JPH11187639A - Magnet moving type linear actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve thrust as well as reduce cost. SOLUTION: A permanent magnet 4 the magnetized direction of which is nearly axial and a permanent magnet 4 the magnetized direction of which is nearly radial are installed. Magnetic flux which is oriented in the magnetized direction and flows to a driving coil 3 side increases, and a magnetic force is effectively obtained. Furthermore, a part of the magnetic flux from the permanent magnets 4 flows in a permanent magnet holding member 5, so that the permanent magnets can be reduced according to the improvement of permeance of the permanent magnets. As a result, the structure contributes to cost reduction as well as to resources saving.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to OA equipment, control equipment, electronic equipment, machine tools, semiconductor and liquid crystal manufacturing equipment,
The present invention relates to a movable magnet linear actuator that generates a linear driving force in medical equipment and the like.

[0002]

2. Description of the Related Art FIG. 18 shows a conventional magnet movable linear actuator. FIG. 18 is a cross-sectional view of a conventional magnet movable linear actuator, wherein 1 is an inner yoke, 2 is an outer yoke, 3 is a drive coil wound around the outer yoke 2, and 4 is shown in FIG. The permanent magnet 5 and the permanent magnet 5 which are magnetized in the different directions are constituted by a permanent magnet holding member constituting a movable part together with the permanent magnet 4.

The operation of the movable magnet type linear actuator constructed as described above will be described below.

[0004] The magnetic effect of the magnetic flux generated by the permanent magnet 4 flowing through the inner yoke 1 and the outer yoke 2 constituting the magnetic circuit and the magnetic flux generated by applying a predetermined current to the drive coil 3 causes the permanent magnet 4 to generate a magnetic force. A force is generated, and this magnetic force becomes a thrust, so that the movable portion including the permanent magnet 4 and the permanent magnet holding member 5 moves.

[0005]

However, in the above-mentioned conventional structure, the use of expensive rare earth magnets is increased along with the improvement of thrust, so that the cost of the motor itself is increased, which is one of the factors that hinder industrialization. Had become.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems. In the movable magnet type linear actuator, a magnetic force is efficiently generated to increase the thrust, and the weight of the permanent magnet can be reduced. It is an object of the present invention to provide a magnet movable linear actuator that can contribute to energy saving and resource saving.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an inner yoke, an outer yoke disposed outside the inner yoke, and winding at least one of the inner yoke and the outer yoke. The rotated drive coil, a permanent magnet holding member disposed between the inner yoke and the outer yoke, and the magnetization direction held by the permanent magnet holding member facing the drive coil is substantially radial. A first permanent magnet and a second permanent magnet whose magnetization direction is substantially axial,
The second permanent magnet is disposed at or near the axial end of the first permanent magnet. If the magnetization direction of the first permanent magnet faces the outside of the yoke, the second permanent magnet The magnetization direction of the permanent magnet is oriented toward the first permanent magnet. If the magnetization direction of the first permanent magnet is oriented toward the center of the yoke, the magnetization direction of the first permanent magnet is equal to the magnetization direction of the first permanent magnet. 1
This is a movable magnet type linear actuator that faces the opposite side of the permanent magnet.

As described above, by arranging a plurality of permanent magnets having a substantially radial magnetization direction and a plurality of permanent magnets having a substantially axial magnetization direction in the axial direction, it is possible to efficiently provide the drive coil side with the permanent magnet. Since the magnetic force is increased by generating a magnetic flux, and the permanent magnet holding member having magnetism is provided on the side not facing the drive coil of the permanent magnet, the permanent magnet can be reduced according to the improvement of the permeance of the permanent magnet. It can contribute to cost reduction and resource saving.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to solve the above-mentioned problems, a movable magnet type linear actuator according to the present invention comprises: an inner yoke; an outer yoke disposed outside the inner yoke; A drive coil wound around at least one of the magnets, a permanent magnet holding member disposed between the inner yoke and the outer yoke, and a magnetization direction held by the permanent magnet holding member so as to face the drive coil. A first permanent magnet having a substantially radial direction and a second permanent magnet having a magnetization direction substantially in an axial direction, wherein the second permanent magnet has an axial end or end of the first permanent magnet. If the magnetization direction of the first permanent magnet faces the outside of the yoke, the magnetization direction of the second permanent magnet faces the first permanent magnet. Magnetization direction of the permanent magnet is the center of the yoke , The magnetization direction of the first permanent magnet is opposite to the first permanent magnet, and the permanent magnet having a substantially radial magnetization direction and the permanent magnet having a substantially axial magnetization direction. By arranging a plurality of magnets in the axial direction, a magnetic flux is efficiently generated on the drive coil side to increase the magnetic force, and the permanent magnet holding member having magnetism is opposed to the drive coil of the permanent magnet. The permanent magnets can be reduced in accordance with the improvement of the permeance of the permanent magnets provided on the side where no permanent magnets are provided, which can contribute to cost reduction and resource saving.

