KR900000100B1 - Brushless motor - Google Patents

Abstract

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Description

Brushless motor

1 is a diagram showing a cross section which is a main part of an embodiment of the present invention.

2 is a diagram showing a state in which the first and second flexible circuit boards used in this embodiment are developed.

3 is a diagram showing each component attached to a first flexible circuit board.

4 is a diagram showing each component attached to a second circuit board.

5 is a partially enlarged view showing a structure for connecting tongue pieces extending from a speed detection coil of a first flexible circuit board to a second flexible circuit board.

6 is a diagram showing a cross section of the main portion of another embodiment of the present invention.

7 is a diagram showing a connection state of the speed detection coil in this embodiment.

8 and 9 are partial enlarged views showing examples in which the connection portions in FIG. 7 are different from each other.

10 is a diagram showing a cross section of the main portion of another embodiment of the present invention.

FIG. 11 is a diagram showing a developed state of the first, second and third flexible circuit boards of this embodiment. FIG.

* Explanation of symbols for main parts of the drawings

10 brushless motor 12 stator

14: rotor 16: stator yoke plate

18, 26, 28: through hole 20: first flexible circuit board

22: second flexible circuit board 24, 74: connection portion

30: driving coil 32, 42: IC

34: speed detection coil 36, 60: tongue

38, 62, 64: connecting conductor pattern 40: transistor

44, 66: connection part 46: lead wire

48, 50: rotor magnet 52: case

54: rotor shaft 56: bearing holder

57: spacer 58: base

70: perforation 72: third flexible circuit board

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless motor, and in particular, the present invention relates to a brushless motor of a axially spaced type used as a driving source for a video tape recorder's rotating head and a disc player.

One example of a conventional brushless motor is disclosed, for example, in US Pat. No. 4,093,897, issued June 6, 1978, or in US Pat. No. 56-57687, filed May 18, 1981.

The conventional brushless motor disclosed herein includes a stator and a rotor, and a stepper coil or driving coil is attached to an upper surface of the stator yoke plate included in the stator via an insulating sheet, and printed on the driving coil. The circuit board is arranged.

A rotor magnet is arranged on this printed circuit board, and the rotor magnet is fixed to the rotor having a shaft.

As the magnetic flux from the rotor magnet is interlinked with the field generated by the drive coil, a rotational lock is generated in the rotor, that is, the rotor reshaft.

In such a conventional brushless motor, since a printed circuit board is interposed between the drive coil and the rotor magnet, the gap between them is large, and therefore the motor efficiency is not very good.

If the motor efficiency is not good, a large current is required for the driving coil, and therefore, various power consumptions arise, such as not only a large power consumption, but also a circuit component capable of supporting such a large current.

Therefore, the main object of the present invention is to provide a brushless motor that can improve the motor efficiency.

The brushless motor of the present invention includes a stator and a rotor, and the stator includes a stator yoke plate made of a magnetic material.

The first flexible circuit board and the second flexible circuit board are attached to both main surfaces of the stator yoke plate, respectively.

A stator coil or a drive coil is attached to the first fusible circuit board, and a rotor magnet fixed to the rotor is provided by facing the drive coil with a gap therebetween.

The first flexible circuit board and the second flexible circuit board are electrically connected.

According to the present invention, since there is only a very small gap between the drive coil and the rotor magnet, the motor efficiency can be significantly improved as compared to the conventional brushless motor.

In addition, such an improvement in motor efficiency brings about advantages such as reduction of power consumption.

In a preferred embodiment of the present invention, a conductor pattern as a speed detecting coil is formed on the first flexible circuit board inside the driving coil.

The speed detection coil is then connected to a second flexible circuit board. On the other hand, a magnetic flux applying means for generating electromotive force in the speed detection coil is installed in the rotor.

The electromotive force generated in the speed detecting coil from the second flexible circuit board is taken out and used for control of the rotational speed as necessary.

