WO2020170941A1 - Pump device - Google Patents

Abstract

A pump device (10A) is provided with an impeller (14) and a housing (26). The housing (26) includes a fixed-side repulsion magnet (44) arranged in such a way as to encircle an internal space (32) inside an outer circumferential wall (40). The impeller (14) includes a movable-side repulsion magnet (76) forming a repulsion mechanism (84A) for generating a repulsive force between the movable-side repulsion magnet (76) and the fixed-side repulsion magnet (44). A dynamic pressure bearing (78) for generating dynamic pressure in a radial direction when the impeller (14) rotates is formed between a side circumferential surface (63) of the impeller (14) and an opposing surface (48a) of the housing (26).

Description

Pump device

The present invention relates to a pump device that causes a fluid to flow.

In artificial heart-lung machines that flow the patient's blood (fluid), the pump system is used as the power source for blood circulation. For example, Japanese Unexamined Patent Application Publication No. 2012-21413 discloses a centrifugal pump device that rotates an impeller provided in a housing, draws blood into the housing by centrifugal force associated with the rotation, and discharges blood from the housing. Has been done.

The pump device disclosed in JP 2012-21413 A forms a magnetic coupling between the motor chamber and the impeller, and rotates the impeller while attracting the magnet (permanent magnet) of the impeller downward. Further, this pump device is provided with magnets on the upper part of the housing and the upper part of the impeller (on the side opposite to the magnetic coupling forming part). As a result, the attractive force of the magnets is generated above and below the impeller, and the impeller rotates in a balanced state near the center of the blood chamber.

By the way, in this type of pump device, blood flows out from the outlet (outflow) side in the housing, so that the negative pressure of blood near the outlet increases. For this reason, the posture of the impeller during rotation is inclined such that the impeller itself near the outflow port is lowered, while the impeller on the opposite side of the outflow port sandwiching the rotating shaft is raised. Inclination of the impeller may adversely affect the blood flow.

In particular, the pump device has a structure that uses a thin bearing that reduces the portion that contacts the impeller, and the posture of the impeller easily tilts when affected by the blood pressure difference. Further, if the impeller continues to rotate while being inclined, the bearing portion may be continuously loaded and damaged (that is, the durability of the pump device may be reduced).

The present invention has been made in relation to the technique of the above-described pump device. By rotating the impeller in a stable posture, a fluid can be satisfactorily flowed and the durability of the pump device can be improved. The purpose is to provide.

In order to achieve the above object, one embodiment of the present invention is a pump device including an impeller, an internal space that houses the impeller, and a housing that has a bearing portion that rotatably supports the impeller. The housing has a fixed-side repulsion magnet arranged so as to circulate in the inner space in a wall portion of the housing, and the impeller causes a repulsion mechanism to generate a repulsive force between the fixed-side repulsion magnet and the fixed-side repulsion magnet. Having a movable side repulsive magnet that forms a space between the side peripheral surface of the impeller and the facing surface of the housing that faces the side peripheral surface of the impeller and flows through the internal space when the impeller rotates. The fluid forms a dynamic pressure bearing that produces a dynamic pressure in the radial direction.

The pump device described above can rotate the impeller with respect to the housing in a non-contact manner by forming a dynamic pressure bearing that generates a dynamic pressure in the radial direction between the side peripheral surface of the impeller and the facing surface of the housing. Moreover, since the fixed-side repulsion magnet and the movable-side repulsion magnet form a repulsion mechanism, it is possible to disperse the impeller in two locations of the dynamic pressure bearing and the repulsion mechanism. This allows the pump device to satisfactorily flow the fluid and suppress the load applied to the bearing portion during rotation of the impeller, thereby improving durability.

It is a perspective view showing the whole pump device composition concerning a 1st embodiment of the present invention. FIG. 2 is a sectional view taken along the line II-II of FIG. 1 showing a separated state of the pump body and the drive device of the pump device. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is a side sectional view showing an important section of a pump device. FIG. 5A is a side sectional view showing, in an enlarged manner, the sheath and the bearing portion of the impeller. FIG. 5B is a side cross-sectional view showing the floating state of the sheath when the impeller rotates. FIG. 6A is a sectional view taken along line VIA-VIA of FIG. 4 showing a magnetic coupling mechanism of a driving magnet and a driven magnet. FIG. 6B is a cross-sectional view taken along line VIB-VIB of FIG. 4 showing the repulsion mechanism of the fixed-side repulsive magnet and the movable-side repulsive magnet. It is a side sectional view which expands and shows a dynamic pressure bearing of an impeller and a housing. It is the perspective view which looked at the fixed side repulsion magnet from the lower side. It is a side sectional view showing a flow of blood of the pump device when the impeller is rotated. It is a side surface sectional view showing the important section of the pump device concerning a 2nd embodiment. It is a side surface sectional view showing the important section of the pump device concerning a 3rd embodiment. It is a side surface sectional view showing the important section of the pump device concerning a 4th embodiment. It is a side surface sectional view showing the important section of the pump device concerning a 5th embodiment. FIG. 14A is a side cross-sectional view showing the main parts of the pump device according to the 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.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment]
The pump apparatus 10A according to the first embodiment of the present invention is an artificial heart-lung machine 12 that assists the cardiopulmonary function of the patient (or substitutes for the heart lung), removes the blood of the patient outside the body, and sends the blood to the body. Used as a power source. As shown in FIG. 1, the pump device 10</b>A has an impeller 14 inside the device and is configured as a centrifugal pump that causes a fluid to flow by a centrifugal force that accompanies the rotation of the impeller 14.

