JP2008263688A - Motor apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor apparatus which can suppress vibration by enhancing rigidity at a part where vibration is generated in primary mode. <P>SOLUTION: A yoke 14 formed of a drum portion 14a and a bottom wall portion 14b is provided, at the opening thereof, with protrusions 14c and 14d protruding outward in the opposite directions perpendicular to the axis of rotation. Two magnets 15a and 15b are secured oppositely to each other to the inner circumferential surface of the drum portion 14a and symmetrically to a line connecting the pair of protrusions 14c and 14d. The maximum amplitude generating direction of the yoke 14 during rotation of the motor traverses the magnets 15a and 15b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a brushed DC motor device used as an actuator for various in-vehicle devices.

  This type of motor device has a bottomed cylindrical yoke housing, and an end cap is fixed to the opening of the yoke housing with a screw. A plurality of magnets as permanent magnets are fixed to the inner surface of the yoke housing. An armature holding portion is formed at the center of the bottom of the yoke housing, a bearing is provided inside the armature holding portion, and a bearing is also provided at the center of the end cap.

  An amateur (armature) is accommodated in the yoke housing. The amateur has an output shaft that is rotatably supported by a bearing, and a tip portion of the output shaft projects outward from the end cap. The amateur has a core fixed to the output shaft and a commutator. A winding is wound around the core, and the winding is connected to the commutator.

  A brush device is fixed to the inner surface of the end cap with a screw. The brush device holds a brush that is in sliding contact with the commutator. In addition, a power feeding unit is assembled to the end cap. The power supply unit supplies power from the outside to the brush. Then, power is supplied from the power supply unit to the armature winding via the brush, the commutator of the segment, and the short-circuit member attached to the winding side, so that the armature rotates and the output shaft rotates. It has become.

An example of such a motor device is described in Patent Document 1. As shown in FIG. 8, the motor device includes a cylindrical yoke 81, a plurality of magnets 82 attached along the inner peripheral surface of the yoke 81, and an electric machine rotatably supported in the yoke 81. And a child 83. Since the bent portion 84 that does not contact the magnet 82 is bent, deformation due to magnetism during rotation is prevented. Further, the contact portion 85 with which the magnet 82 is in contact is not deformed because the magnet 82 is reinforced, and the yoke 81 is difficult to deform as a whole.
Japanese Patent Laid-Open No. 2005-020914

  Generally, in motor devices, rotor mechanical unbalance, current unbalance (magnetic circuit), natural vibration (suction / repulsion) due to the number of poles / slots, and mechanical vibration due to gears (transmitted from outside the motor) Vibration) is synthesized to generate vibration. However, in the motor device described in Patent Document 1, the contact portion 85 is not reinforced by the magnet 82, and the thickness is only the thickness of the yoke 81, so that the rigidity is low, and vibration occurs in that direction. The deformation direction due to the vibration primary mode and the low rigidity portion are close to each other and the amplitude becomes large, so that it is easily affected by the vibration and noise is generated.

  The objective of this invention is providing the motor apparatus which can suppress a vibration by raising the rigidity of the location where the vibration of a primary mode generate | occur | produces.

  A DC motor device according to the present invention is a motor device that rotationally drives a rotating shaft provided with an armature, and is provided at a drum portion that houses the armature, and at one end portion of the drum portion, and supports one end portion of the rotating shaft. A yoke having a bottom wall portion, a pair of projecting portions projecting outward in opposite directions to each other at the other end opening of the drum portion and facing the rotation axis, and an outer periphery of the armature A pair of magnets having inner peripheral surfaces opposed to each other through a gap and attached to the inside of the yoke so as to face each other through a position penetrating the protrusions, and rotating the rotating shaft The maximum amplitude generation direction sometimes generated in the yoke is a direction crossing the magnet.

  A DC motor device according to the present invention is a motor device that rotationally drives a rotary shaft provided with an armature, and is a polygonal drum portion that houses the armature, and one end of the rotary shaft that is provided at one end portion of the drum portion. A yoke having a bottom wall portion for supporting a portion, a pair of projecting portions projecting outward in opposite directions to each other at the other end opening of the drum portion and facing the rotation axis, and An outer peripheral surface of the amateur having an inner peripheral surface opposed through a gap, and a pair of magnets attached to the inside of the yoke so as to oppose each other through a position penetrating the protrusions, and the rotation The maximum amplitude generation direction generated in the yoke when the shaft rotates is a direction crossing the magnet and passing through the corner portion of the drum portion, and the drum portion and the magnet in the maximum amplitude generation direction. Wall thickness combined with the net being greater than the thickness in a portion other than the corner.

