JP6621627B2 - Micro pump - Google Patents

Description

  The present invention relates to a micropump. Specifically, the present invention relates to a micropump having a function of discharging a small amount of liquid and a function of opening and closing the flow of the liquid. More specifically, the present invention relates to a micropump having a tube-side tapered portion on the inner wall of a liquid discharge port of a tube constituting the micropump and a magnet rotor-side tapered portion that can be fitted to the tube-side tapered portion.

  A so-called micropump is generally used as a means for transporting an extremely small amount of liquid. Micro pumps are broadly classified into pumps that can transport liquid intermittently and pumps that can transport liquid continuously. A so-called gear pump is known as a pump capable of transporting liquid continuously. However, the gear pump is not a micro pump suitable for transporting a small amount of liquid.

  By the way, a so-called micro total analysis system (Micro Total Analysis System) makes it possible to downsize a chemical analysis system. For this reason, the micro total analysis system (Micro Total Analysis System) has an advantage that the number of reaction samples to be subjected to chemical analysis can be reduced and the number of reagents can be reduced.

  When performing chemical analysis, it is necessary to send a very small amount of liquid, such as a sample or a reagent, to a substrate or the like equipped with an ultrafine fluid circuit. A micropump is widely used as a liquid feeding means for feeding a very small amount of liquid such as a sample or a reagent.

  The micropump used in the micro total analysis system uses a mechanical micropump that utilizes the mechanical work of the actuator, a body force that directly acts on the fluid by an electric field, and a surface force. There is a non-mechanical micropump (for example, Non-Patent Document 1).

  Among the mechanical micro pumps, a diaphragm type micro pump having a simple structure and a large discharge pressure is widely used (for example, Patent Document 1). The diaphragm type micropump has a problem that the ineffective volume is large because it has a structure for transporting a fluid using a volume change caused by elastic deformation of the diaphragm. Further, the diaphragm type micropump has a problem that pulsation occurs when the liquid is transported.

  In another aspect, the micropump used in the micro total analysis system (Micro Total Analysis System) must have a check valve necessary to prevent the backflow of the liquid from the discharge port to the supply port. I must. Usually, the check valve has a complicated shape and structure. For this reason, it is technically difficult to provide a check valve in the micropump. Moreover, the check valve deteriorates with the use of the micropump. As a result, the strength of the lid portion of the check valve is reduced, and the flow rate of the fluid to be discharged is not constant. Furthermore, a micropump equipped with a check valve cannot handle a liquid having a high viscosity or a liquid containing fine particles such as a colloidal solution.

  From such a technical point of view, a micro pump having a casing having a liquid replenishing port and a discharge port and having an internal cylindrical pump chamber and a screw shaft in which a spiral groove is formed on the outer periphery is proposed. (For example, Patent Document 2).

  Further, a magnetic drive microactuator composed of a rotor made of magnetic photo-curing resin and an electromagnetic coil for driving the rotor has been proposed (for example, Patent Document 3).

  However, the micropump disclosed in Patent Document 2 is only capable of stopping the discharge of liquid from the discharge port by stopping the rotation of the screw shaft included in the micropump. For this reason, liquids that require seamlessness cannot be accurately fed. In addition, since the micropump prevents the backflow and leakage of the liquid only by rotating the screw shaft, it cannot be evaluated that the effect is sufficient.

  Moreover, the magnetic drive microactuator disclosed in Patent Document 3 is merely provided with a small and accurate screw type microrotor, and by changing the rotation of the screw type microrotor. It only controls the migration speed of the fluid.

  In this way, the micropump used in the micro total analysis system (Micro Total Analysis System) discharges a small amount of liquid and opens and closes the flow of the liquid by the rotation of the rotor included in the micropump. Therefore, from the viewpoint of further improving the accuracy of the micro total analysis system (Micro Total Analysis System), the improvement is strongly desired.

  In addition, in order to achieve both the “pump function” for transporting the liquid required for the micropump and the “valve function” for opening and closing the flow of the liquid, the members that can perform these functions are separated from each other. There is a problem that it must be incorporated. As a result, there is a disadvantage that the micropump becomes large. Having a “pump function” capable of transporting an extremely small amount of liquid and controlling the amount of the liquid and a fail-safe function of this function is technically significant as a component constituting the micropump. In addition, this patent applicant presents the following publications as publications in which the above-mentioned literature known invention is described.

Japanese Patent Laid-Open No. 10-110681 JP 2006-144740 A JP 2010-172112 A

Hideki Kadami, Kenjiro Takemura, Ikuo Yamamoto "Electrostatically driven micro screw pump" Transactions of the Japan Society of Mechanical Engineers (C), Vol. 76, No. 770, October 2010

  The present invention has been made in view of such technical circumstances, solves the problems of conventional micropumps, and has a “pump function” capable of transporting an extremely small amount of liquid with a simple structure, and a liquid. It is an object of the present invention to provide a micropump having a “valve function” that can open and close the flow of liquid, and a trace liquid supply device.

  As a result of earnest technical examination, the present inventor has been arranged in a tube for transporting a liquid, and a tapered rotor side that can be fitted to the pipe side tapered portion at least one end of a lead screw shaped magnet rotor. By providing the taper portion, it has been found that a “pump function” that can transport an extremely small amount of liquid and a “valve function” that can open and close the flow of the liquid can be exhibited simultaneously, and the present invention is completed. It came to. That is, according to the present invention, a “pump function” that transports an extremely small amount of liquid and the amount thereof can be freely controlled, a “valve function” that occurs in the transport of liquid, and the function works on the fail-safe side. The present invention relates to a micropump that has both functions and can exhibit these functions in an integrated configuration. More specifically, the present invention comprises the following technical matters.

(1) a plurality of main excitation stators;
A tube disposed inside the main excitation stator and for transporting liquid;
A micropump disposed within the tube of the tube and provided with a lead screw-shaped magnet rotor,
The main excitation stator has a yoke and a coil wound and mounted on the yoke,
The tube has a tube side taper portion on the inner wall of the liquid discharge port of the tube, and
The said magnet rotor has the taper-shaped magnet rotor side taper part which can be fitted to the said tube side taper part in the said magnet rotor one end, The micropump characterized by the above-mentioned.

(2) When the main excitation stator is in an excited state,
The magnet rotor is moved to the axially central portion of the main excitation stator, and the magnet rotor is rotated so that the liquid in the tube is sent out.
When the main excitation stator is in a non-excitation state,
The micropump according to (1), wherein the magnet rotor side taper portion is fitted into the tube side taper portion to stop the flow of liquid in the tube.

