JPH1066302A - Small-sized motor device in rotation driving mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove the cause of noise and obtain a smooth rotation and constant output torque by aligning the shaft center of a rotor iron core to that of a rotor when pivoting the rotor on the stator iron core. SOLUTION: A small-size motor device is provided with a stator assembly 11, a rotor assembly 31, a shaft pressurizing means 41, and an outer case 61. The stator assembly 11 is made by outserting stator iron cores 12a, 12b and then resin-molding bobbins 13a, 13b and a bearing end plate 15, which closes output-side end faces of the stator iron cores and then forms a bearing section 16, into an integral unit, with a non-output side end face of each stator iron core being kept opened, and then winding exciting coils 21a, 21b around the bobbins. The rotor assembly 31 which, having a rotor 32, a rotor shaft, and a lead screw 34 which is an extension of an output side of the rotor shaft at the end of it, is set in the stator iron cores and has it shaft being pivoted by the bearing. The shaft pressurizing means 41 presses the rotor shaft in the shaft direction. In the outer case 61, the shaft pressurizing means and the rotor assembly which pivots the rotor assembly are inserted through an opening and are installed in order. The end of the lead screw 34 is so designed as to be pivoted at the rotation driving mechanism side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small motor device in a rotary drive mechanism, and more particularly, to an improvement in a small motor device applied to focusing in a lens zoom mechanism of a normal video camera or a digital video still camera. It is related to.

[0002]

2. Description of the Related Art Generally, in a video camera, a lens zoom mechanism for variably adjusting a lens magnification is driven by a small-sized motor capable of rotating forward and backward when taking an image. More specifically, the output of the rotor shaft extended through the one end flange portion after holding the small motor incorporated in the outer case against the outer surface of the one end side flange portion of the board bracket. The distal-end-side lead screw is pivotally supported on the inner surface of the other-end-side flange portion, and the rotor shaft is resiliently pressed by the elastic force of a pressing spring piece disposed on the base end side of the rotor shaft in the outer case. The actuator is pressurized in a thrust direction (axial direction), and further, for example, an operating piece that is prevented from rotating by a guide rod or the like is screwed into the lead screw, and the operating piece is connected to a lens zoom mechanism, and the compact size is formed. By selectively rotating the lead screw in either the forward or reverse direction with the driving of the motor, the operation piece is advanced or retracted, and the zoom operation of the lens zoom mechanism is performed. Than is allowed.

[0003] In this type of video camera, in many cases, the peripheral audio is recorded simultaneously with the imaging of the scene while performing the zoom operation of the lens zoom mechanism by driving a small motor. Therefore, it is necessary to avoid various noises inevitably generated by driving the small motor as much as possible, and on the other hand, to further reduce the size of the entire apparatus and simplify the manufacturing process. There is also a demand for an increase in motor torque itself in accordance with the ease of assembling work.

[0004]

However, in the case of the conventional small-sized motor device having the above-mentioned structure, the rotation of the rotor with respect to the stator iron core is reduced in order to reduce the precision accompanying the miniaturization of the entire device. Is not always good, and since the bearing end plate is caulked and fixed to the open end face of the outer case incorporating the stator iron core and the rotor, the core deflection accompanying the caulking, that is, It is easy to be eccentric because the shaft support form on the shaft core collapses, and this eccentric shaft support causes a so-called wobbling phenomenon. At the same time, there is an inconvenience that an unbalanced load applied to the bearing portion causes a backlash of the pivot and causes a frictional noise and a vibration noise.

[0005] Further, the mounting mode of the presser spring piece for pressing the rotor shaft of the small motor in the thrust direction (axial direction) is such that the presser spring piece is pressed into the outer case by light press-fitting into the outer case with a required fitting dimension. Due to the structure that only suppresses the floating property and backlash of the spring piece, the vibration between the outer case and the presser spring piece is caused mainly by the rotational vibration of the lead screw accompanying the driving of the small motor. Noise such as noise and fricative noise may be generated. In other words, with respect to the variation in the inner diameter of the outer case, if the size of the holding spring piece itself is about the plate thickness, the amount of the variation cannot always be effectively absorbed and noise will be generated. Since unnecessary stress is applied to the entire presser spring piece, the spring shape also changes, which may cause a change in spring pressure and, consequently, a change in motor torque.

Further, there is a disadvantage that the steps of manufacturing and assembling are complicated in response to the miniaturization of the apparatus configuration, and the work is not always easy.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem.
Incorporating resin-integral molding into the structure of the small motor itself, making the rotor pivotal support for the stator iron core accurate on a common shaft core for both, effectively eliminating the cause of noise generation, and An object of the present invention is to provide a small-sized motor device in a rotary drive mechanism which is simple in structure and is easy to manufacture and assemble so as to always obtain smooth rotation and constant output torque.

