JP2006006032A - Motor and fan motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor small in size and large in generation torque. <P>SOLUTION: The motor includes a first coil row including a plurality of coils arranged along a prescribed direction, and at least one magnet, and also is provided with first and second magnet rows whose mutual relative positional relationships are fixed and whose relative positional relationships with respect to the first coil row are changeable along the prescribed direction. The first and the second magnet rows are arranged at both sides of the first coil row so as to sandwich it. Each coil of the first coil row substantially has not a core made of a magnetic body, and the motor substantially has not a yoke made of a magnetic body for forming a magnetic circuit. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electric machine such as an electric motor or a generator, and a fan motor using the electric machine.

  There are two types of electric motors: synchronous (synchronous) motors and induction (induction) motors. Also, depending on the rotor, the motor types can be classified into a magnet type using a permanent magnet, a winding type with a coil wound, and a reactance type using a ferromagnetic such as iron. . In the magnet type, the permanent magnet of the rotor is rotated by being attracted by the rotating magnetic field of the stator.

  As a magnet-type synchronous motor, for example, there is a small synchronous motor described in Patent Document 1 below. This small synchronous motor includes a stator core wound with an exciting coil and a rotor including a magnet.

JP-A-8-51745

  However, the conventional motor has a problem that it is heavier than the generated torque and is increased in size when the generated torque is increased.

  Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and to provide an electric motor that is small and light and has a large generated torque.

  In order to achieve at least a part of the above object, an electric motor of the present invention includes a first coil array including a plurality of coils arranged along a predetermined direction, each including at least one magnet, The first and second magnet rows are fixed, and the relative positional relationship with respect to the first coil row is changeable along the predetermined direction. The first and second magnet arrays are disposed on both sides of the first coil array. Each coil of the first coil array has substantially no magnetic core, and the electric motor has substantially no magnetic yoke for forming a magnetic circuit. .

  In this electric motor, since the first and second magnet rows are arranged on both sides of the first coil row, the magnetic flux generated on both sides of the first coil row is effectively used for generating the driving force. It is possible to realize an electric motor that can be used, has high use efficiency of magnetic flux, has high efficiency, and large generated torque.

  This electric motor is light because it has substantially no magnetic core or magnetic yoke, and has an excellent balance between torque and weight when used as an actuator. In addition, since the magnetic core is not provided, stable and smooth rotation is possible without causing cogging. Furthermore, since the magnetic yoke is not substantially included, there is almost no iron loss (eddy current loss), and an efficient motor can be realized.

  The electric motor includes a plurality of coils arranged along the predetermined direction, the relative positional relationship with the first coil array is fixed, and the first and second magnet arrays Further, a second coil array is disposed on either side of the first coil array, with either one interposed therebetween, and each coil of the second coil array is made of a magnetic material. The core may not be substantially included.

  According to such a configuration, the magnetic flux generated on one side of the second coil array can also be used for generating the driving force, and a motor with a large generated torque can be realized.

The electric motor further includes a case for housing the coil array and the magnet array, and each coil of the coil array is wound around a support material formed of a substantially non-magnetic and non-conductive material. The case may be formed of a substantially non-magnetic and non-conductive material.
According to this configuration, an electric motor with almost no iron loss or cogging can be realized.

The electric motor may be configured such that the rotating shaft and the structural material other than the bearing portion are formed of a substantially non-magnetic and non-conductive material.
According to this configuration, the weight can be further reduced, and the iron loss can be further reduced.

  The electric motor may be a rotary motor or a rotary generator in which the coil row and the magnet row rotate relatively along the predetermined direction.

  In the above electric motor, the first coil array includes a first phase coil array including a plurality of coils arranged at a predetermined pitch along the predetermined direction and electrically connected to each other, the second coil array The coil array includes a second phase coil array including a plurality of coils arranged at a predetermined pitch along the predetermined direction and electrically connected to each other, and the first phase coil array and the second phase coil array The phase coil arrays may be arranged at positions shifted from each other by an odd multiple of π / 2 in electrical angle.

  Thus, by providing the first coil group with the first phase coil group and the second coil group with the second phase coil group, it is possible to reliably determine the rotation direction when the electric motor is started.

  In the electric motor, the first coil array includes a first phase coil array including a plurality of coils arranged at a predetermined pitch along the predetermined direction and electrically connected to each other, and the predetermined direction. A second phase coil array including a plurality of coils arranged at a predetermined pitch along the electrical connection, and the first phase coil array and the second phase coil array having an electrical angle It is good also as what is arrange | positioned in the position which mutually shifted | deviated by odd multiple of (pi) / 2.

  As described above, the first coil group includes the first phase coil group and the second phase coil group, so that the rotation direction can be reliably determined at the start of the motor, and the motor can be downsized. Become.

The electric motor further includes a drive signal generation circuit for supplying a first AC drive signal supplied to the first coil array and a second AC drive signal supplied to the second coil array, In the drive signal generation circuit, the polarities of the coils of the first phase coil array and the second phase coil array are such that the centers of the magnets in the first and second magnet arrays face each other. The magnetic flux density in the coil array is maximized at the timing when the center position between adjacent coils belonging to the coil array of the same phase is opposed to the center of the magnet in the first and second magnet arrays. In addition, the first and second AC drive signals may be generated.
According to this configuration, the electric motor can be driven in synchronization with the drive signal.

  In the electric motor, the drive signal generation circuit reverses the current direction of the first phase coil array and the second phase coil array, thereby causing the first phase coil array, the second phase coil array, and the first and second phase coils. It is preferable to be able to reverse the direction of operation with the magnet array.

  In the above electric motor, the drive signal generation circuit responds to an output request to the electric motor and first and second PWM circuits that generate first and second PWM signals whose phases are shifted from each other by π / 2, respectively. A mask circuit that generates the first and second AC drive signals by masking the first and second PWM signals.

  According to this configuration, the output of the electric motor can be adjusted by masking the PWM signal by the mask circuit.

  In the above electric motor, the mask circuit may mask each PWM signal in a symmetric time range centering on a timing at which the polarity of each AC drive signal is inverted.

  Generally, in the vicinity of the timing at which the polarity of each AC drive signal is inverted, the coil does not generate a very effective driving force, and tends to generate an effective driving force in the vicinity of the peak of the AC driving signal. Therefore, according to the above configuration, since the PWM signal is masked in a period in which the coil does not generate an effective driving force, the efficiency of the electric motor can be improved.

  The electric motor further includes a regeneration circuit for regenerating power from the first phase coil and the second phase coil array, and the drive signal generation circuit and the regeneration circuit include the first phase coil array and the second phase coil. It is preferable that the electric motor can be operated in an operation mode in which driving force is generated from one of the coil arrays and electric power is regenerated from the other.

  According to this configuration, the electric motor can be operated while simultaneously performing generation of driving force and regeneration of electric power as necessary.

  In the electric motor, the first coil array includes a first phase coil array including a plurality of coils arranged at a predetermined pitch along the predetermined direction and electrically connected to each other, and the predetermined direction. And a second phase coil array including a plurality of coils arranged at a predetermined pitch along the predetermined direction and electrically connected to each other, and arranged at a predetermined pitch along the predetermined direction and electrically connected to each other A third-phase coil array including a plurality of coils, wherein the first-phase coil array, the second-phase coil array, and the third-phase coil array are shifted from each other by 2π / 3 in electrical angle. It may be arranged at a position.

  Even with this configuration, the magnetic flux generated on both sides of the first coil array can be effectively used for generating the driving force, and the motor can be used with high efficiency, high efficiency, and large generated torque. Can do. In addition, an electric motor excellent in torque and weight balance can be realized. Moreover, stable and smooth rotation is possible without cogging, and an efficient electric motor with almost no iron loss can be realized.

  In addition, you may make it utilize the said electric motor for the fan motor for rotating a fan.

  In addition, the fan motor includes a stator having a first coil array including a plurality of coils arranged in the rotation direction, and at least one magnet, and the relative positional relationship with each other is fixed. A rotor having first and second magnet rows and capable of changing a relative positional relationship of the first and second magnet rows with respect to the first coil row along the rotation direction. The first and second magnet rows of the rotor are arranged on both sides of the first coil row of the stator, and the fan is integrally formed on the outer periphery of the rotor. In addition, each coil of the first coil array substantially does not have a magnetic core, and the fan motor substantially includes a magnetic yoke for forming a magnetic circuit. You do n’t have to .

  Furthermore, in the fan motor, the stator includes a second coil array including a plurality of coils arranged along the rotation direction, and a relative positional relationship with the first coil array is fixed. And the second coil array sandwiches one of the first and second magnet arrays of the rotor and is opposite to the side of the stator on which the first coil array is disposed. It may be arranged on the side.

  According to the above configuration, even if the fan motor is configured to output a corresponding torque in order to rotate the fan at a desired number of rotations, the external dimensions can be made very small. Therefore, since the area occupied by the fan motor with respect to the cross-sectional area of the flow path can be reduced, the loss in the flow path can be suppressed, and the wind efficiency (power / air volume ratio) of the fan can be improved.

