JPS63225721A - Magnetic bearing - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic bearing that allows rotational movement of one member relative to another.

Such a bearing can allow forward and reverse rotation or continuous rotation of one member relative to the other member within a certain limited range.

[Prior Art] In a conventional magnetic bearing, as shown in FIG. 18, the first member is composed of a cylindrical bar magnet, and the second member is composed of two opposing magnets each magnetized to opposite poles. one side (g)
, 08. Body 0
The two surfaces 07) and aF3 of θ each have a cup-shaped depression 09. The cylindrical bar magnet is attached so that the end face of the south pole enters the cup-shaped recess (to) magnetized to the south pole, and the end face of the north pole enters the cup-shaped recess U magnetized to the north pole. ing. If the magnets are strong enough, the magnetic repulsion of the same poles will support the bar magnet between the cup-shaped indentations (lcl) and no physical contact will occur. When it is not too much, a rotational mounting with small frictional forces is maintained.

[Problems to be Solved by the Invention] However, the above-mentioned bearing has the disadvantage that the cylindrical bar magnet also functions as the shaft and therefore requires the same thickness and thickness as the shaft, making it expensive. There is. In addition, only a small portion of the magnetic field generated by the shaft is utilized for bearing support, making the arrangement of the device inefficient.

[Alternative means for solving the problem] The magnetic bearing of the present invention includes a first magnetic member having a through hole drilled along the direction of the magnetic axis, and a first magnetic member that is loosely fitted into the through hole and has a self-containing structure. and a second magnetic member rotatable around an axis parallel to the magnetic axis, and is characterized in that both magnetic axes are substantially parallel and the magnetization directions of the magnetic axes are in the same direction.

Preferably, the through hole and the second magnetic member have a circular cross section. The through hole and the second magnetic member may have a cylindrical shape, or the center portion may be thicker than both ends.
r), or vice versa, both ends may be thicker than the center. Also, the through hole and the second
The magnetic member may be stepped. In all cases, it is desirable that the shapes of the through hole and the second magnetic member are consistent with each other.

At least one of the first magnetic member and the second magnetic member,
It may be an electromagnet, a permanent magnet, or a combination of an electromagnet and a permanent magnet.

The gap between the first magnetic member and the second magnetic member may be filled with oil, or the opposing surfaces of both members may be lined.

When the first magnetic member and the second magnetic member are permanent magnets, the magnets, and when they are electromagnets, the magnetic cores thereof may be laminated with materials having different magnetic permeability.

[Example] Next, the magnetic bearing of the present invention will be explained based on the drawings.

Figures 1 to 7 are sectional views of different embodiments of the magnetic bearing of the present invention, Figures 8 to 11 are sectional views of the structure of the magnetic bearing shown in Figures 2 to 5, respectively, and Figure 12 is the inside of the bearing. A sectional view of an embodiment of the magnetic bearing of the present invention in which the member is an electromagnet,
FIG. 13 is a sectional view of an embodiment of the magnetic bearing of the present invention in which the external member of the bearing is an electromagnet, and FIG. 14 is a sectional view of an embodiment of the magnetic bearing of the present invention in which both the internal and external members of the bearing are electromagnets. FIG. 15 is a cross-sectional view of an embodiment of a magnetic bearing of the present invention in which opposing surfaces of the inner and outer members of the bearing are lined; FIG. FIG. 17 is a cross-sectional view of an embodiment of the magnetic bearing of the present invention, in which the gap is filled with oil. 1 is a sectional view of an embodiment of a magnetic bearing of the present invention.

As is clear from FIG. 1, the magnetic bearing includes an external permanent magnet (1) which is a first magnetic member, and a through hole (2) in which an internal permanent magnet (3) which is a second magnetic member is disposed. It is composed of The magnetic axes of the outer magnet (1) and the inner magnet (2) are parallel and point in the same direction. In this specification, the magnetic axis is treated as one vector pointing from the south pole to the north pole. This means that the north poles of the outer magnet and the inner magnet are both on one end face of the bearing, and the south poles of the unilateral magnet and the inner magnet are both on the other end face of the bearing. Since the cross section of the through hole ('2J) and the internal magnet (3) are circular, the through hole ('2J) and the internal magnet (3) both have a cylindrical shape.
can freely rotate within the through hole (2).

