JP2012039757A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively change magnetic force between a coil and a permanent magnet without enlargement of a magnetic body.SOLUTION: When a motor 10 is not energized, a magnetic body 30 is separated from a low magnetic permeability portion 14 of a yoke 12. Thus, the magnetic permeability of the yoke 12 can be made low and magnetic force between a coil 22 and a pair of permanent magnets 16 can be reduced. When the motor 10 is energized, a magnetic field of the low magnetic permeability portion 14 is enlarged and the magnetic body 30 is brought close to the low magnetic permeability portion 14 by magnetic force. Thus, the magnetic permeability of the yoke 12 is made high and the magnetic force between the coil 22 and a pair of the permanent magnets 16 can be enlarged. The magnetic body 30 slides and can be brought close to and separated from the low magnetic permeability portion 14. Thus, the magnetic permeability of the yoke 12 can effectively be changed by the magnetic body 30 without enlarging the magnetic body 30, and the magnetic force between the coil 22 and a pair of the permanent magnets 16 can effectively be changed.

Description

  The present invention relates to a motor in which a rotor is rotated by the action of a magnetic force between a coil and a permanent magnet and an electric current supplied to the coil.

  In the motor described in Patent Document 1 below, a permanent magnet for a field is provided in a through hole formed in a yoke, and the amount of magnetic flux acting on the armature is changed by rotating the permanent magnet. .

  However, in this motor, the permanent magnet is only rotated in the through hole of the yoke.

  For this reason, in order to effectively change the amount of magnetic flux acting on the armature, it is necessary to increase the magnetic force of the permanent magnet, thereby increasing the size of the permanent magnet.

Japanese Utility Model Publication No. 6-66278

  In view of the above facts, an object of the present invention is to obtain a motor that can effectively change the magnetic force between a coil and a permanent magnet without enlarging the magnetic material.

  The motor according to claim 1, wherein the rotor rotated by the action of the magnetic force between the coil and the permanent magnet and the current supplied to the coil, and the coil, the permanent magnet, and the rotor are disposed inside. A disposed yoke, a low magnetic permeability portion provided in the yoke and having a low magnetic permeability compared to other portions of the yoke, and a magnetic body capable of approaching and separating from the low magnetic permeability portion It is equipped with.

  According to a second aspect of the present invention, in the motor according to the first aspect, the magnetic body is separated from the low magnetic permeability portion, and a current is supplied to the coil so that the magnetic field of the low magnetic permeability portion is changed. There is provided an urging means that is enlarged so that the magnetic body approaches the low magnetic permeability portion against an urging force.

  According to a third aspect of the present invention, in the motor according to the first aspect of the present invention, the motor according to the first aspect includes moving means for moving the magnetic body corresponding to the rotational speed of the rotor so as to approach and separate from the low magnetic permeability portion. ing.

  In the motor according to claim 1, the coil, the permanent magnet, and the rotor are arranged inside the yoke, and the rotor rotates by the action of the magnetic force between the coil and the permanent magnet and the current supplied to the coil. Is done.

  Here, the low magnetic permeability portion provided in the yoke has a lower magnetic permeability than other portions of the yoke, and the magnetic material can be moved closer to and away from the low magnetic permeability portion.

  For this reason, even if it does not enlarge a magnetic body, the magnetic permeability of a yoke can be effectively changed with a magnetic body, and the magnetic force between a coil and a permanent magnet can be changed effectively.

  In the motor according to the second aspect, the biasing means separates the magnetic body from the low magnetic permeability portion of the yoke. For this reason, the magnetic permeability of the yoke can be reduced, the magnetic force between the coil and the permanent magnet can be reduced, and the cogging torque (rotational resistance torque of the rotor) generated in the motor can be reduced.

  Further, when a current is supplied to the coil, the magnetic field of the low-permeability portion of the yoke is increased, and the magnetic body approaches the low-permeability portion against the biasing force of the biasing means. For this reason, the magnetic permeability of the yoke can be increased, the magnetic force between the coil and the permanent magnet can be increased, and the output torque of the motor (the output rotation torque of the rotor) can be increased.

  In the motor according to the third aspect, the moving means moves the magnetic body in accordance with the rotational speed of the rotor so as to approach and separate from the low magnetic permeability portion of the yoke.

