Rotary drive device and pump

Abstract

A pump has a rotor (20), a magnetic bearing (10), and a driving unit (30) that rotationally drives the rotor. The magnetic bearing has a bearing stator (12), a ring-shaped bearing rotor member (11), and the driving unit. The driving unit has a driving stator (32) and a ring-shaped driving rotor member (31). The bearing stator has a plurality of bearing stator cores (17) formed of a magnetic material that are arranged at an outer periphery of the bearing rotor member and form a magnetic circuit with the bearing rotor member, and a bearing coil (18) wound around the bearing stator cores. The bearing stator cores have a first portion (17a) that extends in a first direction orthogonal to a direction facing the bearing rotor member, and a pair of second portions (17b) that extend toward the bearing rotor member from both ends of the first portion in the first direction. The bearing coil is wound around the first portion of the bearing stator cores. The driving stator is formed by passing through a position in the first direction between an outer peripheral surface of the rotor and the first portion of the bearing stator cores, and between the pair of second portions of the bearing stator cores.

Description

Technical Field

[0001] This invention relates to a rotary drive device using magnetic bearings and a pump. Background Technology

[0002] Magnetic bearings are known to support the load on the impeller of a pump unit non-contactly using magnetic force, and drive units are known to rotate the impeller (see, for example, Patent Document 1). Figure 12 As shown, such a magnetic bearing 200 is, for example, composed of a bearing rotor component 206 provided on a rotor 201 having an impeller 200a, and a bearing stator 202 fixed to a housing 209.

[0003] Furthermore, a drive unit 300 is assembled on the inner side of the magnetic bearing 200 in the radial direction. This drive unit 300 consists of a permanent magnet assembly 301 mounted on the rotor 201 and a hollow coil assembly 302 mounted on the outer casing 209. The rotor 201, supported by the magnetic bearing 200, rotates under the action of the drive unit 300.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2005-121157 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] In this magnetic bearing 200, a restoring force toward a predetermined position is applied to the rotor 201 by a magnetic flux φ passing through the magnetic circuit formed by the U-shaped stator core 204 constituting the bearing stator 202 and the bearing rotor component 206. Furthermore, the reaction force of the Lorentz force acting on the air coil assembly 302 is applied to the permanent magnet assembly 301 by the magnetic flux φ passing through the magnetic circuit formed by the permanent magnet assembly 301 and the air coil assembly 302, thereby exerting a rotational force on the rotor 201.

[0009] However, since the bearing stator 202 has a magnetic bearing 200 arranged on the outer side of the rotor 201 in the radial direction, and a hollow coil group 302 with a drive unit 300 arranged on the inner side in the radial direction, and a bearing rotor component 206 and a permanent magnet group 301 are arranged on the rotor 201, when viewed as a rotary drive device including the magnetic bearing 200 and the drive unit 300, the reduction of the size in the radial direction has a general limit. For example, when this rotary drive device is applied to a pump device, there is a problem that it is difficult to achieve the miniaturization of the pump device as a whole.

[0010] The present invention was made in view of the above circumstances, and its object is to provide a rotary drive device and pump that can suppress the radial dimension of the magnetic bearing and the drive unit and can achieve miniaturization.

[0011] Methods for solving technical problems

[0012] The rotary drive device of the present invention comprises: a rotor; a magnetic bearing that supports the rotor non-contactly by magnetic force; and a drive unit for rotating the rotor. The magnetic bearing comprises: a bearing stator disposed on the outer periphery of the rotor and supporting the rotor non-contactly by magnetic force; and an annular bearing rotor member formed of a magnetic material disposed on the rotor and forming a magnetic circuit together with the bearing stator. The drive unit comprises: a drive stator disposed on the outer periphery of the rotor and applying a rotational driving force to the rotor; and an annular drive rotor member disposed on the outer periphery of the bearing rotor member of the rotor and receiving the rotational driving force from the drive stator. The bearing stator comprises: a bearing stator formed of a magnetic material... A plurality of bearing stator cores are disposed on the outer periphery of the bearing rotor component and together with the bearing rotor component form a magnetic circuit; a bearing coil is wound on the bearing stator core, the bearing stator core having: a first portion extending in a first direction orthogonal to the direction facing the bearing rotor component; a pair of second portions extending toward the bearing rotor component from both ends of the first portion in the first direction; the bearing coil is wound on the first portion of the bearing stator core; the drive stator is formed by passing through the outer periphery of the rotor and the first portion of the bearing stator core, and passing through the position in the first direction between the pair of second portions of the bearing stator core.

[0013] In one embodiment of the invention, the bearing stator core is further configured to have a pair of third portions that extend along the first direction toward each other from the end of the pair of second portions on the bearing rotor component side, and then extend toward the bearing rotor component side.

[0014] In another embodiment of the invention, the bearing rotor component includes: an annular bearing magnet; a pair of annular magnetic yokes configured to clamp the bearing magnet in the first direction, the pair of magnetic yokes having: a pair of fourth portions covering two end faces of the bearing magnet in the first direction and extending along the first direction; a pair of fifth portions extending from the end of the pair of fourth portions opposite to the bearing magnet toward the bearing stator side; and a spacer formed of a non-magnetic material disposed between the opposing faces of the pair of fifth portions in the first direction, the spacer being used to provide non-contact support for the drive rotor component by the pair of magnetic yokes and the bearing magnet.

[0015] In another embodiment of the invention, the bearing rotor component includes: an annular bearing magnet; and a pair of annular magnetic yokes configured to clamp the bearing magnet in the first direction. The pair of magnetic yokes includes: a pair of fourth portions covering two end faces of the bearing magnet in the first direction and extending in a direction opposite to the bearing stator; and a pair of fifth portions extending along the first direction in a direction approaching each other, starting from the end of the pair of fourth portions on the side opposite to the bearing stator. A spacer formed of a non-magnetic material is disposed between the opposing faces of the pair of fourth portions in the first direction, closer to the bearing stator than the bearing magnet. The spacer provides non-contact support for the drive rotor component by the pair of magnetic yokes and the bearing magnet. A first gap is formed between the fifth portions and the bearing magnet, and a second gap is provided between the opposing top ends of the pair of fifth portions.

[0016] In another embodiment of the present invention, a plurality of bearing stators are arranged on the outer side of the bearing rotor component in the radial direction along the circumferential direction of the bearing rotor component, and each of the bearing stators is opposite to the bearing rotor component in the radial direction.

[0017] In another embodiment of the invention, the drive stator has an annular drive stator core formed of magnetic material and a drive coil wound in a slot of the drive stator core. The drive stator core is opposite the drive rotor component from the outer side in the radial direction and has a plurality of magnetic poles along the circumferential direction of the drive rotor component.

