JP2000287430A - Brushless motor, pump, and magnetizing method of magnet in brushless motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brushless motor capable of smooth rotation with small torque ripples and a stable output while a magnetic pole position can be detected accurately. SOLUTION: A brushless motor includes a stator 22 fed with a driving current for generating a rotating magnetic field, a rotor 17 with a magnet 21 driven rotatively in a rotating field generated by the stator 22, and a magnetic pole position sensor 23 for detecting a rotating magnetic field of the rotor 17 and detecting the position of the rotor 17. The magnet 21 includes a detecting field generating part 21b used for detection of the rotating position by the rotating position sensor 23, and a driving field generating part 21b used for generating a magnetic field in rotating drive in the rotating magnetic field of the stator 22. In addition, the detecting field generating part 21a and the driving field generating part 21b are differently magnetized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless motor having low noise and vibration and high efficiency, and a pump using the same.
And a method for magnetizing a magnet of a brushless motor.

[0002]

2. Description of the Related Art Conventionally, in brushless motors,
The magnetic pole position is detected by using the magnetic pole position sensor,
2. Description of the Related Art A brushless motor that controls rotation by switching an energized phase in synchronization with rotation of a magnetic pole is known.

[0003] Such a conventional brushless motor is disclosed in, for example, Japanese Patent Application Laid-Open No. 6-86526 (hereinafter referred to as "A"), "a rotor having a magnet for a frequency generator and a rotor magnet integrated with each other. Having a stator having a winding opposed to the rotor,
In a DC brushless motor in which a mounting bracket for supporting a rotating shaft, a bearing, and the like and a circuit board having a control and drive circuit are arranged in an axial gap between the rotor and the stator, a stepped portion is formed on a part of the magnet for the frequency generator. Or, a groove is provided, and an imposition Hall element is arranged on the circuit board as a magnetic pole detection section of the rotor magnet.On the circuit board, a frequency generator coil section is fixed by soldering as one electronic component modularized. A DC brushless motor, characterized in that the frequency generator coil portion is arranged on a high magnetic permeability material such as an iron substrate, is disclosed.

[0004] The brushless motor disclosed in Japanese Patent Application Publication No. H06-27139 will be described below with reference to the drawings.

FIG. 11 is a fragmentary sectional view of a main part of a brushless motor disclosed in Japanese Patent Publication No. A.

In FIG. 11, reference numeral 101 denotes a circuit board, 10
2 is a bracket, 103 is a rotor, 104 is a magnet, 104a is a frequency generator magnet formed at one end of the magnet 104, and 104b is a rotor magnet. The brushless motor of FIG. 11 has an outer rotor structure in which the outside rotates. The frequency generator magnet 104a and the rotor magnet 10
4b is formed as an integral magnet 104. 105 is a rotor magnet 104 of the rotor 103
b, a stator for applying a rotating force to the electromagnetic force
5a is a stator winding, 106 is a shaft as a rotating shaft, 107 is a ball bearing, 108 is a rotor 10
3 is a magnetic pole position sensor such as a Hall element for detecting the position of the magnetic pole of the frequency generator magnet 104a. The circuit board 101 controls the current supply to the stator winding 105a based on the magnetic pole position information detected by the magnetic pole position sensor 108, and as a result, the rotor 103 rotates while continuously generating torque.

As described above, in order to apply a rotational torque to the rotor 103 to perform work, the magnetic pole position sensor 108
The magnet 103 for the frequency generator of the rotor 103
It is very important to detect the magnetic pole position of a. In this brushless motor, a part of a magnetic field generated by the magnet 104 or a leakage magnetic field from the magnet 104 is sensed by the magnetic pole position sensor 108 to detect a magnetic pole position or a change point of the magnetic pole.

In recent years, as the demand for lower vibration noise of electric products and the smoothness of rotational force in electric machines has increased,
Improvements are also needed for brushless motors. Vibration noise and unevenness of rotational force in the brushless motor are mainly caused by cogging due to the magnetic effect of salient poles of the stator.

FIG. 12 is a schematic diagram showing a cross section perpendicular to the rotation axis of a general brushless motor.

In FIG. 12, reference numeral 110 denotes a rotor magnet, 111 denotes a stator, 111a denotes a coil of the stator 111 that generates a drive magnetic field by applying a drive current, and 111b denotes a field of the wound stator 111 of the coil 111a. The iron core 111c is a salient pole of the field iron core 111b.

FIG. 12 shows the distribution of magnetic flux when the coil 111a is not energized.
Is generated by the salient poles 111 of the field iron core 111b.
Concentrate on c. As a result, the magnetic poles of the magnet 110 and the salient poles attract each other, and a torque having a correlation with the number of magnetic poles of the magnet 110 and the number of salient poles is generated. The torque due to the magnetic force is reduced between the salient poles 111c. Accordingly, when the brushless motor rotates, the phase of the drive current supplied to the coil 111a is switched to sequentially excite the salient poles 111c, and when the plurality of magnetic poles of the magnet 110 are sequentially attracted and repelled and rotated, the magnet 11
Due to the rotation angle of 0, the torque becomes uneven, resulting in uneven rotation called cogging. When such cogging occurs, it is transmitted to the casing of the brushless motor, which leads to an increase in vibration and noise.

In a brushless motor, as one method of suppressing such cogging and achieving low vibration noise and smooth rotational force, a magnet 110 mounted on a rotor is used.
Are integrated into a single magnet, and the magnetization distribution in the rotational direction is changed from a conventional rectangular wave type to a sinusoidal type.

By changing the magnetization distribution from a conventional rectangular wave to a sine wave with respect to the rotation direction of the magnet 110, the magnetic field generated in the stator 111 and thereby the salient poles 111c of the stator 111 The torque generated between the rotor and the magnet 110 becomes smooth, so-called torque ripple such as cogging decreases, and the torque during rotation approaches a constant. This reduces fluctuations in the number of rotations, so-called rotation unevenness, and also reduces vibration noise.

[0014]

However, the above-mentioned conventional brushless motor has the following problems.

(1) In order to reduce cogging, if the magnetization distribution of the magnet is magnetized so as to change sinusoidally with respect to the rotation direction of the rotor, a magnetic pole position sensor for detecting the rotation position of the rotor is rectangular. Compared to the case where the magnetic force distribution is magnetized, the change rate of the magnetization change at the change point of the magnetization polarity in the rotation direction of the rotor becomes a smooth change, and the detection error of the change point of the magnetization polarity increases. In particular,
In the case where the rotor is driven at a high speed, this detection error delays the timing of switching the energized phase of the drive current flowing through the coil of the stator from the optimal timing synchronized with the rotation of the rotor, and the efficiency of the brushless motor is reduced. It may cause a decrease.

(2) In order to maintain the detection accuracy of the magnetic pole position even when the magnet is magnetized so that the magnetization distribution of the magnet changes sinusoidally with respect to the rotation direction of the rotor, the arrangement of the magnetic pole position sensor must be changed. Or
It is effective to increase the magnetization of the magnet to increase the generated magnetic field. In the case of the conventional example disclosed in the above-mentioned Publication No. A, it is configured to be used in general air, and it is relatively easy to arrange the magnetic pole position sensor 116 close to the magnet 106. It is. However, for example, when such a brushless motor is applied to a pump for liquid operation such as a water pump, a partition for isolating the stator, the windings, and the circuit board 1 from the liquid is necessary, and the magnet and the There is a great restriction in approaching the magnetic pole position sensor. Increasing the magnetization of the magnet to detect the magnetic pole position generates a magnetic field larger than the magnetic field required for the output of the brushless motor, which is irrational and reduces the size and cost. It is also an obstacle.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems by providing a brushless motor capable of detecting a magnetic pole position with high accuracy while performing smooth rotation with little torque ripple and obtaining a stable output. I do.

Further, the present invention is a pump using a brushless motor which solves the above-mentioned problems, wherein fluctuations in the number of revolutions of the pump are small, pulsation is prevented, vibration noise is small, operation efficiency is high, and pump operation is improved. It is an object of the present invention to provide a pump in which out-of-step is prevented.

Another object of the present invention is to provide a method for magnetizing a magnet of a brushless motor for manufacturing a brushless motor that solves the above problems.

[0020]

According to a first aspect of the present invention, there is provided a brushless motor having a stator for generating a rotating magnetic field by applying a driving current, and a magnet rotatably driven by the rotating magnetic field generated by the stator. A brushless motor including a rotor and a magnetic pole position sensor that detects a rotational position of the rotor by detecting a magnetic field generated by the rotor, wherein the magnet is a detection magnetic field used for detecting a rotational position of the magnetic pole position sensor. A generator comprising: a generator; and a drive magnetic field generator used to generate a magnetic field for rotationally driving by a rotating magnetic field generated by the stator, wherein the detection magnetic field generator and the drive magnetic field generator are magnetized differently. Consisting of

With this configuration, the magnetic pole position can be detected with high accuracy while performing smooth rotation with little torque ripple.
A brushless motor capable of obtaining a stable output can be provided.

According to a second aspect of the present invention, there is provided a pump pressurizing section for rotating a pump chamber and a rotor of the brushless motor according to any one of claims 1 to 8 to apply pressure to a liquid in the pump chamber to form a flow. And a configuration having:

With this configuration, it is possible to provide a pump in which fluctuations in the number of revolutions of the pump are small, pulsation is prevented, vibration noise is small, operation efficiency is high, and step-out during operation of the pump is prevented.