In the heart-lung machine 12, the blood removal tube 16 and the blood supply tube 18 are connected to the pump device 10A to form a circulation circuit for circulating blood with the patient. The blood removal tube 16 has a blood removal lumen 16a inside. The distal end opening of the blood removal tube 16 is placed in an appropriate biological organ (for example, the left ventricle of the heart), so that the pump device 10A sucks the blood of the patient through the blood removal lumen 16a. The blood supply tube 18 has a blood supply lumen 18a inside. The distal end opening of the blood supply tube 18 is left in an appropriate biological organ (for example, the subclavian artery), so that the pump device 10A supplies blood to the patient through the blood supply lumen 18a. The artificial heart-lung machine 12 may have a configuration in which a reservoir, an artificial lung, and the like (both not shown) other than the pump device 10A are connected to an intermediate position of the circulation circuit (blood removal tube 16 or blood supply tube 18). As a result, the artificial heart-lung machine 12 removes foreign matter and oxygenates the blood removed from the body, and returns the blood to the patient's body.

Then, as shown in FIG. 2, the pump device 10A includes a pump body 20 accommodating the impeller 14, a drive device 22 for rotating the impeller 14, and a control unit 24 (Controller) for controlling the drive of the drive device 22. Equipped with. The housing 26 of the pump device 10</b>A is made of a resin material or the like, and includes a main body side housing 28 that forms the external appearance of the pump main body 20 and a drive side housing 30 that forms the external appearance of the drive device 22.

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

The main body housing 28 of the pump main body 20 has an internal space 32 in which the impeller 14 is rotatably accommodated and blood is allowed to flow in and out. The main body side housing 28 is formed in a substantially conical shape on the upper side and a substantially cylindrical shape on the lower side.

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

Further, a blood outflow port 36 connected to the blood supply tube 18 is provided on the substantially cylindrical upper side of the main body side housing 28. As shown in FIG. 3, the blood outflow port 36 projects tangentially from the substantially cylindrical outer peripheral wall 40. Inside the blood outflow port 36, an outflow passage 36 a communicating with the internal space 32 is provided. The outflow passage 36a communicates with an opening 36a1 provided at the protruding end of the blood outflow port 36 and also with an outlet 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 side housing 28. The fin portion 60 of the impeller 14 is arranged on the upper side of the internal space 32 (hereinafter referred to as the upper space 32a). The upper space 32a is composed of 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. In addition, the central portion on the lower side of the upper space 32a is configured by a shaft-shaped portion 38 that protrudes toward the inflow port 34a2 of the blood inflow port 34.

The substantially cylindrical portion of the main body housing 28 includes a cylindrical outer peripheral wall 40, a bottom wall 42 that constitutes a lower end portion of the main body housing 28, and the shaft-shaped portion 38 provided inside the outer peripheral wall 40. including. As a result, the lower side of the internal space 32 (hereinafter referred to as the lower space 32b) is formed in a cylindrical shape, and rotatably accommodates the driven rotary structure portion 62 of the impeller 14 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, which will be described later, provided on the impeller 14. The configuration of the fixed-side repulsion magnet 44 will be described in detail later.

The shaft-shaped portion 38 has a cylindrical inner peripheral wall 48 and a chevron portion 50 connected to an upper end portion of the inner circumferential wall 48, and an insertion hole 52 is formed inside the inner circumferential wall 48 and the chevron portion 50. .. The lower space 32b goes around the side of the insertion hole 52. The insertion hole 52 is open at 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-shaped portion 50 of the shaft-shaped 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 portion 54 is made of a metal material, and has a base portion 56 fixed to the chevron portion 50, and a pin portion 58 protruding upward from the base portion 56 and formed thinner than the base portion 56. When the shaft center is extended, the bearing 54 overlaps with the center of the inflow port 34a2 of the blood inflow port 34, and this shaft also serves as the shaft St of the main body side housing 28 (the shaft 38, the outer peripheral wall 40). Match. That is, the shaft center Si of the impeller 14 pivotally supported by the bearing portion 54 is ideally the same as the shaft 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 in the main body side housing 28 over both the upper space 32a and the lower space 32b. The impeller 14 has a fin portion 60 in the upper portion and a driven rotary structure portion 62 in the lower portion. Inside the fin portion 60 and the driven rotary structure portion 62 is a space portion 64 in which the shaft portion 38 is arranged.

