JP6542694B2 - Magnetic levitation motor and magnetic levitation pump equipped with the same - Google Patents

Description

  The present invention relates to an electric motor that rotates a rotating unit in a floating state at the center of a fixed unit by magnetism, and a magnetic levitation pump including the motor.

  2. Description of the Related Art Conventionally, there is a magnetic levitation motor that eliminates the need for a slide bearing, which is a mechanical sliding member, by magnetically levitating a rotating portion at the center of a fixed portion. The magnetic levitation motor is employed, for example, in a magnetic levitation pump. When the magnetically levitated motor is adopted for a magnetically levitated pump or the like, there is no mechanical sliding member, so maintenance due to the problem of contamination and the problem of consumable parts is not necessary. For this reason, the magnetically levitated pump is employed in the semiconductor industry, in the field of medical fluid related to medicines, in applications that handle two-phase liquid containing gas, and the like.

  As a prior art of this kind, there is a fluid transfer device previously filed by the present applicant (see, for example, Patent Document 1). In this fluid transfer device, the rotating portion that rotates around the rotation axis is magnetically levitated by the radial magnetic flux generated between the first permanent magnet on the stationary side and the second permanent magnet of the rotating portion. In addition, the radial magnetic flux causes a thrust shaft supporting force in the direction opposite to the direction of the external force acting on the acting portion at the axial end of the rotating portion to be generated in the rotating portion.

JP, 2013-231471, A

  However, in the case of the above-mentioned prior art, the radial shaft support portions are disposed apart from the motor portion in the front-rear direction, and magnetic paths are formed so that thrust shaft support force is generated in each. This results in relatively long axial dimensions of the device, which may be difficult to employ for some applications.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetically levitated motor capable of realizing further miniaturization by reducing the axial dimension and a magnetically levitated pump provided with the motor.

  In order to achieve the above object, a magnetic levitation motor according to the present invention comprises a rotating portion disposed inside a fixed portion and rotated about a rotation axis, a stator provided on the fixed portion, and The rotating portion is disposed by a radial magnetic flux generated by a radial direction support magnet, which is disposed before and after an axial direction of the motor portion and a motor portion having a rotor provided in the rotating portion at a distance from a stator. A fixed magnetic member adjacent to a radial direction support portion supported at a center of the fixed portion in a direction orthogonal to the rotation axis and one end portion in the axial direction of the rotary portion and connected to a fixed magnetic portion of the fixed portion It has a wall and a thrust direction force adjustment coil disposed on the fixed magnetic wall and generating thrust magnetic flux superimposed on leakage magnetic flux flowing from the rotating portion of the radial magnetic flux to the fixed magnetic wall via a gap. It includes a thrust direction supporting unit, and a control unit for applying a thrust direction force by the thrust flux in the rotating part by controlling the magnitude of the current applied to the thrust direction force adjustment coil.

  With this configuration, the rotary portion is supported in a noncontact manner by the radial magnetic flux generated by the radial direction support magnets of the radial direction support portions disposed in the front and back direction of the axial direction of the motor portion. Then, thrust magnetic flux generated by the thrust direction force adjustment coil disposed on the fixed magnetic wall is superimposed on leakage magnetic flux of radial magnetic flux flowing from the one end portion in the axial direction of the rotating portion to the fixed magnetic wall. Thereby, the magnitude of the thrust direction force to be applied to the rotating portion can be adjusted by the leakage flux of the radial magnetic flux and the thrust magnetic flux. Therefore, the magnetic path which applies a thrust direction force to the rotating portion is only on the fixed magnetic wall side of the motor portion, and the axial dimension of the rotating portion can be reduced to miniaturize the magnetic levitation motor.

  In addition, the thrust direction force adjustment coil may be disposed in a surface shape in the radial direction of the fixed magnetic wall. According to this structure, it is possible to reduce the axial dimension of the thrust direction force adjustment coil by radially winding the winding dose required for the thrust direction force adjustment coil. The magnetic levitation motor can be further miniaturized by reducing the axial size of the thrust direction force adjustment coil.

  Further, the control unit controls the magnitude and direction of the current applied to the thrust direction force adjustment coil based on the detection result of the thrust position detection unit that detects the position of the rotating unit with respect to the fixed unit. It may be configured to adjust the directional force. According to this structure, the axial position of the rotating portion can be appropriately controlled by appropriately adjusting the magnitude and direction of the current applied to the thrust direction force adjustment coil based on the detection result of the thrust position detection means.

  Further, the control unit adjusts the thrust direction force by adjusting a current that causes the thrust magnetic flux to be generated in the same direction as the direction of the leakage magnetic flux flowing from the rotating portion to the fixed magnetic wall based on the detection result of the thrust position detection unit. It is configured to control the direction of thrust direction force by controlling to apply to the thrust direction force adjustment coil a current that is applied to the coil or causes the thrust magnetic flux in the direction opposite to the direction of the leakage flux. It is also good. According to this structure, the thrust direction force adjustment coil is configured such that a thrust direction force is generated toward one end direction or the other direction of the axial direction with respect to the rotating portion according to a change in the thrust direction position of the rotating portion. The direction of the thrust magnetic flux can be appropriately controlled by the applied current.

  The radial direction support magnet has a plurality of radial direction support coils disposed in the circumferential direction of the fixed portion, and detects the position of the rotating portion relative to the fixed portion between the radial direction support coils. It may have a radial position detecting means. By virtue of such construction, it is possible to calculate a state such as the inclination of the rotating portion based on the detection result of the radial position detection means. The position of the rotating portion can be corrected to an appropriate position by appropriately controlling the current applied to each of the plurality of radial direction support coils disposed around the rotating portion based on the calculation result.

  On the other hand, the magnetically levitated pump according to the present invention comprises any of the magnetically levitated motors inside a casing, and the rotating portion comprises an impeller at an axial center end opposite to the fixed magnetic wall. There is.

  With this configuration, the magnetically levitated motor can be miniaturized, and the casing size of the magnetically levitated pump can be axially reduced. In addition, even if thrust in the axial direction acts on the rotating portion by the negative pressure on the impeller side, the magnetic path of the thrust direction supporting portion provided at the axial end on the opposite side to the impeller causes the opposite direction to the impeller The thrust shaft support force can be generated. Moreover, by reducing the axial dimension of the rotating portion, the area of the rotating portion in contact with the fluid can be reduced, and the fluid friction loss can be reduced.

  According to the present invention, since the magnetic path for applying a thrust direction force to the rotating portion can be made only to one of the motor portions, it is possible to realize further miniaturization of the magnetic levitation motor.

FIG. 1 is a cross-sectional view of a magnetic levitation pump according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the configuration of the magnetic levitation motor shown in FIG. FIG. 3 is a perspective view of a part of the magnetic levitation motor shown in FIG. FIG. 4 is a drawing showing the generation principle of the radial shaft support force in the magnetic levitation motor shown in FIG. FIG. 5 is a drawing showing the radial shaft support force in the magnetic levitation motor shown in FIG. FIG. 6 is a contour diagram of a magnetic field analysis result showing a magnetic flux vector at the time of generation of thrust direction force shown in FIG. FIG. 7 is a drawing showing a state in which the thrust direction force is adjusted in the magnetic levitation motor shown in FIG. FIG. 8 is a drawing showing another state in which the thrust direction force is adjusted in the magnetic levitation motor shown in FIG. FIG. 9 is a contour diagram of a magnetic field analysis result showing a magnetic flux vector at the time of adjustment of the thrust direction force shown in FIG. FIG. 10 is a graph showing the relationship between thrust direction force and current at the time of adjustment of thrust direction force shown in FIG.

  Hereinafter, embodiments of the present invention will be described based on the drawings. In the following embodiments, a magnetic levitation pump 1 provided with a magnetic levitation motor 10 will be described as an example. The concept of the front-rear direction in the specification and claims is that the left direction of the magnetic levitation pump 1 shown in FIG. 1 is the front direction and the right direction is the rear direction. In addition, the direction of the rotational axis L of the rotating unit 50 is “γ direction”, the horizontal radial direction orthogonal to the γ direction is “α direction”, and the vertical radial direction orthogonal to the γ direction is “β direction”. Do.

(Configuration of magnetic levitation pump)
As shown in FIG. 1, the magnetic levitation pump 1 of this embodiment is provided with a magnetic levitation motor 10 inside a casing 2. The magnetic levitation motor 10 is disposed inside the fixed unit 20, and is provided with a rotating unit 50 that rotates around the rotation axis L. The rotating portion 50 is supported in non-contact with the fixed portion 20 by the radial axis supporting force of the magnetic flux generated by the radial direction supporting portion 23 as described later.

  The fixed portion 20 is provided with a stator 21, and a motor portion 40 is configured by a rotor 52 provided on the rotating portion 50 so as to be separated from the stator 21. The motor unit 40 has a plurality of rotor permanent magnets 53 provided around the rotor 52 and a plurality of stator windings 22 provided on the stator 21. The motor unit 40 is a permanent magnet type motor unit. The stator winding 22 of the stator 21 is electrically connected to the control unit 70. The control unit 70 of this embodiment includes a power supply. The control unit 70 controls the current supplied to the stator winding 22 to generate a rotating magnetic field, rotate the rotor 52 of the motor unit 40, and rotate the rotating unit 50. By providing the control unit 70 with an inverter for rotation control, the rotational speed of the rotating unit 50 can be arbitrarily adjusted.

  The rotating portion 50 is provided with the impeller 3 at the front end portion (left end portion) in the axial direction. The rotating portion 50 is covered with a cylindrical cover 4 at its periphery. In addition, the inside of the fixed portion 20 facing the rotating portion 50 is also covered with the cylindrical cover 5. The space between these covers 4 and 5 is a space in which the fluid can move. The impeller 3 is rotated by the rotating unit 50 and sends fluid from the inlet 7 of the pump unit 6 toward the outlet 8.

  Radial direction support portions 23 are provided at positions separated in the front direction and the rear direction of the motor unit 40. The radial direction support portion 23 includes a radial direction support magnet 24 which supports the rotating portion 50 in a noncontact manner. The radial direction support magnet 24 includes a radial direction support coil 26 provided on the front and rear fixed magnetic portions 25, a cylindrical first permanent magnet 28 provided on the outer peripheral position of the fixed portion 20, and a rotating portion 50. And a cylindrical second permanent magnet 54 provided around the

  The radial direction support coil 26 is provided on the fixed magnetic portion 25 extending from the fixed portion 20 toward the rotating portion 50. The radial direction support coil 26 is electrically connected to the control unit 70. The control unit 70 can control the magnitude and direction of the applied current in the radial direction support coil 26. The first permanent magnet 28 is provided on the outer peripheral portion of the fixed portion 20, and is provided separately at the front position and the rear position of the fixed magnetic portion 27 provided at the outer peripheral position of the stator 21. The second permanent magnet 54 is provided around the rotating unit 50, and is provided separately at the front position and the rear position of the rotary magnetic unit 55 provided with the rotor permanent magnet 53 of the rotor 52. .

  A radial position sensor 32 serving as a radial position detecting means for detecting the position of the rotating portion 50 with respect to the fixed portion 20 is provided between the radial direction support coils 26 (see FIG. 3). The radial position sensor 32 is provided on any of the radial direction support portions 23 disposed at the front and back positions in the axial direction of the rotation axis L. Thereby, at the front and rear of the rotary unit 50 with respect to the fixed unit 20, positional changes in the horizontal radial direction α and the vertical radial direction β with respect to the γ direction of the rotational axis L are detected. The radial position sensor 32 can be used, for example, as a displacement sensor that detects the displacement of a sensor target provided on the rotating unit 50 from the fixed unit 20. The radial position sensor 32 is also connected to the control unit 70.

  The fixed portion 20 of the magnetic levitation motor 10 is provided with a fixed magnetic wall 31 having a gap S so as to approach one axial end portion (rear portion) of the rotating portion 50 in the direction opposite to the impeller 3. . The fixed magnetic wall 31 is provided so as to be continuous with the fixed magnetic portion 30 which is continuous with the fixed magnetic portion 25 of the radial direction support 23. The fixed magnetic wall 31 is provided with a thrust direction support portion 60 having a thrust direction force adjustment coil 61 that applies a thrust direction force to the rotating portion 50. The thrust direction force adjustment coil 61 is electrically connected to the control unit 70. The control unit 70 can control the magnitude and direction of the current applied to the thrust direction force adjustment coil 61.

  Further, the fixed magnetic wall 31 is provided with a thrust position sensor 33 which is a thrust position detecting means for detecting the position in the thrust direction of the rear end of the rotating portion 50 and the fixed portion 20. The thrust position sensor 33 can be used, for example, as a displacement sensor that detects displacement of a sensor target provided on the rotating unit 50 from the fixed unit 20. The thrust position sensor 33 is connected to the control unit 70.

  The control unit 70 can be a controller provided with various control circuits. In addition, the control unit 70 can set various parameters by a personal computer or the like. The control unit 70 further includes a terminal connected to a personal computer or the like, a terminal connected to each sensor 33 (a sensor 32 described later), a terminal connected to an inverter, and a terminal connected to other external devices. In addition, the control unit 70 can have a function of emitting an alarm based on the signals from the sensors 33 and 32 (FIG. 3). Furthermore, the control unit 70 can be provided with a function of detecting an overcurrent, an overload or the like. The control unit 70 can stop the magnetic levitation pump 1 by detecting the overcurrent and the overload.