[0018] The pump of the present invention comprises a pump mechanism including a rotor, a magnetic bearing that supports the rotor non-contactly by magnetic force, a drive unit for rotating the rotor, and an impeller mounted on the rotor. The pump is characterized in that the magnetic bearing comprises: a bearing stator disposed on the outer periphery of the rotor and supporting the rotor non-contactly by magnetic force; and an annular bearing rotor component formed of magnetic material disposed on the rotor and forming a magnetic circuit together with the bearing stator. The drive unit comprises: a drive stator disposed on the outer periphery of the rotor and applying a rotational driving force to the rotor; and an annular drive rotor component disposed on the outer periphery of the bearing rotor component on the rotor and receiving the rotational driving force from the drive stator. The bearing stator has... The bearing stator cores, formed of magnetic material, are disposed on the outer periphery of the bearing rotor component and together with the bearing rotor component form a magnetic circuit; a bearing coil is wound on the bearing stator cores, the bearing stator core having: a first portion extending in a first direction orthogonal to the direction facing the bearing rotor component; a pair of second portions extending toward the bearing rotor component from both ends of the first portion in the first direction; and the bearing coil is wound on the first portion of the bearing stator core; the drive stator is formed at a position in the first direction between the outer periphery of the rotor and the first portion of the bearing stator core, and between the pair of second portions of the bearing stator core.

[0019] In one embodiment of the invention, the bearing stator core is further configured to have a pair of third portions that extend along the first direction toward each other from the end of the pair of second portions on the bearing rotor component side, and then extend toward the bearing rotor component side.

[0020] In another embodiment of the invention, the bearing rotor component includes: an annular bearing magnet; a pair of annular magnetic yokes configured to clamp the bearing magnet in the first direction, the pair of magnetic yokes having: a pair of fourth portions covering two end faces of the bearing magnet in the first direction and extending along the first direction; a pair of fifth portions extending toward the bearing stator side from the end of the pair of fourth portions opposite to the bearing magnet; and a spacer formed of a non-magnetic material is disposed between the opposing faces of the pair of fifth portions in the first direction, the spacer being used to provide non-contact support for the drive rotor component by the pair of magnetic yokes and the bearing magnet.

[0021] In another embodiment of the invention, the bearing rotor component includes: an annular bearing magnet; a pair of annular magnetic yokes configured to clamp the bearing magnet in the first direction, the pair of magnetic yokes having: a pair of fourth portions covering two end faces of the bearing magnet in the first direction and extending toward a direction opposite to the bearing stator; a pair of fifth portions extending along the first direction toward a direction approaching each other from the end of the pair of fourth portions on the side opposite to the bearing stator; and a spacer formed of a non-magnetic material is disposed between the opposing faces of the pair of fourth portions in the first direction, which are closer to the bearing stator than the bearing magnet, the spacer being used to provide non-contact support for the drive rotor component by the pair of magnetic yokes and the bearing magnet; a first gap is formed between the fifth portions and the bearing magnet; and a second gap is provided between the opposing top ends of the pair of fifth portions.

[0022] In another embodiment of the present invention, a plurality of bearing stators are arranged on the outer side of the bearing rotor component in the radial direction along the circumferential direction of the bearing rotor component, and each of the bearing stators is opposite to the bearing rotor component in the radial direction.

[0023] In another embodiment of the invention, the drive stator has an annular drive stator core formed of magnetic material and a drive coil wound in a slot of the drive stator core. The drive stator core is opposite the drive rotor component from the outer side in the radial direction and has a plurality of magnetic poles along the circumferential direction of the drive rotor component.

[0024] The effects of the invention

[0025] According to the present invention, the dimensional dimensions in the radial direction, including the magnetic bearing and the drive unit, can be suppressed and miniaturization can be achieved. Attached Figure Description

[0026] Figure 1 This is a schematic longitudinal cross-sectional view showing the overall structure of a pump using a rotary drive device according to the first embodiment of the present invention.

[0027] Figure 2 This is a schematic enlarged longitudinal sectional view of the rotary drive device.

[0028] Figure 3A This is a schematic top view showing the overall structure of the rotary drive device.

[0029] Figure 3B This is a top view schematically showing the overall structure of the drive unit of the rotary drive device.

[0030] Figure 4 This is a perspective view showing a portion of the overall structure of the rotary drive device cut away.

[0031] Figure 5 This is a perspective view showing a portion of the overall structure of the rotor bearing / rotor section of the rotary drive device, cut away from the rest.

[0032] Figure 6 It is a perspective view, partially and schematically showing the overall structure of other pumps that utilize this rotary drive device.

[0033] Figure 7 This is an enlarged longitudinal sectional view schematically showing the rotary drive device according to the second embodiment of the present invention.

[0034] Figure 8 This is a schematic top view showing the overall structure of the rotary drive device.

[0035] Figure 9 This is an enlarged longitudinal sectional view schematically showing the rotary drive device according to the third embodiment of the present invention.

[0036] Figure 10 This is a schematic view of the drive section of the rotary drive device according to the fourth embodiment of the present invention.

[0037] Figure 11A This is a schematic longitudinal cross-sectional view showing the overall structure of a pump using a rotary drive device according to the fifth embodiment of the present invention.

[0038] Figure 11B This is a schematic top view showing the drive section of the rotary drive device.

[0039] Figure 12 This is a schematic longitudinal cross-sectional view showing the overall structure of an existing magnetic bearing and drive unit. Detailed Implementation

[0040] Hereinafter, a detailed description of the rotary drive device and pump according to embodiments of the present invention will be provided with reference to the accompanying drawings. However, the following embodiments do not limit the invention as described in the claims in any way, and not all combinations of features described in the embodiments are necessary for the solution of the invention. Furthermore, in the following embodiments, the same or equivalent constituent elements are labeled with the same reference numerals and repeated descriptions are omitted. Additionally, in the embodiments, there are cases where the proportions and dimensions of each constituent element are exaggerated, and cases where some constituent elements are omitted.

[0041] [First Implementation]

[0042] [Structure of the rotary drive unit and pump]

[0043] Figure 1 This is a schematic longitudinal cross-sectional view showing the overall structure of the pump 100 that uses the rotary drive device 90 of the first embodiment. Figure 2 This is a schematic enlarged longitudinal sectional view of the rotary drive device 90. Figure 3A This is a schematic top view showing the overall structure of the rotary drive device 90. Figure 3B This is a schematic top view showing the overall structure of the drive unit 30. Additionally, Figure 4 This is a perspective view showing a portion of the overall structure of the rotary drive device 90 cut away. Figure 5 It is a perspective view showing a portion of the overall structure of the bearing / rotor section 21 of the rotor 20 of the rotary drive device 90 cut off.

[0044] like Figures 1-5 As shown, the pump 100 of the first embodiment includes: a rotor 20, a magnetic bearing 10 that supports the rotor 20 non-contactly by magnetic force, and a drive unit 30 that drives the rotor 20 to rotate. Furthermore, the pump 100 includes: a pump mechanism including an impeller 22 mounted on the rotor 20, and a control unit 60 that controls the entire pump mechanism. It should be noted that although a pump 100 is shown in this example, if only the function of non-contactly supporting and rotating the rotor 20 is considered in relation to the rotor 20, the magnetic bearing 10, and the drive unit 30, then... Figure 3A as well as Figure 4 As shown, this can be understood as a rotary drive device (bearingless motor) 90 using a magnetic bearing 10. Furthermore, in this rotary drive device 90, if only the function of rotating and driving the rotor 20 is considered, then... Figure 3B As shown, the drive unit 30 can be understood as a motor device (Brushless Motor).

[0045] It should be noted that, in the following description, the direction of the rotation axis (Z-axis) of rotor 20 is referred to as the Z-axis direction (also called the axial direction, Z direction), the radial direction of rotor 20 is referred to as the X-axis direction and the Y-axis direction (also called the radial direction, X direction, and Y direction), the direction of rotation around the X-axis is referred to as the Θ direction, and the direction of rotation around the Y-axis is referred to as the Φ direction. Furthermore, the X-axis, Y-axis, and Z-axis are orthogonal to each other. Additionally, the orientation... Figure 1 The right side of the paper is called the front side of pump 100, and the left side is called the rear side.

[0046] Pump 100, for example, is integrally formed into a cylindrical shape, and has a front housing 41 on one side (front side) in the Z-axis direction. The front housing 41 has a pump chamber A1 formed inside it, and a cylindrical suction port 51 communicating with the pump chamber A1 is located at the center of its front. Additionally, the front housing 41 has a discharge port 52 on its side, communicating with the same pump chamber A1.

[0047] The front housing 41 is connected to the rear housing 42 at its rear end, for example, with an O-ring 41a used for sealing. The rear housing 42 and the front housing 41 together form a sealed space A containing the pump chamber A1. In addition, a cylindrical space (accommodation space) A2 protruding rearward is formed in the rear housing 42.

[0048] The outer radial side (outer peripheral side) of the rear side of the rear housing 42 is covered by a cylindrical outer housing 43. A pump support 43a for supporting the pump 100 is provided at the lower part of the outer housing 43. Furthermore, the rear side of the outer housing 43 is covered by a rear cover 29 that houses the control unit 60 within its internal space. A through-hole 29a for wiring harnesses or the like connected to the control unit 60 is formed in the center of the rear cover 29, and a cable connector 28 is connected to the rear side of this through-hole 29a.

[0049] The rotor 20 is housed in a sealed space A in a state that allows it to float (non-contact support). The rotor 20, for example, is formed entirely of a non-magnetic material such as resin, and is integrally formed of an impeller 22 located at the front end in the Z-axis direction and an annular bearing / rotor portion 21 located at the rear end in the Z-axis direction. The impeller 22 is housed in a pump chamber A1 inside the front housing 41, and together with the pump chamber A1, constitutes a pump mechanism.

[0050] On the other hand, the rear housing 42 has a front flange portion 42a and a cylindrical protrusion 42b protruding rearward from the center of the flange portion 42a. The bearing / rotor portion 21 is housed in a cylindrical space A2 inside the cylindrical protrusion 42b of the rear housing 42. A cylindrical stator support 44 is provided inside the outer housing 43. The stator support 44 forms an annular space A3 surrounding the cylindrical space A2 between the outer peripheral surfaces of the flange portion 42a and the cylindrical protrusion 42b of the rear housing 42. Furthermore, the bearing stator 12, as described below, and the motor stator 32, which serves as the drive stator, are provided in this annular space A3.

[0051] The magnetic bearing 10 has: an annular bearing rotor component 11 made of magnetic material mounted on the inner circumferential side of the bearing / rotor portion 21 of the rotor 20, and a bearing stator 12 disposed, for example, on the outer side of the bearing rotor component 11 in the radial direction at a predetermined interval from the bearing rotor component 11.

[0052] Bearing rotor component 11, for example, Figure 5 As shown, it has: a bearing magnet 13 formed of neodymium magnets shaped into a ring; and a pair of magnetic yokes 14 and 15 formed of annular electromagnetic soft iron, which are concentric with the bearing magnet 13 and configured to sandwich the two end faces of the bearing magnet 13 in the axial direction (Z-axis direction).

[0053] The bearing magnet 13 is, for example, magnetized such that its N and S poles are opposite each other in the axial direction, and that a full circumference in the circumferential direction is of the same pole. It should be noted that the bearing magnet 13, such as... Figure 2 As shown, a bias flux φ1 is provided to the magnetic circuit formed by the bearing rotor assembly 11 and the bearing stator core 17 described below for the bearing stator 12.

[0054] On the other hand, for example, Figure 3A as well as Figure 3B As shown, multiple bearing stators 12 are arranged at four 90° intervals in the circumferential direction of the bearing rotor assembly 11. For example, a pair of bearing stators 12 (12x) facing each other in the X-axis direction controls the position of the rotor 20 in the X-axis direction and the angle in the Φ direction via the control unit 60. Similarly, a pair of bearing stators 12 (12y) facing each other in the Y-axis direction controls the position of the rotor 20 in the Y-axis direction and the angle in the Θ direction. Furthermore, these bearing stators 12 (12x, 12y) control the height of the rotor 20 in the Z-axis direction.

[0055] It should be noted that multiple displacement sensors 16, which can detect the radial direction and the displacement in each rotation direction of the bearing rotor component 11, are arranged on the stator support 44 (for example, four in this case). These sensors are configured at 45° angles to the bearing stator 12 (i.e., they intersect the X-axis and Y-axis directions at 45° angles respectively).

[0056] These displacement sensors 16 can be, for example, eddy current type sensors, but are not limited to these; various sensors can be used. Furthermore, the number of bearing stators 12 is not limited to the number described above; for example, 6, 8, 10, 12, 16, etc., can be used. In addition, although not shown in the figure, the displacement sensors also include sensors that are arranged axially opposite to the bearing / rotor section 21, and are provided together with the aforementioned displacement sensors 16 on, for example, the stator support 44, and are capable of detecting the displacement of the bearing rotor section 11, etc., in both the axial and rotational directions. It should be noted that the arrangement and number of displacement sensors 16, etc., are not limited to these and various arrangements can be used.

[0057] The bearing stator 12 comprises: a bearing stator core 17 formed of a magnetic material such as laminated electromagnetic steel sheets, for example, and a bearing coil 18 wound around the bearing stator core 17. The longitudinal cross-sectional shape of the bearing stator core 17 is a generally C-shape (U-shape) with an open end formed on the side of the bearing rotor member 11. Specifically, as Figure 2 illustrated, the longitudinal cross-sectional shape of the bearing stator core 17, for example, comprises: a first portion 17a extending along a first direction (the Z-axis direction in this example) perpendicular to the direction (radial direction) facing the bearing rotor member 11, and a pair of second portions 17b extending toward the bearing rotor member 11 side from both ends of the first portion 17a in the Z-axis direction. It should be noted that the bearing coil 18 is wound around the first portion 17a.

[0058] It should be noted that as Figure 3A illustrated, although the outer peripheral surface of the bearing rotor member 11 is configured as a curved surface, the magnetic pole surface 17d of the bearing stator core 17 (see Figure 2 ) is formed as a flat surface. Specifically, the magnetic pole surface 17d is formed on the same plane extending along the X-axis direction or the Y-axis direction and the Z-axis direction. Generally, when the magnetic pole surface 17d of the bearing stator core 17 is configured as a curved surface along the outer peripheral surface of the bearing rotor member 11, the biased magnetic flux φ1 of the magnetic field will concentrate at the circumferential ends of the magnetic pole surface 17d. In contrast, if the magnetic pole surface 17d is formed as a flat surface, such concentration of the biased magnetic flux φ1 can be prevented.

[0059] On the other hand, the pair of magnetic yokes 14 and 15 of the bearing rotor member 11 are formed such that their longitudinal cross-sectional shape, for example, comprises: a pair of fourth portions 14a and 15a that cover both end faces of the bearing magnet 13 in the first direction and extend along the first direction, and a pair of fifth portions 14b and 15b extending toward the bearing stator 12 side from the ends of the pair of fourth portions 14a and 15a on the opposite side to the bearing magnet 13.

[0060] The driving unit 30 comprises: an annular motor magnet 31 serving as a driving rotor member, which is disposed on the outer peripheral side of the bearing / rotor portion 21 of the rotor 20, that is, on the outer side in the radial direction of the bearing magnet 13 of the bearing rotor member 11; and a motor stator 32 serving as a driving stator, which is disposed on the outer side in the radial direction of the motor magnet 31 with a predetermined distance from the motor magnet 31, for example. The motor stator 32 applies a rotational driving force to the rotor 20, and the motor magnet 31 receives the rotational driving force from the motor stator 32.

[0061] The motor magnet 31 is formed, for example, of a neodymium magnet magnetized into four poles in the radial direction. The motor magnet 31 is configured to be supported in a non-contact manner with the pair of yokes 14, 15 and the bearing magnet 13 by an annular spacer 19 disposed between the opposing faces of a pair of fifth portions 14b, 15b of the pair of yokes 14, 15 in the first direction, and is housed within the radial dimension (diameter) L1 of the bearing rotor component 11. It should be noted that the spacer 19 is formed of a non-magnetic resin material or a metal material.

[0062] The motor stator 32 has an annular motor stator core 33 formed of magnetic material. The motor stator core 33 faces the motor magnet 31 from the outer side in the radial direction and has multiple magnetic poles along the circumferential direction of the motor magnet 31. The motor stator core 33 has, for example, six slots along the outer circumferential surface of the motor magnet 31 and having concave magnetic pole surfaces. In addition, the motor stator 32 has motor coils 34 wound in the slots of the motor stator core 33 and serving as drive coils. The motor stator 32 is formed in an annular shape, which passes through the Z-direction position between the outer circumferential surface of the rotor 20 and the first portion 17a of the bearing stator core 17, and between a pair of second portions 17b of the bearing stator core 17. That is, the motor stator 32 is disposed between the pair of second portions 17b of the bearing stator core 17 in a manner that is housed within a radial dimension L2 of the bearing stator 12, inside the bearing coil 18 in the radial direction. In addition, such as Figure 3A as well as Figure 3B As shown, in order to detect the rotation angle of the bearing rotor component 11 around the Z-axis, three Hall integrated circuits (HICs) 16a are arranged at 60° intervals between four adjacent slots in the circumferential direction of the motor stator 32. It should be noted that the configuration and number of Hall ICs 16a are not limited to this and various methods can be used.

[0063] Furthermore, the motor stator 32 constructed in this way, such as Figure 3B As shown, the stator of the sensored brushless motor is configured as a three-phase, six-slot, four-pole motor with U-phase, V-phase, and W-phase components, driving the rotor 20, which includes motor magnets 31 that generate magnetic flux φ2 and are magnetically coupled. It should be noted that, except for... Figure 1In the accompanying drawings, the non-magnetic material surrounding the bearing / rotor section 21 is omitted from the illustration. Furthermore, the drive section 30 is not limited to the three-phase, 6-slot, 4-pole brushless motor described above; for example, it can be a structure formed by a motor stator 32 with a 10-pole motor magnet 31 and a 12-slot motor stator core 33, or a structure formed by a motor stator 32 with a 14-pole motor magnet 31 and a 12-slot motor stator core 33. It should be noted that in the case of a sensorless brushless motor, the drive section 30 may, for example, not include the Hall integrated circuit 16a.

[0064] The control unit 60 includes, for example, a first substrate 61, such as a drive substrate equipped with a MOS-FET, which drives the bearing coil 18 of the magnetic bearing 10 and the motor coil 34 of the drive unit 30; a second substrate 62, such as a CPU substrate that controls the magnetic bearing 10 and the drive unit 30; and a third substrate 63, such as an encoder substrate that processes signals from various sensors. Based on detection signals such as voltage changes from all displacement sensors, including the displacement sensor 16 described above, the control unit 60 detects the displacement of the rotor 20 in each direction and in each rotational direction via the third substrate 63. Correspondingly, the second substrate 62 precisely controls the current flowing through the bearing coil 18 of the bearing stator 12 of the magnetic bearing 10. Therefore, the position and angle in the X-axis direction, the position and angle in the Y-axis direction, and the height in the Z-axis direction of the rotor 20 can be controlled in real time, and the rotational position of the rotor 20 can be corrected. In addition, the control unit 60 detects changes in the magnetic field through the second substrate 62 based on the detection signal from the Hall integrated circuit 16a, and performs fine control on the current flowing in the motor coil 34 of the motor stator 32 of the drive unit 30, for example, by controlling the rotation of the rotor 20 through the first substrate 61.

[0065] [Rotary drive unit and pump operation]

[0066] Next, the operation of the pump 100, which uses the rotary drive device 90 configured as described above, will be explained.

[0067] In the pump 100 with the above-described structure, the magnetic circuit of the magnetic bearing 10 and the magnetic circuit of the drive unit 30 are independent of each other and will not interfere with each other. That is, as Figure 2 as well as Figure 3A As shown, the magnetic circuit through which the magnetic flux φ1 formed by the magnetic bearing 10 passes is formed along the XZ plane and the YZ plane, which are parallel to the rotation axis Z of the rotor 20. On the other hand, as Figure 2 as well as Figure 3BAs shown, the magnetic circuit through which the magnetic flux φ2 formed by the drive unit 30 passes is formed along the XY plane orthogonal to the rotation axis Z of the rotor 20. The motor stator 32 is formed in a ring shape passing through a pair of second portions 17b of the bearing stator core 17, and the motor magnet 31 is configured to be closer to the outer periphery than the bearing rotor component 11, so the magnetic circuit of the magnetic bearing 10 is formed around the outer side of the magnetic circuit of the drive unit 30.

[0068] The control unit 60, in order to correct the displacement of the rotor 20 in each axial direction of the XYZ axes and the tilt in the Φ and Θ directions detected by the displacement sensor 16, etc., controls the current flowing in the bearing coil 18 as described above, and adjusts the control magnetic flux generated by the bearing coil 18. As a result, the rotor 20 can be maintained in a predetermined position and posture by the magnetic bearing 10, and supported by the magnetic bearing 10 in a non-contact state.

[0069] If three-phase AC power is supplied to the motor coil 34 of the motor stator 32 of the drive unit 30 in this state, the three-phase brushless motor will operate, and the rotor 20 will rotate in the prescribed direction of rotation. If the rotor 20 rotates, the impeller 22 will rotate non-contactly within the enclosed space A, so the conveying fluid is introduced into the pump chamber A1 through the suction port 51 and discharged from the pump chamber A1 to the outside through the discharge port 52.

[0070] [Effects of the Implementation Method]

[0071] According to the pump 100 using the rotary drive device 90 of this embodiment, the bearing stator 12 of the magnetic bearing 10 and the motor stator 32 of the drive unit 30 are disposed on the outside of the rotor 20, and the motor stator 32 is disposed in the inner space of the bearing stator core 17 of the magnetic bearing 10. Therefore, it is not necessary to place the stator inside the rotor 20, and the overall radial dimension (diameter) Lr of the rotary drive device 90 can be reduced compared to the conventional method.

[0072] Furthermore, since the dimensions of the bearing stator core 17 in the Z-axis direction are set to accommodate the motor stator 32 between a pair of second portions 17b, it is not longer than if the motor stator 32 were not present. However, the bearing coil 18 of the bearing stator 12 is wound around the first portion 17a extending in the Z-axis direction of the bearing stator core 17 and does not protrude in the Z-axis direction. Therefore, the overall dimension Lh of the rotary drive device 90 in the Z-axis direction can be the same as the height of the bearing stator core 17 in the Z-axis direction. Thus, the overall dimension Lh of the rotary drive device 90 in the Z-axis direction can be suppressed to a size that is only slightly larger than the existing size. Therefore, the dimensions of the rotary drive device 90, including the magnetic bearing 10 and the drive unit 30, in both the radial and axial directions can be suppressed to the maximum extent, and substantial miniaturization can be achieved as a whole.

[0073] Specifically, for example, if the radial dimension of a conventional rotary drive is taken as 100%, the radial dimension Lr of the rotary drive 90 can be set to approximately 70%, and compared to the Z-axis dimension (height) of a conventional rotary drive, the increase in the Z-axis dimension Lh of the rotary drive 90 can be suppressed to approximately 1.1 times. Therefore, the pump 100 using the rotary drive 90 can also be miniaturized. Furthermore, in the rotary drive 90 configured in this way, the magnetic bearings 10 support the rotor 20 on both sides in the Z-direction, and the drive unit 30 drives the rotor 20 in the center of the Z-direction, so the balance of the driving force applied to the rotor 20 is very good. In addition, the magnetic bearings 10 and the drive unit 30 do not affect each other's magnetic circuits, so neither of them will hinder the other's performance.

[0074] Furthermore, since the bearing stator 12 and the motor stator 32 are located outside the rotor 20, and the motor stator 32 is arranged in the inner space of the bearing stator core 17 with the bearing stator core 17 spanning both sides in the axial direction, compared with conventional rotary drive devices that use two biaxial magnetic bearings to support both ends of the drive unit 30 in the axial direction in a four-axis or higher manner, the structure is simpler and cheaper, enabling weight reduction and miniaturization. At the same time, since the magnetic levitation of the rotor 20 is controlled by the biaxially controlled magnetic bearing 10, the control structure is not complicated, and the circuit structure of the control system can be simplified. For example, the number of heat-generating elements (bearing coil 18, MOS-FET of the first substrate 61, etc.) can be reduced, and the structure and substrate design of the control unit 60 can be simplified. It should be noted that in the case of the pump 100 of this embodiment, since the impeller 22 is arranged on one side of the rotor 20, when the rotor 20 is tilted relative to the Z-axis, the rotor 20 will tilt around the position on the Z-axis near the impeller 22 as the center of rotation. Therefore, as long as the displacement sensor 16 is positioned away from the impeller 22, preferably at the center of the bearing / rotor section 21 in the Z-axis direction, the position of the rotor 20 in the X-axis direction and the angle in the Φ direction, as well as the position in the Y-axis direction and the angle in the Θ direction, can be detected by the displacement sensor 16. Thus, the tilt of the rotating shaft can also be fully controlled by the two-axis control.

[0075] [Structure of other pumps that utilize rotary drive mechanisms]

[0076] Figure 6 This is a partially perspective and schematic view of the overall structure of another pump 101 that incorporates a rotary drive device 90. (See diagram below.) Figure 6 As shown, the pump 101 has a rotor 20, which is integrated with the impeller 22 of the rotary drive unit 90, inserted, for example, inside the flanged pipe 102. The motor stator 32 of the drive unit 30 and the bearing stator 12 of the magnetic bearing 10 are arranged on the outer periphery of the flanged pipe 102 where the rotor 20 is located. That is, since the rotor 20 is magnetically suspended by the magnetic bearing 10 and the motor stator 32 is not arranged inside, it can be easily arranged inside the flanged pipe 102. Furthermore, the bearing stator 12 and the motor stator 32, which support and drive the rotor 20, can be installed on the outer side of the flanged pipe 102. With this structure, the complex machining of the flanged pipe 102 and the installation of the pump device are eliminated, and the pump 101 can even be used as part of the piping material.

[0077] [Second Implementation]

[0078] [Other structures of the rotary drive device]

[0079] Figure 7 This is an enlarged longitudinal sectional view schematically showing the rotary drive device 90A of the second embodiment. Figure 8 This is a schematic top view showing the overall structure of the rotary drive unit 90A. It should be noted that, within the... Figure 7 as well as Figure 8 In the following description, the same components as in the first embodiment are given the same reference numerals, and therefore repeated descriptions are omitted below.

[0080] The rotary drive device 90A of the second embodiment differs from the rotary drive device 90 of the first embodiment in, for example, the longitudinal section shape of the bearing stator core 17 of the bearing stator 12 of the magnetic bearing 10 is different. That is, the bearing stator core 17 is formed such that, in addition to the first part 17a and the second part 17b described above, its longitudinal section shape also includes a pair of third parts 17c, which extend from the ends of the pair of second parts 17b on the bearing rotor component 11 side along a first direction (in this case, the Z-axis direction) toward each other and then extend toward the bearing rotor component 11 side.

[0081] In other words, in the longitudinal cross-sectional shape of the bearing stator core 17, the open end portion of the C-shape that originally extends towards the bearing rotor component 11 from both ends in the Z-axis direction of the first portion 17a on which the bearing coil 18 is wound (for example, refer to...) Figure 12 It has a pair of key-shaped parts and has open ends close to each other.

[0082] If the bearing stator core 17 has this shape, the length l of the bearing coil 18 in the Z-axis direction can be made larger than the distance La between the opposing faces of the pair of third portions 17c on the open end side of the bearing stator core 17 in the Z-axis direction. Furthermore, the width of the open end side of the bearing stator core 17, i.e., the distance Lb between the faces of the pair of third portions 17c opposite to their opposing faces in the Z-axis direction, can be made smaller than the original length Lh of the bearing stator core 17 in the Z-axis direction (i.e., the dimension of the rotary drive device 90A in the Z-axis direction), and approximately equal to the length Lc of the bearing rotor component 11 in the Z-axis direction. It should be noted that the motor stator 32 of the drive unit 30 is arranged from between the pair of second portions 17b of the bearing stator core 17 to between the pair of third portions 17c.

[0083] In this article, it is generally known that existing magnetic bearings 200 (refer to) Figure 12The greater the restoring force generated, for example, the more approximately equal the length of the stator core 204 of the bearing stator 202 is to the thickness Lf in the axial direction of the bearing rotor component 206, and the thinner the core is, the greater the restoring force. On the other hand, the magnetic flux φ is controlled by the coil 205 of the bearing stator 202. In order to improve responsiveness, the inductance of the coil 205 is preferably as small as possible.

[0084] The inductance of the coil 205 is proportional to the cross-sectional area S of the coil 205 and inversely proportional to the length l of the coil. Therefore, in order to improve the responsiveness of the coil 205, it is necessary to wind the coil 205 on the stator core 204 by reducing the cross-sectional area S of the coil 205 and increasing the length l of the coil 205.

[0085] However, if the coil length l increases, the thickness Lf of the bearing rotor component 206 of rotor 201 in the axial direction will also increase. Therefore, the restoring force of rotor 201 will decrease, especially the restoring torque when rotor 201 is tilted, and the size of the magnetic bearing 200 in the axial direction will increase.

[0086] Here, as mentioned above, the more approximately equal the length Lb of the open end (part 3, 17c) of the bearing stator 12 in the Z-axis direction to the length Lc of the bearing rotor component 11 in the Z-axis direction, and the shorter the length Lc of the bearing rotor component 11 in the Z-axis direction, the greater the restoring force generated by the magnetic bearing 10 of the rotor 20 in terms of position and tilt. This is consistent with... Figure 12 Compared to the existing C-shaped stator core 204 shown, the magnetic bearing 10 of the rotary drive device 90A according to the second embodiment can shorten the length Lb of the portion (third portion 17c) of the open end opposite to the bearing rotor component 11 in the Z-axis direction.

[0087] Therefore, while maintaining the number of turns N of the bearing coil 18, the length Lc of the bearing rotor component 11 in the Z-axis direction can be shorter than that of the existing ones. This allows for miniaturization of the bearing rotor component 11 in the Z-axis direction and ensures sufficient restoring force. On the other hand, as mentioned above, to improve the responsiveness of the magnetic bearing 10, the inductance of the bearing coil 18 needs to be as small as possible. In this regard, according to the magnetic bearing 10 of the second embodiment, since the length Ld of the first portion 17a of the bearing stator core 17 available for winding the bearing coil 18 can be sufficiently ensured, the length l of the bearing coil 18 in the Z-axis direction can be increased, and the cross-sectional area S of the bearing coil 18 can be reduced, thereby suppressing the inductance of the bearing coil 18 and improving responsiveness. It should be noted that, in order to maximize the attractive force of the bearing magnet 13, it is preferable that the width of each of the third portions 17c (protruding poles) of the bearing stator core 17 in the Z-axis direction is approximately equal to the thickness of the yokes 14 and 15 in the Z-axis direction.

[0088] According to the rotary drive device 90A of the second embodiment, it can achieve the same effect as the rotary drive device 90 of the first embodiment, and can further reduce the axial dimension of the bearing rotor component 11. Therefore, it promotes the miniaturization of the bearing / rotor section 21, and further promotes the miniaturization of the rotor 20, and can achieve further miniaturization as a whole.

[0089] [Third Implementation]

[0090] [Other structures of the rotary drive device]

[0091] Figure 9 This is an enlarged longitudinal sectional view schematically showing the rotary drive device 90A of the third embodiment.

[0092] The rotary drive device 90B of the third embodiment, such as Figure 9 As shown, the structure of the bearing rotor component 11 of the magnetic bearing 10, the shape of the motor stator 32, and the arrangement of the motor stator 32 in the inner space of the bearing stator core 17 are different from the rotary drive device 90A of the second embodiment.

[0093] That is, the bearing rotor component 11 is the same in that it has an annular bearing magnet 13 and a pair of annular magnetic yokes 14, 15 arranged concentrically with the bearing magnet 13 in a manner that clamps the bearing magnet 13 on both sides in the axial direction, but the details are different. In the third embodiment, the pair of magnetic yokes 14, 15, for example, have a longitudinal cross-sectional shape that is approximately U-shaped, with one side of the bearing stator 12 open and broken at the center in the Z-axis direction.

[0094] Specifically, the longitudinal cross-sectional shape of the pair of magnetic yokes 14 and 15 is as follows: a pair of fourth portions 14a and 15a, which cover the two end faces of the bearing magnet 13 in the first direction (here, the Z-axis direction) and extend along a second direction orthogonal to the Z-axis direction (here, the radial direction (X-axis direction)); and a pair of fifth portions 14b and 15b, which extend from the ends of the pair of fourth portions 14a and 15a opposite to the bearing stator 12 toward directions that approach each other in the Z-axis direction. The inner circumference of the fourth portions 14a and 15a protrudes further inward and outward than the inner and outer circumference of the bearing magnet 13.

[0095] In the first direction, between the opposing surfaces of the fourth parts 14a and 15a, which are closer to the bearing stator 12 than the bearing magnet 13, a motor magnet 31, supported non-contactly by the yokes 14 and 15 and the bearing magnet 13 via an annular spacer 19, is configured to be housed within the size (diameter) L1 of the bearing rotor component 11. A first gap g1 is formed between the fifth parts 14b and 15b and the bearing magnet 13. Furthermore, a second gap g2 is provided between the opposing top ends of the pair of fifth parts 14b and 15b.

[0096] If the bearing rotor assembly 11 has this shape, the first gap g1 can prevent the two magnetic poles of the bearing magnet 13 from getting too close to the fifth parts 14b and 15b, thus ensuring that the bias flux φ1 generated by the bearing magnet 13 can be stably supplied to the bearing stator 12. Furthermore, the fifth parts 14b and 15b, which have lower magnetic impedance and are connected in parallel with the bearing magnet 13 (which has a higher magnetic impedance), form a magnetic circuit, allowing the control flux φ3 generated by the bearing coil 18 to pass through the bearing rotor assembly 11 with minimal loss. However, without the second gap g2, the two magnetic poles of the bearing magnet 13 would short-circuit through the fifth parts 14b and 15b. Therefore, considering the balance between the stable supply of the bias flux φ1 to the bearing stator 12 and the magnetic impedance of the magnetic circuit through which the control flux φ3 passes, the width of the second gap g2 is preferably appropriately set.

[0097] On the other hand, in this embodiment, unlike Figure 7 In the structure shown, the motor coil 34 constituting the motor stator 32 is not located between the third portions 17c of the bearing stator core 17, but is housed between the second portions 17b. Furthermore, only the top portion of the motor stator core 33 extending towards the rotor 20 is located between the third portions 17c of the bearing stator core 17. That is, in the motor stator 32, inside the bearing coil 18 of the bearing stator 12 in the radial direction, the motor stator core 33 and the motor coil 34 are housed between a pair of second portions 17b of the bearing stator core 17, and the extension portion of the motor stator core 33 is disposed between a pair of third portions 17c, and the motor stator 32 is configured to be housed within dimension L2 in the radial direction of the bearing stator 12.

[0098] According to the rotary drive device 90B of the third embodiment, it can achieve the same effect as the rotary drive device 90A of the second embodiment, and can further reduce the axial dimension of the bearing rotor component 11. Therefore, it can further promote the miniaturization of the bearing / rotor part 21 and the rotor 20, and further realize the overall miniaturization.

[0099] [Fourth Implementation]

[0100] Figure 10 This is a schematic top view of the drive unit 30 of the rotary drive device 90C according to the fourth embodiment.

[0101] In this embodiment, six displacement sensors 16, formed by eddy current sensors or the like, are arranged at 60° intervals between six adjacent slots in the circumferential direction of the motor stator 32. A Hall effect integrated circuit 16a is disposed near a portion of the displacement sensors 16.

[0102] When the displacement sensor 16 is configured in this way, the positions of the slots of the motor stator 32 and the position of the displacement sensor 16 will not interfere, so the displacement sensor 16 can be positioned at the center of the bearing rotor assembly 11 in the Z-axis direction. Therefore, radial displacement and tilt of the rotor 20 can be detected at an appropriate location.

[0103] [Fifth Implementation]

[0104] Figure 11A This is a schematic longitudinal sectional view showing the overall structure of the pump 100A using the rotary drive device 90D of the fifth embodiment. Figure 11B This is a schematic top view of the drive unit 30 of the rotary drive device 90D.

[0105] In this embodiment, four displacement sensors 16 are arranged at 90° intervals along the circumferential direction on the inner circumferential side of the bearing rotor component 11. Specifically, the rear-extending cylindrical protrusion 42b of the rear housing 42 has a centrally located cylindrical protrusion 42c extending forward, and the bearing rotor component 11 is disposed within the annular space A4 formed by the cylindrical protrusions 42b and 42c. Furthermore, four displacement sensors 16 are arranged inside the cylindrical protrusions 42c. In this case, the placement of the displacement sensors 16 is not limited by the motor stator 32, and therefore, the displacement sensors 16 can be easily positioned at the center in the Z-axis direction of the bearing rotor component 11.

[0106] According to this embodiment, similar to the fourth embodiment, the displacement sensor 16 can be disposed at the center of the bearing rotor component 11 in the Z-axis direction, so that the positional offset and tilt of the rotor 20 in the radial direction can be detected at a suitable position.

[0107] While several embodiments of the present invention have been described above, these embodiments are merely illustrative and are not intended to limit the scope of the invention. These novel embodiments can be implemented in a wide variety of other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are also included within the scope and spirit of the invention, and encompass the scope equivalent to the invention described in the claims.

[0108] Explanation of reference numerals in the attached figures

[0109] 10 Magnetic Bearings

[0110] 11 Bearing rotor assembly

[0111] 12 Bearing Stator

[0112] 13 Bearing Magnets

[0113] 14, 15 Magnetic yokes

[0114] 16 Displacement Sensors

[0115] 17 Bearing stator core

[0116] 17a Part 1

[0117] 17b Part 2

[0118] 17c Part 3

[0119] 18 Bearing Coils

[0120] 20 rotors

[0121] 30 Drive Unit

[0122] 31 Motor magnet

[0123] 32 Motor stator

[0124] 33 Motor stator core

[0125] 34 motor coils

[0126] 90 Rotary drive unit

[0127] 100 pumps

Claims

1. A rotary drive device, comprising: Rotor; A magnetic bearing supports the rotor non-contactly by magnetic force; The drive unit drives the rotor to rotate. Its features are, The magnetic bearing comprises: A bearing stator is disposed on the outer periphery of the rotor and supports the rotor non-contactly by magnetic force; A ring-shaped bearing rotor component made of magnetic material is disposed on the rotor and forms a magnetic circuit together with the bearing stator. The driving unit has: A drive stator is disposed on the outer periphery of the rotor and applies a rotational driving force to the rotor; An annular drive rotor component is disposed on the outer periphery of the bearing rotor component of the rotor and receives rotational driving force from the drive stator. The bearing stator has: Multiple bearing stator cores formed of magnetic material are disposed on the outer periphery of the bearing rotor component and together with the bearing rotor component form a magnetic circuit; The bearing coil wound on the bearing stator core The bearing stator core has: The first part extends in a first direction orthogonal to the direction facing the bearing rotor component; A pair of second parts, extending from both ends of the first part in the first direction toward one side of the bearing rotor component, and, The bearing coil is wound on the first part of the bearing stator core. The drive stator is located between the outer peripheral surface of the rotor and the first portion of the bearing stator core, and is formed on the inner side of the bearing stator core in the first direction between the pair of second portions of the bearing stator core.

