Sealing device and pipettor

Abstract

The sealing device comprises a first sealing assembly and a second sealing assembly, the first sealing assembly is arranged at the end, away from a gun head, of an inner cavity, the first sealing assembly comprises a sealing lantern ring, a first pressing plate and a first sealing ring, the sealing lantern ring is embedded in the inner cavity, a part of the first pressing plate is embedded in the inner cavity, and the first pressing plate is partially embedded in the inner cavity. The first sealing ring is arranged on the piston rod and abuts against the sealing lantern ring, the sealing lantern ring is in interference fit with the outer diameter of the piston rod, and the outer wall of the sealing lantern ring is sleeved with the first sealing ring so as to apply radial pressing force to the sealing lantern ring; the second sealing assembly is arranged at the joint of the cylinder body and the gun head and comprises a second sealing ring, a second pressing plate and a push plate, the gun head is sleeved with the second sealing ring, the second pressing plate is embedded in the cylinder body and presses the gun head, and the push plate is connected to the cylinder body so as to press the second pressing plate. According to the technical scheme, the sealing effect and durability of the pipettor are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of pipettes, and in particular to a sealing device and a pipette. Background Art

[0002] As a widely used liquid handling tool in laboratories, pipettes have the functions of accurately aspirating, transferring and releasing liquids. They are widely used in biomedicine, chemical analysis, pharmaceuticals, environmental monitoring and other fields. With the improvement of laboratory automation, the requirements for the accuracy, efficiency, durability and versatility of pipettes are also increasing.

[0003] At present, the sealing device of the pipette usually relies on sealing rings or other rubber materials. Although they can ensure the basic sealing of the liquid, due to long-term liquid operation and high-frequency use, the seals are easily worn, resulting in sealing failure, thereby affecting the accuracy and reliability of the pipette. Summary of the invention

[0004] The main purpose of the present invention is to provide a sealing device and a pipette, aiming to improve the sealing effect and durability of the pipette.

[0005] To achieve the above purpose, the present invention adopts the following technical solution.

[0006] In a first aspect, a sealing device proposed by the present invention is applied to a pipette, wherein the pipette comprises a cylinder, a piston rod and a gun head, wherein an inner cavity is provided in the cylinder, the piston rod is slidably connected to the inner cavity, an inner hole is provided in the gun head, the gun head is connected to the cylinder, the inner hole is connected to the inner cavity, and the sealing device comprises:

[0007] a first sealing assembly, the first sealing assembly being arranged at one end of the inner cavity away from the gun head, the first sealing assembly comprising a sealing collar, a first pressure plate and a first sealing ring, the sealing collar being embedded in the inner cavity, a portion of the first pressure plate being embedded in the inner cavity and abutting against the sealing collar, the sealing collar comprising a sliding portion and a ring pressing portion, the ring pressing portion and the piston rod being clearance-fitted, the sliding portion and the piston rod being interference-fitted, the first sealing ring being sleeved on the outer wall of the sliding portion to apply a radial pressing force to the sealing collar; and

[0008] The second sealing component is arranged at the connection between the cylinder body and the gun head, the second sealing component includes a second sealing ring and a second pressure plate, the second sealing ring is sleeved on the gun head, the second pressure plate is embedded in the cylinder body and presses the gun head, and the push plate is connected to the cylinder body.

[0009] In a possible implementation, the sealing ring is made of polyoxymethylene, polyamide or polytetrafluoroethylene;

[0010] The piston rod is made of ceramic.

[0011] In a possible implementation manner, the wall thickness of the sliding portion is 0.3 mm-0.5 mm.

[0012] In a possible embodiment, a first groove, a second groove and a third groove are provided at the position where the first sealing assembly is installed in the inner cavity, the sliding part is accommodated in the first groove, the first sealing ring is accommodated in the second groove, and the annular pressure part and part of the first pressure plate are accommodated in the third groove.

