Exhaust unloading valve assembly and scroll compressor

Abstract

The utility model provides an exhaust unloading valve assembly and a scroll compressor, the exhaust unloading valve assembly comprises a static scroll plate, a boss is arranged on one side of the static scroll plate deviating from a dynamic scroll plate, the boss is provided with at least one exhaust sinking table, the bottom of the exhaust sinking table is provided with an exhaust hole, and the exhaust hole is communicated with the static scroll plate. A first circulating hole surrounding and laterally communicating with the exhaust hole is formed in the exhaust sinking table; the valve plate is fixed on the upper surface of the static vortex plate, the exhaust sinking table is covered with the valve plate in a sealing mode, and the valve plate is provided with second circulation holes communicated with the first circulation holes respectively; and the valve plug assembly is arranged in the exhaust sinking table, one end of the valve plug assembly is connected to the valve plate, the other end of the valve plug assembly abuts against and blocks the exhaust hole based on the bias force, and after the valve plug assembly is lifted by overcoming the bias force under the impact of gas, the gas entering the first circulation hole is exhausted outwards from the second circulation hole. The back space of the static scroll plate can be fully utilized, the requirement for frequent opening and closing of the valve body can be met, and the overall operation efficiency of the compressor is improved.

Description

Technical Field

[0001] The utility model relates to the field of compressors, in particular to an exhaust unloading valve assembly and a scroll compressor. Background Art

[0002] In a scroll compressor, some high pressure ratio conditions may cause over-compression of the scroll, which will have a negative impact on the refrigeration performance of the compressor and the compressor itself. To solve this problem, it is necessary to set an unloading hole at a suitable position at the bottom of the static scroll disk and set an unloading valve above the unloading hole. When over-compression occurs during the scroll operation, the unloading valve will perform pressure unloading.

[0003] The position of the unloading hole is obtained through pressure calculation and cannot be moved at will. There are both an exhaust port and several unloading ports on the back of the static vortex disk, and the space is very limited. The combination of the above two reasons makes it difficult to arrange the exhaust valve and the unloading valve in a small space.

[0004] The exhaust valve and unloading valve will open and close frequently during the vortex operation, and there are also high requirements for the fatigue resistance of the valve itself. How to ensure the strength of the valve while meeting the reasonable arrangement of the exhaust and unloading valves in the small space behind the static plate is a major problem that needs to be overcome in the design of exhaust and unloading valves.

[0005] Patent CN 218493814 U provides a fixed scroll assembly for an electric scroll compressor, including a fixed scroll, and an integrated exhaust unloading valve plate and a valve plate limit plate arranged on the fixed scroll, an exhaust port and several unloading ports are arranged on the fixed scroll, and an upward valve plate installation sink is arranged on the outer periphery of the exhaust port and the unloading port, and several sink grooves are also arranged on one side of the exhaust port and the unloading port. During the scroll operation, the sink groove can reduce the direct contact area between the exhaust valve plate and the mounting surface, effectively reduce the adsorption force between the exhaust valve plate and the refrigeration oil adhered to the mounting surface, so that the exhaust valve plate opens normally, runs more smoothly, reduces the noise generated by the air flow disorder, enhances the working performance and reliability of the whole machine, and prolongs the service life of the product. The static scroll exhaust solution provided by patent CN 218493814 U adopts a tongue reed and a limit plate as its main structure. When in use, the tongue reed is subjected to fatigue stress for a long time, and there is a risk of the valve plate breaking. In addition, when the engine is frequently started and stopped, the valve plate hits the scroll and makes a loud noise. This is a common problem in the design and actual use of exhaust solutions using tongue reed and limit plate structures.

[0006] In view of the above-mentioned defects, the present invention proposes an exhaust unloading valve assembly and a scroll compressor. Utility Model Content

[0007] In response to the problems in the prior art, the purpose of the present utility model is to provide an exhaust unloading valve assembly and a scroll compressor, which overcome the difficulties of the prior art, can fully utilize the back space of the static scroll disk, can meet the requirements of frequent opening and closing of the valve body, and improve the overall operating efficiency of the compressor.

[0008] The embodiment of the utility model provides an exhaust unloading valve assembly, comprising:

[0009] A stationary scroll, wherein a boss is provided on a side of the stationary scroll away from the movable scroll, the boss is provided with at least one exhaust sink, a bottom of the exhaust sink is provided with an exhaust hole, and a first flow hole surrounding and laterally connected to the exhaust hole is formed inside the exhaust sink;

[0010] A valve plate fixed to the upper surface of the static scroll, the valve plate covers the exhaust sink, and the valve plate is provided with second flow holes respectively connected to the first flow holes;

[0011] The valve plug assembly is arranged in the exhaust sink, one end of the valve plug assembly is connected to the valve plate, and the other end abuts and blocks the exhaust hole based on the bias force. When the valve plug assembly is lifted up by the impact of the gas to overcome the bias force, the gas entering the first flow hole is discharged outward from the second flow hole.

[0012] Preferably, the valve plug assembly comprises:

[0013] A limit post connected to the limit post through hole of the valve plate;

[0014] A valve plug, wherein a limit column pressing portion and a spring thrust portion are provided inside the valve plug, and the limit column pressing portion is sleeved on the limit column;

[0015] A spring is arranged in the spring thrust portion, and the spring thrust portion is elastically supported between the valve plug and the valve plate to press the valve plug toward the exhaust hole.

[0016] Preferably, the second flow holes are distributed around the limiting column through hole.

[0017] Preferably, valve plug limiting parts surrounding the valve plug are respectively provided between the first flow holes inside the exhaust sink, and the valve plug limiting parts jointly limit the stroke of the valve plug.

[0018] Preferably, part of the exhaust holes are configured as pressure relief holes, and the diameter of the pressure relief holes is smaller than the diameter of the exhaust holes.

[0019] Preferably, the exhaust hole is located at the center of the boss, and the pressure relief holes are respectively located on both sides of the exhaust hole.

[0020] Preferably, the circumference of the exhaust hole forms an annular communication area connected to the first flow hole.

[0021] Preferably, the boss is provided with a bolt hole, the valve plate has a bolt through hole, and the valve plate is screwed to the boss by bolts.

[0022] Preferably, a plurality of raised circumferential limiting portions are provided around the edge of the boss, and the edge of the valve plate forms a limiting edge cooperating with the circumferential limiting portions, and the circumferential limiting portions jointly clamp the periphery of the valve plate.

[0023] An embodiment of the utility model further provides a scroll compressor, comprising: an exhaust unloading valve assembly as described above.

[0024] The exhaust unloading valve assembly and scroll compressor of the utility model can make full use of the back space of the static scroll, can meet the requirements of frequent opening and closing of the valve body, and improve the overall operating efficiency of the compressor. On the basis of conforming to the common sense in the field, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the utility model.

[0025] To further understand the features and technical contents of the present application, please refer to the following detailed description and drawings of the present application. However, the detailed description and drawings here are only used to illustrate the present application and do not impose any limitations on the scope of the claims of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and other features and advantages of the present application will become more apparent by describing in detail example embodiments thereof with reference to the attached drawings.

[0027] Figure 1 It is a three-dimensional schematic diagram of the exhaust unloading valve assembly of the utility model.

[0028] Figure 2 It is a three-dimensional schematic diagram of a stationary scroll in the exhaust unloading valve assembly of the utility model.

[0029] Figure 3 It is a three-dimensional schematic diagram of the valve plate in the exhaust unloading valve assembly of the utility model.

[0030] Figure 4 It is a three-dimensional schematic diagram of the valve plug in the exhaust unloading valve assembly of the utility model.

[0031] Figure 5 It is a cross-sectional view of the exhaust sink area in the exhaust unloading valve assembly of the utility model.

[0032] Reference numerals

[0033] 1 Static vortex disc

[0034] 1a Back side of static vortex disk

[0035] 11 Exhaust hole

[0036] 12 Pressure relief hole

[0037] 13 Valve plug limiter

[0038] 14 Exhaust sink

[0039] 15 First flow hole

[0040] 16 Bolt holes

[0041] 17 Circumferential limiter

[0042] 18 Circumferentially connected areas

[0043] 19 Boss

[0044] 2 Valve plate

[0045] 21 Limiting column through hole

[0046] 22 Second flow hole

[0047] 23 Bolt through hole

[0048] 24 Limit edge

[0049] 3 Valve plug

[0050] 31 Limit column press-fit part

[0051] 32 Spring thrust part

[0052] 4 Limiting columns

[0053] 5 Bolts

[0054] 6 Spring DETAILED DESCRIPTION

[0055] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the present application. The present application can also be implemented or applied through other different specific implementation methods, and the details in the present application can also be modified or changed in various ways according to different viewpoints and application systems without departing from the spirit of the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0056] The following is a detailed description of the embodiments of the present application with reference to the accompanying drawings so that those skilled in the art can easily implement the present application. The present application can be embodied in a variety of different forms and is not limited to the embodiments described herein.

[0057] In the representations of the present application, the representations with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics represented in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the represented specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples represented in the present application and the features of the different embodiments or examples, unless they contradict each other.

[0058] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the representation of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0059] In order to clearly describe the present application, components irrelevant to the description are omitted, and the same reference symbols are given to the same or similar components throughout the specification.

[0060] Throughout the specification, when a device is said to be "connected" to another device, this includes not only the case of "direct connection" but also the case of "indirect connection" by placing other elements therebetween. In addition, when a device is said to "include" a certain component, unless otherwise stated, it does not exclude other components, but means that other components may be included.

[0061] When a device is said to be "on" another device, it may be directly on the other device, but there may also be other devices between it. In contrast, when a device is said to be "directly" on another device, there are no other devices between it.

[0062] Although the terms first, second, etc. are used to represent various elements in some examples, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, the first interface and the second interface, etc. are represented. Moreover, as used in this article, the singular forms "one", "one" and "the" are intended to also include plural forms, unless there is an opposite indication in the context. It should be further understood that the terms "comprising" and "including" indicate the existence of features, steps, operations, elements, components, projects, kinds, and / or groups, but do not exclude the existence, occurrence or addition of one or more other features, steps, operations, elements, components, projects, kinds, and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or mean any one or any combination. Therefore, "A, B or C" or "A, B and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C". Only when the combination of elements, functions, steps or operations is inherently mutually exclusive in some way, will there be an exception to this definition.

[0063] The technical terms used herein are only used to refer to specific embodiments and are not intended to limit the present application. The singular form used herein also includes the plural form unless the sentence clearly indicates the contrary meaning. The meaning of "including" used in the specification is to specify specific characteristics, regions, integers, steps, operations, elements and / or components, and does not exclude the existence or addition of other characteristics, regions, integers, steps, operations, elements and / or components.

[0064] Although not defined differently, all terms, including technical and scientific terms used herein, have the same meaning as those generally understood by those skilled in the art to which this application belongs. Terms defined in commonly used dictionaries are additionally interpreted as having meanings consistent with the relevant technical literature and the contents of the current disclosure, and unless defined, shall not be overly interpreted as ideal or very formal meanings.

[0065] Figure 1 It is a three-dimensional schematic diagram of the exhaust unloading valve assembly of the utility model. Figure 2 It is a three-dimensional schematic diagram of a stationary scroll in the exhaust unloading valve assembly of the utility model. Figure 3 It is a three-dimensional schematic diagram of the valve plate in the exhaust unloading valve assembly of the utility model. Figure 4 It is a three-dimensional schematic diagram of the valve plug in the exhaust unloading valve assembly of the utility model. Figure 5 2 is a cross-sectional view of the exhaust sink area in the exhaust unloading valve assembly of the utility model. Figures 1 to 5As shown, the exhaust unloading valve assembly of the utility model includes: a fixed scroll 1, a valve plate 2 and a valve plug assembly. A boss 19 is provided on the side of the fixed scroll 1 away from the movable scroll, and the boss 19 is provided with at least one exhaust sink 14. An exhaust hole 11 is provided at the bottom of the exhaust sink 14, and a first flow hole 15 surrounding and laterally connected to the exhaust hole 11 is formed inside the exhaust sink 14. The valve plate 2 is fixed to the upper surface of the fixed scroll 1, and the valve plate 2 covers the exhaust sink 14. The valve plate 2 is provided with second flow holes 22 respectively connected to the first flow holes 15. The valve plug assembly is arranged in the exhaust sink 14, one end of the valve plug assembly is connected to the valve plate 2, and the other end abuts and blocks the exhaust hole 11 based on the bias force. When the valve plug assembly is lifted up by the impact of the gas to overcome the bias force, the gas entering the first flow hole 15 is discharged from the second flow hole 22. The utility model adopts a spring valve solution when dealing with the strength problem of the valve. Compared with the reed valve, the spring has better fatigue resistance. By reasonably calculating the force that the spring needs to provide when the valve is closed, a suitable spring and initial compression amount can be selected to better meet the use requirements of frequent opening and closing of the valve.

[0066] In a preferred embodiment, the valve plug assembly comprises:

[0067] The limiting post 4 is connected to the limiting post through hole 21 of the valve plate 2 .

[0068] The valve plug 3 has a limit column pressing portion 31 and a spring thrust portion 32 disposed therein, and the limit column pressing portion 31 is sleeved on the limit column 4 .

[0069] The spring 6 is disposed in the spring thrust portion 32 , and the spring thrust portion 32 is elastically supported between the valve plug 3 and the valve plate 2 to press the valve plug 3 toward the exhaust hole 11 , but not limited thereto.

[0070] In a preferred embodiment, the second flow holes 22 are distributed around the limiting column through hole 21 , but not limited thereto.

[0071] In a preferred embodiment, valve plug limiting portions 13 surrounding the valve plug 3 are respectively provided between the first flow holes 15 inside the exhaust sink 14 , and the valve plug limiting portions 13 jointly limit the stroke of the valve plug 3 , but the present invention is not limited thereto.

[0072] In a preferred embodiment, part of the exhaust holes are configured as pressure relief holes 12 , and the diameter of the pressure relief holes 12 is smaller than the diameter of the exhaust holes 11 , but not limited thereto.

[0073] In a preferred embodiment, the exhaust hole 11 is located at the center of the boss 19 , and the pressure relief holes 12 are respectively located on both sides of the exhaust hole 11 , but the present invention is not limited thereto.

[0074] In a preferred embodiment, the circumference of the exhaust hole 11 forms an annular communication area 18 communicating with the first flow hole 15 , but the present invention is not limited thereto.

[0075] In a preferred embodiment, the boss 19 is provided with a bolt hole 16 and the valve plate 2 is provided with a bolt through hole 23 , and the valve plate 2 is screwed to the boss 19 by means of bolts 5 , but the present invention is not limited thereto.

[0076] In a preferred embodiment, a plurality of raised circumferential limiting portions 17 are provided around the edge of the boss 19, and the edge of the valve plate 2 forms a limiting edge 24 that cooperates with the circumferential limiting portions 17, and the circumferential limiting portions 17 jointly clamp the periphery of the valve plate 2, but this is not limited thereto.

[0077] Aiming at the limited space at the back of the static vortex, the utility model effectively utilizes the space at the back of the static vortex through the integrated design of the valve plates of the exhaust valve and the unloading valve and the sunken design of the exhaust port and the unloading port of the static vortex. The joint action of the spring and the limit column enables the valve body to open under the action of high-pressure gas and close under the action of the spring when the compressor is not running.

[0078] The specific implementation of the utility model is as follows:

[0079] refer to Figure 1 , 2 As shown, the valve plug 3 and the spring 6 have been assembled in the exhaust sink 14 on the back of the static vortex 1, and the valve plate 2 is axially limited, and the valve plate 2 is fixed to the static vortex 1 by the bolt 5. The main structure of the back side 1a of the static vortex is a boss 19, and the boss 19 is functionally divided into the following three parts: a circumferential limit portion 17 for limiting the position of the valve plate 2, a bolt hole 16 for fixing the valve plate 2, and an exhaust sink 14 for installing the valve plug 3. The main body of the exhaust sink 14 is a circular hole, and the axial first flow holes 15 are arranged around it, and the valve plug limit portion 13 for limiting the position of the valve plug 3 is formed between the first flow holes 15.

