Linkage shaft structure and reciprocating pump with same

Abstract

The invention relates to a reciprocating pump, in particular to a linkage shaft structure and a reciprocating pump with the linkage shaft structure. A universal driving shaft structure comprises a universal driving shaft extending into a containing cavity, the universal driving shaft comprises two coaxially-arranged universal driving shaft single bodies, the inner ends of the universal driving shaft single bodies extend into the containing cavity and are fixed to a first telescopic body made of flexible materials, and the outer ends of the universal driving shaft single bodies are located outside the containing cavity all the time and used for being connected with a reciprocating moving part. Each first telescopic body comprises a first bottom located on the axial side of the corresponding linkage shaft single body, and the first bottoms of the two first telescopic bodies are located between the two linkage shaft single bodies and are close to each other. According to the linkage structure, the linkage shaft can be prevented from making contact with the cavity wall of the containing cavity, sliding friction generated between the linkage shaft and the supporting structure is avoided, and therefore powder or chippings are prevented from being generated as much as possible, and pollution to pumped fluid is reduced; and the operation efficiency of the reciprocating pump can be improved.

Description

Technical Field

[0001] The invention relates to a reciprocating pump, in particular to a linkage shaft structure and a reciprocating pump having the linkage shaft structure. Background Art

[0002] like Figure 1 The present invention shows an existing reciprocating pump, comprising a pump housing 1, the pump housing 1 comprising a pump head 11 and pump covers 12 located on both sides of the pump head 11, the pump head 11 having piston chambers 111 on opposite sides, the two piston chambers 111 being connected through an accommodating chamber 112, each piston chamber 111 being slidably fitted with a piston shaft 13, the two piston shafts 13 being connected through a linkage shaft 14 and realizing synchronous linkage, a bellows 15 being respectively provided at both ends of the linkage shaft 14, the outer edges of the bellows 15 being connected to the piston chamber 111 The piston chamber 111 is sealed; the bellows 15 divides the piston chamber 111 into a pump chamber 111a and an air chamber 111b; wherein the piston shaft 13 is slidably matched with the pump cover 12, and the pump cover 12 is connected with an air passage 16 for compressed air flow. The compressed air enters and exits the air chamber 111b through the air passage 16 to push the bellows on one side to move. When the bellows on one side drives the linkage shaft 14 to slide, the bellows on the other side are driven to move through the linkage shaft 14, thereby realizing the linkage of the two bellows 15. Among them, the pump head 11 is provided with an inlet 101 and an outlet 102 for transferring fluid, and the inlet 101 and the outlet 102 are both equipped with control valves (not shown in the figure), and the inlet 101 and the outlet 102 are controlled by the control valve to alternately connect with the two pump chambers 111a. The compressed air drives the bellows 15 on both sides to reciprocate, and alternately changes the volume of the pump chambers 111a on both sides, thereby realizing continuous pumping of the fluid.

[0003] However, during the movement of the linkage shaft, since the linkage shaft is in close contact with the wall of the accommodating chamber, wear powder or debris is easily generated during the movement, and the wear powder or debris is mixed into the pumped fluid, causing the pumped fluid to be contaminated, increasing the loss of the fluid system, and may even cause damage to the fluid system. Summary of the invention

[0004] The object of the present invention is to provide a linkage shaft structure which can prevent the linkage shaft from contacting the wall of the accommodating chamber, thereby preventing the generation of powder or debris as much as possible and preventing the pumping fluid from being contaminated.

[0005] To achieve the above object, the present invention adopts the following technical solution: A linkage shaft structure, including a linkage shaft extending into the accommodation cavity, the linkage shaft includes two coaxially arranged linkage shaft monomers, the inner ends of the linkage shaft monomers both extend into the accommodation cavity and are fixed to a first telescopic body made of a flexible material, the outer ends of the linkage shaft monomers are always located outside the accommodation cavity and are used to connect reciprocating members, the first telescopic body includes a first bottom located on the axial side of the linkage shaft monomer, and the first bottoms of the two first telescopic bodies are located between the two linkage shaft monomers and are close to each other.

