JPH02269454A - Brushless motor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brushless motor, and more particularly to the structure of a fan-shaped brushless motor in which coil poles are formed by etching, plating, etc., spiral patterned conductors as stator coils.

Figures 1 to 3 are diagrams showing structural examples of conventional brushless motors, in which Figure 1 is a side sectional view, Figure 2 is an inside plan view,
FIG. 3 is a plan view of the magnetic poles of the rotor magnet. This example is an example of a flat type 8-pole 3-phase brushless motor that detects the rotational position of a rotor magnet using three magnetic field detection elements. In the figure, a rotor magnet 1 has its surface magnetized into eight equal sectors in a fan shape, and is fixed to a rotating shaft 8 via a rotor yoke 6. The rotating shaft 8 is rotatably supported by a bearing 5.5', and a stator is provided opposite the magnetic pole surface of the zero rotor magnet 1. This stator includes a stator coil 2, a stator yoke 3. Magnetic field detection element 4.4', 4'
, and a wiring board 11. The magnetic field detection elements 4.4', 4' are mounted on the wiring board 11, and are arranged and fixed at predetermined angular intervals on the outer peripheral side surface of the stator coil 2 together with the wiring board 11. Magnetic field detection element 4. 4', 4' has 1 rotor magnet 1
The stator coil 2, which detects the rotational position of the rotor magnet 1 by detecting the lateral leakage magnetic field, has a structure of 8 poles per phase, and a 24-pole structure for 3 phases. A frequency power generation coil 15 is fixed between the stator coil 2 and the stator yoke 3 for generating rotational speed signals.The one frequency power generation coil 15 has the same horizontal shape and number of poles as the stator coil 2. is used. Magnetic field detection element 4.4', terminal of 4', terminal of stator coil 2, and frequency generating coil 15
All terminals are connected to conductor patterns on the surface of the wiring board 11 by manual soldering. That is, the magnetic field detection elements 4.4', 4' are connected to the wiring board 11 in advance.
After soldering and fixing it on top and incorporating this as a motor stator.

The terminals of the stator coil 2 and the frequency generating coil 15 are connected on this surface with solder. The wiring board 11 has a structure in which a wiring pattern conductor is provided on an insulating rigid board such as a phenol resin board, and wiring lead wires and connectors are used for connection from this to the driving electronic circuit. Magnetic field detection element 4.
Hall elements are used as 4' and 4', and the input terminals are connected in parallel.

When the stator coil 2 is star-shaped, the number of wiring leads for connection to the driving electronic circuit is 13 in total. Therefore, the surface area of the wiring board 11 becomes large, the connector needs to be large, and the space and weight occupied by the wiring lead wires are also large.
0 has a discontinuous side surface shape in which a part of the side surface is cut out in order to fix the wiring board 11. however,
Conventional brushless motors with the above shape have a configuration in which (a) the wiring board, magnetic field detection element, and frequency power generation coil are each manufactured separately, and then assembled and connected manually when assembling the motor; The assembly accuracy is also low and the assembly work time is long.In particular, the decrease in the assembly precision of the magnetic field detection element and the increase in the work time for soldering lead to a decrease in the smooth rotation of the motor and an increase in cost, respectively. .

(b) There are many terminal connections, making it difficult to automate processing.

(c) The frequency generating coil is thick, and the stator coil volume has to be reduced by that amount, resulting in a decrease in motor efficiency.

(d) Because the accuracy of the pole arrangement of the frequency generation coil is low, the stability of the generated frequency is low.

(e) Since the side magnetic field of the rotor magnet is large and the shield case has a shape with a notch on the side, a large amount of magnetic flux leaks to the outside of the motor, causing large induction noise. In addition, the cogging torque is also large and reduces smooth rotation.

(f) The amount of effective magnetic flux linked to the stator coil decreases, reducing motor efficiency.

(g) Large iron loss tends to occur within the shield case.

(H) The planar dimensions of the motor are large, making high-density mounting impossible.

(S) Since the position is detected using the side magnetic field of the rotor magnet, the position detection means tends to deteriorate.

(v) Since the magnetic field detection element is provided at a position with a large radius, the cogging torque caused by the magnetic material piece in the magnetic field detection element also becomes large.

It had the following drawbacks.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art described above and to provide a brushless motor with a low cost structure suitable for mass production. To achieve the above purpose.