[0080] refer to Figure 3 As shown, the basic shape of the valve plate 2 is consistent with the boss 19 of the static disk, and it is a metal plate. There are through holes for fixing bolts 5 on it, and the number and position correspond to the static disk. The edge of the valve plate 2 has the function of limiting the valve plate 2 limit part of the static disk. The limit post through hole and the flow hole on the valve plate 2 correspond to the static disk respectively. The function of the limit post through hole is to facilitate the passage of the limit post 4.

[0081] refer to Figure 4 As shown, the valve plug 3 is a metal cylinder. The outer cylindrical surface cooperates with the valve plug limit portion 13 of the static vortex 1 to limit the radial position of the valve plug 3. The valve plug 3 has a stepped hole inside, the small hole of the stepped hole (limiting column pressing portion 31) and the limiting column 4 are pressed into fit, the large hole of the stepped hole (limiting column pressing portion 32) is the location for placing the spring 6, and the space where the spring 6 is located is the area surrounded by the limiting column 4 and the large hole of the stepped hole.

[0082] refer to Figure 5As shown, the limit column 4 is pressed into one with the valve plug 3, the valve plug 3 is placed in the exhaust sink on the back of the static disk, the spring 6 is clamped between the limit column and the valve plug 3, the valve plate 2 seals the valve plug 3, the limit column and the spring 6 in the sink, the upper end of the limit column passes through the through hole of the valve plate 2, and the valve plate 2 is fixed to the static disk by the bolt 5.

[0083] When the scroll compressor is not running, all valve plugs 3 are pressed against the cross section on the back side of the exhaust port of the static scroll 1 under the action of the elastic force of the spring 6, so that the exhaust valve and the unloading valve are both in a closed state. When the scroll is running, the pressure acting on the end face of the valve plug 3 at the exhaust port is greater than the elastic force of the spring 6, so that the valve plug 3 is pushed open, and the high-pressure refrigerant is discharged from the exhaust hole 11, through the gap between the valve plug 3 and the static disk (annular connecting area 18), and discharged from the first flow hole 15 and the second flow hole 22 to the outside of the static scroll 1. When the scroll compressor stops, the valve plug 3 is closed again by the action of the spring 6 until it is opened when the scroll is started next time.

[0084] The back structure of the static disk of the utility model is provided with a main exhaust port and at least one unloading port. The exhaust port and the unloading port have a recessed platform on the back side of the static disk. The platform is in the shape of a petal and consists of a valve body limiting part in the middle and a peripheral flow hole. The structure, material, and positioning method of the valve plate 2 in the utility model are that the valve plate 2 is a metal plate with limiting holes, flow holes, and bolt 5 through holes. The relative positioning of the valve plate 2 and the static disk can be pin-positioned or end-face-positioned. The overall structure of the unloading valve in the utility model is composed of the static disk of the back structure, the valve plate 2, the valve plug 3, the limiting column, the spring 6, and the bolt 5. The valve plug 3 and the limiting column are interference fit, and the valve plug 3 is limited by the static disk limiting hole.

[0085] The exhaust unloading valve assembly of the utility model has the following advantages:

[0086] (1) The structure is compact, requiring less space at the back of the stationary scroll 1, and making full use of the space at the back of the scroll.

[0087] (2) It has strong compatibility and can be applied to various combinations of unloading port positions and quantities. By adjusting the positions of the unloading valve and the exhaust valve, the requirements for matching the unloading valve with the unloading hole at a specific position can be met.

[0088] (3) It has strong fatigue resistance. By using the combination of spring 6 and valve body, it can meet the requirements even when the valve body is frequently opened and closed.

