JPH0336217Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a permanent magnet DC motor in which a stator and a rotor are arranged to face each other in the axial direction. Regarding ivy.

[Technical background of the invention and its problems]

Examples of this type of motor include those shown in Figures 3 and 4.
The brushless motor shown in the figure has been provided in the past.
In FIG. 3, the armature coil a on the stator side is wound and fixed on the stator yoke b along the stator yoke b. The permanent magnet c on the rotor side is fixed to the rotor yoke d with a gap in the axial direction relative to the permanent magnet c. However, in such a configuration, since the thickness of both the permanent magnet c and the armature coil a are added in the axial direction of the motor, the thickness of the motor inevitably increases.

On the other hand, in the one shown in FIG. 4, a permanent magnet c is arranged on the outer circumference of a rotor yoke d, and a stator yoke b is provided on the inner circumferential surface of the permanent magnet c so as to face it in the radial direction with a gap therebetween. This configuration has an armature coil a wound around the outer peripheral end of a stator yoke b. However, in such a configuration, although the thickness of the permanent magnet c is not added in the axial direction of the motor, the thickness of the motor still increases due to the restriction on the radial dimension of the armature coil a. Therefore, such a conventional configuration has the disadvantage that it cannot sufficiently cope with the recent demand for thinner motors.

[Purpose of invention]

Therefore, an object of the present invention is to provide a permanent magnet DC motor that can be made sufficiently thin.

[Means to solve the problem]

The permanent magnet DC motor of the present invention includes a stator consisting of a stator yoke and an armature coil disposed on the stator, a substantially disk-shaped rotor yoke disposed axially opposite to the stator, and a field arranged annularly around the stator. and a rotor made of permanent magnets, the stator yoke having an outer circumferential portion facing the inner circumferential portion of the permanent magnet with a predetermined gap in the radial direction. a plurality of first rotor facing portions formed in separate sections, and a plurality of first rotor facing portions formed inwardly of the first rotor facing portions in the stator yoke, respectively corresponding to the first rotor facing portions, and axially connected to the rotor. and a second rotor facing part that protrudes in the axial direction on the rotor side so as to face each other with a predetermined gap therebetween, and then the armature coil is placed on the stator yoke and the second rotor facing part is placed on the stator yoke. It is characterized by its surrounding arrangement.

[Effect]

The first rotor facing part of the stator yoke faces the permanent magnets of the rotor with a predetermined gap in the radial direction, and the second rotor facing part of the stator yoke faces the rotor with a predetermined gap in the axial direction. Since the permanent magnets face each other, a magnetic circuit is formed in which the permanent magnets reach the permanent magnets via the respective first and second rotor opposing parts. With this, when the armature coil is energized,
The rotor rotates due to the interaction between the magnetic flux of the permanent magnet passing through the magnetic circuit and the magnetic flux of the armature coil.

Here, the armature coils are arranged so as to surround the second rotor facing part, and are stacked against the stator yoke similarly to the conventional axial gap type motor (see Fig. 3), and the armature coils are arranged in a manner similar to the conventional radial gap type motor (see Fig. 3). The axial dimension of the entire stator is shorter than that of the motor (see FIG. 4). Moreover, like a conventional radial gap type motor, the permanent magnets face the rotor in the radial direction with an air gap in between, and are arranged side by side with the armature coil.
Unlike conventional axial gap type motors, the thickness of the permanent magnets does not add to the axial dimension of the entire stator, which allows the entire motor consisting of the stator and rotor to be made thinner. become.

[Example of idea]

