JP2002136098A - Linear motor using permanent magnet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linear motor which makes the magnetic flux of each permanent magnet smooth by forcedly adding the magnetic flux in the running direction in the permanent magnet of a magnet group, enlarges the magnetic field component related to the thrust by concentrically generating the magnetic flux on one side of the space, and further reduces the vertical component of the force which crosses the linear motor thrust at a right angle. SOLUTION: In the linear motor which forms a magnet group 1 by alternately disposing permanent magnets 1a, 1b of which the magnetizing direction is opposite each other along the running direction and uses this magnet group 1 as a fixed part or a moving part, commutation magnets 2a, 2b which respectively have a magnetized direction in an approximately rectangular direction against the magnetized direction of the magnet group 1 are disposed between the permanent magnets 1a, 1b which consist of the magnet group 1 respectively, making the magnetized direction of the adjacent commutation magnets 2a, 2b reverse each other, and the width of the commutation magnets 2a, 2b is made larger than that of each permanent magnet 1a, 1b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor using a permanent magnet, and more particularly, to a method for facilitating the flow of magnetic flux of a permanent magnet, generating the magnetic flux by concentrating the magnetic flux in one space, and relating to the thrust. Increase the magnetic field component,
The present invention relates to a linear motor capable of reducing the magnitude of a vertical force component orthogonal to a thrust of a linear motor.

[0002]

2. Description of the Related Art A linear motor controls a current flowing through a coil group with respect to a magnetic field generated by a group of permanent magnets arranged along a running direction, and obtains a thrust by using an electromagnetic force acting on a current in the magnetic field. Power means such as a linear DC motor (LD
M), a linear synchronous motor (LSM), a linear pulse motor (LPM), and the like. In such a linear motor, a permanent magnet group is used as a fixed part, and a coil group is used as a movable part. Conversely, a coil group is used as a fixed part.
There is a method using a magnet group as a movable part. In such a linear motor, in order to efficiently obtain a thrust, permanent magnets whose magnetization directions are opposite to each other are alternately arranged along the running direction to generate a magnetic field.

[0003]

However, as described above, in a conventional linear motor in which permanent magnets whose magnetization directions are opposite to each other are simply arranged alternately, the flow of magnetic flux in the permanent magnet is not smooth. Therefore, there is a problem that the magnitude of the magnetic field obtained at the position of the coil current portion is insufficient. In general, it is desired to minimize the vertical force component orthogonal to the thrust of the linear motor. However, it has been attempted to reduce the vertical force component by adjusting the direction of the magnetic field at the position of the coil current portion. However, in the above-described conventional linear motor, there is no means for adjusting the magnitude of the direction of the magnetic field generated by the magnet group at the position of the coil current portion to reduce the vertical force component.

The present invention has been made in view of the above-mentioned problems of the conventional linear motor using permanent magnets, and forcibly adds a flow of magnetic flux along the running direction to the permanent magnets of the magnet group, thereby providing permanent magnets. Smooth the flow of the magnetic flux of the magnet, generate the magnetic flux concentrated in one side of the space, increase the magnetic field component related to the thrust, and reduce the magnitude of the vertical force component orthogonal to the thrust of the linear motor It is an object of the present invention to provide a linear motor that can perform the operation.

[0005]

In order to achieve the above object, a linear motor using permanent magnets according to the present invention is arranged such that permanent magnets whose magnetization directions are opposite to each other are alternately arranged along the running direction. In a linear motor that forms a magnet group by using the magnet group as a fixed portion or a movable portion, a rectifying magnet having a direction of magnetizing in a direction substantially perpendicular to the direction of magnetization of the magnet group is formed by the magnet. Between the permanent magnets constituting the group, the magnetizing directions of the adjacent rectifying magnets are arranged so that the directions of magnetization are opposite to each other, and the width of the rectifying magnet is set to each of the magnets constituting the magnet group. The width is set to be larger than the width of the permanent magnet.