[0013] In a possible embodiment, a fourth groove, a fifth groove and a sixth groove are provided at the connection between the cylinder body and the gun head, the gun head includes a first step and a second step, the second sealing ring is sleeved on the first step and accommodated in the fourth groove, the second step is accommodated in the fifth groove, and the second pressure plate is pressed against the second step and accommodated in the sixth groove.

[0014] In a possible implementation manner, a push plate is further provided at the connection between the cylinder body and the gun head.

[0015] In the second aspect, the present invention also provides a pipette, comprising a pipette base, a screw drive, a slider, a cylinder body, a piston rod, a gun tip and a sealing device as described in the first aspect or any possible embodiment of the first aspect, wherein a guide rail is provided on the pipette base, the slider is slidably connected to the guide rail and connected to the piston rod, and the screw drive is driven and connected to the slider to drive the slider to drive the piston rod to move.

[0016] The technical solution of the present invention adopts the following method: the first sealing component and the second sealing component are arranged. The first sealing component is arranged at the end of the inner cavity away from the gun head. The first sealing component includes a sealing ring, a first pressure plate and a first sealing ring. The sealing ring is embedded in the inner cavity. Part of the first pressure plate is embedded in the inner cavity and abuts against the sealing ring. The sealing ring is interference fit with the outer diameter of the piston rod. The first sealing ring is sleeved on the outer wall of the sealing ring to apply radial compression force to the sealing ring; the second sealing component is arranged at the connection between the cylinder body and the gun head. The second sealing component includes a second sealing ring, a second pressure plate and a push plate. The second sealing ring is sleeved on the gun head. The second pressure plate is embedded in the cylinder body and presses the gun head. The push plate is connected to the cylinder body to press the second pressure plate. The sealing ring of the present application itself is in close contact with the outer diameter of the piston rod through an interference fit to ensure that the liquid will not leak through the gap when the piston rod slides. However, the friction between the piston rod and the sealing ring needs to be overcome by appropriate radial compression to ensure the sealing effect in long-term use. The first sealing ring is mounted on the outer wall of the sealing ring, and the sealing between the sealing ring and the inner cavity of the cylinder body is strengthened by applying radial compression force. The elasticity of the sealing ring enables it to maintain close contact when the piston rod moves to prevent gas or liquid leakage. Compared with traditional sealing devices, the wear of a single seal (such as an O-ring) is reduced, and the reliability and durability of the seal are improved. The first sealing ring can provide continuous sealing compression when the piston rod moves by closely contacting the outer wall of the sealing ring, ensuring that the sealing ring is always in a stable sealing state and will not fail due to long-term use. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0018] Figure 1 It is a structural schematic diagram of an embodiment of a sealing device of the present invention;

[0019] Figure 2 for Figure 1 A partial enlarged view of the middle A;

[0020] Figure 3 for Figure 1 A partial enlarged view of point B in the middle;

[0021] Figure 4 Schematic diagram of the structure of a pipette according to an embodiment of the present invention.

[0022] Description of Figure Numbers:

[0023] 100, sealing device; 10, first sealing assembly; 11, sealing sleeve; 111, sliding part; 112, ring pressing part; 12, first pressure plate; 13, first sealing ring; 20, second sealing assembly; 21, second sealing ring; 22, second pressure plate; 23, push plate; 30, cylinder body; 301, inner cavity; 3011, first groove; 3012, second groove; 3013, third groove; 3014, fourth groove; 3015, fifth groove; 3016, sixth groove; 31, piston rod; 40, gun head; 401, inner hole; 402, first step; 403, second step; 200, pipette; 201, pipette bottom plate; 2011, guide rail; 202, screw drive; 203, slider.

