JP3414907B2 - motor - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an information device or
The present invention relates to a motor such as a brushless motor used in video / audio equipment.

[0002]

2. Description of the Related Art In recent years, brushless motors have been required to be compact and highly efficient, as information equipment or video / audio equipment have become smaller.

A conventional brushless motor will be described below.

FIG. 23 is a sectional view of a conventional inner rotor type brushless motor.

In FIG. 23, 101 is a cylindrical core having three salient poles, 102 is a coil, 103 is a magnet, 104 is a shaft, 105 is a frame case, 10
6 and 107 are bearings, and 108 is a circuit board on which electronic components are mounted.

As shown in FIG. 23, the inner cylindrical portion of the hollow cylindrical magnet 103 is inserted and fixed to the shaft 104,
One end of the shaft 104 is supported by a bearing 106 attached to the frame case 105, and the other end of the shaft is a bearing 107 attached to a bracket 109.
Is supported by the inner rotor of the double-supported structure. Shaft 104 rotatably held by bearings
The magnet 103 attached to the magnet 10 is magnetized to N and S2 poles, and the magnetic flux generated by energizing the coil 102 wound around the salient pole of the core 101 causes the magnet 10 to move.
3 rotates.

The salient poles of the core 101 are U-phase, V-phase, and
This is a three-phase winding structure that is a W-phase winding. The electronic circuits are energized and driven so that the phases of the induced voltages generated in the three phases are shifted by 120 °. That is, it is driven as a three-phase brushless motor.

[0008]

However, in the above-mentioned conventional structure, the downsizing of equipment has progressed, and a brushless motor having a small size and high efficiency has been demanded today. First, the inner rotor type. In the case of the brushless motor, the volume efficiency of the motor tends to be not so good. The reason will be described below.

FIG. 24A is a simplified sectional view of a magnetic circuit of an inner rotor type brushless motor. FIG. 24B is a diagram showing the motor developed from the inside of the core. The following describes this figure. In the following, for the sake of simplicity, the leakage of magnetic flux will be ignored.

The reciprocal of the speed fluctuation rate μ is often used as a value representing the efficiency η of the motor, and the speed fluctuation rate μ generally has a relation as shown in (Equation 101).

[0011]

[Equation 101]

Here, Φ is the effective magnetic flux of the core, T is the number of coil turns, and R is the coil resistance.

Here, the effective magnetic flux Φ of the core is (Equation 102)
It is expressed as.

[0014]

[Equation 102]

Here, D is the rotor outer diameter, L is the rotor length, and Bg is the magnetic flux density of the gap.

Here, the gap magnetic flux density Bg is (equation 10)
3).

[0017]

[Equation 103]

Here, Br and μr are called residual magnetic flux density and recoil magnetic permeability, respectively, and are constants determined by the material of the magnet. Lm is the thickness of the magnet, and Lg is the air gap between the magnet and the core.

The number of coil turns T and the coil resistance R
The relationship is expressed as (Equation 104).

[0020]

[Equation 104]

Here, K is the proportionality constant determined by the conductivity of the coil and the space factor of the winding, l is the average length per turn of the coil, and S is the cross-sectional area of the coil. Also, this l
Is expressed as (Equation 105) when the R part of the coil is ignored.

[0022]

[Equation 105]

Here, Lc is the coil height and Dc is the coil width.

From the above, (Equation 101) (Equation 102),
Substituting (Equation 103), (Equation 104), and (Equation 105) for rearranging results in (Equation 106).

[0025]

[Equation 106]

This equation does not include the components of the coil resistance R and the number of coil turns T, and shows that the efficiency does not change due to the change of the winding specification.

When other variables are fixed in this equation and L and D are changed so that the rotor volume {πD ² L / 4} becomes constant, rotor length / diameter {L / D} and efficiency The relationship of η is as shown in FIG. According to FIG. 25, the longer the rotor is, the better the efficiency is, but the curve becomes gentle and converges to a certain value.

