JPS60174049A - Rotary electric machine with axial magnetic flux air gap - Google Patents

Abstract

PURPOSE:To increase the output of a motor by using a strong magnet material by using both sides of a disc-shaped magnet rotor. CONSTITUTION:Pole teeth of a stator 4 are alternately excited to S-pole and N- pole by energizing a stator winding 45. A rotor 1 is stopped by the generation of the S-pole and N-pole so that the poles N1, N2, N3, ... of the rotor 1 are opposed to the S-pole of the stator 4 and the poles S1, S2, S3,... of the rotor 1 are opposed to the N-pole of the stator 4. Then, the energization of the stator winding 45 is interrupted, a current is flowed to the stator winding 45', and the poles of the stator 4' are alternately excited to S-poles and N-poles. The rotor 1 is moved to the position that the poles N1, N2, N3,... of the rotor 1 are opposed to the S-pole of the stator 4' and the poles S1, S2, S3,... of the rotor 1 are opposed to the N-pole of the stator 4', and stopped.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a rotating electric machine having a magnetic flux gap in the axial direction,
In particular, it is applied to motors that operate as permanent magnet stepping motors or synchronous motors, with a flat shape, large output, and a rotation with a magnetic flux gap in the axial direction that enables driving at minute step angles. The present invention relates to electrical machinery, and can be used, for example, as a flat stepping motor with minute angle drive for driving the magnetic head of a magnetic disk drive device.

[Background of the invention]

In conventional permanent magnet stepping motors or synchronous motors, a cylindrical permanent magnet is magnetized in the radial direction so that the outer circumferential surface of the cylinder is divided at the same pitch and each section becomes an alternating north pole and south pole. Generally, a configuration is adopted in which stator magnetic poles are arranged on the outer circumferential side of the rotor, and have a magnetic flux gap in the radial direction. Ta. However, this conventional configuration has the following problems. That is, (1) when a cylindrical magnet material is magnetized with a large number of magnetic poles in the radial direction, the strength of the magnetic poles decreases rapidly as the number of poles increases, and the output decreases, so the number of poles is limited.

(2) The output can be increased by lengthening the motor shape in the axial direction, but there are problems such as this is not suitable for a flat configuration. In particular, it is not suitable for flat stepping motors that are required to be driven at minute angles and are used in magnetic disk drive devices, the demand of which has been rapidly increasing recently.

[Purpose of the invention]

The purpose of the present invention is to solve the above-mentioned problems in the prior art, to provide a rotary electric machine having a magnetic flux gap in the axial direction, which has a flat shape, increases output, and enables minute angle drive, and which has good mass productivity. Our goal is to provide the following.

[Summary of the invention]

The present invention is characterized in that, in order to achieve the above object, (a) each section obtained by dividing the disk surface at the same pitch in the circumferential direction alternately becomes a north pole and a south pole, and is orthogonal to the disk surface; A disc-shaped magnet magnetized in the same direction is used as a rotor and is integrally attached to the rotor shaft at the center of the disc.

(b) The rotor shaft is rotatably supported by two front and rear bearings that sandwich the rotor in the center.

(c) The above bearings are each fixedly held at the inner diameter portion of the stator.

(d) These stators consist of stator magnetic pole disks that are placed at positions facing the front and rear magnetized surfaces of the magnet rotor in the axial direction with a small gap in between, and a cylinder that abuts on the outer diameter side of the stator magnetic pole disks. A magnetic circuit formed by a cylindrical outer yoke, a cylindrical inner yoke that abuts on the inner diameter side, an end plate and a yoke that abut the other end surfaces of the outer yoke and the inner yoke, and the outer yoke and the yoke. Each stator winding is wound in the gap between the inner yoke and the stator winding.

(e) The stator magnetic pole disks are each divided into sections in the circumferential direction at the same pitch as the division of the rotor disk surface, so that magnetic poles of different polarity are generated alternately in each section. Numerous holes are drilled in the disk surface in an almost radial pattern.

(f) The above two stators are arranged so that the magnetic poles generated on each stator magnetic pole disk are shifted by one pitch in the circumferential direction. [Embodiment of the invention] The following , an embodiment of the present invention will be explained with reference to the drawings.

