JPS6353315A - Bearing device for rotary shaft - Google Patents

Abstract

PURPOSE:To support a rotary shaft while keeping it magnetically floated so as to obtain the long service life of an electric motor, by separating magnetic resiliency for performing the locating regulation in the radial direction of the rotary shaft from magnetic resiliency for regulating the movement in the axial direction so as to perform the locating regulation. CONSTITUTION:A magnet 8 in a cylindrical shape has a rotary shaft 1 mounted through its center hole and has the disks 6 and 7 attached on its both sides. The magnet 8 is rotated synchronously with the rotary shaft 1. The periphery of a magnet 5 is fitted along inside face of a projecting hole 2a. The resiliency is generated because the mutually facing magnetic poles are in the same polarity. Therefore, the peripheries of the disks 6 and 7, and the magnetic poles on the both sides of the magnetic 5 are kept in the predetermined air length so that they make no contact with each other. A cylindrical magnet 9 is fitted along the inner periphery of a projecting hole 2b on the other side of a housing 2. When the rotary shaft 1 is moved to the right, the magnetic 9 and the disk 10 are accessed each other, and the resiliency is increased so that the rotary shaft 1 is restored in the predetermined position.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is utilized for a rotating shaft and its bearing in a clean room where scattering of oil is avoided.

It is also used as a bearing for the rotor of the electric motor that is the driving source of the polygon mirror that reflects and scans the laser beam. Since such a mirror rotates at a rate of about -10,000 times per minute, there is a drawback that the life of the bearing is short. According to the present invention, since there are no worn parts, a long life can be obtained.

When used as a bearing for a rotating body, it has a long life and does not generate mechanical noise, so it can be used in equipment that meets such requirements.

[Conventional technology]

The technology that has been put into practical use consists of a rotating shaft made of a magnetic material, electromagnets facing each other in the X and Y directions, and a sensor that detects the deviation of the rotating shaft in the X and Y directions to control the energization of the excitation coil of the electromagnet using a servo control. There are devices that control and hold the rotating shaft in a predetermined position.

Another known method is to use magnetic repulsion between like poles of magnets to hold the rotating shaft in a predetermined position.

[Problems to be solved by the present invention] Since devices that use electromagnets utilize magnetic attraction, the device becomes large, and the magnetic attraction is in unstable equilibrium, making the servo device expensive. There is a first problem.

The second problem with the means using magnets is that no examples have been put into practical use because the equilibrium effect is unstable.

Means for Solving Problem C] The first problem is solved because the magnetic repulsion of the same polarity of the magnet is used to hold the rotating shaft.

Also, to hold one end of the rotating shaft, that! The following means are employed to control the position only in the vertical radial direction by the magnetic repulsion of a magnet or electromagnet and to hold the other end of the rotating shaft.

That is, the magnetic repulsion force for regulating the radial position perpendicular to the axial direction of the rotating shaft and the magnetic repulsive force for regulating the axial movement of the rotating shaft are substantially separated.

Because of the above configuration, the position regulation of the rotating shaft is stable and the second
problems have been resolved. If necessary, a small electric stone may be used in some cases, but since a servo device is not required, it can be made small and inexpensive.

[Effect]

According to the above-described means of the present invention, the rotating shaft is held in a predetermined position by the magnetic repulsion of the magnet or electromagnet, so an expensive servo device is not required and there are no parts that wear out, resulting in a long service life. can get.

Since no oil is used, it can be used in clean rooms. Also, high speed rotation is possible.

The action is stable because the magnetic repulsion of the magnet is used to restrict the movement of the rotating shaft in the axial direction and the radial movement perpendicular thereto, thereby holding the rotating shaft in a predetermined position.

〔Example〕

Next, details of the apparatus of the present invention will be explained with reference to embodiments shown in the drawings. Components with the same symbols in the drawings are the same members, so a redundant explanation will be omitted.

FIG. 1 shows the case where the device of the present invention is applied to a semiconductor motor. The dotted line C indicates the outside of the electric motor, and protruding holes 21°λb are provided on both sides of the dotted line C, and bearings 41. j is fitted.

A rotating shaft l is supported by the bearings <z, , r.

The dotted line symbol 3 is a magnet rotor of the electric motor for generating driving torque, which is fixed to the rotating shaft l and serves as its load.

FIG. 2 shows details of the bearing 9.3 described above. The load 3 on the rotating shaft / is omitted, the bearing q is shown on the left, and the bearing S is shown on the right.

The magnet) f has a cylindrical shape, and a rotating shaft / is fitted into its center hole. A ferrite magnet is used as the magnet, but other types of magnets may be used. In addition, all of the drawings show cross sections, and the magnets are dotted portions, and the hatched portions are other members.

A magnet g1 disk 6.7, to which mild steel (magnetic material) disks 6 and 7 are attached on both sides of the magnet g, rotates 1. f
It is configured to rotate in synchronization with +/.

The shorter the length of the arrow A, the more effective the magnetic flux will be concentrated on the outer peripheral surface of the disk 7.

The circumstances described above are exactly the same for disc B.

Since the magnet g is magnetized to N and S poles as shown in the figure, the outer peripheral surfaces of the discs 6 and 7 have N and S poles, respectively, as shown.

It can be made by pressing a mild steel plate with holes.

On the inner surface of the protruding hole α, a magnet of the polarity shown in the figure)r(
It is cylindrical. ) is fitted.

Since the opposing magnetic poles shown in the figure are of the same polarity, a repulsive force acts, and the outer periphery of the disk 6.7 and the magnetic poles on both sides of the magnet S are held at a set gap length and do not come into contact with each other. There isn't.

At the right end of the rotation axis l, there is a cylindrical magnet/2° and a mild steel disk 10 which becomes its yoke. // are fixed to rotate synchronously.

Disc 10. The outer periphery of // has a cross section of ttS as shown in the figure.
The slope is slanted to a certain degree. In other words, it is a part of a conical surface.

The magnetic poles are N and S poles as shown.

As shown in FIG. 1, the symbol b indicates a protruding hole on the right side of the outer casing, into which the outer periphery of the cylindrical magnet 9 is fitted. magnet? magnetic pole and disk 10,1
The gap lengths of the opposing surfaces of / are made equal to each other.

As shown in the figure, the magnetic poles of the magnet) 9 and the disc 10, 1/ are all opposite to each other.

FIG. 3 shows only the above-mentioned magnetic pole faces as line segments. The symbol of each line segment indicates each magnetic pole face in FIG. That is, the line segment S1, 5b indicates the magnetic pole surface of the magnet) 5, and the line segment SC.

! d is magnets) 5 line segment 3I! , 6b shows the magnetic pole surface at a symmetrical position.

Line segments 4a and 7G indicate the magnetic pole surfaces of disks A and 7, and line segment 1
h and qh indicate magnetic pole faces located at symmetrical positions on the disk 6.7.

Sunspot 511. ! rf, rg, 5h and lsc, 7C.

6cL and 7a indicate the center of each line segment, and it is thought that N, 5 magnetic poles are concentrated at this point.

Line segments qa and qh and line segments 9C and 9d are in symmetrical positions,
Line segments qrL, qh and 9c, 9d are magnets)? shows each magnetic pole face.

Line segments 1011 and 10b indicate the magnetic pole faces at symmetrical positions on the disk 10 in FIG. 2, and lines //rL and //b indicate the magnetic pole faces at symmetrical positions on the disk //. It shows.

Black points 9t, 9f, g, and qh are line segments qc.

Deh, shows the center point of 9c, 9d, black point 10C110
d and the black dots //c, //ti indicate the center points of the line segment 101°101) and the line segment //4, //l), respectively.

Each black spot is considered to be a point where the N and S poles of each magnetic pole are concentrated. A dotted line C indicates the rotation axis I.

Rotating shaft 6. ' moves in the direction of arrow Y, the black points 5 and l
, c and the sunspots 3f and 7C are close to each other, so that the repulsive force increases, while the sunspots 6d and 5g and the sunspots 7d and 54 are spaced apart, so that the repulsive force decreases. When the rotation 114bC moves in the opposite direction to the Y direction, the increase/decrease in repulsive force between each sunspot is also reversed. Therefore, the rotation axis C returns to the predetermined position.

The rotating shaft C is magnetically levitated and rotates without contact. When the rotation axis C moves in the direction of the arrow Y, the black point zero and 10
Since e and the sunspots 9f and //e are close to each other, the repulsive force increases, and because the sunspots io t and 9g and the sunspot /l (t and 91 are spaced apart, the repulsive force decreases.

When the rotation i11]C moves in the opposite direction of the arrow Y, the increase/decrease in the repulsive force between the sunspots is reversed. Therefore rotation +111c
returns to its predetermined position.

When the rotation axis C moves in the direction of the arrow X, the black points qe and i
Since o c and sunspots A and 10 d are close to each other, the repulsive force increases, and because sunspots qf and llC and sunspot //d and 91 are spaced apart, the repulsive force decreases.

When the rotation axis C moves in the opposite direction of the arrow X, the increase/decrease in the repulsive force between the sunspots is reversed.

Therefore, the rotation axis C returns to the set position, magnetically levitates, and can rotate without contact.

The rotating shaft l in Fig. 2 is made of a non-magnetic material, and a magnet g
The magnetic path of 72 and 72 is prevented from becoming a flue path.

Su disc 1. ,7,10. The same effect can be obtained even if /l is used as a magnet, and after magnetization, /2 is closely attached to the magnet as shown in the figure. In case of trouble, magnets) t, /l
The same effect can be obtained by using a mild steel cylinder as a simple magnetic path.

What is shown in FIG. 1 is an embodiment in which an electromagnet is used in place of the magnet 90 of the magnetic bearing on the right side of FIG.

In FIG. 9(α), a disc-shaped magnet Nα, 23h whose outer periphery is a slope of about 100 degrees, and a mild steel cylinder 23 are fitted onto a rotating shaft lK and rotate synchronously.

Magnet) 2J4 is magnetized so that the outer peripheral slope part is the north pole and the center part on the right side is the south pole.

Magnet) Uj h is magnetized so that the outer peripheral slope part becomes the S pole and the center part on the left side becomes the N pole.

An excitation coil /3b (cylindrical VC resonator) is attached to the soft steel magnetic core 13. Excitation then rotating shaft/
In addition, the magnetic bearing rotor (indicated by symbols &, ?, and t in Fig. 2), the magnetic rotor 3 (shown in Fig. 1), and the rotor (Fig. 1 (ql symbols 23.23i, 2Jh) )
It can be assembled by fixing and then press-fitting it. In this case, the diameter of the protruding holes 2b is made larger than the diameter of the magnet rotor.

Magnetic core /3, /,3'L S, N pole and magnet 2
．． jh.

Since the S and N poles of 231 face each other, and the opposing surface is a slope, the rotating shaft l floats due to magnetic repulsion and becomes a magnetic bearing, as in the case of Fig. 2, and the effect is also the same. It is.

By the same means, an electromagnet can be used instead of the magnet S on the left side of FIG.

FIG. 7(b) shows another embodiment of the magnetic bearing on the right side of FIG.

In FIG. 7(h), cylindrical magnets)/u, 1 m magnetic discs 10, -D are fixed to the rotating shaft l so as to rotate synchronously.

The magnet/U is magnetized with KN and S poles in the axial direction.

Therefore, the magnetic disk 10. The magnetic poles on the outer periphery of D are concentrated at 5 as shown in the figure, on the right side in the case of the disk 10, and on the left side in the case of the disk //.

A cylindrical magnet/da is fitted inside the protruding hole λb, and is magnetized so that both sides of the inner peripheral surface have iV and S poles.

Regarding the movement of the rotation axis in the Y direction, magnet /lI and disk 10. Due to the repulsive force of the magnetic poles of the same polarity, it floats in equilibrium at the position shown in the figure.

