Roller pump

Abstract

To provide a roller pump for suppressing the entry of liquid into a through-hole through which a shaft part is inserted, while suppressing the degradation of maintainability.SOLUTION: A roller pump 1 to which a flexible tube is mounted can transport liquid through the tube. The roller pump 1 includes a bottom part 10, a shaft part 20, a roller support part 30, a plurality of thrust rollers, and a seal member 50, the plurality of thrust rollers being mounted to the roller support part 30 and arranged side by side in the peripheral direction of the shaft part 20 in view from an axial direction A, the seal member 50 being ring-shaped and inserted through the shaft part 20 so as to contact the roller support part 30 and the bottom part 10 while being located therebetween, to enable the closure of a gap between through-hole 11 and the shaft part 20, the bottom part 10 having a diameter enlarged part 15 where the diameter of an inner peripheral face 151 is enlarged as approaching the direction of extending to the roller support part 30 out of the axial direction A, while storing at least part of the seal member 50.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a roller pump.

Background Art

[0002] The tube pump disclosed in Japanese Patent Application Laid-Open No. 6-218042 (Patent Document 1) rotates a rotor part by pressing an elastic tube disposed in a casing body having a substantially arcuate inner peripheral surface against the arcuate inner peripheral surface by a roller, thereby feeding the liquid in the elastic tube. The rotor part includes a rotor body engaged with a drive shaft. The tube-type pump device disclosed in Japanese Patent Application Laid-Open No. 2004-124811 (Patent Document 2) has a case and a rotating body rotatably housed in a substantially circular housing hole formed on the upper surface of the case. In the case, a circular recess is formed at the center of the housing hole, and a support shaft stands upright at the center of the circular recess.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventional roller pumps include a rotating shaft as disclosed in Patent Documents 1 and 2, and a through hole through which the rotating shaft is inserted is formed. Here, in a roller pump used in an environment where liquids are handled (for example, a roller pump incorporated in a medical device), when a liquid drips onto the roller pump or the like, it becomes a problem that the liquid enters the through hole. Therefore, it is conceivable to provide grease between the shaft portion and the through hole. However, grease is not easy to handle, and providing grease as described above reduces the maintainability of the roller pump.

[0005] This disclosure has been made in view of the above-mentioned problems, and aims to provide a roller pump that can suppress the intrusion of liquid into the through-hole through which the shaft is inserted, while suppressing a decrease in maintainability. [Means for solving the problem]

[0006] A roller pump according to this disclosure is capable of transporting liquid in a tube by attaching a flexible tube. The roller pump comprises a base, a shaft, a roller support, a plurality of pressure rollers, and a sealing member. The shaft is rotatable while being inserted through a through hole formed in the base. The roller support is attached to the shaft and is spaced apart from the base, while facing the base in the axial direction of the shaft. The plurality of pressure rollers are attached to the roller support and are arranged in the circumferential direction of the shaft when viewed from the axial direction. The sealing member is ring-shaped and is inserted through the shaft so as to be in contact with the roller support and the base, and is capable of closing the gap between the through hole and the shaft. The base has an enlarged diameter portion in which the inner circumferential surface widens as it approaches the direction toward the roller support in the axial direction, while accommodating at least a portion of the sealing member. [Effects of the Invention]

[0007] By using the sealing member described above, the maintainability of the roller pump is improved compared to when grease is used. Furthermore, even if liquid drips onto the bottom, the enlarged diameter portion makes it easier for the liquid to flow away from the sealing member. Therefore, the sealing member and the enlarged diameter portion prevent liquid from entering the through hole through which the shaft is inserted. [Brief explanation of the drawing]

[0008] [Figure 1] A front view showing a medical device equipped with a roller pump according to one embodiment of the present disclosure. [Figure 2] This is a side view showing a medical device equipped with a roller pump according to one embodiment of the present disclosure. [Figure 3]Figure 1 is a cross-sectional view of the roller pump as seen from the direction of the arrow III-III. [Figure 4] Figure 2 is a cross-sectional view of the roller pump as seen from the direction of the arrow along line IV-IV. [Modes for carrying out the invention]

[0009] Hereinafter, the configuration of a roller pump according to one embodiment of this disclosure will be described with reference to the drawings. In the following description of the embodiment, the same or corresponding parts in the drawings will be denoted by the same reference numerals, and their descriptions will not be repeated.

[0010] Figure 1 is a front view showing a medical device equipped with a roller pump according to one embodiment of the present disclosure. Figure 2 is a side view showing a medical device equipped with a roller pump according to one embodiment of the present disclosure. As shown in Figures 1 and 2, the roller pump 1 according to one embodiment of the present disclosure is used, for example, in a medical device 100. In the medical device 100, the roller pump 1 transports a liquid, such as bodily fluids like human blood or a drug solution.

[0011] The medical device 100 is specifically a blood purification device. When the roller pump 1 is attached to the blood purification device, the roller pump 1 is used, for example, as a blood pump to transport the patient's blood to the blood purification device. The blood purification device is used, for example, in one of the following: Continuous Renal Replacement Therapy (CRRT), Continuous Hemodiafiltration (CHDF), Continuous Hemofiltration (CHF), Continuous Hemodialysis (CHD), and Slow Continuous UltraFiltration (SCUF).

[0012] Figure 3 is a cross-sectional view of the roller pump in Figure 1, taken from the direction of the arrow III-III. Figure 4 is a cross-sectional view of the roller pump in Figure 2, taken from the direction of the arrow IV-IV. As shown in Figures 3 and 4, the roller pump 1 can transport liquid in a flexible tube 2 by attaching the tube 2 to it. When the roller pump 1 is attached to a medical device 100, the liquid is a bodily fluid such as human blood or a drug solution, as described above, and more specifically, it is blood. Note that only in Figure 4, the tube 2 attached to the roller pump 1 is schematically shown by a dashed line.

[0013] The roller pump 1 comprises a bottom portion 10, a shaft portion 20, a roller support portion 30, a plurality of pressure rollers 40, and a sealing member 50.

[0014] The shaft portion 20 is rotatable while being inserted through a through hole 11 formed in the bottom portion 10. The shaft portion 20 is rotated by a drive device (not shown) located on the opposite side from the roller support portion 30 when viewed from the bottom portion 10. The drive device is, for example, a motor.

[0015] The axial direction A is inclined with respect to the vertical direction Y. This allows for easy attachment of the tube 2 to the roller pump 1. From the viewpoint of ease of attachment of the tube 2, the angle between the axial direction A and the vertical direction Y is preferably 45 degrees or less.

[0016] The roller support portion 30 is attached to the shaft portion 20 and faces the bottom portion 10 in the axial direction A of the shaft portion 20 while being separated from the bottom portion 10. Furthermore, the roller support portion 30 is configured to be removable from the shaft portion 20. This improves the maintainability of the roller pump 1.

[0017] When the roller pump 1 transports a body fluid such as blood or a predetermined liquid such as a chemical solution, cleaning of the roller pump 1 is important. This is because it is necessary to remove the bacterial colonies adhering to the roller pump 1 by such cleaning and prevent cross-infection caused by the use of the roller pump 1. And as for the cleaning of the roller pump 1, it is considered that the cleaning is performed by the operator of the roller pump 1 (medical device 100), rather than a person mainly in charge of the maintenance of the roller pump 1. Therefore, when the roller pump 1 transports a body fluid such as blood, the maintainability of the roller pump 1 is particularly important.

[0018] The roller support portion 30 has a roller support member 31 and a mounting member 32. The roller support member 31 is positioned to cover the shaft portion 20 in the axial direction A from the side opposite to the bottom portion 10. A through hole 311 is formed in the roller support member 31. The through hole 311 extends along the axial direction A. The through hole 311 is positioned so as to overlap the center of the shaft portion 20 when viewed from the axial direction A. The through hole 311 is positioned so as to be visually recognizable from the outside when the roller support portion 30 is viewed from the side opposite to the shaft portion 20 in the axial direction A.

[0019] The mounting member 32 is inserted into the through hole 311. The mounting member 32 fixes the relative positions of the roller support member 31 and the shaft portion 20 and is configured to be removable from the roller support member 31 and the shaft portion 20. Thereby, at the time of maintenance of the roller pump 1, the roller support member 31 can be easily removed from the shaft portion 20. Also, from the viewpoint of ease of maintenance, the roller support member 31 and the shaft portion 20 are fixed to each other only by the mounting member 32.

[0020] From the viewpoint of ease of maintenance, the mounting member 32 is preferably a screw, and more preferably a screw in which loosening due to rotation and vibration of the shaft portion 20 is suppressed. Examples of the mounting member 32 include "Motion Tight (registered trademark)" (manufactured by Artos Screw Co., Ltd.) or "Spring Bolt (registered trademark)" (manufactured by Idea Co., Ltd.).