FIG. 1 is a sectional view of an embodiment in which the present invention is applied to a flat permanent magnet type stepping motor. In Figure 1,
l is a rotor composed of disc-shaped magnets, 2 is this rotor 1
The rotor shafts 3 and 3', which are integral with the rotor shaft, are bearings that sandwich the rotor l in the center and rotatably support the rotor shaft 2 at two positions F in the front and rear, and in the embodiment, are made of porous resin. This is a cylindrical bearing. The rotor l is shown in plan view in Fig. 4(a).
As shown in the cross-sectional view at In the example, divide the sections into 16 equal parts) so that each section becomes the N pole and S pole alternately, and in the direction perpendicular to the disk surface (i.e., if the front side of a certain section is the S pole, then the rear side of that section is magnetized so that the front side becomes the N pole and the rear side becomes the S pole in the adjacent section). In this way, magnetizing the disk surface in the direction perpendicular to the disk surface is easily possible using anisotropic magnet materials, and since the magnetization position is the outermost part of the disk. Compared to the conventional configuration in which the outer periphery of a cylindrical magnet material is magnetized in the radial direction, it is possible to make a stronger magnet, and the magnetization surface is wider and the number of poles can be increased, making it suitable for stepping motors. By applying this method, it is possible to drive at minute step angles.

Returning to FIG. 1, 4 and 4' are stators, respectively, which are attached to the inner circumferential side of the motor case 5 so that the rotor l is sandwiched in the center and the rotor l is placed in the front and rear positions in the axial direction. A cylindrical bearing 3°3' is fixedly held at the portion. Each stator 4, 4' has a stator magnetic pole disk 41, 41' disposed at a position facing the magnetized surface of the rotor 1 in the axial direction with a small gap of about 0.05 wn interposed therebetween; A cylindrical outer yoke 42.42' whose one open end surface is in contact with the outer diameter side of each of these magnetic pole disks 41.41', and a cylindrical outer yoke 42.42' which is in contact with the inner diameter side of each of the magnetic pole disks 4.1.41'. It is formed by a cylindrical inner yoke 43.43' whose one open end surface abuts, and a disc-shaped end plate yoke 44.44' which abuts the other open end surface of each of the outer yoke and the inner yoke. and stator windings 45° 45' respectively wound in the spaces between the outer yokes 42, 42' and the inner yokes 43, 43'. In addition, 4
6.46' is a bobbin frame made of insulating material around which stator winding 45.45' is wound.

Next, the details of the stator magnetic pole disks 41, 41' will be explained in the second section.
This will be explained with reference to FIG. In addition, stators 4 and 4' are
They have exactly the same configuration and are easy to assemble.

The only difference is that the stator magnetic pole disks 41 and 41' are arranged so as to face the magnetized surface of the rotor l. Plan view (a) of one embodiment of the magnetic pole disk 41 and its x-x'
A sectional view is shown, and FIGS. 3(a) and 3(b) show main parts of a plan view of another embodiment. Each of the magnetic pole discs 4 is divided into sections (16 divisions in the embodiment) in which the disc surface is divided in the circumferential direction at the same pitch as the division for magnetizing the disc surface of the rotor 1. A large number (16 holes in the embodiment) of holes 41-H are formed substantially radially so that magnetic poles of different polarities are generated alternately. With such a configuration, when punching out a disk from a magnetic iron plate, holes can also be formed by press punching at the same time.
Alternatively, it can be manufactured with good mass productivity by photo-etching a magnetic disk to form punch holes. Figure 3 shows that when a magnetic pole disk having radial holes as described above is excited by passing a current in a certain direction through the stator winding 45, magnetic poles of different polarity are generated alternately in each section. The magnetic pole disk 41 having a ta+ configuration will be explained. This third
Figure fa) is an example in which the magnetic pole disk 41 is separated into the outer circumferential side and the inner circumferential side, but now the stator winding is excited, and the inside of the magnetic pole disk 41 is moved from the center to the outer circumference. Assuming that the magnetic flux flows in the direction of the arrow shown (◇), two adjacent pole teeth 4l-T (11, 4l-T (21), The magnetic flux flows out and the pole tooth 41
- Magnetic flux flows into the tip of T(2+, that is,
Two adjacent pole teeth 4l-T(11°41-T(21
In this case, magnetic poles of different polarity are generated. Third
Figure (bl) is an example in which the magnetic pole disk 41 is not separated between the outer circumferential side and the inner circumferential side and is partially provided with a twist. Even in this configuration, the excitation of the stator winding allows two adjacent Magnetic poles of different polarity are generated in the pole teeth.In the embodiment shown in FIG. - By making the shape of H as shown in the example, the magnetic flux density of the two adjacent pole teeth becomes maximum at the point where the tsunagari indicated by the dashed line (the sword) becomes the narrowest. Considering the inflow and outflow state of magnetic flux at the narrowest part, it becomes as shown by the arrow (0) in the figure, and therefore, magnetic poles of different polarity are generated in two adjacent pole teeth.

