JPH11243677A - Coaxial linear motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the thrust sand efficiency per unit volume or weight of a motor, by setting a relative position relationship so that the strongest torque can be obtained in a direction that operates the core of a soft magnetic body that is used for an armature. SOLUTION: In a cylindrical mover magnet 11, four cylindrical Nb bonded magnets with an equal length being subjected to inner/outer single-pole magnetization in a sinusoidal manner in the longitudinal direction are overlapped. The magnet 11 is accommodated in a yoke magnetization/mover 12 with a cylindrical inner periphery. A spotless circular disk-shaped core consisting of a unidirectional silicon steel plate with a thickness of 0.35 is formed in a stator as a stator block 25. A ferromagnetic coaxial column body 4 is inserted into the inner diameter of a circular disk and the block 25 is fixed. A coil 3 is located in the interval of the block 25 and is insulated from the end face of the block and the ferromagnetic coaxial column body 4, and the ferromagnetic material is wound alternately with the demagnetizing material. The outer periphery of the block 25 opposes the inner-periphery surface of the mover magnet via a gap, and the lead terminal of the coil 3 is withdrawn toward an adjacent coil side through a small hole on the inner/outer periphery of the circular disk core.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of drastically increasing the thrust of a linear motor by applying a novel electromagnetic technology and making the linear motor compact and high thrust by utilizing the characteristic shape of the magnetic circuit. Related to More specifically, by increasing the electromagnetic force per unit volume by making the electromagnetic core slotless and specifying the relative angle between the magnetization direction and the magnetic field, and by providing a motor structure that is easy to cool, It is possible to generate high thrust by mounting.

[0002]

2. Description of the Related Art There are various types of conventional linear motors, and it is considered that a rotary machine is basically developed.
As a representative example, FIG. 2 shows a basic configuration of a magnetic linear motor. In the drawing, reference numeral 1 denotes a plate-like mover magnet magnetized alternately with N and S poles, and reference numeral 2 denotes a stator obtained by providing a notch on a non-oriented electrical steel sheet and laminating it. The stator 2 has a slot 20, and the excitation coil 3 is inserted into the remaining teeth 21 of the notch. Here, the distance between the adjacent teeth 21 and the N pole and the S pole of the mover magnet 1 is set to be equal, and an exciting current is supplied to the coil 3 so that the adjacent teeth alternately generate n poles and s poles. A synchronous electromagnetic force is generated between the magnetized magnetic poles N and S, and an electromagnetic force for moving the mover magnet 1 in the longitudinal direction is generated. Therefore, a linear guide (not shown) is mounted on the stator 2 to support the mover magnet 1 by a linear bearing, and the polarity of the supplied current is switched to generate a thrust in a certain direction by using a magnetic pole detecting means (not shown). The magnet 1 can be run in a predetermined direction.

The problem with the conventional system shown in FIG. 2 is that various performances such as efficiency do not reach the rotating machine. Regarding the structure of both motors, it is considered that the conventional linear motor is a development of a rotating machine.However, comparing the facing magnetic characteristics of a magnet and a stator in a linear motor to that of a rotating machine, a linear motor generally has a planar magnet. In the rotating machine, since the gap length is relatively large in the ring magnets facing all around, the facing area and the gap magnetic resistance are inferior to those of the rotating machine. Therefore, the size and efficiency of the same output are unavoidable, and its use is limited.

[0004]

The first object of the present invention relates to the above-mentioned basic problems of the conventional linear motor, and relates to a unique linear motor which cannot be returned to the rotating machine, rather than simply developing the rotating machine. An object of the present invention is to provide not only the improvement of the characteristics of the conventional linear motor but also the realization of various characteristics exceeding those of the rotating machine.

[0005] A second object of the present invention is to provide a stator core or a magnet or a magnetic circuit having a novel characteristic which enables the above-mentioned unique configuration, thereby generating a torque exceeding a rotating machine in its basic characteristics. It is in.

A third object of the present invention is to provide a means for providing a novel magnetic directivity enabling the above-mentioned unique configuration, thereby generating a torque that exceeds a rotating machine in its basic characteristics. It is in.

A fourth object of the present invention is to provide a magnetic circuit for facilitating the start of the linear motor having the unique configuration.

A fifth object of the present invention is to make the structure of the mover traveling system energized by the magnetic circuit smaller and simpler than the conventional one.

A sixth object of the present invention is to simplify the structure of a linear motor in comparison with a conventional machine, despite the adoption of various means for solving the above basic problems.
It is to realize a low price.

A seventh object of the present invention is to provide a novel linear motor structure having a heat exchange function for lowering the internal temperature of the linear motor.

An eighth object of the present invention is to provide a structure of a linear motor having a novel heat exchanging function in which the temperature inside the linear motor can be controlled from the outside.

A ninth object of the present invention is to provide a linear motor having a relatively high output or a linear motor used in an adiabatic environment by using a circulation of a heat medium such as a fluid as the heat exchange function, thereby minimizing the linear motor body. To generate high thrust by mounting in a narrow space of an application device.

A tenth object of the present invention is to improve the operational reliability in a freezing environment by keeping the inside of the motor through the heat exchange function in a linear motor used in an extremely constant temperature atmosphere. is there.

An eleventh object of the present invention is to provide a linear motor having a relatively small capacity, by minimizing the linear motor body by using a heat transfer function such as gas or solid as the heat exchange means. To generate high thrust by mounting in a narrow space.

