JPH11113224A - Magnetizing method of permanent magnet type eddy current reducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a magnetizing method of a permanent magnet type eddy current reducer in which magnetization is performed after magnets are coupled to a magnet retaining ring and built in a guide cylinder. SOLUTION: An even number of magnets 20 before magnetization are coupled to the outer peripheral surface of a magnet retaining ring 19 composed of magnetic substance, at equal intervals in the peripheral direction. A guide cylinder 18 is composed of nonmagnetic substance and has the same number of ferromagnetic plates 21 as the magnets 20, at equal intervals in the peripheral direction. In the guide cylinder 18, the magnet retaining ring 19 is so accommodated that each of the magnets 20 overlaps perfectly with each of the ferromagnetic plates 21. The guide cylinder 18 is arranged in a magnetizing equipment 50 having magnetic poles 53a facing the magnets 20. By applying a DC current to an electromagnetic coil 52 of a magnetic core 53 of the magnetizing equipment 50, the magnets 20 are magnetized from the outer peripheral side of the magnetic retaining ring 19. By pivoting the magnet retaining ring 19, in such a manner that two magnets 20 adjacent in the peripheral direction to each of the ferromagnetic plates 21 of the guide cylinder 18 overlap with each other partially, the guide cylinder 18 is led out from the magnetizing equipment 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet type eddy current reduction device mounted on a large cargo vehicle or the like, and more particularly, to a permanent magnet type eddy current reduction device which magnetizes a permanent magnet after assembling the eddy current reduction device. It concerns the magnetic method.

[0002]

2. Description of the Related Art Permanent magnets (hereinafter simply referred to as magnets)
In an eddy current reduction device using a magnet, an even number (8 to 24 poles) of magnets are bonded to the outer peripheral surface of a magnet support ring (yoke) made of a magnetic material such that the magnetic poles on the outer surface are alternately different in the circumferential direction. Agent,
It is attached by a mounting bracket (a non-magnetic material such as aluminum, stainless steel, or synthetic resin). When magnetizing magnets, magnetize magnets one by one in advance, or magnetize them all at the same time, and then attach them to the magnet support ring, or use magnets that are not magnetized (strictly, rare earth metals, etc.). Magnet material)
Was attached to the magnet support ring with an adhesive, a mounting bracket, or the like, and then several or all were magnetized simultaneously.

However, it takes time to magnetize the magnets one by one. For example, after a total of twelve magnets are annularly arranged on the outer peripheral surface of the magnet support ring and coupled, a magnetic field is applied from the outer peripheral side of the magnet support ring. When the magnet support ring is assembled inside a protective cylinder or a guide cylinder having a large number of ferromagnetic plates (pole pieces), the magnet is strongly attached to the guide cylinder. In order to resist the suction force, a rigid and strong assembling jig is required, and great care must be taken so that the worker does not injure his finger or the like.

As a method of magnetizing a rotor of a DC rotating machine, there is a method disclosed in Japanese Patent Application Laid-Open No. 2-133100. This method is applied to a magnet support ring of a permanent magnet type eddy current reduction device. However, the above problem cannot be solved.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to connect a magnet to a magnet support ring in order to eliminate the need for assembling the above-described magnet support ring to the guide cylinder and to eliminate the need for a strong assembling jig. It is another object of the present invention to provide a method of magnetizing a permanent magnet type eddy current reduction device which is magnetized after being assembled to a guide cylinder.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to an eddy current reduction device for generating a braking force by an eddy current using a permanent magnet. An even number of permanent magnets before magnetizing on the surface are joined at predetermined intervals in the circumferential direction, and after accommodating the magnet support ring inside a thin guide tube made of a non-magnetic material, the guide tube is removed. The permanent magnet is disposed inside a magnetizing device having a magnetic pole facing the permanent magnet, and a direct current is applied to an electromagnetic coil of a magnetic core of the magnetizing device so that the polarity is changed from the outer peripheral side of the magnet support ring to the permanent magnet in a circumferential direction. It is characterized by being magnetized so as to be alternately different.

According to another aspect of the present invention, there is provided an eddy current reduction device for generating a braking force due to an eddy current using a permanent magnet, wherein the outer peripheral surface of a magnet support ring made of a magnetic material is magnetized. The magnet support ring is housed inside a guide cylinder made of a non-magnetic material and having the same number of ferromagnetic plates as the permanent magnets at regular intervals in the circumferential direction. After fixing each permanent magnet of the magnet support ring to each ferromagnetic plate of the guide cylinder so as to completely overlap, the magnet support ring of the magnet support ring is provided by a magnetizing device having a magnetic pole facing the outer surface of each ferromagnetic plate. It is characterized in that the permanent magnets are magnetized from the outer peripheral side so that the polarity is alternately different in the circumferential direction.

According to another aspect of the present invention, there is provided an eddy current reduction device for generating a braking force due to an eddy current using a permanent magnet, wherein the outer peripheral surface of a magnet support ring made of a magnetic material is magnetized. The preceding 4n (n is a natural number) permanent magnets are connected at predetermined intervals in the circumferential direction, and are provided inside a guide cylinder made of non-magnetic material and having 2n ferromagnetic plates at equal intervals in the circumferential direction. After accommodating the magnet support ring and fixing the two permanent magnets of the magnet support ring to each ferromagnetic plate of the guide cylinder so as to completely overlap with each other, the ferromagnetic plate has a magnetic pole facing the outer surface of each ferromagnetic plate. The permanent magnet is magnetized from the outer peripheral side of the magnet support ring so that the polarity is alternately different in a circumferential direction by a magnetizing device.

Further, in order to solve the above-mentioned problem, the configuration of the present invention relates to an eddy current reduction device for generating a braking force by an eddy current using a permanent magnet, in an outer peripheral surface of a plurality of magnet support rings made of a magnetic material. An even number of permanent magnets, each before being magnetized, are joined at equal intervals in the circumferential direction, and the plurality of magnets are formed inside a guide cylinder made of a non-magnetic material and having the same number of ferromagnetic plates as the permanent magnets at equal intervals in the circumferential direction. After accommodating a support ring, the permanent magnets of the plurality of magnet support rings are aligned in the axial direction and fixed so as to completely overlap each ferromagnetic plate of the guide cylinder, and then face the outer surface of each ferromagnetic plate. It is characterized in that the permanent magnets are magnetized so that their polarities are alternately different in the circumferential direction from the outer peripheral side of the plurality of magnet support rings by a magnetizing device having magnetic poles.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, before magnetizing a magnet,
The magnet is connected to the magnet support ring and assembled inside the guide tube, and then placed inside the magnetizing device. In the case of a guide cylinder made of a non-magnetic thin plate without a ferromagnetic plate, each magnetic pole of the magnetizing device is opposed to each magnet from the outside of the guide cylinder, and a DC current is passed through the electromagnetic coil of each magnetic pole to magnetize. .

In the case of a guide cylinder having many ferromagnetic plates,
Each magnet of the magnet support ring is fixed to each ferromagnetic plate in advance so as to completely overlap with each other, and then placed inside the magnetizing device. Each magnetic pole of the magnetizing device is opposed to the ferromagnetic plate from outside the guide cylinder,
A direct current is passed through the electromagnetic coil of each magnetic core for magnetization. When two or more magnet support rings are provided inside a guide cylinder having a large number of ferromagnetic plates, the magnets of the respective magnet support rings are fixed to each ferromagnetic plate so as to completely overlap, Are magnetized to have the same polarity. Regarding the magnet support ring housed in the above-described guide cylinder, all magnets may be magnetized at the same time, or some magnets may be magnetized several times and sequentially magnetized.

After magnetizing the magnets of the magnet support ring, the magnet support ring is rotated so that two magnets adjacent in the circumferential direction partially overlap each ferromagnetic plate of the guide cylinder, and the magnetizing device rotates the magnet support ring. Pull out the guide tube.

[0013]

FIG. 2 is a front sectional view showing an upper half of a permanent magnet type eddy current reduction device to which the present invention is applied, and FIG. 3 is a side sectional view showing the same. The permanent magnet type eddy current reduction device according to the present invention,
The braking drum 13 made of an electric conductor is connected to the rotating shaft 4. Therefore, the bearing 3 is mounted on the end wall of the gear box 2 of the vehicle transmission.
The output rotation shaft 4 supported by and projected from the end wall,
A mounting flange 5 having a spline hole 5a is fitted,
And it is fastened by the nut 6 so as not to come off. The end wall of the brake drum 7 of the parking brake and the flange portion 9a integral with the boss 9 of the brake drum 13 of the eddy current reduction device are superimposed on the mounting flange 5 and fastened with a plurality of bolts 10 and nuts 10a. .

