JP7019461B2 - Magnetic transmission for blood pump - Google Patents

Description

The present invention relates to a magnetic transmission for a blood pump.

In recent years, as a blood circulation device for a heart-lung machine, an increasing number of cases have used a centrifugal blood pump device (magnetically coupled centrifugal blood pump device) that transmits the drive torque of an external motor to an impeller in a blood chamber using a magnetic coupling. is doing. According to the magnetically coupled centrifugal blood pump device, the physical communication between the outside and the blood chamber can be completely eliminated, so that the invasion of bacteria and the like into the blood can be prevented, and an expensive external motor can be prevented. It is possible to make only the pump head that comes into contact with blood into a disposable structure while making it reusable.

Currently, magnetically coupled centrifugal blood pump devices with various rotation directions and rotation speed ranges are used, but in most cases, the magnetic coupling method is not compatible. Each disposable pump head requires a dedicated external motor, and even when it is desired to increase the rotation speed and reduce the size of the pump head, the existing external motor cannot be used. Therefore, it is necessary to newly develop an external motor and a drive device.

The following Patent Document 1 discloses a transmission for driving a pump head having a different rotation direction and rotation speed by an existing external motor. Specifically, FIG. 12 of Patent Document 1 discloses a configuration in which a disk-shaped multipolar magnetizing magnet is eccentrically coupled rather than concentrically to reverse the rotation direction. FIG. 13 of Patent Document 1 discloses a configuration in which a mechanical gear is used to shift gears (there is also a description that the gears may be reversed).

U.S. Pat. No. 5,210,148

In the case of the configuration in which the disc-shaped multi-pole magnetizing magnet described above is eccentrically coupled to reverse the rotation direction, a large space is required in the lateral direction, and only a part of the magnetic poles is magnetically coupled, so that the transmission torque is transmitted. There is a problem that In the case of a configuration in which shifting (and reversing) is performed using mechanical gears, there are problems of mechanical noise, durability due to wear of the gears, and reliability.

The present invention has been made in consideration of such problems, and an object of the present invention is to provide a magnetic transmission for a blood pump, which is small in size, has sufficient torque transmission capability, and is reliable and durable. ..

In order to achieve the above object, the present invention is a magnetic transmission for a blood pump, which shifts a rotational driving force generated by a driving unit for driving a blood pump and transmits the rotational driving force to the blood pump. A pole piece configured to face the unit-side drive magnet mounted on the unit concentrically with the unit-side drive magnet, and a rotating body rotatably arranged concentrically with the pole piece. , The driven magnet for magnetic gear held by the rotating body and concentrically arranged with the pole piece and opposed to the pole piece, and held by the rotating body and arranged concentrically with the pole piece. A coupling driven magnet provided in the blood pump and a coupling drive magnet capable of magnetic coupling are provided.

According to the magnetic transmission for a blood pump of the present invention having the above configuration, when the blood pump is attached to the drive unit, the driven magnet for the magnetic gear and the drive magnet for coupling are concentric with the drive magnet on the unit side. Placed in. Therefore, unlike the eccentric coupling method, a large space in the lateral direction is not required, and a compact device can be obtained. Further, unlike the eccentric coupling method, not a part of the magnetic poles but the entire magnetic pole is magnetically coupled, so that a sufficient torque transmission capacity can be obtained. Furthermore, compared to a method of transmitting power using mechanical gears, mechanical noise is small, and durability and reliability are excellent.

The number of magnetic poles of the magnetic gear driven magnet is smaller than the number of magnetic poles of the unit-side driving magnet, and the magnetic gear driven magnet may rotate at a higher speed than the unit-side driving magnet.

With this configuration, the driving force of the driving unit can be accelerated and transmitted to the blood pump.

The number of magnetic poles of the driven magnet for magnetic gear is larger than the number of magnetic poles of the driven magnet on the unit side, and the driven magnet for magnetic gear may rotate at a lower speed than the driven magnet on the unit side.

With this configuration, the driving force of the driving unit can be decelerated and transmitted to the blood pump.

The magnetizing direction of the driven magnet for the magnetic gear may be the radial direction.

The magnetizing direction of the driven magnet for the magnetic gear may be the axial direction.

The magnetizing direction of the magnetic gear driven magnet may be inclined with respect to the axis of the magnetic gear driven magnet.

The magnetizing direction of the coupling drive magnet may be the radial direction.

The magnetizing direction of the coupling drive magnet may be the axial direction.