The fin portion 60 protrudes upward from the upper surface of the conical wall portion 66, the conical wall portion 66 connected to the upper end of the driven rotary structure portion 62, the sheath 68 pivotally supported by the bearing portion 54 at the center of the conical wall portion 66. And a plurality of projecting wall portions 70 that generate a centrifugal force in the upper space 32a during rotation. A space surrounded by the conical wall portion 66 and the pair of protruding wall portions 70 serves as a flow passage 60a through which blood flows, and the flow passage 60a has an open upper portion. 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 passage 60a.

As shown in FIGS. 5A and 5B, the conical wall portion 66 is steeper than the chevron portion 50 of the main body side housing 28, and the upper surface thereof is curved in an arc shape. Therefore, a gap (hereinafter, referred to as an 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) penetrating 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 smoothly connected to the conical wall portion 66, and is formed in a conical shape that sharply inclines upward from the conical wall portion 66, so that the sheath 68 protrudes above the protruding wall portion 70. The lower side of the sheath 68 is also a taper protruding portion 69 protruding in a taper shape toward the portion (base portion 56) where the pin portion 58 is fixed to the main body side housing 28. When the impeller 14 stops rotating, the tapered protrusion 69 has a tapered end portion 69 a contacting the upper surface of the base portion 56 of the bearing portion 54 in a narrow range. When the impeller 14 rotates, the tapered end portion 69a floats above the upper surface of the base portion 56.

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

The hollow portion 72 includes a first hollow 72a into which the pin portion 58 is inserted over the entire extension 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 projects 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 peripheral surface 58a of the pin portion 58 and the inner peripheral surface 68a of the sheath 68 (impeller 14) forming 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. The distance between the outer peripheral surface 58a of the pin portion 58 and the inner peripheral surface 68a of the impeller 14 may be set in the range of 0.1 mm to 0.2 mm. As a result, blood can smoothly flow through the communication gap 59.

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

The configurations of the bearing portion 54 and the hollow portion 72 of the impeller 14 are not limited to the above, and various configurations are possible. For example, a hydrophilic coating may be applied to at least one of the inner peripheral surface 68a of the impeller 14 and the outer peripheral surface 58a of the pin portion 58. As a result, blood easily enters the hollow portion 72 (communication gap 59).

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

The driven rotary structure portion 62 of the impeller 14 is connected to 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 rotary structure portion 62 is set in the range of 20 mm to 50 mm, for example. In this embodiment, the impeller 14 having a diameter of 30 mm is applied.

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

The driven magnet 74 is arranged at the same height position as the drive magnet 92 of the drive device 22 in the mounted state of the pump body 20 and the drive device 22, and forms the magnetic coupling mechanism 104 with the drive magnet 92. More specifically, the driven magnet 74 is fixed on the upper side of the driven rotating structure 62 toward the radially inner side (inner peripheral surface 63a). Further, the axial length (thickness) parallel to the axial center of the driven magnet 74 is designed to be substantially the same as the axial length of the drive magnet 92.

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

As a material forming the driven magnet 74 (driven side multi-pole magnetized ring magnet 75), for example, a hard magnetic material such as alnico, ferrite, or neodymium can be used. The driven magnet 74 is not limited to be configured as a multi-pole magnetized ring, and is formed in a ring shape by arranging a plurality of arc-shaped magnets having counter poles (N pole, S pole) in the circumferential direction. May be.

As shown in FIGS. 4 and 6B, the movable-side repulsion magnet 76 is fixed to the lower side of the driven rotary structure portion 62 radially outward (outer peripheral wall 40 of the main body-side housing 28). That is, the radius R2 of the movable-side repulsion magnet 76 is longer than the radius R1 of the driven magnet 74. Further, the driven magnet 74 and the movable-side repulsive magnet 76 are largely separated vertically in the driven rotation structure portion 62 so that the influence of the mutual magnetic field is suppressed.

The movable-side repulsive magnet 76 is composed of a movable-side inner/outer peripheral single-pole magnetized ring magnet 77 that orbits at a position separated from the axial center Si of the impeller 14 by a predetermined distance. The movable-side inner/outer circumference single-pole magnetized ring magnet 77 has a first polarity (S pole in FIG. 4) along the entire circumference of the outer circumference, and a second polarity opposite to the first polarity over the entire circumference of the inner circumference. It is a ring body magnetized so as to have (N pole in FIG. 4). 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 forming the movable-side repulsive magnet 76 (movable-side inner/outer peripheral single-pole magnetized ring magnet 77) is not particularly limited, and the materials mentioned for the driven magnet 74 can be applied. The movable-side repulsive magnet 76 is not limited to being configured as a single-pole magnetized ring, and a plurality of arc-shaped magnets having counter poles on the inner peripheral portion and the outer peripheral portion are arranged in the circumferential direction to form a ring shape. It may be formed in.

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

The interval I1 of the first gap 80 depends on the viscosity of the flowing fluid, but is set to a range of 0.05 mm to 0.2 mm when the fluid is blood, for example. The inner peripheral surface 63a and the facing surface 48a are parallel to the shaft centers Si and St of the impeller 14 and the shaft-like portion 38, and thus the first gap 80 is formed over the range in which the inner peripheral surface 63a and the facing surface 48a face each other. It The axial region where the inner peripheral surface 63a and the facing surface 48a face each other along the axial center Si of the impeller 14 is preferably set in the range of 10 mm to 100 mm.

Since the first gap 80 is set to have a size within the above range, buoyancy (dynamic pressure) is generated by the blood flowing between the inner peripheral surface 63a and the facing surface 48a when the impeller 14 rotates. To do. That is, the dynamic pressure bearing 78 functions as a journal bearing that supports a load (radial load) in the radial direction orthogonal to the shaft center Si of the impeller 14. For example, the dynamic pressure bearing 78 ensures that the impeller 14 is not in contact with the shaft-like portion 38 by the 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 in the range of 0.8 mm to 1.2 mm, for example.

As described above, the impeller 14 has a portion of the sheath 68 that is axially supported by the bearing portion 54 and a portion of the driven rotary structure portion 62 that is axially supported by the shaft-shaped portion 38. Accordingly, when the impeller 14 rotates, the shaft center Si of the impeller 14 is reliably suppressed from being inclined with respect to the shaft center St of the main body side housing 28 (shaft portion 38).

Then, on the outer peripheral wall 40 facing the driven rotary structure portion 62 of the impeller 14, the fixed side repulsion magnet 44 is installed as described above. As shown in FIGS. 4 and 6B, the fixed-side repulsion magnet 44 is located radially outside and slightly above the movable-side repulsion magnet 76. That is, the fixed-side repulsive magnet 44 is arranged at a position farthest from the axial center St of the main body-side housing 28 (outer peripheral wall 40). The fixed-side repulsive magnet 44 is configured as a fixed-side inner/outer peripheral single-pole magnetized ring magnet 45 that orbits at the longest radius R3 from the axial center St of the body-side housing 28.

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

The material forming the fixed-side repulsion magnet 44 is not particularly limited, and the materials given for the driven magnet 74 can be applied. The fixed-side repulsion magnet 44 is not limited to being configured as a single-pole magnetized ring, and a plurality of arc-shaped magnets having counter poles on the inner peripheral portion and the outer peripheral portion are arranged in the circumferential direction to form a ring shape. It may be formed in.

The repulsion mechanism 84A composed of the movable-side repulsion magnet 76 and the fixed-side repulsion magnet 44 has a repulsion force that pushes radially inward and downward from the outer peripheral wall 40 toward the impeller 14 (movable-side repulsion magnet 76). Repulsive force). That is, the impeller 14 is pressed against the bearing 54 by the repulsion mechanism 84A while being separated from the inflow port 34a2, and receives a force that is pressed radially inward in the entire circumferential direction. The repulsive force of the repulsion mechanism 84A is set to be larger than the attractive force of the magnetic coupling mechanism 104.

Then, the repulsion mechanism 84A according to the present embodiment produces different repulsion forces in the circumferential direction. In detail, as shown in FIG. 8, the fixed-side repulsion magnet 44 includes a main body portion 46 that extends annularly with a constant axial length along the axial center Sf of the fixed-side repulsion magnet 44, and a main body portion 46. It has a convex portion 47 protruding downward from a part. The convex portion 47 is arranged on the opposite side of the formation position of the outflow port 36a2 of the blood outflow port 36 communicating with the internal space 32 with the axis Sf therebetween (see also FIG. 3).

Here, the vicinity of the outlet 36a2 of the blood outflow port 36 is the outflow side of the internal space 32 through which blood flows out from the internal space 32 to the blood outflow port 36. As described above, the pressure on the outflow side becomes lower than that at other points due to the outflow of blood. Especially when a large amount of blood flows in the internal space 32, a large imbalance occurs in the pressure distribution in the internal space 32. In the conventional pump device, due to the pressure drop on the outflow side, the outflow side of the rotating impeller is pushed downward, while the side opposite to the outflow side sandwiching the shaft center Si rises upward. And 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 fixed-side repulsion magnet 44 installed in the main body-side housing 28 is provided on the outflow side ( Hereinafter, it is arranged on the side opposite to the first region 86) (hereinafter referred to as the second region 88). The ranges of the first region 86 and the second region 88 are the fixed side repulsive magnet 44 and the imaginary line L when the imaginary line L connecting the outflow port 36a2 and the impeller 14 and the shaft center Si, St of the main body side housing 28 is drawn. The range including about 1/10 of the entire circumference from the intersection to both sides in the circumferential direction.