  For example, when the rotor rotates at a low speed, the moving means brings the magnetic body closer to the low permeability portion of the yoke. For this reason, the magnetic permeability of the yoke can be increased, the magnetic force between the coil and the permanent magnet can be increased, and the output torque of the motor (the output rotation torque of the rotor) can be increased.

  On the other hand, when the rotor rotates at high speed, the moving means separates the magnetic body from the low magnetic permeability portion of the yoke. For this reason, the magnetic permeability of the yoke can be reduced, the magnetic force between the coil and the permanent magnet can be reduced, the counter electromotive force generated in the coil can be reduced, and the maximum rotation speed of the rotor can be increased.

It is sectional drawing which shows the time of the non-energization of the motor which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the time of electricity supply of the motor which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the control system of the motor which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the time of low speed rotation of the motor which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the time of high speed rotation of the motor which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the control system of the motor which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the motor which concerns on the 3rd Embodiment of this invention. It is sectional drawing which shows the motor which concerns on the 4th Embodiment of this invention. It is sectional drawing which shows the motor which concerns on the 5th Embodiment of this invention. It is sectional drawing which shows the motor which concerns on the 6th Embodiment of this invention.

[First Embodiment]
FIG. 1 shows a sectional view of a motor 10 according to a first embodiment of the present invention.

  The motor 10 according to the present embodiment is a direct current motor (DC motor).

  As shown in FIG. 1, the motor 10 is provided with a container-shaped yoke 12 (housing) having a substantially elliptical cross section (or a circular cross section), and the yoke 12 is made of a magnetic material (for example, a metal such as iron). Has been.

  A pair of low magnetic permeability portions 14 are formed on the yoke 12, and the pair of low magnetic permeability portions 14 are arranged at equal intervals in the circumferential direction of the yoke 12 and face each other across the central axis of the yoke 12. ing. The low magnetic permeability portion 14 is a through hole (gap) that penetrates the yoke 12. The low magnetic permeability portion 14 has a lower magnetic permeability than portions other than the low magnetic permeability portion 14 of the yoke 12. Yes.

  A pair of plate-like permanent magnets 16 are provided in the yoke 12, and the permanent magnets 16 are curved along the inner peripheral surface of the yoke 12 (circumferential surface coaxial with the yoke 12), 12 is fixed to the inner peripheral surface. The pair of permanent magnets 16 is for field use, and the pair of permanent magnets 16 are opposed to each other across the central axis of the yoke 12. Further, the low magnetic permeability portion 14 of the yoke 12 is disposed in the central portion in the circumferential direction of the yoke 12 between the pair of permanent magnets 16.

  A shaft-like rotor 18 (rotor) is provided in the yoke 12, and the rotor 18 is rotatably supported on the same axis as the yoke 12 and is disposed between the pair of permanent magnets 16. Yes.

  The rotor 18 is provided with a predetermined number of core portions 20 having a substantially T-shaped cross section, and the predetermined number of core portions 20 are arranged at equal intervals in the circumferential direction of the rotor 18. The core portion 20 projects outward in the radial direction of the rotor 18, and the tip side portion of the core portion 20 is curved along the circumferential direction of the rotor 18.

  A coil 22 (wire) is wound around the core portion 20. A current can be supplied to the coil 22 via a brush (not shown), and the direction of the current supplied to the coil 22 is determined. It can be changed by a brush according to the rotational position of the rotor 18.

  As shown in FIG. 3, the coil 22 of the motor 10 can be electrically connected to a driver 24 as a driving means via a brush, and the driver 24 is electrically connected to a control circuit 26 as a control means. The driver 24 can supply current to the coil 22 via a brush under the control of the control circuit 26.

  The rotor 18 of the motor 10 is connected to a switch 28 as a drive target (operation member), and the rotor 18 is rotated in conjunction with the operation of the switch 28. The output rotational torque of the rotor 18 (output torque of the motor 10) acts as an operation reaction force of the switch 28.

