JP3948626B2 - Eccentric rotor and vibration motor using the eccentric rotor - Google Patents

Description

  The present invention relates to a small vibration motor used for notifying an incoming call by vibration in a mobile communication terminal device such as a mobile phone.

A mobile communication terminal device such as a mobile phone is equipped with a vibration motor to notify the user of an incoming call by vibrating the device.
The vibration motor is mainly a cylindrical housing with a cylindrical housing with a weight fixed to the output shaft protruding outside the housing, and a flat housing with a coin-shaped housing with the shaft fixed to the housing and the rotor in the housing being eccentric. There is a type vibration motor.
Since the rotor of the flat vibration motor is eccentric and eccentrically supported on a shaft fixed to the housing, a structure in which a bearing, a weight, and a coil are integrally formed with a resin together with a printed wiring board constituting a commutator board is used. It is done.

For example, Japanese Patent Application Laid-Open No. 2002-119915 discloses a configuration in which a bearing is formed by the molding resin itself that constitutes the rotor, and a configuration in which a sintered oil-impregnated bearing is used for the bearing and supported by the molding resin.
Japanese Patent Laid-Open No. 2002-28570 discloses a configuration in which a printed wiring board, an air-core armature coil, a weight, and a bearing are integrally molded simultaneously by resin molding.
The configurations disclosed in these publications all form a flat eccentric rotor by integrating a printed wiring board constituting a commutator board, a bearing, a weight, and a coil by resin molding. It is generally produced by molding.
JP 2002-119915 A JP 2002-28570 A

In recent years, with the progress of downsizing of devices on which vibration motors are mounted, the vibration motors are also required to be downsized. In order to smoothly rotate the eccentric rotor even if the size is reduced, a bearing such as a sintered oil-impregnated bearing is used as the bearing. In addition, since it is necessary to ensure the amount of vibration even if the motor is downsized, the ratio of the area occupied by the coil and the size of the weight is higher than the size of the motor in order to increase the rotation speed and eccentricity. It becomes.
In the case of a vibration motor, since a weight is integrally formed on the rotor, if an impact is applied to the motor due to a fall of the device or the like, the weight is increased by the weight and the impact on the rotor is greater than that of a normal motor.
Since the bearing is small in shape, when it is integrated as a rotor by resin molding, if the mounting strength is not sufficient, the bearing portion will be damaged by impact.
The object of the present invention is to provide an eccentric rotor that maintains the mounting strength of the bearing against the rotor and does not damage the bearing due to impact even if the vibration motor has a large proportion of the size of the coil or weight and the bearing is small. And providing a vibration motor using the eccentric rotor.

In order to solve the above-mentioned problem, as shown in claim 1, the configuration of the eccentric rotor has a plurality of commutator pieces printed on one surface and a plurality of wound air-core armature coils mounted on the other surface. A flat commutator substrate having a shaft insertion hole through which a shaft serving as the center of rotation is inserted, and a cylindrical bearing made of sintered oil-impregnated metal through which the shaft is inserted are integrated into a flat plate shape by resin molding together with a weight. The shaft insertion hole is an opening having a diameter larger than the outer diameter of the shaft and smaller than the outer diameter of the bearing, and the bearing has a shaft insertion hole of the commutator board at the entire circumference of one end thereof. It is assumed that they are arranged in contact with and integrated with a print pattern provided in the periphery .
According to the present invention, since the commutator substrate and the bearing are integrally formed with the resin, the commutator substrate holds the bearing, and the resin and the bearing are separated even when an impact is applied to the rotor. Damage to the bearings is prevented.
That is, strong attachment strength is obtained by the interaction of the attachment strength of the bearing and resin, the printed wiring board and resin, and the printed wiring board and bearing.
Further, when a pattern is printed on the commutator substrate and the pattern and the bearing are in contact with each other, the commutator substrate and one end of the bearing are brought into close contact with each other using elasticity corresponding to the thickness of the pattern as in claim 2. The resin can be molded in the state of being allowed to enter. For this reason, resin can be prevented from entering the shaft insertion hole or the bearing, stable resin molding can be performed, and the mounting strength of the bearing with respect to the rotor can be stabilized.

Et al as described in claim 3 is, the bearing is formed in a cylindrical shape having a stepped portion, integral arranged the step portion in contact with the periphery the shaft insertion hole. If the bearing has a step as described above, the effective length of the bearing can be increased.

As described in claim 4, the vibration motor using such a rotor is supplied with electric power from a housing composed of a case and a bracket, a shaft fixed to the housing, a magnet attached to the housing, and the outside of the housing. 4. A thrust receiver comprising a terminal, a brush electrically connected to the terminal, and an eccentric rotor according to claim 1 to which electric power is supplied from the brush, wherein the commutator board can support the commutator board. The member is provided.
When an impact is applied to the motor, the thrust receiver on the commutator board side must be in contact with the commutator board, not the bearing. By doing so, a configuration in which the commutator substrate and the bearing are in direct contact with each other and the resin is integrally formed becomes effective.

According to the configuration of the eccentric rotor of the present invention, by mounting the entire circumference of the cylindrical bearing end in contact with the commutator substrate constituting the commutator substrate, the mounting strength of the bearing to the rotor is increased, and by impact Even when an excessive load is applied to the rotor, the bearing mounting portion is not damaged, and the rotor can be excellent in impact resistance.
In addition, a motor incorporating the rotor can be resistant to impact.
Furthermore, by providing a pattern on the substrate surface that the bearing end contacts, the adhesion between the substrate and the bearing end can be improved, the bearing and the commutator substrate can be stably contacted, and the resin can be inserted into the shaft insertion hole. And intrusion into the bearing can be prevented. That is, since the stable resin molding can be performed, the attachment strength of the bearing to the rotor can also be stabilized.

1A and 1B are diagrams showing an eccentric rotor of the present invention, in which FIG. 1A is a plan view and FIG. 1B is a cross-sectional view taken along line AA.
FIG. 2 is a plan view showing a printed wiring board constituting the eccentric rotor shown in FIG.
3A and 3B are views showing the weights constituting the eccentric rotor shown in FIG. 2, wherein FIG. 3A is a plan view thereof, and FIG.
FIG. 4 is a cross-sectional view showing a principal part of a side surface of a vibration motor using the eccentric rotor of the present invention.
FIG. 5 is an enlarged view of the AA cross-section bearing portion of the rotor shown in FIG. 1 (a), and (a) and (b) show different embodiments.
FIG. 6 is a cross-sectional view of a main part of a side surface of a vibration motor using another rotor of the present invention.

The rotor R used in the vibration motor M includes a thin printed wiring board 1 such as a so-called glass epoxy board or a flexible board as a commutator board, and a wound-type air core machine having an effective conductor opening angle of 40 to 90 degrees disposed thereon. The weights 30 and the sintered oil-impregnated bearings (hereinafter referred to as bearings) 40 are formed in a D-shaped flat plate shape by resin molding such as injection molding as weights that decenter the center of gravity of the child coils (hereinafter referred to as coils) 20A and 20B and the rotor R.
The printed wiring board 1 directly or indirectly includes the coil placement surfaces 3A and 3B on which the coils are placed, the terminal connection portions 4A and 4B, the center portion 5 on which the bearing 40 is placed, and the holding convex portion 31 of the weight 30. It comprises a holding part 6 that holds it automatically.
The terminal connection portions 4A and 4B are areas where terminal connection patterns 7A, 8A, 7B and 8B for connecting the coil terminals 22A, 23A, 22B and 23B to the corresponding segment 2 are arranged.
In order to increase the weight as much as possible, the weight 30 has a thickness exposed on both surfaces of the flat rotor R and is disposed between the two coils. The weight 30 has a portion embedded in the resin so as to be fixed to the resin while maintaining its strength. For example, the C surface 32 of the outer portion 37 has an outer peripheral side of the rotor R, and the C surface 33 has an inner peripheral side. Then, holding convex portions 31 thinner than the thickness of the rotor R are embedded in the resin portion 15, respectively.
Guide recesses 34, 35, and 36 are formed in the portion of the weight 30 embedded in the resin as positioning portions that determine the position of the rotor when the resin is molded.

The bearing 40 is formed in a cylindrical shape from a sintered oil-impregnated metal, and chamfers are usually formed on the outer periphery and the inner periphery at both ends. The shaft 11 fixed to the housing of the motor M is inserted into the bearing 40, and the rotor R is rotatably supported inside the motor M.
A shaft insertion hole 5a is formed in the central portion 5 of the printed wiring board 1 on which the bearing 40 is placed. The diameter of the shaft insertion hole 5a is larger than the rotation shaft, smaller than the outer diameter of the bearing 40, and The end portion of the bearing 40 is placed so as to touch the center portion 5 so that the resin is not exposed from the shaft insertion hole 5a.
The rotor M is molded from, for example, a polyester-based thermoplastic resin. As a characteristic of the resin molding, the rotor M is attracted or distorted. Therefore, the concave portion 18 is formed on the D-cut side of the resin portion 15 while providing the wall portion 19 on the outer peripheral portion.

