JP2003193993A - DC pump - Google Patents

Abstract

(57) [Summary] [PROBLEMS] The present invention can reduce mechanical loss, omit the configuration such as a shaft and a bearing, extend the life of a pump, reduce the cost, and perform advanced machining for generating dynamic pressure. It is an object of the present invention to provide a DC pump which can eliminate the need for the motor, eliminate variations in the axis of the motor, and reduce vibration and noise. SOLUTION: The DC pump according to the present invention has a shape in which a salient pole 9 farthest from a discharge port 8 of the pump has a gap between the salient pole 9 and the magnet rotor 2 decreasing in a counter-rotating direction of the magnet rotor 2. , And all other salient poles have a shape in which the gap decreases in the rotation direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC pump using a DC brushless motor having a long life and high efficiency.

[0002]

2. Description of the Related Art A vortex pump (friction pump) suitable for thinning a structure that sucks in in the radial direction and discharges in the radial direction is known. FIG. 10 is a block diagram of a conventional vortex flow pump.
In FIG. 10, the pump bearing 105 is inserted,
The pump shaft 104 is mounted. A driven magnet 106 is provided on the outer circumference of the pump bearing 105, and a blade 107 formed of a large number of grooves formed at a predetermined pitch is provided on the outermost circumference in a ring shape. The driven magnet 106 and the blade 107 are integrally formed of a magnetic resin material.

When the motor of this conventional overcurrent pump is energized, its rotational power is transmitted to the driven magnet 106, and the blade 107 is rotated by this rotational power, and this blade 107 gives momentum to the surrounding liquid. , The external liquid is sucked from the radial direction into the pump. The liquid flowing from the suction port 101 flows through the water passage 103 between the blade 107 and the pump casing 108 in the direction of the arrow,
It flows out from the discharge port 102. During this time, the blade action receives kinetic energy to increase the pressure.

By the way, the vortex flow pump shown in FIG.
Due to the pressure difference between the suction port 101 and the discharge port 102 of the pump, a force 109 in the radial direction acts on the motor. This force 109 is generated by the pump shaft 104 and the pump bearing 1
No. 05 and the sealing material cause a load against sliding, but they are supported and balanced by these members, and the blades 107 of the pump are prevented from hitting the pump casing 108 or the like by the force 109.

[0005]

However, in the structure of the conventional vortex flow pump described above, there is a problem that mechanical loss increases because the pressure difference of the pump is balanced with the axial load. This loss is relatively small in the case of a large pump, but especially in the case of a small pump, the ratio tends to relatively increase as the size of the pump becomes smaller. It may be possible to use a dynamic pressure type fluid bearing, but in order to balance with the dynamic pressure of the liquid to be handled, the dynamic pressure is generated in consideration of the force generated by the pressure difference between the inlet and outlet of the pump. However, there is a problem in that the groove processing amount is several μm and precision processing is required. Also in this case, the smaller the pump becomes, the more difficult the machining becomes.

Therefore, the present invention solves the above-mentioned problems of the prior art by reducing the mechanical loss, omitting the structure such as shafts and bearings, extending the life of the pump, reducing the cost, and generating dynamic pressure. It is an object of the present invention to provide a DC pump that can eliminate the need for high-level mechanical processing, does not have variations in the motor shaft center, and can reduce vibration and noise.

[0007]

In order to solve the above-mentioned problems, in the DC pump of the present invention, the salient pole farthest from the pump discharge port is a gap between the salient pole and the magnet rotor in the counter-rotational direction of the magnet rotor. Has a shape that reduces
All the other salient poles are characterized by having a shape in which the gap decreases in the direction of rotation.

As a result, the mechanical loss can be reduced, the configuration such as the shaft and the bearing can be omitted, the life of the pump can be reduced, the cost can be reduced, and the high-level machining for generating the dynamic pressure can be eliminated. Vibration and noise can be reduced without variations in shaft center.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is an armature wound around a plurality of teeth having salient poles formed at the tips, and a ring-shaped armature facing the salient poles and surrounding the salient poles. Equipped with a DC brushless motor with a magnet rotor,
An impeller integrally formed with the magnet rotor and having vanes formed around it, a suction port for accommodating the impeller and sucking fluid in the pump chamber in the radial direction, and a discharge port for discharging fluid in the pump chamber in the radial direction. A DC pump having a provided pump casing, wherein the salient pole farthest from the pump discharge port has a shape in which the gap between the salient pole and the magnet rotor decreases in the direction opposite to the rotation direction of the magnet rotor, The salient poles are all DC pumps characterized by a gap that decreases in the direction of rotation, so only one salient pole with a different shape can generate a force in the direction of the rotation axis. , Other salient poles can be easier to start. In addition, the salient pole, which has a different shape from the other salient poles, is located farthest from the pump outlet, so it is possible to generate a force that balances the radial force due to the pressure difference generated at the outlet, resulting in mechanical loss. Can be reduced.