  The present invention can be realized in various modes. For example, electric actuators, electric motors such as linear motors and rotary motors, generators, actuators and motors thereof, driving methods and driving of the generators, and the like. It can be realized in the form of an apparatus or the like.

Hereinafter, embodiments of the present invention will be described in the following order based on examples.
A. First embodiment (two-phase motor):
B. Second embodiment (two-phase motor: fan motor):
C. Third embodiment (two-phase motor):
D. Various modifications of the two-phase motor:
E. Fourth embodiment (two-phase motor):
F. Fifth embodiment (three-phase motor):
G. Example 6:
H. Other variations:

A. First embodiment (two-phase motor):
FIG. 1A is an explanatory diagram showing a schematic configuration of the electric motor in the first embodiment of the present invention. This electric motor has an A-phase coil array structure 10A, a B-phase coil array structure 20B, a first magnet array structure 30M, and a second magnet array structure 40M.

  The A-phase coil array structure 10A includes a support material 12A and an A-phase coil array 14A fixed to the support material 12A. This A-phase coil array 14A is formed by alternately arranging two types of coils 14A1 and 14A2 excited in opposite directions at a constant pitch Pc. In the state of FIG. 1A, the three coils 14A1 are excited so that the magnetization direction (direction from the N pole to the S pole) is downward, and the other three coils 14A2 have the magnetization direction upward. Excited to become.

  The B phase coil array structure 20B also includes a support material 22B and a B phase coil array 24B fixed to the support material 22B. This B-phase coil array 24B is also formed by alternately arranging two types of coils 24B1 and 24B2 excited in opposite directions at a constant pitch Pc. In the present specification, “coil pitch Pc” is defined as the pitch between coils of the A-phase coil array or the pitch between coils of the B-phase coil array.

  The first magnet array structure 30M includes a support member 32M and a first magnet array 34M fixed to the support member 32M. The first magnet array structure 30M is outside the A-phase coil array structure 10A (upper side in FIG. 1A). ). The permanent magnets of the first magnet row 34M are arranged so that the magnetization direction is in a direction perpendicular to the arrangement direction of the magnet row 34M (the left-right direction in FIG. 1A). The magnets of the first magnet row 34M are arranged at a constant magnetic pole pitch Pm.

  The second magnet array structure 40M also includes a support material 42M and a second magnet array 44M fixed to the support material 42M. The second magnet array structure 40M includes an A-phase coil array structure. Arranged between 10A and B-phase coil array structure 20B. The permanent magnets of the second magnet row 44M are also arranged so that the magnetization direction is in a direction perpendicular to the arrangement direction of the magnet row 44M (the left-right direction in FIG. 1A). The magnets of the second magnet row 44M are also arranged at a constant magnetic pole pitch Pm.

  In this example, the magnetic pole pitch Pm is equal to the coil pitch Pc and corresponds to π in electrical angle. The electrical angle 2π is associated with a mechanical angle or distance that moves when the phase of the motor drive signal changes by 2π. In the first embodiment, when the phases of the drive signals of the A-phase coil group 14A and the B-phase coil group 24B change by 2π, the first magnet array structure 30M and the second magnet array structure 40M each have a coil pitch Pc of 2. Move by a factor of two.

  The A-phase coil group 14A and the B-phase coil group 24B are arranged at positions different from each other by π / 2 in electrical angle. The A-phase coil group 14A and the B-phase coil group 24B differ only in position and have substantially the same configuration in other points. Therefore, hereinafter, only the A-phase coil array will be described except when particularly necessary in the description of the coil array.

  In addition, the first magnet row 34M and the second magnet row 44M are arranged at the same position (that is, a zero electrical angle position) and have substantially the same configuration.

  FIG. 1B shows an example of the waveform of the AC drive signal supplied to the A-phase coil group 14A and the B-phase coil group 24B. Two-phase AC signals are respectively supplied to the A-phase coil group 14A and the B-phase coil group 24B. Further, the phases of the drive signals of the A-phase coil group 14A and the B-phase coil group 24B are shifted from each other by π / 2. The state in FIG. 1A corresponds to a phase zero (or 2π) state.

  The electric motor further includes a position sensor 16A for the A-phase coil group 14A and a position sensor 26B for the B-phase coil group 24B. These are hereinafter referred to as “A phase sensor” and “B phase sensor”. The A-phase sensor 16A is disposed at the center position between the two coils of the A-phase coil array 14A, and the B-phase sensor 26B is disposed at the center position between the two coils of the B-phase coil array 24B. Yes. As these sensors 16A and 26B, those having an analog output having a waveform similar to that of the AC drive signal shown in FIG. 1B are preferably employed. For example, a Hall IC utilizing the Hall effect may be employed. it can. However, it is also possible to employ a sensor having a rectangular wave digital output. It is also possible to perform sensorless driving by omitting the position sensor.

  The support members 12A, 22B, 32M, and 42M are each formed of a nonmagnetic material. Also, among the various members of the electric motor of the present embodiment, the members other than the electric wiring including the coil and the sensor, the magnet, the rotating shaft, and the bearing portion thereof are all non-magnetic and non-conductive materials. Preferably it is formed.

  FIGS. 2A and 2B are diagrams showing a method of connecting two types of coils 14A1 and 14A2 of the A-phase coil array 14A. In the connection method of FIG. 2A, all the coils included in the A-phase coil array 14A are connected in series to the drive signal generation circuit 100. On the other hand, in the connection method of FIG. 2 (B), a plurality of sets of series connections including a pair of coils 14A1 and 14A2 are connected in parallel. In any of these connection methods, the two types of coils 14A1 and 14A2 are always magnetized with opposite polarities.

  3 (A), 3 (B) and FIGS. 4 (A), 4 (B) show the operation of the electric motor of the first embodiment. In the first embodiment, the coil arrays 14A and 24B are configured as a stator, and the magnet arrays 34M and 44M are configured as a rotor. Therefore, in FIGS. 3 (A), 3 (B) and FIGS. 4 (A), 4 (B), the magnet arrays 34M, 44M are moving with time.

  FIG. 3A shows a state at the timing immediately before the phase is 2π. In addition, the solid line arrow drawn between the coil and the magnet indicates the direction of the attractive force, and the broken line arrow indicates the direction of the repulsive force. In this state, the A-phase coil group 14A disposed between the first magnet group 34M and the second magnet group 44M operates in the operating direction (with respect to the first magnet group 34M and the second magnet group 44M). The driving force in the right direction in the figure is not applied, and the magnetic force acts in the direction in which the first magnet row 34M and the second magnet row 44M are attracted to the A-phase coil row 14A. Therefore, it is preferable that the voltage applied to the A-phase coil group 14A is zero at the timing when the phase is 2π.

  On the other hand, the B-phase coil group 24B arranged on the opposite side of the A-phase coil group 14A (lower side in FIG. 3A) across the second magnet group 44M is in the direction of operation to the second magnet group 44M. Driving force is given. Further, since the B-phase coil group 24B gives not only an attractive force but also a repulsive force to the second magnet group 44M, a vertical direction (second magnet group) from the B-phase coil group 24B to the second magnet group 44M. The net force in the direction perpendicular to the 44M motion direction is zero. Therefore, it is preferable that the voltage applied to the B-phase coil group 24B has a peak value at the timing when the phase is 2π.

  As shown in FIG. 1B, the polarity of the A-phase coil group 14A is inverted at the timing when the phase is 2π. FIG. 3B shows a state where the phase is π / 4, and the polarity of the A-phase coil group 14A is reversed from that shown in FIG. In this state, the A-phase coil group 14A gives a driving force in the operating direction to the first magnet group 34M and the second magnet group 44M, and the B-phase coil group 24B gives a driving force in the operating direction to the second magnet group 44M. . FIG. 4A shows a state immediately before the phase is π / 2. In this state, contrary to the state shown in FIG. 3A, only the A-phase coil group 14A applies a driving force in the operation direction to the first magnet group 34M and the second magnet group 44M. At the timing when the phase is π / 2, the polarity of the B-phase coil group 24B is inverted to the polarity shown in FIG. FIG. 4B shows a state where the phase is 3π / 4. In this state, the A-phase coil group 14A gives a driving force in the operating direction to the first magnet group 34M and the second magnet group 44M, and the B-phase coil group 24B gives a driving force in the operating direction to the second magnet group 44M. .

  As can be understood from FIGS. 3 (A), 3 (B) and FIGS. 4 (A), 4 (B), the polarity of the A-phase coil array 14A is such that each coil of the A-phase coil array 14A is the first magnet array. It is switched at the timing of facing each magnet of 34M and the second magnet row 44M. The polarity of the B-phase coil group 24B is switched at a timing at which each coil of the B-phase coil group 24B corresponds to each magnet of the second magnet group 44M. As a result, a driving force can be almost always generated from all the coils, so that a large torque can be generated.

  Note that the period in which the phase is π to 2π is substantially the same as that in FIGS. 3A and 3B and FIGS. 4A and 4B, and thus detailed description thereof is omitted. However, the polarity of the A-phase coil group 14A is inverted again at the timing of the phase π, and the polarity of the B-phase coil group 24B is inverted again at the timing of the phase 3π / 2.

  As can be understood from the above description, the electric motor of this embodiment includes the A-phase coil group 14A and the first magnet group 34M and the second magnet group 44M, and the B-phase coil group 24B and the second phase. The driving force in the operation direction with respect to the first magnet row 34M and the second magnet row 44M is obtained by utilizing the attractive force and the repulsive force between the first magnet row 44M and the second magnet row 44M. In particular, in the present embodiment, since the first magnet row 34M and the second magnet row 44M are arranged on both sides of the A phase coil row 14A, the magnetic flux generated on both sides of the A phase coil row 14A is It can be effectively used for generating driving force. Therefore, compared with the case where only one side of the coil is used for generating the driving force as in the case of a conventional electric motor, it is possible to realize a motor with high efficiency and high torque with high use efficiency of magnetic flux. Further, since the B-phase coil group 24B is also arranged outside the second magnet group 44M (lower side in the above figure), the magnetic flux generated on one side of the B-phase coil group 24B is also used for generating the driving force. can do. Therefore, a motor with a larger torque can be realized.

  Further, in the motor of this embodiment, since a magnetic core is not provided, so-called cogging does not occur, and a smooth and stable operation can be realized. Further, since the yoke for constituting the magnetic circuit is not provided, so-called iron loss (eddy current loss) is extremely small, and an efficient motor can be realized.

  By the way, in a normal motor, it is considered that the utilization efficiency of magnetic flux is reduced if there is no core or yoke. On the other hand, in the electric motor of the present embodiment, the first magnet row 34M and the second magnet row 44M are arranged on both sides of the A-phase coil row 14A. There is no need to provide a yoke. Since the core and yoke cause cogging and increase the weight, it is preferable that there is no core or yoke. Further, if there is no yoke, there is no iron loss, so there is an advantage that high motor efficiency can be obtained.

  5A is a cross-sectional view of the electric motor in the first embodiment, FIG. 5B is a plan view of the first magnet array structure 30M, and FIG. 5C is the A-phase coil array structure 10A. FIG. 5D is a plan view of the second magnet array structure 40M, FIG. 5E is a plan view of the B-phase coil array structure 20B, and FIG. 5F is a cross section shown in FIG. It is the schematic diagram which drew typically. 5B and 5C are views when viewed from the α direction in FIG. 5A, and the plan views of FIGS. 5D and 5E are It is a figure at the time of seeing from (beta) direction.

  The A-phase coil array structure 10A and the B-phase coil array structure 20B constitute a stator, and the first magnet array structure 30M and the second magnet array structure 40M constitute a rotor. That is, the first magnet array structure 30M is outside the A-phase coil array structure 10A (left side in FIG. 5A), and the second magnet array structure 40M is the A-phase coil array structure 10A and the B-phase coil array. Between the structures 20 </ b> B, the shafts 37 are disposed so as to be rotatable. The rotary shaft 37 is connected to the first magnet row structure 30M and the second magnet row so that the first magnet row structure 30M and the second magnet row structure 40M (rotor) and the rotary shaft 37 rotate together. The structure 40M is press-fitted into an opening hole for a rotating shaft at each center. As shown in FIGS. 5 (B) to 5 (E), the first magnet array structure 30M is configured such that six permanent magnets 34M are evenly provided along a circumferential direction on a support member 32M on a substantially disk. It is. Similarly, in the second magnet array structure 40M, six permanent magnets 44M are equally provided on the support member 42M along the circumferential direction. The A-phase coil array structure 10A is configured such that six electromagnetic coils 14A1 and 14A2 are evenly provided on the support member 12A along the circumferential direction. Similarly, in the B-phase coil array structure 20B, six electromagnetic coils 24B1 and 24B2 are equally provided along the circumferential direction on the support member 22B. As can be understood from this description, the operation directions of the first magnet array structure 30M and the second magnet array structure 40M in FIG. 1A (the left-right direction in FIG. 1A) correspond to the rotation direction of the rotor. To do.

  As shown in FIG. 5A, the support member 12A of the A-phase coil array structure 10A is attached to the inside of a hollow cylindrical case 39. One bottom surface (left side in FIG. 5A) of the hollow cylindrical case 39 is closed, and a bearing portion 38 for rotatably holding the rotating shaft 37 is provided at the center thereof. . Further, the other bottom surface of the case 39 is open. The support member 22B of the B-phase coil array structure 20B is attached as a lid to the open bottom surface (right side in FIG. 5A) of the case 39, and the rotating shaft 37 rotates around the support member 22B. A bearing portion 38B is provided for holding it freely.

  Further, as shown in FIG. 5C, an A-phase sensor 16A is provided on the edge of the support material 12A of the A-phase coil array structure 10A, as shown in FIG. B-phase sensors 26B are provided at the edges of the support material 22B. The positions of these sensors 16A and 26B are the same as the positions shown in FIG.

FIG. 6 shows the relationship between the use of the electric actuator as an embodiment of the present invention and a preferable material. For example, there are uses that give priority to the following items.
(1) The price is low.
(2) It must be small.
(3) Low power consumption.
(4) Durability against vibration and impact.
(5) Usability in high temperature environment.
(6) It must be lightweight.
(7) A large torque can be generated.
(8) High rotation is possible.
(9) Be environmentally friendly.

  In the right column of each application in FIG. 6, the permanent magnet, the rotor material (support members 32M and 42M of the magnet array structures 30M and 40M), the bobbin material (coil core material), and the case material (coil array structure) Materials suitable for 10A, 20B supports 12A, 14B, case 39) are shown respectively. The “expensive magnet” means a neodymium magnet, a samarium cobalt magnet, an alnico magnet, or the like. “General resin” means various resins (especially synthetic resins) excluding carbon-based resins and vegetable resins. “Carbon-based resin” means glassy carbon (carbon fiber reinforced resin (CFRP), carbon fiber, etc.) As metals for rotor materials, aluminum, stainless steel, titanium, magnesium, copper, silver, gold Fine ceramics, steatite ceramics, alumina, zircon, and glass can be used as “ceramics”, and plants and wood can be used as “natural materials”. In addition, materials using earth and sand (for example, vegetable resin) can be used.

  As can be understood from these examples, the electric actuator as an embodiment of the present invention uses various nonmagnetic and nonconductive materials as a rotor material, a bobbin material (core material), and a case material. Is possible. However, as the rotor material (support members 32M and 42M of the magnet array structures 30M and 40M), a metal material such as aluminum or an alloy thereof may be used in consideration of strength. Actually, in the first embodiment, aluminum is used as the rotor material. Also in this case, it is preferable that the bobbin material and the case material are made of a substantially non-magnetic and non-conductive material. Here, “substantially non-magnetic and non-conductive material” means that a small part is allowed to be a magnetic substance or a conductor. For example, whether or not the bobbin material is formed of a substantially non-magnetic non-conductive material can be determined by whether or not cogging exists in the motor. Further, whether or not the case material is formed of a substantially non-conductive material is determined by whether or not the iron loss (eddy current loss) due to the case material is equal to or less than a predetermined value (for example, 1% of input). be able to.

  In addition, among the structural materials of the electric actuator, there are also members that are preferably made of a metal material, such as a rotating shaft and a bearing portion. Here, the “structural material” means a member used for supporting the shape of the electric actuator, and means a main member that does not include a small part or a fixture. Rotor material and case material are also a kind of structural material. In the electric actuator of the present invention, it is preferable that the main structural material other than the rotating shaft and the bearing portion is made of a nonmagnetic and nonconductive material.

  FIG. 7 shows the configuration of the drive signal generation circuit 100 in the first embodiment. The drive signal generation circuit 100 includes an operation mode signal generation unit 104, an electronic variable resistor 106, voltage comparators 111 to 114, a multiplexer 120, and a two-stage PWM circuit 130. Among these, the operation mode signal generation unit 104 and the electronic variable resistor 106 are connected to the CPU 110 via the bus 102.

  The operation mode signal generation unit 104 generates an operation mode signal Smode. The operation mode signal Smode is the first bit indicating whether the rotation is normal rotation or reverse rotation, the operation mode using both the AB phase coil arrays, and the operation mode using only the A phase coil arrays. And a second bit indicating. At the time of starting the motor, two coil arrays of A phase and B phase are used in order to reliably determine the rotation direction. However, after the motor starts operation, in an operating state with a small required torque, the rotation can be sufficiently continued even if only the A-phase coil array is used. The second bit of the operation mode signal Smode is a flag for instructing to drive only the A-phase coil array in such a case.

  The voltage across the electronic variable resistor 106 is applied to one input terminal of the four voltage comparators 111 to 114. A phase sensor signal SSA and a phase B sensor signal SSB are supplied to the other input terminals of the voltage comparators 111 to 114. The output signals TPA, BTA, TPB, BTB of the four voltage comparators 111 to 114 are called “mask signals” or “permission signals”. The meaning of these names will be described later.

  The mask signals TPA, BTA, TPB, BTB are input to the multiplexer 120. The multiplexer 120 can reverse the motor by switching the output terminals of the mask signals TPA and BTA for the A phase according to the operation mode signal Smode, and by switching the output terminals of the mask signals TPB and BTB for the B phase. it can. The mask signals TPA, BTA, TPB, BTB output from the multiplexer 120 are supplied to the two-stage PWM circuit 130.