A twelfth object of the present invention is to reduce the inner diameter of the core by applying the fact that the soft magnetic material can be made slotless in a linear motor having a smaller capacity.
An object of the present invention is to generate a high thrust as a micro machine by minimizing a motor body by incorporating a linear guide.

[0016]

SUMMARY OF THE INVENTION A linear motor according to the present invention is a main means for solving the above-mentioned problems, which is a novel torque generating means forming the basis of the present technology and a temperature control means based on a unique core shape. Further, a linear guide structure is included inside the motor.

The former torque generating means will be described as follows. A typical embodiment of the linear motor of the present invention is:
A hard magnetic body having a plurality of magnetized poles, a mover magnet configured to include the hard magnetic body, an armature made of a slotless soft magnetic body having a surface facing the magnetized poles,
The soft magnetic body preferably includes a directional soft magnetic body having an easy axis of magnetization, and one of the armature or the mover magnet is configured as a stator and the other is configured as a mover. Further, a coil for exciting the armature, means for detecting the position of the magnetic pole, a drive circuit for energizing the coil, and a direction substantially orthogonal to one surface of the soft magnetic material It is based on obtaining a high torque by arranging the magnetized poles.

In general, when a linear motor is driven synchronously, it is necessary to deal with the starting dead center. In the linear motor of the present invention, this problem is solved by using a stator block means in which the magnetic characteristics of the single-plate magnetic material or the laminated soft magnetic material are slightly different.

In a typical embodiment, a stator block made of a directional soft magnetic body is provided with an inner diameter for penetrating a coaxial column for coupling itself as an armature. The coaxial column is composed of, for example, a non-magnetic column. Further, through holes or slits other than the axis are used for the purpose of modulation of magnetic directivity, crossing of coil terminals, mounting of a linear guide or the like. Regarding magnetic directivity, when a magnetic resistance means such as a through hole or a slit is provided on a line at a specific angle with respect to the axis of easy magnetization, the magnetic directivity can be emphasized. That is, by partially changing the magnetic resistance or the saturation flux density, each portion of the soft magnetic material is saturated at a different level based on the degree and polarity of magnetization. Therefore, the saturation is slightly released from the portion or the saturation is further advanced, so that the original magnetic directivity of the directivity can be further promoted.

Another main means of the linear motor according to the invention concerns a means which allows control of the internal temperature of the motor based on a unique core shape. That is, the typical linear motor of the present invention utilizes the fact that the plate surface of the soft magnetic material is arranged orthogonal to the direction of the magnetic field, and a through hole can be provided in the soft magnetic material. For example, in the case where a stator made of a disk core is used as the soft magnetic material, the disk core is fixed at a predetermined interval via an axis passing through the inner diameter of the disk. At this time, if the shaft center is a hollow pipe and a heat exchange loop is provided to allow oil, water, magnetic fluid, air compressed gas, or a heat exchange medium to flow through and circulate heat, copper loss and iron loss will result. The heat generated inside the linear motor can be taken out of the motor, and the inside of the motor can be easily cooled through the shaft center. As a result, a large power of the order of kilowatts can be input even in a small size, and a high thrust can be generated by inserting a linear motor into a narrow space.

With respect to the means for enabling heat exchange of the internal temperature of the linear motor according to the present invention, a relatively small capacity model
In addition to providing a circulation loop for heat exchange, heat dissipation by natural convection, a heat pipe, or metal heat conduction can be used. Alternatively, the high temperature of the shaft portion can be transmitted to the peripheral portion outside the motor, and the heat can be radiated through cooling fins or a fan.

Still another main means of the linear motor according to the present invention relates to a structure capable of mounting a linear guide inside the motor based on a unique core shape. That is, in the linear motor of the present invention, a slit, a through hole, or the like can be provided on the end face in the soft magnetic material. For example, in an outer mover structure, an inner stator made of a disk core is used as a soft magnetic material, slits are provided on the outer periphery of the disk core, and a linear guide is mounted through this slit to house the guide inside the mover. can do. As a result, it is possible to provide a linear motor having an extremely slim shape as compared with a normal configuration in which a linear guide is mounted outside the mover.

The structure using the inner peripheral linear guide has another effect. That is, in an example of the linear motor of the present invention, there is a coil between the blocks of the inner stator in which the soft magnetic material is laminated, and the upper portion of the coil usually faces the magnetized inner peripheral surface of the outer mover magnet. When a guide is used, a pole piece is inserted between the coil and the magnetized surface and can be fixed to the inner peripheral linear guide. Also, usually
Since the end face of the laminated block is perpendicular to the coaxial direction, there is no so-called umbrella, but if a crossover portion or an inner peripheral linear guide is provided between the laminated blocks, the umbrella can be fixed relatively easily. The motor characteristics such as torque ripple can be further improved.

As another means that can promote the features of the linear motor of the present invention, an exciting coil and a winding method thereof can be cited. In the linear motor of the present invention, the coil is arranged between the single plate or the block of the soft magnetic material, and the winding is a single winding around the coaxial axis, so that it is an extremely simple winding. However, when the armature is composed of a single plate or a block composed of a few sheets, such as a small capacity model, a sheet coil or printed board may be used to shorten the coil length.
Furthermore, winding may be performed through auxiliary through holes.

