JPH01291652A - Axial gap type brushless motor - Google Patents

Abstract

PURPOSE:To reduce the vibrational noise by integrally molding a plurality of stator coils with an elastic material and by fixing this mold layer to the substrate. CONSTITUTION:In a cylindrical bearing housing 1 a substrate 2 is fixed to its outside circumference. A mold compact 4 integrated with six stator coils 3 is fixed to this substrate 2. The compact 4 is thin disk-shaped with a circular opening 4a in the center and is of a structure where each stator coil 3 is integrally buried in the annularly arranged state with a mold layer 5 made of an elastic material, e.g., styrene-butadiene rubber. A rotor 6 is composed of a shallow- bottomed container-shaped rotor yoke 7 whose undersurface is opened, an annular rotor magnet 8, a boss section 9 and a rotating shaft 10 and is releasably supported to a bearing 11. The stator coil 3 is thereby fixed to the substrate 2 through a mold layer 5 made of an elastic material, so that no vibration of a coil will be conveyed to the substrate 8 as it is absorbed with the elastic force of the mold layer 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an axial gear type brushless smoke in which a plurality of stator coils are arranged on a substrate.

(Prior Art) An axial gap type brushless motor has a configuration in which a plurality of stator coils are disposed on an insulating substrate, and a rotor is provided to face the stator coils with a gap in the radial direction. The rotor is rotated by sequentially energizing the stator coils according to the rotational position of the rotor.

Conventional stator coils are constructed by winding and molding a copper wire with a heat-fusible insulating coating into a predetermined shape, and for example, six pieces are fixed on an insulating substrate in a circular arrangement using a bonding agent. It was to be done.

(Problem to be Solved by the Invention) By the way, in this type of configuration, the electromagnetic force between the stator coil and the rotor magnet also acts in the axial direction, and this changes intermittently according to the switching of the stator coil. . However, in the past, the stator coil was firmly fixed to the substrate by a contact agent, so the intermittent electromagnetic force acting on the stator coil in the axial direction was immediately transmitted to the substrate.
This has caused a problem in that the substrate to which the stator coil is fixed is deflected and vibrates, producing noise.

Furthermore, since each stator coil must be fixed to the substrate with a bonding agent, there is a problem that this work is time-consuming and the assembly cost is high.

The present invention has been made in view of the above circumstances, and its purpose is to create an axial gap that can reduce the vibration of the board as much as possible when the rotor rotates, and also improve the workability of hardening the stator coil to the board. It is to provide type brushless motor.

[Structure of the Invention (Means for Solving the Problem) The axial gap type brushless motor of the present invention rotates a rotor having a rotor magnet by sequentially energizing a plurality of stator coils arranged on a substrate. The stator coil is characterized in that the plurality of stator coils are integrally molded with an elastic material to form a molded body, and a mold layer of the molded body is fixed to the substrate. has.

(Function) According to the above means, the stator coil is fixed to the substrate via the mold layer made of an elastic material, so even if the stator coil vibrates due to electromagnetic force, the vibration is suppressed by the elasticity of the mold layer. It is absorbed by the force and becomes difficult to transmit to the board.

Furthermore, since a plurality of stator fills are integrated by molding, the work of attaching the stator coils to the substrate can be done all at once, improving work efficiency.

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

First, in FIG. 2 showing the overall configuration, 1 is a substantially cylindrical bearing housing, a board 2 is fixed to the outer periphery of the housing, and furthermore, on this board 2, for example, six stator coils 3 are integrated. A molded body 4 is fixed thereto. This molded body 4 is manufactured by the knob method described later, and as shown in FIG. It has a structure in which they are integrally buried in a ring-shaped arrangement in a mold layer 5 made of butadiene rubber. A rotor 6 is composed of a rotor yoke 7 shaped like a shallow container with an open bottom, an annular rotor magnet 8 disposed inside the rotor yoke 7, and a rotor magnet 8 fixed to the center of the rotor yoke 7 by caulking. It is composed of a boss portion 9 and a rotating shaft 10 fixed to the boss portion 9. and,
This rotating shaft 10 is attached to the bearing housing 1 with a bearing 11°1.
The stator coil 3 of the molded body 4 and the rotor magnet 8 are disposed to face each other with a gap in the axial direction.

Next, a method for manufacturing the molded body 4 will be explained with reference to FIG. 3.

First, a strip of copper foil having an insulating layer formed on one side is wound a predetermined number of times around a substantially triangular prism-shaped winding core (not shown) to form a winding body. A copper vibrator for connection is connected to both ends of this copper foil.

Next, six of the winding bodies thus formed are arranged in a ring at predetermined positions in a mold (not shown), and a molding resin made of styrene-butadiene rubber is injected into the mold and solidified. The mold has a structure in which both ends of the mold are sealed to prevent mold resin from flowing into the copper pipe.

By demolding after solidifying the mold resin, a cylindrical mold body 12 is formed as shown in FIG. In the figure, the aforementioned winding body and copper pipe are indicated by reference numerals 13 and 14. Thereafter, the cylindrical molded body 12 is cut into a predetermined thickness as shown by the broken line in FIG. 3 to obtain the molded body 4.

The molded body 4 is arranged so as to overlap at a predetermined position on the substrate 2, and is fixed to the substrate 2 at a portion of the mold layer 5 using, for example, an adhesive, as shown in FIG. At this time, the copper vibrator 14.degree. 14 portion serves as a terminal of the stator coil 3 and is electrically connected to the conductor portion on the substrate 2.

According to this embodiment, when the stator coil 3 is energized, that is, when the rotor 6 rotates, the intermittent electromagnetic force in the axial direction generated between the stator coil 3 and the rotor magnet 8 causes the stator coil 3 to vibrate. However, since the stator coil 3 is fixed to the substrate 2 via the mold layer 5 made of styrene-butadiene rubber, which is an elastic material, the vibration generated in the stator coil 3 is absorbed by the elastic force of the mold layer 5. Therefore, almost no signal is transmitted to the substrate 2. As a result, noise caused by electromagnetic vibration of the stator coil 3 is significantly reduced compared to the conventional case.

In addition, since the six stator coils 3 are integrated by the mold layer 5, the work of hardening the stator coils 3 onto the substrate 2 is not done one by one as in the past, but six.
The stator coils 3 can be processed at once.

Therefore, ease of assembly is greatly improved, automation is easy, and assembly costs are reduced.

Furthermore, in this embodiment, the stator coil 3 is formed not by winding copper wire, but by cutting a cylindrical molded body 12 formed by molding a winding body 13 wound with strip-shaped copper foil. Manufacturability of the stator coil 3 is also improved.

[Effects of the Invention] As is clear from the above description, according to the axial gap type brushless smoke of the present invention, a plurality of stator coils are integrally molded with an elastic material to form a molded body, Since the mold layer of this molded product is fixed to the substrate, the vibration of the stator coil when electricity is applied can be absorbed by the mold layer, reducing the vibration noise generated by the substrate. It has the excellent effect that it can be fixed to the substrate all at once, and its assemblability can be greatly improved.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a longitudinal cross-sectional view showing the state of the stator coil attached to the substrate, Fig. 2 is a longitudinal cross-sectional view showing the overall configuration, and Fig. 3 is a cylindrical shape. It is a perspective view of a molded body. In the drawings, 2 is a substrate, 3 is a stator coil, 4 is a molded body, 5 is a mold layer, 6 is a rotor, and 8 is a rotor magnet. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. A rotor having a rotor magnet is rotated by sequentially energizing a plurality of stator coils arranged on a substrate, and the plurality of stator coils are integrally molded with an elastic material. An axial gap type brushless motor characterized in that the molded body is made into a molded body, and a mold layer of the molded body is fixed to the substrate.