JP7422729B2 - pump equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a pump device for flowing fluid.

In a heart-lung machine that flows a patient's blood (fluid), a pump device is used as a power source for blood circulation. For example, Japanese Patent Laid-Open No. 2012-21413 discloses a centrifugal pump device that rotates an impeller provided in a housing, draws blood into the housing by centrifugal force accompanying this rotation, and discharges blood from the housing. has been done.

The pump device disclosed in Japanese Unexamined Patent Publication No. 2012-21413 forms a magnetic coupling between a motor chamber and an impeller, and rotates the impeller while attracting a magnet (permanent magnet) of the impeller downward. Further, this pump device includes magnets at the upper part of the housing and at the upper part of the impeller (on the opposite side from where the magnetic coupling is formed). As a result, attractive forces of the magnets are generated above and below the impeller, and the impeller rotates in a balanced state near the approximate center of the blood chamber.

By the way, in this type of pump device, when blood flows out from the outflow port side in the housing, the negative pressure of the blood near the outflow port increases. Therefore, when the impeller rotates, the impeller itself is inclined such that the impeller itself near the outlet side is lowered, while the impeller itself on the opposite side of the rotation axis from the outlet is higher. Thus, tilting the impeller may adversely affect blood flow.

In particular, in a pump device that employs a thin bearing portion that contacts the impeller, the posture of the impeller easily tilts when affected by a blood pressure difference. If the impeller continues to rotate while being tilted, a load will continue to be applied to the bearing portion, causing damage (that is, reducing the durability of the pump device).

The present invention has been made in connection with the above-mentioned pump device technology, and provides a pump device that allows fluid to flow well and has increased durability by rotating an impeller in a stable posture. The purpose is to provide.

In order to achieve the above object, one aspect of the present invention is a pump device including an impeller, an internal space accommodating the impeller, and a housing having a bearing portion that rotatably supports the impeller. , the housing has a fixed-side repulsion magnet disposed within a wall of the housing so as to orbit the internal space, and the impeller is a repulsion mechanism that generates a repulsion force between the impeller and the fixed-side repulsion magnet. the impeller has a fin portion and a cylindrical portion protruding from an outer peripheral portion of the fin portion in the axial direction of the impeller; The central portion of the cylindrical portion is pivotally supported, and the inner space is formed between a side circumferential surface of the cylindrical portion and an opposing surface of the housing opposite to the lateral circumferential surface of the cylindrical portion , when the impeller rotates. A dynamic pressure bearing is formed that generates dynamic pressure in the radial direction by flowing fluid.

The above pump device can rotate the impeller without contacting the housing by forming a dynamic pressure bearing that generates dynamic pressure in the radial direction between the side peripheral surface of the impeller and the opposing surface of the housing. Furthermore, since the fixed side repulsion magnet and the movable side repulsion magnet constitute the repulsion mechanism, it becomes possible to pivotally support the impeller at two locations, the dynamic pressure bearing and the repulsion mechanism. Thereby, the pump device can flow the fluid well, suppress the load applied to the bearing portion when the impeller rotates, and improve durability.

1 is a perspective view showing the overall configuration of a pump device according to a first embodiment of the present invention. FIG. 2 is a sectional view taken along line II-II in FIG. 1 showing a separated state of the pump body and drive device of the pump device. 3 is a sectional view taken along line III-III in FIG. 2. FIG. FIG. 3 is a side sectional view showing the main parts of the pump device. FIG. 5A is an enlarged side sectional view showing the sheath and bearing portion of the impeller. FIG. 5B is a side sectional view showing the floating state of the sheath when the impeller rotates. FIG. 6A is a sectional view taken along the line VIA-VIA in FIG. 4 showing the magnetic coupling mechanism of the driving magnet and the driven magnet. FIG. 6B is a cross-sectional view taken along the line VIB-VIB in FIG. 4 showing the repulsion mechanism of the fixed-side repulsion magnet and the movable-side repulsion magnet. FIG. 3 is a side cross-sectional view showing an enlarged view of the impeller and the hydrodynamic bearing of the housing. FIG. 3 is a perspective view of a fixed-side repulsion magnet viewed from below. FIG. 3 is a side cross-sectional view showing the flow of blood in the pump device when the impeller is rotated. FIG. 7 is a side cross-sectional view showing main parts of a pump device according to a second embodiment. It is a side sectional view showing the principal part of the pump device concerning a 3rd embodiment. It is a side sectional view showing the principal part of the pump device concerning a 4th embodiment. It is a side sectional view showing the principal part of the pump device concerning a 5th embodiment. FIG. 14A is a side sectional view showing main parts of a pump device according to a sixth embodiment. FIG. 14B is a side sectional view showing another form of the hollow portion of the impeller in the pump device according to the sixth embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[First embodiment]
The pump device 10A according to the first embodiment of the present invention is an artificial heart-lung device 12 that assists the patient's cardiopulmonary function (or replaces the heart-lung function), and removes the patient's blood from the body and sends the blood into the body. Used as a power source. As shown in FIG. 1, the pump device 10A is configured as a centrifugal pump that has an impeller 14 therein and causes fluid to flow by centrifugal force caused by rotation of the impeller 14.

The heart-lung machine 12 connects a blood removal tube 16 and a blood supply tube 18 to a pump device 10A to form a circulation circuit that circulates blood between the patient and the patient. The blood removal tube 16 has a blood removal lumen 16a inside. When the distal end opening of the blood removal tube 16 is placed in a suitable biological organ (for example, the left ventricle of the heart), the pump device 10A sucks the patient's blood through the blood removal lumen 16a. The blood feeding tube 18 has a blood feeding lumen 18a inside. When the distal opening of the blood feeding tube 18 is placed in a suitable biological organ (for example, the subclavian artery), the pump device 10A sends blood to the patient through the blood feeding lumen 18a. The heart-lung machine 12 may have a configuration in which, in addition to the pump device 10A, a reservoir, an artificial lung, etc. (both not shown) are connected to a midway position of the circulation circuit (the blood removal tube 16 and the blood feeding tube 18). Thereby, the heart-lung machine 12 removes foreign substances and oxygenates the blood that has been drained outside the body, and returns this blood to the patient's body.