2. The rotary drive device as described in claim 1, characterized in that, The bearing stator core is further configured to have a pair of third portions that extend from the end of the pair of second portions on the bearing rotor component side along the first direction toward each other and then toward the bearing rotor component side.

3. The rotary drive device as described in claim 1 or 2, characterized in that, The bearing rotor assembly has: Circular bearing magnet; A pair of annular magnetic yokes are configured to clamp the bearing magnet in the first direction. The pair of magnetic yokes have: A pair of fourth parts cover the two end faces of the bearing magnet in the first direction and extend along the first direction; A pair of fifth parts extend toward the bearing stator side from the end of the pair of fourth parts opposite to the bearing magnet, and... A shim formed of a non-magnetic material is disposed between the opposing surfaces of the pair of fifth portions in the first direction, the shim being used to provide non-contact support for the drive rotor component by the pair of magnetic yokes and the bearing magnets.

4. The rotary drive device as described in claim 1 or 2, characterized in that, The bearing rotor assembly has: Circular bearing magnet; A pair of annular magnetic yokes are configured to clamp the bearing magnet in the first direction. The pair of magnetic yokes have: A pair of fourth parts cover the two end faces of the bearing magnet in the first direction and extend in a direction opposite to the bearing stator; A pair of fifth parts, starting from the end of the pair of fourth parts on the side opposite to the bearing stator, extend along the first direction toward each other, and Between the opposing surfaces of the pair of fourth portions, closer to the bearing stator than the bearing magnets, in the first direction, a shim formed of a non-magnetic material is disposed. This shim serves to provide non-contact support for the drive rotor assembly by the pair of magnetic yokes and the bearing magnets. A first gap is formed between the fifth part and the bearing magnet. A second gap is provided between the respective top ends of the pair of fifth parts that are opposite each other.

5. The rotary drive device as described in claim 1 or 2, characterized in that, A plurality of bearing stators are arranged on the outer side of the bearing rotor component in the radial direction along the circumferential direction of the bearing rotor component, and each of the bearing stators is opposite to the bearing rotor component in the radial direction.

6. The rotary drive device as described in claim 1 or 2, characterized in that, The drive stator has an annular drive stator core formed of magnetic material and drive coils wound in slots of the drive stator core. The drive stator core is opposite the drive rotor component from the outer side in the radial direction and has multiple magnetic poles along the circumferential direction of the drive rotor component.

7. A pump mechanism comprising a rotor, a magnetic bearing that supports the rotor non-contactly by magnetic force, a drive unit for rotating the rotor, and an impeller mounted on the rotor. Its features are, The magnetic bearing comprises: A bearing stator is disposed on the outer periphery of the rotor and supports the rotor non-contactly by magnetic force; A ring-shaped bearing rotor component made of magnetic material is disposed on the rotor and forms a magnetic circuit together with the bearing stator. The driving unit has: A drive stator is disposed on the outer periphery of the rotor and applies a rotational driving force to the rotor; An annular drive rotor component is disposed on the outer periphery of the bearing rotor component of the rotor and receives rotational driving force from the drive stator. The bearing stator has: Multiple bearing stator cores formed of magnetic material are disposed on the outer periphery of the bearing rotor component and together with the bearing rotor component form a magnetic circuit; The bearing coil wound on the bearing stator core The bearing stator core has: The first part extends in a first direction orthogonal to the direction facing the bearing rotor component; A pair of second parts, extending from both ends of the first part in the first direction toward one side of the bearing rotor component, and, The bearing coil is wound on the first part of the bearing stator core. The drive stator is located between the outer peripheral surface of the rotor and the first portion of the bearing stator core, and is formed on the inner side of the bearing stator core in the first direction between the pair of second portions of the bearing stator core.

8. The pump as claimed in claim 7, characterized in that, The bearing stator core is further configured to have a pair of third portions that extend from the end of the pair of second portions on the bearing rotor component side along the first direction toward each other and then toward the bearing rotor component side.

9. The pump as claimed in claim 7 or 8, characterized in that, The bearing rotor assembly has: Circular bearing magnet; A pair of annular magnetic yokes are configured to clamp the bearing magnet in the first direction. The pair of magnetic yokes have: A pair of fourth parts cover the two end faces of the bearing magnet in the first direction and extend along the first direction; A pair of fifth parts extend toward the bearing stator side from the end of the pair of fourth parts opposite to the bearing magnet, and... A shim formed of a non-magnetic material is disposed between the opposing surfaces of the pair of fifth portions in the first direction, the shim being used to provide non-contact support for the drive rotor component by the pair of magnetic yokes and the bearing magnets.

10. The pump as claimed in claim 7 or 8, characterized in that, The bearing rotor assembly has: Circular bearing magnet; A pair of annular magnetic yokes are configured to clamp the bearing magnet in the first direction. The pair of magnetic yokes have: A pair of fourth parts cover the two end faces of the bearing magnet in the first direction and extend in a direction opposite to the bearing stator; A pair of fifth parts, starting from the end of the pair of fourth parts on the side opposite to the bearing stator, extend along the first direction toward each other, and Between the opposing surfaces of the pair of fourth portions, closer to the bearing stator than the bearing magnets, in the first direction, a shim formed of a non-magnetic material is disposed. This shim serves to provide non-contact support for the drive rotor assembly by the pair of magnetic yokes and the bearing magnets. A first gap is formed between the fifth part and the bearing magnet. A second gap is provided between the respective top ends of the pair of fifth parts that are opposite each other.

11. The pump as claimed in claim 7 or 8, characterized in that, A plurality of bearing stators are arranged on the outer side of the bearing rotor component in the radial direction along the circumferential direction of the bearing rotor component, and each of the bearing stators is opposite to the bearing rotor component in the radial direction.

12. The pump as claimed in claim 7 or 8, characterized in that, The drive stator has an annular drive stator core formed of magnetic material and drive coils wound in slots of the drive stator core. The drive stator core is opposite the drive rotor component from the outer side in the radial direction and has multiple magnetic poles along the circumferential direction of the drive rotor component.

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