An embodiment in which the present invention is applied to a brushless motor will be described below with reference to FIGS. 1 and 2. 1
2 is a stator, and 2 is a rotor arranged to face the stator 1 in the axial direction. Rotor 2 is
It comprises a rotor yoke 3 having a short surrounding wall 3a on the outer peripheral edge of a disk, and a permanent magnet 4 for a field fixed to the inner peripheral side of the surrounding wall 3a. The stator yoke 5 of the stator 1 has a substantially circular shape as a whole and is located inside the rotor 2, and has a first rotor that faces the inner circumferential surface of the permanent magnet 4 in the radial direction with a gap in between. The facing portion 6 is formed by bending.
A second rotor facing part 7 is formed on the stator yoke 5 to be located on the inner circumferential side of the first rotor facing part 6, and this part bulges toward the rotor yoke 3 and is connected to the rotor yoke 3 through a gap in the axial direction. They are set up to face each other. The second rotor facing portions 7 are formed in a substantially fan shape that widens toward the outer circumferential side of the stator yoke 5, and a plurality of second rotor facing portions 7 are provided intermittently along the circumferential direction of the stator yoke 5. In particular, in this embodiment, the second rotor facing portion 7 and the rotor yoke 3
The dimension of the gap A between the first rotor facing part 6 and
The axial dimension of the motor is set to be smaller than the dimension of the gap B between the permanent magnet 4 and the permanent magnet 4, and the dimension of the gap A is set to be smaller than the dimension of the gap B between the permanent magnet 4 and the
The size of the gap C between the first rotor facing part 6 and the rotor yoke 3 is set to be smaller than the size of the gap C, so that short circuit from the first rotor facing part 6 to the rotor yoke 3 can be prevented without passing through the second rotor facing part 7. We try to prevent the formation of magnetic circuits as much as possible.
Furthermore, slits 8 are provided in the stator yoke 5 between the second rotor facing portions 7 to increase the magnetic resistance between the second rotor facing portions 7.
Reference numeral 9 denotes an armature coil, which is provided so as to be wound around the second rotor facing portion 7 along the stator yoke 5.

In the above configuration, as indicated by the arrow in FIG. It is formed. Therefore, by energizing the armature coil 9, the rotor 2 rotates due to the interaction between the magnetic flux of the permanent magnet 4 passing through the magnetic circuit and the magnetic flux of the armature coil 9.

Therefore, in this embodiment, the armature coil 9
and permanent magnets are arranged in the radial direction,
Both axial dimensions do not add up to increase the overall axial dimension. Further, since the armature coil 9 is shaped along the stator yoke 5, even if its radial dimension is large, the axial dimension of the entire motor is not increased. As a result, compared to the conventional configuration shown in FIGS. 3 and 4, the axial dimension of the entire motor can be significantly reduced and the motor can be made extremely thin.

[Effect of idea]

As explained above, the present invention has an excellent effect in that the armature coil and the permanent magnet can be arranged in the radial direction of the motor, so that the overall thickness can be significantly reduced.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing one embodiment of the present invention;
The figure is a plan view of the same, and FIGS. 3 and 4 are views corresponding to FIG. 1 showing a conventional motor. In the drawing, 1 is a stator, 2 is a rotor, 3 is a rotor yoke, 4 is a permanent magnet, 5 is a stator yoke,
6 is a first rotor facing portion, 7 is a second rotor facing portion, 8 is a slit, and 9 is an armature coil.

Claims (1)

[Claims for Utility Model Registration] 1. A stator 1 consisting of a stator yoke 5 and an armature coil 9 disposed thereon, a substantially disk-shaped rotor yoke 3 disposed axially facing the stator 1, and an annular rotor yoke 3 arranged axially opposite to the stator 1; It is constructed by combining a rotor 2 consisting of field permanent magnets 4 arranged, and a predetermined gap is formed between the outer periphery of the stator yoke 5 and the inner periphery of the permanent magnets 4 in the radial direction. A plurality of first parts are divided in the circumferential direction so as to face each other and to face each other.
and a rotor-facing portion 6 formed in the stator yoke 5 at a position inside the first rotor-facing portion 6 to correspond to the first rotor-facing portion 6, respectively, and forming a predetermined gap in the axial direction with the rotor 2. A second rotor facing portion 7 protruding in the axial direction on the side of the rotor 2 is provided to face the armature coil 9 and the stator yoke 5.
A permanent magnet DC motor, characterized in that a permanent magnet direct current motor is disposed above the second rotor facing portion 7 so as to surround the second rotor facing portion 7. 2. The permanent magnet DC motor according to claim 1, wherein the second rotor facing portion 7 is formed in a generally fan-shaped bulge that expands toward the outer circumferential side of the stator yoke 5. 3 The stator yoke 5 has a second rotor facing part 7
A permanent magnet DC motor according to claim 1 or 2, characterized in that a slit 8 is formed between the slits 8. 4 The gap between the second rotor facing part 7 and the rotor yoke 3 is the gap between the first rotor facing part 6 and the permanent magnet 4.
3. A permanent magnet DC motor according to any one of claims 1 to 3, wherein the permanent magnet DC motor is set to be smaller than the air gap between the two.