JP2001096500A - Fixing structure for micro-motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing structure for a micro-motor that enables to fix it on a case or the driving unit frame side without using an adhesive. SOLUTION: A male thread part 32 is provided on the outer surface on the output shaft 4 side of a gear box 31 and a female thread part 11c is provided on a driving unit frame 10 in a micro-motor 1 with a reduction gear mechanism. The micro-motor 1 with a reduction gear mechanism is held and fixed on a case or the driving unit frame 10 side screwing the male thread part 32 and the female thread part 11c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure of a micro motor, and more particularly, to a special micro motor having a micro diameter of 3 mm or less, such as a coreless motor and a DC brushless motor, fixed to a housing side, and a base. The present invention relates to a structure for fixing a micro motor, which can be easily fixed to a drive unit frame side and suppresses mounting play at a fixed center position.

[0002]

2. Description of the Related Art A typical example of a field of use of a micro motor having an outer diameter of the order of several mm, such as a cylindrical micro-coreless motor, is a vibration of a vibration generator for silent ringing of a small portable communication terminal such as a mobile phone. Sources are generally known and established. However, in the future, the field of use of extremely small motors will be further reduced in size, and the field of use will shift from coreless motors to DC brushless motors, and from field of portable devices to fields of micromachines. It is considered that the flow will spread to various fields in the future, for example, to a lens driving mechanism at the distal end portion of an endoscope of a medical device or a driving mechanism of a state-of-the-art medical device such as an intrauterine diagnostic treatment apparatus.

FIG. 9 shows a configuration of a miniature motor with a speed reduction mechanism, which is an example of a conventional miniature motor unit.
This will be briefly described with reference to the external appearance schematic diagram of FIG. As shown in FIG. 9, a micro motor with a reduction mechanism generally includes a small driving motor 7 and a gear box 8 attached to a driving shaft of the small motor 7 (not shown in FIG. 9). A structure in which the rotation drive shaft of the motor 7 is reduced in speed and transmitted to the output shaft 4 at the other end of the gear box 8 via a planetary gear mechanism (not shown in FIG. 9) inside the gear box 8. It has become.

[0004]

In recent years, the smallest motor unit represented by the smallest motor with a reduction mechanism described above has an outer diameter of several mm size (substantial diameter of 5 mmφ or less).
And the area of the flat portion on the cylindrical end of the housing case or gear box of the motor exterior becomes smaller, for example, 10 mmφ.
Like a normal size motor, a plurality of female screw mounting holes (screw holes M shown in FIG. 9) provided on the housing case side end flat surface through a part of the hole on the drive unit frame side. It is no longer possible to adopt a mounting and fixing structure in which small diameter screws are screwed together and fixed integrally.

[0005] For this reason, in many cases, an organic adhesive or spot welding which is advantageous in terms of space rather than mechanical is fixed to a housing or a drive unit frame by using an adhesive or the like. If the attached micro motor is adhered to a fixed object (for example, a housing or a drive unit frame) on the base side, the adhesive flows into the components (particularly, the inside of the gear box) during the adhesive filling process, thereby impairing the operation function. In addition, there has been a problem that the organic adhesive may fall off from the fixed object when a large amount of driving is applied during operation due to a temporal change due to heat after bonding.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fixing structure of a micro motor which can be securely fixed to a housing or a drive frame without using a fixing medium such as an adhesive.

[0007]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, as a fixing structure for attaching a micro motor to a housing or the like of a device, the motor is mounted on a housing or a drive unit frame side. A female screw portion is formed at an attachment position, and at least one end of the housing case on the motor side has a cylindrical shape, and is screwed to the female screw portion at least on a drive shaft end portion side of an outer peripheral surface of the cylindrical shape portion. A male screw region is formed, and the female screw portion and the male screw portion are combined, and the motor is screwed to the housing or the drive unit frame side to be mechanically held and fixed.

According to the first aspect of the present invention, by screwing the male screw portion to the female screw portion, even when the micro motor is on the order of several mm in size (particularly, a diameter of 3 mmφ or less). The micro motor can be easily fixed to the mounting position of the housing or the drive unit frame. Therefore, it is not necessary to use an adhesive or the like when fixing to the housing or the drive unit frame side, so that the micro motor does not have a risk of a malfunction of the speed reduction mechanism due to the adhesive entering during the adhesive filling operation. In addition, reliability and yield are improved without deterioration due to aging.

[0009] Further, since the time for drying and curing the adhesive is not required, the time required for the step of mounting the micro motor is also reduced, and it is not necessary to confirm the reliability test such as positional deviation and adhesive strength during drying and curing. In addition, the mounting and fixing work can be simplified. Furthermore, because of the mounting structure by the screw mechanism, it is relatively free to attach and detach, and repair and replacement can be easily performed.

Here, as the housing or the drive unit frame, for example, an outer housing portion of an electronic device itself, a frame such as a drive unit frame including detailed components inside the device, a printed circuit board part of a circuit unit, or the like is used. It is possible, but of course,
It is possible to apply any other thing which becomes a mounting base part. In addition, as examples of the application of the model of the micro motor, a micro coreless motor, a DC brushless micro motor, and a driving motor of another micro size can be used.

The structure of the structure for fixing the micro motor according to the first aspect of the present invention is more specifically, for example, as described in the second aspect, as the ultra-small motor, the drive shaft of the motor is provided on the drive shaft side of the motor. A configuration may be employed in which a reduction gear mechanism (for example, a planetary gear mechanism) for changing the rotation speed is provided, and a cylindrical gear box (for example, a gear box with a screw) into which the reduction mechanism is inserted is used as the cylindrical portion of the micro motor.

In addition, a stator side bearing portion for rotatably holding the micro motor drive shaft is projected from the housing case side end surface of the micro motor body to be protruded.
This bearing part itself may be used as the male screw part of the cylindrical part described above, or conversely, it may be a role of a fitting part as a cylindrical large diameter part of the cylindrical part, that is, a positioning part of a fixed center position. .

According to a third aspect of the present invention, there is provided a micro motor fixing structure according to any one of the first to second aspects, wherein the cylindrical case has a male case excluding a male screw region. A part of the outer peripheral surface of the cylinder is defined as a cylindrical large-diameter portion, which is abutted against the inner peripheral surface of a cylindrical mounting hole provided with a female screw portion of the housing or the drive unit frame, that is, the male screw portion is formed of When screwed into the screw portion, in the range opposed to the combination with the cylindrical large diameter portion of the cylindrical outer peripheral surface,
By fitting and fitting with the outer peripheral surface of the cylindrical large-diameter portion, the mounting play at the fixed center position of the micro motor is minimized,
The positioning structure is adopted.

In general, in a structure in which a female screw and a male screw are screwed into each other to fix an object to each other, since there is usually a small fitting gap between both screw sliding portions, the male screw is The accuracy of the fixed center position on the side is not sufficiently high just by screwing. On the other hand, in a structure in which a cylindrical hole having a perfect circular shape is combined with a cylindrical insert that is also a perfect circular shape, the accuracy of the position and diameter of the hole, or the accuracy of the diameter of the cylindrical member, is generally Tolerance 5
A relatively high accuracy of about 10 μm can be obtained.

Therefore, according to the structure of the third aspect,
The cylindrical housing case or threaded gear box of the micro motor is not only screwed but also fitted and fitted with precision as described above with respect to the inner diameter position of the inner peripheral surface of the cylindrical hole on the mounting side. , Can be arranged at the fixed center position without play.

According to a fourth aspect of the present invention, there is provided an extremely small motor fixing structure for fixing an extremely small motor (for example, an extremely small motor 5 with a speed reduction mechanism) shown in FIG. 8 to a housing or a drive unit frame (10). For example, an arc-shaped cylindrical hole (11) is provided in the drive unit frame, and at least one end of the micro motor is a cylindrical part (for example, a housing case 21), and a male screw is formed on at least one end of the outer peripheral surface of the cylindrical part. Department (22)
And further, as shown in the figure, the diameter of the joint portion of the cylindrical portion near the reduction mechanism 3 side is adjusted to the drive unit frame.
The diameter of the circular cylindrical hole of (10) is larger than that of the cylindrical male screw part as the stopper step D (for example, a step that fits in the gear box 31).
After inserting the (22), the gear box (31) is fitted into the stepped portion L, and the male screw portion is provided with a female screw portion (for example, The nut 13) is screwed to hold and fix the micro motor to the drive unit frame.

According to the fourth aspect of the present invention, the micro motor is attached to the drive frame on the base fixing portion side without using an adhesive by the mechanical fixing means of the bolt and nut. Can be. At the same time, since no curing time for the adhesive is required, the time required for the mounting process can be shortened. In addition, as shown by a symbol D in FIG. 8, a contact portion (the stopper step portion) between the outer peripheral surface of the cylindrical portion and the large inner peripheral surface of the cylindrical hole portion of the drive unit frame is set. Thus, the play at the fixed center position of the micro motor can be suppressed, and the positional accuracy can be sufficiently improved.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS <First Embodiment> Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. The structure will be described in detail. FIG. 1 shows a micro motor 1 with a speed reduction mechanism.
FIG. 2 is a schematic view showing a cross section of a part of the speed reduction mechanism. Also, FIG.
FIG. 4 is a schematic side sectional view illustrating a configuration of a mounting hole portion of the drive unit frame 10 on the side to be mounted, and FIG. 4 is a diagram illustrating a state where the micro motor 1 with a speed reduction mechanism is held and fixed to the drive unit frame 10.

FIGS. 1 and 2 show a micro motor 1 with a speed reduction mechanism.
As shown in FIG.
mm DC brushless motor) and a cylindrical reduction mechanism 3 fixed to an end of the motor on the drive shaft side. This is a drive unit with a speed reducer that reduces the speed by the gear mechanism 3a and finally outputs power from the output shaft 4 of the gear box 31 to the outside.

The structure of the micro motor with a speed reduction mechanism is as follows.
It has substantially the same component configuration as that represented by the conventional micro-coreless motor, and also has an internal configuration of the planetary gear mechanism 3a in the gear box 31 and a gear box 31 on the output shaft side for holding the output shaft 4. The arrangement of the bearing 4a provided on the end side is also substantially the same as that of the known planetary gear mechanism speed reducer.

On the other hand, the gear box 31 (cylindrical integral member) of the speed reduction mechanism 3 of the present invention has the internal gear of the planetary gear mechanism 3a on the inner peripheral surface and the output shaft side on the outer peripheral surface of the cylinder. An external thread portion 32 is provided in a region of a constant width, and a large-diameter cylindrical portion 33 that maintains a smooth circumferential cylindrical surface is partially left on the outer peripheral surface on the other end side of the outer peripheral surface.

The drive unit frame 10 may be a part of a frame part of the drive unit or a part of a block wall at a separated mounting position inside the housing, but structurally as shown in FIG. On the base surface side on the introduction side of the gear box 31, a fitting step portion 11d having an inner diameter substantially the same as the outer diameter of the cylindrical large diameter portion 33 of the gear box 31 is provided. It is provided so as to penetrate the base of the drive unit frame 10 up to the point where it penetrates through 11.

That is, on the inner peripheral surface of the cylindrical hole 11, there is provided a female screw portion 11c which is screwed and fitted in a part of the male screw portion 32 on the outer periphery of the gear box 31 or in a slightly longer region. At the same time, at the end of the inner peripheral surface on the introduction side of the cylindrical hole 11, a fitting step portion 11d is fitted with a cylindrical large diameter portion 33 of the gear box 31 with a diameter slightly larger than the female screw portion 11c. It is formed while leaving the outer peripheral side surface of the cylindrical portion.

As shown in FIG. 4, the ultra-small motor 1 with a reduction mechanism and the drive unit frame 10 having such an arrangement structure by fitting and fitting are provided with a male screw part 32 on the gear box side.
And the female screw portion 11c on the drive unit frame side, the output shaft 4 is arranged and fixed in a state where the output shaft 4 is rotatably projected outward from the cylindrical hole 11.

Here, the fitting step portion 11d on the inner diameter side of the cylindrical hole 11 and the large-diameter cylindrical portion 33 of the gear box 31 are fitted and fitted to each other with substantially the same diameter dimension. The large-diameter cylindrical portion 33 comes into contact with the fitting step portion 11d at the end of the inner peripheral surface of the cylindrical hole 11 to suppress the play of the center displacement of the screw structure of the male screw portion 32 and the female screw portion 11c. Therefore, the error of the fixed center position accuracy with respect to the mounting position of the micro motor 1 with the speed reduction mechanism to the drive unit frame 10 is approximately 5 to 10 μm in tolerance by fitting and fitting, and the accuracy is sufficiently high.

Further, the extremely small motor having the speed reduction mechanism can be directly fixed by mechanical screwing, and the fitting step portion 11 can be fixed.
Since d receives the large-diameter step portion 31a of the gear box 31, the minimal motor 1 with the speed reduction mechanism can be reliably inserted into the cylindrical hole 11 to a certain depth. The height of the projecting dimension from the base portion can always be controlled to be constant.

The structure of this embodiment may be modified as shown in FIG. That is, as another example of the present invention, without providing the male screw portion 32 in the gear box, the bearing 4a is protruded from one end of the gear box 31, and the outer peripheral portion of the protruded bearing 4a is threaded to form a male screw portion. 34 is provided directly and a cylindrical hole
A similar internal thread 11c may be provided on the inner diameter side of 11, and these may be screwed together.

Also in this case, since the outer peripheral surface on the gear box 31 side is in contact with the inner peripheral surface of the cylindrical hole 11 on the base side, the precision of the fixed center position of the micro motor 1 with the speed reduction mechanism is the same as in the previous embodiment. Can be secured.

<Second Embodiment> Next, referring to FIGS. 6 and 7, a description will be given of a mounting structure for fixing an extremely small motor 5 with a speed reduction mechanism to a drive unit frame 10 according to a second embodiment of the present invention. . FIG. 6 is a schematic external view illustrating the configuration of the micro motor 5 with a speed reduction mechanism. FIG.
FIG. 2 is a schematic diagram illustrating a state in which is fixed to a drive unit frame 10.

The micro motor with speed reduction mechanism 5 has substantially the same component structure as the micro motor with speed reduction mechanism 1, but the male screw portion is not provided on the gear box 31 side of the speed reduction mechanism 3, but the motor on the side of the micro motor 2 is reduced. The male screw portion 22 is provided on the outer periphery of the housing case 21.

The external thread portion 22 is threaded over a predetermined length or the entire length from the other end of the outer peripheral surface of the housing case 21 of the DC brushless motor, for example. It is set thinner than the diameter.

In the present embodiment, the cylindrical hole of the drive unit frame 10 is provided so as to extend substantially straight through the drive unit frame 10, and the female screw portion 11c is provided over the entire inner peripheral surface of the cylindrical hole. ing.

As shown in FIG. 7, the ultra-small motor 5 with the speed reduction mechanism having the above-described structure is configured such that the male screw portion 22 of the motor housing case 21 is screwed into the female screw portion 11c to drive the frame. Since it can be fixed directly to the side 10, there is no need to use an adhesive or the like at the time of fixing, and the gear box 31 is
Because of the larger diameter, the micro motor 5 with the speed reduction mechanism is stopped without being screwed more than necessary.

For example, as shown in FIG.
The inner peripheral surface of the cylindrical hole 11 is not provided on the inner peripheral surface of the cylindrical hole 11 without the female screw portion 11c as shown in FIG. It is good also as a structure made to contact in the state fitted. in this case,
After inserting the housing case 21 into the cylindrical hole 11, a nut 13 (fixing member) having a head outer diameter larger than the cylindrical hole 11 is screwed into the male screw portion 22 on one end side, and tightened and fixed. It is also possible to screw and fix the micro motor 5 with the speed reduction mechanism to the drive unit frame 10 with a nut-like member (nut 13).

In this case, since the inner peripheral surface of the cylindrical hole 11 and the outer peripheral cylindrical portion 21a of the housing case 21 are fitted and abutted to each other in a fitted state, the fixed center of the extremely small motor 5 with the speed reduction mechanism with respect to the drive frame 10 is fixed. The position accuracy is sufficiently high.

Note that the present invention is not limited to the above-described two embodiments, and the configuration may be arbitrarily modified without departing from the gist of the present invention. For example, in the micro motor 5 with a speed reduction mechanism, the micro motor 2 without the speed reduction mechanism 3 is provided.
May be used alone. In this case, the outer diameter of one end of the housing case 21, that is, the end of the housing case having the drive shaft is increased, and
May be set.

Also, in the micro motor 1 with a speed reduction mechanism, the external thread 22 may be provided on the housing case side of the motor at the same time. Further, the structure of the gear box 31 of the micro motor 1 with the speed reduction mechanism may be modified. Alternatively, the configuration in which the diameter of the portion where the male screw portion 32 is not provided is reduced may be reversed.

[0038]

According to the micro motor according to the first, second, and fourth aspects, the micro motor is directly fixed to the housing or the drive unit frame by using screws without using an adhesive. It can be used and can be freely attached and detached. Therefore, the minimal motor with the reducer or the minimal motor alone does not have a danger of causing a malfunction due to a flow of a liquid component such as an adhesive or a generated gas into the drive system at the time of mounting and fixing work. The fixing work can be simplified by the combination of positioning by fitting and male and female screws,
The yield is improved and the fixing strength is dramatically improved as compared with the adhesive fixing.

According to the third aspect of the present invention, in addition to being able to be screwed and fixed by the same fixing method as that of the extremely small motor according to the first and second aspects, the installation of the extremely small motor can be performed, for example, with a tolerance of 5 to 10 μm. It can be positioned and fixed at the fixed center position with high accuracy within the error range.

[Brief description of the drawings]

FIG. 1 is a schematic external view illustrating the configuration of a micro motor with a speed reduction mechanism according to a first embodiment of the present invention.

FIG. 2 is a schematic view of a partial cross section showing a structure of a planetary gear portion of the micro motor having a speed reduction mechanism.

FIG. 3 is a schematic sectional view for explaining a mounting hole structure of a drive unit frame used in the first embodiment of the present invention.

FIG. 4 is a schematic diagram illustrating a state in which a micro motor with a speed reduction mechanism is fixed to a drive unit frame in the present embodiment.

FIG. 5 is a schematic diagram of a partial cross section for explaining another example (modification) of the present embodiment.

FIG. 6 is a schematic diagram illustrating a configuration of a micro motor with a speed reduction mechanism used in a second embodiment of the present invention.

FIG. 7 is a schematic diagram illustrating a state in which a micro motor with a speed reduction mechanism is fixed to another drive unit frame in the present embodiment.

FIG. 8 is a schematic diagram illustrating a state in which the minimal motor with a speed reduction mechanism is fixed to another drive unit frame in the present embodiment.

FIG. 9 is a schematic front view and a side view illustrating the configuration of a conventional small motor with a speed reduction mechanism.

[Explanation of symbols]

 1,5 Miniature motor with reduction mechanism 2 Miniature motor 3 Reduction mechanism 3a Planetary gear mechanism 4 Output shaft 6 Small motor with reduction mechanism 7 Small motor 8 Gear box 10 Drive frame 11 Cylindrical hole 11c Female thread 11d Fitting step 13 Nut (fixing means) 21 Housing case 21a Outer surface cylindrical part 22 Male screw part 31 Gear box 31a Large diameter step part 32 Male screw part 33 Cylindrical large diameter part 34 Male screw part

Claims (4)

[Claims] 1. A fixed structure for mounting a micro motor to a housing or the like of a device, wherein a female screw portion is formed at a mounting position of the motor on a housing or a drive unit frame side. At least one end has a cylindrical shape, and at least the drive shaft side end of the outer peripheral surface of the cylindrical portion is formed with a male screw region to be screwed with the female screw, and the male screw is formed on the female screw. A fixing structure for a micro motor, wherein the motor is mechanically held and fixed to a housing or a drive unit frame by screwing. 2. The fixing structure of a micro motor according to claim 1, wherein the micro motor has a speed reduction mechanism at a drive shaft side end of the motor to change the speed of rotation of the drive shaft. At least one end of the gear case side, which is integrally fixed and further into which the reduction mechanism is inserted, has a cylindrical shape, and at least the output shaft side end of the outer peripheral surface of the cylindrical portion has a male screw portion region screwed to the female screw portion. A micro motor with a speed reduction mechanism, wherein the micro motor having the speed reduction mechanism is mechanically held and fixed to a housing or a drive unit frame by forming and screwing the male screw section to the female screw section. Fixed structure. 3. The fixing structure for a micro motor or a micro motor with a reduction gear according to claim 1, wherein a part of a housing case other than a male screw portion region of the cylindrical portion or one of a gear case. The outer peripheral portion of the cylinder is a large-diameter cylindrical portion, and the male screw portion of the contact portion with the inner peripheral wall surface of the mounting cylindrical hole provided with the female screw portion of the housing or the drive unit frame is the female screw. By being fitted and fitted to the outer peripheral surface of the cylindrical large-diameter portion at a portion that is combined with and opposed to the cylindrical large-diameter portion of the cylindrical outer peripheral surface when screwed into the screw portion,
A fixed structure of a micro motor, wherein a precision of a fixed center position of the micro motor is improved. 4. A motor fixing structure for fixing an extremely small motor or an extremely small motor with a speed reducer to a base such as a housing or a drive unit frame, wherein an arc-shaped hole is formed in the housing or the drive unit frame. On the other hand, at least one end of the cylindrical portion of the micro motor is a cylindrical small diameter portion, and an area not less than the thickness of the cylindrical hole on the base portion side from at least the end of the outer peripheral surface of the cylindrical small diameter portion. A male screw portion is formed, and the diameter of the cylindrical small diameter portion near the housing case or gear case side is made larger than the diameter of the cylindrical hole to form a stopper step portion, and further the housing or the drive unit frame side is formed. In a state where the cylindrical small-diameter portion on the side of the extremely small motor is inserted into the arc-shaped hole, a fixing member having a female screw portion is screwed into a male screw portion of the cylindrical small-diameter portion, and the casing or the drive unit frame side In the arc-shaped hole of Fixing structure of minimum motor, characterized by screwed through insert some over data cylindrical small-diameter portion.