According to the second aspect of the invention, the gaps between the salient poles and the inner peripheral surface of the magnet rotor are equal,
The salient pole is formed with a bent portion that extends laterally along the inner peripheral surface of the magnet rotor, and the bending amount of the bent portion of the salient pole farthest from the pump discharge port increases in the counter-rotational direction of the magnet rotor. However, since the bending amount of the other bent portions of the salient poles increases in the rotation direction, the salient poles having only one bending amount differ in the rotation axis direction. Can be generated and other salient poles can be easily activated by increasing the bending amount in the rotational direction, and salient poles with different bending amounts are arranged at the position farthest from the pump discharge port. As a result, it is possible to generate a force that balances the force in the radial direction due to the pressure difference generated at the discharge port, and it is possible to reduce mechanical loss.

According to a third aspect of the present invention, a control device is provided which forms an additional coil by winding only the salient pole farthest from the pump discharge port and controls the magnitude and direction of the current flowing through the coil. The DC pump according to claim 1 or 2, wherein the salient pole additionally wound with a coil can generate a force in a rotation axis direction.
It becomes possible to balance the radial force due to the pressure difference generated by the pump.

According to a fourth aspect of the present invention, a magnetic pole position sensor for detecting the magnetic pole position of the magnet, a rotation speed conversion device for converting the output signal of the magnetic pole position sensor into the rotation speed of the magnet rotor, and the output of the magnetic pole position sensor. 4. The DC pump according to claim 3, further comprising a control device that controls the direction of the current from the signal to the additional coil and the magnitude of the current from the output signal of the rotation speed conversion device to the additional coil.
The salient pole additionally wound with a coil can generate a force in the direction of the rotation axis, and can balance the force in the radial direction due to the pressure difference generated by the pump.

(First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. 1 is a sectional view of a DC pump according to Embodiment 1 of the present invention, and FIG.
FIG. 3 is an explanatory diagram showing the configuration of the DC pump of FIG. 1.

In FIGS. 1 and 2, reference numeral 1 denotes an impeller of a DC pump, which is an eddy-current type impeller having a large number of blades formed by grooves formed at a predetermined pitch on the outer circumference. Is provided with a magnet rotor 2. In the present invention, any type of turbo type DC pump that receives a radial force from a fluid may be used, but a vortex flow pump is typical. Impeller here 1
The blade and the magnet rotor 2 may be made of different materials and fitted together to be integrated, or may be made of a magnetic resin material and the blade and the magnet rotor 2 may be made of the same material and integrated. Reference numeral 3 is a stator core provided on the inner peripheral side of the magnet rotor 2, and 4 is a pump for accommodating the impeller 1 and at the same time recovering the pressure of the kinetic energy applied to the fluid by the impeller 1 and guiding it to a discharge port 8 described later. A pump casing 5 having a chamber constitutes a part of the pump casing 4, and is a casing cover for sealing the pump chamber after housing the impeller 1. Reference numeral 6 denotes a shaft fixed to the pump casing 4, which is inserted into a through hole at the center of the impeller 1 and is slidable because the impeller 1 rotates around. The shaft 6 may be fixed to the pump casing 4 as a separate component by press fitting or insert molding, or may be integrally formed of the same material as the pump casing 4. Then, instead of being fixed to the pump casing 4, it may be configured to be able to rotate while sliding. Reference numeral 7 is a suction port, and 8 is a discharge port. External fluid is sucked from the suction port 7 in the radial direction into the pump, and is discharged from the discharge port 8 in the radial direction to the outside. Reference numeral 9 is one salient pole among a plurality of salient poles that are formed.
Is provided at a position substantially point-symmetrical with. Only the salient pole 9 has an asymmetrical shape with respect to teeth, that is, the gap between the salient pole 9 and the magnet rotor 2 gradually decreases in the direction opposite to the rotation direction (hereinafter, counter rotation direction). Therefore, the magnetic flux on the rear end side of the salient pole 9 having the smaller gap increases, and the magnet rotor 2 on the rear end side portion of the salient pole 9 increases.
The attraction force to On the other hand, in the other salient poles, the gap with the magnet rotor 2 becomes gradually smaller in the rotating direction. Therefore, here it is the pushing force. The sum of the pulling force of the salient poles 9 with respect to the magnet rotor 2 and the pushing force of the salient poles at the point-symmetrical position acts on the impeller 1 in the direction of the axis 6 and the radial direction due to the pressure difference generated from the fluid. Will cancel the power of. This point will be described in detail later.

