JPH10257712A - Eccentric cored vibration motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lighten cogging torque by using a specified number of cores, which have specified pieces of salient poles being biased at specified angles of openings in a plan view and blades being made integrally with these salient poles so that the angles of openings may be within that of the specified number of poles of magnets as a whole in the plan view, for a rotor. SOLUTION: A core 3 has three pieces of salient poles which are made with the angles of openings biased within 180 deg. as a whole, and each blade which is made integrally with these salient poles so that the angle of an opening may be within the four poles +N of a magnet as a whole so that the opposite torque may not occur. A flat cored rotor R is constituted by arranging a plate commutator 7 consisting of a printed wiring board which has an armature coil wound on each salient pole and nine pieces of segment patterns being short-circuited two pieces apart to give proper power to the coil. A pair of axial sliding type of plate brushes 9 whose base ends are planted to an end bracket 2 through the brush base consisting of a flexible board are slid at an angle of substantially 180 deg. on the commutator. Accordingly, the rotor R itself can obtain large vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eccentric cored vibration motor suitable for use as a silent sound source of a small wireless communication device (pager, portable telephone).

[0002]

2. Description of the Related Art Conventionally, a small wireless communication device (pager,
As shown in FIG. 8, an eccentric weight W made of a tungsten alloy is provided on a rotation output shaft S of a small cylindrical DC motor M, and the eccentric weight is used during rotation. 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. In particular, in a flat type motor as shown in FIG. 9, since the eccentric weight must be thin,
The danger during turning is even higher, and the eccentric weight WW is
The size of the eccentric weight cannot be thickened, and there is a possibility that the eccentric weight may be inadvertently deformed in addition to the impact such as dropping.

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).

Since these motors do not have an output shaft and an eccentric weight, they are not restricted by design and are easy to use.
Although it has been well received in the market, for example, there is no danger at the time of turning, the problem that the number of processing steps increases due to the cylindrical coreless winding type is included. In order to vibrate the rotor itself with a cored type instead of the coreless winding type, the present applicant has previously disclosed all three salient pole type cores as shown in Japanese Patent Application No. 4-286978 (U.S. Pat. No. 5,341,057). One that is biased to one side (within 180 degrees) is proposed. Such a configuration may have a relatively high starting voltage, but further improvement is expected because of a certain degree of cogging torque.

[0006] An object of the present invention is disclosed in Japanese Patent Application No. 4-28698.
No. 7 (U.S. Pat. No. 5,341,057) is further improved so that the starting voltage can be reduced by reducing the cogging torque while increasing the amount of movement of the center of gravity for generating the centrifugal force, and the cored structure. An object of the present invention is to provide an eccentric cored vibration motor which is cost effective.

[0007]

Means for solving the above problems can be solved by adopting means for reducing the cogging torque while increasing the amount of movement of the center of gravity for generating centrifugal force. it can. 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, a housing constituting a motor and a 6-pole mounted on the housing and alternately magnetized N and S are described. , A rotor facing the magnet, a shaft supporting the rotor, and three salient poles having an opening angle deviated within 180 degrees when viewed from a plane. At least one core having blades formed so that the opening angle is within the range of 4 poles + N (N is a non-magnetized portion) of the magnet as a whole when viewed from a plane with the salient poles; And a commutator having nine segments that are short-circuited every two to provide appropriate power to the armature coil. The commutator has an odd multiple of the magnetic pole of the magnet. Angle (60 degrees, 180 degrees) it is preferable to a base that includes a brush implanted in a portion of the housing with sliding contact with. In this case, since the three salient poles are formed so that the opening angle is deviated within 180 degrees, the amount of movement of the center of gravity is large, and the opening angle of each blade as a whole is 4 poles of the magnet + N (N is (The non-magnetized portion), so that no counter torque is generated and the field poles of the magnet are increased to 6 poles, so that the cogging torque can be reduced and the start becomes easy. . In another embodiment, the core is made of a single silicon steel plate as described in claim 2, and a cut is made in each blade to reduce cogging torque and effectively converge the magnetic flux of the magnet. It is better to bend in opposite directions. This way,
An extremely thin eccentric cored vibration motor with reduced cogging torque and high efficiency can be obtained. In another embodiment, it is preferable that at least the middle salient pole of the core is widened toward the outside. In this way, the amount of movement of the center of gravity can be increased. Further, as described in claim 4, it is preferable that the core be capable of separating the center salient pole. With this configuration, the winding of the armature coil can be easily performed, and the gap between the blades can be reduced. Still further, as set forth in claim 5, the shaft is fixed to a part of the housing,
It is preferable that the rotor is rotatably mounted on the shaft via a resin bearing integrated with the core cover. In this case, there is no need to prepare a separate bearing, and the structure is simplified.

[0009]

Next, as a first embodiment of the present invention, the configuration of a flat shaft-fixed cored type vibration motor will be described with reference to the cross-sectional view of the main part shown in FIG. In the figure, a housing H comprises a shallow dish-shaped case 1 having a through hole 1a in the center and an end bracket 2 attached to the opening edge of the case 1.
Inside the housing H thus configured, the shaft S is provided with the burring portion 2 raised from the center of the end bracket 2.
It is fixed by being pressed into a. This axis S
, A core 3 formed by pressing one silicon steel plate is rotatably mounted via a resin bearing 4 having a core cover portion 4a integrated therewith. A shallow cylindrical magnet 5 for applying a magnetic field to the core 3 through a radial gap is provided inside the case 1. As shown in FIG. 2, the core 3 has three salient poles 3a, 3b, and 3c formed so that the opening angle is deviated within 180 degrees as a whole as viewed from a plane, and a counter torque is generated integrally with these salient poles. Each blade 3aa, 3bb and 3cc formed so that the opening angle as a whole is within 4 poles of the magnet + N (N is a non-magnetized portion).
Having. These blades are formed with notches 3e # and are turned in opposite directions to each other so that the blades are easily affected by the magnetic flux of the magnet 5. Therefore, the center of the salient pole and the blade configured as described above does not coincide with each other. That is, the amount of movement of the center of gravity is gained by the biased salient poles, and the electrical neutral point is obtained by the blade. The armature coils 6a wound around the salient poles 3a, 3b and 3c,
6b and 6c, and a flat plate commutator 7 composed of a printed wiring board having nine segment patterns 7a, 7b # 7i, which are short-circuited every two to provide appropriate power to the armature coil, It constitutes a flat cored rotor R. The flat plate commutator 7 has a pair of axial sliding contact type flat brushes 9, 9 whose base ends are implanted on the end bracket 2 via a brush base 8 made of a flexible substrate at an opening angle of substantially 180 degrees. Is in sliding contact. In the figure, reference numeral 10 denotes a thrust washer for regulating the vertical movement of the cored rotor R.

Next, the principle of rotation of such a cored motor in a delta connection type will be described with reference to FIG. 3. Prior to that, if the connection relation is clarified in FIG. 3, the electric motor wound around the salient pole 3a will be described. The terminal at the end of winding of the child coil 6a is connected to the segment 7a of the commutator 7, and the terminal at the beginning of winding is connected to the segment 7c. The end of the armature coil 6b wound around the salient pole 3b is further connected to the segment 7c, and the beginning of the coil is connected to the segment 7e. The segment 7e has three salient poles
The winding end terminal of the armature coil 6c wound around c is connected, and the winding start terminal is connected to a segment 7g having the same potential as the segment 7a. Now, when power is applied to a pair of brushes 9, 9 arranged in the neutral portion of the magnetic pole in the same figure, the segment 7b of the commutator 7
Current flows through the armature coil 6b in the direction of the arrow through
The blade 3bb of the salient pole 3b becomes the south pole. Therefore,
The salient pole 3b is repelled by the S pole of the magnet 5 and is drawn to the N pole on the right side, and thus moves in the A direction. Since a current flows through the armature coil 6c in the direction of the arrow to the salient pole 3c on the right side of the salient pole 3b, the blade 3cc becomes an N pole, is repelled by the N pole of the magnet 5, and is attracted to the S pole on the right side thereof. , Also moving in the A direction. The current flowing through the armature coil 6c passes through the segment 7a via the segment 7g, and causes the armature coil 6a to turn the salient pole 3a to the N pole. Therefore, the salient pole 3a is repelled by the N pole of the magnet 5 and drawn to the S pole on the right side thereof. In this way, the cored rotor R rotates in the direction A without generating a counter torque as a whole. FIG. 4 shows the position when the cored rotor R rotates 60 degrees. In this case as well, the direction of the current is reversed, but the motor rotates in the A direction without generating a counter torque. Although the above description has been made with reference to the delta connection type, star connection can be achieved by changing the brush position and the like.

FIG. 5 is a plan view of a main part showing a modified configuration example of the above embodiment, in which a salient pole 33b at the center is widened outward. In this way, the amount of movement of the center of gravity can be increased, and the weight loss of the gap due to the winding can be reduced.

FIG. 6 is a sectional view of a main part of a second embodiment of the present invention in which two cores are stacked. That is, the core 33 is made of two silicon steel plates, and the inner diameter portion 3n is folded back in the opposite direction to the sintered oil-impregnated bearing 4n.
4 is mounted by press-fitting, and is therefore held via the sintered oil-impregnated bearing 44. In this case, if necessary, the blade 3b
A notch 3e may be formed in b to improve the cogging torque. As a modification of this embodiment, a resin bearing may be used as described above.

FIG. 7 shows a third embodiment of the present invention in which a central salient pole 333b is replaced with left and right salient poles 333a, 333.
It is a principal part top view made to be able to separate from c. In this case, the inner diameter portion 333n is provided with a locking portion 3f so that it does not come off due to centrifugal force. This makes it easy to wind the armature coils 6a and 6c around the left and right salient poles 333a and 333c, and after winding the armature coil 6b around the center salient pole 333b, it is sufficient to assemble them.
The spacing between the blades can be reduced regardless of the ease of winding. Therefore, since the structure approaches the slotless structure, the cogging torque can be improved and the start can be simplified. Such a configuration can be adopted in any of the above embodiments. In addition, although one or two cores have been described, it is needless to say that dozens of cores can be used in which the cores are long in the axial direction. Although the above embodiments have been described with reference to the fixed shaft type, the present invention can also be applied to a shaft rotating type in which the shaft is integrated with the rotor.

[0014]

According to the present invention, as described above, the rotor has three salient poles formed so that the opening angle is deviated within 180 degrees when viewed from the plane, and the salient poles are integrally formed with the salient poles as a whole when viewed from the plane. By using at least one core having each blade formed so as to be within 4 poles of the magnet + N (N is a non-magnetized portion), the amount of movement of the center of gravity for generating centrifugal force can be increased. Because it was configured to reduce the cogging torque by securing an electrical neutral point,
A large vibration is obtained by the rotor itself, which is advantageous in cost.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a first embodiment of an eccentric cored vibration motor of the present invention.

FIG. 2 is a plan view of a main part of the core of the embodiment.

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

FIG. 4 is an operation explanatory diagram when the rotor rotates 60 degrees from the operation explanatory diagram.

FIG. 5 is a plan view of a main part of a modification of the embodiment.

FIG. 6 is a sectional view of a main part of a second embodiment of the present invention.

FIG. 7 is a plan view of a main part of a third embodiment of the present invention.

FIG. 8 is a perspective view of a conventional vibration motor.

FIG. 9 is a side view of a conventional flat vibration motor.

[Explanation of symbols]

H Housing 1 Case 2 End bracket R Cored rotor 3 Core 3a, 3b, 3c, 33a, 33b, 33c, 333
a, 333b, 333c Salient poles 3aa, 3bb, 3cc Blade 4 Resin bearing 4a Core cover S-axis 5 Shallow cylindrical magnet 6a, 6b, 6c Armature coil 7 Plate commutator made of printed wiring board 8 Brush base 9 Brush

Claims (5)

[Claims] 1. An eccentric cored vibration motor comprising the following components. 1 Housing that constitutes the motor. 2 A magnet having six field poles mounted on the housing and alternately magnetized N and S. 3 Rotor facing this magnet. 4 Shaft supporting this rotor. 5. The rotor has three salient poles formed so as to be deviated so that the opening angle is within 180 degrees as viewed from a plane, and the salient poles are integrally formed with these salient poles so that the opening angle as a whole is 4
At least one core having each blade formed so as to be within the range of poles + N (N is a non-magnetized portion), an armature coil wound around each of the salient poles, and an electric power appropriately supplied to the armature coil. Consists of a commutator with nine segments that are shorted every other two to give (6) A pair of brushes which are brought into sliding contact with the commutator at an opening angle (60 degrees, 180 degrees) which is an odd multiple of the magnetic pole of the magnet, and whose base is planted in a part of the housing. 2. The core is made of one silicon steel plate, and each blade is cut and bent in opposite directions to reduce cogging torque and effectively converge the magnetic flux of the magnet. 2. The eccentric cored vibration motor according to 1. 3. The core according to claim 1, wherein at least a middle salient pole is divergent toward the outside.
3. The eccentric cored vibration motor according to claim 1. 4. The eccentric cored vibration motor according to claim 1, wherein the core is capable of separating a center salient pole. 5. The shaft is fixed to a part of a housing,
The eccentric cored vibration motor according to any one of claims 1 to 4, wherein the rotor is rotatably mounted on the shaft via a resin bearing integrated with a core cover.