JPS5932985B2 - surface facing motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface-opposed rotor in which a planar stator coil is arranged opposite to a disk-shaped permanent magnet rotor, and its purpose is to simplify the assembly process. An object of the present invention is to provide a surface-opposed motor that can improve performance.

Conventionally, the present inventors used a flat permanent magnet as a rotor, as shown in Japanese Patent Application No. 48-144353 (Japanese Unexamined Patent Publication No. 50-96814), and calculated the magnetic flux in the axial direction of this permanent magnet and the chain. How about placing two coils that intersect? However, although such surface-facing motors are superior in that the coils can be easily formed, they use air-core coils that do not have magnetic material. This poses a problem in that the efficiency of the motor drops significantly, and in order to increase efficiency it is necessary to place a magnetic material together with the coil.

However, in the case of a structure in which there is only one permanent magnet rotor 1 and the coil 4 and the magnetic case 5 are provided on only one surface as in the conventional example shown in FIG. The suction force between the bearings increases, it takes time to adjust the gaps during assembly, mechanical loss in the bearings increases, and efficiency and lifespan tend to deteriorate.

In addition, in order to avoid the attractive force between the permanent magnet rotor 1 and the magnetic body 5, there is also a type of rotor in which the permanent magnet rotor 1 and the magnetic body 5 are connected by a shaft 7, as shown in the conventional example shown in FIG. However, the construction is somewhat difficult and the effective magnetic flux is reduced, resulting in a weaker generated torque.

Conventionally, as disclosed in Japanese Utility Model Publication No. 38-3910, field windings are attached to both magnetic poles of a U-shaped stator core, and both magnetic poles of this stator core are connected to a permanent magnet rotor. A small electric motor has been proposed in which a permanent magnet rotor is arranged in the axial direction and opposed from both sides to the side surface of the rotor. Since the permanent magnet rotor was placed closer to the surface of the permanent magnet rotor than the wire, the permanent magnet rotor easily stopped at a position where its N pole and S pole faced both magnetic poles of the U-shaped stator core. There was a problem in that rotational unevenness was more likely to occur.

The present invention is provided in view of the above-mentioned points, and improves the arrangement relationship between the permanent magnet rotor, the stator coil, and the magnetic body to reduce the attractive force between the permanent magnet rotor and the magnetic body. In addition to reducing mechanical loss in the bearing, it also reduces uneven rotation of the permanent magnet rotor.

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

FIG. 1 shows a sectional view of an embodiment of the present invention, in which a permanent magnet rotor 1 has a disk-shaped magnetic material 8 attached to a shaft 7, for example, a resin portion 16.
The magnetic material 1 is formed by simultaneous molding with the second magnetic material 1.
As shown in Figure A, it is magnetized in the thickness direction.

Through the air gap GG in the thickness direction of this permanent magnet rotor 1,
A planar coil 4.4a serving as a stator is positioned and fixed in the groove of the case 9.

Furthermore, magnetic bodies 5 and 5a used as iron cores are arranged on the back surfaces of the coils 4 and 4a on the case side, forming a magnetic path.

The bearings 10, 10a are fixed to cases 9, 9a, and the cases 9, 9a are connected to each other with screws 1'1.11.

Next, a more detailed explanation of the embodiment shown in FIG. 1 will be given with reference to FIGS. 2 to 4.

Fig. 2 A 1 is a magnetic material 8 constituting the permanent magnet rotor 1
As shown in the figure, the inner periphery of one side of the disc-shaped magnetic material 8 is divided into equal angular intervals, and each region is alternately magnetized to N pole and S pole. and inner magnetic pole 2
The outer periphery of each inner periphery magnetic pole 2 is equally divided into two in the circumferential direction, and each area is alternately magnetized to N and S poles to form an outer periphery magnetic pole 3. The side is magnetized with a different polarity from the single side.

The coils 4, 4a facing the permanent magnet rotor 1 are formed by sandwiching and molding a planar wound coil body 12 between insulators 13, as shown in FIG.
The protrusion 14 of the insulator 13 protruding from the circumference of the coil 4,
4a to the case 9.

