JP3261329B2 - Fixed shaft type motor without output shaft - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output in which a fixed shaft type motor or a pinion without an output shaft is preferably integrated with a rotor, which is suitable as a silent information source of a small wireless communication device (pager, portable telephone) or a vibration source of a massager. The present invention relates to a fixed shaft type motor having no shaft.

[0002]

2. Description of the Related Art Conventionally, a vibration motor having no output shaft, particularly a flat coreless motor has been disclosed in Japanese Patent Application Laid-Open No. 63-290153.
Japanese Patent Application Laid-Open No. 63-111868. These are all shown in FIG.
An eccentric rotor R is disposed in a housing H composed of a bracket 29 and an eccentric rotor R.
The structure is such that it is rotatably supported by oil-impregnated bearings 32 and 33 disposed on the case 28 and the bracket 29 via a shaft 31. Since the eccentric rotor R is fixed to the shaft 31, the housing H
The position is determined by the shaft 31 which is flush with the shaft.

[0003]

However, in the case of the twin bearing type as described above, the coaxiality of the upper and lower bearings becomes important. In the case of a coin-type flat motor having a thickness of about 3 mm, a case,
10μ coaxiality between the fitting part of the bracket and each bearing
The precision of each component is required, for example, it is necessary to keep the accuracy below m. Such a problem should be solved by using a so-called cantilever type bearing in which only one of the bearings is used.However, as can be judged from the thickness of the motor, a soft oil-impregnated bearing has good fixing strength and is practical. However, if the fitting portion of the bearing is lengthened, the fitting margin of the rotor holder fitted to the shaft is shortened, and this also poses a practical problem.

Further, as a vibration motor of a fixed shaft type in which the shaft does not protrude outside the housing, there is one as disclosed in FIG. 1 of Japanese Patent Publication No. 59-14966. However, such a configuration is difficult to assemble because both ends of the shaft are fixed to the bracket as can be determined from the drawings. In other words, when the rotor 12 is mounted on the bearings 5 and 6 mounted on the brackets 2 and 3 via the shaft support brackets 10 and 11, the stator 7 hinders the operation. Cannot be embedded. The bearings 5 and 6 are not attached to the shaft 4 but are unavoidably arranged on the brackets 2 and 3 for the lead wire 9 to be drawn out. Support brackets 10, 11
Since the sliding loss cannot be made as small as that of a shaft, the sliding loss is very large and is not practical.

In order to overcome the above-mentioned problems, the applicant of the present invention does not need to rotate the shaft of a vibration motor having no output shaft that utilizes the vibration of the rotor itself, and furthermore, this shaft is fixed at one end only. Focus on what should be done first
No. 814443 has been commercialized as a fixed-shaft flat coreless vibration motor. Such a motor is easy to assemble the rotor, has excellent cost performance, and is popular in the market. By the way, with the miniaturization of portable equipment, motors that do not require an output shaft, such as threaded geared motors for MD, other than the above-mentioned vibration motors, are increasing in number. And low current consumption. However, as the size becomes smaller, the loss of each part becomes more conspicuous and high efficiency cannot be obtained. That is, it is necessary to minimize the loss between the rotor and the sliding contact portion of the housing that comes into sliding contact with the rotor.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in order to overcome the above-mentioned problems, that is, the rotor and the sliding portion of the housing which is in sliding contact with the rotor are devised to reduce the loss with a simple structure. Another object of the present invention is to provide a fixed shaft motor without an output shaft, which can maintain the reduction of loss for a long period of time and can be easily assembled, and is therefore economically advantageous.

[0007]

The above object can be attained by providing a lubricant holding means at the sliding contact between the rotor and the housing.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides a case (8, 88, 12) and a bracket (1, 11,
A rotor (3, 13) composed of a plurality of armature coils is disposed in a housing (H) composed of B) , a commutator (5, C) is disposed on the rotor, and brushes (7, 77, 78) is brought into sliding contact with the rotor and the magnets (6, 14) are exposed to the rotor through a gap, and the rotor is rotated by incorporating the rotor from the other end of the shaft (2) having one end fixed to a part of the housing. The recesses (8a, 88a, T, 1
2a) The provided so as not to protrude axially outward from the housing, by biasing the rotor in the axial direction shall not in sliding contact with the housing-side around said recess
There was a concentric part of this sliding contact with the shaft and continued in the circumferential direction.
What is necessary is just to provide the lubricant holding | maintenance means which consists of a groove | channel (V) . By doing so, the loss is small, the loss is maintained for a long time, the rotor can be easily assembled, the case and the bracket can be easily insulated, and the thickness can be reduced. Becomes possible. Further, as shown in claim 2, the groove comprises a groove concentric with the shaft and continuous in the circumferential direction.
If the lubricant holding means is provided on the resin body of the rotor or provided on the housing side, it can be easily formed by a mold.

[0009]

First Embodiment A first embodiment of the present invention is applied to a flat coreless vibration motor as shown in FIG. 1, and stands integrally at the center of a bracket 1 constituting a part of a housing H. A thin stainless steel shaft 2 is fixed by press-fitting one end through a raised shaft holder 1a, and a rotor 3 eccentric from an open end is rotatably mounted on the shaft 2. Specifically, the eccentric rotor 3 has three air-core armature coils 3a, 3a, as shown in FIG.
3b and 3c are arranged eccentrically on one side at a pitch of about 60 ° on the back side of the flat plate commutator 5, and are integrally formed with the flat plate commutator 5 connecting the end of each coil with the spark quenching element 4a on the back side with a resin 4 having a low friction coefficient. Molded. That is, the resin 4 itself having a low friction coefficient also serves as a bearing. On the bracket 1, a ring-shaped magnet 6 made of neodymium facing the rotor 3 through a gap is further placed.
A pair of brushes 7, 7 are implanted inside the magnet 6 at a sliding contact opening angle of 90 °, and are brought into sliding contact with the flat plate commutator 5 with an appropriate pressing force.

On the other hand, a case 8 constituting the other part of the housing
Is provided with a tapered through hole 8a in the center of which the other end of the thin stainless steel shaft 2 is mounted, and the periphery of the through hole 8a is crushed to be thin, and the polyester film is provided here. P is pasted through the paste N.
The eccentric rotor 3 is brought into sliding contact with the polyester film P by a pressing force of the pair of brushes 7, 7 via a bank 3d.
Further, a groove V concentric with the shaft and continuous in the circumferential direction is provided, and grease G is embedded in the groove V as a lubricant. For this reason, as described above, the rotor 3 is constantly urged toward the case 8 by the sliding contact pressure of the brush as described above, and is rotatably pressed by the polyester film P. Grease G is used as a lubricant.
Is held for a long time by the groove V.
With this configuration, the rotor 3 that has been prepared in advance is fitted into the bracket 1 that has also been prepared in advance from the open end of the shaft 2, the case 8 is covered, and the opening edge 8b of the bracket 1 Since the outer periphery may be swaged, assembly can be easily performed.

As a modification of the present embodiment, a recessed portion 88a for receiving the other end of the shaft 2 of the case 88 is formed as shown in FIG. Insulation means 11a such as polyethylene terephthalate resin or the like may be formed on the outer periphery of the bracket 11 by outsert molding so as to be insulated from the case 88 during assembly. In this case, the resin 88b having good slidability is concentric with the shaft and is continuous in the circumferential direction.
Grooves V are provided with. In this example, in order to use the case and the bracket as power supply electrodes, one of the brushes 77 is directly soldered to the bracket 11, and the other brush 77 passes under the magnet 6 via the flexible plate F. , Inside the case 88.

In order to form a recess for receiving the other end of the shaft 2 so as to function as an insulator and a slidable member, a case 8 for receiving the shaft 2 as shown in a schematic cross section of a main part of FIG. Is formed to be slightly larger than the shaft 2 so that the other end of the shaft 2 can enter about half of the hole T through a glued polyester film P1 disposed around the shaft. Is also good. In this case, polyester film P1 with glue
It is preferable to crush the perimeter of the through hole T of the case 8 and affix the glued polyester film P1 here so that the thickness and the gap of the motor itself are not sacrificed by the thickness of the motor. In this manner, a configuration in which insulation and slidability are maintained without sacrificing thinness can be obtained.
Therefore, it is needless to say that the present invention can be adopted in the coin battery type.

[0013]

Second Embodiment FIG. 5 shows a cross section of a main part of a second embodiment applied to a shallow cored type flat vibration motor having no output shaft. That is, reference numeral 12 denotes a metal dish-shaped case, and a bracket B is fitted to an opening edge portion thereof. A thin shaft 2 similar to the above is press-fitted and fixed to the bracket B. On the shaft 2, an oil-impregnated bearing J in which a cored rotor 13 formed by winding two eccentric silicon steel plates K in the outer periphery in opposite directions to each other and winding an armature coil 13a is fitted to the shaft 2 is fitted. It is mounted rotatably. A cylindrical commutator C is attached to the rotor 13, and a pair of brushes 7 is provided on a sliding surface of the commutator C.
7 and 78 are slid in contact with each other, and the base thereof is implanted in the bracket B via a brush base 79 made of resin. At the top of the dish-shaped case 12, a resin body formed by outsert molding of a resin having good slidability is arranged, and the other end of the shaft is supported by a recess 12a provided in the resin body at the time of installation. Has become. The groove V continuous in the circumferential direction as described above is provided around the concave portion 12a, and a lubricant such as grease G is held here for a long period of time. The same is true. 14 in the figure
Is a cylindrical field magnet disposed in the rotor 13 with a gap therebetween, and the magnetic center is shifted upward with respect to the center of the rotor 13, whereby the rotor 13 is constantly biased upward. It has become. Therefore, since the rotor 13 is constantly biased in the direction of the slider 15,
There is no possibility that the rotor 13 will fall downward, and the position of the rotor 13 is stabilized.

Instead of the oil-impregnated bearing J, a resin core cover Ka may be extended inward to function as a resin bearing. With this configuration, the rotor can be directly brought into sliding contact with the case ceiling via the resin bearing. Even in such a case, it is needless to say that the groove V continuous in the circumferential direction as described above is provided at a portion where the groove V slides. As another modified example of the second embodiment, it is a matter of course that a battery type using the case and the bracket as electrodes by removing the lead wires and terminals may be used. Further, one end of the shaft may be fixed to the case side instead of the bracket. Also in such an embodiment, since the rotor is at the position where the center of gravity moves in the radial direction, a large centrifugal force is generated during rotation, and the rotor functions as a vibration motor. In each of the above embodiments, the case where the other end of the shaft is held on the case side is shown.
If the strength of fixing the shaft can be obtained, the shaft may be held at only one end, that is, it may not be necessary to provide a through hole on the case side. If you can secure the roughness of the sliding part low by crushing,
Polyester film and the like can be omitted. Also,
In each of the above embodiments, the flat type vibration motor is shown. However, the present invention is not limited to this. Of course, the rotor and the gear, which are a fixed-shaft type normally rotating type, can be integrated into a geared motor. Thus, a cylindrical motor that is long in the axial direction can be used.

[0015]

As described above, according to the present invention, a lubricant such as grease is held by a simple configuration in which a groove concentric with the shaft is provided in one of the sliding contact portions of the rotor and the housing which is in sliding contact with the rotor. can do. Therefore, low current consumption can be maintained for a long time. Also,
Since the rotor is rotatably mounted on the shaft fixed to a part of the housing from the other end, the assembly can be easily performed from one side, which facilitates automation.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a first embodiment of a flat vibration motor having no output shaft according to the present invention.

FIG. 2 is a plan view of the eccentric rotor according to the embodiment.

FIG. 3 is a sectional view of a main part of a modification of the embodiment.

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

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

FIG. 6 is a sectional view of a main part of a conventional flat vibration motor without an output shaft.

[Explanation of symbols]

 1, 11 brackets 2 shafts 3, 13 eccentric rotor 4 resin constituting rotor 5 commutator 6 magnet 7, 77, 78 brush 8, 88 case 11a Insulation means 12 ‥‥ dish-shaped case P ‥‥ polyester film P1 ‥‥ polyester film with glue V ‥‥ groove

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02K 23/58 H02K 5/16 H02K 7/065

Claims (3)

(57) [Claims] 1. A case (8, 88, 12) and a bracket
A rotor (3, 13) comprising a plurality of armature coils is disposed in a housing (H) comprising (1, 11, B) , a commutator (5, C) is disposed on the rotor, and a brush is provided on the commutator. ( 7, 77, 78) in sliding contact,
And a magnet (6, 14) interposed between the rotor and the air gap.
With one end fixed to a part of the housing
The rotor is mounted rotatably by incorporating the rotor from the other end of (2) , and the recess (8) for receiving the other end of the shaft is provided.
a, 88a, T, 12a) to prevent the shaft from protruding outward from the housing, and to urge the rotor in the axial direction around the recess so as to surround the recess.
A shall brought into sliding contact with the housing side circumference, this sliding
A fixed shaft type motor without an output shaft provided with a lubricant holding means comprising a groove (V) concentric with the shaft and continuous in the circumferential direction . 2. A groove which is concentric with the shaft and continuous in the circumferential direction.
2. The fixed shaft type motor without an output shaft according to claim 1, wherein the lubricant holding means is disposed on a resin body of the rotor. 3. A groove which is concentric with the shaft and continuous in the circumferential direction.
The lubricant holding means is provided on the housing side.
The fixed shaft type motor without the output shaft described in 1.