JP2013072324A - Pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pump capable of restraining axis inclination and axis offset of a stator, and deformation of an auxiliary magnetic pole section caused by injection pressure at the molding by restraining increase of a gap accompanying addition of the auxiliary magnetic pole section.SOLUTION: In the pump including: a motor 17; an impeller 16 rotated with the motor 17 and flowing a fluid; and a pump case 13 and a separation plate 2 for forming a pump chamber 11 where the impeller 16 is stored, the motor 17 has a stator 5, and a rotor 4 rotatably driven by the stator 5 and rotating the impeller 16. The stator 5 has a magnetic pole section 63 directly opposite to the rotor 4, and has the auxiliary magnetic pole sections 7 projected in the axial direction Ax on both ends of the magnetic pole section 63 in the axial direction Ax. The separation plate 2 has a cylindrical section 21 wherein its peripheral surface is interposed between the stator 5 and the rotor 4, and is provided with a projection section 25 coming in contact with only the magnetic pole section 63 among the magnetic pole section 63 and the auxiliary magnetic pole sections 7 on the cylindrical outer surface 21a of the cylindrical section 21.

Description

  The present invention relates to a pump.

  2. Description of the Related Art Conventionally, some pumps include a motor that is a drive source, an impeller that is rotationally driven by the motor, and a pump case and a separation plate that form a pump chamber. This type of pump is divided into a pump chamber in which a fluid flows and a motor unit isolated from the fluid by a separation plate. An outer shell of the pump chamber is formed by a pump case, and an impeller and a motor rotor are arranged inside. The motor unit has a motor stator disposed therein and is filled with mold resin. The mold resin fixes the stator to the separation plate and forms an outer shell on the motor unit side.

  By the way, when the separation plate is formed by resin molding, a cylindrical taper disposed between the rotor and the stator of the separation plate is provided with a drawing taper for releasing the separation plate. And by providing this punching taper, a clearance (clearance) is produced between the stator and the cylindrical portion. Therefore, in the case where the outer shell of the motor unit is formed of a mold resin, the stator is easily moved within the clearance by the pressure (injection pressure) at the time of molding. When the stator moves, the axis of the stator tilts, shifts in the center of the stator, and the like, and it becomes difficult to stabilize the balance of electromagnetic force or to vary performance.

  Then, like the pump shown in patent document 1, the rib over the substantially whole length of the axial direction of a cylindrical part is provided in the outer peripheral surface of a cylindrical part, and this projection part is contacted with the inner peripheral surface of a stator, and at the time of mold fabrication Some of them suppress the displacement of the stator due to the injection pressure.

  In addition, as shown in Patent Document 2, the brushless motor that is a driving source of such a pump is formed to be bent in an L shape in a side view on both upper and lower surfaces of a T-shaped tooth portion formed in a tooth portion. Some have a convergence piece attached. In this motor, the magnetic flux guided from the rotor (rotor magnet) is collected by the converging piece, and the collected magnetic flux is joined to the T-shaped tooth portion.

JP 2009-284704 A Japanese Patent Laid-Open No. 09-285044

  However, a motor as shown in Patent Document 2 is used as a pump drive source as shown in Patent Document 1, and projections are applied to the stator inner peripheral surface (the inner peripheral surface of the T-shaped tooth portion) and the converging piece. In the case of contact, the radial distance (gap) between the stator and the rotor tends to increase. And when a protrusion is contact | abutted to a convergence piece, it becomes easy to deform | transform a convergence piece by injection pressure at the time of mold forming, a clearance gap is produced in the contact part with the T-shaped tooth part of a convergence piece, or a T-shaped tooth part. May peel off. When the converging piece creates or leaves a gap at the contact site, the gap between the converging piece and the rotor becomes non-uniform, and the balance of electromagnetic force becomes unstable or the pump performance varies.

  Accordingly, in view of this situation, a pump is provided in which an increase in gap due to the auxiliary magnetic pole portion is suppressed, and the axial inclination and axial misalignment of the stator and the deformation of the auxiliary magnetic pole portion due to the injection pressure during molding are suppressed. That was the issue.

  In order to solve the above problems, a pump according to the present invention includes a motor, an impeller that is rotated by the motor and causes fluid to flow, and a pump case and a separation plate that form a pump chamber that houses the impeller. The motor includes a stator and a rotor that is rotationally driven by the stator and rotates the impeller, the rotor having an outer peripheral surface along a rotation direction, and the stator is a magnetic pole portion facing the outer peripheral surface. An auxiliary magnetic pole portion protruding in the axial direction from the magnetic pole portion is provided at both ends in the axial direction of the magnetic pole portion with respect to the rotational axis of the rotor, and the separation plate is provided between the rotor and the stator. A cylindrical portion interposed between the magnetic pole portion and the magnetic pole portion of the cylindrical portion is provided with a protrusion that contacts only the magnetic pole portion of the magnetic pole portion and the auxiliary magnetic pole portion. It is characterized in.

  As this pump, it is preferable that the inner peripheral surface of the auxiliary magnetic pole portion is offset from the inner peripheral surface of the magnetic pole portion in the radially outward direction.

  As this pump, the rotor has a plurality of magnets arranged in the circumferential direction, and has the same dimension as the dimension in the axial direction of the magnetic pole portion on the circumference passing through the portion facing the magnetic pole portion on the outer peripheral surface of the magnet. It is preferable to provide a groove having a width in the axial direction and recessed in the radial inner direction.

  As the pump, the cylindrical portion has a release taper on the outer peripheral surface of the cylinder, and the protrusion has a smaller taper on the outer surface facing the radially outward direction than the punch taper of the cylindrical outer peripheral surface. It is preferable.

  As the pump, it is preferable that the separation plate includes a bottom portion at one end of a cylindrical portion, and an inclined surface having a gradient toward the bottom portion is provided at an end portion of the projection portion on the bottom portion side.

  By adopting such a configuration, it is possible to suppress an increase in gap due to the attachment of the auxiliary magnetic pole part, and to suppress the inclination of the axial center of the stator due to the injection pressure during molding, the deviation of the axial center, and the deformation of the auxiliary magnetic pole part. it can.

It is sectional drawing of the pump of 1st Embodiment. It is a perspective view of a separation plate. It is an enlarged view of the area | region A of FIG. It is explanatory drawing of an offset dimension. It is a perspective view of the modification of a separation plate.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

<First Embodiment>
As shown in FIG. 1, the pump 1 according to an example of the embodiment includes a motor 17 that is a drive source, an impeller 16 that is driven by the motor 17, and a control unit 15 that controls rotation of the motor 17. . The pump 1 is partitioned into a pump chamber 11 that allows fluid to flow and a motor unit 12 that is isolated from the fluid in the pump chamber 11. The motor unit 12 includes a part of components of the motor 17 (details will be described later) and a control unit 15 and is molded with a mold resin to form an outer shell.

  The mold resin is a thermosetting resin having electrical insulation, and the mold part 12a is configured by curing the thermosetting resin. If the mold resin has a higher thermal conductivity than air, the heat generated in the motor unit 12 is transmitted to the outside of the motor unit 12 such as outside air or fluid in the pump chamber 11 and released. It is preferable because it can also serve as a heat dissipating means.

  The pump chamber 11 is mainly composed of a separation plate 2 that partitions the pump chamber 11 and the motor unit 12 and a pump case 13 that forms an outer shell of the pump 1 on the pump chamber 11 side. And the pump chamber 11 has a space inside, and the impeller 16 is arrange | positioned in this space.

  The pump case 13 is mainly composed of a cylindrical side wall and a substantially circular top surface portion covering one end side of the side wall cylinder. A suction portion 14 for sucking fluid into the pump chamber 11 is provided at the approximate center of the top surface portion, and a discharge portion (not shown) for discharging the fluid in the pump chamber 11 to the outside is provided on the side wall. It is provided.

  The impeller 16 is mainly composed of a disk-shaped shroud, and the shroud is provided with blades for allowing fluid to flow. And it rotates along the circumferential direction of a shroud by the rotational drive of the motor 17. During rotation, the impeller 16 sucks fluid into the pump chamber 11 through the suction portion 14 and applies centrifugal force to the fluid in the pump chamber 11 and discharges the fluid outside the pump chamber 11 through the discharge portion. Therefore, the pump 1 of the present embodiment is a so-called spiral pump that uses the motor 17 as a drive source and causes the fluid to flow in the radially outward direction from the rotation center side by the rotation of the impeller 16.

