WO2008156834A1

WO2008156834A1 - Diesel egr valve stem cleaning washer

Info

Publication number: WO2008156834A1
Application number: PCT/US2008/007707
Authority: WO
Inventors: Bruce M. Hatton
Original assignee: Borgwarner Inc.
Priority date: 2007-06-20
Filing date: 2008-06-19
Publication date: 2008-12-24

Abstract

A stem member cleaning device having a stem member slidably disposed through a bearing guide, with the stem member having a first end and a second end. The present invention also includes a valve member disposed on the first end of the stem member, and an actuator connected to the second end of the stem member. A washer is slidably disposed along the stem member between the bearing guide and the valve member.

Description

DIESEL EGR VALVE STEM CLEANING WASHER

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a PCT International Application of United States Patent Provisional Application No. 60/936,358 filed on June 20, 2007. The disclosure of the above application is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to cleaning devices used for exhaust gas recirculation valves.

BACKGROUND OF THE INVENTION

Exhaust gas recirculation (EGR) valves are generally known. These valves are used to selectively deliver exhaust gas produced by an engine back into the flow of fresh air to reduce exhaust emissions generated by the engine. These valves work in a very dirty environment. One significant problem is the life and effectiveness of seals used on a valve stem to prevent debris from contaminating the bearing guide assembly which can introduce friction between various moving parts. A dirty valve stem will wear the seals, eventually causing seal failure. Techniques currently known to protect the effectiveness of the seals involve keeping the stem clean. These include flow deflecting shields designed to isolate the reciprocating part of the stem from contamination. Other techniques include a scraper with a very small clearance to the stem intended to strip away contaminants as they build up on the stem. While these techniques help, they are not completely capable of preventing contamination from reaching the seals, and creating friction. This friction can delay response time for the valve, or in the worst case scenario, cause the valve to seize up completely.

Accordingly, there exists a need for an improved way of cleaning valves used in an exhaust gas recirculation system. SUMMARY OF THE INVENTION

The present invention is a stem member cleaning device having a stem member slidably disposed through a bearing guide, with the stem member having a first end and a second end. The present invention also includes a valve member disposed on the first end of the stem member, and an actuator connected to the second end of the stem member. A washer is slidably disposed along the stem member between the bearing guide and the valve member.

When the actuator moves the stem member, the washer is free to move along the stem member removing contamination from the stem member. Additionally, when the exhaust gas recirculation valve is used with an engine, vibrations from the engine can also cause the washer to translate along the stem member thereby removing debris. Fluid flow around the stem member can also cause the washer to translate along the stem member, thereby removing debris as well. The more turbulent the flow, the higher the vibration, the faster the actuation, and the more effective the cleaning will be.

Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

Figure 1 is a sectional side view of an exhaust gas recirculation valve in a closed position, according to the present invention;

Figure 2 is a sectional side view of an exhaust gas recirculation valve in an open position, according to the present invention;

Figure 3 is a sectional side view of a first alternate embodiment of an exhaust gas recirculation valve in a closed position, according to the present invention; Figure 4 is a sectional side view of a first alternate embodiment of an exhaust gas recirculation valve in an open position, according to the present invention;

Figure 5 is a sectional side view of a second alternate embodiment of a valve in an open position, according to the present invention;

Figure 6 is a sectional side view of a third alternate embodiment of a valve in an open position, according to the present invention;

Figure 7 is a sectional side view of a fourth alternate embodiment of a valve in an open position, according to present invention; and Figure 8 is a sectional side view of a fifth alternate embodiment of a valve in a closed position, according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

Referring to Figures 1 and 2, a valve incorporating the present invention is generally shown at 10. The valve 10 includes a stem member, or valve stem 12 extending through a bore 14 in a bearing guide 16. The valve stem 12 has a first end and a second end. Connected to the first end of the valve stem 12 is a valve member or poppet valve 18. Connected to the second end of the valve stem 12 is an actuator (not shown). The bearing guide 16 is supported in a housing 20 which has an orifice or inlet port, generally shown at 22, and an outlet port 24. The inlet port 22 is formed by using a seat member, or valve seat 26. The bearing guide 16 includes stepped portions, generally shown at 28, each of which includes a seal retainer 30, and a seal 32. The seal retainers 30 and seals 32 are used for preventing debris from traveling through the bore 14 and coming in contact with the actuator. Slidably disposed on the valve stem 12 is a washer 34. The washer 34 is free to slide along the valve stem 12, and is not held in place at a specific point on the valve stem 12. In this embodiment, air from atmosphere is allowed to enter the housing 20 through an opening 36, and exits the housing 20 through the same outlet port 24 as any exhaust gas that enters the housing 20. However, other air flow paths which may not include the use of air from the atmosphere, or air flow from other sources, may be used, and still be within the scope of the valve according to the present invention. Several of these variations are shown in Figures 5-7, which will be described later.