Further, the magnetizing method for a magnet of a brushless motor according to the present invention provides a stator for generating a rotating magnetic field by applying a driving current, a rotor having a magnet rotated by the rotating magnetic field generated by the stator, and a rotor for the rotor. And a magnetic pole position sensor for detecting the rotational position of the rotor by detecting the magnetic field to be produced, and a magnetizing method for a magnet of a brushless motor comprising: In the radial direction of the magnet, a magnetic field whose polarity is reversed in the form of a rectangular wave with respect to the rotation direction of the magnet is applied. Is applied by applying a magnetic field whose polarity is inverted in a sinusoidal manner with respect to the rotation direction of the magnetic field.

With this configuration, it is possible to provide a method of magnetizing the magnet of the brushless motor for manufacturing the brushless motor.

[0026]

DETAILED DESCRIPTION OF THE INVENTION In order to achieve this object, a brushless motor according to a first aspect of the present invention is configured such that a stator for generating a rotating magnetic field by applying a driving current and a rotating magnetic field generated by the stator. A brush having a magnet having a magnet and a magnetic pole position sensor for detecting a rotational position of the rotor by detecting a magnetic field generated by the rotor, wherein the magnet is used for detecting a rotational position of the magnetic pole position sensor. And a driving magnetic field generating section used for generating a magnetic field for rotationally driving by a rotating magnetic field generated by the stator, wherein the detecting magnetic field generating section and the driving magnetic field generating section have different magnetizations. This is a configuration in which

With this configuration, the following operation can be obtained.

(1) Magnetization is performed so that the change in the magnitude of the magnetization of the drive magnetic field generating section becomes a smooth curve with respect to the rotation direction of the rotor. By magnetizing so as to change sharply at the change point of the magnetization polarity, the magnetic field generated in the stator and thereby the torque generated between the stator and the magnet of the rotor become smooth, and the magnitude of the magnetization of the detection magnetic field generating section becomes large. Since the change in steepness changes sharply at the change point of the magnetization polarity,
Magnetic pole position sensor It is possible to accurately detect the magnetic pole position.

(2) The so-called torque ripple such as cogging is reduced by smoothing the torque generated between the stator and the magnet of the rotor, and the torque during rotation approaches a constant value. And the vibration noise is also reduced.

(3) Since the magnetic pole position sensor accurately detects the magnetic pole position, the phase switching timing of the drive current supplied to the stator can be accurately synchronized with the rotation of the rotor. Operational efficiency is improved and step-out is prevented.

Here, ferrite is used as the magnet,
Samarium cobalt alloy, neodymium iron boron alloy, iron chromium cobalt alloy and the like are preferably used. In particular, when the detection magnetic field generation section and the drive magnetic field generation section are formed by an integral magnet, it is preferable to use a plastic magnet in which ferrite powder is mixed in a resin such as nylon 12, nylon 6, or polyphenylenestyrene sulfide. This is because it has fluidity suitable for injection molding.

Further, the magnet may be constituted by integrating the detection magnetic field generation unit and the drive magnetic field generation unit with an integral magnet, or by combining a plurality of magnets.

As the magnetic pole position sensor, a Hall element, a Hall IC, an induct core or the like is used.

The detection magnetic field generation unit and the drive magnetic field generation unit may have an even number of poles such as four poles, eight poles, and ten poles (the number of poles here is from the N pole to the S pole or the S pole in the circumferential direction of the magnet). The number of pole changes from N to the N pole is referred to, and a case where the number of pole changes is n is called an n pole, where n is always an even number.

According to a second aspect of the present invention, there is provided the brushless motor according to the first aspect, wherein the driving magnetic field generation section has a change in the magnitude of magnetization in a sine wave shape with respect to the rotation direction of the rotor. The detection magnetic field generating unit is magnetized so that the change in the magnitude of the magnetization in the rotation direction of the rotor becomes a rectangular wave.

With this configuration, the following operation is obtained.

(1) Magnetization is performed such that the change in the magnitude of the magnetization of the drive magnetic field generating section becomes sinusoidal with respect to the rotational direction of the rotor, and the change in the magnitude of the magnetization of the detection magnetic field generator is rectangular. As a result, the magnetic field generated in the stator and thereby the torque generated between the stator and the magnet of the rotor become smooth, and the change in the magnitude of the magnetization of the detection magnetic field generating portion is a rectangular wave. For this reason, the change in the magnitude of the magnetization of the detection magnetic field generation unit changes sharply at the change point of the magnetization polarity, and the magnetic pole position sensor can accurately detect the magnetic pole position.

(2) The so-called torque ripple such as cogging is reduced by smoothing the torque generated between the stator and the magnet of the rotor, and the torque during rotation approaches a constant value. And the vibration noise is also reduced.

(3) Since the magnetic pole position sensor accurately detects the magnetic pole position, the phase switching timing of the drive current supplied to the stator can be accurately synchronized with the rotation of the rotor. Operational efficiency is improved and step-out is prevented.

According to a third aspect of the present invention, there is provided the brushless motor according to the first or second aspect, wherein the detection magnetic field generation unit includes a groove formed at a boundary where the polarity of each magnetization is inverted. This is a configuration provided with.

With this configuration, the following operation can be obtained.

(1) Since the groove is formed at the boundary where the polarity of the magnetization of the detection magnetic field generation section is reversed, the magnetic pole is formed at the position where the polarity of the magnetization of the detection magnetic field generation section is reversed with the groove interposed therebetween. It is possible to perform stable rectangular wave magnetization, reduce the size of the detection magnetic field generation unit, and increase the intensity of magnetization of the detection magnetic field generation unit.

(2) Since the detection magnetic field generator can be reduced in size, the brushless motor can be made compact.

(3) Since the intensity of the magnetization of the detection magnetic field generating section can be increased, the magnetic pole position with a small timing shift can be detected.

(4) Since the position of the groove is mechanically determined, the magnetic pole position is prevented from being shifted when the detected magnetic field generator is magnetized.

(5) The magnet can be mechanically strongly fixed to the rotor using the groove, and it is possible to prevent the magnet and the rotor from slipping during rotation.

According to a fourth aspect of the present invention, there is provided the brushless motor according to the third aspect, wherein the rotor includes a fixing portion that fits into the groove of the detection magnetic field generating portion and fixes the magnet. It is what it was.

According to this configuration, the rotor is mechanically strongly fixed to the groove of the magnet, so that an effect of preventing the magnet and the rotor from slipping during rotation can be obtained.

According to a fifth aspect of the present invention, there is provided the brushless motor according to any one of the first to fourth aspects, wherein the detection magnetic field generating section has a magnetization in a direction parallel to the rotation axis of the rotor. It is configured to be magnetized so as to face.

With this configuration, the following operation can be obtained.

(1) The magnetic pole position sensor detects the position of the rotor by detecting the magnetic field generated from the end face perpendicular to the rotation axis of the detected magnetic field generating section of the magnet. The amount of interference with the magnetic field generated from the detection magnetic field generation unit is small, and the change in polarity of the magnetic field generated from the detection magnetic field generation unit can be captured sharply. As a result, it is possible to detect the magnetic pole position with little timing deviation.

(2) Since the magnetic field generated by the detection magnetic field generator is in a direction parallel to the rotation axis of the rotor, the magnetic pole position sensor does not need to be arranged side by side with the stator. And the structure of the brushless motor can be made compact.

According to a sixth aspect of the present invention, there is provided the brushless motor according to any one of the first to fifth aspects, wherein the magnet includes the detection magnetic field generation unit and the drive magnetic field generation unit. It is configured to be constituted by a combination of different magnets.

With this configuration, the following operation is obtained.

(1) Since the detection magnetic field generator and the drive magnetic field generator are composed of different magnet combinations,
The magnets constituting the detection magnetic field generation unit can perform the optimum magnetic pole arrangement for position detection regardless of the magnetic pole positions of the magnets forming the drive magnetic field generation unit.

(2) A magnet suitable for the driving magnetic field generating unit and a magnet which easily magnetizes a sine wave, and a magnet suitable for the driving magnetic field generating unit and a square wave magnetizing shaft or a shaft are used. It is possible to select a magnet which is easy to be magnetized in the parallel direction.

According to a seventh aspect of the present invention, there is provided the brushless motor according to any one of the first to sixth aspects, wherein the detection field generating portion of the magnet is divided into a plurality in the circumferential direction. And a magnet assembly formed as described above.

With this configuration, the following operation is obtained.

(1) It is extremely easy to generate a strong rectangular-wave-shaped magnetization distribution in the detection magnetic field generation section, and this makes it possible to detect a magnetic pole position that is stable and has little timing deviation.

According to an eighth aspect of the present invention, in the brushless motor according to any one of the first to fifth aspects, the detection magnetic field generation unit and the drive magnetic field generation unit are integrated with the magnet. Is formed.

With this configuration, the following operation is obtained.

(1) Since the magnet is integrally formed, it is possible to reduce a tolerance generated at the time of assembling the brushless motor.

(2) Since the magnet is integrally formed, the workability in assembling the brushless motor is improved, and the number of parts is reduced, so that the economy is excellent.

According to a ninth aspect of the present invention, there is provided a pump, which is rotationally driven by a pump chamber and a rotor of the brushless motor according to any one of the first to eighth aspects, and imparts momentum to liquid in the pump chamber to form a flow. And a pressurizing section that performs the pressure control.

With this configuration, the following operation can be obtained.

(1) Since the pressurizing section is driven by the brushless motor according to any one of claims 1 to 8, fluctuations in the number of revolutions of the pump are small, pulsation is prevented, vibration noise is small, and operation efficiency is low. And step-out during operation of the pump is prevented.

According to a tenth aspect of the present invention, there is provided the pump according to the ninth aspect, wherein the rotor is formed in an annular shape, and the pressurizing portion is disposed in the annular portion of the rotor. It is what it was.

With this configuration, the following operation can be obtained.

(1) The space for accommodating the brushless motor can be reduced, and the pump can be made compact.

An eleventh aspect of the present invention is the pump according to the ninth or tenth aspect, further comprising a waterproof partition wall provided between the rotor and the magnetic pole position sensor. It is to be waterproofed by a waterproof partition wall.

With this configuration, the following operation is obtained.

(1) Since the magnetic pole position sensor is waterproof, the magnetic pole position sensor does not deteriorate due to corrosion, electric leakage, or the like.

According to a twelfth aspect of the present invention, there is provided the pump according to any one of the ninth to eleventh aspects, wherein the pressurizing portion includes a rotor support shaft disposed coaxially with the rotor. A suction side is formed in a cylindrical shape, and a discharge side is formed by expanding from a center portion toward a discharge side end, and is rotatably supported on a rotor support shaft, and is coaxial with the inner shroud outside the inner shroud. And an outer shroud fixed to the inner shroud, and a blade provided between the outer shroud and the inner shroud.

With this configuration, the following operation is obtained.

(1) The blade is rotated by the rotation of the inner shroud and the outer shroud, and the liquid in the pump chamber is accelerated by the blade and sent to the discharge side.
Furthermore, since the inner shroud and the outer shroud are formed so that the discharge side is expanded, the liquid sent to the discharge side is further accelerated by centrifugal force and discharged.

(2) Fluctuations in the number of revolutions of the pump are small, pulsation is prevented, vibration noise is small, and operation efficiency is high.

A magnetizing method for a brushless motor according to a thirteenth aspect of the present invention is directed to a rotor having a stator which generates a rotating magnetic field by applying a driving current, and a magnet which is rotationally driven by the rotating magnetic field generated by the stator. And a magnetic pole position sensor for detecting the rotational position of the rotor by detecting a magnetic field generated by the rotor, comprising: a magnetizing method for a magnet of a brushless motor, comprising: a detected magnetic field generating unit formed at one end of the magnet. On the outer side wall of
A magnetic field in which the polarity is reversed in the form of a rectangular wave with respect to the rotation direction of the magnet is applied in the radial direction of the magnet, and the outer peripheral side wall of the drive magnetic field generation part, which is a part other than the detection magnetic field generation part of the magnet, Magnetization is performed by applying a magnetic field whose polarity is inverted in a sine wave shape with respect to the rotation direction.

With this configuration, the following operation is obtained.

The detection magnetic field generation unit is magnetized with magnetization whose polarity is reversed in a rectangular wave shape with respect to the rotation direction of the magnet and which is oriented in the radial direction of the magnet. In addition, magnetization is inverted on the outer peripheral side wall of the driving magnetic field generating portion in a sine wave shape with respect to the rotating direction of the magnet and is directed in the radial direction of the magnet. As a result, in the detection magnetic field generation unit, the magnetization oriented in the radial direction of the magnet such that the change in the magnitude of the magnetization is reversed in a rectangular wave shape with respect to the rotation direction is magnetized, and the magnitude of the magnetization is applied to the drive magnetic field generation unit. This makes it possible to manufacture a magnet of a brushless motor in which the magnetization in the radial direction of the magnet is magnetized such that the change in the polarity is reversed in a sinusoidal manner with respect to the rotation direction.

A magnetizing method for a brushless motor according to a fourteenth aspect of the present invention is directed to a rotor having a stator that generates a rotating magnetic field by applying a driving current and a magnet that is rotated by the rotating magnetic field generated by the stator. And a magnetic pole position sensor for detecting the rotational position of the rotor by detecting a magnetic field generated by the rotor, comprising: a magnetizing method for a magnet of a brushless motor, comprising: a detected magnetic field generating unit formed at one end of the magnet. On the outer side wall of
A magnetic field whose polarity is reversed in the form of a rectangular wave with respect to the rotation direction of the magnet is applied in a direction parallel to the rotation axis of the magnet, and the radius of the magnet is applied to the outer peripheral side wall of the drive magnetic field generation part other than the detection field generation part of the magnet. Magnetization is performed by applying a magnetic field whose polarity is inverted in a sine wave shape with respect to the rotation direction of the magnet in the direction.

With this configuration, the following operation is obtained.

The detection magnetic field generation unit is magnetized with magnetization whose polarity is reversed in a rectangular wave shape with respect to the rotation direction of the magnet and which is oriented in a direction parallel to the rotation axis direction of the magnet. In addition, magnetization is inverted on the outer peripheral side wall of the driving magnetic field generating portion in a sine wave shape with respect to the rotating direction of the magnet and is directed in the radial direction of the magnet. As a result, the detection magnetic field generation section is magnetized with the magnetization oriented in a direction parallel to the rotation axis direction of the magnet such that the change in the magnitude of the magnetization is reversed in a rectangular wave shape with respect to the rotation direction. It is possible to manufacture a magnet of a brushless motor in which magnetization in a radial direction of the magnet is magnetized such that a change in the magnitude of the magnetization is reversed in a sine wave shape with respect to the rotation direction in the portion.

An embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a side view of a main part of a brushless motor according to Embodiment 1 of the present invention and a pump using the same in Embodiment 1 of the present invention.

In FIG. 1, 1 is a pump, 2 is a pump 1
2a is a water supply side casing constituting a rear part of the casing 2, 2a 'is a rear end part of the water supply side casing 2a, and 2b is engaged with a front part of the water supply side casing 2a to constitute a central part of the casing 2. Central casing, 2
The fitting part b ′ is formed at the front end of the central casing 2b and is fitted inside the rear end 2a ′ to connect the water supply casing 2a and the central casing 2b.
c is an inflow-side casing which is engaged with a front portion of the central casing 2b and constitutes a front portion of the casing 2; 3 is a suction joint formed of a hollow tubular body projecting from the center of the front side surface of the inflow-side casing 2c; An O-ring housing groove formed in a groove shape over the entire circumference on the outer wall near the rear end of the suction joint 3, and a hollow tubular member 4 is formed coaxially with the suction joint 3 at the center of the rear side surface of the water supply side casing 2 a. A discharge joint 5 formed of a body has an inflow chamber formed in the shape of a bulged column near the center of the front part in the casing 2 and communicates with the suction joint 3, and 6 has an inflow chamber formed in the rear part of the casing 2 and A water supply chamber communicating with the discharge joint 4,
Reference numeral 7 denotes a rotor storage chamber which is formed at the center of the casing 2 so as to surround the inflow chamber 5 and communicates with the water supply chamber 6. Reference numeral 8 denotes the suction joint 3 and the rotor storage chamber 7 from the front to the center of the casing 2. A drive circuit storage room formed around
Reference numeral 9 denotes a waterproof bulkhead in which the water supply chamber 6 and the rotor storage chamber 7 are separated from the drive circuit storage chamber 8 and whose outer end is continuously connected to the inside of the rear end of the central casing 2b. An inflow-chamber partition 10 ′ is provided at a front end of the inflow-chamber partition 10 and separates the inflow chamber 5 from the rotor storage chamber 7. An O-ring 12 is inserted between the end 2a 'and the fitting portion 2b', and an O-ring 12 is installed in the O-ring receiving groove 3a. The inner wall of the inflow chamber partition 10 is a rotating curved surface having the central axis L of the suction joint 3 and the discharge joint 4 as a rotation axis, and is formed to extend in a curved manner from the front end to the rear end. The drive circuit storage chamber 8 is isolated from the inflow chamber 5 and the water supply chamber 6 by a waterproof partition wall 9 and O-rings 11 and 12 provided at both ends thereof, and is waterproofed.

Reference numeral 13 denotes a columnar rotor support shaft fixedly provided coaxially with the center axis L from the inflow chamber 5 to the water supply chamber 6.
Is a fitting portion formed in a D-cut shape at the front end of the rotor support shaft 13; 14 is a suction-side support member disposed coaxially with the central axis L in the inflow chamber 5 and fixed to the inflow chamber partition 10; 14a is a thrust surface formed in a flat shape on the rear side surface of the suction side support 14, 14b is a D-cut fitting hole formed in the rear end surface of the suction side support 14 and fitted with the fitting portion 13a, Reference numeral 15 denotes a volute for fixing the pressure of the discharged flow, which is fixed at the center of the rear inner surface of the water supply side casing 2a, is formed around the periphery, and returns so that water can flow freely from the water supply chamber 6 to the discharge joint 4. A flow path is formed on the back side, and is a discharge-side support in which the rear end of the inflow chamber 5 is supported at the center.

The side surface of the suction-side support 14 is a rotary curved surface having the central axis L as a rotation axis, and is formed so as to expand in a bulging manner from the front end to the rear end, and the rear end surface is formed in a flat shape. Further, the rotor support shaft 13 is fixed on the center axis L by a front end supported by the fitting hole 14 a and a rear end supported by the discharge-side support 15.

