JPS6152181A - Fan motor - Google Patents

Abstract

PURPOSE:To reduce the size of a fan motor by annularly mounting magnets on the outer periphery of a fan, arranging a plurality of stationary coils outside the magnet, and providing an annular yoke outside the coil, thereby eliminating a wasteful space. CONSTITUTION:Blades 3, 3... are radially mounted on a cylinder 2, at which a rotational shaft 1 is secured to the center, and circular permanent magnets 4 are secured to the outer periphery of the blades 3. A plurality of windows 5 are formed on the bottom of a bottomed cylindrical housing 6, an annular yoke 7 is mounted inside the side wall in the housing 6, stationary coils 8, 8..., are arranged inside the yoke, and bearings 9 are provided at the center of the bottom of the housing 6. Magnetic flux detecting Hall elements 14, 15 for detecting the magnetic flux are mounted at suitable positions on the inner surface of the yoke 7.

Description

DETAILED DESCRIPTION OF THE INVENTION For example, cooling fans for electronic equipment must be made extremely small. However, conventionally t! 7. You can form the fan and the motor separately and connect them directly, or even if they are integrated in advance, it is possible to install the motor inside the fan, so if you increase the torque of the motor, the shaft The length in the direction and therefore the thickness of $1 had to be made extremely large.

When such a device is attached to the wall of an electronic device's casing, a large unused space is created around the device. Therefore, the actual exclusive space of the device can be effectively reduced by the fan device K. The present invention eliminates these drawbacks, especially when it is attached to the wall of an electronic device's casing, etc. without creating an unusable empty space around it. To provide a fan and a motor that can effectively reduce the size of a device by installing a fan.

The present invention is as described in patent zn f@gVc <% 7
Attach a magnet in a ring shape to the outer periphery of the magnet.The outer part of the magnet is connected in the circumferential direction to the N pole, S pole, L (pole...
A plurality of fixed coils are arranged on the outer side 1c of this magnet, and a Km-shaped yoke is provided on the outer side of the coil.

Therefore, the lines of magnetic force leading from the six poles H and E to the yoke intersect with the coils between them, so that by passing current through the coil IC, a rotational force is generated in the magnet 1, that is, the fan inside it. When the magnetic flux moves and the direction of the magnetic flux is reversed, the current in the coil is switched in the opposite direction at the same time, so the rotational force in the same direction continues, causing the fan to rotate continuously. In addition, magnets are arranged in a ring on the outside of the fan consisting of radial blades, and multiple fixed coils and an annular yoke are arranged coaxially on the outside, so the volume required for the motor is reduced. Assuming that is constant, as the length in the circumferential direction increases, the length in the axial direction becomes extremely small, and the fan and its drive motor can be constructed as an extremely thin plate-like integrated YA member. For example, when the fan motor is attached to the wall of the case of an electronic VA device, unnecessary space is not created around it, the device can be packed into a compact size, and the inside of the case can be effectively cooled. .

Figure 1, 2r2? I is a storage example of the present invention, FIG. 2 is a longitudinal sectional view, and FIG. 1 is an A-AUID diagram of FIG. 2.

In this way, a cylindrical body 2 made of synthetic resin or the like with the rotating shaft 1 fixed at the center is connected to a cylindrical body 2 of Ω3, 3. Attach , , , radially and warp.

The outer surface of the magnet 4 has N and S poles alternately formed at intervals of 60 degrees, for example, as shown by the symbols r and S in Fig. 1, and a plurality of windows 5 are formed on the opening and bottom surface. An annular yoke 7 is attached to the inside of the side wall of the wide bottomed cylindrical housing 6, and furthermore, for example, four fixed coils 8.8. ,,
- are arranged so that their axes are perpendicular to the rotating shaft 1, and the bearings are placed at the center of the bottom surface of the housing 6. This is provided. Furthermore, a center bearing 11 is attached to a substantially square base 10 whose length on one side is equal to the diameter of the housing 6, a plurality of windows 12 are widened around the base 10, and bolt holes 13 for mounting are provided at the four corners. It is a provision. That is, the bearings of this base 10 are provided with the grooves 3, 3, . . .
・Fit the fan shaft 1 with the coils 8, 8・
It is assembled into one piece by fitting the housing 6 with the yoke 7 attached, and fitting the other end of the shaft 1 into the bearing 9. Hall element 14 for magnetic flux detection. and 15 are installations.