In operation, the valve 10 is in a closed position as shown in Figure 1. When in this closed position, the poppet valve 18 is in contact with the valve seat 26, and exhaust gas flow will be kept separate from the flow of fresh air into the engine. Air from atmosphere will flow into the housing through the opening 36, and out of the housing through the outlet port 24. When it is desired to have a portion of the exhaust gas from the engine mixed in with the fresh air, the actuator will move the valve stem 12, and therefore the valve poppet 18 to a position similar to that shown in Figure 2. In this position, the exhaust gas will flow through the inlet port 22 and through the outlet port 24, and mix with the air flowing into the engine.

As the air, exhaust gas, or combinations thereof, flows through the valve 10, this flow will cause the washer 34 to move along the valve stem 12 to various positions. The motion of the washer 34 will be erratic including translation, rotations, and any manner of random vibrations along the entire length of the exposed valve stem 12. The opening and closing of the valve 10, along with any vibration transferred to the valve 10 from the engine and gas flow turbulance, will also cause the washer 34 to move along the valve stem 12. As the washer 34 moves along the valve stem 12, any debris which would cause contamination and inhibit the operation of the valve 10 is removed. This effect is continuous, thus preventing the build up of contaminants on the valve stem 12.

An alternate embodiment is shown in Figures 3 and 4. The closed position for the valve is shown in Figure 3, and the open position is shown in Figure 4. In this embodiment, the bearing guide includes an extension 38 which forms a cavity, generally shown at 40. In this embodiment, as the valve stem 12 is moved through the cavity 40, if the washer 34 becomes stuck to the valve stem 12 due to contamination, and the vibrations from the engine do not cause the washer 34 to freely move along the valve stem 12 as the valve stem 12 is moved to open or close the valve 10, the washer 34 will contact either the bearing guide 16 or the extension 38 (depending upon which way the valve stem 12 is being moved). In Figure 4, the washer 34 is shown in contact with the bearing guide 16. As the washer 34 contacts the bearing guide 16 or the extension 38, and the valve stem 12 continues to move in one direction or the other, the washer 34 will be forced to release from the valve stem 12, and be allowed to move along the valve stem 12, allowing the washer 34 to remove contamination.

One of the important characteristics of the present invention is the orientation of the valve stem 12. The valve stem 12 can be oriented horizontally, or vertically. However, it is preferred that the valve stem 12 be oriented horizontally, thereby neutralizing the effects of gravity on the washer 34, and allowing the washer 34 to move along the valve stem 12, instead of being biased toward the first end or the second end. Other embodiments of the present invention are shown in Figures 5-7.

In Figures 1-4, the valve is a "flow through" valve, as well as a "pull-to-open" style valve. The term "flow through" refers to the fresh air flowing through the valve to the intake manifold of the engine. The term "pull-to-open" refers to the valve stem 12 being pulled to open the valve. In Figure 5, the valve 10 is configured as a "push-to-open" style valve, while still remaining a "flow through" valve, with the term "push to open" referring to the valve stem 12 being pushed to open the valve 10. The fresh air still flows from the opening 36 through the valve 10 and to the outlet port 24, and the exhaust gas will flow through the inlet port 22 when the valve 10 is in an open position, as shown in Figure 5.

Referring to Figure 6, the valve 10 has been configured to be a stand alone valve. In this embodiment, the opening 36 has been removed, and fresh air does not flow through the valve 10. The exhaust gas simply flows from the inlet port 22 to the outlet port 24, and mixes with the fresh air at some point downstream from the valve 10. Figure 7 shows what is referred to as a "cartridge" style valve 10. This embodiment is similar to the embodiment shown in Figure 6, with the exception that the entire valve 10 is inserted into an EGR tube 42. The exhaust gas then flows through the inlet port 22, and through the outlet port 24 when the valve 10 is in the open position, as shown in Figure 7. One of the advantages of the valve 10 used in this configuration is that the valve 10 is easily accessible for replacement or maintenance.

