JP6947340B1 - Field magnet and motor with field magnet - Google Patents

Abstract

A plurality of main magnetic pole permanent magnets (41, 51) magnetized in a direction orthogonal to the main surface (5a) of the back yoke (5) and arranged so that the magnetization directions alternate, and a main magnetic pole permanent magnet (41, It is magnetized in a direction different from the magnetization direction of 51), and is arranged so that the magnetization directions alternate, and the main magnetic pole permanent magnets (41, 51) are arranged in the same direction as the arrangement direction of the main magnetic pole permanent magnets (41, 51). A plurality of secondary magnetic pole permanent magnets (61, 71) provided alternately with the magnet, and a non-magnetic layer (6) which is a non-magnetic region are provided, and at least a part of the secondary magnetic pole permanent magnets (61, 71) is provided. The position of the surface facing the main surface (5a) via the non-magnetic layer (6) in the direction orthogonal to the main surface (5a) and facing the main surface (5a) of the secondary magnetic pole permanent magnets (61, 71) is , The position is the same as the position of the surface of the main magnetic pole permanent magnet (41, 51) farthest from the main surface (5a), and the length of the sub magnetic pole permanent magnet (61, 71) is that of the non-magnetic layer (6). A field magnet characterized by being longer or the same length as the length.

Description

The present disclosure relates to a field magnet composed of a permanent magnet and an electric motor including the field magnet.

As a field structure of an electric motor having a permanent magnet, a Halbach magnet array structure has conventionally been used for a permanent magnet for the purpose of concentrating magnet magnetic flux. As a Halbach magnet array, there is an array in which a plurality of main magnetic pole permanent magnets magnetized in the direction of the generated magnetic field and secondary magnetic pole permanent magnets arranged between the main magnetic pole permanent magnets are fixed in a row on the back yoke. ..

While such an array can increase the generated magnetic field, there is a limit to the magnetic field that can be generated. On the other hand, there are two widths of the back yoke, the main magnetic pole permanent magnet, the soft magnetic material arranged on the magnetic field generation side of the main magnetic pole permanent magnet, and the same thickness as each of the main magnetic pole permanent magnet and the soft magnetic material. Some have a secondary magnetic pole permanent magnet. An arrangement has been proposed in which the length of the main magnetic pole permanent magnet on the back yoke side is larger than the length of the soft magnetic material on the generation magnetic field side (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2011-24379

In the arrangement described in Patent Document 1, since the surface on the generated magnetic field side is narrowed, the secondary magnetic pole permanent magnets arranged between the main magnetic pole permanent magnets and the main magnetic pole permanent magnets are fixed in a row to the back yoke. Although the generated magnetic field can be made larger than the arrangement as described above, there is a problem that the magnetic flux originally possessed by the magnet cannot be effectively used.

The present disclosure has been made to solve the above problems, and includes a field magnet and a field magnet capable of improving thrust by a configuration that effectively utilizes the magnetic flux of the original permanent magnet. The purpose is to provide an electric motor.

The field magnet according to the present disclosure differs from a plurality of main magnetic pole permanent magnets that are magnetized in a direction orthogonal to the main surface of the back yoke and arranged so that the magnetization directions alternate, and the magnetization directions of the main magnetic pole permanent magnets. It is magnetized in the direction and arranged so that the magnetization directions alternate, and a plurality of sub-magnetic permanent magnets that are alternately provided with the main magnetic permanent magnets in the same direction as the arrangement direction of the main magnetic permanent magnets and the main magnetic permanent magnets. It is provided with a non-magnetic layer which is a non-magnetic region provided between and another main magnetic pole permanent magnet adjacent to the secondary magnetic pole permanent magnet. The position of the surface facing the main surface of the secondary magnetic pole permanent magnet is the position of the surface of the main magnetic pole permanent magnet farthest from the main surface in the direction orthogonal to the main surface and the main surface. It is at the same position in the direction orthogonal to the surface or at a position farther from the main surface than the position of the surface of the main magnetic pole permanent magnet, and the length in the arrangement direction of the secondary magnetic pole permanent magnet is the same as the length in the arrangement direction of the non-magnetic layer. Alternatively, it is characterized in that it is longer than the length of the non-magnetic layer in the arrangement direction.

According to the field magnet of the present disclosure and the motor provided with the field magnet, the magnetic flux of the permanent magnet can be effectively utilized to improve the thrust.

It is a cross-sectional view of the electric motor provided with the field magnet according to the first embodiment of the present disclosure. It is a vertical sectional view of the electric motor provided with the field magnet according to the first embodiment of the present disclosure. It is a vertical cross-sectional view of the field magnet provided with the field magnet which concerns on Embodiment 1 of this disclosure. It is a figure which shows the relationship between the ratio of the length of a secondary magnetic pole permanent magnet to the length of a non-magnetic layer in the field magnet which concerns on Embodiment 1 of this disclosure, and the rate of increase / decrease of an induced voltage. It is a vertical cross-sectional view explaining the field magnet which concerns on Embodiment 1 of this disclosure, and is a schematic diagram of the magnetic flux density waveform at the air gap surface. It is a vertical cross-sectional view explaining the structure of the field magnet which concerns on Embodiment 1 of this disclosure. It is a vertical sectional view explaining the structure of the field magnet which concerns on Embodiment 2 of this disclosure. It is a figure which shows the magnetic force acting on the field magnetic force which concerns on Embodiment 2 of this disclosure. FIG. 5 is a vertical cross-sectional view of a main part of the field magnet for explaining the magnetic force acting on the field magnet according to the second embodiment of the present disclosure. It is a vertical sectional view explaining the structure of the field magnet which concerns on Embodiment 2 of this disclosure. It is a vertical sectional view explaining the structure of the field magnet which concerns on Embodiment 2 of this disclosure. It is a vertical sectional view explaining the structure of the field magnet which concerns on Embodiment 3 of this disclosure. It is a vertical cross-sectional view explaining the structure of the field magnet which concerns on Embodiment 4 of this disclosure. It is an axial sectional view explaining the structure of the field magnet which concerns on Embodiment 5 of this disclosure. It is an axial sectional view explaining the structure of the field magnet which concerns on Embodiment 5 of this disclosure.

Hereinafter, embodiments will be described with reference to the drawings. It should be noted that the drawings are shown schematically, and for convenience of explanation, the configuration is omitted or the configuration is simplified. Further, the interrelationship between the sizes and positions of the configurations and the like shown in different drawings is not always accurately described and can be changed as appropriate. Further, in the description shown below, similar components are illustrated with the same reference numerals, and their names and functions are also the same. Therefore, detailed description of them may be omitted to avoid duplication.

Embodiment 1.
FIG. 1 is a cross-sectional view showing an electric motor provided with a field magnet according to the first embodiment of the present disclosure, and FIG. 2 is a vertical sectional view showing an electric motor provided with a field magnet according to the first embodiment of the present disclosure. It is a figure. The cross-sectional view is a cross-sectional view in a plane orthogonal to the arrangement direction of the permanent magnets described later, and the vertical cross-sectional view is a plane orthogonal to the main surface of the back yoke described later and parallel to the arrangement direction of the permanent magnets. It is a cross-sectional view in.
Further, in the first embodiment of the present disclosure, a linear motor will be described as an example of the electric motor, but the present invention is not limited to this.

As shown in FIG. 1, the electric motor 10 includes a gantry 100, a pair of guide rails 102 extending from the gantry 100, a stage 101 that can be moved by being guided by the guide rails 102, an armature 2, and a field magnet. It has a child 3.
A field magnet 3 that generates a periodic magnetic field is installed on the gantry 100. The periodic magnetic field here is a periodic magnetic field in which N magnetic poles and S magnetic poles are alternately generated. Further, the armature 2 is supported on the stage 101 by securing an air gap which is a predetermined gap between the stage 101 and the field magnet 3.
With this configuration, the armature 2 supported by the stage 101 is guided by the guide rail 102 and becomes movable in a state of facing the field magnet 3. The armature 2 moves while generating an attractive force and a repulsive force with the periodic magnetic field generated from the field magnet 3. That is, in the embodiment of the present disclosure, the field magnet 3 is configured as a stator in the motor 10, and the armature 2 is configured as a mover in the motor 10.

Needless to say, the field magnet 3 may be used as a mover and the armature 2 may be used as a stator. Further, the configuration of the gantry 100, the stage 101, and the guide rail 102 is not limited to this, and any configuration may be sufficient as long as either one of the field magnet 3 or the armature 2 can be fixed and the other can be moved. .. Hereinafter, each configuration will be further described, but detailed description of each configuration will be omitted because the configurations of the gantry 100, the stage 101, and the guide rail 102 are well-known techniques.

As shown in FIG. 2, the armature 2 includes a core 20 made of an electromagnetic steel plate which is a soft magnetic material, and a coil 21 wound around a tooth 22 portion of the core 20. The armature 2 is attached so that the tip of the teeth 22 faces the field magnet 3 side and is parallel to the surface of the stage 101. With this configuration, the armature 2 can move in the arrangement direction of the permanent magnets constituting the field magnet 3, which will be described later, while ensuring a constant gap between the teeth 22 and the field magnet 3. The core 20 of the armature 2 is manufactured by passing through a laminated body of electrical steel sheets and fastening and integrating them using bolts and nuts.

Here, the traveling direction of the armature 2 is the x direction, the direction across the air gap between the armature 2 and the field magnet 3 is the y direction, and the direction perpendicular to each of the x direction and the y direction is the z direction. Define. For convenience of explanation, the right direction in the drawing on the paper surface is the positive direction of x (+ x direction), the upward direction of the paper surface is the positive direction of y (+ y direction), and the front direction of the paper surface is the positive direction of z (+ z direction). Is defined as. This definition also applies to other embodiments.

The field magnet 3 is composed of a back yoke 5 made of a mass of magnetic material and a permanent magnet.

The back yoke 5 is formed in a plate shape and extends in the x direction, and is arranged so that the main surface 5a of the back yoke 5 is a surface orthogonal to the y direction. The main surface 5a of the back yoke 5 is the surface on the armature 2 side among the surfaces orthogonal to the y direction.

The permanent magnets are the main magnetic pole permanent magnets 41 and 51 magnetized in the y direction, which is the direction of the generated magnetic field, and the secondary magnetic pole permanent magnets 61 and 71 magnetized so as to be different from the magnetic pole directions of the main magnetic pole permanent magnets 41 and 51. And, including. The main magnetic pole permanent magnets 41 and 51 and the sub magnetic pole permanent magnets 61 and 71 are arranged in a Halbach array on the main surface 5a of the back yoke 5 so that the magnetic field strength in a specific direction increases. In the following description, when the main magnetic pole permanent magnets 41 and 51 and the sub magnetic pole permanent magnets 61 and 71 are collectively described, a "permanent magnet" may be used.

As the main magnetic pole permanent magnets 41 and 51, for example, Nd-Fe-B-based sintered magnets produced in a rectangular parallelepiped are used. Further, the main magnetic pole permanent magnets 41 and 51 are magnetized in the y direction, which is the direction across the air gap between the armature 2 and the field magnet 3.

Specifically, as shown by an arrow in FIG. 2, the main magnetic pole permanent magnet 41 is magnetized in the + y direction orthogonal to the main surface 5a of the back yoke 5, and the main magnetic pole permanent magnet 51 is magnetized in the −y direction. It is magnetized. The main magnetic pole permanent magnets 41 and the main magnetic pole permanent magnets 51 are alternately arranged on the main surface 5a of the back yoke 5 in the x direction at intervals. That is, the main magnetic pole permanent magnets 41 and 51 are linearly arranged so that the magnetization directions of the other main magnetic pole permanent magnets 41 and 51 adjacent to each other are opposite (alternating) to each other in the x direction. Further, in the y direction, the main magnetic pole permanent magnets 41 and 51 are provided so as to be located in the + y direction with respect to the back yoke 5.

As the secondary magnetic pole permanent magnets 61 and 71, the same as the main magnetic pole permanent magnets 41 and 51, Nd-Fe-B-based sintered magnets produced in a rectangular parallelepiped are used. Further, the secondary magnetic pole permanent magnets 61 and 71 are magnetized in the x direction, which is the movable direction of the armature 2.

Specifically, the secondary magnetic pole permanent magnet 61 is magnetized in the + x direction, and the secondary magnetic pole permanent magnet 71 is magnetized in the −x direction. Then, the secondary magnetic pole permanent magnets 61 and the secondary magnetic pole permanent magnets 71 are arranged in the same direction as the arrangement directions of the main magnetic pole permanent magnets 41 and 51 at intervals. That is, each of the secondary magnetic pole permanent magnets 61 and 71 is linearly arranged so that the magnetization directions of the other auxiliary magnetic pole permanent magnets 61 and 71 adjacent to each other are opposite (alternating) to each other in the x direction. Further, the secondary magnetic pole permanent magnets 61 and 71 are provided on the + y direction side of the main magnetic pole permanent magnets 41 and 51 in the y direction.

There is a gap between the main magnetic pole permanent magnet 41 and the main magnetic pole permanent magnet 51 in the x direction. This void is a non-magnetic region, and will be described below as the non-magnetic layer 6. Further, a magnetic body 4 is arranged at each distance between the secondary magnetic pole permanent magnet 61 and the secondary magnetic pole permanent magnet 71 in the x direction. Therefore, a linear arrangement in the x direction is formed in which the main magnetic pole permanent magnet 41, the non-magnetic layer 6, the main magnetic pole permanent magnet 51, the non-magnetic layer 6 ... Are repeated in this order. Further, a linear arrangement in the x direction is formed in which the sub-magnetic pole permanent magnet 61, the magnetic body 4, the sub-magnetic pole permanent magnet 71, the magnetic body 4 ... Are repeated in this order. As the magnetic material 4, for example, a material formed by laminating Fe—Co—V-based soft magnetic materials in the z direction is used.

Here, the arrangement relationship between the main magnetic pole permanent magnets 41 and 51 and the sub magnetic pole permanent magnets 61 and 71 will be described.
The main magnetic pole permanent magnets 41 and 51 and the sub magnetic pole permanent magnets 61 and 71 are arranged so as to be staggered in the x direction. Specifically, any of the secondary magnetic pole permanent magnets 61 and 71 is arranged on the + y direction side of the non-magnetic layer 6 between the main magnetic pole permanent magnet 41 and the main magnetic pole permanent magnet 51. In other words, at least a part of the auxiliary magnetic pole permanent magnets 61 and 71 is arranged in the −y direction via the non-magnetic layer 6 so as to face the main surface 5a of the back yoke 5. The y direction is a direction orthogonal to the main surface 5a of the back yoke 5, and the -y direction is a direction from the non-magnetic layer 6 toward the back yoke 5. At this time, the position of the surface of the secondary magnetic pole permanent magnets 61 and 71 facing the main surface 5a in the y direction is the same as the surface of the main magnetic pole permanent magnets 41 and 51 farthest from the main surface 5a. It becomes the position. Alternatively, the positions of the surfaces of the main magnetic pole permanent magnets 41 and 51 are further separated from the main surface 5a in the + y direction than the surface farthest from the main surface 5a. However, even if the positions are distant, the distance is small and the positions are almost the same. The surfaces of the main magnetic pole permanent magnets 41 and 51 farthest from the main surface 5a are the surfaces on the + y direction side of the surfaces orthogonal to the y direction.

Further, one of the main magnetic pole permanent magnets 41 and 51 is arranged so as to be arranged on the −y direction side of the magnetic body 4 located between the secondary magnetic pole permanent magnet 61 and the secondary magnetic pole permanent magnet 71. At this time, the center of the magnetic body 4 in the x direction and the center of any of the main magnetic pole permanent magnets 41 and 51 arranged on the −y direction side of the magnetic body 4 in the x direction are arranged so as to coincide with each other.