  (3) The sub-excitation stator for fitting the magnet rotor side taper portion to the tube side taper portion outside the tube side taper portion is provided. (1) or (2) Micro pump.

(4) When the main excitation stator is in a non-excitation state and the sub excitation stator is in an excitation state,
The micropump according to (3), wherein the magnet rotor side taper portion is fitted to the tube side taper portion to stop the flow of liquid in the tube.

(5) position detecting means for detecting the position of the magnet rotor in the tube of the tube;
A rotating magnetic field control means for controlling a rotating magnetic field generated by the main excitation stator and / or the sub-excitation stator based on the detection result by the detection means;
The micropump according to any one of (1) to (4), further comprising a rotation control unit that controls a rotation direction and a rotation speed of the magnet rotor.

(6) The ratio of the axial length l of the magnet rotor to the axial length L of the main excitation stator is:
The micropump according to any one of (1) to (5), wherein 0.1 ≦ l / L ≦ 1.0.

  (7) The micropump according to any one of (1) to (6), wherein a stopper is provided so that the magnet rotor does not deviate from the range of the axial length of the main excitation stator.

(8) The tube has a tube-side tapered portion on the inner wall of the liquid supply port of the tube, and
The micro pump according to any one of (1) to (7), wherein the magnet rotor has a tapered magnet rotor side taper portion that can be fitted to the tube side taper portion.

  (9) The micropump according to any one of (1) to (8), wherein the magnet rotor is covered with a nonmagnetic material.

  (10) The micropump according to (9), wherein the nonmagnetic material is polytetrafluoroethylene.

  According to the present invention, a “pump function” capable of transporting an extremely small amount of liquid and a “valve function” capable of stopping the liquid transport and opening and closing the liquid flow can be exhibited simultaneously. A micropump is provided. In addition, according to the present invention, there is provided a micropump capable of realizing a valve function required for a pump function as well as a function of feeding an extremely small amount of liquid by a member in the same system. Furthermore, since the micropump of the present invention does not require a bearing device, it can be reduced in size. Moreover, the micropump of the present invention is free from contamination of the transported liquid by the lubricating oil that may flow out of the bearing device.

It is the model figure which showed the external appearance of the micropump. It is sectional drawing (A-A ') of a micropump. It is the figure which showed the perspective view and sectional drawing of the stator for excitation. It is the figure which showed the perspective view and sectional drawing of the stator case for excitation. It is the figure which showed the state which inserted the tube in the stator for excitation. It is the figure which showed the cross-sectional shape (At the time of isolation | separation (a), the time of fitting (b)) of a magnet rotor side taper part and a tube side taper part. It is the schematic diagram which showed the variation of the cross-sectional shape of a magnet rotor side taper part and a tube side taper part. It is the schematic diagram which showed the positional relationship of a tube inner wall and a magnet rotor. It is sectional drawing of micropump D2 (Embodiment 2) provided with the stator for sub excitation. It is the graph which showed the relationship between the rotation speed (rpm) of a magnet rotor, and a liquid discharge amount (microliter / min).

  Hereinafter, embodiments of the present invention will be described based on the drawings as appropriate. In addition, embodiment and the Example of this invention demonstrated below are for the purpose of illustration only, and do not limit the technical scope of this invention. The technical scope of the present invention is limited only by the appended claims. On the condition that the gist of the present invention is not deviated, the present invention can be modified, for example, addition, deletion and replacement of the configuration requirements of the present invention can be performed. All documents mentioned herein are hereby incorporated by reference in their entirety.

<Embodiment 1>
(Micro pump structure)
FIG. 1 is a schematic view showing the structure of the micropump D1 of the present invention. The micro pump D1 includes a liquid tank 20 and a main excitation stator body 26. The micropump D1 includes a casing 12a for protecting the liquid tank 20 at an upper portion thereof. Further, the micropump D1 includes a casing 12b for protecting the main excitation stator case 14 at a lower portion thereof. The casing 12a is fitted and circumscribed to the side surface of the outer peripheral upper portion of the main excitation stator case. The casing 12b is circumscribed and fitted to the side surface of the lower part of the outer periphery of the main excitation stator case.

  The liquid tank 20 includes a liquid tank lid 10 at the top thereof. The liquid tank lid 10 is fitted to the upper outer peripheral side surface of the casing 12 a and is also fitted to the upper surface of the liquid tank 20 to seal the upper surface of the liquid tank 20. The liquid tank lid 10 includes a stopper 22 extending from the center point C toward the lower side of the liquid tank 20. The role of the stopper 22 will be described later.

  Although the material which comprises the liquid tank 20 will not be specifically limited if it is a material suitable for storage and preservation | save of the liquid 40, Stainless steel, Teflon (trademark) etc. can be illustrated.

  Here, the liquid 40 that is the object of transportation of the micro pump D1 of the present invention is a so-called low-viscosity liquid. That is, the micropump D1 of the present invention is intended for a liquid having a viscosity of 0.01 to 2.0 cP. The liquid to be transported by the micropump of the present invention is not particularly limited as long as it has the above viscosity. For example, water, pure water, ultrapure water, acetone, hexane, ethyl acetate, aromatic An organic solvent such as a group compound and a solution containing a drug can be exemplified.

  The material constituting the liquid tank lid 10 is not particularly limited as long as it is excellent in workability and can be seamlessly fitted to the liquid tank 20, but plastic, metal, etc. may be used. It can be illustrated. Although the material which comprises the casing 12a and the casing 12b will not be restrict | limited especially if it is excellent in a mechanical characteristic and durability, Glass, a metal, a plastic etc. can be illustrated.

  A liquid tank inlet 18 for supplying liquid to the liquid tank 20 from the outside is provided on the upper outer peripheral side surface of the casing 12a. Furthermore, a liquid supply tube (not shown) may be communicated with the liquid tank inlet 18 to supply the liquid 40 from the outside of the micropump D1. The liquid 40 discharged from the liquid tank 20 passes through the liquid flow path 200 formed in the tube 30 and is discharged outside.

  FIG. 2 is a cross-sectional view showing an axial cross-sectional structure (A-A ′) of the micropump D <b> 1. As shown in FIG. 2, the liquid tank 20 is inscribed in the casing 12a. The lower part of the liquid tank 20 has a conical shape. A tube insertion port 28 for installing the tube 30 is provided at the lower portion of the liquid tank 20 at the apex of the conical shape.

