JPS583558A - Brushless motor - Google Patents

Abstract

PURPOSE:To improve the arranging accuracy of field detectors and rotating smoothness and to improve the productivity of a brushless motor by forming a stator coil end lead and a frequency generating coil via a pattern conductor on a wiring sheet surface and integrally fixing the detectors. CONSTITUTION:A stator is formed of a wiring sheet 12, a stator yoke 3' and a stator coil 2', the sheet 12 is secured onto a flexible insulating sheet integrally with field detectors 4-4'', the ends are wired with a pattern conductor, and a frequency generating pattern conductor 20 and a stator coil end leading pattern conductor 13 are provided. The yoke 3' is formed with three small through holes 25-25'' at the prescribed positions oppositely to the poles of a rotor magnet 1 in the plane of the yoke. Further, the coil 2' is spirally formed with respective coil poles on the front and back surfaces of an inuslating sheet spirally with the pattern conductors as a pattern coil connected in series with each other between the front and the back surfaces via through hole electrodes.

Description

[Detailed description of the invention] The present invention relates to brushless motors, and more particularly to brushless motors.

1 to 6 are diagrams showing structural examples of conventional brushless motors, in which FIG. 1 is a side sectional view, FIG. 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 5-phase brushless motor that detects the rotational position using three magnetic field detection elements. In the figure 7
The rotor magnet 1 has its surface magnetized into eight equal parts in a fan shape.

The rotor is fixed to a rotating shaft 8 via a rotor yoke 6, and the rotating shaft 8 is rotatably supported by bearings 5 and 5'.A stator is provided opposite the magnetic pole surface of the rotor magnet 1. . This stator has stator coils 2. Stator yoke 3. The magnetic field detection elements 44', 4'', which are composed of magnetic field detection elements 4.4', 4'', and the wiring board 11, are mounted on the wiring board 11, and are attached to the outer peripheral side of the stator coil 2 together with the wiring board 11. They are arranged and fixed at predetermined angular intervals.

The magnetic field detection elements i4', , II'' detect the leakage magnetic field on the sides of the rotor magnet 1 to detect the rotational position.The stator coil 2 has a structure of 8 poles per phase.

The 3-phase has a 24-pole structure. A frequency generating coil 15 is fixed between the stator coil 2 and the stator yoke 6 for generating a rotational speed signal. As the frequency power generation coil 15, one having the same separation shape and the same number of poles as the stator coil 2 is used. The terminals of the magnetic field detection elements 4, 4', 4'', the terminals of the stator coil 2, and the terminals of the frequency generating coil 15 are all connected to the conductor pattern on the surface of the wiring board 110 by manual soldering. That is, Magnetic field detection element 4
After soldering and fixing ゜4' and 4'' onto the wiring board 11 in advance and incorporating this as a motor stator,
The terminals of the stator coil 2 and the frequency generating coil 15 are connected by soldering on this surface. 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 4.4'
, 4" using a Hall element and connecting the input terminals in parallel.

When the stator coil 2 is star-shaped, the number of wiring leads connected to the driving electronic circuit is 16 in total. Therefore, the surface area of the wiring board 11 is large, the connector is also large, and the space and weight occupied by the wiring lead wires are also large. The shield case 10 has a discontinuous side surface with a part of the side surface cut out in order to fix the wiring board 11. However, in the conventional brushless motor having the shape described above.

(a) The wiring board, the magnetic field detection element, and the frequency power generation module are each manufactured separately, and these are assembled and connected manually when assembling the motor, which results in poor assembly accuracy.

In particular, the assembly accuracy of the magnetic field detection element is reduced and the soldering work time is increased, which is characterized by a long assembly time.
Each of these results in a decrease in smooth rotation of the motor and an increase in cost.

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

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

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

(e) The rotor magnet's ψ11 plane magnetic field is thick (.

Also, because the shield case has a notch on the side, there is a large amount of magnetic flux leaking to the outside of the motor.

Causes large induced noise. In addition, the cogging torque is also large (1) which reduces smooth rotation. (f) The amount of effective magnetic flux interlinking with the stator coil decreases, resulting in a decrease in 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.

(1) Since the position is detected by the side magnetic field of the rotor magnet, the accuracy of one position detection tends to decrease. The cogging torque caused by this also increases.

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) On the surface of the wiring sheet, at least the terminal extension portion of the stator coil and the frequency power generation coil are formed using a patterned conductor.

The magnetic field detection element is also integrally fixed, and its terminals are wired with patterned conductors. This greatly reduces the number of terminals to be processed on the stator section during motor assembly, and makes it easier to automate the processing work. The aim is to improve manufacturability and reduce costs, while at the same time improving the alignment accuracy of the magnetic field detection elements and improving the smoothness of one rotation.

(b) Make small holes etc. in the plane of the stator yoke.

A magnetic field detection element is inserted inside these, and the structure is such that the magnetic field detection element does not protrude onto the stator yoke plane and is installed directly under the magnetic field surface of the rotor magnet. This enables accurate position detection even under strong magnetic fields, improving motor efficiency and achieving even smoother rotation.

The main features are:

An embodiment of the present invention will be described below with reference to the drawings.

4 to 10 are diagrams showing a first embodiment 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, and FIG. 5(b) 6 is a plan view of the stator yoke, FIG. 7 is a plan view of the stator coil, FIG. 8 is a laminated cross-sectional view of the stator' coil, and FIG. is a stator coil pole cross-sectional view, the first
FIG. 0 is a diagram showing another example of the structure of the stator yoke suitable for the motor structure of the embodiment. Similarly to the conventional example, this example is a 6-phase, 8-pole brushless system that uses three magnetic field detection elements to detect the magnetic field of the rotor magnet 1, which is magnetized evenly divided into 8 poles in a fan shape to detect the rotational position. This is an example of the structure of a motor. The stator is composed of a wiring sheet 12, a stator yoke 3', and a stator coil 2'. The wiring sheet 12 has magnetic field detection elements a, a', 41 on the flexible insulating sheet surface.
/ is integrally fixed, its terminal is wired with a pattern conductor, and a one-frequency power generation pattern conductor 20 and a stator coil terminal pullout putter/conductor 16 are provided. The stator yoke 6' has five small through holes 25 at predetermined positions facing the magnetic poles of the rotor magnet 1 in its plane.
．． 25'.

The stator coil 2' has a structure in which each coil pole is formed in a spiral shape 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 with a through-hole electrode 61. The coil 50.30' has a structure of 8 poles per phase.In the configuration of this motor, the wiring sheet 12 and the stator are arranged on the side of the stator yoke 3' that faces the rotor magnet 1. The coil 2' is stacked and fixed.

The wiring sheet 12 has the surface on which the magnetic field detection elements 4.4' and 4' are fixed fixed to the stator yoke 3' side, and the magnetic field detection elements 4.
．． 4', 4'' are inserted into respective corresponding eyelets 25, 25', 25'' provided in the plane of the stator yoke 6'. The stator coil 2' has a coil sheet 40.40', 40'' with an 8-pole structure per phase and rotates f magnet 1.
They are laminated and fixed at an electrical angle of Iπ with respect to the rotation direction of the two. An insulating coating 56 is applied on the surface of each coil sheet to prevent short circuits and the like. The terminal end of the stator coil 2' is connected to a stator coil terminal lead-out pattern conductor 13 formed on the wiring sheet 12.

Since the frequency power generation pattern conductor 20 adds the voltages generated under each magnetic field of the two-rotor magnet 1 in series, the dividing angle in the circumferential direction between the conductors is -2n+1-(n=o,
1.2...), and the structure of this example shows the case where n=1. In this structure, the magnetic field detection element 4.
4', 4'' and the frequency power generation turn conductor 20 are integrally provided on the wiring sheet 12 and completed as one composite part. Therefore, when assembling the motor, these terminal wiring work is required. Also, if the stator coil 2' is also composed of patterned coils as in the one example,
Since the shape of the terminal can be made constant, the process of connecting the terminal to the wiring sheet 12 can be easily automated. Magnetic field detection element 44'
・4" is inserted into the plane of the stator yoke 3' and detects the magnetic field directly under the magnetic pole surface of the two-rotor magnet 1 to generate a position signal. Magnetic field detection element 4.4", stator into which the 4" is inserted As for the planar structure of the yoke 3', in addition to the small holes 25, 25' and 25'' as described above, there is also a circular groove 3.
5 is also practical.

In addition, in this structure, if the roundness and concentricity of the groove are increased, the cogging torque of the motor can be reduced compared to the small hole structure. As is clear from the above, the two-wire structure brushless motor can significantly reduce the number of terminal wires and automate manufacturing, thereby realizing cost reduction. The integrated mounting on the top makes it possible to improve the arrangement accuracy due to the structure and 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, which reduces torque ripple and improves the motor speed. The smoothness of rotation can be improved.

Furthermore, since the magnetic field detection element 4.4', 4'') is designed so that it does not protrude toward the stator coil 2' side, the volume of the stator coil can be increased, improving motor efficiency, and reducing the gap between poles. Since it is possible to use a stator coil having a multi-polar structure with no gaps between the stator coils, the stability of the output can be improved.

Furthermore, a flexible wiring trunk 12 is used.

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

11 and 12 are diagrams showing a second embodiment of the brushless motor according to the present invention, in which FIG. 11 is an enlarged cross-sectional view of the motor electromagnetic structure, and FIG. 12 is a stator yoke to which wiring nodes are fixed. FIG. The basic structure of the motor of this embodiment is the same as the motor of the first embodiment, but the motor of this embodiment has magnetic field detection elements 4.4', 4''.
is provided inside the inner peripheral edge of the stator yoke 6''. In this structure.

In order to locate the magnetic field detection elements 4.4', 4'' under the magnetic pole surface of the rotor magnet 1, the inner diameter of the stator yoke 3'' is made larger than the inner diameter of the rotor magnet 1.

The structure and effects of this embodiment are the same as those of the first embodiment.

FIG. 13 is an enlarged sectional view of a motor electromagnetic part structure showing a fifth embodiment of a brushless motor according to the present invention. This example has a structure in which a flat circular annular notch 50 is provided on the inner peripheral part of the stator yoke 3'', and the magnetic field detection element 4 etc. are fitted into this. This embodiment has the same functions and effects as the first and second embodiments.

14 and 15(a) and 15(b) are diagrams showing a fourth embodiment of the brushless motor according to the present invention, and FIG.
The figure is a vertical cross-sectional view, FIG. 15 (a) is a front view of the wiring sheet, and FIG. 15 (b) is a back view.
Magnetic field detection elements 4, 4', 4 integrated and fixed on the surface
'' is inserted into a small hole provided on the back surface of the stator yoke 3' (the surface opposite to the surface on which the stator coil is fixed).The frequency power generation pattern conductor 20 and the stator coil terminal The portion of the wiring sheet 12 provided with the connection pattern conductor 19 is laminated and fixed to the lower side of the stator coil 2' as in the previous embodiment.In this structure, the wiring sheet 12 is
When installing the magnetic field detection element 4.4', 4", the part can be fixed to the back side of the stator yoke 6' and exposed to the outside of the motor, so the integrated circuit of the driving electronic circuit etc. can be mounted in this part. In addition to being able to utilize the space on the outer shell of the motor, it also has the advantage of making it easier to maintain the wiring.

16 to 18 are diagrams showing other structural examples of the wiring sheet used in the brushless motor according to the present invention, and FIG.
6 is a front view, FIG. 17 is a back view, and FIG. 18 is a wiring diagram. This example has a structure in which patterned coils 45, 45' and 45'' formed of patterned conductors are also integrated inside the wiring notebook 12'.
45', 45".

The ends of each winding are led to the back side through through-hole electrodes 31, 31', 31'' at the center of the coil pole, and connected there with a short circuit ring 55 made of a no-turn conductor to form a star-shaped connection.In this structure, , since terminal connection work inside the motor stator is completely unnecessary, the workability of motor assembly can be significantly improved and costs can be reduced. Figure 19(a) is a surface view, and Figure 19(a) is a diagram showing an example.
b) is a back view. This example also applies to the above-mentioned figures 16 to 1.
Similar to the structural example shown in FIG. 8, the stator coil is formed of a patterned coil, and this is integrated into the surface of the wiring sheet 12''.

In this structure, in order to increase the number of coil turns, the coil sheet portion 6
1.62 is provided in a row, and this is folded twice onto the wiring part 60 and stacked.The 0-wire structure also eliminates the need for terminal connections inside the stator. An example of a patterned coil is.

This is a J-to-matching type coil in which 3-phase coils are arranged in the same plane with 2 poles each, and U-phase coils/1. z B a,・a′1
・Constructed by connecting a', a2, a3, a2, aco, and a4 in series, and the ■ phase coil is bl, b'1, b'2, b2,
b5, bλ, bQ-b4.

The W phase coil is still C1'C'l ” C'2 ' C
2'C5'C'5'C'4'' C4 are connected in series. (Here.

an * bn + Cn is the coil pole on the sheet surface +
an r b'l r c; represents the coil pole on the back surface of the sheet. ) As explained above, according to the present invention, there are provided two U-flat planless motors.

(b) The structure in which the single-frequency power generation coil pattern and the magnetic field detection element are integrally provided on the wiring sheet makes it possible to significantly reduce the number of motor terminal wiring processes and the number of assembly steps, and the time required to manufacture the motor. It can be shortened and costs can be reduced.

It is still easy to automate the processing work.

(b) The arrangement accuracy of the magnetic field detection elements can be improved, and 2. smooth rotational performance can be improved.

(c) With the structure in which the magnetic field detection element is placed in a strong magnetic field facing the magnetic pole surface, accurate magnetic field distribution can be obtained and the influence of the offset amount of the output of the magnetic field detection element can be reduced, allowing accurate rotational position detection. be.

(d) When a ball element or the like is used as the magnetic field detection element, the input resistance value thereof can be increased and the power consumption of the part can be reduced.

(e) Since the magnetic field detection element is not provided in the gap between the rotor magnet magnetic pole surface and the stator yoke surface, the space occupied by the stator coil can be increased and motor efficiency can be improved.

(f) For those with a structure in which the magnetic field detection element does not protrude above the stator yoke surface, a multi-pole sheet-like stator coil or a stator coil with a structure in which these are laminated can be used. It is possible to increase the effective conductor length and at the same time create a multi-pole coil structure that has a high output phase averaging effect.
Can improve motor efficiency and output stability. Particularly, in the case of a printed coil in which a stator coil is formed of a patterned conductor, the effect of the structure of the present invention is remarkable.

(g) It is easy to construct a thin motor with high volumetric efficiency.

(TE) Since it is possible to use a full-circumference side-type shield case without a notch on the side surface, magnetic leakage to the outside of the motor can be eliminated.

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, and FIG. 3 is a plan view of magnetic poles of a rotor magnet. FIG. 4 is a vertical sectional view showing a first practical example of the brushless motor according to the present invention, and FIG.
), (bl, and (c) are respectively the front, side, and back views of the wiring sheet, Figure 6 is a stator yoke plan view, Figure 7 is a stator coil plan view, and Figure 8 is a stator coil. 9 is a cross-sectional view of the stator coils, FIG. 10 is a plan view showing another example of the structure of the stator yoke suitable for the motor structure of the embodiment, and FIG. 11 is a cross-sectional view of the stator coil according to the present invention. FIG. 12 is an enlarged sectional view of the motor electromagnetic structure in the second embodiment of the brushless motor, FIG. 12 is a plan view of the stator yoke to which the wiring sheet is fixed, and FIG. 16 is the motor electromagnetic structure in the sixth embodiment. The enlarged cross-sectional view and FIG. 14 are longitudinal cross-sectional views showing the fourth embodiment. FIGS. 17th
18 and 18 are surface views showing other structural examples of the wiring sheet used in the brushless motor according to the present invention, respectively.
A back view and a wiring diagram, and FIGS. 19(a) and 19(b) are a front view and a back view, respectively, showing still another structural example of the wiring sheet. Explanation of symbols 1...Rotor magnet 2, 2'...Stator coil 5, 5', 3''...Stator yoke 4, 4',
4"...Magnetic field detection element 5, 5'...Bearing 6...Rotor yoke 8...Rotary shaft 10...Shield case 11...Wiring board 12, 12', 12"...・Wiring sheet 16・
...Stator coil terminal pull-out pattern conductor 15...Frequency generation coil 19...Stator coil terminal connection pattern conductor 20...
・Frequency power generation coil butter 7 conductor, 25, 25',
25"...Small hole 30, filter O'...patterned coil 31, 31', 31"...through hole electrode 62.
...Insulating sheet 35...Annular groove 36...Insulating coating ao, ao', ao''...Coil sheet 45, 45', 45''...Patterned coil 50...
・Annular notch 55...Short ring 60...Wiring section 61, 62...Coil sheet department agent patent attorney Junnosuke Nakamura 13th figure 12th figure 13th figure 1161; (θ)

Claims (1)

[Scope of Claims] (1) A magnetic field detection element detects the magnetic field of a flat annular rotor magnet whose plane is magnetized equally divided into fan shapes in the circumferential direction to detect the rotational position of the rotor magnet; A flat stator coil having a configuration in which a current corresponding to the magnetic poles of the rotor magnet is controlled by an electronic circuit and supplied to a flat stator coil group provided at a position facing the magnetic pole surface of the rotor magnet to obtain one rotation driving force. A type of brushless motor has a thin film pattern conductor on an insulating sheet surface, and the pattern conductor connects at least a terminal lead-out portion of a stator coil, a patterned coil portion for generating two frequency signals, and a terminal lead-out portion thereof; A wiring sheet is provided within the stator, in which a pattern portion for terminal wiring of the magnetic field detection elements is formed, and the magnetic field detection elements are arranged and fixed on the sheet surface, and the terminal wiring is performed using the pattern conductor. A brushless motor featuring the following ◇
(2. In the brushless motor according to claim 1, the wiring sheet has a shape having a small hole, a notch, a groove, or a recess in a plane, or has a larger inner diameter or outer diameter than the rotor magnet. fixed on the surface of a small flat annular stator yoke, and arranging a magnetic field detection element and a patterned coil section for frequency signal generation in a magnetic field under the magnetic pole surface within the radius of the rotor magnet;
Magnetic field detection elements are inserted into small holes, notches, grooves, or recesses of the stator, or arranged on the inner peripheral edge or outer peripheral portion of the stator yoke, so that the thickness of the magnetic field detecting elements is determined by the fixation of the stator yoke. A brushless motor characterized by being configured so that the child coil does not protrude toward the fixed surface side. (3) In the brushless motor according to claim 1, the wiring sheet has a wiring sheet structure in which a spiral coil is formed on the sheet surface with a patterned conductor and a stator coil is also integrated. A brushless motor characterized by: