JPH10322971A - Diametrical gap type of oscillatory motor equipped with eccentric non-magnetic core - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make this oscillatory motor advantageous also in terms of cost by removing a cogging torque, not withstanding increasing the quantity of shift in the center of gravity, thereby enabling the starting voltage to be lowered. SOLUTION: This motor is equipped with a magnet 4, which has a plurality of magnetic poles placed at one part of a housing H, constituting the motor and magnetized alternately in N and S and an eccentric rotor which is made to face this via a vacant space. In this case, this eccentric rotor R is equipped with an eccentric non-magnetic core 3 which has a plurality of salient poles being biased, so that the angle of aperture is 180 deg. or less as seen in a plan, armature coils 5 which are arranged at these salient poles, a commutator 6 which gives power properly to the armature coil 5, and a pair of brushes 8 which are slid on this commutator 6 and bases of which are planted at one part of the housing H.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radial gap type vibration motor having an eccentric non-magnetic core suitable for use as a silent information source of a small wireless communication device (pager, portable telephone) or the like.

[0002]

2. Description of the Related Art Conventionally, a small wireless communication device (pager,
As shown in FIG. 7, an eccentric weight W made of a tungsten alloy is provided on a rotation output shaft S of a small cylindrical DC motor M as a vibration motor used for a silent information source of a portable telephone. There is known an apparatus that uses a generated centrifugal force to obtain vibration.

[0003]

However, in the case where an eccentric weight is added to the output shaft, the set maker must consider the turning space of the eccentric weight, and the eccentric weight must be taken into account during rotation. The exposed weight is dangerous because the weight is exposed, and if an impact such as a direct drop is applied to the eccentric weight, the shaft may be deformed.

For this reason, the present applicant has previously disclosed a cylindrical coreless type vibration motor in which the output shaft is eliminated and the built-in rotor is eccentric, as disclosed in Japanese Patent Application No. 2-309070 (US Pat.
155), and in a flat motor, Japanese Patent Application No. 63-11868 (U.S. Pat. No. 503,623) discloses that the eccentric weight is deleted and the rotor itself is eccentric to obtain vibration during rotation.
No. 9).

Further, in order to vibrate the rotor itself with a cored type replacing the coreless winding type, the present applicant has previously filed Japanese Patent Application No. 4-286978 (US Pat. No. 5,314,057).
As shown in FIG. 1, a three salient pole type iron core is proposed in which all the cores are biased to one side (within 180 degrees). Such a configuration may have a relatively high starting voltage, but further improvement is expected because of the cogging torque.

An object of the present invention is to provide the above-mentioned Japanese Patent Application No. 4-28.
By further improving 6987 (US Pat. No. 5,341,057), it is possible to reduce the starting voltage by eliminating the cogging torque while increasing the amount of movement of the center of gravity for generating centrifugal force, and to provide a cored type. An object of the present invention is to provide a radial gap type vibration motor having an eccentric non-magnetic core which is advantageous in cost and cost.

[0007]

Means for Solving the Problems The above-mentioned problems can be solved by adopting a means for eliminating the cogging torque while increasing the amount of movement of the center of gravity for generating the centrifugal force. By doing so, the starting can be facilitated and the vibration can be increased.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As one embodiment of the present invention, there is provided a housing constituting a motor. 2 A magnet having a plurality of magnetic poles mounted on a part of the housing and alternately magnetized N and S. 3 Eccentric rotor facing this magnet through a gap. 4. This eccentric rotor has an eccentric non-magnetic core having a plurality of salient poles formed so as to be deviated so that the opening angle is within 180 degrees as viewed from a plane, an armature coil disposed on these salient poles, It consists of a commutator that appropriately supplies power to the child coil. 5 A pair of brushes which are brought into sliding contact with the commutator and whose base is planted in a part of the housing. It is better to consist of As the eccentric nonmagnetic core, a nonmagnetic metal body or a nonmagnetic high-density resin body can be adopted.
By doing so, a radial gap type vibration motor that can eliminate cogging torque and increase the amount of vibration can be obtained.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, as a first embodiment of the present invention, the structure of a vibration motor having a fixed shaft type eccentric non-magnetic core will be described with reference to FIG. Will be described. In the figure, a housing H is composed of a case 1 having a shallow cylindrical shape and a burring portion 1a of a drawing method arranged in the center, and an end bracket 2 attached to an opening edge of the case 1. Inside the housing H thus configured,
The shaft S is fixed by being press-fitted into the burring portion 1a. The shaft S is provided with a half cup formed by integrally molding an eccentric non-magnetic core 3 formed by brass die casting or the like with a sliding resin J1. A mold eccentric rotor R is rotatably mounted via a resin bearing Ja. A ring-shaped magnet 4 made of a neodymium bonded magnet is fixed to the inside of the eccentric rotor R via a radial gap by fitting an inner diameter portion to the burring portion 1a. As shown in FIG. 2, the non-magnetic core 3 of the eccentric rotor R has three projections Jb insulated at a pitch of approximately 60 to 70 degrees with an open angle deviating within 180 degrees as a whole when viewed from a plane. The poles 3a, 3b and 3c are provided, and three air-core armature coils 5a, 5b and 5c are respectively mounted.
On the end bracket side of the nonmagnetic core 3 of the eccentric rotor R, six noble metal segment patterns 6a, 6
A flat commutator 6 made of a printed wiring board with b ‥‥ 6f formed and short-circuited segments facing each other via a through hole on the other surface is attached via an adhesive material 7 to the end bracket 2 from the flexible board. The electric power is received from a pair of brushes 8, 8 implanted through a brush base 2a. Each terminal of the three air-core armature coils 5a, 5b and 5c is connected to a predetermined segment pattern 6a, 6b ‥‥ 6f of the flat plate commutator 6.
Respectively. This eccentric rotor R can be used in the same configuration, but in this embodiment, 3
The air-core armature coils 5a, 5b and 5c and the terminals thereof are protected by the above-mentioned slidable resin J1 or the like to protect the terminals.
b. That is, it is preferable to integrate with the slidable resin J1 after all the working operations. In the drawing, W is a thrust washer for regulating the vertical movement of the eccentric rotor R.

Next, the principle of rotation of such a radial gap type vibration motor in the case of the delta connection type will be described with reference to FIG. 3, but before that, the connection relation will be clarified in FIG. The winding start terminal of the arranged armature coil 5a is connected to the segment 6a of the commutator 6, and the winding end terminal is connected to the segment 6b. The winding start terminal of the armature coil 5b wound around the salient pole 3b is further connected to the segment 6b, and the winding end terminal of the coil is connected to the segment 6c. The end of the armature coil 5c wound around the salient pole 3c is further connected to the segment 6c, and the end of the armature coil 5c is connected to the segment 6d having the same potential as the segment 6a. Now, when power is applied to a pair of brushes 8 having an arrangement opening angle of 90 degrees arranged substantially at the center of the magnetic pole in FIG.
A current flows in the armature coil 5a in the direction of the arrow A through the segment 6a, and a rotational force that moves in the A direction is generated based on the Fleming's left hand rule. Segments 6a to 6
The current flowing through the armature coil 5c through the segment d flows through the armature coil 5b through the segment 6c, and similarly, a rotational force that moves in the direction A is generated. FIG. 3 also shows the position when the eccentric non-magnetic cored rotor R rotates by each angle. In any case, the neutral portion of the magnetic pole is skillfully used to rotate in the A direction without generating a counter torque externally. At this time, since the salient poles 3a, 3b, 3c are non-magnetic, they have no cogging torque and rotate smoothly as in the case of coreless. Although the above description has been made with reference to the delta connection type, star connection can be achieved by changing the relative positions of the magnet and the brush. In the case of this star connection, it is desirable to use each salient pole for the common connection electrode.

FIG. 4 is a sectional view of an essential part showing a modified example of the above embodiment, in which an eccentric non-magnetic core is formed of a high-density resin J2. Even in this case, the amount of movement of the center of gravity can be increased.

FIG. 5 is a longitudinal sectional view of a main part of a second embodiment of the present invention in which a rotary shaft is used. That is, a bearing holder 11a composed of a plurality of projecting columns is provided at the center of the case 11, a hollow bearing M is fitted into the bearing holder 11a, and a high-density resin J is used as the eccentric rotor R1.
1 is attached to the rotation itself via a shaft S2 integrally formed. The proximal end of the shaft S2 is pivotally supported on a receiving portion 11b integral with the case via a sliding abutment plate 11c. Since the other structures are the same as those in the above embodiments, the same reference numerals are given and the description is omitted.

FIG. 6 is a cross-sectional view of a main part showing the features of the configuration of the third embodiment of the present invention. That is, each salient pole 3
a, 3b and 3c at the tip of each blade 33a, 33b
Armature coils 5a, 5b and 5c
c is made to be able to be wound like a normal cored. In this case, for example, since winding can be performed directly on the eccentric core made of the high-density resin J2, the workability is good, the centrifugal force can be increased by each blade, and the blade has a relatively large radial allowance. It becomes suitable.
Further, in each of the embodiments, the armature coil has been described as a delta connection, but may be a star connection.

[0014]

As described above, according to the present invention, the eccentric rotor is constituted by an eccentric non-magnetic core having a plurality of salient poles formed so as to be deviated so that the opening angle is within 180 degrees when viewed from a plane. The cogging torque is eliminated while the amount of movement of the center of gravity is increased, and a large vibration is obtained by the rotor itself, which is advantageous in terms of cost.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a first embodiment of a radial gap type vibration motor having an eccentric non-magnetic core according to the present invention.

FIG. 2 is a cross-sectional view of a main part of the core of the embodiment.

FIG. 3 is an operation explanatory diagram of the embodiment.

FIG. 4 is a longitudinal sectional view of a main part of a modification of the embodiment.

FIG. 5 is a longitudinal sectional view of a main part of the second embodiment.

FIG. 6 is a plan view of a main part of a third embodiment of the present invention.

FIG. 7 is a perspective view of a conventional cylindrical vibration motor.

[Explanation of symbols]

 H Housing 1, 11 Case 2 End bracket R, R1, R2 Eccentric rotor 3 Eccentric non-magnetic core 3a, 3b, 3c, salient poles 33a, 33b, 33c, blade 4 Magnet S, S1 shaft 5 Armature coil 6 Flat plate commutator 6a -6f segment pattern 8 brush J1, J2 resin

Claims (4)

[Claims] 1. A radial gap type vibration motor having an eccentric non-magnetic core comprising the following components. 1 Housing that constitutes the motor. 2 A magnet having a plurality of magnetic poles mounted on a part of the housing and alternately magnetized N and S. 3 Eccentric rotor facing this magnet through a gap. 4. This eccentric rotor has an eccentric non-magnetic core having a plurality of salient poles formed so as to be deviated so that the opening angle is within 180 degrees as viewed from a plane, an armature coil disposed on these salient poles, It consists of a commutator that appropriately supplies power to the child coil. 5 A pair of brushes which are brought into sliding contact with the commutator and whose base is planted in a part of the housing. 2. The radial gap type vibration motor provided with an eccentric non-magnetic core according to claim 1, wherein the eccentric non-magnetic core is made of a non-magnetic metal body. 3. The radial gap type vibration motor provided with an eccentric non-magnetic core according to claim 2, wherein the non-magnetic metal body is used for a common connection portion of the armature coil. 4. The radial gap type vibration motor having an eccentric non-magnetic core according to claim 1, wherein the eccentric non-magnetic core is made of a non-magnetic high-density resin body.