Further, the magnetic bodies 5 and 5a are used as iron cores, and in order to reduce iron loss, it is better to form them with wound iron.

In the above embodiment, for example, the coil body 12 of the coil 4 is positioned with respect to the permanent magnet rotor 1 as shown by the dashed line in FIG.

Further, as shown in FIG. 3, inner circumferential coil portions A and A' of the coil body 12, which face the inner circumferential magnetic poles 2 of the permanent magnet rotor 1, are arranged along the radial direction of the permanent magnet rotor 1. It is configured to form an angle (=180 degrees) obtained by dividing 360 degrees by the number of inner circumferential magnetic poles (-2) of the permanent magnet rotor 1.

Therefore, the current flowing through the inner circumferential coil portions A and A' generates torque in the inner circumferential magnetic pole 2, and the permanent magnet rotor 1 is rotationally driven by this torque.

Also, the dead center position (so-called dead point) where the inner circumferential coil portions A and A' exist on the boundary line of the inner circumferential magnetic pole 2.
In the case of the coil body 12. Since the outer circumferential coil parts B and B' cross over the N and S poles of the outer circumferential magnetic pole 3, torque is generated in the outer circumferential magnetic pole 3 by the coil current flowing through the outer circumferential coil parts B and B'. There is.

Therefore, assuming that the coils 4 and 4a are excited, the section in which torque is generated in the permanent magnet rotor by this exciting current is larger than 180 degrees.

On the other hand, the coil main body position of the coil 4 and the coil main body position of the coil 4a are arranged at an electrical angle of 180°.

Therefore, if the torque when the coil 4 is excited is shown by a solid line, and the torque when the coil 4a is excited is shown by a broken line,
The relationship between the rotation angle θ of the permanent magnet rotor 1 and the torque T is the fourth
As shown in the figure, the coil 4 is excited when the permanent magnet rotor 1 is in the P angle range, and the coil 4a is excited when the permanent magnet rotor 1 is in the Q angle range to rotate in one direction. Therefore, it is possible to obtain a motor that does the following.

Further, point X in FIG. 4 indicates the rotation angle when the permanent magnet rotor 1 and the coil body 12 are in a positional relationship as shown in FIG.

Next, FIGS. 5 and 6 show the magnetized state of the magnetic material 8 and the shape of the coil body 12 when four inner circumferential magnetic poles 2 and eight outer circumferential magnetic poles 3 are provided. .

First, the inner peripheral part of the disk-shaped magnetic material 8 forming the permanent magnet rotor 1 is divided into four parts at equal angular intervals (90 degrees), and each divided area is magnetized alternately to N and S poles. The inner peripheral magnetic poles 2 of four poles are formed.

Further, the outer circumferential area of each inner circumferential magnetic pole 2 is divided into two equal parts in the circumferential direction, and each of the two equally divided areas is alternately magnetized to N pole and S pole to form eight outer circumferential magnetic poles 3. It is formed.

Next, the coil body 12 is arranged along the radial direction of the permanent magnet rotor 1, and rotates 360 degrees to the permanent magnet rotor 1.
Angle (-9) divided by the number of inner magnetic poles 2 (-4 poles)
At the dead center position where the inner circumferential coil parts A and A' are on the boundary line of the inner circumferential magnetic pole 2, the N pole and S of the outer circumferential magnetic pole 3 Outer circumferential coil portions B and B' are provided across the top to generate rotational torque.

Further, FIG. 7 shows the method of excitation of each coil 4, 4a, and the N pole and S pole are
A magnetically sensitive element 6 such as a Hall element that alternately detects the poles and generates an electric signal according to the rotational position of the permanent magnet rotor 1 is arranged at a position facing the inner circumferential magnetic pole 2 of the permanent magnet rotor 1. The output of the magnetically sensitive element 6 is used to alternately turn on and off the switch elements 15, 15a to excite the coil 4.4a.

Note that the magnetically sensitive element 6 may be composed of something other than a Hall element, and in this case, the output of the magnetically sensitive element 6 may be connected to one or both of the switching elements 15 and 15a.

The present invention is configured as described above, and planar stator coils are arranged and fixed oppositely on both sides of a disk-shaped permanent magnet rotor with a gap therebetween, and a magnetic field is attached behind each stator coil. Since the magnetic body is arranged in such a way that the attractive force between the permanent magnet rotor and the magnetic body can be balanced in a well-balanced manner, the load applied to the bearing is reduced, compared to the conventional example shown in Figure 8. This has the effect of reducing mechanical loss and prolonging the service life. Also, in the present invention, since the stator coil and the magnetic body are arranged on both sides of the permanent magnet rotor, assembly can be carried out in one direction of the case. This can only be done from the ground up, and has the advantage of being easier to assemble compared to the conventional structure shown in Figure 9, in which the permanent magnet rotor and magnetic material are placed on both sides of the stator coil. It is something that

Further, in the present invention, since the outer circumferential coil part and the outer circumferential magnetic pole are provided to generate rotational torque at the dead center position where the inner circumferential coil part exists on the boundary line of the inner circumferential magnetic pole, it is different from the conventional permanent magnet rotor. This has the effect of reducing the number of excitation coil lead wires because it is possible to reduce the number of excitation coils to two instead of the minimum of three required to eliminate dead center positions. .

Furthermore, in the present invention, magnetic bodies are arranged on both sides of the permanent magnet rotor via stator coils, so that the small electric motor disclosed in Utility Model Publication No. 38-39] and Publication No. As shown, U is close to the surface of the permanent magnet rotor.
Compared to a configuration in which the magnetic poles of a character-shaped iron core are arranged, there is also the effect that rotational unevenness due to the magnetic attraction force that the permanent magnet rotor receives from the magnetic body is reduced.

Note that if the coils are configured to be alternately excited according to the output of the magnetically sensitive element as shown in the embodiment of the present invention, there is no need to provide a brush or another mechanical switch, and a non-contact This is extremely advantageous as it can improve the lifespan.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of the present invention, and FIG. The openings are an enlarged side view and an enlarged plan view showing the magnetized state of the permanent magnets of the disk-shaped magnetic material rotor, respectively, FIG. 3 is an enlarged plan view with a part of the coil cut away, and FIG. 4 is the same as the above. 5 is an enlarged plan view showing the magnetized state of the disc-shaped magnetic material of another embodiment of the same as above, and FIG. 6 is a partially cutaway view of the coil corresponding to the embodiment of FIG. 5 of the same as above. 7 is a circuit diagram of the same drive circuit 1 as above, FIG. 8 is a schematic sectional view of a conventional example, and FIG. 9 is a schematic sectional view of another conventional example, in which 1 is a permanent magnet rotor, 2 3 is the inner circumferential magnetic pole, 3 is the outer circumferential magnetic pole, and 4.
4a is a coil, 5 and 5a are each a magnetic material, 6 is a magnetic sensing element, G is an air gap, A and A' are inner circumferential coil parts, B and B
' is the outer circumferential coil part.

Claims (1)

[Claims] 1 The inner circumference of one side of the disc-shaped magnetic material is divided into equal angular intervals, and each area is alternately magnetized to N pole and S pole to form an inner circumference magnetic pole, and the outer circumference of each inner circumference magnetic pole is The outer circumferential magnetic pole is formed by alternately magnetizing each area into two halves in the circumferential direction to N and S poles, and the other side of the magnetic material is magnetized with a different polarity from the one side to permanently magnetize it. The magnet rotor is formed by an inner circumferential coil portion that is arranged along the radial direction of the permanent magnet rotor and forms an angle of 360 degrees divided by the number of inner circumferential magnetic poles of the permanent magnet rotor, and an inner circumferential coil portion that forms a magnet rotor. At the dead center position existing on the boundary line of the peripheral magnetic poles, a planar stator coil having an outer circumferential coil portion that crosses over the N and S poles of the outer peripheral magnetic poles and generates rotational torque is connected to both sides of the permanent magnet rotor. What is claimed is: 1. A surface facing motor, characterized in that the coils are arranged and fixed opposite to each other through a gap with respect to a magnetic pole surface, and a magnetic body is arranged behind each of these coils.