As a means for exciting the coil, a single-phase bipolar or a three-phase bipolar is generally used. The magnetic pole detecting means is, for example, a Hall element, and detects a zero crossing of the magnetization of the mover magnet by a Hall voltage, and switches the energization to the coil based on the detection output, thereby driving the mover in a predetermined direction. Or stop. Further, by detecting the presence of the mover magnet using a plurality of sensors, it is possible to reduce the loss by energizing only the peripheral coils facing the mover. When high accuracy is required for positioning, a position detecting means other than the magnetic detecting means is used together.

Yet another means that can facilitate the features of the linear motor of the present invention relates to mover magnets. That is, the magnet has a plurality of magnetic poles in the coaxial direction and is adhesively housed in the yoke. In a typical synchronization configuration,
The magnetic poles are magnetized at equal intervals and equally at intervals of the soft magnetic block, and have a shape of, for example, a long cylinder. Therefore, this magnet may be divided and a plurality of unit magnets having a pair of N poles and S poles may be connected in series. Also in this case,
A yoke made of a soft magnetic material may be interposed between the unit magnets.

There are two cases in which the distance between the magnetic poles of the magnet and the distance between the electromagnetic poles are different. That is, when the linear motor of the present invention is used in a polyphase drive, the magnetic pole interval of the magnet and the electromagnetic pole interval are set to multiples of two and three values, respectively, so that a so-called asynchronous configuration is adopted. Alternatively, a synchronous configuration is used in which the magnetic pole interval of the magnet and the electromagnetic pole interval are equal. In the latter, a plurality of synchronous sequences can be used, and as a result, various characteristics such as cogging torque can be obtained between the synchronous drive and the asynchronous drive.

Still another means that can promote the features of the linear motor of the present invention relates to the case where the lamination constituting the armature includes a directional material. In other words, assuming that there is no skew in the magnetic poles of the magnet, if the laminated laminations or the easy axis of magnetization of each block have the same angle, a deterrent is applied to the rotating spin of the electromagnetic force. If the axes of easy magnetization of the laminated laminations are directed in different directions, the torque in the rotation direction can be reduced. Conversely, the magnet can be skew-magnetized to emphasize the spin of rotation based on the axis of easy magnetization.

The first feature of the means of the present invention is that a soft magnetic material has a notch with its own magnetic circuit,
It can be used as a slotless core that is easy to process and wind.

The second feature of the means of the present invention is that, despite the use of a core having a simple shape, the thrust output can be increased as compared with the conventional case by applying a magnetic field from a different direction from the conventional case. .

The third feature of the various means of the present invention is that the use of a core having a simple shape makes it possible to avoid the occurrence of a start dead center in a synchronous motor.

A fourth feature of the various means of the present invention is that the central portion of the linear motor can be directly cooled by utilizing the fact that the core shape is simple and the arrangement direction is coaxial unlike the conventional one. That the configuration could be provided.

A fifth feature of the means of the present invention is that the size of the linear motor main body is minimized by using the above-described coolable structure, and the linear motor body can be mounted in a narrow space. That is, high thrust can be generated. As a result, it is not necessary to increase the size of the device for mounting the linear motor, and the device can be mounted on various devices to execute advanced movements by computer control or the like.

A sixth feature of the various means of the present invention is that the configuration of a linear motor that can incorporate a linear guide is utilized by utilizing the fact that the core shape is simple and the arrangement direction is coaxial unlike conventional ones. It can provide. As a result, particularly in a small-capacity application device, the space for mounting the linear motor can be reduced, and the overall shape of the device can be reduced.

A seventh feature of the means of the present invention is that the core shape is slotless, a linear guide can be provided on the outer periphery, the inner diameter of the core can be omitted, the shaft can be made axial, and the winding can be made. By utilizing the simplicity, it is possible to configure a very small-diameter linear motor and provide a novel micro device equipped with the linear motor.

[0036]

FIG. 3 shows the results of an experiment using a unidirectional disk as an example of verifying the technical basis regarding the various functions of the above-mentioned means in the present invention. In the figure, reference numeral 22 denotes a four-slot core made of a non-oriented silicon steel plate used for a conventional rotary motor,
3 is a unidirectional slotless disk core. The dimensions of both cores are each 20 mm in outer diameter and 0.5 mm in plate thickness. Here, each core is placed in a parallel magnetic field, each plate surface is arranged in parallel with the magnetic field surface, and the parallel magnetic field is circulated so that the circulating torque τ
Measure R. The results obtained are shown for the case of an applied magnetic field of 400 oe.
21, solid line 231. As described above, even in the slotless core, a torque is generated due to the axis of easy magnetization. When the magnitude of the torque is compared with that of an example of the conventional four-slot core, it can be seen that the maximum value of the generated torque is greatly increased several times. . It is needless to say that no torque can be obtained if the material of the disk is changed to non-directional.

