JPH0417557A - Single-phase brushless motor having iron core - Google Patents

Abstract

PURPOSE:To enable self start without using a special device by changing the magnetizing conditions or the shapes of 2P pieces of magnets, which constitute permanent magnet rotors, and making them correspond to the salient poles of a stator, where coils of the same number are wound. CONSTITUTION:The cap-shaped rotors 16 are made free in rotation by the rotary shaft 5, which are born by the upper and lower bearings 10 and 11 of the bearing house 4 united with a fixing board 3. 2P pieces (6 pieces in the figure) of permanent magnets 2N and 2S are alternately attached to the inside peripheries of the rotors 16, and the circumferential thickness is changed from one end to the other end or the magnetizing force is changed with the same thickness. Winding salient poles 8-1-8-6 as many as the permanent magnets 2N and 2S are formed, a specified interval apart from the permanent magnets 2N and 2S, at the stator armature iron core 7, and thereon armature windings 9 are wound to form stator armatures 12. Hereby, self start can be done easily without using a special device.

Description

[Detailed Description of the Invention] [-Clear Industrial Application Field] The present invention enables the magnetic poles of the N and S poles constituting a permanent magnet rotor to be easily removed without using any special self-starting processing means. Regarding iron-core single-phase brushless motors that are configured to be self-starting simply by devising magnetization or the shape of the permanent magnets that form the N-pole and S-pole, the motor can be started from a particularly low voltage and has a variable rotation speed. It is extremely easy to control, suitable for fan motors that require relatively large torque, can have a large number of windings, does not produce counter torque, has good efficiency, can obtain large torque, and is easy to assemble. It concerns things that can be mass-produced at low cost.

[Prior art] In a brushless motor, the N and S magnetic poles of a permanent magnet rotor are detected by a position sensing element such as a Hall element, and a signal from the position sensing element is input to a transistor to turn on the stator armature. , turn off and rotate the permanent magnet rotor.

Here, in a brushless motor, a circuit (drive circuit, electronic commutation circuit or (Also called a semiconductor rectifier circuit) is required for the number of motor phases, which has the disadvantage of being expensive.

Therefore, it is not cost-effective to use such an expensive brushless motor with a large number of phases in a fan motor or the like that is used for the purpose of simply blowing air and cooling.

For this reason, the fan motor only requires one 9-position detection element, and only one phase of the drive circuit is sufficient.

A single-phase brushless motor is used, which can be constructed at low cost.

In this single-phase brushless motor, unless some measure is taken, the torque will be zero at the two-current switching point in principle. There is a so-called "dead point".

Therefore, in a single-phase brushless motor, in addition to the electromagnetic torque obtained from the armature winding (or the winding salient poles around the armature winding) and the permanent magnet rotor, the cogging torque generated by the cogging torque generating member, etc. The addition prevents the torque at the dead center location from becoming zero, eliminates the stopping phenomenon of the motor at the dead center location, and enables self-starting.

In this way, we solved the problem of dead center and made it possible to start up automatically. In particular, typical examples of the conventional methods of single-phase brushless smoke with iron core are shown below. The radial length of the salient pole surface is gradually shortened so that the radial gap between the two-pole permanent magnet rotor and the winding salient pole surface of the stator armature facing it is inclined. There is a single-phase brushless motor with an iron core.

As for something similar to this kind of thing, Utility Kai 60-1
No. 28483, JP-A-60-183958, JP-A-6
No. 0-213290+' US P 4.

It is often seen in issues such as No. 496.887.

An iron-core single-phase brushless motor disclosed in Japanese Patent Application Laid-open No. 147943/1983 is an example of a motor in which a step is formed in the gap without providing an inclination to the gap. This is a ball shoe attached to the inner surface of a part of the magnetic pole of a magnet rotor, and is essentially a stepped part added to the gap. There is also known a single-phase brushless motor with an iron core, disclosed in Japanese Patent Publication No. 10013/1983, in which a gap is stepped by forming a recess in the salient pole of the first winding.

JP-A-61-1 is similar to this type of product.
No. 12561, No. 1984-478, No. 1984-84
No. 681, JP-A-61-18340, JP-A-61-2
No. 69656, JP-A-61-293148, JP-A-6
2-18958, etc., are the majority party.