[0021] The plurality of pressing rollers 40 are attached to the roller support portion 30 and arranged side by side in the circumferential direction of the shaft portion 20 as viewed from the axial direction A. Specifically, the plurality of pressing rollers 40 are attached to the roller support member 31. Note that the pressing rollers 40 are not shown in FIG. 3.

[0022] The roller pump 1 further includes a stator 45 having a substantially U-shaped outer shape. The stator 45 is located radially outside the shaft portion 20 with respect to the orbits of the plurality of pressing rollers 40 that are displaced by the rotation of the shaft portion 20 as viewed from the axial direction A. In the roller pump 1, the tube 2 is attached between the plurality of pressing rollers 40 and the stator 45. The tube 2 is pressed against the stator 45 by the pressing rollers 40. Further, as the pressing rollers 40 are displaced while pressing the tube 2 against the stator 45, the liquid in the tube 2 is transported.

[0023] The seal member 50 is ring-shaped and is inserted through the shaft portion 20 so as to be positioned between and in contact with the roller support portion 30 and the bottom portion 10, and can close the gap between the through-hole 11 and the shaft portion 20.

[0024] The seal member 50 is a so-called V-ring. The seal member 50 has a main body portion 51, a hinge portion 52, and a lip portion 53.

[0025] The main body portion 51 is attached onto the shaft portion 20 along the circumferential direction of the shaft portion 20. The main body portion 51 has an annular outer shape as viewed from the axial direction A. The main body portion 51 has a contact surface portion 511. The contact surface portion 511 extends radially about the shaft portion 20 and has an annular outer shape as viewed from the axial direction A. At least a part of the contact surface portion 511 is in contact with the roller support portion 30. Thereby, the movement of the seal member 50 in the direction of the axial direction A toward the roller support portion 30 is restricted. In the present embodiment, the contact surface portion 511 extends parallel to the axial direction A, and the entire contact surface portion 511 is in contact with the roller support portion 30. Thereby, the above restriction becomes more reliable.

[0026] The hinge portion 52 is mounted on the shaft portion 20 along its circumferential direction. The hinge portion 52 is connected to the main body portion 51 on the side opposite to the contact surface portion 511 of the main body portion 51. Viewed from the axial direction A, the diameter of the outer circumference of the hinge portion 52 is smaller than the diameter of the outer circumference of the main body portion 51.

[0027] The lip portion 53 has a skirt-like outer shape. The lip portion 53 extends radially outward from the hinge portion 52 to the shaft portion 20. The lip portion 53 extends away from the main body portion 51. Specifically, the lip portion 53 extends diagonally with respect to the axial direction A. The tip 531 of the lip portion 53 is located furthest from the main body portion 51 and the hinge portion 52. The tip 531 of the lip portion 53 is in contact with the bottom portion 10.

[0028] The sealing member 50 is made of an elastically deformable material such as rubber. The sealing member 50 is positioned in a state of elastic deformation such that the axial dimension A of the lip portion 53 is reduced by contacting the roller support portion 30 and the bottom portion 10, respectively.

[0029] The bottom portion 10 accommodates at least a part of the sealing member 50 and has an enlarged diameter portion 15 in which the inner circumferential surface 151 widens as it approaches the direction toward the roller support portion 30 in the axial direction A.

[0030] By using the sealing member 50 arranged as described above, the maintainability of the roller pump 1 is improved compared to when grease is used. Furthermore, even if liquid drips onto the bottom 10, the enlarged diameter portion 15 makes it easier for the liquid to flow away from the sealing member 50. Therefore, the sealing member 50 and the enlarged diameter portion 15 prevent liquid from entering the through hole 11 through which the shaft portion 20 is inserted.

[0031] The enlarged diameter portion 15 is positioned at a distance from the sealing member 50. The bottom portion 10 further has a smooth flat portion 16 located on the through-hole 11 side of the enlarged diameter portion 15 when viewed from the axial direction A. The flat portion 16 is positioned to slide against the sealing member 50, which rotates in conjunction with the rotation of the shaft portion 20. This suppresses the formation of a gap between the rotating sealing member 50 and the bottom portion 10, and further improves the sealing performance of the through-hole 11 by the sealing member 50. In this embodiment, the flat portion 16 is positioned to slide against the tip 531 of the lip portion 53. The flat portion 16 expands in a direction perpendicular to the axial direction A. The through-hole 11 is formed from the flat portion 16.