As shown in FIG. 2, the pump device 10A includes a pump body 20 that houses the impeller 14, a drive device 22 that rotates the impeller 14, and a controller 24 that controls the drive of the drive device 22. Equipped with The housing 26 of the pump device 10A is made of a resin material or the like, and includes a main body housing 28 that forms the appearance of the pump body 20 and a drive side housing 30 that forms the appearance of the drive device 22.

The main body side housing 28 and the drive side housing 30 are configured to be detachable, and can transmit the driving force of the drive device 22 to the impeller 14 of the pump main body 20 by assembling each other during use. After use, the pump body 20 is removed from the drive device 22 and discarded. That is, the pump main body 20 is constructed as a disposable type that can be replaced and discarded or sterilized after each use. On the other hand, the drive device 22 is configured as a reusable type, and a new pump body 20 is attached to operate the impeller 14 of this pump body 20 at the next opportunity of use.

The main body housing 28 of the pump main body 20 rotatably accommodates the impeller 14 and has an internal space 32 through which blood flows in and out. The main body housing 28 has a generally conical upper portion and a generally cylindrical lower portion.

A blood inflow port 34 connected to the blood removal tube 16 is provided in the upper ceiling and center of the main body housing 28 . An inflow path 34 a communicating with the internal space 32 is provided inside the blood inflow port 34 . The inflow path 34a communicates with an opening 34a1 provided at the protruding end of the blood inflow port 34, and also communicates with an inflow port 34a2 provided at the boundary with the internal space 32.

Further, a blood outflow port 36 connected to the blood feeding tube 18 is provided on the generally cylindrical upper side of the main body housing 28 . As shown in FIG. 3, the blood outflow port 36 protrudes tangentially from the generally cylindrical outer peripheral wall 40. As shown in FIG. An outflow path 36a communicating with the internal space 32 is provided inside the blood outflow port 36. The outflow path 36a communicates with an opening 36a1 provided at the protruding end of the blood outflow port 36, and also communicates with an outflow port 36a2 provided at the boundary with the internal space 32.

As shown in FIG. 4, the internal space 32 is formed in a shape corresponding to the outer shape of the main body housing 28. As shown in FIG. The fin portion 60 of the impeller 14 is arranged on the upper side of the internal space 32 (hereinafter referred to as upper space 32a). The upper space 32a is constituted by the inner surface of the conical portion of the main body side housing 28 and the inner surface of the upper portion of the cylindrical portion. Further, the lower central portion of the upper space 32a is constituted by a shaft-shaped portion 38 that protrudes toward the inlet 34a2 of the blood inflow port 34.

The substantially cylindrical portion of the main body housing 28 includes a cylindrical outer circumferential wall 40, a bottom wall 42 constituting the lower end of the main body housing 28, and the above-mentioned shaft-shaped portion 38 provided inside the outer circumferential wall 40. including. As a result, the lower side of the internal space 32 (hereinafter referred to as lower space 32b) is formed into a cylindrical shape, and rotatably accommodates a driven rotation structure 62 of the impeller 14, which will be described later.

A fixed side repulsion magnet 44 is installed near the bottom of the outer peripheral wall 40. The fixed-side repulsion magnet 44 forms a repulsion mechanism 84A that repels each other with a movable-side repulsion magnet 76 (described later) provided on the impeller 14. The configuration of the fixed-side repulsion magnet 44 will be described in detail later.

The shaft portion 38 has a cylindrical inner peripheral wall 48 and a chevron portion 50 connected to the upper end of the inner peripheral wall 48, and has an insertion hole 52 formed inside the inner peripheral wall 48 and the chevron portion 50. . The lower space 32b goes around the side of this insertion hole 52. The insertion hole 52 is open on the lower end side, and the drive side housing 30 is inserted when the pump body 20 and the drive device 22 are assembled.

The chevron portion 50 of the shaft portion 38 has a conical shape, and a bearing portion 54 that rotatably supports the impeller 14 is provided at the center thereof. The bearing section 54 is made of a metal material and has a base section 56 fixed to the chevron section 50 and a pin section 58 that projects upward from the base section 56 and is formed thinner than the base section 56 . When the bearing part 54 is extended, its axis overlaps with the center of the inlet 34a2 of the blood inflow port 34, and this axis also coincides with the axis St of the main body side housing 28 (shaft-shaped part 38, outer peripheral wall 40). Match. That is, the axial center Si of the impeller 14 supported by the bearing portion 54 is ideally the same as the axial center St of the main body side housing 28.

As shown in FIGS. 1 and 4, the impeller 14 is formed in a cylindrical shape and is housed within the main body housing 28 across both the upper space 32a and the lower space 32b. The impeller 14 has a fin section 60 at the top and a driven rotation structure section 62 at the bottom. The inner side of the fin portion 60 and the driven rotation structure portion 62 is a space portion 64 in which the shaft portion 38 is arranged.

The fin portion 60 includes a conical wall portion 66 that continues to the upper end of the driven rotation structure portion 62, a sheath 68 that is rotatably supported by the bearing portion 54 at the center of the conical wall portion 66, and projects upward from the upper surface of the conical wall portion 66. The upper space 32a is provided with a plurality of protruding wall portions 70 to generate centrifugal force in the upper space 32a during rotation. A space surrounded by the conical wall portion 66 and the pair of protruding walls 70 serves as a flow path 60a through which blood flows, and the flow path 60a is open at the top. Note that the shape of the fin portion 60 is not limited to this, and for example, a shroud (not shown) may be provided above the protruding wall portion 70 to cover the flow path 60a.

