Integrated bushing, valve rod sealing device and exhaust gas recirculation valve

Abstract

The present application discloses an integrated bushing (30) for an exhaust gas recirculation valve (1), characterized in that the integrated bushing (30) comprises: a holding portion (32) formed with a through hole (322) and configured for mounting and fixing the integrated bushing (30); and a heat insulating portion (34) formed with a through hole (342) and extending from the holding portion (32). The holding portion (32) and the heat insulating portion (34) are integrally formed as an integral structure. The utility model further relates to a valve rod sealing device (20). The valve rod sealing device (20) comprises the integrated bush (30) and a sealing assembly (50). The utility model further relates to the exhaust gas recirculation valve (1) which is provided with the valve rod sealing device (20).

Description

Technical Field

[0001] The present application generally relates to the field of engines, and in particular, to an integrated bushing for an exhaust gas recirculation valve. The present application further relates to a valve stem sealing device, which includes the integrated bushing. In addition, the present application also relates to an exhaust gas recirculation valve, which includes the valve stem sealing device. Background Art

[0002] The exhaust gas recirculation (EGR) valve controls the exhaust gas flow rate by moving the valve stem up and down. The existing valve stem guide sealing structure includes a sealing ring, a retaining frame, a sealing ring, a sleeve, a scraper, a heat shield and a retaining gasket from top to bottom. This structure has the following disadvantages: 1. When the valve housing is corroded by the exhaust gas environment to produce powder, the structure cannot prevent the dust from entering the gap between the sleeve and the valve stem. After the valve has been working for a long time, the accumulation of dust will increase the resistance to the movement of the valve stem, causing the valve response to be delayed or even causing the valve to be stuck and other serious consequences; 2. After the corrosive pollutants enter, the valve stem may adhere to the scraper or sleeve, resulting in valve failure; 3. When the valve housing is corroded by the exhaust gas environment, the rivet points on the valve housing that fix the retaining gasket will peel off, losing the fixing effect on the retaining gasket, and then the retaining gasket, heat shield and scraper will fall off one after another. Utility Model Content

[0003] One of the objects of the present application is to provide an integrated bushing, valve stem seal and exhaust gas recirculation valve that can overcome at least one of the drawbacks of the prior art.

[0004] One object of the present application is to provide a novel sealing structure of an exhaust gas recirculation valve, which can overcome the shortcomings of traditional sealing structures, improve the sealing performance, and ensure the stable operation of the exhaust gas recirculation system.

[0005] According to a first aspect of the present application, an integrated bushing is provided for an exhaust gas recirculation valve, wherein the integrated bushing comprises:

[0006] a retaining portion formed with a through hole and configured for installation and fixation of the integrated bushing; and

[0007] a heat insulating portion formed with a through hole and extending from the holding portion;

[0008] The holding portion and the heat insulating portion are integrally formed into a unitary structure.

[0009] The integrated bushing is formed as a single component, which can simplify the structure of the bushing, obtain a better sealing effect, prevent dust, debris and contaminants from entering the gap between the sleeve and the valve stem and causing the valve stem to adhere to related components, and can be more securely mounted on the valve housing of the exhaust gas recirculation valve 1

[0010] According to some embodiments of the present application, the retaining portion includes a flange, and the flange is arranged around the through hole of the retaining portion.

[0011] According to some embodiments of the present application, the heat insulating portion includes a first end and a second end opposite to the first end, the first end is integrally formed with the retaining portion, and the second end is a free end.

[0012] According to some embodiments of the present application, the second end surrounds and is close to the valve stem of the exhaust gas recirculation valve when the second end cooperates with the valve stem of the exhaust gas recirculation valve.

[0013] According to some embodiments of the present application, the inner wall of the through hole of the insulation portion is configured to form an accommodation space between the inner wall of the through hole of the insulation portion and the valve stem of the exhaust gas recirculation valve when cooperating with the valve stem of the exhaust gas recirculation valve.

[0014] On the one hand, this arrangement of the insulation part can reduce the contact between the integrated bushing and the valve stem, preventing the integrated bushing from interfering with the operation of the valve stem. On the other hand, the second end is arranged close to the valve stem to reduce the intrusion of dust, debris and contaminants, and the accommodating space can be used to receive the invading dust, debris and contaminants to avoid further intrusion of dust, debris and contaminants into, for example, between the valve stem and the sleeve.

[0015] According to some embodiments of the present application, the retaining portion and the heat insulating portion are made of stainless steel. Stainless steel has excellent corrosion resistance and can meet the mechanical requirements of the installation bushing.

[0016] According to a second aspect of the present application, a valve stem sealing device is provided, which is used for an exhaust gas recirculation valve, characterized in that the valve stem sealing device comprises:

[0017] An integrated bushing as described above;

[0018] A sealing assembly and the integrated bushing are configured to cooperate with each other to seal a valve stem of an exhaust gas recirculation valve.

[0019] According to some embodiments of the present application, the retaining portion or the heat insulating portion is formed with a receiving portion, and the sealing assembly is configured to fit in the receiving portion.

[0020] According to some embodiments of the present application, the retaining portion is formed with a protrusion extending radially inward from the inner wall of the through hole of the retaining portion, and / or the thermal insulation portion is formed with a protrusion extending radially inward from the inner wall of the through hole of the thermal insulation portion, wherein the sealing assembly is configured to fit on the protrusion.

[0021] According to some embodiments of the present application, the size of the through hole of the retaining part and / or the through hole of the insulation part is configured so that when the valve stem sealing device is fitted onto the valve stem of the exhaust gas recirculation valve, the sealing assembly is pushed toward the valve stem of the exhaust gas recirculation valve to enhance the sealing effect of the sealing assembly.

[0022] According to some embodiments of the present application, the sealing assembly includes a sealing member and a retaining member, wherein the sealing member is arranged around the retaining member and radially outside the retaining member, and when the valve stem sealing device is fitted to the valve stem of the exhaust gas recirculation valve, the retaining member is pressed against the valve stem of the exhaust gas recirculation valve. On the one hand, the retaining member plays a role of sealing the valve stem, and on the other hand, with the reciprocating motion of the valve stem, the retaining member also plays a role similar to a scraper, which is used to prevent dust, debris and pollutants adhering to the valve stem and avoid the intrusion of dust, debris and pollutants.

[0023] According to some embodiments of the present application, the valve stem sealing device further comprises at least two sealing rings arranged around the valve stem of the exhaust gas recirculation valve, a sleeve for the valve stem is arranged between the at least two sealing rings and the sealing assembly, and a retainer is arranged between the at least two sealing rings. By arranging the above-mentioned sealing structure on opposite sides of the sleeve, the sealing effect of the valve stem sealing device can be significantly enhanced.

[0024] According to a third aspect of the present application, an exhaust gas recirculation valve is provided, characterized in that the exhaust gas recirculation valve comprises a valve stem sealing device as described above.

[0025] According to some embodiments of the present application, the exhaust gas recirculation valve includes a valve housing having a mounting recess formed thereon, and the retaining portion is configured to be mounted into the mounting recess so that the integrated bushing is fixed to the valve housing.

[0026] According to some embodiments of the present application, the retaining portion is configured to be installed in the mounting recess by interference fit.

[0027] On the one hand, the interference fit between the integrated bushing and the valve housing can ensure a secure installation between the two. On the other hand, even after the valve housing is corroded by the exhaust gas environment, the integrated bushing is not easy to fall off the valve housing because the fitting area of ​​the interference fit is much larger than other methods such as riveting. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] After reading the following detailed description in conjunction with the accompanying drawings, various aspects of the present application will be better understood, in which:

[0029] Figure 1 is a cross-sectional schematic diagram of an exhaust gas recirculation valve according to some embodiments of the present application;

[0030] Figure 2 yes Figure 1 A schematic cross-sectional view of a portion of an exhaust gas recirculation valve in FIG. 1 , showing a valve stem sealing device according to some embodiments of the present application;

[0031] Figure 3 is a cross-sectional perspective view of an integrated bushing according to some embodiments of the present application; and

[0032] Figure 4 is a cross-sectional perspective view of a valve stem sealing device according to some embodiments of the present application.