[0024] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0026] First, in conjunction with reference Figures 1 to 3 As shown, a sealing device 100 proposed by the present invention is applied to a pipette 200, wherein the pipette 200 comprises a cylinder body 30, a piston rod 31 and a gun head 40, wherein an inner cavity 301 is provided in the cylinder body 30, wherein the piston rod 31 is slidably connected to the inner cavity 301, wherein an inner hole 401 is provided in the gun head 40, wherein the gun head 40 is connected to the cylinder body 30, wherein the inner hole 401 is communicated with the inner cavity 301, and wherein the sealing device 100 comprises:

[0027] a first sealing assembly 10, which is disposed at one end of the inner cavity 301 away from the gun head 40, and comprises a sealing collar 11, a first pressure plate 12 and a first sealing ring 13, wherein the sealing collar 11 is embedded in the inner cavity 301, a portion of the first pressure plate 12 is embedded in the inner cavity 301 and abuts against the sealing collar 11, the sealing collar 11 and the outer diameter of the piston rod 31 are interference fit, and the first sealing ring 13 is sleeved on the outer wall of the sealing collar 11 to apply a radial pressing force to the sealing collar 11; and

[0028] The second sealing component 20 is arranged at the connection between the cylinder body 30 and the gun head 40. The second sealing component 20 includes a second sealing ring 21 and a second pressure plate 22. The second sealing ring 21 is sleeved on the gun head 40. The second pressure plate 22 is embedded in the cylinder body 30 and presses the gun head 40.

[0029] In the present embodiment, the cylinder body 30 is used to provide a movable space, and a cavity is provided therein for accommodating the piston rod 31 and for absorbing and releasing liquid. The piston rod 31 is slidably connected to the inner cavity 301 of the cylinder body 30, and participates in the process of absorbing and releasing the liquid. The gun head 40 is connected to one end of the cylinder body 30, and is connected to the inner cavity 301 of the cylinder body 30 through the inner hole 401, and is used to transfer, absorb or release liquid. The first sealing assembly 10 is arranged at the end of the inner cavity 301 of the cylinder body 30 away from the gun head 40, in order to ensure that no air leakage or liquid leakage occurs during the sliding process of the piston rod 31. The sealing collar 11 is the core part of the first sealing assembly 10, which is located in the inner cavity 301 of the cylinder body 30 and is interference fit with the outer diameter of the piston rod 31. Interference fit means that the inner diameter of the sealing ring 11 is slightly smaller than the outer diameter of the piston rod 31, ensuring that the sealing ring 11 can tightly surround the piston rod 31 to prevent liquid or gas leakage. The close contact between the sealing ring 11 and the piston rod 31 ensures that the piston rod 31 always maintains a good sealing effect during the sliding process. The design of the sealing ring 11 usually adopts wear-resistant materials (such as polyoxymethylene, polytetrafluoroethylene, etc.) to improve its durability and reduce friction, thereby extending its service life. The first pressure plate 12 is partially embedded in the inner cavity 301 of the cylinder body 30 and is close to the sealing ring 11. Its function is to press the sealing ring 11 to ensure that it is stable and does not shift, and at the same time strengthen the pressing force of the sealing ring 11 on the piston rod 31. The first pressure plate 12 is connected to the cylinder body 30 by a fixing device such as a screw during installation to ensure that the sealing ring 11 always maintains a sealing contact with the piston rod 31 during the entire operation process. The cooperation between the first pressure plate 12 and the sealing ring 11 ensures that the pressure between the sealing ring 11 and the piston rod 31 is always maintained within a suitable range, avoiding sealing failure due to uneven or unstable pressure. The first sealing ring 13 is sleeved on the outer wall of the sealing ring 11, and its main function is to apply radial compression force to the sealing ring 11 to further enhance the sealing effect. The first sealing ring 13 is usually made of highly elastic, wear-resistant, and high-temperature resistant materials (such as rubber or polyurethane). It provides sealing performance between the outer wall of the sealing ring 11 and the inner cavity 301 of the cylinder body 30 to avoid gas or liquid leakage. The design of the first sealing ring 13 ensures that the sealing ring 11 is always pressed by external force during the sliding process of the piston rod 31, thereby preventing any leakage of air or liquid.