More specifically, the permanent magnets include the secondary magnetic pole permanent magnet 61, the main magnetic pole permanent magnet 41, the secondary magnetic pole permanent magnet 71, the main magnetic pole permanent magnet 51, the secondary magnetic pole permanent magnet 61, and so on in the + x direction. They are arranged repeatedly in order. That is, the main magnetic pole permanent magnet 41 magnetized in the + y direction has a secondary magnetic pole permanent magnet 61 magnetized in the + x direction arranged on the −x direction side thereof, and magnetized in the −x direction on the + x direction side thereof. The secondary magnetic pole permanent magnet 71 is located. On the contrary, in the main magnetic pole permanent magnet 51 magnetized in the −y direction, the secondary magnetic pole permanent magnet 71 magnetized in the −x direction is arranged on the −x direction side thereof, and the + x direction is arranged on the + x direction side thereof. The secondary magnetic pole permanent magnet 61 magnetized toward is located. With this arrangement, the magnetic fields of the main magnetic pole permanent magnets 41 and 51 and the magnetic fields of the sub magnetic pole permanent magnets 61 and 71 can be superimposed. In addition, electromagnetic steel sheets are arranged at both ends of the array.

Next, holding between each configuration will be described. The space between the configurations is held by the adhesion between the faces. Specifically, the distance between the magnetic body 4 and the main magnetic pole permanent magnets 41, 51 in the y direction, the distance between the main magnetic pole permanent magnets 41, 51 and the back yoke 5 in the y direction, the secondary magnetic pole permanent magnets 61, 71 and the magnetic material 4 An adhesive is applied to each of the x-directions of and the surfaces, and the surfaces are attached to each other in close contact with each other. When there are facing surfaces between the main magnetic pole permanent magnets 41 and 51 and the sub magnetic pole permanent magnets 61 and 71 in the y direction, an adhesive is applied and the surfaces are attached to each other in close contact with each other as in the other configurations.

Next, the relationship between the widths of each configuration in the y direction will be described with reference to FIG. FIG. 3 is a vertical cross-sectional view of the field magnet according to the first embodiment of the present disclosure.
The width of the main magnetic pole permanent magnets 41 and 51 in the y direction, which is orthogonal to the main surface 5a of the back yoke 5, is Tm, the width of the non-magnetic layer 6 is Ta, the width of the secondary magnetic pole permanent magnets 61 and 71 is Ts, and the magnetism. Let the width of the body be Td.
At this time, the width Tm of the main magnetic pole permanent magnets 41 and 51 and the width Ta of the non-magnetic layer 6 are the same width.

Further, the width Ts of the secondary magnetic pole permanent magnets 61 and 71 and the width Td of the magnetic body 4 are the same. The back yoke 5 is arranged so that the main surface 5a is orthogonal to the y direction as described above. Therefore, the main magnetic pole permanent magnet 41, the main magnetic pole permanent magnet 51, and the non-magnetic layer 6 arranged on the + y direction side of the main surface 5a of the back yoke 5 have their respective surfaces on the + y direction side with respect to the y direction. It will be orthogonal. Further, the surfaces of the magnetic body 4 and the secondary magnetic pole permanent magnets 61 and 71 arranged on the + y direction side are also orthogonal to the y direction. That is, the position of the surface of the magnetic body 4 facing the air gap and the position of the surface of the secondary magnetic pole permanent magnets 61 and 71 facing the air gap coincide with each other in the y direction.

Next, the relationship between the lengths of each configuration in the x direction (arrangement direction of permanent magnets) will be described.
Let the lengths of the main magnetic pole permanent magnets 41 and 51 be Lm, the length of the non-magnetic layer 6 be La, the lengths of the secondary magnetic pole permanent magnets 61 and 71 be Ls, and the length of the magnetic body 4 be Ld.

The length Ld of the magnetic body 4 is shorter than the length Lm of the main magnetic pole permanent magnets 41 and 51, and longer than the length Ls of the secondary magnetic pole permanent magnets 61 and 71 and the length La of the non-magnetic layer 6. It is composed. The lengths Ls of the secondary magnetic pole permanent magnets 61 and 71 are configured to be the same as the length La of the non-magnetic layer 6 or longer than the length La of the non-magnetic layer 6. The lengths Lm of the main magnetic pole permanent magnets 41 and 51 are shorter than the pole pitch Lp, which is the length of one pole, and longer than the length La of the non-magnetic layer 6. FIG. 3 illustrates a configuration in which the lengths Ls of the secondary magnetic pole permanent magnets 61 and 71 are longer than the length La of the non-magnetic layer 6.

Here, the results of analysis by changing the lengths Ls of the secondary magnetic pole permanent magnets 61 and 71 will be described with reference to FIG. The lengths Ls of the secondary magnetic pole permanent magnets 61 and 71 are changed from the same length as the length La of the non-magnetic layer 6 to be longer. FIG. 4 is a diagram showing the relationship between the ratio Ls / La of the lengths Ls of the secondary magnetic pole permanent magnets 61 and 71 to the length La of the non-magnetic layer 6 and the rate of increase / decrease in the induced voltage. The horizontal axis of the graph shown in FIG. 4 indicates the value of the ratio Ls / La, and the vertical axis represents the length Ls of the secondary magnetic pole permanent magnets 61 and 71 and the length La of the non-magnetic layer 6 (ratio Ls). / La shows the rate of increase / decrease in the ratio of the induced voltage based on 1). Since the induced voltage is generally proportional to the thrust, the increase / decrease in the induced voltage will be mainly described below.

As shown in FIG. 4, the increase / decrease rate has a convex shape in which the value of the increase / decrease rate of the induced voltage increases in the direction of increasing the ratio Ls / La from 1, reaches a peak, and then decreases again. Become. That is, the length Ls of the secondary magnetic pole permanent magnets 61 and 71 is longer than the length La of the non-magnetic layer 6, and is induced in the length when the surface of the main magnetic pole permanent magnets 41 and 51 has a surface portion overlapping in the y direction. It can be seen that the voltage is maximized. More specifically, it can be seen that when the ratio Ls / La is 1 to 2.8, the induced voltage becomes larger than the reference induced voltage.

The change in the magnetic flux density waveform when the lengths Ls of the auxiliary magnetic pole permanent magnets 61 and 71 are changed will be described with reference to FIG. FIG. 5A schematically shows a magnetic flux density waveform on the air gap surface g1. The solid rectangular wave H1 shows the magnetic flux density waveform in the case of a general magnet arrangement, and the wave H2 having a shape close to the broken rectangular wave is a combination of the main magnetic pole permanent magnets 41 and 51 and the secondary magnetic pole permanent magnets 61 and 71. The magnetic flux density waveform in the case of the Halbach array in which the air gap planes are matched is shown. Further, the wave A1 close to the dotted sine wave shows the magnetic flux density waveform when the length Ls of the secondary magnetic pole permanent magnets 61 and 71 shown in A1 of FIG. 5 described later and the length La of the non-magnetic layer 6 are equal. There is. The wave A2, which is close to a solid sine wave, shows a magnetic flux density waveform when the lengths Ls of the secondary magnetic pole permanent magnets 61 and 71 of A2 in FIG. 5, which will be described later, are longer than the length La of the non-magnetic layer 6. Further, the alternate long and short dash line wave A3 shows a magnetic flux density waveform when the lengths Ls of the secondary magnetic pole permanent magnets 61 and 71 are not properly set. The case where the lengths Ls of the secondary magnetic pole permanent magnets 61 and 71 are not properly set is, for example, a case where the lengths La of the non-magnetic layer 6 are too long.

As shown in A of FIG. 5, the case where the length Ls of the secondary magnetic flux permanent magnets 61 and 71 and the length La of the non-magnetic layer 6 are equal (A1) is compared with the case of a general magnet arrangement other than the Halbach array. It can be seen that the magnetic flux density waveform approaches a wave shape close to a sine wave (hereinafter referred to as "substantially sine wave") from a rectangular wave. This is because the magnetic fluxes at the ends of the main magnetic pole permanent magnets 41 and 51 are concentrated near the central portion of the main magnetic pole permanent magnets 41 and 51 due to the influence of the secondary magnetic pole permanent magnets 61 and 71. Further, when the length Ls of the secondary magnetic pole permanent magnets 61 and 71 is longer than the length La of the non-magnetic layer 6 (A2), the magnetic flux is further concentrated near the central portion of the main magnetic pole permanent magnets 41 and 51. You can see that there is. The ends of the main magnetic pole permanent magnets 41 and 51 are originally in a range where the magnetic flux density is not so high, and the effect of magnetic flux concentration near the center of the main magnetic pole permanent magnets 41 and 51 is larger than the decrease in the magnetic flux density. Is.

On the other hand, if the lengths Ls of the secondary magnetic pole permanent magnets 61 and 71 are not properly set, the amount of magnetic flux near the central portion of the main magnetic pole permanent magnets 41 and 51 decreases. As a result, the influence on the person who lowers the induced voltage becomes large. Therefore, by making the lengths Ls of the secondary magnetic pole permanent magnets 61 and 71 longer than the length La of the non-magnetic layer 6 in an appropriate range, the effect of increasing the induced voltage can be obtained.

The state of the magnetic flux line when the lengths Ls of the auxiliary magnetic pole permanent magnets 61 and 71 are changed will be further described. A1 of FIG. 5 is a diagram schematically showing a part of the arrangement when the length Ls of the secondary magnetic pole permanent magnets 61 and 71 and the length La of the non-magnetic layer 6 are equal, and the magnetic flux lines at that time. ..

As shown in A1 of FIG. 5, the magnetic flux from the main magnetic pole permanent magnet 41 travels in the + y direction in the drawing, crosses the air gap surface g1 and penetrates into the armature 2 located ahead of the air gap surface g1. On the other hand, the magnetic flux of the secondary magnetic pole permanent magnet 61 gradually bends in the + y direction while traveling in the + x direction, crosses the air gap surface g1 and penetrates into the armature 2. Similarly, the magnetic flux of the secondary magnetic pole permanent magnet 71 gradually bends in the + y direction while traveling in the −x direction, crosses the air gap surface g1 and penetrates into the armature 2. Therefore, the motor 10 of the present disclosure, which is a linear motor having the secondary magnetic pole permanent magnets 61 and 71, has an air gap surface g1 as compared with a general armature composed of only the permanent magnets corresponding to the main magnetic pole permanent magnets 41 and 51. The magnetic flux density in the vicinity of the central portion of the main magnetic pole permanent magnet 41 of the above is improved. Then, the magnetic flux density waveform on the air gap surface g1 approaches a substantially sine wave.

A2 of FIG. 5 schematically shows a part of the arrangement when the length Ls of the secondary magnetic pole permanent magnet is made larger than the length La of the non-magnetic layer 6 in an appropriate range, and the magnetic flux line at that time. It is a figure. For convenience of explanation, the portions of the main magnetic pole permanent magnets 41 that overlap with the secondary magnetic pole permanent magnets 61 and 71 on the + y direction side are referred to as the main magnetic pole permanent magnets 411 and 412, respectively, and the other portions are referred to as the main magnetic pole permanent magnets 413. Further, the portion of the secondary magnetic pole permanent magnet 61 that overlaps with the main magnetic pole permanent magnet 41 on the −y direction side is referred to as the secondary magnetic pole permanent magnet 611. Similarly, the portion of the secondary magnetic pole permanent magnet 71 that overlaps with the main magnetic pole permanent magnet 41 on the −y direction side is referred to as the secondary magnetic pole permanent magnet 711. The configuration is different from that of A1 in FIG. 5 in that the magnetic material 4 is replaced with the sub-magnetic permanent magnet 61 in the sub-magnetic permanent magnets 611 and 711 of A2.

The magnetic flux from the secondary magnetic pole permanent magnet 611 gradually bends in the + y direction while traveling in the + x direction, crosses the air gap surface g1 and penetrates into the armature 2 located ahead of the air gap surface g1. Similarly, the magnetic flux from the secondary magnetic pole permanent magnet 711 gradually bends in the + y direction while traveling in the −x direction, crosses the air gap surface g1 and penetrates into the armature 2. Since the secondary magnetic pole permanent magnets 61 and 71 are located closer to the central portion of the main magnetic pole permanent magnet 41 as compared with A1, the magnetic flux density in the vicinity of the central portion of the main magnetic pole permanent magnet 41 on the air gap surface g1 is improved.

The magnetic flux from the main magnetic pole permanent magnet 41 also travels in the + y direction in the same manner as A1 in FIG. The magnetic flux density in the vicinity of is lower than that in the configuration in which the magnetic body 4 is arranged as in A1. However, the vicinity of the main magnetic pole permanent magnets 411 and 412 is a position away from the peak of the magnetic flux density waveform, and is originally a range in which the magnetic flux density value is not so high in the substantially sinusoidal waveform. Therefore, by appropriately setting the range of the sub-magnetic pole permanent magnets 611 and 711, even if the magnetic flux density in the vicinity of the main magnetic pole permanent magnets 411 and 421 decreases, the induced voltage is not significantly affected. Therefore, by making the lengths Ls of the secondary magnetic pole permanent magnets 61 and 71 longer than the length La of the non-magnetic layer 6 in an appropriate range, the effect of increasing the induced voltage can be obtained.

Therefore, also in the embodiment of the present disclosure, in the above-described arrangement, the length Ls of the secondary magnetic pole permanent magnets is specifically equal to the length La of the non-magnetic layer 6 or longer than the length La of the non-magnetic layer 6. Is configured so that the ratio Ls / La is 1 to 2.8. When the length Ls of the secondary magnetic pole permanent magnet is longer than the length La of the non-magnetic layer 6, a part of the surface orthogonal to the y direction of the secondary magnetic pole permanent magnet in the −y direction is the main magnetic pole. It faces the main surface 5a of the back yoke 5 in the y direction via the permanent magnets 41 and 51. The ratio Ls / La at this time is configured to be 2.8 or less.

The operation of the electric motor 10 configured as described above will be briefly described.
By configuring the main magnetic pole permanent magnets 41 and 51 and the secondary magnetic pole permanent magnets 61 and 71 as described above, the magnetic fields of the main magnetic pole permanent magnets 41 and 51 and the magnetic fields of the secondary magnetic pole permanent magnets 61 and 71 can be superimposed. .. By superimposing, the periodic magnetic field, which is the distribution of the magnetic flux density formed in the + y direction of the field magnet 3, becomes a substantially sine wave. When the coil 21 of the armature 2 is energized there, the armature 2 is guided by the guide rail 102 by the attractive force and the repulsive force of the magnetic field generated by the energization and the periodic magnetic field, and is guided in the arrangement direction of the permanent magnets. Moving. In the motor 10 of the present disclosure, since the periodic magnetic field formed in the + y direction of the field magnet 3 is a substantially sine wave, the counter electromotive force induced in the coil 21 is also a substantially sine wave.

The effect of having the field magnet 3 having the above-described configuration will be described.
The field magnet 3 in the first embodiment of the present disclosure includes the main magnetic pole permanent magnets 41 and 51 magnetized in the direction of the generated magnetic field and the sub magnetized so as to be different from the directions of the magnetic poles of the main magnetic pole permanent magnets 41 and 51. Includes magnetic pole permanent magnets 61, 71. The main magnetic pole permanent magnets 41 and 51 and the sub magnetic pole permanent magnets 61 and 71 are arranged so as to be staggered in the arrangement direction. The main magnetic pole permanent magnets 41 and 51 are arranged so that the magnetization directions are opposite to those of the other adjacent main magnetic pole permanent magnets 41 and 51, and the sub-magnetic pole permanent magnets 61 and 71 are arranged so as to be opposite to each other. The auxiliary magnetic pole permanent magnets 61 and 71 are arranged so that their magnetization directions are opposite to each other. With this configuration, the magnetic fields of the main magnetic pole permanent magnets 41 and 51 and the magnetic fields of the secondary magnetic pole permanent magnets 61 and 71 can be superposed, and the periodic magnetic field formed in the + y direction of the field magnet 3 is a substantially sinusoidal wave. be able to.
Further, a non-magnetic layer 6 is provided between the main magnetic pole permanent magnet 41 and the main magnetic pole permanent magnet 51 in the x direction. Then, at least a part of the auxiliary magnetic pole permanent magnets 61 and 71 is arranged so as to face the main surface 5a via the non-magnetic layer 6. Further, the surface of the secondary magnetic pole permanent magnets 61 and 71 facing the main surface 5a is at the same position as or farther from the surface of the main magnetic pole permanent magnets 41 and 51 farthest from the main surface 5a in the + y direction. With this configuration, as compared with the case where the main magnetic pole permanent magnets 41 and 51 are adjacent to each other and the case where the main magnetic pole permanent magnets 41 and 51 and the secondary magnetic pole permanent magnets 61 and 71 are adjacent to each other, the secondary magnetic pole permanent magnet 61 The volume of the reverse magnetic field applied to the main magnetic pole permanent magnets 41 and 51 by 71 is reduced, and the demagnetization resistance of the main magnetic pole permanent magnets 41 and 51 is improved. Further, it is possible to reduce the regions of the main magnetic pole permanent magnets 41 and 51 in which the permeance coefficient decreases due to the temperature rise during driving. Therefore, the magnetic flux originally possessed by the permanent magnet can be effectively used, and the magnet volume required to generate the same thrust can be reduced.
Therefore, the magnetic flux of the permanent magnet can be effectively utilized to improve the thrust.

Further, the length Ls in the x direction, which is the arrangement direction of the secondary magnetic pole permanent magnets 61, 71, is configured to be the same as or longer than the length La in the x direction of the non-magnetic layer 6. With this configuration, it is possible to increase the peak value of a substantially sine wave of a periodic magnetic field, which is a distribution of magnetic flux densities formed in the + y direction of the main magnetic pole permanent magnet 41, that is, in the + y direction of the field magnet 3. Further, the length Ls in the x direction, which is the arrangement direction of the secondary magnetic pole permanent magnets 61, 71, and the length La in the x direction of the non-magnetic layer 6 are configured so that the ratio Ls / La is 1 to 2.8. NS. This has the effect of increasing the induced voltage.

Further, when the length Ls in the x direction, which is the arrangement direction of the secondary magnetic pole permanent magnets 61, 71, is configured to be larger than the length La in the x direction of the non-magnetic layer 6, the main magnetic pole permanent magnets 41, 51 It is arranged so as to have a portion overlapping the secondary magnetic pole permanent magnets 61 and 71 on the + y direction side. That is, at least a part of the auxiliary magnetic pole permanent magnets 61 and 71 is arranged so as to face the main surface 5a of the back yoke 5 via the non-magnetic layer 6 in the −y direction. As a result, the range in which the magnetic flux density values of the main magnetic pole permanent magnets 41 and 51 are not higher than those of the others is effectively utilized, and the induced voltage can be further increased. Further, in the case of post-magnetism, the magnetism of the main magnetic pole permanent magnets 41, 51 located directly below the sub-magnetic pole permanent magnets 61, 71 is improved.

Further, a magnetic body 4 is provided between the secondary magnetic pole permanent magnet 61 and the secondary magnetic pole permanent magnet 71 in the x direction. With this configuration, as compared with the case where the magnetic material 4 is made of air or a non-magnetic material, the magnetic saturation of the main magnetic pole permanent magnets 41 and 51 on the + y direction side is relaxed, the generated magnetic field can be made higher, and the generated magnetic field can be made even lower. Loss can be achieved. Further, the magnetic material 4 is formed by laminating soft magnetic materials in the z direction. By forming the magnetic material 4 with a soft magnetic material laminated in the z direction, the effect of reducing the eddy current loss is obtained.

Further, electromagnetic steel sheets are arranged at both ends of the arrangement of permanent magnets. For example, when the secondary magnetic pole permanent magnets 61 and 71 are arranged at the ends, the auxiliary magnetic pole permanent magnets 61 and 71 may fly due to the magnetic force, but this can be avoided by arranging the electromagnetic steel plate at the ends. It becomes possible.

Further, in the electric motor 10, the periodic magnetic field formed in the + y direction of the field magnet 3 is configured to be a substantially sine wave. As a result, the counter electromotive force induced in the coil 21 can also be a substantially sine wave. Therefore, the harmonic component of the fundamental wave, which is a sine wave, can be reduced, and the cogging thrust can be reduced. Then, the generated magnetic field can be increased, and the loss can be reduced.

The magnetization direction of the main magnetic pole permanent magnet 41 is toward + y, the magnetization direction of the main magnetic pole permanent magnet 51 is toward −y, the magnetization direction of the secondary magnetic pole permanent magnet 61 is toward + x, and the secondary magnetic pole permanent magnet 71. The magnetization direction of was defined as the direction toward −x. That is, although the description has been made on the premise that they are orthogonal to each y direction and parallel to the x direction, various patterns can be considered for the magnetization angle. For example, if the + x direction is 0 ° and the −x direction is 180 °, the magnetization direction of the main magnetic pole permanent magnet 41 may be 45 °, and the magnetization direction of the main magnetic pole permanent magnet 51 may be 135 °. In either case, the magnetization directions may be opposite to each other in the arrangement direction. Further, the magnetization direction does not have to be unidirectional in the permanent magnet. For example, it is possible to use a polar anisotropy magnet for the main magnetic pole permanent magnets 41 and 51. By arranging extremely illegal magnets, the magnetization direction can be reversed in the arrangement direction. Therefore, even in these cases, the magnetic flux of the permanent magnet described above can be effectively utilized to improve the thrust.

Further, although the air layer is a non-magnetic layer 6 between the main magnetic pole permanent magnet 41 and the main magnetic pole permanent magnet 51 in the x direction, at least one between the main magnetic pole permanent magnet 41 and the main magnetic pole permanent magnet 51 in the x direction. A spacer made of a non-magnetic material may be arranged in the portion. In this case, in addition to achieving the same effect as when the gap is provided, when a magnetic attraction force is generated between the main magnetic pole permanent magnets 41 and 51 and the sub magnetic pole permanent magnets 61 and 71, the force is applied by the spacer. Can receive. Therefore, the possibility that the permanent magnet is chipped can be reduced.

Further, a cover of a non-magnetic material, for example, a SUS material may be attached with an adhesive so as to cover the field magnet 3, or the SUS material may be fastened and fixed to the back yoke 5 with a bolt. The tightening at that time can be fixed by, for example, riveting or welding. In addition, it can be covered with resin. As a result, each member can be firmly held.

Further, as shown in FIG. 6, the field magnet 3 is entirely composed of the magnetic body 4, and the main magnetic pole permanent magnets 41 and 51 are inserted into the holes 31 provided in the magnetic body 4 from the z-axis direction, respectively. May be good. Similarly, the secondary magnetic pole permanent magnets 61 and 71 may be inserted into the holes 32 provided in the magnetic body 4 from the z-axis direction, respectively. At that time, all or part of the main magnetic pole permanent magnets 41 and 51 may be fixed by the caulking 33. The magnetic body 4 can be fixed by using an adhesive steel plate or fixed by a bolt at, for example, a back yoke portion, and a gap can be provided between the main magnetic pole permanent magnets 41 and 51. The magnetic material 4 here is assumed to be an electromagnetic steel plate, but may be iron.

Further, although it has been explained that the core 20 of the armature 2 is a laminate of electromagnetic steel sheets which are soft magnetic materials, the magnetic material may be, for example, a machined block of SS400 material, and is an armature 2 having a coreless structure without a core. You may. Further, it is said that the core 20 of the armature 2 is manufactured by passing through a laminated body of electrical steel sheets and tightening and integrating using bolts and nuts, but the core 20 is manufactured by crimping and integrating the laminated body of magnetic plates. You may. Even in these configurations, the magnetic flux of the permanent magnet described above can be effectively utilized to achieve the effect of improving the thrust.

Embodiment 2.
Hereinafter, the field magnet according to the second embodiment will be described with reference to the drawings. FIG. 7 is a vertical cross-sectional view illustrating the configuration of the field magnet according to the second embodiment of the present disclosure. FIG. 8 is a diagram showing a magnetic force acting on the field magnetic force according to the second embodiment of the present disclosure.

In the second embodiment of the present disclosure, as shown in FIG. 7, the width Ts of the secondary magnetic pole permanent magnets 61 and 71 in the field magnet 3 in the y direction is smaller than the width Td of the magnetic body 4 in the y direction. It is composed of. Other configurations are the same as those in the first embodiment.

Of the surfaces orthogonal to the y direction of the secondary magnetic pole permanent magnets 61 and 71, the surface on the −y direction side is fixed and acts on the secondary magnetic pole permanent magnets 61 and 71 when the width Ts of the secondary magnetic pole permanent magnets 61 and 71 is changed. The magnetic force in the y direction will be described with reference to FIG. The horizontal axis of FIG. 8 shows the thickness of the air layer generated when the width Ts of the secondary magnetic pole permanent magnets 61 and 71 is made smaller than the width equivalent to that of the magnetic body 4. The vertical axis shows the magnetic force in the y direction acting on the secondary magnetic force permanent magnets 61 and 71. The magnetic force here is the force acting by the permanent magnet.

As shown in FIG. 8, the magnetic force acting on the sub-magnetic force permanent magnets 61 and 71 decreases and increases as the width Ts of the sub-magnetic force permanent magnets 61 and 71 is reduced. That is, when the width Ts of the secondary magnetic pole permanent magnets 61 and 71 is changed, the magnetic force acting on the secondary magnetic pole permanent magnets 61 and 71 also changes.

The point that the magnetic force acting on the sub-magnetic force permanent magnets 61 and 71 changes by reducing the width Ts of the sub-magnetic force permanent magnets 61 and 71 will be described in more detail with reference to FIG. For convenience of explanation, FIG. 9 illustrates only a part of the arrangement of permanent magnets and schematically shows magnetic flux lines and magnetic forces.

FIG. 9B1 is a schematic view of magnetic flux lines and magnetic forces when the width Td of the magnetic body 4 and the width Ts of the secondary magnetic pole permanent magnet 71 are equal and the positions of the surfaces on the air gap sides are the same. The magnetic force acting on the secondary magnetic pole permanent magnet 71 is the attractive force Fa between the magnetic body 4 and the secondary magnetic pole permanent magnet 71 shown in the figure, and the repulsive force between the main magnetic pole permanent magnet 41 and the secondary magnetic pole permanent magnet 71. It is Fr1. As shown in FIG. 8, the magnetic force in the + y direction is due to the repulsive force Fr1.

FIG. 9B2 is a schematic view of magnetic flux lines and magnetic forces when the width Ts of the secondary magnetic force permanent magnet 71 is smaller than the width Td of the magnetic body 4. The magnetic force acting on the secondary magnetic pole permanent magnet 71 is the attractive force Fa between the magnetic body 4 and the secondary magnetic pole permanent magnet 71, the repulsive force Fr2, and the repulsive force Fr1 between the main magnetic pole permanent magnet 41 and the secondary magnetic pole permanent magnet 71. Is. The suction force Fa and the repulsion force Fr2 are different from B1 in FIG. In B2 of FIG. 9, since the width Ts of the secondary magnetic pole permanent magnet 71 is smaller than the width Td of the magnetic body 4, the attractive force Fa is reduced by that amount. Further, among the surfaces of the magnetic body 4 that oppose the secondary magnetic pole permanent magnet 71, the S pole is not generated in the portion facing the air layer generated by reducing the width Td of the secondary magnetic pole permanent magnet 71, and the N pole is formed. Occurs. A repulsive force Fr2 is generated by the N pole and the N pole of the secondary magnetic pole permanent magnet 71.

Therefore, for the secondary magnetic force permanent magnet 71, the magnetic force in the −y direction is received by the extinction of the attractive force Fa and the resultant force of the repulsive force Fr2, and the magnetic force in the + y direction due to the resultant force with the repulsive force Fr1 is shown in FIG. It can be seen that the result is less than the magnetic force in the + y direction in the configuration shown in B1.

B3 of FIG. 9 is a schematic view of magnetic flux lines and magnetic forces when the width Ts of the secondary magnetic pole permanent magnet 71 is smaller than the width Td of the magnetic body 4. The magnetic force acting on the secondary magnetic pole permanent magnet 71 is the attractive force Fa between the magnetic body 4 and the secondary magnetic pole permanent magnet 71, the repulsive force Fr2, the main magnetic pole permanent magnet 41 and the secondary magnetic pole permanent magnet 71, as in B2 of FIG. The repulsive force between and Fr1. However, since the width Ts of the secondary magnetic pole permanent magnet 71 is smaller than the width Td of the magnetic body 4, it is further smaller than the attractive force Fa in B2 of FIG. Further, the S pole is reduced on the surface of the magnetic body 4 facing the secondary magnetic pole permanent magnet 71, and a portion where no magnetic pole is generated is formed. Then, a slight repulsive force Fr2 is generated. As a result, for the secondary magnetic force permanent magnet 71, the magnetic force in the −y direction becomes smaller due to the resultant force of the attractive force Fa and the repulsive force Fr2, and the resultant force with the repulsive force Fr1 becomes the + y direction shown in B1 of FIG. It will be more than the magnetic force of. This is the reason why the magnetic force shown in FIG. 8 decreased and then increased.

Therefore, it is desirable that the widths Ts of the secondary magnetic pole permanent magnets 61 and 71 in the y direction with respect to the width Td of the magnetic material in the y direction be reduced within an appropriate range. Further, it has been explained that if the width Ts of the auxiliary magnetic pole permanent magnets 61 and 71 in the y direction is made too small with respect to the width Td of the magnetic body 4 in the y direction, the magnetic force increases. On the other hand, while maintaining the configuration in which the magnetic fields of the main magnetic pole permanent magnets 41 and 51 and the magnetic fields of the secondary magnetic pole permanent magnets 61 and 71 are superimposed, the secondary magnetic pole permanent magnet 61 with respect to the width Td in the y direction of the magnetic material, By configuring the width Ts of 71 in the y direction to be small, it can be solved without becoming too small.

In the second embodiment of the present disclosure, the volumes of the main magnetic pole permanent magnets 41 and 51 are not changed, and the width Ts of the secondary magnetic pole permanent magnets 61 and 71 in the y direction is smaller than the width Td of the magnetic material in the y direction. It was configured to be. As a result, the magnetic force can be reduced without reducing the amount of magnetic flux on the air gap surface. Therefore, as in the first embodiment, in addition to the effect of effectively utilizing the magnetic flux of the permanent magnet and improving the thrust, the effect of improving the workability when mounting the secondary magnetic pole permanent magnets 61 and 71 is obtained. .. It also has the effect of ensuring a certain level of adhesive strength.

Although the main magnetic pole permanent magnet 41 and the secondary magnetic pole permanent magnet 71 have been described as examples, the main magnetic pole permanent magnet 41 and the secondary magnetic pole permanent magnet 61, the main magnetic pole permanent magnet 51 and the secondary magnetic pole permanent magnet 61, and the main magnetic pole permanent magnet have been described. The same explanation can be given for the 51 and the secondary magnetic pole permanent magnet 71.

Further, as a modification of the second embodiment, as shown in C1 and C2 of FIG. 10, the air gap surface side of the secondary magnetic pole permanent magnets 61 and 71 may be chamfered with C or provided with a corner radius. Even in this case, the magnetic force can be reduced without reducing the amount of magnetic flux on the air gap surface as described above. Then, as in the first embodiment, in addition to the effect that the magnetic flux of the permanent magnet can be effectively utilized to improve the thrust, the workability and the adhesive strength when attaching the secondary magnetic pole permanent magnets 61 and 71 are improved. It has the effect of securing.

Further, as shown in FIG. 11, the air layer generated when the width Ts of the secondary magnetic pole permanent magnets 61 and 71 is made smaller than the width equivalent to that of the magnetic material 4 and the air gap surface side of the secondary magnetic pole permanent magnets 61 and 71. Each member may be molded with a non-magnetic molding material 8 on the surface of the surface. By molding, each member can be firmly fixed. Further, the mold material 8 may also flow into the gaps between the members. When the mold material 8 is configured to fill the space between the main magnetic pole permanent magnets 41 and 51, leakage of the main magnetic pole permanent magnets 41 and 51 is compared with the case where the main magnetic pole permanent magnets 41 and 51 are adjacent to each other. The magnetic flux can be reduced. Therefore, by effectively using the magnetic flux of the permanent magnet, the required volume of the permanent magnet can be reduced, and as a result, the price can be reduced.

Embodiment 3.
Hereinafter, the field magnet according to the third embodiment will be described with reference to FIG. FIG. 12 is a vertical cross-sectional view illustrating the configuration of the field magnet according to the third embodiment of the present disclosure. For convenience of explanation, only a part of the field magnet is shown.

In the third embodiment of the present disclosure, as shown in D1 of FIG. 12, among the corners of the magnetic body 4 formed of a rectangular parallelepiped, the corners on the main magnetic pole permanent magnets 41 and 51 are chamfered by C. Other configurations are the same as those of the first and second embodiments.

Since the magnetic flux follows a path that is as short as possible, leakage flux is likely to occur at the corners of the secondary magnetic pole permanent magnets 61 and 71 as shown in D of FIG. On the other hand, by chamfering the corners of the magnetic body 4 by C, a gap is generated. Therefore, it becomes difficult for the magnetic flux to pass through, so that the leakage flux can be reduced. Since this leakage flux is a reverse magnetic field to the main magnetic pole permanent magnets 41 and 51, it means that the demagnetization strength of the main magnetic pole permanent magnets 41 and 51 is increased.

Therefore, among the corners of the magnetic body 4 formed of the rectangular parallelepiped, the corners on the main magnetic pole permanent magnets 41 and 51 are chamfered to C to effectively utilize the magnetic flux of the permanent magnets and further improve the thrust. It has an effect that can be achieved.

Although the explanation has been given that the corners of the magnetic body 4 are chamfered by C, a configuration in which R is added to the corners may be used. Further, as shown in D2 of FIG. 12, the corners of the secondary magnetic pole permanent magnets 61 and 71 on the main magnetic pole permanent magnets 41 and 51 may be Chamfered or the corners may be rounded. In this case as well, the leakage flux of the secondary magnetic pole permanent magnets 61 and 71 can be reduced, and the demagnetization strength of the permanent magnets can be increased.

Embodiment 4.
Hereinafter, the field magnet according to the fourth embodiment will be described with reference to FIG. FIG. 13 is a vertical cross-sectional view illustrating the configuration of the field magnet according to the fourth embodiment of the present disclosure. For convenience of explanation, only a part of the field magnet is shown.

As shown in FIG. 13, the fourth embodiment of the present disclosure is configured such that the magnetic body 4 and the two auxiliary magnetic pole permanent magnets 61 and 71 are one pole and their air gap surface side has an arc shape. The air gap surface side is a surface on the side that does not face the main magnetic pole permanent magnets 41 and 51. Other configurations are the same as those of the first to third embodiments. The breakdown of the two secondary magnetic pole permanent magnets 61 and 71 is the secondary magnetic pole permanent magnet 61 magnetized in the + x direction, the secondary magnetic pole permanent magnet 61, and the secondary magnetic pole permanent magnet 71 magnetized in the −x direction in which the magnetization direction is opposite. be.

By configuring the magnetic body 4, the secondary magnetic pole permanent magnet 61, and the secondary magnetic pole permanent magnet 71 as one pole so that the air gap surface side thereof has an arc shape, the magnetic flux density waveform in the air gap can be made into a substantially sine wave. , It has the effect of reducing the cogging thrust. Therefore, the magnetic flux of the permanent magnet can be effectively utilized, and the thrust can be further improved.

Embodiment 5.
Hereinafter, the field magnet according to the fifth embodiment will be described with reference to FIGS. 14 and 15. 14 and 15 are vertical cross-sectional views illustrating the configuration of the field magnet according to the fifth embodiment of the present disclosure. For convenience of explanation, some configurations are omitted. Further, in the fifth embodiment of the present disclosure, a rotating machine will be described as an example of the electric motor, but the present invention is not limited to these.

The field magnet 3 in the fifth embodiment is composed of a field core 34 formed in a circular shape and permanent magnets arranged on the outer circumference of the field core 34. Also in the fifth embodiment, one of the armature 2 and the field magnet 3 is a rotatable mover and the other is a stator. That is, the mover constitutes a rotary machine that can rotate. In the present disclosure, as an example, a configuration in which the field magnet 3 serves as a rotor is shown, the direction in which the rotor rotates about the axis of rotation is defined as the circumferential direction, and the direction orthogonal to the axis of the axis of rotation is defined as the radial direction. do. Further, the direction in which the magnetic plates constituting the field magnet 3 described later are laminated is defined as the axial direction.

FIG. 14 shows the two poles of the main magnetic pole permanent magnets 41 and 51 when the field magnet 3 is equally divided in the circumferential direction. Further, E1 to E7 in FIG. 14 show a modification example of the permanent magnet.

As shown in FIG. 14, the field magnet 3 has a field magnet core 34, and the field magnet core 34 is composed of main magnetic pole permanent magnets 41 and 51 and secondary magnetic pole permanent magnets 61 and 71 in a Halbach array. ing. As a method of arranging in the field core 34, there are a method of attaching a magnet to the surface of the field core 34 as shown in FIG. 14 and a method of embedding a permanent magnet inside the field core 34 shown in FIG. be. The method of embedding the permanent magnet inside the field core 34 shown in FIG. 15 will be described later.

The field core 34 shown in FIG. 14 is integrally formed by laminating magnetic plates of electrical steel sheets in the axial direction. Each magnetic plate is manufactured into a desired shape by punching a silicon steel plate which is a soft magnetic material. Then, the main magnetic pole permanent magnets 41 and 51 are arranged in the field magnet core 34. Specifically, the main magnetic pole permanent magnets 41 and 51 are arranged on the outer peripheral surface of the field core 34. Further, a non-magnetic layer 6 is provided at each distance in the circumferential direction from the main magnetic pole permanent magnets 41 and 51.

Sub-magnetic pole permanent magnets 61, 71 are arranged on the radial outer side of the main magnetic pole permanent magnets 41, 51 provided in the field core 34. The secondary magnetic pole permanent magnets 61 and 71 are arranged so that the center of the non-magnetic layer 6 in the circumferential direction and the center of the secondary magnetic pole permanent magnets 61 and 71 in the circumferential direction coincide with each other. The main magnetic pole permanent magnets 41 and 51 and the sub magnetic pole permanent magnets 61 and 71 are held by, for example, being coated with an adhesive as needed.

The specific arrangement order and magnetizing direction of the main magnetic pole permanent magnets 41 and 51 and the sub magnetic pole permanent magnets 61 and 71 are the same as those in the first to fourth embodiments, and the description thereof will be omitted. Further, although not shown, magnetic bodies 4 are arranged at intervals in the circumferential direction of the secondary magnetic pole permanent magnets 61 and 71.

As described above, the outer peripheral surface of the field core 34 is an arc, and permanent magnets are arranged along the arc. At this time, various types of permanent magnet shapes are assumed. The shapes of the permanent magnets arranged in the field core 34 will be described below using E1 to E7.

E1 in FIG. 14 represents a case where the cross-sectional shape of the permanent magnet in the axial direction is rectangular. E2 represents a case where each permanent magnet has an axial cross-sectional shape in which two sides extending in the radial direction at both ends in the circumferential direction face the center of rotation. E3 represents the case where the two sides of each permanent magnet along the circumferential direction are arcs and the two sides are parallel to each other in the axial cross-sectional shape. E4 represents a case composed of a combination of two sides extending in the radial direction of E2 and two sides along the circumferential direction of E3. In E5, one side along the radial outer circumferential direction of each permanent magnet is arcuate, and one side on the center side of the field magnet 3 is a straight line at an angle in contact with the outer circumference of the field magnet core 34. The two sides connecting these sides in the radial direction represent the case of a parallel axial cross-sectional shape. In E6, the portion of the main magnetic pole permanent magnets 41 and 51 that overlaps with the secondary magnetic pole permanent magnets 61 and 71 is flat on one side on the radial outer side of the field magnet 3. Further, the case where one side on the inner side in the radial direction of the field magnet 3 is a straight line having an angle in contact with the outer diameter of the field magnet core 34 and the two sides in the circumferential direction are parallel to each other is represented. In E7, the shapes of the main magnetic pole permanent magnets 41 and 51 and the sub magnetic pole permanent magnets 61 and 71 may be any combination of E1 to E6.

Next, a configuration in which the permanent magnet is embedded inside the field core 34 will be described with reference to FIG. In FIG. 15, in the field core 34, magnetic plates are laminated, and the main magnetic pole permanent magnet storage holes 410 and the sub-magnetic pole permanent magnets 61, 71 which are connected in the axial direction for accommodating the main magnetic pole permanent magnets 41 and 51 are provided. It has a secondary magnetic pole permanent magnet storage hole 610 connected in the axial direction for storage. The main magnetic pole permanent magnets 41 and 51 are inserted and held in the main magnetic pole permanent magnet storage holes 410. Further, the secondary magnetic pole permanent magnets 61 and 71 are inserted and held in the secondary magnetic pole permanent magnet storage holes 610. As shown in F1 to F4 of FIG. 15, the shape of the permanent magnet shown in FIG. 14 described above can be similarly adopted in the embedded configuration. Then, if necessary, a method of applying an adhesive and holding the adhesive by adhesion is used.

In FIG. 15, the space between the main magnetic pole permanent magnet 41 and the main magnetic pole permanent magnet 51 is filled with the field core 34, but the non-magnetic layer 6 can be provided. Further, although not shown, the non-magnetic material may be configured to be provided with a non-magnetic material storage hole for storing the non-magnetic material, or a space between the main magnetic pole permanent magnets 41 and 51 and one storage hole for inserting the non-magnetic material or the non-magnetic material. It is also possible to provide a configuration.

The electric motor 10 configured as described above is the same as the field magnet 3 in the first to fourth embodiments of the present disclosure, except that it is a rotating machine and the configuration of the field magnet, particularly the shape of the permanent magnet is different. It is composed. Therefore, according to the fifth embodiment of the present disclosure, since the field core 34 and the permanent magnet are provided on the arc, it can be applied to a rotary machine tool or a servomotor. Also in the applied rotating machine, the magnetic flux of the permanent magnet similar to that of the first to fourth embodiments can be effectively utilized, and the thrust can be further improved.

Further, in particular, by using a combination as shown in E7 of FIG. 14, the manufacturing cost of the permanent magnet can be minimized and the cogging torque and torque ripple can be reduced.

Further, in the configuration of FIG. 15, since the permanent magnet is embedded in the field core 34, more reluctance torque is used as compared with the configuration in which the permanent magnet is provided on the outer peripheral surface of the field core 34. Can be done.

Although it is described that the permanent magnet is held by an adhesive, a case for holding the permanent magnet may be inserted and fixed, or an electromagnet around which a coil is wound may be inserted and fixed. Further, when providing one storage hole for inserting the main magnetic pole permanent magnets 41 and 51 and the non-magnetic layer 6 or the non-magnetic material, a protrusion or a boundary plate for positioning the main magnetic pole permanent magnets 41 and 51 is inserted. It is possible to arrange the magnets more accurately by providing the grooves to be provided.

Although the present disclosure describes various exemplary embodiments and examples, the various features, embodiments, and functions described in one or more embodiments are those of a particular embodiment. It is not limited to application, but can be applied to embodiments alone or in various combinations.
Therefore, innumerable variations not illustrated are envisioned within the scope of the techniques disclosed herein. For example, it is assumed that at least one component is modified, added or omitted, and further, at least one component is extracted and combined with the components of other embodiments.

2 armor, 3 field magnet, 4 magnetic material, 5 back yoke, 6 non-magnetic layer, 8 mold material, 10 motor, 20 core, 21 coil, 22 teeth, 31, 32 holes, 33 caulking, 34 field magnet Core, 41, 51, 411, 412 Main magnetic pole permanent magnet, 61, 71, 611, 711 Secondary magnetic pole permanent magnet, 100 pedestal, 101 stage, 102 Guide rail, 410 Main magnetic pole permanent magnet storage hole, 610 Secondary magnetic pole permanent magnet storage Hole.

Claims (10)

A plurality of main magnetic pole permanent magnets magnetized in a direction orthogonal to the main surface of the back yoke and arranged on the main surface so that the magnetization directions alternate.
It is magnetized in a direction different from the magnetization direction of the main magnetic pole permanent magnets and is arranged so that the magnetization directions alternate, and is provided alternately with the main magnetic pole permanent magnets in the same direction as the arrangement direction of the main magnetic pole permanent magnets. With multiple secondary magnetic pole permanent magnets,
A non-magnetic layer, which is a non-magnetic region provided between the main magnetic pole permanent magnet and another adjacent main magnetic pole permanent magnet,
With
The secondary magnetic pole permanent magnet is arranged so that at least a part thereof faces the main surface via the non-magnetic layer in a direction orthogonal to the main surface.
The position of the surface of the secondary magnetic pole permanent magnet facing the main surface is the position of the surface of the main magnetic pole permanent magnet farthest from the main surface in the direction orthogonal to the main surface and the direction orthogonal to the main surface. It is at the same position or at a position farther from the main surface than the position of the surface of the main magnetic pole permanent magnet.
The length of the secondary magnetic pole permanent magnet in the arrangement direction is the same as the length of the non-magnetic layer in the arrangement direction or longer than the length of the non-magnetic layer in the arrangement direction.
A field magnet characterized by that. A part of the secondary magnetic pole permanent magnet is arranged so as to face the back yoke in a direction orthogonal to the main surface via the main magnetic pole permanent magnet.
The field magnet according to claim 1, wherein the length of the secondary magnetic pole permanent magnet in the arrangement direction is longer than the length of the non-magnetic layer in the arrangement direction. The field magnet according to claim 2, wherein the ratio of the length in the arrangement direction of the non-magnetic layer to the length in the arrangement direction of the secondary magnetic pole permanent magnet is 2.8 or less. The method according to any one of claims 1 to 3, wherein a magnetic material made of a soft magnetic material is provided between the secondary magnetic pole permanent magnet and another adjacent secondary magnetic pole permanent magnet. Field magnet. The field magnet according to claim 4, wherein the width of the secondary magnetic pole permanent magnet in the direction orthogonal to the main surface is smaller than the width of the magnetic material in the direction orthogonal to the main surface. The field magnet according to claim 4, wherein some of the corners of the magnetic material are C-chamfered or have R at the corners. The field magnet according to claim 4 or 6, wherein the corner of the magnetic material on the side of the permanent magnet of the main magnetic pole is C-chamfered or has an R at the corner. The field magnet according to claim 4, wherein the corner on the side of the main magnetic pole permanent magnet among the corners of the secondary magnetic pole permanent magnet has a C chamfer or a structure in which R is added to the corner. 4. The fourth aspect of the present invention is that when the magnetic material and the two secondary magnetic pole permanent magnets having opposite magnetization directions are used as one pole, the surface on the side not facing the main magnetic pole permanent magnet has an arc shape. The field magnet according to any one of claims 8. The field magnet according to any one of claims 1 to 9 and
An armature arranged with an air gap between it and the field magnet,
The coil provided on the armature and
With
Either one of the armature and the field magnet is movable,
An electric motor in which the main magnetic pole permanent magnet and the sub magnetic pole permanent magnet included in the field magnet are arranged in a linear or arc shape.

Images