Secondly, in order to output a torque equal to or more than a predetermined value, the number of turns of the coil wound around the salient pole must be increased, and the protrusion amount of the salient pole becomes large. There is a problem that the diameter becomes large and it becomes difficult to downsize the motor.

Thirdly, in the above-mentioned conventional structure, it is necessary to dispose the cores in which the coil winding salient poles are arranged at equal intervals around the inner rotor, and the cross-sectional shape of the motor is circular or close thereto. Therefore, there is a problem that it becomes difficult to make the motor thinner.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a motor which is efficient, can be made small and thin, and has a high degree of freedom in mounting on equipment.

[0031]

In order to achieve the above-mentioned object, a motor of the present invention comprises K magnets (K is an integer of 2 or more) in which N and S poles are alternately magnetized in the circumferential direction. A central rotation shaft that stacks K magnets in K stages in the axial direction and integrally holds them, and a core having K-stage coil winding salient poles corresponding to each magnet are provided.
The magnetized position of the S pole and the relative position of the coil winding salient pole are displaced from each other in the circumferential direction, and the phase of the induced voltage generated in the coil winding salient pole of each stage is only one phase, and the phase is It is characterized in that it is set to have a phase suitable for rotating magnets in the same stage.

According to the present invention, the magnetic poles of the magnet and the coil winding salient poles of the core can be arranged in K stages in the motor axial direction. That is, as compared with the conventional example in which the magnetic poles of the magnet and the coil winding salient poles of the core are arranged and developed on the same plane, the present invention is dispersed on the plane of K stages developed in the motor axial direction. The magnetic poles and the coil winding salient poles of the core can be arranged, and as will be described later in detail, it is possible to provide a motor which is advantageous in terms of improved efficiency, downsizing, thinning, and freedom of attachment to a device.

[0033]

DETAILED DESCRIPTION OF THE INVENTION

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described.
A description will be given with reference to the drawings.

FIG. 1 is a sectional view of the brushless motor of the present invention. In FIG. 1, 1a, 1b, 1c are cylindrical cores having two salient poles 7a-7c, 2a, 2b, 2c are resin insulators 3a, 3b for insulating the cores.
3c is a coil wound around each core salient pole, 4a, 4b, 4c
Is a magnet having N and S2 magnetic poles, 5 is a spacer, 6 is a shaft (center rotation axis), 10 is a topped cylindrical frame case, 8 is a bracket, 9a and 9b are bearings,
Reference numeral 11 is a substrate for connecting terminals, and 12 is a terminal pin integrally fixed to the insulator.

As shown in FIG. 1, in the rotor portion, hollow cylindrical magnets 4a, 4b, 4c sandwich a spacer 5, and the inner cylindrical portion of each magnet 4a, 4b, 4c is inserted and fixed to a shaft 6, and the shaft 6 One end of 6 is supported by a bearing 9a attached to the frame case 10, and the other end of the shaft is a bearing 9b attached to the bracket 8.
It is an inner rotor with a double-sided support structure supported by.

The cores 1a, 1b, 1c are formed by stacking silicon steel plates in the thrust direction by press molding, and are insulated by resin insulators 2a, 2b, 2c. In addition, the insulators 2a, 2b, 2
The terminal pin 12 is integrally formed with c, and the winding start and the winding end of the coils 3a, 3b, and 3c are wound around the terminal pin 12 several times during coil winding, and by processing with solder, automation can be achieved. Making it easy.

The cores 1a, 1b and 1c are connected in series with three positioning pins formed by projecting a part of the insulators 2a to 2c as a reference, and are inserted and fixed in the inner circumference of the frame case 10 so that the terminal pins are fixed. Coil 3 in 12
A board 11 for connecting a, 3b and 3c is fixed by soldering.

A bracket 8 to which a bearing 9b is fixed is inserted and fixed in the opening of the frame case 10.

FIG. 2 is a diagram showing a magnetized state of the rotor magnet of the brushless motor.

Magnets 4a and 4 stacked in three stages
As shown in FIG. 2, b and 4c are magnetized so that the magnetized positions of the N and S poles are shifted by 120 ° in each stage.