Reference numeral 16 denotes a cylindrical thrust bearing supported at the center of the rotor support shaft 13, 17 denotes a rotor rotatably supported by the thrust bearing 16, and 18 denotes a thrust bearing 16 having a front portion 18a formed in a cylindrical shape. The inner shroud 19 is rotatably fitted to the inner shroud 18. The inner shroud 18 is formed so that the rear portion 18 b extends in a funnel shape from the center toward the rear end in the expanding direction (diagonal flow direction or centrifugal direction). An outer shroud 19a fixed to the inner shroud on the outside coaxially with a certain distance coaxially with the inner shroud 18 surrounds the outer wall of the inflow chamber partition wall 10 at a certain distance and is formed in a cylindrical shape coaxial with the central axis L. The front portion of the outer shroud 19, 19 b is a flange portion of the outer shroud 19 protruding outward from the front end of the outer shroud 19 in a flange shape, and 19 c is inside the inner shroud 18. The rear parallel portion of the outer shroud 19, which is fixed to the inner shroud 18 so as to surround the vicinity of the portion and is formed in a cylindrical shape coaxial with the central axis L, 19d expands toward the rear end side and expands to the outer surface of the rear portion 18b. A rear end portion 20a of the outer shroud 19 fixed to the rear portion 18b so as to surround it in parallel, and an axial pump chamber formed in an annular shape coaxial with the central axis L between the front portion 18a and the rear parallel portion 19c. , 20
b is an annularly formed centrifugal pump chamber (hereinafter, referred to as a centrifuge, which is used in a broad sense including a mixed flow) that extends rearward and outward between the rear portion 18b and the rear end portion 19d; Reference numeral 21 denotes a cylindrical magnet which is mounted outside the outer shroud 19 and generates a magnetic field used for rotationally driving the rotor 17. Reference numeral 21 a denotes a detection magnetic field generator located at the front end of the magnet 21 and used for detecting a magnetic pole position; Reference numeral 21b denotes a driving magnetic field generation unit located from the center to the rear of the magnet 21 and used for generating a magnetic field for rotational driving.

Inner shroud 18 and outer shroud 1
9 and a blade (described later) constitute a pressurizing section of the pump 1 which gives momentum to water in the pump 1 and forms a water flow. Also, the inner shroud 18, the outer shroud 19, the magnet 2
Reference numeral 1 denotes a rotor 17, which is integrally formed with a rotor support shaft 13
Rotate around. A plurality of blades are protrudingly provided on the inner surface of the casing 20 of the rear parallel portion 19c and the rear end portion 19d. When the rotor 17 rotates, the blades (hereinafter referred to as axial flow) in the axial pump chamber 20a are provided. The water flows from the inflow chamber 5 to the centrifugal pump chamber 20b while rotating. Further, the rotation of the blades (hereinafter, referred to as centrifugal blades) in the centrifugal pump chamber 20b accelerates the water flow from the axial flow pump chamber 20a to the water supply chamber 6 while rotating in the centrifugal pump chamber 20b, and also performs centrifugation. Since the pump chamber 20b is formed in a funnel shape that expands from the front to the rear, the water flow from the axial pump chamber 20a to the water supply chamber 6 while rotating is further accelerated by centrifugal force. That is, the pump 1 is a fugal pump that uses a blade that rotates by the rotation of the rotor 17 to absorb water from the front side of the axial pump chamber 20a and discharge the water in the centrifugal direction from the rear side of the centrifugal pump chamber 20b. The centrifugal direction has a broad meaning including a diagonal flow. The water flow discharged from the rotor 17 is recovered in pressure by a volute formed around the discharge-side support 15, returns in the centripetal direction, flows through the flow path, and flows out of the discharge joint 4.

Reference numeral 22 denotes a stator which is disposed inside the driving circuit storage room 8 around the magnet 21 and generates a driving magnetic field for driving the magnet 21 to rotate.
A magnetic pole position sensor disposed inside the drive circuit storage chamber 8 near the outside of 1a to detect the rotational position of the rotor 17 by detecting the magnetic field of the detection magnetic field generation unit 21a. A circuit board that is provided and controls a drive current that flows through the stator 22 based on the rotational position of the rotor 17 detected by the magnetic pole position sensor 23.

A brushless motor is constituted by the magnet 21 and the stator 22. When a driving current for switching the phase is applied to the stator 22, a rotating magnetic field is generated on the inner peripheral side of the stator 22. The magnet 21 is driven to rotate by the magnetic force. The phase switching of the drive current is performed by the circuit board 24. Also,
As the magnetic pole position sensor 23, a Hall element or the like is used.

In the first embodiment, the brushless motor and the pump of the present invention will be described together with the brushless motor and the pump of the present invention. The brushless motor is not limited to one applied to a pump.

FIG. 2 is a perspective view of the outer shroud of the pump of FIG.

In FIG. 2, 19 is an outer shroud, 1
9a is a front portion, 19b is a flange portion, 19c is a rear parallel portion, 1
Reference numeral 9d denotes a rear end portion, which are the same as those in FIG. 1 and are denoted by the same reference numerals and description thereof is omitted.

Reference numeral 30 denotes a rear parallel part 1 of the outer shroud 19.
A plurality of blades are provided spirally (screw shape) from 9c to the rear end portion 19d, and 30a is an axial flow blade which is a portion located in the rear parallel portion 19c of the blade 30;
Reference numeral 0b denotes a centrifugal blade which is a portion located inside the rear end 19d of the blade 30.

FIG. 3A is a sectional view taken along the central axis of a magnet mounted on the rotor of the brushless motor of the first embodiment provided in the pump of FIG. 1, and FIG. FIG. 3C is a front side view of the magnet of FIG.
FIG. 4 is a rear side view of the magnet of FIG.

FIGS. 3A to 3C show a double concentric arrangement as the arrangement of the magnetic poles of the magnet. However, the magnets shown in FIGS. It is good also as a shape arrangement.

FIG. 3D is a sectional view taken along the central axis of the magnet mounted on the rotor of the brushless motor according to the first embodiment provided in the pump of FIG. 1 when the magnet is arranged in a circumferential shape. 3 (e) is a front side view of the magnet of FIG. 3 (d), and FIG. 3 (f) is a rear side view of the magnet of FIG. 3 (d).

In FIG. 3, 21 is a magnet, 21a
Denotes a detection magnetic field generation unit, and 21b denotes a drive magnetic field generation unit, which are the same as those in FIG. 1 and are denoted by the same reference numerals and description thereof is omitted.

The detection magnetic field generation section 21a and the drive magnetic field generation section 21b are divided into four magnetic domains 21a at equal intervals along the circumferential direction.
-1 to 21a-4 and 21b-1 to 21b-4 are formed, and the magnetic domain of the adjacent detection magnetic field generation unit 21a and the magnetic domain of the drive magnetic field generation unit 21b are the same in the circumferential direction. It has polarity. Magnetic domains 21a-1 to 21a-4,
Each of 21b-1 to 21b-4 is magnetized so that its magnetization is oriented in the radial direction, and the outer surfaces of the detection magnetic field generation unit 21a and the drive magnetic field generation unit 21b have a direction substantially perpendicular to each outer surface. , A magnetic field is formed.

The detection magnetic field generation section 21a is connected to each magnetic domain 21a-
1 to 21a-4 are magnetized so that the magnitude of magnetization changes in a rectangular wave shape along the circumferential direction (hereinafter, this is referred to as rectangular wave magnetization). Each of the magnetic domains 21b-1 to 21b-4 differs in that the magnetization is magnetized so that the magnitude of the magnetization changes in a sine wave shape along the circumferential direction (hereinafter, this is called sine wave magnetization). That is, each of the magnetic domains 21a-1 to 21a of the detection magnetic field generation unit 21a.
At the boundary of −4, the magnitude of the magnetization changes sharply from positive to negative with respect to the circumferential direction, whereas at the boundary of each of the magnetic domains 21b-1 to 21b-4 of the driving magnetic field generating unit 21b, the magnitude of the magnetization is Changes slowly from positive to negative in a sinusoidal manner in the circumferential direction.

In this embodiment, as an example, a case is shown in which the magnet 21 is divided into four magnetic domains in the circumferential direction. However, the number of magnetic domains is not limited to four. Absent.

The driving magnetic field generating section 21b is an area of the magnet 21 that generates a magnetic field used for rotational driving, and the detection magnetic field generating section 21a is an area of the magnet 21 that generates a magnetic field used for detecting a magnetic pole position. is there. Conventionally, in order to obtain a strong magnetic field in manufacturing a magnet, the driving magnetic field generating portion 21b for generating a magnetic field for rotational driving is often manufactured as a split magnet, and is arranged and fixed on a concentric circle when incorporated in the rotor 17. However, due to the development of magnet materials and the development of new magnetizing methods, in recent years, the number of magnets 21 of the rotor 17 has increased. In the first embodiment, the detection magnetic field generation unit 21a
And the drive magnetic field generation unit 21b are configured as an integral magnet 21 and perform magnetization with different magnetic force characteristics at the time of magnetization, and as a result, are used for the magnetic field used for rotational drive and the magnetic pole position detection. And a magnetic field.