[0032] Furthermore, it is preferable that the surface roughness of the flat portion 16 is sufficiently small so that it can slide against the tip 531 of the lip portion 53 of the sealing member 50, which rotates in conjunction with the rotation of the shaft portion 20, without causing any abnormality in the operation of the roller pump 1. This further improves the sealing performance of the through hole 11 by the sealing member 50. The above surface roughness can be achieved by conventionally known methods. For example, if the bottom portion 10 is made of metal, the above surface roughness can be achieved by forming the bottom portion 10 by machining rather than die casting. If the bottom portion 10 is made of resin, the above surface roughness can be achieved by forming the bottom portion 10 by a predetermined resin molding method such as injection molding.

[0033] The lowest portion 151U of the inner circumferential surface 151 of the enlarged diameter portion 15 is inclined downwards as it approaches the roller support portion 30. As a result, any liquid that enters the enlarged diameter portion 15 is discharged by its own weight, thus further suppressing the intrusion of liquid into the through hole 11.

[0034] [Note] As described above, embodiments of this disclosure include the following disclosures.

[0035] (Composition 1) A roller pump (1) capable of transporting liquid inside a flexible tube (2) by attaching the flexible tube (2), Bottom (10) and A shaft portion (20) that is rotatable while being inserted through a through hole (11) formed in the bottom portion (10), A roller support portion (30) is attached to the shaft portion (20) and is spaced apart from the bottom portion (10) while facing the bottom portion (10) in the axial direction (A) of the shaft portion (20), A plurality of pressure rollers (40) are attached to the roller support portion (30) and arranged in the circumferential direction of the shaft portion (20) when viewed from the axial direction (A), The device includes a ring-shaped sealing member (50) that is positioned between the roller support portion (30) and the bottom portion (10), and is inserted into the shaft portion (20) so as to be in contact with them, and capable of closing the gap between the through hole (11) and the shaft portion (20), The bottom portion (10) is A roller pump (1) that accommodates at least a portion of the sealing member (50) and has an enlarged diameter portion (15) in which the inner circumferential surface (151) expands as it approaches the direction toward the roller support portion (30) in the axial direction (A).

[0036] (Configuration 2) The bottom portion (10) is The present invention further has a smooth planar portion (16) located on the through-hole (11) side of the enlarged diameter portion (15) when viewed from the axial direction (A), The enlarged diameter portion (15) is located at a distance from the sealing member (50), The roller pump (1) according to configuration 1, wherein the planar portion (16) is positioned to slide in contact with the sealing member (50) which rotates in conjunction with the rotation of the shaft portion (20).

[0037] (Composition 3) The axial direction (A) is inclined with respect to the vertical direction (Y), The roller pump (1) according to configuration 1 or configuration 2, wherein the lowest portion (151U) of the inner circumferential surface (151) of the enlarged diameter portion (15) is inclined to be located downward as it approaches the roller support portion (30).

[0038] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended. [Explanation of Symbols]

[0039] 1 Roller pump, 2 Tube, 10 Bottom, 11 Through hole, 15 Enlarged diameter section, 151 Inner circumferential surface, 151U section, 16 Flat section, 20 Shaft section, 30 Roller support section, 31 Roller support member, 311 Through hole, 32 Mounting member, 40 Pressing roller, 45 Stator, 50 Seal member, 51 Main body section, 511 Contact surface section, 52 Hinge section, 53 Lip section, 531 Tip, 100 Medical device.

Claims

1. A roller pump capable of transporting liquid inside a flexible tube by attaching the tube, The bottom and, A shaft portion that is rotatable while being inserted into a through hole formed in the bottom, A roller support portion is attached to the shaft portion and is spaced apart from the bottom portion, and faces the bottom portion in the axial direction of the shaft portion, A plurality of pressing rollers are attached to the roller support portion and arranged in the circumferential direction of the shaft portion when viewed from the axial direction, A ring-shaped sealing member is provided, which is positioned between the roller support portion and the bottom portion and inserted through the shaft portion so as to be in contact with them, and which can close the gap between the through hole and the shaft portion. The bottom is, While housing at least a portion of the sealing member, it has an enlarged diameter portion in which the inner circumferential surface widens as it approaches the direction toward the roller support portion in the axial direction, The aforementioned axial direction is inclined with respect to the vertical direction, A roller pump in which the lowest part of the inner circumferential surface of the enlarged diameter portion is inclined to be located downward as it approaches the roller support portion.

2. The bottom is, It further has a smooth flat portion located on the through-hole side of the enlarged diameter portion when viewed from the axial direction, The enlarged diameter portion is positioned at a distance from the sealing member, The roller pump according to claim 1, wherein the planar portion is positioned to slide in contact with the sealing member which rotates in conjunction with the rotation of the shaft portion.

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