[0033] Reference numerals list

[0034] Exhaust gas recirculation valve 1;

[0035] Valve housing 10; valve stem 12; sleeve 14; sealing ring 16; retainer 18; mounting recess 102; accommodating space 122;

[0036] Valve stem sealing device 20;

[0037] Integrated bushing 30; retaining portion 32; heat insulating portion 34; through hole 322; inner wall 323; flange 324; receiving portion 326; protrusion 328; through hole 342; inner wall 343; first end 344; second end 346;

[0038] Sealing assembly 50 ; sealing member 52 ; retaining member 54 . DETAILED DESCRIPTION

[0039] The present application will be described below with reference to the accompanying drawings, wherein the accompanying drawings illustrate several embodiments of the present application. However, it should be understood that the present application can be presented in a variety of different ways and is not limited to the embodiments described below; in fact, the embodiments described below are intended to make the disclosure of the present application more complete and fully explain the scope of protection of the present application to those skilled in the art. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide more additional embodiments.

[0040] It should be understood that the same reference numerals represent the same elements throughout the drawings. In the drawings, the dimensions of certain features may be distorted for clarity.

[0041] It should be understood that the terms used in the specification are only used to describe specific embodiments and are not intended to limit the present application. All terms (including technical terms and scientific terms) used in the specification have the meanings commonly understood by those skilled in the art unless otherwise defined. For the sake of simplicity and / or clarity, well-known functions or structures may not be described in detail.

[0042] The singular forms "a", "the" and "the" used in the specification include the plural forms unless clearly indicated. The terms "include", "comprise" and "contain" used in the specification indicate the presence of the claimed features, but do not exclude the presence of one or more other features. The term "and / or" used in the specification includes any and all combinations of one or more of the relevant listed items. The terms "between X and Y" and "between approximately X and Y" used in the specification should be interpreted as including X and Y. The term "between approximately X and Y" used in this specification means "between approximately X and approximately Y", and the term "from approximately X to Y" used in this specification means "from approximately X to approximately Y".

[0043] In the specification, when an element is said to be "on", "attached", "connected", "coupled" or "contacting" another element, the element may be directly on, attached, connected, coupled or contacting another element, or there may be an intermediate element. In contrast, when an element is said to be "directly" "on", "directly attached", "directly connected", "directly coupled" or "directly contacting" another element, there will be no intermediate element. In the specification, a feature is arranged "adjacent" to another feature, which may refer to a feature having a portion that overlaps with an adjacent feature or a portion that is above or below an adjacent feature.

[0044] In the specification, spatial relational terms such as "upper", "lower", "left", "right", "front", "back", "higher", "lower", etc. may describe the relationship of one feature to another feature in the drawings. It should be understood that the spatial relational terms include different orientations of the device in use or operation in addition to the orientation shown in the drawings. For example, when the device in the drawings is turned over, features previously described as being "below" other features may now be described as being "above" the other features. The device may also be oriented in other ways (rotated 90 degrees or in other orientations), and the relative spatial relationships will be interpreted accordingly.

[0045] The exhaust gas recirculation (EGR) system is a technology used to reduce harmful emissions from internal combustion engines. The exhaust gas recirculation system works by reintroducing a portion of the exhaust gas into the engine to lower the combustion temperature, thereby reducing the formation of nitrogen oxides (NOx) and thus reducing emissions.

[0046] One of the key components of the exhaust gas recirculation system is the exhaust gas recirculation valve, which controls the flow of exhaust gas and guides it into the engine. To ensure the efficient operation of the exhaust gas recirculation system, the exhaust gas recirculation valve must have good sealing performance. The design of the sealing structure not only affects the performance of the exhaust gas recirculation valve, but also directly affects the working efficiency and emission control level of the engine.

[0047] The traditional exhaust gas recirculation valve sealing structure usually includes a sealing ring, a retaining frame, a sealing ring, a sleeve, a scraper, a heat shield and a retaining gasket from top to bottom. Such a sealing structure has some disadvantages. For example, 1. When the valve housing is corroded by the exhaust gas environment to produce powder, the structure cannot prevent the dust from entering the gap between the sleeve and the valve stem. After the valve has been working for a long time, the accumulation of dust will increase the movement resistance of the valve stem, causing the valve response to be delayed or even causing the valve to be stuck and other serious consequences; 2. After the corrosive pollutants enter, it may cause the valve stem to adhere to the scraper or sleeve, resulting in valve failure; 3. When the valve housing is corroded by the exhaust gas environment, the rivet points on the valve housing that fix the retaining gasket will peel off, losing the fixing effect on the retaining gasket, and then causing the retaining gasket, heat shield and scraper to fall off one after another.

[0048] According to the integrated bushing, valve stem sealing device and exhaust gas recirculation valve of the present application, the structures of the scraper, the heat shield and the retaining gasket are improved, so as to overcome the above-mentioned defects existing in the prior art.

[0049] Hereinafter, an exhaust gas recirculation valve 1 and a valve stem sealing device 20 and an integrated bushing 30 thereof according to some embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0050] Figure 1 Schematic cross-sectional view of an exhaust gas recirculation valve 1 according to some embodiments of the present application is shown. The exhaust gas recirculation valve 1 includes a valve housing 10 and a valve stem 12, and the valve stem 12 is disposed in the valve housing 10. A channel for accommodating the valve stem 12 is formed in the valve housing 10, and the valve stem 12 reciprocates in the channel. For the convenience of description, the extension direction of the valve stem 12 (for example, the reciprocating direction of the valve stem 12, or the direction of the valve stem 12) is shown in FIG. Figure 1 The up-down direction of the page shown) is defined as the vertical direction.

[0051] Combined with reference Figure 2 , which shows Figure 1 Schematic cross-sectional view of a portion of the exhaust gas recirculation valve 1 in FIG. The exhaust gas recirculation valve 1 may further include a sealing ring 16 , a sleeve 14 , and a valve stem sealing device 20 , which are arranged in the passage around the valve stem 12 in the longitudinal direction.

[0052] According to some embodiments, two sealing rings 16 may be provided, a retainer 18 is provided between the two sealing rings 16, and the sleeve 14 is located below the sealing ring 16. The above structure may adopt any suitable structure known in the art, and thus will not be described in detail here.

[0053] The valve stem sealing device 20 according to the present application is arranged below the sleeve 14, and will be referred to below. Figure 2-4 The valve stem sealing device 20 and its related structure are described in detail. According to some embodiments of the present application, the valve stem sealing device 20 may include an integrated bushing 30 and a sealing assembly 50, and the sealing assembly 50 and the integrated bushing 30 are configured to cooperate with each other to seal the valve stem 12 of the exhaust gas recirculation valve 1, protecting the valve stem 12 from dust, debris and contaminants.

[0054] According to some embodiments of the present application, the integrated bushing 30 may include: a retaining portion 32, which is formed with a through hole 322 and is configured for installation and fixation of the integrated bushing 30; and a heat insulation portion 34, which is formed with a through hole 342 and extends from the retaining portion 32; wherein the retaining portion 32 and the heat insulation portion 34 are integrally formed into an integral structure.

[0055] like Figure 3 , which shows an embodiment of an integrated bushing 30 according to the present application. The integrated bushing 30 may include a retaining portion 32 and a heat insulating portion 34 formed integrally. The retaining portion 32 may be formed in a circular ring-shaped form, and the valve stem 12 extends through a through hole 322 of the retaining portion 32. The retaining portion 32 may be used for installation and fixation of the integrated bushing 30, such as Figure 2 As shown, the integrated bushing 30 can be installed and fixed to the valve housing 10 of the exhaust gas recirculation valve 1 through the retaining portion 32. The insulation portion 34 can be formed in a cylindrical form, and the valve stem 12 extends through the through hole 342 of the insulation portion 34. The insulation portion 34 can be used as a heat shield to play a role in heat insulation. According to an embodiment of the present application, the retaining portion 32 and the insulation portion 34 are integrally formed into an integral structure. For example, the retaining portion 32 and the insulation portion 34 can be integrally formed so that the integrated bushing 30 is formed as a single component, rather than a structure composed of two or more components. The integrated bushing 30 is formed as a single component, which can simplify the structure of the bushing, obtain a better sealing effect, prevent dust, debris and contaminants from entering the gap between the sleeve and the valve stem and causing adhesion of the valve stem to related components, and can be more firmly installed on the valve housing 10 of the exhaust gas recirculation valve 1 (as described below).

[0056] According to some embodiments of the present application, the holding portion 32 may include a flange 324, which is disposed around the through hole 322 of the holding portion 32. Figure 3As shown, the flange 324 is located radially outside the through hole 322 . The flange 324 is mainly used for installation and fixing. The integrated bushing 30 can be installed and fixed to the valve housing 10 of the exhaust gas recirculation valve 1 through the flange 324 .

[0057] According to some embodiments of the present application, the heat insulating portion 34 may include a first end 344 and a second end 346 opposite to the first end 344, the first end 344 is integrally formed with the retaining portion 32, and the second end 346 is a free end. Figure 3 As shown, the heat insulating portion 34 extends from the first end 344 to the second end 346 in the longitudinal direction, so that the heat insulating portion 34 extends from the retaining portion 32 in the longitudinal direction as a whole. The outer diameter of the first end 344 can be equal to the outer diameter of the second end 346, or it can be greater than the outer diameter of the second end 346. According to some embodiments, the outer diameter of the retaining portion 32 can be greater than or equal to the outer diameter of the heat insulating portion 34. In the illustrated embodiment, it is shown that the outer diameter of the retaining portion 32 is greater than the outer diameter of the heat insulating portion 34, that is, the retaining portion 32 protrudes radially outward relative to the heat insulating portion 34. In some embodiments, it is conceivable that the outer diameter of the retaining portion 32 is equal to the outer diameter of the heat insulating portion 34, so that the integrated bushing 30 is formed in a generally cylindrical form as a whole. Even in other embodiments, the outer diameter of the retaining portion 32 can be smaller than the outer diameter of the heat insulating portion 34.

[0058] According to some embodiments of the present application, the second end 346 may surround and be close to the valve stem 12 of the exhaust gas recirculation valve 1 when cooperating with the valve stem 12 of the exhaust gas recirculation valve 1. Figure 4 As shown, the valve stem 12 extends through the retaining portion 32 and the heat insulating portion 34 of the integrated bushing 30, that is, extends through the through hole 322 of the retaining portion 32 and the through hole 342 of the heat insulating portion 34, so that the retaining portion 32 and the heat insulating portion 34 are both arranged around the valve stem 12. The second end 346 of the heat insulating portion 34 can be as close to the valve stem 12 as possible, so as to form a small gap between the second end 346 and the valve stem 12. The second end 346 is arranged close to the valve stem 12 to reduce the intrusion of dust, debris and contaminants.

[0059] According to some embodiments of the present application, the inner wall 343 of the through hole 342 of the heat insulating portion 34 may be configured to form a receiving space 122 between the inner wall 343 of the through hole 342 of the heat insulating portion 34 and the valve stem 12 of the exhaust gas recirculation valve 1 when the valve stem 12 of the exhaust gas recirculation valve 1 is matched. Figure 4As shown, the inner wall 343 of the through hole 342 of the heat insulating portion 34 can be formed to have a nonlinear shape, such as an arc shape or a curved surface shape, so that when the second end 346 is close to the valve stem 12, the portion between the first end 344 and the second end 346 and the first end 344 radially away from the valve stem 12 relative to the second end 346 form a receiving space 122. On the one hand, such a setting of the heat insulating portion 34 can reduce the contact between the integrated bushing 30 and the valve stem 12, and prevent the integrated bushing 30 from interfering with the operation of the valve stem 12. On the other hand, the second end 346 is arranged close to the valve stem 12 to reduce the intrusion of dust, debris and pollutants, and the receiving space 122 can be used to receive the intruded dust, debris and pollutants to prevent the dust, debris and pollutants from further intruding into, for example, between the valve stem and the sleeve.

[0060] According to some embodiments of the present application, the retaining portion 32 and the heat insulating portion 34 may be made of stainless steel. Stainless steel has excellent corrosion resistance and can meet the mechanical requirements of the installation bushing. It will be appreciated by those skilled in the art that the retaining portion 32 and the heat insulating portion 34 may also be made of any other suitable material.

[0061] According to some embodiments of the present application, the retaining portion 32 or the heat insulating portion 34 may be formed with a receiving portion 326, and the sealing assembly 50 may be configured to fit in the receiving portion 326. Figure 2 and Figure 4 As shown, a receiving portion 326 is formed on the retaining portion 32 to receive the sealing assembly 50. Through the receiving portion 326, the sealing assembly 50 can be matched to the integrated bushing 30 and supported and held by the integrated bushing 30, thereby, the sealing assembly 50 and the integrated bushing 30 can cooperate with each other to seal the valve stem 12 of the exhaust gas recirculation valve 1, protecting the valve stem 12 from dust, debris and pollutants. It is conceivable that the receiving portion 326 can also be formed on other parts of the integrated bushing 30, for example, in an embodiment not shown, the receiving portion 326 can be formed on the insulation portion 34.

[0062] According to some embodiments of the present application, the retaining portion 32 may be formed with a protrusion 328 extending radially inward from the inner wall 323 of the through hole 322 of the retaining portion 32, and / or the insulation portion 34 may be formed with a protrusion extending radially inward from the inner wall 343 of the through hole 342 of the insulation portion 34, wherein the sealing assembly 50 may be configured to fit on the protrusion 328.

[0063] like Figures 2 to 4As shown, the retaining portion 32 is formed with a protrusion 328, which extends radially inward from the inner wall 323 of the through hole 322 of the retaining portion 32, that is, extends toward the valve stem 12, so that the inner wall 323 of the through hole 322 of the retaining portion 32 and the protrusion 328 can form a receiving portion 326 to receive the sealing assembly 50. The protrusion 328 can extend radially inward toward the valve stem 12 to approach the valve stem 12, and a small gap can be formed between the protrusion 328 and the valve stem 12 to reduce the intrusion of dust, debris and pollutants. It can be understood by those skilled in the art that the above-mentioned protrusion can also be formed on other parts of the integrated bushing 30. For example, in an embodiment not shown, the protrusion 328 can extend radially inward from the inner wall 343 of the through hole 342 of the heat insulating portion 34, and form a receiving portion 326 with the inner wall 343 of the through hole 342 of the heat insulating portion 34 to receive the sealing assembly 50.

[0064] In some other embodiments, an annular groove may be formed on the inner wall 323 of the through hole 322 of the retaining portion 32 and / or the inner wall 343 of the through hole 342 of the insulation portion 34 , and the sealing assembly 50 may be directly fitted into the annular groove and supported and retained by the integrated bushing 30 .

[0065] According to some embodiments of the present application, the size of the through hole 322 of the retaining portion 32 and / or the through hole 342 of the insulation portion 34 can be configured so that when the valve stem sealing device 20 is fitted onto the valve stem 12 of the exhaust gas recirculation valve 1, the sealing assembly 50 is pushed toward the valve stem 12 of the exhaust gas recirculation valve 1.

[0066] like Figure 2 and Figure 4 As shown, the inner diameter of the through hole 322 of the retaining portion 32 can be set to be slightly smaller than the outer diameter of the sealing assembly 50, so that the sealing assembly 50 can be installed in the accommodating portion 326 of the integrated bushing 30 in a manner such as an interference fit or a press fit, so that the inner wall 323 of the through hole 322 of the retaining portion 32 applies radial inward pressure to the sealing assembly 50, pushing the sealing assembly 50 toward the valve stem 12 of the exhaust gas recirculation valve 1 to enhance the sealing effect of the sealing assembly 50.

[0067] According to some embodiments of the present application, the sealing assembly 50 may include a sealing member 52 and a retaining member 54, wherein the sealing member 52 is arranged around the retaining member 54 on the radial outside of the retaining member 54, and when the valve stem sealing device 20 is fitted onto the valve stem 12 of the exhaust gas recirculation valve 1, the retaining member 54 is pressed against the valve stem 12 of the exhaust gas recirculation valve 1.

[0068] like Figure 2As shown, the seal 52 can be formed as the outer ring of the seal assembly 50, and the retainer 54 can be formed as the inner ring of the seal assembly 50. The seal 52 and the retainer 54 can be assembled together by, for example, a press fit. The inner diameter of the retainer 54 can be slightly smaller than the outer diameter of the valve stem 12, so that the retainer 54 is assembled to the valve stem 12 in an interference fit manner to achieve a good sealing effect. On the one hand, the retainer 54 plays a role in sealing the valve stem 12. On the other hand, as the valve stem 12 reciprocates, the retainer 54 also plays a role similar to a scraper to prevent dust, debris and pollutants adhering to the valve stem 12 and avoid the intrusion of dust, debris and pollutants.

[0069] According to some embodiments of the present application, the valve stem sealing device 20 may further include at least two sealing rings 16 arranged around the valve stem 12 of the exhaust gas recirculation valve 1, a sleeve 14 for the valve stem 12 is arranged between the at least two sealing rings 16 and the sealing assembly 50, and a retaining frame 18 is arranged between the at least two sealing rings 16.

[0070] like Figure 2 As shown, a sealing ring 16, a retainer 18, a sealing ring 16, a sleeve 14 and a sealing assembly 50 are sequentially arranged around the valve stem 12 from top to bottom along the longitudinal direction. Two or more sealing rings 16 and the sealing assembly 50 are arranged on opposite sides of the sleeve 14 to form a multiple sealing structure. For example, in the illustrated embodiment, a triple sealing structure is formed. In other embodiments, more multiple sealing structures can be formed. In some embodiments, the structure of the sealing ring 16 can be similar to the sealing assembly 50, so that on the one hand, the sealing ring 16 plays a role in sealing the valve stem 12, and on the other hand, with the reciprocating motion of the valve stem 12, the sealing ring 16 can also play a role similar to a scraper to prevent dust, debris and pollutants adhering to the valve stem 12 and avoid the intrusion of dust, debris and pollutants. By arranging the above-mentioned sealing structure on opposite sides of the sleeve 14, the sealing effect of the valve stem sealing device 20 can be significantly enhanced.

[0071] According to some embodiments of the present application, a mounting recess 102 may be formed on the valve housing 10 , and the retaining portion 32 may be configured to be installed in the mounting recess 102 , so that the integrated bushing 30 is fixed to the valve housing 10 .

[0072] like Figure 2 As shown, the valve housing 10 is formed with a mounting recess 102 below the sleeve 14 , into which the flange 324 of the retaining portion 32 is mounted, whereby the integrated bushing 30 formed integrally can be fixed to the valve housing 10 .

[0073] According to some embodiments of the present application, the retaining portion 32 may be configured to be installed in the mounting recess 102 by interference fit. Specifically, the outer diameter of the flange 324 of the retaining portion 32 may be formed to be slightly larger than the inner diameter of the mounting recess 102, so that the flange 324 of the retaining portion 32 forms an interference fit with the mounting recess 102, thereby firmly fixing the integrated bushing 30 to the valve housing 10. On the one hand, such interference fit between the integrated bushing 30 and the valve housing 10 can ensure a firm installation between the two, and on the other hand, even after the valve housing is corroded by the exhaust gas environment, since the fitting area of ​​the interference fit is much larger than other methods such as riveting, the integrated bushing 30 is not easy to fall off from the valve housing 10.

[0074] Although the exemplary embodiments of the present application have been described, it should be understood by those skilled in the art that various changes and modifications can be made to the exemplary embodiments of the present application without departing from the spirit and scope of the present application in essence. Therefore, all changes and modifications are included in the protection scope of the present application as defined by the claims. The present application is defined by the attached claims, and the equivalents of these claims are also included.

Claims

1. An integrated bushing (30) for an exhaust gas recirculation valve (1), characterized in that: The integrated bushing (30) comprises: a retaining portion (32) formed with a through hole (322) and configured for installation and fixation of the integrated bushing (30); and a heat insulating portion (34) formed with a through hole (342) and extending from the holding portion (32); The retaining portion (32) and the heat insulating portion (34) are integrally formed into a unitary structure.

2. The integrated bushing (30) according to claim 1, characterized in that: The retaining portion (32) includes a flange (324) which is arranged around a through hole (322) of the retaining portion (32).

3. The integrated bushing (30) according to claim 1, characterized in that: The heat insulating portion (34) includes a first end (344) and a second end (346) opposite to the first end (344), the first end (344) being integrally formed with the retaining portion (32), and the second end (346) being a free end.

4. The integrated bushing (30) according to claim 3, characterized in that: The second end (346) surrounds and is close to the valve stem (12) of the exhaust gas recirculation valve (1) when mated with the valve stem (12) of the exhaust gas recirculation valve (1).

5. The integrated bushing (30) according to claim 1, characterized in that: The inner wall (343) of the through hole (342) of the heat insulating portion (34) is configured to form a receiving space (122) between the inner wall (343) of the through hole (342) of the heat insulating portion (34) and the valve stem (12) of the exhaust gas recirculation valve (1) when cooperating with the valve stem (12) of the exhaust gas recirculation valve (1).

6. The integrated bushing (30) according to claim 1, characterized in that: The holding portion (32) and the heat insulating portion (34) are made of stainless steel.

7. A valve stem sealing device (20) for an exhaust gas recirculation valve (1), characterized in that: The valve stem sealing device (20) comprises: An integrated bushing (30) according to any one of claims 1 to 6; A sealing assembly (50) is provided, wherein the sealing assembly (50) and the integrated bushing (30) are configured to cooperate with each other to seal a valve stem (12) of an exhaust gas recirculation valve (1).

8. The valve stem sealing device (20) according to claim 7, characterized in that: The retaining portion (32) or the heat insulating portion (34) is formed with a receiving portion (326), and the sealing assembly (50) is configured to fit into the receiving portion (326).

9. The valve stem sealing device (20) according to claim 7, characterized in that: The retaining portion (32) is formed with a protrusion (328) extending radially inward from the inner wall (323) of the through hole (322) of the retaining portion (32), and / or the heat insulating portion (34) is formed with a protrusion extending radially inward from the inner wall (343) of the through hole (342) of the heat insulating portion (34), wherein the sealing assembly (50) is configured to fit on the protrusion.

10. The valve stem sealing device (20) according to claim 7, characterized in that: The through hole (322) of the retaining portion (32) and / or the through hole (342) of the insulating portion (34) are configured in size so that when the valve stem sealing device (20) is fitted onto the valve stem (12) of the exhaust gas recirculation valve (1), the sealing assembly (50) is pushed toward the valve stem (12) of the exhaust gas recirculation valve (1).

11. The valve stem sealing device (20) according to claim 7, characterized in that: The sealing assembly (50) comprises a sealing member (52) and a retaining member (54), wherein the sealing member (52) is arranged around the retaining member (54) and on the radially outer side of the retaining member (54), and when the valve stem sealing device (20) is fitted onto the valve stem (12) of the exhaust gas recirculation valve (1), the retaining member (54) is pressed against the valve stem (12) of the exhaust gas recirculation valve (1).

12. The valve stem sealing device (20) according to claim 7, characterized in that: The valve stem sealing device (20) further comprises at least two sealing rings (16) arranged around the valve stem (12) of the exhaust gas recirculation valve (1), a sleeve (14) for the valve stem (12) being arranged between the at least two sealing rings (16) and the sealing assembly (50), and a retaining frame (18) being arranged between the at least two sealing rings (16).

13. An exhaust gas recirculation valve (1), characterized in that: The exhaust gas recirculation valve (1) comprises a valve stem sealing device (20) according to any one of claims 7 to 12.

14. The exhaust gas recirculation valve (1) according to claim 13, characterized in that The exhaust gas recirculation valve (1) comprises a valve housing (10), a mounting recess (102) is formed on the valve housing (10), and the retaining portion (32) is configured to be mounted in the mounting recess (102) so that the integrated bushing (30) is fixed to the valve housing (10).

15. The exhaust gas recirculation valve (1) according to claim 14, characterized in that The retaining portion (32) is configured to be installed in the installation recess (102) by interference fit.

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