In forming the detection magnetic field generator 21a and the drive magnetic field generator 21b, the drive magnetic field generator 2a
The rotation drive magnet 1b and the magnetic pole position detection magnet 21a may be divided into two parts and magnetized separately. Further, the magnetic pole position detection magnet constituting the detection magnetic field generation unit 21a is further divided into sections of magnetic domains 21a-1 to 21a-4, and each is separately magnetized, or
Similarly, it may be configured as an aggregate of fan-shaped magnets that are magnetized.

FIG. 4A is a diagram showing a change in the magnetic force of the magnet of FIG. 3 along the circumferential direction, and FIG.
It is an enlarged view of the section near the change point of magnetization polarity of (a).

In FIG. 4, the vertical axis represents the magnitude of the relative magnetic force when the maximum magnetic force is set to 1 (hereinafter referred to as relative magnetic force intensity), and the horizontal axis represents the rotation angle of the rotor 17.

Line A is a sine-wave magnetized detection magnetic field generator 2
The line B represents the circumferential change of the magnetic force of the driving magnetic field generating unit 21b having the rectangular wave magnetized.

In FIG. 4, the change point of the magnetization polarity (FIG.
(A) rotation angles 0, 90, 180, 270, 360 degrees)
Attention is paid to the line A representing the magnetic force change in the case of rectangular wave magnetization.
The line B representing the change in the magnetic force of the sine wave magnetization has a gradual change as compared with. As shown in FIG. 1, the circuit board 24 detects the magnetic pole position by the magnetic pole position sensor 23 based on the magnetic field generated by the magnet 21, controls the energization of the winding of the stator 22 (controls the energized phase switching), and rotates the rotor 17. So
For the magnetic pole position sensor 23, the inclination of the magnetic force change at the change point of the magnetization polarity of the magnet 21 is very important.

[0109] In FIG. 4 (b), M ₁ is the hysteresis component of the detection sensitivity of the magnetic pole position sensor 23, showing a variation of the minimum necessary force for the magnetic pole position sensor 23 captures the change in the magnetization polarity. θ ₁ is the amount of displacement between the point of change of the magnetization polarity when the rectangular wave is magnetized and the point of change of the magnetization polarity actually detected by the magnetic pole position sensor 23, and the change in the magnetic force when the square wave is magnetized. corresponding to deviation amounts of the detected positions occurring for hysteresis component M ₁ to the line a representing the. θ ₂ is the amount of displacement between the point of change of the magnetization polarity when the sine wave is magnetized and the point of change of the magnetization polarity actually detected by the magnetic pole position sensor 23, and the change in the magnetic force when the sine wave is magnetized. corresponding to deviation amounts of the detected positions occurring for hysteresis component M ₁ to the line B representing the. clearly,
The deviation θ _{2 in} the case of the sine wave magnetization is larger than the deviation θ _{1 in} the case of the rectangular wave magnetization, and when the rotation position of the rotor 17 is detected by the magnetic pole position sensor 23, the detected magnetic field generating unit The detection accuracy is higher when rectangular wave magnetization is applied than when sine wave magnetization is applied to 21a. In particular, when the rotor 17 is driven at a high speed rotation, this deviation amount delays the timing of the switching of the conduction phase of the driving current flowing through the stator 22 for generating the rotating magnetic field from the optimal timing.
This causes the efficiency of the brushless motor to decrease. Therefore, in the brushless motor according to the first embodiment, the change of the magnetic force at the change point of the magnetization polarity of the detection magnetic field generation unit 21a that generates the magnetic field for detecting the position of the magnetic pole by the magnetic pole position sensor 23 is greatly increased. Accurate magnetic pole position detection and efficient operation are possible.

In the brushless motor according to the first embodiment, as shown by the line B in FIG. 4A, the driving magnetic field generating portion 21b for generating a magnetic field for obtaining the magnetic force for driving the rotor 17 has a sinusoidal shape. By performing the wave magnetization, cogging due to the magnetic effect of the salient poles of the stator 22 is reduced.
The torque ripple generated by the non-linearity of the magnetic force generated by the interaction between the magnetic field generated from the winding and the magnetization of the magnet 21 is reduced.

In the first embodiment, as an example, the case where the magnet is magnetized to four poles is shown. However, the number of magnetized poles is not limited to four. It may be an arbitrary even number of poles. The same applies to the following embodiments.

(Embodiment 2) FIG. 5 is a side view of a main part of a brushless motor according to Embodiment 2 of the present invention and a pump using the same in Embodiment 2 of the present invention.

In FIG. 5, 1 is a pump, 2 is a casing, 2a is a water supply side casing, 2a 'is a rear end portion, 2b
Is a central casing, 2b 'is a fitting part, 2c is an inflow side casing, 3 is a suction joint, 3a is an O-ring housing groove, 4 is a discharge joint, 5 is an inflow chamber, 6 is a water supply chamber, and 7 is a rotor storage chamber. , 8 is a drive circuit storage chamber, 9 is a waterproof partition, 10 is an inflow chamber partition, 10 'is a fitting part, 11 and 12 are O-rings, 13 is a rotor support shaft, 13a is a fitting part, and 14 is a suction side support. Body, 1
4a is a fitting hole, 15 is a discharge side support, 16 is a thrust bearing, 17 is a rotor, 18 is an inner shroud, 18a is a front part, 18b is a rear part, 19 is an outer shroud, 19a is a front part, and 19b is a flange. Part, 19c is a rear parallel part, 19d is a rear end part, 20a is an axial pump chamber, 20b is a centrifugal pump chamber,
21 is a magnet, 21a is a detection magnetic field generation unit, 21b is a drive magnetic field generation unit, 22 is a stator, L is a central axis,
Since these are the same as those in FIG. 1, the same reference numerals are given and the description is omitted.

Reference numeral 60 denotes a driving magnetic field generator 2 on the circuit board 24.
This is a magnetic pole position sensor including a magnetic sensing sensor such as a Hall element disposed at a position opposed to 1b. The magnetic pole position sensor 60 is particularly adapted to respond to a magnetic field in a direction parallel to the central axis L.

FIG. 6A is a sectional view taken along the center axis of a magnet mounted on the rotor of the brushless motor according to the second embodiment provided in the pump of FIG. 5, and FIG. 6 (a) is a front side view of the magnet, and FIG.
FIG. 7 is a rear side view of the magnet of FIG.

FIGS. 6A to 6C show a double concentric arrangement as the arrangement of the magnetic poles of the magnet, but the magnet has the circumference shown in FIGS. 6D to 6F. It is good also as a shape arrangement.

FIG. 6D is a sectional view taken along the central axis of the magnet mounted on the rotor of the brushless motor according to the first embodiment provided in the pump of FIG. 5 when the magnet is arranged in a circumferential shape. 6 (e) is a front side view of the magnet of FIG. 6 (d), and FIG. 6 (f) is a rear side view of the magnet of FIG. 6 (d).

In FIG. 6, 21 is a magnet, 21a
Is a detection magnetic field generation section, 21a-1 to 21a-4 are magnetic domains, 2
Numeral 1b denotes a driving magnetic field generator, and 21b-1 to 21b-4 denote magnetic domains, which are the same as those in FIG.

In the second embodiment, the detection magnetic field generation unit 21a is magnetized so that the magnetization is oriented in the direction along the central axis L, and the drive magnetic field generation unit 21b has the same radius as in the first embodiment. It is magnetized so that the magnetization is oriented in the direction.

The detection magnetic field generation section 21a is provided for each magnetic domain 21a-
1 to 21a-4 are magnetized with a rectangular wave, and in the drive magnetic field generator 21b, the magnetic domains 21b-1 to 21b-4 are magnetized with a sine wave. However, since the driving magnetic field generation unit 21b is magnetized so that the magnetization is oriented in the radial direction, the direction of the magnetic field on the outer surface of the driving magnetic field generation unit 21b is oriented in the radial direction. Are magnetized so that the magnetization is oriented in a direction parallel to the central axis L, the magnetic field on the outer surface of the detection magnetic field generation unit 21a is small, and the detection magnetic field generation unit 21
A strong magnetic field is generated at the end face 21a 'of FIG.

In this embodiment, as an example, a case is shown in which the magnet 21 is divided into four magnetic domains in the circumferential direction. However, the number of magnetic domains is not limited to four. Absent.

The drive magnetic field generator 21b is a region of the magnet 21 that generates a magnetic field used for rotational driving, and the detected magnetic field generator 21a is a region of the magnet 21 that generates a magnetic field used for magnetic pole position detection. is there. That is, the detection magnetic field generation unit 21a and the drive magnetic field generation unit 21b are configured as an integral magnet 21 and perform magnetization with different magnetic force characteristics during magnetization, and as a result, the magnetic field used for rotational drive And a magnetic field used for magnetic pole position detection.

In configuring the detection magnetic field generation unit 21a and the drive magnetic field generation unit 21b, the drive magnetic field generation unit 2a
The rotation drive magnet 1b and the magnetic pole position detection magnet 21a may be divided into two parts and magnetized separately. Further, the magnet for detecting the magnetic pole position, which constitutes the detection magnetic field generation unit 21a, is further divided into sections of magnetic domains 21a-1 to 21a-4, and is magnetized separately or in the same manner. May be configured as a set of magnets.