The magnetizing direction of the coupling drive magnet may be inclined with respect to the axis of the coupling drive magnet.

The pole piece may be made of a dust core or an amorphous iron core.

With this configuration, it is possible to suppress the generation of eddy currents and reduce energy loss.

The driven magnet for the magnetic gear may be divided in the axial direction or the circumferential direction.

With this configuration, it is possible to suppress the generation of eddy currents and reduce energy loss.

The pole piece may have magnetic coupling surfaces on the inner circumference and the outer circumference, and the heights of the pole pieces may be different from each other.

With this configuration, when the unit-side drive magnet is magnetized in the radial direction, it is possible to use a magnetic gear driven magnet having a height higher than that of the unit-side drive magnet and a larger magnetic coupling area.

According to the magnetic transmission for a blood pump of the present invention, it is small in size, has sufficient torque transmission capability, and is reliable and durable.

It is a schematic sectional drawing of the magnetic transmission for blood pumps which concerns on 1st Embodiment of this invention. It is a plane block diagram of the unit side drive magnet. It is a plane block diagram of a pole piece and a driven magnet for a magnetic gear. It is a schematic sectional drawing of the magnetic transmission for blood pumps which concerns on 2nd Embodiment of this invention. It is a schematic sectional drawing of the magnetic transmission for blood pumps which concerns on 3rd Embodiment of this invention.

Hereinafter, a plurality of suitable embodiments of the magnetic transmission for a blood pump according to the present invention will be described with reference to the accompanying drawings. In the second embodiment and the third embodiment, the same or similar elements as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The magnetic transmission 10 for a blood pump shown in FIG. 1 (hereinafter, abbreviated as “transmission 10”) is used to shift the rotational driving force generated by the drive unit 14 and transmit it to the blood pump 16. It is an adapter. The transmission 10 constitutes a part of the heart-lung machine 18 together with the drive unit 14 and the blood pump 16. The heart-lung machine 18 is used in, for example, heart surgery, oxygenates blood bleeding from a patient, removes foreign substances, and returns the blood to the patient.

Although not shown in detail, the artificial heart-lung machine 18 includes a blood pump 16, a drive unit 14, a transmission 10 and a reservoir for temporarily storing blood (venous blood) bleeding from a patient, and oxygen in the blood. It is equipped with an artificial lung that exchanges gas to remove carbon dioxide while adding blood.

The blood pump 16 sends blood from the reservoir to the artificial lung. The blood pump 16 includes at least a housing 20 and an impeller 22 rotatably disposed within the housing 20. The housing 20 has an inflow port 24 connected to the outflow port 26 of the reservoir via a first connection line (not shown) and an outflow port 26 connected to the artificial lung via a second connection line (not shown). The blood flowing from the inflow port 24 into the center of the impeller 22 flows to the outer peripheral side of the impeller 22 while being accelerated by the rotation of the impeller 22, and is discharged from the outflow port 26.

The housing 20 of the blood pump 16 has a base 20a constituting the lower portion, a cover 20b constituting the upper portion, and a side wall portion 20c forming an annular peripheral wall between the base 20a and the cover 20b. An inflow port 24 is provided in the central portion of the cover 20b, and an outflow port 26 is provided in the side wall portion 20c. At the lower part of the base 20a, a mounting convex portion 28 having a circular cross section protruding downward is provided. In the base 20a, an impeller arranging recess 30 is provided on the side opposite to the mounting convex portion 28.

An impeller support shaft 32 projecting toward the cover 20b is provided at the center of the bottom of the base 20a (specifically, the impeller placement recess 30). The impeller 22 is rotatably supported by the impeller support shaft 32 via the bearing 33, and the seal member 35a held by the holding member 35 prevents blood from entering the bearing 33.

Inside the impeller 22, a plurality of blood taxiways 22b extending radially from the substantially center of the impeller 22 toward the outer peripheral side are provided. In the impeller 22, a coupling multi-pole driven magnet 34 magnetized in the radial direction is arranged on the outer periphery of the back yoke 22a in the impeller 22 with the axis (rotation axis) of the impeller 22 as the center. In the present embodiment, the coupling multi-pole driven magnet 34 is arranged near the lower portion and the outer peripheral portion of the impeller 22. The number, size, and the like of the coupling multi-pole driven magnet 34 are set so that they can be magnetically coupled to the coupling driving magnet 50, which will be described later, with a desired coupling force. The coupling multi-pole driven magnet 34 is a ring-shaped magnet with radial multi-pole magnetization, or a plurality of radial magnetized arcuate magnets in which different magnetic poles are arranged alternately in the circumferential direction. It may be arranged as follows.

