Rotational Drive Unit

Abstract

A rotation drive device comprising: a movable body portion Mm having a rotor yoke 5 formed in a ring shape and a ring-shaped rotor magnet 4 obtained by arranging a plurality of magnetic poles along a circumferential direction Ff of an outer peripheral portion 5e of the rotor yoke 5; a fixed body portion Mc obtained by arranging a plurality of stator core portions 2c..., each of which faces an outer peripheral portion Mme of the movable body portion Mm, in an inner peripheral portion 2i of a stator 2 formed in a ring shape at predetermined intervals along the circumferential direction Ff; and a movable body support portion Ms formed of a plurality of support rollers 6... rotatably supporting the movable body portion Mm by being fixed in position with respect to the stator 2 and by bringing roller peripheral surfaces 6f... into abutment with the outer peripheral portion Mme or an inner peripheral portion Mmi of the movable body portion Mm.

Description

[Technical field]

[0001] The present invention relates to a rotary drive device including a fixed body portion having a stator coil wound around a plurality of stator core portions, and a movable body portion having a rotor magnet with a plurality of magnetic poles arranged thereon. [Background technology]

[0002] In general, rotary drive devices (servo motors) used in automatic looms and the like must be able to frequently and quickly control rotation start, stop, speed change, direction change, and other operations during rotation. This means that it is necessary to reduce the weight of the rotor (moving body) to minimize the moment of inertia as much as possible, and a unique special structure is also required because the thread must be manipulated.

[0003] Conventionally, as a rotary drive device used for such an application, there is known a direct electromagnetic drive type rotary selvedge device for a loom disclosed in Patent Documents 1 and 2. The direct electromagnetic drive type rotary selvedge device for a loom disclosed in Patent Document 1 aims to solve the problems that it is necessary to find a suitable bearing device for the leno weaving disc, which enables a relatively narrow structure of the selvedge device and can be incorporated into the selvedge device with a simple structure and at low cost, and in that case, the drive device must be equipped with a rotation angle measurement system, and further, the electromagnetic drive device, the bearing device and the rotation angle measurement system must be sufficiently shielded against dirt. Specifically, in a direct electromagnetic drive type rotary selvedge device in which the leno weaving disc is the rotor of the electromagnetic drive device, the outer race of the rolling bearing is fixed non-rotatably to the leno weaving disc and is arranged coaxially around the rotor central axis, and one centering device supporting the inner race of the rolling bearing is provided in the stator housing.

[0004] In addition, the direct electromagnetic drive type rotary selvedge device for a loom disclosed in Patent Document 2 is intended to provide a narrow-width rotary selvedge device in which a leno weaving disk is the rotor of a direct electromagnetic drive device and a magnetic flux different from the radial magnetic flux appears in the drive device between the rotor and the stator.Specifically, the direct electromagnetic drive type rotary selvedge device for a loom has two yarn ports arranged symmetrically around a central axis and a rotatingly supported leno weaving disk that guides leno weaving yarns supplied from first and second leno weaving bobbins by each yarn port, the leno weaving disk forms the rotor of an electromagnetic drive device, and the stator is contained in a housing that can be connected to a loom, and is configured so that an axial magnetic flux exists between the rotor and the stator. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 11-107129 [Patent Document 2] Japanese Patent Application Publication No. 11-117147 DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0006] However, the above-mentioned conventional rotary drive device (direct electromagnetic drive rotary selvedge device for a loom) has the following problems.

[0007] First, the rotor is supported by a dedicated rolling bearing configured to have a large diameter as a metallic component, and therefore some components, such as the outer race of the rolling bearing that rotates integrally with the rotor, also become large and heavy. Therefore, there is a limit to how much weight the rotor can be made to reduce the moment of inertia and ensure sufficient high-speed responsiveness, and the large size and weight are also disadvantageous in terms of low cost and energy saving, so there is room for further improvement in terms of solving these problems.

[0008] Secondly, the structure in which structural elements such as woven disks and magnets are arranged on the outer circumferential surface or side surface of the rolling bearing is adopted, which makes the overall structure complicated, and the thickness of the entire device increases due to the use of large rolling bearings. As a result, it is not possible to meet the requirement of installation in a narrow space with an interval of about 10 mm, and there is room for further improvement in terms of increasing versatility.

[0009] An object of the present invention is to provide a rotary drive device that solves the problems existing in the background art. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems, the present invention provides a rotary drive device M including a stator 2 having a plurality of stator core portions 2c... integrally provided therewith, a fixed body portion Mc having a stator coil 3... wound around the stator core portions 2c..., a rotor magnet 4 having a plurality of magnetic poles facing the fixed body portion Mc, and a movable body portion Mm having a rotor yoke 5 attached to the rotor magnet 4, the rotor yoke 5 formed in a ring shape, and the plurality of magnetic poles are arranged along the circumferential direction Ff of the outer periphery 5e of the rotor yoke 5. The rotor magnet 4 is characterized in that it comprises a movable body part Mm having a ring-shaped rotor magnet 4, a fixed body part Mc having a plurality of stator core parts 2c... facing the outer periphery Mme of the movable body part Mm arranged at predetermined intervals along the circumferential direction Ff on the inner periphery 2i of the stator 2 formed in a ring shape, and a movable body support part Ms consisting of a plurality of support rollers 6... which are fixed in position relative to the stator 2 and support the movable body part Mm so that it can freely rotate by abutting the roller circumferential surfaces 6f... against the outer periphery Mme or inner periphery Mmi of the movable body part Mm.