FIG. 3 shows the magnets 4a, 4b and 4c.
It is the figure which represented typically the relationship of core 1a, 1b, 1c and coil 3a, 3b, 3c.

As shown in FIGS. 3 and 1, the cores 1a, 1
Corresponding ones of the salient poles 7a to 7c of b and 1c are arranged at the same circumferential position, and each of them is in a vertical line.
Coils 3a, 3b, 3 for the individual cores 1a, 1b, 1c
Reference character c is a single conductor continuously wound around both salient poles 7a to 7c in the same direction. The coils 3a, 3b, 3c in each stage
The winding directions of are the same as shown in FIG.

FIG. 4 shows the structure of the magnet 4a,
It is the figure which showed the waveform of the induced voltage which each coil generate | occur | produces when 4b and 4c rotate.

As shown in FIG. 4, the coils 3a, 3b, 3c
The induced voltages Va, Vb, Vc generated in the
Since the angles a, 4b, and 4c are deviated by 120 °, the waveforms are out of phase by 120 °. Here, one end of each coil 3a, 3b, 3c is commonly connected as a COM, three phases are distributed to the other ends, and a torque is generated by energizing and driving the electronic circuit on the substrate 11 according to the induced voltage of the three phases. Generated, magnets 4a, 4b, 4c
Rotates. That is, it is driven as a three-phase brushless motor. The electronic circuit is supplied with current from a DC power supply.

FIG. 5A is a sectional view showing a simplified magnetic circuit of the brushless motor. FIG. 5B
FIG. 3 is a diagram showing the motor developed from the inside of the core. The following describes this figure. In the following, for the sake of simplicity, the leakage of magnetic flux will be ignored.

The reciprocal of the speed fluctuation rate μ is often used as a value representing the efficiency η of the motor, and the speed fluctuation rate μ generally has a relation as shown in (Equation 1).

[0047]

[Equation 1]

Here, Φ is the effective magnetic flux of the core, T is the number of coil turns, and R is the coil resistance.

Here, the effective magnetic flux Φ of the core is expressed as in (Equation 2).

[0050]

[Equation 2]

Here, D is the rotor outer diameter, L is the rotor length, and Bg is the magnetic flux density in the gap.

Here, the gap magnetic flux density Bg is (Equation 3)
It is expressed as.

[0053]

[Equation 3]

Here, Br and μr are residual magnetic flux density and recoil magnetic permeability, which are constants determined by the material of the magnet. Lm is the thickness of the magnet, and Lg is the air gap between the magnet and the core.

The number of coil turns T and the coil resistance R
The relationship is expressed as in (Equation 4).

[0056]

[Equation 4]

Here, K is the proportionality constant determined by the conductivity of the coil and the space factor of the winding, l is the average length per turn of the coil, and S is the cross-sectional area of the coil. Also, this l
Is expressed as (Equation 5) when the R part of the coil is ignored.

[0058]

[Equation 5]

Here, Lc is the coil height and Dc is the coil width.

From the above, (Equation 1) becomes (Equation 2), (Equation 3),
Substituting (Equation 4) and (Equation 5) and rearranging results in (Equation 6).

[0061]

[Equation 6]

This equation does not include the components of the coil resistance R and the number of coil turns T, and shows that the efficiency does not change due to the change of the winding specification.

When other variables are fixed in this equation and L and D are changed so that the rotor volume {πD ² L / 4} becomes constant, rotor length / diameter {L / D} and efficiency The relationship of η is as shown in FIG. The dotted line in FIG. 6 represents the case of a conventional inner rotor type brushless motor. As shown in FIG. 6, the motor of the present invention is inefficient when the rotor is short as compared with the conventional brushless motor, but the efficiency is improved as the rotor is longer, and the motor reverses at a certain point. Also, in the final convergence value ((Equation 6) and (Equation 106), L
/ D = infinity), the efficiency of the motor of the present invention is
It reaches 1.5 times the efficiency of conventional motors.

