JPH0529259U - Flat coreless vibration motor with eccentric weight - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] To provide a flat coreless vibration motor having a diameter of 14 mm or less that can obtain a desired vibration amount. In a coreless motor including a rotor R including a plurality of air-core coils 2, an eccentric weight 9 made of a non-magnetic material is arranged on the opposite side of the rotor R from the side facing the field magnet 8, and the eccentricity is provided. Part of the weight 9 is the rotor R
At least a part is accommodated in the thickness part of the.
The eccentric weight 9 causes the center of gravity of the rotor R to move in the radial direction from the center, so that the rotor R unbalances during rotation and generates vibration.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a coreless vibration motor with an eccentric weight mounted on a portable radio calling device (pager, product name pager) and used as a silent calling means.

[0002]

[Prior Art]

 As a silent call means such as a pager, an eccentric weight W made of a tungsten alloy is arranged on an output shaft S of a cylindrical coreless direct current motor M as shown in FIG. 2, and a difference in centrifugal force of the eccentric weight W is used during rotation. It is known that the vibration is generated by this.

However, in the case where the eccentric weight W is added to the output shaft, there is a design limitation that the set maker has to consider the turning space of the eccentric weight. ..

In order to overcome the above drawbacks, the applicant previously proposed Japanese Patent Application No. 63-111868 as an eccentric coreless vibration motor in which the eccentric weight is deleted and the rotor itself is eccentric. That is, as shown in FIG. 3, the three armature coils 1a, 1b and 1c are arranged so that they do not overlap each other and the planes are substantially fan-shaped, and they are integrally molded with resin. The rotor 1 is used, and the eccentric rotor is used to generate vibration during rotation.

[0005]

[Problems to be solved by the device]

 The eccentric rotor itself that generates vibration has a large eccentricity in a flat coreless motor with a diameter of 20 mm or more, and a relatively large vibration is obtained, which is well received in the market. When an ultra-compact size of ~ 14 mm is required, the amount of eccentricity (position of the center of gravity) becomes small, and it is difficult to obtain the desired amount of vibration unless the motor is thickened.

Therefore, the present invention intends to provide an ultra-small coreless vibration motor that can obtain a desired vibration amount without sacrificing the thickness of the motor even if the diameter is 12 to 14 mm.

[0007]

[Means for Solving the Problems]

 This invention has been solved by focusing on the fact that the coreless winding is an air-core coil type, and the rotor itself has a small thickness, that is, in a coreless motor including a rotor composed of a plurality of air-core coils, An eccentric weight made of a non-magnetic material is arranged on the opposite side of the rotor from the side facing the field magnet, and at least a part of the eccentric weight is accommodated in the thickness portion of the rotor.

The position where a part of the eccentric weight is housed within the thickness of the rotor is preferably the inner diameter of the air-core coil of the rotor and / or the outer circumference of the rotor.

[0009]

[Action]

 In this way, the dead point can be effectively utilized and the weight of the eccentric weight can be increased. As a result, the eccentric weight arranged on the opposite side of the rotor from the side facing the field magnet can be made extremely thin.

[0010]

【Example】

 FIG. 1 shows a cross section of a main part of a flat coreless vibration motor having the structure of the present invention. The rotor R is constructed by integrally molding a plurality of air-core coils 2 with a shaft 3 together with a resin. One end of the shaft 3 is rotatably supported by the bracket 5 via the bearing 4, and the other end is rotatably supported by the case 7 via the bearing 6 as well. The field magnet 8 is made of a ring-shaped rare earth magnet and is arranged on the bracket 5 so as to face one side of the rotor through a small gap. Reference numeral 9 denotes an eccentric weight made of a high-density non-magnetic metal body, which is a characteristic part of the present invention, and is arranged on the opposite side of the rotor R from the side facing the field magnet 8 and a part of which is housed in the inner diameter of the air-core coil. 9a and a portion 9b arranged on the outer peripheral portion of the rotor. As shown by the imaginary line, this portion 9b may be extended or retracted to a space formed with the case 7 on the outer periphery of the field magnet 8 as required. In the figure, 10 is a flat plate commutator arranged on the rotor R, and 11 is a brush arranged on the bracket 5 so as to press the flat plate commutator with an appropriate pressure.

The above embodiment can be applied to an eccentric rotor as shown in FIG. 3 as a rotor, and the portion accommodated in the thick portion of the rotor may be only the portion 9a accommodated in the inner diameter of the air-core coil. The eccentric weight 9 may be integrally formed with the rotor R or may be separately attached.

[0012]

[Effect of the device]

 Since the present invention is configured as described above, it has the following effects.

Since the eccentric weight is provided with a portion for accommodating in the thickness portion of the rotor, it is possible to secure weight, and as a result, the portion of the rotor on the opposite side of the field magnet can be thin, resulting in a large air gap. There is no harmful effect.

Whether the eccentric weight is bonded or integrally molded, the fixing surface with the rotor is large, and there is no danger of it coming off during rotation. Especially, since a part of the eccentric weight is stored in the inner diameter of the air-core coil, the centrifugal force Since it can support the directional force, there is no danger of it coming off during rotation.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a flat coreless vibration motor with eccentric weight according to the present invention.

FIG. 2 is a perspective view of a conventional vibration motor.

FIG. 3 is a plan view of an eccentric rotor of another conventional vibration motor.

[Explanation of symbols]

 R rotor 2 air core coil 8 field magnet 9 non-magnetic eccentric weight

Claims (2)

[Scope of utility model registration request] 1. In a coreless motor having a rotor composed of a plurality of air-core coils, an eccentric weight made of a non-magnetic material is arranged on the opposite side of the rotor facing the field magnet, and a part of the eccentric weight is provided. A coreless vibration motor with an eccentric weight in which at least a part of the rotor is housed in the thickness portion of the rotor. 2. The flat coreless vibration motor according to claim 1, wherein the position where a part of the eccentric weight is accommodated in the thickness of the rotor is the inner diameter of the air-core coil of the rotor and / or the outer circumference of the rotor.