  The two-stage PWM circuit 130 includes an A-phase PWM circuit 132, a B-phase PWM circuit 134, and four three-state buffer circuits 141 to 144. The A-phase PWM circuit 132 is supplied with an output signal SSA (hereinafter referred to as “A-phase sensor signal”) of the A-phase sensor 16A (FIG. 1A) and an operation mode signal Smode. The B-phase PWM circuit 134 is supplied with the output signal SSB of the B-phase sensor 26B and the operation mode signal Smode. These two PWM circuits 132 and 134 are circuits that generate PWM signals PWMA, #PWMA, PWMB, and #PMWM in response to sensor signals SSA and SSB. The signals #PMWA and #PMWB are signals obtained by inverting the signals PMWA and PMWB. As described above, the sensor signals SSA and SSB are both sine wave signals, and the PWM circuits 132 and 134 execute a known PWM operation according to these sine wave signals.

  The signals PWMA and #PWMA generated by the A-phase PWM circuit 132 are supplied to the input terminals of the two three-state buffer circuits 141 and 142, respectively. The A-phase mask signals TPA and BTA supplied from the multiplexer 120 are supplied to the control terminals of these three-state buffer circuits 141 and 142. Output signals DRVA1 and DRVA2 of the three-state buffer circuits 141 and 142 are drive signals for the A-phase coil array (hereinafter referred to as “A1 drive signal” and “A2 drive signal”). Similarly for the B phase, the PWM circuit 134 and the three-state buffer circuits 143 and 144 generate the drive signals DRVB1 and DRVB2 for the B phase coil array.

  FIG. 8 shows an A-phase driver circuit 150A and a B-phase driver circuit 150B. The A-phase driver circuit 150A is an H-type bridge circuit for supplying AC drive signals DRVA1 and DRVA2 to the A-phase coil group 14A. A white circle attached to the terminal portion of the block indicating the drive signal is negative logic and indicates that the signal is inverted. In addition, arrows with symbols IA1 and IA2 indicate the directions of currents flowing by the A1 drive signal DRVA1 and the A2 drive signal DRVA2, respectively. The configuration of the B phase driver circuit 150B is the same as that of the A phase driver circuit 150A.

  FIG. 9 is a timing chart showing various signal waveforms in the first embodiment. The A-phase sensor signal SSA and the B-phase sensor signal SSB are sine waves whose phases are shifted from each other by π / 2. The A-phase PWM circuit 132 generates a signal PWMA (the seventh signal from the top in FIG. 9) having an average voltage proportional to the level of the A-phase sensor signal SSA. The first A-phase mask signal TPA permits the signal PWMA to be applied to the A-phase coil group 14A while the signal TPA is at the H level, and prohibits it during the L-level period. Similarly, the second A-phase mask signal BTA is allowed to apply the signal #PWMA to the A-phase coil group 14A while the signal BTA is at the H level, and is prohibited during the L-level period. However, the first A-phase mask signal TPA is H level when the average voltage of the PWM signal PWMA is on the positive side, and the second A-phase mask signal BTA is when the average voltage of the PWM signal PWMA is on the negative side. H level. As a result, the drive signal DRVA1 + DRVA2 as shown second from the bottom in FIG. 9 is applied to the A-phase coil group 14A. HiZ indicates a high impedance period. As can be understood from this description, the A-phase mask signals TPA and BTA can be considered as signals allowing the PWM signals PWMA and #PWMA to be applied to the A-phase coil array 14A, and the PWM signals PWMA, It can also be considered as a signal that masks #PWMA so that it is not supplied to the A-phase coil array 14A. The same applies to the B phase.

  FIG. 9 shows an operating state when generating a large torque. At this time, the period (HiZ) in which both of the mask signals TPA and BTA are at the L level is small, and therefore the voltage is applied to the A-phase coil group 14A for most of the time. The hysteresis level at this time is shown at the right end of the waveform of the A-phase sensor signal SSA. Here, the “hysteresis level” means an invalid (ie, unused) signal level range near the zero level of the sine wave signal. It can be seen that the hysteresis level is extremely small when a large torque is generated. The hysteresis level can be changed by changing the duty of the mask signals TPA, BTA, TPB, BTB by changing the resistance of the electronic variable resistor 106.

  FIG. 10 shows an operating state when a small torque is generated. Note that a small torque means high rotation. At this time, the duty of the mask signals TPA, BTA, TPB, BTB is set smaller than that in FIG. . The hysteresis level is also increased.

  As can be understood from a comparison between FIG. 9 and FIG. 10, the period when the first A-phase mask signal TPA is at the H level is the timing at which the A-phase sensor signal SSA has a maximum value (at the time of phase π / 2). ). Similarly, the H-level period of the second A-phase mask signal BTA has a symmetric shape centered around the timing at which the A-phase sensor signal SSA shows a minimum value (at a point of 3π / 2 of the phase). . As described above, the period in which the mask signals TPA and BTA are at the H level has a symmetrical shape with the timing at which the A-phase sensor signal SSA shows the peak value as the center. In other words, the mask periods of the PWM signals PWMA and #PWMA have timings (π and 2π) at which the polarity of the AC drive signal (the waveform shown in FIG. 1B) simulated by the signals PWMA and #PWMA is inverted. It can also be considered that the signals PWMA and #PWMA are set to be masked in the central time range.

  Incidentally, as described with reference to FIG. 3A, the A-phase coil group 14A does not generate a very effective driving force when the phase is in the vicinity of 2π. The same applies when the phase is near π. The A-phase coil group 14A generates the most effective and effective driving force when the phase is in the vicinity of π / 2 and 3π / 2. As shown in FIG. 10 described above, the two-stage PWM circuit 130 of this embodiment does not apply a voltage to the A-phase coil group 14A in the vicinity of π and 2π when the required output of the motor is small, Further, as shown in FIGS. 9 and 10, a voltage is applied to the A-phase coil array 14A with the phase around π / 2 and 3π / 2 as the center. Thus, the A-phase mask signals TPA and BTA mask the PWM signals PWMA and #PWMA so that the period in which the A-phase coil group 14A generates the driving force most efficiently is preferentially used. It is possible to increase the efficiency. When a voltage is applied to the A-phase coil group 14A in the vicinity of π and 2π, as described with reference to FIG. 3A, between the A-phase coil group 14A and the first magnet group 34M, and An attractive force acts strongly between the A-phase coil group 14A and the second magnet group 44M, causing the rotor to vibrate. From this point of view, it is preferable not to apply a voltage to the A-phase coil group 14A when the phase is in the vicinity of π and 2π. These circumstances also apply to the B-phase coil group 24B. However, as shown in FIG. 1B, the phase of the B-phase coil group 24B is reversed at the timings of π / 2 and 3π / 2, so that the phase of the B-phase coil group 24B has π / It is preferable not to apply a voltage in the vicinity of 2 and 3π / 2.

  FIG. 11 shows the rotation speed when the motor of the first embodiment is not loaded. As can be understood from this graph, the motor of the first embodiment rotates at an extremely stable rotational speed up to an extremely low rotational speed when there is no load. This is because cogging does not occur because there is no magnetic core.

  As described above, in the electric motor of the first embodiment, the first magnet array 34M and the second magnet array 44M are provided on both sides of the A-phase coil array 14A, and the magnetic core and yoke are not provided at all. Therefore, it is possible to obtain a large torque with a small size and light weight, and without cogging, it is possible to maintain a stable rotation up to an extremely low rotational speed. Further, since the B-phase coil group 24B is provided outside the second magnet group 44M, a larger torque can be obtained.

B. Second embodiment (two-phase motor: fan motor):
FIG. 12 (A) is a schematic view schematically showing a cross section of an electric motor as a second embodiment of the present invention, and FIG. 12 (B) is a fan using the electric motor of FIG. 12 (A). It is sectional drawing which shows the structure of a motor.

  In the electric motor according to the first embodiment, as shown in FIG. 5F, the first magnet row 34M and the second magnet row 44M are directly connected to the rotating shaft 37, respectively, and the A phase The coil array 14A and the B-phase coil array 24B are connected via the outer peripheral side of the second magnet array 44M. On the other hand, in the electric motor of the second embodiment, as shown in FIG. 12A, the A-phase coil group 14A and the B-phase coil group 24B are arranged in the vicinity of the rotating shaft 37 of the second magnet group 44M. The first magnet row 34M is directly connected to 37, but the second magnet row 44M is connected to the first magnet row 34A via the outer circumference side of the A-phase coil row 14A. It is connected to the magnet row 34M.

  When such an electric motor of the second embodiment is used for a fan motor, for example, a configuration as shown in FIG. That is, the fan motor shown in FIG. 12B mainly includes a hollow cylindrical stator 310 having one end opened, a rotor 320 that is rotatably attached to the stator 310 via a rotating shaft 37, and the rotor 320. And a fan 350 provided on the outer periphery.

  A control / drive unit 300 including a CPU 110, a drive signal generation circuit 100, a driver circuit, and the like is attached to the stator 310, and a support member 22B that supports the B-phase coil array 24B is fixed. Further, a shaft holding member 330 that rotatably holds the rotating shaft 37 is attached to the support member 22B, and the support material 12A that supports the A-phase coil array 14A is further fixed to the shaft holding member 330. Has been. On the other hand, the rotor 320 is integrally formed with a fan 350 on the outer periphery thereof, and a support material for supporting the second magnet array 44M is integrally formed on the inner periphery thereof. The support member has a hollow cylindrical shape with one end opened, and a support member 32M that supports the first magnet row 34M is fitted into the open end as a lid and fixed. Has been. In addition, when the support member 32M is fitted and fixed, the rotor 320 can be fixed to the rotation shaft 37 by inserting and fixing the rotation shaft 37 to the center thereof. A silicon steel material 340 is attached to the support material 32M so as to cover the first magnet row 34M. The silicon steel material 340 blocks magnetic flux leakage and reduces iron loss (eddy current loss).

  The electric motor of the second embodiment also operates in substantially the same manner as the first embodiment and has substantially the same effect. Therefore, the following effects can be expected by using the electric motor of the second embodiment as a fan motor.

  FIG. 13 is an explanatory diagram showing the flow of fluid when a conventional electric motor is used as a fan motor. As shown in FIG. 13, in order to rotate the fan 430 supported by the fan support portion 420 at a desired rotational speed by the fan motor 400 via the rotation shaft 410, the fan motor 400 has a corresponding torque. It is necessary to prepare an electric motor that can output. However, conventionally, such an electric motor has a very large outer cap. When such an electric motor having a large external dimension is used as the fan motor 400, as shown in FIG. There was a problem that the wind power efficiency (power / air volume ratio) of the fan would be reduced. The following can be considered as the loss in the flow path. That is, the fan motor 400 itself suppresses the flow of fluid. Further, as shown in FIG. 13, the fluid vortex 440 is generated at the center of the flow path, thereby generating a negative pressure with respect to the fluid flow by the fan 430 and inhibiting the fluid flow. As the fan 430 rotates at a higher speed, a vacuum state is generated by the fluid vortex 440, thereby further suppressing the flow of the fluid.

  In contrast, in the electric motor of the second embodiment, as described above, a small torque and a large torque can be obtained. Therefore, when the electric motor of the second embodiment is used as a fan motor, a fan is desired. Even if the fan motor is configured to output a corresponding torque in order to rotate at a rotational speed of 2, the external dimensions can be made very small compared to a conventional electric motor. Therefore, since the area occupied by the fan motor with respect to the cross-sectional area of the flow path can be reduced, the loss in the flow path can be suppressed, and the wind efficiency (power / air volume ratio) of the fan can be improved.

C. Third embodiment (two-phase motor):
FIG. 14 is a schematic view schematically showing a cross section of an electric motor as a fourth embodiment of the present invention. The motor of the third embodiment has an insert rotor structure in which a substantially cylindrical double structure rotor is inserted between substantially cylindrical double structure stators. That is, the stator includes two cylindrical members that form a hollow double cylindrical structure. The inner cylindrical member has an A-phase coil row 14A, and the outer cylindrical member has a B-phase coil row 24B. Is arranged. Similarly, the rotor also includes two cylindrical members that form a hollow double cylindrical structure. The inner cylindrical member has a first magnet row 34M, and the outer cylindrical member has a second magnet row. 44M are respectively arranged. A rotation shaft 37 is provided at the center of the rotor. The cylindrical member in which the first magnet row 34M is disposed is inserted inside the A-phase coil row 14A, and the cylindrical member in which the second magnet row 44M is placed is inserted between the coil rows 14A and 24B. Yes. In this way, the structure in which the four hollow cylindrical members are coaxially stacked is hereinafter also referred to as a “hollow multiple cylindrical structure”.

  The electric motor of the third embodiment also operates in substantially the same manner as the first embodiment and has substantially the same effect. As can be understood from this example, the electric actuator of the present invention can be realized in various specific forms.

  In addition, since the electric motor of the third embodiment has the hollow multiple cylindrical structure as described above, there is an advantage that the vibration of the rotor is less than that of the first embodiment. That is, as described with reference to FIGS. 3 and 4, a force acts on the A-phase coil array 14 </ b> A side in the magnet arrays 34 </ b> M and 44 </ b> M according to the attractive force and the repulsive force from the coil arrays 14 </ b> A and 24 </ b> B. Sometimes, force acts on the B phase coil array 24B side. In such a case, the structure of the first embodiment shown in FIG. 5 (the two disk-like members holding the magnet rows 34M and 44M and the two disk-like members holding the coil rows 14A and 24B are alternately arranged. In the structure arranged in (3), the rotor may vibrate up and down while rotating. On the other hand, in the motor having the hollow multi-cylindrical structure shown in FIG. Therefore, there is an advantage that such vibration is difficult to occur.

D. Various modifications of the two-phase motor:
FIG. 15 shows a first modification regarding the arrangement of the coil array and the magnet array of the two-phase motor. In FIG. 15, only the state where the phase is π / 4 is representatively shown. In the motor of the first modification, among the two coil arrays of the motor of the first embodiment shown in FIGS. 1, 3 and 4, only the coil of the B-phase coil array 24B is thinned out to 1/3, The coil pitch PcB is tripled. The configurations of the A-phase coil array 14A and the magnet arrays 34M and 44M are the same as those in the first embodiment.

  As described above, when starting the motor, two coil arrays of A phase and B phase are used to reliably determine the direction of rotation, but after the motor starts operation, only the A phase coil array is used. Even so, the rotation can be continued sufficiently. Therefore, the B-phase coil group 24B only needs to function effectively at least when the motor is started, and may function as an auxiliary as necessary after the motor operation is started. Therefore, in the motor of the first modification, by thinning out the coils of the B-phase coil array 24B as described above, the motor is reduced in weight by the thinned-out coils while maintaining the minimum functions. ing.

  FIG. 16 shows a second modification example regarding the arrangement of the coil array and the magnet array of the two-phase motor. FIG. 16 also shows only a state where the phase is π / 4 as a representative. In the motor of the second modification, the coils of the phase A coil array 14A and the phase B coil array 24B of the motor of the first embodiment shown in FIGS. Is doubled. The configuration of the magnet arrays 34M and 44M is the same as that in the first embodiment. The A-phase coil group 14A of the second modification corresponds to the one in which one of the two types of coils 14A1 and 14A2 (FIG. 1) of the A-phase coil group 14A in the first embodiment is omitted. Accordingly, all the coils of the A-phase coil array 14A of the second modification are always magnetized in the same direction.

  FIG. 17 shows a third modification regarding the arrangement of the coil array and the magnet array of the two-phase motor. FIG. 17 also shows only a state where the phase is π / 4 as a representative. In the motor of the third modification, the coils of the phase A coil array 14A and the phase B coil array 24B of the motor of the first embodiment shown in FIGS. Is tripled. The configuration of the magnet arrays 34M and 44M is the same as that in the first embodiment. In the third modification, the relative positional relationship between the A-phase coil group 14A and the B-phase coil group 24B is shifted by 3π / 2. As can be understood from this, it is sufficient that the A-phase coil group 14A and the B-phase coil group 24B of the two-phase motor have a positional relationship shifted by an odd multiple of π / 2 in electrical angle.

  FIG. 18 shows a fourth modification example regarding the arrangement of the coil array and the magnet array of the two-phase motor. In FIG. 18, only the state where the phase is π / 4 is representatively shown. In the motor of the fourth modified example, the magnet rows 34M and 44M of the motor of the first embodiment shown in FIGS. 1, 3, and 4 are respectively thinned by half to double the magnetic pole pitch Pm. It has the structure made into. However, the positions where the magnets are thinned are shifted by π between the first magnet row 34M and the second magnet row 44M. The configurations of the A-phase coil group 14A and the B-phase coil group 24B are the same as those in the first embodiment.

  The first to fourth modifications described above correspond to the first embodiment in which a part of the coil or a part of the magnet is thinned out, but the motors of these modifications are substantially the same as the first embodiment. You can understand that it works. However, the first embodiment is superior to the first to fourth modifications in terms of magnetic flux utilization efficiency.

  FIG. 19 shows a fifth modification example regarding the arrangement of the coil array and the magnet array of the two-phase motor. In FIG. 19, only the state where the phase is π / 4 is representatively shown. In the motor of the fifth modification, the magnetization direction of the magnet rows 34M and 44M of the motor of the first embodiment shown in FIGS. Direction). The magnetic pole pitch Pm is the same as that of the first embodiment, but the number of magnets is ½ that of the first embodiment. The configurations of the A-phase coil group 14A and the B-phase coil group 24B are the same as those in the first embodiment. However, the magnetization direction of the B-phase coil group 24B is opposite to that of the first embodiment shown in FIGS. Thus, it can be understood that the same operation as in the first embodiment is performed even when the magnetization direction of the magnet is directed to the operation direction of the rotor (in this example, the magnet rows 34M and 44M).

  As can be understood from these various modifications, the number of coils included in the A-phase and B-phase coil arrays and the number of magnets included in the magnet arrays can be set to various values. However, from the viewpoint of magnetic flux utilization efficiency, it is preferable that the number of coils in each phase coil array is equal to the number of magnetic poles (or the number of magnets) in the magnet array.

