JP4909671B2 - Axial gap motor - Google Patents

Description

  The present invention relates to an axial gap type electric motor, and more particularly to an axial gap type electric motor provided with an eccentricity allowing structure for a rotating shaft.

2. Description of the Related Art Conventionally, as an electric motor corresponding to an electric motor that requires low speed and high torque, there is an axial gap type electric motor in which a stator and a rotor are arranged to face each other in the direction of a rotation axis. A conventional axial gap type electric motor includes a stator around which a coil is wound, a rotor that is arranged to face the coil in the direction of the rotation axis, and a plurality of pairs of permanent magnets are arranged in a circumferential magnetomotive force type. And a rotating magnetic field is generated by passing a current through the stator coil, and the rotor is rotated by a magnetic attraction force and a repulsive force between the stator and the rotor (Patent Literature). 1 and 2).
JP 2002-153028 A Japanese Patent Laid-Open No. 11-187635

  However, in these conventional axial gap type electric motors, the vibration transmitted from the outside is amplified and the motor may vibrate due to the increase in weight due to the installation of the electric motor.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an axial gap type electric motor that suppresses vibration of the motor by providing an eccentricity allowing structure.

In the present invention, one of permanent magnets or coils is installed in the circumferential direction at a predetermined interval, and a rotor that is rotatably supported by a fixed object, and the permanent magnet or coil in the direction of the rotation center line of the rotor. A stator provided with the other of the permanent magnet or the coil so as to face one side, and the stator is arranged to face the rotor with a predetermined gap in the direction of the rotation center line of the rotor. In the axial gap type electric motor having an electric motor portion, the rotor and the stator are internally provided, a case for fixing the stator to an inner surface thereof, and the case and the rotor are provided between the case and the rotor. A bearing that rotatably supports the rotor, a bearing that slides against the surface of the case orthogonal to the rotation center line of the rotor, and a biasing force in a direction orthogonal to the center line of the rotor, Of the rotor And biasing means for biasing the case to the center line of the the core wire the stator the same center line, prohibits the relative rotation of the casing relative to the fixed object, and the rotation center line of the rotor An axial gap type electric motor comprising means for permitting sliding in a direction orthogonal to.

  In the present invention, the case has a function as a mass of the dynamic damper. Therefore, by defining the mass of the case and the spring characteristics in the vibration direction according to the vibration characteristics of the vibration system including the rotor and the fixed object. The vibration transmitted from the rotor to the fixed object and the vibration of the electric motor can be reduced.

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

  FIG. 1 is a cross-sectional view showing a configuration of an axial gap type electric motor 1 according to the present invention, and a rotation center line (hereinafter referred to as a center line X1) of a rotor shaft 2 is eccentric with respect to a center line X2 of a case 5. Indicates the state.

In the present embodiment, the rotor shaft 2 that rotates the member to be rotated, the rotor 3 that is fixed to the rotor shaft 2, and the rotor shaft 2 are provided so as to face the rotor 3 with a predetermined gap in the direction of the center line X1. A plurality of electric motor parts 1 a composed of a pair of stators 4 are arranged in the direction of the rotor shaft 2 and housed in the case 5 to constitute the axial air gap type electric motor 1. In addition, although this embodiment demonstrates using the axial direction gap | interval type | mold electric motor 1 provided with the electric motor part 1a of 2 rows, it is not restricted to this, The axial direction gap | interval which consists of more than one or the electric motor part 1a of 1 row. The type motor 1 may be used.

  One end of the rotor shaft 2 is connected to a rotation member (not shown), and the other end is rotatably supported by a fixed object 30 via a bearing 25.

  FIG. 2 is a diagram for explaining the shape of the rotor 3. The rotor 3 includes four equal-length arm portions 6 extending in the orthogonal direction from the center line X1 of the rotor shaft 2 connected to a rotated member (not shown). These arm portions 6 are arranged at equal intervals (90 ° intervals in FIG. 2) in the circumferential direction. A cylindrical ring member 7 that connects the arm portions 6 is fixed to a distal end portion on the outer peripheral side of each arm portion 6.

  As shown in FIG. 1, a permanent magnet 12 is attached to the arm portion 6 of the rotor 3. For example, as shown in FIG. 3, the permanent magnets 12 are each formed in a substantially fan shape when viewed from the direction of the center line X <b> 1, and are fixed so as to sandwich the intermediate portions of the arm portions 6. The permanent magnet 12 is formed so that both end faces 12 a are parallel to a plane orthogonal to the center line X <b> 1 of the rotor shaft 2. Needless to say, the number, shape, and the like of the arm portions 6 are not limited to those in the embodiment.

In the direction of the center line X1 of the rotor shaft 2, the stator 4 is positioned at a pair of opposed positions to the permanent magnet 12 of the rotor 3 on a surface 5e perpendicular to the center line X1 of the rotor shaft 2 of the case 5 described later. Fixed. The stator 4 includes a yoke portion 8 fixed to the case 5, a teeth portion 9 having a substantially fan shape when viewed from the direction of the center line X <b> 2 of the stator 4, and a coil 10 wound around the teeth portion 9. Composed. The yoke portion 8 fixes the tooth portion 9 to the case 5. It plays the role of turning the magnetic flux of the tooth portion 9 in the circumferential direction to flow to another tooth portion 9. The teeth portion 9 is formed to protrude from the yoke portion 8 toward the rotor 3 in the direction of the center line X1, and its end surface is formed in parallel to the end surface 12a of the permanent magnet 12. Further, the coil 10 is insulated from the tooth portion 9 via an insulator or the like (not shown).

  A case 5 for housing each motor part 1a composed of the rotor 3 and the stator 4 has a bottomed cylindrical shape, and a main body part 5a having a space 5f through which the rotor shaft 2 penetrates at the bottom part. A lid 5b having a space 5d through which the rotor shaft 2 passes, and a hollow disk-shaped partition plate disposed so as to partition the inside of the case in a direction perpendicular to the center line X2 of the case 5 5c. Between the case 5 and the fixed object 30, the case 5 does not rotate relative to the fixed object 30, and restricts sliding in a predetermined direction perpendicular to the center line X <b> 1 with respect to the rotor shaft 2. The rotor shaft 2 can be rotated relative to the case 5.

  The partition plate 5c divides the inside of the case 5 into two equally-shaped spaces 5x and 5y arranged in the direction of the center line X2, and the rotor shaft 2 is inserted through the center portion thereof. The motor part 1a is configured in the space parts 5x and 5y, respectively, and the stator 4 is placed on the surface 5e of the case 5 perpendicular to the center line X2 of the case 5 forming the space parts 5x and 5y for housing the motor part 1a. The rotor 3 is fixed between the stators 4 so as to face each other in the direction of the center line X2, and the electric motor unit 1a is configured. In the state where each electric motor part 1a is disposed in the case 5, the respective gaps 14 in the direction of the center line X2 between the rotor 3 and the pair of stators 4 facing the rotor 3 are set to predetermined values. Installed.

  A cylindrical ring member 7 that connects the tips of the arm portions 6 of the rotor 3 is formed around the center line X1. The end faces 7a on both sides of the ring member 7 in the direction of the center line X1 of the rotor shaft 2 are formed so as to face the inner surface 5e of the case 5 and to be orthogonal to the center line X1. The bearings 13 are installed between the both end surfaces 7a and the surface 5e of the case 5, respectively. The bearing 13 is arranged in an annular shape, for example, and allows the case 5 to slide relative to the rotor shaft 2 in a direction orthogonal to the center line X1. Further, the ring member 7 can rotate around the center line X1 of the rotor shaft 2 in a state where the ring member 7 is in sliding contact with the case 5. The bearing 13 may be a slide bearing or the like, but is not limited to this, and any means that enables the case 5 to slide on the rotor shaft 2 and rotate the rotor 3 may be used.

  Here, the diameter in the direction orthogonal to the center line X2 of the spaces 5d and 5f through which the rotor shaft 2 of the case 5 passes is formed larger than the diameter of the rotor shaft 2 by a predetermined amount. As described above, the case 5 is configured to be slidable in a direction orthogonal to the center line X1, but the case 5 is separated from the rotor shaft 2 by the difference between the diameter of the space 5d or the space 5f and the diameter of the rotor shaft 2. In contrast, the amount of movement in the direction perpendicular to the center line X1 of the rotor shaft 2 is defined.

  On the outer peripheral side of the ring member 7, a cylindrical support member 15 having a center line X1 of the rotor shaft 2 as a center line is disposed with a predetermined gap so as to be movable. A bearing 16 is provided between the support member 15 and the ring member 7 so as to be relatively rotatable.

  An annular space 5x1, 5y1 is defined between the outer peripheral surface of the support member 15 and the inner periphery of the case 5. The annular spaces 5x1, 5y1 are separated from the rotor shaft 2 by the case 5 with respect to the rotor shaft 2. When the case 5 is displaced with respect to the support ring 15 as it is displaced in a direction orthogonal to the center line X1 of the shaft 2, the cross section thereof is configured to be deformable. Here, since the support member 15 supports the ring member 7 of the rotor 3 through the bearing 16 on the inner peripheral surface thereof, the support member 15 does not rotate even if the ring member 7 rotates.

  FIG. 3 is a cross-sectional view showing the configuration in the annular spaces 5x1, 5y1 partitioned by the support member 15. Since the annular spaces 5x1, 5y1 have the same configuration, FIG. 3 represents the configuration of the annular space 5y1. To explain.

  As shown in FIG. 3, the annular space 5 y 1 partitioned by the support member 15 is further partitioned into four spaces 5 ya to 5 yd in the circumferential direction by a partition plate 17 provided on the outer periphery of the support member 15. These four spaces 5ya to 5yd are partitioned so that their volumes are equal when the rotation center line X1 of the rotor 3 and the center line X2 of the stator 4 are the same center line. The partition plate 17 has a base end supported by the support member 15 so as to be able to swing, and an urging means such as a torsion coil spring 18 is disposed at the swing center. For this reason, the outer end of the partition plate 17 is pressed against the inner surface 5 f parallel to the center line X <b> 2 of the case 5.

Therefore, the rotor 3 is configured to be supported by the torsion coil spring 18 with respect to the inner peripheral surface 5 f of the case 5 via the support member 15. For this reason, assuming that the spring characteristics of the torsion coil springs 18 are the same, when the rotor 3 is displaced in the direction orthogonal to the rotor shaft 2 with respect to the case 5, the torsion coil spring 18 causes the rotor 3 to have the case 5, That is, a biasing force that is coaxial with the stator 4 acts. Therefore, when the external force in the direction orthogonal to the center line X1 does not act on the rotor 3, the torsion coil spring 18 connects the center line X1 of the rotor 3 and the center line X2 of the stator 4 to the same center line. Hold to match.

  In the present embodiment, the permanent magnet 12 and the coil 10 are installed on the rotor 3 and the stator 4, respectively, but the coil may be installed on the rotor and the permanent magnet may be installed on the stator.

  Next, the operation will be described.

When the coil 10 of the stator 4 is energized, the axial gap type electric motor 1 of the present invention generates a rotating magnetic field. Accordingly, the magnetic attractive force and repulsion between the stator 4 and the rotor 3 are generated. The rotor 3 is rotated in a predetermined direction by the force. By this rotation, a rotation member (not shown) connected to the rotor shaft 2 of the rotor 3 rotates.

Since a linear guide (not shown) is provided between the case 5 and the fixed object 30, no relative rotation occurs between the case 5 and the case 5 with respect to the rotor shaft 2 perpendicular to the center line X2. It is allowed to slide in a predetermined direction. The case 5 is connected to the rotor shaft 2 via a coil spring 18. By adopting such a configuration, the case 5 is configured to be slidable with a predetermined spring characteristic with respect to the rotor shaft 2, and thus the case 5 has a function as a mass of the dynamic damper. Therefore, the vibration transmitted from the rotor shaft 2 to the fixed object 30 is reduced by defining the mass of the case 5 and the spring characteristics in the vibration direction according to the vibration characteristics of the vibration system including the rotor shaft 2 and the fixed object 30. can do. In the present embodiment, the coil spring 18 is installed in the case. However, the present invention is not limited thereto, and the coil spring 18 is installed between the outside of the case 5 and the rotor shaft 2 (rotor 3). Also good. Furthermore, damping means such as a damper may be installed in addition to the coil spring 18.

  Further, the support member 15 supported so as to be relatively rotatable around the center line X1 of the rotor shaft 2 with respect to the ring member 7 of the rotor 3 defines an annular space 5x1, 5y1 between the case 5 and the support member 15 A partition plate 17 urged by a torsion coil spring 18 is interposed between the case 5 and the case 5. For this reason, the urging force of the torsion coil spring 18 acts so that the center line X1 of the rotor 3 and the center line X2 of the stator 4 coincide. For this reason, it becomes easy to maintain the center line X1 of the rotor 3 and the center line X2 of the stator 4 coaxially.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

It is sectional drawing explaining the structure of the axial direction air gap type | mold electric motor 1 of this invention. It is a block diagram of a rotor. It is sectional drawing of the cross section AA of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Axial direction gap | interval motor 1a Motor part 2 Rotor shaft 3 Rotor 4 Stator 5 Case 6 Arm part 7 Ring member 8 Yoke 9 Teeth part 10 Coil 12 Permanent magnet 13 Bearing 14 Air gap 15 Support member 17 Partition plate 18 Coil spring Means )
25 Bearing 30 Fixed object

Claims (4)

A plurality of permanent magnets or coils installed at predetermined intervals in the circumferential direction, and a rotor that is rotatably supported by a fixed object;
A stator provided with the other of the permanent magnet or the coil so as to face one of the permanent magnet or the coil in the rotation center line direction of the rotor,
In the axial gap type electric motor having the electric motor portion arranged so that the stator has a predetermined gap in the rotation center line direction of the rotor and faces the rotor,
A case in which the rotor and the stator are internally provided, and the stator is fixed to an inner surface thereof;
A bearing provided between the case and the rotor and rotatably supporting the rotor, and sliding with respect to a surface of the case perpendicular to a rotation center line of the rotor ;
A biasing means that biases the case so that a biasing force is generated in a direction perpendicular to the centerline of the rotor, and the centerline of the rotor and the centerline of the stator are the same centerline;
An axial gap type electric motor comprising means for prohibiting relative rotation of the case with respect to the fixed object and permitting sliding in a direction perpendicular to a rotation center line of the rotor . The means for prohibiting relative rotation of the case and permitting sliding in a direction perpendicular to the rotation center line of the rotor is a linear guide installed between the fixed object and the case. The axial direction gap type electric motor according to claim 1 characterized by things. A support member disposed on the outer periphery of the bearing so as to be coaxial with the bearing and relatively rotatable,
2. The axial gap type electric motor according to claim 1, wherein the biasing means is provided between the case and the support member. Attenuating means is provided between the case and the rotor,
2. The axial gap type electric motor according to claim 1, wherein the biasing means is a spring provided between the case and the rotor.