A piston pump bellows sealing device

Abstract

The present application discloses a bellows sealing device for a piston pump, which relates to the technical field of sealing technology for liquid hydrogen piston pumps, including a pump body and a piston rod. The pump body includes a pump head that slides with the piston rod, the pump head is fixedly connected with a gland, the gland is sleeved on the piston rod, a packing is arranged between the gland and the piston rod, the gland is provided with an adjustment component for adjusting the tightness of the packing, a coupling is arranged at one end of the piston rod extending out of the pump head, a bellows is arranged between the coupling and the gland, and the bellows is sleeved on the piston rod. In a low-temperature environment, when the packing shrinks due to cold or is damaged by frost, the present application increases the squeezing force of the adjustment component on the packing, so that the packing can produce a certain amount of deformation, realizes the adjustment of the tightness of the packing, ensures the close fit between the packing and the circumferential outer wall of the piston rod and the circumferential inner wall of the gland, ensures the sealing, and also improves the service life of the packing.

Description

Technical Field

[0001] The present application relates to the technical field of liquid hydrogen piston pump sealing technology, and in particular to a piston pump bellows sealing device. Background Art

[0002] As an important energy development direction, hydrogen energy has been widely used in many fields such as clean energy, carbon neutrality, energy storage, fuel cells, etc. Liquid hydrogen is an important technical route for hydrogen energy storage and transportation. The most reasonable way to boost and transport it is to use a 90MPa liquid hydrogen piston pump.

[0003] The piston rod is slidably connected to the pump head of the 90MPa liquid hydrogen piston pump. The circumferential outer wall of the piston rod and the circumferential inner wall of the pump head are sealed by packing. Liquid hydrogen will form a dielectric gas after vaporization. However, in a low-temperature environment, the packing is prone to cold shrinkage or frost damage, causing leakage of the dielectric gas at the packing, and even causing safety hazards such as fire and explosion. This needs to be improved. Summary of the invention

[0004] The purpose of the present application is to provide a piston pump bellows sealing device to solve the problem of potential safety hazards caused by medium gas leakage due to shrinkage or frost damage of the filler in a low-temperature environment.

[0005] The present application provides a piston pump bellows sealing device that adopts the following technical solution:

[0006] A piston pump bellows sealing device comprises a pump body and a piston rod, the pump body comprises a pump head which is slidably matched with the piston rod, the pump head is fixedly connected with a gland, the gland is sleeved on the piston rod, a packing is arranged between the gland and the piston rod, the gland is provided with an adjustment component for adjusting the tightness of the packing, a coupling is arranged at one end of the piston rod extending out of the pump head, a bellows is arranged between the coupling and the gland, and the bellows is sleeved on the piston rod.

[0007] By adopting the above technical scheme, during the sliding of the piston rod, the bellows also telescopes with the piston rod, and the bellows can play a dynamic sealing effect on the piston rod, and the filler located between the circumferential outer wall of the piston rod and the circumferential inner wall of the gland can play a secondary sealing effect on the sliding cooperation of the gland and the piston rod, thereby realizing the effect of double-layer dynamic sealing and improving the dynamic sealing effect when the piston rod and the pump body move relative to each other; at the same time, under the action of the double-layer dynamic seal, the entry of external water vapor into the sealing part is also reduced, and the contact of dust and water vapor with the piston rod and the filler is reduced, thereby playing a dust-proof and anti-frost effect and improving the service life of the filler; in a low-temperature environment, when the filler shrinks due to cold or is damaged by frost, the filler can produce a certain amount of deformation by increasing the extrusion force of the adjusting component on the filler, thereby realizing the adjustment of the tightness of the filler, ensuring the close fit between the filler and the circumferential outer wall of the piston rod and the circumferential inner wall of the gland, and ensuring effective sealing.