As shown in FIGS. 5A and 5B, the conical wall portion 66 is sloped more steeply than the chevron portion 50 of the main body side housing 28, and its upper surface is curved in an arcuate shape. Therefore, a gap (hereinafter referred to as upper gap 66a) is formed between the chevron portion 50 and the conical wall portion 66. The conical wall portion 66 around the sheath 68 is provided with a plurality (three) of washout holes 67 (see also FIG. 3) passing through the conical wall portion 66. The washout hole 67 communicates the upper space 32a above the conical wall portion 66 with the upper gap 66a to allow blood to flow.

The sheath 68 is formed in a conical shape that smoothly extends to the conical wall portion 66 and slopes upward more than the conical wall portion 66, so that the sheath 68 protrudes above the protruding wall portion 70. The lower side of the sheath 68 also has a tapered protrusion 69 that protrudes in a tapered shape toward a portion (base 56) where the pin portion 58 is fixed to the main body housing 28. The tapered protrusion 69 has its tapered end 69a in contact with the upper surface of the base 56 of the bearing 54 in a narrow range when the impeller 14 stops rotating. When the impeller 14 rotates, the tapered end 69a floats from the upper surface of the base 56.

A hollow portion 72 is formed in the center of the sheath 68 along the axial direction of the sheath 68 . The pin portion 58 is inserted into the hollow portion 72, and the upper space 32a on one side of the impeller 14 communicates with the upper gap 66a on the side opposite to the one side.

The hollow part 72 includes a first hollow 72a into which the pin part 58 is inserted throughout the extending direction, and a second hollow 72b that communicates with the upper end of the first hollow 72a and has a larger cross-sectional area than the first hollow 72a. have That is, the pin portion 58 protrudes above the first hollow 72a when the impeller 14 stops rotating.

The diameter of the first hollow 72a is designed to be slightly larger than the diameter of the pin portion 58 of the bearing portion 54. Therefore, a communication gap 59 is formed between the outer circumferential surface 58a of the pin portion 58 and the inner circumferential surface 68a of the sheath 68 (impeller 14) that constitutes the first hollow 72a. Specifically, it is preferable that the diameter of the first hollow 72a is set in the range of 0.8 mm to 1 mm, while the diameter of the pin portion 58 is set in the range of 0.7 mm to 0.9 mm. Further, the distance between the outer circumferential surface 58a of the pin portion 58 and the inner circumferential surface 68a of the impeller 14 is preferably set in a range of 0.1 mm to 0.2 mm. This allows blood to flow smoothly through the communication gap 59.

The communication gap 59 of the first hollow 72a communicates the upper gap 66a inside the sheath 68 with the second hollow 72b. Further, the second hollow 72b extends to the opening at the upper end of the sheath 68. Therefore, when the impeller 14 rotates, the hollow portion 72 forms a sliding bearing between the outer circumferential surface 58a of the pin portion 58 and the inner circumferential surface 68a of the sheath 68, allowing blood to flow.

Note that the configurations of the bearing portion 54 and the hollow portion 72 of the impeller 14 are not limited to those described above, and may take various configurations. For example, at least one of the inner circumferential surface 68a of the impeller 14 and the outer circumferential surface 58a of the pin portion 58 may be coated with a hydrophilic coating. This makes it easier for blood to enter the hollow portion 72 (communication gap 59).

As shown in FIGS. 3 and 4, the plurality of protruding walls 70 extend from a position near the outside of the washout hole 67 to near the outer edge of the conical wall part 66. Each protruding wall portion 70 extends slightly curved in plan view, and thereby, when the impeller 14 rotates, the blood that has entered the flow path 60a smoothly flows outward in the radial direction.

The driven rotation structure portion 62 of the impeller 14 is continuous with the conical wall portion 66 of the fin portion 60 and is formed into a cylindrical shape having a predetermined thickness in the radial direction of the impeller 14 . In a plan view of the impeller 14, the diameter of the driven rotation structure 62 is set, for example, in a range of 20 mm to 50 mm. In this embodiment, an impeller 14 having a diameter of 30 mm is used.

The driven rotation structure 62 faces a side circumferential surface 63 (inner circumferential surface 63a, outer circumferential surface 63b) extending parallel to the axis Si of the impeller 14 and the bottom wall 42 of the main body side housing 28 in a non-contact manner. and a lower end surface. A driven magnet 74 and a movable repulsion magnet 76 are installed inside the driven rotation structure 62 .

The driven magnet 74 is arranged at the same height as the drive magnet 92 of the drive device 22 when the pump body 20 and the drive device 22 are attached, and forms a magnetic coupling mechanism 104 with the drive magnet 92 . More specifically, the driven magnet 74 is fixed on the upper side of the driven rotation structure 62 toward the radially inner side (inner peripheral surface 63a). Further, the axial length (thickness) of the driven magnet 74 parallel to the axis is designed to be approximately the same as the axial length of the driving magnet 92 .

As shown in FIG. 6A, the driven magnet 74 according to this embodiment is configured as a driven multi-pole magnetized ring magnet 75 that revolves around the axis Si of the impeller 14 with a constant radius R1. The driven side multi-polar magnetized ring magnet 75 is magnetized so that a plurality of N poles and S poles are alternately arranged along the circumferential direction. Although the number of polarities of the driven side multipolar magnetized ring magnet 75 is set to six (that is, three opposite poles) in FIG. 6A, it is not limited to this.

Examples of the material constituting the driven magnet 74 (driven side multipolar magnetized ring magnet 75) include hard magnetic materials such as alnico, ferrite, and neodymium. Note that the driven magnet 74 is not limited to being configured as a multipolar magnetized ring, but may be formed into a ring shape by arranging a plurality of arc-shaped magnets having opposite poles (N pole, S pole) in the circumferential direction. You can leave it there.

As shown in FIGS. 4 and 6B, the movable repulsion magnet 76 is fixed on the lower side of the driven rotation structure 62 toward the radially outer side (the outer circumferential wall 40 of the main body housing 28). That is, the radius R2 of the movable repulsive magnet 76 is longer than the radius R1 of the driven magnet 74. Furthermore, the driven magnet 74 and the movable repulsion magnet 76 are vertically separated from each other by a large distance within the driven rotation structure 62 so that the influence of mutual magnetic fields is suppressed.