(Detailed configuration of magnetic levitation motor)
FIG. 2 is a cross-sectional view showing the configuration of the magnetic levitation motor 10, and FIG. 3 is a perspective view of a cross section of a part of the magnetic levitation motor 10 (obliquely upper portion, for 90 degrees). The figure shows a state in which the rotating portion 50 floats at a predetermined gap G at the center of the fixed portion 20.

  As illustrated, the radial direction support portion 23 described above is provided with a plurality of radial direction support coils 26 in the circumferential direction of the fixed portion 20. A plurality of radial direction support coils 26 are arranged in the circumferential direction with respect to the rotation axis L of the rotating portion 50.

  Furthermore, in this embodiment, the thrust direction force adjustment coil 61 is formed in a surface shape that spreads in the radial direction on the inner surface of the fixed magnetic wall 31. The thrust direction force adjustment coil 61 secures the necessary winding dose in the radial direction in a plane. The thrust direction force adjustment coil 61 is formed in a planar shape to reduce the axial dimension. In the drawing, the coil portion is shown in a block shape.

(Principle of radial bearing capacity)
FIG. 4 is a drawing showing the generation principle of the radial shaft support force in the magnetic levitation motor shown in FIG. In this figure, an example in which the radial direction support coil 26α is provided in the horizontal radial direction α and the radial direction support coil 26β is provided in the vertical radial direction β will be described.

  When explaining the vertical radial direction β, the first permanent magnet 28 and the second permanent magnet 54 shown in FIG. 2 generate a first radial magnetic flux Ψs1 which is a radial bias magnetic flux between the fixed portion 20 and the rotating portion 50. It is arranged to make it Then, a direct current is applied to the radial direction support coil 26β in the vertical radial direction β to generate a two-pole radial axis support magnetic flux Ψs2β (right-hand screw law). When this radial shaft support magnetic flux Ψs2β is generated, the radial shaft support magnetic flux Ψs2β is superimposed on the first radial magnetic flux Ψs1 which is a radial bias magnetic flux at the upper portion shown in the figure. And in the lower part of the opposite side which illustrates on both sides of axis of rotation L of radial 1st radial magnetic flux Ψs1, it is canceled by radial-axis support magnetic flux Ψs2β. Therefore, in the vertical radial direction β, in the radial first radial magnetic flux Ψs1, the upper magnetic flux Ψs1 is dense and the lower magnetic flux Ψs1 is sparse. Thereby, the radial axis supporting force Fβ in the positive vertical radial direction β (upward direction) is generated in the rotating portion 50.

  On the other hand, also in the horizontal radial direction α, the radial shaft support magnetic flux generated by applying a direct current to the radial direction support coil 26 α generates a radial shaft support force in the rotating portion 50 as in the vertical radial direction β.

  Then, by causing such a radial shaft support force (Fβ) to be generated by a plurality of radial direction support coils 26 disposed around the rotating portion 50 as shown in FIG. Contactlessly supported at the center of 20.

  In the following description, the radial axis support magnetic flux generated by all the radial direction support coils 26 is referred to as "second radial magnetic flux Ψs2".

(Description of radial shaft support force)
FIG. 5 is a drawing showing the radial shaft support force in the magnetic levitation motor shown in FIG. As shown, a radial magnetic flux Ψs1 (thick arrow), which is a bias magnetic flux, is generated between the permanent magnets 28 and 54 from the N pole to the S pole. In this figure, the position which opposes on both sides of the rotating shaft center L is shown. The radial magnetic flux Ψs1 flows, for example, from the N pole of the first permanent magnet 28 provided at the rear of the fixed portion 20 to the S pole of the first permanent magnet 28 provided at the front via the fixed magnetic portion 27. Then, the N pole of the first permanent magnet 28 is provided at the front of the rotating portion 50 through the fixed magnetic portion 29 and the fixed magnetic portion 25 of the radial direction support portion 23 and the rotating magnetic portion 56 of the rotating portion 50 2 Flow to the S pole of permanent magnet 54. The current flows from the N pole of the second permanent magnet 54 to the S pole of the second permanent magnet 54 provided at the rear via the rotary magnetic portion 55 of the rotating portion 50. The current flows from the N pole of the second permanent magnet 54 to the S pole of the rear first permanent magnet 28 via the fixed magnetic portion 25 of the rotary magnetic portion 57 and the radial direction support portion 23 and the fixed magnetic portion 30. As described above, the radial magnetic flux 流 れ る s 1 flows in a loop through the outer peripheral portion of the fixed portion 20, the fixed magnetic portion 25 of the radial direction support portion 23 provided at the front and back position of the motor portion 40, and the rotating portion 50. .

  Then, to the radial magnetic flux (s1 (thick arrow) generated by the permanent magnets 28 and 54, the radial magnetic flux Ψs2 (thin arrow) generated by the current applied to the radial direction support coil 26 is added. The radial magnetic flux Ψs2 can be generated in the direction of superimposing or canceling the radial magnetic flux Ψs2 on the radial magnetic flux 1s1 according to the direction of the current applied to the radial direction support coil 26.

(Radial direction position control of rotating part)
The control unit 70 (FIG. 1) controls the position of the rotating unit 50 with respect to the fixed unit 20 by controlling the current applied to the plurality of radial direction support coils 26 disposed around the rotating unit 50. This position control is individually performed on the radial direction support coil 26 based on the detection result of the radial position sensor 32 provided between the radial direction support coils 26 at the front and rear of the rotary unit 50. .

  Specifically, the control unit 70 detects the displacement of the rotating unit 50 in real time by the plurality of radial position sensors 32 provided between the radial direction support coils 26. And based on the detection result, states, such as inclination of rotation part 50, are computed. The control unit 70 appropriately controls the current supplied to the plurality of radial direction support coils 26 disposed around the rotating unit 50 based on the calculation result. As a result, the second radial magnetic flux Ψs 2 generated for the rotating unit 50 is controlled. In this control, the magnitude and direction of the current applied to the radial direction support coil 26 are controlled by the control unit 70 (FIG. 1), and the size of the radial magnetic flux Ψs2 generated by the radial direction support coil 26 and the radial magnetic flux Ψs2 The direction in which the radial flux Ψs1 is superimposed or offset is controlled. As a result, the rotating unit 50 is corrected to an appropriate position with respect to the fixed unit 20 in a non-contact state in which the rotating unit 50 is lifted from the fixed unit 20 in the direction orthogonal to the rotation axis L. As described above, the rotary unit 50 is appropriately supported in a non-contact state by the radial direction support units 23 disposed at the axial back and forth positions of the motor unit 40. Hereinafter, the magnetic flux that generates the radial axis supporting force including the first radial magnetic flux Ψs1 and the second radial magnetic flux Ψs2 will be referred to as “radial magnetic flux Ψs1 and Ψs2”.

  Further, since the radial magnetic fluxes s1 and s2 flow from the front to the rear of the rotating portion 50, a part of the radial magnetic fluxes s1 and s2 cross the gap S from the rear end of the rotating portion 50 to the fixed magnetic wall 31 It flows as leakage flux Ψs10. The leaked magnetic flux Ψs10 flows from the fixed magnetic wall 31 to the fixed magnetic unit 30, and returns to the radial magnetic flux Ψs1 and Ψs2. Since the leaked magnetic flux Ψs10 flows from the rotating portion 50 to the fixed magnetic wall 31, the leaked magnetic flux Ψs10 causes the rotating portion 50 to generate a backward thrust force Fγ attracted toward the fixed magnetic wall 31.

  FIG. 6 is a contour diagram of a magnetic field analysis (finite element method analysis) result indicating a magnetic flux vector at the time of generation of the radial axis support force shown in FIG. The shades of color indicate the strength of the magnetic flux, the dark part of the figure indicates the strong part, and the light part indicates the weak part. As illustrated, the main flow of the radial magnetic flux Ψs1 and Ψs2 described above rotates from the first permanent magnet 28 of the fixed portion 20 through the fixed magnetic portion 25 of the radial direction support portion 23 of the front portion as described above It flows to the second permanent magnet 54 of the portion 50. Then, the current flows from the rear part of the rotary part 50 to the first permanent magnet 28 via the fixed magnetic part 25 of the radial direction support part 23 at the rear part. Then, leaked magnetic flux Ψs10 of a part of the radial magnetic flux Ψs1 and Ψs2 flows from the rear of the rotating portion 50 toward the fixed magnetic wall 31.

  Due to the flow of such radial magnetic fluxes s1 and s2, a thrust direction force Fγ directed backward toward the fixed magnetic wall 31 acts on the rotating portion 50 (FIG. 5). Therefore, for example, when the magnetic levitation motor 10 is used for the magnetic levitation pump 1 as shown in FIG. 1, the rotary portion 50 is pulled forward by the negative pressure of the portion of the impeller 3. On the contrary, it is possible to generate a thrust direction force Fγ acting in the opposite rearward direction.

(Example)
FIG. 7 is a drawing showing a state in which the thrust direction force is adjusted in the magnetic levitation motor shown in FIG. FIG. 8 is a drawing showing another state in which the thrust direction force is adjusted in the magnetic levitation motor shown in FIG. FIG. 7 shows a case where the thrust magnetic flux Ψs3 generated by the thrust direction force adjustment coil 61 is superimposed on the leaked magnetic flux Ψs10 of the radial magnetic flux Ψs1 and Ψs2 so as to be repelled. FIG. 8 shows the case where the thrust magnetic flux Ψs3 generated by the thrust direction force adjustment coil 61 is superimposed on the leaked magnetic flux Ψs10 in the same direction.

  As shown in FIG. 7, from the state shown in FIG. 5, the thrust direction force adjustment coil current E1 is applied to the thrust direction force adjustment coil 61 provided on the fixed magnetic wall 31. As a result, the thrust magnetic flux Ψs3 tends to flow from the fixed magnetic wall 31 toward the rear end of the rotating portion 50 (right-hand screw law). The thrust magnetic flux Ψs3 generated by the thrust direction force adjustment coil 61 is superimposed on the radial magnetic flux Ψs1 generated by the radial direction support magnet 24 and the leaked magnetic flux 2s10 of Ψs2. However, the thrust magnetic flux Ψs3 is a magnetic flux that repels the leaked magnetic flux Ψs10 flowing from the rotating portion 50 toward the fixed magnetic wall 31. For this reason, the leaked magnetic flux 流 れ s10 which is going to flow from the rotating part 50 toward the fixed magnetic wall 31 and the thrust magnetic flux Ψs3 which is going to flow from the fixed magnetic wall 31 to the rotating part 50 repel each other in the gap S. It becomes magnetic flux. Therefore, forward thrust direction force −Fγ acts on the rotating portion 50 by superimposing the thrust magnetic flux Ψs3 on the leaked magnetic flux Ψs10. Therefore, the thrust direction force Fγ generated by the radial magnetic flux Ψs1 and Ψs2 can be made the forward thrust direction force −Fγ by the thrust direction force −Fγ generated by the thrust magnetic flux Ψs3 of the thrust direction force adjustment coil 61.

  On the other hand, as shown in FIG. 8, the thrust direction force adjustment coil current E2 in the reverse direction is applied to the thrust direction force adjustment coil 61. Thus, the thrust magnetic flux 重 畳 s3 can be superimposed in the same direction as the leaked magnetic flux Ψs10 of the radial magnetic flux Ψs1 and Ψs2. Therefore, the thrust magnetic flux Ψs3 can be superimposed in the same direction on the leaked magnetic flux 流 れ s10 which is going to flow from the rotating portion 50 toward the fixed magnetic wall 31, and a large backward thrust direction force Fγ can be generated.

  Therefore, the magnitude and direction of the thrust direction force Fγ applied to the rotating portion 50 can be adjusted by adjusting only the magnitude of the current applied to the thrust direction force adjustment coil 61 or the direction.

  FIG. 9 is a contour diagram of a magnetic field analysis (finite element analysis) result indicating a magnetic flux vector at the time of adjustment of the thrust direction force shown in FIG. The shades of color indicate the strength of the magnetic flux, the dark part of the figure indicates the strong part, and the light part indicates the weak part. As illustrated, the main flow of the radial magnetic flux Ψs1 and Ψs2 described above rotates from the first permanent magnet 28 of the fixed portion 20 through the fixed magnetic portion 25 of the radial direction support portion 23 of the front portion as described above It flows to the second permanent magnet 54 of the portion 50. Then, the current flows from the rear portion of the rotating portion 50 to the first permanent magnet 28 via the fixed magnetic portion 25 of the radial direction support portion 23 at the rear portion. Then, leaked magnetic flux Ψs10 of a part of the radial magnetic flux Ψs1 and Ψs2 flows from the rear of the rotating portion 50 toward the fixed magnetic wall 31.

  A portion of the radial magnetic flux Ψs1 and Ψs2 tends to flow toward the fixed magnetic wall 31 from the rear of the rotating portion 50 as the leakage magnetic flux Ψs10. On the other hand, the thrust magnetic flux Ψs 3 generated by the thrust direction force adjustment coil 61 tends to flow from the fixed magnetic wall 31 toward the rotating portion 50. Therefore, the leaked magnetic flux 10s10 and the thrust magnetic flux Ψs3 repel each other at the gap S. By causing the leaked magnetic flux Ψs10 to repel the thrust magnetic flux Ψs3 in this manner, it is possible to cause the rotating portion 50 to act on the fixed magnetic wall 31 with a forward thrust direction force −Fγ.

  Therefore, as shown in FIGS. 7 and 8, the control unit 70 controls the radial magnetic flux Ψs 1 from the rotating unit 50 based on the detection result of the thrust position with respect to the fixed unit 20 of the rotating unit 50 by the thrust position sensor 33. A current to generate the thrust flux Ψs3 in the same direction as the leakage flux Ψs10 of Ψs2 is applied to the thrust direction force adjustment coil 61 or a current to generate the thrust flux Ψs3 in the opposite direction to the direction of the leakage flux Ψs10 By controlling the force applied to the thrust direction force adjustment coil 61, it is possible to generate a thrust direction force Fγ for adjusting the position of the rotating portion 50 in the forward or backward direction.

  That is, the magnitude and direction of the thrust magnetic flux Ψs3 are adjusted in accordance with the thrust direction position of the rotating portion 50, and the thrust direction force Fγ of an appropriate magnitude with respect to the rotating portion 50 in either the axial direction Can occur. As described above, by controlling the thrust magnetic flux Ψs3 superimposed on the leakage flux Ψs10 of the radial magnetic flux Ψs1 and Ψs2 from the rotary unit 50, a thrust direction force Fγ is generated toward the forward or backward direction with respect to the rotary unit 50 Can be controlled to The rotational portion 50 is moved forward of the rotational axis L such that the position in the thrust direction of the rotational portion 50 with respect to the fixed portion 20 is at an appropriate position by the thrust direction force Fγ, or the rotational portion 50 is It can be suitably moved behind L.

  Therefore, for example, when this magnetic levitation motor 10 is used for the magnetic levitation pump 1 shown in FIG. 1, this occurs to the rotating portion 50 in response to the portion of the impeller 3 becoming negative pressure or positive pressure. The direction and magnitude of the thrust direction force Fγ can be adjusted.

(Relationship between current value and thrust direction force in the embodiment)
FIG. 10 is a graph showing the relationship between thrust direction force and current at the time of adjustment of thrust direction force shown in FIG. The vertical axis shown in the drawing represents the thrust direction force Fγ generated from the fixed magnetic wall 31 toward the rotating portion 50. The backward thrust direction force Fγ is “+”, and the forward thrust direction force −Fγ is “−”. The horizontal axis shown indicates the thrust direction force adjustment coil current E1.

  In the case of the magnetic levitation motor 10, the “+” thrust direction force Fγ, which is backward when no current flows through the thrust direction force adjustment coil 61, is the largest. When the thrust direction force adjustment coil current E1 is applied to the thrust direction force adjustment coil 61, the thrust direction force Fγ can be made "about zero". In this state, for example, as shown in FIG. 7, the thrust magnetic flux 3s3 is repelled from the leaked magnetic flux Ψs10 flowing from the rotating portion 50 toward the fixed magnetic wall 31. Furthermore, if the thrust direction force adjustment coil current E1 is further increased from this state, it is possible to bring the thrust direction force Fγ into the “−” state in which it is forward. This makes it possible to exert a forward thrust direction force −Fγ on the rotating portion 50 by the thrust magnetic flux Ψs3 generated by the thrust direction force adjustment coil 61 (FIG. 7).

  From this state, it can be seen that, if the thrust direction force adjustment coil current E1 is further increased, the forward direction thrust direction force -Fγ becomes the backward direction thrust direction force Fγ. This can be said to be because the thrust magnetic flux Ψs3 penetrates the fixed magnetic portion 25 of the radial direction support portion 23 at the rear together with the radial magnetic fluxes s1 and Ψs2, and the backward thrust direction force Fγ becomes large.

  When such a magnetic levitation motor 10 is provided in the magnetic levitation pump 1 of FIG. 1, it acts in the direction of the impeller 3 from the state in which the thrust direction force Fγ is exerted in the opposite direction to the impeller 3 of the rotating unit 50. You can also

(Summary)
As described above, according to the magnetic levitation motor 10 described above, the thrust direction force adjustment coil 61 of the thrust direction support portion 60 is controlled to cause the thrust exerted on the rotating portion 50 in the axial direction of the rotation axis L. It becomes possible to adjust direction force Fγ. Moreover, the magnetic path (the portion through which the thrust magnetic flux Ψ s3 flows) to which the thrust direction force Fγ is applied can be made only on one side of the motor unit 40, and the axial dimension of the rotating unit 50 can be reduced to miniaturize the magnetic levitation motor 10. It becomes possible.

