JPH0614773B2 - Brushless motor - Google Patents

Description

The present invention relates to a brushless motor, and more particularly to the structure of a flat brushless motor.

1 to 3 are views showing a structure example of a conventional brushless motor, FIG. 1 is a side sectional view, FIG. 2 is an inner plan view,
FIG. 3 is a plan view of magnetic poles of the rotor magnet. This example is an example of a flat type 8-pole 3-phase brushless motor that detects a rotational position by using three magnetic field detection elements. In the figure,
The rotor magnet 1 is magnetized into eight fan-shaped surfaces, and is fixed to a rotary shaft 8 via a rotor yoke 6. The rotary shaft 8 is rotatably supported by bearings 5 and 5 '. There is. A stator is provided so as to face the magnetic pole surface of the rotor magnet 1. This stator includes a stator coil 2, a stator yoke 3, magnetic field detection elements 4, 4 ', 4 ", and a wiring board 1.
It consists of 1. The magnetic field detecting elements 4, 4 ′ and 4 ″ are mounted on the wiring board 11 and are arranged and fixed together with the wiring board 11 on the outer peripheral side surface of the stator coil 2 at a predetermined angular interval. At 4'and 4 ", the rotational position is detected by detecting the leakage magnetic field on the side of the rotor magnet 1. The stator coil 2 has a structure of 8 poles per phase and a structure of 24 poles in 3 phases. A frequency generating coil 15 is fixed between the stator coil 2 and the stator yoke 3 for generating a rotation speed signal. The frequency generating coil 15 has the same pole shape and number of poles as the stator coil 2. Terminals of magnetic field detecting elements 4, 4 ', 4 ",
The terminal of the stator coil 2 and the terminal of the frequency generating coil 15 are all manually soldered to the wiring board 11
Connect to the conductor pattern on the surface of. That is, the magnetic field detecting elements 4, 4 ′ and 4 ″ are previously soldered and fixed on the wiring board 11 and incorporated as a motor stator, and then the ends of the stator coil 2 and the frequency generating coil 15 are placed on this surface. The wiring board 11 has a structure in which a wiring pattern conductor is provided on an insulating rigid plate such as a phenol resin plate, and a wiring lead wire and a connector are connected to the driving electronic circuit from now on. When Hall elements are used as the magnetic field detecting elements 4, 4 ', 4 ", the input terminals are connected in parallel, and the stator coil 2 is star-connected, it is used for connecting to the driving electronic circuit. The total number of wiring lead wires is 13. Therefore, the surface area of the wiring board 11 is increased, a large-sized connector is required, and the space and weight occupied by the wiring lead wires are large. Further, the shield case 10 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, in the conventional brushless motor having the above-described shape, (a) the wiring board, the magnetic field detection element, and the frequency generating coil are separately manufactured, and they are manually assembled and connected when assembling the motor. Moreover, the assembling accuracy is low and a long assembling work time is required. In particular, a decrease in the accuracy of assembling the magnetic field detection element and an increase in the soldering work time result in a decrease in the smooth rotation of the motor and an increase in the cost.

(B) It is difficult to automate processing because the number of connected terminals is large.

(C) Since the frequency generating coil is thick and the volume of the stator coil must be reduced accordingly, the motor efficiency is reduced.

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

(E) Since the side surface magnetic field of the rotor magnet is large and the side surface of the shield case has a notch, the leakage magnetic flux to the outside of the motor is large, which causes a large induction noise. In addition, the cogging torque is large, which reduces smooth rotation.

(F) The amount of effective magnetic flux linked to the stator coil is reduced, and the motor efficiency is reduced.

(G) A large iron loss is likely to occur in the shield case.

(H) The plane size of the motor is large and high-density mounting cannot be performed.

(I) Since the position is detected by the side magnetic field of the rotor magnet, the position detection accuracy is likely to decrease.

(G) Since the magnetic field detecting element is provided at a position having a large radius, the cogging torque due to the magnetic piece in the magnetic field detecting element also becomes large.

It had a defect such as.

