seal portion is operable to sealingly engage said air dryer.
15. The air dryer cartridge of claim 14, wherein said outer shell comprises a cylindrical surface, wherein said seal portion is generally concentric with and spaced apart from said cylindrical surface, and wherein said cylindrical surface is operable to engage a portion of said air dryer such that said portion of said air dryer is positioned between said cylindrical surface and said seal portion.
16. The air dryer cartridge of claim 15, wherein said seal portion comprises a cylindrical section extending generally perpendicular from said flap, and a tapered end extending from said cylindrical section.
17. An air dryer cartridge, comprising:
- an outer shell comprising an inlet and an outlet, wherein said outer shell is operable to removably engage an air dryer;
- an inner shell positioned within said outer shell and comprising an inlet and an outlet; and
- a check valve positioned at least partially between said outer shell and said inner shell and sealing between a portion of said outer shell and a portion of said inner shell, wherein said check valve is operable to regulate the rate of flow of fluid through said outlet of said inner shell, and wherein said check valve is operable to sealingly engage said air dryer.
18. The air dryer cartridge of claim 17, wherein said outlet of said inner shell comprises a plurality of holes, wherein said check valve comprises at least one flap moveable between a low flow rate position, in which said flap restricts the rate of flow of fluid through at least a portion of said holes, and a high flow rate position.
19. The air dryer cartridge of claim 18, wherein said check valve comprises a first seal portion coupled with and extending from said flap, wherein said first seal portion seals between a portion of said outer shell and a portion of said inner shell.
20. The air dryer cartridge of claim 19, wherein said check valve comprises a second seal portion coupled with and extending from said first seal portion, wherein said second seal portion is operable to sealingly engage said air dryer.
Type: Application
Filed: Mar 14, 2013
Publication Date: Sep 18, 2014
Applicant: HALDEX BRAKE PRODUCTS CORPORATION (Kansas City, MO)
Inventors: Andrew W. Adams (Lee's Summit, MO), David A. Prater (Kansas City, MO), Michael R. Jenkins (Kansas City, MO)
Application Number: 13/830,050
International Classification: B01D 46/00 (20060101);