FIG. 3 is an enlarged view of a part of FIG. 1, in which a current with the polarity shown by symbols a and h flows through one of the fixed coils 8, and the outer surface of the annular magnet number is shown in the figure. , if it is magnetized as shown by S, magnetic flux as shown by the thin glands a and d with arrows will be generated through the magnet 4 and the yoke.・It is held rotatably. 't.Arrow p to magnet 4
A rotational force such as is applied. In addition, FIG. 4 shows the Hall element 14.
This is an example of a circuit that switches the direction of the current in the two coils 8, 8 on both sides of the coil.
Connect 3d and amplification transistors 21, 32, etc.
Further, a diode 23 for removing back electromotive force is connected to the coil 8. In other words, since a magnetic flux such as the thin wire e acts on the Hall element 14 in FIG. Transistor 18. I9 conducts, 17#20 cuts off, and Koi A/ a, a K is an arrow! A current with the polarity shown flows, and this current generates a rotational force in the direction of the arrow p in the magnet number as described above. Also, assuming that the magnet book rotates due to the rotational force and becomes the north pole position in FIG. 3 or the south pole position, the Hall element 14) t
Since the direction of the applied magnetic flux is also reversed and a negative signal is sent from one terminal, transistor 21 becomes conductive and transistor 22 is cut off. Therefore, transistors 17 and 2
0 is conductive, 1B and 19 are disconnected, and current flows in the direction opposite to arrow I through the coils 8 and 8, so the rotational force applied to magnet 4 maintains the direction of arrow P.

Furthermore, FIG. 5 is a diagram showing the rotational force generated in each part and its direction at each rotational position IVt of the above-mentioned actual flIi example.
That is, the annular permanent magnet 4 connects the coils 8, 8 . .

...and the Hall elements 14, 15 (assuming that they are in the position α), a rotational force is generated in each part of the magnet 4 in the directions and magnitudes shown by the arrows. That is, A large clockwise rotation torque is generated in the magnet 4, and it moves to the position (ri), but at this position (ρ is no longer 4).
A clockwise rotation torque of the same degree as d is generated and the magnet moves to position ri. At this position, counterclockwise rotation torque is generated on a part of the magnet, and part of the clockwise rotation torque is canceled out, but fx continues to rotate due to the clockwise rotation torque.However, when the position of the hole is changed, the direction of the magnetic flux applied to the Hall elements 14 and 15 is reversed, so the coil is rotated by the circuit shown in FIG. The polarity of the current of 8, 8., , , is also reversed and C
The state d) is reached. Therefore, torques as shown by the arrows are generated in each part of the magnet, and when these are combined, a clockwise rotation torque remains, so the magnet +1-2. ('') Continuing clockwise rotation as shown in (1).In this way, in the embodiments shown in Figures 1 and 2, there is only one gap in between where the clockwise rotation torque disappears every 60 degrees of rotation. However, in most of the range, a large amount of clockwise rotation torque is generated that is almost constant and the rotation continues to 0.Also, as mentioned above, if the rotation stops at the position where the torque becomes 0, the next startup will be However, the torque required to start a fan motor is extremely small, and the range in which the torque reaches zero is extremely narrow (as explained in Figure 5). to start.

Further, if necessary, by using a weak permanent magnet or the like to define the stop and position of the motor, the next start can always be performed reliably. In addition, the five embodiments are coils and NFJs.
In contrast, the number of magnetic poles can be set to six.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a sectional view taken along the line A in FIG. 2, FIG. 2 is a vertical sectional view, FIG. 3 is an enlarged view of part 7 of FIG. 1, and FIG. ii. A diagram showing a part of the electric circuit. Figure 5 is a diagram showing the torque generated in each part of the magnet at each rotation angle position. [Here, l is the rotating shaft, 3 is the blade, 4 is the permanent magnet ~ 7 is the yoke, 8 is the coil, 14.1
5 is a Hall element.゛I, 5′″M

Claims (1)

[Claims] An annular magnet having N poles and S poles alternately formed in the circumferential direction of the outer surface is fixed to the outer periphery of the wing of a fan having radial wings formed around the rotating shaft, and the magnet is perpendicular to the rotating shaft. A plurality of fixed coils having axes in the same direction are arranged in a ring on the outside of the annular magnet, and an annular yoke is arranged on the outside of the magnet. A fan motor characterized by being equipped with a circuit that switches the coil current so that a rotational force is always applied in the same direction to the lever fan.