In addition, as a device that can be started automatically by devising the structure of the salient pole, one of the winding salient poles is formed to have a narrow width, as in the iron core type single-phase brushless motor disclosed in Japanese Patent Application Laid-Open No. 61-54845. , there is one in which the winding salient pole is deviated to the other wide salient pole side. Similar to this, there is also one that uses auxiliary salient poles instead of two narrow winding salient poles. Various types of auxiliary salient poles are known in this case, including those with a winding wound around them and those without one winding around them.

In addition, the main winding salient pole and the auxiliary salient pole are shifted in the circumferential direction and overlapped in two stages in the axial direction, the main winding salient pole and the auxiliary salient pole, and the main winding salient pole and the main winding salient pole. There are different types of salient poles with different areas facing the permanent magnet rotor, or different widths of the armature windings of the main and auxiliary salient poles. . For example, similar to these,
Japanese Unexamined Patent Publication No. 152361/1981, Utility Model No. 46881/1983
No., Utility Model No. 61-46882, Utility Model No. 61-4688
No. 4, Japanese Unexamined Patent Publication No. 61-92151, Utility Model Application No. 61-202
No. 178, Utility Model Publication No. 62-68476, Japanese Patent Application Publication No. 61-8
No. 1162, Utility Model No. 61114976, Utility Model No. 53-
Many such as No. 154312 can be seen.

Next, a typical method for producing a single-phase brushless motor with an iron core that can be started automatically is to use an auxiliary magnet for generating detent torque that magnetically attracts the permanent magnet rotor. Examples of this type include 1, e.g. USP 4,103,191
A magnet for generating detent torque is used in the magnetic field generated by the two permanent magnet rotors, that is, on the salient pole surface facing the permanent magnet rotor through an air gap, such as the iron core type single-phase brushless motor of No. There is. Other examples that employ this type of method include JP-A-61-161943 and USP 3.
, No. 433,987, Utility Model Application No. 63-143069, U
There is one shown in SP4,728,833.

Next, as another typical self-startable iron core type single-phase brushless motor, as shown in Japanese Patent Application Laid-Open No. 59-67862, there is an electromagnetic drive type iron core motor in which an electromagnetic structure is arranged around the outer periphery of a permanent magnet rotor. There are single-phase brushless motors, and many of this type are also available.

In addition, so that it can be started automatically, it was
As seen in No. 473, there are many iron core type single-phase brushless motors with devised cogging torque generating members. For example, similar products of this type include USP 4,40
There are issues such as No. 4,484.

There are also iron core type single phase brushless motors that can be started automatically by devising the magnetization of the permanent magnet rotor. The width of the N-pole and S-pole of the magnet rotor has been devised. There are other permanent magnet rotors with different magnetization widths, such as USP4.
, 737.674, JP-A-5:3-23010, JP-A-58-25024, and JP-A-58-95971.

In addition, some permanent magnet rotors have been devised so that they can be started automatically by varying the strength of the magnetization. For example, there is a single-phase brushless motor with an iron core in which a part of the north pole and south pole of a permanent magnet rotor is more strongly magnetized than other parts.

A similar example of this type of magnetization peak and magnetization pitch is published in Japanese Patent Application Laid-Open No. 62-1479.
No. 44, Japanese Patent Application Publication No. 173966/1983, Japanese Patent Application Publication No. 1987-4
No. 1383, JP-A-59-50760, JP-A-59-
No. 67861, JP-A-59-139852, etc.

In addition, a typical iron core single-phase brushless motor using a substantially non-magnetized part has an N pole on the magnetic rotor as in USP 4,115.715.

S poles and O poles (non-magnetized poles) are alternately formed.

Similar to this, JP-A-61-15236
No. 2, Special Publication No. 60-46634, Japanese Patent Publication No. 53-230
No. 08, JP-A-57-34761, JP-A-56'-8
There are issues such as No. 1071.

[Problems with the prior art] First, in the conventional method of forming an inclination in the gap and in the iron core type single-phase brushless motor and similar devices in which the gap is stepped, the radial length of the gap increases. It has the advantage of being able to rotate relatively smoothly.

