Dual-tube peristaltic pump that reduces pressure fluctuations

Abstract

The present invention discloses a double-tube peristaltic pump capable of reducing pressure fluctuations, comprising a housing, a pump head and a pump tube, wherein the pump head is built into the housing, and the two pump tubes have the same structure and are respectively arranged between the inner wall of the housing and the outer peripheral wall of the pump head. The pump head is provided with a group of extrusion parts whose number is greater than 1 and is an odd number, and the two pump tubes are successively divided into a pressure relief section, a transmission section and a relaxation relief section, and the central angle of the transmission section is greater than or equal to the angle between the two adjacent extrusion parts and the axis of the pump head, and the two input ends of the two pump tubes are jointly connected to the same input pipeline, and the two output ends of the two pump tubes are jointly connected to the same output pipeline, and the pump head drives the extrusion part to squeeze the two pump tubes in turn by rotating to generate an extrusion force for driving the flow of fluid in the tubes, and the extrusion force on the transmission sections of the two pump tubes has a time difference so that the pressure changes in the two pump tubes complement each other, thereby reducing the pressure change fluctuations in the output pipeline and the input pipeline. This scheme effectively reduces the pressure fluctuations in the output and input pipelines.

Description

Technical Field

[0001] The invention relates to the technical field of medical devices, and in particular to a double-tube peristaltic pump used in an ultrasonic emulsification suction head and capable of reducing pressure fluctuations. Background Art

[0002] Conventional peristaltic pumps, as disclosed in announcement numbers CN 107269504 B and CN 111456930 B, are usually composed of a housing, a pump head, and a pump tube. The pump head is rotated to continuously squeeze or release the elastic pump tube to move the fluid in the pump tube. Since the pump head of the peristaltic pump does not contact the fluid in the tube, the cleanliness of the fluid in the pump tube can be ensured, and therefore, it is widely used in surgical operations, such as the suction and / or perfusion of fluids in ophthalmic operations.

[0003] Usually, a peristaltic pump is used in the suction system of phacoemulsification in ophthalmic surgery to form fluid suction and / or perfusion. However, due to the extremely high precision requirements of ophthalmic surgery, the intraocular pressure fluctuation cannot be too large, so a peristaltic pump with very small pressure fluctuation is needed to assist the operation. Existing similar peristaltic pumps have certain limitations in reducing pressure fluctuations. Common methods include: ① Adding a damper (generally a small cavity covered with a soft film) at the inlet and outlet, which can effectively reduce pressure fluctuations due to its buffering effect. However, this method will cause a large delay in flow and pressure changes when the peristaltic pump is started or stopped or the speed is changed, resulting in the inability to accurately and quickly control the flow and pressure. ② Reduce the inner diameter of the pump tube to reduce the fluid volume between the rollers, thereby reducing pressure fluctuations. Although this method has a certain effect on reducing pressure fluctuations, it will significantly reduce the overall flow rate of the peristaltic pump at the same speed. In order to ensure the flow rate, the speed of the peristaltic pump needs to be increased, which will shorten the service life of the hose on the one hand and increase the difficulty of motor control on the other hand. ③ Increase the number of rollers to reduce the volume of fluid between the two rollers, increase the fluctuation frequency, and reduce pressure fluctuations. This method will shorten the service life of the hose. At the same time, due to the increase in the number of rollers, the volume of fluid occupied in the pump tube will also be reduced to a certain extent.