  The DC motor device according to the present invention is characterized in that a reinforcing spacer is disposed between the inside of the corner and the outer surface of the magnet.

  The direct current motor device of the present invention is characterized in that a thick portion that contacts the inner surface of the corner portion of the drum portion is formed on the outer peripheral surface of the magnet.

  According to the present invention, the pair of magnets attached to the inside of the yoke are opposed to each other via a position penetrating the pair of protrusions, so that the maximum amplitude generation direction generated in the yoke when the rotating shaft rotates is Even when the direction crosses the magnet, the direction is reinforced by the magnet, has high rigidity, and can suppress vibration.

  Further, according to the present invention, since the combined thickness of the drum portion and the magnet in the maximum amplitude generating direction is larger than the thickness in the portion other than the corner portion, the maximum amplitude generating direction generated in the yoke when the rotating shaft rotates Even when crossing the magnet and passing through the corners of the drum part, the rigidity of the part is high, and vibrations can be suppressed.

  Further, according to the present invention, since the reinforcing spacer is disposed between the inside of the corner and the outer surface of the magnet, the arc-shaped magnet that has been conventionally used while suppressing vibration by increasing rigidity. It has the effect that can be used.

  Furthermore, according to the present invention, since the thick portion that contacts the inner surface of the corner portion of the drum portion is formed on the outer peripheral surface of the magnet, the maximum amplitude generation direction generated in the yoke when the rotating shaft rotates crosses the magnet. Even in the direction passing through the corner portion of the drum portion, the rigidity of the portion is high and the vibration can be suppressed.

  FIG. 1 is a sectional view of a motor device according to an embodiment of the present invention.

  The motor device 11 includes a motor body 12 and a speed reduction mechanism 13. A magnet 15 is fixed to the inner peripheral surface of the drum portion 14a of the yoke 14 that accommodates the motor main body 12 with an adhesive or the like, and a base end side of the rotary shaft 16 is rotatable on the bottom wall portion 14b. A supporting bearing 17 is provided. The magnet 15 is a permanent magnet having an arc-shaped cross section generally used for a DC motor, and is constituted by a pair of magnets 15a (inner N pole / outer S pole) and 15b (inner S pole / outer N pole). ing. The pair of magnets 15 are provided on the inner peripheral surface of the drum portion 14a of the yoke 14 so as to face each other.

  The bearing 17 has a spherical outer periphery and is configured to automatically align the rotary shaft 16. Reference numeral 18 denotes a support ball that supports the base end portion of the rotation shaft in the axial direction, and the support ball 18 allows the rotation shaft 16 to rotate with respect to the yoke 14 with almost no resistance. Reference numeral 19 denotes a fixing plate for preventing the bearing from coming off to the right in FIG.

  An armature (armature) 21 having a core around which an armature winding is wound so as to be surrounded by the magnet 15 is provided inside the pair of magnets 15 fixed to the inner peripheral surface of the drum portion 14a of the yoke 14. The armature 21 is opposed to the magnet 15 through a minute gap (air gap). The armature 21 includes, for example, 12 slots, and armature windings (not shown) are wound around the slots by lap winding. The armature 21 is integrally provided on the rotating shaft 16 so that the center axis of the armature 21 and the center axis of the rotating shaft 16 coincide with each other.

  A commutator (commutator) 22 is integrally provided on the rotating shaft 16 so as to coincide with the central axis of the rotating shaft 16, and the commutator 22 has an armature winding wound around the core of the armature 21. A segment (conductive portion) 23 to be connected is provided. A plurality of (for example, twelve) segments 23 are provided at predetermined intervals along the circumferential direction of the commutator 22. That is, the commutator 22 is configured by resin molding, and the segment 23 is molded and fixed to the outer peripheral surface of the cylindrical insulating member 24.

  A pair of brushes 25 are in sliding contact with the commutator 22. These brushes 25 are urged by springs 26 and pressed against the commutator 22 with a predetermined force. A driving current is supplied from the power supply unit 28 to the brush substrate 27 to which the brush 25 is attached. This drive current is supplied to the armature winding of the armature 21 through the brush 25 and the commutator 22 to generate an electromagnetic force that rotates the armature 21.

