WO2008041474A1

WO2008041474A1 - Magnetic encoder and rolling bearing

Info

Publication number: WO2008041474A1
Application number: PCT/JP2007/068093
Authority: WO
Inventors: Takayuki Norimatsu
Original assignee: Ntn Corporation
Priority date: 2006-10-03
Filing date: 2007-09-18
Publication date: 2008-04-10

Abstract

A magnetic encoder (16a) comprises a plastic multipolar magnet (23a) which is formed in a disk shape and has a through hole at its center and magnetic poles alternately arranged in the circumferential direction and a slinger (24a) which has a cylindrical part (28a), a flange (28b) extending from one end of the cylindrical part (28a) radially outwardly, and a flange part (28c) extending from the radial outer end of the flange (28b) in the radial direction and the cross section of which is formed in a generally inverted Z-shape. The multipolar magnet (23a) is press-fitted into the radial inner side of the flange part (28c) and held by the slinger (24a).

Description

Specification

Magnetic encoder and rolling bearing

Technical field

The present invention relates to a magnetic encoder and a rolling bearing, and more particularly to a magnetic encoder provided in a rolling bearing that supports a rotating shaft and a rolling bearing provided with such a magnetic encoder.

Background art

[0002] Conventionally, as a bearing used for an ABS (Antilock Brake System) device of a car, there is a rolling bearing with a seal provided with a magnetic encoder. Such a rolling bearing is disclosed, for example, in Japanese Patent Laid-Open Publication No. 2001-255337. According to Japanese Patent Laid-Open Publication No. 2001-255337, rotation detection for detecting the number of rotations and the direction of rotation is disclosed. The device consists of a magnetic encoder and a rotation sensor (rotational speed detection sensor) The magnetic encoder consists of a multipole magnet with alternating magnetic poles in the circumferential direction and a core metal (slinger) supporting it The rotation sensor detects the alternately arranged magnetic poles of the magnetic encoder which rotates with the rotation shaft, and in this way, the rotation detection device detects the number of rotations and the like.

[0003] Here, a basic configuration of a conventional sealed rolling bearing provided with a magnetic encoder will be briefly described. FIG. 9 is a cross-sectional view showing a part of a conventional sealed rolling bearing provided with a magnetic encoder. Referring to FIG. 9, the rolling bearing 101 detects the outer ring 102, the inner ring 103, the ball 104, the cage 105 for holding the ball 104, the seal 106 for sealing the inside of the bearing, and the rotation speed and the like. And a magnetic encoder 107. The magnetic encoder 107 includes a slinger 108 fixed to the inner ring 103 and a multipolar magnet 109 mounted on the outer side of the slinger 108. The multipolar magnet 109 and the slinger 108 are bonded by an adhesive at their contact surfaces 110a and 110b. Thus, the multipolar magnet 109 is held by the slinger 108.

A conventional magnetic encoder generally uses ferrite as a magnetic powder and a rubber multipole magnet using rubber as a binder for binding the ferrite. Here, rare earth magnetic powder with excellent magnetic properties is used as a substitute for ferrite This makes it possible to detect the rotational speed with high accuracy. Plastic is used as a binder for binding such rare earth magnetic powder. Such plastic multipole magnets are suitable as magnetic encoders.

However, plastic multipolar magnets have low adhesive strength with adhesives! Therefore, when included in the magnetic encoder configured as shown in FIG. 9, there is a risk that the multipolar magnet may come off the slinger. This tendency is particularly noticeable when equipped with rolling bearings used in harsh environments such as mud water, salt water, high and low temperatures, such as rolling bearings for automobiles. Disclosure of the invention

An object of the present invention is to provide a magnetic encoder in which the detachment of a multipole magnet is prevented.

[0007] Another object of the present invention is to provide a magnetic encoder having improved corrosion resistance.

[0008] Still another object of the present invention is to provide a rolling bearing with a reduced risk of breakage.

[0009] Still another object of the present invention is to provide a rolling bearing capable of achieving a long life.

The magnetic encoder according to the present invention has a disk shape, and has a through hole at its center, and a plastic multipole magnet in which magnetic poles are alternately arranged in the circumferential direction, a cylindrical portion, and a cylinder. And a flange extending in the outer diameter side from one end of the portion, and a flange extending in the axial direction from the end on the outer diameter side of the flange, the cross section including a slinger having a substantially inverted Z shape. Here, the multipole magnet is pressed into the inner diameter side of the buttocks and held by the slinger.

[0011] With this configuration, the multipolar magnet can be press-fitted and held by utilizing the inner diameter side portion of the collar portion provided in the slinger. In this case, since the holding is not by adhesion using an adhesive or the like, the holding power will not be weakened even with a plastic multipolar magnet. Therefore, the detachment of the multipolar magnet can be prevented.

[0012] Preferably, the axial end of the collar is crimped to the inner diameter side. In this way, in addition to press-fitting, the multipole magnet can be held also by caulking, and the detachment of the multipole magnet can be prevented more reliably.

More preferably, the crimped portion crimped to the inner diameter side is continued in the circumferential direction. like this By doing this, the detachment of the multipolar magnet can be prevented more reliably.

More preferably, notches extending in the axial direction are provided in the collar portion at a plurality of circumferential positions. By this, the force required for press-fitting can be reduced and the press-fitting can be easily performed.

More preferably, the multipolar magnet is made of a plastic including a rare earth magnetic powder and a binder as a binder for binding the rare earth magnetic powder. Here, an anti-glare coating is formed on the surface of the multipolar magnet.

[0016] A multipolar magnet containing rare earth magnetic powder is easy to generate. Here, when a magnetic encoder is used as a bearing for an automobile, it is often exposed to salt water, muddy water, and the like. Then, there is a risk that the magnetic encoder may be generated.

Here, the multipole magnet is made of a plastic containing rare earth magnetic powder and a plastic as a binder for binding the rare earth magnetic powder, and a surface of the multipole magnet is coated with a fireproofing coating. By forming so as to be formed, the surface of the multipolar magnet containing the rare earth magnetic powder can be covered with the antiglare coating. Then, it is possible to suppress the generation of the rare earth magnetic powder contained in the multipolar magnet. Therefore, the corrosion resistance of a magnetic encoder including such a multipolar magnet can be improved.

[0018] More preferably, an anti-glare coating is formed on the surface of the magnetic encoder. This makes it possible to cover the entire surface of the magnetic encoder, including the multipolar magnet and the slinger, with a dustproof coating. Then, the corrosion resistance can be further improved. In addition, since the multipole magnet and the slinger can be integrated to form the anti-glare coating, the productivity of the magnetic encoder can be improved.

More preferably, the antiglare coating is a coating of metal. By doing so, the corrosion resistance can be more appropriately improved.

Further, the antiglare coating may be formed by electrodeposition coating. By so doing, the antidust-treated coating can be formed more uniformly, so dimensional accuracy can be improved. In addition, the bondability between the antiglare coating and the multipolar magnet can be improved.

Preferably, the electrodeposition coating is a cationic electrodeposition coating. By doing this, it is possible to prevent the elution of metal ions on the side of the multipolar magnet that is the object to be coated, and it is possible to more appropriately protect the antiglare coating. It is a power to form.

[0022] In another aspect of the present invention, the rolling bearing includes any of the above-described magnetic encoders. Such rolling bearings include magnetic encoders that prevent the multipole magnets from falling off, so there is little risk of breakage. In addition, since a magnetic encoder having improved corrosion resistance is included, a long life can be achieved.

That is, according to the present invention, as described above, the slinger is provided with the collar portion extending in the axial direction from the outer diameter end of the side portion, so that the inner diameter side portion of the collar portion is utilized. The force S can be used to press in the multipolar magnet. The plastic multipole magnet is pressed into the inner diameter of the buttocks, so it does not fall off easily. Therefore, the detachment of the multipolar magnet can be prevented

In addition, the surface of the multipolar magnet containing the rare earth magnetic powder can be covered with the antiglare coating, and the generation of the rare earth magnetic powder contained in the multipolar magnet can be suppressed. Therefore, the corrosion resistance of a magnetic encoder including such a multipolar magnet can be improved.

In addition, since such a rolling bearing includes a magnetic encoder that prevents the multipole magnet from falling off, there is little risk of breakage.

In addition, since such a rolling bearing includes a magnetic encoder with improved corrosion resistance, it can exert a long life S.

Brief description of the drawings

FIG. 1 is a cross-sectional view showing a part of a rolling bearing according to an embodiment of the present invention.

FIG. 2 is a conceptual view showing the configuration of a multipolar magnet.

FIG. 3 is a cross-sectional view showing a part of the magnetic encoder before caulking the end.

FIG. 4 is a cross-sectional view showing a part of the magnetic encoder after the end is crimped.

FIG. 5 is a cross-sectional view showing a part of a magnetic encoder according to another embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a part of a rolling bearing according to another embodiment of the present invention.

[FIG. 7] A sectional view showing a part of a magnetic encoder according to still another embodiment of the present invention.

FIG. 8 is a schematic cross-sectional view showing an axle support structure including the rolling bearing according to the present invention.

FIG. 9 is a cross-sectional view showing a part of a conventional rolling bearing. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a part of a rolling bearing according to an embodiment of the present invention. Referring to FIG. 1, a rolling bearing 11 supports a rotating shaft (not shown). The rolling bearing 11 holds a ball 12 as a rolling element, an inner member 13 arranged on the inner diameter side of the ball 12, an outer member 14 arranged on the outer diameter side of the ball 12, and the ball 12. And a magnetic encoder 16a for detecting the number of revolutions and the like of the rotating shaft, and a seal 17 for sealing the inside of the bearing. The inner member 13 is fixed to the rotation shaft and rotates with the rotation shaft. On the other hand, the outer member 14 is fixed to a housing (not shown). The balls 12 roll on raceways 18a and 18b provided on the inner member 13 and the outer member 14 when the rotation shaft rotates.

The seal 17 includes a cored bar 31 having rigidity and an elastic member 32 having elasticity. The cored bar 31 is attached and fixed to the outer member 14. The elastic member 32 is configured to cover a part of the cored bar 31. The elastic member 32 is in contact with a slinger 24a included in a magnetic encoder 16a described later at a plurality of points with an appropriate pressure. In this way, the interior 19 of the rolling bearing 11 is sealed. By doing this, it is intended to prevent the leakage of the lubricating oil sealed in the inside 19 and prevent the foreign matter from entering the inside 19 of the rolling bearing 11.

The rotation detection device 21 for detecting the number of rotations and the like of the rotation shaft includes a magnetic encoder 16 a included in the rolling bearing 11 and a rotation sensor 22. The magnetic encoder 16a and the rotation sensor 22 are provided at mutually opposing positions. The rotation sensor 22 is, for example, attached and fixed to the housing together with the outer member 14 and the like. The magnetic encoder 16a includes a multipole magnet 23a in which magnetic poles are alternately arranged in the circumferential direction, and a slinger 24a holding the multipole magnet 23a.

The multipolar magnet 23a held by the slinger 24a rotates with the inner member 13 as the rotation shaft rotates. At this time, the change of the magnetic force of the N pole and the S pole of the multipolar magnet 23a is read by the detection unit 25 of the rotation sensor 22 which is disposed axially outward and is provided at a position facing the multipolar magnet 23a. Thus, the rotation detection device 21 detects the number of rotations and the like of the rotation shaft.

Here, respective members constituting the magnetic encoder 16a will be described. First, multipolar magnets The configuration of 23a will be described. FIG. 2 is a conceptual view showing the configuration of the multipolar magnet 23a. Referring to FIGS. 1 and 2, multipole magnet 23a is a disk-like member and has a through hole at its center. The multipole magnet 23a is magnetized in multiple poles in the circumferential direction, and is configured to alternately arrange the N pole 27a and the S pole 27b on a PCD (Pitch Circle Diameter: 26) 26 Ru.

The multipolar magnet 23a is a plastic magnet using a plastic as a binder for the rare earth magnetic powder. Examples of the rare earth magnetic powder include samarium iron (SmFeN) magnetic powder and neodymium iron (NdFeB) magnetic powder. With such a rare earth magnetic powder, it is possible to obtain a multipolar magnet 23a capable of efficiently detecting the magnetic force.

Furthermore, the magnetic powder may be a combination of the above-mentioned materials. Specifically, a mixture of samarium iron-based magnetic powder and neodymium iron-based magnetic powder may, for example, be mentioned.

Next, the configuration of the slinger 24a will be described. The slinger 24a includes a cylindrical portion 28a, a flange 28b extending to the outer diameter side from one end of the cylindrical portion 28a, and a flange portion 28c axially extending from the outer diameter end of the flange 28b. There is a substantially reverse Z-shape. Here, the inner diameter of the ridge portion 28c is configured to be slightly smaller than the maximum outer diameter of the multipolar magnet 23a. By this, it is possible to press-fit the multipolar magnet 23a to the inside diameter side of the flange portion 28c. The slinger 24a is made of metal. The slinger 24 a is fixed to the inner member 13 such that the inner diameter surface of the cylindrical portion 28 a is press-fitted to the outer diameter surface of the inner member 13.

Next, the arrangement of the multipolar magnet 23a and the slinger 24a will be described. The multipolar magnet 23a is attached to the slinger 24a. Specifically, of the multipole magnet 23a, the surface 29a located on the inner side and the surface 29b located on the outer side of the flange 28b are mounted in contact with each other.

Here, the multipolar magnet 23a is press-fitted to the inner diameter side of the flange portion 28c and held by the slinger 24a. Further, the axial end 28d of the flange portion 28c is bent to the inner diameter side and crimped. That is, at the time of press-fitting, as shown in FIG. 3, the axial end 28d of the flange 28c is straight in the axial direction. After the multipolar magnet 23a is press-fit into the slinger 24a, the end 28d is bent to the inner diameter side and crimped to make it the state shown in FIG. Such caulking is formed continuously in the circumferential direction. With such a configuration, the force S of pressing in the multipolar magnet 23a can be obtained by utilizing the inner diameter side portion of the flange portion 28c. Since the multipolar magnet 23a is press-fitted to the inner diameter side of the flange portion 28c, it does not fall off easily. In this case, since the holding is not by adhesion using an adhesive or the like, the holding power does not become weak even with a plastic multipolar magnet. Therefore, the detachment of the multipolar magnet 23a can be prevented. In addition, since the rolling bearing 11 including such a magnetic encoder 16a is prevented from falling off the multipolar magnet 23a, there is little risk of breakage.

The axial end portion 28d of the flange portion 28c is crimped to the inner diameter side, so that the multipolar magnet 23a can be more reliably prevented from falling off.

Further, the ridge portion 28c may not extend in the circumferential direction. That is, notches extending in the axial direction may be provided at a plurality of circumferential positions of the collar portion 28c, and the notches may be press-fitted on the inner diameter side of the claw-like portion located between the notches. By doing this, it is possible to reduce the force required at the time of press-in, and it is possible to easily press-in S. In this case, the multipole magnet can be more properly held by providing the notches in the circumferential direction substantially equidistantly and positioning the claw-like portions in the circumferential direction without bias.

Also in this case, similarly, after the press-fitting, the claws may be bent to the inner diameter side and crimped. In this case, since the claw-like portion is not continuous in the circumferential direction, it can be easily crimped with a force S.

Specifically, the multipole magnet 23a may have the following configuration. That is, the multipolar magnet 23a is made of plastic including rare earth magnetic powder and plastic as a binder for binding the rare earth magnetic powder. The multipolar magnet 23a uses a thermoplastic resin, a thermosetting resin or the like as a binder for the rare earth magnetic powder! Examples of the rare earth magnetic powder include the above-described samarium iron magnetic powder and neodymium iron magnetic powder. With such a rare earth magnetic powder, as described above, the force S can be obtained to obtain the multipole magnet 23a capable of efficiently detecting the magnetic force. The magnetic powder may be a combination of the above-mentioned materials, specifically, a mixture of samarium iron-based magnetic powder and neodymium iron-based magnetic powder.

Incidentally, a plastic as a binder for binding the rare earth magnetic powder is PPS (polyphenylene sulfide). It may be a thermoplastic resin such as PA (polyamide), or a thermosetting resin such as epoxy resin or phenol resin! /. When a thermoplastic resin is used as a binder, a predetermined amount of rare earth magnetic powder is added to the thermoplastic resin, kneaded, dispersed, and molded by injection molding or the like to form the final shape of the multipolar magnet 23a. What can you do? When a thermosetting resin is used, a predetermined amount of rare earth magnetic powder is added to the thermosetting resin, kneaded, dispersed, and molded by heat compression molding or the like to obtain a final multipolar electrode. It can be in the shape of a magnet 23a.

Here, on the surface of the multipolar magnet 23a, a coating of a stick may be formed as a mildew-resistant coating. By configuring in this manner, the surface of the multipolar magnet 23a can be covered with a film of metal having good corrosion resistance. Then, it is possible to suppress the generation of the rare earth magnetic powder contained in the multipolar magnet 23a. Therefore, the force S can be made to improve the corrosion resistance of the multipolar magnet 23a. As a result, it is possible to improve the corrosion resistance of the magnetic encoder including the multipolar magnet 23a. Examples of such a metal include metal such as zinc metal, nickel metal, zinc metal and the like. The thickness of the film is about several meters to several tens of meters, and the illustration thereof is omitted in FIG.

Note that the antiglare coating may be formed by electrodeposition coating. By forming the antiglare coating by electrodeposition coating, the bondability between the antiglare coating and the multipolar magnet is improved. Furthermore, the film thickness of the antiglare treatment film can be formed uniformly. Therefore, the dimensional accuracy of the multipolar magnet can be improved.

Here, in the electrodeposition coating, an object to be coated, that is, an anion-type electrodeposition coating in which the force S serving as a multipolar magnet here is the positive pole side, and the multipolar magnet side is used. There are two types of cation type that make it to the negative pole side. In this case, in order to perform electrodeposition coating, cationic electrodeposition coating in which the multipolar magnet side is the negative electrode side is preferable. By doing this, it is possible to prevent the elution of the metal ions on the multipolar magnet side, and therefore, it is possible to properly form a mildew-proof coating.

Yes

In addition, a coating of metal as a mildew-proof coating may be formed on the surface of the multipolar magnet, and may be held by a slinger having a substantially L-shaped cross section. FIG. 5 is a cross-sectional view showing a part of the magnetic encoder 16e in this case. Figure 6 shows a rolling including such a magnetic encoder 16e FIG. 2 is a cross-sectional view showing a part of a bearing 11; The rolling bearing 11 shown in FIG. 6 includes an inner ring as the inner member 13, an outer ring as the outer member 14, and a rubber portion as the elastic member 32. The basic configuration of the rolling bearing 11 shown in FIG. 6 is the same as that of the rolling bearing 11 shown in FIG. In FIG. 5 and the like, the film thickness of the film 30 of the resin is shown as thick in view of easy understanding.

The slinger 24e includes a cylindrical portion 28e and a flange 28f extending outward from one end of the cylindrical portion 28e. The cross section of the slinger 24e is substantially L-shaped. The cylindrical portion 28 e of the slinger 24 e is press-fitted to the inner ring as the inner member 13.

The multipolar magnet 23e is held by the slinger 24e by bonding the inner surface 29f of the bearing and the outer surface 29e of the bearing of the flange 28f with an adhesive or the like. In this case, the multipolar magnet 23e is held by the slinger 24e through the coating 30 of the metal. The multipolar magnet 23e held by the slinger 24e rotates with the inner ring as the inner member 13 as the rotation shaft rotates. At this time, the change in the magnetic force of the N pole 27a and the S pole 27b of the multipole magnet 23e is detected by the detection sensor of the rotation sensor 22 disposed on the axially outer side and provided at the position facing the multipole magnet 23e. Read. Thus, the rotation detection device 21 detects the number of rotations and the like of the rotation shaft.

Here, on the surface of the multipolar magnet 23e, a coating 30 of a stick as a fireproofing coating is formed. By configuring in this manner, the surface of the multipolar magnet 23e can be covered with the coating 30 with good corrosion resistance. Then, the generation of the rare earth magnetic powder contained in the multipolar magnet 23e can be suppressed. Therefore, the force S can be made to improve the corrosion resistance of the multipolar magnet 23e. As a result, the corrosion resistance of the magnetic encoder including the multipolar magnet 23e is improved by the force S.

In the above-described embodiment, the force of forming the coating of the film only on the multipolar magnet included in the magnetic encoder is not limited to this. The coating of the film is formed on the entire surface of the magnetic encoder. It may be formed. That is, after the multipolar magnet and the slinger are bonded and integrated, a coating film of metal may be formed on this surface.

Referring to FIG. 7, in the magnetic encoder 36, first, the inner surface 39a of the bearing of the multipolar magnet 37 and the outer surface 39b of the bearing of the ringer 38 are bonded and integrated. A metal coating 40 is formed on the surface of the multipole magnet 37 and the slinger 38 integrated with each other. in this way By configuring, the entire surface of the magnetic encoder 36 can be covered with the coating 40 of plastic. Then, the corrosion resistance of the magnetic encoder 36 can be further improved.

[0053] A rolling bearing including such a magnetic encoder is provided in a support structure of an automobile axle. FIG. 8 is a schematic cross-sectional view showing an axle support structure. Referring to FIG. 8, an axle support structure 61 includes a hub wheel 62 rotating with an axle (not shown) and a rolling bearing 71 supporting the axle. The flange 64 of the hub wheel 62 is fixed by bolts 63 to the wheel (not shown). The rolling bearing 71 is a double-row angyura ball bearing, and includes a double-row ball 72, an inner ring 73, an outer ring 74, a cage 75, a seal 76, and a magnetic encoder (not shown). .

The inner ring 73 is fixed to the hub ring 62 and constitutes an inner member together with the hub ring 62 and rotates with the rotation of the axle. The outer ring 74 is fixed to a housing (not shown) disposed on the outer diameter side, and constitutes an outer member. Further, the seal 76 includes a magnetic encoder including a multipolar magnet and a slinger, and the rotation sensor 77 can detect the number of rotations.

As described above, the axle support structure 61 is configured. Such an axle support structure 61 can prevent the multipolar magnet included in the magnetic encoder from falling off from the slinger.

The rotational speed of the axle, etc. can be detected reliably. In addition, since such an axle support structure 61 includes a magnetic encoder with improved corrosion resistance, a long life can be achieved.

The shape of the slinger may be substantially L-shaped or substantially Z-shaped in cross section. Furthermore, the cylindrical portion may extend in the circumferential direction, or may be in the shape of a tongue partially provided with a notch.

In the above embodiment, although the case where balls are used as the rolling elements has been described, the present invention is also applicable to the case where tapered rollers are used as the rolling elements. In addition, the present invention is also applicable to rolling bearings of a type not including a seal, and rolling bearings including races such as an outer ring and an inner ring.

Further, the magnetic encoder described above is not limited to the force included in the rolling bearing, and may be included in the sliding bearing. Furthermore, the present invention may be applied not only to the rotation shaft and the like but also to detect the rotation speed of other rotation members, etc., and together with the detection sensor, a rotation detection device may be configured to detect the rotation speed etc. . Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the illustrated embodiments. Various modifications and variations can be made to the illustrated embodiment within the same or equivalent scope of the present invention.

Industrial applicability

[0060] The magnetic encoder according to the present invention is effectively used for rolling bearings and the like for automobiles because the corrosion resistance is improved.

[0061] The rolling bearing according to the present invention is effectively used when a long life is required because it is provided with a magnetic encoder such as for an automobile with a reduced risk of breakage.

Claims

The scope of the claims

[1] A plastic multipole magnet having a disc shape, a through hole at the center thereof, and magnetic poles alternately arranged in the circumferential direction;

A cylindrical portion, a flange extending to the outer diameter side from one end of the cylindrical portion, and a flange portion extending in the axial direction from the outer diameter end of the flange, the cross section of which is substantially reverse Z-shaped A magnetic encoder including a certain slider,

The magnetic encoder, wherein the multipolar magnet is press-fitted to the inner diameter side of the collar and held by the slinger.

[2] The magnetic encoder according to claim 1, wherein an axial end of the flange portion is crimped to an inner diameter side.

[3] The magnetic encoder according to claim 2, wherein the crimped portion crimped to the inner diameter side is continued in the circumferential direction.

[4] The magnetic encoder according to claim 1, wherein the collar portion is provided with notches extending in the axial direction at a plurality of circumferential positions.

[5] The multipolar magnet is made of a plastic including a rare earth magnetic powder and a plastic as a binder for binding the rare earth magnetic powder,

The magnetic encoder according to claim 1, wherein a anti-glare coating is formed on the surface of the multipolar magnet.

[6] The magnetic encoder according to claim 5, wherein a anti-glare coating is formed on the surface of the magnetic encoder.

[7] The magnetic encoder according to claim 5, wherein the protection coating is a coating of metal.

[8] The magnetic encoder according to claim 5, wherein the protection coating is formed by electrodeposition coating.

[9] The magnetic encoder according to claim 8, wherein the electrodeposition coating is cationic electrodeposition coating.

[10] A rolling bearing comprising the magnetic encoder according to claim 1.