JPH04109838A - Brushless motor - Google Patents

Abstract

PURPOSE:To obtain a brushless motor in which vibration and noise are suppressed by coupling the magnet side of a rotor plate through a floating member provided with tooth like irregularities to a shaft. CONSTITUTION:Slit 15 in a rotor plate 13 is initially formed as a discontinuous circle having a coupling part which is cut off when a floating member FM 16 is secured to the slit 15 thus coupling the shaft side 13a and the magnet side 13b through the FM 16. It is then subjected to drive control similar to conventional one, but vibration on the magnet side 13b produced through suction/repelling to/from a magnet 14 is blocked by the slit 15 in the rotor plate 13 and absorbed by the FM 16 coupled with the slit 15 thereby prevented from being transmitted to the shaft side 13a. Furthermore, since the FM 16 is provided with tooth like irregularities 16a, apparent hardness is lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of a rotor portion in a brushless motor.

[Prior Art] FIG. 5 is a sectional view showing a conventional brushless motor disclosed in, for example, Japanese Utility Model Application Publication No. Sho 63-167380. That is, a shaft 22 is rotatably supported by the holder 20 via a bearing 21, and a rotor plate 23 formed in the shape of a bottomed container is fixed to the shaft 22. Mounted on the holder 20 are a substrate 24 forming an electronic circuit and a stator core 26 around which a coil 25 is wound. A magnet 27 is attached to the rotor plate 23 so that it faces the outer periphery of the stator core 26 with a predetermined gap, and the rotor plate 23
An FG magnet 28 is provided at the peripheral end of the FG magnet 28 .

The conventional brushless motor is configured as described above, and the rotor plate 23 is connected to the electronic circuit mounted on the board 24.
The polarity of the magnet 27 is detected, and energization of the coil 25 is controlled.

As a result, a magnetic field is generated in the coil 25, and an attractive and repulsive force is applied to the magnet 27 through the stator core 26, thereby causing the magnet 27, rotor plate 23, and shaft 22 to rotate.

[Problems to be Solved by the Invention] In the conventional brush smoker described above, the shaft 22 and the magnet 27 are connected to the metal rotor plate 2.
3, and the suction with the stator core 26.
Vibrations generated in the magnet 27 due to the repulsive force are transmitted through the rotor plate 23 to the shaft 22 and bearing 21, causing vibrations and noise in the motor itself, and the vibrations transmitted to the shaft 22 are transmitted to the impeller, etc. This includes problems that need to be solved, such as inducing resonance with other parts attached to the shaft 22 and causing vibration and noise in the entire device. Solving the above-mentioned problems with other parts such as an impeller requires individual countermeasures and is not a good idea. Alternatively, for example, there is a method of dividing the rotor plate 23 into the shaft side and the magnet side and connecting them using floating material, but since the hardness of the floating material increases over time, it is necessary to suppress the apparent hardness. There are certain challenges.

The present invention was made to solve the problems of the prior art, and aims to provide a flangeless motor with low vibration and noise.

[Means for Solving the Problems] A brushless motor according to the present invention has a rotor plate connected to the Macnet side to a shaft via a floating member provided with tooth-shaped irregularities.

[Function] In the present invention, vibrations generated in the magnet due to the attraction and repulsion with the stator core are blocked or absorbed by the floating material, and are not transmitted to the shaft side. Further, since the floating material is provided with tooth-shaped irregularities, it is possible to suppress an increase in hardness of the floating material due to changes over time.

[Example] Figures 1 to 3 show an example of the present invention. In the figures, 1 is a bracket made of steel plate, and a shaft hole 2 is drilled in the upper part, and a bearing 3 is installed in the lower part of the bracket. It is set up. 4
5 is a stopper provided at the bottom of the bearing 3, and 5 is a bear link holder, which has another bearing 6 disposed at the bottom so as to face the bearing 3.

A stator core 7 is installed inside the bracket 1, and a drive coil 8 is wound around the stator core. 9 is a board on which electronic components are mounted and an electronic circuit is configured. Reference numeral 10 denotes a microwave molded portion, in which the stator core 7, the substrate 9, and the hair ring holder 5 are microwave molded in the bracket 1, and a shaft hole 11 is formed in the center.

A shaft 12 is rotatably held relative to the bracket 1 via the bearing 3.6.

Reference numeral 13 denotes a metal rotor plate shaped like a bottomed container, which is press-fitted onto the shaft 12 with its open portion facing downward, and encloses the stator core 7. A magnet 14 is provided on the inner circumferential surface of the rotor plate 13, and faces the stator core 7 with a predetermined gap in the rotational radial direction. Reference numeral 15 denotes a slit formed in the top of the rotor plate 13, surrounding the shaft hole 11, and connecting the rotor plate 13 to the shaft side 13a and the magnet side 1.
It is divided into 3b.

Reference numeral 16 denotes a floating material made of, for example, synthetic resin or rubber, which is attached to the slit 15, and has tooth row-like irregularities 16a on its surface, and connects the shaft side 13a and magnet side 13b of the rotor plate 13. There is. This floating material 16- has the strength to hold the rotor plate 13 and the magnet 14, and also has the property of not transmitting vibrations. Initially, the slit 15 of the rotor plate 13 is formed into a discontinuous circular shape with a connecting part, but the continuous part is cut off when the floating material 16 is fixed to the slit 15, and the floating material 16 forms the shaft side 13a and the magnet side. 13b are connected to each other.

In the brushless motor configured as described above, the polarity of the magnet 14 of the rotor plate 13 is detected by an electronic circuit mounted on the board 9, and energization of the drive coil 8 is controlled. This generates a magnetic field in the drive coil 8, which passes through the stator core 7 and
- Magnet 14. by applying attraction/repulsion force to Soto 14. The rotor plate 13 and shaft 12 rotate. Vibration on the magnet side 13b caused by attraction and repulsion acting on the magnet 14 is blocked by the third slit 15 of the rotor plate 13, and the slit 15
It is absorbed by the floating material 16 connecting the parts and does not reach the shaft side 13a. Therefore, magnet side 1
The vibration of the motor 3b is transmitted to the shaft 12 and the bearing 3.6, and does not cause vibration or noise of the motor itself, resulting in a brushless motor with low vibration and noise. Since the hardness of the floating material 16 increases over time, it is necessary to suppress the apparent hardness, but since the tooth row-like unevenness 16a is provided, the apparent hardness of the floating material 16 can be suppressed.

Incidentally, as shown in FIG. 4, the shaft hole 11 of the rotor plate 13 may be formed large, and the shaft 12 and the rotor plate 13 may be connected via a floating material 16 having tooth row-like unevenness 16a. It may be used in combination with the configuration of the above embodiment.

[Effects of the Invention] As is clear from the above description of the embodiments, according to the present invention, vibrations generated in the magnet due to attraction and repulsion with the stator core are blocked or absorbed by the floating material, and are not transmitted to the shaft side. As a result, vibration and noise are reduced, and the tooth row-like unevenness of the floating material suppresses an increase in hardness due to changes in the floating material over time.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the configuration of a brushless motor as an embodiment of the present invention, FIG. 2 is a perspective view of the rotor plate portion thereof, FIG. 3 is a plan view of the rotor plate portion, and FIG. A sectional view of a brushless motor showing another embodiment of the present invention, and FIG. 5 is a sectional view of a conventional brushless motor. In the figure, 1 is a bracket, 36 is a bearing,
7 is a stator core, 8 is a drive coil, 9 is a substrate, 12 is a shaft, 13 is a rotor plate, 13a is a shaft side, 13b is a magnet side, 14 is a magnet, 15 is a slit, 16 is a floating material, and 16a is an unevenness. . Note that the same reference numerals in the figures indicate the same or equivalent parts. Figure 1 Agent Masuo Oiwa (and 2 others) 1&a: Unevenness Figure Figure 1? / Do0

Claims (1)

[Claims] A bracket having a stator core wound with a drive coil therein, a shaft supported by the bracket, and a rotor plate fixed to the shaft with a magnet facing the shaft with a predetermined gap in the rotation radial direction, A brushless motor characterized in that the magnet side of the rotor plate is connected to the shaft via a floating material having a toothed pattern.