E. Fourth embodiment (two-phase motor):
20 (A), 20 (B) and FIGS. 21 (A), 21 (B) are explanatory views showing a schematic configuration and operation of an electric motor as a fourth embodiment of the present invention. In the motor of the fourth embodiment, the first magnet row 34M and the second magnet row 44M are arranged on both sides of the coil row 54AB. The coil group 54AB corresponds to a combination of both the A-phase coil group 14A and the B-phase coil group 24B of the motor of the first embodiment shown in FIGS. That is, the coil array 54AB includes two types of coils 14A1 and 14A2 included in the A-phase coil array 14A and two types of coils 24B1 and 24B2 included in the B-phase coil array 24B, which are in a predetermined order. It is arranged with. 20 (A), 20 (B) and FIGS. 21 (A), 21 (B), the coils of the A-phase coil array are drawn with solid lines and the coils of the B-phase coil array are drawn with broken lines for convenience of illustration. ing. The coil pitch Pc is defined as the pitch between the coils in the A phase coil array or the pitch between the coils in the B phase coil array. Therefore, the coil pitch Pc in the fourth embodiment is the same as that in the first embodiment. .

  Since the coil array 54AB of the fourth embodiment has the A-phase and B-phase coil arrays, the rotation direction can be reliably determined only by the coil array 54AB when the motor is started. Accordingly, in the electric motor of the fourth embodiment, only the coil group 54AB disposed between the first magnet group 34M and the second magnet group 44M is provided, and the second magnet group 44M is sandwiched between them. No other coil array is provided on the opposite side of coil array 54AB (the lower side in FIGS. 20 and 21).

  22A is a cross-sectional view of the electric motor in the fourth embodiment, FIG. 22B is a plan view of the first magnet array structure 30M, and FIG. 22C is a plan view of the coil array structure 50AB. FIG. 22 (D) is a plan view of the second magnet array structure 40M, and FIG. 22 (E) is a schematic diagram schematically depicting the cross section shown in FIG. 22 (A). Note that the plan views of FIGS. 22 (B) and 22 (C) are views when viewed from the α direction in FIG. 22 (A), and the plan views of FIGS. 22 (D) and 22 (E) are It is a figure at the time of seeing from (beta) direction.

  The configuration of the electric motor shown in FIG. 22 is different from the configuration of the electric motor shown in FIG. 5 in that, as shown in FIG. 22C, a coil array structure 50AB has twelve electromagnetic coils on a support material 52AB. 14A1, 14A2, 24B1, and 24B2 are provided uniformly along the circumferential direction. In addition, the coil array is not disposed outside the second magnet array structure 40M (on the right side in FIG. 22A), and instead a case lid 39a including a bearing portion 38a is attached. It is. As shown in FIG. 22C, a sensor 56AB is provided on the edge of the support member 52AB of the coil array structure 50AB.

  According to the electric motor of the fourth embodiment, the same effect as that of the first embodiment can be obtained. In addition, both the A-phase coil array 14A and the B-phase coil array 24B are combined as a coil array 54AB, and the second magnet array Since no other coil array is provided on the outer side of 44M (the lower side in FIGS. 20 and 21 and the right side in FIG. 22A), it can be further reduced in size and weight.

  In the case where the effective use of the magnetic flux of the magnet is more important than the reduction in size and weight, the opposite side of the coil group 54AB across the second magnet group 44M (the lower side in FIG. 20 and FIG. 22 (A) on the right side), or on the opposite side of the coil group 54AB across the first magnet group 34M (upper side in FIGS. 20 and 21, left side in FIG. 22 (A)), the same as the coil group 54 You may make it provide the coil row | line | column which put together the coil row | line | column of a structure, ie, both A phase coil row | line | column 14A and B phase coil row | line | column 24B.

F. Fifth embodiment (three-phase motor):
23 (A) to 23 (C) are explanatory views showing a schematic configuration and operation of an electric motor in the fifth embodiment of the present invention. The motor of the fifth embodiment is a three-phase motor having three coil rows of A phase, B phase, and C phase, and the first magnet row 74M and the second magnet on both sides of the coil row 84ABC. Row 94M is arranged. The first magnet row 74M has the same configuration as the first magnet row 34M in the first embodiment shown in FIG. 3A, and the second magnet row 94M is the same as the second magnet row 44M. It has a configuration. The coil array 84ABC includes an A-phase coil array coil 84A, a B-phase coil array coil 84B, and a C-phase coil array coil 84C, which are arranged in a predetermined order. . 23A to 23C, for convenience of illustration, the coils of the A phase coil array are drawn with solid lines, the coils of the B phase coil array are drawn with dotted lines, and the coils of the C phase coil array are drawn with broken lines. . The coil pitch Pc of each phase of A phase, B phase, and C phase is twice the magnetic pole pitch Pm and corresponds to 2π in electrical angle. The A-phase, B-phase, and C-phase coils are arranged at positions that are sequentially shifted by π / 3 in electrical angle.

  FIG. 23A shows a state immediately before the phase is 2π. At the timing when the phase is 2π, the polarity of the phase A coil array 84A is reversed. FIG. 23B shows a state immediately before the phase is π / 3. At the timing when the phase is π / 3, the polarity of the C-phase coil array 84C is reversed. FIG. 23C shows a state immediately before the phase is 2π / 3. At the timing when the phase is 2π / 3, the polarity of the B-phase coil group 84B is reversed.

  Also in the three-phase motor of the fifth embodiment, the polarity (magnetization direction) of the A-phase coil group 84A is such that each coil of the A-phase coil group 84A is each magnet of the first magnet group 74M and the second magnet group 94M. Is switched at the timing of facing. The same applies to the B-phase coil array and the C-phase coil array. As a result, a driving force can always be generated from all the coils, so that a large torque can be generated.

  Also in the electric motor of the fifth embodiment, since the first magnet row 74M and the second magnet row 94M are arranged on both sides of the coil row 84ABC, the magnetic flux generated on both sides of the coil row 84ABC. Can be effectively used for generating the driving force. Therefore, compared with the case where only one side of the coil is used for generating the driving force as in the case of a conventional electric motor, it is possible to realize a motor with high efficiency and high torque with high use efficiency of magnetic flux.

  Note that the three-phase motor of the fifth embodiment does not have a magnetic core and does not have a yoke that forms a magnetic circuit, as in the first embodiment. Moreover, it is preferable that all the structural materials other than the rotating shaft and the bearing portion are formed of a nonmagnetic and nonconductive material.

  FIG. 24 is a block diagram showing the configuration of the drive signal generation circuit in the fifth embodiment. In the drive signal generation circuit 100a, a circuit portion for the C phase (for example, voltage comparators 115 and 116) is added to the circuit for the two-phase motor shown in FIG. 7, and a sine wave generation circuit 108 is added. It is a thing.

  The sine wave generation circuit 108 generates three sine wave signals SA, SB, SC whose phases are sequentially shifted by 2π / 3 in accordance with the three-phase sensor signals SSA, SSB, SSC. The three sine wave signals SA, SB and SC are input to the voltage comparators 111 to 116 and also supplied to the two-stage PWM circuit 130a. The multiplexer 120a and the two-stage PWM circuit 130a are obtained by changing these circuits shown in FIG. 6 for three phases. The two-stage PWM circuit 130a outputs three-phase drive signal pairs (DRVA1, DRVA2), (DRVB1, DRVB2), and (DRVC1, DRVC2). Note that the waveforms of the drive signals are substantially the same as those shown in FIGS. 9 and 10, except that the phase difference of each phase is 2π / 3.

  FIG. 25 is a block diagram showing the configuration of the driver circuit in the fifth embodiment. The driver circuit 150ABC is a three-phase bridge circuit for driving the coil arrays 91A, 92B, and 93C.

  FIG. 26 is a timing chart showing the sensor signals of the fifth embodiment and the excitation directions of the coils of each phase. The A, B, and C phase sensor signals SSA, SSB, and SSC are digital signals that switch between an H level and an L level every period of π in electrical angle. In addition, the phase of each phase is sequentially shifted by 2π / 3. In the lower part of FIG. 26, the excitation directions of the A, B, and C phase coil arrays are shown. The excitation direction of each coil array is determined by the logical operation of the three sensor signals SSA, SSB, SSC.

  27A to 27F show current directions in the six periods P1 to P6 in FIG. In this embodiment, the A, B, and C phase coil arrays are star-connected, but may be delta-connected. In the period P1, current flows from the B-phase coil array to the A-phase and C-phase coil arrays. In the period P2, current flows from the B-phase and C-phase coil arrays to the A-phase coil array. In this way, a large torque can be generated by driving each coil array so that a current always flows through each of the A, B, and C phase coil arrays.

  Also in the three-phase motor of the fifth embodiment, the first magnet array 74M and the second magnet array 94M are provided on both sides of the coil array 84ABC, and the driving force is obtained by effectively using the magnetic flux generated on both sides of the coil array 84ABC. Therefore, a large driving force can be obtained. Further, the three-phase motor of the fifth embodiment is also configured such that a magnetic core and yoke are not provided at all, so that a large torque can be obtained with a light weight. Further, there is no cogging and stable rotation can be maintained up to an extremely low rotational speed.