[0011] In this case, according to a preferred embodiment of the invention, it is preferable to use a radial bearing 6b for the support roller 6. In this case, when forming the radial bearing 6b, the entirety of it or at least a part including the outer ring portion 6be may be made of a non-magnetic material, or the entirety may be made of a magnetic material. When it is made of a magnetic material, a separate roller covering ring 6br made of a non-magnetic material may be integrally provided on the outer circumferential surface of the radial bearing 6b. On the other hand, it is preferable to use an integrally molded magnet that is divided and magnetized into multiple poles in the circumferential direction Ff as the rotor magnet 4. In addition, it is preferable to form the rotor yoke 5 thinner than the thickness of the rotor magnet 4. Also, it is preferable to provide the fixed body portion Mc with a ring-shaped base portion 11 that supports one end surface 2s of the stator 2 and arranges the movable body support portion Ms. As a result, the fixed body Mc accommodates the support rollers 6 arranged on the base portion 11 in accommodation spaces 12 formed by removing some of the stator core portions 2c from the plurality of stator core portions 2c, thereby allowing the roller circumferential surfaces 6f of the support rollers 6 to abut against the outer circumferential portion Mme or inner circumferential portion Mmi of the movable body portion Mm, and also allows the roller circumferential surfaces 6f of the support rollers 6 arranged on the base portion 11 to abut against the outer circumferential portion Mme or inner circumferential portion Mmi of the movable body portion Mm at a position offset in the axial direction Fs with respect to the stator 2. When the roller circumferential surfaces 6f of the support rollers 6 are offset in the axial direction Fs with respect to the stator 2, it is preferable to integrally provide a ring-shaped auxiliary body Mms, in which the roller circumferential surfaces 6f of the support rollers 6 abut against the outer circumferential portion Mme or inner circumferential portion Mmi, by extending the movable body Mm in the axial direction Fs. On the other hand, the movable body portion Mm may be provided with a roller guide 13 having stopper portions 14p, 14q for regulating the relative displacement in the axial direction Fs of the support rollers 6..., and this roller guide 13 may be made entirely or at least partially of a lubricating synthetic resin material. Also, this roller guide 13 may be provided with covering sheet portions 15d, 15u for covering the inner peripheral surface 5i of the rotor yoke 5 and / or the outer peripheral surface 4e of the rotor magnet 4, and the covering sheet portion 15u for covering the outer peripheral surface 4e of the rotor magnet 4 in this roller guide 13 may be made of a non-magnetic metal material.In addition, a part of the stator core portions 2c... may be formed as sensor support portions 2ca, 2cb that support the sensors 16a, 16b. The movable body portion Mm may be configured as a hollow portion Sa on the inside of the inner periphery portion Mmi, or may be configured as specific function portions Sb, Sc that perform specific functions by rotation on the inside of the inner periphery portion Mmi. Effect of the Invention

[0012] The rotation drive device M according to the present invention having such a configuration provides the following remarkable effects.

[0013] (1) The movable body Mm has a ring-shaped rotor yoke 5 and a ring-shaped rotor magnet 4 with multiple magnetic poles arranged along the circumferential direction Ff of the outer periphery 5e of the rotor yoke 5, so that it is possible to eliminate the need for a conventional large-sized rolling bearing for rotating the movable body Mm. This makes it possible to significantly reduce the weight of the movable body Mm, and to reduce the moment of inertia while handling high torque, thereby ensuring sufficiently high-speed responsiveness in the rotary drive device M, and further improving cost reduction and energy saving.

[0014] (2) The fixed body Mc has a plurality of stator core parts 2c… that face the outer periphery Mme of the movable body part Mm and are arranged at a predetermined interval along the circumferential direction Ff on the inner periphery 2i of the stator 2 formed in a ring shape, and the movable body support part Ms is made of a plurality of support rollers 6… that are fixed in position with respect to the stator 2 and support the movable body part Mm rotatably by abutting the roller circumferential surface 6f… against the outer periphery Mme or the inner periphery Mmi of the movable body part Mm, so that the overall structure can be simplified and in particular the entire device can be made thin. As a result, the rotary drive device M can be provided as a versatile and expandable device that can be installed in a narrow space with an interval of about 10 mm or less.

[0015] (3) In a preferred embodiment, by using radial bearings 6b... as the support rollers 6..., general-purpose parts such as ball bearings which are small, lightweight, and available in a wide variety of sizes can be used, so that the desired higher performance rotation drive device M can be obtained easily and at low cost.

[0016] (4) In a preferred embodiment, when constructing the radial bearing 6b, the entirety or at least a part thereof including the outer ring portion 6be can be made of a non-magnetic material, thereby eliminating or reducing the magnetic attraction force between the rotor magnet 4 and the radial bearing 6b. This reduces the pressure in the sliding portions of the radial bearing 6b and enhances the durability of the radial bearing 6b.

[0017] (5) In a preferred embodiment, when constructing the radial bearing 6b, the entirety of the radial bearing 6b can be made from a magnetic material. This increases the magnetic attraction force between the rotor magnet 4 and the radial bearing 6b, allowing the movable body part Mm to rotate (move) stably at the neutral point position between the rotor magnet 4 and the radial bearing 6b.

[0018] (6) In a preferred embodiment, when constructing the radial bearing 6b, a separate roller covering ring 6br made of a nonmagnetic material is integrally provided on the outer circumferential surface of the radial bearing 6b. This reduces the magnetic attraction force between the rotor magnet 4 and the radial bearing 6b and improves durability. In particular, it is possible to reduce cogging and suppress vibration during rotation of the movable body part Mm.

[0019] (7) In a preferred embodiment, the rotor magnet 4 is an integrally molded magnet that is divided into multiple poles in the circumferential direction Ff. This eliminates the need to assemble multiple individual magnets, making assembly easier, more uniform, stronger, and less costly. In addition, the rotor magnet 4 can be made thinner, which contributes to further reducing the moment of inertia by reducing the weight of the movable body portion Mm.

[0020] (8) In a preferred embodiment, when forming the rotor yoke 5, if it is formed thinner than the rotor magnet 4, then in addition to making the rotor magnet 4 thinner, it is possible to reduce the weight while avoiding saturation of the magnetic circuit by dividing the multiple poles into multiple magnetizations. In particular, it is possible to minimize the weight of the rotor yoke 5 and rotor magnet 4, which have a large specific gravity, and this can be implemented as an optimal form for constructing the movable body portion Mm.

[0021] (9) In a preferred embodiment, a ring-shaped base portion 11 that supports one end face 2s of the stator 2 and arranges the movable body support portion Ms is provided on the fixed body portion Mc. This base portion 11 can function as part of the mechanical components of the fixed body portion Mc, and can be used not only as the support rollers 6... but also as a housing functional portion for arranging a circuit board, etc., or an attachment functional portion when installing the rotary drive device M.

[0022] (10) In a preferred embodiment, when constructing the fixed body portion Mc, the support rollers 6... arranged on the base portion 11 are accommodated in an accommodation space 12... formed by removing some of the stator core portions 2c... from the multiple stator core portions 2c.... By making the roller circumferential surfaces 6f... of the support rollers 6... abut against the outer circumferential portion Mme or the inner circumferential portion Mmi of the movable body portion Mm, each support roller 6... can be arranged in the same position as the stator core portions 2c... in the axial direction Fs. This avoids unnecessary protrusion of each support roller 6... in the radial and axial directions Fs, and makes it possible to rationally thin the movable body portion Mm and further the rotary drive device M.

[0023] (11) In a preferred embodiment, when constructing the fixed body portion Mc, the roller peripheral surfaces 6f... of the support rollers 6... arranged on the base portion 11 are abutted against the outer peripheral portion Mme or the inner peripheral portion Mmi of the movable body portion Mm at a position offset in the axial direction Fs relative to the stator 2. This makes it possible to abut the support rollers 6... against the inner peripheral portion Mmi of the movable body portion Mm or to arrange the support rollers 6... side by side in the axial direction Fs relative to the stator 2. Therefore, particularly when there is no requirement for the rotary drive device M to be thin, it is possible to provide a variety of rotary drive devices M constructed by adding various functions using the hollow portion.