  The end of the tube 30 serving as the liquid supply port reaches the vicinity of the lower portion of the liquid tank 20. The inside of the tube 30 is a liquid flow path 200 for the liquid 40. The liquid 40 stored in the liquid tank 20 passes through the tube 30 and is discharged from the end of the liquid flow path 200.

  The tube 30 communicates with the inside of the main excitation stator body 26 built in the liquid tank 20 and the main excitation stator case 14. The tube 30 may be integrally formed through the liquid tank 20 and the main excitation stator case 14. Further, the tube 30 may not be integrally formed through the liquid tank 20 and the main excitation stator case 14. The tube 30 may be configured by a combination of a liquid supply tube 16a and a liquid discharge tube 16b. In addition, the material which comprises the tube 30 can be suitably employ | adopted according to the property of the liquid 40 to convey, and may be a hydrophilic material or a hydrophobic material. Moreover, the material which comprises the tube 30 will not be restrict | limited especially if it is a nonmagnetic material, The composite material containing organic materials, such as a plastics, a metal, a metal, etc. may be sufficient.

(Main excitation stator)
The micro pump D1 incorporates a main body 26 (stator) for main excitation. FIG. 3 is a view showing the main body 26 for main excitation. 3A is a perspective view of the main excitation stator body 26, and FIG. 3B is a top view of the main excitation stator body 26.

  As shown in FIG. 3A, the main excitation stator body 26 may be composed of a first yoke (26a), a second yoke (26b), and a third yoke (26c). Each yoke is a salient pole type field pole. The first yoke (26a), the second yoke (26b), and the third yoke (26c) constituting the main excitation stator body 26 generate a rotating magnetic field when an alternating current is applied. The exciting stator body 26 including the first yoke (26a), the second yoke (26b), and the third yoke (26c) is a three-pole main exciting stator body 26. The material constituting the main excitation stator body 26 is not particularly limited as long as it has a high magnetic permeability and can easily pass through a magnetic field, but a silicon steel plate, an electromagnetic steel plate, or the like can be used. The main excitation stator body 26 preferably employs a thin laminate made of a silicon steel plate in order to reduce eddy current loss generated in the axial direction of the rotating magnetic field due to alternating current.

  Each of the first yoke (26a), the second yoke (26b), and the third yoke (26c) has a substantially H-shaped radial cross-sectional shape. As shown in FIG. 3B, each of the first yoke (26a), the second yoke (26b), and the third yoke (26c) has a phase angle of approximately 120 ° toward the center in the radial direction. Therefore, it is arranged.

The main excitation stator body 26 includes the first yoke (26a), the second yoke (26b), and the third yoke (26c), thereby moving and rotating the magnet rotor 100 in the tube 30. A rotating magnetic field can be generated. The first yoke (26a), the second yoke (26b), and the third yoke (26c) are wound with a coil 26d for flowing a three-phase alternating current UVW phase current. The ends of the coil 26d wound around the first yoke (26a) are designated as R ₁ and R ₂ , respectively. The ends of the coil 26d wound around the second yoke (26b) are denoted as T ₁ and T ₂ , respectively. The ends of the coil 26d wound around the third yoke (26c) are denoted as S ₁ and S ₂ , respectively. Each end of the coil 26d wound around the first yoke (26a), the second yoke (26b), and the third yoke (26c) forms an electric circuit and is connected to a power source. The main excitation stator body 26 can generate a rotating magnetic field having the same frequency as the alternating current applied by the power supply, with the center point C (see FIG. 3) as the center.

  The configuration of the main excitation stator body 26 is not limited to this as long as it can generate a rotating magnetic field. For example, when the rotor magnet is magnetized in two poles, it may be composed of a first yoke and a second yoke having a substantially semicircular radial cross-sectional shape. FIG. 3C is a perspective view of the main excitation stator body 27, and FIG. 3D is a top view of the main excitation stator body 27. As shown in FIG. 3C, the main excitation stator body 27 is composed of a first yoke (27a) and a second yoke (27b). Each yoke is a salient pole type field pole. The first yoke (27a) and the second yoke (27b) constituting the main excitation stator body 27 generate a rotating magnetic field when an alternating current is applied. The exciting stator body 27 composed of the first yoke (27a) and the second yoke (27b) is a two-pole main exciting stator body 27. The two-pole main excitation stator body 27 generates a rotating magnetic field so that the magnet rotor rotates only in one direction. This rotating magnetic field has a magnetic field distribution so that a bias of two poles occurs. In general, an N pole and an S pole are required to form a single phase. That is, two poles are required to form one phase. For example, in order to form three phases, six electrodes are required.

  The main main body for excitation 26 mounted on the micropump D1 of the present invention may be composed of three poles: a first yoke (26a), a second yoke (26b), and a third yoke (26c). Since the magnet rotor 100 mounted on the microphone pump D1 of the present invention has an inner diameter and a length of about several millimeters, each phase is a single three pole, and a coil 26d is wound to form an N pole. Alternatively, the counter electrode of the S pole exists as a virtual magnetic pole to generate a rotating magnetic field.

  A coil 26d for generating a rotating magnetic field is wound around the concave portion of each yoke. The coil 26d wound around each yoke is connected to a power source and is applied with an alternating current. A rotating magnetic field is generated by applying an alternating current to the coil 26d. The coil 26d wound around each yoke and the number of turns of the coil 26d are not particularly limited as long as the magnet rotor can be sufficiently driven and rotated. For example, the coil 26d has an outer diameter of 0.1 to 0.5 mm, and may be a formal wire, a polyurethane copper wire, a polyester copper wire, a polyesterimide copper wire, a polyamideimide copper wire, a polyimide copper wire, or the like. . Further, the number of turns of the coil 26d is not particularly limited, but 20 to 100 T is preferable from the viewpoint of designing the main excitation stator body 26 in a compact manner. Even when the main excitation stator body is a two-pole type, a coil 27c for generating a rotating magnetic field is wound around the concave portion of each yoke. A rotating magnetic field is generated by applying an alternating current to the coil 27c.

  FIG. 4 is a perspective view and a sectional view of the main excitation stator case 14. As shown in FIGS. 4A and 4B, a first yoke (26a), a second yoke (26b), and a third yoke that constitute an excitation stator body 26 (three poles) in the main excitation stator case 14 Each yoke of (26c) is set. As shown in FIGS. 4A and 4B, the yokes of the first yoke (26a), the second yoke (26b), and the third yoke (26c) each have a holding space 25 for the main excitation stator case. And is fixed by using an epoxy resin or the like. As shown in FIGS. 4C and 4D, the main excitation stator case 14 has the first yoke (27a) and the second yoke (27b) constituting the main excitation stator body 27 (two poles). It is set. As shown in FIGS. 4C and 4D, the yokes of the first yoke (27a) and the second yoke (27b) are inserted into the holding space 25 of the main excitation stator case.

  FIG. 5 is a view showing a state in which the tube 30 is inserted into the main main body for excitation 26 (three poles). In FIG. 5, a tube 30 is inserted into a tube insertion opening 28 provided in the main body 26 for main excitation. An alternating current is applied to the coil 26d wound around the first yoke (26a), the second yoke (26b), and the third yoke (26c) constituting the main excitation stator body 26, whereby a rotating magnetic field is generated. appear. The generated rotating magnetic field passes through the non-magnetic tube 30.

(Magnet rotor)
Next, the magnet rotor 100 that plays a central role in the micropump D1 of the present invention will be described. The magnet rotor 100 is disposed in the tube 30. Inside the tube 30 is a liquid flow path 200 for the liquid 40. The magnet rotor 100 moves in the axial direction in the tube 30 according to the distribution of the rotating magnetic field generated by the main main body 26 for excitation. Further, the magnet rotor 100 rotates in the tube 30. Specifically, the magnet rotor 100 performs forward rotation, negative (reverse) rotation, and rotation stop in the radial direction.

  The shape of the magnet rotor 100 is such that the magnet rotor 100 can move in the axial direction within the tube 30, and is positively rotated (for example, clockwise) or negative (reverse) (for example, counterclockwise) in the radial direction. ) And a shape that can transport the liquid 40 is not particularly limited. A preferable shape of the magnet rotor 100 is a lead screw shape.

  For example, a case where the magnet rotor 100 has a lead screw shape will be described. The lead angle (θ) of the screw of the magnet rotor 100 having a lead screw shape is not particularly limited as long as the liquid 40 can flow, but is 0 to 40 °. It is preferable for the lead angle (θ) to fall within this range because the low-viscosity liquid 40 can be efficiently transported.

  The screw tooth width (e) of the magnet rotor 100 having a lead screw shape is preferably 0.10 to 2.00 mm. It is preferable for the width (e) of the screw teeth to be in such a range because the liquid 40 having a low viscosity can be efficiently transported.

  The size of the magnet rotor 100 having a lead screw shape depends on the inner diameter and the axial length of the tube 30. The magnet rotor 100 having a lead screw shape has a helical pitch of 0.05 to 5.0 mm when the outer diameter is 0.1 to 5.0 mm and the axial length l is 0.4 to 10.0 mm. It is preferable that The length l in the axial direction of the magnet rotor 100 is determined by the relative relationship with the length L in the axial direction of the main excitation stator body 26.

  Specifically, the ratio of the axial length l of the magnet rotor 100 and the axial length L of the main exciting stator body 26 is determined to satisfy 0.1 ≦ l / L ≦ 1.0. The axial length l of the magnet rotor 100 does not exceed the axial length L of the main main body 26 for excitation. The ratio between the axial length l of the magnet rotor 100 and the axial length L of the main excitation stator body 26 is determined so that the magnet rotor 100 exists in the region of the rotating magnetic field generated by the main excitation stator body 26. Value.

  The magnet rotor 100 may be composed of a magnet or may be made using a magnetic photo-curing resin. That is, the magnet rotor 100 includes those produced by processing and molding a magnet itself and those produced by processing and molding a magnetic photo-curing resin.

  The magnet constituting the magnet rotor 100 is not particularly limited as long as it has a lead screw shape and can form a predetermined size. For example, a cast magnet, a plastic working magnet, a ferrite Examples include magnets, rare earth magnets, bonded magnets, and special magnets.

  Examples of cast magnets include alnico magnets and iron / chromium / cobalt magnets. Examples of the plastic working magnet include iron-manganese and iron-chromium-cobalt magnets. Examples of ferrite magnets include barium and strontium magnets. Examples of rare earth magnets include samarium-cobalt magnets and neodymium-iron-boron magnets. Examples of bond magnets include ferrite-based iron-manganese magnets and niobium-iron-boron-based magnets. Other examples include manganese-aluminum / carbon magnets, praseodymium magnets, and platinum magnets.

  The magnet illustrated in this way is used as a material for the magnet rotor 100 and cut into a lead screw shape. Note that the cutting method and the magnetizing method by magnetic anisotropy differ depending on the magnet employed as the material, and can be performed according to a regular method as appropriate. The magnet rotor 100 may be magnetized with two poles in the radial direction of the magnet rotor with respect to the minor axis direction of the magnet rotor 100. The magnetic anisotropy in the radial direction as described above is preferable because the rotation, movement, and stop of the magnet rotor 100 can be precisely controlled.

  The case where the magnet rotor 100 is produced using a magnetic photo-curing resin will be described. The magnetic photocurable resin is composed of a photocurable resin, magnetic fine particles, and a thickener. Examples of the photocurable resin include acrylic resins, epoxy resins, oxetane resins, urethane resins, and silicon resins. Examples of the magnetic fine particles include rare earth fine particles and ferrite fine particles. Examples of the thickener include fume silica and calcium carbonate. The magnetic photocurable resin is formed by mixing and stirring a photocurable resin, magnetic fine particles, and a thickener.

  The magnet rotor 100 is manufactured using a magnet or a magnetic photo-curing resin, and the surface of the magnet rotor 100 may be processed or may be covered with a nonmagnetic material. The nonmagnetic material is not particularly limited, but may be a so-called Teflon resin or epoxy resin. Examples of the Teflon resin include polytetrafluoroethylene, and examples of the epoxy resin include bisphenol A and bisphenol F. Further, the magnet rotor 100 can be used as both the hydrophilic magnet rotor 100 and the hydrophobic magnet rotor 100 by carefully adopting a nonmagnetic material.

(Magnet rotor taper and tube taper)
FIG. 6 shows the cross-sectional shapes of the magnet rotor side taper portion 160 and the tube side taper portion 180. FIG. 6A is a cross-sectional view before the magnet rotor side tapered portion 160 and the tube side tapered portion 180 are fitted. The magnet rotor 100 moves in the tube 30 in the axial direction. Magnet rotor 100 moves depending on the distribution of the rotating magnetic field generated from main body 26 for main excitation. When the main excitation stator body 26 is in an excited state, the magnet rotor 100 is located near the center of the tube 30 that is the most stable position in terms of potential. In this case, the magnet rotor side taper portion 160 and the tube side taper portion 180 are separated.

  FIG. 6B is a cross-sectional view when the magnet rotor side taper portion 160 and the tube side taper portion 180 are fitted. When the exciting stator body 26 is in a non-excited state, the magnet rotor 100 moves from the vicinity of the center of the tube 30 to the tube side taper portion 180 by a reaction force or the like, and the magnet rotor side taper portion 160 and the tube side. The tapered portion 180 is fitted.

  The magnet rotor side taper portion 160 is not particularly limited as long as the magnet rotor side taper portion 160 can be fitted to the tube side taper portion 180 provided in the liquid discharge tube 16b. FIG. 7 is a model diagram showing a combination of a magnet rotor side taper portion 160 provided on the liquid discharge tube 16b side and a tube side taper portion 180 provided on the liquid discharge tube 16b.

  FIG. 7A shows a magnet rotor 100 in which the shape of the magnet rotor side taper portion 160 is a pintle shape, and a tube side taper having a recess that can be fitted to the magnet rotor side taper portion 160. FIG. The magnet rotor 100 in which the shape of the magnet rotor side taper portion 160 is a pintle shape can be referred to as a so-called “threaded” type magnet rotor.

  FIG. 7B has a magnet rotor 100 in which the tip shape of the magnet rotor side taper portion 160 is pointed, and a pointed recess that can be fitted to the magnet rotor side taper portion 160. It is the model figure which showed the tube side taper part 180 which has. FIG. 7C illustrates a magnet rotor 100 having a step shape in the shape of the magnet rotor side taper portion 160 and further having a button-like convex portion on the step portion, and the magnet rotor side taper portion 160. It is the model figure which showed the tube side taper part 180 which has a button-shaped recessed part which can be fitted. FIG. 7D shows a tube side taper in which the tip shape of the magnet rotor side taper portion 160 is a pintle shape, and a cylindrical intermediate portion is provided between the tip portion and the “threaded” type magnet rotor portion. FIG.

  As is clear from FIGS. 7A to 7D, the magnet rotor side taper portion 160 provided in the micropump D1 is in a three-dimensional direction with the tube side taper portion 180 provided in the liquid discharge tube 16b. It can be fitted by making contact. For this reason, it is possible to prevent the liquid 40 passing through the tube 30 from entering the flow path 200 of the liquid discharge tube 16b. That is, the micropump D1 of the present invention constructs a seamless structure by the cooperative relationship between the magnet rotor side taper portion 160 and the tube side taper portion 180 provided in the liquid discharge tube 16b, and completely discharges the liquid 40. The valve function of being able to shut out is demonstrated.

  Furthermore, a screw part may be provided in the magnet rotor side taper part 160, and a groove part may be provided in the tube side taper part 180 so as to be fitted to the screw part. Further, a joint (not shown) may be provided on the inner wall of the tube side taper portion 180 so that the magnet rotor side taper portion 160 can be easily fitted to the tube side taper portion 180.

(Liquid discharge tube)
The liquid discharge tube 16b has a liquid flow path 200 through which the liquid 40 is transported. The inner diameter of the liquid discharge tube 16 b is not particularly limited as long as the liquid 40 does not flow out due to the surface tension of the liquid 40, but is preferably 0.100 to 10 mm ^2. . The inner diameter of the liquid discharge tube 16b is particularly preferably 100 μm ^{2 to} 1.0 mm ² .

(Relationship between magnet rotor and inner wall of tube)
FIG. 8 is a schematic diagram showing the relationship between the tube inner wall 30 </ b> W and the magnet rotor 100. A magnet rotor 100 is disposed in the tube 30.

  The magnet rotor 100 has a magnet rotor screw part 120, a magnet rotor bar-like part 140, and a magnet rotor side taper part 160. The magnet rotor 100 has a magnet rotor side taper 160 on the liquid discharge tube 16b side. The magnet rotor side taper portion 160 has a shape that fits with the tube side taper portion 180 provided in the liquid discharge tube 16b.

The inside of the tube 30 is filled with the liquid 40 transported by the micropump D1. Magnet rotor 100 is affected by the rotating magnetic field generated by main body 26 for main excitation. For this reason, the magnet rotor 100 moves to the end of one side of the exciting stator body 26 via the liquid 40 in the tube 30 filled with the liquid 40.

  As shown in FIG. 8, the magnet rotor 100 rotates in the tube 30 while maintaining a constant distance d between the inner wall 30 </ b> W of the tube and the outer edge of the lead screw constituting the magnet rotor 100. . The magnet rotor 100 can move in the axial direction in the tube 30 and can rotate in the radial direction. Even when the magnet rotor 100 moves in the axial direction and rotates in the radial direction in the tube 30, the magnet rotor 100 has a constant distance d from the outer edge portion of the lead screw constituting the magnet rotor 100. It is rotating in the tube 30 while maintaining the interval. Thus, the micropump of the present invention can control the magnet rotor 100 by the rotating magnetic field without providing a bearing.

  The distance d from the outer edge portion of the lead screw constituting the magnet rotor 100 is a distance for transporting the liquid 40 without the outer edge portion of the lead screw constituting the magnet rotor 100 coming into contact with the inner wall of the tube 30. If there is no particular limitation, it is preferably 1.0 to 30.0 μm. It is preferable that the distance d is in such a range because the volume difference between the internal volume of the tube 30 and the volume occupied by the magnet rotor 100 can be 1.0 to 100 μl.

  The magnet rotor screw part 120 has a magnet rotor screw groove part 120S. The magnet rotor screw groove 120S has a groove structure. The liquid 40 moving in the tube 30 enters the magnet rotor screw groove 120S. As the magnet rotor 100 rotates and moves in the tube 30, the liquid 40 that has entered the magnet rotor screw groove 120S is transported.

  The magnet rotor 100 rotates within the tube 30 while maintaining a constant distance d between the tube inner wall 30 </ b> W and the outer edge of the lead screw that constitutes the magnet rotor 100. A gap is formed between the tube inner wall 30W and the outer edge of the lead screw.

  The total amount of the liquid 40 passing through the gap formed between the tube inner wall 30W and the outer edge of the lead screw and the liquid 40 entering the magnet rotor screw groove 120S is the amount of the liquid 40 transported by the micropump D1. It becomes.

(Operation / function of micro pump D1)
Next, the operation and function of the micropump D1 of the present invention will be described. First, the liquid tank lid 10 of the liquid tank 20 is removed, and a required amount of liquid 40 is injected into the liquid tank 20. The inside of the tube 30 is filled with the liquid 40. The magnet rotor 100 rotates in the tube 30 filled with the liquid 40.

