JPH03230744A - Brushless motor - Google Patents

Abstract

PURPOSE:To reduce vibration and noises of motor itself by providing a slit to a rotor plate equipped with a magnet, and connecting the slit with a floating material. CONSTITUTION:Force-fit and fixation of a rotor plate 22 to a shaft 20 are made at a fitting section 22a. A magnet 23 is provided to the internal wall of the rotor plate, and they are opposed to each other through a stator core 15 and a specific space. A slit 24 is provided to the rotor plate 22, it is placed between the magnet 23 side and fitting section 22a, and the rotor plate 22 is divided into the circumferential side 25 and peripheral side 26. A floating material 27 is formed of rubber of synthetic resin, the circumferential side 25 is connected to the peripheral side 26 by connecting the slit 24 of the rotor plate 22 therewith, strength to hold the rotor plate 22 and magnet 23 is obtained, and a characteristic having no propagation of vibration is also obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a structure of a rotor portion in a brushless motor and a method of manufacturing the same.

[Conventional technology]

FIG. 6 is a diagram showing a conventional brushless motor disclosed in, for example, Japanese Utility Model Application Publication No. 63-167380. In the figure, (1) is a holder with a bearing (2) inside and a coil (3).
A stator core (2) and a substrate (5) are mounted on which the stator core (2) is wound. (6) is a shaft, on which a rotor plate rotor plate supported by the bearing (2) and formed in a bottomed shape is fixed. .8 is a magnet mounted on the rotor plate and facing the stator core (A) at a predetermined distance;
(9) is the FG provided at the peripheral end of the rotor plate rotor.
It's a magnet.

A conventional brushless motor is configured as described above, and is controlled by detecting the polarity of the magnet 8 of the rotor plate (7) using an electronic circuit (not shown) mounted on the board (to), and energizing the coil (3). be done. Due to this.

A magnetic field is generated in the coil (3), which applies attraction and repulsion to the magnet (8) through the stator core (2), thereby holding the magnet 8, rotor plate (7), and shaft (6) in the bearing (2). rotated.

[Problem to be solved by the invention]

In the conventional brushless motor as described above, the shaft (6) and the magnet 8) are connected by metal via the rotor plate (7), and the magnet (8) is connected by attraction and repulsion with the stator core (4). The vibrations generated at 81 pass through the rotor plate σ) to the shaft (6) and the bearing (
21, causing vibration and noise in the motor itself, and the vibration transmitted to the shaft (6) induces resonance with other parts such as the impeller (not shown), causing vibration and noise in the entire device. If these problems are to be addressed using other parts such as impellers, individual measures must be taken, which is disadvantageous in terms of cost and reliability due to lack of compatibility. Further, for example, when the rotor plate (7) is divided into an inner part and an outer part in advance and is floated, it is necessary to maintain coaxiality between the inner part and the outer part.

For this reason, coaxial misalignment is likely to occur, and stator core (A)
and the rotor plate bottom, the rotor plate (
7) becomes less reliable due to torque unevenness due to rotation. On the other hand, by making the rotor plate rotor into two pieces, there was a problem in that it was disadvantageous in terms of cost, such as an increase in the setting process.

This invention was made to solve the problem,
A brushless motor with low vibration and noise from the motor itself, which prevents resonance between devices connected to the motor, and which allows floating of the rotor plate with high coaxiality without the need for special jigs or tools. The purpose is to obtain.

[Means to solve the problem]

A brushless motor according to the present invention includes a bracket having a substrate having electronic components and a stator core wound with a drive coil therein, a shaft supported by the bracket, and a predetermined gap between the shaft and the stator core in the direction of rotation radius. The rotor plate is provided with a fixed rotor plate having magnets facing each other via the rotor plate, a slit is provided in the rotor plate, and the rotor plate is connected to the slit by a floating material.

In addition, the divided parts divided through the slits are connected at the connecting parts to form a rotor plate,
After connecting the slits with a floating material, the connecting portion is cut.

Further, a 70-ting material is fixed to the joint between the rotor plate and the shaft.

[Effect]

In this invention, there is provided a bracket having a board having an electronic component therein and a stator core around which a drive coil is wound, a shaft supported by the bracket, and a shaft connected to the stator core through a predetermined gap in the rotation radius direction. a rotor plate fixed with opposing magnets, a slit provided in the rotor plate;
By connecting the slits with the floating material, the floating material blocks and absorbs vibrations generated in the magnets of the rotor plate from propagating through the rotor plate to the shaft and the bearing.

In addition, the divided parts divided through the slits are connected at the connecting parts to form a rotor plate,
After connecting the slits with the floating material, the connecting part was cut, so that the coaxiality of the rotor plate after cutting was maintained as before cutting. By fixing the material, the vibration generated in the magnet of the rotor plate is blocked from propagating from the rotor plate to the shaft by the floating material, and is also absorbed.

〔Example〕

Figures 1 to 3 (a), (b), and (c) are views showing an embodiment of the present invention. In the figures, the decoy is a bracket made of steel plate with a shaft hole (11) in the upper part. is bored, and a bearing (12) is installed in the lower part thereof.

(13) is a bearing holder, and the stopper (14) provided at the bottom of this bearing (12) is a bearing holder, and another bearing (13) is provided at the bottom so as to face the bearing (12).
12) is installed internally. (15) is the above bracket (1
In the stator core installed in 01, the drive coil (16)
is wound. (I7) is a board, electronic components (17
a) is implemented. (18) is a range mold part, and the stator core (15) is placed inside the bracket f101.
), the substrate (17) and the bearing case (14) are resin molded, and at the same time a shaft hole (19) is formed. (20) is the shaft, and the above bearing (12)
It is rotatably held with respect to the bracket αα via the bracket αα.

(21) is an axial slit provided in this shaft, and is located at the joint with the rotor plate, which will be described later.

(22) is a rotor plate, which has a bottomed shape with an opening at the bottom, and connects the shaft (22a) with the central fitting part (22a).
20) through the shaft slit <21>.

(23) is a magnet provided on the inner wall of the rotor plate, and faces the stator core (15) in the rotational radial direction with a predetermined gap in between. (24) is a slit provided in the rotor plate (22) and located between the magnet (23) side and the fitting part (22a>), which connects the rotor plate plate 22) to the inner circumference side (25> and the outer circumference 126). It is divided into (27) is a floating material made of, for example, rubber made of synthetic resin, and is connected to the slits (24) of the rotor plate (22) so that the inner peripheral side (25)
and the outer peripheral side (26), and connect the rotor plate (22).
It is made of a material that has the strength to hold the magnet (23) and the material that does not propagate vibrations. Reference numeral (28) denotes a connection portion between the inner circumferential portion (25) and the outer circumferential portion (26) of the rotor plate (22), and a plurality of these are provided. <2
8a) is the cutting trace of this connection, (29) is the spring washer, and (29a) is the board (17) to the stator core (15).
This is a mounting bolt.

In the brushless motor configured as described above, the floating method of the rotor plate (22) is shown in Figure 3 (
As shown in a), (b), and (c), the slit (24
) and fix the floating material (27) to the outer periphery (26
) and the inner peripheral part (25), the plurality of connecting parts (
By cutting 28), the outer peripheral part (26) and the inner peripheral part (
25), there is no longer a metal connection part, and both connections are made with floating material (27) as shown in Figure 2.
) only. Then, the magnet (23) is attached to the rotor plate (22) and fixed to the shaft (20), and then the shaft (20) is attached to the bracket for assembly. Next, as in the conventional case, the drive coil (16) is energized under control by an electronic circuit (not shown) in the electronic component (17a) mounted on the board (17). This generates a magnetic field in the drive coil (16), which exerts attraction and repulsion on the magnet (23) through the stator core (15), thereby rotating the magnet (23), rotor brake (22), and shaft (20).

At this time, vibrations generated by the attraction and repulsion of the magnet (23) are blocked by the slit (24) of the rotor plate (22) and are not propagated to the shaft (20) and bearing (12).

In the above embodiment, the rotor plate (22) is floating, but as shown in FIG.
0) and the gap (20) between the shafts (20).
31) and by fixing the floating material (27) in this gap, floating is achieved in a wide adhesive area between the rotor plate (22) and the shaft (20), and this is also effective in terms of strength. In this way, even if the joint (32) between the rotor plate (22) and the shaft (20) is floating, the same effect as in the above embodiment can be obtained.

In addition, the rotor plate (22) and the rotor plate (
22) and the joint portion (31) of the shaft (20) at the same time, the above embodiment can be further improved.

In addition, as shown in Fig. 5, the shaft (20) and rotor plate (20) of the inner rotor type brushless motor
2) A floating material (27) may be fixed and floated in between, and the same effect as the embodiment shown in FIG. 1 can be obtained.

〔Effect of the invention〕

As explained above, the present invention includes: a bracket having a substrate having electronic components and a stator core around which a drive coil is wound; a shaft supported by the bracket;
The shaft is provided with a rotor plate fixed to the stator core with a magnet facing the stator core through a predetermined gap in the direction of rotation radius, a slit is provided in the rotor plate, and the slit is connected with a floating material. Since the floating material blocks the vibration generated in the magnet from propagating through the rotor plate and then to the shaft, it is possible to reduce the noise and vibration of the motor itself, as well as reduce the noise and vibration generated between the motor and the parts and devices connected to it. resonance can be prevented.

In addition, the divided parts divided through the slits are connected at the connecting parts to form a rotor plate,
After connecting the slits with a floating material, the connecting part is cut, so the coaxiality between the center of fit of the rotor plate with the shaft and the divided part is the same as that of the undivided rotor plate, and the characteristics are guaranteed. , special jig,
Floating can be done easily without the need for tools.

Furthermore, since the floating material is fixed to the joint between the rotor plate and the shaft, the vibrations from the magnet are not propagated to the shaft, and floating can be further strengthened.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional side view showing one embodiment of the present invention, FIG. 2 is a perspective view of the rotor plate, and FIGS. 3(a) and (b).
) and (c) are plan views showing the procedure for floating the rotor plate, FIG. 4 is a cross-sectional side view showing another embodiment of the present invention, and FIG. 5 is a cross-sectional view showing another embodiment of the present invention. A side view, FIG. 6 is a cross-sectional side view showing a conventional brushless motor. In addition, QOI is a bracket, (15) is a stator core,
(16) is a drive coil, (17) is a board, (17a) is an electronic component, (20) is a shaft, (22) is a rotor plate, (23) is a magnet, (24) is a slit, (
25) is the inner peripheral side, (26) is the outer peripheral side, (27) is the floating material, (28) is the connecting portion, and (32) is the joint portion.

Claims (3)

[Claims] (1) A bracket having a board with electronic components and a stator core around which a drive coil is wound, a shaft supported by the bracket, and a shaft that faces the stator core with a predetermined gap in the direction of rotation radius. and a rotor plate fixed with a magnet,
A brushless motor characterized in that the rotor plate has slits, and the slits are connected by a floating material. (2) A rotor plate is formed by connecting the divided parts through the slits at the connecting parts,
Claim 1, characterized in that after the slits are connected with a floating material, the connecting portion is cut.
Brushless motor as described in section. (3) The brushless motor according to claim 1, characterized in that a floating material is fixed to the joint between the rotor plate and the shaft.