When the DC pump of the first embodiment is supplied with electric power from an external power source, a current controlled by an electric circuit provided in the pump flows through the coil of the stator core 3 to generate a rotating magnetic field. . When this rotating magnetic field acts on the magnet rotor 2, a physical force is generated on the magnet rotor 2. Since this magnet rotor 2 is integrated with the ring impeller 1, rotational torque acts on the impeller 1 and the impeller 1 starts rotating due to this rotational torque. The blades provided on the outer circumference of the impeller 1 impart momentum, and thus kinetic energy, to the fluid flowing from the suction port 7 by the rotation of the impeller 1, and the kinetic energy gradually increases the pressure of the fluid in the pump casing 4. It is discharged from the discharge port 8. The high pressure of the discharge port 8 is from the vicinity of the discharge port to the shaft 6
It becomes a force in the direction. However, in the first embodiment,
A force that opposes this force can be generated by the salient pole 9 and the salient pole at this point-symmetrical position to eliminate the load on the shaft 6.

Now, the force generated by the salient poles 9 having different shapes in the DC pump of the first embodiment will be described with reference to FIGS. 4 is an explanatory diagram of a force generated by the motor of the DC pump according to the first embodiment of the present invention, and FIG. 5 is an explanatory diagram of a force when the magnet rotor of the DC pump of FIG. 4 rotates clockwise by 30 degrees. , Fig. 6
FIG. 6 is an explanatory diagram of a force when the magnet rotor of the DC pump of FIG. 5 rotates clockwise by 30 degrees. When power is externally supplied to the winding of the stator core 3 in FIG. 4, the magnet rotor 10 rotates in the direction of the arrow. The arrows around the magnet rotor 10 indicate the radial force generated from each salient pole. Reference numerals 11 and 12 denote radial forces generated from the salient poles at corresponding positions.
Reference numeral 13 is a radial force generated from the salient pole 9 having a shape different from that of the other salient poles. The salient pole 9 is arranged at a position farthest from the pump discharge port, that is, at a position substantially symmetrical with respect to the axis 6. ing. At this time, since the salient poles are symmetrically arranged around the salient pole 9, the radial force 12, 1
Forces other than 3 are balanced. Therefore, the radial force 12,
The resultant force 13 acts on the discharge port 8 of the pump. In this way, the salient poles 9 are shaped differently from the other salient poles, and the resultant force of the radial forces 12, 13 is generated by the action of the motor so as to balance the radial force due to the pressure difference generated by the pump. If so, the load on the shaft 6 can be eliminated.

The state of the salient pole expansion region 14 will be described with reference to FIGS. 4 to 6. First, as shown in FIG. 4, a current flows through the salient poles of the salient pole expansion region 14 so as to become N poles.
Push out the N pole of 0 and draw the S pole. In FIG. 5, in which the magnet rotor 10 is rotated 30 degrees clockwise from FIG. 4, the S pole of the magnet rotor 10 is attracted by the salient poles. Further, in FIG. 6 in which the magnet rotor 10 is rotated 30 degrees clockwise from FIG. 5, the salient pole has an S
A current flows so as to form a pole, and pushes out the S pole of the magnet rotor 10 and draws the N pole. The state of the magnet rotor 10 when further rotated from the state of FIG.
It is the same as the one explained in the above, and this is repeated.

FIG. 7 is an enlarged view for explaining the radial force generated from the salient poles of the DC pump of FIG. In FIG. 7, when a current flows so that the salient pole 14a becomes the N pole, the force 15, N for attracting the S pole of the magnet rotor 10 is attracted.
A force 16 is generated that pushes the pole out. Where salient pole 14
Since a has a non-symmetrical shape with respect to the teeth, that is, the gap with the magnet rotor 10 becomes gradually smaller as “a” moves toward the rotation direction.
The force 16 that pushes the pole out is greater. This is to obtain smoothness when starting the DC brushless motor. The force components 15 and 16 in the normal direction are A,
It becomes B and the resultant force becomes the radial force 11. The same applies to other salient poles, and the radial force 13
However, since the salient pole 9 has an asymmetrical shape in which the gap between the salient pole 9 and the magnet rotor 10 gradually increases as the salient pole 9 moves in the rotating direction, the force acts in the opposite direction.

In the DC pump of the first embodiment, the load on the shaft 6 is balanced and balanced, the life of the shaft can be extended, and the rotation of the impeller 1 can be stabilized. In addition, since all salient poles of the stator core 3 in contact with the outer peripheral surface of the salient pole have the same diameter, they are easily and evenly inserted when press-fitted into the pump casing 4, so that there is no variation in the shaft center of the motor and noise and vibration are eliminated. Can be reduced.

(Second Embodiment) The second embodiment of the present invention will be described with reference to FIG. The DC pump of the second embodiment eliminates the shaft of the first embodiment, makes the impeller 1 ring-shaped, and forms a groove 1 ′ for generating a dynamic pressure on the inner and side surfaces of the impeller 1 to perform a bearing action. It is processed. FIG. 3 is an explanatory diagram showing the configuration of the DC pump according to the second embodiment of the present invention. The DC pump of the second embodiment does not have a shaft, and the stator core 3 has the same configuration as that of the first embodiment, and therefore the description thereof is omitted here.

In the DC pump of the second embodiment, as in the first embodiment, the resultant force of the radial forces 12, 13 generated by the salient pole 9 of FIG. 4 and the radial force generated by the pressure difference of the pump are applied. By balancing well with the force,
It is a shaftless pump with the shaft abolished. Since the forces in the radial direction are well balanced, it is possible to consider only the groove 1'of the impeller for generating the dynamic pressure, and it is not necessary to consider extra pressure balance, and the groove 1'can be processed. Easier to do.

The DC pump of the second embodiment is the impeller 1
Since it has a good balance in the radial direction, it is possible to reduce the cost because it is possible to use a shaftless pump without the shaft. Further, the impeller 1 is prevented from coming into contact with the pump casing 4, a long-life pump can be provided, and vibration and noise can be reduced. Further, since the balance in the radial direction is good, it is possible to eliminate the need for processing in consideration of the extra pressure balance of the groove 1'of the impeller for generating the dynamic pressure. In addition, since all salient poles of the stator core 3 in contact with the outer peripheral surface of the salient pole have the same diameter, they are easily and evenly inserted when press-fitting into the pump casing, and there is no variation in the axial center of the motor and noise and vibration are eliminated. It can be reduced.

(Third Embodiment) A third embodiment of the present invention will be described with reference to FIG. The DC pump according to the third embodiment uses the stator core shown in FIG. 8 in the pump configured as shown in FIG. FIG. 8 is a block diagram of a DC pump having a structure in which the end portion of the stator core is bent in a direction perpendicular to the radial direction of the motor. The bending amount is shown in the arrows C-C and the arrow D-D, but only one of the plurality of salient poles is bent only in the salient pole 9 at the position of the arrow D-D. Differently, all other salient poles 17 have arrow C-
It is the same as the bending amount shown in C. The bending portion 17a shown in the arrow view C-C becomes wider as it goes in the rotation direction of the magnet rotor 10, and the bending portion 9a in the arrow view DD as it goes in the counter rotation direction of the magnet rotor 10 becomes wider. Grows larger. Bent portion 9a of this arrow view D-D
Is a bent portion 9a of the salient pole 9 which is located farthest from the pump discharge port 8 and which is substantially point-symmetric with respect to the pump discharge port 8 with respect to the shaft 6.

In the first and second embodiments, the stator core 3 is adjusted by the gap with the magnet. However, in the third embodiment, the salient poles 9 and 17 are bent in the vertical direction, and the gap is adjusted by the bending amount. It is possible to carry out the same adjustment as above, and it is easy to assemble and adjust. In the DC pump of the third embodiment, the load on the shaft 6 is balanced and balanced, the life of the shaft 6 can be extended, and the rotation of the impeller 1 can be stabilized. Further, since the outer peripheral surfaces of the salient poles 9 and 17 of the stator core 3 are in contact with the pump casing 4, they can be easily and evenly inserted when being press-fitted into the pump casing 4, and the noise and vibration can be reduced without variations in the axial center of the motor. .

(Fourth Embodiment) A fourth embodiment of the present invention will be described with reference to FIG. As shown in FIG. 3, the DC pump of the fourth embodiment eliminates the shaft 6 of the first embodiment, makes the impeller 1 ring-shaped, and generates dynamic pressure on the inner and side surfaces of the impeller 1 to perform the bearing action. The groove 1 ′ for machining is processed, and the stator core 3 of FIG. 8 is used for this. The detailed description is the same as that of the third embodiment, and will be omitted.

The DC pump of the fourth embodiment is the impeller 1
Since the radial balance is good, a shaftless pump in which the shaft 6 is abolished can be obtained, and the cost can be reduced. Further, since the impeller 1 is prevented from hitting the pump casing 4, it is possible to provide a long-life pump and reduce vibration and noise. Further, since the balance in the radial direction is good, it is possible to eliminate the need for processing in consideration of the extra pressure balance of the groove 1'of the impeller for generating the dynamic pressure. In addition, since all salient poles of the stator core 3 where the salient poles 9 and 17 are in contact with each other have the same diameter, the salient poles are easily and evenly inserted when press-fitted into the pump casing.・ Vibration can be reduced.

(Fifth Embodiment) The fifth embodiment of the present invention will be described with reference to FIG. The DC pump of the fifth embodiment is different from the pumps of the first to fourth embodiments in that when the radial force due to the pressure difference is not canceled by the salient poles 9 having different shapes, the salient poles 9 are not balanced. It is an additional winding on the tooth. The impeller 1 rotates in a well-balanced manner by applying a force due to the shape of the salient pole 9 to the radial force due to the pressure difference and by balancing the force due to the additional winding with the magnetic force.

The DC pump of the fifth embodiment is the impeller 1
Can be prevented from coming into contact with the pump casing 4, etc., so that a long-life pump can be provided and vibration and noise can be reduced.

(Sixth Embodiment) A sixth embodiment of the present invention will be described with reference to FIG. Similar to the fifth embodiment, the DC pump of the sixth embodiment is balanced without being canceled by the salient poles 9 having different radial forces due to the pressure difference in the pumps of the first to fourth embodiments. If not. 9A is a graph of the force and time exerted by the salient poles of the DC pump on the magnet rotor according to the sixth embodiment of the present invention, and FIG. 9B is a control circuit diagram of the DC pump of FIG. 9A. As shown in FIG. 9B, a magnetic pole position sensor 2 that detects the magnetic pole position of the magnet by forming an additional coil 24 by forming an additional winding on the tooth of the salient pole 9
0, a rotation speed conversion device 21 that converts the output signal of the magnetic pole position sensor 20 into the rotation speed of the magnet rotor 10, a current direction to the additional coil 24 from the output signal of the magnetic pole position sensor 20, and an output of the rotation speed conversion device 21. A control device 22 for controlling the magnitude of the current from the signal to the additional coil 24 is provided. The control device 22 controls the power supply unit 23 to control the magnitude and direction of the current supplied to the additional coil 24.

As shown in FIGS. 4 to 6, the forces generated by the salient poles 9 on the magnet rotor 10 are the same in FIGS. 4 and 6, but in the case of FIG. Since the poles of the magnet rotor 10 are changed between the salient poles, the forces shown in FIGS. 4 and 6 act. FIG. 9A shows this state. The area 18 in FIG. 9A is where the force generated from the salient poles 9 on the magnet rotor 10 disappears, and cogging occurs at this position. Therefore, the magnetic pole position sensor 20 is arranged between the salient pole 9 and the front salient pole of FIG. 5, and the timing at which the pole of the magnet changes is used as the output signal of the magnetic pole position sensor 20, and the rotation speed of the magnet rotor 10 is changed from that signal. Rotation speed conversion device 2 for conversion
1 is set. Further, a control device 22 is provided for controlling the direction and magnitude of the current supplied to the additional coil 24 which is additionally wound by adding the signal from the magnetic pole position sensor 20. As described above, by providing the rotation speed conversion device 21 and the current control device 22, smooth rotation can be achieved.

As described above, the impeller rotates in a well-balanced manner by counterbalancing the radial force generated by the pressure difference of the pump with the force generated by the additionally wound salient poles, and further, the rotation. Smooth rotation can be achieved by using the number conversion device 21 and the control device 22.

The DC pump of the sixth embodiment is the impeller 1
Is prevented from coming into contact with the pump casing 4 and rotates smoothly, so that a long-life pump can be provided and vibration and noise can be reduced.

[0033]

As described above, the DC pump of the present invention generates a force for balancing by the action of the DC brushless motor in order to balance the force in the radial direction due to the pressure difference generated in the pump. Therefore, mechanical loss can be reduced, the load on the shaft can be reduced, or the shaft and bearings can be abolished to prolong the life of the pump and reduce the cost.
Noise and vibration can be reduced.

When a dynamic pressure type fluid bearing is used to balance the dynamic pressure of the liquid handled by the pump, a complicated groove is conventionally used to support the radial force generated by the pressure difference between the suction port and the discharge port. Had to be formed, but DC
Since it is balanced by the action of the brushless motor and further balanced by the dynamic pressure, it is possible to eliminate the need for advanced machining.

[Brief description of drawings]

FIG. 1 is a sectional view of a DC pump according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the configuration of the DC pump of FIG.

FIG. 3 is an explanatory diagram showing a configuration of a DC pump according to the second embodiment of the present invention.

FIG. 4 is an explanatory diagram of a force generated by the motor of the DC pump according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram of force when the magnet rotor of the DC pump of FIG. 4 rotates clockwise by 30 degrees.

6 is an explanatory view of force when the magnet rotor of the DC pump of FIG. 5 rotates clockwise by 30 degrees.

7 is an enlarged view for explaining the radial force generated from the salient poles of the DC pump of FIG.

FIG. 8 is a configuration diagram of a DC pump having a structure in which an end portion of a stator core is bent in a direction perpendicular to a radial direction of a motor.

FIG. 9A is a control circuit diagram of the DC pump shown in FIG. 9B, which is a graph of force and time exerted by a salient pole of the DC pump on the magnet rotor according to the sixth embodiment of the present invention.

FIG. 10 is a configuration diagram of a conventional vortex flow pump.

[Explanation of symbols]

1 impeller 1'groove 2 magnet rotor 3 Stator core 4,108 Pump casing 5 casing cover 6 axes 7,101 Suction port 8,102 outlet 9,17 salient poles 9a, 17a Bent section 10 magnet rotor 11,12,13 Radial force 14 Salient pole expansion area 15,16,109 force 18 areas 103 waterway 104 pump shaft 105 pump bearing 106 driven magnet 107 feathers

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI Theme Coat (Reference) H02K 3/18 H02K 3/18 Z 5H607 7/14 7/14 B H02P 6/16 1/16 C // H02K 1/16 H02P 6/02 351N (72) Inventor, Yoichi Susato, No. 1006, Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F term (reference) 3H020 AA01 BA06 BA11 CA08 DA04 EA07 3H022 AA01 BA03 BA07 CA06 CA50 DA07 DA08 DA09 DA12 DA13 DA15 DA20 5H002 AA04 AA05 AE07 5H560 BB04 BB12 DA08 DB07 XA11 5H603 AA01 BB01 BB10 BB13 CA01 CA05 CB02 CC11 CC17 CD21 5H607 AA04 BB01 BB09 BB14 BB17 CC05 DD02 DD17 HFF06H01H06H

Claims (4)

[Claims] 1. An armature wound around a plurality of teeth having salient poles formed at the tips thereof, and a DC brushless motor having a ring-shaped magnet rotor arranged facing the salient poles and surrounding the salient poles. An impeller that is integrated with the magnet rotor and has blades formed around it; a suction port that accommodates the impeller and that sucks fluid from the pump chamber in the radial direction; and a discharge port that discharges fluid from the pump chamber in the radial direction. DC with pump casing with outlet
In the pump, the salient pole farthest from the pump discharge port has a shape in which the gap between the magnet rotor and the magnet rotor decreases in the counter-rotational direction, and all other salient poles rotate in the rotational direction. A DC pump having a shape in which the gap decreases toward the front. 2. A gap between each salient pole and the inner peripheral surface of the magnet rotor is equal, and each salient pole is formed with a bent portion extending laterally along the inner peripheral surface of the magnet rotor. The bending amount of the bent portion of the salient pole farthest from the discharge port increases in the counter-rotational direction of the magnet rotor, and the bending amount of the bent portions of the other salient poles increases in the rotational direction. The DC pump according to claim 1. 3. An additional coil is formed by winding only the salient pole farthest from the pump discharge port, and a control device for controlling the magnitude and direction of the current flowing through the coil is provided. The DC pump according to claim 1 or 2. 4. A magnetic pole position sensor for detecting a magnetic pole position of a magnet, a rotation speed conversion device for converting an output signal of the magnetic pole position sensor into a rotation speed of a magnet rotor, and an output signal of the magnetic pole position sensor to an additional coil. 4. The DC pump according to claim 3, further comprising a control device that controls the direction of the current and the magnitude of the current to the additional coil from the output signal of the rotation speed conversion device.