  Next, a three-phase AC power supply (not shown) is turned on, and an AC voltage is applied to the coil 26d wound around the main body 26 for main excitation. Due to the rotating magnetic field generated by the main excitation stator body 26, the magnet rotor 100 moves to the vicinity of the central portion of the excitation stator body 26 and starts normal rotation (or reverse rotation). Here, the micropump D1 is a synchronous motor, and normally no torque is generated.

  However, in the micropump D1 of the present invention, since the magnet rotor 100 is a magnetic body, a current is generated in the axial direction of the magnet rotor screw portion 120 by the rotating magnetic field generated by the main body 26 for main excitation. By intersecting, it is possible to start as a so-called “cage induction motor”. Thus, after the micropump D1 is activated, torque is generated as a synchronous motor by the synchronous pulling torque, and the liquid 40 is transported.

(Control means)
The micro pump D1 includes a position detection unit that detects the position of the magnet rotor 100 in the tube 30 as a control device. As the position detection means, various sensors such as a magnetic sensor and a photoelectric sensor can be employed. The position detection means can detect position data (X-axis direction, Y-axis direction, Z-axis direction) of the magnet rotor 100 in the tube 30.

  The position data Px of the magnet rotor 100 in the X-axis direction is position data in the axial direction of the tube 30 in the tube. The position data Py of the magnet rotor 100 in the Y-axis direction is position data orthogonal to the position in the radial direction of the tube 30 in the tube. The position data Pz of the magnet rotor 100 in the Z-axis direction is position data orthogonal to the position in the Y-axis direction in the radial direction of the tube 30. Position data in the tube 30 can be detected by the position detection means, and the rotating magnetic field can be controlled based on the detected position data. The position data of the magnet rotor 100 detected by the position detection means is transmitted to the rotating magnetic field control means.

  Further, the micropump D1 includes a rotating magnetic field control means for adjusting a rotating magnetic field generated by the main excitation stator body 26 as a control device outside thereof. The rotating magnetic field control means controls the direction and magnitude of the rotating magnetic field. By controlling the direction and magnitude of the rotating magnetic field, the position of the magnet rotor 100 within the tube 30 can be controlled.

  Moreover, the micro pump D1 is provided with a rotation control means for controlling the rotation direction and the rotation speed of the magnet rotor 100 as a control device outside thereof. The direction of rotation of the magnet rotor 100 is two directions: forward rotation and negative rotation (reverse rotation). The rotation control means has a function of stopping the rotation of the magnet rotor 100. The rotation control unit can control the rotation of the magnet rotor 100 by detecting the polar magnetism of the magnet rotor 100. The rotation control means is composed of a predetermined electric circuit. The forward rotation state, the negative rotation (reverse rotation) state, and the stop state of the rotation control unit can be displayed by a light source such as an LED. One rotation of the magnet rotor 100 can be expressed as one rotation with one cycle of turning on and off a light source such as an LED.

  The rotation control unit controls the rotation speed of the magnet rotor 100. The rotational speed of the magnet rotor 100 can be adjusted according to the transport amount of the liquid 40. The rotation speed of the magnet rotor 100 is not particularly limited, but is 100 to 10,000 rotations / minute. For example, when it is desired to set the transport amount of the liquid 40 to 0.01 to 0.1 ml / min, the rotation speed of the magnet rotor 100 is preferably set to 100 to 1000 rpm. The rotation control means can freely change the AC frequency by inverter control and adjust the rotation speed of the magnet rotor 100.

(stopper)
The micropump D1 includes a liquid tank lid 10. A stopper 22 extending from the center point C of the liquid tank lid 10 toward the lower side of the liquid tank 20 is provided. The stopper 22 is a member for preventing the magnet rotor 100 from deviating from the region of the rotating magnetic field generated by the main main body for excitation 26 in the tube 30. When the magnet rotor 100 deviates from the rotating magnetic field generated by the main excitation stator body 26, the stopper 22 pushes back the magnet rotor 100 moving toward the liquid supply tube 16a.

  The magnet rotor 100 returns to the area of the rotating magnetic field generated by the main excitation stator body 26 by the drag of the stopper 22. The magnet rotor 100 rotates forward (reverse) and moves in the tube 30 at a potential stable position.

  The ratio between the axial length l of the magnet rotor 100 and the axial length L of the main main body for excitation 26 is adjusted so that 0.1 ≦ l / L ≦ 1.0. If the value of l / L is 0.1 ≦ l / L ≦ 1.0, the magnet rotor 100 is present in the region of the rotating magnetic field generated by the main body 26 for main excitation. However, depending on the strength of the rotating magnetic field generated by the main excitation stator body 26 and the propulsive force of the magnet rotor 100, a case may occur in which the magnet rotor 100 deviates from the region of the rotating magnetic field. Even when such a case occurs, the presence of the stopper 22 makes it possible to arrange the magnet rotor 100 in the region of the rotating magnetic field generated by the main main body for excitation 26. The end of the stopper 22 collides with the end of the magnet rotor 100 on the liquid supply tube 16a side.

<Embodiment 2>
The second embodiment is a micro pump provided with a sub-excitation stator 52 for fitting the magnet rotor side taper portion 160 to the tube side taper portion outside the tube side taper portion 180 in the micro pump of the first embodiment. . The micropump of Embodiment 1 uses a reaction force or the like to fit the magnet rotor side taper portion to the tube side taper portion. In the second embodiment, the sub-excitation stator 52 is provided separately from the main excitation stator body 26 outside the tube-side taper portion in order to securely fit the magnet rotor-side taper portion 160 to the tube-side taper portion 180. The configuration is adopted.

  FIG. 9 is a cross-sectional view of the micropump D2 including the sub-excitation stator of the second embodiment. As shown in FIG. 9, the micro pump D <b> 2 of the second embodiment includes a sub-excitation stator 52. The sub-excitation stator 52 is provided outside the tube side taper portion 180. The sub-excitation stator 52 is housed in the sub-excitation stator case 50. The structure of the sub-excitation stator 52 is substantially the same as that of the main excitation stator. The sub-excitation stator 52 has a role of fitting the magnet rotor side taper portion 160 to the tube side taper portion.

  The sub-excitation stator 52 is not excited by a three-phase power source. The sub-excitation stator is, for example, a single-phase excitation only in the U phase among the three-phase power supplies, and is a direct current half excitation by inserting a diode so that S and N are not alternately inverted to an AC power supply.