With this configuration, as in the first embodiment, the change in the magnetic force at the change point of the magnetization polarity of the detection magnetic field generation unit 21a that generates the magnetic field for detecting the position of the magnetic pole by the magnetic pole position sensor 60 is greatly and sharply increased. By doing so, accurate magnetic pole position detection, and eventually efficient operation is possible,
At the same time, the driving magnetic field generator 21b for generating a magnetic field for obtaining the magnetic force for driving the rotor 17 is sine-wave-magnetized to reduce the cogging due to the magnetic effect of the salient poles of the stator 22 and to reduce the winding of the stator 22. Thus, it is possible to reduce the ripple of the torque generated due to the nonlinearity of the magnetic force generated by the interaction between the generated magnetic field and the magnetization of the magnet 21.

In the present embodiment, the magnetic field generated by the detection magnetic field generator 21a is set in a direction parallel to the central axis L. Therefore, the magnetic pole position sensor 60 does not need to be arranged side by side with the stator 22. Stator 22 forward
Since it can be mounted on the circuit board 24 vertically arranged in the vertical direction, the configuration can be made compact.

(Embodiment 3) FIG. 7A is a perspective view of a magnet mounted on a rotor of a brushless motor according to Embodiment 3 of the present invention, and FIG. 7B is a perspective view of FIG. FIG. 7C is a cross-sectional view taken along the center axis of the magnet, and FIG. 7C is a side view of the magnet shown in FIG.

In FIG. 7, 21 is a magnet, 21a
Denotes a detection magnetic field generation unit, 21b denotes a drive magnetic field generation unit, and L denotes a central axis. These are the same as those in the first or second embodiment, and are denoted by the same reference numerals and description thereof is omitted.

21a 'is an end face of the detection magnetic field generation section 21a,
21c is a groove formed radially on the end face 21a 'at equal intervals in the radial direction with the center axis L as the center, and 17' is a rotor 17
This is a fixing portion for fixing the magnet 21 to the magnet. Fixed part 1
Reference numeral 7 'corresponds to the outer shroud 19 in FIG. 1 or FIG. The groove 21c is formed at the boundary where the polarity of magnetization reverses.

The end 17a 'of the fixing portion 17' is fitted in the groove 21c, and fixes the fixing portion 17 'to the magnet 21. Thus, by forming the groove 21c in the magnet 21, it is possible to prevent the magnet 21 and the fixed portion 17 'from slipping during rotation.

The groove 21c is provided in the detection magnetic field generation section 21a.
In order to act as a magnetic resistance when a rectangular wave is magnetized,
It is possible to easily perform rectangular wave magnetization on the detection magnetic field generation unit 21a.

(Embodiment 4) Next, a method of magnetizing a magnet mounted on a rotor of a brushless motor according to Embodiment 1 of the present invention will be described.

FIG. 8 is a perspective view of a magnet mounted on a rotor of a brushless motor and a magnetizing device therefor according to Embodiment 4 of the present invention.

In FIG. 8, 21 is a magnet, 21a
Denotes a detection magnetic field generation unit, and 21b denotes a drive magnetic field generation unit, which are the same as those in the first embodiment, and are denoted by the same reference numerals and description thereof is omitted.

Reference numeral 21c denotes a groove formed on the end face of the magnet 21 on the side of the detection magnetic field generation section 21a so as to be radial with the rotation axis of the magnet 21 as a center, so as to make the magnetization characteristics of the detection magnetic field generation section 21a rectangular. The groove 21c is formed to improve the rectangular wave magnetization, and the rate of change of the magnetization at the position where the magnetization polarity of the magnet 21 is reversed has sufficient detection accuracy as a magnetic field for detecting the magnetic pole position. This may not be necessary if a rate of change capable of producing a magnetic field capable of obtaining the following can be obtained.

Reference numeral 40 denotes a detection magnetization magnetizing device for magnetizing the detection magnetic field generation unit 21a, and 41 denotes a detection magnetization magnetization yoke which is made of a ferromagnetic material such as iron and through which a magnetic field for magnetization is passed. is there. The detection magnetization magnetizing yoke 41 includes a cylindrical outer cylinder 41a and a plurality of salient poles 4 protruding from the inner measuring section at equal intervals.
1b, and the detection magnetic field generating portion 21a can be inserted into a cylindrical space 43 surrounded by the respective salient pole portions 41b in the cylinder of the yoke 41 for detection magnetization magnetization. A connecting portion 41c in which the salient pole portion 41b is connected to the outer cylinder 41a is formed in a constricted shape, and a winding 42 is wound around each connecting portion 41c.

Reference numeral 50 denotes a drive magnetization magnetizing device for magnetizing the drive magnetic field generation unit 21b, and reference numeral 51 denotes a drive magnetization magnetization yoke which is made of a ferromagnetic material such as iron and passes a magnetic field for magnetization therein. is there. The drive magnetizing yoke 51 includes a cylindrical outer cylinder 51a, and a plurality of salient poles 5 protruding from the inner measuring section at equal intervals.
1b, and the driving magnetic field generating portion 21b can be inserted into the cylindrical space 53 surrounded by the salient pole portions 51b in the cylinder of the driving magnetization magnetizing yoke 51. A connecting portion 51c in which the salient pole portion 51b is connected to the outer cylinder 51a is formed in a constricted shape, and a winding 52 is wound around each connecting portion 51c.

In the detection magnetization magnetization device 40 and the drive magnetization magnetization device 50 configured as described above, the magnet 2
The method of magnetizing No. 1 will be described.

The detection magnetization magnetizing device 40 is provided with each salient pole portion 41b.
Gap 44 formed in the middle of the sensor and the detection magnetic field generation section 21a
Are arranged close to each other so that the position of each groove 21c is matched. In this state, a current is passed through the winding 42,
A magnetic field is generated in the winding 42. The magnetic flux is converged in the yoke 41 for detection magnetization magnetization having high magnetic permeability, and a strong magnetic field is applied to the detection magnetic field generation unit 21a from the inner surface of the salient pole part 41b facing the outer surface of the detection magnetic field generation unit 21a. The generator 21a is magnetized so that the magnetization is oriented in the radial direction. At this time, a magnetic flux in the opposite direction is generated from the salient pole portions 41b adjacent to each other with the gap portion 44 therebetween. This is because the winding direction of the winding 42 wound around the connecting portion 41c connected to the adjacent salient pole portion 41b adjacent to the gap portion 44 is the same, and the energizing direction is reversed, or This is performed by making the winding direction of the winding 42 wound around the connecting portion 41c connected to the salient pole portion 41b adjacent to the electrode 44 via the reverse direction opposite to that of the current supply direction. Thereby, on the inner surface of the salient pole portion 41b facing the outer surface of the detection magnetic field generation portion 21a,
In the circumferential direction, a rectangular wave-shaped magnetic field whose polarity is suddenly inverted is formed in the gap portion 44, and the detected magnetic field generating portion 21
a is magnetized with a rectangular wave.

On the other hand, the drive magnetization magnetizing device 50 is arranged by inserting the drive magnetic field generator 21b into the cylindrical space 53.
In this state, a current is applied to the winding 52 and the winding 5
A magnetic field is generated in 2. The magnetic flux is converged in the drive magnetization magnetizing yoke 51 having a high magnetic permeability, and the drive magnetic field generation unit 21b
A strong magnetic field is applied to the driving magnetic field generation unit 21b from the inner surface of the salient pole portion 51b facing the outer surface of the driving magnetic field generation unit 21b.
b is magnetized so that the magnetization is oriented in the radial direction. On this occasion,
A magnetic flux in the opposite direction is generated from each adjacent salient pole portion 51b. This is because the winding direction of the winding 52 wound around the connecting portion 51c connected to the adjacent salient pole portion 51b is the same and the energizing direction is reversed, or the connecting portion is connected to the adjacent salient pole portion 51b. This is performed by setting the winding direction of the winding 52 wound around the provided connecting portion 51c to the opposite direction and the same energizing direction. As a result, the end surface of the salient pole portion 51b facing the driving magnetic field generation portion 21b is provided with respect to the circumferential direction.
A magnetic field whose intensity and polarity changes in a sinusoidal manner is formed, and the driving magnetic field generator 21b is magnetized in a sinusoidal manner.

Here, the outer cylinder 51a and each connecting portion 51
c, in consideration of the magnetic resistance component of the magnetic flux path formed by the salient pole part 51b and the magnet 21 and the magnetic flux path in the magnet 21, the salient pole part 51b is so shaped as to perform sine wave magnetization on the drive magnetic field generating part 21b. Adjust the shape of.

In the above example, the windings 42 and 52
Although the method of exciting using a magnetic field is described above, a method using a permanent magnet as an excitation source may be used as long as a magnetic field for magnetizing can be obtained.

(Embodiment 5) Next, a method of magnetizing a magnet mounted on a rotor of a brushless motor according to Embodiment 2 of the present invention will be described.

FIG. 9 is a perspective view of a magnet mounted on a rotor of a brushless motor and a magnetizing device thereof according to a fifth embodiment of the present invention, and FIG.
FIG. 10B is a cross-sectional end view taken along the line arrow, and FIG.
FIG.