However, in order to obtain an iron core type single-phase brushless motor that can be started up from a low voltage and capable of variable speed control, the above-mentioned gap length must be formed to be even longer.

If this is done, the gap length in the radial direction becomes long, so a large torque cannot be obtained and there is a drawback that efficiency is extremely low.

Part 1 Furthermore, since both lateral ends of the salient pole piece of the 9-winding salient pole pass in parallel with the lateral ends of the magnetic poles of the N and S poles of the permanent magnet rotor, a large cogging torque is generated. The large generated cogging torque becomes an obstacle to starting from a low voltage and enabling variable speed control even in a low voltage state, and has the drawback that accurate variable speed control is not possible.

Generally, for iron core type single phase brushless motors.

Since the predetermined purpose is achieved by ensuring self-starting even though it is a single phase, it is not configured to be able to start up from a low voltage and also to be able to perform variable speed control from a low voltage state.

In addition, the method of narrowing the opening angle width of the winding salient pole including other auxiliary salient poles adjacent to the winding salient pole and deflecting it to one winding salient pole results in a narrower width of the second winding salient pole. Therefore, it is difficult to use two windings, and the auxiliary salient pole causes eddy current loss, resulting in poor efficiency.Also, the cogging torque generated by the auxiliary salient pole is large, making it difficult to rotate smoothly. Naturally, this system also has the disadvantage that it cannot be started up from a low voltage as described above and that variable speed control cannot be performed accurately from a low voltage state, and that it is expensive due to its complicated structure.

In addition, in the case where the winding salient pole and the other winding salient pole are integrally formed in the radial direction, the width of the slot for winding the armature winding between the first winding salient poles becomes narrower.

In particular, when the structure is designed to obtain large torque by forming a large number of salient poles, it is difficult to mass-produce it, and it is also inferior in terms of mass-production and efficiency, such as the inability to wind the armature winding with many turns. However, it has the disadvantage that large torque cannot be obtained.

Naturally, this method cannot be started from a low voltage as described above and cannot perform variable speed control with high precision from a low voltage state.

Moreover, it has the disadvantage of being expensive due to its complicated structure.

Furthermore, since the magnetic attraction force and the purpose of use for the self-starting type using detent torque, which is different from the type using cogging torque, it is generally difficult to compare the two. Therefore, it is different from the prior art which the present invention is intended to solve. Therefore, we will not compare the advantages and disadvantages of this type of motor and a single-phase brushless motor with an iron core that can self-start using cogging torque.

Iron-core single-phase brushless motors that use electromagnets to enable self-starting have the drawbacks of complex structures, poor mass production, and high costs. Particularly in this case, if one attempts to construct something that requires a relatively large torque, the above-mentioned drawbacks will be further exacerbated.

A cogging torque generating member is provided at the lower end of a permanent magnet rotor (not shown) located on the outer periphery of a salient pole piece, and the leakage magnetic flux of the permanent magnet rotor is utilized. However, in cases where relatively large torque is required and there are a large number of winding salient poles, the magnetic Since the attraction force is larger than the magnetic attraction force between the leakage magnetic flux of the permanent magnet rotor and the cogging torque generating member, there is a risk that it may not be sufficient to cause safe and reliable self-starting. be.

In addition, other similar iron core type brushless motors have the same drawbacks as those described above, or have additional drawbacks.

Next, there are iron-core single-phase brushless motors in which the N and S poles of the permanent magnet rotor have different magnetization widths.

Since it is not self-starting using cogging torque, it has the advantage of being able to rotate smoothly. However, there is a drawback that large torque cannot be obtained.

In addition, in conventional iron-core single-phase brushless motors, which have a permanent magnet rotor with different magnetization strengths, it is difficult to magnetize them, and it is not suitable for mass production. In some cases, there is a risk that safe and reliable self-starting may not be possible.