In the above embodiment, the magnets are deviated by 120 ° from each other, but the magnets 4a, 4b and 4c are deviated by 60 ° from each other in FIG. By reversing the winding directions of the coils 3a and 3c and the coil 3b as described above, or reversing the connection of the coils with the same winding direction, the phase of the induced voltage is set to 1
The shape is shifted by 20 ° and three-phase drive is possible in the same manner.

The cores 1a, 1b, 1 of the motor shown in FIG.
Although the outer diameter of c is shown to be circular, it is also possible to provide a motor with good mountability to equipment by forming a flat portion 1P on the outer peripheral portion as shown in FIG.

Further, in the present embodiment, the phases of the induced voltages of the three stages are shifted by 120 ° by shifting the magnetizing directions. However, as shown in FIG.
With the magnetization directions of a, 4b, and 4c fixed, the cores 1a, 1
When the direction between the salient poles 7a to 7c of b and 1c is shifted, or as shown in FIG.
Even when the directions of both stages of a to 7c and the magnets 4a, 4b, 4c are shifted, it is possible to similarly drive as a three-phase brushless motor by shifting the phase of the induced voltage by 120 °. It is possible. Especially in FIG.
In the case of, the windings of the upper and lower cores 1a and 1c are connected to the intermediate core 1b.
The height of the motor can be suppressed and the motor can be downsized by storing the motor in the slot portion.

In this embodiment, the motor has a three-stage structure. However, by using a K-stage structure (n = 2, 3, 4, ...), a K-phase brushless motor is generally used in a wide range. Can be used.

(Embodiment 2) Next, the magnets 4a, 4
A second embodiment of the present invention will be described in which the number of magnetized magnetic poles b and 4c is not two but more than two. The number of magnetized magnetic poles of the magnets 4a, 4b and 4c, and the configuration excluding the salient poles 7a to 7c and the coils 3a to 3b of the cores 1a, 1b and 1c corresponding thereto are the same as those shown in the first embodiment. is there. FIG. 11 shows that the magnets 4a, 4b and 4c have 6 magnetic poles, and the salient poles 7a to 7 of the cores 1a, 1b and 1c.
It is a figure showing the relation of a magnet, a core, and a coil in case c is 4 poles.

FIG. 11 shows a cylindrical magnet 4a, 4b, 4c having 6 poles magnetized by magnetizing N and S poles at a pitch of 60 ° in the circumferential direction, and the magnets 4a, 4 described above.
In accordance with the magnetizing pitches of b and 4c, four core salient poles 7a to 7c corresponding to two magnetizing N and S magnetic poles are arranged on each side of the core as shown in the figure. It has a three-tiered structure.

In the case of this configuration, as shown in the figure, the cores 1a-1
It becomes easy to provide the flat portion 60 on c, and even in a multi-slot motor, a so-called oval-shaped motor having a small one dimension in the radial direction of the motor can be easily configured.

FIG. 12 shows that the magnets 4a, 4b and 4c have 6 magnetic poles, and the salient poles 7a to 7 of the cores 1a, 1b and 1c.
It is the figure which showed another example of the relationship of a magnet, a core, and a coil in case c is 4 poles.

FIG. 12 shows a cylindrical magnet 4a, 4b, 4c having 6 poles magnetized by magnetizing N and S poles at a pitch of 60 ° in the circumferential direction, and the magnets 4a, 4 described above.
Cores 1a to 1c in which four salient poles 7a to 7c corresponding to two magnetizing N and S poles are arranged on one side as shown in the figure in accordance with the magnetizing pitches b and 4c. For each 3
It has a vertically arranged structure.

In the case of this structure, as shown in the drawing, a motor having a small size on one side with respect to the axial center of the core can be formed. When this motor is mounted on equipment, if it is restricted only in one direction in the circumferential direction of the motor, for example, by using it for a spindle motor of an optical disk device, the size of the motor can be increased even if the height is the same. It can be used as an output motor.