A first embodiment of the present invention will be described with reference to FIGS.
In the rotor R, the printed wiring board 1, the two coils 20A and 20B mounted on the printed wiring board 1, the weight 30 and the bearing 40 are formed in a flat plate shape by resin molding such as injection molding, and the outer shape by the resin portion 15 is formed. It is formed in a D shape.
The reason why it is D-shaped is to make the opposite side lighter across the rotating shaft of the weight 30 in order to increase the amount of eccentricity as a vibration motor.
The weight 30 is made of a high specific gravity material such as a tungsten alloy, and the substrate may be a circular substrate as long as the weight effect is sufficient.
The coils 20A and 20B are wound air-core coils having an effective conductor opening angle of 40 ° to 90 °, and each coil has two terminals 22A, 23A and 22B, 23B. The coils 20A and 20B are arranged on the rotor R at an arrangement of about 140 °. Regarding this coil arrangement, for example, the coil 20A and the coil 20B can be stacked in a plurality of stages, and the coils can be arranged in two places, and the effective conductor opening angle and arrangement angle can be appropriately determined. . The number of coils can also be three (three locations).

The maximum thickness of the resin portion 15 is the same as the maximum thickness of the weight 30 and the printed wiring board 1 and the coils 20A and 20B mounted thereon. Then, the maximum thickness portion 38 of the weight 30 is exposed on both surfaces of the rotor R, and the lower surface 1A of the printed wiring board 1 and the upper surfaces of the coils 20A and 20B are exposed from the rotor R. In this way, the thickness of the rotor R can be minimized while effectively using each member. In particular, the weight 30 can increase the amount of eccentricity up to the thickness of the printed wiring board.
The step 16 is a step for causing the upper end portion 40 </ b> B of the bearing 40 to protrude from the upper surface of the resin portion 15.
The printed wiring board 1 includes coil placement portions 3A and 3B on which the coils 20A and 20B are placed on the upper surface 1B side, and terminal connection patterns 7A for connecting the terminals 22A and 23A and 22B and 23B of the coils 20A and 20B. Terminal connection portions 4A and 4B are formed in which 8A, 7B and 8B are formed on the upper surface 1B side. A plurality of commutator pieces 2 (six in this embodiment) are printed on the lower surface 1 </ b> A side of the printed wiring board 1.
Since the circuit configuration for connecting these patterns and commutator pieces is not directly related to the present invention, the description thereof will be omitted.
A shaft insertion hole 5a through which the shaft 11 passes is formed in the central portion 5 of the printed wiring board 1, and a cylindrical bearing 40 is disposed on the upper surface 1B side. The opening diameter of the shaft insertion hole 5a is slightly larger than the shaft 11 and smaller than the outer diameter of the bearing 40 so that the one end portion 40A of the bearing 40 and the upper surface 1B of the printed wiring board 1 are in direct contact with each other.

The bearing 40 is made of, for example, sintered oil-impregnated metal, and a C surface 41 is often formed as a chamfer at both end portions 40A and 40B. The bearing 40 and the printed wiring board 1 are arranged so that the entire circumference of the end of the cylinder is in contact with the end other than the C surface 41.
If the bearing is placed on the printed wiring board and the rotor R is formed by resin molding in this way, the bearing is supported by the printed wiring board even if an impact in the direction of the shaft 11 is applied to the motor M. Thus, the rotor R can be configured to be extremely resistant to impact.
When the printed wiring board 1 and the bearing 40 are mounted on an injection mold, the end 40B of the bearing 40 and the lower surface 1A of the printed wiring board 1 are pressed by the mold, but depending on the variation of the components, the shaft insertion hole 5a may be inserted. In order to prevent the resin from entering, it is necessary to further increase the adhesion between the end 40B and the upper surface 1B.
The details are shown in FIGS. 5 (a) and 5 (b).
In FIG. 5A, an annular pattern 5b is printed on the upper surface 1B of the printed wiring board 1 around the shaft insertion hole 5a. The bearing 40 is positioned so that the entire circumference of the end portion 40 </ b> A overlaps the annular pattern 5 b and is resin-molded in a state where it is placed on the printed wiring board 1. An annular pattern 5c is also formed around the shaft insertion hole 5a on the lower surface 1A of the printed wiring board 1.
When the printed wiring board 1 and the bearing 40 are mounted on the injection mold, the mold and the bearing 40, the bearing 40 and the printed wiring board 1, and the printed wiring board 1 and the mold are respectively utilized by utilizing the elasticity of the annular patterns 5b and 5c. Can be adhered.
FIG. 5B shows another example of the relationship between the bearing and the shaft insertion hole. Even if the C surface 41 is in contact with the edge of the shaft insertion hole 5f, the end 40A of the bearing 40 is prevented from protruding from the lower surface 1A of the printed wiring board 1, and the molding resin is prevented from entering the shaft insertion hole 5f. The bearing 40 and the resin portion 15 are prevented from protruding from the lower surface 1A of the printed wiring board 1.
At that time, the C surface 41 comes into contact with the inner peripheral portion of the annular pattern 5b so as to be crimped.
The annular patterns 5b and 5c can be omitted depending on the thickness and variation of each member. Further, the annular pattern 5b is not limited to an annular shape, and may be any shape that allows the end portion 40A of the bearing 40 to contact.