[0008]

According to a first aspect of the present invention, there is provided a small-sized motor device for a rotary drive mechanism according to the present invention, wherein a cylindrical stator iron core is inserted in an axial direction. In this state, a bobbin portion is arranged around the stator iron core by a resin material, and an output side end face is closed by a bearing end plate portion forming a bearing portion on the shaft core line,
A stator molded body integrally molded with resin so that the non-output side end face is opened, and a stator assembly in which an exciting winding is wound around a bobbin portion, and a little larger than the inner diameter of the stator iron core It has a rotor that has a small outer diameter and is magnetized in the required form,
A rotor assembly in which a lead screw is extended to an output side of a rotor shaft for fixing the rotor on a shaft center line, and a shaft pressing means provided with a pressing spring piece for pressing the rotor shaft to the output side A shaft pressurizing means and a stator assembly are sequentially mounted from the opening side, and the rotor assembly is mounted inside a stator iron core. And an outer case that presses a rotor shaft pivotally supported by the bearing portion with a pressing spring piece to house the rotor shaft and pulls a lead screw to an output side to hold the rotor shaft. Is characterized in that the tip of the output-side lead screw can be pivotally supported by a rotary drive mechanism.

In the small motor device according to the first aspect of the present invention, as a stator assembly, a bearing end plate portion for closing a bobbin portion and an output side end portion is provided in a state where a stator iron core is outsert. Since the molding is performed, the configuration of the stator assembly is simplified, and the bearing portion for the stator iron core is accurately positioned on the same common shaft core. Also, after the shaft pressing means and the stator assembly are sequentially mounted in the outer case and the rotor assembly is inserted, the lead screw extension end side of the rotor shaft is pivoted to the bearing portion. By supporting and installing the rotor shaft, the supporting state of the rotor shaft with respect to the stator core is accurately regulated, and the non-output side end of the rotor shaft is connected to the output side by the pressing spring piece of the shaft pressing means. Pressed,
Further, the entire device can be easily assembled by pivotally supporting the tip of the output side lead screw of the rotor shaft by the rotation drive mechanism. And, in the aspect assembled as described above,
The rotor assembly can be effectively supported on the stator assembly on the same axis without causing runout, and the rotor assembly is pressed in the thrust direction with a constant elastic force by the pressing spring piece. As a result, the cause of noise generation is eliminated as expected, and smooth rotation and constant output torque can always be obtained.

According to a second aspect of the present invention, there is provided a small-sized motor device in the rotary drive mechanism according to the first aspect, wherein the shaft pressing means includes an insert base plate, and the insert base plate. A pressing spring member including a pressing spring piece cut and raised to the pressing surface side including the center portion of the pressing spring member, and the insert base plate portion is inserted into a vibration-absorbing resin body member to be integrated therewith. It is characterized by being resin molded.

According to the second aspect of the present invention, the insert base plate portion of the presser spring member is inserted into a resin body member having a vibration absorbing property and is integrally molded with the resin, and the presser spring piece is inserted from the insert base plate portion. Since the portion is protruded, the vibration applied to the pressing spring piece is effectively absorbed by the resin body member.

According to a third aspect of the present invention, there is provided a small-sized motor device in the rotary drive mechanism according to the second aspect, wherein the resin main body member of the shaft pressing means is provided on the non-pressing surface side with the outside. It is characterized in that it has a spacer portion for appropriately separating from the inner end surface of the case.

According to the third aspect of the present invention, the area of contact of the resin main body member with the inner end surface of the outer case is reduced by the spacer portion, and transmission of rotational vibration to the outer case is effectively suppressed.

According to a fourth aspect of the present invention, there is provided a small-sized motor device in the rotary drive mechanism according to the first aspect, wherein the bearing portion has an oil groove or the like capable of holding lubricating oil on an inner surface of the bearing. It is characterized by having lubrication means.

In the small motor device according to the fourth aspect, the rotor assembly can be smoothly rotated by lubrication means such as an oil groove provided in the bearing portion.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a small motor device in a rotary drive mechanism according to the present invention will be described in detail with reference to FIGS.

FIG. 1 is a longitudinal sectional view showing a schematic configuration of an entire small motor device to which an embodiment of the present invention is applied.
2 (a) and 2 (b) are a vertical sectional view and an end view showing a stator assembly of the small motor taken out. Further, FIG. 3 is a front view showing the shaft pressurizing mechanism taken out, FIG. 4 is a vertical sectional view taken along line AA of FIG. 3, and FIG.
FIG. 3 is a front view showing a pressing spring member inserted into the shaft pressing mechanism.

In the embodiment shown in each of these figures,
The small motor device has a forward / reverse rotatable small motor 10 serving as a driving source.
A stator assembly 11 and a rotor assembly 31 which are integrally formed, and an outer case 61 which accommodates the stator assembly 11 via a shaft pressing mechanism 40 and houses the rotor assembly 31 therein. In this case, the rotor case 31 is separately fixed and held, and the rotor assembly 31 which is pressed in the thrust direction (axial direction) by the shaft pressing mechanism 40 is used as a bearing pivot. A supporting substrate bracket (corresponding to the rotation drive mechanism) 71 is provided.

The stator assembly 11 is shown in FIG.
As shown in (b), two stator iron cores 12a and 12b which are cylindrically arranged in the axial direction and are arranged side by side in such a manner that the magnetic pole parts are shifted from each other are provided, and the respective stator irons Core 12
a, 12b, the non-output side end faces of the stator cores 12a, 12b (corresponding to the left end side in FIG. 2 (a)) are left open, and the bobbin portions 13 around the outer periphery are opened.
a, 13b and the terminal extraction portions 14a, 14b on the peripheral flanges of the bobbin portions 13a, 13b, and the output side end faces of the stator cores 12a, 12b (corresponding to the right end side in FIG. 2 (a)). ) Is closed, and each of the bearing end plate portions 15 forming the pivot shaft hole 16 on the axis of the shaft is integrally formed by resin molding. Here, for the pivot shaft hole 16, a plurality of oil grooves (not particularly shown) or the like capable of holding the lubricating oil are formed on the inner surface of the bearing in order to smoothly rotate. preferable.

Therefore, each stator core 12a,
When the stator assembly 11 is formed by integrally molding the bobbin portions 13a and 13b including the 12b and the bearing end plate 15 for closing the output side end face, the stator iron core 12a,
The pivot shaft hole 16 for the shaft 12b is accurately positioned on the same common shaft center, so that the shaft pivot of the rotor assembly 31 described below can be satisfactorily and effectively performed. The gap between the cores 12a, 12b and the rotor of the rotor assembly 31, that is, the so-called air gap, can be assembled to a minimum. Can be easily achieved and the motor torque can be easily increased.

Exciting windings 17a and 17b are wound around the bobbin portions 13a and 13b integrally formed with the stator iron cores 12a and 12b, respectively. Each terminal 18a having the winding start end and the winding end end implanted in the terminal extraction portions 14a, 14b,
18b.

The rotor assembly 31 has an outer diameter slightly smaller than the cylindrical inner diameter of each of the stator cores 12a, 12b by an amount corresponding to the air gap.
A rotor 32 composed of a magnet having an axial length within an effective range extending therebetween and magnetized in a required form;
2 is constituted by a rotor shaft 33 that penetrates and fixes the shaft 2 on a shaft core line, and a lead screw 34 that serves as an output shaft by extending the output side at the tip end of the rotor shaft 33. Spherical convex surface 3 with concentric non-output end
3a, and the tip end of the lead screw 34 is similarly formed as a concentric spherical concave surface 34a.
Then, the rotor assembly 31 is, as described above,
The rotor 32 is fitted and inserted into each of the stator cores 12a and 12b, and the extension side of the lead screw 34 of the rotor shaft 33 is pivotally supported by the pivot shaft hole 16 so as to be lead screw. By pulling out 34 to the output side, a motor main part is constituted.

In the case of this embodiment, the shaft pressing mechanism 41 includes an insert base plate portion 43 and a center portion of the insert base plate portion 43, as shown in FIGS. A pressing spring member 42 is provided which includes a pressing spring piece portion 47 which is protruded by applying a required elastic force by cutting and raising the pressing surface side at a required angle. The central portion of the presser spring piece 47 other than the cut-and-raised portion is cut into the cutout 44 over a required range, and at the right place on the plate surface, in this case, both left and right directions parallel to the presser spring piece 47. Each protruding part 45 and each hole part 46 for insert connection are formed on the edge and the back surface of the plate surface part in the vertical direction, respectively. The presser spring member 42 includes an insert base plate 43 excluding the presser spring piece 47 and the hole 46.
Are inserted into a resin body member 51 having a vibration-absorbing property and molded into a resin, so that the whole of them is integrally formed. Further, the non-pressing surface side of the resin body member 51 (the cut and rise In this case, a spacer portion 52 composed of a hemispherical convex portion is protrudingly provided at an appropriate position on the surface side opposite to the side (in this case, at an equiangular interval). The spacer 52
Alternatively, for example, a ring-shaped rib portion or the like may be protruded.

The outer case 61 has a cylindrical shape with a bottom and an open end on the output side, and each terminal take-out portion 14a, 14b of the stator assembly 11 is opened from the open end surface.
A notch 62 for receiving the small motor 10 is cut out to form an outer casing of the small motor 10. That is, with respect to the outer case 61, the shaft pressing mechanism 41 and the stator assembly 11 that incorporates the rotor assembly 31 and are pivotally supported in order from the opening end face side toward the inside. In this state, the spherical convex surface 33a formed on the non-output side end of the rotor shaft 33 is brought into contact with the pressing spring piece 47 of the pressing spring member 42, and is axially mounted. (Thrust direction) While being pressed against the output side with a predetermined resilient force, the lead screw 34 serving as the output shaft is projected to the outside to substantially constitute the small-sized motor 10.

In this case, the substrate bracket 71 serving as the rotation drive mechanism is made of a pair of flange portions 72a, 7a facing each other by using, for example, a vibration absorbing plate material such as a vibration damping plate.
2b, a center opening 73a for receiving the lead screw 34 protruding to the outside of the small motor 10 is formed concentrically with respect to the flange portion 72a on one end side, and A center opening 73b for receiving and holding a bearing member 74 with a separately provided bearing recess (corresponding to a bearing on the rotation drive mechanism) 75 is similarly formed on the flange portion 72b. Here, it is desirable that the bearing concave portion 75 retain lubricating oil on the inner surface corresponding to the bearing in order to smoothly rotate. For example, the bearing concave portion 75 is formed in a normal bearing portion form. In some cases, a plurality of oil grooves or the like may be formed on the inner surface of the bearing.

Here, in the case of this embodiment, as apparent from FIG. 1, first, as described above, the shaft pressing mechanism 41 and the rotating The stator assembly 11 having the child assembly 31 pivotally supported therein is sequentially assembled and mounted. At this time, the shaft pressing mechanism 41 is provided on the inner peripheral surface of the outer case 61 with a resin body having a vibration absorbing property. It is non-movably fitted via the member 51 and is indirectly contacted with the inner end face of the outer case 61 via the respective spacer portions 52. In other words, the vibration transmission to the outer case 61 through the contact surface is suppressed as much as possible by keeping the contact in a smaller area, and at the same time, the shaft pressing mechanism 41 is stably fixed.
Further, the rotor assembly 31 includes the shaft pressing mechanism 41.
While being pressed to the output side by the holding spring piece portion 47, the stator assembly 11 is accurately pivotally supported on a common shaft center line without causing rotation unevenness or the like. Combined with the pressing of the pressing spring piece 47 to the output side, a stable motor torque as expected is always secured.

Next, with respect to the board bracket 71, the opening side of the outer case 61 is appropriately attached and fixed to the flange portion 72a at one end from the outside, and a lead screw projecting inward through the center opening 73a. The bearing ball 76 is inserted into the bearing recess 75 of the bearing member 74 provided on the other end side flange portion 72b.
And the entire device is assembled in this way.

That is, the small motor 10
In a state where the entire device including the rotor assembly is assembled, the rotor 32 of the rotor assembly 31 extends between the stator iron cores 12a and 12b of the stator assembly 11 so that the pivot shaft hole 16 on the same axis is formed. In addition, the leading end of the lead screw 34 extended from the rotor shaft 33 is supported by a bearing recess 75 through a bearing ball 76, and at the same time, the output of the rotor shaft 33 is not output. A side end portion of the pressing spring piece 47 of the pressing spring member 42 provided in the shaft pressing mechanism 41
And the rotor assembly 31, substantially the lead screw 34, can be pressed to the output side by the resilient pressure applied to the pressing spring piece 47.

Therefore, according to the small motor device in the rotary drive mechanism of the present embodiment employing the above configuration, the lead screw 34 which is the output shaft is selected in either the forward or reverse direction by the control drive of the small motor 10. The lead screw 34 is driven to rotate, and the screw advance / retreat operation accompanying the rotation of the lead screw 34 is taken out as a motor output. The above assembling work is not necessarily complicated, and can be easily performed in combination with the small number of parts. As a result, the cause of noise generation is effectively eliminated, and the smooth operation is always achieved. Rotation and constant output torque are obtained.

[0030]

As described above in detail, according to the small motor device in the rotary drive mechanism according to the first aspect of the present invention, the shaft pressing means and the rotor are provided in the outer case. The stator assembly incorporating the assembly is sequentially mounted, and the lead screw extension side of the rotor shaft is pivotally supported on the bearing portion and mounted inside, and the lead screw is pivotally supported on the rotation drive mechanism side. With this, together with the integral molding of the stator assembly, the shaft support of the rotor shaft with respect to the stator core can be accurately and pivotally supported on the same shaft, and at the same time, by the pressing spring piece. The rotor assembly can be pressed in the thrust direction with a constant elastic force. As a result, the whole small motor device can be assembled very easily with little number of parts and without any skill. Along with Period as cause of the noise is eliminated, it is always output torque constant and smooth rotation can be obtained.

Further, in the small motor device of the rotary drive mechanism according to the second and third aspects of the present invention, as the shaft pressing means, the insert base plate portion of the presser spring member is integrally formed in a resin main body member having a vibration absorbing property. Is formed on the non-pressing surface side of the resin main body member, and a spacer portion is formed on the non-pressing surface side of the resin body member so as to be spaced apart from the inner end surface of the outer case. Vibration can be effectively absorbed, and transmission of rotational vibration to the outer case can be suppressed well.

Further, in the small motor device of the rotary drive mechanism according to the present invention, a lubricating means such as an oil groove capable of holding lubricating oil is provided on the inner surface of the bearing of the bearing portion, so that the rotor assembly can be smoothly operated. Rotation is possible.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a schematic configuration of an entire small motor device to which an embodiment of the present invention is applied.

FIG. 2 is a longitudinal sectional view (FIG. 2 (a)) and an end view (FIG. 2 (b)) showing the stator assembly of the small motor taken out.

FIG. 3 is a front view showing the shaft pressurizing mechanism.

FIG. 4 is a vertical sectional view taken along the line AA of FIG. 3;

FIG. 5 is a front view showing a pressing spring member inserted into the shaft pressing mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Small motor 11 Stator assembly 12a, 12b Two stator iron cores 13a, 13b Bobbin part 14a, 14b Terminal extraction part 15 Bearing end plate part 16 Pivot shaft hole 21a, 21b Excitation winding 22a, 22b Terminal 31 Rotor assembly 32 Rotor 33 Rotor shaft 33a Spherical convex surface on the base end side of rotor shaft 34 Lead screw 34a Spherical concave surface on the distal end portion of lead screw 41 Shaft pressing mechanism 42 Presser spring member 43 Insert base plate portion 44 Cutting Part 45 Projecting part 46 Hole part 47 Pressing spring piece part 51 Resin body member 52 Spacer part 61 Outer case 62 Notch part 71 Board bracket (rotation drive mechanism side) 72a One end side flange part 72b Other end side flange part 73a One end Center opening 73b of the flange on the other side 73b center opening of the flange on the other end Receiving member 75 bearing recess 76 bearing balls

Claims (4)

[Claims] 1. A bobbin portion is arranged around a periphery of the stator core with a resin material in a state where the cylindrical stator core is outsert in an axial direction, and an output side end face is supported on the shaft core line. A stator assembly, which is provided with a stator molded body integrally formed of resin so as to be closed by a bearing end plate portion forming a non-output side and an opening on a non-output side end surface, and in which an exciting winding is wound around a bobbin portion A rotor having an outer diameter slightly smaller than the inner diameter of the stator core and magnetized in a required form, and a lead screw on an output side of a rotor shaft for fixing the rotor on an axis. A shaft assembly having a presser spring piece for pressing the rotor shaft to the output side; an opening formed on the output side to have a bottomed cylindrical shape; The shaft pressing means and the stator assembly are sequentially mounted from the side,
In addition, the rotor assembly is inserted into the stator core, the rotor shaft pivotally supported by the bearing portion is pressed by a pressing spring piece to house the rotor shaft, and the lead screw is pulled out to the output side. A small motor device in the rotary drive mechanism, characterized in that the rotary drive mechanism comprises: an outer case for holding the output shaft of the rotor shaft; 2. The pressurizing spring member comprising an insert base plate portion and a presser spring piece portion cut and raised to a pressing surface side including a center portion of the insert base plate portion and projected. 2. The small motor device in a rotary drive mechanism according to claim 1, wherein the insert base plate portion is inserted into a resin body member having a vibration absorbing property and is integrally molded with resin. 3. The apparatus according to claim 2, wherein the resin body member of the shaft pressing means has a spacer portion on a non-pressing surface side for appropriately separating the inner case from the inner end surface of the outer case. Small motor device in rotary drive mechanism. 4. The small motor device according to claim 1, wherein the bearing portion has a lubricating means such as an oil groove capable of holding a lubricating oil on an inner surface of the bearing.