JPH09131020A - Flat vibrating motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable smooth rotation without flattering an eccentric frame by constituting a rotor of a slide bearing and an eccentric frame, and attaching a magnetic plate facing only some magnetic poles of a magnet for driving to the rotor. SOLUTION: A resinous flat frame 7 is fixed to the periphery of a slide bearing 4. A careless coil 6 is attached into each hole 7c of the eccentric frame 7. A circular flange 7b erected in axial direction toward the side of a magnet 5 for drive is made at the margin on periphery side of the eccentric frame 7. A magnetic plate 8 is attached to the end face on the side of the magnet 5 for drive of the eccentric frame 7. The magnetic plate 8 is fan-shaped, and is in the shape of covering one end face of the eccentric frame 7. Therefore, oscillation is generated by the unbalance of the weight of the eccentric frame 7, and weight is obtained by attachment of the magnetic plate 8, and vibration is obtained even at low revolution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat vibration motor in which a plurality of air-core coils are eccentrically arranged on one side of a rotor. For example, a pager, a PHS (simple mobile phone), etc. It can be used for such a purpose as that the reception of the individual call signal is notified by emitting vibration.

[0002]

2. Description of the Related Art In a pager, PHS, or the like, a flat vibration motor for generating vibration by rotation may be used as one of means for notifying that an individual call signal has been received. FIG. 8 shows an example of such a flat type vibration motor.

In FIG. 8, a hole is formed in the center of a circular bottom plate 32, and one end of a fixed shaft 33 is fixed to this hole. A ring-shaped driving magnet 35 is attached to the outer periphery of the fixed shaft 33 on the bottom plate 32. Further, the slide bearing 3 is provided on the outer peripheral surface of the fixed shaft 33.
8 is inserted. The plain bearing 38 has a hole at the center, and this hole is inserted through the outer peripheral surface of the fixed shaft 33. An eccentric frame 37 made of resin is attached to the outer peripheral surface of the slide bearing 38. Eccentric frame 3
The fan 7 has a hole 37a at a position deviated from the center of gravity, and the hole 37a is fitted and fixed to the outer peripheral surface of the slide bearing 38. Further, the hole 37 of the eccentric frame 37
Holes 37b are formed at positions radially deviated from a, and a plurality of coils 36 are attached to the holes 37b. The lower end surface of the coil 36 faces the upper end surface of the drive magnet 35 attached to the substrate 32 with a certain gap. For this reason, the brush 39 provided on the bottom plate 32 and the planar commutator 40 slidingly contacting the brush 39 are provided.
By sequentially energizing each coil 36 through the coil 36, the coil 36 is biased by the driving magnet 35, and the rotor including the eccentric frame 37 and the slide bearing 38 rotates with respect to the stator member such as the bottom plate 32 and the fixed shaft 33. Driven. Further, since the eccentric frame 36 is fan-shaped and is attached to the slide bearing 38 at the portion of the hole 37a formed at a position deviated from the center of gravity, continuous rotation causes continuous vibration due to unbalance of weight. To be

A case 31 is attached to the upper end of the fixed shaft 33. The case 31 is cup-shaped and has a peripheral wall 3 on the outer periphery.
1a, and the lower end of the peripheral wall 31a is attached to the outer peripheral edge of the bottom plate 32.

[0005]

In the flat type vibration motor having the above-described structure, since the slide bearing 38 having the eccentric frame 37 attached thereto is rotated on the outer periphery of the fixed shaft 33, the outer peripheral surface of the fixed shaft 33 and the inner portion of the bearing 38 are rotated. A clearance having an appropriate size (several μm) is provided between the peripheral surface and the peripheral surface. Therefore, when the eccentric frame 37 is rotationally driven, as shown in FIG.
The eccentric frame 37 flaps due to the clearance between the fixed shaft 33 and the bearing 38, and the sliding bearing 38 of the fixed shaft 33
The point of contact with is not constant. If the slide bearing 38 is rotated while a fixed portion of the fixed shaft 33 is in constant contact with the slide bearing 38, the oil retained in the slide bearing 38 will seep out due to the pumping action as shown in FIG. 9B. However, an oil film is formed, and the slide bearing 38 is smoothly rotated. However, as described above, the eccentric frame 37
If the position where the fixed shaft 33 comes into contact with the sliding bearing 38 is not constant, the oil retained on the metal shaft 38 will not act as a pump and an oil film will not be formed, and smooth rotation of the eccentric frame 37 will be impossible. Has become. If the eccentric frame 37 is not rotated smoothly, the following problems will occur. 1. The operating noise increases. 2. Deterioration of current value due to rotation loss. 3. Since the eccentric frame 37 is made of a lightweight resin, sufficient vibration cannot be obtained unless the number of rotations is increased, but the number of rotations decreases due to rotation loss, and a sufficient amount of vibration cannot be obtained. 4. The plain bearing 38 is worn and shortens its life.

In the above example, the shaft-fixing type flat vibration motor is used. However, the rotary shaft is inserted through the metal bearing fixed to the bottom plate or the case, and the rotary shaft is rotatably supported by the metal bearing. Also in the shaft rotation type flat vibration motor described above, the vibration frame fixed to the rotary shaft flutters due to the clearance between the metal bearing and the rotary shaft, and thus has the problems 1 to 4 described above.

The present invention has been made in order to solve the problems of the prior art as described above, and an object thereof is to provide a flat type vibration motor capable of smoothly rotating the eccentric frame without fluttering. To do.

[0008]

According to the first aspect of the present invention,
A flat cup-shaped case, a bottom plate covering the opening of the case, a fixed shaft having at least one end fixed to the case or the bottom plate, a sliding bearing having the fixed shaft inserted through the central hole, and a drive magnet arranged on the case or the bottom plate. A flattened frame that holds a plurality of air-core coils facing the drive magnet and has an eccentric frame provided with a slide bearing at a position deviated from the center of gravity, and the eccentric frame vibrates by energizing the air-core coil. In the type vibration motor, the slide bearing and the eccentric frame form a rotor, and the rotor is provided with a magnetic plate facing only a part of magnetic poles of the driving magnet.

According to a second aspect of the present invention, there is provided a flat cup-shaped case, a bottom plate covering an opening of the case, a case and a bearing fixed to the bottom plate, a rotary shaft inserted through a central hole of a bearing, the case or the bottom plate. An eccentric frame that holds an installed drive magnet and a plurality of air-core coils facing the drive magnet and is fixed to a fixed shaft at a position deviated from the center of gravity and energizes the air-core coil. Is a flat type vibration motor in which the rotating shaft and the eccentric frame constitute a rotor, and the rotor is provided with a magnetic plate facing only a part of the magnetic poles of the driving magnet. Is characterized by.

According to a third aspect of the present invention, the eccentric frame and the magnetic plate are integrally molded, and the magnetic plate holds the coil and has an arc-shaped collar portion on the outer peripheral edge. .

Since the magnetic plate attached to the rotor is attracted by the drive magnet, the eccentric frame tilts in a certain direction, and in the case of the shaft fixed type, a specific portion of the fixed shaft comes into contact with the inner peripheral surface of the slide bearing. However, in the case of the shaft rotation type, a specific portion of the inner peripheral surface of the bearing comes into contact with the outer peripheral surface of the rotating shaft, and the eccentric frame is rotationally driven without fluttering.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a flat vibration motor according to the present invention will be described below with reference to the drawings. 1 and 2, a hole 2a is formed in the center of the bottom plate 2, and a fixed shaft 3 is fixed to the hole 2a by press fitting, welding, bonding or the like. A ring-shaped drive magnet 5 is attached to a portion of the bottom plate 2 on the outer peripheral side of the fixed shaft 3.

A slide bearing 4 is inserted through the fixed shaft 3. The slide bearing 4 has a cylindrical shape, and an inner peripheral surface thereof is inserted into an outer peripheral surface of the fixed shaft 3. In addition, the slide bearing 4
It is made of a sintered material obtained by sintering metal powder, has innumerable pores on its surface, and is impregnated with lubricating oil. An eccentric frame 7 made of resin is fixed to the outer peripheral surface of the slide bearing 4. The eccentric frame 7 has a substantially fan shape, and has a hole 7a at a position deviated from the center of gravity, and the inner peripheral surface of the hole 7a is fixed to the outer peripheral surface of the slide bearing 4.

On the eccentric frame 7, three holes 7c are formed at concentric circles centering on the hole 7a in the circumferential direction, and the air core coil 6 is attached to each hole 7c. There is. Of these three holes 7c, the central hole 7c is completely surrounded by the eccentric frame 7,
The two holes 7c located on both sides are partially opened. Further, on the outer peripheral edge of the eccentric frame 7, there is formed an arc-shaped brim portion 7b which is erected in the axial direction toward the driving magnet 5 side.

A magnetic plate 8 is attached to the end surface of the eccentric frame 7 on the drive magnet 5 side (the lower end surface in FIG. 1). As shown in FIG. 3, the magnetic plate 8 is fan-shaped, has a shape covering one end surface of the eccentric frame 7, and has a hole 8a at a position deviated from the center of gravity. As shown in FIG. 1, such a magnetic plate 8 has its end surface bonded to the end surface of the eccentric frame 7, or the inner peripheral surface of the hole 8a to the outer peripheral surface of the slide bearing 4, Alternatively, they are attached by spot welding.
Since the magnetic plate 8 is a thin plate, it may be bent along the outer peripheral portion of the eccentric frame 7 in order to increase the strength. By attaching the magnetic plate 8, the opening of the hole 7c of the eccentric frame 7 on the drive magnet 5 side is closed, and the air-core coil 6 is prevented from falling downward.

On the outer peripheral surface of the slide bearing 4 and on the magnetic plate 8
A plane commutator 9 is attached to the surface of the drive magnet 5 side. On the end surface of the plane commutator 9 on the side of the driving magnet 5, nine fan-shaped electrodes 9a are formed radially around the slide bearing 4, and each electrode 9a is an air-core coil attached to the eccentric frame 7. It is connected with 6.
Further, a brush (not shown) is in sliding contact with a specific electrode 9a of the flat commutator 9, the air core coil 3 is energized via the brush and the flat commutator 9, and the eccentric frame 7 and the air core coil 6 are connected to the rotor. The energization of the air-core coil 6 is controlled to be switched according to the rotational position of the eccentric frame 7, and the eccentric frame 7 and the slide bearing 4 rotate continuously.

A flat cup-shaped case 1 is attached to the upper end of the fixed shaft 3. Since the lower end portion of the peripheral wall 1a of the case 1 is attached to the outer periphery of the bottom plate 2, the case 1 includes an eccentric frame 7 and a stator member such as a driving magnet 5 attached to the bottom plate 2 on the upper side. And a stator member such as the driving magnet 5 is housed inside the case 1.

In the above flat type vibration motor, when the eccentric frame 7 is rotationally driven by switching the energization of the air core coils 6 as described above, vibration is generated due to the imbalance of the weight of the eccentric frame 7. It has become. Therefore, the eccentric frame 7 is continuously driven to rotate by switching the energization to each air core coil 6 according to the rotational position of the eccentric frame 7, and the vibration due to the imbalance of the weight of the eccentric frame 7 is continuously generated. It

According to the above flat type vibration motor, the eccentric frame 7 has the flange portion 7b which is erected in the axial direction toward the driving magnet 5 on the outer peripheral edge of the eccentric frame 7. The weight can be increased, and a sufficient amount of vibration can be obtained even at low speed rotation. Further, since the magnetic plate 8 is attached to one end surface of the eccentric frame 7, sufficient weight can be obtained also by this, and a sufficient amount of vibration can be obtained even at low speed rotation.

Further, as shown in FIG. 4, the eccentric frame 7
The magnetic plate 8 attached to the end face of the drive magnet 5
Since it rotates while being attracted by a part of the magnetic poles, the eccentric frame 7 and the slide bearing 4 incline in a certain direction, and the portions of the fixed shaft 3 with the specific symbols A and A'always contact the inner peripheral surface of the slide bearing 4. However, the rotor including the eccentric frame 7 and the slide bearing 4 does not flap during rotation. Therefore, the lubricating oil retained in the slide bearing 4 is always supplied to the portion between the fixed shaft 3 and the slide bearing 4 by the pump action, so that the slide bearing 4 can be smoothly rotated and driven, and the wear can be suppressed to reduce the bearing portion. It is possible to extend the life of the. Moreover, since the slide bearing 4 is smoothly driven to rotate, the operating noise is reduced, and the deterioration of the current value and the decrease of the vibration amount due to the rotation loss can be eliminated. Further, the magnetic plate 8 attached to the end surface of the eccentric frame 7 is attracted by the driving magnet 5, whereby a brush and a plane commutator 9 (not shown) are shown.
Since it slides at a constant pressure, the jumping phenomenon of the brush can be eliminated.

In the above embodiment, the magnetic plate 8 is provided on the lower end surface side of the eccentric frame 7, that is, on the driving magnet 5 side.
However, it is not limited to this. As shown in FIG. 5, the magnetic plate 8 may be arranged on the upper end surface side of the eccentric frame 7, that is, on the side opposite to the driving magnet 5. The example shown in FIG. 5 also has the same effect as that of the above embodiment.

Further, as shown in FIG. 6, the magnetic plate attracted by the driving magnet 5 may form the eccentric frame 10. The eccentric frame 10 has a substantially fan shape, and has a burring portion 10b at a position deviated from the center of gravity, and the inner peripheral surface of the burring portion 10b has a plain bearing 4a.
Is fixed to the outer peripheral surface of the. Further, on the eccentric frame 10, three holes 10c are formed at positions concentrically centered on the burring portion 10b in the circumferential direction, and the air core coil 6 is attached to each hole 10c. There is. Further, on the outer peripheral edge of the eccentric frame 10, in order to increase the strength of the eccentric frame 10 itself, an arc-shaped collar portion 10a bent in the axial direction toward the driving magnet 5 side is formed. Burring part 10
A plane commutator 9 is attached to the outer peripheral surface of b. The plane commutator 9 covers the inner peripheral portion of the hole 10c.
A terminal is formed in a portion of the flat commutator 9 covering the hole 10c, and the terminal is connected to the electrode of the air-core coil 6. Further, the air core coil 6 is supported by the portion of the planar commutator 9 covered in the hole 10c without dropping downward from the hole 10c.

As described above, even if the eccentric frame 10 is formed from the magnetic plate attracted by the driving magnet 5, the end surface of the eccentric frame 10 is attracted by the driving magnet 5, so that the eccentric frame 10 and the slide bearing are formed. 4 is tilted in a certain direction, and a specific part of the fixed shaft 3 is always a slide bearing 4
Since it contacts the inner peripheral surface of the rotor, the rotor including the eccentric frame 10 and the slide bearing 4 does not flutter during rotation.
Therefore, the lubricating oil retained in the slide bearing 4 is constantly supplied to the portion between the fixed shaft 3 and the slide bearing 4 by the pump action, so that the slide bearing 4 can be smoothly driven to rotate, and the wear of the bearing portion is prevented. It can be suppressed and the life can be extended. Moreover, since the slide bearing 4 is smoothly driven to rotate, the operating noise is reduced, and the deterioration of the current value and the decrease of the vibration amount due to the rotation loss can be eliminated. Further, since the eccentric frame 10 is attracted by the drive magnet 5, the brush (not shown) and the flat commutator 9 slide with a constant pressure, so that the jumping phenomenon of the brush can be eliminated. Further, since the eccentric frame 10 also serves as a magnetic plate attracted to the driving magnet 5, the number of parts can be reduced and the manufacturing cost can be reduced. Further, since the arc-shaped collar portion 10a is provided on the outer peripheral edge of the eccentric frame 10 formed of a magnetic plate, the strength of the eccentric frame 10 is improved, and the eccentricity is increased to increase vibration. . When forming the eccentric frame 10 from the magnetic plate attracted to the drive magnet 5, it may be formed by sintering metal powder containing magnetic powder such as iron.

The flat vibration motor is a shaft fixed type motor, but of course, the rotary shaft that is rotatably inserted in the bearing fixed to the case or the bottom plate and the outer peripheral surface of the rotary shaft. It is also applicable to a shaft rotation type flat type vibration motor consisting of an eccentric frame fixed to the. As shown in FIG. 7, the shaft rotation type flat vibration motor includes a flat cup-shaped case 11, a bottom plate 12 that covers an opening of the case 11, the case 11 and bearings 14 and 14 fixed to the bottom plate 12. ', The rotating shaft 13 inserted through the central hole of the bearing 14, 14', the driving magnet 15 disposed on the case 11 or the bottom plate 12, and the plurality of air-core coils 16 facing the driving magnet 15. And an eccentric frame 17 fixed to the rotating shaft 13 at a position deviated from the center of gravity. The rotating shaft 13
The eccentric frame 17 constitutes a rotor, and a magnetic plate 18 facing a specific end surface of the drive magnet 15 is attached to the rotor. The eccentric frame 17 is used in such an axial rotation type flat vibration motor.
By attaching the magnetic plate 18 to the eccentric frame or forming the eccentric frame 17 itself from the magnetic plate 18, the eccentric frame 17 is attracted by the driving magnet 15 and tilted in a certain direction, and the outer peripheral surface of the rotary shaft 13 is always Bearing 1
The eccentric frame 17 is rotationally driven without fluttering because the eccentric frame 17 comes into contact with a specific portion of the inner peripheral surface of the lug 4, 14 '. Therefore, the lubricating oil held in the bearings 14, 14 'is constantly pumped by the lubricating oil so that the lubricating oil is always retained by the rotating shaft 13 and the bearings 14, 14'.
The rotary shaft 13 and the eccentric frame 17 can be smoothly rotated, and the same effect as in the case of fixing the shaft can be obtained.

[0025]

According to the first aspect of the present invention, the slide bearing and the eccentric frame constitute a rotor, and the rotor is provided with a magnetic plate facing a specific end surface of the drive magnet. It is possible to increase the weight and to obtain a sufficient vibration amount even at low speed rotation. Also, since the magnetic plate is attracted in one direction by the drive magnet, the eccentric frame and the slide bearing are tilted in a certain direction, and a specific part of the fixed shaft is always in contact with the inner peripheral surface of the slide bearing. It is possible to eliminate fluttering of the frame and the slide bearing. In addition, the lubricating oil retained in the plain bearings is constantly supplied to the part between the fixed shaft and the plain bearings by the pump action, so that the plain bearings can be smoothly rotated, preventing wear of the bearing parts and extending the service life. Can be achieved. Further, since the slide bearing smoothly rotates with respect to the fixed shaft, operating noise is reduced, and it is possible to eliminate deterioration of current value and reduction of vibration amount due to rotation loss. Further, since the magnetic plate attached to the end surface of the eccentric frame is attracted by the driving magnet, the brush and the plane commutator slide with a constant pressure, and therefore the jumping phenomenon of the brush can be eliminated. . When the eccentric frame and the magnetic plate are integrally formed and the coil is held by the magnetic plate, the number of parts can be reduced and the manufacturing cost can be improved. Further, the strength can be improved by forming an arc-shaped collar portion on the outer peripheral edge of the magnetic plate.

According to the second aspect of the present invention, the rotating shaft and the eccentric frame constitute a rotor, and the rotor is provided with a magnetic plate facing a specific end surface of the driving magnet. The weight of the frame can be increased, and a sufficient amount of vibration can be obtained even at low speed rotation. Further, since the magnetic plate is attracted by the driving magnet, the eccentric frame and the bearing are tilted in a certain direction,
It is possible to prevent the eccentric frame from fluttering during rotation, because a specific part of the bearing and the outer peripheral surface of the rotating shaft are constantly in contact with each other. Further, since the lubricating oil retained in the bearing is constantly supplied to the portion between the rotary shaft and the bearing by the pump action, the rotary shaft can be smoothly driven to rotate, and the life of the bearing portion can be extended. It will be possible. Further, since the rotary shaft is smoothly driven to rotate with respect to the bearing, operating noise is reduced, and deterioration of current value and reduction of vibration amount due to rotation loss can be eliminated. Further, since the magnetic plate attached to the end surface of the eccentric frame is attracted by the driving magnet, the brush and the plane commutator slide with a constant pressure, and therefore the jumping phenomenon of the brush can be eliminated. . When the eccentric frame and the magnetic plate are integrally formed and the coil is held by the magnetic plate, the number of parts can be reduced and the manufacturing cost can be improved. Further, the strength can be improved by forming an arc-shaped collar portion on the outer peripheral edge of the magnetic plate.

According to the third aspect of the present invention, the eccentric frame and the magnetic plate are integrally formed, and the magnetic plate holds the coil and has an arc-shaped collar portion on the outer peripheral edge. Therefore, the strength of the eccentric frame is improved, and the degree of eccentricity is increased so that the vibration can be increased.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a flat vibration motor according to the present invention.

FIG. 2 is a plan view showing a rotor and a driving magnet of the flat vibration motor of the above.

FIG. 3 is a plan view showing an embodiment of a magnetic plate used in the above flat vibration motor.

FIG. 4 is a sectional view showing an operation example of the above flat vibration motor.

FIG. 5 is a sectional view showing another embodiment of a flat vibration motor according to the present invention.

FIG. 6 is a sectional view showing still another embodiment of the flat vibration motor according to the present invention.

FIG. 7 is a cross-sectional view showing still another embodiment of the flat vibration motor according to the present invention.

FIG. 8 is a sectional view showing an example of a conventional flat vibration motor.

FIG. 9 shows an operation example of a conventional flat vibration motor,
(A) is an enlarged cross-sectional view of a main part, and (b) is a plan view showing an enlarged main part.

[Explanation of symbols] 1 case 2 bottom plate 3 fixed shaft 5 driving magnet 6 air core coil 7 eccentric frame 7a slide bearing 8 magnetic plate

Claims (3)

[Claims] 1. A flat cup-shaped case, a bottom plate covering an opening of the case, the case or a fixed shaft having at least one end fixed to the bottom plate, a slide bearing having the fixed shaft inserted through a central hole, and the case. Alternatively, the air core is provided with a drive magnet disposed on the bottom plate, and an eccentric frame that holds a plurality of air core coils facing the drive magnet and is provided with the slide bearing at a position deviated from the center of gravity. A flat vibration motor in which an eccentric frame generates vibration by energizing a coil, wherein the slide bearing and the eccentric frame constitute a rotor, and the rotor includes only a part of magnetic poles of the drive magnet. A flat type vibration motor having magnetic plates facing each other. 2. A flat cup-shaped case, a bottom plate covering an opening of the case, a bearing fixed to the case and the bottom plate, a rotary shaft inserted in a central hole of the bearing, and arranged on the case or the bottom plate. An eccentric frame is provided which is provided with a drive magnet and a plurality of air-core coils facing the drive magnet, and which is provided with an eccentric frame fixed to a fixed shaft at a position deviated from the center of gravity. A flat type vibration motor in which a frame generates vibration, wherein the rotating shaft and an eccentric frame constitute a rotor, and a magnetic plate facing only a part of magnetic poles of the driving magnet is attached to the rotor. The flat type vibration motor is characterized by 3. The eccentric frame and the magnetic plate are integrally molded, and the magnetic plate holds a coil, and
The flat type vibration motor according to claim 1 or 2, further comprising an arc-shaped collar portion on the outer peripheral edge.