According to this preferred embodiment, since the stator yoke plate is interposed between the position where the electromotive force generated in the speed detecting coil is taken out and the rotor magnet, noise generated by the rotor magnet is protected by the stator yoke plate. Can be prevented from overlapping the generated electromotive force (AC signal).

And if the speed detecting coil is connected to the second flexible circuit board, tongues protruding from the first flexible circuit board are used, and the tongues are formed through the through holes formed in the stator yoke player. By connecting to the predetermined pattern of the flexible circuit board 2, the configuration of the means for withdrawing the speed detection coil is simplified, and the assembly thereof is extremely easy.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram showing a cross section of a main portion of an embodiment of the present invention. The brushless motor 10 includes a spatter 12 and a rotor 14. The stator 12 includes a stator yoke plate 16 formed of a magnetic material such as a silicon steel sheet, and is fixed to the base 58 via a suitable spacer 57. Through-holes 18 are formed at approximately the center of the spatter yoke plate 16. First and second flexible circuit boards 20 and 22 are provided at both main surfaces of the stator yoke plate 16, respectively.

The first and second flexible circuit boards 20 and 22 are integrally formed including the connecting portion 24 as shown in FIG.

Through-holes 26 and 28 are formed in the flexible circuit boards 20 and 22, respectively, corresponding to the through-holes 18 formed in the stator yoke plate 16 described above in the center.

The first and second flexible circuit boards 20 and 22 are formed of the stator yoke plate 16 by adhesive or double-sided tape, respectively, so that the through holes 26 and 28 coincide with the through holes 18. It is attached to the corresponding main surface.

In addition, the flexible circuit boards 20 and 22 can be formed by printing or blowing conductive plates according to the shape of the conductor pattern to be formed on the flexible insulating film such as synthetic resin.

However, the conductive pattern may be formed by electroless plating or by attaching copper foil to form a conductive film over the entire surface of the flexible insulating film, and then removing the unnecessary portion by etching. Can be.

The first flexible circuit board 20 attached to the stator yoke plate 16 faces the rotor 14 as shown in FIG. 1, and the first flexible circuit board 20 has a third As shown in the figure, six stator coils to drive coils 30 are arranged in an annular manner and attached.

In this way, since the extremely thin first flexible circuit board 20 is interposed between the drive coil 30 and the stator yoke plate 16, the heat generated in the drive coil 30 immediately becomes the stator yoke plate 16. The heat radiation can be carried out extremely well since it is transmitted to and dissipated therefrom.

Furthermore, three ICs 32 are attached on the first flexible circuit board 20 as sensors for detecting the rotational position of the rotor 14 (see FIG. 1). The brushless motor 10 of this embodiment is thus constructed as a three-phase brushless motor furnace.

However, the noodles and constants can be arbitrarily designed. In addition, the first flexible substrate 20 is provided with a conductor pattern (not shown) constituting a predetermined circuit by connecting the terminal of the drive coil 30 and the hole IC 32 to the terminal, respectively.

Furthermore, in the first flexible circuit board 20, a conductor pattern for the speed detecting coil 34 is formed around the through-hole 26 in the center of the drive coil 30 arranged in an annular shape. do.

A tongue piece 36 is formed by protruding inward from a circumference defining a through hole 26 of the first flexible circuit board 20.

The tongue piece 36 is provided with a connecting conductor pattern 38 extending from both ends of the speed detecting coil 34.

Although not shown, the second flexible circuit board 22 attached to the stator yoke plate 16 is also provided with a conductor pattern constituting a predetermined circuit connection.

In the second flexible circuit board 22, as shown in FIG. 4, three transistors 40 and the power of the driving coil 30 (see FIG. 3) in cooperation with these transistors 40 are shown. An IC 42 for controlling supply is attached and constituted as a circuit as shown in FIG. 5 of US Pat. No. 4,093,397 by the above-described conductor pattern.

Such a control circuit is already well known, and a detailed description thereof will be omitted.

