JPH0756623Y2 - Axial gap type brushless motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of Invention] (Industrial field of application) The present invention relates to an axial gap type brushless motor having a structure in which a position detection element is mounted on a printed circuit board having a conductor pattern for frequency power generation.

(Prior Art) In this type of axial gap type brushless motor, an armature coil is fixed to a stator yoke, and a rotor provided with a rotor magnet made of a permanent magnet has a magnetized surface of the rotor magnet facing the armature coil. So that the shaft of the rotor is supported by the bearing housing provided on the stator yoke, and the flat plate-shaped printed circuit board is disposed on the stator yoke so as to face the magnetized surface of the rotor magnet. There is one in which a conductor pattern for frequency power generation provided on this printed board is opposed to the magnetized surface of the rotor magnet, and a position detection element is attached to the printed board. In this case, therefore, if the position detecting element is directly mounted on the printed circuit board, the position detecting element projects too much to the rotor magnet side, so that it is necessary to increase the distance between the printed circuit board and the rotor magnet. However, this causes a problem that the conductor pattern for frequency power generation is too far from the magnetized surface of the rotor magnet. For this reason, conventionally, an opening is formed in a printed circuit board, a holder made of synthetic resin is attached to this opening, and the position detection element is supported by this holder. The surface of the conductor pattern is substantially flush with the surface.

(Problems to be solved by the invention) However, in the above conventional configuration, since the position detecting element is mounted on the printed circuit board via the holder, a separate holder is required for mounting the position detecting element, and the number of parts is increased accordingly. However, there is a drawback in that the assembly work is troublesome.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an axial gap type brushless motor which can reduce the number of parts for mounting a position detection element and can easily perform an assembly work.

[Structure of the Invention] (Means for Solving the Problem) An axial gap type brushless motor of the present invention has an armature coil and a field magnetizing surface and a frequency generating magnetizing surface in the same plane. A permanent magnet type rotor arranged such that its magnetized surface faces the armature coil, and a non-flexible raw print having a predetermined wall thickness arranged so as to face the magnetized surface of this rotor. A substrate, a position detecting element mounted on a surface of the printed circuit board that faces the magnetized surface for magnetizing the rotor, and the printed circuit board is provided so as to face the magnetized surface for frequency power generation of the rotor. And a conductor pattern for frequency power generation, wherein the printed circuit board is formed such that a portion provided with the frequency power generation conductor pattern protrudes in the magnetizing surface direction of the rotor from the mounting surface of the position detecting element. With the part Having characterized in that a step is formed between the parts.

(Operation) According to the above means, a step is formed between the portion of the printed circuit board on which the conductor pattern for frequency power generation is provided and the other portion, and the height of the position detecting element can be absorbed by the step. The position detecting element can be directly attached to the printed circuit board in such a form that the conductor pattern is not too far from the magnetized surface of the rotor. Therefore, since the position detecting element can be directly attached to the printed circuit board, a conventional holder is not required for mounting the position detecting element, so that the number of parts can be reduced correspondingly and the assembling work can be easily performed.

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

First, in FIG. 1, reference numeral 1 is a stator yoke, and a plurality of, for example, three armature coils 3 are fixedly arranged in a recess 2 of the stator yoke, and a bearing housing is provided in the center of the recess 2 with bearings 4 and 4 inside. 5 is fixed in a penetrating state. Further, a convex portion 6 is formed in an end ring shape on the outer peripheral portion of the concave portion 2 of the stator yoke 1. Reference numeral 7 denotes a permanent magnet type rotor in which a rotor magnet 9 made of an annular permanent magnet is fixed to the inner surface of the rotor yoke 8, and a rotary shaft 11 fixed to the center of the rotor yoke 8 via a boss 10 of the bearing housing 5. Bearing 4,4
The rotor magnet 9 is rotatably supported, and the magnetized surface of the lower surface of the rotor magnet 9 faces the upper surface of the armature coil 3 with a predetermined gap. On the magnetized surface of the rotor magnet 9, a field magnetized surface 12a is formed in an annular shape in a portion facing the armature coil 3, and a multi-pole magnetized surface is formed on the outer peripheral portion of the magnetic field magnetized surface 12a. The magnetized surface 12b for frequency power generation is formed in an annular shape.

Reference numeral 13 denotes a non-flexible printed circuit board having a predetermined thickness fixed to the stator yoke 1 so as to face the magnetized surface of the rotor magnet 9, and is shown in FIG. As shown, an opening 14 is formed, and the upper end of each armature coil 3 is located in the opening 14 and slightly protrudes upward. Each opening 14 is on the top surface of the printed circuit board 13.
Three position detecting elements 15 are arranged between them, and each position detecting element 15 is a field magnetizing surface 12 of the rotor magnet 9.
Facing a. Further, the printed circuit board 13 is provided with a convex portion 16 projecting toward the rotor magnet 9 side in a ring shape having an end corresponding to the convex portion 6 of the stator yoke 1, and the rotor magnet 9 is formed on the upper surface of the convex portion 16. Magnetic surface for frequency power generation
A conductor pattern 17 for frequency power generation is provided opposite to 12b. In this case, the convex portion 16 is formed by half-cutting by pressing. Here, the conductor pattern 17 on the upper surface of the convex portion 16, the upper surface of each position detection element 15, and each armature coil 3
It is set to be substantially flush with the upper surface of. In addition, on the upper surface of the printed circuit board 13, the IC 1 for configuring the control circuit is formed.
8, electrical components such as capacitors 19 are provided.