Thereby, with respect to the first distance D1 between the main body portion 46 of the fixed-side repulsion magnet 44 in the first area 86 and the rotating movable-side repulsion magnet 76, the convex portion 47 of the fixed-side repulsion magnet 44 in the second area 88 is The second distance D2 from the rotating movable-side repulsion magnet 76 becomes shorter. Therefore, the repulsive force of the repulsive mechanism 84Ab in the peripheral portion of the second region 88 is larger than the repulsive force of the repulsive mechanism 84Aa in the peripheral portion of the first region 86. By the repulsion mechanism 84Ab, the second region 88 of the impeller 14 is pushed downward more strongly than the other portion (the portion of the main body portion 46 where the convex portion 47 does not exist), so that the impeller 14 may have an inclined posture. Suppressed.

The amount of protrusion of the convex portion 47 from the main body portion 46 may be appropriately designed in consideration of the repulsive force of the repulsion mechanism 84Ab with respect to the repulsion mechanism 84Aa. For example, the thickness of the convex portion 47 with respect to the thickness of the main body portion 46 may be set to 0.1 to 1 times (that is, the thickness of the fixed-side repulsive magnet 44 in the second region 88 is fixed in the first region 86). It is set to 1.1 to 2 times the thickness of the side repulsion magnet 44).

The arc length of the convex portion 47 of the fixed-side repulsion magnet 44 is not particularly limited, but is about 1/4 to 1/8 of the circumferential length 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 has a movable-side repulsion when the impeller 14 is horizontal (the axial center Si of the impeller 14 matches the axial center St of the shaft-like 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-side repulsive magnet 76 when the impeller 14 is horizontal.

As shown in FIGS. 2 and 4, the drive device 22 of the pump device 10</b>A includes a drive side housing 30 and a motor mechanism 90 housed in the drive side housing 30. Further, the drive device 22 has a drive magnet 92 which is provided in the motor mechanism 90 and attracts the impeller 14.

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

The body-side housing 28 of the pump body 20 and the drive-side housing 30 of the drive device 22 have an engagement structure 98 that can be removably positioned and fixed to each other. In the present embodiment, the engagement structure 98 inserts the central convex portion 96 into the insertion hole 52 of the main body housing 28, and inserts the bottom wall 42 of the main body housing 28 into the mounting groove 94, so that both devices are connected. Engage. It is needless to say 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 unit 24. The shaft portion 100 projects from the motor main body 90a and is inserted into the projecting space inside the central projecting portion 96, and a disc-shaped rotating portion 102 that projects radially outward is provided at the upper end portion thereof. In the mounted state of the pump body 20 and the drive device 22, the shaft center Si of the impeller 14 and the shaft center Ss of the shaft portion 100 overlap each other.

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

As shown in FIG. 6A, the drive magnet 92 according to the present embodiment is configured as a drive-side multi-pole magnetized ring magnet 93 that orbits with a radius R4 shorter than the driven magnet 74 with respect to the axis Ss of the shaft portion 100. There is. Like the driven magnet 74, the drive-side multi-pole magnetized ring magnet 93 is magnetized so that a plurality of (six) polarities (N poles, S poles) are alternately arranged along the circumferential direction. The drive magnet 92 is disposed inside the driven magnet 74 so as to face the driven magnet 74 in a mounted state of the pump body 20 and the drive device 22, thereby forming a magnetic coupling mechanism 104 between the driven magnet 74 and the driven magnet 74.

As the material forming the driving magnet 92, the materials mentioned for the driven magnet 74 can be appropriately selected. Further, the drive magnet 92 is not limited to be configured as a multi-pole magnetized ring, and is formed in a ring shape by arranging a plurality of arc-shaped magnets having counter poles (N pole, S pole) in the circumferential direction. May be.

Returning to FIG. 2, the control unit 24 (Controller) of the pump device 10A is configured by a well-known computer having an input/output interface (not shown), a memory and a processor, 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 operates the operation buttons to set the driving content of the pump device 10A. The control unit 24 controls the supply of the electric power of the battery based on the user setting information to rotate the shaft unit 100 in the range of 0 to 10000 rpm, for example.

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

The artificial heart-lung machine 12 including the pump device 10A is constructed for a patient who assists the 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 body 20 and connects the blood supply tube 18 to the blood outflow port 36 of the pump body 20. Here, the movable-side repulsion magnet 76 and the fixed-side repulsion magnet 44 of the pump body 20 constitute the repulsion mechanism 84A because the movable-side repulsion surface 77a and the fixed-side repulsion surface 45a having the same polarity are close to each other. doing. Therefore, the impeller 14 is pressed against the bottom wall 42 side of the main body side housing 28, and the sheath 68 of the impeller 14 can be prevented from coming off from the bearing portion 54 when the pump main body 20 is carried. Then, as shown in FIG. 2, by mounting the pump body 20 on the drive device 22, the pump device 10A is assembled. At this time, the engagement structure 98 positions and fixes the pump body 20 and the drive device 22 to each other.