In addition, after being attached to the stator yoke plate 16, which is the first and second flexible circuit boards 20 and 22, the tongue piece 36 is again passed through the through hole 18 of the stator yoke plate 16. It returns and draws out on the predetermined | prescribed conductor pattern 38 (not shown) of the 2nd flexible circuit board 22. FIG.

And the connecting conductor pattern 38 (refer FIG. 2) formed in this tongue piece 36 is electrically connected to the conductor pattern of the 2nd flexible circuit board 22, and is fixed mechanically. This connected state is shown in FIG.

The lead wire 46 is connected to the connecting portion 44 of the tongue piece 36. The lead wire 46 is thus connected to the speed detecting coil 34 formed on the first flexible circuit board 20 via the connecting portion 44 and the connecting conductor pattern 38 of the tongue piece 36. do.

In this way, when the electromotive force from the speed detecting coil 34 is drawn out from the second flexible circuit board 22, the configuration becomes very simple, and therefore, the assembly can also be easily performed.

The rotor 14 shown in FIG. 1 has a gap in the axial direction interposed between the drive oil 30 attached to the first flexible circuit board 20 attached to the bottom surface of the stator yoke plate 16. And an annular rotor magnet 48 facing each other. As such, since there is only a very small air gap between the rotor magnet 48 and the drive coil 30, a significant improvement in the motor efficiency can be expected as compared to the conventional motor.

The rotor 14 also includes a ring-shaped magnet 50 opposite the speed detection coil 34 formed in the first flexible circuit board 20 inside the rotor magnet 48.

In this way, on the first flexible circuit board 20, the speed detecting coil 34 is formed inside the driving coil 30, while the power generating magnet 50 is formed inside the rotor magnet 48. On the other hand, by disposing the power generation magnet 50 in the rotor magnet 48, the power generation magnet 50 can affect the drive coil 30 to overcome the problem that the rotation torque is reduced or the rotation irregularity occurs have.

As a result, a more compact brushless motor can be obtained.

The magnets 48 and 50 are both constituted as dist-shoped mulitipole magnets with different poles formed in their circumferential direction and magnetized in their thick direction (axial direction). The magnet 50 is densely formed from the rotor magnet 48.

The rotor 14 comprises a dish-shaped case 52 to which these magnets 48 and 50 are fixed, and in the center of the case 52 the rotor shaft 54 is attached to the bearing holder 56. The bearing holder 56 is attached to a base 58 opposite the driven member (not shown).

Therefore, when the rotor 14 is rotated by the interaction between the drive coil 30 and the rotor magnet 48, the driven member is rotated accordingly.

At the same time, the magnetic fluxes of the magnetization zones of the magnet 50 are sequentially connected to the speed detection coil 34 according to the rotation thereof, and the second flexible circuit board 22 is connected to the speed detection coil 34 in accordance with this rotation. An AC signal is output from the connected lead wire 46. This AC signal is used for the control of the rotational speed of the rotor 14 in the same manner as in the above-mentioned US patent.

Further, in the first embodiment, the speed detecting coil 34 (see FIG. 3) is pulled out or connected to the rear surface of the stator 12, that is, to the second flexible circuit board 22, so that the tongue pieces 36 are separately provided. ).

However, such tongue tongue is not particularly necessary, and the connecting part 24 shown in FIG. 2 may also be used.

6 is a diagram showing a cross section of a main portion of another embodiment of the present invention. This embodiment differs from the embodiment of FIG. 1 in the following points.

In other words, separate brush first and second circuit boards 20 and 22 are attached to both main surfaces of the stator yoke plate 16 of the brushless motor 10 shown in FIG. And the second flexible circuit board 22 is formed with tongues 60 protruding outward from the outer circumference, and the tongues 60 come back along the side of the stator yoke plate 16 to form the first tongue. It is connected on the flexible circuit board 20.

