JPH0574189U - Variable air gap type motor - Google Patents

Abstract

(57) [Summary] [Configuration] A rotor 11 having a conical shape is used. With the rotor 11 attracted by the electromagnet 2, the ridgeline 11
The inclination is such that a is parallel to the upper surface of the electromagnet 2. Rotor 1
Line contact between 1 and lining 9 increases the frictional force. The distance between the rotor 11 and the electromagnet 2 is made uniform and reduced. Six fan-shaped magnet pieces 12 are interposed between the frame 3 and the electromagnet 2. The polarity of each magnet piece 12 is set to be the same as that of the corresponding electromagnet 2, and the magnetic flux of the magnet piece 12 is prevented from weakening the magnetic flux of the electromagnet 2. [Effect] Slip between the rotor 11 and the lining 9 is less likely to occur, and the attractive force between the rotor 11 and the electromagnet 2 is increased, so that the rotation speed, the rotation torque, and the stationary torque are improved. The magnetic flux utilization efficiency of the electromagnet 2 and the magnet piece 12 is improved. A strong magnet can be used as the magnet piece 12 to obtain a high static torque.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a variable air gap type motor that obtains a rotating force by rotating the rotor by rubbing the rotor, and in particular, increases the frictional force between the rotor (rotor) and the stator (stator) and It relates to those that have improved usage efficiency.

[0002]

[Prior Art]

 Generally, there is a variable air gap type motor as one of the motors used for obtaining low speed and high torque. A conventional motor of this type is shown in FIG. The stator 1 has, for example, six electromagnets 2 arranged annularly on a frame 3 (see FIG. 3). The electromagnet 2 is formed by winding a winding 5 around a fan-shaped iron core 4. The disc-shaped rotor 6 is supported by a shaft 8 via a universal joint 7. On the other hand, a lining 9 is formed in an annular shape on the upper edge of the frame 3. By sequentially exciting the electromagnet 2, the rotor 6 is rubbed and rotated.

FIG. 3 is an explanatory diagram of excitation of the electromagnet 2. As shown in FIG. 3A, when the reference symbols # 1 to # 6 are attached to the respective electromagnetic stones 2, as shown in FIG. 3B, the square wave current is applied to the electromagnets # 1 to # 6 at a predetermined timing. It As a result, the rotor is subjected to a rubbing rotation by applying a rotational force counterclockwise as viewed in FIG.

Returning to FIG. 2, the scrubbing rotation will be described. The rotor 6 rotates about the shaft center of the rotor 6 while contacting the lining 9, and also revolves about the shaft center of the shaft 8. At this time, since there is a difference in diameter between the rotor 6 and the lining 9, the shaft 8 rotates in the direction opposite to the revolution direction as the rotor 6 revolves. As a result, low speed and high torque torque can be obtained.

Further, in the above configuration, there is a disadvantage that the electromagnet 2 must be continuously excited to obtain the static torque. Therefore, as shown in FIG. 4, the ring-shaped permanent magnet 10 is attached to the stator 1, A motor for fixing the electromagnet 2 on this has been proposed. According to this motor, the static torque can be obtained by the magnetic force of the permanent magnet 10 without exciting the electromagnet 2.

[0006]

[Problems to be solved by the device]

 However, the conventional variable air gap type motor has the following problems.

(1) Since the contact between the rotor 6 and the lining 9 is point contact, sufficient frictional force cannot be obtained at the contact portion between the two, and slippage occurs when the speed or torque is increased.

(2) Since the rotor 6 is a circular flat plate, the distance between the rotor 6 and the electromagnet 2 increases toward the center of the rotor 6, and the magnetic flux of the electromagnet 2 cannot be used effectively.

(3) Since three of the six electromagnets 2 operate in opposite polarities to the permanent magnet 10, the generated magnetic flux is weakened by the magnetic flux of the permanent magnet 10, and the magnetic flux of the electromagnet 2 is used. Efficiency is hindered.

In view of these problems, the present invention increases the frictional force between the rotor and the stator and uses the magnetic flux of the electromagnet in a variable air gap type motor that obtains a rotational force by rotating the rotor by rubbing the rotor. The purpose is to improve efficiency.

[0011]

[Means for Solving the Problems]

 This invention is provided with a stator in which a plurality of electromagnets are annularly installed so that the polarities are alternately arranged, and a rotor which is rotatably rubbed around the shaft center of the stator as a center of revolution, and the rotors are attracted by the electromagnets. It is a motor that rotates by rubbing and obtains rotational force by the diameter difference between the rotor and the stator.When the electromagnet is not driven, the permanent magnet that sucks and holds the rotor in the posture during rotation is superimposed on the electromagnet. The following measures have been taken in the variable air gap type motor that has been installed as described above.

(1) The rotor has a conical shape. This conical conical surface is inclined so that the following conditions are satisfied. In other words, when the rotor takes the posture during the rubbing rotation, the closest point of the conical surface to the stator is tilted so as to be almost perpendicular to the axial center of the stator.

(2) The permanent magnet is composed of a plurality of magnet pieces corresponding to each electromagnet. Furthermore, each magnet piece shall have the same polarity as that of each electromagnet.

[0014]

[Action]

 According to this invention, since the rotor has a conical shape having a conical surface with a predetermined inclination, the contact between the rotor and the lining is a line contact, and a stable friction force can be obtained. Moreover, the distance between the rotor and the stator is constant, and the distance does not increase toward the center as in the conventional structure, so that the distance between the electromagnet and the rotor can be made uniform and reduced, and the suction can be reduced. It leads to improvement of strength.

As a permanent magnet for generating static torque, a magnet piece having the same polarity as the polarity of each electromagnet is provided so as to overlap each electromagnet. That is, each magnet piece is mounted at a position where the generated magnetic flux matches the magnetic flux of the corresponding electromagnet. Therefore, when each electromagnet is driven, the magnetic flux of the magnet piece always works in the direction of strengthening the magnetic flux of the electromagnet.

[0016]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an outline of a variable air gap type motor according to an embodiment of the present invention. In the figure, the same or corresponding parts as in the conventional case are designated by the same reference numerals, and the description thereof will be omitted. In this embodiment, as the rotor, instead of the disc-shaped rotor 6, a hollow-cylindrical rotor 11 is used. This rotor 11 is assumed to satisfy the following conditions. That is, as shown in the figure, the inclination of the conical surface of the rotor 11 is set so that the ridgeline 11a seen from the side of the rotor 11 is parallel to the upper surface of the electromagnet 2 when the rotor is attracted by the electromagnet 2. It As a result, the rotor 11 and the lining 9 come into line contact with each other, so that the frictional force is stable and slippage between the two is unlikely to occur. Further, since the distance between the rotor 11 and the electromagnet 2 is uniform in the radial direction of the rotor 11, the distance between the two can be set smaller than in the conventional case, and the attraction force can be increased. From these points, the rotation speed, rotation torque, and static torque can be improved.

As the permanent magnet for generating the static torque, a plurality of magnet pieces 12 are used instead of the ring-shaped permanent magnet 10. That is, six fan-shaped magnet pieces 12 similar to the iron core 4 are attached to the frame 3 in an annular shape, and the electromagnet 2 is fixed onto each magnet piece 12. In this embodiment, the voltage pattern shown in FIG. 3B is adopted as the drive voltage for each electromagnet 2. Therefore, the polarity of each electromagnet 2 is set to one. Each magnet piece 12 is arranged so as to have the same polarity as that of the corresponding electromagnet 2. As a result, when each electromagnet 2 is driven, the magnetic flux generated by the electromagnet 2 and the magnetic flux of the magnet piece 12 are always in the same direction, and the magnetic flux of the magnet piece 12 works in the direction of strengthening the magnetic flux of the electromagnet 2. Therefore, a strong magnet can be used as the magnet piece 12, and a high static torque can be obtained.

[0019]

[Effect of the device]

 As described above, according to the present invention, the rotor and the stator are brought into line contact with each other to increase the frictional force, and it is difficult for slippage to occur between the rotor and the stator. Further, since the distance between the rotor and the stator is constant in the radial direction of the rotor, there is an advantage that the distance between the electromagnet and the rotor can be made uniform and reduced, and the magnetic flux can be utilized more effectively to improve the attractive force.

Further, since the permanent magnet for generating the static torque does not weaken the magnetic flux of the electromagnet and always works in the direction of strengthening the magnetic flux of the electromagnet, it is advantageous in the utilization efficiency of the magnetic flux. Moreover, even if a strong permanent magnet is used, there is no problem, and there is an advantage that a high static torque can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an outline of a variable air gap type motor according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an example of a conventional variable air gap type motor.

FIG. 3 is an explanatory diagram of excitation of an electromagnet in the motor of FIG.

FIG. 4 is an explanatory view showing an example of a conventional variable air gap type motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Stator 2 ... Electromagnet 3 ... Frame 9 ... Lining 11 ... Cone-shaped rotor 12 ... Magnet piece

Claims (1)

[Scope of utility model registration request] 1. A stator comprising a plurality of electromagnets arranged annularly so that polarities are alternately arranged, and a rotor rotatable by rubbing around the shaft center of the stator as a revolving center. The rotor is attracted by the electromagnets. A motor for performing a rubbing rotation to obtain a rotational force by a difference in diameter between a rotor and a stator, wherein a permanent magnet that attracts and holds the rotor in the posture during the rubbing rotation is superposed on the electromagnet when the electromagnet is not driven. In the variable air gap type motor mounted as described above, the rotor has a conical shape, and the conical conical surface has the closest portion to the stator substantially perpendicular to the axial center of the stator when the rotor takes the posture. It is inclined, and the permanent magnet is composed of a plurality of magnet pieces corresponding to each electromagnet, and each magnet piece has the same polarity as that of each electromagnet. Form motor.