JP2751204B2 - Method of manufacturing flat rotor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat-type motor, and more particularly to a flat-type rotor serving as a rotating part and a method of manufacturing the same.

2. Description of the Related Art In recent years, since flat motors are required to be small (small rotor diameter), high torque, and high-precision rotation, motors using rare earth magnets as rotor magnets are increasing.

Hereinafter, an example of a conventional flat motor will be described with reference to the drawings.

FIG. 5 is a sectional view showing an example of a conventional flat motor.
11 is a chassis (bearing housing), 12A and 12B are bearings press-fitted into the chassis 11, 13 is a stator yoke, 14 is an adhesive to the stator yoke 13,
For example, a flexible printed circuit board attached with a double-sided adhesive tape is shown, and a plurality of coils 15 are provided in an annular shape on the surface opposite to the stator yoke 13. Reference numeral 16 denotes a screw, and the stator yoke 13 and the flexible printed circuit board 14 are mounted on the chassis 11 so as not to face the rotor magnet 19.
It is to be fixed at ~ 4 parts. Reference numeral 17 denotes a rotor, which is composed of a rotor frame 1, a rotor magnet 19, and a rotor boss 20.
An annular rotor magnet 19 magnetized so that the N pole and the S pole face each other alternately with the rotor frame 15 is disposed.
The rotor boss 20 is pressed into the center of the rotor frame 1 and the rotor boss 20 is fixed to the rotor frame 1 with the screw 21. Reference numeral 22 denotes a shaft whose one end is press-fitted into the rotor boss 20, the shaft 22 is supported by the chassis 11 via the bearings 12A and 12B, and a flange 23 is press-fitted on a portion opposite to the rotor boss 20. .

The rotor 17 of the flat motor configured as described above is
Generally, the rotor magnet 19 is bonded to the rotor frame 1 by heating with a two-component epoxy adhesive on the basis of the shaft 22 or by pressure bonding using an anaerobic adhesive. It is magnetized.

In this case, it is necessary to adjust the balance of the rotor 17 since the amount of unbalance of the rotor due to uneven application of the adhesive increases. Also, when the rotor magnet 19 is attached to the rotor frame 1 with the adhesive A as shown in FIG. 6 (a), the height H varies depending on the amount of the adhesive A, so that it hits the coil 15 shown in FIG. It is necessary to control the dimensions. Further, the rotor shown in FIG. 6 (b) fits the outer periphery of the rotor magnet 19 in the inner periphery of the rotor frame 1 and magnetizes from the P direction without using an adhesive, thereby attracting the rotor magnet 19 to the attraction force. Thus, the rotor frame 1 and the rotor magnet 19 are fixed. In the case of this example, it is possible to obtain a good flat-type motor without a balance correction due to an adverse effect of the adhesive, a variation in the height dimension of the rotor magnet 19, and the like. FIG. 7A shows another conventional example. In this example, a frequency generating magnet 18 is attached to the outer periphery of the rotor frame 1 or integrally formed with the rotor 17 shown in FIG. Reference numeral 27 denotes a magnetically sensitive element. Generally, the rotor magnet 19 is magnetized with eight poles, and the frequency generating magnet 18 is magnetized with n poles (n is an even number) larger than eight poles on the outer periphery. In FIG. 7, the output from the magnetic sensing element 27 when the rotor magnet 19 is magnetized for 8 poles of N and S poles and the frequency power generation magnet and the pole 18 is magnetized for 60 poles of N and S poles on its outer periphery. B of FIG. 7 (b) shows the signal waveform. In this case, even if the rotor magnet 19 and the frequency power generation magnet 18 are magnetized simultaneously, the rotor magnet 19 is magnetized first and then the frequency power generation magnet 18 is magnetized. Due to the influence of magnetism, the signal of the magnetic sensing element 27 always generates four swells per rotation.

Problems to be Solved by the Invention However, in the above-described configuration, it is necessary to correct the balance due to the adverse effect of the adhesive A in the rotor as shown in FIG. It is necessary to control the height H of the magnet 19. In the rotor shown in FIG. 6 (b), although the above-mentioned problem is eliminated, when a magnet having a high HC and which cannot be easily magnetized, such as the rare earth magnet, is used, the magnetized yoke is applied only from one side P direction. However, there is a disadvantage that it is not completely magnetized even when magnetized. In the case of a rotor having a frequency generating magnet 18 as shown in FIG. 7 (a), if the rotor magnet 1 is inserted into the rotor frame 1 and then magnetized, the output of the magnetically sensitive element 27 is obtained. Has the problem that undulations occur as in the output waveform shown in B of FIG. 7 (b). In order to solve this, it is conceivable to put a rotor magnet that has already been magnetized into the rotor frame. In this case, however, the rotor magnet is strongly applied to the rotor frame due to the attraction between the rotor magnet and the rotor frame. There was a problem that it could be damaged.

The present invention has been made in view of the above problems, and has as its object to provide a flat rotor having high dimensional accuracy and not disturbing the magnetic force of a frequency power generation magnet, and a method of manufacturing the same.