[0024] (12) In a preferred embodiment, when constructing the movable body portion Mm, by providing a ring-shaped auxiliary body portion Mms integrally with the outer peripheral portion Mme or the inner peripheral portion Mmi so that the roller circumferential surfaces 6f... of the support rollers 6... abut against the outer peripheral portion Mme or the inner peripheral portion Mmi by extending the ring-shaped auxiliary body portion Mms in the axial direction Fs, the support rollers 6... can be arranged in line with the stator 2 in the axial direction Fs. Therefore, by increasing the number of stator core portions 2c... and stator coils 3..., the performance of the fixed body portion Mc can be improved, and further the stability and smoothness of support for the movable body portion Mm can be enhanced.

[0025] (13) In a preferred embodiment, when constructing the movable body portion Mm, a roller guide 13 having stopper portions 14p, 14q that regulate the relative displacement in the axial direction Fs of the support rollers 6... is provided. This allows the relative displacement of the movable body portion Mm in the axial direction Fs with respect to the fixed body portion Mc to be regulated by magnetic force, but in the event of mechanical displacement due to external disturbances or the like, this is regulated by the stopper portions 14p, 14q. This makes it possible to prevent the movable body portion Mm from coming loose (falling off) from the fixed body portion Mc, thereby further improving stability and reliability.

[0026] (14) In a preferred embodiment, when forming the roller guide 13, all or at least a portion of it can be made from a lubricating synthetic resin material. This allows the physical properties of the lubricating synthetic resin material to be utilized, thereby enabling smooth rotation (movement) of the movable body portion Mm and effectively absorbing vibrations and noise during rotation (movement).

[0027] (15) In a preferred embodiment, when forming the roller guide 13, covering sheet portions 15d, 15u are provided to cover the inner surface 5i of the rotor yoke 5 and / or the outer surface 4e of the rotor magnet 4. This allows the support rollers 6... to come into contact with the movable body portion Mm and then come into contact with the covering sheet portion 15d or 15u. This makes it possible to more effectively absorb vibrations and noise, and to facilitate smooth rotation (movement), while also improving control responsiveness.

[0028] (16) In a preferred embodiment, the covering sheet portion 15u covering the outer peripheral surface 4e of the rotor magnet 4 in the roller guide 13 is made of a non-magnetic metal material, which can accommodate a rotor magnet 4 composed of a combination of multiple single-pole magnets. In addition, the flatness precision of the outer peripheral portion Mme of the movable body portion Mm can be improved, so that the contact with the support rollers 6... can be made more stable, and the gap between the stator core portions 2c... can be made smaller, thereby increasing the magnetic flux density.

[0029] (17) In a preferred embodiment, when forming multiple stator core portions 2c..., some of them can be formed as sensor support portions 2ca, 2cb that support the sensors 16a, 16b. This eliminates the need to secure a location for installing the sensors 16a, 16b outside the stator 2. This makes it possible to avoid problems such as larger size and complication when providing various sensors 16a, 16b.

[0030] (18) In a preferred embodiment, when configuring the movable body portion Mm, the area inside the inner circumferential portion Mmi is configured as a hollow portion Sa. This is particularly suitable for use in an automatic loom or the like that utilizes the hollow portion (space) Sa to supply yarn or the like.

[0031] (19) In a preferred embodiment, when constructing the movable body portion Mm, specific function portions Sb, Sc that produce specific functions through rotation can be configured inward from the inner peripheral portion Mmi. This can provide a rotation drive device M that is highly versatile and has excellent expandability, and can be used and adapted for a variety of purposes, such as an RGB color filter for an optical device (such as a single-panel projector) that projects color-separated light, or a blower for special purposes. [Brief description of the drawings]

[0032] [Figure 1] FIG. 1 is a front view of a rotary drive device according to a first embodiment of the present invention, including a partial cross-sectional portion thereof, with a dust cover removed; [Diagram 2] A cross-sectional view of the rotary drive device taken along line A1-A1 in FIG. 1 (including an enlarged view of the area within dashed line A3), [Diagram 3] A cross-sectional view of the rotary drive device taken along line A2-A2 in FIG. [Figure 4] FIG. 2 is an exploded cross-sectional view showing a part of a roller guide in the rotation drive device; [Diagram 5] FIG. 2 is a rear view of the rotary drive device; [Figure 6] FIG. 4 is a front view of a movable body portion in the rotary drive device; [Figure 7] A flowchart for explaining a method for manufacturing the rotary drive device; [Figure 8] FIG. 11 is a front view of a rotary drive device according to a second embodiment of the present invention, with a dust cover removed and including a partially cutaway portion; [Figure 9] A cross-sectional view of the rotary drive device taken along line A4-A4 in FIG. 8 (including an enlarged view of the area within dashed line A6); [Figure 10] FIG. 8 is a cross-sectional view of the rotary drive device according to the embodiment; [Figure 11] FIG. 11 is a bottom view of the portion of the rotation drive device shown in FIG. [Figure 12] FIG. 10 is an enlarged explanatory view of the portion within the dashed line A7 in FIG. 9 of the rotation drive device; [Figure 13] FIG. 13 is a front view of a dust cover including a partially cut-away portion of a rotary drive device according to a third embodiment of the present invention; [Figure 14] 15A-15C are cross-sectional views of the movable body portion of the rotary drive device; [Figure 15] A cross-sectional view of the rotary drive device taken along line A9-A9 in FIG. [Figure 16] 13, a cross-sectional view of the rotary drive device taken along line A10-A10 in FIG. [Figure 17] FIG. 13 is a front view of a modified example of the rotation drive device with a dust cover cut away; [Explanation of symbols]

[0033] M: rotary drive device, Mm: movable body part, Mme: outer periphery of movable body part, Mmi: inner periphery of movable body part, Mms: auxiliary body part, Mc: fixed body part, Mc: outer periphery of fixed body part, Ms: movable body support part, 2: stator, 2c...: stator core part, 2ca: sensor support part, 2cb: sensor support part, 2i: inner periphery of stator, 2s: one end face of stator, 3...: stator coil, 4: rotor magnet, 4e: outer periphery of rotor magnet, 5: rotor yoke, 5e: outer periphery of rotor yoke, 5i: inner periphery of rotor yoke surface, 6...: support roller, 6f...: roller peripheral surface, 6b: radial bearing, 6be: outer ring of radial bearing, 6br: roller covering ring, 11: base portion, 12...: accommodation space, 13: roller guide, 14p: stopper portion, 14q: stopper portion, 15d: covering sheet portion, 15u: covering sheet portion, 16a: sensor, 16b: sensor, Ff: circumferential direction, Fs: axial direction, Zp: side area on one side, Zq: side area on the other side, Sa: hollow portion, Sb: specific function portion (filter function portion), Sc: specific function portion (air blowing function portion) BEST MODE FOR CARRYING OUT THEINVENTION

[0034] Next, preferred embodiments (first, second and third embodiments) of the present invention will be described in detail with reference to the drawings.