[0006] The linkage shaft of the present invention includes two coaxially arranged linkage shaft monomers, and the first bottoms of the first telescopic bodies made of flexible materials are provided on the axial sides of the two linkage shaft monomers. By making the two first bottoms close to or even in contact with each other, in the case of a reciprocating pump, since the two linkage shaft monomers are respectively connected to the piston shafts of the reciprocating pump as reciprocating members, and due to the presence of compressed air in the air ducts on both sides, the abutment between the two linkage shaft monomers can be ensured, thereby avoiding the contact friction between the outer wall of the linkage shaft monomer and the cavity wall of the accommodation cavity, and enabling the linkage of the two linkage shaft monomers.

[0007] During the movement of the linkage shaft monomer of the present invention, the first bottom of the first telescopic body made of a flexible material will correspondingly expand and contract, avoiding the relative sliding of the linkage shaft monomer due to movement, thereby avoiding the wear of the linkage shaft monomer and the cavity wall of the accommodation cavity, avoiding the generation of powder or debris, and ultimately avoiding the contamination of the pumped fluid.

[0008] Preferably, the first telescopic body is sleeved outside the linkage shaft monomer, the first telescopic body further includes a first telescopic portion located on the circumferential outer side of the linkage shaft monomer and a first fixing portion for sealing treatment with the cavity wall of the accommodation cavity. One end of the first telescopic portion is connected to the first bottom, the other end of the first telescopic portion extends away from the first bottom side and is connected to the first fixing portion, and the first telescopic portion does not contact the cavity wall of the accommodation cavity.

[0009] By making the first telescopic body have a first telescopic portion, and the first fixing portion at the end of the first telescopic portion is in contact with and sealed to the cavity wall of the accommodation cavity, the first telescopic body can play a certain supporting role for the linkage shaft monomer. And the first telescopic portion does not contact the cavity wall of the accommodation cavity, which can further avoid the generation of powder and debris to avoid the contamination of the pumped fluid.

[0010] Preferably, the first bottoms of the two first telescopic bodies are connected and fixed to each other by means of welding, bonding or integral molding.

[0011] By connecting and fixing the two first telescopic bodies, the concentricity of the two can be ensured, effectively avoiding the situation that the two linkage shaft monomers are not coaxial and misaligned due to installation errors or deviations caused by long-term use, and improving the reliability of the reciprocating movement and mutual switching of the linkage shaft structure of the present invention.

[0012] Preferably, an elastic body is provided between the two first telescopic bodies, and two ends of the elastic body are respectively abutted against or fixedly connected to the first bottoms of the two first telescopic bodies.

[0013] When an elastic body is arranged between the two telescopic bodies, the two linkage shaft monomers can realize delayed linkage, which can reduce the overall discharge pressure fluctuation of the reciprocating pump and effectively suppress the pulsation of the fluid on the discharge side. The elastic body can be a metal spring.

[0014] Preferably, the first telescopic portion is in a V-shaped bellows shape.

[0015] The first telescopic part is in the shape of a V-shaped bellows. The V-shaped bellows has a small pitch and a large number of waves. Compared with the existing commonly used U-shaped bellows structures, the V-shaped bellows occupies a small volume while obtaining the same displacement. The first telescopic body using the V-shaped bellows has the advantage of miniaturization and is more suitable for installation in the same accommodating cavity with the linkage shaft monomer.

[0016] Preferably, the outer diameter of the first bottom portion gradually decreases from a side close to the first fixing portion to a side far from the first fixing portion.

[0017] By making the first bottom part in a frustum shape, the first bottom part can be prevented from being too heavy, thereby avoiding contact and friction between the first bottom part and the wall of the accommodating chamber as much as possible.

[0018] Preferably, the linkage shaft monomer and the first telescopic body are both made of fluororesin material.

[0019] The two linkage shaft monomers and the two first telescopic bodies are both made of fluororesin material, which can avoid being corroded by the fluid during the process of pumping the fluid, and avoid pollutants such as ions or particles being precipitated due to fluid immersion, thereby affecting the cleanliness of the fluid.

[0020] The invention also discloses a reciprocating pump with the linkage shaft structure.

[0021] Preferably, the reciprocating pump includes a pump housing, the piston shaft has the accommodating cavity located in the middle, and the piston shaft is provided with a piston cavity connected to the accommodating cavity on opposite sides, one end of the piston shaft as the reciprocating movable part extends into the piston cavity, and the piston shaft is provided with a second telescopic body, the second telescopic body includes a second telescopic part located on the circumferential outer side of the piston shaft, a second bottom located on the axial side of the piston, and a second fixing part for fixing to the piston shaft, and one end of the piston shaft and the linkage shaft monomer are fixed to the second bottom of the second telescopic part. The piston shafts are separated by the second telescopic body, which can prevent the air chamber and the pump chamber from leaking through the assembly gap between the piston shaft and the second telescopic body.

