JPH0538093A - Flat oscillation brushless motor - Google Patents

Abstract

PURPOSE:To provide a flat oscillation brushless motor producing an oscillation in the thrust direction which can be sensed easily by human body. CONSTITUTION:A protrusion 2 is provided on the outer periphery of a rotor frame 1 and a groove 4, represented by a function y=a.sin(2ntheta), is made in the inner periphery of a motor casing 3 opposing to the rotor frame 1. When the rotor is rotated, vibration takes place in the thrust direction as well as the radial direction and thereby oscillation can be sensed easily.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat type vibration brushless motor used as a vibration source for portable communication devices and the like.

[0002]

2. Description of the Related Art In recent years, as a portable communication device, for example, a portable pager is a notification using sound, so that the sound is transmitted to a person other than a specific person, and the sound is transmitted on a conference table or in a quiet library. The sound was jarring.

Therefore, there has been proposed a device which can notify only a specific person by utilizing the vibration, and there has been a device which uses a motor as the vibration source.

A conventional flat type vibration brushless motor of this type will be described with reference to FIG.

As shown in the figure, the N pole and S for generating magnetic flux
A flat type annular magnet 11 having poles alternately magnetized is fixed to a rotor frame 12 by shifting the concentricity of inner and outer diameters of the magnet 11 to generate vibration. Rotor frame 1
2 is fixed to the rotor boss 14 so as to keep a constant gap.

A stator winding fixed to the motor shaft 16 via a metal 15 press-fitted into the rotor boss 14 and fixed with a predetermined gap between the magnet 11 and the back yoke 13. The wire 17 is fixed to the motor case 18 and the motor cover 19.

In the above structure, when the stator winding 17 is energized, the magnetic circuit formed by the magnet 11 and the back yoke 13 has the following characteristics: B, magnetic flux density, I, current, l, effective conductor length, n, winding pattern. The force of F = B × I × l × n acts to rotate the rotor. At this time, since the center of the inner and outer diameters of the magnet 11 and the center of the motor shaft 16 are eccentric, centrifugal force is generated in the radial direction, and the flat vibration brushless motor vibrates.

[0008]

In such a conventional flat type vibration brushless motor, since vibration is generated in the radial direction, it is difficult to obtain vibration in the thrust direction, which is the mounting surface of the motor, and it is difficult for the human body to sense it. Since only directional vibration can be generated, it was necessary to increase the rotation speed of the motor and to supply a large amount of current.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a flat type vibrating brushless motor which can generate vibration in the thrust direction and can be easily sensed by the human body.

[0010]

In order to achieve the above object, the flat type vibrating brushless motor of the present invention has a magnetic pole of N.
A flat annular magnet magnetized alternately to the pole and the S pole,
The rotor has a yoke arranged to face the magnet in a constant space, and a stator winding having a plurality of windings arranged in the space, and a motor case for fixing the stator winding are provided. A convex portion is provided on the outer peripheral portion of the rotor, and a · amplitude, n · an integer are set on the inner peripheral portion of the motor case facing the convex portion, and Y =
A groove represented by a function of a · sin (2nθ) is provided and configured.

[0011]

According to the flat type vibration brushless motor of the present invention, when the rotor rotates, the convex portion provided on the outer peripheral portion of the rotor moves along the groove of the motor case, so that vibration is generated in the thrust direction. Become.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
Will be described with reference to.

The same parts as those of the conventional example are designated by the same reference numerals and detailed description thereof will be omitted. As shown in the figure, a convex portion 2 is provided on the outer peripheral portion of the rotor frame 1, and the circumferential portion of the motor case 3 facing the outer peripheral portion of the rotor frame 1 has a · amplitude, n · an integer, and Y = a · A groove 4 represented by a function of sin (2nθ) is provided.

In the plan view of the groove 4 shown in FIG. 3, the groove 4 is a function of n = 1.

The operation of the above structure will be described below.
When the rotor rotates, the convex portion 2 provided on the outer peripheral portion of the rotor frame 1 moves along the groove 4 provided on the motor case 3, so that the rotor performs thrust motion without being twisted with the metal 15 and the vibration occurs in the radial direction. Not only is it generated in the thrust direction.

[0016]

As is apparent from the above embodiments, according to the present invention, a convex portion is provided on the outer peripheral portion of the rotor, and a groove for thrusting the rotor is provided on the inner peripheral portion of the motor case facing the convex portion. Therefore, not only the vibration in the radial direction but also the vibration in the thrust direction can be generated, and it is possible to provide the flat type vibration brushless motor that makes it easy for the human body to detect the vibration generation.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a flat type vibration brushless motor according to an embodiment of the present invention.

FIG. 2 is a plan view of the flat type vibration brushless motor.

FIG. 3 is a plan development view of a groove of a motor case of the flat type vibration brushless motor.

FIG. 4 is a sectional view of a conventional flat type vibration brushless motor.

[Explanation of symbols]

 1 rotor frame 2 convex part 3 motor case 4 groove 11 magnet 13 yoke 17 stator winding

Claims (1)

Claim: What is claimed is: 1. A flat annular magnet whose magnetic poles are alternately magnetized into N poles and S poles, and a yoke arranged in opposition to the magnets in a constant air gap. A stator winding having a plurality of windings disposed between the stator winding and a motor case for fixing the stator winding is provided, and a convex portion is provided on an outer peripheral portion of the rotor, and the motor case is opposed to the convex portion. A flat type vibration brushless motor having a groove represented by a function of Y = a · sin (2nθ) where a · amplitude and n · integer are provided around the circumference.