  The motor device 11 includes a gear case 29 made of aluminum die casting that houses therein a speed reduction mechanism 13 that decelerates the rotation of the rotary shaft 16. The gear case 29 is fixedly provided with a ball bearing 30 that rotatably supports the rotary shaft 16.

  Projections 14c and 14d projecting in opposite directions are provided at the opening of the drum section 14a of the yoke 14, and the base end side of the gear case 29 is connected to the projecting sections 14c and 14d of the yoke 14 by screws (not shown). It is fixed secretly via a sealing material (not shown). Further, the front end side of the gear case 29 is secretly closed by the adjustment member 31. The adjustment member 31 includes a ball 32 in a recess provided in the adjustment member 31, and the tip end side of the rotating shaft 16 is in contact with the ball 32. The contact force of the ball 32 with respect to the rotating shaft 16 is adjusted by adjusting the screwing amount of the adjusting member 31 with respect to the gear case 29 to prevent the rotating shaft 16 from rattling in the axial direction.

  A worm 33 having a spiral tooth portion formed on the outer periphery is integrally provided on the distal end side of the rotating shaft 16, and the worm 33 can rotate together with the rotating shaft 16. The worm 33 meshes with teeth (not shown) of the worm wheel 34, and the worm 33 and the worm wheel 34 constitute the speed reduction mechanism 13.

  Between the speed reduction mechanism 13 and the control board 35, a cover 36 that partitions the speed reduction mechanism 13 and the control board 35 is disposed. The cover 36 is formed of a resin molded product such as plastic, and holds the control board 35 and plays a role of preventing the grease applied to the speed reduction mechanism 13 from scattering and adhering to the control board 35. .

  Above the control board 35 in FIG. 1 is an outer side having a heat sink 37 for preventing rainwater, dust, and the like from entering the inside of the gear case 29 and dissipating the temperature rise of the control board 35 to the outside. The cover 38 is secured to the gear case 29 in a secret manner. The outer cover 38 is integrally formed with a heat sink 37 formed of a resin with excellent heat dissipation.

  FIG. 2 is a front view of only the yoke and magnet in the motor device shown in FIG. 1 as seen from the yoke opening. As shown in FIG. 2, the yoke 14 is formed of a bottom wall portion 14b and a drum portion 14a. Both the outer peripheral surface and the inner peripheral surface of the drum portion 14a are formed in a cylindrical shape, and have the same thickness over the entire periphery. A flange 14e is formed in the opening of the yoke 14 in a circular shape over the entire circumference of the opening toward the outside in the direction perpendicular to the central axis. A pair of triangular protrusions 14c and 14d are formed on the upper and lower sides in FIG. 2 at the opening of the yoke 14 so as to extend outward in the direction perpendicular to the central axis and to the flange 14e. The pair of projecting portions 14c and 14d project in opposite directions with respect to the central axis. Further, screw holes 14f and 14g for screwing to the gear case 29 are drilled in the protrusions 14c and 14d.

  Two magnets 15a and 15b are fixed to the inner peripheral surface of the cylindrical drum portion 14a. The two magnets 15a, 15b have an arc shape whose outer peripheral surface is along the inner peripheral surface of the drum portion 14a, and the inner peripheral surfaces are also formed in an arc shape. The two magnets 15a and 15b have a central angle of 90 degrees or more and less than 180 degrees, and have the same shape that is symmetrical to each other. The two magnets 15a and 15b are arranged so as to face each other in line symmetry with respect to a straight line connecting the pair of protruding portions 14c and 14d. That is, the two magnets 15a and 15b are disposed so that the inter-pole portions are positioned at the pair of projecting portions 14c and 14d.

  In motor devices, rotor mechanical unbalance, current unbalance (magnetic circuit), natural vibration (suction / repulsion) due to the number of poles / slots, and mechanical vibration due to gears (transmitted from outside the motor) Vibration) is synthesized to generate vibration. In the cylindrical yoke 14 in which the pair of protrusions 14c and 14d are formed, the maximum amplitude of the vibration primary mode is generated in the direction of the arrow in FIG. 2 with the positions of the protrusions 14c and 14d as nodes. However, the direction of the arrow in FIG. 2 is a place crossing the two magnets 15a and 15b, and the drum portion 14a is reinforced by the two magnets 15a and 15b, and the rigidity is increased. Therefore, vibration generated in the direction of the arrow can be suppressed, and noise and the like can be suppressed. In the simulation performed by the applicant, the maximum displacement amount was reduced by about 10% compared to the conventional product.