  As shown in FIG. 1, a pair of plate-like (or columnar) magnetic bodies 30 are arranged outside the yoke 12, and the magnetic bodies 30 are made of a metal such as iron (may be a magnet). One end of a coil spring 32 as urging means is connected to the magnetic body 30, and the axial direction of the coil spring 32 is arranged along the radial direction of the yoke 12. The other end of the coil spring 32 is fixed to the outside of the yoke 12 in the radial direction from the magnetic body 30, and the magnetic body 30 is opposed to the low permeability portion 14 of the yoke 12 in the radial direction of the yoke 12. Therefore, it is separated from the low magnetic permeability part 14. The magnetic body 30 is moved (slid) toward the yoke 12 against the urging force of the coil spring 32, thereby approaching the low magnetic permeability portion 14 of the yoke 12 and being inserted (inserted) into the low magnetic permeability portion 14. ) Has been made possible.

  Next, the operation of the present embodiment will be described.

  As shown in FIG. 1, when the motor 10 is not energized, no current is supplied to the coil 22 and the rotor 18 is not rotated. Further, when the rotor 18 is rotated in conjunction with the operation of the switch 28, cogging torque (rotational resistance torque of the rotor 18) is applied to the motor 10 by the magnetic force between the coil 22 and the pair of permanent magnets 16. appear.

  As shown in FIG. 2, when the motor 10 is energized, current is supplied from the driver 24 to the coil 22 by the control of the control circuit 26, so that the magnetic force between the coil 22 and the pair of permanent magnets 16 is supplied to the coil 22. The rotor 18 is rotated by the action of the generated current. As a result, the output rotational torque of the rotor 18 (output torque of the motor 10) acts on the switch 28 as an operation reaction force.

  Here, when the motor 10 is not energized, the coil spring 32 separates the magnetic body 30 from the low permeability portion 14 of the yoke 12. For this reason, the magnetic permeability of the yoke 12 (low magnetic permeability part 14) can be made low, and the magnetic force between the coil 22 and a pair of permanent magnets 16 can be made small. Thereby, when the switch 28 is operated, the cogging torque (rotational resistance torque of the rotor 18) generated in the motor 10 can be reduced, and the operation feeling of the switch 28 can be improved.

  On the other hand, when the motor 10 is energized, a current is supplied to the coil 22, so that the magnetic field of the low permeability portion 14 of the yoke 12 is increased and the magnetic body 30 resists the biasing force of the coil spring 32 by the magnetic force. The low magnetic permeability part 14 is approached and inserted (adsorbed). For this reason, the magnetic permeability of the yoke 12 (low magnetic permeability part 14) can be increased, and the magnetic force between the coil 22 and the pair of permanent magnets 16 can be increased. As a result, the output torque of the motor 10 (the output rotation torque of the rotor 18) can be increased, and the operation reaction force of the switch 28 can be prevented from decreasing.

  As described above, when the output torque of the motor 10 is used as the operation reaction force of the switch 28, the operation feeling of the switch 28 can be improved and the operation reaction force of the switch 28 can be prevented from being lowered.

  Further, the magnetic body 30 is slid with respect to the low magnetic permeability portion 14 of the yoke 12 so as to be able to approach and separate. Therefore, the magnetic body 30 can effectively change the magnetic permeability of the yoke 12 (low magnetic permeability portion 14) without increasing the size of the magnetic body 30. The magnetic force can be effectively changed.

  In the present embodiment, the biasing means is the coil spring 32, but the biasing means may be a leaf spring or the like.

[Second Embodiment]
FIG. 4 is a sectional view showing a motor 50 according to the second embodiment of the present invention.

  The motor 50 according to the present embodiment has substantially the same configuration as that of the first embodiment, but differs in the following points.

  The motor 50 according to the present embodiment is for driving a vehicle (for example, a hybrid vehicle or an electric vehicle) as a driving target, and the coil spring 32 in the first embodiment is not provided.

  As shown in FIG. 4, a linear actuator 52 as a moving means is connected to the magnetic body 30, and the linear actuator 52 is driven to move the magnetic body 30 to the yoke 12 in the radial direction of the yoke 12. It is possible to move (slide) in a state facing the low magnetic permeability portion 14. As a result, the magnetic body 30 can approach and be inserted (inserted) into the low magnetic permeability portion 14 and can be separated from the low magnetic permeability portion 14.

  As shown in FIG. 6, the rotor 18 of the motor 50 is provided with a sensor 54 as detection means, and the sensor 54 can detect the rotation angle or the rotation angular velocity of the rotor 18. The sensor 54 is electrically connected to the control circuit 26, and a linear actuator 52 is electrically connected to the control circuit 26, and the control circuit 26 detects the rotor 18 based on the detection result of the sensor 54. The rotational speed (including the rotational angular speed) is detected, and the drive of the linear actuator 52 is controlled.

  Next, the operation of the present embodiment will be described.

  When the motor 50 is energized, current is supplied from the driver 24 to the coil 22 under the control of the control circuit 26, so that the magnetic force between the coil 22 and the pair of permanent magnets 16 and the current supplied to the coil 22 are affected. Thus, the rotor 18 is rotated. Thereby, the output rotational torque of the rotor 18 (the output torque of the motor 50) is used as the driving force of the vehicle.

  Here, as shown in FIG. 4, when the motor 50 (rotor 18) rotates at a low speed (when the control circuit 26 detects that the rotation speed of the rotor 18 is low), the linear actuator 52 performs control. By being driven by the control of the circuit 26, the magnetic body 30 is inserted close to the low permeability portion 14 of the yoke 12. For this reason, the magnetic permeability of the yoke 12 (low magnetic permeability part 14) can be increased, and the magnetic force between the coil 22 and the pair of permanent magnets 16 can be increased. As a result, the output torque of the motor 50 (the output rotation torque of the rotor 18) can be increased, and the driving torque of the vehicle can be increased.

  On the other hand, as shown in FIG. 5, when the motor 50 (rotor 18) rotates at high speed (when the control circuit 26 detects that the rotation speed of the rotor 18 is high), the linear actuator 52 is controlled by the control circuit. The magnetic body 30 is separated from the low magnetic permeability portion 14 of the yoke 12 by being driven by the control 26. For this reason, the magnetic permeability of the yoke 12 (low magnetic permeability part 14) can be made low, and the magnetic force between the coil 22 and a pair of permanent magnets 16 can be made small. Thereby, the counter electromotive force generated in the coil 22 can be reduced, the maximum rotation speed of the rotor 18 can be increased, and the maximum drive speed of the vehicle can be increased.

  As described above, the high output performance in a wide region from the low speed rotation region to the high speed rotation region required for the motor 50 for driving the vehicle can be realized by one motor 50.

  Further, the magnetic body 30 is slid with respect to the low magnetic permeability portion 14 of the yoke 12 so as to be able to approach and separate. Therefore, the magnetic body 30 can effectively change the magnetic permeability of the yoke 12 (low magnetic permeability portion 14) without increasing the size of the magnetic body 30. The magnetic force can be effectively changed.

  In the present embodiment, when the rotational speed of the motor 50 is low, the linear actuator 52 inserts the magnetic body 30 into the low permeability portion 14 of the yoke 12 and when the rotational speed of the motor 50 is high. The linear actuator 52 separates the magnetic body 30 from the low magnetic permeability portion 14 of the yoke 12, but the linear actuator 52 moves the magnetic body 30 to the low speed of the yoke 12 as the rotational speed of the motor 50 changes from low speed to high speed. The magnetic permeability portion 14 may be gradually separated (continuously steplessly).

[Third Embodiment]
FIG. 7 is a sectional view showing a motor 60 according to the third embodiment of the present invention.

  The motor 60 according to the present embodiment has substantially the same configuration as the first embodiment or the second embodiment, but differs in the following points.

  The motor 60 according to the present embodiment is a so-called IPM motor.

  As shown in FIG. 7, the permanent magnets 16 have a flat plate shape and are provided in a predetermined number inside the rotor 18, and the predetermined number of permanent magnets 16 are arranged at equal intervals in the circumferential direction of the rotor 18. Has been.

  In the yoke 12, a cylindrical stator 62 (stator) is provided outside the rotor 18 in the radial direction, and the stator 62 is fixed to the inner peripheral surface of the yoke 12.

  The predetermined number of core portions 20 have a substantially I-shaped cross section and are provided on the stator 62. The predetermined number of core portions 20 protrude inward in the radial direction of the stator 62, and the stator. 62 are arranged at equal intervals in the circumferential direction. Although not shown in FIG. 7, a coil 22 is wound around the core portion 20.

  Here, also in the present embodiment, the same operations and effects as those of the first embodiment or the second embodiment can be achieved.

[Fourth Embodiment]
FIG. 8 shows a sectional view of a motor 70 according to a fourth embodiment of the present invention.

  The motor 70 according to the present embodiment has substantially the same configuration as that of the third embodiment, but differs in the following points.