The magnet/S is magnetized with the polarity shown, and the magnet/left has a cylindrical shape and is fitted onto the inner peripheral surface of the magnet IQ.

Regarding the movement of the rotation axis in the X direction, the magnet/left and the disk 10. It is balanced by the repulsive force of the same polarity of // and floats to the position shown in the figure.

Therefore, it has the same effect as the magnetic bearing on the right side of FIG. 2.

Instead of magnet /2 - use a mild steel cylinder, disk 1
0. The same effect can be obtained by using a disc-shaped magnet as in the embodiment shown in FIG. 7(-L).

What is shown in FIG. 3 is another embodiment that has the same effect as FIG. 7(h).

In FIG. 5, the rotation axis lK is a magnetic disk /'), 1
g, /9 and cylindrical magnet /A, 22 are arranged as shown in the figure and configured to rotate together synchronously. magnets)/A, u is N in the axial direction as shown in the diagram.
, the S pole is magnetized.

Inside the protruding hole 2h of the outer casing is a cylindrical magnet)
The outer periphery of is fitted, and both sides of the inner peripheral surface are magnetized to N and S magnetic poles.

The outer periphery of the cylindrical non-magnetic material support 2/1 has a protruding hole 2b.
A cylindrical magnet 2/ is fitted onto the inner peripheral surface of the magnet, and both end surfaces thereof are magnetized to N and S poles.

Regarding the movement of the rotation axis / in the Y direction, magneso), 2
Equilibrium is maintained by the repulsive force of the same polarity between 0 and the disk /'/, /g, and for movement in the X direction, equilibrium is maintained by the repulsive force of the same polarity of the magnet)2/ and the disk /g, /9. The rotation axis l floats up while being held. Therefore, it is a magnetic bearing.

The smaller the length of the arrow 1, that is, the part of the disc/7.1g that protrudes from the magnet nol, the greater the magnetic repulsion (
and is valid.

The same purpose can be achieved even if the disk it is divided at points indicated by dotted lines. Also, as in the embodiment shown in Fig. 7, the magnets/L and 2 are made of mild steel cylinders, and the disks/7, 1g (divided by dotted lines)/9.
It can also be implemented as a magnet.

〔effect〕

As can be seen from the above embodiments, there is an effect that the rotating shaft can be magnetically levitated and supported from its support body without consuming any power or with a small amount of power. Semiconductor motors are made by removing brushes and commutators to create stable and long-life motors, but with the device of the present invention, the shaft bearings, which are the only wear parts, can be removed, making it even more stable and long-lasting. There is an effect that can be obtained.

Furthermore, since it can be performed at high speed, it has the effect of finding a wide range of uses. It also has the effect of eliminating mechanical noise.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram when the present invention is applied to an electric motor, FIG. 2 is an explanatory diagram of a cross section of the device of the present invention, FIG. 3 is an explanatory diagram of the operation of the device of the present invention, and FIG. and FIG. 5 respectively show sectional views of other embodiments of the device of the present invention. /, c...rotation axis, j, j4. B... Outer casing and protruding holes on both sides, 3... Magnet rotor, Ge,
j...borium bearing, A, ? , 10. //,
/the law of nature. /I, /9... basal body disc, S, 9. Za, /2
, /41°/! ;, 2D, 2/, /A, 2
-1... Cylindrical magnet, /, 3. '/3LL...
・Magnetic core, /,? h...excitation coil,
2J b...disc-shaped magnet, 2/shin...cylindrical support, , 23...mild steel cylinder.

Claims (3)

[Claims] (1) A rotating shaft and a load fixed to a part thereof, and a magnetic pole fixed to one end of the rotating shaft and rotating synchronously, with one side of the circumference serving as a north pole and the other side serving as a south pole. The magnetic rotor 1 has a cylindrical shape with the outer side fixed to the main body, and the magnetic poles on the inner circumferential surface of the magnetic rotor are opposite to the above-mentioned N and S poles with an air gap between them, and the magnetic rotor between the same poles is A first stator that suppresses radial movement perpendicular to the axial direction of the rotating shaft and holds it in a set position by repulsive force; It penetrates and rotates synchronously with the rotating shaft, and one side of the circumference is a part of a conical surface and has a north pole with an angle of approximately 45 degrees, and the other side is a part of a conical surface with an angle of approximately 45 degrees inclination. A second magnet rotor is fixed to the main body on the outside and has a cylindrical shape, and the magnetic poles on the inner circumferential surface of the rotor are connected to each other through an air force having a width equal to the above-mentioned N and S poles. Consisting of a second stator with opposing poles and a magnetic repulsion force between the same poles to prevent movement of the rotating shaft in the axial direction and radial direction perpendicular to the axial direction and hold it in a set position. A rotating shaft bearing device characterized by: (2) A rotating shaft and a load fixed to a part thereof, and a magnetic pole fixed to one end of the rotating shaft and rotating synchronously, with one side of the circumference serving as a north pole and the other side serving as a south pole. The magnetic rotor 1 has a cylindrical shape with the outer side fixed to the main body, and the magnetic poles on the inner circumferential surface of the magnetic rotor are opposite to the above-mentioned N and S poles with an air gap between them, and the magnetic rotor between the same poles is A first stator that suppresses radial movement perpendicular to the axial direction of the rotating shaft and holds it in a set position by repulsive force; A third magnet rotor is inserted through the rotor and rotates synchronously with the rotating shaft, and the protruding part on one side of the circumferential part is the N pole and the protruding part on the other side is the S pole, and the outer side is attached to the main body. It is fixed and has a cylindrical shape, and the magnetic poles on its inner circumferential surface face the N and S poles of the third magnet rotor with an air gap between them, and due to the magnetic repulsion between the same poles,
a third stator that suppresses movement in the radial direction perpendicular to the axial direction of the rotating shaft and holds it in a set position; a third stator fixed to the inner peripheral surface of the cylindrical member of the stator; The magnetic poles on both end faces face the N and S poles on the inner surface of the third magnet rotor with a gap in between, and due to the magnetic repulsion between the same poles,
A bearing device for a rotating shaft, comprising a fourth stator that suppresses axial movement of the rotating shaft and holds the rotating shaft at a set position. (3) A rotating shaft and a load fixed to a part thereof, and a magnetic pole fixed to one end of the rotating shaft and rotating synchronously, with one side of the circumference serving as a north pole and the other side serving as a south pole. The magnetic rotor 1 has a cylindrical shape with the outer side fixed to the main body, and the magnetic poles on the inner circumferential surface of the magnetic rotor are opposite to the above-mentioned N and S poles with an air gap between them, and the magnetic rotor between the same poles is A first stator that suppresses radial movement perpendicular to the axial direction of the rotating shaft and holds it in a set position by repulsive force; A fourth magnet rotor is inserted through the rotor and rotates in synchronization with the rotating shaft, and the protrusion on one side of the circumferential part serves as the N-pole magnetic pole, and the protrusion on the other side serves as the S-pole magnetic pole. It is fixed to the main body and has a cylindrical shape, and the magnetic poles on the inner circumferential surface face the N and S of the fourth magnet rotor with the same poles across an air gap, and the magnetic repulsion between the two poles causes the axis of the rotating shaft to A fifth stator that prevents movement in the radial direction perpendicular to the direction and holds it at a set position, and a rotating shaft inserted through the central part, rotates in synchronization with the rotating shaft, and has a circumferential part protruding on one side. The inside of the part becomes the N pole, and the inside of the protrusion on the other side becomes the S pole.
The fifth magnet rotor is fixed to the main body and has a cylindrical shape, and the magnetic poles on both end faces are the N and S poles on the inner surface of the protrusion of the fifth magnet rotor. The same poles face each other through a gap, and due to the magnetic repulsion between the same poles,
A bearing device for a rotating shaft, comprising a sixth stator that suppresses axial movement of the rotating shaft and holds the rotating shaft at a set position.