[0008] Optionally, the circumferential inner wall of the pressure cover is provided with a discharge groove for placing the filler and a threaded groove connected to the discharge groove, and the adjustment assembly includes a slotted nut threadedly connected to the threaded groove and a dust ring placed in the threaded groove, and the dust ring is located between the slotted nut and the filler.

[0009] By adopting the above technical scheme, the circumferential inner wall of the dust ring fits with the circumferential outer wall of the piston rod, which has a dust-proof effect. The packing is placed in the discharge trough, and the circumferential outer wall of the packing fits with the groove wall of the discharge trough, and the circumferential inner wall of the packing fits with the circumferential outer wall of the piston rod. By tightening the slotted nut, the slotted nut abuts against the side of the notch of the dust ring facing the threaded groove, and the dust ring abuts against the side of the notch of the packing facing the discharge trough. By adjusting the tightness of the slotted nut, the extrusion pressure on the packing can be adjusted, and the tightness of the packing can be adjusted to ensure the sealing effect of the packing. Combined with the dust-proof effect of the dust ring, the sealing and dust-proof effects of the liquid hydrogen piston pump are guaranteed; at the same time, the structure is simple and easy to operate.

[0010] Optionally, a dust collecting groove is provided on the circumferential inner wall of the dustproof ring.

[0011] By adopting the above technical solution, dust or overflowed medium gas is between the circumferential inner wall of the dustproof ring and the circumferential outer wall of the piston rod, which can easily cause a gap between the dustproof ring and the piston rod, affecting the dustproof and sealing effects. Dust or overflowed medium gas enters the dust collecting groove, which can effectively reduce the gap between the dustproof ring and the piston rod, thereby maintaining the sealing and dustproof properties.

[0012] Optionally, the gland is provided with bolts, and the pump head is provided with screw holes threadedly connected to the bolts.

[0013] By adopting the above technical solution, the gland and the pump head are fixedly connected by tightening the bolts and the screw holes, and the effect of quick disassembly and assembly is achieved, with a simple structure and convenient operation.

[0014] Optionally, the pump head is provided with a sliding groove that is slidably matched with the piston rod, and the circumferential groove wall of the sliding groove is provided with an annular groove, and a sealing component is embedded in the annular groove.

[0015] By adopting the above technical solution, the sealing assembly is embedded in the annular groove, the circumferential outer wall of the sealing assembly is in contact with the circumferential groove wall of the annular groove, and the circumferential inner wall of the sealing assembly is in contact with the circumferential outer wall of the piston rod, which effectively reduces the medium gas from entering the bellows and ensures the sealing performance.

[0016] Optionally, the pump head is provided with a give-way groove connected to the sliding groove, the pressure cover is provided with a give-way portion, the give-way portion is embedded in the give-way groove, a sealing ring is provided between the give-way portion and the sealing assembly, and the give-way groove is provided with an embedding groove for the sealing ring to be embedded.

[0017] By adopting the above technical scheme, the circumferential outer wall of the giving way portion is fitted with the circumferential groove wall of the giving way groove, and the end of the giving way portion close to the giving way groove is abutted with the end of the sealing assembly close to the giving way portion. At the same time, the sealing ring is embedded in the embedding groove, one side of the sealing ring is tightly abutted with the end of the sealing assembly close to the giving way portion, and the other side of the sealing ring is tightly abutted with the end of the giving way portion close to the giving way groove, which effectively reduces the medium gas on the circumferential outer wall of the piston rod from escaping from the giving way portion and the sealing assembly, thereby ensuring the sealing performance.

[0018] Optionally, the sealing assembly is provided with an air inlet hole and an air outlet hole, and the sealing assembly is provided with an air inlet pipe connected to the air inlet hole and an air outlet pipe connected to the air outlet hole, and the air inlet pipe and the air outlet pipe both pass through the pump body at one end away from the sealing assembly.

[0019] By adopting the above technical solution, the air inlet pipe is injected with air through an external device, and the air flow passes through the air inlet pipe, the air inlet hole, the circumferential side wall of the piston rod, the air outlet hole, and the air outlet pipe in sequence. The medium gas on the outer surface of the piston rod can be taken away by the air flow, which effectively reduces the medium gas from leaking into the bellows and reduces the low temperature of the packing caused by the medium gas, so as to ensure the sealing effect and service life of the packing.

[0020] Optionally, the bellows includes a first connecting end and a second connecting end, the first connecting end is fixedly connected to the coupling via a first throat hoop, and the second connecting end is fixedly connected to the gland via a second throat hoop.

[0021] By adopting the above technical scheme, the first connecting end is sleeved on the circumferential outer wall of the coupling and is fixedly connected to the coupling through the first throat hoop, and the second connecting end is sleeved on the circumferential outer wall of the gland and is fixedly connected to the gland through the second throat hoop, thereby realizing a fixed connection between the bellows, the piston rod and the gland, and realizing the dustproof and dynamic sealing effect of the bellows on the piston rod, and the structure is simple and the operation is convenient.

[0022] Optionally, sealing gaskets are provided on the circumferential inner walls of the first connecting end and the second connecting end.

[0023] By adopting the above technical scheme, the sealing gasket at the first connecting end, under the action of the first throat hoop, has its circumferential inner wall pressed against the circumferential outer wall of the coupling, and the circumferential outer wall pressed against the circumferential inner wall of the first connecting end; the sealing gasket at the second connecting end, under the action of the second throat hoop, has its circumferential inner wall pressed against the circumferential outer wall of the coupling, and the circumferential outer wall pressed against the circumferential inner wall of the second connecting end, thereby ensuring the sealing between the bellows, the piston rod and the pressure cover.

[0024] Optionally, the pump body is provided with a barrier layer, the barrier layer is arranged on the circumferential side wall of the pump head, and the barrier layer is provided with a cavity.

[0025] By adopting the above technical solution, a cavity is set in the barrier layer, which can play a role in heat preservation and protect the filler from excessive cold transferred by the low-temperature medium gas, thereby reducing the loss of cold, having an energy-saving effect and reducing the gasification amount of liquid hydrogen.

[0026] In summary, the present application includes at least one of the following beneficial technical effects:

[0027] 1. During the sliding of the piston rod, the bellows also allows the piston rod to perform telescopic movement, and the bellows can play a dynamic sealing role for the piston rod. The filler located between the circumferential outer wall of the piston rod and the circumferential inner wall of the gland can play a secondary sealing role for the sliding cooperation between the gland and the piston rod, thereby achieving a double-layer dynamic sealing effect and improving the dynamic sealing effect when the piston rod and the pump body move relative to each other; at the same time, under the action of the double-layer dynamic seal, dust and external water vapor are reduced from contacting the piston rod and the filler, which plays a dust-proof and anti-frost effect and improves the service life of the filler; in a low-temperature environment, when the filler shrinks due to cold or is damaged by frost, the filler can produce a certain amount of deformation by increasing the extrusion force of the adjusting component on the filler, thereby adjusting the tightness of the filler, ensuring that the filler fits tightly with the circumferential outer wall of the piston rod and the circumferential inner wall of the gland, and ensuring effective sealing;

[0028] 2. The cavity is set in the barrier layer to keep warm and protect the filler from excessive cold transferred by the low-temperature medium gas, thereby reducing the loss of cold, saving energy and reducing the gasification amount of liquid hydrogen;

[0029] 3. The air inlet pipe is injected with air through an external device. The air flow passes through the air inlet pipe, the air inlet hole, the circumferential side wall of the piston rod, the air outlet hole, and the air outlet pipe in sequence. The medium gas on the outer surface of the piston rod can be taken away by the air flow, which effectively reduces the medium gas from entering the bellows and reduces the low temperature of the packing caused by the medium gas, so as to ensure the sealing effect of the packing;

[0030] 4. Dust or overflowing medium gas is between the circumferential inner wall of the dustproof ring and the circumferential outer wall of the piston rod, which will cause a gap between the dustproof ring and the piston rod, affecting the dustproof and sealing effects. Dust or overflowing medium gas enters the dust collecting groove, effectively reducing the gap between the dustproof ring and the piston rod, maintaining the sealing and dustproof properties;

[0031] 5. It can realize the effect of quick disassembly and assembly, with simple structure and easy operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present application;

[0033] Figure 2 It is a schematic diagram of the local structure of an embodiment of the present application;

[0034] Figure 3 is a schematic structural diagram of a bellows, a piston rod and a gland in an embodiment of the present application;

[0035] Figure 4 It is an enlarged schematic diagram of point A of the embodiment of the present application.

[0036] Explanation of the reference numerals: 1. Pump body; 11. Pump head; 12. Screw hole; 13. Slide groove; 14. Ring groove; 15. Make way groove; 16. Embedded groove; 17. Barrier layer; 18. Cavity; 2. Piston rod; 21. Coupling; 3. Pressure cover; 31. Discharge trough; 32. Threaded groove; 33. Bolt; 34. Make way portion; 4. Packing; 5. Adjustment assembly; 51. Slotted nut; 52. Dust ring; 53. Dust collecting groove; 6. Bellows; 61. First connecting end; 62. Second connecting end; 63. First throat hoop; 64. Second throat hoop; 65. Sealing gasket; 7. Sealing assembly; 71. Air inlet; 72. Air outlet; 73. Air inlet pipe; 74. Air outlet pipe; 8. Sealing ring. DETAILED DESCRIPTION

[0037] The following is combined with Figure 1-4 This application is described in further detail.

[0038] The embodiment of the present application discloses a piston pump bellows sealing device.

[0039] Reference Figure 1 , Figure 2A bellows sealing device for a piston pump comprises a pump body 1, a piston rod 2 slidably connected to the pump body 1, a pump head 11 integrally formed on the pump body 1, and a sliding groove 13 for the piston rod 2 to be inserted and slidably connected is provided on the pump head 11. The pump head 11 is fixedly connected with a gland 3, which is sleeved on the piston rod 2, and a packing 4 is embedded between the circumferential inner wall of the gland 3 and the circumferential outer wall of the piston rod 2. The packing 4 is made of stainless steel metal or non-metallic composite material and has certain thermal expansion and contraction characteristics. The gland 3 is installed with an adjustment component 5 for adjusting the tightness of the packing 4. A coupling 21 is integrally formed on one end of the piston rod 2 extending out of the pump head 11, and a bellows 6 is installed between the coupling 21 and the gland 3, and the bellows 6 is sleeved on the piston rod 2.

[0040] Reference Figure 2 , Figure 3 The gland 3 is provided with a plurality of mounting holes, in which bolts 33 are connected, and the pump head 11 is provided with screw holes 12 corresponding to the mounting holes one by one and threadedly connected to the corresponding bolts 33, and the gland 3 and the pump head 11 are fixedly connected by tightening the bolts 33.

[0041] Reference Figure 3 , Figure 4 The circumferential inner wall of the gland 3 is provided with a discharge groove 31 for placing the packing 4. The circumferential inner wall of the packing 4 is in contact with the circumferential outer wall of the piston rod 2, and the circumferential outer wall is in contact with the groove wall of the discharge groove 31. The end of the gland 3 facing away from the pump head 11 is provided with a threaded groove 32 connected to the discharge groove 31. The threaded groove 32 is coaxial with the discharge groove 31, and the threaded portion of the threaded groove 32 is provided on the circumferential groove wall of the threaded groove 32.