As shown in FIGS. 4 and 6A, in the mounted state, the driven magnet 74 and the drive magnet 92 are arranged at the same height position. The driven magnet 74 (driven side multi-pole magnetized ring magnet 75) and the drive magnet 92 (driving side multi-pole magnetized ring magnet 93) which are adjacent to each other in the radial direction have different polarities opposed to each other, and the magnetic coupling mechanism 104. To form. That is, the driven-side multi-pole magnetized ring magnet 75 and the drive-side multi-pole magnetized ring magnet 93 generate a magnetic coupling force (magnetic coupling force), and the rotational force of the rotating portion 102 can be transmitted to the impeller 14. To do.

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

As shown in FIG. 9, when the impeller 14 rotates, the blood that has flowed into the internal space 32 from the inflow passage 34a wraps around from the radially outer side of the upper space 32a to the lower space 32b. When the blood flows downward through the second gap 82 between the inner peripheral surface 40a of the outer peripheral wall 40 and the outer peripheral surface 63b of the driven rotary structure portion 62, the blood heads radially inward on the lower end side of the lower space 32b. Further, the blood flows upward in the first gap 80 between the facing surface 48a of the shaft-shaped portion 38 and the inner peripheral surface 63a of the driven rotary structure portion 62 to reach the upper gap 66a.

A part of the blood flowing in the upper gap 66a moves to the upper space 32a through the plurality of washout holes 67 of the impeller 14 (see FIG. 5B). Further, 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. That is, the bearing portion 54 and the sheath 68 are kept in a non-contact state as much as possible during rotation, whereby the generation of frictional heat can be suppressed and blood can be satisfactorily flowed.

Further, the movable-side repulsion magnet 76 (movable-side inner/outer circumference single-pole magnetized ring magnet 77) and the fixed-side repulsion magnet 44 (fixed-side inner/outer circumference single-pole magnetized ring magnet 45) of the pump body 20 are even in the entire circumferential direction. Apply repulsive force. Further, even when the impeller 14 tries to float toward the inlet 34a2 side due to the blood flowing around to the lower side of the impeller 14 when the impeller 14 rotates, the repulsive force of the repulsion mechanism 84A is received, so that the floating of the impeller 14 can be reliably suppressed. it can.

In particular, in a state where the axis Si of the impeller 14 coincides with the axis St of the main body side housing 28, the fixed side repulsion magnet 44 having the convex portion 47 and the movable side repulsion magnet 76 cause the second region 88 of the rotating impeller 14 to rotate. Apply a strong repulsive force to. Therefore, the repulsion mechanism 84Ab suppresses the rise (inclination) of the impeller 14 on the second region 88 side even if the pressure on the outlet 36a2 side of the internal space 32 becomes low due to the outflow of blood from the outflow passage 36a. Therefore, the pump device 10A can stably rotate the impeller 14 while maintaining the non-contact state between the impeller 14 and the main body side housing 28, and allow the blood to flow well.

Further, the first gap 80 between the facing surface 48a of the shaft-shaped portion 38 of the main body side housing 28 and the inner peripheral surface 63a of the impeller 14 receives a radial load during rotation of the impeller 14 (for example, at 3000 rpm or more). The dynamic pressure bearing 78 is formed. As a result, the rotational posture of the impeller 14 can be kept more stable, the axial center Si of the impeller 14 can be aligned with the axial center St of the main body side housing 28, and the load on the bearing portion 54 can be reduced. Become.

The present invention is not limited to the above-described embodiment, and various modifications can be made according to 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 radially inside the magnetic coupling mechanism 104. The fixed-side repulsion magnet 44 may be provided not only in the pump body 20 (main-body-side housing 28) but also in the drive device 22 (drive-side housing 30).

Also, the means for generating different repulsive forces in the repulsion mechanism 84A is not limited to providing the convex portion 47 on the fixed-side repulsion magnet 44. For example, the fixed-side repulsion 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 set to be larger than that of the first region 86. The magnetic force of the second region 88 may be increased. Further, 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 that suppresses the magnetic force may be arranged at a circumferential position other than the second region 88, or the second region. A magnetic force derivative such as a soft magnetic material may be arranged at 88.

The dynamic pressure bearing 78 forming the journal shaft may be formed in the second gap 82 (between the outer peripheral surface 63b of the impeller 14 and the inner peripheral surface 40a of the outer peripheral wall 40). Further, the dynamic pressure bearing 78 may increase the dynamic pressure by providing a concave portion (a groove, a notch, or the like) in one of the side peripheral surface 63 of the impeller 14 and the facing surface 48a of the housing 26. The dynamic pressure bearing 78 is not limited to be formed on the entire surface facing the side peripheral surface 63 along the axis Si of the impeller 14, and may be formed, for example, near the lower portion of the side peripheral surface 63 of the impeller 14. Good.

Some examples of other embodiments will be described below. In the following description, elements having the same configurations or functions as those of the above-described embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

[Second Embodiment]
In the pump device 10B according to the second embodiment, as shown in FIG. 10, the axial center Sf of the annular fixed-side repulsion magnet 44 is inclined with respect to the axial center St of the main body housing 28 (axial center Si of the impeller 14). The repulsion mechanism 84B is configured to be different from the above pump device 10A. Further, the fixed-side repulsive magnet 44 includes only the annular main body portion 46 without the above-mentioned convex portion 47, and extends in the circumferential direction in a rectangular shape having a certain size in a sectional view.

Specifically, the axial center Sf of the fixed-side repulsion magnet 44 is set so that the second region 88 side is lower in the outer wall 40 than the first region 86 side (the fixed-side repulsion magnet 44 is movable-side repulsion). It is slightly inclined (toward the magnet 76). For example, the inclination angle of the axis Sf of the fixed-side repulsion magnet 44 with respect to the axis St of the main body side housing 28 is preferably 5° or less, and more preferably set in the range of 0.5° to 3°. Good to be done. Even if the fixed side repulsive magnet 44 is installed in an inclined manner in this way, the second distance D2 between the movable side repulsive magnet 76 on the second region 88 side and the fixed side repulsive magnet 44 is the movable side repulsive force on the first region 86 side. The distance is shorter than the first distance D1 between the magnet 76 and the fixed-side repulsive magnet 44.

In the pump device 10B configured as described above, the repulsive force of the repulsion mechanism 84Bb in the second region 88 becomes larger than the repulsive force of the repulsion mechanism 84Ba in the first region 86 when the impeller 14 rotates. Therefore, the pump device 10B can stably make the axial center Si of the impeller 14 and the axial center St of the main body side housing 28 coincide with each other even when the pressure on the outflow side of the internal space 32 becomes low. Therefore, the pump device 10B has the same effects as the pump device 10A according to the first embodiment. Particularly, in the pump device 10B, the structure of the fixed-side repulsion magnet 44 is simplified, and the manufacturing cost can be suppressed.

[Third Embodiment]
As shown in FIG. 11, the pump device 10C according to the third embodiment forms a repulsion mechanism 84C by offsetting the shaft center Sf of the annular fixed-side repulsion magnet 44 with respect to the shaft center St of the main body side housing 28. This is different from the pump devices 10A and 10B described above. Further, the fixed-side repulsion magnet 44, similarly to the second embodiment, includes only the annular main body portion 46 without the convex portion 47, and extends in the circumferential direction in a square shape having a constant size in a sectional view. There is.

Specifically, the fixed-side repulsive magnet 44 is arranged so that its axial center Sf is displaced from the axial center St of the main body side housing 28 toward the first region 86 side. For example, the offset amount of the shaft center Sf of the fixed side repulsion magnet 44 with respect to the shaft center 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 repulsion surface 45a on the second region 88 side of the fixed-side repulsion surface 45a on the first region 86 side is arranged near the inner peripheral surface 40a (internal space 32) in the outer peripheral wall 40.

Even if the fixed side repulsive magnet 44 is installed in this manner, the second distance D2 between the movable side repulsive magnet 76 on the second region 88 side and the fixed side repulsive magnet 44 is also the same as the movable side repulsive magnet 76 on the first region 86 side. And becomes closer than the first distance D1 of the fixed-side repulsion magnet 44. Therefore, in the pump device 10C as well, when the impeller 14 rotates, the repulsive force of the repulsion mechanism 84Cb in the second region 88 becomes larger than the repulsive force of the repulsion mechanism 84Ca in the first region 86, so that the first and second embodiments. The same effects as the pump devices 10A and 10B according to the present invention are obtained.

[Fourth Embodiment]
In the pump device 10D according to the fourth embodiment, as shown in FIG. 12, by increasing the interval I1 of the first gap 80, the dynamic pressure bearing 78 is provided between the inner peripheral surface 63a of the impeller 14 and the facing surface 48a. It is different from the pump devices 10A to 10C in that it is not formed. That is, the pump device 10D can maintain the posture of the impeller 14 stably by appropriately setting the repulsive force of the repulsion mechanisms 84A to 84C without forming the dynamic pressure bearing 78.

[Fifth Embodiment]
As shown in FIG. 13, in the pump device 10E according to the fifth embodiment, the fixed-side repulsive magnet 44 is configured only by the annular main body portion 46, while the dynamic pressure bearing 78 suppresses the inclination of the impeller 14. It is different from the pump devices 10A to 10D in that That is, the fixed-side repulsion magnet 44 and the movable-side repulsion magnet 76 form a repulsion mechanism 84D that exerts a uniform repulsion force by being spaced at equal intervals D′ in the circumferential direction. As described above, the pump device 10E stabilizes the posture of the impeller 14 by appropriately exerting the dynamic pressure of the dynamic pressure bearing 78 without changing the repulsive force in the circumferential direction of the impeller 14 by the repulsion mechanisms 84A to 84C. It is also possible to keep it as it is.