[0004] Therefore, how to reduce the fluctuation of fluid flow pressure while ensuring a certain flow rate is an urgent problem that needs to be solved. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a double-tube peristaltic pump for use in an phacoemulsification suction head and capable of reducing pressure fluctuations.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A double-tube peristaltic pump capable of reducing pressure fluctuations comprises a shell, a pump head and two pump tubes, wherein the pump head is rotatably built into the shell, the two pump tubes have the same structure and are respectively arranged between the inner wall of the shell and the outer peripheral wall of the pump head, a group of extrusion parts whose number is greater than 1 and is an odd number are arranged on the pump head, the two pump tubes are divided into a pressure relief section, a transmission section and a relaxation section in sequence along the rotation direction of the pump head, the central angle of the transmission section is greater than or equal to the angle between two adjacent extrusion parts and the axis of the pump head, the two input ends of the two pump tubes are connected to the same input pipeline, the two output ends of the two pump tubes are connected to the same output pipeline, the pump head drives the extrusion parts to squeeze the two pump tubes in sequence by rotating to generate an extrusion force for driving the fluid flow in the tubes, the extrusion force on the transmission sections of the two pump tubes has a time difference so that the pressure changes in the two pump tubes are complementary, thereby reducing the pressure change fluctuations of the output pipeline and the input pipeline.

[0008] Preferably, two identical extrusion curved surfaces are relatively arranged on the inner wall of the shell, and each of the extrusion curved surfaces is composed of a first arc segment, a second arc segment, and a third arc segment connected in sequence. In the diameter direction of the pump head, the spacing between the first arc segment, the second arc segment, the third arc segment and the outermost end of the extrusion portion is different, so that the pump tube of a single diameter is arranged between the extrusion curved surface and the pump head to form the pressure relief section, the transmission section and the relaxation section.

[0009] Preferably, in the diameter direction of the pump head, the distance between the first arc segment and the outermost end of the extrusion portion gradually decreases along the rotation direction of the pump head, and the distance between the beginning of the first arc segment and the outermost end of the extrusion portion is not less than the diameter of the pump tube, where the pump tube is not squeezed by the extrusion portion; the distance between the end of the first arc segment and the outermost end of the extrusion portion is the smallest, where the extrusion pressure of the extrusion portion on the pump tube is the largest.

[0010] Preferably, in the diameter direction of the pump head, the distance between the second arc segment and the outermost end of the extrusion portion remains consistent along the rotation direction of the pump head, and the distance between the second arc segment and the outermost end of the extrusion portion is less than or equal to twice the wall thickness of the pump tube.

[0011] Preferably, in the diameter direction of the pump head, the distance between the third arc segment and the outermost end of the extrusion portion gradually increases along the rotation direction of the pump head, and the distance between the beginning of the third arc segment and the outermost end of the extrusion portion is the smallest, where the extrusion pressure of the extrusion portion on the pump tube is the largest; the distance between the end of the third arc segment and the outermost end of the extrusion portion is not less than the diameter of the pump tube, where the pump tube is not squeezed by the extrusion portion.

[0012] Preferably, the two pump tubes are symmetrically arranged relative to the axis of the pump head.

[0013] Preferably, the extrusion portion is a roller, and the roller is rotatably disposed on the outer peripheral wall of the pump head.

[0014] Preferably, the pump head is provided with a group of slide grooves along its diameter direction, a telescopic arm is slidably provided in each of the slide grooves, the rollers are rotatably provided at the outer ends of the telescopic arms, and a group of the telescopic arms move synchronously, so that a group of the rollers can be synchronously extended and retracted relative to the pump head.

[0015] Preferably, the pump head also includes a rotating cover and a driving shaft, the driving shaft passes through the pump body of the pump head and is fixedly connected to the rotating cover, a group of guide holes are provided on the rotating cover, the top of the telescopic arm has a connecting rod, the connecting rod is passed through the guide hole, the rotating cover rotates so that the guide hole drives the connecting rod to move along its hole wall, and then drives the telescopic arm to synchronously slide along the slide groove to extend or retract the roller.

[0016] Preferably, at least one of the guide holes is formed with a portion at an end portion close to the outer edge of the rotating cover that can limit the dead point position of the connecting rod, so that the roller remains in an extended state.