[0022] Preferably, the end of the piston shaft away from the second bottom is slidably fitted in the sleeve, the sleeve is fixed to the pump housing, the end of the sleeve close to the second bottom is provided with an inner limit protrusion extending circumferentially inward, and the portion of the piston shaft located in the sleeve has an outer limit protrusion extending circumferentially outward. The limit protrusion structure is conducive to improving the coaxiality of the piston shaft and the linkage shaft monomer during assembly and operation, and is conducive to reducing the movement resistance of the telescopic body and improving the operating efficiency of the reciprocating pump.

[0023] The linkage structure of the present invention can avoid contact between the linkage shaft and the wall of the accommodating chamber, and avoid sliding friction between the linkage shaft and the supporting structure, thereby avoiding the generation of powder or debris as much as possible and reducing contamination of the pumped fluid; and can reduce internal leakage of the reciprocating pump caused by wear of the linkage shaft and expansion of the assembly gap of the pumped fluid, thereby improving the operating efficiency of the reciprocating pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The figure is a schematic diagram of the structure of an existing reciprocating pump.

[0025] Figure 2 This is a structural schematic diagram of the linkage shaft structure of Example 1.

[0026] Figure 3 for Figure 2 A structural schematic diagram of the connection between the intermediate linkage shaft monomer and the reciprocating movable part.

[0027] Figure 4 This is a structural schematic diagram of the linkage shaft structure of Example 3.

[0028] Figure 5 This is a structural schematic diagram of a reciprocating pump according to Example 4 of the present invention.

[0029] Figure 6 This is a structural schematic diagram of the linkage shaft structure of Example 5 of the present invention. DETAILED DESCRIPTION

[0030] The present invention will be further described below based on the accompanying drawings and specific embodiments.

[0031] Example 1 Depend on Figure 2 and Figure 3 As shown, this embodiment discloses a linkage shaft structure for a reciprocating pump, which is arranged in a pump casing. The pump casing includes a pump head 11. The pump head 11 is formed with a accommodating cavity 112 that passes through the left and right sides. The linkage shaft includes two coaxially arranged linkage shaft monomers 2. The inner ends of the linkage shaft monomers 2 are both extended into the accommodating cavity 112 and fixed to a first telescopic body 3 made of flexible material. The outer ends of the linkage shaft monomers 2 are always located outside the accommodating cavity 112 and are fixed to the reciprocating moving part.

[0032] The first telescopic body 3 is sleeved outside the linkage shaft unit 2. The first telescopic body 3 includes a first telescopic part 31 located on the circumferential outer side of the linkage shaft unit 2, a first fixing part 32 for sealing treatment with the wall of the accommodating cavity 112, and a first bottom part 33 located on the axial side of the linkage shaft unit 2. The first bottom parts 33 of the two first telescopic bodies 3 are located between the two linkage shaft units 2 and are in contact with each other.

[0033] Among them, one end of the first telescopic part 31 is connected to the first bottom part 33, the other end of the first telescopic part 31 extends away from the first bottom part 33 and is connected to the first fixing part 32. The first telescopic body 3 has a cylindrical structure with one end open. An annular groove with an inner diameter larger than the inner diameter of the deviating end of the accommodating cavity 112 is formed at the opening of the accommodating cavity 112, and the first fixing part 32 is fixed at the annular groove.

[0034] The first telescopic part 31 of this embodiment is in the shape of a V-shaped corrugated pipe. Since the V-shaped corrugated pipe has a small pitch and many waves, compared with the existing commonly used corrugated pipe structures such as U-shaped corrugated pipes, when obtaining the same displacement, the V-shaped corrugated pipe occupies a small volume. The first telescopic body 3 using the V-shaped corrugated pipe has the advantage of being miniaturizable and is more suitable for being installed with the linkage shaft unit 2 in the narrow accommodating cavity 112. The circumferential side of the first telescopic part 31 constituting the V-shaped corrugated pipe has a plurality of alternately continuous valley parts and peak parts. The distance between the tops of the two peak parts symmetrically arranged up and down along the central axis of the first telescopic part 31 is the maximum outer diameter. By making the maximum outer diameter of the first telescopic part 31 smaller than the minimum inner diameter of the accommodating cavity 112, it is possible to prevent the first telescopic part 31 from coming into contact with or rubbing against the inner side wall of the shaft housing 10 during the telescopic process.