  As shown in FIG. 2, the separation plate 2 is provided to extend radially outward from a cylindrical portion 21, a bottom portion 22 that closes one end portion of the cylindrical portion 21, and an opening-side end portion of the cylindrical portion 21. The flange portion 23 is formed. As shown in FIG. 1, the flange portion 23 has a surface facing the top surface portion, and the impeller 16 is rotatably disposed therebetween. The cylindrical portion 21 has the inner peripheral side of the cylinder inside the pump chamber 11 and the outer peripheral side becomes the motor portion 12. The cylindrical portion 21 protects the conductive member of the motor 17 and the control portion 15 from inside the pump chamber 11 (fluid). The bottom 22 has a circular plate shape when viewed in the axial direction Ax, and a support shaft 3 (details will be described later) is attached to the approximate center of the circle.

  As shown in FIG. 1, the motor 17 is composed mainly of the rotor 4, the stator 5, and the support shaft 3. In the motor 17, the rotor 4 and the support shaft 3 are disposed on the inner peripheral side (in the pump chamber 11) of the cylindrical portion 21, and the stator 5 serves as the conductive member of the motor 17 on the outer peripheral side (motor portion 12). Placed in.

  The rotor 4 is formed in a substantially cylindrical shape, and a shroud is provided substantially concentrically and integrally at one end in the axial direction Ax. The rotor 4 includes a plurality of magnets 41. The plurality of magnets 41 are arranged side by side in the circumferential direction and form a cylindrical outer peripheral surface 4a of the rotor 4. Further, the support shaft 3 is disposed substantially concentrically on the inner peripheral side of the rotor 4, and the rotor 4 is rotationally driven by the stator 5 with the support shaft 3 as a rotation center.

  The support shaft 3 is rotatable around an axis and has a bearing 31 attached thereto, and the rotor 4 is supported via the bearing 31 so as to be rotatable around the axis. The support shaft 3 has one end in the axial direction Ax fixed to the first mounting portion 13 a provided in the pump case 13, and the other end to the second mounting portion provided in the bottom portion 22. Fixed. In the following description, unless otherwise specified, the axial direction Ax of the rotor 4 is simply referred to as the axial direction Ax and is used as a direction reference.

  The stator 5 includes a core 51 formed of a magnetic metal material, a coil 52 in which a conducting wire is wound around the core 51, and an insulating portion 53 that electrically insulates the core 51 and the coil 52 from each other. .

  The core 51 includes an annular portion 61 disposed substantially concentrically with the rotor 4, teeth 62 projecting radially inward (rotor 4 side) from the inner peripheral surface of the annular portion 61, and end portions of the teeth 62 on the rotor 4 side. The main body is composed of the magnetic pole portion 63 formed in the above. The core 51 is formed by laminating a plate-like member (first plate-like member 8a) that integrally forms the annular portion 61, the teeth 62, and the magnetic pole portion 63 in the axial direction Ax.

  The teeth 62 protrude from the annular portion 61 in the radially inward direction and are formed in a prismatic shape, and are so-called radially arranged in substantially equal intervals in the circumferential direction, and a plurality (six in this embodiment) are provided in the annular portion 61. It is. In the teeth 62, copper wires are wound around the side surfaces of the prisms along the protruding direction (inward radial direction) via the insulating portions 53, and the coils 52 are formed outside the prisms. The teeth 62 protrude from the coil 52 in the radially inward direction, which is the end on the rotor 4 side, and the protruding tip serves as a magnetic pole part 63.

  The magnetic pole part 63 is longer in the circumferential direction than the teeth 62 and has an arc shape when viewed in the axial direction Ax. The arc is substantially concentric with the rotor 4 and the inner circumferential surface 63a of the arc has a diameter. It faces the outer peripheral surface 4a of the rotor 4 via the cylindrical portion 21 in the inward direction. And the magnetic pole part 63 is the dimension (same dimension) as the dimension in the axial direction Ax of the annular part 61 and the teeth 62 in the axial direction Ax.

  The magnetic pole part 63 is provided with auxiliary magnetic pole parts 7 at both ends in the axial direction Ax. The auxiliary magnetic pole portion 7 is mainly composed of an auxiliary magnetic pole piece 71 provided to extend from the end portion in the axial direction Ax of the magnetic pole portion 63 in a direction away from the magnetic pole portion 63 along the axial direction Ax.