  The motor 70 according to the present embodiment is a so-called SPM motor.

  As shown in FIG. 8, the permanent magnets 16 are formed in a substantially semi-cylindrical shape, and a predetermined number of permanent magnets 16 are fixed to the outer peripheral surface of the rotor 18. Arranged at intervals.

  Here, also in this embodiment, the same operations and effects as those of the third embodiment can be achieved.

[Fifth Embodiment]
FIG. 9 is a sectional view showing a motor 80 according to the fifth embodiment of the present invention.

  The motor 80 according to the present embodiment has substantially the same configuration as the first embodiment or the second embodiment, but differs in the following points.

  The motor 80 according to the present embodiment is a so-called brushless DC motor.

  As shown in FIG. 9, the permanent magnet 16 is formed in a cylindrical shape to constitute a rotor 18.

  In the yoke 12, a cylindrical stator 62 (stator) is provided outside the rotor 18 (permanent magnet 16) in the radial direction. The stator 62 is fixed to the inner peripheral surface of the yoke 12. Yes.

  The predetermined number of core portions 20 are provided on the stator 62, and the predetermined number of core portions 20 are arranged at equal intervals in the circumferential direction of the stator 62. The core portion 20 protrudes inward in the radial direction of the stator 62, and the tip side portion of the core portion 20 is curved along the circumferential direction of the stator 62.

  A driver 24 can be electrically connected to the coil 22 wound around the core unit 20 without using a brush, and the driver 24 can supply current to the coil 22 under the control of the control circuit 26. In addition, the direction of the current supplied to the coil 22 can be changed according to the rotational position of the rotor 18.

  Here, also in the present embodiment, the same operations and effects as those of the first embodiment or the second embodiment can be achieved.

[Sixth Embodiment]
FIG. 10 is a sectional view showing a motor 90 according to the sixth embodiment of the present invention.

  The motor 90 according to the present embodiment has substantially the same configuration as the first embodiment or the second embodiment, but differs in the following points.

  The motor 90 according to the present embodiment is a so-called coreless motor.

  As shown in FIG. 10, the permanent magnet 16 has a cylindrical shape, and the permanent magnet 16 is coaxially fixed in the yoke 12.

  The rotor 18 is made of resin and has a bottomed cylindrical shape. The rotor 18 is rotatably supported coaxially with the yoke 12, and the cylindrical portion is disposed between the yoke 12 and the permanent magnet 16. ing.

  The rotor 18 is not provided with the core portion 20, and the coil 22 is enclosed in the rotor 18.

  Here, also in the present embodiment, the same operations and effects as those of the first embodiment or the second embodiment can be achieved.

  In each of the above embodiments, the yoke 12 is provided with a pair of low magnetic permeability portions 14 to which the magnetic body 30 can approach and separate, but the yoke 12 has the low magnetic permeability portions 14 to which the magnetic body 30 can approach and separate. One or three or more may be provided.

  In each of the above embodiments, the through hole of the yoke 12 is the low magnetic permeability portion 14, but the concave portion (thin wall portion) of the yoke 12 is the low magnetic permeability portion 14, or the low magnetic permeability material portion of the yoke 12 is used. The low permeability portion 14 may be used.

DESCRIPTION OF SYMBOLS 10 Motor 12 Yoke 14 Low-permeability part 16 Permanent magnet 18 Rotor 22 Coil 30 Magnetic body 32 Coil spring (biasing means)
50 Motor 52 Linear actuator (moving means)
60 motor 70 motor 80 motor 90 motor

Claims (3)

A rotor rotated by the action of the magnetic force between the coil and the permanent magnet and the current supplied to the coil;
A yoke in which the coil, the permanent magnet, and the rotor are disposed, and
A low magnetic permeability portion provided in the yoke and having a lower magnetic permeability than other portions of the yoke;
A magnetic body capable of approaching and separating from the low magnetic permeability portion;
With motor.   The magnetic body is separated from the low-permeability portion, and a current is supplied to the coil, so that the magnetic field of the low-permeability portion is increased and the magnetic body resists an urging force. The motor according to claim 1, further comprising an urging means that is approached by the motor.   The motor according to claim 1, further comprising a moving unit that moves the magnetic body in accordance with a rotation speed of the rotor so as to approach and separate the low magnetic permeability portion.

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