The braking drum 13 is made of a material having a high magnetic permeability such as iron, and is connected at its base end to a number of support arms (spokes) 12 extending radially from the boss 9. A large number of heat radiation fins 13a are provided on the outer peripheral wall of the braking drum 13 at equal intervals in the circumferential direction.

A guide cylinder 18 having a box-shaped inner space 15 is coaxially arranged inside the braking drum 13. The immobile guide cylinder 18 made of a non-magnetic material is fixed to a frame plate 31 externally fitted to the protruding wall 2a of the gear box 2 with an axial bolt 32 and a radial bolt 32a. The guide tube 18 may be formed by connecting an annular end wall plate to both ends of an outer peripheral wall portion 18a and an inner peripheral wall portion 18b, but the illustrated guide tube 18 has a left half portion made of a magnetic material such as iron. A cylindrical portion having a U-shaped cross section and a cylindrical portion having an inverted L-shaped cross section in the right half made of a non-magnetic material such as aluminum are connected by a number of bolts 14.

A large number of openings are provided in the outer peripheral wall portion 18a of the guide cylinder 18 facing the inner peripheral surface of the braking drum 13 at equal circumferential intervals, and a ferromagnetic plate (pole piece) 21 is fitted and fixed in each opening. Is done. In practice, the ferromagnetic plate 21 is
a is cast when aluminum is cast from aluminum.

A plurality of actuators (not shown) are supported on the frame plate 31 having the reinforcing ribs 31a at equal intervals in the circumferential direction. The actuator fits a piston into a cylinder to define a pair of fluid pressure chambers, and a magnet support ring 19 is attached to an end of a rod 17 projecting from the piston to the inner space 15 of the guide cylinder 18.
Will be combined. The magnet support ring 19 is the inner space 1 of the guide cylinder 18.
5 is supported movably in the axial direction. On the outer peripheral wall of the magnet support ring 19, the magnets 20 facing the even number or 4n (n is a natural number) ferromagnetic plates 21, respectively, are coupled so that the polarities are alternately different in the circumferential direction.

At the time of braking, as shown in FIGS. 2 and 3, the magnet support ring 19 is protruded into the brake drum 13 by the rod 17 of the actuator. When the rotating brake drum 13 crosses the magnetic field from the magnet 20 via the ferromagnetic plate 21 to the inner peripheral surface of the brake drum 13, an eddy current is generated in the brake drum 13 and exerts a braking torque on the brake drum 13. At this time, as shown in FIG. 3, a magnetic circuit 40 is formed between the magnet support ring 19 and the braking drum 13. The braking drum 13 generates heat due to the eddy current and is cooled by the outside air directly or through the heat radiation fin 13a.

When the brake is not applied, if the magnet support ring 19 is moved to the left in FIG. 2 by the actuator and retreated from the brake drum 13, the magnet 20 does not exert a magnetic field on the brake drum 13, and the brake drum 13 applies the braking torque. Does not occur. As described above, the eddy current reduction device includes the magnet 20 and the braking drum 1.
3 generates a braking force based on the eddy current generated by the relative rotation.

As shown in FIG. 1, according to the present invention, in a permanent magnet type eddy current reduction device as described above, a magnet 20 (strictly called a magnet material) before being magnetized is attached to a magnet support ring 19. After being joined by the metal fitting 54, the guide tube 18 is housed in the inner space 15. For this reason, the magnet support ring 19
Is fitted to the inner peripheral wall 18b of the guide cylinder 18, and then the inner peripheral wall 18b is attached to the outer peripheral wall 18a by a number of bolts 14 (FIG. 2).
To join. Each magnet 20 has a trapezoidal cross section. An even number of magnets 20 are arranged on the outer peripheral surface of the magnet support ring 19 at regular intervals in the circumferential direction, and a mounting bracket made of a non-magnetic material having an inverted trapezoidal cross section between the magnets. 54, and each mounting bracket 5
4 are fastened to the magnet support ring 19. As described above, the magnet support ring 19 to which the magnets 20 before magnetization are coupled is housed inside the guide tube 18 so that each magnet 20 completely overlaps each ferromagnetic plate 21. Is arranged inside the magnetizing device 50.