The movable side repulsive magnet 76 is configured as a movable side monopolar magnetized ring magnet 77 that orbits at a position a predetermined distance away from the axis Si of the impeller 14 . The movable side inner and outer circumferential unipolar magnetized ring magnet 77 has a first polarity (S pole in FIG. 4) over the entire outer circumference, and has a second polarity opposite to the first polarity over the entire inner circumference. It is a ring body that is magnetized to have a N pole (in FIG. 4, N pole). That is, the outer peripheral surface of the movable-side repulsive magnet 76 is a movable-side repulsive surface 77a in which the first polarity is always present along the circumferential direction.

The material constituting the movable side repulsive magnet 76 (the movable side inner and outer circumferential unipolar magnetized ring magnet 77) is not particularly limited, and the materials mentioned for the driven magnet 74 can be applied. Note that the movable side repulsion magnet 76 is not limited to being configured as a unipolar magnetized ring, but can be formed into a ring shape by arranging a plurality of arc-shaped magnets having opposite poles on the inner circumference and the outer circumference in the circumferential direction. may be formed.

Further, as shown in FIG. 7, when the impeller 14 rotates, the pump device 10A has an inner circumferential surface 63a of the driven rotation structure 62 and a main body side housing 28 (shaft-like portion 38) facing the inner circumferential surface 63a. A dynamic pressure bearing 78 is formed between the inner circumferential wall 48 and the opposing surface 48a. Specifically, the first gap 80 formed between the inner circumferential surface 63a and the opposing surface 48a is formed between the outer circumferential surface 63b of the driven rotation structure 62 and the inner circumferential surface 40a of the outer circumferential wall 40 of the main body side housing 28. The second gap 82 is formed smaller than the second gap 82 formed between the two gaps.

The interval I1 of the first gap 80 depends on the viscosity of the flowing fluid, but is set in the range of 0.05 mm to 0.2 mm when the fluid is blood, for example. The inner circumferential surface 63a and the opposing surface 48a are parallel to the axes Si and St of the impeller 14 and the shaft portion 38, and therefore the first gap 80 is formed over the range where the inner circumferential surface 63a and the opposing surface 48a face each other. Ru. The area in the axial direction where the inner circumferential surface 63a and the facing surface 48a face each other along the axis Si of the impeller 14 is preferably set in a range of 10 mm to 100 mm.

Since the first gap 80 is set to a dimension within the above range, when the impeller 14 rotates, buoyancy (dynamic pressure) is generated by the blood flowing between the inner circumferential surface 63a and the opposing surface 48a. do. In other words, the hydrodynamic bearing 78 functions as a journal bearing that supports a load in a radial direction (radial load) perpendicular to the axis Si of the impeller 14. For example, the dynamic pressure bearing 78 ensures that the impeller 14 does not come into contact with the shaft portion 38 due to blood flowing through the first gap 80 when the impeller 14 rotates at 3000 rpm or more. On the other hand, the interval I2 of the second gap 82 is set, for example, in a range of 0.8 mm to 1.2 mm.

In this way, the impeller 14 has a portion in the sheath 68 that is pivotally supported by the bearing portion 54 and a portion in the driven rotation structure portion 62 that is pivotally supported by the shaft-shaped portion 38. This reliably prevents the axial center Si of the impeller 14 from tilting with respect to the axial center St of the main body side housing 28 (shaft-like portion 38) when the impeller 14 rotates.

The fixed side repulsion magnet 44 is installed on the outer circumferential wall 40 of the impeller 14 facing the driven rotation structure 62 as described above. As shown in FIGS. 4 and 6B, the fixed repulsion magnet 44 is located radially outward and slightly above the movable repulsion magnet 76. That is, the fixed-side repulsive magnet 44 is disposed at the farthest position from the axis St of the main body-side housing 28 (outer peripheral wall 40). The fixed-side repulsion magnet 44 is configured as a fixed-side magnetized ring magnet 45 with unipolar inner and outer peripheries that revolves around the axis St of the main body housing 28 at the longest radius R3.

The fixed side inner and outer circumferential monopolar magnetized ring magnet 45 has a first polarity (N pole in FIG. 4) over the entire outer circumference, and has a second polarity opposite to the first polarity over the entire inner circumference. It is a ring body that is magnetized to have an S pole (in FIG. 4, S pole). That is, the inner circumferential surface of the fixed-side repulsion magnet 44 is a fixed-side repulsion surface 45a in which the same polarity as the movable-side repulsion magnet 76 always exists along the circumferential direction.

The material constituting the stationary repulsion magnet 44 is not particularly limited, and the materials listed above for the driven magnet 74 may be used. Note that the fixed side repulsive magnet 44 is not limited to being configured as a unipolar magnetized ring, but can be formed into a ring shape by arranging a plurality of arc-shaped magnets having opposite poles on the inner circumference and the outer circumference in the circumferential direction. may be formed.

The repulsion mechanism 84A composed of the movable side repulsion magnet 76 and the fixed side repulsion magnet 44 has a repulsion force ( repulsion). In other words, the impeller 14 is separated from the inlet 34a2 and pressed against the bearing portion 54 by the repulsion mechanism 84A, and receives a force that presses the entire circumferential direction inward in the radial direction. The repulsive force of the repulsive mechanism 84A is set to be larger than the attractive force of the magnetic coupling mechanism 104.

The repulsion mechanism 84A according to this embodiment generates different repulsion forces in the circumferential direction. Specifically, as shown in FIG. 8, the fixed-side repulsive magnet 44 includes a main body portion 46 that extends annularly with a constant axial length along the axis Sf of the fixed-side repulsive magnet 44; It has a convex portion 47 that protrudes downward from one part. The convex portion 47 is disposed on the opposite side of the axis Sf from the location where the outflow port 36a2 of the blood outflow port 36 communicating with the internal space 32 is formed (see also FIG. 3).