In the present embodiment, the rotation of the impeller 22 is supported by a bearing 33 such as a rolling bearing arranged in the impeller, but such a rotation support method of the impeller does not affect the present invention, and the impeller does not affect the present invention. The rotation of the head may be pivot support in the blood contact surface as shown in Japanese Patent No. 6134702, or support by a dynamic pressure bearing as shown in Japanese Patent No. 2989233.

The drive unit 14 includes a motor 36, a rotating member 37 (for example, a rotating plate) fixed to the output shaft portion 36a of the motor 36, a unit-side driving magnet 38 attached to the rotating member 37, and a case for accommodating these. It has 40 and. The motor 36 may be either an AC motor or a DC motor, but a variable speed motor is preferable. The rotation speed of the motor 36 is controlled by a control unit (not shown).

As shown in FIG. 2, the unit-side drive magnet 38 is a disk-shaped magnet magnetized with multiple poles in the axial direction, which is arranged concentrically with the output shaft portion 36a of the motor 36. In the present embodiment, the number of magnetic poles of the unit-side drive magnet 38 is six. That is, the unit-side drive magnet 38 has three magnetic pole pairs composed of an S-pole magnet and an N-pole magnet arranged in the circumferential direction on the side facing the transmission 10. The number of magnetic poles of the unit-side drive magnet 38 may be an even number of 4 or less, or an even number of 8 or more.

As shown in FIG. 1, the case 40 has an upper plate 42 facing the unit-side drive magnet 38. The upper plate 42 is close to the unit-side drive magnet 38 and faces the unit-side drive magnet 38 in a non-contact manner. The transmission 10 is configured to be arranged on the upper plate 42. A hook-shaped fixing engaging portion 43 capable of engaging with the transmission 10 and fixing the transmission 10 is provided on the upper portion of the case 40.

The transmission 10 is detachably configured to be attached to and detached from the drive unit 14, and the blood pump 16 is detachably configured to be attached to and detached from the drive unit 14. The transmission 10 includes a pole piece 44, a rotating body 46 arranged coaxially with the pole piece 44, a driven magnet 48 for magnetic gear held by the rotating body 46 so as to face the pole piece 44, and a magnetic gear. It includes a coupling drive magnet 50 held by the rotating body 46 at a position different from that of the driven magnet 48.

The transmission 10 further includes a housing 52 that houses a pole piece 44, a rotating body 46, a driven magnet 48 for magnetic gears, and a driving magnet 50 for coupling. At the lower part of the outer circumference of the housing 52, an engaging protrusion 57 that can be engaged with the fixing engaging portion 43 provided in the case 40 of the drive unit 14 is provided.

The pole piece 44 is configured to be concentrically opposed to the unit-side drive magnet 38 with respect to the unit-side drive magnet 38. The pole piece 44 is preferably made of a soft magnetic material such as a laminated silicon steel plate. As shown in FIG. 3, a plurality of pole pieces 44 (four in the present embodiment) are arranged around the axis a (rotation axis) of the rotating body 46 at intervals in the circumferential direction. That is, a pole piece row 45 composed of a plurality of pole pieces 44 arranged at intervals in the circumferential direction is provided. The plurality of pole pieces 44 are fixed to the lower housing 52a constituting the lower part of the housing 52.

In the present embodiment, the pole piece 44 has a lower surface 44a perpendicular to the axis a and an inner side surface 44b parallel to the axis, and is formed in a shape close to a triangle as a whole. When the transmission 10 is mounted on the drive unit 14, the lower surface 44a of the pole piece 44 faces the unit-side drive magnet 38 of the drive unit 14 via the case 40 of the drive unit 14 and the housing 52 of the transmission 10. .. The inner side surface 44b of the pole piece 44 is formed in an arc shape centered on the axis a (see FIG. 3). The pole piece 44 is made of a soft magnetic material such as a laminated silicon steel plate, more preferably a dust core or an amorphous iron core.

A shaft member 54 projecting upward is fixed to the center of the lower housing 52a. The shaft member 54 may be a portion integrally molded with the lower housing 52a. The rotating body 46 is rotatably supported by the shaft member 54 concentrically with the pole piece 44 (pole piece row 45) via the bearing 55.