In the first flexible circuit board 20, as shown in FIG. 7, a speed detecting coil 34 is formed around the defining hole of the through hole 26, and both ends of the speed detecting coil 34 are formed. Is connected to a connecting conductor pattern 62 formed on the first flexible circuit board 20.

On the other hand, a connecting conductor pattern 64 is also formed in the tongue piece 60 so that these two conductor patterns 62 and 64 are connected at the connecting portion 66 as shown in FIG.

The tongue piece 60 is formed with a notch 68 or a perforation 70 at its tip, as shown enlarged in FIG. 8 or 9. The notches 68 or the perforations 70 are provided in the conductor pattern 64 of the tongue piece 60 and are positioned so as to correspond to the conductor pattern 62 for connection of the first flexible circuit board 20. In this state, it is connected by soldering.

By forming the notches 68 or the perforations 70 at the tip to the connecting portion of the tongue piece 60 in this manner, the area of the connecting part 66 which is contacted by soldering becomes large, and the connecting conductor pattern 64 of the tongue piece 60 is connected. The connection with the connection conductor pattern 62 of the 1st flexible circuit board 20 is performed more firmly.

Contrary to the embodiment of FIG. 6, the tongue piece 60 may be drawn from the first flexible circuit board 20 and drawn out to the second flexible circuit board 22.

In this embodiment, the magnets 48 and 50 are not integrated as shown in FIG. 6, and like the first embodiment, separate magnets may be used.

10 is a diagram showing a cross section of main parts of another embodiment of the present invention. This embodiment includes a third flexible circuit board 72 except for the following, wherein the third flexible circuit board 72 includes a first and a second flexible circuit board 20. And a connection portion 24 and 74 together with (22).

As in the first embodiment, the first and second flexible circuit boards 20 and 22 are attached to both main surfaces of the stator yoke plate 16, and the first flexible circuit board 20 is attached. ), The driving coil 30 is attached, and electronic components such as transistors and ICs are attached to the second flexible circuit board 22.

The third flexible circuit board 72 is returned to the driving coil 30 again and attached to the upper surface of the driving coil 30.

The speed detecting coil 34 is different from the above embodiment, and is formed on the third flexible circuit board 72, not on the first flexible circuit board 20. A tongue piece 36 is formed on the third flexible circuit board 72 as in the first embodiment described above, and the tongue piece 36 is formed on the second flexible circuit board 22 through the through hole. Is withdrawn and connected there.

Accordingly, the AC signal induced in the speed detection coil 34 from the second flexible circuit board 22 through the tongue piece 36 is transferred to the speed detection coil 34 formed on the third flexible circuit board 72. It is taken out.

In this way, when the third flexible circuit board 72 is interposed between the driving coil 30 and the rotor magnet 48, the rotor magnet 48 is placed on the power generation magnet (the magnet 50 of the first embodiment). Equivalent) can be used as

On the other hand, since the third flexible circuit board 72 is extremely thin, there is no problem that the gap between the drive coil 30 and the rotor magnet 48 becomes too large.

Since the present invention is constituted as described above, only a very small gap is required between the drive coil and the rotor magnet, so that the motor efficiency can be significantly improved as compared with the conventional brushless motor. However, the improvement of the motor efficiency has the advantage of reducing the power consumption.

In addition, since the stator yoke plate is interposed between the position where the electromotive force generated in the speed detecting coil is extracted and the rotor magnet, the electromotive force extracting part is protected by the stator yoke plate, so noise generated by the rotor magnet is generated. Superimposition on the AC signal) can be prevented.

And if the speed detecting coil is connected to the second flexible circuit board, tongues protruding from the first flexible circuit board are used, and the tongues are provided with through holes formed in the stator yoke plater. When the predetermined number of the second flexible circuit boards is connected to the pattern through this, the configuration of the means for drawing out the speed detection coil is simplified, and the assembly thereof is extremely easy.

Claims (14)

A stator yoke plate 16 formed of a magnetic material, first and second flexible circuit boards 20 and 22 attached to two peripheries of the stator yoke plate 16 described above, and It is provided in the drive coil 30, the rotor 14, and the above-mentioned rotor 14 which are arrange | positioned at the 1st flexible circuit board 20, and opposes the said drive coil 30 through a predetermined clearance gap. Different poles are formed in the circumferential direction, and the rotor magnet 48 magnetized in the thick direction, the first flexible circuit board 20 described above, and the second flexible circuit board described above ( And a connecting means for electrically connecting the 22). The method according to claim 1, wherein the aforementioned connecting means includes a connecting portion (24) for integrally connecting the first and second flexible circuit boards (20) and (22). The flexible circuit board 20, 22 of the brushless motor, characterized in that the above-described stator yoke plate 16 is attached to the corresponding main surface, respectively. 3. The speed detecting coil (34) formed in the first flexible circuit board (20) described above, and the rotor (14) described above, and the electromotive force is applied to the speed detecting coil (34). Brushless motor comprising a magnetic flux imparting means for generating. 4. The brush of claim 3, wherein the speed detecting coil 34 is formed inside the driving coil 30, and the magnet ring is disposed inside the rotor magnet 48. Res Moter. 4. The second flexible circuit board according to claim 3, wherein the above-mentioned speed detecting coil (34) is connected to the above-mentioned second circuit board (22) and the above-mentioned second flexible circuit board through the above-described coil connecting means. A brushless motor, characterized in that it comprises means for blowing up the electromotive force generated in the above-described speed detection coil (34) delivered to (22). 6. The through hole (18) and (26) according to claim 5, wherein the stator yoke plate (16) and the first and second flexible circuit boards (20) and (22) are substantially centered on the main surface of the unitary frame. (28) is formed, and the above-described coil connection means includes tongue pieces (36) formed by protruding from a circumference defining the aforementioned through holes (26) of the first flexible circuit board (20). The tongue piece 36 is returned through the above-mentioned through hole 18, and is connected to the 2nd flexible circuit board 22, The brushless motor characterized by the above-mentioned. 7. A brush according to claim 6, comprising a circuit component (32) attached to said second flexible circuit board (22) and for controlling power supply to said drive coil (30). Res Moter. 2. A circuit according to claim 1, comprising circuit components (40) (42) attached to said second flexible circuit board (22) and for controlling the supply of power to said drive coil (30). Featuring a brushless motor. The speed detecting coil (34) formed on the first flexible circuit board (20) described above and the rotor (14) described above for generating electromotive force in the aforementioned speed detecting coil. A second flexible circuit board (2) through the magnetic flux applying means, the coil detecting means for connecting the aforementioned speed detecting coil 34 to the second flexible circuit board 22 described above, and the coil connecting means described above. And a means for extracting the electromotive force generated in the above-described speed detecting coil delivered to 22). 10. A brush according to claim 9, wherein said connecting means comprises tongue tongues (60) drawn out from one of said first and second flexible circuit boards (20) and (22) to the other. Res Moter. 12. The tongue piece 60 according to claim 10, wherein the tongue piece 60 includes a connection portion 66, and the above-described connection portion 66 is formed with a cutout 6 or a perforation 70 to more secure the connection. Brushless Moter. 3. A third flexible circuit board (72) according to claim 2, characterized in that it comprises a third flexible circuit board (72) connected to the first flexible circuit board (20) described above and returned over the drive coil (30). Brushless Moter. 13. The electromotive force according to claim 12, which is provided in the speed detecting coil (34) formed on the third flexible circuit board (72) and the rotor (14) described above. Brushless motor comprising a magnetic flux imparting means for generating a. 14. The second flexible circuit board according to claim 13, wherein the speed detecting coil (34) is connected to the second flexible circuit board (22) described above, and the second flexible circuit board is connected to the second flexible circuit board through the coil connecting means. Brushless motor, characterized in that for extracting the electromotive force generated in the above-described speed detection coil (34) guided to (22).

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