  FIG. 3 is a front view of only a yoke and a magnet in a motor device according to another embodiment of the present invention as viewed from the yoke opening. FIG. 4 is a perspective view of the yoke shown in FIG. 3 as viewed from the bottom. As shown in FIGS. 3 and 4, the yoke 54 is formed of a bottom wall portion 54b and a drum portion 54a. Both the outer peripheral surface and the inner peripheral surface of the drum portion 54a are formed in a regular octagonal cylindrical shape. Further, a circular flange 54e is formed in the opening of the yoke 54 in a circular shape over the entire circumference of the opening toward the outside in the direction perpendicular to the central axis. A pair of triangular protrusions 54c and 54d are formed on the upper and lower sides of the opening of the yoke 54 in FIG. 3 so as to extend outward in the direction perpendicular to the central axis and to the flange 54e. The pair of protrusions 54c and 54d protrude in opposite directions with respect to the central axis. Further, screw holes 54f and 54g for screwing to the gear case 29 are drilled in the protrusions 54c and 54d.

  Two magnets 55a and 55b are fixed to the inner peripheral surface of the regular octagonal cylindrical drum portion 54a. The outer peripheral surfaces of the two magnets 55a and 55b have a polygonal line shape along the inner peripheral surface of the regular octagonal cylindrical drum portion 54a, and the inner peripheral surfaces are formed in an arc shape. The two magnets 55a and 55b have a central angle of 90 degrees or more and less than 180 degrees, and have the same shape that is symmetrical to each other. The two magnets 55a and 55b are arranged so as to face each other symmetrically with respect to a straight line connecting the pair of protrusions 54c and 54d. That is, the two magnets 55a and 55b are arranged so that the inter-pole portions are positioned at the pair of projecting portions 54c and 54d. As shown in FIG. 3, the thickness of the magnets 55a and 55b at the corners of the regular octagon is formed to be larger than the thickness at the portions other than the corners. As a result, the drum portion 54a and the magnets at the corners are formed. The combined thickness of 55a and 55b is larger than the thickness of the portion other than the corners.

  Here, in the regular octagonal cylindrical yoke 54 in which the pair of protrusions 54c and 54d are formed, the maximum amplitude of the vibration primary mode is in the direction of the arrow in FIG. 3 with the positions of the protrusions 54c and 54d as nodes. appear. However, the direction of the arrow in FIG. 3 is a location that crosses the corner of the regular octagonal cylindrical drum portion 54a, and the combined thickness of the drum portion 54a and the magnets 55a and 55b at this location is the thickness at the other location. It is larger than the thickness and the rigidity is increased. Therefore, even if vibration occurs in the direction of the arrow, the vibration can be suppressed and noise or the like can be suppressed. In the simulation performed by the applicant, the maximum displacement amount was reduced by about 14% compared to the conventional product.

  FIG. 5 is a front view of only a yoke and a magnet in a motor device according to still another embodiment of the present invention as viewed from the yoke opening. FIG. 6 is a perspective view of the yoke and magnet shown in FIG. 5 viewed from the yoke opening. As shown in FIGS. 5 and 6, the yoke 64 is formed of a bottom wall portion 64b and a drum portion 64a. Both the outer peripheral surface and the inner peripheral surface of the drum portion 64a are formed in a regular octagonal cylindrical shape. In this embodiment, a spacer 66 made of a material that can be used as a magnetic circuit is embedded in a corner portion of the inner peripheral surface of the drum portion 64a from the opening portion toward the bottom wall portion 64b, and the entire inner peripheral surface of the drum portion is cylindrical. It formed so that it might become a shape. In addition, a flange 64e is formed in the opening of the yoke 64 in a circular shape over the entire circumference of the opening toward the outside in the direction perpendicular to the central axis. A pair of triangular protrusions 64c and 64d are formed on the upper and lower sides of FIG. 5 at the opening of the yoke 64 so as to extend outward in the direction perpendicular to the central axis and to the flange 64e. The pair of projecting portions 64c and 64d project in opposite directions with respect to the central axis. In addition, screw holes 64f and 64g for screw fixing to the gear case 29 are drilled in the projecting portions 64c and 64d.