  The coils 20A and 20B are arranged on the rotor R at an arrangement angle of about 140 °, and a weight 30 for decentering the rotor R is arranged between the coils on the 140 ° side. The weight 30 is a high specific gravity weight formed by, for example, sintering a tungsten alloy, and the outer shape portion 37 is formed in a T shape formed in an arc shape along the outer periphery of the rotor R. If the maximum thickness portion 38 is the same as the thickness of the rotor R and is exposed on both surfaces of the rotor R, the amount of eccentricity can be increased. A concave notch 9 is formed in the printed wiring board 1 so as to expose the maximum thickness portion 38 of the weight.

Around the maximum thickness portion 38, a C surface 32 for embedding the weight 30 in the resin is formed in an arc shape along the outer periphery of the rotor R, and a C surface 33 is also formed in an arc shape along the outer shape of the coils 20A and 20B. Has been. The weight 30 is embedded in the resin portion 15 so that the resin is well wound around the weight 30 during molding by utilizing the C surface, and the weight 30 is firmly fixed to the rotor R. The weight 30 is also formed with a holding convex portion 31 continuously with the C surface 33 in the direction of the axis 11.
The holding convex portion 31 is embedded in the resin portion 15 and is supported in the direction of the axis 11 by the holding portion 6 formed on the printed wiring board 1. If the thickness of the holding convex portion 31 is reduced, the resin flows between the upper surface 1B of the printed wiring board 1 and the holding convex portion 31, and the weight 30 can be stably fixed to the rotor R. It will be indirectly supported in the thickness direction.
Guide recesses 34 and 35 for determining the position of the weight 30 at the time of resin molding are formed in the outer portion of the weight 30 where the C surface 32 and the C surface 33 intersect. When the weight 30 is attached to the molding die during resin molding, the guide recesses 34 and 35 are attached to the guide pins attached to the die.
The guide recesses 34 and 35 are not formed in the maximum thickness portion 38, but can be avoided as much as possible by reducing the amount of eccentricity of the weight 30 by providing the guide recesses 34 and 35 in the portions of the C surfaces 32 and 33. Since the C surfaces 32 and 33 are for embedding the outer portion of the weight 30 in the resin, the shape is not limited to the C surface, and the outer portion may be continuously formed in a concave shape. Further, a plurality of guide recesses 34 and 35 may be provided on the C surface 32 or the C surface 33 to the extent that the flow of the resin is not hindered instead of the intersection of the C surfaces 32 and 33.
The hole 17 formed in the resin portion 15 is formed by the guide pin.

The guide concave portion may be provided in the holding convex portion 31. For example, as shown in FIG. 3, by providing the concave portion 36 in the holding convex portion 31, the eccentric amount of the maximum thickness portion 38 is not reduced. The recess 36 may be an opening penetrating in the thickness direction, and if necessary, an opening is provided at a corresponding position of the printed wiring board 1 so that the relative position with the substrate can be adjusted simultaneously.
On the outer shape portion 37 of the weight 30, two convex portions 39 that are spherical toward the outside of the rotor R are formed. When the weight 30 is attached to the molding die, play is provided between the guide pin and the guide recesses 34 and 35 for easy attachment. If the outer portion 37 contacts the inner wall surface of the mold when the weight 30 rattles due to the play, the flow of resin to the outer peripheral side of the weight 30 becomes worse.
When the weight 30 rattles, the convex portion 39 hits the inner wall surface of the mold to prevent the outer portion 37 from coming into contact with the inner wall surface of the mold, and the resin flows well to the weight 30 so that the resin portion 15 Can be formed. The shape of the convex portion 39 is not limited to a spherical shape, and any shape may be used as long as the tip side has a small area and comes into contact with the mold and does not hinder the flow of the resin.