[0042] Reference Figure 3 , Figure 4 The adjustment assembly 5 includes a slotted nut 51 threadedly connected to the thread groove 32, and a dust ring 52 placed in the thread groove 32. The slotted dust ring 52 abuts against the end faces of the packing 4 facing each other. The slotted nut 51 abuts against the end faces of the dust ring 52 facing each other. The slotted nut 51 and the dust ring 52 are both sleeved on the piston rod 2, and the circumferential inner wall of the dust ring 52 fits the circumferential outer wall of the piston rod 2. The dust ring 52 is provided with a connecting groove, and the connecting groove includes an abutting surface and a guide surface. The abutting surface abuts against the end face of the slotted nut 51, and the guide surface plays a guiding and limiting role in the cooperation between the slotted nut 51 and the dust ring 52. The circumferential inner wall of the dust ring 52 is provided with a dust collecting groove 53.

[0043] Reference Figure 2 , Figure 3The circumferential groove wall of the sliding groove 13 is provided with an annular groove 14, and a sealing component 7 is embedded in the annular groove 14. The sealing component 7 is composed of more than a dozen parts such as a guide sleeve, a spring, a sealing ring 8, a packing 4, a clamping ring, etc. The circumferential outer wall of the sealing component 7 is in contact with the circumferential groove wall of the annular groove 14, and the circumferential inner wall is in contact with the circumferential outer wall of the piston rod 2. The pump head 11 is provided with a makeshift groove 15 which is coaxial with and connected to the sliding groove 13. The gland 3 is integrally formed with a makeshift portion 34 which is embedded in the makeshift groove 15. The discharge groove 31 extends to the circumferential inner wall of the makeshift portion 34. The circumferential outer wall of the makeshift portion 34 is in contact with the circumferential groove wall of the makeshift groove 15. An embedding groove 16 which is coaxial with the makeshift portion 34 is provided at one end of the makeshift portion 34 close to the sealing assembly 7. A sealing ring 8 is embedded in the embedding groove 16. One end of the sealing ring 8 abuts against the circumferential groove wall of the embedding groove 16, and the other end abuts against one end of the sealing assembly 7 close to the makeshift portion 34.

[0044] Reference Figure 2 , Figure 3 The circumferential side walls of the sealing component 7 are relatively provided with an air inlet hole 71 and an air outlet hole 72. The sealing component 7 is fixedly connected with an air inlet pipe 73 and an air outlet pipe 74. One end of the air inlet pipe 73 is connected to the air inlet hole 71 and the other end passes through the pump body 1. One end of the air outlet pipe 74 is connected to the air outlet hole 72 and the other end passes through the pump body 1.

[0045] Reference Figure 2 , Figure 3 The bellows 6 includes a first connecting end 61 and a second connecting end 62. The first connecting end 61 is fixedly connected to the circumferential side wall of the coupling 21 through a first throat hoop 63, and the second connecting end 62 is fixedly connected to the circumferential side wall of the gland 3 through a second throat hoop 64. The circumferential inner walls of the first connecting end 61 and the second connecting end 62 are both connected with a sealing gasket 65. The circumferential inner wall of the sealing gasket 65 on the first connecting end 61 abuts against the circumferential outer wall of the coupling 21, and the circumferential outer wall abuts against the circumferential inner wall of the first connecting end 61. The circumferential inner wall of the sealing gasket 65 on the second connecting end 62 abuts against the circumferential outer wall of the gland 3, and the circumferential outer wall abuts against the circumferential inner wall of the second connecting end 62.

[0046] Reference Figure 2 , Figure 3 The pump body 1 is integrally formed with an annular barrier layer 17 , which is arranged on the circumferential side wall of the pump head 11 , and the barrier layer 17 is hollow and has a cavity 18 .