Next, the unidirectional disk core 23 used in the measurement of FIG. 3 is placed in a magnetic field perpendicular to the plate surface and is rotated to measure the torque τL. When the obtained result is shown in comparison with the case where the same core 23 used in FIG. 3 is rotated in a parallel magnetic field in the case of the applied magnetic field of 1000 oe, the curve of FIG. 4 is obtained. In the figure, a chain line 232 indicates a torque when the magnetic field circulates in a parallel magnetic field, and a solid line 233 indicates a torque when a magnetic field of the same strength is applied to the same core from the vertical direction and indicates a maximum value at 45 °. Comparing the maximum amplitudes of both curves, it can be seen that even with the same core, the generated torque reaches several times in the vertical magnetic field. Therefore, the solid line 233 is shown in FIG.
Compared with the case of the conventional slot core of the chain line 221 of
It can be seen that if the direction of the magnetic field with respect to the soft magnetic material is specified, a large ratio can be obtained as a simple product.

The linear motor according to the present invention is based on the application of the action of the easy axis in FIGS. In particular, the operation and effect based on the magnetic field from a different direction from that of the related art in FIG. 4 are used. The electromagnetic force in this case is based on a mixture of the effects of both the axis of easy magnetization and the relative angle between the magnetic field and the plate surface.
Such an action changes the magnetization direction of the mover magnet,
During the movement, the generated magnetic flux is in contact with the plate surface of the soft magnetic material.
The emphasis is placed on arranging to include moments that make angles close to °. In terms of materials,
It is emphasized by the use of grain-oriented electrical steel sheets and magnetic resistance by through holes or slits, or the use of anisotropic magnets. That is, when a saturation hole is provided in the slot core, not only the magnetic flux in a specific direction can be emphasized according to the cross-sectional shape of the motor, but also the saturation magnetic flux can be increased.

With respect to the linear motor according to the invention, another useful effect relates to cooling inside the motor. This function is realized by the fact that the shape of the soft magnetic material has become slotless and is not directly related to the magnetic characteristics.However, the structure that can directly cool the inside of the motor is extremely useful for miniaturization of linear motors. is there. However, regarding the cooling action itself by fluid, for example, the cooling system of an internal combustion engine or X
Since it has already been proved by cooling the electrode target of the wire tube, it will be described here that a linear motor to which such a cooling action can be applied can be provided.

FIG. 1 shows an end of an outer mover / inner stator type magnetic linear motor 100 according to a first embodiment of the present invention. This drawing is a diagram for explaining the basic technology of the present invention. In the figures, the cross-sectional view of the magnetic circuit and the components necessary for the description of the driving are shown at the levels necessary for explaining the operation of the present invention. In FIG. 1, the same symbols as those in FIG. The cylindrical mover magnet 11 is formed by superposing four cylindrical Nd bonded magnets of the same length, which are magnetized inside and outside unipolarly in a sine wave shape in the longitudinal direction, and has a yoke magnetized pole and mover having a cylindrical inner periphery. 12
Is stored in. The material may be isotropic, but if anisotropy is used, the effect of magnetic field deflection described later can be promoted. The difference between the isotropic property and the anisotropy of the magnet is not so remarkable as the difference between the non-directional property and the directivity of the magnetic steel sheet. The stator 2 is formed by laminating a slotless disk core made of a unidirectional silicon steel plate having a thickness of 0.35 mm in a shape to be described later to form a stator block 25, and the inner diameter of the disk has a ferromagnetic coaxial column. The body 4 is inserted to fix the block 25. The thickness of the blocks and the distance between adjacent blocks are equal, and the blocks are arranged at the same distance as the magnetized magnetic poles. A coil 3 is provided between the blocks 25, and is insulated from the end face of the block and the ferromagnetic coaxial column 4 and is alternately wound with a magnetized magnetic source. Further, a magnetic sensor (not shown) is mounted near the mover magnet 1 during the interval between the blocks 25. The outer periphery of the block 25 is opposed to the inner peripheral surface of the mover magnet 1 via a gap, and the lead terminal of the coil 3 is drawn out to the adjacent coil side through a small hole provided on the inner and outer periphery of the disk core described later. .

Here, the shape of the practical disk core 24 is shown in FIG. In this embodiment, the axis of easy magnetization of the disk is
The direction [100] 230 is the direction of the arrow. Disc core 2
4 has an inner diameter 241 in the center of the direction 23 of the axis of easy magnetization.
A pair of saturation holes 243 are provided on a line perpendicular to 0 and as a result, the magnetic directivity is emphasized. In general, the magnetic directivity changes variously depending on the combination of the direction 230 of the easy axis and the saturation hole 243. Disc core 24
A small hole 242 is provided on a line inclined about 60 ° with respect to the direction of the arrow on the inner diameter side and the outer circumference side of. In this example,
The stator blocks 25 are formed by laminating the easy axes of the disk cores 24 in the same direction.

Since the magnetic circuit of the linear motor 100 shown in FIG. 1 has a so-called synchronous configuration, the outer periphery of the block 25 faces the magnetic poles of the mover magnet 1 respectively. Since the blocks are discs, the magnetic flux flow when there is a magnetized magnetic pole in the middle of each block flows, possibly including an angle component of 45 ° on the plate surface of the block, as can be seen from the solid line 233 in FIG. Generates strong electromagnetic force. The magnetic flux flowing from the magnetized magnetic pole to the surface of the block passes through the plate surface of the adjacent block via the ferromagnetic coaxial column 4 between the blocks, and returns to a different pole. According to the disk core 24 of FIG. 5, the magnetic flux flows strongly along the axis of easy magnetization, particularly in the direction of the arrow. The magnetic flux flows through the air gap of each part, the disk core 24 or the stator block 25.
And the magnetic characteristics of the coaxial column 4. Further, by selecting the shape and arrangement of the saturation hole 243 with respect to the axis of easy magnetization, the magnetic flux flow is hindered and local saturation occurs, and as a result, the magnetic directivity can be changed.

