JP4533278B2 - Drive device - Google Patents

Description

  The present invention relates to a cylindrical drive device that rotates around an axis.

  2. Description of the Related Art Conventionally, a driving device in a light amount adjusting device has been proposed in which a diameter around a rotation axis is reduced and an output is increased (for example, see Patent Document 1).

  FIG. 7 is an exploded perspective view illustrating a configuration of a driving device according to a conventional example (Patent Document 1). FIG. 8 is a cross-sectional view showing the internal structure of the drive device in an assembled state.

  7 and 8, the driving device includes a magnet 101, a coil 102, a stator 103, and an auxiliary stator 104. The magnet 101 has a cylindrical shape, an outer peripheral surface is divided into four in the circumferential direction, and is composed of a permanent magnet that is alternately magnetized to S and N poles and can rotate about a shaft portion. The magnet 101 is obtained by integrally forming shaft portions 101e and 101f and an output pin 101d. The coil 102 is disposed on one side of the magnet 101 in the axial direction and excites the stator 103.

  The stator 103 includes a cylindrical portion, a tooth-shaped outer magnetic pole portion 103a extending from the cylindrical portion in the axial direction, and a columnar inner cylinder 103b. The outer magnetic pole part 103a is disposed so as to face the outer peripheral surface of the magnet 101 with a gap. Further, the inner cylinder 103b is disposed so as to face the inner peripheral surface of the magnet 101 with a gap. The auxiliary stator 104 is fixed to the outer peripheral portion of the inner cylinder 103b of the stator 103, and constitutes an inner magnetic pole part together with the inner cylinder 103b.

  By switching the energization direction to the coil 102 and switching the polarities of the outer magnetic pole portion 103a, the inner magnetic pole portion, and the auxiliary stator 104, the magnet 101 is reciprocally rotated about the shaft portion. Further, the rotation of the magnet 101 is restricted by bringing the output pin 101d of the magnet 1 into contact with the guide groove 105a provided in the ground plate 105 constituting the light amount adjusting device.

  In the driving device, the magnetic flux generated by energizing the coil 102 flows from the outer magnetic pole portion 103a to the opposing inner magnetic pole portion or from the inner magnetic pole portion to the opposing outer magnetic pole portion 103a. It acts effectively on the magnet 101 located between the parts. Further, the distance between the outer magnetic pole part 103a and the inner magnetic pole part is set to a distance obtained by adding the gap between the magnet 101 and the outer magnetic pole part 103a and the gap between the magnet 101 and the inner magnetic pole part to the thickness of the cylindrical magnet 101. can do. Therefore, the resistance of the magnetic circuit composed of the outer magnetic pole part 103a and the inner magnetic pole part can be reduced. The smaller the resistance of the magnetic circuit, the more magnetic flux can be generated with less current, and the output of the drive device is improved.

  The driving device described in Patent Document 1 requires a predetermined gap between the magnet 101 and the outer magnetic pole portion 103a and the inner magnetic pole portion, and accordingly, the distance between the outer magnetic pole portion 103a and the inner magnetic pole portion increases. The resistance of the magnetic circuit increases. In addition, a predetermined interval is required between the inner diameter portion of the magnet 101 and the inner magnetic pole portion facing the magnet 101, and managing this at the time of manufacturing leads to an increase in cost. Further, it is difficult in terms of strength to reduce the thickness of the cylindrical magnet 101 in the radial direction in order to reduce the diameter of the driving device or to reduce the distance between the outer magnetic pole portion 103a and the inner magnetic pole portion. There is a drawback.

  Therefore, the present applicant has proposed the following drive device as a drive device that eliminates these drawbacks (see, for example, Patent Document 2).

  The drive device described in Patent Document 2 includes a magnet, a coil, a stator, and a rotor. The magnet is composed of a substantially cylindrical permanent magnet whose outer peripheral surface is divided in the circumferential direction and is alternately magnetized to different poles. The coil is arranged concentrically with the magnet and aligned in the axial direction of the magnet. The stator is excited by a coil with at least one tooth-shaped outer magnetic pole portion facing the outer peripheral surface of the magnet. The rotor is made of a soft magnetic material and is configured to be rotatable, and is inserted into the inner diameter portion of the coil and fixed to the inner diameter portion of the magnet.

  In the drive device, the outer diameter of the coil is substantially the same as the outer diameter of the magnet, and the coils are arranged side by side in the axial direction of the magnet. Further, since the inner diameter of the coil can be set to a dimension in which a gap is provided in the outer diameter of the portion that overlaps the coil of the rotor, the inner diameter of the coil can be made smaller than that of the driving device described in Patent Document 1, and the coil Since the number of turns can be maximized, the output of the driving device can be increased.

  Also, assuming that the part that faces the outer magnetic pole part of the rotor and is fixed to the inner peripheral surface of the magnet is called the inner magnetic pole part, the magnetic flux generated by the coil is generated by the inner magnetic pole part and the inner magnetic pole part facing the outer peripheral surface of the magnet. It passes between the inner magnetic pole part of the rotor fixed to the peripheral surface. Therefore, the magnetic flux effectively acts on the magnet. At this time, since it is not necessary to provide a gap necessary for the driving device described in Patent Document 1 between the inner magnetic pole portion facing the inner peripheral surface of the magnet, the distance between the outer magnetic pole portion and the inner magnetic pole portion. Can be made smaller. Therefore, the magnetic resistance can be reduced and the output of the drive device can be increased.

Further, since the rotor is fixed to the inner diameter portion of the magnet, the magnet is excellent in mechanical strength, and the magnet can be thinned, so that the driving device can be downsized.
JP 2002-49076 A JP 2004-208478 A

  In order to make the driving device described in Patent Document 2 higher in output, for example, it is necessary to make the magnet have high magnetic force characteristics, or to set a small gap between the magnet and the outer magnetic pole part. is there. If a magnet having a high magnetic force is used, the cost generally increases. Further, if the gap between the magnet and the outer magnetic pole part is set small, there is a problem that the possibility that the outer peripheral surface of the magnet and the outer magnetic pole part come into contact with each other depending on the assembly becomes high.

  An object of the present invention is to provide a driving device that achieves high output while reducing the size and the number of components and cost.

In order to achieve the above-mentioned object, the drive device of the present invention has an inner magnetic pole part and shaft parts at both ends, has a rotor formed of a soft magnetic material, and has a cylindrical shape, and is fixed to the inner magnetic pole part. A magnet having a magnetized portion in which the outer peripheral surface of the cylindrical shape is divided and magnetized in a circumferential direction, a winding portion around which a coil is wound , and the rotor to which the magnet is fixed A hollow cylindrical portion to be housed is formed, and a bobbin in which grooves are formed at equal intervals in the circumferential direction on the inner peripheral side of the hollow cylindrical portion, and a tooth- shaped outer magnetic pole portion formed of a soft magnetic material There a first stator that will be formed to extend, is formed of a soft magnetic material, and a second stator yoke portion of the tooth-shaped Ru is formed to extend, and the outer from the winding portion By fitting the magnetic pole part into the groove part, the outer magnetic pole part The first stator receives one shaft portion of the rotor, and the yoke portion is fitted into the groove portion from the hollow cylindrical portion side. The yoke portion is disposed at a position facing the magnetized portion, the second stator receives the other shaft portion of the rotor, restricts the position of the rotor in the axial direction , and energizes the coil. wherein with the outer magnetic pole portion is excited by the yoke portion is excited through the rotor, wherein the fact that the poles appearing pole appearing in the outer magnetic pole portion to the yoke portion becomes different from each other in this case .