Figure 8 shows another alternate embodiment of a valve 10 according to the present invention. In this embodiment, the housing is shaped differently, where the inlet port 22 is on two sides of the housing 20, the outlet port 24 is adjacent the inlet port 22, and the valve poppet 18 is located between the inlet port 22 and the outlet port 24. Also included is a bushing 44 secured to a cap 46. As the valve stem 12 and valve poppet 18 move between an open position and a closed position, a portion of the valve stem 12 slides in the bushing 44. The washer 34 acts to remove contamination from the valve stem 12, thereby preventing contamination from becoming lodged between the outer diameter of the valve stem 12 which slides in and out of the bushing 44, and the inner diameter of the bushing 44.

The valve 10 of the present invention can also be used as what is referred to as a "cold side valve," or a "hot side valve". Both of these configurations involve the use of an exhaust gas recirculation (EGR) cooler, which is used for cooling exhaust gas prior to re-entry into the engine. If the valve 10 of the present invention is used as a cold side valve, the valve 10 will be located downstream of the EGR cooler. If the valve 10 of the present invention is used as a hot side valve, the valve 10 will be used upstream of the EGR cooler.

The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.

Claims

CLAIMSWhat is claimed is:

1. A stem member cleaning device, comprising: a stem member, slidably disposed through a bearing guide, said stem member having a first end and a second end; a valve member disposed on said first end of said stem member; an actuator connected to said second end of said stem member; and a washer slidably disposed along said stem member between said bearing guide and said valve member, such that said washer is free to move along said stem member as said actuator moves said stem member, removing contamination from said stem member.

2. The stem member cleaning device of claim 1 , further comprising: a seat member; and an orifice formed as a portion of said seat member, said orifice operably associated with said valve member, wherein said actuator moves said stem member such that said valve member selectively contacts said seat member, thereby selectively allowing fluid flow through said orifice of said seat member.

3. The stem member cleaning device of claim 2, further comprising: a housing; an opening formed as a portion of said housing; and an outlet port formed as a portion of said housing and operably associated with said orifice such that fluid flows through said opening into said housing and out of said housing through said outlet port and fluid flows from said orifice to said outlet port when said actuator moves said stem member and said valve member away from said seat member, and fluid flow through said housing will cause said washer to move along said stem member.

4. The stem member cleaning device of claim 1 , further comprising an extension connected to said bearing guide, said washer being slidably disposed on said stem member between said bearing guide and said extension, and as said actuator moves said stem member, said washer moves between said bearing guide and said extension, removing contamination from said stem member.

5. The stem member cleaning device of claim 1 , wherein said stem member and said washer are operably associated with an engine, and vibrations from said engine will cause said washer to translate along said stem member, removing debris from said stem member.

6. The stem member cleaning device of claim 1 , said valve member and said stem member further comprising of a push-to-open configuration.

7. The stem member cleaning device of claim 1, said valve member and said stem member further comprising of a cartridge style configuration.

8. The stem member cleaning device of claim 1, said valve member and said stem member further comprising of a stand alone configuration.

9. The stem member cleaning device of claim 1 , said valve member and said stem member further comprising of a flow through configuration.

10. The stem member cleaning device of claim 1 , further comprising an exhaust gas recirculation (EGR) cooler, said stem member and said valve member positioned upstream of said EGR cooler.

11. The stem member cleaning device of claim 1 , further comprising an exhaust gas recirculation (EGR) cooler, said stem member and said valve member located downstream of said EGR cooler.

12. A washer used in an exhaust gas recirculation valve, comprising: a bearing guide having a bore; a housing, said bearing guide disposed within said housing, said housing having an opening and an outlet port such that fluid flows into said opening, through said housing and said outlet port; a stem member extending through said bore, said stem member having a first end and a second end; a valve member connected to said first end of said stem member, said second end of said stem member connected to an actuator; a seat member operably connected to said housing and operably associated with said valve member, said seat member having an orifice; and a washer slidably disposed on said stem member between said bearing guide and said valve member such that said washer is free to translate along said stem member as said actuator selectively moves said stem member to cause said valve member to selectively contact said seat member, and when said valve member is moved away from said seat member, fluid will flow through said orifice into said housing and out of said outlet port.

13. The washer used in an exhaust gas recirculation valve of claim 12, wherein said stem member and said washer are operably associated with an engine, and when said engine vibrates, said washer will move on said stem member and remove contamination from said stem member.