Stator magnetic pole disks 41', 41 having the above configuration
The two stators 4 and 4' each have a stator magnetic pole disk 41, 41' that is approximately 0.0 0.05 in the axial direction with respect to the magnetized surface of the rotor 1.
The magnetic poles formed on the two magnetic pole disks 41 and 41' are arranged so as to face each other through a small gap of 0.05 tone, and the magnetic poles generated on the two magnetic pole disks 41 and 41' are arranged by one pitch, in the example, the central angle is 36 degrees (1/32 degree), and the circumference is It is fixedly attached to the inner circumferential side of the motor case 5 so that the existing position is shifted in the direction.

In addition, in the embodiment shown in FIG. 1, ring-shaped gap pieces are installed between the end faces of the bearings 3 and 3' and the front and rear sides of the rotor 1 in order to maintain the above-mentioned small magnetic flux gap in the axial direction. The case is shown in which the magnetized surface of the rotor l and the stator magnetic pole disk 41.4
In order to prevent mechanical contact between It is also possible to form a structure in which the stator magnetic pole disk and the rotor are opposed to each other via this solid lubricant film.

The step movement operation of the embodiment stepping motor having the above configuration will be explained with reference to FIGS. 5 and 6. Figure 5 shows a developed view of the rotor 1 and stators 4, 4', (al is the rotor when current flows in the direction of the arrow in the stator winding 45 (winding terminals are A and B). and both stators. At this time, the stator winding 45' (C and D are the winding terminals) is not energized. By energizing the stator winding 45, each pole of the stator 4 The L teeth alternately have S pole,
Excited to n-pole. Due to the generation of these S and N poles,
The rotor l is in the position shown, i.e. rotor 1 N,, N2
．． N3. The magnetic poles of ... oppose the S pole of the stator 4, and the SL of the rotor 1.

S2. S3. It stops at a position where the magnetic pole of . . . opposes the 0 pole of the stator 4. Next, moving to figure +b1, by cutting off the current to the stator winding 45 and passing current in the direction of the arrow to the stator winding 45', each pole tooth of the stator 4' is alternately set as shown in the figure. It is excited to S pole and N pole. Due to the generation of these south and n poles, the rotor l has its N, , N
2. N3. The magnetic poles of . . . are opposed to the S pole of the stator 4', s3. The magnetic poles of . . . move to a position opposite to the n-pole of the stator 4' and stop. Since the stator 4 is misaligned, from (a) to (b) above
Step 1 As shown in the energization sequence in Fig. 6, the energization to the stator winding 45' is cut off, and the stator winding 45 is energized in the opposite direction to that shown in Fig. 6(a). By passing current in directions B and A, S poles and n poles are generated alternately on the pole teeth of the stator 4. An S pole is generated at the position, which cuts off the current to the rotary stator winding 45, causing the stator winding 45'1 to
(b) Contrary to the case shown in the figure, the current is moved in the D and C directions. This completes one cycle, and then returns to the state shown in the fai diagram again, and by passing current through the stator winding 45 in the A-B direction, the rotor l reaches a certain magnetic pole Nl.
” As shown in Figure 6, the step movement/movement state is as follows.
The stator windings 45, 45' are energized (A, B), (C-
D), <B-A), <D→C), (A→B).