The present invention relates to a brushless motor.

(a) It is equipped with a plurality of coil poles, and the plurality of coil poles are formed of spiral pattern conductors on a plane of an insulating material, and the rotation in a plane opposite to the magnetic pole surface of the rotor magnet. and a stator coil arranged concentrically with the rotation axis of the child magnet.

(b) A stator yoke on which the stator coil is fixed on a flat surface.

(c) position detection means configured to detect the magnetic field of the magnetic poles of the rotor magnet and generate a signal corresponding to the position of the magnetic poles;

(d) A portion that is located in a plane opposite to the magnetic poles of the rotor magnet and is arranged along the circumferential direction of rotation in which the plurality of magnetic poles of the rotor magnet are arranged, and whose component is perpendicular to the circumferential direction. are arranged at a plurality of locations in the circumferential direction at intervals corresponding to the arrangement pitch of the magnetic poles of the rotor magnet, are formed of patterned conductors at least on the surface of the insulating material, and when the rotor magnet rotates. Formed so that, due to changes in magnetic flux from the magnetic pole surface of the rotor magnet, a back electromotive force having a frequency characteristic proportional to the rotational speed of the rotor magnet is generated by adding the components perpendicular to the circumferential direction. rotational speed signal generating means having a continuous configuration;

(e) The rotor magnet has at least a flat part of an insulating material in a portion facing the magnetic pole surface, and at least the rotational speed signal generating means and the stator coil are disposed on the flat part on the flat part. A wiring board having a configuration formed in the following.

In the above configuration, the rotational speed signal generating means generates a back electromotive force proportional to the rotational speed of the rotor magnet in the patterned conductor due to a change in magnetic flux due to rotation of the rotor magnet. Further, the wiring board is provided with the stator coil and the patterned conductor of the rotational speed signal generating means in a predetermined insulated state and connected state, and the stator coil and the patterned conductor of the rotation speed signal generating means are provided at a predetermined position on the magnetic pole facing surface of the first rotor magnet. The rotational speed signal generating means is held, and the terminal portions thereof are drawn out to the outside of the motor electromagnetic section.

The present invention will be explained below with reference to the drawings. 4 to 10 are diagrams of related motor structures for explaining the principle structure of the brushless motor according to the present invention, in which FIG. 4 is a longitudinal sectional view, FIG. 5(a) is a surface view of a wiring sheet, 6 (b) is a side view thereof, (c) is a back view thereof, FIG. 6 is a plan view of the stator yoke, FIG. 7 is a plan view of the stator coil, and FIG. 8 is a laminated cross-sectional view of the stator coil. FIG. 9 is a stator coil polar cross-sectional view.

FIG. 10 is a diagram showing another structural example of a stator yoke suitable for the motor structure. Similar to the conventional example, this example also uses three magnetic field detection elements and detects the magnetic field of the rotor magnet 1, which is magnetized evenly divided into eight poles on a plane in a fan shape, to detect the rotational position. This is an example of the structure of a brushless motor. The stator is composed of a wiring sheet 12, a stator yoke 3', and a stator coil 2'. The wiring sheet 12 integrally fixes the magnetic field detection elements 4, 4', 4' on the surface of a flexible insulating sheet, and wires the terminals with a patterned conductor, and also has a one-frequency power generation patterned conductor 20. It has a structure in which a stator coil terminal drawer pattern conductor 13 is provided. The stator yoke 3' has three through holes 25.2 at predetermined positions facing the magnetic poles of the rotor magnet 1 in its plane.
5' and 25' are provided. The stator coil 2' is a patterned coil 30.3 in which each coil pole is spirally formed with a patterned conductor on the front and back surfaces of an insulating sheet 32, and the front and back sides are connected in series by a through-hole electrode 31.
0', and has 8 poles per phase, the wiring sheet 12 and the stator coil 2 are placed on the side of the stator yoke 3' facing the rotor magnet 1.
′ are stacked and fixed. The surface of the wiring sheet 12 on which the magnetic field detection elements 4, 4'4' are fixed is fixed to the stator yoke 3' side.

The magnetic field detection elements 4.4', 4' are provided in the plane of the stator yoke 3' through corresponding small holes 25°25',
Insert into 25'. Stator coil 2' has 8 per phase.
The coil sheets 40° 40' and 40' having a polar structure are arranged at an electrical angle of 2/3π with respect to the rotational direction of the rotor magnet 1.
Stack them at different angles and fix them. An insulating coating 36 is applied on the surface of each coil sheet to prevent short circuits and the like. The terminal of the stator coil 2' is formed on the wiring sheet 12, and the 0-frequency power generation pattern conductor 20 connected to the stator coil terminal pull-out pattern conductor 13 is connected to the voltage generated under each magnetic pole of the rotor magnet 1. In order to add them in series, the dividing angle in the circumferential direction between the conductors is set to be π/(2n+1) (n=0.1, 2...) in electrical angle, and the structure of this example is as follows. The case where n=1 is shown. In this structure.

The magnetic field detection elements 4.4', 4' and the frequency power generation pattern conductor 20 are integrally provided on the wiring sheet 12, and are completed as one composite component. Therefore, when assembling the motor, these terminal wiring operations are not necessary, and only the terminal wiring of the stator coil 2' needs to be done. Furthermore, if the stator coil 2' is also formed of a patterned coil as in this example, the terminal shape can be made constant, so that the terminal connection process onto the wiring sheet 12 can be easily automated.

The magnetic field detection elements 4.4', 4' are inserted into the plane of the stator yoke 3' and detect the magnetic field directly under the magnetic pole face of the single rotor magnet 1 to generate a position signal. Magnetic field detection element 4.4'
, 4' are inserted into the stator yoke 3', in addition to the above-described small holes 25.degree. 25', 25', a structure in which an annular groove 35 is provided is also practical.

Note that this structure has the advantage that the cogging torque of the motor can be reduced more than the small hole structure by increasing the roundness and concentricity of the groove. As is clear from the above, in the brushless motor of this structure, it is possible to significantly reduce the number of terminal wiring and automate the manufacturing, thereby realizing cost reduction. Integral mounting on the wiring sheet 12 improves the arrangement accuracy due to the structure and improves the position detection accuracy by the position detection method in a strong magnetic field directly under the magnetic pole surface of the rotor magnet 1, thereby reducing torque ripple. The rotational smoothness of the motor can be improved. Furthermore, the structure is such that the magnetic field detection elements 4.4', 4' do not protrude toward the stator coil 2' side.

In addition to increasing the volume of the stator coil and improving motor efficiency, it is also possible to use a stator coil with a multi-pole structure without gaps between poles, which improves output stability. can.

Moreover, since the flexible wiring sheet 12 is used.

High-density mounting is possible without increasing the planar dimensions of the motor.

11 and 12 are diagrams showing an example of the mounting structure of the stator yoke and the magnetic field detection element in relation to the brushless motor according to the present invention, and FIG. 11 is an enlarged sectional view of the motor electromagnetic part structure;
FIG. 12 is a plan view of the stator yoke to which the wiring sheet is fixed. In the single structure, the magnetic field detection elements 4.4', 4'
is provided inside the inner peripheral edge of the stator yoke 3'. In this structure, the inner diameter of the stator yoke 3' is made larger than the inner diameter of the rotor magnet 1 in order to position the magnetic field detection elements 4.4', 4' below the magnetic pole surface of the rotor magnet 1. The functions and effects of this structure are the same as those of the above structure.

FIG. 13 is an enlarged sectional view of the motor electromagnetic part structure showing another example of the stator yoke structure and the mounting structure of the magnetic field detection element in relation to the brushless motor according to the present invention. This example has a structure in which a flat annular notch 5o is provided in the inner peripheral part of the stator yoke 3'', and the magnetic field detection element 4, etc. is fitted into this.This structure also has the same structure as that described above. It has similar actions and effects.

FIGS. 14 and 15 (a) and (b) are also diagrams showing examples of motor structures related to the brushless motor according to the present invention,
FIG. 14 is a longitudinal sectional view, FIG. 15(a) is a front view of the wiring sheet, and FIG. 15(b) is a back view. In this example, magnetic field detection elements 4.4' are integrated and fixed on the wiring sheet 12.
, 4' are inserted from the back surface of the stator yoke 3' (the surface opposite to the surface on which the stator coil is fixed) into small holes provided in that surface. The wiring sheet 12 in the portion where the terminal connection pattern conductor 19 is provided is connected to the stator coil 2' as in the above structure.
Stack it on the bottom side and fix it. In this structure, the magnetic field detection element 4.4'4' of the wiring sheet 12 can be fixed to the back side of the stator yoke 3' and exposed to the outside of the motor. In addition to being able to utilize the space on the outer shell of the motor to mount circuits such as integrated circuits, it also has the advantage of making wiring easier to maintain.

16 to 18 are diagrams showing structural examples of a wiring sheet as a wiring board used in the brushless motor of the present invention, and FIG. 16 is a surface view of the sheet.

FIG. 17 is a back view thereof, and FIG. 18 is a wiring diagram.

The present invention has a structure in which patterned coils 45, 45', 45' formed of patterned conductors are also integrated within the wiring sheet 12'. Patterned coil 45.45'
, 45' are each led to the back side through a through-hole electrode 31, 31', 31' at the center of the coil pole, and connected there with a shorting ring 55 made of a patterned conductor to form a star shape. With this structure, there is no need for any terminal connection work within the motor stator, so the workability of motor assembly can be significantly improved and costs can be reduced.

FIGS. 19(a) and 19(b) are diagrams showing still another structural example of the wiring sheet according to the present invention, with FIG. 19(a) being a front view and FIG. 19(b) being a back view thereof.

Similar to the structures shown in FIGS. 16 to 18, this structure also has a stator coil formed of a patterned coil, which is integrated into the surface of the wiring sheet 12'. In this structure, coil sheet parts 61 and 62 are provided continuously in order to increase the number of coil turns, and these are connected to the wiring part 60.
It has a structure that is folded upward and stacked. This structure also eliminates the need for terminal connections within the stator. In addition, the patterned coil of this example is a non-matching type coil in which two poles of three-phase coils are arranged in the same plane, and the U-phase coil is a-type, a-e, 8, a2, a3, a3, a,
・Constructed by connecting A4 in series, V phase coil is B
bd ・b2 ・b2・ba-b3b4' ・b4, and the W phase coil is C1・ClC2・C3・ca・C3
It is constructed by connecting φc4 and C4 in series.

(Here, +i an, bn, crI represent the coil poles on the front surface of the sheet, and % ans bncr1' represent the coil poles on the back surface of the sheet.) As explained above, according to the present invention,
In flat brushless motors.

(a) A structure in which the frequency power generation pattern and the coil pattern are integrally provided on the wiring sheet.

It is possible to significantly reduce the number of unwired motor ends and the number of assembly steps, shortening motor manufacturing time and lowering costs. In addition, processing work is also easy to automate.

(b) Since the uniformity of coil poles, arrangement accuracy, linkage rate with magnetic flux, etc. can be easily improved, motor efficiency and output stability can also be easily improved.

(c) It is easy to construct a thin and small motor.

Effects such as this can be obtained.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an example of the structure of a conventional flat brushless motor, FIG. 2 is an inside plan view thereof, and FIG. 3 is a plan view of the magnetic poles of the rotor magnet. 4 to 10 are diagrams showing examples of related motor structures for explaining the brushless motor according to the present invention, and FIG. 4 is a longitudinal sectional view;
Figure 5(a). (b) and (c) are respectively a front view, a side view, and a back view of the wiring sheet, Fig. 6 is a plan view of the stator yoke, Fig. 7 is a plan view of the stator coil, and Fig. 8 is a plan view of the stator coil. FIG. 9 is a cross-sectional view of a stator coil, and FIG. 10 is a plan view showing another structural example of a stator yoke suitable for the motor structure. 11 and 12 are diagrams showing structural examples of the stator yoke structure and the mounting structure of the magnetic field detection element in relation to the present invention, and FIG. 11 is an enlarged sectional view of the motor electromagnetic part structure;
FIG. 2 is a plan view of the stator yoke to which the wiring sheet is fixed. Fig. 13 is a diagram showing a structural example of a stator yoke structure and a mounting structure for a magnetic field detection element related to the present invention, and an enlarged sectional view of a motor electromagnetic section, and Fig. 14 also shows a motor structure related to the present invention. 15(a) and (b).
) are a front view and a back view, respectively, of a wiring sheet for a motor having the structure. FIGS. 16, 17, and 18 show structural examples of wiring sheets used in the brushless motor of the present invention, and are respectively a front view, a back view, and a wiring diagram. FIGS. 19(a) and 19(b) are a front view and a back view, respectively, showing still another structural example of the wiring sheet according to the present invention. Explanation of symbols 1... Rotor magnet 2.2'... Stator coil 3.3'3'... Stator yoke 4.4', 4'... Magnetic field detection element 5.5'.・・Bearing 6・Rotor yoke 8・
...Rotating shaft 1o...Shield case 11
...Wiring board 12.12'12'...Wiring sheet 13...
- Stator coil terminal pull-out pattern conductor 15... Frequency generation coil 19... Stator coil terminal connection pattern conductor 20...
・Frequency power generation pattern conductor 25.25', 25'...Small hole 30.30'...Patterned coil 31.31'31'...Through hole electrode 32・
...Insulating sheet 35...Annular groove 36...Insulating coating 4o, 40', 40'...Coil sheet 45.45
' , 45'... Patterned coil 50... Annular notch 55... Short circuit ring 60... Wiring part 61. 62...Coil seat part

