Gas bearing assembly

Abstract

The invention discloses a gas bearing assembly which comprises an air cylinder and a piston which are connected in a clearance fit mode, the piston is inserted into the air cylinder from one end of the air cylinder in the axial direction, a compression cavity is formed between the end of the piston and the other end of the air cylinder, and a communicated sealing gap is formed between the piston and the air cylinder. An air storage chamber is formed in the piston, the side wall of the piston is provided with a vent hole set used for being communicated with the sealing gap, the top of the piston is provided with a valve hole set used for being communicated with the compression cavity, the outer wall of the air cylinder is axially provided with an annular groove in a surrounding mode, and the annular groove is provided with a first hole set and a second hole set which are communicated with the sealing gap. According to the gas bearing assembly, 2-5 MPa high-pressure gas can enter the gap through the vent hole set to form a compact gas film, the safety of the gas bearing is improved, and the service life of the gas bearing is prolonged.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, and more particularly to a gas bearing assembly. Background Technology

[0002] With technological advancements, the application of linear compressor technology has gradually shifted from military and aerospace fields to civilian sectors, and its application scope continues to expand. Linear compressors utilize advanced technologies such as linear motor drive, leaf spring support, and gap sealing, offering advantages such as compact structure, light weight, oil-free operation, fewer moving parts, high reliability, low noise, low vibration, wear resistance, and long service life. In particular, the elimination of moving parts through the use of gas bearings significantly improves fatigue life.

[0003] Gas bearings utilize gas as a lubricant, forming an "air film" between the shaft and bushing. By using gas to isolate the surfaces of two relatively moving and easily contacting components at a certain distance, gas bearings replace dry friction between solid surfaces with wet friction between the gas and the solid surface. This makes them ideal support components that avoid direct contact between the contact surface and the stationary surface, featuring low friction, no pollution, high rotational accuracy, and the ability to operate under both low and high temperature conditions. Although the smaller gap seal of gas bearings can reduce leakage losses, the insufficient stiffness of the compressor's flexible leaf springs can easily cause friction between the piston and cylinder, leading to a reduction in piston or cylinder life. Furthermore, at 2-5 MPa high pressure, it is difficult for high-pressure gas to form a dense air film when entering the gap through the static pressure orifice. Summary of the Invention

[0004] The purpose of this invention is to provide a gas bearing assembly to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention employs the following technical means: A gas bearing assembly includes a cylinder and a piston connected with a clearance fit. The piston is inserted into the cylinder from one end along the axial direction, forming a compression chamber between the end of the piston and the other end of the cylinder. A sealing gap with communication is formed between the piston and the cylinder. A gas storage chamber is formed inside the piston. The side wall of the piston is provided with a group of vent holes for communicating with the sealing gap. The top of the piston is provided with a group of valve holes for communicating with the compression chamber. An annular groove is axially arranged around the outer wall of the cylinder. The annular groove is provided with a first group of holes and a second group of holes communicating with the sealing gap.

[0006] In some embodiments, the piston includes a top-sealed hollow cylinder made of aluminum alloy or titanium alloy. A base is provided on the bottom outer wall of the hollow cylinder. The base includes a first annular base and a second annular base. The first annular base is located on the bottom outer wall of the hollow cylinder, and the bottom of the first annular base is provided with the second annular base. The outer diameter of the second annular base is smaller than the outer diameter of the first annular base, and the inner diameter of the second annular base is larger than the inner diameter of the hollow cylinder. The base has several assembly holes. Two sets of symmetrical first vent holes are provided on the side wall of the hollow cylinder. A connection hole for connecting with a valve plate assembly is provided at the center of the top of the hollow cylinder. The top of the hollow cylinder has three sets of sequentially and evenly arranged first valve holes, second valve holes, and third valve holes.

[0007] In some embodiments, the first vent is located at the middle of the side wall of the hollow cylinder, and its central axis is located on the horizontal central section of the hollow cylinder.

