JP2008148547A - Vibration motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration motor having an eccentric rotor. <P>SOLUTION: In the eccentric rotor that includes an eccentric rotating body, the eccentric rotor includes a base body, and a fit-in body fitted into the base body; density of the fit-in body is larger than that of the base body; and the eccentric rotor is a complex structure, and can improve vibration force and is low cost. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a motor, and more particularly to an eccentric rotor structure and a vibration motor having the eccentric rotor structure.

  In various devices or equipment, the motor usually plays an extremely important role. Vibration motors are widely applied as an incoming call function used for a small wireless telephone calling device, a mobile phone, or the like, or a calling function in a PDA or medical device or a vibration sensation function of a game machine. In accordance with the development of modern society, the structure of the vibration motor must be improved.

Current vibration motors include a stator and an eccentric rotor that is rotatably mounted within the stator. The eccentric rotor is provided with an eccentric that does not overlap the center of gravity and the center of the rotating shaft. When the eccentric is rotated, vibration is generated by centrifugal force. Since the eccentric of the eccentric rotor is manufactured from a material such as a copper alloy or an aluminum alloy, the cost of the eccentric is low. However, since the density of copper is 8.9 grams per cubic centimeter (g / cm ³ ) and the density of aluminum is 2.7 grams per cubic centimeter (g / cm ³ ), the weight of the eccentric rotor is light and vibration The power is small.

  In view of the above problems, there are provided an eccentric rotor that is low in cost and capable of improving the vibration force, and a vibration motor including the eccentric rotor.

  In the eccentric rotor including the eccentric rotating body, the eccentric rotor includes a base body and an insertion body fitted into the base body, and the density of the insertion body is higher than the density of the substrate.

  A frame, a stator accommodated in the frame, and an eccentric rotor rotatable in the stator, the stator including two pole pieces and a central axis, the eccentric rotor being A vibration motor including a bearing surrounding the outer peripheral surface of the central shaft, a permanent magnet surrounding the outer peripheral portion of the bearing, and an eccentric rotating body connected to the permanent magnet, wherein the eccentric rotating body is an outer peripheral surface of the bearing A base body surrounding the base body, and an insert body fitted into the base body, and the density of the insert body is greater than the density of the substrate.

  A stator and an eccentric rotor rotatable in the stator, wherein the eccentric rotor includes an eccentric rotator, wherein the eccentric rotator is fitted into a base and the base. The density of the insert is greater than the density of the substrate.

  The eccentric rotating body of the present invention has a composite structure. That is, since the substrate is manufactured from a material having a low density, the production cost can be reduced and the processing and manufacturing can be simplified. Since the insertion body fitted in the base body is manufactured from a material having a density higher than that of the base body, the weight and vibration force of the eccentric rotating body can be improved.

  Hereinafter, the configuration of a specific embodiment according to the present invention will be described in detail with reference to the drawings.

  See FIGS. 1-3. The vibration motor of the present invention can be applied to equipment such as a mobile phone, a massage device, and a game machine controller. The vibration motor includes a frame 30, a stator 10 formed by overlapping two pole piece sets 11, and an eccentric rotor 20 accommodated in the center of the stator 10.

  The frame 30 is manufactured from a magnetic material such as an electrogalvanized steel sheet (SECC), and includes a cylindrical upper frame 30a and a lower frame 30b. At the end portions where the upper frame body 30a and the lower frame body 30b face each other, rectangular cutout portions 32a and 32b having the same size and position are formed.

  Each of the pole piece groups 11 includes an upper pole piece unit 10a and a lower pole piece unit 10b that are installed opposite to each other. The upper pole piece unit 10a and the lower pole piece unit 10b are manufactured from a magnetic material, for example, an electrogalvanized steel sheet. Each upper pole piece unit 10a includes an annular body 12a, and a connecting portion 14a is formed at the center of the annular body 12a. A plurality of pole pieces 16a are formed on the surface of the annular body 12a so as to bend vertically from the inner edge toward the lower pole piece unit 10b. A circular recess 140a having a circular hole 141a at the center is formed at the center of the connecting portion 14a. A central shaft 23 is inserted into the circular hole 141a, and five small holes located in the recess 140 are provided around the circular hole 141a.

