Sealing structure for inflation inlet of refrigerating machine

Abstract

The utility model provides a refrigerator inflation inlet sealing structure which comprises a sealing screw assembly, the sealing screw assembly comprises an inflation screw and a sealing gasket, the inflation screw is in threaded connection with an inflation inlet of a refrigerator crankcase, a protruding face is formed on the bottom face of the sealing gasket, and the sealing gasket is in threaded connection with the inflation screw. A shaft shoulder end face matched with the protruding face is arranged at an inflation inlet of the refrigerator crankcase, and the protruding face is embedded into a shaft shoulder. According to the sealing structure for the inflation inlet of the refrigerating machine, a multi-layer sealing structure is formed between the inflation inlet of the refrigerating machine and the bottom of the sealing gasket, and the sealing reliability is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to low temperature refrigeration technical field especially relates to a stirling cryocooler inflation mouth sealing structure. BACKGROUND

[0002] In recent years, with the wide application of infrared technology in military fields such as infrared imaging, reconnaissance warning, early warning monitoring, guidance, mid-high altitude long-range air defense and other fields, forest fire prevention, gas detection and other aspects, infrared focal plane detector technology has developed rapidly. As an important component of the infrared detector Dewar refrigeration assembly (IDDCA assembly), the main function of the Stirling cryocooler is to provide a low-temperature working environment for the infrared detector, reduce the noise of the infrared detector, improve the sensitivity and resolution of the infrared detector, and thus improve the infrared imaging effect.

[0003] Generally, the rotary integrated Stirling cryocooler has the characteristics of compact structure, small volume, light weight and low power consumption. Such Stirling cryocooler can meet the functional requirements of various tactical weapon equipment, civil fire prevention, gas detection and other infrared detection.

[0004] High-purity helium is the working medium required for the normal operation of the Stirling cryocooler. The Stirling cryocooler cavity is filled with high-purity helium at a relatively high pressure, generally from more than ten atmospheres to more than forty atmospheres or even higher pressure. The mechanical sealing structure is required to achieve the long-term reliable sealing of the high-pressure high-purity helium required by the Stirling cryocooler into the cryocooler cavity, and this mechanical sealing structure is called the inflation sealing structure.

[0005] The existing rotary integrated Stirling cryocooler seals each main part by sealing wires, sealing rings, C-shaped rings and other structural forms. The sealing structure of the inflation port for the cryocooler generally includes an inflation screw and a sealing gasket. By applying torque to the inflation screw, the sealing gasket is deformed, tightly fitted with the surface of the crankcase and compressed, thereby sealing it.

[0006] However, the cryocooler will experience harsh environmental conditions such as vibration, high and low temperature during use. Under the conditions of vibration and high and low temperature, the sealing structure at the inflation port of the cryocooler is prone to loose or even short-term or permanent failure due to the poor tightness of the sealing gasket with the surface of the crankcase shell and the mating surface of the inflation screw on both sides, resulting in the failure of the cryocooler. INVENTION CONTENTS

[0007] The utility model provides a refrigerating machine inflation port sealing structure to solve the refrigerating machine inflation port sealing structure is easy to be impacted by external force, high and low temperature thermal stress impact or natural time effect when forming the sealed state, the torque of screw reduces if, and the sealing surface formed by the conventional sealing structure is easy to appear the problem of air leakage even failure.

[0008] The utility model discloses a refrigerating machine inflation port sealing structure, including sealing screw subassembly, the sealing screw subassembly includes inflation screw and sealing gasket, wherein, the inflation screw is connected with the inflation port of refrigerating machine crankcase thread, the bottom surface of sealing gasket forms the convex surface, the inflation port of refrigerating machine crankcase is provided with the shoulder end surface of adaptation with the convex surface, the convex surface is embedded in the shoulder.

[0009] In one embodiment, the top surface of the sealing gasket is provided with a groove adapted to the head of the inflation screw.

[0010] In one embodiment, the bottom surface of the sealing gasket and the convex surface are circular arc surfaces.

[0011] In one embodiment, the sealing gasket has elasticity in the axial direction.

[0012] In one embodiment, the sealing gasket is formed of a metal thin-wall material with certain rigidity and elasticity, and the sealing gasket deforms after being extruded.