In the above configuration, the maximum thickness portion of the weight 30 is exposed on both sides of the rotor R. However, the entire weight 30 is placed on the upper surface 1B of the printed wiring board 1 and the maximum thickness portion is exposed on one side of the rotor. However, if a guide recess or guide opening is provided in the part embedded in the resin and a guide pin hole is formed in the corresponding position of the printed wiring board, the weight can be reduced without sacrificing the eccentricity of the maximum thickness portion of the weight. Positioning becomes possible.
In addition, by positioning the weight 30 with the guide pins of the mold, it is not necessary to bond the weight 30 on the substrate, so that the process is reduced.

As described above, in the rotor R, the printed wiring board 1, the coils 20 </ b> A and 20 </ b> B, the weight 30 and the bearing 40 are integrated by resin molding, and the resin portion 15 is formed into a D-shaped flat plate shape. At this time, the coils 20A and 20B and the weight 30 may all be within a range of 180 ° with respect to the shaft 11, but are often difficult depending on the size of each member.
Also in this embodiment, a part of the coils 20A and 20B, the connection patterns 7A, 8A, 7B, and 8B must be arranged on the opposite side of the weight 30 with the bearing 11 interposed therebetween, that is, on the opposite side to the center of gravity. In such a case, it is necessary to reduce the weight of the portion opposite to the center of gravity as much as possible.
Further, in the case of resin molding, if the thickness of the resin is large, sinking or distortion occurs, so that it is desirable that the thickness is thin.

The resin portion 15 formed in the portions of the connection patterns 7A, 8A, 7B, and 8B needs a certain thickness to solder the terminals 22 and 23 and to cover the connection portions with resin to prevent disconnection. Therefore, avoid the connection patterns 7A, 8A, 7B, 8B and the terminals 22A, 23A, 22B, 23B in the thick part of the resin part 15 on the side opposite to the center of gravity with the concave part 18 having the wall part 19 on the outermost periphery. Is provided.
The concave portion 18 reduces the weight on the side opposite to the center of gravity and prevents distortion due to thickness, and the wall portion 19 ensures the strength of the outer peripheral portion to maintain the flatness of the rotor R.
The shape of the recess can be appropriately determined by the arrangement of the connection patterns 7A, 8A, 7B, 8B and the terminals 22A, 23A, 22B, 23B.

FIG. 4 shows an example of a vibration motor using the above-described rotor.
In the motor M, a stainless steel thin plate disc-shaped bracket 52 is fixed to a stainless steel thin plate cylindrical cap-shaped case 51 to form a housing H, the shaft 11 is fixed to the burring portion 55 of the bracket 52, and the rotor R is fixed to the shaft 11. Rotation is supported.
The bracket 52 is formed of a thin printed wiring board such as a flexible substrate or a glass epoxy substrate, and a brush base 53 for supplying electric power to the rotor by a brush 54 is attached.
A pair of brushes 54 (one side is shown in FIG. 1) is attached around the shaft 11 of the brush base 52, and one end side is led out from the opening 51a to the outside of the housing H as a power supply terminal 52a. The bracket 52 is provided with a terminal placement portion 52a on which the power supply terminal 55 is placed. The free end side of the brush 54 is in sliding contact with the commutator piece 2 of the rotor R.
A ring-shaped magnet G is attached to the inner surface of the bracket 52. The magnet G is an axial gap type magnet with four poles magnetized in the circumferential direction, and faces the rotor R.

One end of the shaft 11 is press-fitted and fixed to a burring portion 55 provided in the center of the bracket 52, and the other end is attached to a recess 51 a provided in the center of the housing 51 with a sliding sheet 56 therebetween. The rotor R is rotatably supported on the shaft 11 by a bearing 40.
Since the rotor R is always pushed to the case 51 side by the brush 54, the upper surface side of the rotor R is in direct contact with the sliding sheet 56 and the lower surface side is the center of the printed wiring board 1 on the lower surface 1A side. The part 5 is opposed to a thrust receiver 57 made of a slidable washer.
When an impact in the direction of the shaft 11 is applied to the vibration motor, the rotor R moves in the axial direction. When moved upward, the end 40B of the bearing 40 hits the housing, and when moved downward, the lower surface 1A hits the thrust receiver 57.
In any case, since the bearing 40 and the printed wiring board 1 are integrated in contact with each other, the mounting strength of the bearing 40 to the rotor is large, and the bearing portion is not damaged.
Various configurations other than the rotor R such as the housing H, the brush base 53, and the like constituting the vibration motor M are conceivable and need not be limited to the above embodiment. It is possible to use the configuration of a vibration motor using a mechanical commutator with a fixed shaft type that has been filed so far.

