JPS60219952A - Motor - Google Patents

Abstract

PURPOSE:To reduce the size of a motor by placing directly a sheetlike coil on a stator yoke, and placing a circuit board on the opposite side of the yoke, thereby reducing a gap between the yoke and a rotor. CONSTITUTION:A sheetlike coil unit 33 in which a sheetlike coil 30 is laminated through an insulating adhesive layer 36 is placed directly through an insulating adhesive layer on the surface of the side opposite to a rotor (permanent magnet 8) on a stator yoke 35. Further, a circuit board (printed board) 34' is placed on the opposite side surface of the yoke 35, coil connecting terminals 31, 32 are led to the outer or inner peripheral side of the yoke 35, connected with the board 34'. Thus, a gap size gc' can be reduced. When holes are opened at the yoke 35 and the board 34' to bury a magnetic sensitive element 12, the outer diameter can be reduced.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a motor, particularly a surface-facing flat brushless motor, and particularly a sheet-filed surface-facing brushless motor in which a coil is formed into a sheet by a printed wiring technique such as etching or plating. It is related to flattened brushless morph.

[Prior art]

BACKGROUND OF THE INVENTION Conventionally, as a brushless motor, one having a structure as shown in cross section in FIG. 1 is known as a brushless motor of this type with facing surfaces. That is, reference numeral 1 denotes a rotating shaft, into which a pedestal 6 is press-fitted, and is supported by a flat bearing 3 and a ball bearing 4 mounted on a housing 2 . A rotor yoke 7 is attached to the pedestal 6 to which a multi-pole magnetized disk-shaped permanent magnet 8 is fixed. A stator yoke 9 is provided integrally with the housing 2 so as to face the permanent magnet 8 and form a magnetic circuit. A coil 1 is provided on the surface of the stator yoke 9 facing the permanent magnet 8.
1 is connected to and placed on the wiring printed board 10 via this.

12 is a magnetic sensing element that detects the position of the permanent magnet 8;
It is fixed on a printed circuit board 10, and the timing of the current flowing through the coil 11 is switched based on the output signal from this element 12 to apply rotational force to the permanent magnet 8 and, therefore, to the rotating shaft 1.

In this way, this type of surface-facing brushless motor has a simple structure, high reliability, and since it is coreless, it has advantages such as less rotational unevenness, and because the thickness of the motor body is small, It is widely used because it allows devices to be made smaller and more flexible in mounting.

Here, in the motor with the above configuration, the coil 11 is constructed using printed wiring technology as shown in FIG. 2(a), (
By forming the sheet-like coil 30 as shown in b), it is possible to further reduce the coil thickness C in FIG. 1. That is, Figure 2 (IL) l (b)
1 shows the front and back patterns of the sheet coil 300, respectively. In the same figure (a), the conductor pattern is formed in a spiral shape going inward clockwise from the coil connection terminal 31, and in the center part 33a, By welding, through-holes, etc., conduction is established with the center portion 33b of a similar spiral conductor pattern on the back side shown in FIG. 3(b). On the other hand, the conductor pattern on the back side has a pattern that goes outward from the center part 33b counterclockwise in the figure (b), and at the outermost periphery,
Continuing with the adjacent pattern on the right, it now forms a spiral pattern going inward clockwise, and the central part 3
It reaches 3c. This central portion 33C is electrically connected to a corresponding central portion 33d of a similar pattern on the front side shown in FIG. In this way, one sheet fill is
All the coils are connected in series from terminal 31 to terminal 32. One or more of these sheet coils 30 are used to form one phase, and a predetermined angle is set for the number of phases, for example, in the case of three phases with eight poles, 15°
The coils are stacked one on top of the other while being shifted in the rotational direction, thereby forming an extremely thin coil unit 33 as shown in a perspective view in FIG.

According to such a sheet coil unit 33, the gap gC between the stator yoke 35 and the magnet 8 can be made smaller as shown in cross section in FIG. 4 by making the sheet coil unit 33 thinner, and therefore the magnet thickness Mt can be made smaller. Since the same gap magnetic flux can be obtained even if the motor is made thinner, the motor can be made smaller and lighter.

However, in such a sheet coil unit 33, unlike conventional wire-wound coils, it is impossible to wire at the center or just outside the swirling coil, so the fourth
As shown in cross section in the figure, a large printed board 34 was provided between the stator yoke 35 and the coil unit 33, and coil connection terminals 31, 32 were connected to this.

For this reason, even if the sheet coil unit 33 is used to reduce the coil thickness, the printed board 34
Since the coil is interposed between the stator yoke 35 and the coil unit 33, the effect of reducing the thickness of the coil is reduced accordingly.