[0089] (4) The production cost is low. When responding to different unloading port position requirements, only the shape and size of the valve plate 2 need to be changed, and the remaining parts can be used universally, thereby reducing the production cost.

[0090] This embodiment also provides a scroll compressor, including: the above-mentioned exhaust unloading valve assembly. The scroll compressor of the utility model includes the structural features, technology and effects of the above-mentioned exhaust unloading valve assembly, which will not be described in detail here.

[0091] In summary, the exhaust unloading valve assembly and the scroll compressor of the present invention can fully utilize the back space of the static scroll disk, meet the requirements of frequent opening and closing of the valve body, and improve the overall operating efficiency of the compressor.

[0092] The above contents are further detailed descriptions of the present invention in combination with specific preferred implementations, and the specific implementation of the present invention cannot be considered to be limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. An exhaust unloading valve assembly, characterized in that: include: A stationary scroll (1), wherein a boss (19) is provided on a side of the stationary scroll (1) away from the movable scroll, the boss (19) is provided with at least one exhaust sink (14), a bottom of the exhaust sink (14) is provided with an exhaust hole (11), and a first flow hole (15) surrounding and laterally connected to the exhaust hole (11) is formed inside the exhaust sink (14); A valve plate (2) is fixed to the upper surface of the static scroll (1), the valve plate (2) covers the exhaust sink (14), and the valve plate (2) is provided with second flow holes (22) respectively connected to the first flow holes (15); A valve plug assembly is arranged in the exhaust sink (14), one end of the valve plug assembly is connected to the valve plate (2), and the other end abuts against and blocks the exhaust hole (11) based on a biasing force. When the valve plug assembly is lifted up by the impact of the gas to overcome the biasing force, the gas entering the first flow hole (15) is discharged outward from the second flow hole (22).

2. The exhaust unloading valve assembly according to claim 1, characterized in that: The valve plug assembly comprises: A limit post (4) connected to the limit post through hole (21) of the valve plate (2); A valve plug (3), wherein a limit column pressing portion (31) and a spring thrust portion (32) are provided inside the valve plug (3), and the limit column pressing portion (31) is sleeved on the limit column (4); A spring (6) is arranged in the spring thrust portion (32), and the spring thrust portion (32) is elastically supported between the valve plug (3) and the valve plate (2) to press the valve plug (3) toward the exhaust hole (11).

3. The exhaust unloading valve assembly according to claim 2, characterized in that: The second flow holes (22) are distributed around the limiting column through hole (21).

4. The exhaust unloading valve assembly according to claim 1, characterized in that: A valve plug limiting portion (13) surrounding the valve plug (3) is respectively provided between the first flow holes (15) inside the exhaust sink (14), and the valve plug limiting portion (13) jointly limits the stroke of the valve plug (3).

5. The exhaust unloading valve assembly according to claim 1, characterized in that: Some of the exhaust holes are configured as pressure relief holes (12), and the diameter of the pressure relief holes (12) is smaller than the diameter of the exhaust holes (11).

6. The exhaust unloading valve assembly according to claim 5, characterized in that: The exhaust hole (11) is located at the center of the boss (19), and the pressure relief holes (12) are respectively located on both sides of the exhaust hole (11).

7. The exhaust unloading valve assembly according to claim 5, characterized in that: The exhaust hole (11) forms an annular communication area (18) in the circumferential direction that communicates with the first flow hole (15).

8. The exhaust unloading valve assembly according to claim 1, characterized in that: The boss (19) is provided with a bolt hole (16), the valve plate (2) is provided with a bolt through hole (23), and the valve plate (2) is screwed to the boss (19) via bolts (5).

9. The exhaust unloading valve assembly according to claim 1, characterized in that: The edge of the boss (19) is provided with a plurality of raised circumferential limiting portions (17) in the circumferential direction, and the edge of the valve plate (2) forms a limiting edge (24) that cooperates with the circumferential limiting portions (17), and the circumferential limiting portions (17) are jointly clamped with the periphery of the valve plate (2).

10. A scroll compressor, characterized in that: include: The exhaust unloader valve assembly as claimed in claim 1.

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