[0035] Both the two first telescopic bodies 3 and the two linkage shaft units 2 of this embodiment are made of fluororesin materials, which can prevent being corroded by the fluid during the process of pumping the fluid, and prevent the precipitation of ions or particulate pollutants due to fluid impregnation, thus affecting the cleanliness of the fluid.

[0036] As Figure 3 shown, the two reciprocating members of this embodiment are respectively a first reciprocating member 13a and a second reciprocating member 13b, the two linkage shafts 2 are respectively a first linkage shaft unit 2a and a second linkage shaft unit 2b. The first reciprocating member 13a is fixed to the first linkage shaft unit 2a, the second reciprocating member 13b is fixed to the second linkage shaft unit 2b, the two first telescopic bodies 3 are respectively a first telescopic body 3a and a first telescopic body 3b. The first telescopic body 3a is sleeved and fixed on the first linkage shaft unit 2a, and the first telescopic body 3b is sleeved and fixed on the second linkage shaft unit 2b.

[0037] Two reciprocating members are constituted by a combination of a driving member and a driven member; when the first reciprocating member 13a is the driving member, the first reciprocating member 13a drives the first linkage shaft unit 2a connected thereto to move. During the movement of the first linkage shaft unit 2a, the first telescopic body 3a fixedly connected to the first linkage shaft unit 2a synchronously extends, and the first telescopic body 3b on the other side correspondingly shortens, and drives the second linkage shaft unit 2b to move. The second linkage shaft unit 2b drives the second reciprocating member 13b to move accordingly through the movement.

[0038] During the movement of the first linkage shaft unit 2a and the second linkage shaft unit 2b, through the corresponding expansion and contraction of the first telescopic body 3a and the first telescopic body 3b, the relative sliding of the linkage shaft units due to movement is avoided. Moreover, when the first telescopic body 3a and the first telescopic body 3b expand and contract, since the circumferences of the first telescopic body 3a and the first telescopic body 3b do not contact or rub against the wall of the accommodation cavity 112 of the pump housing, the generation of wear powder or debris is avoided. After the first linkage shaft unit 2a and the second linkage shaft unit 2b move to the set position, the first reciprocating member 13a and the second reciprocating member 13b are mutually switched, so that the first reciprocating member 13a is switched to the driven member, and the second reciprocating member 13b is switched to the driving member. The first linkage shaft unit 2a and the second linkage shaft unit 2b move along the opposite previous moving directions inside the pump housing and drive the first reciprocating member 13a as the driven member to move accordingly; by circulating the above operations, the linkage between the two reciprocating members can be continuously realized.

[0039] Among them, the first bottoms 33 of the two first telescopic bodies 3 are fixedly connected to each other. The first bottoms 33 of the two first telescopic bodies 3 are arranged in a fixed connection manner. In this connection manner, the two linkage shaft units 2 can always maintain a coaxial line state during the reciprocating movement and mutual switching. This connection manner is more reliable and can effectively avoid the situation that the two linkage shaft units 2 are not coaxial and misaligned due to installation errors or deviations caused by long-term use, and improve the reliability of the reciprocating movement and mutual switching of the linkage shaft structure.

[0040] Embodiment 2 A reciprocating pump includes a pump housing. The pump housing includes a pump head and pump covers on both sides of the pump head. Both opposite sides of the pump head have piston cavities. A piston shaft is slidably fitted in each piston cavity. The two piston shafts are synchronously linked through the linkage shaft structure described in Embodiment 1.

[0041] Embodiment 3 A linkage shaft structure, as Figure 4As shown in the figure, the difference between this embodiment and Embodiment 1 is that an elastic body 4 is provided between the two first telescopic bodies 3. Both ends of the elastic body 4 are respectively abutted or fixedly connected to the first bottom 33 of a first telescopic body 3, and the elastic body 4 is a metal spring.

[0042] As Figure 5 shown in the figure, in the connection mode of Embodiment 2, a delayed linkage can be achieved between the first linkage shaft unit 2a and the second linkage shaft unit 2b. For example, when the first reciprocating member 13a drives the first linkage shaft unit 2a to start moving in the direction of extending into the first telescopic body 3a, the first linkage shaft unit 2a first applies a force to compress the elastic body 4 through the first bottom 33 of the first telescopic body 3a, and then applies the thrust to the second linkage shaft unit 2b to drive it to move, so that there is a delayed linkage between the first linkage shaft unit 2a and the second linkage shaft unit 2b.

[0043] Embodiment 4 A reciprocating pump includes the linkage shaft structure of Embodiment 3. As Figure 5 shown in the figure, the reciprocating pump of this embodiment includes a pump housing 1. The pump housing 1 includes a pump head 11 and pump covers 12 located on both sides of the pump head 11. The pump head 11 has a receiving cavity 112 in the middle. Both opposite sides of the pump head 11 have piston cavities 111. The two piston cavities 111 communicate with the receiving cavity 112. One end of a piston shaft 13 serving as a reciprocating member extends into the piston cavity 111, and the other end of the piston shaft 13 is slidably fitted in a bushing 18, and the bushing 18 is fixed to the pump cover 12. Among them, the piston shaft 13 of this embodiment is made of a metal material such as stainless steel.

[0044] A second telescopic body 5 is sleeved outside the piston shaft 13. The second telescopic body 5 includes a second telescopic portion 51 located on the circumferential outer side of the piston shaft 13, a second bottom 53 located on the axial side of the piston shaft 13, and a second fixing portion 52 for fixing to the pump housing 1. One end of the piston shaft 13 and the linkage shaft unit 2 are both fixed to the second bottom 53 of the second telescopic body 5. Among them, an inner limiting protrusion 181 extending inward in the circumferential direction is provided at one end of the bushing 18 close to the second bottom 53, and an outer limiting protrusion 131 extending outward in the circumferential direction is provided on the part of the piston shaft 13 located in the bushing 18. Among them, fixing holes for cooperating with the piston shaft 13 and fitting holes for cooperating with the linkage shaft unit 2 are respectively provided on both sides of the second bottom 53. The second telescopic body 5 of this embodiment is also made of a fluororesin material.

[0045] The reciprocating pump of this embodiment is provided with a detection device 17 for detecting the displacement of the piston shaft 13 as a reciprocating moving part. Before the first linkage shaft unit 2a moves to the set position, the first reciprocating moving part 13a and the second reciprocating moving part 13b can be switched with each other through the detection device 17, so that the first reciprocating moving part 13a is switched to a follower, and the second reciprocating moving part 13b is switched to a driving part. The second reciprocating moving part 13b drives the second linkage shaft unit 2b to move along the moving direction opposite to the previous one, and the elastic body 4 is further compressed and contracted. Therefore, there is a stage where the first linkage shaft unit 2a and the second linkage shaft unit 2b move towards the center of the elastic body 4 at the same time. As the second linkage shaft unit 2b moves further, the elastic body 4 releases part of the elastic potential energy it has accumulated, the elastic body 4 elongates, the first telescopic body 3a correspondingly shortens, and drives the first linkage shaft unit 2a to move in the direction of protruding from the first telescopic body 3a. By circulating the above operations, the delayed linkage between the two piston shafts 13 as reciprocating moving parts can be continuously realized, different forms of reciprocating movements are achieved, and the linkage requirements of special working conditions are met.

[0046] The piston chamber 111 of this embodiment is separated by the second telescopic body 5 into non-communicating air chambers 111b and pump chambers 111a, and the air chambers 111b and pump chambers 111a on both sides of the pump housing 1 are relatively symmetrical. A suction port 101 and a discharge port 102 for transferring fluid are respectively provided on the central axis of the pump head 1, and control valves (not shown in the figure) are arranged in both the suction port 101 and the discharge port 102. By means of the control valves, the suction port 101 and the discharge port 102 are alternately connected to the two pump chambers 111a, so as to prevent the fluid inhaled into the pump from being mixed with the fluid discharged out of the pump while realizing the suction and discharge of the fluid. The length of the linkage shaft unit 2 (the first linkage shaft unit 2a and the second linkage shaft unit 2b) of this embodiment is greater than the length of the first telescopic body 3. The ends of the two linkage shaft units 2 away from each other are both located in the pump chamber 111a and are fixedly connected to the second bottom 53 of the second telescopic body 5 located in the piston chamber 111; the two piston shafts 13 (the first reciprocating moving part 13a and the second reciprocating moving part 13b) are coaxially arranged with the shaft sleeve 18 and the linkage shaft unit 2; compressed air enters the pump chamber 111a of the piston chamber 111 through the air passage 16, or the compressed air in the air chamber 111b is discharged out of the pump.

[0047] When using the reciprocating pump of this embodiment for liquid pumping, the liquid to be pumped fills the inner spaces of the two pump chambers 111a and the two first telescopic bodies 3 communicated with the pump chambers 111a. A control valve (electromagnetic reversing valve) used in a matching manner is provided outside the reciprocating pump. The signal line of the detection device 17 is electrically connected to the electromagnetic reversing valve; the outer end of the air passage 16 is connected to the electromagnetic reversing valve through an external pipeline; the electromagnetic reversing valve is also connected to compressed air. Under the control of the electromagnetic reversing valve, the compressed air flows towards the left air chamber 111b in the reciprocating pump. The compressed air is introduced into the left air chamber 111b through the air passage 16. The pressure in the left air chamber 111b rises with the introduction of the compressed air, thereby driving the left second telescopic body 5 to elongate and the second bottom 53 to move to the right. At this time, the left 111b correspondingly shrinks, and the pressure in the left 111b rises, further forcing the control valve to connect the discharge port 102 with the pump chamber 111a, and the liquid in the pump chamber 111a is discharged out from the discharge port 102.

[0048] During the process of the second bottom 53 moving towards the center of the pump head 11, the second bottom 53 drives the first linkage shaft unit 2a to move together. During the movement of the first linkage shaft unit 2a, the first telescopic body 3a fixedly connected to the first linkage shaft unit 2a synchronously elongates, and the first telescopic body 3b on the other side correspondingly shortens and drives the second linkage shaft unit 2b to move. The moving direction of the second linkage shaft unit 2b is the direction extending out from the first telescopic body 3b; during the movement of the first linkage shaft unit 2a and the second linkage shaft unit 2b, through the corresponding expansion and contraction of the two first telescopic bodies 3 (the first telescopic body 3a and the first telescopic body 3b), the situation of relative sliding of the shaft due to movement is avoided. And when the flexible telescopic body 30 expands and contracts, since the circumferential side 32 of the flexible telescopic body 30 does not contact or rub against the inner side wall of the shaft housing 10, the generation of wear powder or debris is avoided.

[0049] The second linkage shaft monomer 2b moves to drive the second bottom portion 53 on the right side to move in a direction away from the first linkage shaft monomer 2a. During the movement of the second bottom portion 53 on the right side, the second telescopic body 5 on the right side is shortened, and the pump chamber 111a on the right side is correspondingly expanded, and the pressure in the pump chamber 111a decreases, thereby forcing the control valve to connect the suction port 16 with the pump chamber 111a, and the pumped liquid is introduced into the pump chamber 111a from the suction port 101; at the same time, the air chamber 111b is correspondingly reduced, and the compressed air in the air chamber 111b flows outward through the air passage 16 and is introduced into the electromagnetic reversing valve. ; During the movement of the second bottom 53, the second bottom 53 also drives the piston shaft 13 to move, and the piston shaft 13 continuously slides into the shaft sleeve 18. When the metal piston shaft 13 slides to a set position close to the detection device 17, the detection device 17 generates a control signal and transmits it to the electromagnetic reversing valve via a signal line to switch the flow direction of the compressed air between different air chambers on both sides, so that the second telescopic bodies 5 on both sides are alternately extended and retracted, so that the pump chambers on both sides can alternately suck and discharge liquid; by cycling the above operations, the reciprocating pump can continuously pump liquid.

[0050] Example 5 A linkage shaft structure, such as Figure 6 As shown, compared with Embodiment 1, this embodiment has the following difference: the outer diameter of the first bottom 33 of the first telescopic body 3 gradually decreases from the side close to the first fixing portion 32 to the side away from the first fixing portion 32 .

[0051] After the first telescopic body 3 is fixedly installed on the inner side of the accommodating cavity 112, the first telescopic body 3 is in a horizontal state. However, since the first telescopic body 3 with a V-shaped bellows structure has a relatively small rigidity, and when the first telescopic body 3 is made of a fluororesin material, the rigidity of the first telescopic body 3 is further reduced. When the first bottom 33 of the first telescopic body 3 is too heavy, the first bottom 33 will have a certain linear displacement perpendicular to the direction of its central axis, which may cause the first telescopic body 3 to contact or rub against the wall of the accommodating cavity 112. By adjusting the structure of the first bottom 33 of the first telescopic body 3 and setting the first bottom 33 to be in an inverted cone shape, it is possible to avoid the first bottom 33 of the first telescopic body 3 being too heavy, and further avoid the first telescopic body 3 from contacting or rubbing against the wall of the accommodating cavity 112.

[0052] The linkage structure of this embodiment can avoid contact between the linkage shaft and the wall of the accommodating chamber, and avoid sliding friction between the linkage shaft and the supporting structure, thereby avoiding the generation of powder or debris as much as possible and reducing contamination of the pumped fluid; and can reduce internal leakage of the reciprocating pump caused by wear of the linkage shaft and expansion of the assembly gap of the pumped fluid, thereby improving the operating efficiency of the reciprocating pump.

Claims

1. A linkage shaft structure, comprising a linkage shaft extending into an accommodation cavity, characterized in that: The linkage shaft includes two coaxial linkage shaft monomers. The inner ends of the linkage shaft monomers extend into the accommodation cavity and are fixed to a first telescopic body made of a flexible material. The outer ends of the linkage shaft monomers are always located outside the accommodation cavity and are used to connect the reciprocating member. The first telescopic body includes a first bottom portion located on the axial side of the linkage shaft monomer. The first bottom portions of the two first telescopic bodies are located between the two linkage shaft monomers and are close to each other.

2. The linkage shaft structure according to claim 1, wherein: The first telescopic body is sleeved outside the linkage shaft monomer. The first telescopic body further includes a first telescopic portion located on the circumferential outer side of the linkage shaft monomer and a first fixing portion for sealing treatment with the cavity wall of the accommodation cavity. One end of the first telescopic portion is connected to the first bottom portion, and the other end of the first telescopic portion extends away from the first bottom portion and is connected to the first fixing portion. The first telescopic portion does not contact the cavity wall of the accommodation cavity.

3. The linkage shaft structure according to claim 1 or 2, characterized in that: The first bottom portions of the two first telescopic bodies are connected and fixed to each other.

4. The linkage shaft structure according to claim 1 or 2, characterized in that: An elastic body is provided between the two first telescopic bodies. The two ends of the elastic body are respectively connected to the first bottom portions of the two first telescopic bodies.

5. The linkage shaft structure according to claim 1, characterized in that: The first telescopic portion is in the shape of a V-shaped corrugated pipe.

6. The linkage shaft structure according to claim 1 or 5, characterized in that: The outer diameter of the first bottom portion gradually decreases from the side close to the first fixing portion to the side far from the first fixing portion.

7. The linkage shaft structure according to claim 1 or 2, characterized in that: Both the linkage shaft monomer and the first telescopic body are made of fluororesin material.

8. A reciprocating pump having the linkage shaft structure according to any one of claims 1 to 7.

9. The reciprocating pump according to claim 8, comprising a pump housing having the accommodation chamber located in the middle thereof, and piston chambers communicating with the accommodation chamber are respectively provided on two opposite sides of the pump housing. One end of a piston shaft serving as the reciprocating moving member extends into the piston chamber, and is characterized in that: A second telescopic body is sleeved outside the piston shaft. The second telescopic body includes a second telescopic portion located on the circumferential outer side of the piston shaft, a second bottom portion located on the axial side of the piston shaft, and a second fixing portion for fixing to the pump housing. One end of the piston shaft and the linkage shaft monomer are both fixed to the second bottom portion of the second telescopic body.

10. The reciprocating pump according to claim 9, characterized in that: One end of the piston shaft away from the second bottom portion is slidably fitted in a shaft sleeve. The shaft sleeve is fixed to the pump housing. One end of the shaft sleeve close to the second bottom portion is provided with an inner limiting protrusion extending inward in the circumferential direction. The portion of the piston shaft located inside the shaft sleeve has an outer limiting protrusion extending outward in the circumferential direction.

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