In order to eliminate this drawback, there is a brushless motor in which the stator includes a wiring board provided with a magnetic field detection element and a frequency power generation pattern conductor, a stator yoke, and a stator coil. 4 to 9 are views showing an example of such a brushless motor. FIG. 4 is a longitudinal sectional view, FIG. 5 (a) is a front view of a wiring sheet, and FIG. 5 (b) is a side view thereof. (C)
Is a rear view thereof, FIG. 6 is a plan view of a stator yoke, FIG. 7 is a plan view of a stator coil, FIG. 8 is a stacked sectional view of a stator coil, and FIG. 9 is a sectional view of a stator coil pole. Like this example, this example uses three magnetic field detecting elements and detects the rotational position by detecting the magnetic field of the rotor magnet 1 which is magnetized in a fan shape into 8 poles in a plane. It is a structural example of a motor. The stator comprises a wiring sheet 12, a stator yoke 3 ', and a stator coil 2'. The wiring sheet 12 includes the magnetic field detecting elements 4, on the surface of the flexible insulating sheet.
4'and 4 "are integrally fixed, and the terminals thereof are wired by a pattern conductor, and the frequency power generation pattern conductor 20
And a stator coil terminal lead-out pattern conductor 13 are provided. The stator yoke 3'has a structure in which three penetrating small holes 25, 25 ', 25 "are provided at predetermined positions in the plane facing the magnetic poles of the rotor magnet 1. The stator coil 2'is also provided. Insulate each coil pole from the insulation sheet 32
The pattern coils 30 and 30 'are formed in a spiral shape on the front and back surfaces by pattern conductors, and the front and back surfaces are connected in series by through-hole electrodes 31, and the structure has eight poles per phase. In the structure of this motor, the wiring sheet 12 and the stator coil 2'are laminated and fixed on the surface side of the stator yoke 3'which faces the rotor magnet 1. Wiring sheet 1
Reference numeral 2 designates the surface on which the magnetic field detecting elements 4, 4 ', 4 "are fixed on the side of the fixed yoke 3', and the magnetic field detecting elements 4, 4 ', 4" are provided in the plane of the stator yoke 3'. Insert into the corresponding small holes 25, 25 ', 25 ". The stator coil 2'has a coil sheet 40, 4 of 8 pole structure per phase.
0 ′ and 40 ″ are electrical angles with respect to the rotation direction of the rotor magnet 1. The angle of is shifted and laminated and fixed. An insulating coating 36 is provided on the surface of each coil sheet to prevent a short circuit or the like. The ends of the stator coil 2 ′ are connected to the stator coil terminal lead-out pattern conductor 13 formed on the wiring sheet 12. Since the frequency power generation pattern conductor 20 series-adds the voltage generated under each magnetic pole of the rotor magnet 1, the division angle in the circumferential direction between the conductors is an electrical angle. (N = 0, 1, 2, ...) And the structure of this example shows the case of n = 1. 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 completed as one composite component. At times, these terminal wiring operations are unnecessary, and only the terminal wiring of the stator coil 2'may be performed. In addition, if the stator coil 2'is also composed of a patterned coil as in this example, its terminal shape is changed. Wiring sheet 12 because it can be kept constant
It is easy to automate the terminal connection process to the above. The magnetic field detecting elements 4, 4 ′ and 4 ″ are inserted in the surface of the stator yoke 3 ′ and detect the magnetic field immediately below the magnetic pole surface of the rotor magnet 1 to generate a position signal.

As is apparent from the above, the brushless motor of this structure can significantly reduce the number of terminal wires and automate the manufacturing, so that the cost can be reduced and the magnetic field detecting elements 4, 4 ', 4 "can be reduced. Since it is possible to improve the alignment accuracy by the integrated mounting structure on the wiring sheet 12 and the position detection accuracy by the position detection method in the strong magnetic field just below the magnetic pole surface of the rotor magnet 1, it is possible to reduce the torque ripple. Further, the smoothness of rotation of the motor can be improved. Further, since the magnetic field detecting elements 4, 4 ', 4 "are not projected to the side of the stator coil 2', the volume of the stator coil can be increased and the motor can be improved. In addition to improving efficiency, it is possible to use a stator coil having a multi-pole structure with no gap between the poles, which can improve output stability.
Moreover, since the flexible wiring sheet 12 is used, high-density mounting is possible without increasing the planar size of the motor.

However, in the brushless motor, at least the terminal wiring of the stator coil needs to be performed on the wiring sheet 12, so that there is a problem that the workability cannot be improved and the cost cannot be sufficiently reduced.

The purpose of the present invention is. It is an object of the present invention to provide a low-cost brushless motor suitable for mass production without the above-mentioned drawbacks of the prior art.

In order to achieve the above object, the present invention provides: (a) a stator having a structure in which coil conductors having a plurality of phases are formed of patterned conductors on one substrate and laminated in a direction parallel to the rotation axis of a rotor magnet. In a brushless motor having a coil, (b) the substrate is a flexible insulating substrate that is bent in-plane to form a laminated structure, and (c) the coil pole is provided on the substrate with a terminal and its terminal. The lead-out portion is composed of an integrated pattern conductor, and a plurality of coil pole groups corresponding to all phases of the motor are divided and arranged for each coil pole group on a plurality of laminated surfaces of the substrate, and the terminal or its lead-out portion is arranged. Has a portion that is bent together with the substrate between the stacking surfaces.

Next, examples of the present invention will be described. Since the characteristic of the present invention lies in the wiring sheet (substrate), it will be mainly described below.

10 to 12 are explanatory views of the principle of the stator coil used in the brushless motor of the present invention. FIG. 10 is a front view, FIG. 11 is a rear view, and FIG. 12 is a connection diagram. In this example, the patterned coils 45, 45 ′, 45 ″ formed of the pattern conductor are also integrally provided in the wiring sheet 12 ′, and the frequency power generation pattern conductor 20 is
The pattern coils 45, 45 ', 45 "and the stator coil terminal pattern conductor 13 are divided and provided on the front and back of the wiring sheet 12'. The pattern coils 45, 45 ', 45 ″ is a through-hole electrode 31, 31 ′, 3 centered on the coil pole at the end of winding.
1 "leads to the back side, where it is connected by a short-circuit ring 55 made of a pattern conductor and connected in a star shape. With this structure, the work of connecting the terminals inside the motor stator can be completely eliminated, so that the motor assembly Assembling workability including accuracy improvement can be significantly reduced, and cost can be reduced.Because the coil and the frequency signal generator can be made thin, the rotor magnet magnetic pole surface and the stator yoke surface can be separated. The distance can be reduced, the motor efficiency can be improved, and the motor can be easily made smaller and thinner.

13 (a) and 13 (b) are views showing a structural example of a stator coil used in the brushless motor of the present invention, FIG. 13 (a) is a front view and FIG. 13 (b) is a rear view. This example also
Similar to the structure example shown in FIGS. 10 to 12, the stator coil is formed by a pattern coil and is integrated into the wiring sheet 12 ″ surface. In order to increase the number of coil turns, the coil sheet portions 61 and 62 are continuously provided, and the coil sheet portions 61 and 62 are bent and laminated on the wiring portion 60. In this structure as well, terminal connection in the stator is not required at all. The patterned coil of this example has two 3-phase coils in the same plane.
It is a non-matching type coil arranged pole by pole, and the U-phase coil is a
₁ a ₁ ′ · a ₂ ′ · a ₂ · a ₃ · a ₃ ′ · a ₄ ′ · a ₄
Are connected in series, and the V-phase coil is b ₁ · b ₁ ′ ·
b ₂ ′ · b ₂ · b ₃ · b ₃ ′ · b ₄ ′ · b ₄ and W
The phase coil is c ₁ · c ₁ ′ · c ₂ ′ · c ₂ · c ₃ · c ₃ ′
・ C ₄ ′ and c ₄ are connected in series.
_(Where, a _n, b n, the coil pole of _{c n} is the seat surface,
a _n represents a _{', b n', c n} ' sheet back surface of the coil electrode. As described above, according to the present invention, in a flat brushless motor, all-phase coil poles of a patterned conductor, their ends, and their lead-out portions are integrally formed on a flexible substrate. Since the board is bent to form a laminated structure, no terminal connection work is required inside the stator, which reduces the number of parts, the number of assembly steps, the manufacturing time of the motor, the cost reduction, and the high accuracy of assembly. In addition, there is an effect that the efficiency can be improved, and the motor can be easily improved in size and thickness.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a structural example of a conventional flat type brushless motor, FIG. 2 is an inner plan view, and FIG. 3 is a magnetic pole plan view of a rotor magnet. FIG. 4 is a vertical cross-sectional view showing another example of the brushless motor, and FIGS. 5 (a), (b), (c).
Is a front view, a side view and a back view of the wiring sheet, FIG. 6 is a stator yoke plan view, FIG. 7 is a stator coil plan view, FIG. 8 is a laminated sectional view of the stator coil, and FIG. FIG. 3 is a stator coil pole sectional view. FIGS. 10, 11 and 12 are explanatory views of the principle of the stator coil used in the brushless motor of the present invention, and FIG. 13 is an embodiment of the stator coil used in the brushless motor of the present invention. Explanation of symbols 1 ... Rotor magnet 2, 2 '... Stator coil 3, 3' ... Stator yoke 4, 4 ', 4 "... Magnetic field detecting element 5, 5' ... Bearing 6 ... Rotation Child yoke 8 ... Rotating shaft 10 ... Shield case 11 ... Wiring board 12, 12 ', 12 "... Wiring sheet 13 ... Stator coil terminal pattern conductor 15 ... Frequency generating coil 20 ... Frequency generating pattern Conductor 25,25 ', 25 "... Small hole 30,30' ... Patterned coil 31,31 ', 31" ... Through hole electrode 32 ... Insulating sheet 36 ... Insulating coating 40,40', 40 "... ... Coil sheet 45, 45 ', 45 "... Patterned coil 55 ... Short-circuit ring 60 ... Wiring section 61, 62 ... Coil sheet section

Claims (2)

[Claims] 1. A brushless motor having a stator coil in which a plurality of phase coil poles are formed of a patterned conductor on a single substrate and are stacked in a direction parallel to the rotation axis of a rotor magnet. Is a flexible insulating substrate, which is bent in-plane to have a laminated structure, and the coil pole is composed of a patterned conductor in which the terminal and the terminal lead-out portion are integrated on the substrate, A plurality of coil pole groups corresponding to all phases are divided and arranged for each coil pole group on a plurality of laminated surfaces of the substrate, and the terminal or its lead portion has a portion that is bent together with the substrate between the laminated surfaces. A brushless motor having the above-mentioned configuration. 2. The brushless motor according to claim 1, wherein the substrate includes a rotational speed signal generating means made of a patterned conductor.