[0017] The beneficial effects of the present invention are mainly reflected in:

[0018] 1. Two pump tubes are arranged opposite to each other, and the extrusion curved surface is used to form a gradually changing distance between the pump head, so that a slow pressure section and a slow relaxation section with gradually changing extrusion pressure are formed in each pump tube to gradually increase or decrease the extrusion amount of the pump tube, so as to reduce the pressure change fluctuation in each pump tube. An odd number of extrusion parts are set to rotate and extrude the two pump tubes, so that there is a phase difference in the pressure change curves between the two pump tubes, thereby making the pressure fluctuations between the two pump tubes complementary. The output ends of the two pump tubes are connected to the same output pipeline to achieve the ultimate purpose of reducing the pressure fluctuation in the output pipeline, and ensure the safety and stability of use;

[0019] 2. A transmission section is provided between the pressure relief section and the release relief section, and the arc of the transmission section is set to be concentric with the rotating arc of the extrusion part to ensure that the distance between the transmission section and the extrusion part remains unchanged, and the arc angle of the transmission section is not less than the arc angle between the extrusion parts to ensure that at least one extrusion part will press the transmission section during the rotation of the pump head, and the distance between the second arc section and the extrusion part is not greater than 2 times the wall of the pump tube, so that there is always an extrusion part pressing the pump tube in the transmission section, ensuring that the fluid in the transmission section remains in a cut-off state, avoiding fluid leakage or backflow problems, and further reducing the overall pressure fluctuation of the pump tube;

[0020] 3. Compared with a single pump tube structure, the two pump tubes can not only reduce the pressure fluctuation in the output pipeline, but also ensure sufficient flow without increasing the speed or the number of extrusion parts, and also increase the service life of the pump tube;

[0021] 4. The extrusion part can be extended and retracted relative to the pump head, so that the extrusion part can be contracted during installation to increase the distance between the pump head and the extrusion curved surface to facilitate the installation of the pump tube. When the pump tube is installed, the extrusion part is extended to extrude the pump tube. Such a structure greatly facilitates the installation of the pump tube and reduces unnecessary wear on the pump tube during installation. The guide hole on the rotating cover is formed with a dead point position that can limit the position of the extrusion part to lock the extended state of the extrusion part, ensuring that the extrusion part will not be reversely squeezed and retracted by the fluid when in use. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The technical solution of the present invention is further described below in conjunction with the accompanying drawings:

[0023] Figure 1 : A schematic diagram of an embodiment of the present invention;

[0024] Figure 2 : The effect of double pump tubes complementing each other to reduce pressure fluctuations;

[0025] Figure 3 : Schematic diagram of an extruded curved surface in an embodiment of the present invention;

[0026] Figure 4 : A schematic diagram of a pressure relief section during operation of an embodiment of the present invention;

[0027] Figure 5 : A schematic diagram of a transmission segment during operation of an embodiment of the present invention;

[0028] Figure 6 : A schematic diagram of a slow-loosening section during the working process of an embodiment of the present invention;

[0029] Figure 7 : The effect of extruding the curved surface to reduce pressure fluctuations;

[0030] Figure 8 : An exploded schematic diagram of a pump head in an embodiment of the present invention;

[0031] Fig. 9 : A schematic diagram of the state of the pump head when it is installed in an embodiment of the present invention;

[0032] Fig.10 : Schematic diagram of the pump head in the working state according to the embodiment of the present invention. DETAILED DESCRIPTION

[0033] The present invention will be described in detail below in conjunction with the specific embodiments shown in the accompanying drawings. However, these embodiments are not limited to the present invention, and any structural, methodological, or functional changes made by a person skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0034] In the description of the scheme, it should be noted that the terms "center", "up", "down", "left", "right", "front", "back", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of description and simplified description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance. Moreover, in the description of the scheme, with the operator as a reference, the direction close to the operator is the proximal end, and the direction away from the operator is the distal end.

[0035] like Figures 1 to 10 As shown, the present invention discloses a double-tube peristaltic pump capable of reducing pressure fluctuations, comprising a housing 1, a pump head 2 and two pump tubes 3, wherein the pump head 2 is rotatably built into the housing 1, the two pump tubes 3 have the same structure and are respectively arranged between the inner wall of the housing 1 and the outer peripheral wall of the pump head 2, a group of extrusion parts whose number is greater than 1 and is an odd number are arranged on the pump head 2, the two pump tubes 3 are sequentially divided into a pressure relief section 100, a transmission section 200 and a relaxation relief section 300 along the rotation direction of the pump head 2, and the central angle of the transmission section 200 is greater than or equal to the central angle of the two adjacent sections. The angle between the extrusion part and the axis of the pump head 2, the two input ends 301 of the two pump tubes 3 are connected to the same input pipeline 4, and the two output ends 302 of the two pump tubes 3 are connected to the same output pipeline 5. The pump head 2 drives the extrusion part to squeeze the two pump tubes 3 in turn by rotation to generate an extrusion force to drive the fluid flow in the tubes. The extrusion force exerted on the transmission sections 200 of the two pump tubes 3 has a time difference so that the pressure changes in the two pump tubes 3 are complementary, thereby reducing the pressure change fluctuations of the output pipeline 5 and the input pipeline 4.

[0036] Preferably, the two pump tubes 3 are divided in half within the spacing between the housing 1 and the pump head 2 to maximize the use of the space within the housing 1. The two pump tubes 3 are axially symmetrically arranged relative to the axis of the pump head 2, specifically, the pressure relief section 100, the transmission section 200 and the relief section 300 in the two pump tubes 3 are axially symmetrically arranged. In one feasible embodiment, the first arc segment 101 and the third arc segment 103 may be symmetrically arranged relative to the second arc segment 102. In other feasible embodiments, the pressure relief section 100 and the relief section 300 in the same pump tube 3 may not be symmetrical relative to the transmission section 200, and the specific lengths of the pressure relief section 100, the transmission section 200 and the relief section 300 are determined according to the actual pressure regulation requirements and are not limited here.

[0037] The extrusion part in this solution can be any suitable structure or element that can extrude the pump tube, such as a sphere, a bump, etc. In a preferred embodiment, the extrusion part is a roller 201, and the roller 201 is rotatably arranged on the outer peripheral wall of the pump head 2, so that the roller 201 and the pump tube 3 have an extrusion force, and a rolling friction is formed between the two, so as to minimize the friction of the roller 201 on the outer wall of the pump tube 3, ensure the integrity of the pump tube 3, improve the service life of the pump tube 3, and save the driving force required for the rotation of the pump head 2.

[0038] The difference between the pressure relief section 100, the transmission section 200 and the relaxation section 300 lies in the different extrusion forces of the extrusion part. There are many feasible ways to form the pressure relief section 100, the transmission section 200 and the relaxation section 300, such as using a pump tube with a gradually changing diameter and placing it in a shell with an inner contour of a whole circle; or using a pump tube with a single diameter and placing it in a shell with an inner contour of a non-circular, etc.

[0039] like Figure 3-Figure 6As shown, in a preferred embodiment, the present scheme arranges two pump tubes 3 relatively between the shell 1 and the pump head 2, the pump tube 3 is a tube body of a single diameter, and two sections of extrusion curved surfaces are relatively arranged on the inner wall of the shell 1, each section of the extrusion curved surface is sequentially composed of a first arc segment 101, a second arc segment 102, and a third arc segment 103 connected to each other, and in the diameter direction of the pump head 2, the first arc segment 101, the second arc segment 102, the third arc segment 103 and the outermost end of the extrusion portion have different spacings, so that the pump tube 3 of a single diameter is arranged between the extrusion curved surface and the pump head 2 to form the pressure relief section 100, the transmission section 200 and the relaxation section 300. After the pump head 2 rotates, the outermost ends of a group of extrusion parts (i.e., rollers 201) form a full-circle rotating curved surface, so that after the pump tube 3 of a single diameter is set between the extrusion curved surface and the pump head 2, the rollers 201 can produce different extrusion effects by rotating, thereby forming the pressure relief section 100, the transmission section 200 and the relaxation section 300 whose extrusion force gradually changes slowly, so as to gradually increase or decrease the extrusion amount of the pump tube 3, and then gradually increase or decrease the pressure in the pump tube 3, so as to reduce the pressure change fluctuation in each pump tube 3.

