WO2015098709A1

WO2015098709A1 - Centrifugal pump system

Info

Publication number: WO2015098709A1
Application number: PCT/JP2014/083612
Authority: WO
Inventors: 板持洋介
Original assignee: テルモ株式会社
Priority date: 2013-12-27
Filing date: 2014-12-18
Publication date: 2015-07-02
Also published as: JP6434423B2; JPWO2015098709A1

Abstract

This centrifugal pump system (10) is provided with: a centrifugal pump (11) provided with a housing (26), and an impeller (28) which is rotatably disposed inside the housing (26), and which reacts to magnetism; and a drive transmission unit (34) which, while magnetically attracting or repelling the impeller (28), transmits the rotational force of a motor (37) to the impeller (28). The drive transmission unit (34) is capable of changing the magnetic force applied to the impeller (28), in accordance with the rotational speed of the motor (37).

Description

Centrifugal pump system

The present invention relates to a centrifugal pump system for feeding a liquid such as blood.

During heart surgery, a heart-lung machine is used. The artificial heart-lung machine constitutes an extracorporeal circuit, and performs oxygenation of blood removed from a patient, removal of foreign substances, and the like. There are various types of cardiopulmonary apparatus depending on the type of oxygenator, the type of pump, the position of the pump, etc., but usually a reservoir (blood reservoir), oxygenator, heat exchanger, pump and those (See Japanese Patent Application Laid-Open No. 2009-160265).

A centrifugal pump is an example of a pump used in an oxygenator. A centrifugal pump generally includes a housing, an impeller rotatably disposed in the housing, a shaft provided in the center of the impeller, and a bearing that rotatably supports the shaft. This centrifugal pump operates as a centrifugal pump system by being attached to a pump drive unit. A centrifugal pump system rotates an impeller in a housing by a pump drive unit, draws the blood of the patient to the center of rotation, and pushes the blood to the outer peripheral side of the impeller by the centrifugal force at the time of rotation. Perform blood pumping.

By the way, the impeller of the centrifugal pump system is located closer to the lower side in the housing at the time of low speed rotation, and is displaced to the upper side in the housing by buoyancy at the time of high speed rotation. Show. For this reason, for example, when blood is sent by continuously performing low-speed rotation, a large load is continuously applied from the impeller to the lower bearing that pivotally supports the impeller. As a result, the blood property of the pivot support portion is remarkably changed, resulting in inconvenience of generating a thrombus. On the other hand, when performing high-speed rotation, the impeller is displaced upward in the housing, so that the torque transmission rate between the pump drive unit and the impeller is reduced, and it is difficult to smoothly rotate the impeller. There is.

The present invention has been made to solve the above-described problem, and is a centrifugal pump system capable of satisfactorily feeding body fluid by adopting a configuration capable of appropriately setting a load during rotation of an impeller. The purpose is to provide.

In order to achieve the above object, a centrifugal pump system according to the present invention includes a centrifugal pump including a housing, an impeller rotatably disposed in the housing and responsive to magnetism, and an axial direction of the impeller A drive transmission unit that transmits the rotational force of the drive source to the impeller while magnetically attracting or repelling, and the drive transmission unit is applied to the impeller based on the rotational speed of the impeller or the drive source The magnetic force can be varied.

According to the above, in the centrifugal pump system, the load when the impeller rotates can be appropriately set by the drive transmission unit changing the magnetic force applied to the impeller in accordance with the rotation speed of the impeller or the drive source. That is, in the structure in which the impeller is rotated magnetically, the load in the axial direction of the impeller can be appropriately controlled by changing the magnetic force applied to the impeller when the impeller rotates. As a result, the centrifugal pump system can suppress the body fluid from changing under the influence of the load of the impeller (for example, the occurrence of a thrombus), and the body fluid can be sent well.

In this case, the drive transmission unit is arranged below the housing and has a magnetic force applied at a second rotational speed that is lower than the first rotational speed of the impeller than a magnetic force applied at the first rotational speed of the impeller. It is preferable to weaken.

As described above, the load applied to the impeller in the downward direction at the second rotational speed can be reduced by weakening the magnetic force applied at the second rotational speed rather than the magnetic force applied at the first rotational speed. Therefore, for example, even when the impeller is rotated at a low speed in order to suppress hemolysis of the blood, the blood can be fed satisfactorily.

Further, the centrifugal pump system displaces the drive transmission unit, and the separation at the second rotation speed of the impeller is greater than a separation distance between the impeller and the drive transmission unit at the first rotation speed of the impeller. It is good to further have a displacement mechanism part which lengthens distance.

As described above, the centrifugal pump system can easily change the magnetic force applied to the impeller by including the displacement mechanism unit that changes the separation distance between the impeller and the drive transmission unit. That is, by making the separation distance at the second rotational speed of the impeller longer than the separation distance at the first rotational speed, the magnetic force at the second rotational speed can be easily weakened, and the load on the impeller can be reliably reduced. it can.

In addition to the above configuration, the drive transmission unit includes an electromagnet capable of controlling the magnetic force applied to the impeller by supply power, and the electromagnet is more effective at the first rotational speed than the magnetic force at the second rotational speed. It is preferable to be controlled so as to increase the magnetic force.

Thus, when the drive transmission unit has an electromagnet, when the impeller is rotated at the first rotation speed (at high speed rotation), a strong magnetic force can be applied to the impeller, and the impeller can be sufficiently attracted to rotate. Can do. For this reason, the centrifugal pump system can satisfactorily transmit the rotational force from the drive transmission unit to the impeller even during high-speed rotation.

Furthermore, the displacement mechanism unit may be configured to displace the drive transmission unit and the drive source integrally.

As described above, when the drive transmission unit and the drive source are integrally displaced, the centrifugal pump system can easily control the fluctuation of the magnetic force while simplifying the structure of the rotation control of the impeller.

Here, the centrifugal pump may include a shaft that is provided at the center of the impeller and has shaft ends at both ends in the axial direction, and a bearing that pivotally supports each of the shaft ends.

Such a pivot support structure with a shaft and a bearing concentrates stress from the shaft toward the bearing, but the drive transmission unit fluctuates the magnetic force applied to the impeller, thereby improving the load applied to the bearing. Can be controlled.

In this case, a detection unit that detects a pressure or load between at least one of the bearings and the housing, and a control unit that varies the magnetic force applied to the impeller based on the detected pressure or load. It may be.

In this way, the load of the impeller can be controlled with higher accuracy by changing the magnetic force applied to the impeller based on the pressure or load applied to the bearing by the control unit, and the change in body fluid can be further suppressed. .

Furthermore, the impeller has a plurality of guide passages for allowing fluid to flow from the center of rotation outward in the rotational radial direction, and the guide passage is surrounded by a wall portion constituting the impeller, and the outer periphery in the rotational radial direction. It is preferable that it extends linearly toward.

As described above, the guide path is linearly extended outward in the rotational radial direction while being surrounded by the wall portion constituting the impeller, so that the body fluid (fluid) is linearly centrifuged in the impeller. Can lead to. Thereby, even if the rotational speed of an impeller is low speed (2nd rotational speed), the improvement of the amount of body fluids delivered is achieved. Moreover, the load in the axial direction of the impeller can be reduced as described above even during low-speed rotation.

According to the present invention, the centrifugal pump system can supply body fluid satisfactorily by adopting a configuration in which the load during rotation of the impeller can be appropriately set.

It is a schematic explanatory drawing which shows the heart-lung machine provided with the centrifugal pump system which concerns on one Embodiment of this invention. It is sectional drawing which shows the upper part of the centrifugal pump and pump drive part of the centrifugal pump system of FIG. 3A is a plan view showing the centrifugal pump of FIG. 1, and FIG. 3B is a plan view showing the drive transmission unit of FIG. 4A is a cross-sectional view showing a state of the centrifugal pump of FIG. 1 during low-speed rotation, and FIG. 4B is a cross-sectional view of a state of the centrifugal pump of FIG. 1 during high-speed rotation. It is a reference graph which shows the relationship between the separation distance of the drive side magnet of a centrifugal pump system, and a driven side magnet, the transmission torque to an impeller, and the coupling force between magnets. It is sectional drawing of the centrifugal pump system which concerns on a 1st modification. FIG. 7A is a plan view for explaining an outline of a centrifugal pump system according to a second modification, and FIG. 7B is a cross-sectional view showing a state of the centrifugal pump system according to the second modification during low-speed rotation. FIG. 7C is a cross-sectional view showing a state of the centrifugal pump system according to the second modification during high-speed rotation. FIG. 8A is a partial side view illustrating an outline of a centrifugal pump system according to a third modification, and FIG. 8B is a plan view schematically illustrating a configuration of a drive transmission unit of the centrifugal pump system according to the fourth modification. It is.

Hereinafter, preferred embodiments of the centrifugal pump system according to the present invention will be described with reference to the accompanying drawings.

A centrifugal pump system 10 according to an embodiment of the present invention is applied to a heart-lung machine 12 as shown in FIG. The heart-lung machine 12 is used, for example, in cardiac surgery, etc., and performs oxygenation of blood removed from a patient, removal of foreign substances, and the like, and returns the blood to the patient.

The artificial heart-lung machine 12 includes, for example, a reservoir 14 and an artificial lung 18 in addition to the centrifugal pump system 10, and these components are connected via a tube to form a circulation circuit structure with a patient. More specifically, the reservoir 14, the centrifugal pump system 10, and the oxygenator 18 are connected in series with a tube in order from the upstream side (patient side) of the liquid feeding. For example, a tube having flexibility and transparency is applied, and a blood removal line 24, a first connection line 23, a second connection line 33, and a blood return line 44 are configured as a blood flow path.

The reservoir 14 of the heart-lung machine 12 temporarily stores blood (venous blood) removed from the patient. The reservoir 14 includes a reservoir body 20, a blood inflow port 21 provided at the upper part of the reservoir body 20, and a blood outflow port 22 provided at the lower part of the reservoir body 20. The blood inflow port 21 is connected to a blood removal line 24 for delivering blood from a blood removal cannula inserted into the patient. The blood outflow port 22 is connected to the centrifugal pump system 10 via the first connection line 23.

In the reservoir body 20, a blood filter (not shown) for filtering blood that has flowed in through the blood inflow port 21 is disposed. The reservoir body 20 is further provided with an inflow port (not shown) connected to a cardiotomy line for feeding blood from the patient's operative field.

The centrifugal pump system 10 according to the present embodiment is disposed on the downstream side of the reservoir 14 and has a function of drawing blood from the reservoir 14 and further sending the blood to the artificial lung 18 on the downstream side. The centrifugal pump system 10 includes a centrifugal pump 11, a pump driving unit 16, and a control unit 45.

Centrifugal pump 11 is a mechanism part that is replaced for each procedure and is disposable or sterilized in order to cause the patient's blood to flow inside. The centrifugal pump 11 includes at least a housing 26 and an impeller 28 that is rotatably disposed in the housing 26.

The housing 26 includes a blood inflow port 30 connected to the blood outflow port 22 of the reservoir 14 through the first connection line 23, and a blood outflow port 32 connected to the oxygenator 18 through the second connection line 33. Have. As shown in FIG. 2, the housing 26 includes a base 48 that forms the lower part and a cover 50 that forms the upper part. The base 48 and the cover 50 form a space 26a (hereinafter referred to as “accommodating space 26a”) in which the impeller 28 is accommodated.

The base 48 has a substantially disc shape as a whole, and has a circular bottom wall 51 and a peripheral wall 52 that protrudes upward from the outer peripheral portion of the bottom wall 51 and that is continuous in the circumferential direction. A concave first arrangement portion 54 is provided at the center of the bottom wall 51. Further, a substantially cylindrical mounted portion 53 is formed on the bottom surface of the bottom wall 51 so as to protrude downward.

The cover 50 has a disk-shaped top wall 56 and a peripheral wall 57 that protrudes downward from the outer periphery of the top wall 56 and is continuous in the circumferential direction. The lower end of the peripheral wall 57 of the cover 50 and the upper end of the peripheral wall 52 of the base 48 are fixed to each other by an appropriate joining means such as an adhesive while being fitted to each other. In FIG. 2, the lower end of the peripheral wall 57 of the cover 50 is fitted inside the upper end of the peripheral wall 52 of the base 48, but the upper end of the peripheral wall 52 of the base 48 is inside the lower end of the peripheral wall 57 of the cover 50. May be fitted.

The cover 50 is provided with a protruding cylindrical portion 58 protruding upward from the center of the top wall 56. The protruding cylinder 58 has a hollow structure with the upper end closed and opened downward. A concave second arrangement portion 60 is provided inside the upper portion of the protruding cylinder portion 58.

The cover 50 is provided with the blood inflow port 30 described above. The blood inflow port 30 extends in a direction intersecting with the protruding cylinder portion 58 (inclined direction in the illustrated example). The lumen 30a of the blood inflow port 30 communicates with the accommodation space 26a via the lumen 58a of the protruding cylinder portion 58.