Even when the number of poles of the magnet and the number of salient poles of the core are different as described above, 2n poles (n is an integer of 1 or more) magnetized with N and S poles at equal angular pitches in the circumferential direction. Three cylindrical magnets having magnetism and protrusions of 2 m poles (m is an integer of 1 or more, m ≦ n) corresponding to the N poles of the magnetized magnets and the S poles of the magnetized magnets according to the magnetizing pitch of the magnets. Three cores having poles are vertically stacked in three layers in the axial direction, and the relative angle between the magnetization of the magnets and the cores is 12 in each of the three layers.
By displacing each by 0 / n °, it is possible to similarly drive as a three-phase brushless motor.

Further, in the present embodiment, the motor has a three-stage structure. However, by adopting a K-stage (K = 2, 3, 4, ...) Structure, the K-phase brushless motor generally has a wide range. Can be used.

(Embodiment 3) A third embodiment of the present invention will be described below with reference to the drawings.

FIG. 13 is a half sectional view of the brushless motor of the present invention. In FIG. 13, 21 is a core, 22a, 2
2b and 22c are coils wound on the salient poles 20a, 20b and 20c of the core 1, 23a, 23b and 23c are three-stage magnets, 24 is a spacer, 25 is a shaft, 26 is a frame, 27 is a bearing, 28 is a substrate. , 29 are covers.

As shown in FIG. 13, in the rotor portion, hollow cylindrical magnets 23a, 23b and 23c are provided with spacers 24,
The inner cylindrical portion of each of the magnets 23a to 23c is inserted and fixed to the shaft 25 with the magnet 24 sandwiched therebetween, and both ends of the shaft 25 serve as an inner rotor having a double-sided support structure supported by bearings 27 attached to a frame 26. There is.

Further, the two cores 21 located on both sides respectively have three salient poles 20a to 20c provided in three rows in a vertical row and a magnetic circuit section connecting them by cutting an iron ingot. Formed and insulated by electrodeposition coating. In this core 21, after the coils 22a, 22b and 22c are wound around the salient poles 20a to 20c, both ends of the core 21 are inserted into the frame 26, and the coils 22a to 22c are inserted.
Of the terminal wire is soldered to the substrate 28 on which the connection pattern is printed.

FIG. 14 is a diagram showing a magnetized state of the magnet of the brushless motor.

As shown in FIG. 14, the magnets 23a, 23b and 23c are magnetized such that the magnetizing directions are shifted by 120 ° in the circumferential direction between the respective stages.

FIG. 15 shows the magnets 23a-23c.
, Salient poles 20a to 20c of the core 21, and coils 22a to
It is the figure which represented typically the relationship of 22c.

As shown in FIG. 15, the coils 22a to 22c are provided.
Are connected to one group of the magnets 23a to 23c as one group.

FIG. 16 is a diagram showing the waveform of the induced voltage generated in each coil when the rotor magnet rotates with this configuration. As shown in FIG. 16, the coils 22a, 2
The induced voltages Va, Vb, Vc generated in 2b, 22c are
Since the magnetizing angles of the magnets 23a, 23b, and 23c are shifted by 120 °, the phases are shifted by 120 °. Here, one end of each coil 22a to 22c is commonly connected as a COM, three phases are distributed to the other end, and torque is generated by energizing and driving by an electronic circuit according to the induced voltage of these three phases, and the magnet rotates. To do. That is, it is driven as a three-phase brushless motor.

FIG. 17A is a simplified sectional view of the magnetic circuit of the brushless motor of the present invention. FIG. 17B is a diagram showing the motor developed from the inside of the core.
The following describes this figure. In the following, for the sake of simplicity, the leakage of magnetic flux will be ignored.

The reciprocal of the speed fluctuation rate μ is often used as a value representing the efficiency η of the motor, and the speed fluctuation rate μ generally has a relationship as shown in (Equation 11).

[0087]

[Equation 11]

Here, Φ is the effective magnetic flux of the core, T is the number of coil turns, and R is the coil resistance.

Here, the effective magnetic flux Φ of the core is expressed as in (Equation 12).

[0090]

[Equation 12]

Here, D is the rotor outer diameter, L is the rotor length, and Bg is the magnetic flux density of the gap.

Here, the gap magnetic flux density Bg is (equation 1)
3).

[0093]

[Equation 13]

Here, Br and μr are residual magnetic flux density and recoil magnetic permeability, which are constants determined by the material of the magnet. Lm is the thickness of the magnet, and Lg is the air gap between the magnet and the core.

The number of coil turns T and the coil resistance R
The relationship is expressed as in (Equation 14).

[0096]

[Equation 14]

Here, K is the proportionality constant determined by the conductivity of the coil and the space factor of the winding, l is the average length per turn of the coil, and S is the cross-sectional area of the coil. Also, this l
Is expressed as (Equation 15) when the R part of the coil is ignored.

[0098]

[Equation 15]

Here, Lc is the coil height and Dc is the coil width.

From the above, (Equation 11) becomes (Equation 12), (Equation 1)
Substituting (3), (Equation 14), and (Equation 15) and rearranging,
It becomes like (Equation 16).

[0101]

[Equation 16]

This equation does not include the components of the coil resistance R and the number of coil turns T, and shows that the efficiency does not change due to the change of the winding specification.

When other variables are fixed in this equation and L and D are changed so that the rotor volume {πD ² L / 4} becomes constant, rotor length / diameter {L / D} and efficiency η 18 is as shown in FIG. 18. The dotted line in FIG. 18 shows the case of the conventional inner rotor type brushless motor. From FIG. 18, the motor of the present invention is less efficient than the conventional brushless motor when the rotor is short, but the efficiency is better as the rotor is longer, and the motor reverses at a certain point. In the final convergence value (when L / D = infinity in (Equation 16) and (Equation 106)), the efficiency of the motor of the present invention reaches 1.5 times that of the conventional motor.

Further, in this embodiment, the three-stage salient pole 20a is used.
Although the case where the number of cores 21 integrally including .about.20c is two is shown, it can be widely used when q number (q = 1, 2, 3, 4, ...) Is used. In particular, when two (or one) cores 21 are used as in this embodiment, the thickness in the radial direction of the motor can be reduced to almost the same as the diameters of the magnets 23a to 23c. Then, it is possible to configure a motor of high output, which can increase the diameters of the magnets 23a to 23c.

In FIG. 19, magnets 23a to 23c have four magnetic poles, three cores 21 and three salient poles 20a to 20c.
It is a figure showing an example of a relation of a core, a magnet, and a coil in the case of a pole.

In FIG. 19, three cylindrical magnets 23a to 23c having N and S poles magnetized at 90 ° pitch in the circumferential direction and having four poles are arranged in parallel with the axial direction. The salient poles 20a to 20c of the pole and the salient poles 20a to 2c
The core 21 that integrally fixes the magnetic circuit part that connects 0c
The cores 21 are arranged according to the magnetization pitch of the magnets 23a to 23c. With this configuration, when the motor is attached to the device, if it is restricted only in one direction in the circumferential direction of the motor, for example, by using it in a spindle motor of an optical disk device, etc., even at the same height,
Since the size of the motor can be increased, a high output motor can be used.

Further, in the present embodiment, the motor has a three-stage structure. However, by adopting a K-stage (K = 2, 3, 4, ...) Structure, a K-phase brushless motor is generally widely used. Can be used.

(Embodiment 4) A fourth embodiment of the present invention will be described below with reference to the drawings.

In FIG. 20, 31 is a magnet and 32 is a magnet.
Is a shaft into which a magnet is inserted and fixed.

In the motors of the first to third embodiments described above, the rotor has a structure in which three magnets are inserted and fixed to the shaft with spacers sandwiched therebetween, but in the present embodiment, the single magnet 31 is used as the shaft. The magnet 31 is inserted and fixed, and the magnetization of the magnet 31 is switched to three stages as shown in FIG. With this configuration, the number of parts that have been divided into three becomes one, so that the cost of the parts can be suppressed, and at the same time, the deterioration of the motor characteristics due to the angle accuracy of the three-stage magnet due to assembly can be reduced.

Further, in the present embodiment, the magnetization is configured by switching in three steps, but the same effect can be obtained when skew magnetization is performed as shown in FIG. Further, when the skew magnetization is performed, the switching of the magnetic flux becomes smooth, and the cogging torque of the motor becomes small.

(Embodiment 5) Although each of the above embodiments relates to a brushless motor, the present invention can also be applied to a motor with a brush. The embodiment is shown in FIG.

The magnet shown in FIG. 22 has magnets 23a to 23c, the core 21 and the salient pole 20 as in the case of FIG.
a to 20c and coils 22a to 22c are provided, the brush 71 and the commutator 72 are provided, the DC power is distributed to the coils 22a to 22c, and the induced voltage of the corresponding salient poles 20a to 20c in each of the three stages. Are configured to be 120 ° out of phase with each other.

[0114]

According to the present invention, it is possible to provide a motor which is highly efficient, can be made compact and thin, and has a high degree of freedom in mounting on equipment.

[Brief description of drawings]

1A and 1B show a brushless motor according to a first embodiment of the present invention, in which FIG. 1A is a vertical sectional view thereof, and FIG.

FIG. 2 is a perspective view showing a magnetized state of the rotor magnet.

FIG. 3 is a diagram schematically showing the relationship between the magnet, the salient pole of the core, and the coil.

FIG. 4 is a diagram showing a waveform of the induced voltage.

FIG. 5A is a simplified cross-sectional view of a magnetic circuit of the brushless motor. (B) The figure which expanded the said brushless motor from the inside of a core.

FIG. 6 is a diagram showing the efficiency of the brushless motor in comparison with a conventional brushless motor.

FIG. 7 is a diagram schematically showing the relationship between the magnet, the salient poles of the core, and the coil when the magnetization of the rotor magnet is shifted by 60 °.

FIG. 8 is a brushless motor 1 having a flat surface on the outer peripheral portion.
The disassembled perspective view which shows an example.

FIG. 9 is an exploded perspective view showing a configuration in which the direction of salient poles of the core is shifted while the magnetizing direction of the magnet is constant.

FIG. 10 is an exploded perspective view showing the configuration when the magnetizing direction of the magnet and the direction of the salient poles of the core are both deviated.

FIG. 11 is a diagram schematically showing a relationship between a magnet, a salient pole of a core, and a coil in the brushless motor according to the second embodiment of the present invention.

FIG. 12 is a diagram schematically showing a relationship between a magnet, a salient pole of a core, and a coil in a modified example of the second embodiment of the present invention.

13A and 13B show a brushless motor according to a third embodiment of the present invention, in which FIG. 13A is a longitudinal sectional view thereof, and FIG. 13B is a transverse sectional view thereof.

FIG. 14 is a perspective view showing a magnetized state of the rotor magnet.

FIG. 15 is a diagram schematically showing a relationship between a magnet, a salient pole of a core, and a coil of the brushless motor.

FIG. 16 is a view showing a waveform of the induced voltage.

FIG. 17A is a simplified sectional view of a magnetic circuit of the brushless motor. (B) The figure which expanded the said brushless motor from the inside of a core.

FIG. 18 is a diagram showing the efficiency of the brushless motor in comparison with a conventional brushless motor.

FIG. 19 is a diagram schematically showing a relationship between a magnet, a salient pole of a core, and a coil in a modified example of the third embodiment.

FIG. 20 is a perspective view showing a configuration of a rotor magnet according to a fourth embodiment of the present invention.

FIG. 21 is a perspective view showing a configuration of a rotor magnet that is skew-magnetized as a modification of the fourth embodiment.

FIG. 22 is a sectional view showing a brush motor according to a fifth embodiment of the present invention.

FIG. 23 is a sectional view of a conventional brushless motor.

FIG. 24A is a simplified sectional view of a magnetic circuit of a conventional brushless motor. (B) The figure which expanded the conventional brushless motor from the inside of a core.

FIG. 25 is a diagram showing the efficiency of the brushless motor.

[Explanation of symbols]

1a, 1b, 1c core 2a, 2b, 2c insulator 3a, 3b, 3c coils 4a, b, c magnet 5 spacers 6 shafts 7a, 7b, 7c salient pole 8 brackets 9a, 9b bearing 11 board 12 terminal pins 20a, 20b, 20c salient pole 21 core 22a, 22b, 22c coil 23a, 23b, 23c Magnet 24 spacer 25 shaft 26 frames 27 bearings 28 substrate 29 cover 31 magnet 32 shaft 71 brush 72 Commutator

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Miyuki Furuya 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) Reference JP-A-6-311711 (JP, A) JP-A-6- 351206 (JP, A) Actual development 1-120779 (JP, U) Actual development Sho 64-25897 (JP, U) Actual development Sho 61-92155 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02K 16/00 H02K 21/16 H02K 29/00

Claims (12)

(57) [Claims] 1. A K magnet (K is an integer of 2 or more) in which N and S poles are alternately magnetized in the circumferential direction, and a center for stacking the K magnets axially in K steps and integrally holding them. The rotary shaft and the core having K-stage coil winding salient poles corresponding to each magnet are provided, and the magnetizing positions of the N and S poles of each stage magnet and the coil winding salient
The relative positions of the poles deviate from each other in the circumferential direction, and the phase of the induced voltage generated in the coil winding salient pole of each stage is one phase.
The motor is characterized in that the phase is set so as to be suitable only for rotating the magnets of the same stage. 2. A core having a coil winding salient pole for each stage is divided and formed, and the divided magnet and the core are combined to form a unit for each stage. The motor according to claim 1, wherein the motor is assembled on a shaft and cores of respective stages are assembled together. 3. The motor according to claim 1, wherein the magnets at each stage are integrally formed by a single magnet, and the magnetization of the N and S poles is switched at each stage. 4. The motor according to claim 1, wherein the magnets at the respective stages are integrally formed by a single magnet, and the N and S poles are magnetized in a skew manner. 5. The coil winding salient poles of each stage are arranged on a straight line parallel to the central rotation axis.
Motor described. 6. The coil winding salient poles of each stage are arranged at positions displaced from each other in the circumferential direction between the stages.
The motor according to 2, 3, or 4. 7. The motor according to claim 1, wherein a flat portion is provided on the outer periphery of the core. 8. A pair of coil-wound salient poles arranged at positions facing each other in each stage.
The motor according to 4, 5, 6 or 7. 9. An electronic circuit for controlling a DC power supply and applying a current to a coil so that a phase of an induced voltage generated in a coil winding salient pole of each stage becomes a phase suitable for rotating a magnet of the same stage. The motor according to claim 1, 2, 3, 4, 5, 6, 7, or 8 which operates as a brushless motor. 10. A brush and a commutator for distributing a DC power supply and applying a current to the coils so that the phases of the induced voltages generated in the coil winding salient poles of the respective stages are suitable for rotating the magnets of the same stage. 9. The motor according to claim 1, 2, 3, 4, 5, 6, 7 or 8 which comprises a brush motor. 11. K = 3, 2n in which N and S poles are alternately magnetized at an equal angular pitch in the circumferential direction.
3 magnets with poles (n is an integer of 1 or more)
Each magnet has 2m poles (m is an integer of 1 or more, m ≦ n) corresponding to m poles for each of the N and S poles of each magnet in 3 stages, and each magnet has 3 poles. The magnetized position of the magnetic pole is shifted by 120 / n ° or 60 / n ° among the three stages, and the phase of the induced voltage generated in the coil winding salient pole is the same.
Claims 1, 2, 3, 4, 5, 6, 7, wherein there is only one phase, and the three stages are offset by 120 °.
The motor according to 8, 9, or 10. 12. A magnet, which is divided into two in the circumferential direction and is magnetized into N and S poles, a central rotating shaft for stacking the three magnets in three axial stages, and holding them integrally, and each magnet. And a core having three-stage coil winding salient poles corresponding to each other, and the magnetizing positions of the N and S poles of each stage magnet are 120
The phase of the induced voltage generated in each stage coil winding salient pole is the same.
Then, the motor has only one phase and is configured so as to be shifted by 120 ° between the three stages.