  Two magnets 65a and 65b are fixed to the inner peripheral surface of the drum portion 64a in which the spacer 66 is embedded and the inner peripheral surface has a cylindrical shape. The two magnets 65a and 65b have an arc shape whose outer peripheral surface is along the inner peripheral surface of the drum portion 64a, and the inner peripheral surfaces are also formed in an arc shape. The two magnets 65a and 65b have a central angle of 90 degrees or more and less than 180 degrees, and have the same shape that is symmetrical to each other. Since the inner peripheral surface of the drum portion 64a has a cylindrical shape with the spacer 66 embedded therein, a magnet on an arc generally used in a motor device can be used. The two magnets 65a and 65b are arranged so as to face each other symmetrically with respect to a straight line connecting the pair of projecting portions 64c and 64d. That is, the two magnets 65a and 65b are arranged so that the inter-pole portions are positioned at the pair of projecting portions 64c and 64d. As shown in FIG. 5, the thickness of the magnets 65a and 65b at the corner portions of the regular octagon is equal to the thickness at the portions other than the corner portions, but the spacer 66 is embedded in the inner peripheral surface of the drum portion 64a. As a result, the combined thickness of the drum portion 64a, the magnets 65a and 65b, and the spacer 66 at the corner portion is larger than the thickness at the portion other than the corner portion.

  Here, in the regular octagonal cylindrical yoke 64 in which the pair of protrusions 64c and 64d are formed, the maximum amplitude of the vibration primary mode is in the direction of the arrow in FIG. 5 with the positions of the protrusions 64c and 64d as nodes. appear. However, the direction of the arrow in FIG. 5 is a portion that crosses the corner of the regular octagonal cylindrical drum portion 64a, and the combined thickness of the drum portion 64a, the magnets 65a and 65b, and the spacer 66 in this portion It is larger than the wall thickness at the location, and the rigidity is increased. Therefore, even if vibration occurs in the direction of the arrow, the vibration can be suppressed and noise or the like can be suppressed. In the simulation performed by the applicant, the maximum displacement amount was reduced by about 14% compared to the conventional product.

  FIG. 7 is a front view of only a yoke and a magnet in a motor device according to still another embodiment of the present invention as viewed from the yoke opening. As shown in FIG. 7, the yoke 74 is formed of a bottom wall portion 74b and a drum portion 74a. The outer peripheral surface of the drum part 74a is formed in a regular octagonal cylinder shape, and the inner peripheral surface is formed in a cylindrical shape. A flange 74e is formed in the opening of the yoke 74 in a circular shape over the entire circumference of the opening toward the outside in the direction perpendicular to the central axis. A pair of triangular protrusions 74c and 74d are formed on the upper and lower sides of FIG. 7 at the opening of the yoke 74 so as to extend outward in the direction perpendicular to the central axis and to the flange 74e. The pair of projecting portions 74c and 74d project in opposite directions with respect to the central axis. Further, screw holes 74f and 74g for screwing to the gear case 29 are drilled in the projecting portions 74c and 74d.

  Two magnets 75a and 75b are fixed to the inner peripheral surface of the drum portion 74a whose inner peripheral surface is cylindrical. The two magnets 75a and 75b have an arc shape whose outer peripheral surface is along the inner peripheral surface of the drum portion 74a, and the inner peripheral surfaces are also formed in an arc shape. The two magnets 75a and 75b have a central angle of 90 degrees or more and less than 180 degrees, and have the same shape that is symmetrical to each other. Since the inner peripheral surface of the drum portion 74a has a cylindrical shape, a magnet on an arc generally used in a motor device can be used. The two magnets 75a and 75b are arranged so as to face each other symmetrically with respect to a straight line connecting the pair of projecting portions 74c and 74d. That is, the two magnets 75a and 75b are arranged so that the inter-pole portions are positioned at the pair of projecting portions 74c and 74d. As shown in FIG. 7, the thickness of the magnets 75a and 75b at the corner portions of the regular octagon is equal to the thickness at the portions other than the corner portions, but the thickness of the drum portion 74a at the corner portions is the thickness at the portions other than the corner portions. Since it is larger than the thickness, as a result, the combined thickness of the drum portion 74a and the magnets 75a and 75b in the corner portion is larger than the thickness in the portion other than the corner portion.

  Here, in the regular octagonal cylindrical yoke 74 in which the pair of protrusions 74c and 74d are formed, the maximum amplitude of the vibration primary mode is in the direction of the arrow in FIG. 7 with the positions of the protrusions 74c and 74d as nodes. appear. However, the direction of the arrow in FIG. 7 is a location that crosses the corner of the regular octagonal cylindrical drum portion 74a, and the combined thickness of the drum portion 74a and the magnets 75a and 75b at this location is the thickness at other locations. It is larger than the thickness and the rigidity is increased. Therefore, even if vibration occurs in the direction of the arrow, the vibration can be suppressed and noise or the like can be suppressed.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, although the motor device of the present invention is a wiper motor, it may be changed to a motor used for other devices. Further, the shape of the drum portion of the yoke is not limited to a cylindrical shape or a regular octagonal cylindrical shape, but may be a regular polygonal shape, and the magnet may be fixed along the inner peripheral surface thereof.

It is sectional drawing of the motor apparatus which is one Embodiment of this invention. It is the front view which looked at only the yoke and magnet in the motor apparatus shown in FIG. 1 from the yoke opening part. It is the front view which looked at only the yoke and magnet in the motor apparatus which is other embodiment of this invention from the yoke opening part. It is the perspective view which looked at the yoke shown in FIG. 3 from the bottom part. It is the front view which looked at only the yoke and magnet in the motor apparatus which is further another embodiment of this invention from the yoke opening part. It is the perspective view which looked at the yoke and magnet shown in FIG. 5 from the yoke opening part. It is the front view which looked at only the yoke and magnet in the motor apparatus which is further another embodiment of this invention from the yoke opening part. It is an axial sectional view showing a conventional motor device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Motor apparatus 12 Motor main body 13 Deceleration mechanism 14 Yoke 14a Drum part 14b Bottom wall part 14c, 14d Projection part 14e Flange 14f, 14g Screw hole 15a, 15b Magnet 16 Rotating shaft 17 Bearing 18 Support ball 19 Fixing plate 21 Amateur 22 Commutator 23 Segment 24 Insulating member 25 Brush 26 Spring 27 Brush substrate 28 Power supply portion 29 Gear case 30 Ball bearing 31 Adjustment member 32 Ball 33 Worm 34 Warm wheel 35 Control substrate 36 Cover 37 Heat sink 38 Outer cover 54 Yoke 54a Drum portion 54b Bottom wall portion 54c, 54d Projection 54e Flange 54f, 54g Screw hole 55a, 55b Magnet 64 Yoke 64a Drum 64b Bottom wall 64c, 64d Projection 64e Flange 64f, 64g Holes 65a, 65b Magnet 66 spacer 74 yoke 74a drum portion 74b bottom wall 74c, 74d projecting portion 74e flange 74f, 74 g screw holes 75a, 75b magnet 81 yoke 82 magnet 83 armature 84 bent portion 85 abutting portion

Claims (4)

A motor device that rotationally drives a rotating shaft provided with an amateur,
The drum portion for housing the armature, the bottom wall portion provided at one end portion of the drum portion for supporting one end portion of the rotating shaft, and the other end opening portion of the drum portion facing the rotating shaft at right angles. And a yoke having a pair of protrusions protruding outward in opposite directions to each other;
A pair of magnets that have an inner peripheral surface that opposes the outer peripheral surface of the amateur via a gap, and that are attached to the inside of the yoke so as to oppose each other through a position that penetrates the protrusions;
The motor device according to claim 1, wherein a direction in which a maximum amplitude is generated in the yoke during rotation of the rotating shaft is a direction across the magnet. A motor device that rotationally drives a rotating shaft provided with an amateur,
A polygonal drum portion that accommodates the armature, a bottom wall portion that is provided at one end portion of the drum portion and supports one end portion of the rotating shaft, and a second end opening portion of the drum portion that is perpendicular to the rotating shaft. A yoke having a pair of protrusions facing outward and projecting outward in opposite directions to each other;
A pair of magnets that have an inner peripheral surface that opposes the outer peripheral surface of the amateur via a gap, and that are attached to the inside of the yoke so as to oppose each other through a position that penetrates the protrusions;
The maximum amplitude generation direction generated in the yoke when the rotating shaft rotates is a direction crossing the magnet and passing through the corner of the drum portion, and the drum portion and the magnet in the maximum amplitude generation direction are combined. A motor device characterized in that the wall thickness is larger than the wall thickness in a portion other than the corner portion.   The motor device according to claim 2, wherein a reinforcing spacer is disposed between the inside of the corner portion and the outer surface of the magnet.   3. The motor device according to claim 2, wherein a thick portion that contacts an inner surface of the corner portion of the drum portion is formed on the outer peripheral surface of the magnet.

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