Means for Solving the Problems In order to solve the above problems, the present invention provides a rotor frame in which two or more through holes are provided in a plane portion of a rotor frame in which a rotor magnet pre-magnetized is fitted. When disposing the rotor magnet on the rotor frame, the pins are passed through the through holes, these pins are brought into contact with the rotor magnet to hold the rotor magnet, and the pins are pulled to dispose the rotor magnet on the rotor frame. is there.

According to the present invention, two or more through-holes are provided in the plane portion of the rotor frame that contacts the rotor magnet by the above-described method. Therefore, before the rotor magnet is attached to the rotor frame (single unit), the magnet is magnetized. The rotor magnet, which is magnetized by passing the pin through each pin, placing the rotor magnet on the pin, and then gently pulling the pin, can be attached by the magnetic force without violently hitting the rotor frame. The rotor frame has a circumferentially convex portion formed around the center of the shaft. If the inner or outer periphery of the rotor magnet is in contact with the projected portion, the rotor magnet can be mounted on the rotor frame without eccentricity. be able to. Further, even when the frequency generating magnet is provided on the outer peripheral portion, the magnet is not affected by the action of magnetizing the rotor magnet.

Embodiment Hereinafter, a method for manufacturing a rotor used in a flat motor according to an embodiment of the present invention will be described with reference to the drawings.

1 (a), 1 (b) and 1 (c) show a flat rotor according to a first embodiment of the present invention. The same parts as those in the conventional configuration are denoted by the same reference numerals as in the conventional example (FIG. 5), and the description thereof will be omitted.

In this figure, reference numeral 1 denotes a rotor frame formed of an iron plate, which is mounted substantially perpendicular to the rotation shaft 22. Also, a through hole is formed in a plane portion of the rotor frame 1 with the rotor magnet 19.
5a, 5b, 5c are provided by, for example, press working. Reference numeral 4 denotes four convex portions formed by press working so as to contact the inner periphery of the rotor magnet 19.
Are positioned concentrically on the rotating shaft 22. Reference numeral 2 denotes a hole formed in the center of the rotor frame 1, and in this case, the rotating shaft 22 penetrates. Reference numeral 3 denotes a screw hole for fixing the rotor 17, and reference numeral 18 denotes a frequency power generation magnet fixed to the rotor frame 1 by bonding or the like, and is multipolarly magnetized (even number) on an end face 18a opposite to the rotor frame 1.

The flat motor configured as described above will be described below with reference to FIGS. 1, 2 and 3.

FIG. 2 (a) is a diagram showing the magnetized state of the rotor magnet and the frequency generating magnet as viewed from the upper surface of FIG. 1 (a). The rotor magnet 19 has eight poles of NS magnetized and the outer peripheral portion of the frequency generating magnet. Has a 60 pole NS magnetisation. FIG. 3 is a sectional view showing an overall view of a motor using the flat rotor of the present invention. 11 is a chassis (bearing housing), 12A and 12B are bearings press-fitted into the chassis 11, and
Reference numeral 13 denotes a stator yoke, and reference numeral 14 denotes a printed circuit board attached to the stator yoke 13 with an adhesive (for example, a double-sided tape). 26 is a power generation coil,
14 is formed by etching. Also, a plurality of coils are provided on the surface of the printed circuit board 14 opposite to the stator yoke 13.
15 is fixed by an adhesive in a ring shape.

16 is a screw, the stator yoke 13, the printed circuit board 14
Is fixed to the chassis 11 at three places. 17
Indicates a rotor, rotor frame 1, rotor magnet 19
And the frequency generating magnet 18 and the rotor frame 1
An annular rotor magnet 19 that is magnetized so that the N pole and the S pole face the coil 15 alternately is disposed therein.
The rotation shaft 22 is inserted into the center of the rotor frame 1. 21 is a screw for attaching the rotor 17 to the rotor boss 20
It is divided into three places at equal intervals of 120 ゜. The rotating shaft 22 is supported by the chassis 11 via the bearings 12A and 12B, and a flange 23 is press-fitted on a side opposite to the rotor boss 20. The above is the flat type motor using the rotor of the present invention. According to this embodiment, the rotor frame 1 is provided with through holes 5a, 5b, 5c as shown in FIGS. 1 (a) and 1 (b). By providing the rotor frame 1 with a cut and raised concentrically with respect to the rotating shaft 22, the rotor magnet 19 can be accurately attached to the rotor frame 1 without the need for an adhesive, thereby providing a motor that does not require balance adjustment as a rotating body. I can do it.

Next, the manufacturing method of the present invention will be described with reference to FIG.

In the figure, 7 is a pin, and 8 is a jig to which the pin 7 is fixed. First, the pin 7 is passed through the through hole 5. Next, the rotor magnet 19 that has been multipolarly magnetized in the end face direction is placed on the pin 7 in advance. At this time, the rotor magnet 19
Is adjusted so as to be located between the convex portion 4 and the frequency power generation magnet 18. Then, the pin 7 is gently pulled back to bring the rotor magnet 19 into contact with the rotor frame 1 and to be held by the magnetic force of the rotor magnet 19.

Therefore, since the magnetized rotor magnet 19 is attached to the rotor frame 1 while being held by the pin 7, damage at the time of attaching the rotor magnet 19 can be prevented, and the magnetized state of the frequency generator magnet 18 is not disturbed.

This will be described with reference to FIG. A in FIG. 2 (b) is a magnetic flux distribution emitted from the rotor magnet 19, B and C are magnetic flux distributions of the frequency generating magnet 18, and B is a comparative example according to a conventional method. 1 shows a magnetic flux distribution waveform when the rotor magnet 19 is attached and the rotor magnet 19 is also magnetized.
Four swells occur during rotation. C is a magnetic flux distribution waveform of the frequency generating magnet 18 when the rotor of the present invention is used. Since the magnetized magnet is already mounted as the rotor magnet 19, the frequency generating magnet 18 is hardly affected.

Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

FIG. 4 is a sectional view (a) and a rear view (b) of a rotor of a flat type motor according to a second embodiment of the present invention. In the figure, 1 is a rotor frame, 2 is a hole into which a rotating shaft is inserted,
3 is a screw hole for attaching the rotor 17 to the rotor boss 20
There are three of them at equal intervals of 120 ゜. 19 is a rotor magnet, 5
Reference numerals a and 5b denote through holes formed in a 180 ° diagonal line, and the above is the same as the configuration shown in FIG. The difference from FIG. 1 is that the positioning portion of the rotor magnet 19 is provided on the outer peripheral portion of the rotor frame 1 over the entire circumference.

The rotor of the flat type motor configured as described above will be described below.

In this case, since it is assumed that the signal for controlling the speed of the motor is performed by a position detecting element (not shown) such as a Hall element, a frequency generating magnet for controlling the speed is not particularly provided. However, for example, when a rare earth magnet is used as the rotor magnet 19, the holding force Hc is high, and in order to sufficiently bring out the performance of the magnet, the rotor magnet 19 is in a single state, and the magnetized yokes are applied to the upper and lower surfaces of the rotor magnet 19, as if the rotor magnet 19 It is common to magnetize 19 as a sandwich. In this case, place the magnetized rotor magnet 19 on the pins set up in the holes 5a and 5b, and prepare a jig that can pull the pins gently. 2 can be fitted into the rotor frame 1 while being centered.

In the first embodiment, the frequency generating magnet 18 is magnetized on the end face on the opposite side of the rotor frame 1, but may be magnetized on the outer circumferential surface. It may be a magnetically sensitive element. In the second embodiment, the through hole 5
Although a and 5b are on a diagonal line of 180 °, they may be three places of 120 ° or four places of 90 °.

Effect of the Invention As described above, the present invention provides a protrusion that regulates the position of a rotor magnet pre-magnetized on a rotor frame and a through hole, further passes a pin through the through hole, and attaches these pins to the rotor magnet. The rotor magnet is coerced by being brought into contact with the rotor magnet, and the rotor magnet is disposed on the rotor frame by pulling a pin. By inserting the magnetized rotor magnet, the rotor magnet can be mounted without being damaged. Can also
There is no need to use an adhesive. Furthermore, in the case of a rotor with a frequency generating magnet, which is capable of improving the balance accuracy and dimensional accuracy, it is possible to provide an excellent flat rotor which does not disturb its signal and a method of manufacturing the same.

[Brief description of the drawings]

1 (a) and 1 (b) are a cross-sectional view and a rear view of a flat rotor according to an embodiment of the present invention, and FIG. 1 (c) is a cross-sectional view for explaining a rotor magnet mounting process of the rotor. 2 (a) is a plan view showing a state of magnetization of the rotor magnet and the frequency power generation magnet of FIG. 1, and FIG. 2 (b) is a magnetization of the rotor magnet and the frequency power generation magnet. FIG. 3 is an overall view of a flat type motor using the rotor of the present invention, and FIGS. 4 (a) and 4 (b) are sectional views and plan views of a rotor showing another embodiment of the present invention. FIG. 5 is a cross-sectional view showing a conventional flat motor, FIGS. 6A and 6B are cross-sectional views of a rotor used in the conventional flat motor, and FIGS.
FIG. 1A is a diagram showing the relationship between a rotor magnet of a conventional rotor, a frequency generating magnet, and a magnetically sensitive element, and FIG. 2B is a diagram showing the magnetization distribution of the rotor magnet and the output waveform of the magnetically sensitive element. 1 ... rotor frame, 4 ... convex, 5, 5a, 5b, 5c ... through hole, 7 ... pin, 17 ... rotor, 18 ... frequency generator magnet, 19 ... rotor magnet, 22 ... Axis of rotation.

Claims (1)

(57) [Claims] 1. An annular rotor magnet which is prepolarized in the direction of an end face, a rotor frame for holding the rotor magnet, and a convex portion which contacts the inside or outside of the rotor magnet on the rotor frame. And
Further, in the method of manufacturing a flat rotor having two or more through-holes provided in a plane portion of the rotor frame, a pin is passed through the through-hole, and these pins are brought into contact with the rotor magnet to hold the rotor magnet. A method of manufacturing a flat rotor in which a rotor magnet and a rotor frame are arranged by pulling a pin.