Here, the vicinity of the outflow port 36a2 of the blood outflow port 36 becomes the outflow side of the internal space 32 where blood flows out from the internal space 32 to the blood outflow port 36. As mentioned above, the pressure on the outflow side becomes lower than that on other parts due to blood flowing out. In particular, if a large amount of blood flows into the internal space 32, a large imbalance will occur in the pressure distribution in the internal space 32. In conventional pump devices, as the pressure decreases on the outflow side, the outflow side of the rotating impeller is pushed downward, while the side opposite to the outflow side across the axis Si rises upward. As a result, the rotation of the impeller becomes unstable.

On the other hand, as shown in FIGS. 3, 4, and 8, in the pump device 10A, the convex portion 47 of the stationary repulsion magnet 44 installed in the main body housing 28 is placed on the outflow side ( It is arranged on the opposite side (hereinafter referred to as a second area 88) to the first area 86 (hereinafter referred to as a first area 86). The range of the first region 86 and the second region 88 is determined by drawing the imaginary line L connecting the outlet 36a2, the impeller 14, and the axes Si and St of the main body housing 28, and the fixed side repulsion magnet 44 and the imaginary line L. This refers to the range extending from the intersection to approximately 1/10 of the total circumferential length on both sides in the circumferential direction.

As a result, the convex portion 47 of the fixed repulsion magnet 44 in the second region 88 is The second distance D2 from the rotating movable repulsion magnet 76 is shorter. Therefore, the repulsive force of the repulsive mechanism 84Ab in the peripheral part of the second region 88 is larger than the repulsive force of the repulsive mechanism 84Aa in the peripheral part of the first region 86. By the repulsion mechanism 84Ab, the second region 88 of the impeller 14 is pushed downward more strongly than other parts (parts of the main body part 46 where the convex part 47 does not exist), so that the impeller 14 can be in an inclined posture. suppressed.

The amount by which the convex portion 47 protrudes from the main body portion 46 may be appropriately designed in consideration of the repulsive force of the repulsive mechanism 84Ab against the repulsive mechanism 84Aa. For example, the thickness of the convex portion 47 is preferably set to 0.1 to 1 times the thickness of the main body portion 46 (that is, the thickness of the fixed side repulsive magnet 44 in the second region 88 is (The thickness is set to 1.1 to 2 times the thickness of the side repelling magnet 44).

Further, the arc length of the convex portion 47 of the fixed side repulsion magnet 44 is not particularly limited, but is approximately 1/4 to 1/8 of the circumference of the fixed side repulsion magnet 44 formed in an annular shape. Good to have. Further, in a side cross-sectional view of the pump device 10A, the lower end of the convex portion 47 is a movable side repulsion when the impeller 14 is horizontal (the state in which the axis Si of the impeller 14 is aligned with the axis St of the shaft portion 38). It is arranged below the upper end of the magnet 76. On the other hand, the lower end of the main body portion 46 is arranged above the upper end of the movable repulsion magnet 76 when the impeller 14 is horizontal.

As shown in FIGS. 2 and 4, the drive device 22 of the pump device 10A includes a drive-side housing 30 and a motor mechanism 90 housed within the drive-side housing 30. Further, the drive device 22 includes a drive magnet 92 that is provided on the motor mechanism 90 and is attracted to the impeller 14 .

The drive-side housing 30 includes an upper housing 30a having a cylindrical mounting groove 94 on the upper surface into which the pump body 20 (main housing 28) is mounted, and a lower housing 30b connected to the lower side of the upper housing 30a. It is made up of. Further, a radially inner portion of the drive-side housing 30 than the mounting groove 94 is a central convex portion 96 that is inserted into the insertion hole 52 of the main body-side housing 28 .

The main body side housing 28 of the pump main body 20 and the drive side housing 30 of the drive device 22 have an engagement structure 98 that can be detachably positioned and fixed to each other. In this embodiment, the engagement structure 98 allows both devices to be connected by inserting the central protrusion 96 into the insertion hole 52 of the main body housing 28 and inserting the bottom wall 42 of the main body housing 28 into the mounting groove 94. engage. Note that it goes without saying that the engagement structure 98 may adopt various configurations.

A motor main body 90a of the motor mechanism 90 is provided inside the lower housing 30b, and the motor main body 90a rotates the shaft portion 100 at an appropriate rotation speed under the control of the control section 24. The shaft portion 100 protrudes from the motor body 90a and is inserted into a protrusion space within the central convex portion 96, and is provided at its upper end with a disk-shaped rotating portion 102 that protrudes radially outward. When the pump body 20 and the drive device 22 are attached, the axial center Si of the impeller 14 and the axial center Ss of the shaft portion 100 overlap with each other.

The rotating part 102 has a holding part 102a whose radially outer peripheral surface is partially cut out in a side cross-sectional view, and the driving magnet 92 is held in the holding part 102a. That is, the rotating part 102 arranges the driving magnet 92 at a predetermined radial position and height position (inside the central convex part 96) within the driving side housing 30, and rotates the driving magnet 92 as the shaft part 100 rotates. Rotate.

As shown in FIG. 6A, the drive magnet 92 according to the present embodiment is configured as a drive-side multipolar magnetized ring magnet 93 that revolves around the axis Ss of the shaft portion 100 with a radius R4 shorter than that of the driven magnet 74. There is. The drive side multi-polar magnetized ring magnet 93, like the driven magnet 74, is magnetized so that a plurality of (six) polarities (N pole, S pole) are arranged alternately along the circumferential direction. The drive magnet 92 forms a magnetic coupling mechanism 104 between the driven magnet 74 and the driven magnet 74 by being disposed inside the driven magnet 74 and facing the driven magnet 74 when the pump body 20 and the drive device 22 are attached.

The material composing the drive magnet 92 may be selected from the materials listed for the driven magnet 74 as appropriate. Further, the drive magnet 92 is not limited to being configured as a multi-polar magnetized ring, but may be formed into a ring shape by arranging a plurality of arc-shaped magnets having opposite poles (N pole, S pole) in the circumferential direction. You can leave it there.

Returning to FIG. 2, the controller 24 of the pump device 10A is constituted by a well-known computer having an input/output interface, a memory, and a processor (not shown), and controls the drive of the motor mechanism 90. A monitor, a speaker, operation buttons, etc. (not shown) are provided on the outer surface of the control unit 24, and a user such as a doctor or a nurse sets the drive content of the pump device 10A by operating the operation buttons. The control unit 24 controls the supply of battery power based on the user's setting information, and rotates the shaft unit 100 within a range of, for example, 0 to 10,000 rpm.

The pump device 10A according to this embodiment is basically configured as described above, and its operation will be described below.

A heart-lung machine 12 including a pump device 10A is constructed for a patient to assist with cardiopulmonary function. When constructing the heart-lung machine 12, the user connects the blood removal tube 16 to the blood inflow port 34 of the pump main body 20, and connects the blood feeding tube 18 to the blood outflow port 36 of the pump main body 20. Here, the movable side repulsion magnet 76 and the fixed side repulsion magnet 44 of the pump body 20 constitute a repulsion mechanism 84A because the movable side repulsion surface 77a and the fixed side repulsion surface 45a of the same polarity are close to each other. are doing. Therefore, the impeller 14 is pressed against the bottom wall 42 side of the main body housing 28, and the sheath 68 of the impeller 14 can be prevented from coming off from the bearing part 54 when the pump main body 20 is being carried. Then, as shown in FIG. 2, the pump body 20 is attached to the drive device 22 to assemble the pump device 10A. At this time, the engagement structure 98 positions and fixes the pump body 20 and the drive device 22 with respect to each other.

As shown in FIGS. 4 and 6A, in the attached state, the driven magnet 74 and the driving magnet 92 are arranged at the same height position. The radially adjacent driven magnet 74 (driven side multipolar magnetized ring magnet 75) and drive magnet 92 (drive side multipolar magnetized ring magnet 93) have different polarities facing each other to form a magnetic coupling mechanism 104. form. That is, the driven side multi-polar magnetized ring magnet 75 and the driving side multi-polar magnetized ring magnet 93 generate a magnetic coupling force (magnetic coupling force), and can transmit the rotational force of the rotating part 102 to the impeller 14. do.

Therefore, when the motor mechanism 90 of the drive device 22 rotates the shaft portion 100, the driven rotation structure portion 62 rotates with it, and the impeller 14 can be rotated within the main body housing 28. The fin portion 60 rotating within the upper space 32a generates centrifugal force to cause blood to flow.

As shown in FIG. 9, when the impeller 14 rotates, blood that has flowed into the internal space 32 from the inflow path 34a flows from the radially outer side of the upper space 32a into the lower space 32b. When the blood flows downward through the second gap 82 between the inner circumferential surface 40a of the outer circumferential wall 40 and the outer circumferential surface 63b of the driven rotation structure 62, it heads radially inward at the lower end side of the lower space 32b. Further, the blood flows upward through the first gap 80 between the opposing surface 48a of the shaft-shaped portion 38 and the inner circumferential surface 63a of the driven rotation structure 62, and reaches the upper gap 66a.

A portion of the blood that has flowed into the upper gap 66a passes through the plurality of washout holes 67 of the impeller 14 and moves to the upper space 32a (see FIG. 5B). Furthermore, the other part of the blood moves to the upper space 32a through the hollow part 72 (first hollow 72a, second hollow 72b) of the sheath 68 floating from the bearing part 54. In other words, by keeping the bearing portion 54 and the sheath 68 in a non-contact state as much as possible during rotation, generation of frictional heat can be suppressed and blood can flow favorably.

In addition, the movable side repulsion magnet 76 (movable side inner and outer periphery unipolar magnetized ring magnets 77) and fixed side repulsion magnet 44 (fixed side inner and outer periphery unipolar magnetized ring magnets 45) of the pump body 20 are uniformly distributed throughout the circumferential direction. Apply a repulsive force to the object. Furthermore, even if the impeller 14 tries to float toward the inlet port 34a2 due to the blood flowing around to the lower side of the impeller 14 when the impeller 14 rotates, it will receive the repulsive force of the repulsion mechanism 84A, so that the floating of the impeller 14 can be reliably suppressed. can.

Particularly, when the axis Si of the impeller 14 is aligned with the axis St of the main body housing 28, the fixed side repulsion magnet 44 having the convex portion 47 and the movable side repulsion magnet 76 move to the second area 88 of the rotating impeller 14. applies a strong repulsive force to Therefore, even if the pressure on the outflow port 36a2 side of the internal space 32 becomes low due to the outflow of blood from the outflow path 36a, the repulsion mechanism 84Ab suppresses the rise (inclination) of the impeller 14 on the second region 88 side. Therefore, the pump device 10A can stably rotate the impeller 14 while maintaining a non-contact state between the impeller 14 and the main body housing 28, thereby allowing blood to flow favorably.

Further, the first gap 80 between the opposing surface 48a of the shaft-shaped portion 38 of the main body side housing 28 and the inner circumferential surface 63a of the impeller 14 receives a radial load while the impeller 14 is rotating (for example, at 3000 rpm or more). A hydrodynamic bearing 78 is formed. This makes it possible to maintain the rotational posture of the impeller 14 more stably, align the axis Si of the impeller 14 with the axis St of the main body housing 28, and reduce the load on the bearing portion 54. Become.

Note that the present invention is not limited to the above-described embodiments, and various modifications can be made in accordance with the gist of the invention. For example, the positional relationship between the magnetic coupling mechanism 104 and the repulsion mechanism 84A is not particularly limited. As an example, the repulsion mechanism 84A may be located above the magnetic coupling mechanism 104, or may be located inside the magnetic coupling mechanism 104 in the radial direction. The fixed side repulsive magnet 44 may be provided not only in the pump body 20 (body side housing 28) but also in the drive device 22 (drive side housing 30).

Further, the means for generating different repulsive forces in the repulsion mechanism 84A is not limited to providing the convex portion 47 on the fixed repulsion magnet 44. For example, the fixed side repulsive magnet 44 is configured by the main body portion 46 without the convex portion 47, and by changing the material of the first region 86 and the material of the second region 88, the magnetic force of the first region 86 is stronger than the magnetic force of the first region 86. The structure may be such that the magnetic force of the two regions 88 is increased. For example, the fixed side repulsion magnet 44 may be configured by the main body portion 46 without the convex portion 47, and a member for suppressing magnetic force may be disposed at a circumferential location other than the second region 88, or the second region A magnetic force inducer such as a soft magnetic material may be arranged at 88 .

The dynamic pressure bearing 78 constituting the journal shaft may be formed in the second gap 82 (between the outer circumferential surface 63b of the impeller 14 and the inner circumferential surface 40a of the outer circumferential wall 40). Further, the dynamic pressure bearing 78 may increase the dynamic pressure by providing a recess (groove, notch, etc.) in either the side circumferential surface 63 of the impeller 14 or the opposing surface 48a of the housing 26. The hydrodynamic bearing 78 is not limited to being formed on the entire side circumferential surface 63 and the opposing surface along the axis Si of the impeller 14, but may be formed near the bottom of the side circumferential surface 63 of the impeller 14, for example. good.

Some examples of other embodiments will be described below. In the following description, elements having the same configuration or the same function as those in the above-described embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[Second embodiment]
As shown in FIG. 10, the pump device 10B according to the second embodiment has an axial center Sf of an annular fixed side repulsion magnet 44 inclined with respect to an axial center St of a main body housing 28 (an axial center Si of the impeller 14). This pump device differs from the pump device 10A described above in that a repulsion mechanism 84B is constituted by a repulsion mechanism 84B. Furthermore, the fixed side repulsion magnet 44 does not include the above-mentioned convex portion 47 but only has an annular main body portion 46, and extends in the circumferential direction in a rectangular shape having a constant size when viewed in cross section.

Specifically, the axis Sf of the fixed-side repulsive magnet 44 is set such that the second region 88 side is lower downwardly than the first region 86 side within the outer peripheral wall 40 (the fixed-side repulsive magnet 44 is lower than the movable-side repulsive magnet 44). (in the direction approaching the magnet 76). For example, the inclination angle of the axis Sf of the stationary repulsion magnet 44 with respect to the axis St of the main body housing 28 is preferably 5° or less, and more preferably set in the range of 0.5° to 3°. It would be good if it were done. By installing the fixed side repulsion magnet 44 at an angle in this way, the second distance D2 between the movable side repulsion magnet 76 on the second region 88 side and the fixed side repulsion magnet 44 can be adjusted so that the movable side repulsion magnet 44 on the first region 86 side The distance is shorter than the first distance D1 between the magnet 76 and the fixed repulsion magnet 44.

In the pump device 10B configured as described above, when the impeller 14 rotates, the repulsive force of the repulsive mechanism 84Bb of the second region 88 is greater than the repulsive force of the repulsive mechanism 84Ba of the first region 86. Therefore, in the pump device 10B, even if the pressure on the outflow side of the internal space 32 becomes low, the axial center Si of the impeller 14 and the axial center St of the main body housing 28 can be stably aligned. Therefore, the pump device 10B can obtain the same effects as the pump device 10A according to the first embodiment. In particular, in this pump device 10B, the structure of the fixed side repulsive magnet 44 is simplified, making it possible to suppress manufacturing costs.

[Third embodiment]
In the pump device 10C according to the third embodiment, as shown in FIG. 11, the repulsion mechanism 84C is configured by offsetting the axis Sf of the annular fixed side repulsion magnet 44 with respect to the axis St of the main body side housing 28. This differs from the above-mentioned pump devices 10A and 10B in that Further, similarly to the second embodiment, the fixed side repulsion magnet 44 does not include a convex portion 47 and only has an annular main body portion 46, and has a rectangular shape with a constant size when viewed in cross section and extends in the circumferential direction. There is.

Specifically, the fixed-side repulsion magnet 44 is arranged so that its axis Sf is shifted toward the first region 86 side with respect to the axis St of the main body-side housing 28. For example, the amount of offset of the axis Sf of the stationary repulsion magnet 44 with respect to the axis St of the main body side housing 28 is preferably 1.5 mm or less, and more preferably set in the range of 0.1 mm to 1 mm. Good. As a result, the fixed-side repulsive surface 45a on the second region 88 side is arranged closer to the inner peripheral surface 40a (internal space 32) in the outer peripheral wall 40 than the fixed-side repulsive surface 45a on the first region 86 side.

By installing the fixed side repulsion magnet 44 in this way, the second distance D2 between the movable side repulsion magnet 76 on the second region 88 side and the fixed side repulsion magnet 44 is also and becomes closer than the first distance D1 of the fixed side repulsive magnet 44. Therefore, in the pump device 10C, when the impeller 14 rotates, the repulsion force of the repulsion mechanism 84Cb of the second region 88 is also larger than the repulsion force of the repulsion mechanism 84Ca of the first region 86. Effects similar to those of the pump devices 10A and 10B can be obtained.

[Fourth embodiment]
As shown in FIG. 12, the pump device 10D according to the fourth embodiment has a dynamic pressure bearing 78 between the inner circumferential surface 63a and the opposing surface 48a of the impeller 14 by increasing the interval I1 of the first gap 80. This differs from the pump devices 10A to 10C in that it has a configuration in which no formation is formed. That is, the pump device 10D can maintain the attitude of the impeller 14 stably by appropriately setting the repulsion forces of the repulsion mechanisms 84A to 84C, even without forming the dynamic pressure bearing 78.

[Fifth embodiment]
As shown in FIG. 13, the pump device 10E according to the fifth embodiment has a configuration in which the fixed side repulsion magnet 44 is configured only with an annular main body portion 46, while the inclination of the impeller 14 is suppressed by a hydrodynamic bearing 78. This differs from the pump devices 10A to 10D in that That is, the fixed side repulsion magnet 44 and the movable side repulsion magnet 76 constitute a repulsion mechanism 84D that exerts an even repulsion force by being spaced apart at equal intervals D' in the circumferential direction. In this way, the pump device 10E stabilizes the posture of the impeller 14 by appropriately applying the dynamic pressure of the dynamic pressure bearing 78, without changing the repulsive force in the circumferential direction of the impeller 14 using the repulsion mechanisms 84A to 84C. It is also possible to maintain

[Sixth embodiment]
As shown in FIG. 14A, the pump device 10F according to the sixth embodiment has the above pump devices 10A to 10E in that a convex portion 106 (wing body) is provided in the hollow portion 72 formed in the sheath 68 of the impeller 14. different from. The convex portion 106 of the hollow portion 72 applies fluid force to the blood flowing in the hollow portion 72 when the impeller 14 rotates, thereby making it possible to make the blood flow more smoothly. Note that the structure that applies fluid force to blood in the hollow portion 72 is not limited to the convex portion 106, but may be a concave portion 108 (groove) as shown in FIG. 14B. For example, by forming the spiral recess 108, blood can flow in the axial direction.

The technical ideas and effects that can be understood from the above-described embodiments will be described below.

The pump devices 10A to 10C, 10E are configured by forming a dynamic pressure bearing 78 that generates dynamic pressure in the radial direction between the side circumferential surface 63 of the impeller 14 and the opposing surface 48a (or inner circumferential surface 40a) of the housing 26. , the impeller 14 can be rotated without contacting the housing 26. Moreover, since the fixed side repulsion magnet 44 and the movable side repulsion magnet 76 constitute the repulsion mechanisms 84A to 84D, the impeller 14 can be pivotally supported at two locations, the dynamic pressure bearing 78 and the repulsion mechanisms 84A to 84D. becomes possible. Thereby, the pump devices 10A to 10C, 10E can flow the fluid well, suppress the load applied to the bearing portion 54 when the impeller 14 rotates, and improve durability.

Further, the fluid is blood, and by setting the interval between the side circumferential surface 63 of the impeller 14 and the opposing surface 48a (or inner circumferential surface 40a) of the housing 26 in the range of 0.05 mm to 0.2 mm, A hydrodynamic bearing 78 is formed. Thereby, in the pump devices 10A to 10C, 10E, the dynamic pressure bearing 78 can be reliably formed without special processing on the side circumferential surface 63 of the impeller 14 or the opposing surface 48a of the housing 26. .

Further, the diameter of the impeller 14 is set in a range of 20 mm to 50 mm, and the dynamic pressure bearing 78 is formed when the impeller 14 rotates at 3000 rpm or more. As a result, the pump devices 10A to 10C, 10E rotatably support the impeller 14 by the bearing portion 54 when the rotation speed of the impeller 14 is low, and when the rotation speed of the impeller 14 increases, the impeller 14 is rotatably supported by the dynamic pressure bearing 78. This allows the impeller 14 to rotate stably.

Further, the area in the axial direction where the side circumferential surface 63 of the impeller 14 and the opposing surface 48a (or inner circumferential surface 40a) of the housing 26 face each other along the axis Si of the impeller 14 is set to a range of 10 mm to 100 mm. be done. Thereby, the hydrodynamic bearing 78 can more stably support the impeller 14 and rotate the impeller 14.

Further, the housing 26 has a shaft portion 38 that is inserted into the cylindrical impeller 14, and the dynamic pressure bearing 78 has an inner circumferential surface 63a of the impeller 14 and an outer circumferential surface (opposed surface 48a) of the shaft portion 38. formed between. As a result, the hydrodynamic bearing 78 can pivotally support the rotation of the impeller 14 inside the impeller 14, further stabilizing the rotational posture of the impeller 14, and suppressing fluid damage (blood hemolysis, etc.). It becomes possible to do so.

Further, the dynamic pressure bearing 78 is formed radially inside the repulsion mechanisms 84A to 84D. As a result, the pump devices 10A to 10C and 10E can guide the fluid that has flowed through the repulsion mechanisms 84A to 84D to the radially inner dynamic pressure bearing 78 and cause the fluid to flow while pivotally supporting the impeller 14. Furthermore, the dynamic pressure bearing 78 can sufficiently exert dynamic pressure.

Claims (6)

impeller and
A pump device comprising: an internal space that accommodates the impeller; and a housing having a bearing that rotatably supports the impeller,
The housing has a fixed-side repulsion magnet disposed within a wall of the housing so as to orbit the internal space,
The impeller has a movable repulsion magnet that forms a repulsion mechanism that generates a repulsion force with the fixed repulsion magnet,
The impeller is
A fin part,
a cylindrical part protruding from an outer peripheral part of the fin part in the axial direction of the impeller;
The bearing part pivotally supports the center part of the fin part,
A dynamic pressure in the radial direction is generated between the side circumferential surface of the cylindrical portion and the opposing surface of the housing that faces the side circumferential surface of the cylindrical portion due to the fluid flowing in the internal space when the impeller rotates. A pump device that forms a dynamic pressure bearing that generates. The pump device according to claim 1,
the fluid is blood;
A pump device, wherein the dynamic pressure bearing is formed by setting a distance between a side circumferential surface of the impeller and a facing surface of the housing to be in a range of 0.05 mm to 0.2 mm. The pump device according to claim 2,
The diameter of the impeller is set in a range of 20 mm to 50 mm,
The dynamic pressure bearing is formed when the impeller rotates at 3000 rpm or more. Pump device. The pump device according to any one of claims 1 to 3,
In the pump device, an axial region where the side peripheral surface of the impeller and the facing surface of the housing face each other along the axis of the impeller is set in a range of 10 mm to 100 mm. The pump device according to any one of claims 1 to 4,
The housing has a shaft portion inserted into the cylindrical impeller,
The hydrodynamic bearing is formed between the inner circumferential surface of the impeller and the outer circumferential surface of the shaft-shaped portion. The pump device according to claim 5,
The dynamic pressure bearing is formed radially inside the repulsion mechanism.

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