According to the present invention, it is possible to realize a high-output driving device, yet compact.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an exploded perspective view showing components of a drive device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing an internal structure of the drive device in an assembled state. 3 is a cross-sectional view taken along line AA of FIG. 2 in the first state of the drive device, and FIG. 4 is a cross-sectional view taken along line AA of FIG. 2 in the second state of the drive device. FIG. 5 is a diagram illustrating a state of the driving device viewed from the direction B of FIG. 2, and FIG. 6 is a diagram illustrating a state of the driving device viewed from the direction B of FIG. 2. is there.

  1 to 6, the drive device is configured as a microactuator including a magnet 1, a coil 2, a bobbin 3, a first stator 4, a rotor 5, a bearing 6, and a second stator 7.

  The magnet 1 is configured as a cylindrical plastic magnet, and a rotor 5 is fixed to an inner diameter portion thereof. As shown in FIG. 3, the magnet 1 has an outer peripheral surface divided into n parts in the circumferential direction (four parts in the present embodiment) and magnetized portions 1a alternately magnetized to S and N poles, 1b, 1c, 1d. The magnetized portions 1a and 1c have an N-polar outer peripheral surface, and the magnetized portions 1b and 1d have a predetermined phase relationship so that the magnetized portions 1a to 1d of the magnet 1 and a pin 5d (described later) of the rotor 5 have a predetermined phase relationship. The outer peripheral surface is magnetized to the S pole. In this embodiment, the number of magnetic poles of the magnet 1 is four, but any number of poles may be used as long as it is at least two or more.

  The coil 2 has a large number of conducting wires wound around a bobbin 3 in a cylindrical shape. The coil 2 is disposed concentrically with the magnet 1 and adjacent to the magnet 1 in the axial direction. The outer diameter of the coil 2 is set to be approximately the same as the outer diameter of the magnet 1.

  The bobbin 3 is formed of an insulating material such as plastic and a non-magnetic material, and includes a cylindrical winding portion around which the coil 2 is wound, and a hollow cylindrical portion 3e having a larger outer diameter than the winding portion. Has been. Grooves 3a, 3b, 3c, and 3d are formed at equal intervals in the circumferential direction on the inner peripheral side of the hollow cylindrical portion 3e. The hollow cylindrical portion 3e is arranged in a state of covering the outer peripheral portion with a predetermined gap on the outer peripheral portion of the magnet 1. The bobbin 3 holds the second stator 7 via the hollow cylindrical portion 3e.

  The first stator 4 is made of a soft magnetic material, and has a cylindrical portion having a hole 4c and n / 2 (two in the present embodiment) teeth extending in the axial direction from the cylindrical portion. The outer magnetic pole portions 4a and 4b are shaped. The outer magnetic pole portions 4 a and 4 b are formed by cutting out cylindrical members, are opposed to each other with a predetermined gap along the outer peripheral surface of the magnet 1, and are arranged in parallel with the axis of the magnet 1. Further, the outer magnetic pole portions 4a and 4b are set in a positional relationship shifted by 720 / n degrees (180 degrees in the present embodiment) in the circumferential direction. In the first stator 4, the outer magnetic pole portions 4 a and 4 b are fitted into the groove portions 3 a and 3 c provided in the hollow cylindrical portion 3 e of the bobbin 3 and are fixed to the groove portions 3 a and 3 c (FIG. 3).

  The rotor 5 is made of a soft magnetic material and includes an inner magnetic pole portion 5a, a shaft portion 5b, a shaft portion 5c, and an output pin 5d. The rotor 5 serves as an output shaft of the driving device, and is fixed to the inner diameter portion of the magnet 1 by the inner magnetic pole portion 5a so that the output pin 5d and the magnetization phase of the magnet 1 have a predetermined relationship. . The rotor 5 is configured to rotate integrally with the magnet 1 by being fixed to the inner diameter portion of the magnet 1. The inner magnetic pole part 5 a faces the outer magnetic pole parts 4 a and 4 b of the first stator 4 through the magnet 1. Here, the distance between the outer magnetic pole portions 4a and 4b of the first stator 4 and the inner magnetic pole portion 5a of the rotor 5 is formed smaller than that of the conventional one.