Further, by fixing the first permanent magnet and the second permanent magnet to the permanent magnet holding member so as to face the drive coil, the distance between the drive coil and the permanent magnet can be reduced. In addition, the magnetic flux from the permanent magnet easily flows into the drive coil.

Further, by using a permanent magnet holding member having magnetism as the permanent magnet holding member, the magnetic flux of the first permanent magnet can easily flow through the permanent magnet holding member.

A cylindrical inner yoke having magnetism;
A magnetic outer yoke disposed substantially concentrically with the inner yoke and a predetermined gap; a drive coil wound around at least one of the inner yoke and the outer yoke; A first permanent magnet holding member having magnetism disposed substantially concentrically in an air gap of the yoke, and a first magnetized direction held by the permanent magnet holding member so as to face the drive coil is substantially radial. A permanent magnet and a second permanent magnet having a magnetization direction substantially in the axial direction, wherein the second permanent magnet is disposed at an axial end of the first permanent magnet; If the magnetization direction of the magnet faces the outside of the yoke, the magnetization direction of the second permanent magnet faces the first permanent magnet, and the magnetization direction of the first permanent magnet faces the center of the yoke. , The magnetization direction of the first permanent magnet May be configured to face the opposite side of said first permanent magnet.

[0013] Also, a configuration may be provided that includes a first permanent magnet whose magnetization direction is directed to the yoke center side and a first permanent magnet whose magnetization direction is directed to the outside of the yoke.

Further, when a second permanent magnet is disposed between the first permanent magnet whose magnetization direction faces the yoke center side and the first permanent magnet whose magnetization direction faces the outside of the yoke, An efficient permanent magnet arrangement is provided.

Further, the permanent magnet is divided in a substantially circumferential direction. Further, at least one of the inner yoke and the outer yoke is divided in a substantially circumferential direction.

Further, at least one of the inner yoke and the outer yoke is made of a thin plate, and the laminating direction is substantially the circumferential direction.

Further, at least one of the inner yoke and the outer yoke is made of a thin plate, and the laminating direction is divided in the axial direction and substantially in the circumferential direction.

Further, the thin plate forming at least one of the inner yoke and the outer yoke is a directional magnetic plate.

Further, the permanent magnet holding member is made of a high resistance member such as ferrite.

Further, the permanent magnet holding member has a plurality of slits in a substantially circumferential direction.

Further, at least one end of the permanent magnet holding member has an L-shape.

Further, a collision preventing cushioning material is provided on at least one of the inner yoke and the permanent magnet holding member.

Further, the movable magnet type linear actuator of the present invention is applied to a compressor.

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a sectional view of a movable magnet type linear actuator according to a first embodiment of the present invention. In FIG. 1, 1 is an inner yoke, 2 is an outer yoke, and 3 is an outer yoke. A drive coil 5 wound around the yoke 2 is a permanent magnet holding member, and 4 is a permanent magnet magnetized in the direction shown in FIG.

The operation of the movable magnet type linear actuator configured as described above will be described below.

The magnetic action of the magnetic flux generated by the permanent magnet 4 flowing through the inner yoke 1, the outer yoke 2 and the permanent magnet holding member 5 constituting the magnetic circuit, and the magnetic flux generated by applying a predetermined current to the drive coil 3 Then, a magnetic force is generated in the permanent magnet 4 and the permanent magnet holding member 5, and the magnetic force becomes a thrust to move the movable portion including the permanent magnet 4 and the permanent magnet holding member 5. At this time, the permanent magnet 4
Are arranged in the magnetization direction as shown in FIG. 1, the magnetic flux flowing to the drive coil 3 side increases, and a magnetic force can be obtained efficiently. Further, since a part of the magnetic flux from the permanent magnet 4 flows through the permanent magnet holding member 5 having magnetism, the number of the permanent magnets can be reduced in accordance with the improvement of the permeance of the permanent magnets, which can contribute to cost reduction and resource saving. .

