JPH01170355A - Coil for flat brushless motor - Google Patents

Abstract

PURPOSE:To equalize the output of a position detector and the counter electromotive output patterns of phases and to reduce a torque ripple and wow and flutter by suitably determining the pattern of a coil for a flat brushless motor. CONSTITUTION:Unit coil poles 1a-1i formed of 9 spiral pattern conductors and through holes 4a-4c for disposing position detectors are formed on one coil sheet 1. 4 spiral unit coil poles of the poles 1a-1d are deformed, the positional relationship of deforming phase coils as a whole and the total sum of deforming amounts are electromagnetically equalized equivalently so that the sum of the patterns of the counter-electromotive output of the same phase coils become the same among the phases. The position detectors are buried in the holes 4a-4c so that the outputs become the same.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coil for a flat brushless motor.

[Conventional technology]

BACKGROUND ART Recently, electronic devices have become smaller and smaller, and there is a strong demand for smaller and thinner motors used as drive sources for each device. Furthermore, in order to achieve an ultra-thin motor, it is necessary to make the armature coil thinner, and sheet-like coils are used, in which patterned conductors are formed by plating, etching, etc. on both or one side of a flat insulating thin film. There is. Furthermore, in order to eliminate the increase in the air gap between the magnet and the opposing yoke due to the thickness of the position detection element that detects the position of the rotor magnet, for example,
Publication No. 1-263203, Utility Model Application Publication No. 61-27480,
There is one disclosed in Japanese Utility Model Application Publication No. 61-46885.

[Problem that the invention seeks to solve]

However, the third
In a motor with a surface facing structure as shown in the figure, the number of poles of the spiral coil arranged on the circumference facing the ring-shaped magnetic pole is 4th.
As shown in the figure, the number of 2P pieces is the same as the number of magnetic poles, and unless in the case of -phase drive, it is necessary to stack multiple printed coil sheets according to the number of phases, making the motor smaller and thinner for multiphase drive. There were limits to the demands for change. In addition, the position detection element is constructed by deforming a part of the coil pattern of each printed coil sheet of a plurality of stacked coil units to create a margin, as shown in FIG. Embedded, Utsukai Showa 61-4688
As shown in Figure 6 of Publication No. 5, all of the coils were buried in a specific printed coil sheet among the laminated sheets.

However, in the case of the example disclosed in Japanese Utility Model Application Publication No. 61-27480, the output of the position detecting element varies due to the difference in the distance between the position detecting element and the magnetic pole. It was necessary to provide an external mechanism to keep the value constant. In the case of the example disclosed in Japanese Utility Model Application Publication No. 61-46885, the output of the position detection element is constant, but it is necessary to partially deform the pattern of the specific printed coil sheet on which the position detection element is attached, and to change the magnetic pole and each The difference in the distance between the phase coil sheets causes a difference in the back electromotive force ratio cover turn that occurs between each phase, which may cause deterioration in motor performance such as torque ripple and wow flutter.

[Means to solve the problem]

In the present invention, the above problems are solved by making the motor coil have the following configuration. That is, the present invention provides a ring-shaped rotor magnet having 2P magnetic poles (P is an integer of 1 or more) on a plane, and a spiral of m phases (m is an integer of 2 or more) facing the rotor magnet. A flat brushless motor comprising one printed coil sheet in which a plurality of shaped unit coil poles are arranged in a plane, and a position detection element for the rotor magnet embedded in a part other than the conductor pattern on the printed coil sheet. In a coil for use in a spiral printed coil, spiral unit coil poles of m7 pieces (α is the number of coil poles with the same phase of 2 or more) are closely connected to each other on both the front and back sides of a flat insulating thin film for each phase number m. The number mα of spiral unit coil poles arranged adjacent to each other on one surface satisfies mα<2P, and among the spiral unit coil poles on one surface, m or more spiral unit coils A part of the conductor pattern forming the pole is deformed, and a through hole or notch is provided in the blank space on the insulating thin film surface caused by the deformation, and m position detection elements are inserted into the printed coil sheet. The conductor pattern is arranged so as to be at least partially buried in the thickness direction, and the deformed shape of the conductor pattern is deformed so that the pattern of the back electromotive force due to the in-phase coil including the deformed spiral unit coil pole is the same for each phase. This is a coil for a flat brushless motor, which is characterized by being a coil for a flat brushless motor.

[Effect]

By configuring the motor coil according to the present invention, the output of the position detection element and the back electromotive force cover turn of each phase are made the same, and a high-performance, compact, and thin motor with low torque ripple and wow and flutter is realized. Ru.

The distance between adjacent spiral unit coil poles is 1.0 m, taking into account the coil wiring and insulation between the conductor and the outside.
m or less, preferably 0.6 mm or less, more preferably 0.3 mm or less. Also, considering the same point, the distance between the through hole or notch for position detection element placement and the deformed spiral unit coil pole should be 1.4 nun or less, preferably 1.4 nun or less. Otsm or less, more preferably 0.5 mm or less.

[Embodiment]

The present invention will be described in detail below with reference to the drawings.

FIG. 1(A) is a plan view showing one embodiment of a coil for a three-phase drive flat brushless motor used in the present invention.
A unit coil pole formed by nine spiral pattern conductors and a through hole for arranging a position detection element are provided on one coil sheet.

