Motors and devices using them

Abstract

To provide a motor which can further stably rotate a mover in a non-contact manner by a simpler structure, and to provide an apparatus using the same.SOLUTION: A motor has a first portion including a plurality of permanent magnets, and a second portion including a plurality of coils. The first portion or the second portion is constituted so as to be rotatable with a rotating shaft as a center. The plurality of permanent magnets are circumferentially arranged with the rotating shaft as a center. The plurality of coils are arranged so as to oppose the plurality of permanent magnets in a direction along the rotating shaft. The motor further has a control part for controlling a rotational speed and a posture of the rotating first portion or the rotating second portion by controlling currents which are applied on the plurality of coils.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] The present invention relates to a motor and an apparatus using the same. [Background technology]

[0002] Patent Document 1 describes an axial type magnetically levitated rotating device in which a rotor is axially magnetically levitated along its axial direction and rotated in a non-contact manner around its axis, and an axial type magnetically levitated centrifugal pump using the same. Patent Document 2 also describes an axial type magnetically levitated rotary motor and a rotating device using this motor. Patent Documents 1 and 2 describe high-speed rotating machines, high-speed spindles for machine tools, artificial hearts, centrifugal pumps, and vacuum pumps as examples of applications of such rotating devices. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-016677 A [Patent Document 2] Japanese Patent Application Publication No. 08-322194 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the rotating device described in Patent Document 1, rotation is controlled by a lower stator arranged below the rotor, while the attitude of the rotor is maintained by an upper stator arranged above the rotor, making it difficult to avoid the entire device becoming larger and more complicated.

[0005] In addition, in the motor described in Patent Document 2, the stator located at the top is provided with a winding that is used for both rotating and levitating the rotor, but only the axial position of the rotor is controlled, and no control of other tilt components is performed. For this reason, there is a risk that the rotation of the motor described in Patent Document 2 may become unstable.

[0006] An object of the present invention is to provide a motor capable of rotating a mover more stably in a non-contact manner with a simpler structure, and a device using the same. [Means for solving the problem]

[0007] A motor according to one aspect of the present invention has a first portion including a plurality of permanent magnets and a second portion including a plurality of coils, the first portion or the second portion is configured to be rotatable about a rotation axis, the plurality of permanent magnets are arranged circumferentially about the rotation axis, the plurality of coils are arranged to face the plurality of permanent magnets in a direction along the rotation axis, and a current applied to the plurality of coils is controlled. Regulation Your department The control unit controls the attitude of the first part or the second part in six axis directions while applying a torque to the rotating first part or the second part. . A motor according to another aspect of the present invention has a first part including a plurality of permanent magnets and a second part including a plurality of coils, wherein the first part or the second part is configured to be rotatable around a rotation axis, the plurality of permanent magnets are arranged circumferentially around the rotation axis, the plurality of coils are arranged so as to face the plurality of permanent magnets in a direction along the rotation axis, and a control unit is provided that controls the attitude of the rotating first part or the second part in six axial directions by controlling the current applied to the plurality of coils, and the plurality of coils are arranged so that at least three of the plurality of coils face each of the plurality of permanent magnets. Effect of the Invention

[0008] According to the present invention, it is possible to rotate the mover more stably in a non-contact manner with a simpler structure. [Brief description of the drawings]

[0009] [Figure 1A] 1 is a schematic diagram showing a rotating device according to a first embodiment of the present invention. [Figure 1B] 1 is a schematic diagram showing a rotating device according to a first embodiment of the present invention. [Figure 1C] 1 is a schematic diagram showing a rotating device according to a first embodiment of the present invention. [Figure 1D] 1 is a schematic diagram showing a rotating device according to a first embodiment of the present invention. [Figure 1E] 1 is a schematic diagram showing coordinate axes and directions used to explain a rotating device according to a first embodiment of the present invention. [Diagram 2] 2 is a schematic diagram showing a control unit of the rotating device according to the first embodiment of the present invention. FIG. [Diagram 3]3A to 3C are schematic diagrams illustrating a method for controlling the attitude of a mover in the rotating device according to the first embodiment of the present invention. [Figure 4] 4 is a graph illustrating a thrust constant of a coil in the rotating device according to the first embodiment of the present invention. [Figure 5A] 5A to 5C are schematic diagrams illustrating a method of applying torque to a mover in the rotating device according to the first embodiment of the present invention. [Figure 5B] 5A to 5C are schematic diagrams illustrating a method of applying torque to a mover in the rotating device according to the first embodiment of the present invention. [Figure 6] FIG. 4 is a schematic diagram showing a rotating device according to a second embodiment of the present invention. [Figure 7] FIG. 11 is a schematic diagram showing a control unit of a rotating device according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [First embodiment] Hereinafter, a first embodiment of the present invention will be described with reference to the drawings, using FIGS. 1A to 5B. First, the overall configuration of a rotating device including a motor according to this embodiment will be described with reference to Figs. 1A to 1E. Fig. 1A is a longitudinal sectional view taken along a rotation axis of the rotating device according to this embodiment. Fig. 1B is a sectional view taken along line BB' in Fig. 1A. Fig. 1C is a sectional view taken along line CC' in Fig. 1A. Fig. 1D is a sectional view taken along line DD' in Fig. 1A. Fig. 1E is a schematic diagram showing coordinate axes and directions used in the following description of the rotating device.

[0011] Here, the coordinate axes and directions used in the following description are defined. First, the axis along the axis of rotation around which the mover 101 described later rotates is defined as the Z axis. The XY plane is taken to be perpendicular to the Z axis, and the X and Y axes are taken to be perpendicular to each other on the XY plane. The direction along the X axis is defined as the X direction, the direction along the Y axis is defined as the Y direction, and the direction along the Z axis is defined as the Z direction. The direction of rotation around the X axis is defined as the Wx direction, the direction of rotation around the Y axis is defined as the Wy direction, and the direction of rotation around the Z axis is defined as the Wz direction. The positive directions of rotation in the Wx direction, Wy direction, and Wz direction are right-handed screw directions with respect to the positive directions of the X axis, Y axis, and each axis along which the X axis extends, respectively. Each axis and each direction is shown in FIG. 1E. The R axis is taken to be in the direction in which the radius increases with the Z axis as the central axis.

[0012] As shown in Fig. 1A, a pump 10 according to this embodiment includes a motor 20 having a mover 101 as a first part and a stator 201 as a second part. The motor 20 is an axial magnetic levitation motor. In this embodiment, a pump 10 in which fins 104 (see Fig. 1C) are attached to the mover 101 will be described as an example of a rotating device in which the motor 20 is used. The fins 104 are rotating members that rotate together with the mover 101.

[0013] The stator 201 is configured as a housing having an intake port 202, an exhaust port 203, and a pump chamber 204. The pump chamber 204 is formed in an annular shape with the Z-axis as its central axis. A circular movable element 101 is rotatably housed in the pump chamber 204. The intake port 202 is disposed so as to be located at the center of the pump chamber 204, and is connected to the inner periphery of the pump chamber 204. The exhaust port 203 is connected to the outer periphery of the pump chamber 204.

[0014] Furthermore, the stator 201 has a plurality of coils 205 disposed so as to face the mover 101 housed in the pump chamber 204. The plurality of coils 205 are circumferentially arranged so as to face the upper surface of the annular mover 101 in the Z direction.

[0015] On the other hand, the mover 101 is configured as an annular impeller housed in the pump chamber 204. The mover 101 has a plurality of permanent magnets 102, a yoke plate 103, and a plurality of fins 104. The plurality of permanent magnets 102 are attached to the annular yoke plate 103 at the upper portion of the mover 101 so as to face the upper surface of the mover 101. The mover 101 rotates within the pump chamber 204 of the stator 201 about the Z-axis as the rotation axis.

[0016] In the pump 10, as described below, a force acting between the coil 205 to which a current is applied and the permanent magnet 102 causes the mover 101 housed in the pump chamber 204 to float in the Z direction and rotate in a predetermined direction around an axis along the Z axis as the rotation axis. The Z direction in which the mover 101 floats is, for example, the vertical direction, but may be a direction other than the vertical direction. When the mover 101 rotates, a fluid flows from the intake port 202 into the pump chamber 204, and the flowed-in fluid is discharged from the exhaust port 203. In this way, the pump 10 operates to suck in a fluid from the intake port 202 and discharge the sucked fluid from the exhaust port 203 to transfer the fluid. The pump 10 is configured to transfer, for example, a liquid as the fluid, but may also be configured to transfer a gas as the fluid.

[0017] The pump 10 has an attitude sensor 210, a Wz rotation angle sensor 211, and an XY sensor 212. The attitude sensor 210, the Wz rotation angle sensor 211, and the XY sensor 212 are attached to the stator 201 and installed.

[0018] The attitude sensors 210 are attached to the stator 201 at three or more locations so as to face the mover 101 in the Z direction. Each attitude sensor 210 can detect and output the distance to the mover 101 in the Z direction. The attitude (Z, Wx, and Wy) of the mover 101 can be calculated from the output of the attitude sensors 210 installed at three or more locations. Here, of the attitude of the mover 101, Z is the position of the mover 101 in the Z direction, Wx is the rotation angle of the mover 101 in the Wx direction, and Wy is the rotation angle of the mover 101 in the Wy direction (see FIG. 1E).

[0019] The Wz rotation angle sensor 211 is attached to the stator 201 so as to face the outer circumferential surface, upper surface, or lower surface of the mover 101. The Wz rotation angle sensor 211 can detect and output the rotation angle of the mover 101 in the Wz direction. A scale (not shown) is attached to the surface of the mover 101 facing the Wz rotation angle sensor 211. The Wz rotation angle sensor 211 can detect the rotation angle of the mover 101 in the Wz direction by reading the pattern on the scale of the mover 101.

[0020] The XY sensors 212 are attached to two locations on the stator 201 so as to face the mover 101 in the X and Y directions. The XY sensors 212 attached to two locations can detect and output the distances between the mover 101 and the XY sensors 212 in the X and Y directions, respectively.

[0021] In the mover 101, the multiple permanent magnets 102 are arranged circumferentially around the rotation axis of the mover 101. Specifically, as shown in FIG. 1B, four permanent magnets 102a, 102b, 102c, and 102d are attached circumferentially as the multiple permanent magnets 102 in a plane along the XY plane, and are arranged in the Wz direction. However, the number of the multiple permanent magnets 102 is not limited to four and can be changed as appropriate. The four permanent magnets 102a, 102b, 102c, and 102d are attached magnetized so that the polarity of the magnetic poles facing upward on the coil 205 side of the stator 201 is alternately different in the XY plane, and the N poles and S poles are alternately arranged in the Wz direction. The permanent magnets 102a, 102b, 102c, and 102d are magnetized so that the coil 205 side is N pole, S pole, N pole, and S pole in order.

[0022] In the following description, the four permanent magnets 102 will be distinguished by using the indices "a," "b," "c," and "d," and the four permanent magnets 102 will be appropriately referred to as permanent magnet 102a, permanent magnet 102b, permanent magnet 102c, or permanent magnet 102d.

[0023] As shown in FIG. 1C, twelve coils 205 are attached and installed on the stator 201 so as to be aligned in the Wz direction as the plurality of coils 205 facing the permanent magnets 102 of the mover 101 in the Z direction within a plane along the XY plane. However, the number of the plurality of coils 205 is not limited to twelve and can be changed as appropriate. The coils 205 are cored coils or air-core coils configured by winding a conductor around an iron core or an air core. All of the plurality of coils 205 may be cored coils or air-core coils, or some of the plurality of coils 205 may be cored coils and the rest may be air-core coils.

[0024] In the stator 201, the multiple coils 205 are preferably arranged such that at least three of the multiple coils 205 face each of the multiple permanent magnets 102 of the mover 101. By having at least three coils 205 face each permanent magnet 102, it becomes possible to control the rotation speed and attitude of the mover 101 with high precision by the force acting between the permanent magnets 102 and the coils 205.

[0025] In the following description, the symbol “j” (j is an integer satisfying 1≦j≦12) is used as an index to distinguish the 12 coils 205, and the 12 coils 205 are appropriately written as coil 205-j to distinguish them.

[0026] In the following description, the reference of the rotation coordinate in the Wz direction of the mover 101 is the boundary between the permanent magnets 102a and 102d. The reference of the rotation coordinate in the Wz direction of the stator 201 is the boundary between the coils 205-1 and 205-12. The magnitude of the rotation angle of the mover 101 in the Wz direction is θ.

[0027] 1D, the mover 101 is provided with a plurality of fins 104 on a surface along the XY plane. The plurality of fins 104 are provided, for example, in a curved spiral shape inclined at a predetermined angle with respect to the radial direction of the annular mover 101. The plurality of fins 104 rotate integrally with the mover 101, and push out the fluid sucked into the pump chamber 204 from the intake port 202 toward the exhaust port 203. The shape of the plurality of fins 104 can be appropriately changed depending on the type of pump 10.

[0028] The pump 10 is provided with a control unit 30 that controls the pump 10. The control unit 30 controls, for example, the attitude of the mover 101, the rotation speed of the mover 101, etc. The control unit 30 will be further described with reference to FIG. 2. FIG. 2 is a schematic diagram showing the control unit 30 of the pump 10. The control unit 30 can constitute a part of the pump 10.

[0029] 2, the control unit 30 has an integrated controller 300, an attitude controller 301, and a coil controller 302. The integrated controller 300, the attitude controller 301, and the coil controller 302 execute control programs corresponding to the respective processes and perform various calculations to execute the respective processes. Note that all or a part of the control unit 30 may be provided separately from the mover 101 and the stator 201, or may be provided in the stator 201.

[0030] The integrated controller 300 is connected to a posture controller 301 so as to be able to communicate with it. The posture controller 301 is connected to a coil controller 302 so as to be able to communicate with it. The posture controller 301 is also connected to a posture sensor 210, a Wz rotation angle sensor 211, and an XY sensor 212. The coil controller 302 is connected to the 12 coils 205 installed on the stator 201 as described above. The 12 coils 205 are arranged in a coil unit, with three coils 205 functioning as a U-phase coil, a V-phase coil, and a W-phase coil, arranged in sequence in the Wz direction. The 12 coils 205 are each provided with a current sensor 312 that detects and outputs a current applied to the coil 205 in a corresponding manner. The coil controller 302 is connected to each current sensor 312.

[0031] The integrated controller 300 controls the mover 101 by issuing a target value for the attitude of the mover 101 to the attitude controller 301 .

[0032] The attitude controller 301 calculates a torque vector indicating the torque to be applied to the mover 101 based on the target attitude value from the integrated controller 300 and the outputs of the attitude sensor 210, the Wz rotation angle sensor 211, and the XY sensor 212. The attitude controller 301 can detect the rotation angle and attitude of the mover 101 based on the outputs of the attitude sensor 210, the Wz rotation angle sensor 211, and the XY sensor 212.

[0033] The coil controller 302 calculates a current to be applied to each coil 205 based on the torque vector calculated by the posture controller 301. The coil controller 302 controls and applies a current to each coil 205 according to the calculated current. The coil controller 302 can detect a current value of each coil 205 based on an output of each current sensor 312. In addition, a current control device (not shown) is connected to each coil 205. The coil controller 302 can independently control the current value of each coil 205 by controlling each current control device according to the detected current value of each coil 205.

[0034] Next, a method of controlling the attitude of the mover 101 by the control unit 30 will be described with reference to Fig. 3. Fig. 3 is a schematic diagram for explaining a method of controlling the attitude of the mover 101 in the pump 10, and shows a schematic control loop for calculating the magnitude of the force applied to the mover 101. In Fig. 3, ref is a target value for the attitude of the mover 101 commanded from the integrated controller 300 to the attitude controller 301, and pos is attitude information of the mover 101 acquired from the sensor group. The sensor group includes an attitude sensor 210, a Wz rotation angle sensor 211, and an XY sensor 212.

[0035] 3, the attitude controller 301 calculates a torque vector T indicating the torque to be applied to the mover 101 from the difference err between the target attitude value ref and the current attitude information pos. The attitude controller 301 may be, for example, a controller using PID control, or may be a controller using an appropriate filter according to the characteristics of the mover 101. Such a controller can stabilize the attitude of the mover 101.

[0036] The coil controller 302 calculates a current vector I indicating a current to be applied to each coil 205, based on the torque vector T calculated by the posture controller 301. The coil controller 302 applies a current according to the calculated current vector I to each coil 205.

[0037] When a current is applied to each coil 205 in this way, it acts as a force F on the mover 101, causing the mover 101 to rotate. A group of sensors, including an attitude sensor 210, a Wz rotation angle sensor 211, and an XY sensor 212, detects the attitude of the rotating mover 101 and acquires attitude information pos.

[0038] Here, torque vector T indicating the torque applied to the mover 101 is expressed by the following formula (1). Note that Tx, Ty, and Tz are three-axis components of force, which are the X-, Y-, and Z-directional components of the force, respectively. Also, Twx, Twy, and Twz are three-axis components of moment, which are the X-, Y-, and Z-axial components of the moment, respectively. T=(Tx,Ty,Tz,Twx,Twy,Twz) ...Formula (1)

[0039] The control unit 30 controls the six-axis components (Tx, Ty, Tz, Twx, Twy, Twz) of the torque vector T to control the attitude of the mover 101 in six axes while controlling the rotation of the mover 101. As a result, in the pump 10 according to this embodiment, the mover 101 can be levitated and rotated stably without contacting the stator 201.

[0040] A method for applying torque vector T to mover 101 by coil 205 under the control of control unit 30 will be further described below with reference to Figs. 4 to 5B. Fig. 4 is a graph showing a typical thrust constant of coil 205. Figs. 5A and 5B are schematic diagrams for explaining a method for applying torque to mover 101.

[0041] 5A shows the state of the mover 101 when the rotation angle θ = 0. In this case, the permanent magnet 102a is located below the coils 205-1, 205-2, and 205-3.

[0042] Fig. 4 shows the magnitude of torque in the q-axis and d-axis directions per unit current of coil 205, i.e., the thrust constant, when mover 101 is in a state where rotation angle θ = 0. The q-axis and d-axis shown here correspond to the q-axis and d-axis in motor control theory, respectively. In Fig. 5A, the q-axis direction corresponds to the Wz direction, and the d-axis direction corresponds to the Z direction.

[0043] 4, Eq is the thrust constant in the q-axis direction, and Ed is the thrust constant in the d-axis direction. Eq and Ed vary depending on the rotation angle θ of the mover 101 and the index j of the coil 205. In Eq and Ed, the first argument represents the index j (1 to 12) of the coil 205, and the second argument represents the rotation angle θ of the mover 101. Eq and Ed can be expressed as Eq(j, θ) and Ed(j, θ) using the index j and the rotation angle θ, respectively.

[0044] For example, when the rotation angle θ=0, a permanent magnet 102a with its S pole facing the coil 205-1 side is located opposite the coil 205-1 in the Z direction, and a permanent magnet 102d with its N pole facing the coil 205-1 side is located in the -Wz direction. Therefore, if a unit current is applied to the coil 205-1 so that the S pole appears on the surface of the coil 205-1 on the mover 101 side, a force that rotates the mover 101 in the +Wz direction and a force that pushes the mover 101 down in the -Z direction are generated. Therefore, when the unit current is applied in this way, Eq(1,0) becomes a positive value and Ed(1,0) becomes a negative value.

[0045] Fig. 4 is a graph showing the thrust constants plotted as described above for each coil 205. Fig. 5B shows the magnitude of the force applied to the permanent magnet 102 as a reaction to the coil 205-j and its thrust constant.

[0046] The magnitude of the force acting between the coil 205-j and the mover 101 is given by the following equations (2-1) and (2-2), where Fwz is the force acting in the Wz direction and Fz is the force acting in the Z direction. Here, Ij is the current value applied to the coil 205-j and is an element of the current vector I. Also, * is a multiplication symbol. Fwz=Eq(j,θ)*Ij …Equation (2-1) Fz = Ed(j, θ) * Ij ... Equation (2-2)

[0047] Therefore, for all twelve coils 205, if the angle of coil 205-j is φj and the distance between the rotation axis of mover 101 and coil 205-j is r, each component of torque vector T is calculated by the following equations (3-1) to (3-6). Note that the symbol Σ is defined as the sum of j=1 to 12. Tx=-ΣEq(j,θ)*Ij*sinφj …Equation (3-1) Ty=ΣEq(j,θ)*Ij*cosφj …Equation (3-2) Tz = ΣEd(j,θ)*Ij … Equation (3-3) Twx=r*ΣEd(j,θ)*Ij*sinφj …Equation (3-4) Twy=r*ΣEd(j,θ)*Ij*cosφj …Equation (3-5) Twz=r*ΣEq(j,θ)*Ij …Equation (3-6)

[0048] In the control unit 30, the coil controller 302 can calculate a current vector having as its elements a current value Ij that satisfies the desired torque vector T calculated by the posture controller 301, and apply the current vector to each coil 205-j.

[0049] Since there are an infinite number of combinations of the current values ​​Ij, which are elements of the current vector I, that satisfy the formulas (3-1) to (3-6), they can be calculated by various calculation methods. In the following, an example of a calculation method for a combination of the current values ​​Ij of the current vector I that can be used in the coil controller 302 will be described.

[0050] Here, symbols including those used above will be defined and organized again. j: index (1 to 12) for distinguishing coil 205 φj: angle of the jth coil 205-j θ: rotation angle Eq(j, θ): Force per unit current in the q-axis direction acting between the j-th coil 205-j and the mover 101 at a rotation angle θ Ed(j, θ): Force per unit current in the d-axis direction acting between the j-th coil 205-j and the mover 101 at a rotation angle θ i: Indicator of the components of the torque vector T (1 to 6, 1: X direction, 2: Y direction, 3: Z direction, 4: Wx direction, 5: Wy direction, 6: Wz direction) I: current vector, a column vector with 12 elements Ij: Element of current vector I K: elementary current vector, which is a column vector with 6 elements Ki: Elements of the fundamental current vector K M: a matrix with elements in row i and column j Inv: Inverse matrix symbol Transpose: Symbol for transposed matrix *: matrix and scalar element multiplication symbol

[0051] Furthermore, elements Mij of matrix M are defined as row vectors M1 to M6 expressed by the following equations (4-1) to (4-6), where Mi=(Mi1, Mi2, ..., Mi12). M1={Eq(1,θ)*sinφ1,Eq(2,θ)*sinφ2,…,Eq(12,θ)*sinφ12} …Equation (4-1) M2={Eq(1,θ)*cosφ1,Eq(2,θ)*cosφ2,…,Eq(12,θ)*cosφ12} …Equation (4-2) M3={Ed(1,θ),Ed(2,θ),…,Ed(12,θ)} …Equation (4-3) M4={r*Ed(1,θ)*sinφ1,r*Ed(2,θ)*sinφ2,…,r*Ed(12,θ)*sinφ12} …Formula (4-4) M5={r*Ed(1,θ)*cosφ1,r*Ed(2,θ)*cosφ2,…,r*Ed(12,θ)*cosφ12} …Formula (4-5) M6={r*Eq(1,θ),r*Eq(2,θ),…,r*Ed(12,θ)} …Equation (4-6)

[0052] The torque vector T whose components are represented by equations (3-1) to (3-6) can be expressed by the following equation (5-1) using a matrix M whose matrix elements are represented by equations (4-1) to (4-6). T=M*I…Formula (5-1)

[0053] Furthermore, a fundamental current vector K, which is a column vector having six elements Ki, is defined, and a matrix Transpose(M) is defined as the transpose matrix of the matrix M. Then, based on the amount of current applied to each coil 205 and the contribution rate of the amount of current to the torque vector T, the current vector I can be expressed by the following equation (5-2). I=Transpose(M)*K …Equation (5-2)

[0054] Then, equation (5-1) can be transformed into the following equation (5-3) using equation (5-2). T=M*I =M*Transpose(M)*K …Formula (5-3)

[0055] Furthermore, equation (5-3) can be transformed into the following equation (5-4). Inv(M*Transpose(M))*T=K ...Equation (5-4)

[0056] Therefore, the current vector I can finally be determined by the following equation (5-5). I=Transpose(M)*K =Transpose(M)*Inv(M*Transpose(M))*T …Formula (5-5)

[0057] In formula (5-5), since M*Transpose(M) is a square symmetric matrix, its inverse matrix Inv(M*Transpose(M)) can always be calculated. Therefore, formula (5-5) can finally determine a unique combination of elements Ij of the current vector I. The coil controller 302 can calculate the combination of current values ​​Ij of the current vector I as described above and apply a current of current value Ij to each coil 205j.

[0058] In this manner, in this embodiment, it is possible to apply torque along six independent axes to the mover 101. Therefore, in this embodiment, the mover 101 can be levitated from the stator 201, and the rotation speed and attitude of the mover 101 can be controlled more stably in a non-contact manner.

[0059] Furthermore, in this embodiment, by controlling the current applied to the coil 205 of the stator 201, which exerts a force between the coil 205 and the permanent magnet 102 of the mover 101, it is possible to control the rotation speed and attitude of the mover 101 while levitating the mover 101. In this manner, in this embodiment, the permanent magnet 102 and the coil 205 are used for both control of the rotation and control of the attitude of the mover 101, so that the structure of the pump 10 including the motor 20 can be simplified.

[0060] As described above, according to this embodiment, the mover 101 can be rotated more stably in a non-contact manner with a simpler structure.

[0061] As described above, a cored coil or an air-cored coil is used as the coil 205 of the stator 201. When the coil 205 is a cored coil, an attractive force always acts between the coil 205 and the permanent magnet 102 regardless of whether a current is applied to the coil 205 or not.

[0062] Therefore, in the case where coil 205 is a cored coil, for example, when the Z direction in Fig. 1A is vertical, gravity always acts on mover 101, but all or part of that gravity can be canceled by the above-mentioned attractive force. Therefore, in this case, the torque in the Z direction applied to coil 205 can be reduced. As a result, the current value applied to coil 205 can be reduced, and the amount of heat generated by coil 205 can be reduced.

[0063] [Second embodiment] A second embodiment of the present invention will be described with reference to Fig. 6. Fig. 6 is a schematic diagram showing a pump 10 according to this embodiment. Note that the same components as those in the first embodiment are given the same reference numerals, and descriptions thereof will be omitted or simplified.

[0064] The basic configuration of pump 10 according to this embodiment is substantially the same as that of embodiment 1. Pump 10 according to this embodiment further includes a configuration for further stabilizing the attitude of mover 101 in addition to the configuration of embodiment 1.

[0065] 6, the pump 10 according to this embodiment has a soft magnetic member 601 and a permanent magnet 602 as a configuration for stabilizing the posture of the mover 101 in the Z direction. The soft magnetic member 601 is disposed on the mover 101. The permanent magnet 602 is disposed on the stator 201. The soft magnetic member 601 and the permanent magnet 602 function as a first attraction portion and a second attraction portion, respectively, which exert an attractive force on each other.

[0066] The multiple permanent magnets 102 and the multiple coils 205 face each other at the upper end, which is one end, of the rotating mover 101, in the Z direction along the rotation axis of the mover 101. In contrast, the soft magnetic member 601 and the permanent magnet 602 face each other at the lower end, which is the other end, of the rotating mover 101, in the Z direction along the rotation axis of the mover 101.

[0067] The soft magnetic member 601 is attached and installed under the mover 101 so as to be located on the side opposite to the surface of the permanent magnet 102 facing the coil 205 in the Z direction. The soft magnetic member 601 is made of a soft magnetic material, and is a member that can be attracted by the permanent magnet 602 due to an attractive force acting between the soft magnetic member 601 and the permanent magnet 602. The soft magnetic member 601 is made of, for example, iron or the like, which is a material with high magnetic permeability.

[0068] On the other hand, the permanent magnet 602 is disposed in the stator 201 at a position facing the soft magnetic member 601 .

[0069] In this embodiment, an attractive force acts in the Z direction between the soft magnetic member 601 and the permanent magnet 602 that are installed as described above. Due to this attractive force, a force that attracts the mover 101 acts in the Z direction even when the Z direction is not the vertical direction. Therefore, according to this embodiment, the attitude of the mover 101 can be further stabilized.

[0070] In the above, the case where the soft magnetic member 601 is provided in the mover 101 and the permanent magnet 602 is provided in the stator 201 has been described, but the present invention is not limited to this. For example, the soft magnetic member 601 and the permanent magnet 602 may be installed in the mover 101 and the stator 201, respectively, interchangeably. That is, the permanent magnet 602 may be installed in the mover 101 as a first attraction portion, and the soft magnetic member 601 may be installed in the stator 201 as a second attraction portion.

[0071] Also, a coil may be provided as a first attraction part instead of the soft magnetic member 601 provided on either the mover 101 or the stator 201. In this case, a current is applied to the coil so that an attractive force is applied between the coil and a permanent magnet 602 provided on the other of the mover 101 or the stator 201 as a second attraction part.

[0072] [Third embodiment] A third embodiment of the present invention will be described with reference to Fig. 7. Fig. 7 is a schematic diagram showing the configuration of the control unit 30 of the pump 10 according to this embodiment. Note that the same components as those in the first and second embodiments are given the same reference numerals, and the description thereof will be omitted or simplified.

[0073] The basic configuration of the pump 10 according to this embodiment is almost the same as that of the first embodiment. The pump 10 according to this embodiment is obtained by changing the wiring of the multiple coils 205 in the configuration of the first embodiment.

[0074] As shown in Fig. 7, in this embodiment, the coils 205 are connected in groups of three by star connection. That is, in the twelve coils 205, each set of coils 205-1 to 205-3, coils 205-4 to 205-6, coils 205-7 to 205-9, and coils 205-10 to 205-12 is connected in a star connection. Each set of three coils 205 connected in a star connection constitutes a three-phase coil. Thus, in this embodiment, the multiple coils 205 are configured of four three-phase coils.

[0075] When the coils 205-j are star-connected as in this embodiment, the four conditions expressed by the following equations (6-1) to (6-4) are added to the current value Ij of each coil 205-j. I1+I2+I3=0…Formula (6-1) I4+I5+I6=0…Formula (6-2) I7+I8+I9=0 …Formula (6-3) I10+I11+I12=0…Formula (6-4)

[0076] In this case, it is possible to further add a condition that the torque component Twx about the X-axis and the torque component Twz about the Z-axis are equally divided between the coils 205-1 to 205-6 and the coils 205-7 to 205-12, respectively.

[0077] The condition for equally dividing the component Twx about the X-axis between the coils 205-1 to 205-6 and the coils 205-7 to 205-12 is expressed by the following formula (6-5). Σ(j=1,2,3,4,5,6)Ed(j,θ)*Ij*Sinφj=Σ(j=7,8,9,10,11,12)Ed(j,θ)*Ij*Sinφj …Equation (6-5)

[0078] Moreover, the condition for equally dividing the component about the Z axis Twz between the coils 205-1 to 205-6 and the coils 205-7 to 205-12 is expressed by the following formula (6-6). Σ(j=1,2,3,4,5,6)Eq(j,θ)*Ij=Σ(j=7,8,9,10,11,12)Eq(j,θ)*Ij …Equation (6-6)

[0079] In formulas (6-5) and (6-6), the symbol Σ does not mean the sum for all j=1 to 12, but means the sum for the j written in parentheses to the right of the symbol Σ.

[0080] By combining the equations (6-1) to (6-6) thus obtained with the equations (3-1) to (3-6), 12 conditions are obtained, making it possible to determine the current values ​​Ij, which are the 12 elements of the current vector I. The control unit 30 including the attitude controller 301 and the coil controller 302 can determine the current value Ij using these 12 conditions and apply it to each coil 205-j.

[0081] As in this embodiment, the multiple coils 205 are configured and operated using four three-phase coils, thereby simplifying the wiring of the coils 205. Therefore, in this embodiment, the configuration of the motor 20 and the pump 10 including the motor 20 can be further simplified.

[0082] In the above, the case where the star connection is adopted for the coil 205 in the configuration according to the first embodiment has been described, but the present invention is not limited to this. In the configuration according to the second embodiment, the star connection can also be adopted for the coil 205 as in the present embodiment.

[0083] [Modified embodiment] The present invention is not limited to the above-described embodiment, and various modifications are possible.

[0084] For example, in the above embodiment, a case has been described in which a plurality of permanent magnets 102 are provided in the mover 101 and a plurality of coils 205 are provided in the stator 201, but the present invention is not limited to this. The plurality of permanent magnets 102 and the plurality of coils 205 may be arranged interchangeably in the mover 101, which is the first part, and the stator 201, which is the second part. That is, the plurality of coils 205 may be arranged in the mover 101, and a plurality of permanent magnets 102 may be arranged in the stator 201.

[0085] In the above embodiment, the pump 10 has been described as an example of a rotating device using the motor 20, but the present invention is not limited to this. In addition to the pump 10, other rotating devices using the motor 20 may include, for example, high-speed rotating machines, high-speed spindles for machine tools, and artificial hearts. Depending on the rotating device, a rotating member that rotates together with the mover 101 may be configured.

Claims

1. a first portion including a plurality of permanent magnets; a second portion including a plurality of coils; The first portion or the second portion is configured to be rotatable about a rotation axis, the plurality of permanent magnets are arranged circumferentially around the rotation axis, the plurality of coils are disposed to face the plurality of permanent magnets in a direction along the rotation axis, a control unit that controls a posture of the rotating first portion or the second portion in six axis directions by controlling a current applied to the plurality of coils; The plurality of coils are arranged such that at least three of the plurality of coils face each of the plurality of permanent magnets. A motor characterized by:

2. The coil is a cored coil.

2. The motor according to claim 1.

3. a first suction portion disposed in the first portion; a second suction portion that is installed in the second portion and exerts a suction force between the second suction portion and the first suction portion; the plurality of permanent magnets and the plurality of coils face each other on one end side of the rotating first part or the rotating second part in the direction along the rotation axis, The first suction portion and the second suction portion face each other on the other end side of the rotating first portion or the second portion in the direction along the rotation axis.

3. The motor according to claim 1 or 2.

4. the first attraction portion is a soft magnetic member or a coil, The second attraction portion is a permanent magnet.

4. The motor according to claim 3.

5. the first attraction portion is a permanent magnet, The second attraction portion is a soft magnetic member or a coil.

4. The motor according to claim 3.

6. The plurality of coils are configured as three-phase coils.

6. A motor according to claim 1, wherein the first and second rotors are arranged in a first direction.

7. The first portion is a mover that rotates about the rotation axis.

7. A motor according to claim 1, wherein the first and second rotors are arranged in a first direction.

8. A motor according to any one of claims 1 to 7; a rotating member that rotates together with the first part or the second part; An apparatus comprising:

9. The rotating first part or the second part is accommodated in a pump chamber, The rotating member is a fin.

9. The device according to claim 8.

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