[0035] First, the configuration of a rotation drive device M according to a first example of this embodiment will be described with reference to FIGS.

[0036] 1 shows the overall configuration of the mechanical portion of the rotation drive device M. The rotation drive device M is broadly composed of a fixed body portion Mc, a movable body portion Mm, and a movable body support portion Ms.

[0037] The fixed body Mc includes the stator 2 shown in FIG. 1, which is integrally formed into a ring shape. In this case, when constructing the stator 2, if a laminate of multiple non-oriented electromagnetic steel sheets such as silicon steel sheets is used, eddy current loss can be effectively reduced. The stator 2 has multiple stator core parts 2c... arranged at predetermined intervals along the circumferential direction Ff and integrally formed with the inner periphery 2i, each of which has a T-shape protruding toward the center. It is desirable to select the width dimension in the axial direction Fs of the stator core parts 2c to be approximately 0.8 times or less the width dimension in the axial direction Fs of the rotor magnet 4 described later. By selecting in this manner, the magnetic attraction force between the rotor magnet 4 and the stator core parts 2c can be made uniform, so that the movable body part Mm described later can be stably held at the magnetic center position.

[0038] Each stator core portion 2c faces the outer circumferential portion Mme of the movable body portion Mm with a small gap therebetween. In the illustrated example, a pitch (spacing) is selected between each stator core portion 2c such that the number of poles of the stator core portions 2c is 24 when the spacing between the stator core portions 2c is set constant, and an arrangement pattern is sequentially formed in which three consecutive stator core portions 2c remain and the next stator core portion 2c is removed to form the accommodation spaces 12. As a result, the entire stator core portions 2c are set to 18 poles, and six accommodation spaces 12 are provided at regular intervals in the circumferential direction Ff.

[0039] Additionally, the winding portion of each stator core portion 2c is coated with epoxy resin, polyimide resin, or the like to ensure insulation. Stator coils 3 wound with coil wire (magnet wire) using insulating conductor are attached to the stator core portions 2c. Note that in FIG. 1, the stator coils 3 are shown only in the cross-sectional area, and are omitted in other areas.

[0040] Furthermore, the fixed body part Mc is provided with a ring-shaped base part 11 having an outer diameter larger than that of the stator 2. This base part 11 is preferably integrally formed from an aluminum material having high thermal conductivity (heat dissipation) and being non-magnetic. As shown in Figs. 1 and 2, this base part 11 is placed on one end face 2s (back face) of the stator 2 and fixed with fixing screws 21... to support the stator 2, and a movable body support part Ms, which will be described later, is disposed on the front side of this base part 11. In the drawings, reference numeral 22 denotes a circuit board attached to the inner face of the base part 11.

[0041] In this way, by providing the fixed body portion Mc with a ring-shaped base portion 11 that supports one end face 2s of the stator 2 and arranges the movable body support portion Ms, this base portion 11 can function as part of the mechanical components of the fixed body portion Mc, and can therefore be used not only as the support rollers 6... but also as a housing functional portion for arranging a circuit board, etc., or an attachment functional portion when installing the rotary drive device M.

[0042] On the other hand, the movable body support part Ms is composed of six support rollers 6... whose positions are fixed with respect to the stator 2. In this case, as shown in Figs. 2 and 3, roller support shaft parts 6s... that rotatably support the centers of the support rollers 6... are attached to the base part 11, and the positions of the support rollers 6... are selected so that they can be accommodated in the six accommodation spaces 12... described above, and the outer diameters of the support rollers 6 are selected so that the roller circumferential surfaces 6f of the support rollers 6 abut against the outer circumferential part Mme of the movable body part Mm. The movable body part Mm and the movable body support part Ms are shown in Fig. 6. Note that the six support rollers 6... have the function of supporting the movable body part Mm rotatably by abutting the roller circumferential surfaces 6f... against the outer circumferential part Mme of the movable body part Mm described later. Therefore, the six support rollers 6... can be composed of a plurality of support rollers 6..., generally three or more, taking into consideration the number of stator core parts 2c....

[0043] Radial bearings 6b such as ball bearings or roller bearings are used for each of the support rollers 6. By using radial bearings 6b as the support rollers 6, general-purpose parts such as ball bearings that are small, lightweight, and available in a wide variety of sizes can be used, so that the intended higher performance rotation drive device M can be obtained easily and at low cost.

[0044] The radial bearing 6b shown as an example is entirely made of a magnetic material. If the radial bearing 6b is entirely made of a magnetic material in this way, the magnetic attraction force between the rotor magnet 4 and the radial bearing 6b, which will be described later, can be increased, so that the movable body Mm can rotate (move) stably at the neutral point between the rotor magnet 4 and the radial bearing 6b.

[0045] On the other hand, the radial bearing 6b can be selected from various types depending on the material of which it is made. As an example, the entire radial bearing 6b or at least a part including the outer ring portion 6be (see FIG. 2) can be made of a non-magnetic material. In this way, if the entire radial bearing 6b or at least a part including the outer ring portion 6be is made of a non-magnetic material, the magnetic attraction force between the rotor magnet 4 and the radial bearing 6b can be eliminated or reduced, so that the pressure in the sliding portion of the radial bearing 6b can be reduced and the durability of the radial bearing 6b can be improved. On the other hand, as in the second embodiment described later, a separate roller cover ring 6br (see FIG. 9) made of a non-magnetic material can be integrally provided on the outer circumferential surface of the radial bearing 6b. If such a roller cover ring 6br is provided, the magnetic attraction force between the rotor magnet 4 and the radial bearing 6b can be reduced and durability can be improved, and in particular, cogging can be reduced and vibration during rotation of the movable body portion Mm can be suppressed.

[0046] In addition, when attaching the support roller 6 (radial bearing 6b) to the base portion 11, as shown in Figure 2, a roller support shaft portion 6s is formed using a mounting screw 23 and a collar 24, and the collar 24 is inserted into the inner hole of the support roller 6. The mounting screw 23 is then passed through the collar 24 to screw it into a screw hole 25 formed in the base portion 11.

[0047] In this way, when constructing the fixed body portion Mc, the support rollers 6... arranged on the base portion 11 are accommodated in an accommodation space 12... formed by removing some of the stator core portions 2c... from the multiple stator core portions 2c..., so that the roller circumferential surfaces 6f... of the support rollers 6... are abutted against the outer circumferential portion Mme or inner circumferential portion Mmi of the movable body portion Mm. This allows each support roller 6... to be arranged in the same position as the stator core portions 2c... in the axial direction Fs, thereby avoiding unnecessary protrusion of each support roller 6... in the radial and axial directions Fs, and achieving a rational thinning of the movable body portion Mm and further the rotary drive device M.

[0048] On the other hand, the movable body portion Mm is configured to include a rotor yoke 5 formed in a ring shape, and a ring-shaped rotor magnet 4 having a plurality of magnetic poles arranged along the circumferential direction Ff of the outer periphery 5e of the rotor yoke 5.

[0049] In this case, a ring-shaped one-piece magnet divided into 32 poles in the circumferential direction Ff is used for the rotor magnet 4. By using this type of rotor magnet 4, there is no need to assemble multiple individual magnets, which makes assembly easier, more uniform, stronger, and less costly. In particular, it makes it possible to make the rotor magnet 4 thinner, which contributes to further reducing the moment of inertia by reducing the weight of the movable body part Mm.

[0050] Moreover, the rotor yoke 5 is integrally formed into a ring shape from a soft magnetic material such as iron. In this case, the rotor yoke 5 is formed thinner than the rotor magnet 4. Forming it in this manner makes it possible to reduce the thickness of the rotor magnet 4 and to avoid saturation of the magnetic circuit by separately magnetizing multiple poles, thereby making it possible to reduce the weight, which is an optimal form when configuring the movable body part Mm, particularly since it is possible to minimize the weight of the rotor yoke 5 and rotor magnet 4, which have a large specific gravity. Then, the rotor magnet 4 can be assembled so that the inner peripheral part 4i of the rotor magnet 4 abuts against the outer peripheral part 5e of the rotor yoke 5.

[0051] Furthermore, the movable body portion Mm includes a roller guide 13. The illustrated roller guide 13 is configured by combining a first ring member 13a and a second ring member 13b. Each of the ring members 13a and 13b is integrally molded into a ring shape using a lubricating synthetic resin that has a small moment of inertia and abrasion load and is excellent in abrasion resistance. Examples of the lubricating synthetic resin that can be used include fluororesin, cast nylon resin, ultra-high molecular weight polyethylene resin, and polyacetal resin.

[0052] In this way, when forming the roller guide 13 (first ring member 13a and second ring member 13b), if the entirety is formed from a lubricating synthetic resin material, the physical properties of the lubricating synthetic resin material can be utilized, thereby realizing smooth rotation (movement) of the movable body part Mm and effectively absorbing vibrations and noise during rotation (movement). Note that, in the illustrated example, the entirety of the roller guide 13 is integrally formed from a lubricating synthetic resin material, but it is also possible to form a part of it from a lubricating synthetic resin material and the remaining part from another material (such as a non-magnetic metal material), as in a second embodiment described later.

[0053] 2, one of the first ring members 13a is composed of a ring-shaped covering sheet portion 15d that covers the inner peripheral surface 5i of the rotor yoke 5, and a ring-shaped stopper portion 14p that is integrally formed with one end edge of the covering sheet portion 15d in the axial direction Fs to regulate the relative displacement of the support rollers 6 in the axial direction Fs. The covering sheet portion 15d is formed to a constant thickness as a whole, and the stopper portion 14p extends radially outward from the covering sheet portion 15d, and a concave portion is formed on the inner surface of the stopper portion 14p into which the edge portion of the rotor yoke 5 and the edge portion of the rotor magnet 4 can be fitted (see FIG. 4). Reference numerals 31, 31 denote thread guides provided at positions 180° apart on the inner peripheral surface of the roller guide portion 13.

[0054] The other second ring member 13b is composed of a ring-shaped covering sheet portion 15u that covers the outer peripheral surface 4e of the rotor magnet 4, and a ring-shaped stopper portion 14q that is integrally formed with the other end edge of the covering sheet portion 15u in the axial direction Fs to regulate the relative displacement of the support rollers 6 in the axial direction Fs. The covering sheet portion 15u is formed to a constant thickness as a whole, and the stopper portion 14q is formed to extend radially outward from the covering sheet portion 15u. Furthermore, a holding portion 13bh is integrally formed radially inward from the stopper portion 14q, and a concave portion is formed on the inner surface of the holding portion 13bh into which the edge portion of the rotor yoke 5 and the edge portion of the rotor magnet 4 can be fitted (see FIG. 4).

[0055] As a result, when the movable body portion Mm, the fixed body portion Mc, and the movable body support portion Ms are assembled, as shown in Figure 2, the tip of one stopper portion 14p is located at the radial middle portion of the end face on one side of the outer ring portion 6be of the support roller 6 (radial bearing 6b), and the tip of the other stopper portion 14q is located at the radial middle portion of the end face on the other side of the outer ring portion 6be, thereby regulating the relative displacement in the axial direction Fs of the support rollers 6...

[0056] In this way, when constructing the movable body portion Mm, if a roller guide portion 13 having stopper portions 14p, 14q that regulate the relative displacement in the axial direction Fs of the support rollers 6... is provided, the relative displacement of the movable body portion Mm in the axial direction Fs with respect to the fixed body portion Mc is regulated by magnetic force, but if mechanical displacement occurs due to external disturbances or the like, it is regulated by the stopper portions 14p, 14q, so that it is possible to prevent the movable body portion Mm from coming loose from the fixed body portion Mc, thereby further improving stability and reliability.

[0057] Furthermore, when forming the roller guide 13, if covering sheet portions 15d, 15u are provided to cover the inner surface 5i of the rotor yoke 5 and the outer surface 4e of the rotor magnet 4, when the support rollers 6... abut against the movable body portion Mm, they can abut against the covering sheet portion 15d or 15u, thereby making it possible to more effectively absorb vibration and noise and smooth rotation (movement), and also to improve control responsiveness.

[0058] On the other hand, as shown in FIG. 2, a dust cover 17 is attached to one side region Zp from the inner periphery Mmi of the movable body part Mm to the outer periphery Mce of the fixed body part Mc, which is located on the front side (opposite side to the base part 11), and the side region Zp is entirely (or partially) covered with a ring-shaped dust cover 17s made of a resin sheet. In this case, the dust cover 17s is a resin sheet that is lightly brought into contact (sliding) with the roller guide 13 or the like to shield the space, and can be made of nylon resin, polyethylene terephthalate resin, fluororesin, polyurethane resin, or the like. It is preferable to improve the wear resistance by selecting a material different from that of the roller guide 13 or the like. In addition, when an optical sensor is built in, it is preferable to consider the light shielding property. Furthermore, it is preferable to make the dust cover 17 from an aluminum material that has high thermal conductivity (heat dissipation) and is non-magnetic.

[0059] By installing such a dustproof cover 17, even when the device is used in a place where dust is likely to be generated, such as an automatic loom, dust generated by lint and the like can be prevented from entering the inside of the rotary drive device M from the dustproof cover 17 side, thereby contributing to improving the reliability and durability of the rotary drive device M.

[0060] On the other hand, on the outside of the base portion 11, that is, on the other side region Zq from the inner periphery Mmi of the movable body portion Mm to the outer periphery Mce of the fixed body portion Mc, a ring-shaped dustproof sheet 18 made of, for example, a resin sheet is attached to cover the whole (or part) of this side region Zq. In this case, except for the shape, it can be formed in the same manner as the dustproof sheet 17s described above. A rear view of the rotation drive device 1 with the dustproof sheet 18 attached is shown in FIG. 5.