  The sub-excitation stator 52 functions as an excitation state when the main excitation stator body 26 is in a non-excitation state. When the sub-excitation stator 52 is in an excited state, the magnet rotor 100 moves to the vicinity of the liquid discharge tube 16b, which is the most stable position in terms of potential.

  Further, the magnet rotor side taper portion 160 constituting the magnet rotor 100 is affected by the rotating magnetic field generated by the sub-excitation stator 52 and is fitted to the tube side taper portion 180. When the magnet rotor side taper portion 160 is fitted to the tube side taper portion 180, the rotation of the magnet rotor 100 can be controlled by the rotation control means described above. For example, after the magnet rotor side taper portion 160 comes into contact with the tube side taper portion 180, the magnet rotor side taper portion 160 is firmly fitted to the tube side taper portion 180 by rotating the magnet rotor side taper portion 160 1 to 10 times. Match. When the magnet rotor side taper portion 160 is firmly fitted to the tube side taper portion 180, the valve function of the micropump of the present invention can be further enhanced.

  When the magnet rotor side taper portion 160 is firmly fitted to the tube side taper portion 180, the flow path 200 of the liquid 40 is completely closed. When the liquid 40 having a desired volume is transported through the tube 30, the supply of the three-phase AC power to the main exciting stator body 26 is cut off. Thereafter, a single-phase alternating current is supplied to the sub-excitation stator 52. The magnet rotor 100 is moved toward the liquid discharge tube 16b. The magnet rotor side taper portion 160 is fitted to the tube side taper portion 180 to stop the transport of the liquid 40. That is, the micro pump of the present invention can exhibit the function of a check valve. In this way, a series of operations of the micropump D2 of the second embodiment is completed.

<Embodiment 3>
Embodiment 3 is a micro-pump of Embodiment 1, which has a tube-side tapered portion 240 at the liquid supply port of the tube 30 constituting the micro-pump and can be fitted to the tube-side tapered portion. This is a micro pump having a tapered portion 220. That is, the micropump of the third embodiment has tube side taper portions 180 and 240 at both the liquid discharge port and the liquid supply port of the tube 30, respectively, and can be fitted to these tube side taper portions. This is a micropump in which the magnet rotor side taper portions 160 and 220 are provided in both the liquid discharge port and the liquid supply port.

  The micropump of the third embodiment has tube-side tapered portions at both the liquid discharge port and the liquid supply port of the tube 30, and is fitted to the tube-side tapered portion at both the liquid discharge port and the liquid supply port. The magnet rotor side taper part which can do is provided. The fitting of the tube side taper portion and the magnet rotor side taper portion corresponds to the role of the stopper 22 described above.

  The micropump D3 according to the third embodiment can stop the flow of the liquid 40 not only at the liquid discharge port but also at the liquid supply port. The valve function of the micropump of the present invention can be further enhanced.

  Hereinafter, although an example is given with a comparative example and the effect of the present invention is explained concretely, the present invention is not limited to this example.

  A micropump (hereinafter referred to as “small pump”) is composed of three elements: a liquid tank that stores oil, a small pump, and a valve function by fitting a magnet rotor and a tube that perform a valve function. The liquid tank is made by cutting a stainless steel container, and the liquid tank lid is threaded to inject and seal the oil. In addition, a small hole was made in the liquid tank lid so that the oil tank was not evacuated. The small pump is cut from magnet material, the tip of the lead screw that has been threaded, the rotor shaft that is magnetized in two poles in the radial direction that has been tapered, and the ultra-thin of non-magnetic stainless steel In the pipe, a taper portion was provided inside the pipe, and the rotor of the lead screw was fitted with the taper portion, and the function of opening and closing the oil sent through the pipe was provided.

  The stator of a small pump has three poles, a silicon steel plate with a thickness of 0.35 t is punched out, and a thin core bobbin formed of plastic is mounted on a stator core formed by lamination, and 0.2φ Insulation-coated copper wire is wound up with each pole 50T aligned, and the Hall IC chip is set on the stator unit that has been star-connected as the U, V, and W phases of the motor, and the terminal processing of the connection is performed together with the winding connection. The performed stator unit was produced. A unit of this example was manufactured, and the small tank was placed so as to be on top, and the motor was driven.

Drive voltage: 12V
Rotor rotation speed: 115 rotations / minute Lead screw: 1.98φ, pitch: 1.5
Lead screw taper: C2
Liquid sending pipe: outer diameter 2.1φ, inner diameter 2φ
Oil: high ten oil, viscosity: 0.5 cP
Speed temperature: 27 ° C

(result)
Oil layer flow rate 0.05 mL / min When the drive power is OFF: The fluid valve was closed.
When the drive power is ON: The fluid valve is open, and the fluid is continuously delivered.
The above results were confirmed.
Further, in order to ensure that the opening / closing function as a valve function is functioned, the motor is controlled by driving with a forward rotation signal of 10 rotations to rotate the fluid to be sent when the valve is opened to ensure the valve opening. On the other hand, with respect to the valve closing, after the fluid discharge stop signal, the rotor is rotated 10 times so that the valve closing is reliably controlled by the control signal for ensuring the valve closing.

  The small pump is composed of a liquid tank and a pump unit. The pump part is a three-pole structure by laminating silicon steel plate materials as a main excitation stator with a tapered lead screw that is a magnet rotor, a pipe with a tapered tube on the inner wall with a thin tube through which fluid flows, and a main excitation stator Hall IC that detects the magnetic pole position of the magnet rotor for winding the coil around the yoke and its stator, and providing the valve opening and closing coil for opening and closing the valve on the outside, and for timing of motor excitation It consists of.

  The liquid tank was manufactured using stainless steel with pipes having an outer diameter of 20φ, an inner diameter of 15φ, and an outer diameter length of 20 l. The outlet of the fluid is provided with a joint that can be coupled to a rotor pipe having an outer diameter of 2.1φ. The pump part is a photocuring resin mixed with 60 vol% of 1μ fine powder of NdFeB magnet. The outer diameter is 1.98φ, the pitch is 1.5, the outer diameter is 2.1, the inner diameter is 2.1φ, the inner diameter is 2φ, and the pipe is 30φ. One side of this was provided with a joint with the tank, and was c7 tapered from a position 7 mm from one end.

  The main excitation stator and the sub-excitation stator are each provided with a 0.2φ formal wire wound by 50 T, and arranged above the stator yoke (liquid supply side) and below (liquid discharge side). At the time of liquid discharge corresponding to the state in which the valve is opened, a current is supplied to the main excitation stator, the electromagnetic rotor is forcibly pulled up to the center of the tube, a discharge signal is input, and liquid transport is started. On the other hand, when the liquid discharge is stopped, which corresponds to the closed state of the valve, the discharge signal is stopped and the rotation of the magnet rotor is stopped. It moves to the taper part provided on the discharge side and is fitted to stop the discharge of the fluid. With this main excitation stator and sub-excitation stator, the small pump can send a very small amount of liquid “pump function” and the “valve” that can stop the liquid flow and open and close the liquid flow Demonstrate "function".

  In the small pump of the present invention, the magnetic anisotropy in the diametrical direction has a diameter of 1.99φ with a pitch of 2.0 mm and a depth of 1.0 mm of the magnet rotor screw portion with respect to the 3-pole structure of the main excitation stator. Wearing. The magnet rotor was coated with polytetrafluoroethylene, and a magnet rotor magnetized with two poles in the diameter direction was constituted. A liquid flow path was formed with a polytetrafluoroethylene pipe outer diameter of 2.2φ and an inner diameter of 2φ. The magnet rotor may be a lead screw type magnet rotor inserted into a case made of a non-magnetic material and designed to prevent rotation.

  The main excitation stator was formed by laminating 25 0.75 mm silicon steel plates and producing a three-pole structure with a total length of 20 mm. A coil winding frame is manufactured by an insulation process, a 0.16φ formal wire is wound on each of three poles 30T to form phases A, B, and C, and a lead screw rotor is drawn up on a main excitation stator and a flow pipe. A small pump was made.

  Further, in the small pump of the present invention, when the fluid is discharged by driving the pump, the magnet rotor receives a reaction force, the position of the magnet rotor is changed with respect to the main excitation stator, and the pump efficiency is significantly reduced. . Therefore, a stopper that receives the reaction force of the magnet rotor is provided inside the tube that forms the flow path with the magnet rotor. As a stopper, a pipe thinner than the pipe for forming the flow path, an outer diameter of 1.985φ and an inner diameter of 1.70φ were inserted and fixed at both ends of the flow path to form a flow path.

  As a role of the stopper, it was confirmed that even if a piece or the like is inserted into the flow path, it plays that role. As a result, it was proved that the discharge pressure remained linear with respect to the rotation speed of the magnet rotor even when the discharge pressure increased, and the magnet rotor position was in a normal position with respect to the stator. In addition, the graph of the discharge pressure with respect to rotation speed is shown in FIG.

  The micropump of the present invention can deliver a very small amount of liquid and can exhibit a valve function that can open and close the flow of the liquid. The micropump of the present invention can be applied not only to a micro total analysis system (Micro Total Analysis System) but also to a microchemical synthesis analysis system such as a lab-on-chip, and is extremely versatile. For this reason, the contribution to the chemical field, biochemical field, and medical / dental field is extremely large. The micropump of the present invention can also be applied to fuel cells, continuous administration of drugs and supplements to patients with diseases, fragrance spray devices, and lubricating oil supply devices. Can also be expected.

D1 Micropump (Embodiment 1)
D2 Micropump (Embodiment 2)
10 Liquid tank lid 12a Casing (liquid tank)
12b Casing (excitation stator)
14 Main excitation stator case 16a Liquid supply tube 16b Liquid discharge tube 18 Liquid tank inlet 20 Liquid tank 22 Stopper 24 Tube fixing member
25 Stator case holding space for main excitation 26 Stator body for main excitation (3 poles)
26a 1st yoke 26b 2nd yoke 26c 3rd yoke 26d Coil 27 Stator body for main excitation (2 poles)
27a First yoke 27b Second yoke 27c Coil 28 Tube insertion port 30 Tube 30W Tube inner wall 40 Liquid (fluid)
40f Liquid flow 50 Sub-excitation stator case 52 Sub-excitation stator 100 Magnet rotor 120 Magnet rotor screw portion 120S Magnet rotor screw groove portion 140 Magnet rotor rod-shaped portion 160 Magnet rotor side taper portion (liquid discharge tube side)
180 Tube side taper (liquid discharge tube side)
200 Liquid flow path 220 Magnet rotor side taper part (liquid supply tube side)
240 Tube side taper (liquid supply tube side)

Claims (9)

And the main excitation stator,
A tube disposed inside the main excitation stator and for transporting liquid;
A micropump disposed within the tube of the tube and provided with a lead screw-shaped magnet rotor,
The main excitation stator has a yoke and a coil wound and mounted on the yoke,
The tube has a tube side taper portion on the inner wall of the liquid discharge port of the tube, and
The magnet rotor has a tapered magnet rotor side taper portion that can be fitted to the tube side taper portion at one end of the magnet rotor ,
A micropump comprising a sub-excitation stator for fitting the magnet rotor side taper portion to the tube side taper portion outside the tube side taper portion . When the main excitation stator is in an excited state,
The magnet rotor is moved to the axially central portion of the main excitation stator, and the magnet rotor is rotated so that the liquid in the tube is sent out.
When the main excitation stator is in a non-excitation state,
2. The micropump according to claim 1, wherein the magnet rotor side taper portion is fitted into the tube side taper portion to stop the liquid flow in the tube. When the main excitation stator is in a non-excitation state and the sub excitation stator is in an excitation state,
3. The micropump according to claim 1, wherein the magnet rotor side taper portion is fitted into the tube side taper portion to stop the flow of liquid in the tube. Position detecting means for detecting the position of the magnet rotor in the tube;
A rotating magnetic field control means for controlling a rotating magnetic field generated by the main excitation stator and / or the sub-excitation stator based on the detection result by the detection means;
The micropump according to any one of claims 1 to 3, characterized in that and a rotation control means for controlling the rotational direction and the rotational speed of the magnet rotor. The ratio of the axial length l of the magnet rotor and the axial length L of the main excitation stator is:
It is 0.1 <= l / L <= 1.0, The micropump of any one of Claims 1-4 characterized by the above-mentioned. The micropump according to any one of claims 1 to 5, characterized in that said magnet rotor provided a stopper so as not to move a departure from the scope of the axial length of the main excitation stator. The tube has a tube-side tapered portion on the inner wall of the liquid supply port of the tube, and the magnet rotor has a tapered magnet rotor-side tapered portion that can be fitted to the tube-side tapered portion. The micropump according to any one of claims 1 to 6, wherein: The micro pump according to any one of claims 1 to 7, wherein the magnet rotor is coated with a nonmagnetic material. 9. The micropump according to claim 8 , wherein the nonmagnetic material is polytetrafluoroethylene.

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