[Problems to be solved by the invention] The present invention is capable of magnetizing the N-pole and S-pole, or forming the N-pole and S-pole, which constitute a permanent magnet rotor, without using any special self-starting processing means. By simply modifying the shape of the permanent magnet, it can be configured to start automatically, and magnetization can be done extremely easily by simply modifying the magnetization yoke, and in particular, it can be started from a low voltage. In this way, precise variable speed control of the rotation can be performed extremely easily, and a relatively large torque can be generated, efficiency is good, and assembly is easy.
The objective was to obtain a single-phase steelless motor with an iron core that could be mass-produced at low cost.

[Means for Solving the Problems of the Invention] The present invention has been made to solve the problems of the conventional iron core type single-phase brushless motor. This can be achieved by providing a single-phase brushless motor with an iron core, which is characterized by consisting of the constituent elements (1) to (2).

Constituent element (1): Equipped with a permanent magnet rotor formed by alternately arranging 2P (P is an integer of 1 or more) N-pole and S-pole magnetic poles in an annular shape.

Component ①: Winding salient poles having salient pole pieces formed with an opening angle width of approximately one magnetic pole width of the permanent magnet rotor through a radial gap with the permanent magnet rotor at appropriate locations in the same phase position. (m is an integer greater than or equal to 1) stay armature iron core formed by winding an armature winding around arbitrary k (k is an integer greater than or equal to 1, K≦m) winding salient poles. A stator armature having a phase structure is provided and is arranged to rotate relative to the permanent magnet rotor.

Component (2): The permanent magnet rotor is formed such that the opening angle of one of the N and S poles is formed to have an opening angle width that substantially matches the opening angle width of the salient pole piece of the winding salient pole.

Component ■: The permanent magnet rotor is arranged such that the other end of its N pole and S pole are parallel to the circumferential end extending in the axial direction of the salient pole piece. The magnetic poles of pole and south pole are formed by magnetization.

Component (2): The above permanent magnet rotor has one end of its N pole and S pole located 1/4 to 3/4 from one end of the one end.
N at the one end so that the magnetic force of the N pole and S pole gradually weakens in a skewed manner with respect to the axial direction over the angle θ of the magnetic pole width, from the 8 degree position to the one end.
The magnetic poles of the pole and S pole are magnetized in a skewed manner.

A second object of the present invention is to improve the permanent magnet rotor with its N
Pole, one end of the magnetic pole of S pole is 2 1/4 from one end of the one end
or 3/4 of the magnetic pole width, from the 8 degree position to the one end, so that the magnetic force of the N pole and S pole becomes weaker in a skewed manner with respect to the axial direction. This can be achieved by forming skew-shaped recesses in the magnetic poles of the N and S poles.

[Operation of the invention] Permanent magnet rotor 2, 2' N pole, S pole permanent magnet 2N,
The other lateral ends 2Na, 2Sa, 2°Na2' Sa of the magnetic poles 2S, N pole, and S pole are formed so that they are parallel to the lateral end 15a of the salient pole piece 15. Therefore, the lateral end 15a of the salient pole piece 15 and the N and S poles of the permanent magnets 2N, 2S, and N of the permanent magnet rotor 2゜2'
very.

Magnetic pole of S pole 2°N, 2' The other end in the lateral direction of S 2Na, 2
A sufficiently large cogging torque is generated by Sa, 2' Na, and 2' Sa, and moreover, the permanent magnet rotors 2, 2
' N pole, S pole permanent magnet 2N, 2S, N pole, S pole magnetic pole 2' N, 2' S end part 2Nb, 2Sb, 2"N
b, 2' Sb is.

The one end 2Nb as if it were skew magnetized.
, 2Sb, 2' Nb, one end in the lateral direction of 2''sb 2Nc
, 2Sc, 2' Nc, 1/4 to 3/ from 2' Sc
From the 8 degree position over the angle θ of 4 magnetic pole widths, the above one end 2
As Nc, 2Sc, and 2' Na2 Sc are reached, the N pole 2N is gradually changed.

The permanent magnets 2N, 2S, N and S poles of the permanent magnet rotor 2.2' are arranged such that the magnetic force of the S pole 2S is weakened in the skewed manner with respect to the axial direction. N, 2'
One end of S 2Nb, 2Sb.

Since the magnetic poles of 2°Nb and 2' Sb are magnetized in a skewed manner, the permanent magnets 2N, 2S, and N poles of the salient pole pieces 15 and the permanent magnet rotor 2.2° are N and S poles. , magnetic pole 2 of S pole
``N, 2' The part with strong magnetic force generates a large magnetic attraction force compared to other parts, and is preferentially opposed to the part at that position.For this reason, when no electricity is applied, the The permanent magnet rotor 2.2'' stops at a position where it can start automatically, avoiding the dead center position.

For this reason, when the current is turned on at startup (rotation can be started with a low voltage), the permanent magnet rotor 2.
' is self-starting and rotates in a predetermined direction. During rotation, the permanent magnets of the N and S poles of the permanent magnet rotor 2.2' are located at the break in the electromagnetic torque generated by energizing the 9 groups of armature windings, that is, at the dead center. 2N, 2S
, N pole, S pole, 2°N, 2''S and the magnetic attraction force caused by the salient pole piece 15 generates cogging torque, so rotational torque is generated at any point during rotation. As a result, since rotational torque is generated at any point during rotation, continuous rotation can be continued.

Also, cogging torque is not generated by providing a dedicated cogging torque generating member.

Permanent magnet rotor 2.2 for driving faces a stator armature 12 consisting of eight groups of winding salient poles around which an armature winding 9 is wound.N pole and south pole permanent magnets 2N.

Since the magnetic poles 2''N and 2°S of 2S, N pole, and S pole are magnetized in a skewed manner at one end to enable self-starting as described above, the cogging torque for self-starting is Because it occurs gradually and naturally.

It does not require any special parts and can be started up from a low voltage and continue to rotate smoothly, making it possible to produce a 1.1" iron-core single-phase brushless motor at low cost that can perform variable speed control and self-start even from a low voltage state. can be formed into

[Embodiments of the Invention] Fig. 1 is an exploded perspective view of a core type single-phase brushless motor 1 showing a first embodiment of the present invention, Fig. 2 is a sectional view of the same edge, and Fig.
The figure shows the correspondence between the stator armature core 7 and the permanent magnet rotor 2 used in the single-phase brushless motor 1, and Figure 4 shows the relationship between the single-phase brushless motor 1 and the permanent magnet when the single-phase brushless motor 1 is not energized. FIG. 5 is a developed view showing the relationship between the single-phase brushless motor 1 and the permanent magnet rotor 2 when the single-phase brushless motor 1 generates the maximum starting torque. below.

A first embodiment of the present invention will be described with reference to FIGS. 1 to 5.

The fixed plate 3 has a bearing house 4 integrally formed with the same member in its center. A stator armature core 7 is fixed to the outer periphery of a bearing house 4 formed on the upper part of the fixed plate 3. The stator armature core 7 has a through hole 6 in the center of which a rotary shaft 5 is rotatably passed. Ball bearings 10.11 are housed at both upper and lower ends of the inner periphery of the bearing house 4, and the rotating shaft 5 is rotatably supported by the ball bearings 10.11. On the outer periphery of the bearing house 4, six winding salient poles 8-1.
. . , 8-6 respectively have armature windings 9-1. ...,
A stator armature 12 formed by winding wires 9-6 is fixed by suitable means.

The stator armature 12 is disposed opposite to the permanent magnet rotor 2 fixed to the inner periphery of an annular rotor yoke 14 via a fine radial gap 13 so as to rotate relative to the permanent magnet rotor 2 .

The stator armature core 7 is made of laminated steel, and is fixed to the outer periphery of the bearing house 4, and includes six T-shaped winding salient poles 8 extending radially at equal intervals in the radial outward direction.
The six-winding salient pole 8 has a radial gap 13 with the N-pole permanent magnet 2N and S-pole permanent magnet 2S forming the permanent magnet rotor 2 at its radial outer peripheral tip. The salient pole pieces 15 are formed to face each other via the two electrodes. Winding salient pole 8 is.