When the outer peripheral end surface of the block 25 is directly below the magnetized magnetic pole, the relationship between the magnetized magnetic pole and the block outer peripheral surface is 0 °.
As can be seen from the solid line 233 in FIG. 4, no electromagnetic force is generated. Since the motor of FIG. 1 has a synchronous configuration, when the mover magnet 1 is stabilized at this position at the time of startup, it becomes a startup dead center. This starting dead center can be avoided by stacking disc cores of different properties. That is, the theta block 25 is formed by laminating discs having slightly different outer diameters of disc cores, specifications of saturation holes, angles of easy axes of magnetization, and the like. Alternatively, the starting dead center is eliminated by making the intervals of the data blocks 25 slightly unequal.

In FIG. 1, the coils 3 alternately wound with the magnetized and demagnetized coils are, for example, all connected in series and are excited by a single-phase bipolar circuit. As a result, the stator block 2
5, the induction magnetic flux flows, and electromagnetic poles having different polarities alternately occur on the outer periphery of the adjacent stator block 25. Accordingly, when the position of the magnetic pole of the mover magnet 1 is detected, and the direction of energization of the coil 3 is switched so that a repulsive force or an attractive force is always generated with respect to the magnetized magnetic pole facing these electromagnetic poles, the mover moves along the same axis. Driven in a certain direction

In the case of FIG. 1, the disk core 24 is laminated such that the direction of the axis of easy magnetization and the saturation hole are uniform, so that no spin is applied to the mover magnet. The electromagnetic force between the disk and the magnetic poles approaches the orientation of FIG. 4 when the magnetic poles of the magnet are in the middle of the stator block.
Note that a torque reduction of about 10% occurs due to the inner diameter and the through hole.

The present invention has been described with reference to the first embodiment of FIG. 1 and it has been shown that a simple linear motor can be constituted by a slotless disk core. Since the first embodiment shows the basic operation of the present invention, various variations will be described as follows.

In the embodiment shown in FIG. 1, the coaxial column is made of a ferromagnetic material. However, a non-magnetic material can be used without any change in that an electromagnetic pole is generated on the outer periphery of the stator block 25. Further, a ferromagnetic material concentric with a non-magnetic coaxial pillar can be placed between the blocks. For example, the inner peripheral yoke is formed by stacking ferromagnetic cylinders having different diameters, and can be mounted on the outer periphery of the coaxial column 4 and at intervals between the stator blocks 25.

In the magnetic circuit shown in FIG.
There are no auxiliary poles or pole pieces on the outer circumference of 5, but they can be used to improve torque ripple and for other purposes. In the present invention, the pole pieces are arranged so as to promote the magnetic field in the 45 ° direction.

In the first embodiment, a directional stator core is used, and the magnet is made of a sine wave magnet made of an isotropic material. However, in order to emphasize the magnetic field in the coaxial direction, a yoke between magnetic poles and a non-sine wave magnet are used. Magnetic or anisotropic materials can be used.

In FIG. 1, the magnetic directivity of the disk core is aligned in one direction. On the other hand, it is also possible to disperse and circulate in the direction of the axis of easy magnetization for each block to generate a uniform torque over the entire circumference of the gnet. it can. In addition, the mover can be run while rotating spin is applied by skew magnetization of an easy axis or a magnet.

In the embodiment shown in FIG.
Is composed of a plurality of divided cylindrical magnets of the same length, which are magnetized inside and outside unipolar.Other magnetizing methods and a ring-shaped magnet molded integrally can be used. It is also possible to insert a yoke such as a shape. In addition, the width of the stator block 25 and the distance between adjacent blocks, or the use of coils between the blocks is fixed, but it may be irregular at the end of the coaxial column for the purpose of braking or the like.

In FIG. 1, the excitation circuit is a single-phase bipolar. However, other excitation circuits can be used. In particular, in a three-phase bipolar, the stator block is set to a multiple of 3 and the number of poles of the magnet is set to a multiple of 2 as is well known, and in the case of a DC power supply, one phase is removed to excite. When the coaxial length is long, it is desirable that the coil element to be excited be only the coil facing the mover. Further, for the purpose of braking or the like, the coil or excitation specification can be made unique at the end of the coaxial column.

In FIG. 1, the commutation of the exciting current is performed by detecting a zero crossing of magnetization by a magnetic sensor. However, when high accuracy is required, it is desirable to use a position detecting means such as an encoder together.

The motor configuration shown in FIG.
Although it is an outer mover and the armature side is a stator, the armature may be a mover. In addition, the inner diameter of the disk can be expanded to form an outer stator / inner mover as a donut-shaped disk. Further, the operation and effect of the present invention do not prevent the linear motor from being configured using the electromagnet formed by the armature on both the stator side mover side.

[0055]

Embodiment 2 By the way, the disk core of the present invention has another advantage not seen in the past in addition to the torque characteristics. In the conventional linear motor structure, simple cooling was difficult, but in the linear motor structure of the present invention, heat exchange with a heat flow medium or the like was performed through a coaxial column passing through the inner diameter of the disk core. Thus, the inside of the motor can be directly cooled with a simple structure. This simple heat exchange mechanism is a fundamental feature of the present invention alongside the directional magnetic circuit.

The second embodiment of the present invention relates to such a coolable linear motor. In the embodiment of FIG. 1, a hollow pipe 41 is provided inside the coaxial column 4, and can be connected to, for example, a heat exchange circulation loop as shown in FIG. In the illustrated circulation loop, the hollow pipe of the linear motor 100 is connected via a hose 5 to a radiator 6 and a fluid pump 7. Linear motor 1
When the internal temperature of the internal combustion engine 00 rises to a predetermined value due to heat generation due to copper loss and iron loss, a temperature sensor (not shown) detects this and the pump 7 operates, and the fluid heat medium is supplied to the pump 7.
As a result, the heat flows into the hollow pipe 41 inside the motor, and the heat generated inside the motor is carried out to the outside of the motor by the fluid, the heat is dissipated by the radiator 6, and the cooled low-temperature fluid flows back into the motor. Therefore, it is possible to directly cool the inside of the motor in a nearly perfect form, and it is possible to input large power on the order of kilowatts even with a small motor shape, and as a result, to insert it into a small space and generate high thrust Becomes possible.

As a heat flow medium of the fluid circulation loop of FIG. 6, in addition to liquids such as water, oil, chlorofluorocarbon, and magnetic fluid, air may be used depending on the situation. Regarding the cooling method, in the case of FIG. 6, the closed loop is forced circulation, but depending on the capacity of the motor, it is not sufficient to selectively use the radiator 6 or the pump 7, or natural convection is used, or even open loop release Good.

When the fluid is aqueous, the ferromagnetic coaxial column 4 is disadvantageous in terms of electrical insulation or rust prevention. In such a case, it is necessary to use a non-magnetic material as the coaxial column 4 and a rust-free substance as the connection hose 5, or to perform a surface treatment on the hollow pipe.

In the circulation loop of FIG. 6, a single linear motor is used. However, when a plurality of motors are used and they are driven in tandem with outputs of the same phase or different phases, the flow path of the heat exchange loop is Connect hollow pipes in series and parallel,
Alternatively, one cooling circulation loop can be shared.

The purpose of the circulation loop of FIG. 6 is to cool the heat generated by copper loss and iron loss inside the motor, but it is indispensable when heat is not dissipated in a vacuum atmosphere and heat is adiabatically accumulated. Means. Conversely, in a cryogenic environment encountered by, for example, an aircraft, the heat exchange action of the circulation loop is diverted to circulate a relatively high temperature fluid through the hollow pipe 41, thereby keeping the motor warm through the heat flow medium. Can be. Therefore, freezing of the device is prevented, and as a result, the reliability of operation can be improved.

[0061]

Embodiment 3 FIG. 7 shows a third embodiment of the linear motor according to the present invention. This figure shows the entire structure of a single linear motor for operating the first embodiment of FIG. 1 in the circulation loop of the second embodiment of FIG. In the figure, a pair of linear guides 8 are provided on both sides of the coaxial column 4 in parallel with each other,
The end is fixed to the end of the coaxial column 4 via the fixing screw 91 of the end plate 9. The housing 13 including the magnet mover is slidably supported by a pair of linear guides 8 via a linear bearing (not shown), and a coaxial thrust is transmitted to a load weight via a weight mounting screw hole 131 of the housing 13. The pair of fluid couplings 42 is connected to a cooling circulation loop via a connection hose (not shown). A damper is used at the end of the stroke of the housing 13 if necessary. When a plurality of motors are connected in series, the linear guide 8 can be shared by the plurality of motors.

[0062]

[Embodiment 4] On the other hand, in a small model such as for OA, a hollow pipe 4
A gas such as air is suitable as the fluid flowing through the device. In models with smaller capacities, heat generated inside the motor is guided to the outside of the motor via a heat pipe housed in the hollow pipe 41 or a good conductor such as a filled metal, and natural convection is selectively performed using radiation fins and fans. Can be dissipated in the range of forced cooling.

FIG. 8 is a sectional view of a main part of a linear motor suitable for such a relatively small capacity according to a fourth embodiment of the present invention. In the center of the figure, there is a coaxial column 4 whose both ends are supported on a base by end plates (not shown). An insulating bobbin 31 is provided outside the coaxial column 4, and a coil 3 is provided outside the insulating bobbin 31. A pair of slits are provided at two points on the outer periphery of the disk core, and a pair of outer linear guides 81 are fitted into the slits. A screw hole 132 is provided inside the housing 13, and the ball 82 of the linear bearing is pressed by a bolt from the side. As a result, the ball 82 comes into opposing contact with the linear guide 81, and the housing 13 slides on the guide 81. Compressed air flows through the hollow pipe 41 and is jetted from the air-permeable coaxial column 4 to lower the internal temperature of the motor.

When the motor internal linear guide is provided as described above, various members can be easily supported by using the guide as a support. Such a member is, for example, an auxiliary pole of the armature. That is, so-called umbrellas can be extended on both sides of the stator block 25, or pole pieces with auxiliary grooves can be easily attached.
The same applies to the attachment of the magnetic sensor.

Further, in the linear motor of the present invention having an extremely small size, the inner diameter of the stator core 24 can be made extremely small.
In the case of the extremely small size, even if the heat radiation cooling function of the coaxial column is reduced due to an increase in the surface area per unit weight of the motor, no practical problem occurs. Therefore, the heat conduction of the coaxial column itself can be used, or the coaxial column can be omitted by using a core having no inner diameter.