[Sixth Embodiment]
As shown in FIG. 14A, the pump device 10F according to the sixth embodiment has the above-described pump devices 10A to 10E in that the hollow portion 72 formed in the sheath 68 of the impeller 14 is provided with the convex portion 106 (feather). Different from The convex portion 106 of the hollow portion 72 gives a flowing force to the blood flowing in the hollow portion 72 when the impeller 14 rotates, so that the blood can flow more smoothly. Note that the structure for imparting a fluid force to blood in the hollow portion 72 is not limited to the convex portion 106, and may be a concave portion 108 (groove) as shown in FIG. 14B. For example, the formation of the spiral recess 108 allows blood to flow in the axial direction.

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

The pump devices 10A to 10C and 10E form the dynamic pressure bearing 78 between the side peripheral surface 63 of the impeller 14 and the facing surface 48a (or the inner peripheral surface 40a) of the housing 26 to generate the dynamic pressure in the radial direction. The impeller 14 can be rotated without contact with 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 is axially supported by being dispersed in two places, the dynamic pressure bearing 78 and the repulsion mechanisms 84A to 84D. Is possible. As a result, the pump devices 10A to 10C and 10E allow the fluid to flow favorably, suppress the load applied to the bearing portion 54 when the impeller 14 rotates, and improve the durability.

Further, the fluid is blood, and the distance between the side peripheral surface 63 of the impeller 14 and the facing surface 48a (or the inner peripheral surface 40a) of the housing 26 is set in the range of 0.05 mm to 0.2 mm, A dynamic pressure bearing 78 is formed. As a result, in the pump devices 10A to 10C and 10E, the dynamic pressure bearing 78 can be reliably formed without performing special processing on the side peripheral surface 63 of the impeller 14 or the facing surface 48a of the housing 26. ..

Further, the diameter of the impeller 14 is set in the 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, in the pump devices 10A to 10C and 10E, the impeller 14 is rotatably supported by the shaft support of the bearing portion 54 when the rotational speed of the impeller 14 is low, and the hydrodynamic bearing 78 increases when the rotational speed of the impeller 14 increases. Thus, the impeller 14 can be stably rotated.

Further, the axial area where the side peripheral surface 63 of the impeller 14 and the facing surface 48a (or the inner peripheral surface 40a) of the housing 26 face each other along the axial center Si of the impeller 14 is set in the range of 10 mm to 100 mm. To be done. As a result, the dynamic pressure bearing 78 can support the impeller 14 more stably and rotate the impeller 14.

The housing 26 has a shaft-shaped portion 38 that is inserted into the cylindrical impeller 14, and the dynamic pressure bearing 78 has an inner peripheral surface 63 a of the impeller 14 and an outer peripheral surface (opposing surface 48 a) of the shaft-shaped portion 38. Formed between. As a result, the dynamic pressure bearing 78 can pivotally support the rotation of the impeller 14 inside the impeller 14, further stabilizes the rotational posture of the impeller 14, and suppresses fluid damage (hemolysis of blood, etc.). It becomes possible to do.

Further, the dynamic pressure bearing 78 is formed radially inward of the repulsion mechanisms 84A to 84D. Accordingly, the pump devices 10A to 10C and 10E can guide the fluid flowing through the repulsion mechanisms 84A to 84D while pivotally supporting the impeller 14 to the dynamic pressure bearing 78 on the radially inner side to cause the fluid to flow. Further, the dynamic pressure bearing 78 can sufficiently exert the dynamic pressure.

Claims (6)

With an impeller,
A pump device comprising: an internal space that houses the impeller; and a housing that has a bearing portion that rotatably supports the impeller,
The housing has a fixed-side repulsion magnet arranged so as to circulate in the inner space within a wall portion of the housing,
The impeller has a movable-side repulsive magnet that forms a repulsive mechanism that generates a repulsive force between the impeller and the fixed-side repulsive magnet,
Between the side peripheral surface of the impeller and the facing surface of the housing facing the side peripheral surface of the impeller, a dynamic pressure that generates a dynamic pressure in the radial direction by the fluid flowing in the internal space when the impeller rotates. A pump device that forms a bearing. The pump device according to claim 1,
The fluid is blood,
A pump device in which the dynamic pressure bearing is formed by setting a distance between a side peripheral surface of the impeller and a facing surface of the housing within 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 the range of 20 mm to 50 mm,
The dynamic pressure bearing is a pump device formed when the impeller rotates at 3000 rpm or more. The pump device according to any one of claims 1 to 3,
A pump device in which an axial region where the side peripheral surface of the impeller and the facing surface of the housing face each other along the axial center 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-shaped portion that is inserted into the tubular impeller,
The dynamic pressure bearing is a pump device formed between an inner peripheral surface of the impeller and an outer peripheral surface of the shaft-shaped portion. The pump device according to claim 5,
The dynamic pressure bearing is a pump device formed radially inward of the repulsion mechanism.

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