In the explanation of the above step operation, in order to simplify the explanation, the rotor 1 is divided into 16 equal parts of the disk surface. Alternately, in the direction perpendicular to the disk surface, N and S poles are placed in each section.
It is assumed that the magnet is polarized to become a pole, but as shown in Fig. 4 (bl
As shown in , if the front side of one section is S'+WA, even if the rear side of that section is magnetized to be N pole, the difference is such that the moving direction of rotor 1 is reversed. They are the same in that they perform step operations. In addition, Fig. 5 (b
1, by passing current through the stator winding 45' in the C-D direction, the pole teeth of the stator 4' are alternately S pole and 11 poles are generated as shown in the figure. On the contrary, S
Even if an n-pole is generated at the pole position and an S-pole is generated at the n-pole position, the step operation is the same, except that the moving direction of the rotor 1 is opposite to the above.

〔Effect of the invention〕

As explained above, according to the present invention, (1) since both sides of the disk-shaped magnet rotor are used, stronger magnetic materials (for example, anisotropic (ferrite, etc.) can be used to create a motor with a large output.

(2) Since the magnetized surface of the disc-shaped magnet rotor is wide and the number of magnetic poles can be increased, a motor with a minute step angle can be achieved.

(3) Since the stator magnetic poles are disposed in a plane, it is easy to obtain a motor with high precision, and a motor with a minute step angle can be obtained.

(4) A disk-shaped rotor is sandwiched between stators from the front and back, and each stator consists of one stator magnetic pole disk, one set of cylindrical yokes, one end plate yoke, and one end plate yoke. Since it has a simple structure formed from stator windings, it is easy to assemble and has the advantage that it has good productivity and can be made into a flat motor.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a diagram showing an example of a stator magnetic pole disc used in the present invention. fal is a plan view, tb) is its xx' cross-sectional view, and FIG. 3(a). (bl is a plan view of main parts showing other embodiments of the stator magnetic pole disc used in the present invention, FIG. 4 is a diagram showing an example of the rotor used in the present invention, (a) is a plan view, (bl is its x-x'
Cross-sectional view, FIG. 5(a), (BL is an explanatory diagram of the step operation as a stepping motor, and FIG. 6 is a diagram showing the energization sequence and rotor position for the steering knob operation. [Explanation of symbols] 1... Rotor 2... Rotor shaft 3. 3'... Bearing 4, 4'... Stator 41, 4
1'...Stator magnetic pole disk 42, 42'...Outer yoke 43, 43'...Inner yoke 44.44'...End plate yoke 45, 45'
... Stator winding 46, 46'... Pobin frame 5.
...Motor Case Patent Attorney Junnosuke Nakamura Volume 1 IP2 Diagram

Claims (1)

[Scope of Claims] (a) A disc shape in which each section obtained by dividing the disc surface at the same pitch in the circumferential direction becomes an N pole and an S pole alternately, and is magnetized in a direction perpendicular to the disc surface. A magnet is used as a rotor and is integrally attached to the rotor shaft at the center of the disc.i. (b) The rotor shaft is rotatably supported by two bearings, front and rear, sandwiched at the center of rotational pre-electrification. (c) Each of the above bearings is fixedly held at the inner diameter portion of the stator. (d) These stators consist of stator magnetic pole disks that are placed at positions facing the front and rear magnetized surfaces of the magnet rotor in the axial direction with a small gap in between, and a cylinder that abuts on the outer diameter side of the stator magnetic pole disks. 3. A cylindrical inner yoke that abuts the inner diameter side of the outer yoke. - a magnetic circuit formed by an end plate yoke that abuts the other end surface of each of the outer yoke and the inner yoke, and a fixing device wound around the space between the outer yoke and the inner yoke. Each is composed of a child winding. (e) The stator magnetic pole disks are each divided into sections in the circumferential direction at the same pitch as the division of the rotor disk surface, so that magnetic poles of different polarity are generated alternately in each section. Numerous holes are drilled in the disk surface in an almost radial pattern. (f) A rotating electrical machine having a magnetic flux gap in the axial direction, wherein the two stators are arranged at positions corresponding to respective stator magnetic pole disks.