When the transmission 10 is mounted on the drive unit 14, the axis a of the rotating body 46 is arranged coaxially with the axis of the motor 36. The rotating body 46 has a small diameter portion 58 and a large diameter portion 60. A bearing 55 is arranged on the inner peripheral portion of the small diameter portion 58. A driven magnet 48 for a magnetic gear is arranged on the outer peripheral portion of the small diameter portion 58. Specifically, the small diameter portion 58 is provided with a magnet placement groove 62, and the magnet placement groove 62 holds the magnetic gear driven magnet 48.

The driven magnet 48 for the magnetic gear is arranged concentrically with the pole piece row 45 and is arranged facing the pole piece row 45. The magnetizing direction of the driven magnet 48 for the magnetic gear is the radial direction. The outer peripheral surface of the driven magnet 48 for a magnetic gear is formed in an arc shape parallel to the axis a and centered on the axis a. The driven magnet 48 for a magnetic gear has a plurality of magnetic poles arranged in the circumferential direction. In the present embodiment, the number of magnetic poles of the driven magnet 48 for the magnetic gear is two. The number of magnetic poles of the driven magnet 48 for the magnetic gear can be arbitrarily set as long as it is an even number different from the number of magnetic poles of the unit-side drive magnet 38.

The size (outer diameter, axial length) and magnetic flux density of the driven magnet 48 for magnetic gear are sufficient for transmitting the rotational driving force accompanied by shifting from the driving magnet 38 on the unit side to the driven magnet 48 for magnetic gear. It is set so that the torque transmission capacity can be obtained. A back yoke 65 made of a soft magnetic material such as a laminated silicon steel plate is arranged on the inner circumference of the driven magnet 48 for a magnetic gear. The back yoke 65 has the effect of increasing the outer peripheral magnetic flux density of the driven magnet 48 for the magnetic gear and blocking the inward magnetic flux, and suppresses heat generation due to the eddy current generated in the bearing 55 arranged inside due to this effect. be able to. In the present embodiment, the driven magnet 48 for a magnetic gear is a stack of magnets divided into a plurality of magnets in the axial direction as shown in FIG. With such a divided structure, it is possible to suppress heat generation due to eddy currents that may occur in the magnet. The driven magnet 48 for the magnetic gear may be an integral magnet (not divided in the axial direction) in the axial direction.

The large-diameter portion 60 of the rotating body 46 is configured concentrically with the small-diameter portion 58, and has an outer diameter larger than that of the small-diameter portion 58. The large diameter portion 60 is provided above the small diameter portion 58. A coupling drive magnet 50 is arranged on the large diameter portion 60. Specifically, the large diameter portion 60 is provided with a magnet placement groove 64. The coupling drive magnet 50 is held inside the back yoke 49 concentrically with the shaft a in the magnet placement groove 64. The coupling drive magnet 50 is a ring-shaped magnet in which radial multipolar magnetism is applied, or a plurality of radial magnetized arcuate magnets so that different magnetic poles are arranged alternately in the circumferential direction. It may be arranged.

The upper portion (large diameter portion 60) of the rotating body 46 faces the ceiling portion 53 of the upper housing 52b of the housing 52. Specifically, the ceiling portion 53 of the upper housing 52b is provided with a protruding portion 66 projecting downward toward the inside of the housing 52. The protrusion 66 is inserted inside the large diameter portion 60 of the rotating body 46. In the ceiling portion 53, a mounting recess 68 is provided on the opposite side of the protruding portion 66. The mounting protrusion 28 of the blood pump 16 can be inserted into the mounting recess 68.

In this actual embodiment, the coupling drive magnet 50 having a diameter larger than that of the coupling driven magnet 34 is arranged outside the coupling driven magnet 34, but the diameter is smaller than that of the coupling driven magnet 34 for coupling. The structure may be such that the driving magnet is arranged inside the coupling driven magnet. In this case, the protruding portion 66 of the housing 52 is projected upward (pump side) instead of downward, a coupling drive magnet is arranged inside the protrusion 66, and the impeller 22 and the housing 20 are provided with recesses recessed on the pump inflow side, respectively. , The structure may be such that the driven magnet for coupling is arranged on the outer peripheral portion of the recess.

When the magnetizing direction of the coupling driven magnet is the axial direction, the coupling drive magnet may be magnetized in the axial direction. In this case, the protruding portion 66 in the housing 52 can be omitted. Further, when the magnetizing direction of the coupling driven magnet is tilted with respect to the pump rotation axis, the magnetism direction of the coupling drive magnet may be tilted at the same angle with respect to the rotation axis of the pump drive magnet.

When the blood pump 16 is attached to the transmission 10, the coupling drive magnet 50 provided in the transmission 10 and the coupling multi-pole driven magnet 34 provided in the blood pump 16 are formed in the housing 52 and the housing 20. Facing each other through. As a result, the coupling drive magnet 50 provided in the transmission 10 and the coupling multi-pole driven magnet 34 provided in the blood pump 16 are magnetically coupled. Therefore, when the rotating body 46 is rotated, the rotational driving force is transmitted from the coupling driving magnet 50 to the coupling multi-pole driven magnet 34. When the blood pump 16 is attached to the transmission 10, the impeller 22 is arranged coaxially with the rotating body 46.

In the present embodiment, the number of magnetic poles of the driven magnet 48 for magnetic gear is smaller than the number of magnetic poles of the unit-side drive magnet 38. Therefore, the driven magnet 48 for the magnetic gear rotates at a higher speed than the unit-side drive magnet 38. That is, the transmission 10 according to the present embodiment is configured as a speed-increasing gear mechanism that accelerates the rotational driving force of the drive unit 14 and transmits it to the blood pump 16. When the number of magnetic poles of the unit-side drive magnet 38 is Na and the number of magnetic poles of the magnetic gear driven magnet 48 is Nb, the magnetic gear driven magnet 48 rotates at a speed Na / Nb times that of the unit-side drive magnet 38. In the case of this embodiment, since Na / Nb = 3, the driven magnet 48 for the magnetic gear rotates at a speed three times that of the unit-side drive magnet 38.

The number of magnetic poles of the driven magnet 48 for the magnetic gear may be larger than the number of magnetic poles of the unit-side drive magnet 38. In this case, the driven magnet 48 for the magnetic gear rotates at a lower speed than the unit-side drive magnet 38. That is, in this case, the transmission 10 is configured as a reduction gear mechanism that decelerates the rotational driving force of the drive unit 14 and transmits it to the blood pump 16.

The number of pole pieces 44 can be arbitrarily set, but the number of magnetic poles Na of the unit-side drive magnet 38, the number of magnetic poles Nb of the driven magnet 48 for magnetic gears, and the number of pole pieces Nc that maximizes the transmission torque are It has a relationship of Nc = (Na + Nb) / 2. Therefore, when the number of magnetic poles Na of the unit-side drive magnet 38 is 6 and the number of magnetic poles Nb of the driven magnet 48 for the magnetic gear is 2, the number of pole pieces Nc that maximizes the transmission torque is 4. In this embodiment, the number of pole pieces 44 is set so that the transmission torque is maximized.

Next, the operation of the transmission 10 configured as described above will be described.

As shown in FIG. 1, in order to drive the blood pump 16 by the drive unit 14, the transmission 10 is attached to the drive unit 14, and the blood pump 16 is attached to the transmission 10. In this way, when the transmission 10 is attached to the drive unit 14 and the blood pump 16 is attached to the transmission 10, the output shaft portion 36a of the motor 36 and the shaft of the transmission 10 (the shaft of the rotating body 46) are attached. a) and the axis of the blood pump 16 (the axis of the impeller 22) are arranged coaxially.

As the motor 36 rotates, the unit-side drive magnet 38 rotates. The pole piece 44 in the transmission 10 is concentrically arranged to face the unit-side drive magnet 38, and the magnetic force of the unit-side drive magnet 38 faces the pole piece 44 concentrically via the pole piece 44. It acts on the arranged magnetic gear driven magnet 48. As a result, the driven magnet 48 for magnetic gear and the rotating body 46 have a rotation speed opposite to the rotation direction of the unit-side drive magnet 38 and different from the unit-side drive magnet 38 (in this embodiment, the unit-side drive magnet). Rotates at a speed (faster than 38).

As the rotating body 46 rotates, the coupling drive magnet 50 also rotates integrally with the magnetic gear driven magnet 48. Therefore, the coupling multi-pole driven magnet 34 that is magnetically coupled to the coupling drive magnet 50 rotates, and the impeller 22 holding the coupling multi-pole driven magnet 34 is in the same direction as the magnetic gear driven magnet 48. And rotate at the same speed. The rotation of the impeller 22 introduces blood from a reservoir (not shown) into the blood pump 16 via the inflow port 24 and is pumped through the outflow port 26 into an artificial lung (not shown).