[0030] The second sealing assembly 20 is located at the connection between the cylinder body 30 and the gun head 40, and is mainly used to ensure the sealing of the connection between the gun head 40 and the cylinder body 30 to prevent liquid from leaking outside the gun head 40. The second sealing ring 21 is sleeved on the gun head 40 to ensure the airtightness between the gun head 40 and the cylinder body 30. The second pressing plate 22 is embedded in the inner cavity 301 of the cylinder body 30 and presses the gun head 40, thereby further enhancing the pressing effect of the second sealing ring 21 to prevent leakage.

[0031] The sealing ring 11 itself is in close contact with the outer diameter of the piston rod 31 through an interference fit to ensure that the liquid will not leak through the gap when the piston rod 31 slides. However, the friction between the piston rod 31 and the sealing ring 11 needs to be overcome by appropriate radial compression to ensure the sealing effect during long-term use. The first sealing ring 13 is sleeved on the outer wall of the sealing ring 11, and the sealing between the sealing ring 11 and the inner cavity 301 of the cylinder body 30 is strengthened by applying radial compression. The elasticity of the sealing ring enables it to maintain close contact when the piston rod 31 moves to prevent gas or liquid leakage. Compared with traditional sealing devices, the wear of a single seal (such as an O-ring) is reduced, and the reliability and durability of the seal are improved. The first sealing ring 13 can provide continuous sealing compression when the piston rod 31 moves by being in close contact with the outer wall of the sealing ring 11, ensuring that the sealing ring 11 is always in a stable sealing state and will not fail due to long-term use.

[0032] Combined with reference Figure 2 As shown, in a possible embodiment, the sealing ring 11 includes a sliding portion 111 and a ring pressing portion 112, the ring pressing portion 112 and the piston rod 31 are clearance fit, the sliding portion 111 and the piston rod 31 are interference fit, and the first sealing ring 13 is sleeved on the outer wall of the sliding portion 111.

[0033] In the present embodiment, the sliding part 111 and the ring pressing part 112 can be integrally formed, and the sliding part 111 is located on the inner side of the sealing ring 11, and is interference fit with the outer diameter of the piston rod 31, that is, the inner diameter of the sliding part 111 is slightly smaller than the outer diameter of the piston rod 31, thereby ensuring that the sliding part 111 and the piston rod 31 can maintain close contact. The sliding part 111 is the contact surface between the piston rod 31 and the inner cavity 301 of the cylinder body 30. When the piston rod 31 slides, the interference fit of the sliding part 111 ensures that no air or liquid leaks to the outside of the cylinder body 30, thereby ensuring the sealing of the pipette 200. The sliding part 111 is usually made of wear-resistant and corrosion-resistant materials (such as polytetrafluoroethylene, polyoxymethylene, etc.) to reduce friction with the piston rod 31 and extend the service life. The ring pressing portion 112 is located on the outside of the sealing collar 11, and is closely matched with the design of the inner cavity 301 of the cylinder body 30, usually in a clearance fit manner, which allows the ring pressing portion 112 to maintain a certain space between the inner cavity 301 of the cylinder body 30 during installation, so that it can produce elastic deformation when under pressure. The main function of the ring pressing portion 112 is to help the sealing collar 11 to be stably installed in the inner cavity 301 of the cylinder body 30 through contact with the inner cavity 301 of the cylinder body 30, and to provide stability to the sealing collar 11 through its elastic characteristics. The ring pressing portion 112 also compresses the sealing collar 11 through external pressure (such as the pressing force from the first pressing plate 12), thereby enhancing the sealing effect.

[0034] In a possible implementation, the sealing ring 11 is made of polyoxymethylene, polyamide or polytetrafluoroethylene;

[0035] The piston rod 31 is made of ceramic.

[0036] In the present embodiment, polyoxymethylene is a high-strength, wear-resistant engineering plastic, which is widely used in applications requiring high mechanical strength and low friction coefficient. Polyoxymethylene has excellent wear resistance, low friction coefficient, good rigidity and chemical resistance, so it can effectively reduce the friction between the sliding parts 111 and extend the service life of the sealing ring 11. The sealing ring 11 made of polyoxymethylene can maintain low wear under high-frequency movement of the piston rod 31, and due to its good self-lubricating property, it reduces the heat generated by friction and further improves the sealing performance. Polyamide, commonly known as nylon, is an engineering plastic with excellent mechanical properties, especially in terms of high strength, high toughness and wear resistance. Polyamide materials can provide good strength and wear resistance, especially under friction and compression loads. The advantages of polyamide are good dimensional stability and strong impact resistance, making it suitable for sealing applications that need to withstand certain mechanical shocks and continuous sliding. Polytetrafluoroethylene is an extremely corrosion-resistant polymer material with excellent chemical stability, low friction coefficient, excellent temperature resistance (good stability in high temperature environment), and low water absorption, which avoids the influence of environmental humidity on the sealing effect. The sealing ring 11 made of polytetrafluoroethylene can withstand more harsh chemical environments and high-temperature working conditions, and is an ideal material for use under extreme conditions (such as high temperature and highly corrosive liquids). Ceramic is a material with extremely high hardness and strong wear resistance. The piston rod 31 made of ceramic material has strong wear resistance and chemical stability, and is particularly suitable for use in a sealing device 100 that requires high wear resistance and long-term use without deformation.

[0037] In a possible implementation manner, the wall thickness of the sliding portion 111 is 0.3 mm-0.5 mm.

[0038] In this embodiment, if the wall thickness of the sliding portion 111 is too thin, the material may be plastically deformed due to friction during long-term use, affecting the sealing effect. Too thin a wall thickness may also reduce the strength of the sealing ring 11, causing the sliding portion 111 to be easily damaged during use. In addition, too thin a wall thickness may cause the sliding portion 111 to have insufficient elasticity and be unable to effectively maintain close contact with the piston rod 31, which may cause gas or liquid leakage and affect the use effect of the pipette 200.

[0039] If the wall thickness of the sliding portion 111 is too thick, the elasticity and flexibility of the sealing collar 11 as a whole will be reduced. Thicker wall thickness will increase friction resistance, affecting the smoothness of movement of the piston rod 31, thereby increasing energy consumption and reducing efficiency. Too thick wall thickness may increase manufacturing costs and is not easy to accommodate in a small volume, precision pipette 200 device, thereby affecting the overall design and size of the device.

[0040] In the wall thickness range of 0.3mm-0.5mm, the sliding portion 111 can have sufficient strength and durability while maintaining appropriate elasticity. This wall thickness range provides sufficient elasticity and toughness, so that the sliding portion 111 can maintain sealing during the contact process with the piston rod 31 to avoid air leakage. This wall thickness range can also ensure that the sealing ring 11 is not easily deformed or damaged during long-term use, and at the same time does not increase excessive friction resistance, so that the sliding of the piston rod 31 is smoother, and the operating efficiency of the pipette 200 is improved.

[0041] In a possible embodiment, the position where the first sealing assembly 10 is installed in the inner cavity 301 is provided with a first groove 3011, a second groove 3012 and a third groove 3013, the sliding portion 111 is accommodated in the first groove 3011, the first sealing ring 13 is accommodated in the second groove 3012, and the annular pressure portion 112 and part of the first pressure plate 12 are accommodated in the third groove 3013.

[0042] Combined with reference Figure 2 As shown, in this embodiment, the first groove 3011 is used to accommodate the sliding part 111. The sliding part 111 is a part of the sealing collar 11. It is in sliding contact with the piston rod 31 and is responsible for maintaining good sealing and reducing friction. The function of the first groove 3011 is to accurately accommodate the sliding part 111 therein, ensuring that the sliding part 111 can always maintain close contact with the piston rod 31 during the movement of the piston rod 31, thereby avoiding air leakage. The size and shape of the groove should match the shape of the sliding part 111 to ensure that the sliding part 111 can be stably embedded and will not be offset or misaligned when the piston rod 31 slides.

