JPH07123682A - Cylindrical linear actuator - Google Patents

Abstract

PURPOSE:To restrict the circumferential move of a movable piece which constitutes a cylindrical linear actuator. CONSTITUTION:A stator 2, composed of a center yoke 4 and a side yoke 6 each in cylindrical shape and a first permanent magnet 5, and a movable piece 3, which are composed of a winding 9, a winding retaining member 10, and a second permanent magnet each in cylindrical shape, are constituted in the shape of a coaxial cylinder so that the magnetic field made by the first permanent magnet 5 and the magnetic field made by the second permanent magnet 7 may be constituted at least one each a specified interval apart severally in circumferential direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical linear actuator having a holding force for suppressing the circumferential displacement of a movable part due to an external force, and it relates to a handling device, a catching device, an inspection device (various contacts). Probes), optical devices (various mirrors, various lenses), detection devices (various sensors), etc. are used for driving all or part of them.

[0002]

2. Description of the Related Art The structure and operation of a conventional cylindrical linear actuator will be described based on an example shown in FIGS.

FIG. 1 is a perspective sectional view for the purpose of explaining the structure of a conventional cylindrical linear actuator. The cylindrical linear actuator comprises a stator 2 and a mover 3 each of which has a cylindrical shape. Is composed of.

The stator 2 has a cylindrical center yoke 4, and a cylindrical side yoke 6 arranged around the center yoke 4 in a coaxial cylindrical shape at a predetermined interval.
The first permanent magnet 5 is formed of a cylindrical first permanent magnet 5 fixed to the inner cylindrical surface of the side yoke 6. The outer cylindrical surface of the center yoke 4 and the first permanent magnet 5 are opposed to each other with a predetermined gap. A fixed magnetic circuit is formed through a cylindrical void 8 formed by the inner cylindrical surface.

The mover 3 has a structure in which a part of the center yoke 4 is housed inside the cylindrical void 8 and can move smoothly in the axial direction. The winding 9 and the winding are respectively cylindrical. The wire holding member 10 is formed into a coaxial cylindrical shape, and a terminal portion of the winding 9 has a terminal 11 attached to a part of the winding holding member 10.
Electrically connected to.

FIG. 2 shows the conventional cylindrical linear type shown in FIG.
It is a sectional view for the purpose of explaining the configuration of the magnetic flux of the actuator, and shows a section of a stator 2 and a mover 3 which are arranged in a coaxial cylindrical shape.

The first permanent magnet 5 is fixed to the inner cylindrical surface of the side yoke 6 so that the magnetic pole surface having the polarity of the S pole faces the outer cylindrical surface of the center yoke 4 with a predetermined gap. Between the stator 2 and the mover 3, the side yoke 6, the center yoke 4, and the S pole of the first permanent magnet 5 are arranged closer to each other than the magnetic pole surface having the polarity of the N pole of the first permanent magnet 5. The magnetic flux Φa flows in the direction of the arrow to the magnetic pole surface having the polarity, forming a closed magnetic path continuous in the circumferential direction. That is, a magnetic field having a directivity from the outer cylindrical surface of the center yoke 4 toward the inner cylindrical surface of the first permanent magnet 5 is formed in the cylindrical void 8.

When a current having a predetermined magnitude is applied to the winding 9 through the terminal 11 in the direction shown in FIG. 2, the mover 3 moves in the direction of arrow A according to the Bil's rule, and the current is applied to the winding 9. When currents having a predetermined magnitude in different directions are passed through the terminal 11, the mover 3 moves in the arrow B direction.

The conventional cylindrical linear actuator shown in FIGS. 1 and 2 is easy to machine and assemble, has high efficiency, displacement (amplitude) and velocity (frequency).
Because of its ease of control, it is widely used as a drive source for loads that require high thrust, high speed and small displacement, and as a vibration source for various vibration devices. However, it is necessary to provide a bearing device that smoothly slides the movable part in the axial direction with a function to prevent the displacement in the circumferential direction due to the external force of the movable part, which complicates the bearing mechanism and increases the quality of the bearing device. It was a thing.

[0010]

The problem to be solved is that the movable part of the cylindrical linear actuator freely changes in the circumferential direction.

[0011]

[Means for Solving the Problems] The cylindrical linear device of the present invention
In order to solve the above problems, the actuator has a structure shown in FIG.
The stator 2 of the conventional cylindrical linear actuator shown in
The first permanent magnets 5 are arranged so that at least one or more magnetic fields formed by the first permanent magnets 5 constituting the above in the cylindrical space 8 in the radial direction are formed at predetermined intervals in the circumferential direction. Further, further, at least one magnetic field having the same directionality as the magnetic field formed by the first permanent magnet 5 is formed in a part of the mover 3 at a predetermined interval in the circumferential direction,
By attaching at least one or more second permanent magnets, a holding force is generated in the mover in order to regulate the circumferential fluctuation.

[0012]

The operation of the cylindrical linear actuator of the present invention will be described with reference to the operation principle explanatory diagrams shown in FIGS.

FIG. 3 is a layout view of permanent magnets for the purpose of explaining the principle of operation. The permanent magnets 20a and 20b are rectangular flat plates having a length a and a height b of the bottom side, and the length of the bottom side. It shows an arrangement with a flat plate-shaped permanent magnet 21 having a rectangular shape of a and height d.

The plate-shaped permanent magnet 20a and the plate-shaped permanent magnet 2
0b is installed with the magnetic pole surfaces having different polarities facing each other with a space c therebetween, and the flat plate-shaped permanent magnet 21 is located in the space formed by the facing magnetic pole surfaces of the flat plate-shaped permanent magnet 20a and the flat plate-shaped permanent magnet 20b. So that they can move freely in the direction of arrow C or in the direction of arrow D, the magnetic pole faces of the flat plate-like permanent magnet 21 and the flat plate-like permanent magnet 2 facing each other.
The magnetic pole surface of 0a, the magnetic pole surface of the flat plate-shaped permanent magnet 21 and the magnetic pole surface of the flat plate-shaped permanent magnet 20b are arranged so as to have different polarities.

FIGS. 4 (a) to 4 (c) are sectional views taken along the line ee of FIG. 3 for the purpose of explaining the principle of operation. The plate-shaped permanent magnet 20a and the plate-shaped permanent magnet 21 shown by hatching are shown in FIG. It shows the arrangement of.

When the flat plate-shaped permanent magnet 21 is moved from the position shown in FIG. 4A to the position shown in FIG. 4B by a predetermined distance,
The flat plate permanent magnet 21 has an attractive force F in the direction of the arrow between the magnetic field formed between the flat plate permanent magnet 20a and the flat plate permanent magnet 20b and the magnetic field formed by the flat plate permanent magnet 21.
a acts. That is, a holding force is applied to the flat plate-shaped permanent magnet 21 so as to stay at the position shown in FIG. 4A in the magnetic field formed between the flat plate-shaped permanent magnet 20a and the flat plate-shaped permanent magnet 20b.

When the flat plate-shaped permanent magnet 21 is moved from the position shown in FIG. 4A to the position shown in FIG. 4C by a predetermined distance,
The flat plate permanent magnet 21 has an attractive force F in the direction of the arrow between the magnetic field formed between the flat plate permanent magnet 20a and the flat plate permanent magnet 20b and the magnetic field formed by the flat plate permanent magnet 21.
b acts. That is, a holding force is applied to the flat plate-shaped permanent magnet 21 so as to stay at the position shown in FIG. 4A in the magnetic field formed between the flat plate-shaped permanent magnet 20a and the flat plate-shaped permanent magnet 20b.

Similarly, the flat plate-shaped permanent magnet 21 is shown in FIG.
Even when the plate-shaped permanent magnet 20a is installed at a position moved in the height b direction from the position shown in FIG. 5, the plate-shaped permanent magnet 21 is formed between the plate-shaped permanent magnet 20a and the plate-shaped permanent magnet 20b. The holding force acts to stay in the applied magnetic field.

The cylindrical linear actuator of the present invention comprises the plate-shaped permanent magnet 20a, the plate-shaped permanent magnet 20b and the plate-shaped permanent magnet 21 shown in FIGS. 3 and 4, which are formed in a cylindrical shape. In the magnetic field formed between the flat-plate permanent magnet 20a configured and the flat-plate permanent magnet 20b configured in the cylindrical shape, the flat-plate permanent magnet 21 configured in the cylindrical shape and the winding configured in the cylindrical shape. Place the line and B
The force acting between the current flowing in the winding and the magnetic field according to the il law is moved in the arrow C direction or the arrow D direction between the cylindrical permanent magnet 21 and the cylindrical winding. It is the thrust to make it.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the cylindrical linear actuator of the present invention will be described with reference to FIGS.

FIG. 5 is a perspective sectional view showing the first and second embodiments of the cylindrical linear actuator of the present invention. The cylindrical linear actuator is a stator 2 having a cylindrical shape. And the mover 3 are mainly configured in a coaxial cylindrical shape.

The stator 2 includes a center yoke 4 having a cylindrical shape, side yokes 6 having a cylindrical shape arranged coaxially around the center yoke 4 at predetermined intervals, and side yokes. An outer cylinder surface of the center yoke 4 and an inner cylinder of the first permanent magnet 5, which are formed of a cylindrical first permanent magnet 5 fixed to the inner cylindrical surface of the yoke 6 and face each other with a predetermined gap. A fixed magnetic circuit is formed through a cylindrical void 8 formed by the plane and the axial direction.

The mover 3 has a structure in which the center yoke 4 is housed inside the cylindrical void 8 and can be smoothly moved in the axial direction. The winding holding member 10 has a cylindrical shape, and the winding. A cylindrical winding 9 mounted on a part of the outer cylindrical surface of the holding member 10, and a cylindrical second permanent magnet 7 fixed to a part of the inner cylindrical surface of the winding holding member 10. Is formed into a coaxial cylindrical shape.

On a part of the inner cylindrical surface of the winding holding member 10, the mover 3 is separated from the outer cylindrical surface of the center yoke 4 and the inner cylindrical surface of the first permanent magnet 5 by a predetermined gap. A pair of cylindrical bearings 15 is mounted for the purpose of smoothly moving in the cylindrical space 8 in the axial direction. A terminal portion of the winding 9 is electrically connected to a terminal 11 mounted on a part of the winding holding member 10.

Center yoke 4 and side yoke 6
Is formed of various magnetic materials having excellent magnetic properties, and if necessary, heat treatment is performed to improve the magnetic properties.

The winding holding member 10 is made of various synthetic resins having a predetermined mechanical strength, and the bearing 15 is mainly made of various oil-impregnated bearing materials or various solid bearing materials having lubricity in a cylindrical shape. . The inner cylindrical surface of the bearing 15 is
The bearing 15 has a structure that smoothly slides on the outer cylindrical surface of the center yoke 4. Generally, the bearing 15 can be integrally formed with the winding holding member 10 by a synthetic resin having a small contact resistance such as PPS. .

FIG. 6 is a perspective view showing the structure of the first permanent magnet 5 of the first embodiment of the cylindrical linear actuator of the present invention shown in FIG. The first permanent magnet 5 constituting the stator 2 is a spacer 12 made of a non-magnetic material.
The permanent magnet piece 5a which is formed into a cylindrical shape by the permanent magnet piece 5a via a and constitutes the outer cylindrical surface of the first permanent magnet 5.
The magnetic pole faces of are configured to have the same polarity. In general, the first permanent magnet 5 can be formed by forming various permanent magnet materials into a cylindrical shape and magnetizing the portion of the permanent magnet piece 5a in the radial direction.

FIG. 7 is a perspective view showing the structure of the second permanent magnet 7 of the first embodiment of the cylindrical linear actuator of the present invention shown in FIG. The permanent magnet 7 is a spacer 13 made of a non-magnetic material.
The permanent magnet piece 7a is formed in a cylindrical shape by the permanent magnet piece 7a via a and forms the outer cylindrical surface of the second permanent magnet 7.
The magnetic pole faces of are configured to have the same polarity. In general, the second permanent magnet 7 can be formed by forming various permanent magnet materials into a cylindrical shape and magnetizing the permanent magnet piece 7a in the radial direction.

The magnetic pole surface of the permanent magnet piece 5a forming the inner cylindrical surface of the first permanent magnet 5 and the magnetic pole surface of the permanent magnet piece 7a forming the outer cylindrical surface of the second permanent magnet 7 are different from each other. When a direct current voltage having a predetermined polarity is applied to the winding 9 via the terminal 11, the mover 3 moves the bearing 1 in the cylindrical space 8 formed by the stator 2.
When a DC voltage having a different polarity is applied to the winding 9 via the terminal 11, the mover 3 moves the bearing 15 inside the cylindrical void 8 formed by the stator 2. To move in the direction of arrow F.

FIG. 8 shows the arrangement of the first permanent magnets 5 and the second permanent magnets 7 of the first embodiment of the cylindrical linear actuator of the present invention shown in FIG. As described above, the permanent magnet piece 5a and the permanent magnet piece 7a are formed by the spacers 12a and 13a formed at a predetermined angle θa.
And are arranged in a coaxial cylindrical shape.

The permanent magnet piece 7a forming the mover 3 includes
Permanent magnet piece 5a and center yoke 4 which constitute the stator 2
A circumferential force acts to stay in the magnetic field formed by and. That is, a holding force acts on the second permanent magnet that constitutes the mover 3 so as to prevent rotation in the arrow G direction or the arrow H direction, and the mover 3 moves in the arrow G direction or the arrow H direction. Prevent.

A second embodiment of the cylindrical linear actuator of the present invention will be described with reference to FIGS. 5, 9 and 10.

FIG. 9 is a perspective view showing the structure of the first permanent magnet 5 of the second embodiment of the cylindrical linear actuator of the present invention shown in FIG. The first permanent magnet 5 constituting the stator 2 is a spacer 12 made of a non-magnetic material.
a, 12b, 12c, 12d through the permanent magnet piece 5a,
The permanent magnet pieces 5a, 5b, which are cylindrically formed by 5b, 5c, 5d, and which form the outer cylindrical surface of the first permanent magnet 5,
The magnetic pole surfaces 5c and 5d are configured to have the same polarity. Generally, the first permanent magnet 5 is formed by forming various permanent magnet materials into a cylindrical shape, and the permanent magnet pieces 5a, 5b,
The portions 5c and 5d can be magnetized in the radial direction.

FIG. 10 shows the second permanent magnet 7 of the second embodiment of the cylindrical linear actuator of the present invention shown in FIG.
It is a perspective view which shows the structure of. The second permanent magnet 7 forming the mover 3 is a spacer 1 made of a non-magnetic material.
Permanent magnet piece 7 through 3a, 13b, 13c, 13d
Permanent magnet pieces 7a, 7 which are cylindrically formed by a, 7b, 7c, 7d and form the outer cylindrical surface of the second permanent magnet 7.
The magnetic pole surfaces b, 7c and 7d are configured to have the same polarity. Generally, the second permanent magnet 7 is formed by forming various permanent magnet materials into a cylindrical shape, and the permanent magnet pieces 7a, 7
The portions b, 7c, and 7d can be magnetized in the radial direction.

The magnetic pole surfaces of the permanent magnet pieces 5a, 5b, 5c, 5d forming the inner cylindrical surface of the first permanent magnet 5 and the permanent magnet pieces 7a, 7 forming the outer cylindrical surface of the second permanent magnet 5.
The magnetic pole surfaces b, 7c, and 7d are configured to have different polarities.

A third embodiment of the cylindrical linear actuator of the present invention will be described with reference to FIGS. 11 to 13.

FIG. 11 is a perspective sectional view showing a third embodiment of the cylindrical linear actuator of the present invention. The cylindrical linear actuator comprises a stator 2 and a mover 3 each having a cylindrical shape. It is mainly composed of a coaxial cylinder.

The stator 2 includes a center yoke 4 having a cylindrical shape, side yokes 6 having a cylindrical shape, which are arranged around the center yoke 4 at predetermined intervals in coaxial cylindrical shapes, and a center yoke 4. A cylindrical first permanent magnet 51 fixed to the outer cylindrical surface of the yoke 4 and a cylindrical first permanent magnet 5 fixed to the inner cylindrical surface of the side yoke 6.
2, a fixed magnetic field is provided via a cylindrical air gap 8 formed in the axial direction by the outer cylindrical surface of the first permanent magnet 51 and the inner cylindrical surface of the first permanent magnet 52 that face each other with a predetermined gap. Form a circuit.

The mover 3 has a structure in which the center yoke 4 and the first permanent magnet 51 are housed inside the cylindrical void 8 and can be smoothly moved in the axial direction, and a cylindrical winding is formed. A wire holding member 10, a cylindrical second permanent magnet 7 mounted on a part of the outer cylindrical surface of the winding holding member 10, and a winding mounted on the outer cylindrical surface of the second permanent magnet 7. And 9 form a coaxial cylindrical shape.

A shaft 14 in the form of a round bar having a circular cross section is fixed to the central portion of the center yoke 4, and the winding holding member 1
In a part of 0, the movable element 3 is separated from the outer cylindrical surface of the first permanent magnet 51 and the inner cylindrical surface of the first permanent magnet 52 by a predetermined gap, and the movable element 3 is provided in the cylindrical void 8 with a shaft 14 inside. A cylindrical bearing 15 is mounted for the purpose of smoothly moving in the axial direction via the. A terminal portion of the winding 9 is electrically connected to a terminal 11 mounted on a part of the winding holding member 10.

FIG. 12 is a perspective sectional view showing the construction of the first permanent magnet 51 and the first permanent magnet 52 of the third embodiment of the cylindrical linear actuator of the present invention shown in FIG. The first permanent magnet 51 forming the stator 2 includes spacers 141a and 141b formed of a non-magnetic material.
The permanent magnet pieces 51a and 51b are formed into a cylindrical shape through the magnetic poles 51a and 51b, and the magnetic pole surfaces of the permanent magnet pieces 51a and 51b that form the outer cylindrical surface of the first permanent magnet 51 have the same polarity. The first permanent magnet 52 constituting the stator 2 is a spacer 1 formed of a non-magnetic material.
The magnetic pole surfaces of the permanent magnet pieces 52a, 52b, which are cylindrically formed by the permanent magnet pieces 52a, 52b via the 42a, 142b and form the outer cylindrical surface of the first permanent magnet 52, have the same polarity. Is composed of. In general,
The first permanent magnet 51 is formed by forming various permanent magnet materials into a cylindrical shape, and includes the permanent magnet piece 51a and the permanent magnet piece 51b.
Can be magnetized in the radial direction. The first permanent magnet 52 has a similar structure.

FIG. 13 is a perspective view showing the structure of the second permanent magnet 7 of the third embodiment of the cylindrical linear actuator of the present invention shown in FIG. The second which constitutes the mover 3
The permanent magnet 7 of FIG. 2 is cylindrically formed by the permanent magnet pieces 7a and 7b via the spacers 13a and 13b formed of a non-magnetic material, and forms the outer cylindrical surface of the second permanent magnet 7. , 7b are configured to have the same polarity. In general, the second permanent magnet 7 can be formed by forming various permanent magnet materials into a cylindrical shape and magnetizing the portions of the permanent magnet piece 7a and the permanent magnet piece 7b in the radial direction.

The magnetic pole surfaces of the permanent magnet pieces 51a and 51b that form the outer cylindrical surface of the first permanent magnet 51 and the magnetic pole surfaces of the permanent magnet pieces 7a and 7b that form the inner cylindrical surface of the second permanent magnet 7. Are magnetic pole surfaces of the permanent magnet pieces 52a and 52b that are configured to have different polarities and that form the inner cylindrical surface of the first permanent magnet 52, and the permanent cylindrical surfaces that form the outer cylindrical surface of the second permanent magnet 7. The magnetic pole surfaces of the magnet pieces 7a and 7b are configured to have different polarities.

In the cylindrical linear actuator of the present invention shown in FIGS. 11 to 13, when a DC voltage having a predetermined polarity is applied to the winding 9 through the terminal 11, the mover 3 is moved.
Moves in the direction of arrow E through the bearing 15 and the shaft 14 in the cylindrical space 8 formed by the stator 2 and applies DC voltages having different polarities to the winding 9 through the terminal 11,
The mover 3 moves in the cylindrical space 8 formed by the stator 2 in the direction of arrow F via the bearing 15 and the shaft 14.

Center yoke 4 and side yoke 6
Is formed of various magnetic materials having excellent magnetic properties, and if necessary, heat treatment is performed to improve the magnetic properties.

The winding holding member 10 is made of various synthetic resins having a predetermined mechanical strength, and the bearing 15 is mainly formed of a linear ball bearing or various solid bearing materials having lubricity in a cylindrical shape. The inner cylindrical surface of the bearing 15 has a structure that smoothly slides on the outer cylindrical surface of the shaft 14 fixed to the central portion of the center yoke 4.
In general, the bearing 15 can be integrally formed with the winding holding member 10 by a synthetic resin having a low contact resistance such as PPS.

A fourth embodiment of the cylindrical linear actuator of the present invention will be described with reference to FIGS. 14 to 16.

FIG. 14 is a cross-sectional view showing a fourth embodiment of the cylindrical linear actuator of the present invention. The cylindrical linear actuator comprises a stator 2 and a mover 3 which are respectively cylindrical. It is configured as a coaxial cylinder.

The stator 2 includes a center yoke 4 having a cylindrical shape, side yokes 6 having a cylindrical shape arranged coaxially around the center yoke 4 at predetermined intervals, and side yokes. An outer cylinder surface of the center yoke 4 and an inner cylinder of the first permanent magnet 5, which are formed of a cylindrical first permanent magnet 5 fixed to the inner cylindrical surface of the yoke 6 and face each other with a predetermined gap. A fixed magnetic circuit is formed through a cylindrical void 8 formed by the plane and the axial direction.

The mover 3 has a structure in which the center yoke 4 is housed inside the cylindrical void 8 and can be smoothly moved in the axial direction. A cylindrical second permanent magnet 71 mounted on a part of the outer cylindrical surface of the wire holding member 10, a second permanent magnet 72 having a cylindrical shape, and a winding 9 having a cylindrical shape to form a coaxial cylinder. Configured into a shape.

The mover 3 smoothly moves in the cylindrical void 8 with a predetermined gap from the inner cylindrical surface of the first permanent magnet 5 and the outer cylindrical surface of the center yoke 4, and is further movable. A round rod-shaped shaft 14 fixed to the central portion of the winding holding member 10 that constitutes the child 3 has a cylindrical space in which a bearing 15 is mounted inside a central portion of the center yoke 4. The bearing 15 slides smoothly in the axial direction. A terminal portion of the winding 9 is electrically connected to a terminal 11 mounted on a part of the winding holding member 10.

FIG. 15 is a perspective view showing the structure of the first permanent magnet 5 of the fourth embodiment of the cylindrical linear actuator of the present invention shown in FIG.
The permanent magnet 5 of FIG. 1 is cylindrically formed by the permanent magnet pieces 5a and 5b via the spacers 12a and 12b formed of a non-magnetic material, and forms the outer cylindrical surface of the first permanent magnet 5. The magnetic pole faces 5b are configured to have the same polarity. In general, the first permanent magnet 5 can be formed by forming various permanent magnet materials into a cylindrical shape and magnetizing the portions of the permanent magnet piece 5a and the permanent magnet piece 5b in the radial direction.

FIG. 16 is a perspective view showing the structure of the second permanent magnets 71, 72 of the fourth embodiment of the cylindrical linear actuator of the present invention shown in FIG. The second permanent magnet 71 forming the mover 3 includes a third permanent magnet 151a,
A second permanent magnet 72 that is configured in a cylindrical shape by the permanent magnet pieces 71a and 71b via 151b and that constitutes the mover 3.
Is cylindrically configured by the permanent magnet pieces 72a and 72b via the third permanent magnets 152a and 152b.

The magnetic pole surfaces of the permanent magnet pieces 71a and 71b, which form the outer cylindrical surface of the second permanent magnet 71, are configured to have the same polarity, and form the outer cylindrical surface of the second permanent magnet 71. Third permanent magnets 151a, 151
The magnetic pole surfaces of b are adjacent permanent magnet pieces 71a and 7a.
It is configured to have a polarity different from that of 1b.

The magnetic pole surfaces of the permanent magnet pieces 72a and 72b, which form the outer cylindrical surface of the second permanent magnet 72, are configured to have the same polarity, and form the outer cylindrical surface of the second permanent magnet 72. Third permanent magnets 152a, 152
The magnetic pole surfaces of b are the adjacent permanent magnet pieces 72a, 7
2b has a polarity different from that of 2b.

Generally, the second permanent magnet 71 is formed by forming various permanent magnet materials into a cylindrical shape, and the permanent magnet pieces 71a and 71b are formed.
And a portion forming the third permanent magnets 151a and 151b may be magnetized in different directions in the radial direction. Second permanent magnet 7
Also in No. 2, it is configured similarly.

Center yoke 4 and side yoke 6
Is formed of various magnetic materials having excellent magnetic properties, and if necessary, heat treatment is performed to improve the magnetic properties.

The bearing 15 is formed of a linear ball bearing or various solid bearing materials having lubricity mainly in a cylindrical shape, and the inner cylindrical surface of the bearing 15 is fixed to a part of the winding holding member 10 by the shaft 14. It has a structure that smoothly slides on the outer cylindrical surface of. In general, the bearing 15 can be integrally formed with the winding holding member 10 by a synthetic resin having a low contact resistance such as PPS.

In general, in the cylindrical linear actuator shown in FIGS. 1 to 16, the side yoke 6 and the center yoke 4 formed by a plurality of members are formed by a magnetic metal such as electromagnetic soft iron or carbon steel. Is
Each of them is mechanically and magnetically connected by press fitting or screws, etc., but is usually integrally formed by sintering of metal having good magnetic characteristics or lost wax.

The mover 3 is usually constructed by winding a predetermined number of strands around the winding holding member 10 to form the winding 9. However, the winding 9 formed by the self-bonding wire is made of various synthetic resins. By insert molding, the winding 9 and the winding holding member 10 can be integrally formed and configured.

[0061]

As described above, the cylindrical linear actuator of the present invention makes it possible to regulate the displacement of the mover in the circumferential direction, and has the following effects. . (1) Regardless of the position in the axial direction, a self-holding force in the circumferential direction is applied to the mover 3 to regulate the displacement of the mover 3 in the circumferential direction, thereby simplifying and lowering the cost of the bearing device. It will be realized. (2) The self-holding force in the axial direction is applied to the mover 3 at both ends of the effective stroke. That is, when the movable element 3 exceeds the range of the effective stroke during the operation of the cylindrical linear actuator of the present invention, the attraction force which opposes the moving direction of the movable element 3 acts, and the following effects are obtained. (A) Preventing the mover 3 from descending when not energized or moving the mover 3
It is possible to reduce the spring constant of the spring mounted for the purpose of returning to the non-energization state. (B) The slowdown operation becomes easy with respect to the movement of the effective stroke. (C) When the stroke exceeds the effective stroke, the thrust is extremely reduced, so that it is possible to reduce the impact on the stopper or the like at the end portion in the moving direction. (4) By superposing the magnetic field of the second permanent magnet mounted on the mover 3 on the magnetic field formed in the cylindrical void 8 constituting the stator 2, the magnetic field in the cylindrical void 8 is increased,
The thrust can be increased. (5) It is possible to concentrate the magnetic flux in the cylindrical air gap 8 on the windings forming the mover 3, and increase the thrust force. (6) In the conventional cylindrical linear actuator, although a part of the magnetic flux at the end of the permanent magnet forming the stator 2 becomes a leakage magnetic flux to reduce the thrust, the cylindrical linear actuator of the present invention In this case, the leakage magnetic flux is extremely reduced, and the linearity of thrust within the range of the effective stroke is improved.

[Brief description of drawings]

FIG. 1 is a perspective sectional view for explaining the structure of a conventional linear actuator.

FIG. 2 is a sectional view for the purpose of explaining the configuration of magnetic flux of the conventional linear actuator shown in FIG.

FIG. 3 is a layout diagram of permanent magnets for the purpose of explaining the operation principle of the linear actuator of the present invention.

4 (a) to 4 (e) are ee cross-sectional views of FIG. 3 for the purpose of explaining the operating principle.

FIG. 5 is a perspective sectional view showing a first embodiment and a second embodiment of the linear actuator of the present invention.

FIG. 6 is a perspective view of a permanent magnet constituting the stator of the first embodiment of the linear actuator of the present invention shown in FIG.

FIG. 7 is a perspective view of a permanent magnet constituting the mover of the first embodiment of the linear actuator of the present invention shown in FIG.

FIG. 8 is a layout view of a permanent magnet constituting a mover and a permanent magnet constituting a stator of the first embodiment of the linear actuator of the present invention shown in FIG.

FIG. 9 is a perspective view of a permanent magnet constituting a stator showing a second embodiment of the linear actuator of the present invention shown in FIG.

FIG. 10 is a perspective view of a permanent magnet constituting a mover showing a second embodiment of the linear actuator of the present invention shown in FIG.

FIG. 11 is a sectional view showing a third embodiment of the linear actuator of the present invention.

FIG. 12 is a perspective sectional view of a permanent magnet constituting the stator of the linear actuator of the present invention shown in FIG.

13 is a perspective view of a permanent magnet constituting the mover 3 of the linear actuator of the present invention shown in FIG.

FIG. 14 is a sectional view showing a fourth embodiment of the linear actuator of the present invention.

FIG. 15 is a perspective view of a permanent magnet constituting the stator of the linear actuator of the present invention shown in FIG.

FIG. 16 is a perspective view of a permanent magnet constituting a mover of the linear actuator of the present invention shown in FIG.

[Explanation of symbols]

 2 stator 3 mover 4 center yoke 5 first permanent magnets 5a, 5b, 5c, 5d permanent magnet piece 6 side yoke 7 second permanent magnets 7a, 7b, 7c, 7d permanent magnet piece 8 cylindrical void 9 winding wire 10 winding holding member 11 terminal 12a, 12b, 12c, 12d spacer 13a, 13b, 13c, 13d spacer 14 shaft 15 bearing 20a, 20b flat plate permanent magnet 21 flat plate permanent magnet 51 first permanent magnet 51a, 51b Permanent magnet piece 52 First permanent magnet 52a, 52b Permanent magnet piece 71 Second permanent magnet 71a, 71b Permanent magnet piece 72 Second permanent magnet 72a, 72b Permanent magnet piece 141a, 141b Third permanent magnet 142a, 142b Third permanent magnet 151a, 151b Third permanent magnet 152a, 152b Third permanent magnet

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[Procedure amendment]

[Submission date] May 16, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

4 (a) to 4 ( c ) are ee cross-sectional views of FIG. 3 for the purpose of explaining the operating principle.

Claims (3)

[Claims] 1. A stator formed in a cylindrical shape by at least one or more yokes and a first permanent magnet forming a fixed magnetic circuit, and an opening formed in one end of the stator in the axial direction. And a winding having a cylindrical space having a cylindrical space and a structure capable of moving in the cylindrical space in the axial direction through the opening, and having a cylindrical space capable of housing a part of the stator therein. In a cylindrical linear actuator including a mover configured in a cylindrical shape by a wire holding member, a magnetic field formed by the first permanent magnet in a radial direction in the cylindrical gap is circumferentially spaced by a predetermined distance. The first permanent magnets are arranged so that at least one or more of them are formed apart from each other, and a magnetic field having the same directionality as the magnetic field formed by the first permanent magnets is further provided in a part of the mover, At a predetermined interval in the circumferential direction A cylindrical linear actuator, characterized in that it is equipped with at least one or more second permanent magnets so that at least one or more is formed. 2. At least one or more of the first aspect, wherein at least one of a stator and a mover forming a magnetic field formed at a predetermined interval in a circumferential direction is provided with a first portion in a portion forming the interval. 3. The cylindrical linear actuator according to claim 2, wherein the third permanent magnet is mounted so that a magnetic pole surface having a different polarity from the magnetic pole surface of the permanent magnet or the second permanent magnet is adjacent. 3. The first permanent magnet or the first permanent magnet or the first permanent magnet is provided in a portion of the stator and the mover, which forms a magnetic field formed at a predetermined interval in the circumferential direction at least one of the stator and the mover. The cylindrical linear actuator according to claim 1, wherein the third permanent magnets are mounted so that the magnetic pole surfaces having a different polarity from the magnetic pole surfaces of the second permanent magnet are adjacent to each other.