In this case, the transmission 10 according to the present embodiment has the following effects.

According to the transmission 10, when the blood pump 16 is attached to the drive unit 14, the driven magnet 48 for magnetic gear and the drive magnet 50 for coupling are arranged concentrically with the drive magnet 38 on the unit side. Therefore, unlike the eccentric coupling method, a large space in the lateral direction is not required, and a compact device can be obtained. Further, unlike the eccentric coupling method, not a part of the magnetic poles but the entire magnetic pole is magnetically coupled, so that a sufficient torque transmission capacity can be obtained. Furthermore, compared to a method of transmitting power using mechanical gears, mechanical noise is small, and durability and reliability are excellent.

The number of magnetic poles of the magnetic gear driven magnet 48 is smaller than the number of magnetic poles of the unit-side driving magnet 38, and the magnetic gear driven magnet 48 rotates at a higher speed than the unit-side driving magnet 38. With this configuration, the driving force of the driving unit 14 can be accelerated and transmitted to the blood pump 16. When the number of magnetic poles of the driven magnet 48 for the magnetic gear is larger than the number of magnetic poles of the unit-side drive magnet 38, the driving force of the drive unit 14 can be decelerated and transmitted to the blood pump 16.

The pole piece 44 is made of a soft magnetic material such as a laminated silicon steel plate, more preferably a dust core or an amorphous iron core. With this configuration, it is possible to suppress the generation of eddy currents and reduce energy loss.

At least one of the unit-side drive magnet 38, the magnetic gear driven magnet 48, the coupling drive magnet 50, and the coupling multi-pole driven magnet 34 may be arranged so as to form a Halbach array. The Halbach array is a magnetic circuit that maximizes the magnetic field strength in a particular direction by optimizing the direction of magnetism. By applying such a Halbach array, it becomes possible to satisfactorily increase the torque transmission capacity.

The magnetic transmission 10a for a blood pump (hereinafter, abbreviated as "transmission 10a") according to the second embodiment of the present invention shown in FIG. 4 is detachably configured on the drive unit 14 and the blood pump 16a. Is configured to be removable. In the impeller 70 rotatably arranged in the housing 80 of the blood pump 16a, a plurality of coupling driven magnets 72 are arranged in the circumferential direction around the axis of the impeller 70. The coupling driven magnet 72 is arranged radially outside the mounting convex portion 28 provided at the lower part of the blood pump 16a. The magnetizing direction of the coupling driven magnet 72 is the axial direction.

The transmission 10a includes a pole piece 74, a rotating body 76 arranged coaxially with the pole piece 74, a driven magnet 77 for magnetic gear held by the rotating body 76 so as to face the pole piece 74, and a magnetic gear. A coupling drive magnet 78 held by the rotating body 76 at a position different from that of the driven magnet 77, and a housing 80 for accommodating these are provided. The driven magnet 77 for magnetic gear and the driving magnet 78 for coupling are ring-shaped magnets subjected to axial multi-pole magnetization, or magnets such as columnar magnets or arc-shaped magnets magnetized in a plurality of axial directions. , The magnets may be arranged so that different magnetic poles are arranged alternately in the circumferential direction.

A plurality of pole pieces 74 are arranged in the circumferential direction around the axis a of the rotating body 76. That is, a pole piece row 75 composed of a plurality of pole pieces 74 arranged at intervals in the circumferential direction is provided. The pole piece 74 is configured to be concentrically opposed to the unit-side drive magnet 38 with respect to the unit-side drive magnet 38. The pole piece 74 is a plate-like body having a lower surface 74a that faces the unit-side drive magnet 38 in the axial direction and an upper surface 74b that faces the driven magnet 77 for magnetic gears in the axial direction.

The rotating body 76 is rotatably supported by a shaft member 82 provided at the center of the housing 80 via a bearing 84. The rotating body 76 has a small diameter portion 86 and a large diameter portion 88. A driven magnet 77 for a magnetic gear is held in the lower part of the small diameter portion 86. The magnetizing direction of the driven magnet 77 for the magnetic gear is the axial direction. The driven magnet 77 for a magnetic gear faces the pole piece 74 (pole piece row 75) in the axial direction.

In the present embodiment, the number of magnetic poles of the driven magnet 77 for magnetic gear is an even number larger than the number of magnetic poles of the unit-side drive magnet 38. Therefore, the driven magnet 77 for the magnetic gear rotates at a lower speed than the unit-side drive magnet 38. That is, the transmission 10a is configured as a reduction gear mechanism that decelerates the rotational driving force of the drive unit 14 and transmits it to the blood pump 16a.

The number of pole pieces 74 should be set so that the transmission torque in the magnetic gear is maximized. For example, when the number of magnetic poles Na of the unit-side drive magnet 38 is 10 and the number of magnetic poles Nb of the driven magnet 77 for magnetic gear is 12, the number Nc of the pole pieces 74 that maximizes the transmission torque is 11.

On the large-diameter portion 88 of the rotating body 76, a plurality of coupling driving magnets 78 are arranged in the circumferential direction about the axis a of the rotating body 76. The magnetizing direction of the coupling drive magnet 78 is the axial direction. When the blood pump 16a is attached to the transmission 10a, the coupling drive magnet 78 provided in the transmission 10a and the coupling driven magnet 72 provided in the blood pump 16a are axially oriented via the housing 80. Facing each other. As a result, the coupling drive magnet 78 provided in the transmission 10a and the coupling driven magnet 72 provided in the blood pump 16a are magnetically coupled.

According to the transmission 10a according to the second embodiment, as with the transmission 10 according to the first embodiment, the transmission device 10a is small in size, has sufficient torque transmission capability, has low mechanical noise, and is durable and reliable. It is also excellent in sex. Further, in the second embodiment, the magnetizing direction of the magnetic gear driven magnet 77 is the axial direction, and the magnetic gear driven magnet 77 faces the pole piece 74 in the axial direction. Compared with the transmission 10 according to the embodiment, it is easy to reduce the height dimension in the axial direction.

In the second embodiment, the magnetizing directions of the coupling drive magnet 78 and the coupling driven magnet 72 are in the axial direction, and the coupling drive magnet 78 and the coupling driven magnet 72 face each other in the axial direction. Therefore, the magnetic coupling area can be increased without increasing the axial dimensions of the coupling driving magnet 78 and the coupling driven magnet 72. Therefore, the magnetic coupling force between the blood pump 16a and the transmission 10a can be increased without increasing the size of the blood pump 16a and the transmission 10a.

Of the second embodiment, the same or similar actions and effects as those of the first embodiment can be obtained with respect to the portion common to the first embodiment.

The unit-side drive magnet 38 in the drive unit 14 of the first embodiment shown in FIG. 1 and the second embodiment shown in FIG. 4 is axially magnetized, but in the case of radial magnetism, a pole is used. The magnetic coupling surface on the drive unit 14 side of the pieces 44 and 74 may be a radial outer peripheral surface or an inner peripheral surface parallel to the motor rotation axis.

In the magnetic transmission 10b for a blood pump (hereinafter, abbreviated as "transmission 10b") according to the third embodiment shown in FIG. 5, the unit-side drive magnet 90 has a magnetic coupling surface 90a on the inner peripheral side in the radial direction. It is magnetized. Further, in the transmission 10b, the pole piece 92 is higher than the magnetic coupling surface 92a having the same height (same axial length) as the unit-side driving magnet 90 on the outer periphery and the magnetic coupling surface 90a on the inner circumference of the unit-side driving magnet 90. It has a high magnetic coupling surface 92b (long axial length).

With such a configuration, it becomes possible to arrange a larger driven magnet 48 for magnetic gear in the limited space of the unit side drive magnet 90, and the first embodiment having the unit side drive magnet 38 which is axially magnetized. In the case of adapting to the drive unit 14a having the unit-side drive magnet 90 of radial magnetism in which the space for arranging the driven magnet 48 for magnetic gear is limited as compared with the drive unit 14 of the above, it is possible to obtain sufficient torque transmission capability. can.

When using a drive unit equipped with a unit-side drive magnet that is radially magnetized with a magnetic coupling surface on the outer peripheral side, the magnetic coupling surface on the inner circumference of the pole piece shall be the same height as the unit-side drive magnet. The outer circumference of the pole piece may be a magnetic coupling surface having a height higher than that of the drive magnet on the unit side.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

For example, the magnetizing direction of the driven magnet for magnetic gear may be inclined with respect to the axis of the driven magnet for magnetic gear. That is, the magnetizing direction of the driven magnet for magnetic gear may be larger than 0 ° and smaller than 90 ° with respect to the axis of the driven magnet for magnetic gear. The magnetizing direction of the coupling drive magnet may be inclined with respect to the axis of the coupling drive magnet. That is, the magnetizing direction of the coupling drive magnet may be larger than 0 ° and smaller than 90 ° with respect to the axis of the coupling drive magnet.