In the case of the above-described configuration, the position of the rotor magnet 9 in the rotor 7 is detected by the position detecting element 15, and the armature coil 3 is electrically disconnected based on the detection signal from the position detecting element 15, so that the rotor 7 It is driven to rotate. When the rotor 7 is rotated, an induced voltage is generated in the conductor pattern 17 for frequency power generation, and this is output as a signal having a frequency synchronized with the rotation speed of the rotor 7, and is applied to the armature coil 3 based on this output signal. The voltage is controlled to rotate the rotor 7 at a constant speed.

According to the above-mentioned embodiment, the position detecting element is formed on the printed circuit board 13 where the conductor pattern 17 for frequency power generation is applied.
Since it is made to project in the magnetizing surface direction of the rotor magnet 9 from the mounting surface of 15, the height difference of the position detecting element 15 can be absorbed by the step difference between the part provided with the conductor pattern 17 and the other part. As a result, the position detecting element 15 can be directly mounted on the printed circuit board 13 in a form in which the conductor pattern 17 is not too far from the frequency power generation magnetized surface 12b of the rotor magnet 9. Therefore, since the position detection element 15 can be directly mounted on the printed circuit board 13, a conventional holder is not required for mounting the position detection element 15, and therefore the number of parts can be reduced by the fact that the holder is not required. Assembling work can be easily performed. Moreover, in this case, the conductor pattern 17 for frequency power generation and the magnetized surface 12b for frequency power generation of the rotor magnet 9 can be brought close to each other, and the position detection element 15 and the rotor magnet 9 can be arranged.
Since it can be brought close to the field magnetized surface 12a of
Good detection accuracy of the conductor pattern 17 and the position detection element 15 can be ensured.

The printed circuit board 13 is a conductor pattern for frequency power generation.
Since the portion marked with 17 protrudes from the surrounding other portion and has a shape in which a step is formed between the portion and the other portion, the conductor pattern thereof is different from that of a simple plate-shaped one. The mechanical strength of the part with 17 is increased, and the printed circuit board 13
Since it becomes difficult to displace in the thickness direction of, the distance between the conductor pattern 17 and the frequency power generation magnetized surface 12b of the rotor magnet 9 can be always set more uniformly over the whole,
As a frequency generator (FG), a stable signal can always be obtained. Furthermore, since the printed circuit board 13 has the above-described shape, it becomes difficult for the portion to which the position detection element 15 is attached to be displaced in the thickness direction of the printed circuit board 13,
Since the distance between the position detection element 15 and the rotor magnet 9 can be set more uniformly, torque unevenness can be reduced.

Although the conductor pattern 17 on the printed circuit board 13, the upper surface of the position detecting element 15, and the upper surface of the armature coil 3 are set to be substantially flush with each other in the above-described embodiments, they are not necessarily flush with each other. It doesn't have to be.

[Advantages of the Invention] As is clear from the above description, according to the present invention, the portion of the printed circuit board on which the conductor pattern for frequency power generation is provided protrudes in the direction of the magnetized surface of the rotor from the mounting surface of the position detection element. Since the step is formed between the portion and the other portion, the position detecting element and the conductor pattern are brought close to the magnetized surface of the rotor while mounting the position detecting element on the printed circuit board. be able to. Therefore, since the position detecting element can be directly attached to the printed circuit board, the conventional holder is not required for mounting the position detecting element, and the number of parts can be reduced because the holder is not required, and the assembling work is easy. Can be done. In addition, the printed circuit board has a shape in which a portion provided with a conductor pattern for frequency power generation is projected from other surrounding portions and a step is formed between the portion and the other portion. Compared to a mere flat plate, the mechanical strength of the part where the conductor pattern is applied increases and it becomes difficult to displace in the thickness direction of the printed circuit board.Therefore, between the conductor pattern and the magnetized surface for frequency power generation of the rotor. The distance can always be set more evenly over the whole range and the frequency generator (F
G) will always be able to obtain a stable signal. Further, since the printed circuit board has the above-mentioned shape, it is difficult for the portion where the position detection element is attached to be displaced in the thickness direction of the printed circuit board, and the distance between the position detection element and the rotor is set more uniformly. Therefore, it is possible to reduce torque unevenness.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is an overall vertical sectional view and FIG. 2 is a plan view of a printed circuit board. In the drawing, 3 is an armature coil, 7 is a rotor, 9 is a rotor magnet, 12a is a field magnetizing surface, 12b is a frequency generating magnetizing surface, 13 is a printed circuit board, 15 is a position detecting element, and 16 is convex. Department,
Reference numeral 17 indicates a conductor pattern for frequency power generation.

Claims (1)

[Scope of utility model registration request] 1. A permanent magnet type having an armature coil, a field magnetizing surface and a frequency generating magnetizing surface in the same plane, and the magnetizing surface is arranged so as to face the armature coil. Rotor, a non-flexible printed circuit board having a predetermined thickness and arranged so as to face the magnetized surface of the rotor, and the magnetic circuitized surface of the rotor facing the magnetized surface of the rotor. A position detection element mounted on the surface, and a conductor pattern for frequency power generation, which is applied to the printed board so as to face the magnetized surface for frequency power generation of the rotor, and the printed board has the frequency A portion provided with a power generation conductor pattern is formed so as to project in the magnetizing surface direction of the rotor from the mounting surface of the position detecting element, and a step is formed between this portion and other portions. Axial gap type brush Sumota.