In the above description, the drive coil 3 is wound around the outer yoke 2, but it is also possible to wind the drive coil 3 around the inner yoke 1. The number of cylindrical permanent magnets is not limited to two, but may be one, three or more.

Also, there may be a small gap between the permanent magnet 4 whose magnetization direction is substantially axial and the permanent magnet 4 whose magnetization direction is substantially radial.

(Embodiment 2) FIG. 2 is a sectional view of a movable magnet type linear actuator according to a second embodiment of the present invention. In FIG. 2, 1 is an inner yoke, 2 is an outer yoke, and 3 is an outer yoke. The drive coil 5 wound around the yoke 2 is a permanent magnet holding member, and 4 is a permanent magnet magnetized in the direction shown in FIG. The difference from FIG. 1 is that the permanent magnet 4 is divided substantially in the circumferential direction as shown in FIG.

The operation of the movable magnet type linear actuator configured as described above will be described below.

The magnetic action of the magnetic flux generated by the permanent magnet 4 flowing through the inner yoke 1, the outer yoke 2, and the permanent magnet holding member 5 constituting the magnetic circuit, and the magnetic flux generated by applying a predetermined current to the drive coil 3 Then, a magnetic force is generated in the permanent magnet 4 and the permanent magnet holding member 5, and the magnetic force becomes a thrust, so that the movable portion including the permanent magnet 4 and the permanent magnet holding member 5 moves. At this time, the permanent magnet 4
Are arranged in the magnetization direction as shown in FIG. 2, the magnetic flux flowing to the drive coil 3 side increases, and the magnetic force can be obtained efficiently. Further, since a part of the magnetic flux from the permanent magnet 4 flows through the permanent magnet holding member 5 having magnetism, the number of the permanent magnets can be reduced in accordance with the improvement of the permeance of the permanent magnets, which can contribute to cost reduction and resource saving. . Further, since the permanent magnet 4 is divided substantially in the circumferential direction, it can be easily magnetized and assembled.

In the above description, the drive coil 3 is wound around the outer yoke 2, but the drive coil 3 may be wound around the inner yoke 1.

(Embodiment 3) FIG. 4 is a sectional view of a movable magnet type linear actuator according to a third embodiment of the present invention. In FIG. 4, 1 is an inner yoke, 2 is an outer yoke, and 3 is an outer yoke. The drive coil 5 wound around the yoke 2 is a permanent magnet holding member, and 4 is a permanent magnet magnetized in the direction shown in FIG. The difference from FIG. 1 is that the inner yoke 1 and the outer yoke 2 are divided in a substantially circumferential direction as shown in FIG. FIG. 5 shows only the inner yoke 1.

The operation of the movable magnet type linear actuator configured as described above will be described below.

The magnetic action of the magnetic flux generated by the permanent magnet 4 flowing through the inner yoke 1, the outer yoke 2 and the permanent magnet holding member 5 constituting the magnetic circuit, and the magnetic flux generated by applying a predetermined current to the drive coil 3 Then, a magnetic force is generated in the permanent magnet 4 and the permanent magnet holding member 5, and the magnetic force becomes a thrust, so that the movable portion including the permanent magnet 4 and the permanent magnet holding member 5 moves. At this time, the permanent magnet 4
Are arranged in the magnetization direction as shown in FIG. 4, the magnetic flux flowing to the drive coil 3 side increases, and a magnetic force can be obtained efficiently. Further, since a part of the magnetic flux from the permanent magnet 4 flows through the permanent magnet holding member 5 having magnetism, the number of the permanent magnets can be reduced in accordance with the improvement of the permeance of the permanent magnets, which can contribute to cost reduction and resource saving. . Further, since the inner yoke 1 and the outer yoke 2 are divided in a substantially circumferential direction, eddy currents generated therein and heat generated by the eddy currents can be suppressed, and assembly can be easily performed.

In the above description, the drive coil 3 is wound around the outer yoke 2, but it is also possible to wind the drive coil 3 around the inner yoke 1.

(Embodiment 4) FIG. 6 is a sectional view of a movable magnet type linear actuator according to a fourth embodiment of the present invention. In FIG. 6, 1 is an inner yoke, 2 is an outer yoke, and 3 is an outer yoke. The drive coil 5 wound around the yoke 2 is a permanent magnet holding member, and 4 is a permanent magnet magnetized in the direction shown in FIG. The difference from FIG. 1 is that the inner yoke 1 and the outer yoke 2 are formed of thin plates, and the laminating direction is a substantially circumferential direction as shown in FIG. FIG. 7 shows only the inner yoke 1.

The operation of the movable magnet type linear actuator configured as described above will be described below.

The magnetic action of the magnetic flux generated by the permanent magnet 4 flowing through the inner yoke 1, the outer yoke 2 and the permanent magnet holding member 5 constituting the magnetic circuit, and the magnetic flux generated by applying a predetermined current to the drive coil 3 Then, a magnetic force is generated in the permanent magnet 4 and the permanent magnet holding member 5, and the magnetic force becomes a thrust, so that the movable portion including the permanent magnet 4 and the permanent magnet holding member 5 moves. At this time, the permanent magnet 4
Are arranged in the magnetization direction as shown in FIG. 6, the magnetic flux flowing to the drive coil 3 side increases, and a magnetic force can be obtained efficiently. Further, since a part of the magnetic flux from the permanent magnet 4 flows through the permanent magnet holding member 5 having magnetism, the number of the permanent magnets can be reduced in accordance with the improvement of the permeance of the permanent magnets, which can contribute to cost reduction and resource saving. . Further, by laminating the inner yoke 1 and the outer yoke 2 substantially in the circumferential direction, it is possible to suppress eddy currents generated therein and heat generated by the eddy currents.

In the above description, the drive coil 3 is wound around the outer yoke 2, but it is also possible to wind the drive coil 3 around the inner yoke 1. Further, the inner yoke 1 and the outer yoke 2 are stacked substantially in the circumferential direction as shown in FIG. 7, but the present invention can also be carried out by stacking as shown in FIG.

(Embodiment 5) FIG. 9 is a sectional view of a movable magnet type linear actuator according to a fifth embodiment of the present invention. In FIG. 9, reference numeral 1 denotes an inner yoke, 2 denotes an outer yoke, and 3 denotes an outer yoke. A drive coil 5 wound around the yoke 2 is a permanent magnet holding member, and 4 is a permanent magnet magnetized in the direction shown in FIG. The difference from FIG. 1 is that the inner yoke 1 and the outer yoke 2 are divided substantially in the circumferential direction as shown in FIG. 10 and are laminated in the axial direction. FIG. 10 shows only the inner yoke 1.

The operation of the movable magnet type linear actuator configured as described above will be described below.

By the magnetic action of the magnetic flux generated by the permanent magnet 4 flowing through the inner yoke 1, the outer yoke 2 and the permanent magnet holding member 5 constituting the magnetic circuit, and the magnetic flux generated by applying a predetermined current to the drive coil 3. Then, a magnetic force is generated in the permanent magnet 4 and the permanent magnet holding member 5, and the magnetic force becomes a thrust, so that the movable portion including the permanent magnet 4 and the permanent magnet holding member 5 moves. At this time, the permanent magnet 4
Are arranged in the magnetization direction as shown in FIG. 9, the magnetic flux flowing to the drive coil 3 side increases, and a magnetic force can be obtained efficiently. Further, since a part of the magnetic flux from the permanent magnet 4 flows through the permanent magnet holding member 5 having magnetism, the number of the permanent magnets can be reduced in accordance with the improvement of the permeance of the permanent magnets, which can contribute to cost reduction and resource saving. . Further, since the inner yoke 1 and the outer yoke 2 are divided substantially in the circumferential direction and stacked in the axial direction, eddy currents generated therein and heat generated by the eddy currents can be suppressed, and assembly is facilitated. be able to.

In the above description, the drive coil 3 is wound around the outer yoke 2, but it is also possible to wind the drive coil 3 around the inner yoke 1.

(Embodiment 6) FIG. 11 is a sectional view of a movable magnet type linear actuator according to a sixth embodiment of the present invention. In FIG. 11, 1 is an inner yoke, 2 is an outer yoke, and 3 is an outer yoke. Drive coil wound around the yoke 2, 5
Is a permanent magnet holding member, and 4 is a permanent magnet magnetized in the direction shown in FIG. 6 is different from FIG.
And that the thin plate forming the outer yoke 2 is a directional magnetic plate.

The operation of the movable magnet type linear actuator configured as described above will be described below.

The magnetic action of the magnetic flux generated by the permanent magnet 4 flowing through the inner yoke 1, the outer yoke 2 and the permanent magnet holding member 5 constituting the magnetic circuit, and the magnetic flux generated by applying a predetermined current to the drive coil 3 Then, a magnetic force is generated in the permanent magnet 4 and the permanent magnet holding member 5, and the magnetic force becomes a thrust, so that the movable portion including the permanent magnet 4 and the permanent magnet holding member 5 moves. At this time, the permanent magnet 4
Are arranged in the magnetization direction as shown in FIG. 11, the magnetic flux flowing to the drive coil 3 side increases, and the magnetic force can be obtained efficiently. Further, since a part of the magnetic flux from the permanent magnet 4 flows through the permanent magnet holding member 5 having magnetism, the number of the permanent magnets can be reduced in accordance with the improvement of the permeance of the permanent magnets, which can contribute to cost reduction and resource saving. . Further, since the inner yoke 1 and the outer yoke 2 are made of directional magnetic plates, the magnetic resistance in the yoke can be reduced, and the magnetic force can be increased.

In the above description, the drive coil 3 is wound around the outer yoke 2, but it is also possible to wind the drive coil 3 around the inner yoke 1.

(Embodiment 7) FIG. 12 is a sectional view of a movable magnet type linear actuator according to a seventh embodiment of the present invention. In FIG. 12, 1 is an inner yoke, 2 is an outer yoke, and 3 is an outer yoke. Drive coil wound around the yoke 2, 5
Is a permanent magnet holding member, and 4 is a permanent magnet magnetized in the direction shown in FIG. The difference from FIG. 1 is that the permanent magnet holding member 5 is a high resistance member.

The operation of the movable magnet type linear actuator configured as described above will be described below.

The magnetic action of the magnetic flux generated by the permanent magnet 4 flowing through the inner yoke 1, the outer yoke 2 and the permanent magnet holding member 5 constituting the magnetic circuit, and the magnetic flux generated by applying a predetermined current to the drive coil 3 Then, a magnetic force is generated in the permanent magnet 4 and the permanent magnet holding member 5, and the magnetic force becomes a thrust, so that the movable portion including the permanent magnet 4 and the permanent magnet holding member 5 moves. At this time, the permanent magnet 4
Are arranged in the magnetization direction as shown in FIG. 12, the magnetic flux flowing to the drive coil 3 side increases, and the magnetic force can be obtained efficiently. Further, since a part of the magnetic flux from the permanent magnet 4 flows through the permanent magnet holding member 5 having magnetism, the number of the permanent magnets can be reduced in accordance with the improvement of the permeance of the permanent magnets, which can contribute to cost reduction and resource saving. . In addition, since the permanent magnet holding member 5 is made of a high-resistance member, eddy current generated therein and heat generated by the eddy current can be suppressed, and demagnetization of the permanent magnet 4 due to heat generation of the permanent magnet holding member 5 can be suppressed. be able to.

In the above description, the drive coil 3 is wound around the outer yoke 2, but it is also possible to wind the drive coil 3 around the inner yoke 1.

(Embodiment 8) FIG. 13 is a sectional view of a movable magnet type linear actuator according to an eighth embodiment of the present invention. In FIG. 13, reference numeral 1 denotes an inner yoke, 2 denotes an outer yoke, and 3 denotes an outer yoke. Drive coil wound around the yoke 2, 5
Is a permanent magnet holding member, and 4 is a permanent magnet magnetized in the direction shown in FIG. The difference from FIG. 1 is that the permanent magnet holding member 5 is provided with a slit as shown in FIG.

The operation of the thus configured magnetic movable linear actuator will be described below.

The magnetic action of the magnetic flux generated by the permanent magnet 4 flowing through the inner yoke 1, the outer yoke 2 and the permanent magnet holding member 5 constituting the magnetic circuit, and the magnetic flux generated by applying a predetermined current to the drive coil 3 Then, a magnetic force is generated in the permanent magnet 4 and the permanent magnet holding member 5, and the magnetic force becomes a thrust, so that the movable portion including the permanent magnet 4 and the permanent magnet holding member 5 moves. At this time, the permanent magnet 4
Are arranged in the magnetization direction as shown in FIG. 13, the magnetic flux flowing to the drive coil 3 side increases, and the magnetic force can be obtained efficiently. Further, since a part of the magnetic flux from the permanent magnet 4 flows through the permanent magnet holding member 5 having magnetism, the number of the permanent magnets can be reduced in accordance with the improvement of the permeance of the permanent magnets, which can contribute to cost reduction and resource saving. . Further, since the slit is provided in the permanent magnet holding member 5, eddy current generated therein and heat generated by the eddy current can be suppressed, and furthermore, demagnetization of the permanent magnet 4 due to heat generation of the permanent magnet holding member 5 can be suppressed. Can be.

In the above description, the drive coil 3 is wound around the outer yoke 2, but it is also possible to wind the drive coil 3 around the inner yoke 1.

(Embodiment 9) FIG. 15 is a sectional view of a movable magnet type linear actuator according to a ninth embodiment of the present invention. In FIG. 15, 1 is an inner yoke, 2 is an outer yoke, and 3 is an outer yoke. Drive coil wound around the yoke 2, 5
Is a permanent magnet holding member, and 4 is a permanent magnet magnetized in the direction shown in FIG. The difference from FIG. 1 is that the end of the permanent magnet holding member 5 is L-shaped as shown in FIG.

The operation of the movable magnet type linear actuator configured as described above will be described below.

The magnetic action of the magnetic flux generated by the permanent magnet 4 flowing through the inner yoke 1, the outer yoke 2 and the permanent magnet holding member 5 constituting the magnetic circuit and the magnetic flux generated by applying a predetermined current to the drive coil 3 Then, a magnetic force is generated in the permanent magnet 4 and the permanent magnet holding member 5, and the magnetic force becomes a thrust, so that the movable portion including the permanent magnet 4 and the permanent magnet holding member 5 moves. At this time, the permanent magnet 4
Are arranged in the magnetization direction as shown in FIG. 12, the magnetic flux flowing to the drive coil 3 side increases, and the magnetic force can be obtained efficiently. Further, since a part of the magnetic flux from the permanent magnet 4 flows through the permanent magnet holding member 5 having magnetism, the number of the permanent magnets can be reduced in accordance with the improvement of the permeance of the permanent magnets, which can contribute to cost reduction and resource saving. . In addition, since the end of the permanent magnet holding member 5 is L-shaped, the positioning of the permanent magnet 4 can be facilitated.

In the above description, the drive coil 3 is wound around the outer yoke 2, but it is also possible to wind the drive coil 3 around the inner yoke 1.

(Embodiment 10) FIG. 17 is a sectional view of a movable magnet type linear actuator according to a tenth embodiment of the present invention. In FIG. 17, reference numeral 1 denotes an inner yoke, 2 denotes an outer yoke, and 3 denotes an outer yoke. A drive coil 5 wound around the yoke 2 is a permanent magnet holding member, 4 is a permanent magnet magnetized in the direction shown in FIG. 17, and 6 is a collision preventing spring.
The difference from FIG. 1 is that a collision preventing spring 6 is provided on the inner yoke 1.

The operation of the thus configured magnetic movable linear actuator will be described below.

The magnetic action of the magnetic flux generated by the permanent magnet 4 flowing through the inner yoke 1, the outer yoke 2 and the permanent magnet holding member 5 constituting the magnetic circuit and the magnetic flux generated by applying a predetermined current to the drive coil 3 Then, a magnetic force is generated in the permanent magnet 4 and the permanent magnet holding member 5, and the magnetic force becomes a thrust, so that the movable portion including the permanent magnet 4 and the permanent magnet holding member 5 moves. At this time, the permanent magnet 4
Are arranged in the magnetization direction as shown in FIG. 12, the magnetic flux flowing to the drive coil 3 side increases, and the magnetic force can be obtained efficiently. Further, since a part of the magnetic flux from the permanent magnet 4 flows through the permanent magnet holding member 5 having magnetism, the number of the permanent magnets can be reduced in accordance with the improvement of the permeance of the permanent magnets, which can contribute to cost reduction and resource saving. . Further, by providing the inner yoke 1 with a collision preventing spring, damage due to collision between the inner yoke 1 and the permanent magnet holding member 5 can be prevented.

In the above description, the drive coil 3 is wound around the outer yoke 2, but it is also possible to wind the drive coil 3 around the inner yoke 1.

[0066]

As is apparent from the above embodiment, claims 1, 4, 5, 7, 8, 9, 10, 11, 12, 13, 1
According to the inventions described in (4) and (16), the permanent magnet having the substantially radial magnetization direction and the permanent magnet having the substantially axial magnetization direction are disposed in the axial direction, so that the drive coil side is efficiently provided. A magnetic flux can be generated to increase the magnetic force.

Further, since the cylindrical permanent magnet is divided in the substantially circumferential direction, the above-described effects can be obtained, and the permanent magnet can be easily magnetized and assembled.

Further, since at least one of the yokes is divided substantially in the circumferential direction, the above-described effects can be obtained, and eddy currents generated in the yokes and heat generation due to the eddy currents can be suppressed. Easy to assemble.

Further, since at least one of the yokes is made of a thin plate and the product bidirectional is substantially in the circumferential direction, the above-described effects are obtained, and the eddy current generated in the yoke and the heat generated by the eddy current are suppressed. can do.

Further, since at least one of the yokes is made of a thin plate, and the laminating direction is divided in the axial direction and substantially in the circumferential direction, the above-described effect is obtained and the eddy current generated in the yoke is obtained. In addition, heat generation due to eddy current can be suppressed, and assembly can be further facilitated.

Further, since at least one of the yokes is made of a thin plate and the thin plate has directionality, the above-described effect is obtained, and the magnetic resistance at the yoke is reduced, so that the thrust is further improved. High acceleration can be obtained.

Further, by using a high resistance member for the permanent magnet holding member, the effects described above can be obtained, and eddy currents generated in the permanent magnet holding member and heat generation due to the eddy current can be suppressed. Can suppress the demagnetization of the permanent magnet.

Further, since the permanent magnet holding member has a plurality of slits in a substantially circumferential direction, the above-described effects can be obtained, and eddy current generated in the permanent magnet holding member and heat generation due to the eddy current are suppressed. In addition, demagnetization of the permanent magnet due to heat generation can be suppressed.

Further, since at least one end of the permanent magnet holding member has an L-shape, the above-described effects can be obtained, and the positioning of the permanent magnet can be facilitated.

Further, according to the second aspect of the present invention, the permanent magnet holding member having magnetism is provided on the side not facing the drive coil of the permanent magnet, so that the number of permanent magnets can be reduced in accordance with the improvement in the permeance of the permanent magnet. Therefore, it can contribute to cost reduction and resource saving.

Further, according to the third aspect of the present invention, the magnetic flux can flow through the permanent magnet holding member by making the permanent magnet holding member magnetic.

Further, according to the present invention, by disposing the second permanent magnet between the plurality of first permanent magnets,
A magnetic flux can be efficiently generated on the drive coil side efficiently, and the magnetic force can be increased.

Further, in the invention according to the fifteenth aspect, by providing a collision preventing cushioning material on at least one of the inner yoke and the permanent magnet holding member, it is possible to prevent breakage due to collision between the inner yoke and the permanent magnet holding member.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a movable magnet type linear actuator according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a movable magnet type linear actuator according to a second embodiment of the present invention;

FIG. 3 is a bird's-eye view of a permanent magnet according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing a movable magnet type linear actuator according to a third embodiment of the present invention.

FIG. 5 is a bird's-eye view of an inner yoke according to a third embodiment of the present invention.

FIG. 6 is a sectional view showing a movable magnet type linear actuator according to a fourth embodiment of the present invention.

FIG. 7 is a top view of an inner yoke according to a fourth embodiment of the present invention.

FIG. 8 is a top view of an inner yoke according to a fourth embodiment of the present invention.

FIG. 9 is a sectional view showing a movable magnet type linear actuator according to a fifth embodiment of the present invention.

FIG. 10 is a bird's-eye view of an inner yoke according to a fifth embodiment of the present invention.

FIG. 11 is a sectional view showing a movable magnet type linear actuator according to a sixth embodiment of the present invention.

FIG. 12 is a sectional view showing a movable magnet type linear actuator according to a seventh embodiment of the present invention.

FIG. 13 is a sectional view showing a movable magnet type linear actuator according to an eighth embodiment of the present invention.

FIG. 14 is a bird's-eye view of a permanent magnet holding member according to an eighth embodiment of the present invention.

FIG. 15 is a sectional view showing a movable magnet type linear actuator according to a ninth embodiment of the present invention.

FIG. 16 is a bird's-eye view of a permanent magnet holding member according to a ninth embodiment of the present invention.

FIG. 17 is a sectional view showing a movable magnet type linear actuator according to a ninth embodiment of the present invention.

FIG. 18 is a sectional view showing a conventional magnet movable linear actuator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inner yoke 2 Outer yoke 3 Drive coil 4 Permanent magnet 5 Permanent magnet holding member 6 Collision prevention spring

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Sugimatsu Hasegawa 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (16)

[Claims] An inner yoke; an outer yoke disposed outside the inner yoke; a drive coil wound around at least one of the inner yoke and the outer yoke; A permanent magnet holding member disposed therebetween, a first permanent magnet held by the permanent magnet holding member having a substantially radial magnetization direction, and a second permanent magnet having a magnetization direction substantially axis direction.
Wherein the second permanent magnet is the first permanent magnet.
If the magnetization direction of the first permanent magnet faces the outside of the yoke, the magnetization direction of the second permanent magnet is set to the first permanent magnet. If the magnetization direction of the first permanent magnet is facing the magnet and the magnetization direction of the first permanent magnet is facing the center of the yoke, the magnetization direction of the first permanent magnet is facing the opposite side of the first permanent magnet. A movable magnet type linear actuator characterized by the above-mentioned. 2. The movable magnet linear actuator according to claim 1, wherein the first permanent magnet and the second permanent magnet are fixed to the permanent magnet holding member so as to face the drive coil. 3. The permanent magnet holding member has magnetism.
The movable magnet type linear actuator as described in the above. 4. A cylindrical inner yoke having magnetism, an outer yoke having magnetism disposed substantially concentrically with the inner yoke and a predetermined gap, and at least one of the inner yoke and the outer yoke. A permanent magnet holding member having magnetism disposed substantially concentrically in an air gap between the inner yoke and the outer yoke, and the permanent magnet holding member facing the drive coil. A first permanent magnet whose magnetization direction is substantially radial direction and a second permanent magnet whose magnetization direction is substantially axial direction, wherein the second permanent magnet is formed of the first permanent magnet. Disposed at an axial end, if the magnetization direction of the first permanent magnet is directed to the outside of the yoke, the magnetization direction of the second permanent magnet is directed to the first permanent magnet; The direction of magnetization of the first permanent magnet is the center of the yoke. If facing said first magnet movable type linear actuator, wherein a magnetization direction of the permanent magnet faces the opposite side of said first permanent magnet. 5. The first magnetic recording medium, wherein the magnetization direction is directed toward the center of the yoke.
And a first magnet whose magnetization direction faces the outside of the yoke.
The movable magnet linear actuator according to claim 1, further comprising: a permanent magnet. 6. A first magnet having a magnetization direction facing the center of the yoke.
And a first magnet whose magnetization direction faces the outside of the yoke.
4. The movable magnet type linear actuator according to claim 3, wherein a second permanent magnet is disposed between the actuator and the permanent magnet. 7. The linear actuator according to claim 1, wherein the permanent magnet is divided in a substantially circumferential direction. 8. The movable magnet type linear actuator according to claim 1, wherein at least one of the inner yoke and the outer yoke is divided in a substantially circumferential direction. 9. The movable magnet type linear actuator according to claim 1, wherein at least one of the inner yoke and the outer yoke is formed of a thin plate, and a laminating direction thereof is substantially a circumferential direction. 10. The apparatus according to claim 1, wherein at least one of the inner yoke and the outer yoke is formed of a thin plate, and the laminating direction is divided in the axial direction and substantially in the circumferential direction. Magnet movable linear actuator. 11. The thin plate forming at least one of the inner yoke and the outer yoke is a directional magnetic plate.
The movable magnet type linear actuator as described in the above. 12. The movable magnet linear actuator according to claim 1, wherein the permanent magnet holding member is made of a high-resistance member such as ferrite. 13. The magnet movable linear actuator according to claim 1, wherein the permanent magnet holding member has a plurality of slits in a substantially circumferential direction. 14. The linear actuator according to claim 1, wherein at least one end of the permanent magnet holding member has an L-shape. 15. The movable magnet type linear actuator according to claim 1, wherein a collision preventing cushioning material is provided on at least one of the inner yoke and the permanent magnet holding member. 16. A compressor using the magnet movable linear actuator according to claim 1.