[0040] The rollers 201 in this solution can be an odd number of 3, 5, 7 or more. An odd number of rollers 201 are set to rotate and squeeze the two pump tubes 3, so that there is a phase difference in the pressure change curves between the two pump tubes 3, and then the pressure fluctuations between the two pump tubes 3 are complementary. The output ends 302 of the two pump tubes 3 are connected to the same output pipeline 5, so as to achieve the ultimate goal of reducing the pressure fluctuations in the output pipeline 5 and ensure safety and stability in use.

[0041] Specifically, in the diameter direction of the pump head 2, the distance between the first arc segment 101 and the outermost end of the extrusion portion gradually decreases along the rotation direction of the pump head 2, so that the cross-sectional area of ​​the pressure relief section 100 gradually decreases, that is, the amount of pump tube 3 extruded by the pressure relief section 100 gradually increases, so that the pressure in the pressure relief section 100 gradually increases, achieving the purpose of gentle pressure increase. Compared with sudden compression, such a structure can significantly reduce the pressure fluctuation in the pressure relief section 100. The distance between the beginning of the first arc segment 101 and the outermost end of the extrusion portion is not less than the diameter of the pump tube 3, where the pump tube 3 is not squeezed by the extrusion portion and is in a natural state; the distance between the end of the first arc segment 101 and the outermost end of the extrusion portion is the smallest, where the extrusion pressure of the extrusion portion on the pump tube 3 is the largest, and the distance here is preferably less than or equal to twice the wall thickness of the pump tube 3, so that the roller 201 cuts off the fluid in the pump tube 3 here. The pressure variation law in the pressure relief section 100 is determined by the angle between the first arc section 101 and the rotating curved surface of the roller 201. The larger the angle between the two, the greater the pressure fluctuation in the pressure relief section 100, and the smaller the angle between the two, the smaller the pressure fluctuation in the pressure relief section 100. In a preferred embodiment, the angle between the first arc section 101 and the rotating curved surface of the roller 201 preferably adopts a linear variation to make the pressure in the pressure relief section 100 increase linearly, so as to achieve the purpose of gentle pressure increase.

[0042] Similarly, in the diameter direction of the pump head 2, the distance between the third arc segment 103 and the outermost end of the extrusion portion gradually increases along the rotation direction of the pump head 2, and the distance between the beginning of the third arc segment 103 and the outermost end of the extrusion portion is the smallest, where the extrusion pressure of the extrusion portion on the pump tube 3 is the largest; the distance between the end of the third arc segment 103 and the outermost end of the extrusion portion is not less than the diameter of the pump tube 3, where the pump tube 3 is not squeezed by the extrusion portion and is in a natural state. In a preferred embodiment, the angle between the third arc segment 103 and the rotating surface of the roller 201 is also preferably linearly changed to reduce the pressure in the slow-release section 300 linearly, thereby achieving the purpose of gentle pressure reduction.

[0043] The second arc segment 102 is concentric with the rotation arc of the roller 201, so that in the diameter direction of the pump head 2, the distance between the second arc segment 102 and the outermost end of the extrusion portion is consistent along the rotation direction of the pump head 2. The distance between the second arc segment 102 and the roller 201 is less than or equal to twice the wall thickness of the pump tube 3, so that the roller 201 cuts off the fluid in the pump tube 3. The end of the first arc segment 101 is the beginning of the second arc segment 102, and the beginning of the third arc segment 103 is the end of the second arc segment 102. The fluid in the transmission section 200 is squeezed by the roller 201, and is uniformly transmitted along the rotation direction of the tube 201 through the rotation of the roller 201.

[0044] A transmission section 200 is arranged between the pressure relief section 100 and the release relief section 300, and the distance between the transmission section 200 and the outermost end of the extrusion section remains unchanged, and the arc angle of the transmission section 200 is greater than or equal to the arc angle between the rollers 201 (that is, the arc angle of the transmission section 200 is ≥360 degrees / number of rollers). Such a structural arrangement can ensure that during the rotation of the pump head 2, there are always rollers 201 to press the pump tube 3 in the transmission section 200, ensuring that the fluid in the transmission section 200 remains in a cut-off state, thereby avoiding fluid leakage or backflow problems, and further reducing the overall pressure fluctuation of the pump tube 3.

[0045] like Figure 7 As shown, it is a comparison diagram of the pressure fluctuation in the output pipeline at the same flow rate without the extrusion curved surface and with the extrusion curved surface in this solution. The dotted line part is the pressure fluctuation curve without the extrusion curved surface, and the solid line part is the pressure fluctuation curve with the extrusion curved surface. It can be seen that the extrusion curved surface provided in this solution can significantly reduce the pressure fluctuation in the output pipeline 5.

[0046] like Figure 1As shown, the working principle of the complementary pressure fluctuation between the two pump tubes 3 is explained according to this figure: in this figure, 7 rollers are preferably used to cooperate with the two pump tubes 3 to perform peristalsis. For the convenience of explanation, the rollers 201 in the figure are marked as 201-1 to 201-7 in sequence, the pump tube 3 located in the upper half of the housing 1 is marked as 3-1, and the pump tube 3 located in the lower half of the housing 1 is marked as 3-2. When the pump head 2 rotates counterclockwise, negative pressure is formed at the input ends 301 of the pump tubes 3-1 and 3-2, respectively, so that the fluid in the input pipeline 4 enters the pump tubes 3-1 and 3-2 respectively, and is output from the output ends 302 of the pump tubes 3-1 and 3-2 to the output pipeline 5 through the rotation of the pump head 2. The roller 201-1 is located in the middle of the pressure relief section 100 and has not yet compressed the pump tube 3-1, while the roller 201-2 is already located in the transmission section 200 and compresses the pump tube 3-1. At this time, the pump tube 3-1 is only compressed by the roller 201-2, and the pressure in the pump tube 3-1 reaches the minimum. At the same time, the rollers 201-5 and 201-6 are respectively located at the beginning and the end of the transmission section 200, and both compress the pump tube 3-2. At this time, the pressure in the pump tube 3-2 reaches the maximum. The pressures in the input end 301 and the output end 302 of the pump tube 3-1 and the pump tube 3-2 will be superimposed and offset each other, forming a complementary relationship, so that the pressure fluctuations in the input pipeline 4 and the output pipeline 5 are reduced.

[0047] Further Figure 2 As shown, it is a comparison diagram of pressure fluctuations of a single pump tube and a double pump tube in this solution. The dotted lines are the individual pressure fluctuation curves in the pump tubes 3-1 and 3-2, respectively, and the solid lines are the pressure fluctuation curves in the output pipeline 5. It can be seen that the two pump tubes 3 in this solution can reduce the pressure fluctuation in the output pipeline 5 compared to the single pump tube structure, and the double pump tube structure can also ensure sufficient flow compared to the single pump tube, and there is no need to increase the rotation speed or the number of rollers 201, which also increases the service life of the pump tube 3.

[0048] The extrusion part can be directly fixed on the peripheral wall of the pump head 2, or the extrusion part can be telescopically arranged through a telescopic structure. In order to facilitate the assembly of the pump head 2, the pump head 2 in this solution sets the roller 201 as a telescopic structure to change its outer diameter, so that the roller 201 can be retracted during installation to reduce the outer diameter of the pump head 2 to increase the distance between the pump head 2 and the extrusion curved surface, so as to facilitate the installation of the pump tube 3; when the pump tube 3 is installed, the roller 201 is extended to squeeze the pump tube 3. Such a structure greatly facilitates the installation of the pump tube 3 and reduces unnecessary wear of the pump tube 3 during installation.

[0049] The pump head 2 is provided with a group of slide grooves 202 along its diameter direction. Specifically, the slide grooves 202 are evenly distributed radially from the axis of the pump head 2 to its outer wall. A telescopic arm 203 is slidably provided in each of the slide grooves 202. The rollers 201 are rotatably provided at the outer ends of the telescopic arms 203. A group of the telescopic arms 203 move synchronously, so that a group of the rollers 201 can be synchronously extended and retracted relative to the pump head 2. The slide grooves 202 preferably extend straight.

[0050] The telescopic arm 203 in this solution can adopt any driving structure that can drive it to synchronously move along the slide groove 202. In a preferred embodiment, the pump head 2 also includes a rotating cover 204 and a driving shaft 205, the driving shaft 205 passes through the pump body of the pump head 2 and is fixedly connected to the rotating cover 204, the rotating cover 204 is provided with a group of guide holes 2041, the top of the telescopic arm 203 has a connecting rod 2031, the connecting rod 2031 is inserted into the guiding holes 2041, the rotating cover 204 rotates so that the guiding holes 2041 drive the connecting rod 2031 to move along its hole wall, and then drives the telescopic arm 203 to synchronously slide along the slide groove 202 to extend or retract the roller 201. The driving shaft 205 is a motor shaft, which is fixedly connected to the rotating cover 204 through a non-circular connecting end to drive the rotating cover 204 to rotate synchronously.

[0051] Further, the guide hole 2041 has a variety of feasible embodiments, which can be a combination of one or more of an arc-shaped through hole, a J-shaped through hole, and an L-shaped through hole. At least one of the guide holes 2041 is formed with a dead point position that can limit the connection rod 2031 at the end near the outer edge of the rotating cover 204, so that the roller 201 remains in an extended state. The guide hole 2041 on the rotating cover 204 is formed with a dead point position that can limit the position of the roller 201, so as to lock the extended state of the roller 201, and ensure that the roller will not be reversely squeezed and retracted by the fluid in the use state.

[0052] In a preferred embodiment, the guide hole 2041 is an arc-shaped through hole. When the connecting rod 2031 moves to the two ends of the guide hole 2041, the ends of the guide hole 2041 can lock the connecting rod 2031 due to the curvature to prevent the connecting rod 2031 from retracting, thereby ensuring that the position of the roller 201 is constant when in use, thereby ensuring its pressing effect on the pump tube 3.

[0053] It should be understood that although this specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation mode may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0054] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. Double tube peristaltic pump that can reduce pressure fluctuations, characterized by: The invention comprises a housing (1), a pump head (2) and two pump tubes (3), wherein the pump head (2) is rotatably built into the housing (1), the two pump tubes (3) have the same structure and are respectively arranged between the inner wall of the housing (1) and the outer peripheral wall of the pump head (2), the pump head (2) is provided with a group of extrusion parts whose number is greater than 1 and is an odd number, the two pump tubes (3) are divided into a pressure relief section (100), a transmission section (200) and a release section (300) in sequence along the rotation direction of the pump head (2), the central angle of the transmission section (200) is greater than or equal to the angle between the axis of two adjacent extrusion parts and the pump head (2), the two input ends (301) of the two pump tubes (3) are connected to the same input pipeline (4), the two output ends (302) of the two pump tubes (3) are connected to the same output pipeline (5), and the pump head (2) drives the extrusion parts to squeeze in sequence by rotating. The two pump tubes (3) generate an extrusion force driving the flow of fluid in the tubes. The extrusion forces on the transmission sections (200) of the two pump tubes (3) have a time difference so that the pressure changes in the two pump tubes (3) complement each other, thereby reducing the pressure change fluctuations of the output pipeline (5) and the input pipeline (4). Two identical extrusion curved surfaces are arranged on the inner wall of the housing (1) in opposite directions. Each of the extrusion curved surfaces is composed of a first arc segment (101), a second arc segment (102), and a third arc segment (103) connected in sequence. In the diameter direction of the pump head (2), the first arc segment (101), the second arc segment (102), the third arc segment (103) and the outermost end of the extrusion portion have different spacings, so that the pump tube (3) of a single diameter is arranged between the extrusion curved surface and the pump head (2) to form the pressure relief section (100), the transmission section (200) and the relaxation section (300).

2. The double-tube peristaltic pump capable of reducing pressure fluctuations according to claim 1, characterized in that: In the diameter direction of the pump head (2), the distance between the first arc segment (101) and the outermost end of the extrusion portion gradually decreases along the rotation direction of the pump head (2), and the distance between the beginning of the first arc segment (101) and the outermost end of the extrusion portion is not less than the diameter of the pump tube (3), and the pump tube (3) is not squeezed by the extrusion portion at this point; the distance between the end of the first arc segment (101) and the outermost end of the extrusion portion is the smallest, and the extrusion pressure of the extrusion portion on the pump tube (3) is the largest at this point.

3. The double-tube peristaltic pump capable of reducing pressure fluctuations according to claim 2, characterized in that: In the diameter direction of the pump head (2), the distance between the second arc segment (102) and the outermost end of the extrusion portion remains consistent along the rotation direction of the pump head (2), and the distance between the second arc segment (102) and the outermost end of the extrusion portion is less than or equal to twice the wall thickness of the pump tube (3).

4. The double-tube peristaltic pump capable of reducing pressure fluctuations according to claim 3, characterized in that: In the diameter direction of the pump head (2), the distance between the third arc segment (103) and the outermost end of the extrusion portion gradually increases along the rotation direction of the pump head (2), and the distance between the beginning of the third arc segment (103) and the outermost end of the extrusion portion is the smallest, where the extrusion pressure of the extrusion portion on the pump tube (3) is the largest; the distance between the end of the third arc segment (103) and the outermost end of the extrusion portion is not less than the diameter of the pump tube (3), where the pump tube (3) is not squeezed by the extrusion portion.

5. The double-tube peristaltic pump capable of reducing pressure fluctuations according to claim 4, characterized in that: The two pump tubes (3) are arranged symmetrically relative to the axis center of the pump head (2).

6. The double-tube peristaltic pump capable of reducing pressure fluctuation according to any one of claims 1 to 5, characterized in that: The extrusion portion is a roller (201), and the roller (201) is rotatably arranged on the outer peripheral wall of the pump head (2).

7. The double-tube peristaltic pump capable of reducing pressure fluctuations according to claim 6, characterized in that: The pump head (2) is provided with a group of slide grooves (202) along its radial direction, a telescopic arm (203) is slidably provided in each of the slide grooves (202), the rollers (201) are rotatably provided at the outer ends of the telescopic arms (203), and a group of the telescopic arms (203) move synchronously, so that a group of the rollers (201) can be synchronously extended and retracted relative to the pump head (2).

8. The double-tube peristaltic pump capable of reducing pressure fluctuations according to claim 7, characterized in that: The pump head (2) further comprises a rotating cover (204) and a driving shaft (205), wherein the driving shaft (205) passes through the pump body of the pump head (2) and is fixedly connected to the rotating cover (204), wherein a group of guide holes (2041) are provided on the rotating cover (204), wherein the top of the telescopic arm (203) has a connecting rod (2031), wherein the connecting rod (2031) passes through the guiding hole (2041), and wherein the rotating cover (204) rotates so that the guiding hole (2041) drives the connecting rod (2031) to move along the hole wall thereof, thereby driving the telescopic arm (203) to slide synchronously along the slide groove (202) to extend or retract the roller (201).

9. The double-tube peristaltic pump capable of reducing pressure fluctuations according to claim 8, characterized in that: At least one of the guide holes (2041) is formed at an end portion close to the outer edge of the rotating cover (204) with a dead point position that can limit the connecting rod (2031) so that the roller (201) remains in an extended state.

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