[0043] The second groove 3012 is used to accommodate the first sealing ring 13. The first sealing ring 13 is sleeved on the outer wall of the sealing ring 11 to enhance the sealing performance. The second groove 3012 is used to stably accommodate the first sealing ring 13 between the sealing ring 11 and the piston rod 31. Through reasonable groove design, it is ensured that the first sealing ring 13 can always be kept in a compressed state during the working process to avoid gas or liquid leakage. The size and depth of the second groove 3012 also need to be precisely controlled to ensure that the sealing ring can be compressed and will not be squeezed out or fail.

[0044] The third groove 3013 is used to accommodate the annular pressing portion 112 and the first pressing plate 12. The annular pressing portion 112 is a part of the sealing collar 11. It applies radial pressing force to the sealing collar 11 by cooperating with the first pressing plate 12 to ensure the sealing effect between the sliding portion 111 and the piston rod 31. The function of the third groove 3013 is to accommodate the annular pressing portion 112 and part of the first pressing plate 12 so that they can be accurately fixed in the inner cavity 301. Through this design, the third groove 3013 ensures the matching accuracy between the annular pressing portion 112 and the first pressing plate 12, so that the annular pressing portion 112 can apply uniform pressing force to the first sealing ring 13 during operation, ensuring that there is no leakage between the sealing collar 11 and the piston rod 31.

[0045] Combined with reference Figure 3 As shown, in a possible embodiment, a fourth groove 3014, a fifth groove 3015 and a sixth groove 3016 are provided at the connection between the cylinder body 30 and the gun head 40, the gun head 40 includes a first step 402 and a second step 403, the second sealing ring 21 is sleeved on the first step 402 and accommodated in the fourth groove 3014, the second step 403 is accommodated in the fifth groove 3015, the second pressure plate 22 is pressed against the second step 403 and accommodated in the sixth groove 3016.

[0046] In this embodiment, the fourth groove 3014 is used to accommodate the second sealing ring 21, and the function of the second sealing ring 21 is to prevent liquid or gas from leaking at the connection between the cylinder body 30 and the gun head 40. The fourth groove 3014 enables the second sealing ring 21 to be accurately accommodated at the connection and ensures that it is always in a compressed state during operation, thereby achieving a good sealing effect. By reasonably designing the size of the fourth groove 3014, it is ensured that the second sealing ring 21 will not be pressed out of the groove or lose its sealing function during use, while maintaining good elasticity and sealing performance.

[0047] The fifth groove 3015 is used to accommodate the second step 403, which is a part of the gun head 40 and plays a supporting and fixing role at the connection between the cylinder body 30 and the gun head 40. The fifth groove 3015 can accommodate the second step 403, ensuring that it can stably cooperate with the cylinder body 30 during assembly and avoid deviation or looseness during operation. The size and depth of the fifth groove 3015 should match the shape of the second step 403, so as to ensure that the step can be accurately embedded and ensure the tight fit of the seal and the assembly.

[0048] The sixth groove 3016 is used to accommodate the second pressing plate 22 and press the second step 403. The second pressing plate 22 is an important component, which is responsible for applying pressure to the second step 403 to ensure that the second sealing ring 21 is always in a compressed state to prevent liquid or gas leakage. The function of the sixth groove 3016 is to accommodate the second pressing plate 22 to ensure that it can be accurately positioned and does not shift during the compression process. By designing the appropriate size of the sixth groove 3016, the second pressing plate 22 can firmly press the second step 403, thereby further enhancing the sealing performance.

[0049] In a possible implementation manner, a push plate 23 is further provided at the connection between the cylinder body 30 and the gun head 40 .

