Compressor piston seal device

Abstract

This invention relates to the field of compressor technology, and more particularly to a compressor piston sealing device. The compressor piston sealing device includes a piston rod, a gland, a seal, and a drive mechanism. The gland is detachably connected to the end of the piston rod and is coaxially arranged with the piston rod. The seal is spirally wound around the outer edge of the piston rod near the gland, and the outer edge of the seal protrudes beyond the outer circumferential surface of both the piston rod and the gland. The drive mechanism is located on the side of the gland near the piston rod, with one end connected to the gland and the other end connected to the seal. The drive mechanism can drive the seal to move circumferentially along the piston rod and expand radially, so that the outer edge of the seal fits against the cylinder wall and forms a seal. This compressor piston sealing device can dynamically fill the circumferentially uneven gap between the piston and cylinder caused by long-term wear of the seal, improving sealing performance and reducing maintenance costs.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, and more particularly to a compressor piston sealing device. Background Technology

[0002] Hydrogen energy is a clean and efficient new energy source, and its application scale continues to expand in industries such as hydrogen refueling stations, chemical hydrogen production, and energy storage. As the core pressurization equipment in the hydrogen energy storage, transportation, and refueling process, the hydrogen compressor plays a crucial role in compressing low-pressure hydrogen to high-pressure conditions. Hydrogen molecules are extremely small and have exceptional permeability. Under high-pressure operating conditions, the equipment's sealing structure is subjected to alternating loads and media erosion for extended periods. The dynamic sealing performance between the piston and the cylinder wall directly determines the hydrogen leakage, operating energy consumption, safety stability, and overall service life of the hydrogen compressor.

[0003] In related technologies, the piston seal of hydrogen compressors often adopts an integrated elastic sealing ring, which relies on the elastic deformation of the elastic sealing ring itself to achieve passive cylinder sealing. After long-term friction wear, the preload of the elastic sealing ring decays rapidly, and an uneven circumferential gap is formed between the piston and the cylinder, resulting in a significant decrease in sealing performance. Moreover, after wear, the entire machine must be shut down for disassembly and replacement of the seal, which is a cumbersome disassembly and assembly process and has high downtime maintenance costs.

[0004] Therefore, there is an urgent need to design a compressor piston sealing device to solve the above technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a compressor piston sealing device that can dynamically fill the circumferential uneven gap between the piston and cylinder caused by long-term wear of the seal, thereby improving sealing performance and reducing maintenance costs.

[0006] To achieve this objective, the present invention adopts the following technical solution: This invention provides a compressor piston sealing device, comprising: Piston column; A pressure cap, which is detachably connected to the end of the piston rod and is coaxially arranged with the piston rod; A sealing element, wherein the sealing element is spirally coiled around the outer edge of the piston rod near the end of the gland, and the outer edge of the sealing element protrudes from the outer circumferential surface of the piston rod and the gland; A drive mechanism is provided on the side of the pressure plate near the piston rod. One end of the drive mechanism is connected to the pressure plate, and the other end is driven to the seal. The drive mechanism can drive the seal to move circumferentially along the piston rod and expand radially so that the outer edge of the seal fits against the cylinder wall and forms a seal.

[0007] As an optional technical solution for a compressor piston sealing device, the drive mechanism includes a scissor lift that is retractable along the circumference of the gland. The scissor lift has a fixed end and a movable end. The fixed end is fixed to the gland, and the movable end can slide along the circumference of the gland. The side of the scissor lift away from the gland is connected to the seal.

[0008] As an optional technical solution for a compressor piston sealing device, the end face of the pressure cap facing the piston column is coaxially provided with an annular groove, one end of the scissor bracket is slidably assembled in the annular groove, and the outer edge of the scissor bracket away from the pressure cap is pressed against the sealing element.

[0009] As an optional technical solution for a compressor piston sealing device, the scissor lift is formed by hinged multiple sets of scissor arms arranged in a ring array along the piston column axis; wherein, each set of scissor arms includes a first scissor arm and a second scissor arm that are rotatably connected to each other; the ends of two adjacent sets of scissor arms are hinged to each other, and each hinge position of the scissor arm set is provided with a guide block, and the guide block is slidably engaged with the annular groove. The guide block on one of the scissor arms located at the end of the scissor lift is fixed to the inner wall of the annular groove to form the fixed end.

[0010] As an optional technical solution for a compressor piston sealing device, the drive mechanism further includes an electric push rod and a rotating rod. The electric push rod is provided on the side wall of the piston rod near the scissor arm, and the telescopic end of the electric push rod is positioned towards the scissor arm assembly where the fixed end is located. The telescopic end of the electric push rod is provided with a rotating rod that rotates horizontally, and the end of the rotating rod away from the electric push rod is rotatably connected to the outer wall of the scissor arm assembly at the fixed end. The electric push rod pushes the scissor arm assembly through the rotating rod, causing the scissor frame to retract or expand along the annular groove.

[0011] As an optional technical solution for a compressor piston sealing device, the drive mechanism further includes a locking post, which is fixed to the outer edge of the scissor lift away from the gland. The sealing element has a slot corresponding to the position of the locking post, and the locking post is engaged with the slot.

[0012] As an optional technical solution for a compressor piston sealing device, the outer edge of the side wall of the scissor lift away from the gland is also vertically fixed with several limiting posts, the limiting posts slide against the inner wall of the seal, and the locking post and the limiting posts are located on the same arc trajectory.

[0013] As an optional technical solution for a compressor piston sealing device, the two ends of the seal are respectively provided with a first inclined portion and a second inclined portion, the inclined surfaces of the first inclined portion and the second inclined portion are complementary; a reinforcing portion is provided on the side wall of the first inclined portion near the piston column axis.

[0014] As an optional technical solution for a compressor piston sealing device, the reinforcing part rolls against a horizontally arranged drive wheel on the side near the piston column axis, and a pneumatic telescopic rod is provided on the side of the drive wheel away from the reinforcing part. The pneumatic telescopic rod is fixed to the end side wall of the piston column. The pneumatic telescopic rod is configured to apply a radial auxiliary support force to the reinforcing part through the drive wheel.

[0015] As an optional technical solution for a compressor piston sealing device, a sealing element and a pressure cap are provided at both ends of the piston column. The outer edge of the side wall of the pressure cap near the piston column abuts against the sealing element. The sealing element is slidably disposed at the end of the piston column near the pressure cap along the radial direction of the piston column. The piston rod has a pressure stabilizing chamber inside, which is located between two seals at both ends of the piston rod. The pressure stabilizing chamber is connected to an external gas source through a connecting pipe to inject inert gas into the pressure stabilizing chamber and maintain pressure balance.

[0016] The beneficial effects of the present invention include at least the following: This invention provides a compressor piston sealing device, which includes a piston rod, a gland, a seal, and a drive mechanism. The gland is detachably connected to the end of the piston rod and is coaxially arranged with the piston rod. The seal is spirally wound around the outer edge of the piston rod near the gland, and its outer edge protrudes beyond the outer circumferential surface of both the piston rod and the gland. The drive mechanism is located on the side of the gland near the piston rod, with one end connected to the gland and the other end connected to the seal. The drive mechanism can drive the seal to move circumferentially along the piston rod and expand radially, so that the outer edge of the seal fits against the cylinder wall and forms a seal.

[0017] The seal is spirally coiled around the outer edge of the piston rod near the gland, with its outer edge protruding beyond the outer circumference of both the piston rod and the gland. Instead of a monolithic annular seal structure, the seal does not form a closed, continuous ring. Therefore, during radial expansion, it does not experience axial thinning or warping due to circumferential stretching, thus avoiding the reduced contact area and localized wear caused by axial thinning in traditional annular seals. The drive mechanism moves the seal circumferentially along the piston rod and expands radially. This radial expansion ensures the seal maintains its preload against the cylinder wall, forming a stable basic seal. The circumferential movement allows the seal to actively fill the uneven circumferential gaps between the piston rod and cylinder caused by long-term wear, achieving active compensation for seal wear and improving sealing performance. Unlike traditional solutions, which require forced shutdown and replacement after sealing performance deteriorates to a certain level, this significantly extends the seal's lifespan and reduces maintenance costs. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the compressor piston sealing device provided in an embodiment of the present invention; Figure 2 This is an exploded view of the gland, seal, and drive mechanism provided in the embodiments of the present invention; Figure 3 This is an exploded view of the sealing element and driving mechanism provided in the embodiments of the present invention; Figure 4 This is a schematic diagram of the structure of the sealing element provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the drive mechanism provided in an embodiment of the present invention; Figure 6 This is a schematic diagram showing the connection relationship between the gland, the seal, and the drive mechanism provided in an embodiment of the present invention; Figure 7 This is a schematic diagram showing the connection relationship between the pressure cap and the drive mechanism provided in an embodiment of the present invention.

[0020] Figure Labels 10. Piston column; 20. Pressure cap; 21. Annular groove; 30. Sealing element; 31. First inclined portion; 32. Second inclined portion; 33. Reinforcing portion; 34. Slot; 40. Drive mechanism; 41. Scissor lift frame; 42. Scissor arm assembly; 421. First scissor arm; 422. Second scissor arm; 43. Guide block; 44. Electric push rod; 45. Rotating rod; 46. Locking pin; 47. Drive wheel; 48. Pneumatic telescopic rod; 401. Fixed end; 402. Movable end. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0023] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0024] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are used only for the convenience of describing the invention and for 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 invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0025] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0027] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0028] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0029] This embodiment provides a compressor piston sealing device that can dynamically fill the circumferential uneven gap between the piston and cylinder caused by long-term wear of the seal, thereby improving sealing performance and reducing maintenance costs.

[0030] like Figures 1-7 As shown, the compressor piston sealing device mainly includes a piston rod 10, a gland 20, a seal 30, and a drive mechanism 40. The gland 20 is detachably connected to the end of the piston rod 10 and is coaxially arranged with the piston rod 10. The seal 30 is spirally coiled around the outer edge of the piston rod 10 near the gland 20, and its outer edge protrudes beyond the outer circumferential surface of both the piston rod 10 and the gland 20. The drive mechanism 40 is located on the side of the gland 20 near the piston rod 10. One end of the drive mechanism 40 is connected to the gland 20, and the other end is drivenly connected to the seal 30. The drive mechanism 40 can drive the seal 30 to move circumferentially along the piston rod 10 and expand radially, so that the outer edge of the seal 30 fits against the cylinder wall and forms a seal.

[0031] Based on the above design, in this embodiment, the seal 30 is spirally coiled around the outer edge of the piston rod 10 near the end of the gland 20, and the outer edge of the seal 30 protrudes beyond the outer circumferential surface of the piston rod 10 and the gland 20. The seal 30 adopts a spiral coiling method rather than an integral annular sealing structure. The seal 30 itself does not form a closed continuous ring, therefore, during radial expansion, it will not experience axial thinning or warping deformation due to circumferential stretching. This avoids the phenomenon of reduced contact area and localized wear caused by axial thinning when using traditional annular seal rings with external support. The drive mechanism 40 drives the seal 30 to move circumferentially and expand radially along the piston rod 10. The radial expansion allows the seal 30 to maintain a preload and adhere to the cylinder wall, forming a stable basic seal. The circumferential movement allows the seal 30 to actively fill the uneven circumferential gap between the piston rod 10 and the cylinder caused by long-term wear, realizing active compensation for the wear of the seal 30, improving the sealing performance. Unlike traditional solutions, it does not require forced shutdown and replacement after the sealing performance deteriorates to a certain extent, significantly extending the service life of the seal 30 and reducing maintenance costs.

[0032] In this embodiment, the sealing element 30 is a flexible long strip structure with a spiral coil. When the driving mechanism 40 drives it to move circumferentially, each segment of the sealing element 30 moves as a whole along the spiral path, so that the sealing material in the original locally worn area is pushed and replaced. This makes full use of the material reserves of the sealing element 30 itself to compensate for wear. This is fundamentally different from the traditional annular sealing ring, which is stretched circumferentially as a continuous whole when it is supported externally, resulting in axial thinning and warping. While ensuring the sealing performance, it will not aggravate wear or reduce the contact surface, thereby improving the sealing performance.

[0033] In some alternative embodiments, the material of the seal 30 can be a high-temperature resistant, chemically resistant, and sufficiently flexible material such as polytetrafluoroethylene, polyimide, polyetheretherketone, or carbon fiber reinforced composite material.

[0034] like Figures 2-7 As shown, the drive mechanism 40 in this embodiment includes a scissor lift 41 that is circumferentially retractable along the pressure cover 20. The scissor lift 41 has a fixed end 401 and a movable end 402. The fixed end 401 is fixed to the pressure cover 20, and the movable end 402 can slide circumferentially along the pressure cover 20. The side of the scissor lift 41 away from the pressure cover 20 is connected to the seal 30.

[0035] Specifically, the scissor lift 41, as the core transmission component of the drive mechanism 40, has the characteristic of being circumferentially retractable along the pressure cap 20. When the scissor lift 41 retracts, the movable end 402 moves closer to the fixed end 401, and through the connection between the scissor lift 41 and the seal 30, it pulls the seal 30 to move circumferentially along the piston column 10, thereby achieving circumferential displacement compensation of the seal 30. When the scissor lift 41 extends, the movable end 402 moves away from the fixed end 401, and the included angle between each scissor arm assembly 42 of the scissor lift 41 increases, causing the side of the scissor lift 41 away from the pressure cap 20 to expand outward in a direction away from the axis of the piston column 10, thereby pushing the seal 30 radially outward, so that the outer edge of the seal 30 is in contact with the cylinder wall with a pre-tightening force.

[0036] Understandably, the fixed end 401 of the scissor lift 41 is fixed to the pressure cap 20, providing a stable mechanical reference point for the entire drive mechanism 40; the movable end 402 can slide circumferentially along the pressure cap 20, providing driving force for the circumferential movement of the seal 30.

[0037] In some alternative implementations, the extension stroke of the scissor lift 41 can be designed according to the actual wear of the seal 30, typically in the range of several millimeters to tens of millimeters; the range of the extension and retraction angles of the scissor lift 41 is determined by the initial included angle and the maximum allowable included angle of the scissor arm assembly 42, and is generally designed to be between 30° and 150°.

[0038] like Figure 2 As shown, in this embodiment, the end face of the pressure cap 20 facing the piston column 10 is coaxially provided with an annular groove 21, one end of the scissor bracket 41 is slidably assembled in the annular groove 21, and the outer edge of the scissor bracket 41 away from the pressure cap 20 is pressed against the seal 30.

[0039] Specifically, the annular groove 21 provides guiding constraints for the sliding of the scissor lift 41, ensuring that during the retraction or extension process, each intersecting node of the scissor lift 41 can only move along the trajectory of the annular groove 21, that is, slide circumferentially along the piston rod 10, and cannot undergo radial offset or axial movement. This guiding constraint ensures the stability and repeatability of the telescopic movement of the scissor lift 41, avoiding problems such as skewing, jamming, or deviation from the predetermined trajectory during the movement of the scissor lift 41.

[0040] like Figure 5As shown, the scissor lift 41 in this embodiment is formed by hinged multiple sets of scissor arms 42 arranged in a ring array along the axial direction of the piston rod 10. Each set of scissor arms 42 includes a first scissor arm 421 and a second scissor arm 422 that are rotatably connected to each other. The ends of adjacent sets of scissor arms 42 are hinged to each other, and each hinge position of the scissor arms 42 is provided with a guide block 43, which slides in conjunction with the annular groove 21. The guide block 43 on one of the scissor arms 42 at the end of the scissor lift 41 is fixed to the inner wall of the annular groove 21 to form a fixed end 401. The fixed end 401 serves as the mechanical reference point for the telescopic movement of the scissor lift 41 and remains stationary during the telescopic process. This ensures that the displacement of the movable end 402 relative to the fixed end 401 is entirely determined by the change in the hinge angle, facilitating precise control of the radial expansion and circumferential displacement of the seal 30.

[0041] Specifically, multiple sets of scissor arm assemblies 42 are arranged in a ring array along the axial direction of the piston column 10, forming a continuous grid structure in the circumferential direction of the scissor frame 41, capable of covering the entire circumference of the seal 30. Each set of scissor arm assemblies 42 consists of a first scissor arm 421 and a second scissor arm 422 that are rotatably connected to form an "X-shaped" hinge unit. When the included angle between the first scissor arm 421 and the second scissor arm 422 changes, the length of this hinge unit along the extension direction changes accordingly, thus achieving the telescopic function. The ends of adjacent sets of scissor arm assemblies 42 are hinged to each other, so that multiple "X-shaped" hinge units are connected in series to form a continuously telescopic chain structure. When a thrust or pull force is applied to the scissor arm assembly 42, all hinge points are synchronously linked, and the included angle between each hinge unit changes synchronously, ensuring that the scissor frame 41 as a whole contracts or extends uniformly in the circumferential direction.

[0042] The guide block 43 slides into the annular groove 21, so that each hinge node of the scissor lift 41 is constrained to move within the annular groove 21.

[0043] In some optional embodiments, the number of scissor arm assemblies 42 can be selected according to the diameter of the seal 30. When the diameter is larger, the number of scissor arm assemblies 42 is increased to improve the uniformity of radial thrust. Generally, 4 to 12 sets are set. The initial state of the crossing angle between the first scissor arm 421 and the second scissor arm 422 is generally designed to be between 60° and 120° to ensure sufficient extension stroke and radial thrust.

[0044] like Figure 5As shown, the drive mechanism 40 in this embodiment also includes an electric push rod 44 and a rotating rod 45. The piston rod 10 is provided with an electric push rod 44 on the side wall near the scissor lift 41. The telescopic end of the electric push rod 44 is positioned towards the scissor arm assembly 42 where the fixed end 401 is located. The telescopic end of the electric push rod 44 is horizontally rotatably provided with a rotating rod 45. The end of the rotating rod 45 away from the electric push rod 44 is rotatably connected to the outer wall of the scissor arm assembly 42 at the fixed end 401. The electric push rod 44 pushes the scissor arm assembly 42 through the rotating rod 45, causing the scissor lift 41 to retract or extend along the annular groove 21.

[0045] Specifically, the electric push rod 44 serves as the drive source, and its linear extension and retraction motion is converted into a thrust on the scissor arm assembly 42 via the rotating rod 45. The two ends of the rotating rod 45 are rotatably connected to the extension and retraction ends of the electric push rod 44 and the outer wall of the scissor arm assembly 42, respectively, forming a crank-connecting rod type transmission structure. When the electric push rod 44 retracts, it pushes the rotating rod 45 to move the scissor arm assembly 42 along the annular groove 21 towards the movable end 402, reducing the angle between adjacent hinge points, causing the scissor frame 41 to retract as a whole, and the movable end 402 moves circumferentially along the pressure cap 20, pulling the seal 30 to generate circumferential displacement compensation. When the electric push rod 44 extends, it pulls the scissor arm assembly 42 to move in the opposite direction, increasing the angle between hinge points, causing the scissor frame 41 to extend as a whole, and pushing the seal 30 radially outward to adhere to the cylinder wall.

[0046] In some alternative implementations, the electric actuator 44 may be a linear actuator driven by a stepper motor or a servo cylinder to achieve precise stroke control; the rotating rod 45 may be made of high-strength alloy steel, and its two ends may be rotatedly connected by pins or bearings to reduce friction.

[0047] like Figure 5 As shown, the drive mechanism 40 in this embodiment also includes a locking post 46. The locking post 46 is fixed to the outer edge of the scissor lift 41 away from the pressure cap 20. The sealing member 30 has a slot 34 at the position corresponding to the locking post 46. The locking post 46 is engaged with the slot 34.

[0048] Specifically, the locking post 46 is fixed to the outer edge of the scissor lift 41, and the seal 30 is engaged with the locking post 46 via the slot 34, thus achieving a detachable connection between the seal 30 and the drive mechanism 40. When the seal 30 needs to be replaced or maintained, it can be disassembled simply by detaching the slot 34 of the seal 30 from the locking post 46, without disassembling the entire assembly of the drive mechanism 40 or the pressure cap 20, greatly simplifying the replacement process of the seal 30.