The magnetic repulsion of the same polarity of the outer magnet (1) and the inner magnet (3) prevents the opposing sides of both magnets from coming into contact, thus providing a low friction bearing.

A low friction bearing maintains its low friction condition unless the load applied to or connected to the bearing member is large enough to overcome the magnetic repulsion.

If the magnetic repulsion force is lost, the opposing surfaces of the bearing will come into contact and contact will occur due to high frictional force.

2 to 7 show various selectable shapes of the through hole (2) and internal magnet (3), but these shapes are not limited to those shown. These shapes are preferred over those shown in FIG. This is because the relative axial movement of the internal magnet (3) with respect to the external magnet (1) is restrained not only magnetically but also physically. A hole passing through the axis of the second magnet (3) (
4) shows one mode in which a load is applied to that part of the bearing. Many other forms of loading internal or external magnets could be employed, but these are obvious and not critical to the invention;
I will not write about them here.

In order to construct a bearing of the type shown in Figures 2 to 7, it is necessary that either the internal magnet (3) or the external magnet (1) be divided into two halves so that they can be combined. For example, in the example shown in FIGS. 8 and 9, the two halves are screwed together. Of course, these two halves may be joined by other methods. For example, in Figure 10,
The two halves of the internal magnet (3) are joined by a hollow bolt (5) inserted into the hole (4), and further by a nut (6).
It shows the state where it is tightened. Figure 11 shows
The two halves of the magnet (1) are connected to the bolt (7) and nut (6).
) shows a configuration that is connected by

So far, we have described the case where permanent magnets are used, but the same effect can be obtained by using electromagnets as either the internal or external magnets, as shown in FIGS. 12 and 13, respectively. FIG. 14 shows a configuration example in which both the internal magnet and the external magnet are electromagnets. The electromagnet may be of a substantially conventional type or of any other suitable type, for example consisting of a winding of superconducting wire. .

FIG. 15 shows a configuration in which the opposing surfaces of the first and second magnets are provided with linings (9). A low-friction material is used in the lining member to ensure low-friction contact even if the internal and external bearing surfaces come into contact due to overload.

The damping function can be changed by injecting oil into the gap between the outer magnet (1) and the inner magnet (3). 16th
The figure shows a configuration where oil is injected into the gap through an opening. In this method, the circulating oil is cooled before being injected to cool the bearing.

To reduce the induction of eddy currents, the outer and inner magnets or, in the case of electromagnets, their covers may be of laminated construction.

In order to be able to vary the strength of the magnetic field lines applied to the bearing and to be able to cope with different load ranges, separate windings 0υ and 02) may be installed, for example as shown in FIG. It may also be incorporated into the outer magnet (1).

To change the magnetic field near the gap between the magnets,
The magnet or magnetic core may also be laminated with materials of different magnetic permeability. This type of modification is particularly useful for preventing axial movement of the inner and outer magnets. - If the bearing is used in a high-temperature environment, or if the bearing rotates at high speed and generates a considerable amount of heat, the entire bearing must be cooled.

Cooling can be achieved by injecting liquid nitrogen into a network of tubes inside one or the other of the bearing members. This method is illustrated in FIG. 17, in which liquid nitrogen is injected through the inlet and exits through the outlet.

It should be understood that bearings of the type described above can be applied wherever ball bearings, bush bearings, air or gas bearings have traditionally been used. These bearings are used in many things such as motors, automobiles, robots, gas turbine engines, power generation turbines, and crushing mills, to name a few.

Although the invention has been described in which both parts of the bearing are magnetic, they do not necessarily have to be. For example, the member may only have a magnetized portion or may simply include a magnet.

[Brief explanation of drawings]

Figures 1 to 7 are cross-sectional views of different embodiments of the magnetic bearing of the present invention, Figures 8 to 11 are cross-sectional views of the structure of the magnetic bearing shown in Figures 2 to 5, respectively, and Figure 12 is the internal member of the bearing. is a cross-sectional view of an embodiment of the magnetic bearing of the present invention in which the external member of the bearing is an electromagnet, FIG. 13 is a cross-sectional view of an embodiment of the magnetic bearing of the present invention in which the external member of the bearing is an electromagnet, and FIG. and FIG. 15 is a cross-sectional view of an embodiment of a magnetic bearing of the present invention in which both the inner member and the outer member are electromagnets. FIG. FIG. 16 is a cross-sectional view of an embodiment of the magnetic bearing of the present invention in which the gap between the internal and external members of the bearing is filled with oil, and FIG. FIG. 18 is a cross-sectional view of an embodiment of the magnetic bearing of the present invention, which is constituted by an electromagnet and is cooled by a low-temperature medium. FIG. 18 is a schematic explanatory view of a conventional magnetic bearing. (Main symbols in the drawings) (1) Second magnetic member (2) Second through hole (3): Second magnetic member patent applicant Nistele Crude and one other person R61 1: First magnetic member 2: Through hole 3: Second magnetic member 1: First magnetic member 1: First magnetic member 2: Through hole 3: Second magnetic member 1: First magnetic member 2: Through hole F/;'', 8 1: First magnetic member 2 : Through hole 1: First magnetic member 1: First magnetic member 2: Through hole 8G, // ?φ book FIG, /2 Drawing tsu, -4- Drawing can (N 1: First magnetic member 2: Through hole 3: Second magnetic member FIG, 15 1: First magnetic member FIG, Stone drawing engraving procedure amendment book type) % type % Relationship with the indication case of 1 case Patent applicant address Commonwealth of Australia, 2 Ellen Press, Ingleburn, South Wales, 6 Name Nistel Crude Nationality Commonwealth of Australia 1 idiot 4 agents 540 5 Date of amendment order February 23, 1985 (Date of dispatch) 7 Contents of amendment ( 1) Replace FIGS. 12-14 and 17 with the "corrected drawings (FIGS. 12-14 and 17)" attached separately. 8 List of attached documents

Claims (1)

[Scope of Claims] 1. A first magnetic member having a through hole drilled along the direction of the magnetic axis, and a first magnetic member that is loosely fitted into the through hole and is rotatable around an axis parallel to its own magnetic axis. A magnetic bearing comprising a second magnetic member, wherein both magnetic axes are substantially parallel and the magnetization directions of the magnetic axes are in the same direction. 2. The magnetic bearing according to claim 1, wherein the through hole and the second magnetic member have a circular cross section. 3. The magnetic bearing according to claim 2, wherein the through hole and the second magnetic member are cylindrical. 4. The magnetic bearing according to claim 2, wherein the center portion of the through hole and the second magnetic member is thicker than the end portions. 5. The magnetic bearing according to claim 2, wherein the end portions of the through hole and the second magnetic member are thicker than the center portion. 6. The magnetic bearing according to claim 2, wherein the through hole and the second magnetic member are stepped. 7. The magnetic bearing according to claim 1, 2, 3, 4, 5, or 6, wherein at least one of the first magnetic member and the second magnetic member is an electromagnet. 8 Claims 1, 2, 3, 4, 5, 6 or 8, wherein the gap between the first magnetic member and the second magnetic member is filled with oil. The magnetic bearing described in item 7. 9 Claims 1, 2, and 3 in which the opposing surfaces of the first magnetic member and the second magnetic member are lined.
The magnetic bearing according to item 1, 4, 5, 6, 7 or 8. 10 Claims 1, 2, 3, 4, and 4, characterized in that the first magnetic member and the second magnetic member include regions laminated with materials having different magnetic permeabilities. The magnetic bearing according to item 5, 6, 7, 8 or 9. 11 Claims 1, 2, 3, 4, 5, 6, 7, wherein at least one of the first magnetic member and the second magnetic member is cooled. Sections 8 and 9
The magnetic bearing according to item 1 or item 10.