[0061] Therefore, by providing such a dustproof sheet 18, it is possible to prevent dust from entering the interior of the rotary drive device M from the base portion 11 side, thereby contributing to improving the reliability and durability of the rotary drive device M, and in particular, by combining it with the dustproof cover 17, a more effective dustproof effect can be obtained.

[0062] Next, an example of a manufacturing procedure for the rotation drive device M according to the first embodiment will be described according to the flowchart shown in FIG. 7 with reference to FIGS.

[0063] First, the unmagnetized rotor magnet 4 is fixed to the rotor yoke 5 (step S1). In this case, the rotor yoke 5 and the rotor magnet 4 are positioned and fixed using an adhesive or the like (step S1). Then, a magnetization process is performed on the unmagnetized rotor magnet 4 fixed to the rotor yoke 5 (step S2).

[0064] Next, the first ring member 13a is attached to one end side of the integrated rotor yoke 5 and rotor magnet 4 using an adhesive or the like (step S3). In this case, as shown in Fig. 4, the first ring member 13a is displaced relative to the rotor yoke 5 and rotor magnet 4 in the direction of the arrow F1, and the covering sheet portion 15d is inserted inside the rotor yoke 5 and assembled at the position of the imaginary line, and one end of the rotor yoke 5 and rotor magnet 4 is abutted (fitted) against the inner surface of the stopper portion 14p.

[0065] Also, the second ring member 13b is attached to the other end side of the rotor yoke 5 and the rotor magnet 4 using adhesive or the like (step S4). In this case, similarly to the first ring member 13a side, the second ring member 13b is displaced relative to the rotor yoke 5 and the rotor magnet 4 in the direction of the arrow F2, and the covering sheet portion 15u is assembled to the outer circumferential surface of the rotor magnet 4 as shown by the imaginary line, and the other end portions of the rotor yoke 5 and the rotor magnet 4 are abutted (fitted) against the inner surface of the holding portion 13bh of the second ring member 13b. This completes the assembly of the movable body intermediate assembly on the movable body portion Mm side (step S5).

[0066] Meanwhile, coil wire is wound around each stator core portion 2c of the stator 2 (step S6). As a result, the stator coils 3 are attached to each stator core portion 2c. Also, the circuit board 22 is attached to the base portion 11 (step S7). Then, the stator 2 is attached to the base portion 11, and the stator coils 3 of the stator 2 are connected to the circuit board 22 by soldering or the like (steps S8 and S9). This completes the assembly of the fixed body intermediate assembly on the fixed body portion Mc side (step S10).

[0067] Next, the movable body intermediate assembly is set in a fixed position relative to the fixed body intermediate assembly (step S11). In this state, the six support rollers 6 are accommodated in the respective accommodation spaces 12, and the support rollers 6 are attached to the base portion 11 (step S12). The support rollers 6 are attached by inserting a collar 24 into the inner hole of the support roller 6, and threading the attachment screw 23 into the collar 24 and the screw hole 25 formed in the base portion 11, as shown in FIG. 2. As a result, each support roller 6 is configured as a movable body support portion Ms that is rotatably supported by a roller support shaft portion 6s formed by the attachment screw 23 and the collar 24, and stopper portions 14p and 14q are arranged on both sides of the outer ring portions 6be of each support roller 6, i.e., the radial bearings 6b, and the radial bearings 6b prevent the movable body portion Mm from coming off in the axial direction Fs.

[0068] Thereafter, the dustproof sheet 17s is attached to the dustproof cover 17, and the dustproof sheet 18 is attached to the base portion 11 (steps S13 and S14). The dustproof cover 17 with the dustproof sheet 17s attached thereto is attached to the base portion 11 using the fixing screws 26... (step S15). In this way, the desired rotation drive device M can be obtained.

[0069] The rotary drive device M thus configured can be driven to rotate as a three-phase DC brushless motor by connecting the stator coils 3 and sensors (not shown) to a drive controller (not shown) via a circuit board 22. In this case, the stator coils 3 in each phase can be connected by a known connection method such as star connection or delta connection, and in particular, a bipolar drive method can be adopted to reduce torque ripple. Although a three-phase is exemplified, various multi-phase methods such as two-phase, four-phase, and five-phase can be used. In addition, when configuring the movable body portion Mm, the inside of the inner periphery portion Mmi is configured as a hollow portion Sa, so that the hollow portion (space) Sa is used inwardly to supply yarn or the like, making it particularly suitable for use in an automatic loom or the like that utilizes the hollow portion (space) Sa to supply yarn or the like.

[0070] Therefore, according to the rotary drive device M of the first embodiment, as its basic configuration, it is configured with a rotor yoke 5 formed in a ring shape, a movable body part Mm having a rotor magnet 4 having a plurality of magnetic poles arranged in a ring shape along the circumferential direction Ff of the outer periphery 5e of the rotor yoke 5, a fixed body part Mc having a plurality of stator core parts 2c... facing the outer periphery Mme of the movable body part Mm arranged at a predetermined interval along the circumferential direction Ff on the inner periphery 2i of the stator 2 formed in a ring shape, and a movable body support part Ms consisting of a plurality of support rollers 6... whose position is fixed with respect to the stator 2 and which rotatably supports the movable body part Mm by abutting the roller peripheral surfaces 6f... against the outer periphery Mme or inner periphery Mmi of the movable body part Mm, so that it is possible to eliminate the conventional large rolling bearing that rotates the movable body part Mm. This makes it possible to realize a significant weight reduction in the movable body portion Mm, and makes it possible to reduce the moment of inertia while handling high torque, ensuring sufficiently high-speed responsiveness in the rotary drive device M, while also improving cost and energy saving. Moreover, in addition to being able to further simplify the overall structure, it is possible to realize a thinner overall device. As a result, it is possible to provide a rotary drive device M that is highly versatile and expandable, and can fully meet the requirements for installation in narrow spaces with spacings of about 10 mm or less. Second Example

[0071] Next, a rotation drive device M according to a second embodiment of the present invention will be described with reference to FIGS.

[0072] The second embodiment has the same basic configuration as the first embodiment, but differs from the first embodiment in that a sensor system is added and in that a modified example of the detailed configuration is shown.

[0073] First, as shown in Fig. 11 and Fig. 12, three Hall sensors (Hall ICs) 41, 42, 43 for detecting the magnetic poles of the rotor magnet 4 are arranged at predetermined intervals along the circumferential direction Ff on the circuit board 22 located near the rotor magnet 4. Each Hall sensor 41, 42, 43 has a function of detecting the magnetic pole position of the rotor magnet 4, and based on this detection result, in the illustrated example, switching control can be performed when operating as a three-phase DC brushless motor. Note that 40 denotes a sensor yoke. This sensor yoke 40 is intended to minimize magnetic pole position detection errors that occur in the processing circuits of the Hall sensors 41, 42, 43 during forward and reverse rotation, and a plate made of a soft magnetic material such as iron is attached to the back side of the circuit board 22.

[0074] In the second embodiment, when forming the multiple stator core portions 2c..., some of them are formed as sensor support portions 2ca, 2cb that support the sensors 16a, 16b. In this case, the six housing spaces 12... formed in the stator 2 of the first embodiment are changed to three housing spaces 12..., and the three stator core portions 2c... existing in the remaining housing spaces 12... are changed to three sensor mounting portions 2ca, 2cb, 2cc. In the illustrated example, two sensor mounting portions 2ca, 2cb are used, but in order to ensure balance of the magnetic circuit, three sensor mounting portions 2ca, 2cb, 2cc formed in a shape similar to the shape of the stator core portion 2c are provided. Therefore, the number of support rollers 6... is changed to three.

[0075] A substrate 16ap having an origin detection sensor 16a mounted thereon is attached to the tip of one sensor mounting portion 2ca, and a substrate 16bp having a rotation speed detection sensor 16b mounted thereon is attached to the tip of the other sensor mounting portion 2cb. In this case, as shown in Fig. 12, when viewed from the side, the origin detection sensor 16a is disposed toward the end of the axial direction Fs, and the rotation speed detection sensor 16b is disposed toward the center of the axial direction Fs, as shown by the virtual line in Fig. 12. Both the origin detection sensor 16a and the rotation speed detection sensor 16b use photoreflectors (reflective optical sensors).

[0076] In this way, when forming multiple stator core portions 2c..., if some of them are formed as sensor support portions 2ca, 2cb that support the sensors 16a, 16b, there is no need to secure a location for installing the sensors 16a, 16b outside the stator 2. Therefore, even when various sensors 16a, 16b are provided, the problems of large size and complication can be avoided.

[0077] 12, on the movable body portion Mm side, a black mark 44 detected by the origin detection sensor 16a is displayed at a predetermined position on the peripheral surface of the tip of the stopper portion 14p described above. Also, a continuous pattern 46 consisting of 180 sets of repeated black and white patterns detected by the rotation speed detection sensor 16b is displayed on the outer surface of a ring-shaped sheet guide 45 provided on the outer peripheral surface of the rotor magnet 4. This sheet guide 45 has the same form as the above-mentioned covering sheet portion 15u formed independently.

[0078] In this case, the sheet guide 45 is made of a non-magnetic metal material and basically becomes a part of the second ring member 13b of the roller guide 13. That is, the covering sheet portion 15u covering the outer circumferential surface 4e of the rotor magnet 4 is formed thinly from a non-magnetic metal material. In this way, if the covering sheet portion 15u is formed of the sheet guide 45 using a non-magnetic metal material, it can be used for the rotor magnet 4 formed by combining a plurality of single-pole magnets, and the flatness accuracy of the outer circumferential portion Mme of the movable body portion Mm can be further improved, so that the contact with the support rollers 6... can be more stabilized, and the gap between the stator core portions 2c... can be made smaller to increase the magnetic flux density. Therefore, when forming the sheet guide 45, it is desirable to make the thickness as thin as possible.

[0079] Furthermore, in the second embodiment, reference numeral 32 denotes a thread guide part formed in a pipe shape from another highly durable material (ceramics, etc.). In the second embodiment, when constructing the thread guide 31, the thread guide part 32 is embedded in the first ring member 13a by insert molding or assembly to the portion where the hole is to be formed.

[0080] Further, 47 denotes a resin roller covering ring attached to the peripheral surface 6f of the support roller 6. By using such a roller covering ring 47, the sheet guide 45 with which the peripheral surface 6f of the support roller 6 abuts can be made of, for example, a resin material or a metal material that has superior wear resistance to resin materials and a small coefficient of expansion and is different from the material of the roller guide 13. In addition, it is possible to reduce the influence of the magnetic circuit.

[0081] In addition, in the second embodiment shown in Figures 8 to 12, the same parts and parts with the same functions as those in the first embodiment shown in Figures 1 to 6 are given the same reference numerals to clarify the configuration, and detailed explanations thereof will be omitted. Even in such a second embodiment, it is possible to obtain the same functions and effects as those in the first embodiment. Third embodiment

[0082] Next, a rotation drive device M according to a third example of this embodiment will be described with reference to Figs.

[0083] The third embodiment differs from the first and second embodiments in that the number of basic poles is changed, the position of the movable body support part Ms (support rollers 6...) arranged on the fixed body part Mc is changed, and specific function parts Sb, Sc which produce specific functions when rotated are provided inward from the inner circumference Mmi of the ring-shaped movable body part Mm.

[0084] 17, in the third embodiment, the basic pole numbers of the stator core portions 2c are set to 12 poles, and the rotor magnet 4 is set to 16 poles. In the third embodiment, the accommodation spaces 12 for accommodating the support rollers 6 are not provided.

[0085] Furthermore, in the third embodiment, when constructing the fixed body Mc, the position of the movable body support part Ms (support rollers 6...) in the axial direction Fs is changed as shown in FIG. 15. That is, the roller circumferential surface 6f... of the support rollers 6... arranged on the base part 11 is made to abut against the outer circumferential part Mme of the movable body part Mm at a position offset in the axial direction Fs with respect to the stator 2. Therefore, the support rollers 6... and the stator core part 2c... are arranged in a state of being lined up front and back in the axial direction Fs. With this configuration, it is possible to abut the support rollers 6... against the inner circumferential part Mmi of the movable body part Mm or to arrange the support rollers 6... in the axial direction Fs with respect to the stator 2. Therefore, in particular, when a reduction in thickness of the rotation drive device M is not required, a configuration in which various functions are added by utilizing the hollow part, that is, a variety of rotation drive devices M can be constructed.

[0086] For this reason, when constructing the movable body part Mm, as shown in FIG. 15, the rotor magnet 4 constituting the movable body part Mm is removed, the rotor yoke 5 and the first ring member 13a are extended in the axial direction Fs, and the position of the second ring member 13b is changed. As a result, the dimensions of the movable body part Mm in the first embodiment are obtained by adding a ring-shaped auxiliary body part Mms to the axial direction Fs. In other words, the movable body part Mm is extended in the axial direction Fs and set to an axial width that is approximately twice that of the movable body part Mm in the first embodiment. As a result, the roller circumferential surface 6f of the support rollers 6 abuts against the outer circumferential part Mme of the auxiliary body part Mms. With this configuration, as described above, the support rollers 6 can be arranged in the axial direction Fs with respect to the stator 2, and by increasing the number (number of poles) of the stator core parts 2c and the stator coils 3, it is possible to improve the performance of the fixed body part Mc and further increase the stability and smoothness of support for the movable body part Mm.

[0087] Furthermore, in the first and second embodiments, when constructing the movable body portion Mm, a hollow portion Sa was formed inward from the inner peripheral portion Mmi of the ring-shaped movable body portion Mm, but in the third embodiment, specific function portions Sb, Sc are provided which produce specific functions through rotation.