[0049] Furthermore, the locking post 46 is located on the outer edge of the scissor lift 41 away from the pressure cap 20, that is, the locking post 46 is located between the scissor lift 41 and the seal 30, and its locking direction is set in the vertical direction, so that the installation and removal of the seal 30 are carried out in the vertical direction, thereby not affecting the circumferential extension and retraction function of the scissor lift 41.

[0050] In some optional embodiments, the locking post 46 can be cylindrical, T-shaped, spherical, mushroom-shaped, or other shapes that can reliably engage with the slot 34; the opening direction of the slot 34 is consistent with the insertion direction of the locking post 46, and an appropriate fitting gap is reserved between the inner wall of the slot 34 and the outer wall of the locking post 46 to allow the seal 30 to slide and rotate relative to the locking post 46; the material of the locking post 46 can be stainless steel or wear-resistant alloy steel.

[0051] In some alternative embodiments, a plurality of limiting posts are vertically fixed to the outer edge of the side wall of the scissor lift 41 away from the pressure cap 20. The limiting posts slide against the inner wall of the seal 30, and the locking post 46 and the limiting posts are located on the same arc trajectory.

[0052] During the circumferential movement and radial expansion of the seal 30 along the scissor lift 41, the limiting posts serve as multi-point guides and supports. The inner wall of the seal 30 slides at each limiting post, thus constraining the circumferential movement of the seal 30 to the trajectory defined by each limiting post, preventing the seal 30 from axially shifting or radially wobbling during movement.

[0053] like Figure 4 As shown, in this embodiment, the two ends of the seal 30 are respectively provided with a first inclined portion 31 and a second inclined portion 32, and the inclined surfaces of the first inclined portion 31 and the second inclined portion 32 are complementary; a reinforcing portion 33 is provided on the side wall of the first inclined portion 31 near the axis of the piston column 10.

[0054] Specifically, the seal 30 is a spirally coiled long strip structure, and there must be joints at both ends. The complementary design of the inclined surfaces of the first inclined portion 31 and the second inclined portion 32 allows the inclined surfaces of the first inclined portion 31 and the second inclined portion 32 to fit together or align after the seal 30 is coiled, forming a continuous transition surface and avoiding steps, gaps, or leakage channels at the ends of the seal 30. When the gland 20 is installed, due to the geometric characteristics of the spiral coil, a potential gap may form at the end of the seal 30 near the piston rod 10. The first inclined portion 31 achieves a smooth transition with the end plane of the piston rod 10 through its inclined surface, which not only does not obstruct the installation of the seal 30, but also allows it to fit tightly with the inclined surface of the second inclined portion 32 at the other end, eliminating the risk of leakage at the joint.

[0055] A reinforcing part 33 is provided on one side wall of the first inclined portion 31 near the axis of the piston column 10. The reinforcing part 33 is used to enhance the structural strength and wear resistance of the area of ​​the first inclined portion 31. Since the first inclined portion 31 is located at the end of the spiral coil, the friction and stress in this area are relatively concentrated during the circumferential movement of the seal 30. The setting of the reinforcing part 33 effectively prevents premature wear and deformation of the end area and extends the overall service life of the seal 30.

[0056] For example, the slope angle of the first inclined portion 31 and the second inclined portion 32 can be designed to be 30°-60° to ensure sufficient overlap area to achieve sealing without affecting the spiral winding installation of the seal 30.

[0057] like Figure 4 and Figure 6 As shown, in this embodiment, the reinforcing part 33 rolls against a horizontally arranged drive wheel 47 on the side near the axis of the piston column 10. The drive wheel 47 is provided with a pneumatic telescopic rod 48 on the side away from the reinforcing part 33. The pneumatic telescopic rod 48 is fixed to the end side wall of the piston column 10. The pneumatic telescopic rod 48 is configured to apply radial auxiliary support force to the reinforcing part 33 through the drive wheel 47.

[0058] Specifically, the drive wheel 47 rolls against the side of the reinforcement 33 near the axis of the piston rod 10, providing rolling radial support for the reinforcement 33. By using rolling contact instead of sliding contact, the friction between the reinforcement 33 and the support structure is changed from sliding friction to rolling friction, which significantly reduces motion resistance. This makes the movement of the reinforcement 33 area of ​​the seal 30 smoother during circumferential movement, reducing wear and energy consumption of the seal 30.

[0059] The pneumatic telescopic rod 48 is fixed to the end side wall of the piston rod 10, and its telescopic end applies radial auxiliary support force to the reinforcement part 33 through the drive wheel 47. The radial thrust of the pneumatic telescopic rod 48 is transmitted to the reinforcement part 33 through the drive wheel 47, so that the outer edge of the seal 30 at the reinforcement part 33 always adheres to the cylinder wall with a stable contact pressure.

[0060] Pneumatic drive is inherently safe. In flammable and explosive environments such as hydrogen compressors, electric devices may generate electrical sparks, posing a safety hazard. The pneumatic telescopic rod 48 uses compressed gas as its power source and does not generate electrical sparks during operation, possessing explosion-proof characteristics. It is particularly suitable for compression conditions of flammable and explosive media such as hydrogen, thus improving safety.

[0061] like Figure 1As shown, in this embodiment, both ends of the piston column 10 are provided with a seal 30 and a pressure cap 20, that is, the piston column 10 is a double-acting piston structure, with independent seals 30 and pressure caps 20 at both ends. The outer edge of the side wall of each pressure cap 20 near the piston column 10 abuts against the corresponding seal 30. The outer edge of the end face of the pressure cap 20 presses against the end face or side face of the seal 30, restricting the axial displacement of the seal 30 and preventing the seal 30 from moving axially under gas pressure.

[0062] The sealing element 30 is radially slidable at the end of the piston rod 10 near the pressure cap 20. A pressure-stabilizing chamber is provided inside the piston rod 10, located between the two sealing elements 30 at both ends of the piston rod 10. The pressure-stabilizing chamber is connected to an external gas source via a connecting pipe to inject inert gas and maintain pressure balance. Exemplarily, the pressure-stabilizing chamber can be connected to an external gas source via a connecting pipe that extends from inside or along the side wall of the piston rod 10 and connects to an external inert gas supply device. The external gas source injects inert gas, such as nitrogen, into the pressure-stabilizing chamber through the connecting pipe to maintain pressure balance within the chamber.

[0063] In some alternative implementations, the branches of the air supply line of the pressure stabilizing chamber can be connected to all the pneumatic telescopic rods 48, providing a unified driving air source for the pneumatic telescopic rods 48. This eliminates the need to arrange multiple independent air supply lines, simplifies the internal air circuit layout of the compressor, reduces leak points at pipe joints, and lowers the risk of air leakage.

[0064] The compressor piston sealing device in this embodiment can be applied to hydrogen compressors, specifically in scenarios including hydrogen refueling station compressors or other hydrogen booster equipment in the hydrogen energy industry chain.

[0065] Obviously, the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

[0066] Note that in the description of this specification, the references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. A compressor piston sealing device, characterized in that, include: Piston column (10); A pressure cap (20) is detachably connected to the end of the piston rod (10), and the pressure cap (20) is coaxially arranged with the piston rod (10); A sealing element (30) is spirally coiled around the outer edge of the piston rod (10) near the end of the pressure cap (20), and the outer edge of the sealing element (30) protrudes from the outer circumferential surface of the piston rod (10) and the pressure cap (20); A drive mechanism (40) is provided on the side of the pressure cap (20) near the piston rod (10). One end of the drive mechanism (40) is connected to the pressure cap (20), and the other end is driven to connect to the seal (30). The drive mechanism (40) can drive the seal (30) to move circumferentially along the piston rod (10) and expand radially so that the outer edge of the seal (30) fits against the cylinder wall and forms a seal.

2. The compressor piston sealing device according to claim 1, characterized in that, The drive mechanism (40) includes a scissor lift (41) that is circumferentially retractable along the pressure cap (20). The scissor lift (41) has a fixed end (401) and a movable end (402). The fixed end (401) is fixed to the pressure cap (20), and the movable end (402) can slide circumferentially along the pressure cap (20). The side of the scissor lift (41) away from the pressure cap (20) is connected to the seal (30).

3. The compressor piston sealing device according to claim 2, characterized in that, The end face of the pressure cap (20) facing the piston column (10) is provided with an annular groove (21) on the same axis. One end of the scissor lift (41) is slidably fitted into the annular groove (21). The outer edge of the scissor lift (41) away from the pressure cap (20) is pressed against the seal (30).

4. The compressor piston sealing device according to claim 3, characterized in that, The scissor lift (41) is formed by hinged multiple sets of scissor arms (42) arranged in a ring array along the axial direction of the piston column (10); wherein each set of scissor arms (42) includes a first scissor arm (421) and a second scissor arm (422) that are rotatably connected to each other; the ends of two adjacent sets of scissor arms (42) are hinged to each other, and each hinge position of the scissor arms (42) is provided with a guide block (43), and the guide block (43) is slidably engaged with the annular groove (21); The guide block (43) on one of the scissor arm assemblies (42) located at the end of the scissor lift (41) is fixed to the inner wall of the annular groove (21) to form the fixed end (401).

5. The compressor piston sealing device according to claim 4, characterized in that, The drive mechanism (40) also includes an electric push rod (44) and a rotating rod (45). The piston rod (10) is provided with the electric push rod (44) on the side wall near the scissor lift (41). The telescopic end of the electric push rod (44) is arranged towards the scissor arm assembly (42) where the fixed end (401) is located. The telescopic end of the electric push rod (44) is provided with a rotating rod (45) that rotates horizontally. The end of the rotating rod (45) away from the electric push rod (44) is rotatably connected to the outer wall of the scissor arm assembly (42) of the fixed end (401). The electric push rod (44) pushes the scissor arm assembly (42) through the rotating rod (45) to cause the scissor frame (41) to retract or expand along the annular groove (21).

6. The compressor piston sealing device according to claim 2, characterized in that, The drive mechanism (40) also includes a locking post (46), which is fixed to the outer edge of the scissor lift (41) away from the pressure cap (20). The sealing member (30) has a slot (34) corresponding to the position of the locking post (46), and the locking post (46) is engaged with the slot (34).

7. The compressor piston sealing device according to claim 6, characterized in that, The outer edge of the side wall of the scissor lift (41) away from the pressure cap (20) is also vertically fixed with several limiting posts. The limiting posts slide against the inner wall of the seal (30). The locking post (46) and the limiting posts are located on the same arc trajectory.

8. The compressor piston sealing device according to claim 1, characterized in that, The sealing element (30) is provided with a first inclined portion (31) and a second inclined portion (32) at both ends, and the inclined surfaces of the first inclined portion (31) and the second inclined portion (32) are complementary; a reinforcing portion (33) is provided on the side wall of the first inclined portion (31) near the axis of the piston column (10).

9. The compressor piston sealing device according to claim 8, characterized in that, The reinforcing part (33) rolls against a horizontally arranged drive wheel (47) on the side near the axis of the piston column (10). A pneumatic telescopic rod (48) is provided on the side of the drive wheel (47) away from the reinforcing part (33). The pneumatic telescopic rod (48) is fixed to the end side wall of the piston column (10). The pneumatic telescopic rod (48) is configured to apply a radial auxiliary support force to the reinforcing part (33) through the drive wheel (47).

10. The compressor piston sealing device according to any one of claims 1-9, characterized in that, Both ends of the piston rod (10) are provided with a sealing element (30) and a pressure cap (20). The outer edge of the side wall of the pressure cap (20) near the piston rod (10) abuts against the sealing element (30). The sealing element (30) is slidably disposed at the end of the piston rod (10) near the pressure cap (20) along the radial direction of the piston rod (10). The piston column (10) is provided with a pressure stabilizing chamber. The pressure stabilizing chamber is located between two seals (30) at both ends of the piston column (10). The pressure stabilizing chamber is connected to an external gas source through a connecting pipe to inject inert gas into the pressure stabilizing chamber and maintain pressure balance.

Images