  The bearing 6 is made of a soft magnetic material and includes a large diameter portion 6a and a small diameter portion 6b. The small diameter portion 6b is fixed to the hole 4c of the first stator 4 by, for example, press fitting, adhesion, welding, or the like. The large-diameter portion 6 a is fixed to the bobbin 3 and the first stator 4 integrally by being fitted to the inner diameter portion of the bobbin 3. The bearing 6 rotatably supports the shaft portion 5b of the rotor 5 at the inner diameter portion 6c.

  As described above, the outer magnetic pole portions 4a and 4b of the first stator 4 face the outer peripheral surface of the magnet 1 with a predetermined gap and also face the inner magnetic pole portion 5a of the rotor 5 made of a soft magnetic material. . Further, the first stator 4 and the rotor 5 form a magnetic circuit via the bearing 6. As a result, when the coil 2 is energized, the outer magnetic pole portions 4a and 4b of the first stator 4 and the inner magnetic pole portion 5a of the rotor 5 are excited to have opposite polarities.

  The second stator 7 is made of a soft magnetic material, and has a disc portion having a guide groove 7c and a hole 7d, and n / 2 pieces (in the present embodiment) extended from the disc portion in the axial direction. In this case, the two yoke teeth 7a and 7b are formed. The second stator 7 is disposed on the opposite side to the coil 2 with the magnet 1 interposed therebetween in the axial direction. The yoke parts 7 a and 7 b are bent with respect to the disk part, and face each other with a predetermined gap along the outer peripheral surface of the magnet 1 and are arranged parallel to the axis of the magnet 1. The disk portion also serves as the top plate of the driving device.

  In the second stator 7, the yoke portions 7a and 7b are fitted into the groove portions 3b and 3d of the hollow cylindrical portion 3e of the bobbin 3 (FIG. 3), and the disk portion is fixed to the end surface of the hollow cylindrical portion 3e (see FIG. 2). Since the second stator 7 is fixed to the bobbin 3 made of a nonmagnetic material, the second stator 7 is arranged with a magnetic gap from the outer magnetic pole portions 4a, 4b of the first stator 4. The shaft portion 5c of the rotor 5 is rotatably fitted in the hole 7d of the disc portion of the second stator 7. The yoke portions 7 a and 7 b are excited by the coil 2 via the rotor 5.

  As described above, the yoke portions 7a and 7b of the second stator 7 and the outer magnetic pole portions 4a and 4b of the first stator 4 maintain a magnetic gap. Thus, the polarity of the yoke portions 7a and 7b of the second stator 7 when excited by energization of the coil 2 is different from the polarity of the outer magnetic pole portions 4a and 4b of the first stator 4 (reverse polarity). Polarity).

  Further, the rotor 5 is assembled without being detached from the drive device by restricting one of the rotors 5 in the axial direction by the bobbin 3 and the other by the second stator 7 (FIG. 2). Further, the output pin 5d of the rotor 5 is brought into contact with one end portion or the other end portion in the longitudinal direction in the guide groove 7c of the disc portion of the second stator 7 (FIGS. 5 and 6). Regulate rotation.

  Next, the operation and action of the drive device of the present embodiment having the above configuration will be described in detail with reference to FIGS.

  First, the relationship between the phase of the magnetized portion of the magnet 1 and the output pin 5d of the rotor 5 when the rotational position of the magnet 1 rotating integrally with the rotor 5 is shown in FIG.

  In the state where the rotational position of the magnet 1 is as shown in FIG. 3, the output pin 5d of the rotor 5 is in contact with one end in the longitudinal direction in the guide groove 7c of the second stator 7 as shown in FIG. In the position where clockwise rotation in FIG. 3 is prevented. At the rotational position of the magnet 1 as shown in FIG. 3, the centers of the magnetized portions 1 a, 1 c, 1 b and 1 d of the magnet 1 are the yoke portions 7 a and 7 b of the second stator 7 and the outer magnetic pole of the first stator 4. It is located slightly on the counterclockwise side with respect to the centers of the portions 4a and 4b.

  When the coil 2 is not energized at this position, the centers of the magnetized portions 1 a, 1 c, 1 b and 1 d of the magnet 1 are the yoke portions 7 a and 7 b of the second stator 7 and the outer magnetic pole of the first stator 4. A magnetic force acts in a direction that attempts to coincide with the centers of the portions 4a and 4b. Along with this, a force to rotate clockwise acts on the rotor 5 and the magnet 1. In this state, as described above, the output pin 5d of the rotor 5 comes into contact with one end portion in the longitudinal direction of the guide groove 7c of the second stator 7 as shown in FIG. 5, and the rotor 5 and the magnet 1 rotate in the clockwise direction. Stopped by being blocked.

  Next, the relationship between the phase of the magnetized portion of the magnet 1 and the output pin 5d of the rotor 5 when the rotational position of the magnet 1 rotating integrally with the rotor 5 is shown in FIG.

  When the rotational position of the magnet 1 is as shown in FIG. 4, the output pin 5d of the rotor 5 contacts the other end in the longitudinal direction in the guide groove 7c of the second stator 7 as shown in FIG. Is in a position where counterclockwise rotation in FIG. 4 is prevented. At the rotational position of the magnet 1 as shown in FIG. 4, the centers of the magnetized portions 1 b, 1 d, 1 a and 1 c of the magnet 1 are the yoke portions 7 a and 7 b of the second stator 7 and the outer magnetic pole of the first stator 4. It is positioned slightly clockwise with respect to the centers of the portions 4a and 4b.

  When the coil 2 is not energized at this position, the centers of the magnetized portions 1b, 1d, 1a and 1c of the magnet 1 are the yoke portions 7a and 7b of the second stator 7 and the outer magnetic pole of the first stator 4. A magnetic force acts in a direction that attempts to coincide with the centers of the portions 4a and 4b. Along with this, a force to rotate counterclockwise acts on the rotor 5 and the magnet 1. In this state, as described above, the output pin 5d of the rotor 5 comes into contact with the other longitudinal end in the guide groove 7c of the second stator 7 as shown in FIG. 6, and the rotor 5 and the magnet 1 are counterclockwise. It is stopped by being prevented from rotating.

  3 and 5, the magnetized portions 1 a, 1 c, 1 b and 1 d of the magnet 1 are centered on the yoke portions 7 a and 7 b of the second stator 7 and the outer magnetic pole portions 4 a and 4 b of the first stator 4. It is a state located slightly on the counterclockwise side with respect to the center of the. In addition, the output pin 5d of the rotor 5 is in contact with one longitudinal end portion in the guide groove 7c of the second stator 7, and the rotor 5 and the magnet 1 are prevented from rotating in the clockwise direction. This is the first state.

  The coil 2 is energized from the first state, the outer magnetic pole portions 4a, 4b of the first stator 4 are S poles, the inner magnetic pole portion 5a of the rotor 5 located at the inner diameter portion of the magnet 1 is N pole, The yoke portions 7a and 7b of the second stator 7 are excited to the N pole. Accordingly, the south poles appearing on the outer magnetic pole portions 4 a and 4 b of the first stator 4 mainly act on the magnetized portions 1 b and 1 d of the magnet 1. Further, the N poles appearing on the yoke portions 7 a and 7 b of the second stator 7 mainly act on the magnetized portions 1 a and 1 c of the magnet 1. Thereby, the rotor 5 and the magnet 1 are rotated counterclockwise.

  As shown in FIG. 6, the output pin 5d of the rotor 5 contacts the other end in the longitudinal direction in the guide groove 7c of the second stator 7, and the rotor 5 and the magnet 1 are prevented from rotating counterclockwise. Rotate to position and stop. Even if the coil 2 is de-energized in this state, the rotor 5 and the magnet 1 are maintained in this position as described above.

  4 and 6, the magnets 1 b, 1 d, 1 a and 1 c of the magnet 1 are centered at the yoke portions 7 a and 7 b of the second stator 7 and the outer magnetic pole portions 4 a and 4 b of the first stator 4. It is in the state located slightly clockwise with respect to the center. In addition, the output pin 5d of the rotor 5 is in contact with the other longitudinal end portion in the guide groove 7c of the second stator 7, and the rotor 5 and the magnet 1 are prevented from rotating counterclockwise. This is the second state.

  The coil 2 is energized from the second state, the outer magnetic pole parts 4a and 4b of the first stator 4 are N poles, the inner magnetic pole part 5a of the rotor 5 located at the inner diameter part of the magnet 1 is the S pole, The yoke portions 7a and 7b of the second stator 7 are excited to the S pole. Accordingly, the N poles appearing on the outer magnetic pole portions 4 a and 4 b of the first stator 4 mainly act on the magnetized portions 1 a and 1 c of the magnet 1. Further, the south poles appearing on the yoke portions 7 a and 7 b of the second stator 7 mainly act on the magnetized portions 1 b and 1 d of the magnet 1. Thereby, the rotor 5 and the magnet 1 are rotated clockwise.

  As shown in FIG. 5, the output pin 5d of the rotor 5 comes into contact with one end portion in the longitudinal direction of the guide groove 7c of the second stator 7, and the rotor 5 and the magnet 1 reach a position where rotation in the clockwise direction is prevented. Rotate and stop. Even if the coil 2 is de-energized in this state, the rotor 5 and the magnet 1 are maintained in this position as described above.

  From the above, the drive device according to the present embodiment is a drive device in which the rotor 5 fixed to the inner diameter portion of the magnet 1 can reciprocate within a predetermined angle by changing the energization direction to the coil 2. .

  Next, features of the drive device according to the present embodiment will be described.

  Since the inner diameter portion of the magnet 1 is filled with the rotor 5 in this driving device, the mechanical strength of the magnet is increased as compared with the driving device described in Patent Document 1 (Japanese Patent Laid-Open No. 2002-49076). Further, since the rotor 5 acts as a back metal, the magnetic deterioration of the magnet 1 is small. Moreover, since the mechanical strength of the magnet 1 is large and the magnetic deterioration is reduced, the thickness of the magnet 1 in the radial direction can be reduced, and the microactuator is very compact with respect to the diameter.

  Further, in the present driving device, the outer magnetic pole portions 4a and 4b of the first stator 4 and the inner magnetic pole portion 5a of the rotor 5 that face the outer peripheral surface and the inner peripheral surface of the magnet 1, respectively, form a magnetic path that sandwiches the magnet 1. Since it is formed, the magnetic resistance is reduced. The distance between the outer magnetic pole portions 4a and 4b of the first stator 4 and the inner magnetic pole portion 5a of the rotor 5 is only the thickness of the magnet 1 and the gap between the magnet 1 and the outer magnetic pole portions 4a and 4b. It becomes. Therefore, since the gap can be reduced as compared with the driving device described in Patent Document 1, the magnetic force generated by the coil 2 effectively acts on the magnet 1. As described above, it is possible to realize a drive device having a high output and a compact and stable operating characteristic.

  On the other hand, the driving device described in Patent Document 1 needs to be assembled while maintaining a gap between the outer diameter portion of the magnet and the outer magnetic pole portion with high accuracy, and the inner magnetic pole portion located at the position facing the inner diameter portion of the magnet is also a magnet. However, it is necessary to provide a predetermined gap. For this reason, if the variation in the component accuracy or the assembly accuracy is poor, the gap cannot be secured, and a defect such as the inner magnetic pole portion coming into contact with the magnet may occur.

  On the other hand, this drive device only manages the gap between the outer diameter portion of the magnet 1 and the outer magnetic pole portions 4a and 4b of the first stator 4 and the yoke portions 7a and 7b of the second stator 7. Therefore, the assembly becomes easy and the possibility of occurrence of defects is reduced.

  Further, in the present driving device, the outer magnetic pole portions 4a and 4b of the first stator 4 are excited by the coil 2, and the poles appearing in the outer magnetic pole portions 4a and 4b act on the magnetized portion of the magnet 1 to generate a driving force. appear. In addition to this, the yoke portions 7a and 7b of the second stator 7 are excited by the coil 2 via the rotor 5, and the poles appearing on the yoke portions 7a and 7b act on the magnetized portion of the magnet 1 to drive force. Is generated.

  The entire driving force of the present driving device is of a type that generates driving force only by the outer magnetic pole portion of the first stator, as in the driving device described in Patent Document 2 (Japanese Patent Laid-Open No. 2004-208478). Compared to the above, the driving force is large while being compact. Moreover, since the second stator 7 also functions as a member that regulates the position of the rotor 5 in the axial direction, there is no increase in cost compared to the drive device described in Patent Document 2.

  Further, in the present driving device, the disc portion of the second stator 7 also serves as the top plate of the driving device, and the hollow cylindrical portion of the bobbin 3 around which the coil 2 is wound around the disc portion of the second stator 7. Since it is set as the structure hold | maintained by the end surface of 3e, it becomes unnecessary to provide a top plate and a 2nd stator holding member separately. As a result, the number of parts and the cost can be reduced.

  Furthermore, the drive device of the present embodiment has the following characteristics.

  Since the magnetic flux generated by energizing the coil 2 crosses the magnet 1 between the outer magnetic pole portions 4 a and 4 b of the first stator 4 and the inner magnetic pole portion 5 a of the rotor 5, it acts effectively.

  Further, the outer magnetic pole portions 4a and 4b of the first stator 4 are formed in a tooth shape extending in a direction parallel to the axial direction of the substantially cylindrical magnet 1, so that the dimension in the diameter direction of the driving device is set. It can be made small. Thereby, it becomes possible to make a very small-diameter cylindrical microactuator.

  In addition, since the coil 2 is constituted by one, it is possible to simplify the configuration of the current-carrying wiring and control circuit for the coil 2 and to reduce the cost.

  As described above, according to the present embodiment, the outer diameter of the drive device is not limited to the outer diameter of the magnet 1, but the outer magnetic pole portions 4 a and 4 b of the first stator 4 and the yoke of the second stator 7. It is sufficient that the portions 7a and 7b are large enough to face the magnet 1. Further, the axial length of the driving device may be a length obtained by adding the length of the coil 2 to the length of the magnet 1. That is, the outer magnetic pole portions 4a and 4b of the first stator 4 and the yoke portions 7a and 7b of the second stator 7 are formed in a tooth shape parallel to the axis of the magnet 1, and one coil is adjacent to the magnet 1 in the axial direction. Since 2 is disposed, the drive device can be very miniaturized.

  Further, in addition to exciting the outer magnetic pole portions 4a and 4b of the first stator 4 and causing the pole appearing in the outer magnetic pole portion to act on the magnetized portion of the magnet 1 to generate a driving force, the second stator 7 The yoke portions 7a and 7b are excited, and the poles appearing on the yoke portions act on the magnetized portion of the magnet 1 to generate a driving force. Further, the distance between the outer magnetic pole portions 4 a and 4 b of the first stator 4 and the inner magnetic pole portion 5 a of the rotor 5 is made smaller than that of the conventional driving device. As a result, a large driving force can be generated as a whole, and a high-output driving device can be realized.

  The second stator 7 functions as a member for regulating the position of the rotor 5 in the axial direction, and the disk portion of the second stator 7 also serves as the top plate of the driving device. The part is held by the bobbin 3. As a result, the number of parts and the cost can be reduced.

  Further, when the drive device is assembled, only the gap between the outer diameter portion of the magnet 1 and the outer magnetic pole portions 4a and 4b of the first stator 4 and the yoke portions 7a and 7b of the second stator 7 is managed. Good. Furthermore, the components constituting the drive device are easier to manufacture than the conventional drive device. As a result, it is possible to easily manage accuracy during assembly of the drive device.

  In addition, by fixing the rotor 5 to the inner diameter portion of the magnet 1, it is possible to increase the mechanical strength of the magnet 1 and to reduce magnetic deterioration.

[Other embodiments]
In the above embodiment, the case where the two outer magnetic pole portions 4a and 4b are disposed on the first stator 4 is described as an example. However, the present invention is not limited to this, and the first stator 4 is not limited thereto. It suffices if at least one outer magnetic pole portion is disposed on the surface.

  In the above-described embodiment, the case where the two stators 7a and 7b are disposed on the second stator 7 is described as an example. However, the present invention is not limited to this, and the second stator 7 includes It is sufficient that at least one yoke portion is provided.

It is a disassembled perspective view which shows the component of the drive device which concerns on embodiment of this invention. It is sectional drawing which shows the internal structure in the assembly completion state of the drive device of FIG. It is sectional drawing which follows the AA line of FIG. 2 in the 1st state of a drive device. It is sectional drawing which follows the AA line of FIG. 2 in the 2nd state of a drive device. It is a figure which shows the state seen from the B direction of FIG. 2 in the 1st state of a drive device. It is a figure which shows the state seen from the B direction of FIG. 2 in the 2nd state of a drive device. It is a disassembled perspective view which shows the structure of the drive device which concerns on a prior art example. It is sectional drawing which shows the internal structure in the assembly completion state of the drive device of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnet 1a, 1b, 1c, 1d Magnetized part 2 Coil 3 Bobbin 4 1st stator 4a, 4b Outer magnetic pole part 5 Rotor 5a Inner magnetic pole part 6 Bearing 7 Second stator 7a, 7b Yoke part

Claims (2)

A rotor having an inner magnetic pole portion and shaft portions at both ends, and formed of a soft magnetic material;
A magnet having a magnetized portion having a cylindrical shape and fixed to the inner magnetic pole portion, wherein the outer peripheral surface of the cylindrical shape is magnetized by being divided in a circumferential direction;
A winding portion around which the coil is wound and a hollow cylindrical portion that accommodates the rotor to which the magnet is fixed are formed, and a groove portion is formed at a position that is equidistant in the circumferential direction on the inner peripheral side of the hollow cylindrical portion. Bobbins,
Is formed of a soft magnetic material, a first stator outer magnetic pole portion of the tooth-shaped Ru is formed to extend,
Is formed of a soft magnetic material, and a second stator yoke portion of the tooth-shaped Ru is formed to extend, and,
By fitting the outer magnetic pole part into the groove part from the winding part side, the outer magnetic pole part is arranged at a position facing the magnetized part, and the first stator is one of the rotors. Receive the shaft,
By fitting the yoke part into the groove part from the hollow cylindrical part side, the yoke part is disposed at a position facing the magnetized part, and the second stator is the other shaft part of the rotor. In response, the axial position of the rotor is regulated,
Wherein with the outer magnetic pole portion is excited by energization of the coil, the yoke portion is excited through the rotor, the poles appearing in electrode and the yoke portion appearing in the outer magnetic pole portion at this time is different from each other A drive device characterized by that. An output pin is formed in the rotor, and the output pin is inserted through the second stator, and a guide groove for limiting a rotation range of the rotor is formed.
The position where the center of the magnetized portion is slightly rotated in the first rotation direction with respect to the center of the outer magnetic pole portion and the yoke portion is a position where the output pin contacts one end portion of the guide groove,
The output pin is located at the position where the center of the magnetized portion is slightly rotated in the second rotation direction opposite to the first rotation direction with respect to the center of the outer magnetic pole portion and the yoke portion. The drive device according to claim 1, wherein the drive device is in a position where it abuts against the other end .

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