〔the purpose〕

The present invention was made in view of the above-mentioned problems, and it is possible to reduce the thickness of the coil by placing a sheet-like coil directly on the stator yoke and further reducing the gap between the stator yoke and the magnet. It is an object of the present invention to provide a motor which is capable of increasing the effectiveness of the manufacturing process and ensuring good connection between the coil and the wiring board.

〔Example〕

The present invention will be explained below based on the drawings. Figure 5(a)
l (b) shows a cross section of the structure of an embodiment of the present invention, in which the same reference numerals as in Figures 1 to 4 refer to the same items, and the dashed items refer to the corresponding items. It shows. A coil unit 33 formed by laminating a plurality of sheet-like coils 30 is attached to the surface of the stator yoke 35 facing the permanent magnet 8 using an insulating adhesive or
It is fixed with adhesive while inserting an insulating sheet. A wiring board (printed board) 34' is mounted on the surface of the stator yoke 35 opposite to the coil mounting surface, and is fixed by adhesive, caulking, or the like. The magnetic sensing element 12 is positioned by making holes in the stator yoke 35 and the printed board 34', and is connected and fixed to the printed board 34'. Therefore, the rotation accuracy is improved, and the outer diameter of the motor body is almost the same as the coil diameter, allowing the motor to be made smaller.

The outer diameters d and r of the printed board 34' are the same as those of the stator yoke 35.
It is formed larger than the outer diameter OC of at least the portion where the coil connection terminals 31 and 32 are connected. Figure 5 (
b) is an enlarged sectional view of that part.

30 is a sheet-like coil, and 36 is an insulating adhesive layer. Since the connection part of the coil connection terminals 31 and 32 on the printed board 34' is larger than the stator yoke 35, even if the coil connection terminals 31 and 32 are bent and wired to the back and side as shown, the stator yoke There is no fear of short circuit with 35. In this case, the printed board 34' only needs to be made larger, for example by one fin, and the diameter of the motor becomes much smaller than before, making it much smaller, lighter, and thinner than conventional sheet coil motors. can do. In this way, the gap gσ between the stator yoke 35 and the permanent magnet 8 can be made smaller than gc in FIG. 4, and thereby the magnet thickness Mt' can also be made smaller than Mt. In this embodiment, the coil connection terminals 31 and 32 are connected to a printed board 34' having a larger outer diameter than the stator yoke 35.
Although the wiring is bent at the outer diameter part of the stator yoke 34', it goes without saying that the same effect can be obtained even if the wiring is carried out at an inner diameter part where the inner diameter of the printed board 35 is smaller than the inner diameter of the stator yoke 34'.

〔effect〕

As described above, according to the present invention, the sheet coil is placed directly on the stator yoke, and the wiring board is placed on the opposite surface of the stator yoke, and the connection terminal of the sheet coil is placed on the wiring board on the opposite side of the stator yoke. Since the wires are bent and wired, the gap between the permanent magnets and the stator yoke can be made smaller than before, and the thickness of the magnets can therefore be further reduced to make the motor smaller and thinner. , costs are also reduced accordingly.

Further, when connecting the coil connecting terminal to the wiring board, the risk of short circuit between the edge of the stator yoke and the coil connecting terminal is reduced, and reliability is improved.

[Brief explanation of drawings]

FIG. 1 is a structural sectional view of an example of a conventional surface-facing brushless motor, FIGS. 2(-) and (b) are plan views of conductor patterns of sheet coils, and FIG. 3 is a perspective view of a sheet coil unit. FIG. 4 is a structural sectional view of a conventional motor using the coil unit shown in FIG. 3, and FIGS. 5(a) and 5(b) are structural sectional views of an embodiment of the present invention. 8...Permanent magnet 30...Sheet coil 31.32-...Coil connection terminal 33...
・Sheet coil unit 35... Stator yoke 34'... Wiring board (printed board) 5 7 σ Fig. 2 Fig. 4 1 (H' □)

Claims (1)

[Claims] A disc-shaped permanent magnet that is rotatably supported and magnetized with multiple poles, and a stator yoke that forms a magnetic path in opposition to the permanent magnet.
A motor comprising a sheet-like coil placed on the stator yoke so as to face the permanent magnet,
A wiring board is placed on the opposite side of the fill mounting surface of the stator yoke, and coil connecting terminals are made to protrude radially outward or inward from the coil, and the terminals are connected to the outer periphery of the stator yoke. Alternatively, the motor is characterized in that it is bent so as to bypass the inner circumference and connected to a required location on the wiring board.