  The lower pole piece unit 10b includes an annular body 12b and a plurality of pole pieces 16b. The size of the annular body 12b is the same as the annular body 12a of the upper pole piece unit 10a. The pole pieces 16b are formed by bending vertically from the inner edge of the annular body 12b toward the upper pole piece unit 10a. A circular hole 14b is formed at the center of the annular body 12b, and two perforations 120 and a protrusion 122 are formed in the annular body 12b of the two lower pole piece units 10b. The perforations 120 and the protrusions 122 are spaced apart so that there is the same distance between them. The protrusion 122 of each lower pole piece unit 10b is formed to protrude into the perforation 120 of the other lower pole piece unit 10b and is accommodated in the perforation 120 to fix the pole piece set 11.

  Two terminals 13b are respectively formed on the two annular bodies 12b of the two lower pole piece units 10b. The terminal 13b is a rectangular column that is integrally formed extending radially from the outer edge of the annular body 12b of the lower pole piece unit 10b. One of the two terminals 13b of the lower pole piece unit 10b is bent toward the other lower pole piece unit 10b, so that the four terminals 13b are parallel to each other and at a constant interval therebetween. Arranged above.

  The rotor 20 includes a bearing 22, an eccentric rotating body 24, an annular permanent magnet 26, a spacer 25a, and a spacer 25b. The central shaft 23 is accommodated in the bearing 22, and the spacers 25 a and 25 b are installed at the upper and lower ends of the bearing 22 so as to be positioned at both ends of the central shaft 23. The eccentric rotator 24 is provided so as to surround the outside of the bearing 23, and the permanent magnet 26 is provided so as to surround the outer surface of the eccentric rotator 24.

  As shown in FIG. 4, the eccentric rotating body 24 includes a base body 240 that is a cylindrical body, and an insertion body 244 that is a cylindrical body that is fitted into the base body 240 along the axial direction. The shape of the insertion body 244 according to the present invention is not limited to the above-described embodiment, and can be formed into a cone, a prism, or other irregular shapes. The shape of the permanent magnet 26 and the position corresponding to the eccentric rotating body 24 are not limited to the above-described embodiment. For example, the permanent magnet 26 is formed in a U shape or the permanent magnet 26 is eccentric. It can be provided in the rotating body.

  The base body 240 includes a cylindrical sleeve 241 and a half-columnar eccentric 242. A through hole 241a along the axial direction is provided at the center of the sleeve 241 and the bearing 22 is inserted into the through hole 241a. The eccentric rotator 24 and the bearing 22 are engaged in an interference fit system (relative rotation is impossible). The eccentric 242 is integrally formed on the outer peripheral surface of the sleeve 241. An upper end and a lower end of the eccentric 242 protrude from both ends of the sleeve 241, and step portions (not shown) for supporting the spacer 25 a and the spacer 25 b are formed at both ends of the sleeve 241, respectively. The upper surface of the eccentric 242 and the upper surface of the permanent magnet form a plane having the same height, and the lower surface of the eccentric 242 and the lower surface of the permanent magnet have the same height. Form a plane. The fitting body 244 is fitted in the middle of the eccentric 242.

  The base body 240 of the eccentric rotating body 24 is manufactured from a material such as plastic, bakelite, aluminum, aluminum alloy, copper, copper alloy, and the insertion body 244 is made of tungsten, tungsten steel, Manufactured from a tungsten alloy such as tungsten copper. The fitting body 244 and the eccentric rotating body 24 are engaged by a fitting method or a rivet fastening method. The outer peripheral surface of the eccentric 242 of the eccentric rotating body 24 is in close contact with the inner surface of the permanent magnet 26 and is integrally attached with an adhesive. When the rotor 20 rotates, regular vibration is generated by the centrifugal force of the eccentric rotating body 24.

  When assembling the vibration motor, each pole piece set 11 is assembled so that the upper pole piece unit 10a and the lower pole piece unit 10b face each other. Then, a constant interval is formed between the annular body 12a and the annular body 12b, and the pole pieces 16a and 16b are meshed with each other along the circumferential direction. That is, between the annular body 12a and the annular body 12b, the pole piece 16a and the pole piece 16b mesh with each other to form a cylindrical pole piece wall 60 on which a coil can be wound. Next, after filling the molten plastic material into the gap between the five small holes of the concave portion 140a and the pole piece wall 60, when the plastic material is solidified, the upper pole piece unit 10a and the lower pole piece unit 10b Are fixed together. Next, a coil (not shown) is wound around a recess formed by the annular body 12a, the annular body 12b, and the pole piece wall 60.

  The two lower pole piece units 10b of the two pole piece sets 11 are connected to each other at the middle portion of the stator, and the two protrusions 122 of the one lower pole piece unit 10b have corresponding lower pole piece units. Each is inserted into a perforation 120 of 10b and the two pole pieces are secured together. The two upper pole piece units 10 a are respectively located at both ends of the stator 10, and a space for accommodating the rotor 20 is formed at the center of the stator 10. The four terminals 13b are arranged on one surface so as to be parallel to each other and to have a constant interval therebetween. One end of the coil is electrically connected to the terminal 13b via an insulating rubber or the like attached to the terminal 13b. Therefore, the coil can be easily electrically connected to an external power source via the terminal 13b.

  Next, the rotor 20 is accommodated in the stator 10, the central shaft 23 is rotatably accommodated in the bearing 22, and both ends of the central shaft 23 are disposed on the two upper pole piece units 10a. It fixes in the circular hole of the two recessed parts 140a. The upper frame body 30 a and the lower frame body 30 b are respectively installed at both ends of the stator 10 to form a cylindrical frame body 30. Then, an insertion port through which the four terminals 13b are formed is formed by the two rectangular cutouts 32a and 32b.

  When the vibration motor is electrically connected to an external power source, the eccentric rotating body 24 is rotated and a centrifugal force is formed. The centrifugal force is first transmitted from the center shaft 23 of the vibration motor to the connecting portion 14a of each upper pole piece unit 10a, and then from the annular body 12a of the upper pole piece unit 10a to the upper pole piece unit. 10a, and then transmitted from the outer edge of the upper pole piece unit 10a to the frame 30 of the vibration motor. Therefore, vibration is generated in the electronic device using the vibration motor.

  As described above, the eccentric rotating body 24 has a composite structure. That is, since the base 240 of the eccentric rotor 20 is manufactured from inexpensive plastic, bakelite, aluminum, aluminum alloy, copper, copper alloy, etc., the production cost can be reduced and the processing process can be simplified. The fitting body 244 fitted into the base body 240 is made of tungsten, a tungsten alloy, or a material larger than the density of the base body 240. Since tungsten is the metal with the highest density (density is 19.29 grams per cubic centimeter), the density of alloys made of tungsten is also greater than the density of aluminum or copper alloys. Therefore, when an insertion body 244 made of a material having a high density such as tungsten or tungsten alloy is fitted into the base body 240, the weight and vibration force of the eccentric rotor 24 are improved, and the eccentric rotor 20 The cost of production can be reduced.

  In other embodiments, the eccentric rotator 24 may have other shapes. In the second embodiment shown in FIG. 5, the base body 240a of the eccentric rotating body 24a includes a sleeve 241 that is a cylindrical body and an eccentric 242a that surrounds the sleeve 241. In the eccentric 242a, three cylindrical inserts 244 are fitted, and the three inserts 244 have the same interval along the circumferential direction of the eccentric 242a. So as to be separated from each other. That is, the insertion bodies 244 are provided at the middle and both ends of the eccentric 242 respectively, and both ends and side surfaces of each insertion body 244 are exposed on the surface of the eccentric. Compared with the first embodiment, in this embodiment, since the number of the inserting bodies 244 is increased, the weight and vibration force of the eccentric rotating body 24 are increased. The quantity and position of the inserts 244 are not limited to the above-described embodiment, and can be appropriately changed and implemented within the scope of the claims.

  FIG. 6 shows an eccentric rotating body 24b according to the third embodiment. In this embodiment, the insertion body 244b of the base body 240b of the eccentric rotating body 24b is formed in a part of a cylindrical body, and the cross section is an irregular quadrilateral. The two opposite sides on both sides of the quadrilateral are arcs with different lengths, and the two opposite sides on the left and right sides are straight lines connected to the ends of the two arcs. The quadrilateral is symmetrical with respect to a line connecting the midpoints of the two arcs, and the two opposing faces on the front and rear sides of the fitting 244b are all arc surfaces, and the arc surface having a small area and the eccentricity The side surface of the child 242b is located on the same outer peripheral surface.

  FIG. 7 shows an eccentric rotating body 24c according to the fourth embodiment. The sleeve 241c and the fitting body 244c of the eccentric rotating body 24c are different from the above-described embodiments. Three protrusions 2411 extending outward from the outer surface are formed on the sleeve 241c that is the cylindrical body. The protrusions 2411 are spaced apart so as to have the same interval. Of the three protrusions 2411, any two protrusions 2411 are formed with protrusions 2412 whose upper ends are bent and extended. The upper and lower surfaces of the sleeve 241c and the upper and lower surfaces of the protruding portion 2411 are placed on the same plane. The fitting body 244c is fitted between two projecting portions 2411 where the protrusion 2412 is formed, and the upper end and the lower end of the fitting body 244c project outward from the upper end and the lower end of the sleeve 241c. The upper surface and the lower surface of 244c are placed on the same plane as the upper surface and the lower surface of the permanent magnet 26.

  From a bird's-eye view, the insertion body 244c is an irregular polygon, includes a short inner arc and a long outer arc, and has V-shaped opposing angles on both the left and right sides. Projections 2412 are formed on two adjacent projecting parts 2411 of the sleeve 241c, and the two projecting parts 2412 are engaged with V-shaped opposing angles of the fitting body 244c, so that the fitting body 244c is It is fixed to the sleeve 241c. In the embodiment, the weight of the eccentric rotator 24 includes the weight of the eccentric 242 of the half cylinder and the weight of the fitting 244, and the weight of the eccentric rotator 24a is the half cylinder. The weight of the body eccentric member 242a and the weight of the fitting member 244 are included, and the weight of the eccentric rotating member 24b includes the weight of the eccentric member 242b of the half cylinder and the weight of the fitting member 244b. However, in this embodiment, the half-cylindrical eccentrics 242, 242a and 242b are not provided, and the weight of the eccentric portion is constituted by the fitting body 244c.

It is a three-dimensional exploded view of the best embodiment of the vibration motor according to the present invention. It is an assembly drawing of a vibration motor. It is a perspective view which shows the structure inside a vibration motor. FIG. 2 is a three-dimensional enlarged perspective view of the eccentric rotator shown in FIG. 1. It is an expansion perspective view of the solid of the 2nd example of an eccentric rotating body. It is an expansion perspective view of the solid of the 3rd example of an eccentric rotating body. It is an expansion perspective view of the solid of the 4th example of an eccentric rotating body.

Explanation of symbols

10 stator 10a upper pole piece unit 10b lower pole piece unit 11 pole piece set 12a annular body 12b annular body 13b terminal 14a connecting part 14b hole 16a pole piece 16b pole piece 20 rotor 22 bearing 23 central shaft 24 eccentric rotating body 24a eccentric rotation Body 24b Eccentric Rotating Body 24c Eccentric Rotating Body 25a Spacer 25b Spacer 26 Permanent Magnet 30 Frame 30a Upper Frame 30b Lower Frame 32a Notch 32b Notch 60 Polar Single Wall 120 Perforation 122 Projection 140a Recess 141a Circular Hole 240 Base 240a Base 240b Base 241 Sleeve 241a Through-hole 241c Sleeve 242 Eccentric element 242a Eccentric element 242b Eccentric element 244 Fitting body 244b Fitting body 244c Fitting body 2411 Protruding part 2412 Protruding part

Claims (16)

In an eccentric rotor including an eccentric rotor,
The eccentric rotor includes a base body, and an insertion body fitted into the base body,
An eccentric rotor, wherein the density of the insert is greater than the density of the base.   The eccentric rotor further includes a bearing, and the base includes a cylindrical sleeve and an eccentric that is a half cylinder surrounding the outer peripheral surface of the sleeve, and the center of the sleeve is along the axial direction. The eccentric rotor according to claim 1, further comprising a through hole into which the bearing is inserted.   The eccentric rotor according to claim 2, wherein the sleeve and the eccentric are integrally formed.   The eccentric rotor according to claim 2, wherein the sleeve and the bearing are fitted by an interference fit fixing method. The substrate is manufactured from materials such as plastic, bakelite, aluminum, aluminum alloy, copper, copper alloy,
The eccentric rotor according to claim 1, wherein the insertion body is manufactured from a material such as tungsten or a tungsten alloy.   The eccentric rotor according to claim 1, wherein the insertion body is a cylinder, a cone, a prism, or the like.   The eccentric rotor according to claim 1, wherein the eccentric rotor further includes a permanent magnet, and the permanent magnet is provided on an inner surface or an outer peripheral surface of the eccentric rotating body.   The eccentric rotating body and the permanent magnet are attached by an adhesive, and the upper end surface of the insertion body is placed on the same plane as the upper end surface of the permanent magnet, and the lower end surface of the insertion body is the permanent magnet The eccentric rotor according to claim 7, wherein the eccentric rotor is placed on the same plane as the lower end surface of the rotor.   The eccentric rotor according to claim 1, wherein the base and the insertion body are engaged by a fitting method or a riveting method. A frame,
A stator accommodated in the frame;
An eccentric rotor rotatable within the stator,
The stator includes two pole pieces and a central axis;
In the vibration motor, the eccentric rotor includes a bearing that surrounds the outer peripheral surface of the central shaft, a permanent magnet that surrounds the outer peripheral portion of the bearing, and an eccentric rotating body that is connected to the permanent magnet.
The eccentric rotating body includes a base body surrounding an outer peripheral surface of the bearing, and an insertion body fitted into the base body, and the density of the insertion body is larger than the density of the substrate.   Each of the pole piece sets includes an upper pole piece unit and a lower pole piece unit, and the two pole piece sets have a target structure and are provided so as to surround an outer peripheral surface of the eccentric rotor. The vibration motor according to claim 10.   The base includes a cylindrical sleeve and a half-column eccentric, and the sleeve and the eccentric are integrally manufactured from a material such as tungsten, a tungsten alloy, copper, or a copper alloy. The vibration motor according to claim 10.   The vibration according to claim 10, wherein the insertion body is manufactured from a material such as tungsten or a tungsten alloy, and the base and the insertion body are coupled to each other by a fitting method or a riveting method. motor. A stator,
An eccentric rotor rotatable within the stator,
The eccentric rotor is an eccentric rotor including an eccentric rotor,
The eccentric rotating body includes a base body and an insertion body fitted into the base body, and the density of the insertion body is larger than the density of the substrate.   The vibration motor according to claim 14, wherein the eccentric rotor further includes a bearing and a permanent magnet surrounding an outer peripheral portion of the bearing, and the eccentric rotating body is connected to the permanent magnet.   The stator includes two pole piece sets and a central axis, and each pole piece set includes an upper pole piece unit and a lower pole piece unit, and the two pole piece sets have a target structure, and the eccentricity 16. The rotor according to claim 15, wherein the central shaft is inserted into the bearing, and both ends of the central shaft are fixed to the upper pole piece unit of the pole piece set. Vibration motor.

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