The cover 50 is further provided with the blood outflow port 32 described above. The blood outflow port 32 extends tangentially from the outer surface of the peripheral wall 57 of the cover 50. The lumen 32a of the blood outflow port 32 communicates with the accommodation space 26a.

Examples of the constituent material of the housing 26 (base 48 and cover 50) include various types of glass, polyvinyl chloride, polyethylene, polypropylene, cyclic polyolefin, polystyrene, poly- (4-methylpentene-1), polycarbonate, acrylic resin, Various resins such as acrylonitrile-butadiene-styrene copolymers, polyesters such as polyethylene terephthalate, polyethylene naphthalate, butadiene-styrene copolymers, polyamides (eg nylon 6, nylon 6,6, nylon 6,10, nylon 12) Materials. The housing 26 may be made of a transparent material so that blood flowing in the housing 26 can be visually recognized.

The impeller 28 accommodated in the housing 26 is rotated relative to the housing 26 when the rotational force is transmitted from the pump drive unit 16. The impeller 28 includes a first rotor 87 that constitutes a bottom portion, a second rotor 88 that is concentrically stacked on the first rotor 87, and a rotor cover 89 that is concentrically stacked on the second rotor 88. .

Further, as shown in FIG. 3A, a plurality of blood guide paths 84 extending radially and obliquely downward from the approximate center of the impeller 28 are provided in the impeller 28. The plurality of blood guide paths 84 are formed between the second rotor 88 and the rotor cover 89. The plurality of flow path forming walls 91 projecting downward from the lower surface of the rotor cover 89 constitute wall portions on both sides of the blood guide path 84. The flow path forming wall 91 has a structure in which blood does not flow out in the rotation direction (no washout hole) by continuously extending outward in the radial direction. The upper surface of the rotor cover 89 has a conical shape, and an opening 92 is formed at the center thereof. The blood guiding path 84 is not limited to a straight line as shown in FIG. 3A, but may be a curved line.

Blood that has flowed from the blood inflow port 30 into the center of the impeller 28 enters the blood guide path 84 through the opening 92. Then, while being accelerated by the centrifugal force of rotation of the impeller 28, the blood flows in the blood guide path 84 outward in the rotational radial direction. The blood discharged from the end of the blood guide path 84 (the outer peripheral side of the impeller 28) flows to the blood outflow port 32 and is discharged from the blood outflow port 32 to the second connection line 33.

In order to rotate the impeller 28 within the housing 26, a shaft 62 (rotary shaft) is provided at the center of the impeller 28 as shown in FIG. The shaft 62 is a straight bar-like member and has spherical shaft ends 66 at both ends in the axial direction. The shaft 62 is fixed to the impeller 28 in a state where the shaft 62 is inserted into an insertion hole 63 that passes through the central portion of the impeller 28 in the axial direction. The shaft 62 and the impeller 28 are mutually fixed in a state in which relative rotation is impossible and relative displacement in the axial direction is impossible. In the present embodiment, the protrusions 65 provided on the inner peripheral wall forming the insertion hole 63 of the impeller 28 are engaged with the grooves 64 provided in the shaft 62, whereby the shaft 62 and the impeller 28 are mutually fixed. The

The shaft end 66 of the shaft 62 protrudes downward and upward from the impeller 28, respectively. Hereinafter, when the two shaft ends 66 are distinguished from each other, the lower shaft end 66 is referred to as a “first shaft end 66A” and the upper shaft end 66 is referred to as a “second shaft end 66B”.

The constituent material of the shaft 62 can be selected from the materials exemplified above as the constituent material of the housing 26, for example. In particular, the shaft 62 is preferably made of a ceramic material such as alumina ceramic having excellent wear resistance and slidability.

The centrifugal pump 11 (housing 26) includes a bearing 70 that pivotally supports each shaft end 66 of the shaft 62. Hereinafter, the lower bearing that pivotally supports the first shaft end 66A is referred to as “first bearing 70A”, and the upper bearing that pivotally supports the second shaft end 66B is referred to as “second bearing 70B”. The shaft 62 is rotatably held between the first bearing 70A and the second bearing 70B in a state where a predetermined tightening load is applied in the axial direction in the housing 26.

The first bearing 70A has a spherically recessed bearing surface 73 that contacts the first shaft end 66A. The radius of curvature of the bearing surface 73 is larger than the radius of curvature of the first shaft end 66A. 70 A of 1st bearings are arrange | positioned at the 1st arrangement | positioning part 54 provided in the center part of the base 48. As shown in FIG.

The second bearing 70B has a spherically recessed bearing surface 73 that contacts the second shaft end 66B. The radius of curvature of the bearing surface 73 is larger than the radius of curvature of the second shaft end 66B. The second bearing 70 </ b> B is arranged in the second arrangement part 60 provided in the protruding cylinder part 58 of the cover 50.

The constituent material of the bearing 70 can be selected from the materials exemplified above as the constituent material of the housing 26, for example. In particular, the constituent material of the bearing 70 is preferably composed of ultrahigh molecular weight polyethylene having excellent wear resistance and self-lubricating properties.

1 to 3A, a plurality (six in FIG. 3A) of driven side magnets 86 are provided in the impeller 28 at intervals in the circumferential direction. The driven magnet 86 is a magnetic reactant that rotates the impeller 28 around the shaft 62 in response to the magnetism transmitted from the pump drive unit 16. The plurality of driven magnets 86 are held by a plurality of magnet holding portions 90 provided on the upper surface of the first rotor 87. The driven magnet 86 can be preferably a permanent magnet, but is not particularly limited. For example, a ferromagnetic metal may be used as a magnetic reactant in place of the driven magnet 86.

On the other hand, the pump drive unit 16 of the centrifugal pump system 10 is a mechanism unit that drives the impeller 28 of the centrifugal pump 11 described above. The centrifugal pump system 10 can use the pump drive unit 16 by replacing only the centrifugal pump 11 for each patient or procedure.

The pump drive unit 16 includes a drive transmission unit 34 that magnetically attracts the driven magnet 86 (forms a magnetic coupling with the impeller 28), and transmits the rotational force of the drive transmission unit 34 by magnetism. The impeller 28 is rotated. In addition to the drive transmission unit 34, the pump drive unit 16 includes a motor 37 (drive source) that rotates the drive transmission unit 34, and a displacement mechanism unit that integrally displaces the drive transmission unit 34 and the motor 37 up and down. 38 and a case 39 for housing them.

The drive transmission unit 34 includes a rotating member 35 and a driving magnet 36 (magnetic reactant) attached to the rotating member 35. The rotating member 35 is formed in a disk shape, for example, and its central portion is fixedly supported on the rotating shaft 37 a of the motor 37. On the upper surface of the rotating member 35, a magnet holding portion 35a of the driving side magnet 36 is provided, and the driving side magnet 36 is disposed with respect to the magnet holding portion 35a. The magnet holding part 35a preferably has a magnetic shield function capable of reducing the influence of the magnetism of the drive-side magnet 36 on the surroundings so that the magnetism has directivity.

As shown in FIG. 3B, a plurality of drive side magnets 36 (for example, the number corresponding to the driven side magnets 86) may be arranged at intervals in the circumferential direction around the rotation shaft 37a of the motor 37. The magnet holding portion 35a is also provided on the rotating member 35 corresponding to the number of drive side magnets 36 arranged. The number of arrangement of the drive side magnet 36 and the driven side magnet 86 is not particularly limited, and the number of arrangement of the drive side magnet 36 and the driven side magnet 86 may be different.

Further, the drive-side magnet 36 according to the present embodiment includes two types of magnetic reactants, a permanent magnet 36a and an electromagnet 36b. For example, the permanent magnets 36 a and the electromagnets 36 b may be arranged alternately along the circumferential direction of the rotating member 35. The electromagnet 36b is configured such that a conducting wire 46a is wound around the core material 46b in a coil shape and has a polarity at the upper end of the core material 46b. The electromagnet 36b can generate a stronger magnetic force than the permanent magnet 36a by the current supplied through the conducting wire 46a. The plurality of conductive wires 46a are wired in a hollow rotating shaft 37a and externally connected by connecting means (for example, connection of a slip ring and a terminal) capable of supplying power while allowing rotation at an intermediate position of the rotating shaft 37a. It is connected to the power supply line 47a (see FIG. 1). The power supply line 47a is connected to an external power supply 47 (see FIG. 1) whose output is controlled by the control unit 45.

The plurality of drive-side magnets 36 and the plurality of driven-side magnets 86 are arranged with their opposite surfaces having opposite polarities in order to exert an attractive force between them. For example, when the upper surface of the drive-side magnet 36 is N-pole, the lower surface of the driven-side magnet 86 is S-pole, and when the upper surface of the drive-side magnet 36 is S-pole, the lower surface of the driven-side magnet 86 is N-pole. The winding state of the conducting wire 46a and the current supply direction are set so that the electromagnet 36b also satisfies this polarity.

Further, the driving side magnet 36 is formed in a fan shape larger than the planar shape of the driven side magnet 86 in a plan view, for example. Thereby, the drive side magnet 36 can form a magnetic coupling favorably with the driven side magnet 86. Of course, the shapes of the drive side magnet 36 and the driven side magnet 86 are not particularly limited.

Further, the drive transmission unit 34 may be arranged with the auxiliary magnet 40 facing the opposite polarity to the adjacent drive side magnet 36 at the position indicated by the two-dot chain line in FIG. 3B. The auxiliary magnet 40 applies a repulsive force to the driven magnet 86, thereby reducing the shearing force applied in the rotation direction when the rotational driving force is transmitted between the impellers 28. Of course, the auxiliary magnet 40 may be disposed on the driven magnet 86 side.

1, the motor 37 that rotates the drive transmission unit 34 has the hollow rotation shaft 37a as described above, and the rotation shaft 37a rotates based on the set speed of the control unit 45. A rotating member 35 is attached to the tip (upper end) of the rotating shaft 37a. The motor 37 may be either an AC motor or a DC motor, but a variable speed motor is preferable. For example, when a stepping motor is used as the motor 37, blood flow control in the centrifugal pump 11 is easy. Moreover, the drive transmission part 34 may be configured not only to be attached to the rotating shaft 37a but also to constitute a part of the rotor (not shown) of the motor 37 and directly receive the driving force from the stator (not shown). .

Also, the displacement mechanism unit 38 of the pump drive unit 16 varies the separation distance of the drive transmission unit 34 (drive side magnet 36) with respect to the centrifugal pump 11 (the driven side magnet 86 of the impeller 28). That is, the displacement mechanism unit 38 has a function of adjusting the magnetic force acting between the driving side magnet 36 and the driven side magnet 86 by changing the separation distance.

The displacement mechanism unit 38 includes, for example, a pedestal 38a that fixes and supports the motor 37, hydraulic cylinders 38b provided at four corners of the pedestal 38a that supports and displaces the pedestal 38a, and a supply that supplies or discharges hydraulic pressure from the hydraulic cylinder 38b. Part 38c. The supply unit 38c adjusts the height of the pedestal 38a by uniformly supplying a predetermined amount of oil to each hydraulic cylinder 38b under the control of the control unit 45. Accordingly, the displacement mechanism unit 38 can move the entire drive side magnet 36 up and down uniformly without inclining the drive side magnet 36 of the drive transmission unit 34 with respect to the driven side magnet 86.

The number and arrangement positions of the hydraulic cylinders 38b may be freely designed. For example, the central part of the base 38a may be supported by one hydraulic cylinder 38b. Moreover, the structure of the displacement mechanism part 38 is not limited to the said structure, A mechanical structure by a motor, a gear, etc., or an electric actuator, an air cylinder, etc. can be applied.

The case 39 of the pump drive unit 16 is configured as a housing that houses the drive transmission unit 34, the motor 37, and the displacement mechanism unit 38. At the upper part of the case 39, a mounting part 39a for mounting and fixing the centrifugal pump 11 and a detection sensor 39b for detecting the rotational speed of the impeller 28 are provided.

The mounting portion 39a is configured as an annular groove provided in the center of the upper surface of the case 39, and the mounted portion 53 provided on the lower surface of the base 48 of the centrifugal pump 11 is mounted on the mounting portion 39a. The mounted portion 53 of the centrifugal pump 11 includes an annular fitting wall 53a whose inner cross section is formed in a tapered shape along the axial direction. The centrifugal pump system 10 can firmly fix the centrifugal pump 11 to the pump drive unit 16 by taper fitting the fitting wall 53a to the mounting portion 39a (groove portion).

In addition, the mounting mechanism of the centrifugal pump 11 and the pump drive unit 16 is not particularly limited. For example, a spline fitting structure in which a concave portion extending in the vertical direction is cut out at a predetermined position of the mounting portion 39a (groove portion) and a convex portion that fits into the concave portion is formed on the fitting wall 53a. In addition, various structures that can stably fix the centrifugal pump 11 such as a screw mechanism and a lock mechanism can be adopted as the mounting mechanism.

The detection sensor 39b is provided at a predetermined position on the upper surface of the case 39, and is connected to the control unit 45 so that a detection signal can be transmitted (see FIG. 1). For example, an encoder can be applied to the detection sensor 39 b, and the rotational speed (the number of rotations) of the impeller 28 is detected in a state where the centrifugal pump 11 is disposed in the pump drive unit 16, and is output to the control unit 45. For this reason, it is preferable to provide a structure for the detection sensor 39b to perform detection (for example, a structure in which a part is a transmission part in optical detection) on the impeller 28 side. As the detection sensor 39b, various sensors capable of measuring the rotation speed can be applied, and the rotation speed of the rotation member 35 and the drive side magnet 36 may be detected, or provided on the centrifugal pump 11 side. May be. The detection signal transmission means may be either wired or wireless.

Referring back to FIG. 1, the control unit 45 includes a computer having an input unit, a display unit, a storage unit, and a calculation unit (not shown), and controls the driving of the motor 37, the driving of the displacement mechanism unit 38, and the magnetic force of the electromagnet 36b. The input unit of the control unit 45 includes a switch capable of switching the rotation speed of the impeller 28 to a plurality of stages, for example, 3000 rpm (high speed rotation: first rotation speed) and 1500 rpm (low speed rotation: second rotation speed). Thereby, the user can set a rotation speed according to the procedure and the blood state of the patient. The rotational speed of the impeller 28 is preferably set in the range of 0 to 3000 rpm, and the input unit is not only configured to switch the rotational speed in stages, but also numerically input the rotational speed and the rotational speed in an analog manner. It may be configured to switch.

The control unit 45 rotates the motor 37 based on the set rotation speed, and rotates the impeller 28 of the centrifugal pump 11 via the drive transmission unit 34. When the rotation speed of the impeller 28 is set to 3000 rpm or less, hemolysis and thrombus formation are easily suppressed. The impeller 28 may be rotatable at 3000 rpm or higher. When the rotation of the impeller 28 is controlled by the control unit 45, feedback control may be performed based on the detection signal of the detection sensor 39b. Thereby, the rotational speed of the impeller 28 can be controlled with high accuracy.

Also, the control unit 45 according to the present embodiment controls the driving of the displacement mechanism unit 38 based on the detection signal of the detection sensor 39b. That is, the control unit 45 adjusts the hydraulic amount of the supply unit 38c according to the rotational speed of the impeller 28, and adjusts the displacement of the pedestal 38a via the hydraulic cylinder 38b. Thereby, based on the rotational speed of the impeller 28, the vertical position of the drive transmission part 34 and the motor 37 mounted on the base 38a fluctuate | varies.

Furthermore, the control unit 45 operates the external power supply 47 according to the rotational speed of the impeller 28 and supplies a current to the electromagnet 36 b of the drive side magnet 36. Thereby, the electromagnet 36b can apply a strong magnetic force to the driven magnet 86 at a predetermined timing, and can strengthen the magnetic coupling with the impeller 28. The control of the drive transmission unit 34 by the control unit 45 will be described in detail later.

On the other hand, the oxygenator 18 of the oxygenator 12 includes a main body 41, a blood inflow port 42 provided on the upstream side of the main body 41, and a blood outflow port 43 provided on the downstream side of the main body 41. The blood inflow port 42 is connected to the centrifugal pump system 10 via the second connection line 33. The blood outflow port 43 is connected to a return line 44 that returns blood to the patient.

The main body 41 of the artificial lung 18 performs gas exchange for adding oxygen to the blood flowing from the centrifugal pump system 10 via the blood inlet port 42 and removing carbon dioxide. The artificial lung 18 also has a heat exchange function for changing the temperature of blood. The control unit 45 described above may be configured to control the operation of the oxygenator 18 (that is, a configuration to control the entire operation of the heart-lung machine 12). Thereby, the blood flow of the patient can be accurately and easily controlled during the procedure.

The centrifugal pump system 10 according to the present embodiment is basically configured as described above, and the operation and effect will be described below.

In order to facilitate understanding of the present invention, the general operation of the centrifugal pump impeller will be described first. The impeller of the centrifugal pump guides blood radially outward and obliquely downward when rotating, thereby causing a phenomenon that the impeller itself floats upward as the rotational speed increases. For this reason, when the impeller rotates at a low speed (for example, 1500 rpm), the load applied to the lower bearing from the impeller shaft is larger than the load applied when the impeller rotates at a high speed (for example, 3000 rpm). When blood is caught in the bearing while the impeller is rotating in a state where the load on the lower bearing is large, the friction energy also increases in the bearing that receives the load, so that there is a high possibility that thrombus will occur.

Therefore, the centrifugal pump system 10 according to the present embodiment performs control to vary the magnetic force applied to the driven magnet 86 based on the rotational speed of the impeller 28 when the pump driving unit 16 rotationally drives the impeller 28. As a result, the degree to which the impeller 28 is attracted downward during rotation (the load on the lower side in the rotational axis direction) is adjusted, and an appropriate load can be applied to the first bearing 70A.

That is, the centrifugal pump system 10 displaces the driving magnet 36 downward during the low-speed rotation (second rotation speed) of the impeller 28 shown in FIG. 4A, and the high-speed rotation (first rotation speed) of the impeller 28 shown in FIG. 4B. Sometimes the drive side magnet 36 is displaced upward. Further, the centrifugal pump system 10 stops the driving of the electromagnet 36b of the driving side magnet 36 at the time of low speed rotation, and drives the electromagnet 36b at the time of high speed rotation. With these controls, it is possible to satisfactorily adjust the attractive force (magnetic force) that acts between the drive-side magnet 36 and the driven-side magnet 86 during low-speed rotation and high-speed rotation.

More specifically, the user can rotate the impeller 28 by mounting the mounted portion 53 of the centrifugal pump 11 on the mounting portion 39a of the pump driving portion 16 in the use of the heart-lung machine 12 constructed as shown in FIG. State. In the rotatable state, current supply from the external power supply 47 to the electromagnet 36b is stopped by the control unit 45, whereby the permanent magnet 36a and the driven magnet 86 facing the permanent magnet 36a are magnetically coupled (mutual attractive force between them). The working state). In the present embodiment, the control is simplified by switching between driving or stopping of the electromagnet 36b. However, in order to adjust the entire magnetic force applied between the impeller 28 and the drive transmission unit 34, the output of the external power supply 47 is output. The electromagnet 36b may be appropriately driven by control. Thereafter, the user sets the rotational speed (low-speed rotation or high-speed rotation) of the centrifugal pump 11 by the input unit of the control unit 45 and drives the centrifugal pump system 10.

The control unit 45 drives the motor 37 to rotate according to the set rotation speed. Thereby, the pump drive unit 16 rotates the drive transmission unit 34 at the upper end of the rotation shaft 37 a, and the drive side magnet 36 of the drive transmission unit 34 rotates the driven side magnet 86. The centrifugal pump 11 rotates the impeller 28 around the shaft 62 in the housing 26. As a result, the centrifugal pump 11 sucks blood into the housing 26 from the blood inflow port 30 and draws blood from the housing 26 into the blood outflow port 32. Discharge.

Further, the control unit 45 adjusts the rotational speed of the motor 37 by detecting the actual rotational speed of the impeller 28 by the detection sensor 39b when the impeller 28 rotates. That is, the pump drive unit 16 can accurately adjust the rotation of the impeller 28 to the rotation speed set by the user. For example, the pump drive unit 16 can continue the rotation of the impeller 28 while maintaining the low speed rotation (1500 rpm) shown in FIG. 4A. it can.

In the centrifugal pump system 10, in the low speed rotation of the impeller 28, the control unit 45 controls the driving of the displacement mechanism unit 38 (see FIG. 1), and sets the height position of the drive transmission unit 34 (drive side magnet 36). adjust. At this time, the drive transmission unit 34 outputs the constant magnetic flux of the permanent magnet 36a in the vertical direction by stopping the driving of the electromagnet 36b. In the adjustment of the height position, the control unit 45 performs a low-speed rotation separation distance D _L between the drive-side magnet 36 and the driven-side magnet 86 based on the detection of the low-speed rotation (or setting of the input unit) by the detection sensor 39b. Set to. The control unit 45 may prepare a threshold value (for example, 2000 rpm) in advance for rotation detection and determine low-speed rotation or high-speed rotation.

Under the control of the control unit 45, the displacement mechanism unit 38 varies the hydraulic supply amount of the supply unit 38c to displace the base 38a supported by the hydraulic cylinder 38b to an appropriate height position. Attraction Thus, acting displacement driving side magnet 36 in a position matching the distance D _L for low-speed rotation that is set (i.e., than during high-speed rotation spaced) is, between the permanent magnets 36a and the driven side magnet 86 Weaken.

As the impeller 28 is weakened as described above, the upward buoyancy in the housing 26 increases during low-speed rotation. In other words, by by increasing the distance D _L weaken the magnetic force, it is possible to adjust the magnetic force between the permanent magnets 36a and the driven side magnet 86 satisfactorily. As a result, the centrifugal pump system 10 can reduce the influence of the shaft 62 on the blood by reducing the load applied to the first bearing 70A from the shaft 62 when the impeller 28 rotates at a low speed.

Conversely, the control unit 45 sets the separation distance D _H for high-speed rotation between the drive-side magnet 36 and the driven-side magnet 86 in the high-speed rotation of the impeller 28. The separation distance D _H for high speed rotation is set shorter than the separation distance D _L for low speed rotation. The separation distances D _L and D _H may be obtained in advance so as to obtain an appropriate magnetic force through experiments or the like, and stored in the storage unit of the control unit 45. The displacement mechanism unit 38 displaces the drive side magnet 36 to a position that coincides with the set separation distance _DH (that is, closer to that at the time of low speed rotation), and reduces the attractive force applied to the driven side magnet 86 by the permanent magnet 36a. Strengthen than during rotation.

Further, when the control unit 45 determines high-speed rotation, the control unit 45 controls the external power supply 47 to drive the electromagnet 36b by supplying a predetermined amount of current to the electromagnet 36b. The electromagnet 36b attracts the driven magnet 86 downward more strongly by applying a stronger magnetic force to the driven magnet 86 than the permanent magnet 36a.

The impeller 28 is attracted as described above, so that upward buoyancy in the housing 26 can be suppressed during high-speed rotation. That is, the centrifugal pump system 10 can make the load applied from the shaft 62 to the first bearing 70 </ b> A heavier than the conventional one when the impeller 28 rotates at high speed (similar to the load during low-speed rotation).

Here, the impeller floats relatively easily during high-speed rotation by the magnetic force of the conventional permanent magnet. On the other hand, the centrifugal pump system 10 according to the present embodiment can sufficiently prevent the impeller 28 from floating by causing the electromagnet 36b to generate a stronger magnetic force. As a result, the centrifugal pump system 10 controls so that the load applied from the shaft 62 to the first bearing 70A does not fluctuate greatly during the low-speed rotation and the high-speed rotation of the impeller 28. Suppresses blood and can send blood. Note that, when the impeller 28 rotates at high speed, the influence of the impeller 28 on blood is increased, so the load between the shaft 62 and the first bearing 70A may be slightly weaker than at low speed.

For reference, the measurement results of FIG. 5 are shown for the separation distances D _L and D _H between the drive side magnet 36 and the driven side magnet 86 and the fluctuations in the transmission torque and magnetic force (coupling force) to the impeller 28 by the drive transmission unit 34. The description will be given with reference. As can be understood from FIG. 5, the transmission torque and the coupling force decrease as the separation distances D _L and D _H increase. Therefore, the longer the distance D _L during low-speed rotation of the impeller 28, it can be seen that may reduce the force applied to the impeller 28. Incidentally, the distance D _L becomes longer, but also decreases the transmission torque, can be rotated sufficiently impeller 28 even with a small transmission torque at low speed rotation. Conversely, if the separation distance _DH is shortened when the impeller 28 rotates at high speed, the magnetic force applied to the impeller 28 can be increased, and the impeller 28 can be rotated with a larger transmission torque. As shown in FIG. 5, the transmission torque and the coupling force decrease along a gentle curve (non-linearly) as the separation distance increases, so the control unit 45 is optimal for the rotational speed of the impeller 28. It is preferable to design the control so that the separation distance (transmission torque, coupling force) is obtained.

As described above, in the centrifugal pump system 10 according to this embodiment, the drive transmission unit 34 varies the magnetic force applied to the impeller 28 in accordance with the rotation speed of the motor 37, so that the load during rotation of the impeller 28 is appropriately set. Can be set to In other words, the centrifugal pump system 10 that magnetically rotates the impeller 28 can appropriately adjust the load in the rotation axis direction of the impeller 28 by changing the magnetic force applied to the driven magnet 86 when the impeller 28 rotates. Thereby, the centrifugal pump system 10 can suppress the change of blood due to the influence of the load of the impeller 28 (for example, the generation of a thrombus), and the blood can be fed satisfactorily.

In this case, the drive transmission unit 34 can reduce the load applied to the first bearing 70A by the shaft 62 of the impeller 28 during low-speed rotation by weakening the magnetic force applied during low-speed rotation than the magnetic force applied during high-speed rotation. Therefore, even when the impeller 28 is rotated at a low speed in order to suppress hemolysis of the blood, the blood can be fed satisfactorily. Furthermore, the centrifugal pump system 10, the displacement mechanism 38, the distance D _L of the low speed rotation of the impeller 28 by longer than the distance D _H of the high-speed rotation, weakened easily force during low-speed rotation The load on the impeller 28 can be reliably reduced. Further, since the drive transmission unit 34 includes the electromagnet 36b, when the impeller 28 is rotated at a high speed, a strong magnetic force can be applied to the impeller 28, and the impeller 28 can be sufficiently attracted and rotated. For this reason, even during high-speed rotation, the rotational force of the drive transmission unit 34 can be well transmitted to the impeller 28 (reducing magnetic decoupling) and rotated. The centrifugal pump system 10 can easily control the fluctuation of the magnetic force while simplifying the structure of the rotation control of the impeller 28 by integrally displacing the drive transmission unit 34 and the motor 37.

Here, in the pivot support structure including the shaft 62 and the bearing 70, stress is applied intensively from the shaft 62 toward the bearing 70. However, the load applied to the bearing 70 can be appropriately controlled by changing the magnetic force applied to the impeller 28 by the drive transmission unit 34.

Further, the blood guide path 84 of the impeller 28 is linearly extended outward in the rotational radial direction while being surrounded by the flow path forming wall 91, so that blood (fluid) is centrifuged in the impeller 28. Can be guided linearly in the direction. Thereby, even if the rotational speed of the impeller 28 is low, the amount of blood delivered can be improved. Further, when the impeller 28 rotates at a low speed, the load in the rotation axis direction of the impeller 28 can be reduced as described above.

The centrifugal pump system 10 is not limited to the above-described embodiment, and various modifications and application examples can be adopted. As an example, the centrifugal pump 11 of the centrifugal pump system 10 only needs to have a structure capable of rotating the impeller 28 within the housing 26, and the shaft support structure by the shaft 62 and the bearing 70 may have other designs. For example, the shaft support structure of the centrifugal pump 11 may be a one-point pivot support structure, and may employ a ball bearing as the bearing. The impeller may not have a rotating shaft.

Further, the displacement of the drive transmission unit 34 may be configured to mechanically displace the vertical position in conjunction with a low-speed rotation or high-speed rotation switch operation of the impeller 28 by the user without being controlled by the control unit 45, for example. .

Further, the displacement of the drive transmission unit 34 is not limited to switching between the low speed rotation and the high speed rotation of the motor 37 (that is, the impeller 28), and the drive transmission unit 34 is displaced continuously or stepwise according to a change in the rotation speed of the impeller 28. You may let them. At this time, it is preferable to control the state of the drive transmission unit 34 (the separation distance between the drive side magnet 36 and the driven side magnet 86, the magnetic force of the electromagnet 36b) based on the change in the coupling force shown in FIG.

Hereinafter, modified examples of the present embodiment will be described based on some illustrated examples. In the following description, the same configuration as the centrifugal pump system 10 according to the present embodiment or the configuration having the same function is denoted by the same reference numeral, and the detailed description thereof is omitted.

The centrifugal pump system 10A according to the first modification shown in FIG. 6 includes a sensor device 94 (detection unit) in each of the first arrangement unit 54 and the second arrangement unit 60 of the centrifugal pump 11A, and the control unit 45A includes the sensor device. It is configured to receive 94 output signals. The sensor device 94 includes a load sensor (or pressure sensor) that detects a load received from the shaft 62 via the first bearing 70A or the second bearing 70B, and a transmitter that outputs a detection value of the load sensor. In this case, examples of the load sensor include a strain gauge and a load cell. As the transmitter, for example, an RFID (also referred to as a wireless tag, an IC tag, or a mu chip) that stores individual information in a minute IC chip and transmits information wirelessly can be applied.

The axial load of the shaft 62 acts on the first sensor device 94A on the first bearing 70A side via the first bearing 70A. The axial load of the shaft 62 acts on the second sensor device 94B on the second bearing 70B side via the second bearing 70B.

The control unit 45A receives the load detection signals from the first and

second sensor devices

94A and 94B during the rotation of the impeller 28 of the centrifugal pump 11A, and performs control to correct the fluctuation of the magnetic force applied to the impeller 28. Specifically, the control unit 45A largely (roughly) fluctuates the vertical position of the drive transmission unit 34 as described above with reference to the setting of the low speed rotation or the high speed rotation of the impeller 28, and the electromagnet 36b is turned on / off. Switch. During actual rotation of the impeller 28, the vertical position of the drive transmission unit 34 is finely adjusted based on the load applied to the first bearing 70A and the load applied to the second bearing 70B.

In the rotation of the impeller 28, it is preferable that the load applied to the first bearing 70A and the load applied to the second bearing 70B are substantially the same. For this reason, the control unit 45A compares the load detected by the first sensor device 94A with the load detected by the second sensor device 94B, and the height position of the drive transmission unit 34 so that the load difference approaches zero. Adjust. For example, when the load on the first sensor device 94A side is large, it can be said that the attractive force between the drive-side magnet 36 and the driven-side magnet 86 is large, so the control unit 45A displaces the drive transmission unit 34 downward. On the other hand, when the load on the second sensor device 94B side is large, it can be said that the attractive force between the driving side magnet 36 and the driven side magnet 86 is small, so the control unit 45A displaces the drive transmission unit 34 upward. .

As described above, the centrifugal pump system 10A can adjust the magnetic force applied to the impeller 28 with higher accuracy by using the loads of the first and

second bearings

70A and 70B during the rotation of the impeller 28. Generation can be further suppressed. The sensor device 94 may be installed only on either the first bearing 70A or the second bearing 70B. If one load of the bearing 70 is detected, the load of the whole shaft 62 can be estimated and the drive transmission part 34 can be displaced (magnetic force is fluctuated).

Moreover, the

centrifugal pump systems

10 and 10A can adjust the fluctuation of the magnetic force applied to the impeller 28 (displacement of the drive transmission unit 34) using various sensors in addition to the load sensor and the pressure sensor. For example, a magnetic sensor for detecting the magnetic force between the drive side magnet 36 and the driven side magnet 86 may be provided on the top of the pump drive unit 16 and the drive transmission unit 34 may be displaced based on the magnetic force detected by the magnetic sensor. .

The centrifugal pump system 10B according to the second modified example shown in FIGS. 7A to 7C has a configuration in which the driving side magnet 36A of the pump driving unit 16A exerts a repulsive force (repulsive force) with the driven side magnet 86 of the impeller 28. (See also FIG. 1). That is, the upper surface side where the drive side magnet 36A faces the driven side magnet 86 is set to the same polarity as the lower surface side where the driven side magnet 86 faces the drive side magnet 36A.

In this case, as shown in FIG. 7A, when the centrifugal pump 11 is mounted, the driving magnet 36A and the driven magnet 86 are stable in mutual position due to the mutual repulsive force that causes the phases to shift in the circumferential direction. Turn into. Therefore, in the present embodiment, the driving side magnet 36 </ b> A and the driven side magnet 86 according to the second modification are also impeller with the rotation of the drive transmission unit 34, as in the state in which an attractive force acts between the driving side magnet 36 and the driven side magnet 86. 28 can be rotated. Even in this case, it goes without saying that both the permanent magnet 36a and the electromagnet 36b can be used.

Here, the drive side magnet 36 </ b> A causes an effect of floating the impeller 28 in the housing 26, contrary to the action of attraction, by exerting a repulsive force with the driven side magnet 86. That is, when the magnetic force between the driving side magnet 36A and the driven side magnet 86 is strong, the impeller 28 is floated upward.

Therefore, as shown in FIGS. 7B and 7C, at the time of low-speed rotation of the impeller 28, the distance D _L between the driving-side magnet 36A and the driven magnet 86 to shorten, at the high-speed rotation of the impeller 28 is driven Control is performed so that the separation distance _DH between the side magnet 36A and the driven magnet 86 is increased. Thereby, also in the centrifugal pump system 10B, the load in the rotation axis direction of the impeller 28 can be controlled with high accuracy.

A centrifugal pump system 10C according to the third modified example shown in FIG. 8A has a drive transmission unit 34A having a drive-side magnet 36 above the centrifugal pump 11 (see also FIG. 1). The drive side magnet 36 applies a magnetic force (attractive force or repulsive force) to the driven side magnet 86 provided on the impeller 28 in the centrifugal pump 11 to rotate the impeller 28 as the drive transmission unit 34A rotates. . The drive transmission unit 34A can change the magnetic force applied to the impeller 28 by a displacement mechanism unit or magnetic force changing means (not shown). Therefore, also in this centrifugal pump system 10C, the load in the rotation axis direction of the impeller 28 can be appropriately adjusted. In short, in the present invention, the location of the drive transmission unit 34 that rotates the impeller 28 is not particularly limited.

The centrifugal pump system 10D according to the fourth modification shown in FIG. 8B is different from the centrifugal pump system 10 according to the present embodiment in the arrangement relationship between the permanent magnet 36a and the electromagnet 36b of the drive side magnet 36. Specifically, the permanent magnet 36 a is disposed closer to the radially outer side of the rotating member 35, and the electromagnet 36 b is disposed closer to the radially inner side of the rotating member 35. Even if comprised in this way, it is possible to perform the same control as the centrifugal pump system 10, and the same effect can be acquired.

In short, the drive-side magnet 36 is not particularly limited with respect to the arrangement relationship between the permanent magnet 36a and the electromagnet 36b, and various structures that can change the magnetic force applied to the driven-side magnet 86 can be adopted. Further, for example, the drive-side magnet 36 can be composed of only the electromagnet 36b. In this case, when the drive transmission unit 34 (impeller 28) rotates at a low speed, the magnetic force is weakened by supplying a lower supply amount of current to the electromagnet 36b than at the time of high speed rotation, and the load on the impeller 28 can be reduced.

In the above description, the present invention has been described with reference to preferred embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. Yes.

Claims

A centrifugal pump (11) comprising a housing (26) and an impeller (28) rotatably disposed in the housing (26) and responsive to magnetism;
And a drive transmission portion (34) for transmitting the rotational force of the drive source (37) to the impeller (28) while magnetically attracting or repelling in the axial direction of the impeller (28),
The drive transmission unit (34) can vary the magnetic force applied to the impeller (28) based on the rotational speed of the impeller (28) or the drive source (37). 10A-10D).
The centrifugal pump system (10, 10A, 10D) according to claim 1,
The drive transmission unit (34) is disposed below the housing (26), and is more than the first rotational speed of the impeller (28) than the magnetic force applied at the first rotational speed of the impeller (28). A centrifugal pump system (10, 10A, 10D) characterized by weakening a magnetic force applied at a slow second rotation speed.
The centrifugal pump system (10, 10A, 10D) according to claim 2,
The drive transmission part (34) is displaced, and the impeller (28) has a larger distance than the separation distance between the impeller (28) and the drive transmission part (34) at the first rotational speed of the impeller (28). The centrifugal pump system (10, 10A, 10D) further comprising a displacement mechanism (38) for increasing the separation distance at the second rotational speed.
The centrifugal pump system (10, 10A, 10D) according to claim 3,
The drive transmission unit (34) has an electromagnet (36b) capable of controlling the magnetic force applied to the impeller (28) by supply power,
The centrifugal pump system (10, 10A, 10D), wherein the electromagnet (36b) is controlled so as to increase the magnetic force at the first rotational speed than the magnetic force at the second rotational speed.
The centrifugal pump system (10, 10A, 10D) according to claim 3,
The centrifugal mechanism (10, 10A, 10D) characterized in that the displacement mechanism (38) integrally displaces the drive transmission unit (34) and the drive source (37).
The centrifugal pump system (10, 10A-10D) according to claim 1,
The centrifugal pump (11)
A shaft (62) provided in the center of the impeller (28) and having axial ends (66) at both axial ends;
A centrifugal pump system (10, 10A to 10D), comprising: a bearing (70) pivotally supporting each of the shaft ends (66).
The centrifugal pump system (10A) according to claim 6,
A detector (94) for detecting pressure or load between at least one of the bearings (70) and the housing (26);
A centrifugal pump system (10A), further comprising: a control unit (45A) that varies a magnetic force applied to the impeller (28) based on the detected pressure or the load.
The centrifugal pump system (10, 10A-10D) according to claim 1,
The impeller (28) has a plurality of guide paths (84) for allowing fluid to flow outward from the center of rotation in the radial direction of rotation,
The guide path (84) extends linearly toward the outer side in the rotational radial direction while being surrounded by a wall (91) constituting the impeller (28). Pump system (10, 10A-10D).