  The auxiliary magnetic pole piece 71 has an arc shape substantially concentric with the magnetic pole portion 63 when viewed in the axial direction Ax, and is disposed on the radially inner side (the rotor 4 side) from the portion where the coil 52 of the stator 5 is provided. The auxiliary magnetic pole piece 71 has an arcuate inner peripheral surface 71 a offset from the inner peripheral surface 63 a of the magnetic pole part 63 in the radially outward direction and faces the outer peripheral surface 4 a of the rotor 4. Therefore, the inner peripheral surfaces 63a and R of the magnetic pole part 63 and the auxiliary magnetic pole part 7 are the magnetic pole face 5a of the stator 5, and the stator 5 faces the magnet 41 while suppressing the dimension of the magnetic pole part 63 in the axial direction Ax. The magnetic pole surface 5a is widened.

  Further, the auxiliary magnetic pole piece 71 is formed by laminating arc-shaped plate members (second plate members 8b) in the axial direction Ax. Each of the auxiliary magnetic pole pieces 71 has an end on the magnetic pole part 63 side in the axial direction Ax (a plate surface of the second plate-like member 8b) as an end in the axial direction Ax of the magnetic pole part 63 (of the first plate-like member 8a). (The plate surface) is attached to the end of the magnetic pole part 63. The auxiliary magnetic pole piece 71 includes a first magnetic pole piece 72a provided at one end (flange 23 side) in the axial direction Ax of the magnetic pole part 63, and an end (on the opposite side of the magnetic pole part 63 in the axial direction Ax ( A distinction is made between the second magnetic pole piece 72b provided on the bottom 22 side).

  The insulating portion 53 covers the outer surface of the core 51 and the outer peripheral surface of the auxiliary magnetic pole portion 7 and insulates the core 51 and the auxiliary magnetic pole portion 7 from the coil 52. Specifically, the insulating portion 53 includes an outer peripheral surface of the magnetic pole portion 63, an outer surface around which the winding of the tooth 62 is wound, a part of the outer peripheral surface and an inner peripheral surface of the annular portion 61, and an end surface in the axial direction Ax. The outer peripheral surface of the auxiliary magnetic pole part 7 and the surface of the extended tip are covered. Therefore, the insulating part 53 insulates the core 51 and the auxiliary magnetic pole part 7 from the conducting wire wound around the teeth 62.

  And the insulating part 53 has the 1st leg part 53a which protruded to the flange part 23 side in the axial direction Ax in the site | part which covers one end surface which faces the axial direction Ax of the cyclic | annular part 61. As shown in FIG. The stator 5 is positioned in the motor portion 12 in the axial direction Ax by abutting the protruding tip of the first leg portion 53a with the flange portion 23. The insulating portion 53 has a second leg portion 53b that protrudes in the opposite direction to the first leg portion 53a at a portion that covers the end face on the opposite side of the annular portion 61. The second leg portion 53b defines the position of the control unit 15 in the axial direction Ax through the terminal pin 53c attached, and is electrically connected to the control unit 15 and the coil 52.

  Further, the portion of the insulating portion 53 that covers the auxiliary magnetic pole portion 7 has a rising portion 54a that covers the outer peripheral surface of the auxiliary magnetic pole portion 7 from the outer peripheral side, and a diameter that covers the extended tip of the auxiliary magnetic pole portion 7 in the axial direction Ax in the axial direction Ax. The inner projecting piece 54b constitutes a main body. The rising portion 54a rises in the direction away from the tooth 62 along the axial direction Ax, and the radially protruding piece 54b is formed to protrude radially inward from the leading end of the rising portion 54a in the axial direction Ax. The insulating portion 53 is the rising portion 54a and the in-diameter protruding piece 54b, and the pressure at the time of forming the coil 52 (at the time of winding) or molding is directly applied to the outer peripheral surface of the auxiliary magnetic pole portion 7 or the extended tip. The auxiliary magnetic pole part 7 is protected by making it difficult to apply. Therefore, the auxiliary magnetic pole portion 7 is prevented from being deformed in the radially inward direction or the axial direction Ax when the coil 52 is formed (when the winding is wound) or during molding.

  By the way, the separation plate 2 in the present embodiment is a resin molded product formed by resin molding. As shown in FIG. 3, the separation plate 2 is removed (released) from the mold during resin molding. A draft taper (see T2 in the figure) is provided in the cylindrical portion 21. The draft taper is, for example, about 0.5 to 1.0. Therefore, the separation plate 2 has a taper, and the outer diameter of the cylindrical portion 21 is such that the outer diameter of the cylindrical portion 21 is the largest at the end portion on the flange portion 23 side and decreases toward the bottom portion 22 side (cylindrical outer peripheral surface 21a). Is inclined.

  As shown in FIG. 2, the cylindrical outer peripheral surface 21 a has a plurality of protrusions 24 from the end on the flange portion 23 side to the end on the bottom portion 22 side (in this embodiment, the same number of six magnetic pole portions 63 as the number of protrusions 24). The protrusions 24 are arranged in the circumferential direction at substantially equal intervals. The protruding portion 24 has substantially the same taper as the drawing taper, and is formed to protrude radially outward from the cylindrical outer peripheral surface 21a.

  Therefore, the protruding portion 24 has a protruding amount in the radially outward direction from the cylindrical outer peripheral surface 21a toward the bottom portion 22 side, and the outer surface facing the radially outward direction is positioned substantially parallel to the axial direction Ax. The protrusion 24 is located between the magnetic pole parts 63 arranged in the circumferential direction, and the end of the magnetic pole part 63 in the circumferential direction is in contact with the side surface of the protrusion 24 facing the circumferential direction. The Therefore, the protrusion 24 defines the position of the magnetic pole part 63 in the circumferential direction, and suppresses the movement of the magnetic pole part 63 (core 51) in the circumferential direction during molding or the like.

  Furthermore, the cylindrical outer peripheral surface 21a is provided with a protruding portion 25 that protrudes in the radially outward direction at a substantially center between the protruding portion 24 in the circumferential direction. A plurality of the protrusions 25 are formed at substantially equal intervals in the circumferential direction (the same number as the magnetic pole parts 63), and are rectangular in plan view when viewed in the radial direction along the protruding direction.

  As shown in FIG. 3, the protruding portion 25 faces the magnetic pole portion 63 and is positioned at substantially the same height as the magnetic pole portion 63 in the axial direction Ax. Furthermore, since the protrusion part 25 is located in the approximate center between the protrusion parts 24, it is located in a line with the teeth 62 which form the magnetic pole part 63 which opposes in a radial direction.

  The protrusion 25 is in contact with the magnetic pole part 63 at the approximate center of the arc of the magnetic pole part 63 and is not in contact with the auxiliary magnetic pole part 7. The protrusion 25 abuts only on the magnetic pole portion 63, thereby positioning the core 51 (stator 5) in the radial direction when the stator 5 is attached to the separation plate 2, and in the radially inward direction of the core 51 during molding. Suppresses movement.

  And the protrusion part 25 has a taper (refer T2 in FIG. 3) whose outer surface 25a (contact surface with the magnetic pole part 63) which faces radial direction is small compared with a draft taper, for example. The outer surface 25a is continuous with the cylindrical outer peripheral surface 21a on the flange portion 23 side, and the outer surface 25a has a shape having no step at the boundary in the axial direction Ax between the end on the flange portion 23 side and the cylindrical outer peripheral surface 21a. The shape has no facing end face). Further, the projection 25 has an end surface (step with the cylindrical outer peripheral surface 21a) on the bottom 22 side, and this end surface is an inclined surface 25b having a gradient that approaches the radially inward direction toward the bottom 22 side.

  In addition, the rotor 4 is provided with a groove portion 42 that is recessed in the radially inward direction on the outer peripheral surface 4a that is mainly formed by the magnet 41, and the groove portion 42 is formed in an annular shape along the circumferential direction. The groove 42 has a rectangular cross-sectional shape cut in the diameter direction, and the dimension in the axial direction Ax (the axial direction Ax width) is substantially the same as the axial direction Ax width of the magnetic pole part 63. . Furthermore, the height of the groove 42 in the axial direction Ax is substantially the same as the height of the magnetic pole 63, and the bottom 42 a facing the radially outward direction of the groove 42 is the inner peripheral surface 63 a of the magnetic pole 63. The groove portion 42 is provided on the circumference passing through the portion facing the magnetic pole portion 63 of the outer peripheral surface 4a.

  The groove 42 has a dimension (depth L2) from the outer peripheral surface 4a to the bottom surface 42a of the rotor 4 in the radial direction, as shown in FIG. 3, from the inner peripheral surface 63a of the magnetic pole portion 63 in the radial direction to the auxiliary magnetic pole portion 7. The inner diameter 71a is substantially the same as the dimension (offset dimension L1). Therefore, the distance from the bottom surface 42a of the groove portion 42 to the inner peripheral surface 63a of the magnetic pole portion 63 directly facing the bottom surface 42a and the auxiliary magnetic pole portion 7 directly facing this portion from a portion other than the bottom surface 42a on the outer peripheral surface 4a of the rotor 4 The distance to the inner peripheral surface 71a is substantially equal.

  As described above, the pump 1 according to the present embodiment can prevent the first magnetic pole piece 72a from coming into contact with the cylindrical outer peripheral surface 21a by providing the protruding portion 25. It is possible to make it difficult for the first magnetic pole piece 72a to be deformed due to contact. The inner peripheral surface 71a of the first magnetic pole piece 72a and the cylindrical outer peripheral surface 21a are arranged by offsetting the inner peripheral surface 71a of the auxiliary magnetic pole portion 7 in the radially outward direction with respect to the inner peripheral surface 63a of the magnetic pole portion 63. It is possible to easily reduce the clearance with. Therefore, the gap between the magnetic pole surface 5a and the outer peripheral surface 4a of the rotor 4 can be easily reduced, and the reduction in motor efficiency associated with securing the clearance for the auxiliary magnetic pole portion 7 (increasing the gap) can be easily suppressed. it can.

  Furthermore, the magnetic pole part 63 is provided by providing the groove part 42 having a depth L2 substantially the same as the offset dimension L1 on the circumference passing through the part facing the magnetic pole part 63 on the surface facing the magnetic pole face 5a of the magnet 41. And the gap with the auxiliary magnetic pole part 7 can be made substantially the same size. Therefore, it is possible to make it difficult for the gap between the magnetic pole surface 5a of the stator 5 having the offset auxiliary magnetic pole portion 7 and the magnet 41 to be uneven, and it is easy to suppress deterioration of the electromagnetic force balance, and motor performance (pump performance). ) Is less likely to occur.

  In addition, since the protrusion 25 has a smaller taper on the outer surface 25a than the taper taper, the moldability of the separation plate 2 is improved by suppressing a decrease in releasability associated with the attachment of the protrusion 25, and It is possible to make it difficult for the stator 5 to be tilted or misaligned when the separation plate 2 is attached. Further, by providing the inclined surface 25b on the bottom 22 side of the protrusion 25, the stator 5 can be guided and attached to the separation plate 2 by the inclined surface 25b (gradient) when the pump is assembled. Therefore, it is possible to easily improve the workability at the time of attachment, and it is possible to make it difficult for the stator 5 to be tilted or misaligned.

  Further, by eliminating the step between the flange portion 23 side of the protrusion 25 and the cylindrical outer peripheral surface 21a, the gap between the magnetic pole surface 5a and the outer peripheral surface 4a of the rotor 4 can be easily reduced, and the auxiliary magnetic pole portion 7 is used. It is possible to easily suppress a decrease in motor efficiency associated with securing the clearance. Then, by eliminating the step, the projection 25 becomes difficult to be caught by the molding die when the separation plate 2 is released, and when the separation plate 2 is molded, the projection 25 can be formed together with the molding of the separation plate 2. it can.

The offset dimension L1 preferably satisfies the following expression 1 as shown in FIG.
Formula 1: L1 ≧ (L3 + DT1) × tan (T1)
This equation 1 is defined as T2 when the taper is a taper defined between the cylindrical outer peripheral surface 21a and the inner peripheral surface 63a of the magnetic pole portion 63, and L3 is the dimension in the axial direction Ax of the first magnetic pole piece 72a. This is a conditional expression when the dimensional tolerance in the axial direction Ax of the piece 71 is ± DT1.

  Further, in the spiral pump, the groove portion 42 is formed when the impeller 16 (rotor 4) moves toward the suction portion 14 in the axial direction Ax due to pressure fluctuation in the pump chamber 11 due to fluid flow when the impeller 16 rotates. In addition, it is preferable to face the magnetic pole part 63 side by side in the radial direction. As shown in FIG. 1, the state where the impeller 16 moves to the suction portion 14 side means that the end portion on the impeller 16 side in the axial direction Ax of the bearing 31 is on the receiving plate 32 fixed to the support shaft 3. In this state, the pump 1 performs work (fluid flow). In this case, when the fluid flows, when the fluid moves, the substantially entire inner peripheral surface 63a of the magnetic pole portion 63 faces the bottom surface 42a of the groove portion 42, and the gap between the magnetic pole surface 5a and the magnet 41 is increased. It becomes almost uniform. For this reason, when the pump 1 performs work (fluid flow), the balance of electromagnetic force can be made unstable, and variations in pump performance can be made difficult to occur.

  Further, as shown in FIG. 5, a step (end surface) may be provided on the flange portion 23 side of the projection portion 25 by cutting the cylindrical portion 21 after the separation plate 2 is formed or by providing the projection portion 25 as a separate member. Good. In this case, when the protrusion 25 is brought into contact with only the magnetic pole portion 63, it becomes easy to form a clearance between the auxiliary magnetic pole portion 7 and the cylindrical outer peripheral surface 21a, and the inner peripheral surface 63a of the magnetic pole portion 63 and the auxiliary magnetic pole portion are easily formed. The inner peripheral surface 71a of the part 7 can be arranged substantially flush. Furthermore, by making the inner peripheral surfaces 63a and 71a substantially flush, the magnet 41 (rotor 4) without the groove portion 42 can be used to make the gap between the magnetic pole surface 5a and the rotor 4 substantially uniform.

  In addition, numerical values such as the drawing taper and the taper of the protrusion 25 are merely examples, and are not limited to these numerical values. Further, the pump 1 is not limited to the centrifugal pump as in the first embodiment, but may be a vortex pump, and is not limited to the centrifugal pump, but is an axial flow pump or the like that causes fluid to flow in the axial direction Ax. However, the configuration is not limited to these examples.

DESCRIPTION OF SYMBOLS 1 Pump 11 Pump chamber 13 Pump case 17 Motor 16 Impeller 2 Separation plate 21 Cylindrical part 21a Cylindrical outer peripheral surface 25 Projection part 4 Rotor 4a Outer peripheral surface 5 Stator 63 Magnetic pole part 7 Auxiliary magnetic pole part Ax Axial direction

Claims (5)

A motor, an impeller that is rotated by the motor to flow fluid, and a pump case and a separation plate that form a pump chamber that houses the impeller,
The motor includes a stator and a rotor that is rotated by the stator and rotates the impeller.
The rotor has an outer peripheral surface along a rotation direction;
The stator has a magnetic pole portion facing the outer peripheral surface;
Based on the rotation axis of the rotor,
Provided at both ends in the axial direction of the magnetic pole portion is an auxiliary magnetic pole portion protruding in the axial direction from the magnetic pole portion,
The separation plate comprises a cylindrical portion interposed between the rotor and the stator facing each other,
2. A pump according to claim 1, wherein a projection that contacts only the magnetic pole portion of the magnetic pole portion and the auxiliary magnetic pole portion is provided on a cylindrical outer peripheral surface facing the magnetic pole portion of the cylindrical portion. 2. The pump according to claim 1, wherein an inner peripheral surface of the auxiliary magnetic pole portion is located offset in a radially outward direction from an inner peripheral surface of the magnetic pole portion. The rotor has a plurality of magnets arranged in a circumferential direction;
On the circumference passing through the portion of the outer peripheral surface of the magnet facing the magnetic pole portion, a groove portion having the same dimension as the magnetic pole portion in the axial direction and having a width in the axial direction and recessed in the radial direction is provided. The pump according to claim 2. The cylindrical portion has a release taper for release on the outer peripheral surface of the cylinder,
The pump according to any one of claims 1 to 3, wherein the protrusion has a taper on an outer surface facing in a radially outward direction, which is smaller than the taper taper of the outer peripheral surface of the cylinder. The separation plate includes a bottom portion at one end of the cylindrical portion;
The pump according to any one of claims 1 to 4, wherein an inclined surface having a gradient toward the bottom is provided at an end of the protrusion on the bottom side.

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