FIG. 1(B) is a cross-sectional view of the coil, and FIG. 1(C) is
Rotor magnet (6) placed opposite this coil
In the plan view, it is composed of 12 poles (P=6). 1st
In Figure (A), (la) to (11) are spiral unit coil poles, and (2a) to (21) are through holes provided in the center of each coil pole and are flat insulating thin films (3). The spiral pattern conductors formed on both sides of the board are electrically connected. Here, among the nine spiral unit coil poles, the coil pole (
1a), (1d), and (Ig) are in phase (this is referred to as U phase), and coil poles (1b), (1e), and (1h) are in phase (
This is the V phase), coil poles (1c), (1f), (
11) is in phase (this is assumed to be W phase). In addition, the four spiral unit coil poles (1a) to (1d) are deformed to form a coil within 1.4 mm, preferably within 1.0 vats, more preferably within 0.5 vats from the pattern end of these coil poles. Through-holes (4a) to (4c) for arranging the position detection element, which are substantially the same size as the position detection element, are provided in the insulating thin film part located at a distance of less than mm, and the position detection element is inserted into the coil. are arranged in one piece.

In this embodiment, the U-phase coil poles (la) and (1d) are deformed symmetrically with respect to an imaginary line passing from the axis center to the coil pole center. As shown in Fig. 2, the shapes of the spiral unit coil poles of each phase are the deformed part (5a) of the U-phase coil pole (1a), the deformed part (5d) of the
), the deformed portion (5f) of the W-phase coil pole (1c) is equivalent to each phase in the relative positional relationship with the magnetic pole, and the amount of deformation is equal for each phase, and the deformed portion of the U-phase coil pole (ld) (5b), deformed part of the ■ phase coil pole (1b) (5c
), the deformed portion (5e) of the W-phase coil pole (1c) is equivalent to each phase in the relative positional relationship with the magnetic pole, and the amount of deformation is equal to each phase. Therefore, as a whole, the positional relationship of deformation of each phase coil and the total amount of deformation are electromagnetically equivalent, and the total pattern of back electromotive forces due to the same phase coils is the same for each phase.

Furthermore, since the position detection element is embedded in a through hole that is substantially the same size as the position detection element, the distance from the magnet surface and the distance in the radial direction of the coil can be shortened, allowing for highly accurate placement. They can be the same.

Next, other embodiments of the present invention will be described.

FIG. 3 is a plan view showing another embodiment of the flat brushless motor phase coil used in the present invention, which is provided with a unit coil pole formed by nine spiral pattern conductors and a through hole for arranging a position detection element. It is a diagram.

Here, among the nine unit coil poles, coil poles (a) to (C
) is deformed in the central part of the three coil poles where the through holes are located, and within 1.4 mra, preferably within 1.0 mm, more preferably within 0.5 mm from the edge of the deformation pattern of the three deformed coil poles. On an insulating thin film part that is within a distance of
Through-holes (4a) to (4c) for arranging the position detecting element, which are the same size as the position detecting element, are provided, and the position detecting element is disposed integrally with the coil here. In the embodiment of FIG.
The deformed parts of the phase coil pole (1a), V-phase coil pole (1b), and W-phase coil pole (1c) are equivalent to each phase in the relative positional relationship with the magnetic pole, and the sum of the back electromotive force cover patterns of the same-phase coils is They become identical.

Note that the method of deforming the coil pattern is not limited to this embodiment; any deformation may be used as long as it is electromagnetically equivalent and the back electromotive forces of each phase are equal in the motor.

〔Effect of the invention〕

By using a flat brushless motor phase coil with the above configuration, when it is incorporated into a motor, the output of the position detection element and the back electromotive force cover turn of each phase are the same, and the torque ripple and wow and flutter are small. Performance and small size
A thin motor can be obtained.

In addition, the position detection element can be installed with high accuracy by simply embedding it in the through hole for position detection element placement, which is highly effective in improving assembly work efficiency.

[Brief explanation of the drawing]

Figures 1 (A), (B), and (C) are a plan view and a sectional view of the coil used in the present invention, and a corresponding plan view showing the division of the magnet used, and Figure 2 is the same as in Figure 1. FIG. 3 is a plan view showing the pattern shape of each unit coil pole of the coil of the embodiment.
The figure is a plan view showing another embodiment of the coil used in the present invention. FIGS. 4(A) and 4(B) show an example of a conventional flat brushless motor, showing an exploded perspective view and a sectional view, respectively.
FIG. 5 is a plan view showing an example of the correspondence between the conventional number of magnet divisions and the number of coil divisions. Top...Coil sheet 1a=1i...Unit coil poles 2.2a to 21...Through holes 3...Insulating thin film 4.4a to 4c...Through holes or cuts for arranging position detection elements Notch 4゛...Position detection element 58-5f...Coil pattern deformation part work...Rotor magnet patent applicant Asahi Kasei Corporation Figure 5 Mu J4 Figure (A) Figure (C) Figure 2 Figure 3

Claims (1)

[Claims] A ring-shaped rotor magnet having 2P magnetic poles (P is an integer of 1 or more) on a plane, and m-phase (m is an integer of 2 or more) spiral unit coil poles facing the rotor magnet. A coil for a flat brushless motor comprising one printed coil sheet in which a plurality of printed coil sheets are arranged in a plane, and a position detection element of the rotor magnet embedded in a part other than the conductor pattern on the printed coil sheet, In a spiral printed coil, mα (α is the number of coil poles with the same phase of 2 or more) spiral unit coil poles are arranged closely adjacent to each other for each phase number m on both the front and back surfaces of a flat insulating thin film. The number mα of spiral unit coil poles arranged on one surface satisfies mα<2P, and the conductor forms m or more spiral unit coil poles among the spiral unit coil poles on one surface. A part of the pattern is deformed, and a through hole or notch is provided in the blank space on the insulating thin film surface caused by the deformation, and m or less position detection elements are arranged at least in the thickness direction of the printed coil sheet. The conductor pattern is arranged so as to be partially buried, and the deformed shape of the conductor pattern is deformed so that the pattern of the back electromotive force due to the in-phase coil including the deformed spiral unit coil pole is the same for each phase. A coil for flat brushless motors characterized by