[0050] In this embodiment, the push plate 23 is located at the connection between the cylinder 30 and the gun head 40. Its main function is to help the pipette to complete the unloading and recycling functions of the TIP head. After the pipette completes the liquid absorption and transfer, the TIP head needs to be taken out of the gun head 40 and reinstalled into the TIP head installation hole of the reagent strip. The push plate 23 helps push the TIP head off the gun head 40 by applying downward pressure, thereby realizing the unloading process of the TIP head.

[0051] Second, combined with reference Figure 4 As shown, the present invention further provides a pipette 200, comprising a pipette base plate 201, a screw drive 202, a slider 203, a cylinder body 30, a piston rod 31, a gun head 40, and a sealing device 100 as described in the first aspect or any possible embodiment of the first aspect, wherein a guide rail 2011 is provided on the pipette base plate 201, the slider 203 is slidably connected to the guide rail 2011 and connected to the piston rod 31, and the screw drive 202 is drivingly connected to the slider 203 to drive the slider 203 to drive the piston rod 31 to move. The specific structure of the sealing device 100 refers to the above embodiment. Since the present pipette 200 adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here one by one.

[0052] In the present embodiment, the pipetting base plate 201 is used as the bottom support structure of the pipette 200, and is responsible for providing a stable platform for supporting other components of the entire pipette 200. It is usually connected to the cylinder 30 and other moving parts, and ensures the position accuracy of each component during the movement. A guide rail 2011 is designed on the pipetting base plate 201, and the function of this guide rail 2011 is to provide a sliding track for the slider 203, ensuring that the slider 203 can move smoothly on the correct path. The guide rail 2011 is the track for the movement of the slider 203, ensuring that the slider 203 slides smoothly and accurately along the specified direction. The design of the guide rail 2011 usually has certain wear resistance and corrosion resistance to adapt to long-term work. The slider 203 is a mobile component that cooperates with the guide rail 2011, and its main function is to convert the movement of the screw drive 202 into the linear movement of the piston rod 31. The slider 203 is connected with the piston rod 31, so that the piston rod 31 can move up and down with the sliding of the slider 203. Slider 203 is connected with base plate by guide rail 2011, ensures that it keeps straight track when moving, and has stability. Screw drive 202 is the driving system of whole pipette 200, is responsible for generating linear motion by rotation, and pushes slider 203 to slide on guide rail 2011. Screw drive 202 is often driven by electric motor, and realizes high-precision motion control by accurate screw-nut cooperation. Screw drive 202 drives the connecting part of nut and slider 203 to carry out linear motion by rotating screw, thereby pushes slider 203 to slide along guide rail 2011, and then drives piston rod 31 to move up and down. Piston rod 31 carries out up and down reciprocating motion by cooperation with inner cavity 301 of cylinder body 30. The upward and downward movement of piston rod 31 is transmitted by the motion of slider 203, ensures that pipette 200 can complete the absorption and discharge of liquid. The outside of the piston rod 31 is usually interference fit with the sliding part 111 of the sealing collar 11, and the sealing device 100 ensures that no liquid or gas leakage occurs during the up and down movement of the piston rod 31. The piston rod 31 and the sealing device 100 work closely together to ensure the sealing of the pipette 200 and the accuracy of absorbing liquid. The cylinder body 30 is a carrier for the sliding of the piston rod 31, and its inner cavity 301 cooperates with the movement of the piston rod 31, and is usually equipped with a suitable sealing device 100 to prevent liquid or gas leakage. The gun head 40 is connected to the end of the cylinder body 30 and is usually used to connect and control the suction head (such as TIP head). The gun head 40 is sealed with the cylinder body 30 to ensure that the liquid can be accurately transferred from the inside of the pipette 200 to the external container or sample. In the structure of the pipette 200, the design of the sealing device 100 is crucial to ensure that when the piston rod 31 moves up and down, the inner cavity 301 of the pipette 200 maintains good sealing with the external environment to prevent liquid leakage. The precise coordination of the sealing components such as the sealing collar 11 , the sealing ring and the pressure plate ensures the sealing effect during the process of sucking and discharging the liquid, and guarantees the high-precision operation of the pipette 200 .The screw drive 202 drives the slider 203 to move, and the slider 203 drives the piston rod 31 to move up and down through the connection with the piston rod 31, forming the absorption and discharge action of the liquid. During the movement of the piston rod 31, the sealing device 100 can effectively prevent the leakage of liquid or gas, ensuring that the pipette 200 can complete the liquid transfer, absorption and discharge under precise control. Through the high-precision control of the screw drive 202, the pipette 200 can complete the accurate absorption and discharge of liquid. The motion trajectory of the slider 203 is stable, and it can ensure that the piston rod 31 moves up and down according to the predetermined path. The precise matching of the sealing device 100, the piston rod 31 and the cylinder body 30 avoids the leakage of liquid or gas, and ensures the long-term stable use of the pipette 200. By combining the sealing device 100, the mechanical drive system and the precise operating mechanism, the pipette 200 of the present application can efficiently and stably perform the liquid transfer task, and is widely used in laboratories, industries and biomedical fields.

[0053] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of this application, it should be understood that if the terms "upper", "lower", "left", "right", etc. indicate an orientation or position relationship based on the orientation or position relationship shown in the drawings, it is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0054] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A sealing device, applied to a pipette, the pipette comprising a cylinder, a piston rod and a gun head, the cylinder is provided with an inner cavity, the piston rod is slidably connected to the inner cavity, the gun head is provided with an inner hole, the gun head is connected to the cylinder, the inner hole is connected to the inner cavity, and the characteristics are as follows: The sealing device comprises: a first sealing assembly, the first sealing assembly being arranged at one end of the inner cavity away from the gun head, the first sealing assembly comprising a sealing collar, a first pressure plate and a first sealing ring, the sealing collar being embedded in the inner cavity, a portion of the first pressure plate being embedded in the inner cavity and abutting against the sealing collar, the sealing collar comprising a sliding portion and a ring pressing portion, the ring pressing portion and the piston rod being clearance-fitted, the sliding portion and the piston rod being interference-fitted, the first sealing ring being sleeved on the outer wall of the sliding portion to apply a radial pressing force to the sealing collar; and The second sealing component is arranged at the connection between the cylinder body and the gun head, and the second sealing component includes a second sealing ring, a second pressure plate and a push plate. The second sealing ring is sleeved on the gun head, and the second pressure plate is embedded in the cylinder body and presses the gun head.

2. The sealing device according to claim 1, characterized in that: The sealing ring is made of polyoxymethylene, polyamide or polytetrafluoroethylene; The piston rod is made of ceramic.

3. The sealing device according to claim 2, characterized in that: The wall thickness of the sliding part is 0.3mm-0.5mm.

4. The sealing device according to claim 1, characterized in that: The position where the first sealing assembly is installed in the inner cavity is provided with a first groove, a second groove and a third groove, the sliding part is accommodated in the first groove, the first sealing ring is accommodated in the second groove, and the annular pressure part and part of the first pressure plate are accommodated in the third groove.

5. The sealing device according to claim 1, characterized in that: A fourth groove, a fifth groove and a sixth groove are provided at the connection between the cylinder body and the gun head. The gun head includes a first step and a second step. The second sealing ring is sleeved on the first step and accommodated in the fourth groove. The second step is accommodated in the fifth groove. The second pressure plate is pressed against the second step and accommodated in the sixth groove.

6. The sealing device according to claim 1, characterized in that: A push plate is also provided at the connection between the cylinder body and the gun head.

7. A pipette, characterized in that: It includes a pipetting base plate, a screw drive, a slider, a cylinder body, a piston rod, a gun head and a sealing device as described in any one of claims 1 to 6, wherein a guide rail is arranged on the pipetting base plate, the slider is slidably connected to the guide rail and connected to the piston rod, and the screw drive is driven to connect the slider to drive the slider to drive the piston rod to move.

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