9 and 10, 21 is a magnet, 21a is a detection magnetic field generation unit, 21b is a drive magnetic field generation unit, 21c is a groove, 50 is a drive magnetization magnetizing device, 51 is a drive magnetization magnetization yoke, 51a Is an outer cylinder, 51b is a salient pole portion, 5
1c is a connecting portion, 52 is a winding, 53 is a columnar space,
Since these are the same as in the second embodiment, the same reference numerals are given and the description is omitted. Further, as in the case of the fourth embodiment, the groove 21c is formed to improve rectangular wave magnetization, and the rate of change of the magnetization at the position where the magnetization polarity of the magnet 21 is reversed is different from the magnetic pole position. This may not be necessary if a change rate capable of producing a magnetic field capable of obtaining sufficient detection accuracy as a magnetic field for detection can be obtained.

Reference numeral 70 denotes a detection magnetization magnetizing device for magnetizing the detection magnetic field generation unit 21a, and reference numeral 71 denotes a detection magnetization magnetization yoke made of a ferromagnetic material such as iron and for passing a magnetizing magnetic field therein. is there. The detection magnetization magnetizing yoke 71 has a short cylindrical base 71a serving as a base, and a plurality of radially straight grooves having a circular hole 71e at the center thereof, which is located opposite one end face of the base 71a. A magnetic field generating portion 71b divided into an arcuate ring having the same radius as the base portion 71a by a base portion 71c, and a cylindrical connecting portion 71d connecting the base portion 71a and each magnetic field generating portion 71b.
And is composed of Each detection magnetization magnetization yoke 71c of the detection magnetization magnetization yoke 71 is formed to have the same angle with respect to the circumferential direction as each groove 21c of the magnet 21 (see FIG. 10B). Reference numeral 72 denotes a winding wound around each connecting portion 71d of the yoke 71 for detecting magnetization magnetization. By passing a current for magnetization through the winding 72,
A magnetic field for magnetization is generated from the magnetic field generation unit 71b.

In the detection magnetizing device 70 and the driving magnetizing device 50 configured as described above, the magnet 2
The method of magnetizing No. 1 will be described.

The detection magnetizing device 70 includes a magnetic field generating section 71.
The detection magnetizing yokes 71c formed in b and the grooves 21c of the detection magnetic field generator 21a are arranged close to each other so that the positions thereof match. In this state, a current is supplied to the winding 72 to generate a magnetic field in the winding 72. The magnetic flux is focused in the yoke 71 for detection magnetization magnetization having high magnetic permeability,
A strong magnetic field is applied to the detection magnetic field generation unit 21a from the end face of the magnetic field generation unit 71b facing the detection magnetic field generation unit 21a, and the detection magnetic field generation unit 21a is magnetized. At this time, a magnetic flux in the opposite direction is generated from the magnetic field generation unit 71b adjacent to the detection magnetization magnetization yoke 71c. This is because the magnetic field generation units 7 adjacent to each other with the detection magnetization magnetization yoke 71c interposed therebetween.
1b, the winding direction of the winding 72 wound around the connecting portion 71d is the same, and the energizing direction is opposite, or
A winding 7 wound around a connecting portion 71d connected to a magnetic field generating portion 71b adjacent to the detection magnetizing yoke 71c.
This is performed by making the winding direction of 2 opposite and making the energizing direction the same. As a result, on the end face of the magnetic field generating section 71b opposed to the detected magnetic field generating section 21a, a rectangular wave-shaped magnetic field whose polarity is rapidly reversed in the detection magnetization magnetizing yoke 71c is formed in the circumferential direction. Magnetic field generator 2
1a is rectangular-wave-magnetized such that the magnetization is directed in a direction parallel to the central axis L.

The magnetization of the drive magnetic field generator 21b by the drive magnetization magnetizing device 50 is the same as that of the fourth embodiment, and the description is omitted.

In the above example, the winding 72 and the winding 52
Although the method of exciting using a magnetic field is described above, a method using a permanent magnet as an excitation source may be used as long as a magnetic field for magnetizing can be obtained.

[0150]

As described above, according to the brushless motor of the present invention, the following advantageous effects can be obtained.

According to the first aspect of the present invention, (1) the so-called torque ripple such as cogging is reduced by smoothing the torque generated between the stator and the magnet of the rotor, and Since the torque approaches a constant value, it is possible to provide a brushless motor with less fluctuation in the number of revolutions and less vibration noise.

(2) Since the magnetic pole position sensor accurately detects the magnetic pole position, the phase switching timing of the drive current to be supplied to the stator can be accurately synchronized with the rotation of the rotor, and the operating efficiency can be improved. It is possible to provide a brushless motor that is excellent and in which step-out is prevented.

According to the second aspect of the present invention, (1) a brushless motor having a small fluctuation in the number of revolutions and a small vibration noise due to a smooth torque generated between the stator and the magnet of the rotor. Can be provided.

(2) Since the magnetic pole position is accurately detected by the magnetic pole position sensor, the phase switching timing of the drive current to be supplied to the stator can be accurately synchronized with the rotation of the rotor, and the operating efficiency can be improved. It is possible to provide a brushless motor that is excellent and in which step-out is prevented.

According to the third aspect of the present invention, (1) Since the detection magnetic field generator can be downsized, it is possible to provide a brushless motor which can be made compact.

(2) Since the intensity of the magnetization of the detection magnetic field generation section can be increased, it is possible to provide a brushless motor capable of detecting a magnetic pole position with a small timing shift.

(3) Since the position of the groove is determined mechanically, the displacement of the magnetic pole position at the time of magnetization of the detection magnetic field generating portion is prevented, and a brushless motor having no magnetization error at the time of magnetization is provided. Can be provided.

(4) To provide a brushless motor capable of mechanically strongly fixing a magnet to a rotor by using a groove and preventing slippage between the magnet and the rotor during rotation. Can be.

According to the fourth aspect of the present invention, there is provided a brushless motor capable of preventing the magnet and the rotor from slipping during rotation since the rotor is mechanically strongly fixed in the groove of the magnet. can do.

According to the fifth aspect of the present invention, (1) the detection of the magnetic field from the driving magnetic field generation unit has a small amount of interference with the magnetic field generated from the magnetic field generation unit, and the polarity of the magnetic field generated from the detection magnetic field generation unit Changes can be captured sharply. Thereby, it is possible to provide a brushless motor capable of detecting the magnetic pole position with a small timing shift.

(2) A brushless motor can be provided which can be mounted on a circuit board disposed in front of the stator and perpendicular to the stator, so that the structure of the brushless motor can be made compact.

According to the sixth aspect of the present invention, (1) Since the detection magnetic field generation unit and the drive magnetic field generation unit are formed by a combination of different magnets, the magnets forming the detection magnetic field generation unit are driven It is possible to provide a brushless motor capable of performing an optimum magnetic pole arrangement for position detection regardless of the magnetic pole positions of the magnets constituting the magnetic field generating unit.

(2) A magnet suitable for the driving magnetic field generating unit and a magnet which easily magnetizes a sine wave, and a magnet suitable for the driving magnetic field generating unit and a rectangular wave magnetizing shaft or a shaft are used. It is possible to provide a brushless motor capable of selecting magnets that are easily magnetized in parallel directions.

According to the seventh aspect of the present invention, it is extremely easy to generate a strong rectangular wave-like magnetization distribution in the detection magnetic field generation section, and it is possible to detect a magnetic pole position with a small amount of timing deviation and stable. Can be provided.

According to the eighth aspect of the present invention, (1) Since the magnet is integrally formed, it is possible to reduce the tolerance generated at the time of assembling, and to easily obtain high assembling accuracy. A motor can be provided.

(2) Since the magnet is integrally formed, it is possible to provide a brushless motor which is excellent in workability at the time of assembling and economical because the number of parts is reduced.

Further, according to the pump of the present invention, the following advantageous effects can be obtained.

According to the ninth aspect of the present invention, since the pressurizing section is driven by the brushless motor according to any one of the first to eighth aspects, fluctuations in the number of revolutions of the pump are small and pulsation is prevented. , Low vibration noise, high operation efficiency,
Step-out during operation of the pump can be prevented and a pump can be provided.

According to the tenth aspect of the present invention, it is possible to provide a stable and highly efficient small pump with little pulsation.

According to the eleventh aspect of the present invention, since the magnetic pole position sensor is waterproof, the magnetic pole position sensor does not deteriorate due to corrosion, electric leakage, etc., and provides a stable and highly efficient pump with little pulsation. can do.

According to the twelfth aspect of the present invention, it is possible to provide a pump that has a small fluctuation in the number of revolutions of the pump, prevents pulsation, has low vibration noise, and has a high operating efficiency.

According to the magnetizing method of the magnet of the brushless motor of the present invention, the following advantageous effects can be obtained.

According to the thirteenth aspect of the present invention, the magnet is oriented in the radial direction of the magnet such that the change in the magnitude of the magnetization is reversed in a rectangular wave shape with respect to the rotation direction in the detection magnetic field generating portion. Manufacture of a brushless motor magnet that is magnetized and magnetized in a driving magnetic field generating portion and magnetized in a radial direction of a magnet such that a change in the magnitude of the magnetization is inverted in a sine wave shape with respect to the rotation direction. It is possible to provide a method of magnetizing a magnet of a brushless motor capable of performing the above.

According to the fourteenth aspect of the present invention, the detection magnetic field generating unit is configured so that the change in the magnitude of the magnetization is in a direction parallel to the rotation axis direction of the magnet such that the polarity is reversed in a rectangular wave shape with respect to the rotation direction. The brushless motor of the brushless motor in which the magnetized magnetic field is magnetized so that the magnetized magnetic field is magnetized such that the change in the magnitude of the magnetic field is inverted in a sine wave shape with respect to the rotational direction in the driving magnetic field generating section. A magnetizing method for a magnet of a brushless motor capable of manufacturing a magnet can be provided.