14. The washer used in an exhaust gas recirculation valve of claim 12, wherein said washer will translate along said stem member to remove contamination from said stem member as fluid flows through said housing.

15. The washer used in an exhaust gas recirculation valve of claim 12, further comprising: said bearing guide having an extension to form a cavity; and said washer being disposed in said cavity, and as said actuator moves said stem member and said valve member toward said seat member, said washer is pressed against said extension, causing said washer to remove debris from said stem member, and as said actuator moves said stem member and said valve member away from said seat member, said washer is pressed against said bearing guide, causing said washer to remove debris from said stem member.

16. The washer used in an exhaust gas recirculation valve of claim 12, said stem member, said valve member, and said seat member further comprising a push-to-open configuration.

17. The washer used in an exhaust gas recirculation valve of claim 12, said stem member, said valve member, and said seat member further comprising a pull-to-open configuration.

18. The washer used in an exhaust gas recirculation valve of claim 12, said stem member, said valve member, and said seat member further comprising a cartridge style configuration.

19. The washer used in an exhaust gas recirculation valve of claim 12, said stem member, said valve member, and said seat member further comprising a stand alone configuration.

20. The washer used in an exhaust gas recirculation valve of claim 12, said stem member, said valve member, and said seat member further comprising a flow through configuration.

21. The washer used in an exhaust gas recirculation valve of claim 12, further comprising an exhaust gas recirculation cooler, and said stem member, said valve member, and said seat member are located downstream of said exhaust gas recirculation cooler.

22. The washer used in an exhaust gas recirculation valve of claim 12, further comprising an exhaust gas recirculation cooler, and said stem member, said valve member, and said seat member are located upstream of said exhaust gas recirculation cooler.

23. A cleaning device for an exhaust gas recirculation valve, comprising: a valve stem having a poppet valve connected to a first end of said valve stem, and an actuator connected to a second end of said valve stem; a bearing guide disposed within a housing having an opening and an outlet port such that fluid flows from said opening to said outlet port through said housing; a bore formed as a portion of said bearing guide, said bore circumscribing said valve stem; a valve seat having an inlet port, said valve seat operably connected to said housing, and said valve seat operably associated with said poppet valve; and a washer slidably disposed on said valve stem, said actuator selectively moves said valve stem to cause said poppet valve to be selectively in contact with said valve seat, and when said poppet valve is not in contact with said valve seat, fluid will flow through said inlet port of said valve seat into said housing and out of said outlet port, and fluid flow through said housing will cause said washer will move along said valve stem to remove debris from said valve stem.

24. The cleaning device for an exhaust gas recirculation valve of claim 23, further comprising: an extension operably connected to said bearing guide; and a cavity formed by a portion of said bearing guide and said extension, said washer is disposed on said valve stem in said cavity, and when said actuator moves said valve stem, said washer will move along said valve stem to remove debris from said valve stem.

25. The cleaning device for an exhaust gas recirculation valve of claim 24, wherein as said washer becomes affixed to said valve stem due to debris, said actuator moves said washer toward said valve seat, and said washer will contact said extension and be released from said stem member.

26. The cleaning device for an exhaust gas recirculation valve of claim 24, wherein as said washer becomes affixed to said valve stem due to debris, said actuator moves said washer away from said valve seat, and said washer will contact said bearing guide and be released from said stem member.

27. The cleaning device for an exhaust gas recirculation valve of claim 23, said valve stem, said valve seat, and said poppet valve further comprising a pull-to-open configuration.

28. The cleaning device for an exhaust gas recirculation valve of claim 23, said valve stem, said valve seat, and said poppet valve further comprising a cartridge style configuration.

29. The cleaning device for an exhaust gas recirculation valve of claim 23, said valve stem, said valve seat, and said poppet valve further comprising of a stand alone configuration.

30. The cleaning device for an exhaust gas recirculation valve of claim 23, said valve stem, said valve seat, and said poppet valve further comprising of a flow through configuration.

31. The cleaning device for an exhaust gas recirculation valve of claim 23, further comprising an exhaust gas recirculation cooler, and said valve stem, said valve seat, and said poppet valve are located downstream of said exhaust gas recirculation cooler.

32. The cleaning device for an exhaust gas recirculation valve of claim 23, further comprising an exhaust gas recirculation cooler, and said valve stem, said valve seat, and said poppet valve are located upstream of said exhaust gas recirculation cooler.