In the minimal linear motor of the present invention in which the inner diameter of the core or the coaxial column is omitted, the function of supporting the coaxial column is provided by the linear guide provided on the outer periphery of the core. In the case where there is no inner diameter, the excitation coil is mounted, for example, on a bobbin in advance by flat winding. Alternatively, the winding frame may be removed and attached using a welding magnet wire or the like. Further, in a linear motor having a very small size, the linear guide can be eliminated. As a method of supporting the mover magnet 1 in this case, a disk core or the like having an uneven portion on the outer periphery is arranged with a reduced interval. Therefore, the coil between the plates
A thin coil such as a sheet coil is suitable.

The above description has been made with respect to the four embodiments which simply show the operation of the present invention. Among these embodiments, the first and second embodiments belong to the basics of the present invention, and the third and fourth embodiments show application forms. In the embodiment of the present invention, a combination of a stator made of a soft magnetic material and a mover made of a hard magnetic material is used, but a soft magnetic material may be used as a hard magnetic mover for the stator. It can also be an electromagnet.

The first embodiment relates to the improvement of the generated torque itself.
Various modifications may be made without departing from the technical scope of the present invention. The second embodiment relates to a method enabling application to an extremely small space, and this can be variously modified and used without departing from the technical base of the present invention.

The third and fourth embodiments can be widely applied to various devices. Specifically, the third embodiment can be used as, for example, an automatic door or an actuator for opening a loom, and can be mounted in a small space to generate high thrust and driven in various patterns according to computer control. can do.

The fourth embodiment is suitable for micromachine sizes, for example, from OA use to medical use. Since the core has a slotless shape, it can be easily manufactured despite its extremely small size. Such an extremely small size motor is suitable for, for example, driving a reading arm of a magnetic recording device or a micropump.

[0071]

According to the present invention, the direction acting on the core of the soft magnetic material used for the armature of the linear motor is set to a relative positional relationship so that the strongest torque can be obtained. There is an effect that the thrust per hit and therefore the efficiency can be increased more than before. Note that the configuration of the linear motor of the present invention does not correspond to the structure of the rotating machine, unlike the conventional linear motor.

According to the present invention, since a core used for an armature of a linear motor can be made slotless, a simple shape such as a disk can be used. As a result, the processability can be improved, and the thrust per unit volume or weight of the motor and, therefore, the efficiency can be increased more than before.

According to the present invention, a direction is introduced into the magnetic circuit of the linear motor, the direction of the axis of easy magnetization of the magnetic steel sheet is set, and a magnetic resistance portion such as a through hole is provided at a key point of the magnetic steel sheet. Since the magnetic flux distribution is improved by setting the maximum electromagnetic force on the magnetic member, the thrust per unit volume or weight of the motor and thus the efficiency can be increased more than before.

According to the present invention, there is provided a method for avoiding a starting dead center when a linear motor is used as a synchronous motor. This has the effect that it can be achieved by a simple method of giving a slight difference.

According to the present invention, the core used for the armature of the linear motor can be made slotless, and a simple shape such as a disk can be used. Or a linear guide can be built in the outer periphery of the disk core, so that the mechanical structure of the motor can be simplified.

According to the large-capacity linear motor of the present invention,
By making the inside of the coaxial column hollow and circulating a thermal medium through it, the heat inside the motor is transferred to the outside of the motor and dissipated, minimizing the volume or weight per capacity of the motor body In addition, it is possible to provide an effect that a high thrust can be obtained, thereby enabling mounting to an application device having a narrow mounting space.

According to the small capacity linear motor of the present invention,
The interior of the coaxial column is hollowed out, and a material having good heat conduction properties is provided in it to conduct heat generated inside the motor to the outside of the motor and dissipate the heat motor, thereby minimizing the motor volume or weight per thrust. Therefore, it is possible to provide an effect that the application device can be mounted in a narrow space.

According to the linear motor having a smaller capacity according to the present invention, the mover magnet can be supported on the outer periphery of the armature core by omitting the small coaxial column or the built-in linear guide. Can be provided.

[Brief description of the drawings]

FIG. 1 is a first embodiment for describing a basic operation of the present invention, and shows a main part of a magnetic circuit of a magnet linear motor using a disk core.

FIG. 2 is a drawing for explaining the operation of a conventional linear motor, and shows a main part of a magnetic circuit of a magnet linear motor including a flat magnet and a non-directional armature.

FIG. 3 shows a difference in basic circling torque between a conventional slot core and a directional disk according to the present invention as a basic technology of the linear motor of the present invention.

FIG. 4 shows a basic torque difference when a magnetic field is applied to the directional disk according to the present invention from different directions as a basic technology of the linear motor of the present invention.

FIG. 5 shows the shape of a typical disk slot score core used in an embodiment of the present invention.

FIG. 6 shows a configuration of a relatively large-capacity magnet linear motor according to a second embodiment of the present invention, which includes a cooling circulation loop using a heat flow medium.

FIG. 7 shows a mechanical configuration including an external linear guide in a magnet linear motor according to a third embodiment of the present invention.

FIG. 8 shows a structure of a relatively small-capacity magnet linear motor according to a fourth embodiment of the present invention, which has a circulation loop by gas and a linear guide inside the motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mover magnet 13 Housing 2 Stator 230 Easy magnetization axis 24 Slotless disk core 241 Inner diameter of slotless disk core 243 Saturation hole of core 25 Stator block 3 Excitation coil 4 Coaxial column 41 Coaxial column hollow pipe 42 Fluid coupling 7 Fluid pump 8 Linear guide Page 23

Claims (7)

[Claims] At least one of a stator and a mover comprises a soft magnetic material to constitute an armature, or at least one of the stator and the mover comprises a hard magnetic material, wherein the hard magnetic material comprises a magnetized magnetic pole, The armature has an electromagnetic pole, the magnetized magnetic pole and the electromagnetic pole are arranged to face each other via an air gap, and the traveling direction of the mover and the plate surface direction of the soft magnetic body are arranged so as to be substantially orthogonal. The soft magnetic body is composed of a single plate or a block in which a plurality of slotless cores are stacked, and a coaxial column including non-magnetic or magnetic is arranged so that the blocks are coaxially arranged. A coil is wound, and a linear guide and a linear bearing for moving the mover in parallel with the longitudinal direction of the coaxial column are provided, and the coaxial column and the guide are fixed. A coaxial linear motor, wherein the mover is propelled in parallel with the coaxial direction by an electromagnetic force generated between the magnetized magnetic pole and the electromagnetic pole. 2. The hard magnetic body forms a mover including an isotropic or anisotropic material, and the soft magnetic body forms a stator including a non-directional or directional electromagnetic steel strip. The soft magnetic body is provided with a through-hole for fixing itself along the coaxial column, and for changing magnetic saturation or magnetic directivity, or for winding, or for mounting the guide. A through hole or slit is provided, and a coaxial columnar body is provided for arranging the soft magnetic material on the same axis. The linear guide is mounted on an inner peripheral side of the hard magnetic material and an outer peripheral portion of the soft magnetic material. A patent is provided in which a linear bearing is provided on a parallel surface on an inner periphery of the hard magnetic body, and the mover is caused to travel in parallel with a longitudinal direction of the coaxial column by contact between the linear guide and the bearing. Contract The coaxial linear motor according to claim 1. 3. The hard magnetic body is formed of a cylindrical shape or a partial cylindrical shape, and the magnetized magnetic poles include a magnetic flux component forming approximately 45 ° between the stators at portions set at the same interval. Magnetized, the soft magnetic material forms a theta as a block formed by laminating disk veneers or disk veneers with different characteristics, and arranges the soft magnetic material as a stator at the center of the disk or block. A through hole is provided, each block is arranged on the coaxial column by the through hole at an angle exhibiting the same or different circulating characteristics, and the inner linear guide is provided with an auxiliary pole or umbrella of the soft magnetic material. The coaxial column is mounted in a through hole of the block, and a magnet wire, a sheet coil, or a printed surface coil of the soft magnetic material is provided in a gap between the blocks. The excitation coil is formed by,
Means for detecting the position of the magnetic pole is provided around the gap between the blocks, and a drive circuit for energizing the coil is provided, and at least the exciting coil around the magnetized magnetic pole is magnetized, demagnetized or non-magnetized. 3. The coaxial linear motor according to claim 1, wherein the motor is excited including energization. 4. The soft magnetic body is a disc-shaped core made of a grain-oriented electrical steel sheet, and the disc core has different characteristics with respect to a shape such as an outer diameter, saturation, magnetization, and the like. The easy axis of magnetization of the plate is stacked at a specific angle with the coaxial to form the stator, and the plate surface is provided with a through hole or slit for wiring or coil terminal withdrawal or for mounting a linear guide, 4. The coaxial linear motor according to claim 1, wherein a part of the through hole or the slit is disposed on a line of an axis of easy magnetization passing on a center line of the disk or at a peripheral angle thereof. . 5. The coaxial column has a hollow portion, and has a natural or forced circulation means or a heat exchange means for flowing a fluid such as a liquid or a gas into the hollow portion,
Alternatively, the hollow part has a means for allowing gas or compressed gas to flow therethrough, and when the fluid becomes high temperature due to heat generation inside the motor or an adiabatic atmosphere such as a vacuum, the heat is absorbed by the fluid. By carrying out heat radiation to the outside of the motor or returning to the hollow part, the inside of the motor body is cooled to minimize the volume or weight per thrust, and conversely, in an environment where the motor is overcooled, the fluid is removed. The coaxial linear motor according to any one of claims 1 to 4, wherein the motor is kept warm through the motor. 6. A hollow portion of the pillar body includes a heat pipe or a solid or semi-solid heat conductor, and a heat radiation means is provided at a portion thermally connected to the heat conductor and developed outside the motor body. Based on the heat conduction effect of the good heat conductor, the internal heat generated in the motor main body is carried out to the outside, and the motor is miniaturized by radiating heat by the natural or forced air cooling means through the heat radiating means and cooling the motor main body part. The coaxial linear motor according to any one of claims 1 to 5, wherein: 7. An armature core made of a soft magnetic material having an uneven portion on an outer peripheral portion, wherein the soft magnetic material has an extremely small inner diameter or no inner diameter, and is directly used as a linear guide by using the uneven portion. 7. The coaxial linear motor according to claim 1, wherein: