JP2006161990A - Bearing for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing for a wheel capable of preventing impairing of corrosion resistance of a magnetic encoder by rust received from an internal member and a shaft. <P>SOLUTION: This bearing comprises double row rolling elements 3 between rolling faces 1a, 2a opposite to each other, of an external member 1 mounted on a car body and the internal member 2 to which the wheel is mounted, and the magnetic encoder 10 is fitted to an outer periphery of an inboard-side end of the internal member 2. The internal member 2 is composed of a hub wheel 5 and an inner ring 6 fitted to an outer periphery of a shaft portion 5b of the hub wheel 5. At least one of the inner ring 6, the shaft portion 5b of the hub wheel 5 and a shaft 22a to which the hub wheel 5 is fitted, is subjected to rust resistant or composed of a corrosion-resisting material. A rust diffusion inhibiting member may be mounted between the inner ring 6 and the magnetic encoder 10, for the application of the rust-proofing treatment and the corrosion-resisting material. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wheel bearing provided with a magnetic encoder for detecting rotation.

  Conventionally, the following structure is often used as an anti-skid rotation detection device for preventing automobile skid. That is, the rotation detection device is composed of a toothed rotor and a sensing sensor, and is generally arranged so as to be separated from the seal device for sealing the bearing and constitute one independent rotation detection device. . Such a conventional example has a structure in which a toothed rotor fitted to a rotating shaft is sensed and detected by a rotation detection sensor attached to a knuckle, and a bearing used is provided independently on the side thereof. Protected against intrusion of moisture or foreign matter by the sealed device.

  As another example, Patent Document 1 discloses a bearing seal having a rotation detection device for detecting wheel rotation for the purpose of reducing the mounting space of the rotation detection device and dramatically improving the sensing performance. A structure is shown in which an elastic member mixed with magnetic powder is circumferentially vulcanized and bonded in the radial direction of a slinger to be used, and magnetic poles are alternately arranged there.

  Further, in Patent Document 2, for the purpose of reducing the dimension in the axial direction, improving the degree of sealing between the rotating member and the fixed member, and enabling easy attachment, Is shown, and a rotary disk is attached to the rotary member, and a multi-polar coder is attached to the rotary disk. The coder used is made of an elastomer to which magnetic particles are added, and is a sealing means in which the side surface of the coder is substantially flush with the fixing member.

  A coder made of plastic (plastomer) containing magnetic powder or magnetic particles can be formed into a bowl using a mold suitable for the product shape, like conventional injection molding or compression molding. Or by forming the sheet by extrusion molding using a T-shaped die or sheet molding such as calendering, and making it into a product shape by punching, etc., and then adhesively fixing on a metal substrate with an adhesive or the like You may make it. In this case, the metal substrate may be assembled in advance in the mold as in the case of insert molding, and then the molten resin may be poured and the bonding process may be simultaneously processed.

Japanese Patent No. 2816783 JP-A-6-281018

However, each of the above magnetic encoders contains a magnetic powder in a multipolar magnet. On the other hand, when used for a bearing for an automobile, etc., it is placed in a harsh environment exposed to road surface salty mud water. Rust generation during long-term use becomes a problem. In particular, when the content of magnetic powder is increased for miniaturization, rust is likely to occur. Then, although it thought about carrying out the antirust process of the multi-pole magnet of a magnetic encoder, selection of an appropriate antirust material is difficult.
In addition, the elastomer or plastomer in which the multipolar magnet contains the magnetic powder as described above has various problems as described below. The thing made into the sintered compact which sintered the powder mixed with powder was proposed (Japanese Patent Application No. 2001-290300). When such a multipolar magnet is used, a rust prevention treatment according to the characteristics is required.

Therefore, the applicant of the present invention has formed a surface of a sintered body to be a multipolar magnet with an anticorrosion film of a clear high anticorrosion paint (Japanese Patent Application No. 2003-012710) and a sintered to be a multipolar magnet. The body surface was subjected to cationic electrodeposition (Japanese Patent Application No. 2003-279563). These are all excellent in the corrosion resistance of the multipolar magnet itself.
However, when the rust generated from the inner ring and the shaft comes into contact with the magnetic encoder, so-called rust is generated, which adversely affects the corrosion resistance of the magnetic encoder. Such a problem of rust is particularly likely to occur in a magnetic encoder using a sintered multi-pole magnet in which the amount of magnetic powder is increased to increase the magnetic force.

An object of the present invention is to provide a wheel bearing capable of preventing the corrosion resistance of a magnetic encoder from being deteriorated by rust from inner members and shafts.
Another object of the present invention is to secure a magnetic force that enables stable sensing to the magnetic encoder, and to prevent the problem of deterioration in corrosion resistance due to the rust.

A wheel bearing according to a first aspect of the present invention has an outer member attached to the vehicle body having a double row rolling surface on the inner periphery, and a rolling surface facing the respective rolling surfaces on the outer periphery. For a wheel comprising an inner member to which a wheel is attached and a double row rolling element interposed between these opposing rolling surfaces, and a magnetic encoder fitted to the outer periphery of the inboard side end of the inner member. The bearing is characterized in that a rust-proofing treatment is performed around the end portion on the inboard side of the inner member. The wheel bearing may be for a driving wheel or a driven wheel.
According to this structure, since the rust prevention process is performed around the end part of the inboard member on the inboard side, the corrosion resistance of the end part side of the inboard member on the inboard side is improved. Therefore, it is possible to prevent the rust generated in the inner member from coming into contact with the surface of the magnetic encoder and reducing the corrosion resistance of the magnetic encoder. That is, the corrosion resistance of the magnetic encoder is prevented from being reduced due to rust.

When the inner member is a hub wheel having a wheel mounting flange and an inner ring fitted to the outer periphery of the shaft part of the hub wheel, and when the magnetic encoder is fitted to the outer periphery of the inner ring, Rust prevention treatment may be applied to at least one of the inner ring and the shaft part of the hub ring.
In the case of this configuration, at least one of the inner ring and the shaft part of the hub ring is subjected to rust prevention treatment, so that the corrosion resistance of the magnetic encoder is prevented from being lowered by rust from the shaft part of the inner ring or the hub ring. .

A wheel bearing according to a second aspect of the present invention has an outer member attached to the vehicle body having a double row rolling surface on the inner periphery, and a rolling surface facing the respective rolling surfaces on the outer periphery. An inboard member on which the wheel is mounted, a double row rolling element interposed between the facing rolling surfaces, and a shaft fitted to the inner diameter surface of the inner member, the inboard side of the inner member In the wheel bearing in which a magnetic encoder is fitted to the outer periphery of the end, the shaft is subjected to rust prevention treatment.
In the case of this configuration, since the shaft fitted to the inner diameter surface of the inner member is subjected to rust prevention treatment, it is possible to prevent the corrosion resistance of the magnetic encoder from being lowered due to the rust generated on the shaft and coming into contact with the surface of the magnetic encoder. .

  In the first and second inventions, various surface treatments can be applied to the rust prevention treatment, and painting or plating may be used. As the coating, a clear-type highly anticorrosive coating film treatment, cationic electrodeposition, or the like can be applied.

A wheel bearing according to a third aspect of the present invention has an outer member attached to the vehicle body having a double row rolling surface on the inner periphery, and a rolling surface facing the respective rolling surfaces on the outer periphery. For a wheel comprising an inner member to which a wheel is attached and a double row rolling element interposed between these opposing rolling surfaces, and a magnetic encoder fitted to the outer periphery of the inboard side end of the inner member. The bearing is characterized in that the periphery of the inboard side end portion of the inner member is made of a corrosion-resistant material. Examples of the corrosion-resistant material used for these include stainless steel, aminium, titanium, and magnesium. The wheel bearing may be for a driving wheel or a driven wheel.
According to this configuration, since the periphery of the end portion on the inboard side of the inner member is made of the corrosion resistant material, the corrosion resistance around the end portion of the inner member is improved. Therefore, it is possible to prevent the rust generated in the inner member from coming into contact with the surface of the magnetic encoder and reducing the corrosion resistance of the magnetic encoder.

In a third aspect of the invention, the inner member includes a hub wheel having a wheel mounting flange and an inner ring fitted to the outer periphery of the shaft portion of the hub wheel, and the magnetic encoder is fitted to the outer periphery of the inner ring. When combined, at least one of the inner ring and the hub ring may be made of a corrosion-resistant material.
Also in this configuration, since at least one of the inner ring and the hub ring is made of a corrosion-resistant material, it is possible to prevent the corrosion resistance of the magnetic encoder from being lowered due to rust from the inner ring and the hub ring.

A wheel bearing according to a fourth aspect of the present invention has an outer member attached to the vehicle body having a double row rolling surface on the inner periphery, and a rolling surface facing each of the rolling surfaces on the outer periphery. An inner member to which a wheel is attached; a double row rolling element interposed between the opposing rolling surfaces; and a shaft fitted to an inner diameter surface of the inner ring; and an inboard side end of the inner member. In a wheel bearing in which a magnetic encoder is fitted on the outer periphery, the shaft is made of a corrosion-resistant material.
When the shaft is made of a corrosion-resistant material, it is possible to prevent the corrosion resistance of the magnetic encoder from being lowered by rust from the shaft.

A wheel bearing according to a fifth aspect of the present invention has an outer member attached to the vehicle body having a double row rolling surface on the inner periphery, and a rolling surface facing each of the rolling surfaces on the outer periphery. An inner member to which a wheel is attached, and a double row rolling element interposed between the opposing rolling surfaces, the inner member having a hub wheel having a wheel mounting flange, and the hub wheel An inner ring fitted to the outer periphery of the shaft portion, and in the wheel bearing in which the magnetic encoder is fitted to the outer periphery of the inner ring, the inner ring, the shaft portion of the hub wheel, and the inner member are fitted. A rust movement preventing member for preventing rust generated from any of the shafts from moving to the magnetic encoder is provided between the inner ring and the magnetic encoder. The wheel bearing may be for a driving wheel or a driven wheel.
In this configuration, the rust generated from any of the inner ring, the shaft part of the hub ring, and the shaft is prevented from moving to the magnetic encoder by the rust movement preventing member. Therefore, it is possible to prevent the rust generated on the inner member and the shaft from coming into contact with the surface of the magnetic encoder and reducing the corrosion resistance of the magnetic encoder. That is, the corrosion resistance of the magnetic encoder is prevented from being reduced due to rust.

In any one of the first to fifth inventions according to the present invention, the magnetic encoder supports a multipolar magnet in which magnetic poles are alternately formed in a circumferential direction, and supports the multipolar magnet, and is arranged on an outer periphery of the inner member. A sintered body including a cored bar to be fitted and the multipolar magnet may be a sintered body obtained by sintering a mixed powder of magnetic powder and nonmagnetic metal powder.
Since this multi-pole magnet is a sintered body obtained by sintering a mixed powder of magnetic powder and non-magnetic metal powder, stable sensing is achieved by increasing the blending ratio of magnetic powder while ensuring the strength of the sintered body. Therefore, it is possible to secure a magnetic force that can be obtained and to achieve compactness. When the blending ratio of the magnetic powder is increased, rust is likely to be generated, so that the influence of rust from the inner member and the shaft is large. However, rust is prevented by adopting any one of the first to fifth aspects of the invention. Therefore, while ensuring the strength of the sintered body, it is possible to increase the blending ratio of the magnetic powder to ensure the magnetic force that can provide stable sensing, to achieve compactness, and to have excellent corrosion resistance against rust, etc. .

In the wheel bearing according to the first aspect of the present invention, in the wheel bearing in which the magnetic encoder is fitted to the outer periphery of the inner member, the inner member has an antirust treatment around the end portion on the inboard side. It is possible to prevent the corrosion resistance of the magnetic encoder from being reduced by rust from the inner member.
In the wheel bearing according to the second aspect of the present invention, in the wheel bearing in which the magnetic encoder is fitted to the outer periphery of the inner member, the shaft fitted to the inner member is subjected to rust prevention treatment. It is prevented that the corrosion resistance of the magnetic encoder is reduced due to the received rust.
The wheel bearing according to a third aspect of the present invention is a wheel bearing in which a magnetic encoder is fitted to the outer periphery of the inner member, and the inner periphery of the inner member is made of a corrosion resistant material. It is prevented that the corrosion resistance of the magnetic encoder is reduced due to the rust from the side members.
In the wheel bearing according to a fourth aspect of the present invention, in the wheel bearing in which the magnetic encoder is fitted to the outer periphery of the inner member, the shaft fitted to the inner diameter surface of the inner ring is made of a corrosion-resistant material. It is prevented that the corrosion resistance of the magnetic encoder is reduced due to the received rust.
A wheel bearing according to a fifth aspect of the present invention is a rust movement inhibitor that prevents rust generated from any of an inner ring, a shaft portion of a hub ring, and a shaft to which an inner member is fitted from moving to a magnetic encoder. Since the member is provided between the inner ring and the magnetic encoder, it is possible to prevent the corrosion resistance of the magnetic encoder from being lowered due to rust from the inner member or the shaft.
In these first to fifth inventions, the magnetic encoder includes a multipolar magnet having magnetic poles alternately formed in the circumferential direction, and a core bar that supports the multipolar magnet and is fitted to the outer periphery of the inner member. When the above-mentioned multipolar magnet is a sintered body obtained by sintering a mixed powder of magnetic powder and nonmagnetic metal powder, it secures the magnetic force to obtain stable sensing while ensuring the strength of the sintered body. And the deterioration of the corrosion resistance due to the rust is prevented.

  A first embodiment of the present invention will be described with reference to FIGS. This wheel bearing device with a magnetic encoder includes an outer member 1 having a double row rolling surface 1a on the inner periphery, and an inner member 2 having a rolling surface 2a facing the respective rolling surfaces 1a on the outer periphery. And a double row rolling element 3 interposed between the facing rolling surfaces 1a and 2a. This wheel bearing device is a double-row angular ball bearing type, and the rolling elements 5 are formed of balls, and are held by a cage 4 for each row. Each rolling surface 1a, 2a consists of the inner surface of a groove having an arcuate cross section, and is formed so that the contact angle is back to back. The outboard side end and the inboard side end of the bearing space between the outer member 1 and the inner member 2 are sealed by sealing means 8 and 9, respectively. In this specification, the side closer to the outer side in the vehicle width direction of the vehicle when attached to the vehicle is referred to as the outboard side, and the side closer to the center of the vehicle is referred to as the inboard side.

  The outer member 1 is a member on the fixed side, and has a flange 1b for mounting the vehicle body on the outer periphery, and the whole is an integral part. The outer member 1 is fitted into a mounting hole provided in a knuckle (not shown) of a suspension device for a vehicle body, and is a bolt inserted into the flange 1b for mounting the vehicle body or a screwed bolt (not shown). ) To secure the knuckle.

  The inner member 2 is a member on the rotating side, and is a hub wheel 5 having a wheel mounting flange 5a and an inner ring fitted to the outer periphery of the inboard side portion of the shaft portion 5b of the hub wheel 5. 6 The hub wheel 5 and the inner ring 6 are formed with the rolling surfaces 2a of the respective rows. The flange 5a of the hub wheel 5 is provided with bolt press-fitting holes at a plurality of locations in the circumferential direction, and brake wheels and wheels (not shown) are attached by bolts 7 press-fitted into the holes.

  Specifically, the inner ring 6 is fitted to an inner ring fitting surface 5c formed on the outer circumference of the hub ring 5 so as to have a step smaller than that of other parts and to have a smaller diameter. Further, the inboard side width surface of the inner ring 6 is pressed in the axial direction by the crimping portion 5e that crimps the inboard side end of the hub ring 5 to the outer diameter side, and the inner ring fitting surface 5c of the hub ring 5 is pressed. It will be in the state clamped by the level | step difference 5d and the crimping part 5e which follow an edge part. The caulking portion 5b is caulked by swing caulking or the like.

  The outer diameter surface on the inboard side of the rolling surface 2a of the inner ring 6 is formed as a stepped cylindrical surface having a small diameter outer diameter surface 6b on the inboard side and a large diameter outer diameter surface 6a on the outboard side, and the large diameter portion 6a. The magnetic encoder 10 is fitted to the above. The level difference between the large-diameter outer diameter surface 6a and the small-diameter outer diameter surface 6b is such a small level that a gap is generated between the large-diameter portion 6a and the inner diameter surface of the magnetic encoder 10 when the magnetic encoder 10 is press-fitted into the large-diameter portion 6a. There may be. Further, the outer diameter surface on the inboard side of the rolling surface 2a of the inner ring 6 may be a cylindrical surface without such a step.

  When the wheel bearing is assembled to the vehicle, the stem portion 22a of the constant velocity joint outer ring 22 serving as one joint member is inserted into the central hole 21 of the hub 5 and is spline-fitted, and the tip of the stem portion 22a is inserted. The constant velocity joint outer ring 22 is coupled to the inner member 2 by tightening the nut 23 screwed into the inner member 2.

  As shown in enlarged views in FIGS. 2 and 3, the magnetic encoder 10 includes a disk-shaped multipolar magnet 14 in which magnetic poles are alternately formed in the circumferential direction, and a cored bar 11 that supports the multipolar magnet 14. Composed. The core metal 11 has a cylindrical portion 11a fitted to the outer diameter surface of the inner ring 6, and a standing plate portion 11b extending from one end of the cylindrical portion 11a to the outer diameter side. The multipolar magnet 14 is a standing plate portion. It is arranged on the outward surface of 11b. From the outer diameter edge of the upright plate portion 11b, there is a flange portion 11c extending to the opposite side of the cylindrical portion 11a in the axial direction, and the multi-pole magnet 14 is cored by caulking the flange portion 11c to the inner diameter side. 11 is attached. The core metal 11 is made of a press-formed product of a metal plate such as a steel plate.

  The multipolar magnet 14 is a sintered body obtained by molding and sintering a mixed powder of magnetic powder and nonmagnetic metal powder, and magnetic poles N and S are alternately magnetized in the circumferential direction. The magnetization is performed, for example, after sintering.

  The magnetic powder mixed in the multipolar magnet 14 may be isotropic or anisotropic ferrite powder such as barium-based and strontium-based. The magnetic powder may be a rare earth magnetic material. For example, samarium iron (SmFeN) magnetic powder and neodymium iron (NdFeB) magnetic powder, which are rare earth magnetic materials, may be used alone. The magnetic powder may be manganese aluminum (MnAl) gas atomized powder. The magnetic powder may be a mixture of any two or more of these samarium iron (SmFeN) magnetic powder, neodymium iron (NdFeB) magnetic powder, and manganese aluminum (MnAl) gas atomized powder.

  The non-magnetic metal powder forming the multipolar magnet 14 may be a powder of tin, copper, aluminum, nickel, zinc, tungsten, manganese, or a non-magnetic stainless steel metal powder alone (one type). Body, a mixed powder composed of two or more kinds, or an alloy powder composed of two or more kinds can be used.

  In FIG. 2, the sealing means 9 on the inboard side is a combination seal including the magnetic encoder 10 and the sealing member 12 fitted to the inner diameter surface of the outer member 2, and is a sealing means with a magnetic encoder. The core 11 of the magnetic encoder 10 also functions as a slinger.

The seal member 12 includes a core bar 17 having an inverted L-shaped cross section facing the core bar 10 of the magnetic encoder 10 and a rubber-like elastic body 16 fixed to the core bar 17 by vulcanization adhesion or the like. . The core metal 17 is fitted to the inner diameter surface of the outer member 1 at the cylindrical portion 17a. The elastic body 16 includes two radial-side seal lips 16 a that are in contact with the upright plate portion 16 a of the core 11 of the magnetic encoder 10 and two radial sides that are in contact with the outer diameter surface of the cylindrical portion 11 a of the core 11. It consists of seal lips 16b and 16c. These two radial-side seal lips 16b, 16c have tips opposite to each other in the axial direction, and the rolling lip 3b-side seal lip 16b functions as a grease leakage prevention means.
A gap forming the labyrinth seal 18 is formed between the cylindrical portion 17 a of the core 17 of the seal member 12 and the outer diameter end of the magnetic encoder 10.

  A magnetic sensor 15 is installed through a predetermined gap with respect to the multipolar magnet 14 of the magnetic encoder 10. The magnetic sensor 15 is attached to the outer member 1 or attached to a knuckle (not shown) to which the outer member 1 is attached. The magnetic sensor 15 may be a Hall element, a magnetoresistive element, or the like disposed so as to face a part of the multipolar magnet 14 in the circumferential direction, and may be disposed so as to face the entire circumference of the multipolar magnet 14. Alternatively, a coil with a core or yoke may be used.

  An anticorrosive film 30 is provided as an antirust treatment around the inboard side end of the inner member 2. The periphery of the end portion on the inboard side of the inner member 2 referred to here is, for example, a portion closer to the inboard side than the rolling surface 2a on the inboard side of the inner member 2. In this embodiment, specifically, the anticorrosion film 30 is provided on the end faces 6c, 6d on the inboard side and the outer diameter surface of the inner ring 6. When the outer diameter surface of the inner ring 6 has a stepped shape as described above, the anticorrosion coating 30 extends over the small diameter outer diameter surface 6b, the large diameter outer diameter surface 6a, and the end surface 6d serving as a step between them. Provided.

As with the anticorrosion film 30 on the inner ring 6, the shaft 5b of the hub wheel 5 in FIG. 1 is provided with an anticorrosion film (not shown) around the end portion on the inboard side, and the hub wheel 5 is fitted with the shaft. It is preferable to apply an anticorrosion film (not shown) to the stem portion 22 a of the constant velocity joint outer ring 22. The range in which the anticorrosive film is applied to the hub wheel 6 is, for example, a portion closer to the inboard side than the rolling surface 2a on the inboard side. When the caulking portion 5e is provided, the caulking portion 5e also has an anticorrosive film.
The range in which the anticorrosion film is applied to the stem portion 22a is, for example, a portion on the inboard side with respect to the rolling surface 2a on the inboard side, and a range on the outboard side with respect to the cup portion 22b of the constant velocity joint outer ring 22.

  The anticorrosion coating 30 on the inner ring 6 and the anticorrosion coating on the hub wheel 5 and the stem portion 22a can be a coating or plating layer by painting or plating. As the coating, a film treatment of a clear high anticorrosion paint or electrodeposition such as cationic electrodeposition can be applied.

Examples of clear anticorrosive paints include modified epoxy paints, modified epoxy phenol curable paints, epoxy melamine paints, and acrylic paints. Among these, modified epoxy phenol curable paints and epoxy melamine paints are particularly suitable.
There are two types of electrodeposition coating: anionic electrodeposition with a base material as a positive electrode and cationic electrodeposition with a negative electrode. Cationic electrodeposition is more excellent in rust prevention. When the anticorrosion coating 30 is an electrodeposition coating, the moisture content is about 10 percent or less, and drying and baking are performed to form the final coating.

  The multipolar magnet 14 of the magnetic encoder 10 is also preferably subjected to rust prevention treatment. As for the antirust treatment of the multipolar magnet 14, various surface treatments can be applied as in the formation of the anticorrosion film 30 on the inner ring 6, and may be painted or plated. As the coating, a clear-type highly anticorrosive coating film treatment, cationic electrodeposition, or the like can be applied. The rust prevention treatment of the magnetic encoder 10 may be performed in a state where the core metal 11 and the multipolar magnet 14 are integrated.

According to the wheel bearing of this configuration, the rotation of the inner member 1 rotating together with the wheel is detected by the magnetic sensor 15 via the magnetic encoder 10 attached to the inner member 1, and the wheel rotation speed is detected. The
In general, the wheel bearing is exposed to a road surface environment, and the magnetic encoder 10, the inner ring 6, the hub wheel 5, the constant velocity joint outer ring 16, and the like may be subjected to salt mud water. As a result, when the stem 6a of the inner ring 6, the hub wheel 5 and the constant velocity joint outer ring 16 is rusted, the rust adheres to the multipolar magnet 14 of the magnetic encoder 10 and the corrosion resistance of the magnetic encoder 10 decreases. However, in this embodiment, since the anticorrosion film 30 is applied to the inner ring 6 and the anticorrosion film is also applied to the stem portion 6a of the hub ring 5 and the constant velocity joint outer ring 16, the inner ring 6, the shaft part 5b of the hub ring 5, Further, the occurrence of rust on the stem portion 6a of the constant velocity joint outer ring 16 is prevented, and the corrosion resistance of the magnetic encoder 10 is prevented from being deteriorated by rust from these members. When the magnetic encoder 10 is provided with an anticorrosion film, the corrosion resistance is further improved. Therefore, the anticorrosion property of the magnetic encoder 10 is ensured even in a harsh environment subject to salt mud water.

  In this embodiment, since the multipolar magnet 14 of the magnetic encoder 10 is made of a sintered body mixed with magnetic powder, the blending ratio of the magnetic powder is increased and stable sensing is obtained while ensuring the strength of the sintered body. The magnetic force can be secured and the wear resistance is excellent. The surface hardness of the multipolar magnet 14 is harder than that of a conventional elastic member or elastomer coder containing magnetic powder or magnetic particles. For this reason, when applied to the rotation detection device 20 for detecting wheel rotation, particles such as sand particles bite into the gap between the surface of the multipolar magnet 14 on the rotating side and the surface of the magnetic sensor 15 on the fixed side while the vehicle is running. Even if it is inserted, wear damage of the multipolar magnet 14 hardly occurs, and there is a significant reduction effect of wear as compared with a conventional elastic body.

  In this embodiment, the sealing means 7 is composed of the sealing member 12 attached to the outer member 1 and the core 1 of the magnetic encoder 10, and the magnetic encoder 10 constitutes a part of the sealing means 9. Therefore, both the function as the magnetic encoder 10 and the sealing function can be obtained with a compact configuration. In particular, since the sealing member 12 is formed to have the side lip 16a and the two radial lips 16a and 16b, the sealing function is excellent.

  In the above embodiment, the anticorrosion film 30 such as the inner ring 6 is provided, but instead of providing the anticorrosion film 30, the inner ring 6 may be made of an anticorrosive material. Further, the hub wheel 5 and the constant velocity joint outer ring 16 may be made of a corrosion resistant material. Among these, for example, the inner ring 6 and the constant velocity joint outer ring 16 may be made of a corrosion-resistant material, and the hub ring 5 may be made of a general steel material. Examples of the corrosion-resistant material used for these include stainless steel, aminium, titanium, and magnesium.

  As described above, even when the inner ring 6, the hub ring 5 and the constant velocity joint outer ring 16 are made of a corrosion-resistant material, the inner ring 6, the shaft portion 5b of the hub ring 5, the constant velocity joint outer ring 16 and the like are obtained. It is prevented that the corrosion resistance of the magnetic encoder 10 is lowered due to rust.

  Note that the corrosion-resistant material and the anticorrosion film may be appropriately combined. For example, the inner ring 6, which is a relatively small part, may be made of a corrosion-resistant material, and the hub ring 5 and the constant velocity joint outer ring 16 may be subjected to a surface treatment for forming an anticorrosive film that serves as an antirust treatment.

  4 and 5 show still other embodiments of the present invention. In each of these embodiments, a rust movement prevention member 40 is provided between the inner ring 6 and the magnetic encoder 10 in place of the configuration in which the anticorrosion film 30 such as the inner ring 6 is applied in the embodiment shown in FIGS. Is. The rust movement preventing member 40 may be any member that can prevent the rust generated in any of the inner ring 6, the shaft portion 5 b of the hub wheel 5, and the constant velocity joint outer ring 16 from moving to the magnetic encoder 10. The rust movement preventing member 40 is made of a corrosion-resistant metal material, or a steel plate, steel material or the like whose surface is subjected to rust prevention treatment is used. As the corrosion-resistant material and the antirust treatment, those described above for the inner ring 6 can be used. The rust movement preventing member 40 protrudes from an end surface 6d between the large-diameter outer diameter surface 6a and the small-diameter outer diameter surface 6b of the inner ring 6 in the case of an inner ring with an outer circumferential step in FIG. It is provided as follows.

  The rust movement preventing member 40 in the embodiment of FIG. 4 is a ring-shaped member obtained by forming a thin plate with an inverted L-shaped cross section, and a corner portion between the large-diameter outer-diameter surface 6a of the inner ring 6 and the end surface 6d following the inboard side. It is provided to cover. In this example, the rust movement preventing member 40 protrudes from the end face 6d by the thickness. On the large outer diameter surface 6a of the inner ring 6, a stepped portion 43 for fitting corresponding to the plate thickness of the rust movement preventing member 40 is provided, and the rust movement preventing member 40 is fitted into the stepped portion 43, thereby moving the rust. The blocking member 40 does not interfere with the press-fitting work of the magnetic encoder 10 into the inner ring 6.

  In the embodiment of FIG. 5, the rust movement prevention member 40 is a plate formed in a cylindrical shape, and is fitted to the outer periphery of the fitting step portion 43 of the inner ring 6 so that the inboard side end becomes the step surface of the inner ring 6. It protrudes from the end face 6d.

4 and 5, even if rust occurs on the inner ring 6, the shaft portion 5b of the hub wheel 5 (FIG. 1), the stem portion 16a of the constant velocity joint outer ring 16, or the like, The movement of rust to the magnetic encoder 10 is blocked by the rust movement blocking member 40 interposed between the encoder 10 and the encoder 10. Therefore, the corrosion resistance of the magnetic encoder 10 is prevented from being reduced by rust from the inner ring 6, the shaft portion 5b of the hub ring 5, the constant velocity joint outer ring 16, and the like.
The other configurations and effects in the embodiments of FIGS. 4 and 5 are the same as those of the first embodiment shown in FIGS.

FIG. 6 shows another embodiment of the wheel bearing. This wheel bearing is of the second generation type, and the inner member 1 includes a hub wheel 5A and double-row inner rings 6A and 6B fitted to the outer periphery of the shaft portion 5Ab of the hub wheel 5A. . The end surface of the inner ring 6B on the inboard side is pressed against the hub wheel 5A by the step surface of the constant velocity joint outer ring 22.
In this configuration, any one of the following configurations (1) to (3) is taken to prevent rust.
(1) As in the first embodiment, at least one of the inner ring 6B on the inboard side, the shaft portion 5Ab of the hub wheel 5A, and the stem portion 22a of the constant velocity joint outer ring 22 is described in the first embodiment. Rust prevention treatment similar to that of the anticorrosion coating 30 (FIG. 2) is performed.
(2) At least one of the inner ring 6B on the inboard side, the hub ring 5A, and the constant velocity joint outer ring 16 is made of a corrosion-resistant material.
(3) Rust generated from any of the inner ring 6B on the inboard side, the shaft portion 5Ab of the hub wheel 5A, and the constant velocity joint outer ring 22 moves to the magnetic encoder 10 as in the example of FIG. 4 or FIG. A rust movement preventing member (not shown) for preventing the above is provided between the inner ring 6B and the magnetic encoder 10.

  Also in this configuration, the corrosion resistance of the magnetic encoder 10 is prevented from being reduced by rust from the inner ring 6, the shaft portion 5b of the hub wheel 5, the constant velocity joint outer ring 22, and the like, as in the above embodiments. .

  In each of the above embodiments, the multipolar magnet 14 of the magnetic encoder 10 is a sintered body, but the multipolar magnet 14 may be a rubber magnet or a plastic magnet. Further, the present invention can be applied not only to wheel bearings for supporting driving wheels but also to wheel bearings for supporting driven wheels.

It is sectional drawing of the bearing apparatus for wheels with a magnetic encoder which concerns on one Embodiment of this invention. It is the partial expanded sectional view. It is a fragmentary perspective view of the magnetic encoder. It is a partial expanded sectional view of the wheel bearing which concerns on other embodiment of this invention. It is a partial expanded sectional view of the wheel bearing which concerns on other embodiment of this invention. It is sectional drawing of the wheel bearing which concerns on other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Outer member 2 ... Inner member 1a, 2a ... Rolling surface 3 ... Rolling element 5 ... Hub wheel 5b ... Shaft part 5A ... Hub wheel 5Ab ... Shaft part 6 ... Inner ring 6A, 6B ... Inner ring 6a ... Outer diameter Diameter surface 6b ... Small diameter outer diameter surfaces 6c and 6d ... End face 9 ... Sealing means 15 ... Magnetic sensor 22 ... Constant velocity joint outer ring 22a ... Stem portion (shaft)
30 ... Anticorrosion film 40 ... Rust movement prevention member

Claims (9)

  An outer member that has a double-row rolling surface on the inner periphery and is attached to the vehicle body, an inner member that has a rolling surface that faces each of the rolling surfaces on the outer periphery and that has wheels attached thereto, and these opposing rolling members. A double row rolling element interposed between running surfaces, and a wheel bearing in which a magnetic encoder is fitted to an outer periphery of an inboard side end of the inner member, and an inboard side end of the inner member A bearing for a wheel characterized in that a rust prevention treatment is applied to the periphery of the part.   2. The inner member according to claim 1, wherein the inner member includes a hub wheel having a wheel mounting flange and an inner ring fitted to an outer periphery of a shaft portion of the hub wheel, and the magnetic encoder is fitted to the outer periphery of the inner ring. And at least one of the inner ring and the shaft part of the hub ring is subjected to a rust prevention treatment.   An outer member that has a double-row rolling surface on the inner periphery and is attached to the vehicle body, an inner member that has a rolling surface that faces each of the rolling surfaces on the outer periphery and that has wheels attached thereto, and these opposing rolling members. For a wheel having a double row rolling element interposed between running surfaces and a shaft fitted to the inner diameter surface of the inner member, and a magnetic encoder fitted to the outer periphery of the inboard side end of the inner member A bearing for a wheel, wherein the shaft is subjected to rust prevention treatment.   The wheel bearing according to any one of claims 1 to 3, wherein the antirust treatment is painting or plating.   An outer member that has a double-row rolling surface on the inner periphery and is attached to the vehicle body, an inner member that has a rolling surface that faces each of the rolling surfaces on the outer periphery and that has wheels attached thereto, and these opposing rolling members. A double row rolling element interposed between running surfaces, and a wheel bearing in which a magnetic encoder is fitted to an outer periphery of an inboard side end of the inner member, and an inboard side end of the inner member A wheel bearing characterized in that the periphery of the part is made of a corrosion-resistant material.   6. The inner member according to claim 5, wherein the inner member includes a hub wheel having a wheel mounting flange and an inner ring fitted to an outer periphery of a shaft portion of the hub wheel, and the magnetic encoder is fitted to the outer periphery of the inner ring. And at least one of the inner ring and the hub ring is made of a corrosion-resistant material.   An outer member that has a double-row rolling surface on the inner periphery and is attached to the vehicle body, an inner member that has a rolling surface that faces each of the rolling surfaces on the outer periphery and that has wheels attached thereto, and these opposing rolling members. In a wheel bearing comprising a double row rolling element interposed between running surfaces and a shaft fitted to an inner diameter surface of the inner ring, and a magnetic encoder fitted to an outer periphery of an inboard side end of the inner member. The wheel bearing is characterized in that the shaft is made of a corrosion-resistant material.   An outer member that has a double-row rolling surface on the inner periphery and is attached to the vehicle body, an inner member that has a rolling surface that faces each of the rolling surfaces on the outer periphery and that has wheels attached thereto, and these opposing rolling members. A double row rolling element interposed between the running surfaces, the inner member is a hub wheel having a wheel mounting flange, and an inner ring fitted to the outer periphery of the shaft portion of the hub wheel, In a wheel bearing in which the magnetic encoder is fitted to the outer circumference of the inner ring, rust generated from any of the inner ring, the shaft portion of the hub wheel, and the shaft to which the inner member is fitted moves to the magnetic encoder. A wheel bearing characterized in that a rust movement preventing member for preventing this is provided between the inner ring and the magnetic encoder.   The magnetic encoder according to any one of claims 1 to 8, wherein the magnetic encoder supports a multipolar magnet having magnetic poles alternately formed in a circumferential direction, and supports the multipolar magnet, and is fitted to an outer periphery of the inner member. A wheel bearing comprising a cored bar to be joined, wherein the multipolar magnet is a sintered body obtained by sintering a mixed powder of magnetic powder and nonmagnetic metal powder.

Images