The blood pump has a pump body having a built-in impeller and a flexible shaft connected to the pump body, and the flexible shaft can be connected to a magnetic transmission for a blood pump, and a coupling provided on the flexible shaft is provided. The driven magnet may be magnetically coupled to the coupling drive magnet provided in the magnetic transmission for the blood pump.

10, 10a ... Magnetic transmission for blood pump 14 ... Drive unit 16, 16a ... Blood pump 34, 72 ... Coupling driven magnet 38 ... Unit side drive magnet 44, 74 ... Pole piece 46, 76 ... Rotating body 48, 77 ... Driven magnets for magnetic gears 50, 78 ... Drive magnets for coupling

Claims (9)

A magnetic transmission for a blood pump that shifts the rotational driving force generated by the drive unit for driving the blood pump and transmits it to the blood pump.
A pole piece configured to face the unit-side drive magnet mounted on the drive unit concentrically with the unit-side drive magnet.
A rotating body rotatably arranged concentrically with the pole piece,
A driven magnet for a magnetic gear, which is held by the rotating body, is arranged concentrically with the pole piece, is arranged opposite to the pole piece, and has a magnetizing direction in the radial direction .
It is held by the rotating body, arranged concentrically with the pole piece, and includes a coupling driven magnet provided in the blood pump and a coupling drive magnet capable of magnetic coupling .
The pole piece is
A lower surface that is formed perpendicular to the axis of the rotating body and that faces the unit-side drive magnet in the axial direction.
It is formed parallel to the axis and has an inner surface that is radially opposed to the driven magnet for the magnetic gear .
A magnetic transmission for a blood pump characterized by that. In the magnetic transmission for a blood pump according to claim 1,
The number of magnetic poles of the driven magnet for the magnetic gear is smaller than the number of magnetic poles of the unit-side drive magnet.
The driven magnet for the magnetic gear rotates at a higher speed than the unit-side drive magnet.
A magnetic transmission for a blood pump characterized by that. In the magnetic transmission for a blood pump according to claim 1,
The number of magnetic poles of the driven magnet for the magnetic gear is larger than the number of magnetic poles of the unit-side drive magnet.
The driven magnet for the magnetic gear rotates at a lower speed than the unit-side drive magnet.
A magnetic transmission for a blood pump characterized by that. The magnetic transmission for a blood pump according to any one of claims 1 to 3.
The rotating body has a small diameter portion and a large diameter portion, and has a small diameter portion and a large diameter portion.
The driven magnet for the magnetic gear is arranged in the small diameter portion, and the driven magnet is arranged.
The coupling drive magnet is arranged in the large diameter portion, and the coupling drive magnet is arranged.
The magnetic transmission for a blood pump includes a housing for accommodating the pole piece, the rotating body, the driven magnet for the magnetic gear, and the driving magnet for coupling.
The ceiling of the housing is provided with a downwardly projecting portion.
On the opposite side of the protrusion, a mounting recess into which the mounting protrusion of the blood pump can be inserted is provided.
The protrusion is inserted inside the large diameter portion.
A magnetic transmission for a blood pump characterized by that. In the magnetic transmission for a blood pump according to any one of claims 1 to 4 .
The magnetizing direction of the coupling drive magnet is the radial direction.
A magnetic transmission for a blood pump characterized by that. In the magnetic transmission for a blood pump according to any one of claims 1 to 4 .
The magnetizing direction of the coupling drive magnet is the axial direction.
A magnetic transmission for a blood pump characterized by that. In the magnetic transmission for a blood pump according to any one of claims 1 to 4 .
The magnetizing direction of the coupling drive magnet is inclined with respect to the axis of the coupling drive magnet.
A magnetic transmission for a blood pump characterized by that. In the magnetic transmission for a blood pump according to any one of claims 1 to 7 .
The pole piece is made of a dust core or an amorphous iron core.
A magnetic transmission for a blood pump characterized by that. The magnetic transmission for a blood pump according to any one of claims 1 to 8 .
The driven magnet for the magnetic gear is divided in the axial direction or the circumferential direction.
A magnetic transmission for a blood pump characterized by that.

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