[0008] In some embodiments, the first hole group and the second hole group are located at the two ends of the annular groove, and the first air hole in the first hole group and the second air hole in the second hole group are alternately distributed. The first hole group and the second hole group connect the compression chamber and the outside of the cylinder.

[0009] In some embodiments, the first hole group includes six groups of first air holes evenly distributed on the cylinder, and the second hole group includes six groups of second air holes evenly distributed on the cylinder, wherein the first air holes and the second air holes are evenly distributed circumferentially at 90 degrees.

[0010] In some embodiments, the first pore and the second pore have the same structure.

[0011] In some embodiments, the first vent includes a first part and a second part disposed on the side wall of the cylinder from the inside to the outside and connected in sequence, wherein the first part and the second part are connected to form a first vent that communicates with the sealing gap.

[0012] In some embodiments, the diameter of the first part is smaller than the diameter of the second part.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The gas bearing assembly of this invention can form a dense gas film by allowing high-pressure gas of 2-5MPa to enter the gap through the vent hole group, thereby improving the safety of the gas bearing and extending its service life. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of one embodiment of the product of the present invention; Figure 2This is a schematic diagram of the product structure according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the piston part of the product according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the piston part of the product according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the cylinder part of the product according to an embodiment of the present invention; Figure 6 This is a top view of the cylinder section of the product according to an embodiment of the present invention; Figure 7 This is a schematic cross-sectional view of the cylinder along section AA of an embodiment of the present invention; Figure 8 Products of the embodiments of the present invention Figure 7 Enlarged schematic diagram of section B; Figure 9 This is a schematic diagram of a partial structure of a product according to an embodiment of the present invention; Figure 10 This is a schematic cross-sectional view of one embodiment of the product of the present invention; Figure 11 This is a schematic diagram of an exhaust valve assembly structure disclosed in an embodiment of the present invention. Detailed Implementation

[0015] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. The following embodiments and drawings are only used to more clearly illustrate the technical solution of this application, and are therefore merely examples and should not be used to limit the scope of protection of this application. The drawings only schematically show the parts related to the technical solution of this application, and do not represent their actual structure as a product.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0017] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0018] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0019] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0020] In the description of the embodiments of this application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0021] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0022] Figure 1 This is a schematic diagram of one embodiment of the product of the present invention, showing a gas bearing assembly implemented together with a valve plate assembly and an exhaust valve assembly. The exhaust valve assembly is connected to the end face of the inner through hole of the cylinder 100 via a conical spring installed inside a sealing cover at the cylinder end. The exhaust valve, the cylinder, and the sealing cover form an exhaust chamber. Figure 10 The structure of the exhaust valve assembly is merely an example and does not represent the actual structure of the exhaust valve assembly. Figure 11A structure of an exhaust valve assembly is disclosed. In this embodiment, a gas bearing assembly includes a cylinder 100 and a piston 200 connected by a clearance fit. The piston 200 is inserted into the cylinder 100 axially from one end of the cylinder 100, forming a compression chamber 300 between the end of the piston 200 and the other end of the cylinder 100. A sealing gap 400 with communication is formed between the piston 200 and the cylinder 100. An air storage chamber 210 is formed inside the piston 200. The side wall of the piston 200 is provided with a group of vent holes 220 for communicating with the sealing gap 400. The top of the piston 200 is provided with a group of valve holes 230 for communicating with the compression chamber 300. An annular groove 110 is axially arranged around the outer wall of the cylinder 100. The annular groove 110 is provided with a first group of holes 120 and a second group of holes 130 communicating with the sealing gap 400. In this embodiment, the interconnected arrangement of the gas storage chamber 210, the vent group 220, the sealing gap 400, the first hole group 120, the second hole group 130, and the compression chamber 300 provides a stable gas supply channel for gas film formation. At the same time, it achieves pressure balance between the sealing gap 400, the compression chamber 300, and the outside of the cylinder 100, avoiding problems such as poor gas flow or excessive leakage caused by a single channel. Moreover, the sealing gap 400 can not only reserve the necessary space for gas film formation, but also effectively avoid local pressure accumulation through the interconnected arrangement. This solves the contradiction between the traditional sealing gap 400's leak prevention and gas film formation, effectively balancing the sealing performance and support reliability of the gas bearing assembly.

[0023] In some embodiments, the piston 200 includes a top-sealed hollow cylinder 240 made of aluminum alloy or titanium alloy. In this embodiment, aluminum alloy or titanium alloy is used to meet the lightweight requirements of high-speed reciprocating motion in linear compressors, reduce drive energy consumption, and possess high strength, wear resistance, and corrosion resistance, making it suitable for long-term use under oil-free conditions, thereby extending the service life of the piston 200. A base 250 is provided on the bottom outer wall of the hollow cylinder 240. The base 250 includes a first annular base 251 and a second annular base 252. The first annular base 251 is disposed on the bottom outer wall of the hollow cylinder 240, and the bottom of the first annular base 251 is provided with the second annular base 252. The outer diameter of the second annular base 252 is smaller than the outer diameter of the first annular base 251, and the inner diameter of the second annular base 252 is larger than the inner diameter of the hollow cylinder 240. The base 250 has several mounting holes 253. In this embodiment, the base 250 is a stepped structure with two-stage annular base platforms. On the one hand, it can be precisely fixed to the drive mechanism through the mounting holes 253. On the other hand, it can use the size difference to form an axial limit to avoid axial displacement during the movement of the piston 200. At the same time, the outer diameter of the second annular base platform 252 is smaller than that of the first annular base platform 251, and the inner diameter is larger than that of the hollow cylinder 240, which reduces the interference between the base 250 and other components and ensures gas flow and movement flexibility. The hollow cylinder 240 has two sets of symmetrical first vent holes 221 on its sidewall, forming a vent hole group 220. A connection hole 241 for connecting with a valve plate assembly is located at the center of the top of the hollow cylinder 240. The top of the hollow cylinder 240 has three sets of sequentially and evenly arranged first valve holes 242, second valve holes 243, and third valve holes 244, forming a valve hole group 230. In this embodiment, the two sets of symmetrical first vent holes 221 ensure uniform gas supply from the gas storage chamber 210 to the sealing gap 400, avoiding localized gas film loss. The three sets of evenly arranged valve holes 230 increase the gas exchange area with the compression chamber 300, improving compression efficiency. Simultaneously, in conjunction with the valve assembly, they achieve unidirectional gas flow, ensuring stable pressure in the compression chamber 300 and preventing gas backflow from affecting compressor performance.

[0024] In some embodiments, the first vent 221 is located at the middle of the side wall of the hollow cylinder 240, and its central axis is located on the horizontal central section of the hollow cylinder 240. In this embodiment, the central axis of the first vent 221 is located on the horizontal central section, so that the gas output from the gas storage chamber 210 can diffuse evenly from the middle of the sealing gap 400 to both the upper and lower sides, avoiding the gas film being thin at the top and thick at the bottom or vice versa due to the position of the first vent 221 being too high or too low, ensuring that the piston 200 is subjected to balanced circumferential force and reducing the risk of uneven wear. Moreover, the first vent 221 located at the middle position allows the gas to reach the corresponding hole group area of ​​the annular groove 110 of the cylinder 100 through the shortest path after entering the sealing gap 400, reducing the flow resistance of the gas in the gap and improving the gas film formation efficiency, especially suitable for the rapid gas film establishment requirements under high pressure conditions.

[0025] In some embodiments, the first hole group 120 and the second hole group 130 are respectively located at both ends of the annular groove 110, and the first air hole 121 in the first hole group 120 and the second air hole 131 in the second hole group 130 are alternately distributed. The first hole group 120 and the second hole group 130 connect the compression chamber 300 and the outside of the cylinder 100. In this embodiment, the first hole group 120 and the second hole group 130 are respectively located at both ends of the annular groove 110, and the air holes are arranged alternately, so that high-pressure gas enters the sealing gap 400 from multiple points around the cylinder 100 alternately, avoiding local gas excess and gas film instability caused by concentrated air holes, and ensuring that the gas film fully covers the circumference and has a uniform thickness. The first hole group 120 and the second hole group 130 are connected to the outside of the compression chamber 300 and the cylinder 100, forming a two-way circulation of external air supply, sealing gap air film, and compression chamber 300 return air. On the one hand, the gas required for the air film can be supplied from the outside, and on the other hand, the air film thickness can be adjusted by the pressure of the compression chamber 300, forming a return air pressure relief under high pressure and air supply pressure enhancement under low pressure, solving the problem of easy rupture of the air film under high pressure conditions; at the same time, the two-way circulation can reduce the gas retention in the sealing gap 400 and reduce leakage loss.

[0026] In some embodiments, the first hole group 120 includes six sets of first air holes 121 evenly distributed on the cylinder 100, and the second hole group 130 includes six sets of second air holes 131 evenly distributed on the cylinder 100. The first air holes 121 and the second air holes 131 are evenly distributed circumferentially at 90 degrees. In this embodiment, a total of 12 air holes are provided, which, in conjunction with the 90° circumferential distribution, means that one air hole is provided every 30°. This allows gas to enter the sealing gap 400 from all directions around the cylinder 100 without any dead angles, completely solving the problem of weak local gas film caused by traditional designs with few air holes. It is especially suitable for the characteristics of rapid gas diffusion under high pressure, ensuring a dense gas film. Moreover, the even distribution of the 12 air holes makes the gas pressure in the sealing gap 400 consistent along the circumferential direction, so that the support force of the cylinder 100 on the piston 200 is balanced, avoiding radial displacement of the piston 200 due to circumferential pressure difference during piston movement, reducing the risk of friction between the cylinder 100 and the piston 200, and reducing operating noise and vibration.

[0027] In some embodiments, the first vent 121 and the second vent 131 have the same structure. In this embodiment, the first vent 121 and the second vent 131 with the same structure have the same gas flow coefficient and throttling effect, so that the gas supply pressure and flow rate of the first vent group 120 and the second vent group 130 are completely consistent, avoiding uneven gas supply between the two vent groups due to differences in vent structure, and further enhancing the uniformity and stability of the gas film.

[0028] In some embodiments, the first vent 121 includes a first part 1211 and a second part 1212 disposed on the side wall of the cylinder 100 from the inside out and connected sequentially. The first part 1211 and the second part 1212 are connected to form a first vent 121 communicating with the sealing gap 400. In this embodiment, the first part 1211 and the second part 1212 of the first vent 121 are two-section connected structures, so that when the gas enters the sealing gap 400 from the outside of the cylinder 100, it is guided by the second part 1212 and the first part 1211 in an orderly manner, avoiding the gas film disturbance caused by the gas directly impacting the sealing gap 400; at the same time, the two-section structure facilitates the control of the vent precision during the processing, especially the precise control of the orifice diameter of the first part 1211 communicating with the sealing gap 400, ensuring the accuracy of the gas supply. Compared to a single through hole, it can reduce the structural weakening of the cylinder 100 sidewall caused by the opening. Especially under high pressure conditions, it can prevent fatigue cracks from forming at the edge of the hole due to pressure impact, extend the service life of the cylinder 100, and facilitate cleaning and maintenance in the later stage.

[0029] In some embodiments, the diameter of the first part 1211 is smaller than the diameter of the second part 1212. In this embodiment, the larger diameter of the second part 1212 allows it to accommodate more high-pressure gas, thus acting as a buffer. The smaller diameter of the first part 1211 increases the flow rate and stabilizes the pressure of the gas as it passes through, solving the problem of excessively rapid diffusion and loose gas film caused by the direct entry of high-pressure gas into the gap. This ensures that the gas pressure entering the sealing gap 400 is sufficient to quickly form a dense and stable gas film. The smaller diameter of the first part 1211 reduces gas leakage, while the larger diameter of the second part 1212 reduces the resistance when the gas enters, achieving a balance between stable high-pressure gas supply and controllable leakage loss. This is particularly suitable for high-pressure conditions of 2-5 MPa, ensuring both the gas film support and preventing excessive leakage from affecting compressor efficiency.

[0030] The specific embodiments disclosed in this invention fall within the scope of protection of the claims of this invention, and are specific subordinate implementations of the characteristic parts of this invention. The protection content of the specific embodiments is merely an explanation of the scope of protection of the claims of this invention, and the scope of protection of this invention is not limited to the protection content of the specific embodiments. The protection content of the specific embodiments should not be construed as a limitation on the scope of protection of the claims of this invention. All product structural connection relationships falling within the scope of protection of this invention are also within the scope of protection of this invention. Conventional technical improvements to the structure of product components without departing from the essence of protection of this invention, such as the improvements to the structure of some parts of the product as described in the specific embodiments of this invention, will also fall within the essence of protection of this invention.

Claims

1. A gas bearing assembly, characterized in that: The device includes a cylinder and a piston connected with a clearance fit. The piston is inserted into the cylinder from one end along the axial direction, forming a compression chamber between the end of the piston and the other end of the cylinder. A sealing gap with communication is formed between the piston and the cylinder. An air storage chamber is formed inside the piston. The side wall of the piston is provided with a group of vent holes for communicating with the sealing gap. The top of the piston is provided with a group of valve holes for communicating with the compression chamber. The outer wall of the cylinder is axially surrounded by an annular groove. The annular groove is provided with a first group of holes and a second group of holes communicating with the sealing gap.

2. A gas bearing assembly according to claim 1, characterized in that: The piston includes a top-sealed hollow cylinder made of aluminum alloy or titanium alloy. A base is provided on the bottom outer wall of the hollow cylinder. The base includes a first annular base and a second annular base. The first annular base is located on the bottom outer wall of the hollow cylinder, and the second annular base is located at the bottom of the first annular base. The outer diameter of the second annular base is smaller than the outer diameter of the first annular base, and the inner diameter of the second annular base is larger than the inner diameter of the hollow cylinder. Several assembly holes are provided on the base. Two sets of symmetrical first vent holes are provided on the side wall of the hollow cylinder. A connection hole for connecting with a valve plate assembly is provided at the center of the top of the hollow cylinder. Three sets of sequentially and evenly arranged first valve holes, second valve holes, and third valve holes are provided on the top of the hollow cylinder.

3. A gas bearing assembly according to claim 2, characterized in that: The first vent is located in the middle of the side wall of the hollow cylinder, and its central axis is located on the horizontal central section of the hollow cylinder.

4. A gas bearing assembly according to claim 1, characterized in that: The first hole group and the second hole group are located at the two ends of the annular groove, and the first air hole in the first hole group and the second air hole in the second hole group are alternately distributed. The first hole group and the second hole group connect the compression chamber and the outside of the cylinder.

5. A gas bearing assembly according to claim 4, characterized in that: The first hole group includes six sets of first air holes evenly distributed on the cylinder, and the second hole group includes six sets of second air holes evenly distributed on the cylinder. The first air holes and the second air holes are evenly distributed circumferentially at 90 degrees.

6. A gas bearing assembly according to claim 4, characterized in that: The first pore has the same structure as the second pore.

7. A gas bearing assembly according to claim 6, characterized in that: The first vent includes a first part and a second part that are arranged from the inside to the outside on the side wall of the cylinder and are connected in sequence. The first part and the second part are connected to form a first vent that communicates with the sealing gap.

8. A gas bearing assembly according to claim 7, characterized in that: The diameter of the first part is smaller than the diameter of the second part.

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