[0013] In one embodiment, the surface of the sealing gasket is electroplated with a plating layer, and the material of the plating layer is electroplated tin or electroplated copper.

[0014] In one embodiment, the inside of the sealing gasket is hollow, and the wall thickness of the sealing gasket is 0.5-1 mm.

[0015] In one embodiment, the inflation screw and the sealing gasket are formed into an integral structure through crimping.

[0016] In one embodiment, the shoulder of the inflation port is provided with a space accommodating the axial deformation of the main body of the sealing gasket.

[0017] In one embodiment, the upper end of the sealing gasket is in clearance fit with the crankcase.

[0018] Compared with the prior art, the refrigerating machine inflation port sealing structure of the utility model forms a multilayer sealing structure between the inflation port of the refrigerating machine and the bottom of the sealing gasket, improving the sealing reliability.

[0019] The above technical features can be combined in various technically feasible ways to produce new embodiments, as long as the purpose of the utility model can be achieved. BRIEF DESCRIPTION OF DRAWINGS

[0020] In the following, the present application will be described in more detail based on non-limiting embodiments and with reference to the drawings. In which:

[0021] Figure 1 The sealing state of the refrigeration machine air inlet sealing structure according to the present application is shown when being inflated;

[0022] Figure 2 The position state of the refrigeration machine air inlet sealing structure in Figure 1 is shown after being sealed;

[0023] Figure 3 The shape of the sealing gasket after being deformed in the sealing state of Figure 1 is shown;

[0024] Figure 4A and Figure 4B The perspective view of the sealing gasket is shown.

[0025] In the drawings, the same components are denoted by the same reference numerals. The drawings are not drawn to scale.

[0026] In which, the reference numerals are:

[0027] 1, inflation screw; 2, sealing gasket; 21, convex surface; 22, groove; 23, bottom surface; 3, crankcase; 31, shoulder end surface; 32, shaft shoulder; 33, accommodating portion. DETAILED DESCRIPTION

[0028] The present application will be further described in detail below in combination with the drawings and specific embodiments. It should be noted that, as long as there is no conflict, each embodiment in the present application and each feature in each embodiment can be combined with each other, and the formed technical solutions are within the protection scope of the present application.

[0029] The parts not described in the present application can be realized by using or referring to the existing technology.

[0030] As shown in Figure 1 and Figure 2 , the refrigeration machine air inlet sealing structure of the present application comprises a sealing screw assembly, the sealing screw assembly comprises an inflation screw 1 and a sealing gasket 2, wherein the inflation screw 1 is threadedly connected with the air inlet of the refrigeration machine crankcase 3, the sealing gasket 2 has a convex surface 21 formed on the bottom surface 23, the air inlet of the refrigeration machine crankcase is provided with a shoulder end surface 31 which is adapted to the convex surface 21, and the convex surface 21 is embedded in the shaft shoulder 32.

[0031] As shown in Figure 1 and Figure 2As shown, the refrigeration machine air charging port sealing structure, the air charging screw 1 is screwed with the crankcase 3, when the air charging screw 1 is screwed with the crankcase 3, the air charging screw 1 applies downward force to the sealing gasket 2, the sealing gasket 2 is gradually deformed, the convex surface 21 of the sealing gasket 2 is pressed with the shaft shoulder surface, the bottom surface 23 is pressed with the stepped surface of the shaft shoulder end surface 31, thereby forming two sealing surfaces, and the sealing effect is improved.

[0032] In an optional embodiment, the top surface of the sealing gasket 2 is provided with a groove 22 matched with the head of the air charging screw 1.

[0033] Specifically, in use (before charging), the head of the air charging screw 1 is placed in the groove 22 at the top end of the sealing gasket 2, and by pre-pressing the air charging screw 1, the sealing gasket 2 and the air charging screw 1 can be relatively fixed, so that the air charging screw 1 can be screwed into the crankcase 3 together with the sealing gasket 2.

[0034] When air charging sealing is needed, the air charging screw is screwed through the thread and the crankcase air charging port, and is screwed into a part (for example Figure 1 As shown, at this time, the inner cavity of the refrigeration machine and the external air source are charged through the thread gap between the air charging screw 1 and the crankcase 3, the gap between the top end of the sealing gasket 2 and the crankcase 3, and the air charging path and direction are as shown. Figure 3

[0035] In an optional embodiment, the bottom surface 23 and the convex surface 21 of the sealing gasket 2 are circular arc surfaces.

[0036] Figure 4A And Figure 4B As shown, the bottom surface 23 and the convex surface 21 of the sealing gasket 2 are circular arc surfaces, wherein, Figure 2 And Figure 3 As shown, the bottom surface 23 and the convex surface 21 of the sealing gasket 2 are circular arc surfaces, wherein, Figure 3 The two points A and B are the top surfaces of the circular arc surfaces, under the pressure of the air charging screw 1 at the top, the sealing gasket 2 will gradually deform, and two annular surface sealing structures are formed between the sealing gasket 2 and the sealing plane of the crankcase 3, the sealing area is increased, and a double-stage sealing effect is formed.

[0037] At the same time, since the inside of the crankcase 3 is high-pressure gas and the outside is normal-pressure gas, a significant pressure difference is formed between the inside and the outside, so the internal high-pressure gas also extrudes the sealing surface from the inside to the outside at the two places A and B, the fitting state is further strengthened, and the reliability of the sealing effect is ensured.

[0038] ​In one embodiment, the sealing gasket 2 has axial elasticity. As shown in Figure 3 Due to the pressure of the upper inflation screw 1, the C point of the sealing gasket forms an outward convex arc surface, so the sealing gasket 2 should have axial elasticity.

[0039] It should be noted that the sealing gasket 2 has a certain strength, and under the condition of no pressure of the inflation screw 1, only the pressure of the gas in the crankcase 3 is not enough to make the C point form an outward convex arc deformation, so in the case of vibration working condition and thermal expansion and contraction of the gap between the parts at high and low temperatures, the sealing gasket can offset the slight movement of the parts caused by vibration, high and low temperature and other working conditions by the arc elastic deformation ability of the gasket. When the refrigerator is subjected to high and low temperature impact, vibration impact and other external influences, even if the inflation screw is loose or shaken, the sealing surface of the A point and the B point of the sealing gasket can always be in sealing and fitting state with the sealing surface of the crankcase, ensuring good sealing effect and avoiding the case of temporary leakage and rapid pressure reduction.

[0040] In one embodiment, the sealing gasket 2 is formed of a metal thin-walled material with certain rigidity and elasticity, and the sealing gasket 2 has axial elasticity and deforms after being extruded.

[0041] In one embodiment, the surface of the sealing gasket 2 is plated with a plating layer, and the material of the plating layer is electroplated tin or electroplated copper.

[0042] The sealing gasket 2 is made of a metal thin-walled material (such as nanometer metal material) with sufficient rigidity and elasticity by electrocasting and other methods to complete the support process. The metal thin-walled material with certain rigidity and elasticity will deform after being extruded, thereby forming a good sealing surface and closely fitting with the surface of the metal part connected thereto. In order to achieve better sealing effect, the surface is usually plated, such as electroplated tin, electroplated copper, etc.

[0043] In one embodiment, the inside of the sealing gasket 2 is hollow, and the wall thickness of the sealing gasket 2 is preferably 0.5-1mm. Since the inside of the sealing gasket is in a hollow state, after sealing, the pressure in the cavity inside the sealing gasket 2 is high pressure (greater than the external pressure of the sealing gasket 2), so the high pressure will further enhance the pressure of the sealing gasket 2 on the crankcase 3 at point B, thereby strengthening the sealing effect.

[0044] In one embodiment, the inflation screw 1 and the sealing gasket 2 are formed into an integrated structure by pressure bonding. When in use, the head of the inflation screw 1 is placed in the groove 22 at the top end of the sealing gasket 2, and the sealing gasket 2 and the inflation screw 1 can be relatively fixed by pre-pressing the inflation screw 1.

[0045] In one embodiment, the gassing port is provided with a space (accommodation part 33) accommodating the axial deformation of the main body of the sealing gasket 2 at the shoulder end surface 31.

[0046] As shown in Figure 2 and Figure 3 , due to the pressure effect of the upper gassing screw 1, the C point position of the sealing gasket 2 forms an outwardly convex circular arc surface, and the space (accommodation part) 33 accommodates the axial deformation of the sealing gasket 2.