[0047] The implementation principle of a piston pump bellows sealing device in the embodiment of the present application is:

[0048] During the sliding movement of the piston rod 2, the bellows 6 also performs telescopic movement with the piston rod 2, and the bellows 6 can play a dynamic sealing role for the piston rod 2. The filler 4 located between the circumferential outer wall of the piston rod 2 and the circumferential inner wall of the gland 3 can play a secondary sealing role for the sliding cooperation between the gland 3 and the piston rod 2, thereby achieving a double-layer dynamic sealing effect and improving the dynamic sealing effect when the piston rod 2 and the pump body 1 move relative to each other; at the same time, under the action of the double-layer dynamic seal, dust and external water vapor are reduced from contacting the piston rod 2 and the filler 4, thereby playing a dustproof role. , and anti-frost effect, thereby increasing the service life of the packing 4; in a low-temperature environment, when the packing 4 shrinks or is damaged by frost due to cold, by further tightening the slotted nut 51, the slotted nut 51 is further pressed against the dust ring 52, and the dust ring 52 is further pressed against the packing 4, thereby increasing the extrusion force on the packing 4, so that the packing 4 can produce a certain amount of deformation, so that the circumferential inner wall of the packing 4 is kept in close contact with the circumferential outer wall of the piston rod 2, and the circumferential outer wall is kept in close contact with the circumferential groove wall of the discharge groove 31, thereby realizing the adjustment of the tightness of the packing 4.

[0049] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A piston pump bellows sealing device, comprising a pump body (1) and a piston rod (2), characterized in that: The pump body (1) comprises a pump head (11) which is slidably matched with the piston rod (2); the pump head (11) is fixedly connected with a gland (3); the gland (3) is sleeved on the piston rod (2); a packing (4) is arranged between the gland (3) and the piston rod (2); the gland (3) is provided with an adjustment component (5) for adjusting the tightness of the packing (4); a coupling (21) is arranged at one end of the piston rod (2) extending out of the pump head (11); a bellows (6) is arranged between the coupling (21) and the gland (3); the bellows (6) is sleeved on the piston rod (2); The circumferential inner wall of the gland (3) is provided with a discharge groove (31) for placing the filler (4) and a thread groove (32) connected to the discharge groove (31); the adjustment component (5) comprises a slotted nut (51) threadedly connected to the thread groove (32) and a dust ring (52) placed in the thread groove (32); the dust ring (52) is located between the slotted nut (51) and the filler (4); The circumferential inner wall of the dustproof ring (52) is provided with a dust collecting groove (53); The pump head (11) is provided with a sliding groove (13) for slidingly cooperating with the piston rod (2); a ring groove (14) is provided on the circumferential groove wall of the sliding groove (13); a sealing component (7) is embedded in the ring groove (14); The pump head (11) is provided with a clearance groove (15) connected to the sliding groove (13); the gland (3) is provided with a clearance portion (34), the clearance portion (34) is embedded in the clearance groove (15); a sealing ring (8) is provided between the clearance portion (34) and the sealing assembly (7); the clearance groove (15) is provided with an embedding groove (16) for the sealing ring (8) to be embedded; The sealing component (7) is provided with an air inlet hole (71) and an air outlet hole (72), and the sealing component (7) is provided with an air inlet pipe (73) connected to the air inlet hole (71) and an air outlet pipe (74) connected to the air outlet hole (72); the ends of the air inlet pipe (73) and the air outlet pipe (74) away from the sealing component (7) both pass through the pump body (1).

2. The piston pump bellows sealing device according to claim 1, characterized in that: The gland (3) is provided with a bolt (33), and the pump head (11) is provided with a screw hole (12) threadedly connected to the bolt (33).

3. The piston pump bellows sealing device according to claim 1, characterized in that: The bellows (6) comprises a first connecting end (61) and a second connecting end (62); the first connecting end (61) is fixedly connected to the coupling (21) via a first throat hoop (63); and the second connecting end (62) is fixedly connected to the gland (3) via a second throat hoop (64).

4. The piston pump bellows sealing device according to claim 3, characterized in that: The circumferential inner walls of the first connecting end (61) and the second connecting end (62) are both provided with sealing gaskets (65).

5. The piston pump bellows sealing device according to claim 1, characterized in that: The pump body (1) is provided with a barrier layer (17), the barrier layer (17) is arranged on the circumferential side wall of the pump head (11), and the barrier layer (17) is provided with a cavity (18).

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