[Brief description of the drawings]

FIG. 1 is a side view of a main part of a brushless motor according to a first embodiment of the present invention and a pump using the brushless motor according to the first embodiment of the present invention;

FIG. 2 is a perspective view of the outer shroud of the pump of FIG. 1;

FIG. 3 (a) Embodiment 1 internally provided in the pump of FIG.
3 (b) is a front side view of the magnet shown in FIG. 3 (a), (c) is a rear side view of the magnet shown in FIG. 3 (a), and (d) is a magnet. FIG. 3D is a sectional view taken along a central axis of a magnet mounted on the rotor of the brushless motor according to the first embodiment provided in the pump of FIG. (F) Rear side view of the magnet of FIG. 3 (d)

4A is a diagram showing a change in magnetic force along the circumferential direction of the magnet of FIG. 3; FIG. 4B is an enlarged view of a section near a change point of the magnetization polarity in FIG. 4A;

FIG. 5 is a side view of a main part of a brushless motor according to a second embodiment of the present invention and a pump using the brushless motor according to the second embodiment of the present invention;

FIG. 6 (a) Embodiment 2 internally provided in the pump of FIG.
6 (a) is a front side view of the magnet of FIG. 6 (a), and (c) is a rear side view of the magnet of FIG. 6 (a). FIG. 6D is a sectional view taken along a central axis of a magnet mounted on the rotor of the brushless motor according to the first embodiment provided in the pump of FIG. (F) Rear side view of the magnet of FIG. 6 (d)

7A is a perspective view of a magnet mounted on a rotor of a brushless motor according to a third embodiment of the present invention. FIG. 7B is a cross-sectional view of the magnet shown in FIG. FIG. 3A is a side view of the magnet as viewed from the detection magnetic field generation unit side.

FIG. 8 is a perspective view of a magnet mounted on a rotor of a brushless motor and a magnetizing device thereof according to a fourth embodiment of the present invention.

FIG. 9 is a perspective view of a magnet mounted on a rotor of a brushless motor and a magnetizing device thereof according to a fifth embodiment of the present invention.

10A is a sectional end view taken along the line AA of FIG. 9; FIG. 10B is a sectional end view taken along the line BB of FIG. 9;

FIG. 11 is a fragmentary cross-sectional view of a brushless motor disclosed in Japanese Patent Publication No. A;

FIG. 12 is a schematic view showing a cross section perpendicular to a rotation axis of a general brushless motor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Pump 2 Casing 2a Water supply side casing 2a 'Rear end 2b Central part casing 2b' Fitting part 2c Inflow side casing 3 Suction joint 3a O-ring storage groove 4 Discharge joint 5 Inflow chamber 6 Water supply chamber 7 Rotor storage chamber 8 Drive Circuit storage room 9 Waterproof partition wall 10 Inflow chamber partition wall 10 'Fitting portion 11, 12 O-ring 13 Rotor support shaft 13a Fitting portion 14 Suction side support 14a Fitting hole 15 Discharge side support 16 Thrust bearing 17 Rotor 17' Fixed Part 17a 'end part 18 inner shroud 18a front part 18b rear part 19 outer shroud 19a front part 19b flange 19c rear parallel part 19d rear end 20a axial flow pump room 20b centrifugal pump room 21 magnet 21a detection magnetic field generation unit 21a' end surface 21a-1, 21a-2, 21a-3, 21a-4 Magnetic domain 21b Driving magnetic field Sections 21b-1, 21b-2, 21b-3, 21b-4 Magnetic domain 21c Groove 22 Stator 23 Magnetic pole position sensor 24 Circuit board 30 Blade 30a Axial blade 30b Centrifugal blade 40 Detected magnetizing device 41 Yoke for detecting magnetized magnetization 41a outer cylinder 41b salient pole part 41c connecting part 42 winding 43 columnar space 44 gap 50 driving magnetizing device 51 driving magnetizing yoke 51a outer cylinder 51b salient pole 51c connecting part 52 winding 53 cylindrical space Reference Signs List 60 Magnetic pole position sensor 70 Detected magnetizing device 71 Detected magnetizing yoke 71a Base 71b Magnetic field generating unit 71d Connecting unit 71e Circular hole 72 Winding L Central axis 101 Circuit board 102 Bracket 103 Rotor 104 Magnet 104a Frequency generator Magnet 104b Rotor magnet 105 Stator 05a winding 106 shaft 107 ball bearing 108 magnetic position sensor (Hall element) 110 magnet 111 stator 111a coil 111b field magnetic iron core 111c salient

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H02K 15/03 H02K 15/03 G 21/14 21/14 M (72) Inventor Yoichi Sukusato Yoichi Kadoma, Osaka Pref. 1006 F-term in Matsushita Electric Industrial Co., Ltd. (reference)

Claims (14)

[Claims] 1. A stator that generates a rotating magnetic field by applying a driving current, a rotor having a magnet that is driven to rotate by the rotating magnetic field generated by the stator, and a rotor formed by detecting a magnetic field generated by the rotor. A magnetic pole position sensor that detects a rotational position, a brushless motor including: a magnet, wherein the magnet is a detection magnetic field generating unit that is used to detect the rotational position of the magnetic pole position sensor;
A driving magnetic field generating unit used for generating a magnetic field for rotationally driving by the rotating magnetic field generated by the stator, wherein the detection magnetic field generating unit and the driving magnetic field generating unit are magnetized differently. A brushless motor. 2. The method according to claim 1, wherein the driving magnetic field generator is magnetized so that a change in the magnitude of magnetization becomes a sine wave with respect to the rotation direction of the rotor. 2. The brushless motor according to claim 1, wherein the magnetization is changed so that the change in the magnitude of the magnetization becomes a rectangular wave. 3. The brushless motor according to claim 1, wherein the detection magnetic field generation unit includes a groove formed at a boundary where the magnetization polarity is inverted. 4. The brushless motor according to claim 3, wherein the rotor includes a fixing portion that fits into the groove of the detection magnetic field generating portion and fixes the magnet. 5. The brushless motor according to claim 1, wherein the detection magnetic field generation unit is magnetized so that magnetization is directed in a direction parallel to a rotation axis of the rotor. . 6. The brushless motor according to claim 1, wherein the magnet includes a combination of magnets in which the detection magnetic field generation unit and the drive magnetic field generation unit are different. 7. The magnet according to claim 1, wherein the magnet is constituted by an assembly of magnets in which the detection magnetic field generating section is divided into a plurality in the circumferential direction. Brushless motor. 8. The brushless motor according to claim 1, wherein said detection magnetic field generation section and said drive magnetic field generation section are formed by an integral magnet. 9. A brushless motor according to any one of claims 1 to 8, comprising a pump chamber, and a pressurizing section which is rotationally driven by the rotor to apply momentum to the liquid in the pump chamber to form a flow. A pump characterized in that: 10. The pump according to claim 9, wherein said rotor is formed in an annular shape, and said pressurizing section is disposed inside the annular shape of said rotor. 11. The magnetic pole position sensor according to claim 9, further comprising a waterproof partition wall disposed between the rotor and the magnetic pole position sensor, wherein the magnetic pole position sensor is waterproofed by the waterproof partition wall. Pump. 12. The pressurizing section includes a rotor support shaft disposed coaxially with the rotor, a suction side formed in a cylindrical shape, and a discharge side formed by expanding from a center to a discharge side end. An inner shroud rotatably supported on the rotor support shaft,
An outer shroud fixed to the inner shroud coaxially with the inner shroud outside the inner shroud;
10. A blade provided between the outer shroud and the inner shroud.
A pump according to any one of claims 1 to 11. 13. A rotor having a stator for generating a rotating magnetic field by applying a driving current, a rotor having a magnet driven to rotate by the rotating magnetic field generated by the stator, and detecting a magnetic field generated by the rotor to generate a rotating magnetic field. A magnet pole position sensor for detecting a rotational position, the magnetizing method of a magnet of a brushless motor, comprising: a detection magnetic field generation unit formed at one end of the magnet; A magnetic field whose polarity is reversed in the form of a rectangular wave with respect to the rotation direction of the magnet is applied. A brushless mode characterized in that magnetization is performed by applying a magnetic field whose polarity is reversed in a sine wave Magnetizing method of the magnet. 14. A stator for generating a rotating magnetic field by applying a driving current, a rotor having a magnet driven to rotate by the rotating magnetic field generated by the stator, and detecting the magnetic field generated by the rotor to detect the rotation of the rotor. A magnet pole position sensor for detecting a rotation position, the magnetizing method of a magnet of a brushless motor, comprising: a detection magnetic field generating unit formed at one end of the magnet; A magnetic field whose polarity is inverted in a rectangular wave shape with respect to the rotation direction of the magnet in a desired direction, and on the outer peripheral side wall of the driving magnetic field generating portion which is a portion other than the detection magnetic field generating portion of the magnet, the radial direction of the magnet is used. The magnetizing device is characterized in that magnetization is performed by applying a magnetic field whose polarity is reversed in a sine wave shape with respect to the rotation direction of the magnet. Magnetizing method of the magnet of Resumota.