[0047] In one embodiment, as shown in Figure 2 , the upper end portion of the sealing gasket 2 is in clearance fit with the crankcase 3. The gassing of the refrigeration machine cavity and the external gas source is carried out through the clearance fit between the gassing screw and the crankcase, and the clearance between the top end of the sealing gasket and the crankcase.

[0048] When the gassing work is completed and the sealing is ready to be carried out, a hexagonal wrench is inserted into the hexagonal hole in the gassing screw 1, and a torque is applied to it (wherein the torque applied to the gassing screw 1 when sealing cannot be less than 40 lib-in), the gassing screw 1 and the crankcase 3 are tightened, at this time the head of the gassing screw 1 exerts a downward force on the sealing gasket 2, the sealing gasket 2 is gradually deformed, the convex surface 21 of the sealing gasket 2 is pressed against the shoulder surface, and the bottom surface 23 is pressed against the stepped surface of the shoulder end surface 31, thereby forming two sealing surfaces and improving the sealing effect. According to the actual application data, the Stirling refrigeration machine using the sealing structure of the utility model can achieve a low leakage rate of 5x10 -9 mbar.L / s.

[0049] Among them, the position of the sealing gasket point A is sealed by the first layer, and the position outside the B point (the position of the circular arc surface except the B point) is the same as the basic pressure of the working environment. During the tightening of the gassing screw 1, the deformation of the sealing gasket at the B point position is basically not affected by the internal pressure of the crankcase, and the deformation of the gasket is more sufficient, thereby improving the sealing reliability.

[0050] Unless otherwise defined, technical terms or scientific terms used in the present application shall have the ordinary meaning as understood by a person of ordinary skill in the art to which the present application pertains. The term "comprising" or "including" or similar words used in the present application intends to encompass the elements or objects listed after the word and their equivalents, and does not exclude other elements or objects. The term "connected" or "coupled" or similar words used in the present application does not limit to physical or mechanical connection, but can include electrical connection, whether direct or indirect. In the description of the present application, the terms "top", "bottom", "top surface", "bottom surface" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and when the absolute position of the described object is changed, the relative positional relationship may also be changed accordingly, so it cannot be understood as a limitation on the present application.

[0051] At this point, those skilled in the art should realize that although the present application has been described with reference to the preferred embodiments, various modifications can be made to it and equivalent components can be substituted therein without departing from the scope of the present application. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A seal for a refrigeration machine charge port, comprising: The sealing screw assembly comprises an inflation screw and a sealing gasket, the inflation screw is screwed with an inflation port of a refrigerating machine crankcase, a convex surface is formed on the bottom surface of the sealing gasket, a shaft shoulder end surface which is matched with the convex surface is arranged at the inflation port of the refrigerating machine crankcase, and the convex surface is embedded in the shaft shoulder.

2. The chiller gas inlet seal structure of claim 1, wherein, A groove which is matched with the head of the inflation screw is arranged on the top surface of the sealing gasket.

3. The chiller gas inlet seal structure of claim 2, wherein, The bottom surface and the convex surface of the sealing gasket are circular arc surfaces.

4. The chiller gas inlet seal structure of claim 1, wherein, The sealing gasket has elasticity in the axial direction.

5. The air charge inlet seal structure for a refrigerator as defined in claim 4, wherein The sealing gasket is formed by a metal thin-wall material with certain rigidity and elasticity, and the sealing gasket is deformed after being extruded.

6. The air charge seal structure for a refrigerator compressor of claim 5 wherein, The surface of the sealing gasket is plated with a plating layer, and the material of the plating layer is electroplated tin or electroplated copper.

7. The air charge seal structure for a refrigerator compressor of claim 6 wherein, The inside of the sealing gasket is hollow, and the wall thickness of the sealing gasket is 0.5-1 mm.

8. The air charge inlet seal structure for a refrigerator as defined in claim 2, wherein The inflation screw and the sealing gasket are formed into an integrated structure by crimping.

9. The chiller gas inlet seal structure of any of claims 1-8, wherein, A space which accommodates the axial deformation of the main body of the sealing gasket is arranged at the shaft shoulder of the inflation port.

10. A chiller gas inlet seal structure according to any one of claims 1-8, wherein, The upper end of the sealing gasket is matched with the crankcase in a gap.

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