In order to form an iron-core single-phase brushless motor 1 that is highly efficient and generates large torque without introducing counter-torque, the opening angle width between both lateral ends 15a of the salient pole piece 15 is adjusted by rotating a permanent magnet. The opening angle width is approximately equal to the width of one magnetic pole of the N pole 2N and S pole 2S of the child 2. In the iron core type single-phase brushless motor 1 of this embodiment, N-pole permanent magnets are magnetized on the inner surface of the cup-shaped rotor yoke 14 fixed to the one-rotation shaft 5 with a pitch of approximately 60 degrees and a T width [55 degrees]. 2N, S
A two-rotor 16 is formed by arranging permanent magnets 2S of poles at equal intervals and fixing a six-pole permanent magnet rotor 2.

Therefore, the opening angle width of the salient pole piece 15 is 1 of the permanent magnet rotor 2.
When the magnetic pole width is T width, the opening angle width of approximately T is equal to it [
55°]. The wire-wound salient pole 8 having the salient pole piece 15 formed to have an opening angle width of approximately T width has six wire-wound salient poles 8 arranged at equal intervals so as to be in the same phase position and to have a single-phase arrangement. -1. ..., forming 8-6. Six winding salient poles 8-1. ..., 8-6 respectively.

As mentioned above, the armature winding 9-1. ..., 9-6 is wound.

As shown in FIGS. 4 and 5, one terminal 9-1a of the armature winding 9-1 and the other terminal 9-2 of the armature winding 9-2
b, one terminal 9-3a of the armature winding 9-3, the other terminal 9-4b of the armature winding 9-4, one terminal 9-5a of the armature winding 9-5, and the armature winding The other terminal 9 of wire 9-6
6b are connected in series to the semiconductor rectifier circuit 17, and the other terminal 9-1b of the armature winding 9-1, one terminal 9-2a of the armature winding 9-2, and the armature winding 9 -3 other terminal 9-3b, one terminal 9- of armature winding 9-4
4a, the other terminal 9-5b of the armature winding 9-5, and one terminal 9-6a of the armature winding 9-6 are connected in series and connected to the semiconductor rectifier circuit 17, respectively. A single Hall element or a magnetoelectric transducer 20 such as a Hall IC used as a position detection element is arranged at an appropriate position on the upper surface of one circuit mounting board fixed to the upper part of the fixing plate 3 using screws 18. The magnetic poles of the north-pole permanent magnet 2N and the south-pole permanent magnet 2S of the permanent magnet rotor 2 can be detected. This magnetoelectric conversion element 20 needs to be disposed at a desired position, and is disposed, for example, at a position below the other lateral end 15a of the salient pole piece 15 of the first winding and 8-1. The above circuit wiring board 1
A semiconductor rectifier 217 is disposed on the upper part of 9.

In FIGS. 4 and 5, 22-1 is a positive power supply terminal;
22-2 indicates a negative power supply terminal.

Iron core type single-phase brushless motor 1 formed in this way
However, since it is a single-phase brushless motor, in order to enable self-starting rotation and continuous rotation without using a special self-starting processing means, an N-pole permanent magnet 2N forming the permanent magnet rotor 2 is used. , the magnetic poles of the S-pole permanent magnet 2S are formed as follows.

First, the first condition is that the opening angle is approximately equal to the opening angle width of the salient pole piece 15 of the wire-wound salient pole 8, and the second condition is that the N-pole permanent magnet 2N , formed so that the other ends 2Na and 2Sa of the S-pole permanent magnet 2S are parallel to the lateral end 15a extending in the axial direction of the salient pole piece 15,
As a third condition, the permanent magnet 2 of the permanent magnet rotor 2
N.

One end portion 2Nb, 2Sb of 2S is connected to the permanent magnet 2N, 2S.
2 over an angle θ of 1/4 to 3/4 magnetic pole width from one end 2Nc, 2Sc to the other end 2Na, 2Sa.
The one end portion 2Nb is arranged such that the magnetic force of the permanent magnets 2N and 2S gradually weakens in a skewed manner with respect to the axial direction from the angular position of θ to the one end portions 2Na and 2Sa.

Forming a skew-shaped recess 21 in 2Sb.

Such a skewed recess 21 is fixed with permanent magnets 2N and 2S.
When formed at one end 2Nb, 2Sb of the permanent magnet 2
The magnetic poles of the permanent magnet 2N2S are gradually magnetized in a skewed manner with respect to the axial direction from the angle θ position of the above 1/4 to 3/4 magnetic pole width of the permanent magnet 2N2S to one end 2Nc2Sc [skewed magnetized portion 21a ] Can be formed immediately.

Desirably, the opening angle θ of the skewed magnetized portion 21a is
Set it to approximately T/2 degrees [27,5 degrees].

The above-mentioned skew-shaped magnetized portion 21a has the permanent magnets 2N, 2
As it reaches the upper part of S in the axial direction, the skew magnetized portion 21
The reason why the magnetized area of a is increased is to enable the magnetoelectric conversion element 20 to detect the permanent magnets 2N and 2S.

According to the iron core type single-phase brushless motor 1 including the permanent magnet rotor 2 having the permanent magnets 2N and 2S in which such a skewed magnetized portion 21a is formed.

When no current is applied, the permanent magnets 2N and 2S are stopped in the state shown in FIG.

That is, this is because the parts of the permanent magnets 2N and 2S having a large area of strong magnetic force stop at a magnetically stable position with the salient pole piece 15. When stopped in this stable state, as is clear from the state shown in FIG. 4, the magnetoelectric transducer 20 detects the permanent magnet 2N [or magnetic pole 2S], and starts automatically to generate rotational torque. I am in a position to do so.

Therefore, with reference to FIG. 4, the known semiconductor rectifier 17
When the power is turned on, a signal detecting the N-pole permanent magnet 2N is output from the output terminal of the magnetoelectric conversion element 20, and the transistor in the known semiconductor rectifier 17 starts up from a low voltage and operates. As shown in the figure, current flows through the armature windings 9-1, . ..., rotational torque in the direction of arrow F is generated due to the repulsion/attraction phenomenon between the magnetic poles and the permanent magnet rotor 2 occurring at 8-6, and the rotor 16 having the permanent magnet rotor 2 rotates in the same direction. When the rotor 16 rotates a little in the direction of arrow F, the maximum rotational torque is generated as shown in FIG. do.

After this, although there is a dead center position where one rotation torque is not generated, the first rotor 16 rotates in the direction of arrow F due to inertia, and cogging torque is generated again as shown in Fig. 4, allowing it to start automatically. Therefore, nine rotation torque is generated and the first rotor 16 continues to rotate.

FIG. 6 is an exploded perspective view of a 1° iron core type brushless motor showing a second embodiment of the present invention.
The only difference is that a permanent magnet rotor 2' is used instead of the permanent magnet rotor 2, so only the permanent magnet rotor 2' will be described below.

This permanent magnet rotor 2'' has a circular magnet member 2.
3 is the permanent magnet 2N with the above N and S poles.

2S same square (7) N [i, S magnetic pole 2' N, 2'
S is applied at a pitch of approximately 60 degrees, and the code is 2' Nb
One end portion 2'Nb, 2'Sb indicated by 2'Sb is connected to a skew-shaped magnetized portion 21''a by a skew-shaped recess 21'.
It becomes.

Note that the part indicated by the symbol "O" is the O pole 24. In other words, it is a non-magnetized portion or a substantially non-magnetized portion. 2 Na
is Ni magnetic pole 2'N other end 2 Sa is S& magnetic pole 2'
The other end of S, 2' Nc is a Ni magnet'! The other end of Ii2'N, 2'Sc, indicates the other end of the S-pole magnetic pole 2°S.

According to the annular permanent magnet rotor 2' formed in this way, the magnetic poles of N pole 2' N and 58ii2' S are integrally formed, so compared to the permanent magnet rotor 2, this arrangement is It has the advantage that it can be positioned and arranged extremely easily, making assembly easy.

[Effects of the Invention] The present invention does not require the provision of a new and separate cogging torque generating member, and merely provides a permanent magnet rotor with N poles,
Suitable for variable speed control that can be started up and operated from a low voltage with good performance by simply changing the shape of the S-pole permanent magnet, the magnetization of the magnetic pole, or the shape of the permanent magnet that forms the S-pole. A core type single-phase brushless motor with one position detection element can be easily formed.

Of course, there is no increase in the number of parts as in the case of 1 or more, that is, the number of parts is small, so assembly is easy and there is an advantage that a highly reliable product can be constructed at low cost.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of an iron core type single-phase brushless motor showing a first embodiment of the present invention, Fig. 2 is a vertical sectional view of the same, and Fig. 3 is a stator armature core used in the same single-phase brushless motor. Fig. 4 is an exploded view showing the relationship between the single-phase brushless motor and the permanent magnet rotor when the same single-phase brushless motor is not energized, and Fig. 5 is a corresponding diagram of the same single-phase brushless motor and the permanent magnet rotor. An exploded view showing the relationship between the single-phase brushless motor and the permanent magnet rotor when the motor generates the maximum starting torque, and FIG. 6 is an exploded perspective view of the iron core type single-phase brushless motor showing the second embodiment of the present invention. It is. [Explanation of symbols] 1.1” ... Iron core type single-phase brushless motor, 2.2
'...Permanent magnet rotor, 2N...N-pole permanent magnet, 2°N...N-pole magnetic pole 2Na, 2' Na--
other end. 2Nb, 2'Nb...one end. 2Nc, 2' Nc...one end, 2S...S pole permanent magnet, 2'S...magnetic pole 2Sa, 2' Sa...other end. 2Sb, 2°sb...one end. 2Sc, 2' Sc...One end, 3...Fixing plate 4 ・
・Bearing house, 5...rotating shaft. 6... Through hole, 7... Stator armature core. 8.8-1. ..., 8-6... Winding salient pole. 9.9-1. ..., 9-6... armature winding 10
．． 11...Ball bearing. 12... Stator armature, 13... Air gap 14...
Rotor yoke, 15... salient pole piece. 15a... Side end portion, 16... Rotor. 17... Semiconductor rectifier circuit, 18... Screw 19...
Circuit wiring board, 20... Magnetoelectric conversion element, 21... Skew-shaped recess, 21a... Skew-shaped magnetized part, 22
-1... Positive side power terminal, 22-2... Negative side power terminal, 23... Annular magnet member, 24... 0 pole (
non-magnetized portion or substantially non-magnetized portion).

Claims (2)

[Claims] (1) A single-phase brushless motor with an iron core, characterized by comprising the following components 1 to 5. 1N pole, S pole magnetic pole alternately 2P (P is an integer greater than or equal to 1)
Equipped with a permanent magnet rotor arranged in a circular ring. 2. A winding salient pole having a salient pole piece formed with an opening angle width of approximately one magnetic pole width of the permanent magnet rotor through a radial gap with the permanent magnet rotor is placed at an appropriate location in the same phase position m (m is an integer greater than or equal to 1)
A stator armature with a single-phase structure is provided by winding armature windings around arbitrary k (k is an integer of 1 or more, K≦m) winding salient poles of a stator armature iron core. , be arranged so as to rotate relative to the above permanent magnet rotor. 3. In the permanent magnet rotor, the opening angle of one of the north and south poles is formed to have an opening angle width that substantially matches the opening angle width of the salient pole pieces of the winding salient poles. 4. The permanent magnet rotor is arranged such that the other ends of the magnetic poles of the N and S poles are parallel to the circumferential ends extending in the axial direction of the salient pole pieces. The magnetic poles of the poles are formed by magnetization. 5 The above permanent magnet rotor has one end of its N pole and S pole extending over an angle θ of 1/4 to 3/4 magnetic pole width from one end of said one end, and from a position of said θ degree to said one end. The N and S poles at one end are magnetized in a skewed manner so that the magnetic force of the N and S poles gradually weakens in a skewed manner with respect to the axial direction. (2) The above permanent magnet rotor has one end of its N pole and S pole extending over an angle θ of 1/4 to 3/4 magnetic pole width from one end of the one end, and from the position of the θ degree. A skew-shaped recess is formed in the N-pole and S-pole at the one end so that the magnetic force of the N-pole and S-pole gradually weakens in a skewed manner with respect to the axial direction as it reaches the one end. The iron core type single-phase brushless motor according to claim 1, characterized in that: