JPH0691733B2 - Magnetic drive - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to an improvement of a magnetic drive device that uses magnetic force to perform non-contact drive.

[Prior art]

In the recent semiconductor industry, vacuum application equipment is used in many manufacturing processes. Vacuum is also used for magnetic recording, optical recording, display elements, etc., and vacuum technology is also required for vacuum furnaces and vapor deposition. These vacuum application errors and the mechanism for performing various tests, inspections, and other operations in the research and development work in a vacuum container that is shielded from the outside air under conditions that do not impair the high vacuum degree. Therefore, a non-contact drive is required. In a device that uses magnetic force to perform non-contact drive,
It is desirable that the linear advance and retreat along an axis and the rotation about that axis can be done individually or simultaneously and that the drive control is precise.

[Problems to be Solved by the Invention]

In view of the above demands, the object of the present invention is to provide a magnetic drive device capable of accurately performing a rotational movement about a certain axis and a forward / backward movement along the axis separately or independently. Especially.

[Means for Solving the Problems]

A first aspect of a magnetic drive device of the present invention is to movably enclose a ferromagnetic core inside a cylinder made of a non-magnetic material and to place a magnetic structure outside the cylinder, and to arrange the external magnetic structure along the surface of the cylinder. In a magnetic drive device configured to move the ferromagnetic core by rotating around the cylinder axis and rectilinear motion parallel to the cylinder axis, the ferromagnetic core is connected to the rotor core of the motor. The two or more shaped parts are magnetically connected to each other with a ferromagnetic material around the axis, and the external magnetic structure corresponds to the shape of the stator core of the motor. Prepare the same number of rotor core-shaped parts, arrange ring-shaped magnets between them and integrate them, and divide them into two or more in terms of the radial cross section and axial cross section of the cylinder, and correspond to each other by separating the cylinder. A pair of magnetic poles at different positions is formed, thereby generating a plurality of loop magnetic circuits adjacent to each other in the radial cross section and the axial cross section, thereby enabling precise control of rotational force and thrust. It is characterized by According to a second aspect of the present invention, a ferromagnetic core is movably contained inside a cylinder made of a non-magnetic material, and a magnetic structure is placed outside the cylinder. In a magnetic drive device configured to move a ferromagnetic core by performing a rotational motion centered on and a rectilinear motion parallel to the axis of a cylinder, a part of the ferromagnetic core has a disk shape. 2 or more of them, each of which is magnetically connected around the axis with a ferromagnetic material, and a part of the external magnetic structure having a ring shape corresponding thereto Prepare the same number of parts, and arrange ring-shaped magnets between them to form an integrated unit, and form a set of magnetic poles that are divided with respect to the axial cross section of the cylinder and are separated from each other in the cylinder, and that correspond to each other, Thereby the axial cross-section odor In addition to generating an infinite number of loop-shaped magnetic circuits, the remaining part of the ferromagnetic core is composed of parts that have a cross section of the rotor core of the motor and extend in the axial direction, and a spacer is provided between the part and the part. The external magnetic structure is made up of parts that have a cross section of the stator core of the corresponding motor and have a shape that extends in the axial direction, and are placed with a spacer between them and the radius of the cylinder. A set of magnetic poles that are divided into two or more with respect to the directional cross-section and are located at corresponding positions with each other across a cylinder is formed, thereby generating an infinite number of loop-shaped magnetic circuits in the radial cross-section, and precise control of rotational force and thrust force is possible. It is characterized by being able to perform. As the material of the ferromagnetic core, commonly used iron or its alloy, especially electromagnetic mild steel may be used, and the spacer may be made of non-magnetic metal or alloy such as stainless steel or brass. The material of the magnets and poles is also optional, alnico,
It can be selected from rare earth alloys and other ferromagnetic alloys, or various ferrites.

[Work]

The first aspect will be described with reference to the drawings.
As shown in FIG. 3 to FIG. 3, a cylinder 1 made of a non-magnetic material is extended, a magnetic structure 3 is provided on the outside, a ferromagnetic core 2 is provided inside, and an operating lever 4 is fixed at the center thereof. Has been done. The ferromagnetic core 2 has two or more portions (7 in the figure) having the shape of a rotor core of a motor having an appropriate number of poles (6 poles in the figure).
Each of them is magnetically connected with a ferromagnetic material around each axis. This, of course, may be machined from a single piece of material. On the other hand, in the external magnetic structure 3, the same number of magnetic poles 31 having a stator core shape as the number of poles corresponding to the above-mentioned ferromagnetic core 2 are prepared, and the ring-shaped magnet 33 is arranged between them. And become one. The direction of magnetization of these magnets is
The pattern illustrated in FIG. 3A may be followed. Reference numeral 7 is a case for integrally forming the external magnetic structure. Explaining the operation of the device having the above structure, magnetic flux as shown in FIGS. 4A and 4B is formed between the external magnetic structure 3 and the ferromagnetic core 2, and these magnetic fluxes are mutually formed in the axial section. It becomes a large number of adjacent loop magnetic circuits. By forming such a magnetic circuit, the magnetic driving force is strengthened, and when a slight deviation occurs in the axial direction or the radial direction between the magnetic poles facing each other from the inside and the outside across the cylinder,
A strong force that eliminates the gap works. In this way, when the external magnetic structure 3 is moved in the axial direction, the poles divided and arranged in the axial direction of the ferromagnetic core 2 inside the cylinder follow it and move forward and backward at will. Yes, on the other hand, when rotating the external magnetic structure,
Circumferentially divided poles of the ferromagnetic core follow and move, allowing rotation in any direction. It is of course optional to perform forward / backward rotation and forward / reverse rotation at the same time. In the second aspect of the present invention described above, as shown in FIGS. 5 to 8, the ferromagnetic core 5 has two or more portions 51 having a disc shape which is not divided in the circumferential direction. (4 in the figure
A thrust-generating portion 5A that is magnetically connected to each other by a ferromagnetic material around the shaft, and a ferromagnetic body 55 having the shape of a rotor core of a motor that extends in the axial direction. It consists of the generation part 5B. The external magnetic structure 6 that drives the non-magnetic material cylinder by driving the cylinder is adapted to the shape of the ferromagnetic core 5, and the same number of annular magnetic poles 61 as the disk is prepared. Then, a thrust generating portion 6 is formed by arranging ring-shaped magnets 63 between them and integrating them.
A, and a number of magnetic poles 65 extending in the axial direction corresponding to the shape of the rotor core are prepared, and a magnet 66 having a shape in which a cylinder is divided is arranged between the magnetic poles 65 to integrate the magnetic force.
It consists of 6B. Both the ferromagnetic core 5 and the external magnetic structure 6 are provided with an appropriate gap between the thrust generating portions 5A and 6A and the rotational force generating portions 5B and 6B with spacers 5C and 6C made of a non-magnetic material. Prevent interference. The difference between this device and the above-mentioned embodiment is that a part for only rotating force and a part for only thrust are provided separately. As a result, both the forward and backward movements and the rotation can be controlled more precisely. The reason is that when looking at the thrust first, since the disk-shaped ferromagnetic body 51 and the annular magnetic pole 61 closely correspond to each other over the entire circumference, a high-density magnetic flux is applied in the circumferential direction. Can be focused on average, ensuring a large driving force and a short response time. Moreover, since this magnetic flux is not affected by rotation at all, even in motion involving rotation,
The above effects are secured. With respect to rotation, it is even more advantageous as can be seen by comparing the magnetic flux shown in FIG. 8 with FIG. 4B. Since the rotor iron core-shaped ferromagnetic body 51 and the magnetic poles 61 which are long in the axial direction and correspond to the poles thereof closely correspond to each other at a long distance without being divided in the axial direction, a magnetic flux of high density is generated here as well. Can be focused on average in the axial direction,
After all, a large driving force and a short response time are guaranteed. The fact that the magnetic flux that drives the rotation is not affected by the forward or backward movement at all is similar to the fact that the magnetic flux that gives the thrust is not affected by the rotation. The driving force of the device of the present invention is naturally determined by factors such as the magnitude of the available magnetic flux and the distance between the ferromagnetic core and the external magnetic structure. Therefore, in any of the first and second aspects described above, in order to obtain the desired thrust force and rotational force, particularly when the magnitude of the driving force required by the thrust force and the rotational force is different, the strength is increased accordingly. The shape and size of the magnetic core and the external magnetic structure should be selected and designed. Also regarding this design and manufacture, the second aspect in which the thrust and the rotational force are separately provided is advantageous, and by simply adjusting the axial lengths of the thrust generating portion and the rotational force generating portion, A desired combination of thrust and rotational force is easily realized.

【The invention's effect】

The magnetic drive device of the present invention can obtain a strong drive force in both the rotational force about the shaft and the thrust in the axial direction by the action mechanism described above, and precisely control the rotation and forward / backward with a short follow-up time. Can be done. In the second aspect, the rotation and the forward and backward movements can be performed without mutual influence. Although the above description has focused on a non-contact drive mechanism used in a vacuum device, the present invention is not limited to this, and for example, a valve used for a flow path of a radioactive liquid or a harmful liquid, etc. However, it can be used as a drive mechanism for equipment that is extremely leak-proof, and has a wide range of applications.

[Brief description of drawings]

FIGS. 1 to 4 show a first example of the device of the present invention, FIG. 1 is a cross-sectional view taken along the line II of FIG. 2, and FIG. 2 is FIG. 2 is a longitudinal sectional view taken along line II-II of FIG. 3, FIGS. 3A and 3B are exploded perspective views of a main part of the apparatus, and FIGS. 4A and 4B are enlarged sectional views illustrating the operating principle of the apparatus. . FIGS. 5 to 8 show a second example of the device of the present invention, FIG. 5A is a cross-sectional view taken along the line VA-VA in FIG. 6, and FIG. 5B is the same. FIG. 6 is a horizontal cross-sectional view at the VB-VB position, FIG. 6 is a vertical cross-sectional view at the VI-VI position of FIGS. 5A and 5B, and FIGS. 7A and 7B are exploded perspective views of the main part of the apparatus. , FIG. 8 is an enlarged cross-sectional view corresponding to FIG. 4B for explaining the operation principle of the device. 1 …… Cylinder of non-magnetic material 2 …… Ferromagnet core 21 …… Ferromagnet 3 …… External magnetic structure 31 …… Magnetic pole, 33 …… Magnet 4 …… Operating lever 5 …… Ferromagnet core 5A… … Thrust generation part, 5B …… Rotation force generation part 6 …… External magnetic structure 6A …… Thrust generation part, 6B …… Rotation force generation part 5C, 6C …… Spacer 7 …… External magnetic structure case

Claims (4)

[Claims] 1. A ferromagnetic core is movably contained inside a cylinder made of a non-magnetic material, and a magnetic structure is placed outside the cylinder, and the outer magnetic structure is centered on the axis of the cylinder along the surface of the cylinder. In a magnetic drive device configured to move a ferromagnetic core by rotating motion and rectilinear motion parallel to the axis of a cylinder, the ferromagnetic core has two or more parts having the shape of a rotor core of a motor. , Around each of the axes is magnetically connected with a ferromagnetic material,
Prepare the same number of parts that the external magnetic structure has the shape of the stator core of the motor corresponding to this, and arrange the ring-shaped magnets between them to form an integrated structure. Forming a set of magnetic poles that are divided into two or more with respect to a radial cross section and an axial cross section and that correspond to each other across a cylinder, thereby generating a plurality of loop magnetic circuits adjacent to each other in the axial cross section,
A device characterized by enabling precise control of rotational force and thrust. 2. The magnetic drive device according to claim 1, wherein the inside of the cylinder made of a non-magnetic material is evacuated. 3. A ferromagnetic core is movably included inside a cylinder made of a non-magnetic material, and a magnetic structure is placed outside the cylinder, and the external magnetic structure is centered on the axis of the cylinder along the surface of the cylinder. In a magnetic drive device configured to move a ferromagnetic core by rotating and linearly moving in parallel to the axis of a cylinder, a part of the ferromagnetic core is made up of two or more parts having a disk shape. , The parts around the axis are magnetically connected with a ferromagnetic material, and a part of the external magnetic structure has the same ring-shaped parts as the above-mentioned disk-shaped parts. Prepared, and arranged ring-shaped magnets between them to form a unit, and to form a set of magnetic poles that are divided with respect to the axial cross section of the cylinder and are located at mutually corresponding positions across the cylinder. Innumerable Le in cross section In addition to generating a loop-shaped magnetic circuit, the remaining part of the ferromagnetic core is composed of a part that has a cross section of the rotor core of the motor and extends in the axial direction, and is placed with a spacer between it and the part. , The remaining part of the external magnetic structure is constituted by a part having a cross section of the stator core of the corresponding motor and extending in the axial direction, and is placed via the above part and a spacer, and the radial cross section of the cylinder is 2 or more. A pair of magnetic poles that are divided into two parts and are located at corresponding positions across a cylinder are formed, thereby generating innumerable loop-shaped magnetic circuits in the radial cross section, and precise control of rotational force and thrust force can be performed. A device characterized by the above. 4. The magnetic drive device according to claim 3, wherein the inside of the cylinder made of a non-magnetic material is evacuated.