The magnetizing device 50 has a large number of magnetic cores 53 (the same number as the magnets 20) on the inner peripheral wall of a cylindrical yoke 51 made of a magnetic material.
Are arranged at equal intervals in the circumferential direction, and an electromagnetic coil 52 is attached to each magnetic core 53.
Wrapped around. Each magnetic core 53 has a rectangular section extending to the center of the yoke 51, and the circumferential dimension and the axial dimension of the tip of each magnetic core 53, that is, the end face of the magnetic pole 53 a are formed to be the same as the ferromagnetic plate 21. .

Each of the ferromagnetic plates 21 of the guide cylinder 18 is
The respective magnets 20 are positioned so as to overlap with the respective magnetic poles 53a, and are positioned so as to overlap with the respective ferromagnetic plates 21.
Next, when direct currents in opposite directions are applied to the electromagnetic coils 52 adjacent to each other in the circumferential direction, a magnetic circuit is generated as shown by an arrow y in FIG. That is, from the magnetizing magnetic pole 53a,
A magnetic circuit y is formed on the ferromagnetic plate 21, the magnet 20, the magnet support ring 19, the adjacent magnet 20, the ferromagnetic plate 21, the magnetic core 53, the yoke 51, and the adjacent magnetic core 53, and the magnet 20 is magnetized. Next, the power supply to each electromagnetic coil 52 is stopped, and the guide cylinder 18 is turned off.
When the magnet support ring 19 is rotated by half the pitch of the arrangement of the magnets 20, the pair of magnets 20 adjacent in the circumferential direction partially overlap the common ferromagnetic plate 21. The attractive force exerted on the magnetic pole 53a by the magnetized magnet 20 becomes weak,
The guide cylinder 18 can be easily pulled out from the magnetizing device 50, and the generation of a demagnetizing field after the guide cylinder 18 is pulled out is suppressed by the ferromagnetic plate 21, so that the magnet 20 does not demagnetize. In the above-described embodiment, instead of magnetizing all magnets 20 collectively, some magnets 20 may be magnetized in several times.

When two or more magnet support rings 19, 19a are provided inside the guide cylinder 18 having a large number of ferromagnetic plates 21, the magnets of the respective magnet support rings 19, 19a are provided on each ferromagnetic plate 21. 20 and 20a are entirely overlapped, and the magnets 20 and 20a are
20a are all magnetized to the same polarity. That is, as shown in FIGS. 4 and 5, a guide cylinder 18 having an inner space 15 having a box-shaped cross section is provided.
Are evenly spaced (2n, n
Is a natural number), while a magnet support ring 19a is rotatably supported by a bearing 22a on the inner peripheral wall 18b, and a bearing is mounted on a thin cylindrical portion 19b in the left half of the magnet support ring 19a. The magnet support ring 19 is rotatably supported by 22. The magnet support ring 19a has an arm 26 projecting outward from the thin cylindrical portion 19b through a slit 28 on the left end wall of the guide cylinder 18 and a piston rod 25 of the actuator 24.
Linked to Similarly, the magnet support ring 19 has an arm protruding outward through a slit in the left end wall of the guide cylinder 18 and connected to a piston rod of another actuator. The actuator 24 is formed by inserting a piston into a cylinder 27,
The piston rod 25 projects from the piston to the outside.

As shown in FIG. 5, the outer peripheral surface of the magnet support ring 19 has 4n
The magnets 20 are connected at predetermined intervals. 4n magnets 20a are coupled at predetermined intervals to the outer peripheral surface of the magnet support ring 19a such that two magnets face each ferromagnetic plate 21 at a time.

In order to magnetize the magnets 20 and 20a, the magnets 20 and 20a which have not been magnetized beforehand are connected to the magnet support rings 19 and 19a, respectively, as shown in FIG. Rotatably housed, two magnets 20,
Positioning is performed so that the entire surface 20a faces each ferromagnetic plate 21. Next, the guide cylinder 18 is arranged inside the magnetizing device 50 such that the ferromagnetic plate 21 entirely faces the magnetic pole 53a. When a direct current is applied to the electromagnetic coil 52 wound around the magnetic core 53 so that the directions of the magnetic fields passing through the adjacent magnetic cores 53 are opposite to each other, each of the magnetic coils opposes the ferromagnetic plate 21 as in the embodiment shown in FIG. The four magnets 20, 20a to be magnetized have the same polarity.

Next, when the energization of the electromagnetic coil 52 is stopped and each magnet support ring 19, 19a is rotated by an arrangement pitch of the magnets 20, 20a, as shown in FIG. As a result, the polarities of the magnets 20 and 20a arranged in the circumferential direction are opposite to each other, so that each ferromagnetic plate 21 and each magnet support ring 1
A short-circuit magnetic circuit 40a is generated between the magnets 9 and 19a, the attraction force exerted by the magnets 20 and 20a on the magnetic pole 53a is reduced, and the guide cylinder 18 can be easily pulled out from the magnetizing device 50.

FIG. 5 shows an eddy current type speed reducer in which a guide cylinder 18 is actually provided inside the brake drum 13. In the illustrated non-braking state, each ferromagnetic plate 21 and the magnet support rings 19, 1
9a, a short-circuit magnetic circuit 40a is generated, and no braking force is applied to the braking drum 13. When the magnet support rings 19, 19a are rotated by the pitch of the arrangement of the magnets 20, 20a, the four magnets 20, 20a facing each ferromagnetic plate 21 have the same polarity, and the magnetic fields of the magnets 20, 20a are strong. It acts on the brake drum 13 rotating while passing through the magnetic plate 21, and exerts a braking force based on the eddy current on the brake drum 13. At this time, the four magnets 20, 20a perform the same function as the magnet 20 shown in FIG. 3, and a magnetic circuit is formed between the magnet support rings 19, 19a and the braking drum 13.

The present invention is not limited to each of the above-described embodiments, but is directed to a thin guide cylinder made of a non-magnetic material without a ferromagnetic plate as disclosed in Japanese Patent Application No. 7-336180. The present invention is also applicable to a permanent magnet type eddy current reduction device having a magnet support ring housed therein. In this case, the respective magnetic poles of the magnetizing device are opposed to the respective magnets of the magnet support ring from the outer peripheral side of the thin guide cylinder, and a DC current is supplied to the electromagnetic coils of the respective magnetic cores for magnetization.
In order to take out the guide cylinder from the magnetizing device after the magnetization, the guide cylinder is moved in the axial direction from the magnetizing device to the inside of the magnetic cylinder.

[0029]

As described above, the present invention relates to an eddy current reduction device for generating a braking force by an eddy current using a permanent magnet, which is attached to an outer peripheral surface of one or a plurality of magnet support rings made of a magnetic material. An even number or 4n permanent magnets before magnetism are connected at predetermined intervals in the circumferential direction, and the magnet support ring is housed inside a thin guide cylinder made of a non-magnetic material. The magnet is disposed inside a magnetizing device having a magnetic pole facing the magnet, and a direct current is applied to an electromagnetic coil of a magnetic core of the magnetizing device so that the polarity is changed from the outer peripheral side of the magnet support ring to the permanent magnet. The following effects can be obtained because the magnets are alternately magnetized one by one or two by two in the direction.

The assemblability of the magnet support ring with respect to the guide cylinder is improved, and the worker does not have to worry about damaging his / her finger or hand when assembling the magnet support ring.

After the magnets of the magnet support ring are magnetized, the magnets are rotated by rotating the magnet support ring to a position where two circumferentially adjacent magnets partially overlap the ferromagnetic plate of the guide cylinder. The suction force exerted on the device is weakened, and the guide cylinder can be easily pulled out of the magnetizing device.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a magnetizing method of a reciprocating permanent magnet type eddy current reduction device according to the present invention.

FIG. 2 is a side sectional view of the eddy current type speed reducer.

FIG. 3 is a front sectional view of the eddy current type speed reducer during braking.

FIG. 4 is a side sectional view showing a magnetizing method of the rotary permanent magnet eddy current reduction device according to the present invention.

FIG. 5 is a front sectional view of the eddy current type speed reducer when no braking is performed.

[Explanation of symbols]

4: rotating shaft 9: boss 9a: flange 12: support arm 13: braking drum 13a: heat radiation fin 14: bolt 15: inner space 1
7: Rod 18: Guide tube 18a: Outer peripheral wall 18
b: inner peripheral wall portion 19, 19a: magnet support cylinder 19b: thin cylindrical portion 20, 20a: permanent magnet 21: ferromagnetic plate
22, 22a: Bearing 24: Actuator 25: Rod 26: Arm 27: Cylinder 28: Slit 3
1: frame plate 40, 40a: magnetic circuit 50: magnetizing device
51: Yoke 52: Electromagnetic coil 53: Magnetic core 53a: Magnetic pole 54:
Mounting bracket 55: bolt

Claims (6)

[Claims] In an eddy current reduction device for generating a braking force by eddy current using a permanent magnet, a permanent magnet before magnetizing is provided on an outer peripheral surface of a magnet support ring made of a magnetic material at a predetermined interval in a circumferential direction. After the magnet support ring is accommodated inside the guide cylinder, the guide cylinder is disposed inside a magnetizing device having a magnetic pole facing the permanent magnet via the guide cylinder, and the magnetizing is performed. A magnetizing method for a permanent magnet type eddy current reduction device, characterized in that a direct current is passed through an electromagnetic coil of a magnetic core of the device to magnetize the permanent magnet from an outer peripheral side of the magnet support ring. 2. An eddy current reduction device for generating a braking force due to an eddy current by using a permanent magnet, wherein an even number of permanent magnets before magnetizing are fixed on an outer peripheral surface of a magnet support ring made of a magnetic material in a circumferential direction. After connecting the magnet support ring inside a thin guide tube made of a non-magnetic material, the magnet support ring is connected to the inside of a magnetizing device having a magnetic pole facing the permanent magnet via the guide tube. The guide cylinder is disposed, and a direct current is passed through an electromagnetic coil of a magnetic core of the magnetizing device to magnetize the permanent magnets from the outer peripheral side of the magnet support ring so that the polarities are alternately different in a circumferential direction. A method for magnetizing a permanent magnet type eddy current reduction device. 3. An eddy current reduction device for generating a braking force due to an eddy current using a permanent magnet, wherein an even number of permanent magnets before magnetizing are arranged at equal circumferential intervals on an outer peripheral surface of a magnet support ring made of a magnetic material. The magnet support ring is housed inside a guide cylinder that is coupled, is made of a nonmagnetic material, and has the same number of ferromagnetic plates as the permanent magnets at equal intervals in the circumferential direction. The magnet support ring is accommodated in each ferromagnetic plate of the guide cylinder. After the permanent magnets of the ring are fixed so as to completely overlap each other, the polarity alternates in the circumferential direction from the outer peripheral side of the magnet support ring to the permanent magnets by a magnetizing device having magnetic poles facing the outer surface of each ferromagnetic plate. A method for magnetizing a permanent magnet type eddy current reduction device, characterized in that the magnetizing is performed differently. 4. An eddy current reduction device for generating a braking force due to an eddy current by using a permanent magnet, wherein 4n permanent magnets before magnetizing are fixed on an outer peripheral surface of a magnet support ring made of a magnetic material in a circumferential direction. Combined at intervals, made of non-magnetic material and 2n
The magnet support ring is housed inside a guide cylinder having a plurality of ferromagnetic plates at equal intervals in the circumferential direction, and the two permanent magnets of the magnet support ring entirely overlap each ferromagnetic plate of the guide cylinder. After fixing the permanent magnets to the permanent magnets, the magnets are magnetized from the outer peripheral side of the magnet support ring so that the polarities are different every two pieces in the circumferential direction from the outer peripheral side of the magnet support ring. A method of magnetizing a permanent magnet type eddy current reduction device. 5. An eddy current reduction device for generating a braking force by an eddy current using permanent magnets, wherein an even number of permanent magnets before magnetization are respectively provided on the outer peripheral surfaces of a plurality of magnet support rings made of a magnetic material in the circumferential direction. The plurality of magnet support rings are housed inside a guide cylinder which is made of non-magnetic material and has the same number of ferromagnetic plates as the permanent magnets at equal intervals in the circumferential direction. After the permanent magnets are aligned in the axial direction and fixed so as to completely overlap each ferromagnetic plate of the guide cylinder, the plurality of magnet support rings are rotated by a magnetizing device having a magnetic pole facing the outer surface of each ferromagnetic plate. A method of magnetizing a permanent magnet type eddy current reduction device, characterized in that the permanent magnets are magnetized so that their polarities alternately differ in the circumferential direction from the outer peripheral side of the magnet. 6. The magnet support so that, after magnetizing the permanent magnet, two permanent magnets adjacent to each other in the circumferential direction of the magnet support ring and having different polarities overlap each other on each ferromagnetic plate of the guide cylinder. The magnetizing method for a permanent magnet type eddy current reduction device according to any one of claims 3 to 5, wherein the ring is rotated to pull out the guide cylinder from the magnetizing device.