  Moreover, by controlling the magnitude and direction of the current applied to the thrust direction force adjustment coil 61, it is possible to apply the thrust direction force Fγ to the rotating portion 50 in either the forward or backward direction. It becomes.

  In addition, since the axial dimension of the rotary unit 50 in the magnetic levitation motor 10 can be reduced, when used in the magnetic levitation pump 1, the area of the rotary unit 50 in contact with the fluid is small and the fluid friction loss is small. It is possible to

(Other embodiments)
The sizes of the rotating portion 50, the fixing portion 20, etc. of the magnetic levitation motor 10 in the above-described embodiment are merely an example, and each size may be formed to a suitable size according to the application, and the size of each configuration is the above It is not limited to the embodiment.

  Further, although the magnetic levitation pump 1 is described as an example in the above embodiment, the magnetic levitation motor 10 can be used in other devices, and the application is not limited to the magnetic levitation pump 1.

  Furthermore, the embodiment described above shows an example, and the number of radial direction support coils 26 may be changed, and various changes can be made within the scope of the present invention without departing from the scope of the present invention. It is not limited to the above embodiment.

1 Maglev pump
2 casing
Reference Signs List 3 impeller 10 magnetic levitation motor 20 fixed portion 23 radial direction support portion 24 radial direction support magnet 26 radial direction support coil 28 first permanent magnet 30 fixed magnetic portion 31 fixed magnetic wall 32 radial position sensor (radial position detection means)
33 Thrust position sensor (Thrust position detection means)
DESCRIPTION OF SYMBOLS 40 motor part 50 rotation part 54 2nd permanent magnet 60 thrust direction support part 61 thrust direction force adjustment coil 70 control part
S Clearance Ψs1 First radial flux Ψs10 Leakage flux Ψs2 Second radial flux Ψs3 Thrust flux

Claims (6)

Fixed part,
A rotating unit disposed inside the fixed unit and rotated about a rotation axis;
Between the fixed part and the rotating part, a motor part comprising a stator provided on the fixed part and a rotor separated from the stator and provided on the rotating part;
Wherein at a position radially spaced from the axis of the motor unit are arranged side by side in the longitudinal direction of the shaft center, the rotation axis of the rotating portion at the center of the fixed portion by a radial magnetic flux generated by in radial direction supporting magnets A radial support that supports in a non-contacting direction in a direction orthogonal to the
Wherein is from one end of the axis of the rotating part is spaced apart in the axial direction, a fixed magnetic wall continuous with the fixed magnetic portion before Symbol fixing portion close to the rotating portion, disposed on said stationary magnetic wall, the A thrust direction support portion having a thrust direction force adjustment coil that generates a thrust magnetic flux to be superimposed on the leakage magnetic flux flowing from the rotating portion to the fixed magnetic wall through the gap;
A control unit configured to control a magnitude of a current applied to the thrust direction force adjustment coil to cause a thrust direction force to be applied to the rotating unit by the thrust magnetic flux, and a magnetic levitation electric motor. 2. The magnetic levitation motor according to claim 1, wherein the thrust direction force adjustment coil is disposed in a surface shape in a radial direction of the fixed magnetic wall that extends in a radial direction from the rotation axis .   The control unit controls the magnitude and the direction of the current applied to the thrust direction force adjustment coil based on the detection result of the thrust position detection unit that detects the position of the rotating portion with respect to the fixed portion, thereby controlling the thrust direction force. A magnetic levitation motor according to claim 1 or 2, wherein the motor is configured to adjust.   The control unit causes the thrust direction force adjustment coil to generate a current that generates the thrust magnetic flux in the same direction as the direction of the leaked magnetic flux flowing from the rotating portion to the fixed magnetic wall based on the detection result of the thrust position detection unit. The direction of thrust direction force is controlled by controlling to apply a current to the thrust direction force adjustment coil to generate the thrust magnetic flux in the direction opposite to the direction of the leakage magnetic flux, A magnetic levitation motor according to Item 3. The radial direction support magnet has a plurality of radial direction support coils disposed in the circumferential direction of the fixed portion, and corrects the position of the rotating portion to an appropriate position between the radial direction support coils. wherein it comprises a radial position detection means for detecting a positional change in the radial direction with respect to the fixed part of the rotating part and a magnetic levitation motor according to any one of claims 1 to 4. A magnetic levitation motor according to any one of claims 1 to 5 is provided inside a casing,
The magnetic levitation pump according to claim 1, wherein the rotating portion includes an impeller at an axial end opposite to the fixed magnetic wall.

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