In a linear motor using this permanent magnet, a rectifying magnet having a direction of magnetizing in a direction substantially perpendicular to the direction of magnetization of the magnet group is provided between the permanent magnets of the magnet group.
Since the magnetizing directions of the adjacent rectifying magnets are arranged to be opposite to each other, and the flow of the magnetic flux along the running direction is forcibly added to the permanent magnet, the directions of the magnetic fluxes are mutually different. In addition to smoothing the flow of magnetic flux into the permanent magnet in the opposite direction, the magnetic flux can be generated by concentrating the magnetic flux in one side of the space, thereby reducing the magnetic field component related to the thrust obtained at the coil current part position Can be bigger. Furthermore, since the magnetic fluxes in opposite directions in each permanent magnet of the magnet group are connected in the space outside the permanent magnet over a distance corresponding to the length of the magnetizing direction of the rectifying magnet, the traveling The reluctance along the direction is increased, and the magnetic field component along the running direction is reduced, so that the component of the magnetic field generated by the magnet group can be reduced without impairing the magnitude of the magnetic field component involved in thrust generation. The magnitude of the magnetic field component contributing to the generation of force can be reduced, and the vertical force acting on a linear motor, which is generally desired to be minimized, can be reduced. By setting the width of the rectifying magnet to be larger than the width of the permanent magnet, the magnetic field for generating the perpendicular force can be further reduced as compared with the case where the widths are equal.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a linear motor using a permanent magnet according to the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of a linear motor using a permanent magnet according to the present invention. This linear motor includes a linear DC motor (LDM) and a linear synchronous motor (LS
M), linear pulse motor (LPM), etc.
The magnet group 1 is formed by alternately arranging strip-shaped permanent magnets 1a and 1b whose magnetization directions P1 and P2 are opposite to each other along the running direction 4 of the linear motor. In this linear motor, the magnet group 1 is used as one of a fixed portion and a movable portion, and a coil current portion (not shown) is used as the other of the fixed portion and the movable portion.

In this embodiment, on the basis of such a structure, as shown in FIG. 1, directions of magnetizing the magnet group 1 in directions P3 and P4 substantially perpendicular to the magnetizing directions P1 and P2. The magnetizing directions P3 and P4 of the adjacent rectifying magnets 2a and 2b are opposite to each other between the permanent magnets 1a and 1b that constitute the magnet group 1. It is arranged as follows. Further, the rectifying magnet 2
a, 2b, the magnetization directions P3, P4 are
In cooperation with the directions P1 and P2 of the magnetization of b, the rectifier magnets 2a,
2b and the width W of the rectifying magnets 2a, 2b.
2 is the width W1 of the permanent magnets 1a and 1b constituting the magnet group 1.
Is larger. Note that the directions of the widths W1 and W2 coincide with the traveling direction 4 of the linear motor.

Here, in making the width W2 of the rectifying magnets 2a, 2b larger than the width Wl of the permanent magnets 1a, 1b,
If the width W1 is too small compared to the width W2, the magnitude of the magnetic field component (the component orthogonal to the running direction) that generates the thrust obtained at the position of the coil current portion decreases, but as a result of the magnetic field simulation analysis, W1 ≧ In the range of 1 / 2W2, the magnetic field for generating the vertical force can be reduced without reducing the magnitude of the magnetic field component for generating the thrust (the component orthogonal to the running direction).

Thus, in the linear motor of the present embodiment, the magnetic fluxes which are in the opposite directions in each of the permanent magnets 1a and 1b of the magnet group 1 are orthogonal to the magnetization directions P1 and P2 of the permanent magnets 1a and 1b. The rectifying magnets 2a and 2b having the directions of magnetization in the directions P3 and P4, respectively, smoothly guide and flow. As a result, the leakage of the magnetic flux is reduced, and the magnetic flux is concentrated and generated in the space on the side of the coil current portion. As a result, the magnetic field component that generates the thrust obtained at the position of the coil current portion (perpendicular to the running direction) Component) can be increased in size.

Further, in the linear motor of the present embodiment, the magnetic fluxes in the permanent magnets 1a and 1b of the magnet group 1 in the opposite directions from each other cause the space outside the permanent magnets 1a and 1b to rectify the magnet 2a.
Since the connection is performed over a distance corresponding to the length of the magnetization directions P3 and P4 of the magnetization directions a and 2b, the magnetic resistance along the traveling direction 4 increases while the magnitude of the magnetic field component along the traveling direction 4 increases. Therefore, the vertical force acting on the linear motor whose miniaturization is generally desired can be reduced. By setting the width W2 of the rectifying magnets 2a and 2b to be larger than the width W1 of the permanent magnets 1a and 1b, the magnetic field for generating the perpendicular force is further increased as compared with the case where the width W2 is equal to the width W1. Can be reduced.

On the other hand, as a permanent magnet group used in a conventional linear motor, as shown in FIG. 2, strip-shaped permanent magnets 3a and 3b having different magnetization directions are arranged in the running direction of the linear motor. A magnet group 3 alternately arranged along 4 is used. However, in a conventional linear motor that generates a magnetic field by simply alternately arranging permanent magnets 3a and 3b whose magnetization directions are opposite to each other along the running direction 4 of the linear motor, adjacent permanent magnets 3a and 3b
The flows of the magnetic flux in 3b are opposite to each other as shown by arrows P1 and P2.

As a result, the magnetic flux in the permanent magnets 3a and 3b crosses the space outside the permanent magnet having a large reluctance, and the space where the magnetic flux leaks outside the magnet depends on the side 6 where the coil current portion is located and the coil. Because there are two surfaces on the side 7 where there is no current part,
As a result, the magnitude of the magnetic field component (the component orthogonal to the running direction) that generates the thrust obtained at the coil current portion position is reduced. Also, permanent magnets 3a in opposite directions to each other,
Since the magnetic flux in 3b is connected to the space outside the permanent magnets 3a and 3b over a short distance, the magnetic field of the traveling direction component becomes large, and the vertical force acting on the linear motor whose miniaturization is desired is large. There are disadvantages.

Although the embodiments of the present invention have been described above, although not particularly shown in the drawings, each of the permanent magnets 1a, 1a,
It is also possible to dispose an iron plate acting as a yoke behind 1b or the rectifying magnets 2a and 2b, and in such a case, the effect obtained in the present embodiment can be similarly obtained.

[0016]

According to the linear motor using the permanent magnet of the present invention, a rectifying motor having a magnetizing direction between the permanent magnets of the magnet group in a direction substantially perpendicular to the magnetizing direction of the magnet group. The magnets are arranged such that the magnetizing directions of the adjacent rectifying magnets are opposite to each other, and the flow of magnetic flux along the running direction is forcibly added to the permanent magnets. In addition to smoothing the flow of the magnetic flux into the permanent magnets whose directions are opposite to each other, the magnetic flux can be generated by concentrating the magnetic flux in one side of the space, thereby participating in the thrust obtained at the position of the coil current portion. The magnetic field component can be increased. Furthermore, since the magnetic fluxes in opposite directions in each permanent magnet of the magnet group are connected in the space outside the permanent magnet over a distance corresponding to the length of the magnetizing direction of the rectifying magnet, the traveling The reluctance along the direction is increased, and the magnetic field component along the running direction is reduced, so that the component of the magnetic field generated by the magnet group can be reduced without impairing the magnitude of the magnetic field component involved in thrust generation. The magnitude of the magnetic field component contributing to the generation of force can be reduced, and the vertical force acting on a linear motor, which is generally desired to be minimized, can be reduced. By setting the width of the rectifying magnet to be larger than the width of the permanent magnet, the magnetic field for generating the perpendicular force can be further reduced as compared with the case where the widths are equal.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an arrangement of permanent magnets according to an embodiment of a linear motor of the present invention.

FIG. 2 is a perspective view showing an arrangement of permanent magnets of a conventional linear motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnet group 1a Permanent magnet 1b Permanent magnet 2a Rectifying magnet 2b Rectifying magnet 4 Running direction of linear motor 6 Side with coil current part 7 Side without coil current part P1, P2 Direction of magnetization of permanent magnet P3, P4 Direction of magnetization of commutating magnet

Claims (1)

[Claims] 1. A linear motor in which permanent magnets whose magnetization directions are opposite to each other are alternately arranged along a running direction to form a magnet group, and the magnet group is used as a fixed part or a movable part. A rectifying magnet having a direction of magnetizing in a direction substantially perpendicular to the direction of magnetization of the magnet group, between the permanent magnets constituting the magnet group, the direction of magnetization between adjacent rectifying magnets. A linear motor using permanent magnets, wherein the motors are arranged so as to be opposite to each other, and the width of the rectifying magnet is set to be larger than the width of each permanent magnet constituting the magnet group.