FIG. 6 shows a rotor R1 and a vibration motor M1 using the rotor R1 as another embodiment of the present invention.
The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.
The rotor R1 has coils 20A and 20B mounted on the printed wiring board 101, and is integrated with the bearing 140 and the weight 30 by resin molding.
The bearing 140 has a cylindrical shape having a stepped portion 140a, and a large diameter portion 141 and a small diameter portion 142 are continuously formed. The step portion 140a forms one end portion of the large diameter portion 141.
The shaft insertion hole 105a of the printed wiring board 101 is an opening having a diameter larger than the small diameter portion 142 and smaller than the large diameter portion 141, and the stepped portion 140a of the bearing 140 is placed on the upper surface 101A.
The small-diameter portion 142 protrudes through the printed wiring board 101 to the lower surface 101A side. If it is such a shape, the effective length as a bearing can be lengthened.
Annular patterns 105b and 105c are printed around the shaft insertion hole 105a, and the annular pattern 105b is formed in contact with the stepped portion 140a. Each action is the same as 5b and 5c.
A cylindrical spacer 157 is provided around the burring portion 55 to regulate the downward movement of the rotor R1 in the thrust direction. The inner diameter of the spacer 157 is set such that the small diameter portion 142 of the bearing 140 can be inserted, and the bearing 140 and the spacer 157 are not in direct contact with each other.
When an impact is applied to the vibration motor M1 and the rotor R1 moves in the direction of the spacer, the spacer 157 supports the lower surface 101A of the printed wiring board 101. The operation is the same as in the first embodiment.

1A and 1B are views showing an eccentric rotor of the present invention, in which FIG. 1A is a plan view thereof and FIG. FIG. 2 is a plan view showing a printed wiring board constituting the eccentric rotor shown in FIG. 3A and 3B are views showing the weights constituting the eccentric rotor shown in FIG. 2, wherein FIG. 3A is a plan view thereof, and FIG. FIG. 4 is a cross-sectional view of the main part of the side of a vibration motor using the eccentric rotor of the present invention. FIG. 5 is an enlarged view of the AA cross-section bearing portion of the rotor shown in FIG. 1 (a), and (a) and (b) show different embodiments. FIG. 6 is a cross-sectional view showing a principal part of a side surface of a vibration motor using another rotor of the present invention.

Explanation of symbols

R rotor 1 printed wiring board 5a, 5f shaft insertion hole 2 20A, 20B coil 30 weight 40 bearing 40A bearing end

Claims (4)

A plurality of commutator pieces printed on one surface, a plurality of wound air-core armature coils placed on the other surface, and a plate-like commutator substrate having a shaft insertion hole through which a shaft serving as a rotation center is inserted; An eccentric rotor in which a cylindrical bearing made of sintered oil-impregnated metal into which the shaft is inserted is integrated with a weight into a flat plate shape by resin molding, and the shaft insertion hole is larger than the outer diameter of the shaft The opening is smaller in diameter than the outer diameter of the bearing, and the bearing is integrally arranged with its entire circumference in contact with a printed pattern provided around the shaft insertion hole of the commutator substrate. Eccentric rotor. The eccentric rotor according to claim 1, wherein the rotor is resin-molded in a state in which the commutator substrate and one end of the bearing are in close contact with each other by using elasticity corresponding to the thickness of the printed pattern .   The eccentric rotor according to claim 1, wherein the bearing is formed in a cylindrical shape having a stepped portion, and the stepped portion is arranged so as to be in contact with and around the shaft insertion hole. A housing composed of a case and a bracket, a shaft fixed to the housing, a magnet attached to the housing, a terminal to which power is supplied from the outside of the housing, a brush electrically connected to the terminal, and power from the brush A vibration motor comprising the eccentric rotor according to claim 1, wherein a thrust receiving member capable of supporting the commutator substrate is provided on the commutator substrate side.

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