[0088] As an example, Fig. 13 shows an RGB color filter (filter function unit) Sb of an optical device (such as a single-panel projector) that projects color-separated light, in which a red filter 51, a green filter 52, and a blue filter 53 are arranged in sequence in an area divided into three equal parts in the circumferential direction Ff. Meanwhile, Fig. 17 shows another example of a blower fan (blower function unit) Sc made up of seven fan blades 61... In this case, since there is no motor or the like that would interfere with the blowing of air in the central position, it is possible to efficiently blow air into the interior of a relatively thin pipe or the like.

[0089] In this way, when constructing the movable body portion Mm, if specific function portions Sb, Sc that produce specific functions through rotation are configured inward from the inner circumference portion Mmi, then it is possible to provide a rotational drive device M that is highly versatile and expandable, and can be utilized and applied for various purposes, such as an RGB color filter for an optical device (such as a single-panel projector) that projects color-separated light, or an air blower (blower fan) for special purposes, as shown as an example.

[0090] Additionally, in the third embodiment shown in Figures 13 to 17, the same parts and parts with the same functions as those in the first and second embodiments shown in Figures 1 to 12 are given the same reference numerals to clarify the configuration, and detailed descriptions thereof will be omitted.

[0091] Although this third embodiment does not surpass the first and second embodiments in terms of achieving a thin design, it can achieve the same effects as the first embodiment, such as making it possible to reduce the weight of the movable body portion Mm.

[0092] Although the preferred embodiments (first embodiment, second embodiment, and third embodiment) have been described in detail above, the present invention is not limited to such embodiments, and the detailed configuration, shape, material, quantity, numerical values, etc. can be changed, added, or deleted as desired without departing from the gist of the present invention.

[0093] For example, the number (number of poles) of the stator core parts 2c... and the number of poles of the rotor magnet 4 are not limited to the illustrated number (number of poles), and generally can be implemented based on any multiple. In addition, the roller circumferential surface 6f... is in contact with the outer circumferential portion Mme of the movable body part Mm, but the roller circumferential surface 6f... is in contact with the inner circumferential portion Mmi of the movable body part Mm (auxiliary body part Mms). In addition, the roller guide 13 is provided with the covering sheet parts 15d, 15u that cover the inner circumferential surface 5i of the rotor yoke 5 and the outer circumferential surface 4e of the rotor magnet 4, but the roller guide 13 is provided with only one of the covering sheet parts 15d and 15u. On the other hand, it is preferable to use the radial bearings 6b... as the support rollers 6..., but this does not exclude the roller function using rollers or the like that have a simple structure. On the other hand, the sensor support parts 2ca, 2cb, the dust cover 17 including the dust sheet 17s, and the dust sheet 18 can be replaced with other configurations having similar functions, and are not necessarily essential components. [Industrial Applicability]

[0094] The rotary drive device of the present invention has a hollow space inside, and can be used for a variety of purposes, such as automatic looms, RGB color filters (optical devices), and air blowers, as well as aperture control devices, shutter devices (optical control devices), and robot hand devices, in which various specific functional parts can be added.

Claims

1. A rotary drive device comprising: a fixed body portion having a stator formed by integrally forming a plurality of stator core portions and a stator coil wound around the stator core portion; a rotor magnet having a plurality of magnetic poles facing the fixed body portion; and a rotor yoke attached to the rotor magnet, wherein the movable body portion has the rotor yoke formed in a ring shape and a ring-shaped rotor magnet having a plurality of magnetic poles arranged along the circumferential direction of the outer periphery of the rotor yoke; the fixed body portion having a plurality of stator core portions facing the outer periphery of the movable body portion arranged at predetermined intervals along the circumferential direction on the inner periphery of the stator formed in a ring shape; and a movable body support portion consisting of a plurality of support rollers that fix a position relative to the stator and support the movable body portion so that it can freely rotate by abutting the roller circumferential surface with the outer periphery or inner periphery of the movable body portion.

2. 2. The rotary drive device according to claim 1, wherein the support rollers use radial bearings.

3. 3. The rotary drive device according to claim 2, wherein the radial bearing is entirely or at least partially made of a non-magnetic material, the part including an outer ring being made of the non-magnetic material.

4. 3. The rotary drive device according to claim 2, wherein the radial bearing is entirely made of a magnetic material.

5. 5. The rotary drive device according to claim 4, wherein the radial bearing has a separate roller covering ring made of a non-magnetic material and integrally provided on an outer circumferential surface thereof.

6. 2. The rotary drive device according to claim 1, wherein the rotor magnet is an integrally molded magnet divided into a plurality of poles in the circumferential direction.

7. 7. The rotary drive device according to claim 1, wherein the rotor yoke is formed to be thinner than the rotor magnet.

8. 2. The rotary drive device according to claim 1, wherein the fixed body portion includes a ring-shaped base portion that supports one end surface of the stator and on which the movable body support portion is disposed.

9. The rotary drive device according to claim 8, characterized in that the fixed body portion accommodates the support roller arranged on the base portion in an accommodation space formed by removing some of the stator core portions from the plurality of stator core portions, thereby abutting the roller circumferential surface of the support roller against the outer circumferential portion or the inner circumferential portion of the movable body portion.

10. The rotary drive device according to claim 8, characterized in that the fixed body portion is configured by abutting the roller circumferential surface of the support roller arranged on the base portion against the outer circumferential portion or the inner circumferential portion of the movable body portion at a position axially offset with respect to the stator.

11. The rotary drive device according to claim 10, characterized in that the movable body portion is integrally provided with a ring-shaped auxiliary body portion, the outer or inner circumference of which is in contact with the roller peripheral surface of the support roller, by extending in the axial direction.

12. The rotary drive device according to any one of claims 1 to 11, characterized in that the movable body portion is provided with a roller guide having a stopper portion that regulates relative axial displacement of the support roller.

13. 13. The rotary drive device according to claim 12, wherein the roller guide is entirely or at least partially made of a lubricating synthetic resin material.

14. 14. The rotary drive device according to claim 12, wherein the roller guide has a covering sheet portion that covers an inner peripheral surface of the rotor yoke and / or an outer peripheral surface of the rotor magnet.

15. 15. The rotary drive device according to claim 14, wherein the roller guide has a covering sheet portion which covers an outer peripheral surface of the rotor magnet and is made of a non-magnetic metallic material.

16. 2. The rotary drive device according to claim 1, wherein a part of the plurality of stator core portions is formed as a sensor support portion for supporting a sensor.

17. 2. The rotary drive device according to claim 1, wherein the movable body portion is configured as a hollow portion on the inside of an inner periphery.

18. 2. The rotary drive device according to claim 1, wherein the movable body portion is configured as a specific function portion that produces a specific function by rotation, the specific function being located inward from the inner periphery.

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