Claims (6)

[Claims] 1. The position of the magnetic pole of the rotor magnet (1), which is composed of a plurality of magnetic poles arranged in the circumferential direction, is detected, and the current from the power source is electronically applied to the stator coil in accordance with the position of the magnetic pole of the rotor magnet (1). A brushless motor configured to obtain rotational driving force by supplying power under control of a circuit, comprising a plurality of coil poles, the plurality of coil poles being formed of a spiral patterned conductor on a plane of an insulating material. and a stator coil having a configuration that is arranged concentrically with the rotation axis of the rotor magnet (1) in a plane facing the magnetic pole surface of the rotor magnet (1), and a stator coil made of a magnetic material; The stator yoke (3', 3''
, 3'''), a position detection means configured to detect the magnetic field of the magnetic pole of the rotor magnet (1) and generate a signal corresponding to the position of the magnetic pole, and the rotor magnet (1)
The rotor magnet (1) is disposed in a plane opposite to the magnetic poles of the rotor magnet (1) along the rotational circumferential direction in which a plurality of magnetic poles are arranged, and the portion of the component perpendicular to the circumferential direction is The rotor magnet (1) is arranged at a plurality of locations in the direction at intervals corresponding to the arrangement pitch of the magnetic poles of the rotor magnet (1), and is formed of patterned conductors (20) on at least the surface of the insulating material; ), due to changes in the magnetic flux from the magnetic pole surface of the rotor magnet (1), a back electromotive force with a frequency characteristic proportional to the rotational speed of the rotor magnet (1) changes to a component perpendicular to the circumferential direction. a rotational speed signal generating means having a continuous configuration formed so that the signal is generated by adding the rotational speed signal in sections; and at least a flat section of an insulating material at a section facing the magnetic pole surface of the rotor magnet (1). , the planar portion is provided with a wiring board (12', 12'') having a configuration in which at least the rotational speed signal generating means and the stator coil are formed on the surface thereof; A brushless motor featuring 2. The brushless motor according to claim 1, wherein the wiring board (12', 12'') is made of a flexible material. 3. The wiring board (12') is such that the surface on which the rotational speed signal generating means is formed and the surface on which the stator coil is formed are integral with each other within the range that faces the magnetic pole surface of the rotor magnet (1). The brushless motor according to claim 1 or 2, which has a configuration comprising: 4. The wiring board (12'') is provided with a bent portion between the surface where the rotational speed signal generating means is formed and the surface where the stator coil is formed, and when bent at the bent portion, The brushless motor according to claim 1 or 2, wherein the both surfaces are laminated concentrically with each other. 5. The wiring board (12', 12'') includes a wiring part (16) to which the terminal of the position detection means is wired, and the position detection means is arranged to face the magnetic pole surface of the rotor magnet (1). The brushless motor according to claim 1, 2, 3, or 4, which has a configuration arranged in a plane. 6. The wiring board (12', 12'') includes a protruding portion that protrudes toward the outside of the stator yoke,
The projecting portion is provided with at least a patterned conductor (13) for leading out the terminal of the stator coil and a patterned conductor (17) for leading out the terminal of the rotational speed signal generating means. Range 1st, 2nd, 3rd, 4th
Or the brushless motor described in item 5.