  The three-phase motor can also be used as a fan motor as in the second embodiment, or can be configured as a cylindrical motor as in the third embodiment. Also, the same modifications as the various modifications of the two-phase motor described above can be applied to the three-phase motor of the fifth embodiment.

G. Example 6:
FIG. 28 is a block diagram showing the internal configuration of the drive circuit unit in the sixth embodiment. Since the hardware configuration other than the drive circuit unit is the same as that of the first embodiment described above, description thereof is omitted.

  The drive circuit unit 500 includes a CPU 110, a drive control unit 100, a regeneration control unit 200, a driver circuit 150, and a rectifier circuit 250. The two control units 100 and 200 are connected to the CPU 110 via the bus 102. The drive control unit 100 and the driver circuit 150 are circuits that perform control when a driving force is generated in the electric actuator. In addition, the regeneration control unit 200 and the rectifier circuit 250 are circuits that perform control when power is regenerated from the electric actuator. The regeneration control unit 200 and the rectifier circuit 250 are collectively referred to as a “regeneration circuit”.

  The drive control unit 100 is the same as the drive signal generation circuit 100 described with reference to FIG. The driver circuit 150 is a circuit composed of the A-phase driver circuit 150A and the B-phase driver circuit 150B described with reference to FIG. Therefore, description of the internal configuration and operation of these circuits 100 and 150 is omitted.

  FIG. 29 is a block diagram showing the internal configuration of the regeneration control unit 200 and the rectifier circuit 250. Regenerative control unit 200 includes an A-phase charge switching unit 202, a B-phase charge switching unit 204, and an electronic variable resistor 206 connected to bus 102. Output signals of the two charge switching units 202 and 204 are given to input terminals of the two AND circuits 211 and 212, respectively.

  The A-phase charge switching unit 202 outputs a “1” level signal when recovering regenerative power from the A-phase coil array 14A, and outputs a “0” level signal when not recovering. The same applies to the B-phase charge switching unit 204. Note that these signal levels are switched by the CPU 110. Further, the presence / absence of regeneration from the A-phase coil group 14A and the presence / absence of regeneration from the B-phase coil group 24B can be set independently. Therefore, for example, it is possible to regenerate electric power from the B-phase coil group 24B while generating a driving force in the actuator using the A-phase coil group 14A.

  Similarly, the drive control unit 100 can independently set whether to generate a driving force using the A-phase coil group 14A and whether to generate a driving force using the B-phase coil group 24B. You may comprise as follows. For example, the operation mode signal generation unit 104 of FIG. 7 can output a signal indicating whether or not the A-phase coil group 14A is driven and a signal indicating whether or not the B-phase coil group 24B is driven. 104 may be configured. In this way, it is possible to operate the electric actuator in an operation mode in which the driving force is generated on any one of the two coil arrays 14A and 24B and the power is regenerated on the other.

  The voltage across the electronic variable resistor 206 is applied to one of the two input terminals of the four voltage comparators 221 to 224. A phase sensor signal SSA and a phase B sensor signal SSB are supplied to the other input terminals of the voltage comparators 221 to 224. The output signals TPA, BTA, TPB, BTB of the four voltage comparators 221 to 224 can be called “mask signals” or “permission signals”.

  The mask signals TPA and BTA for the A phase coil are input to the OR circuit 231, and the mask signals TPB and BTB for the B phase are input to the other OR circuit 232. The outputs of these OR circuits 231 and 232 are given to the input terminals of the two AND circuits 211 and 212 described above. The output signals MSKA and MSKB of these AND circuits 211 and 212 are also called “mask signals” or “permission signals”.

  By the way, the configuration of the electronic variable resistor 206 and the four voltage comparators 221 to 224 is the same as the configuration of the electronic variable resistor 106 and the four voltage comparators 111 to 114 of the drive signal generation circuit 100 shown in FIG. is there. Therefore, the output signal of the OR circuit 231 for the A phase coil corresponds to the logical sum of the mask signals TPA and BTA shown in FIG. When the output signal of the A-phase charge switching unit 202 is “1” level, the mask signal MSKA output from the AND circuit 211 for the A-phase coil is the same as the output signal of the OR circuit 231. These operations are the same for the B phase.

  The rectifier circuit 250 includes a full-wave rectifier circuit 252 including a plurality of diodes, two gate transistors 261 and 262, a buffer circuit 271 and an inverter circuit 272 (NOT circuit) as a circuit for the A-phase coil. ing. The same circuit is provided for the B phase. The gate transistors 261 and 262 are connected to a power supply wiring 280 for regeneration.

  The AC power generated in the A-phase coil array 14A during power regeneration is rectified by the full-wave rectifier circuit 252. A gate signal of the A-phase coil and its inverted signal are given to the gates of the gate transistors 261 and 262, and the gate transistors 261 and 262 are controlled to be turned on / off accordingly. Accordingly, when at least one of the mask signals TPA and BTA output from the voltage comparators 221 and 222 is at the H level, the regenerative power is output to the power supply wiring 280, while both the mask signals TPA and BTA are at the L level. Then, power regeneration is prohibited.

  As can be understood from the above description, it is possible to recover the regenerative power using the regenerative control unit 200 and the rectifier circuit 250. Further, the regeneration control unit 200 and the rectifier circuit 250 collect regenerative power from the A-phase coil array 14A and the B-phase coil array 24B in accordance with the mask signal MSKA for the A-phase coil and the mask signal MSKB for the B-phase coil. It is possible to limit the period during which the power is regenerated and thereby adjust the amount of regenerative power.

  As described above, in the electric actuator of this embodiment, since the magnetic core is not provided, so-called cogging does not occur even during regeneration, and a smooth and stable operation can be realized. Further, since the yoke for configuring the magnetic circuit is not provided, so-called iron loss (eddy current loss) is extremely small, and regenerative power can be efficiently recovered.

  Note that the drive circuit unit of the sixth embodiment can be applied to electric actuators of other embodiments and modifications other than the first embodiment.

H. Other variations:
(1) In the above-described embodiments and modifications, a configuration in which the first magnet row and the second magnet row are arranged on both sides of the coil row (hereinafter referred to as a basic configuration), and in addition to this basic configuration, a magnet is further provided. Although the configuration in which another coil row is arranged outside the row has been adopted, the present invention is not limited to this. That is, a configuration in which the above basic configuration is repeatedly arranged in two or more stages (for example, a first magnet row, a first coil row, a second magnet row, a third magnet row, a second coil row, a fourth magnet) Etc.), a configuration in which coil rows and magnet rows are alternately arranged, and a configuration including two or more stages of the above basic configuration (for example, a first magnet row, a first coil row, a first row, etc.) 2 magnet rows, second coil rows, third magnet rows,..., Etc.) may be adopted.

For example, as a specific example of the latter, in a three-phase motor, the first magnet row, the A phase coil row, the second magnet row, the B phase coil row, the third magnet row, and the C phase coil row are arranged in this order. Similarly to the case of the fifth embodiment, the coils of the A phase, the B phase, and the C phase may be sequentially shifted by π / 3 in electrical angle.
That is, the electric motor of the present invention only needs to include at least one stage of the basic configuration.

(2) Although the rotary motor has been described in the above-described embodiments and modifications, the present invention can be applied to various electric actuators other than the rotary motor, for example, a linear motor. . When the present invention is applied to a linear motor, for example, it is sufficient that at least one magnet in a magnet array is provided. Further, the present invention is not limited to an actuator, and can be applied to a generator.

(3) In the above embodiment, the plurality of coil arrays constitutes the stator and the magnet array configures the rotor. However, the configuration can be reversed. In general, the present invention can be applied to an actuator or a generator that can change the relative positions of a plurality of coil arrays and magnet arrays.

(4) The circuit configurations used in the above embodiments and modifications are examples, and various circuit configurations other than these can be employed.

It is explanatory drawing which shows schematic structure and the alternating current drive signal of the electric motor in 1st Example of this invention. It is explanatory drawing which shows the connection method of two types of coils of A phase coil row | line | column. It is explanatory drawing which shows operation | movement of the electric motor of 1st Example. It is explanatory drawing which shows operation | movement of the electric motor of 1st Example. It is explanatory drawing which shows the mechanical structure of the electric motor in 1st Example. It is explanatory drawing which shows the relationship between the use of the electric actuator as an Example of this invention, and a preferable material. It is a block diagram which shows the structure of the drive signal generation circuit in 1st Example. It is a block diagram which shows the structure of the driver circuit in 1st Example. It is a timing chart which shows the signal waveform at the time of large torque generation of the motor of 1st Example. It is a timing chart which shows the signal waveform at the time of the small torque generation | occurrence | production of the motor of 1st Example. It is a graph which shows the rotation speed at the time of no load of the motor of 1st Example. It is explanatory drawing which shows the cross section of the electric motor as 2nd Example of this invention, and the structure of the fan motor using the electric motor. It is explanatory drawing which shows the flow of the fluid at the time of utilizing the conventional electric motor as a fan motor. It is the schematic diagram which drew typically the cross section of the electric motor as 4th Example of this invention. It is explanatory drawing which shows the 1st modification regarding the arrangement | sequence of the coil row | line | column and magnet row | line | column of a two-phase motor. It is explanatory drawing which shows the 2nd modification regarding the arrangement | sequence of the coil row | line | column and magnet row | line | column of a two-phase motor. It is explanatory drawing which shows the 3rd modification regarding the arrangement | sequence of the coil row | line | column and magnet row | line | column of a two-phase motor. It is explanatory drawing which shows the 4th modification regarding the arrangement | sequence of the coil row | line | column and magnet row | line | column of a two-phase motor. It is explanatory drawing which shows the 5th modification regarding the arrangement | sequence of the coil row | line | column and magnet row | line | column of a two-phase motor. It is explanatory drawing which shows schematic structure and operation | movement of the electric motor as 4th Example of this invention. It is explanatory drawing which shows schematic structure and operation | movement of the electric motor as 4th Example of this invention. It is explanatory drawing which shows the mechanical structure of the electric motor in 4th Example. It is explanatory drawing which shows schematic structure and operation | movement of the electric motor in 5th Example of this invention. It is a block diagram which shows the structure of the drive signal generation circuit in 5th Example. It is a block diagram which shows the structure of the driver circuit in 5th Example. It is a timing chart which shows the excitation direction of the sensor signal of 5th Example, and the coil of each phase. It is explanatory drawing which shows the electric current direction in six periods P1-P6 of 5th Example. It is a block diagram which shows the internal structure of the drive circuit unit in 6th Example. It is a block diagram which shows the internal structure of a regeneration control part and a rectifier circuit.

Explanation of symbols

10A ... A phase coil array structure 12A, 14B ... Support material 14A ... A phase coil array 14A1,14A2 ... Electromagnetic coil 16A ... A phase sensor 20B ... B phase coil array structure 22B ... support material 24B ... B phase coil array 24B1, 24B2 ... coil 26B ... B phase sensor 30M ... first magnet array structure 32M ... support material 34M ... first Magnet row 37 ... Rotating shaft 38 ... Bearing portion 38B ... Bearing portion 38a ... Bearing portion 39 ... Case 39a ... Case lid 40M ... Second magnet row structure 42M .. Support material 44M ... second magnet array 50AB ... coil array structure 52AB ... support material 54 ... coil array 54AB ... coil array 56AB ... sensor 74M ... first magnet Row 84A ... A phase coil row 84ABC ... Coil row 84B ... B phase coil row 84C ... C phase coil row 91A, 92B, 93C ... Coil row 94M ... Second Stone train 100 ... Drive signal generation circuit 100a ... Drive signal generation circuit 102 ... Bus 104 ... Operation mode signal generation unit 106 ... Electronic variable resistor 108 ... Sine wave generation circuit 110. ..CPU
DESCRIPTION OF SYMBOLS 111-116 ... Voltage comparator 120 ... Multiplexer 120a ... Multiplexer 132 ... A phase PWM circuit 134 ... B phase PWM circuit 150 ... Driver circuit 150A ... A phase driver circuit 150ABC ... Driver circuit 150B ... B phase driver circuit 200 ... Regeneration control unit 202 ... A phase charge switching unit 204 ... B phase charge switching unit 206 ... Electronic variable resistor 211, 212. .. AND circuit 221 to 224... Voltage comparator 231, 232... OR circuit 250... Rectifier circuit 252... Full-wave rectifier circuit 261, 262. ... Inverter circuit 280 ... Power supply wiring 300 ... Control / drive unit 310 ... Stator 320 ... Rotor 330 ... Shaft holding member 340 ... Silicon steel 350 ... Fan 400 .. Fan motor 410 ... Rotating shaft 420 ... F Down support portion 430 ... fan 440 ... fluid vortex 500 ... driving circuit unit

Claims (16)

An electric motor,
A first coil array including a plurality of coils arranged along a predetermined direction;
Each of the first and second magnets includes at least one magnet, the relative positional relationship of which is fixed to each other, and the relative positional relationship with respect to the first coil array is changeable along the predetermined direction. Two magnet rows;
With
The first and second magnet rows are arranged on both sides of the first coil row, and
Each coil of the first coil array has substantially no magnetic core,
The electric motor does not substantially have a magnetic yoke for forming a magnetic circuit. The electric motor according to claim 1,
A plurality of coils arranged along the predetermined direction, the relative positional relationship with the first coil array being fixed, and one of the first and second magnet arrays being And further comprising a second coil array disposed on a side opposite to the side on which the first coil array is disposed,
Each coil of the second coil array is an electric motor that does not substantially have a magnetic core. The electric motor according to claim 1 or 2,
A case for storing the coil array and the magnet array, further comprising:
Each coil of the coil array is wound around a support made of a substantially non-magnetic and non-conductive material,
The case is an electric motor formed of a substantially non-magnetic and non-conductive material. In the electric motor according to any one of claims 1 to 3,
The structural material other than the rotating shaft and the bearing portion is an electric motor that is formed of a substantially non-magnetic and non-conductive material. In the electric motor according to any one of claims 1 to 4,
The electric motor is an electric motor that is a rotary motor or a rotary generator in which the coil array and the magnet array rotate relatively along the predetermined direction. The electric motor according to claim 2,
The first coil array includes a first phase coil array including a plurality of coils arranged at a predetermined pitch along the predetermined direction and electrically connected to each other,
The second coil array includes a second phase coil array including a plurality of coils arranged at a predetermined pitch along the predetermined direction and electrically connected to each other,
The electric motor in which the first phase coil array and the second phase coil array are arranged at positions shifted from each other by an odd multiple of π / 2 in electrical angle. The electric motor according to claim 1,
The first coil array is:
A first phase coil array including a plurality of coils arranged at a predetermined pitch along the predetermined direction and electrically connected to each other;
A second phase coil array including a plurality of coils arranged at a predetermined pitch along the predetermined direction and electrically connected to each other;
With
The first phase coil array and the second phase coil array are arranged at positions shifted from each other by an odd multiple of π / 2 in electrical angle. In the electric motor according to claim 6 or 7,
A drive signal generation circuit for supplying a first AC drive signal supplied to the first coil array and a second AC drive signal supplied to the second coil array;
In the drive signal generation circuit, the polarities of the coils of the first phase coil array and the second phase coil array are such that the centers of the magnets in the first and second magnet arrays face each other. The magnetic flux density in the coil array is maximized at the timing when the center position between adjacent coils belonging to the coil array of the same phase is opposed to the center of the magnet in the first and second magnet arrays. And an electric motor for generating the first and second AC drive signals. The electric motor according to claim 8, wherein
The drive signal generation circuit reverses the current direction of the first phase coil row and the second phase coil row to thereby reverse the first phase coil and second phase coil row, and the first and second magnet rows. It is possible to reverse the direction of operation of the motor. The electric motor according to claim 8 or 9,
The drive signal generation circuit includes:
First and second PWM circuits that respectively generate first and second PWM signals whose phases are shifted from each other by π / 2;
A mask circuit that generates the first and second AC drive signals by masking the first and second PWM signals in response to an output request to the motor;
Comprising an electric motor. The electric motor according to claim 10,
The said mask circuit is an electric motor which masks each PWM signal in the symmetrical time range centering on the timing which the polarity of each AC drive signal inverts. The electric motor according to any one of claims 8 to 11,
A regenerative circuit for regenerating power from the first phase coil and the second phase coil array,
The drive signal generation circuit and the regenerative circuit can operate the electric motor in an operation mode in which driving force is generated from one of the first phase coil array and the second phase coil array and power is regenerated from the other. There is an electric motor. The electric motor according to claim 1,
The first coil array is:
A first phase coil array including a plurality of coils arranged at a predetermined pitch along the predetermined direction and electrically connected to each other;
A second phase coil array including a plurality of coils arranged at a predetermined pitch along the predetermined direction and electrically connected to each other;
A third phase coil array including a plurality of coils arranged at a predetermined pitch along the predetermined direction and electrically connected to each other;
With
The first-phase coil group, the second-phase coil group, and the third-phase coil group are arranged at positions shifted from each other by 2π / 3 in electrical angle. A fan motor for rotating the fan,
A fan motor using the electric motor according to claim 1. A fan motor for rotating the fan,
A stator having a first coil array including a plurality of coils arranged along a rotation direction;
Each of the first and second magnet arrays includes at least one magnet and has a first and second magnet array in which a relative positional relationship with each other is fixed, and the first and second magnet arrays with respect to the first coil array A rotor capable of changing a relative positional relationship along the rotation direction;
With
The first and second magnet rows of the rotor are arranged on both sides of the first coil row of the stator,
The fan is integrally formed on the outer periphery of the rotor,
Each coil of the first coil array has substantially no magnetic core,
The fan motor substantially does not have a magnetic yoke for forming a magnetic circuit. The fan motor according to claim 15, wherein
The stator further includes a second coil array that includes a plurality of coils arranged along the rotation direction, and in which a relative positional relationship with the first coil array is fixed,
The second coil array sandwiches one of the first and second magnet arrays of the rotor and is disposed on the opposite side of the stator from the side on which the first coil array is disposed. There is a fan motor.

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