JP2011089633A - Wheel bearing device with rotating speed detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel bearing device with a rotating speed detector enhancing positioning accuracy to improve reliability in rotating speed detection while enhancing airtightness of a fitting part of a protective cover to protect a magnetic encoder and enhancing rigidity to suppress deformation. <P>SOLUTION: A protective cover 10 formed in cup shape from synthetic resin of a non-magnetic material includes a fitting part 10a fitted into an outer member 2; a collar part 10b projected radially outward and brought into close contact with an end face 2c of the outer member 2; a disk-like shielding part 10c extended radially inward, with a sensor placed in proximity to the side face; a bottom part 10e blocking the end of the inner member 1 through an inclined part 10d; and a stepped part 10f bulging into a recess 7a of a fastening part 7, at the center of the bottom 10e. A large end face 5b of an inner ring 5 is arranged with a level difference L1 on the inner side from the end face 2c of the outer member 2, and a detection surface of a magnetic encoder 14 is arranged projecting by an amount (a) from the end face 2c of the outer member 2. The projecting amount (a) is set to be not smaller than the level difference L1 and to be smaller than the thickness t of the shielding part 10c. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a wheel bearing device with a rotational speed detection device that rotatably supports a wheel of an automobile or the like and incorporates a rotational speed detection device that detects the rotational speed of the wheel.

  Rotation speed detection device with built-in rotation speed detection device for detecting the rotation speed of the vehicle and controlling the anti-lock brake system (ABS) while supporting the wheel of the automobile to the suspension system. Wheel bearing devices are generally known. Conventionally, in such a wheel bearing device, a sealing device is provided between an inner member and an outer member that are in rolling contact with a rolling element, and a magnetic encoder in which magnetic poles are alternately arranged in a circumferential direction is provided as the sealing device. It is integrated with. A rotational speed sensor that is arranged facing this magnetic encoder and detects a change in magnetic pole of the magnetic encoder accompanying the rotation of the wheel is mounted on the knuckle after the wheel bearing device is mounted on the knuckle constituting the suspension device. .

  A structure as shown in FIG. 8 is known as an example of such a wheel bearing device with a rotational speed detection device. The wheel bearing device with a rotational speed detection device includes an outer member 50, an inner member 51, and a plurality of balls 52 accommodated between the outer member 50 and the inner member 51. The inner member 51 includes a hub ring 53 and an inner ring 54 press-fitted into the hub ring 53.

  The outer member 50 integrally has a vehicle body mounting flange 50b fixed to the knuckle 65 constituting the suspension device on the outer periphery, and double row outer rolling surfaces 50a and 50a are integrally formed on the inner periphery. A sensor 63 is supported and fixed to the knuckle 65 by a screw 66.

  The hub wheel 53 integrally has a wheel mounting flange 55 for mounting a wheel (not shown) at one end, an inner rolling surface 53a on the outer periphery, and a small diameter step extending in the axial direction from the inner rolling surface 53a. A portion 53b is formed. The inner ring 54 has an inner rolling surface 54a formed on the outer periphery, and is fixed in the axial direction by a caulking portion 53c formed by plastically deforming an end portion of the small diameter step portion 53b.

  A seal ring 56 is fitted and fixed to the outer end portion of the outer member 50, and the lip of the seal ring 56 is in sliding contact with the base portion 55 a of the wheel mounting flange 55. On the other hand, an encoder 57 is fitted and fixed to the outer peripheral surface of the inner end portion of the inner ring 54. The encoder 57 includes a support ring 58 having an L-shaped cross section, and an annular encoder body 59 attached and supported on the side surface of the support ring 58 over the entire circumference. In the encoder body 59, magnetic poles N and S are alternately magnetized at equal intervals in the circumferential direction.

  The inner end opening of the outer member 50 is closed by the cover 60. The cover 60 is formed in a petri dish from a nonmagnetic plate material such as a non-magnetic stainless steel plate, an aluminum alloy plate, or a high-functional resin, and has a circular closing plate portion 61 and an outer peripheral edge portion of the closing plate portion 61. And a cylindrical fitting portion 62 formed in the above.

  The side surface of the encoder main body 59 constituting the encoder 57 is disposed close to and opposed to the cover 60, and the detection unit 64 of the sensor 63 is adjacent to the side surface of the cover 60. The detection unit 64 and the encoder main body 59 are covered with each other. Proximity facing each other via 60. Thereby, the presence of the cover 60 can prevent water, iron powder, magnetic fragments, etc. from entering between the sensor 63 and the encoder 57, thereby preventing the sensor 63 and the encoder 57 from being damaged. It is possible to prevent the regular and periodic magnetic property changes of the main body 59 from being disturbed or deteriorated (see, for example, Patent Document 1).

JP 2000-249138 A

  However, such a conventional wheel bearing device with a rotational speed detection device has the following problems. First, the positioning of the cover 60 with respect to the outer member 50 is unstable. When the cover 60 is mounted, the bearing alone is transported, assembled to a vehicle, or mounted on wheels, the cover 60 is moved to a specified position by a stepping stone or the like. There is a risk of losing.

  Further, since the shape of the cover 60 is a simple U-shaped cross section, the rigidity is insufficient, and the cover 60 may be deformed by contact with a flying stone or the like, and may come into contact with the encoder main body 59. Furthermore, since the detection unit 64 of the sensor 63 faces the encoder 57 via the cover 60, the air gap may increase and the detection accuracy may decrease.

  The present invention has been made in view of such circumstances, and improves the airtightness of the fitting portion between the protective cover and the outer member to protect the magnetic encoder, and also increases the rigidity of the protective cover to suppress deformation. However, an object of the present invention is to provide a wheel bearing device with a rotational speed detection device that improves positioning accuracy and improves the reliability of rotational speed detection.

  In order to achieve such an object, the invention according to claim 1 of the present invention includes an outer member in which a double row outer rolling surface is integrally formed on the inner periphery, and a wheel attachment for attaching a wheel to one end. The hub ring has a flange integrally formed with a small diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small diameter step portion of the hub ring. An inner member in which a double-row inner rolling surface facing the running surface is formed, and a double-row rolling element that is movably accommodated between the inner and outer members. And a magnetic encoder externally fitted to the inner ring, a seal is attached to the outer end of the outer member, and a protective cover is attached to the inner end of the outer member, The opening of the annular space formed by the outer member and the inner member is sealed. In the wheel bearing device with a speed detection device, the inner ring is supported with respect to the hub wheel in a state in which a predetermined bearing preload is applied by a crimping portion formed by plastically deforming an end portion of the small diameter step portion of the hub wheel. A cylindrical fitting portion that is fixed in the axial direction, the protective cover is formed into a cup shape by injection molding of a non-magnetic synthetic resin, and the fitting portion is fitted in the outer member, A flange that protrudes radially outward from the flange and closely contacts the inner end face of the outer member, and a disk that extends radially inward from the flange and has the sensor close to the inner side surface. And a bottom portion for closing the inner side end portion of the inner member from the shielding portion through an inclined portion, and the protective cover is positioned by abutting against the end surface of the outer member. ing.

  As described above, in the wheel bearing device with a rotation speed detection device of the inner ring rotation type, in a state where a predetermined bearing preload is applied by the crimping portion formed by plastically deforming the end portion of the small diameter step portion of the hub wheel. A cylindrical fitting portion in which the inner ring is fixed in the axial direction with respect to the hub ring, and the protective cover is formed in a cup shape by injection molding of a synthetic resin of a non-magnetic material, and is fitted into the outer member; A flange portion protruding radially outward from the fitting portion and closely contacting the inner end surface of the outer member; and extending radially inward from the flange portion, and the sensor on the inner side surface A disc-shaped shielding part that is adjacent to the bottom part and a bottom part that covers the inner side end of the inner member from the shielding part through an inclined part, and the protective cover abuts against the end surface of the outer member. Therefore, the elastic modulus of material (compression rate) is applied to the outer member. Highly synthetic resin cover is closely fitted and fitted, and the fitting part is highly airtight, protecting the magnetic encoder from water, iron powder, magnetic fragments, etc. In addition, the rigidity of the protective cover is increased by the stepped shape including the collar portion, and deformation due to flying stones or the like can be suppressed. Furthermore, since the flange is press-fitted until it comes into close contact with the inner end face of the outer member, the positioning accuracy of the protective cover with respect to the outer member can be increased, and highly reliable speed detection can be achieved through accurate air gap adjustment. Can be done.

  Preferably, as in the invention described in claim 2, a cored bar formed into a substantially L-shaped cross section by press working from a steel plate at a portion of the fitting portion and the flange portion of the protective cover is insert-molded. As a result, the airtightness of the fitting portion of the protective cover can be further improved, and the rigidity of the protective cover can be further increased.

  More preferably, if the cored bar is formed of a non-magnetic austenitic stainless steel plate as in the invention described in claim 3, the speed can be detected accurately without affecting the flow path of the magnetic flux. can do.

  Moreover, if the stepped part which bulges in the recess of the said crimping part is formed in the center part of the bottom part of the said protective cover like invention of Claim 4, the rigidity of a protective cover is still higher. Therefore, deformation due to stepping stones can be suppressed.

  Preferably, as in the invention described in claim 5, if the stepped portion is formed in a substantially rectangular cross section along the shape of the recess of the caulking portion, the rigidity of the protective cover is further increased. Become.

  According to a sixth aspect of the present invention, the detection surface of the magnetic encoder is arranged so as to protrude by a from the inner end surface of the outer member, and the protrusion amount a is determined by the shielding portion of the protective cover. If the thickness is set to be smaller than the thickness t (a <t), the protective cover can be prevented from coming into contact with the inner ring, and the air gap can be set small, so that the detection accuracy can be increased.

  Moreover, if the recessed part is formed in the shielding part of the said protective cover so that it may adjoin to a magnetic encoder like the invention of Claim 7, and the sensor is arrange | positioned in this recessed part, the rigidity of a protective cover will be improved, If stepping stones collide with the protective cover to prevent deformation, the air gap can be set small, and the detection accuracy can be increased.

  Further, as in the invention described in claim 8, if the amount c of the recess is set to be smaller than the thickness b of the flange portion of the protective cover (c <b), the protective cover comes into contact with the inner ring. While maintaining the rigidity of the protective cover, it is possible to prevent a stepping stone or the like from colliding with the protective cover to prevent deformation, and to set the air gap small.

  Further, as in the ninth aspect of the invention, if the concave portion is formed in an eyebrow shape, there is an error in the circumferential positioning accuracy of the protective cover with respect to the sensor while maintaining the rigidity of the protective cover. Is acceptable.

  Further, as in the invention described in claim 10, a reinforcing material made of GF may be added to the protective cover in an amount of 10 to 50 wt%, and as in the invention described in claim 11, the protection A reinforcing material made of CF may be added to the cover in an amount of 5 to 50 wt%. Thereby, intensity | strength and rigidity become high and durability can be improved over a long period of time.

  Further, as in the invention described in claim 12, if the protective cover is made of one of polyamide 66, polyamide 6/12, and polyphenylene sulfide, the sensing performance of the rotational speed sensor is not adversely affected. In addition, it is excellent in corrosion resistance and has high strength and rigidity, so that durability can be maintained over a long period of time.

  The wheel bearing device with a rotational speed detection device according to the present invention is integrally formed with an outer member in which a double row outer rolling surface is integrally formed on the inner periphery and a wheel mounting flange for mounting a wheel on one end. A hub ring having a small-diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small-diameter step portion of the hub wheel, and facing the outer surface of the double row on the outer periphery. An inner member in which a double-row inner rolling surface is formed, a double-row rolling element housed between the inner member and the outer member so as to roll freely, and the inner ring A magnetic encoder externally fitted to the outer member, and a seal is attached to an outer end of the outer member, and a protective cover is attached to an inner end of the outer member. Speed at which the opening of the annular space formed by the inner member and the inner member is sealed In the wheel bearing device with a take-out device, the inner ring is supported with respect to the hub ring in a state where a predetermined bearing preload is applied by a crimping portion formed by plastically deforming an end portion of the small-diameter step portion of the hub ring. A cylindrical fitting portion that is fixed in the axial direction, the protective cover is formed into a cup shape by injection molding of a non-magnetic synthetic resin, and is fitted into the outer member, and from this fitting portion A flange that protrudes radially outward and is in close contact with the inner end surface of the outer member, and a disk-like shape that extends radially inward from the flange and the sensor is close to the inner side surface And a bottom portion that closes the inner side end portion of the inner member from the shielding portion through an inclined portion, and the protective cover is positioned in contact with the end surface of the outer member. As a result, the outer member has a high elastic modulus (compression rate). The grease cover is closely fitted and fitted, and the air tightness of the fitting part increases, protecting the magnetic encoder from water, iron powder, magnetic fragments, etc., and at the end of the outer member Moreover, the rigidity of the protective cover is increased by the stepped shape including the collar portion, and deformation due to flying stones or the like can be suppressed. Furthermore, since the flange is press-fitted until it comes into close contact with the inner end face of the outer member, the positioning accuracy of the protective cover with respect to the outer member can be increased, and highly reliable speed detection can be achieved through accurate air gap adjustment. Can be done.

1 is a longitudinal sectional view showing a first embodiment of a wheel bearing device with a rotation speed detection device according to the present invention. It is a principal part enlarged view of FIG. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the wheel bearing apparatus with a rotational speed detection apparatus which concerns on this invention. It is a principal part enlarged view of FIG. It is a longitudinal cross-sectional view which shows 3rd Embodiment of the wheel bearing apparatus with a rotational speed detection apparatus which concerns on this invention. It is a principal part enlarged view of FIG. It is a VII arrow line view of FIG. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus with a rotational speed detection apparatus.

  A vehicle body mounting flange to be attached to the knuckle on the outer periphery, an outer member in which a double row outer rolling surface is integrally formed on the inner periphery, and a wheel mounting flange to mount a wheel on one end A hub wheel integrally formed and having one inner rolling surface opposed to the double-row outer rolling surface on the outer periphery, and a small-diameter step portion extending in the axial direction from the inner rolling surface, and the hub wheel An inner member formed of an inner ring that is press-fitted into the small-diameter step portion and formed with the other inner rolling surface opposite to the double row outer rolling surface, and the inner member and the outer member. A double row rolling element housed between the running surfaces so as to be freely rollable, and a magnetic encoder externally fitted to the inner ring, and a seal is attached to the outer end of the outer member, and A protective cover is attached to the inner side end of the outer member, and the outer member In the wheel bearing device with a rotational speed detection device in which the opening of the annular space formed by the inner member is sealed, by the crimping portion formed by plastically deforming the end portion of the small diameter step portion of the hub wheel, The inner ring is axially fixed to the hub ring in a state where a predetermined bearing preload is applied, and the protective cover is formed into a cup shape by injection molding of a non-magnetic synthetic resin. A cylindrical fitting portion fitted in the member, a flange portion that protrudes radially outward from the fitting portion, and is in close contact with the inner side end surface of the outer member, and a diameter from the flange portion A disc-shaped shielding portion that extends inward in the direction and in which the sensor is close to the side surface on the inner side, a bottom portion that covers the inner side end portion of the inner member from the shielding portion via an inclined portion, and the bottom portion A stepped portion that bulges into the recess of the caulking portion The large end surface of the inner ring protrudes from the inner end surface of the outer member to the inner side by a predetermined step L1 and the detection surface of the magnetic encoder projects by a, and this protrusion amount a is determined by the inner ring. The thickness t of the protective cover is set to be smaller than the thickness t of the protective cover, and the thickness t of the protective cover is set to be smaller than the thickness b of the flange (L1 ≦ a). <T <b).

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing a first embodiment of a wheel bearing device with a rotational speed detection device according to the present invention, and FIG. 2 is an enlarged view of a main part of FIG. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 1), and the side closer to the center is referred to as the inner side (right side in FIG. 1).

  This wheel bearing device with a rotational speed detecting device is for a driven wheel called a third generation, and is housed between the inner member 1, the outer member 2, and both the members 1 and 2 so as to roll freely. Double-row rolling elements (balls) 3 and 3 are provided. The inner member 1 includes a hub ring 4 and an inner ring 5 press-fitted into the hub ring 4 through a predetermined shimiro.

  The outer member 2 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and integrally has a vehicle body mounting flange 2b for mounting to a knuckle (not shown) on the outer periphery. Double row outer rolling surfaces 2a, 2a are integrally formed. These double-row outer raceway surfaces 2a and 2a are formed with a hardened layer having a surface hardness of 58 to 64 HRC by induction hardening.

  The hub wheel 4 integrally has a wheel mounting flange 6 for mounting a wheel (not shown) at an end portion on the outer side, and hub bolts 6a are implanted at circumferentially equidistant positions of the wheel mounting flange 6. Yes. Moreover, the inner side rolling surface 4a which opposes one (outer side) of the said double row outer side rolling surface 2a, 2a and the small diameter step part 4b extended in an axial direction from this inner side rolling surface 4a are formed in outer periphery. Yes. On the other hand, the inner ring 5 is formed on the outer periphery with an inner rolling surface 5a facing the other (inner side) of the double row outer rolling surfaces 2a, 2a, and a small-diameter step portion 4b of the hub wheel 4 via a predetermined shimoshiro. It is press-fitted. The inner ring 5 is fixed in the axial direction in a state where a predetermined bearing preload is applied by a crimping portion 7 formed by plastically deforming an end portion of the small-diameter stepped portion 4b of the hub wheel 4 radially outward. .

  Between the double row outer rolling surfaces 2a, 2a of the outer member 2 and the double row inner rolling surfaces 4a, 5a facing these, the double row rolling elements 3, 3 are respectively accommodated, and the cage 8 , 8 are held so as to roll freely. A seal 9 is attached to the outer opening of the annular space formed between the outer member 2 and the inner member 1, and a protective cover 10 is attached to the inner opening. This prevents leakage of the lubricating grease sealed inside the bearing and prevents rainwater and dust from entering the bearing from the outside.

  In addition, although the double row angular contact ball bearing which used the ball for the rolling element 3 was illustrated here, not only this but the double row tapered roller bearing which uses the tapered roller for the rolling element 3 may be sufficient. In addition, here, a third generation structure in which the inner rolling surface 4a is formed directly on the outer periphery of the hub wheel 4 is illustrated, but although not shown, a pair of inner rings are press-fitted and fixed to the small-diameter step portion of the hub wheel. It may be a first generation or second generation structure.

  The hub wheel 4 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and extends from the inner rolling surface 4a to the base 6b on the inner side of the wheel mounting flange 6 to the small diameter step 4b. The surface is hardened by induction hardening in the range of 58 to 64 HRC. In addition, the crimping part 7 is made into the surface hardness after a forge process. This facilitates the caulking process, prevents the occurrence of microcracks during the process, improves not only the wear resistance of the base part 6b serving as the seal land part of the seal 9, but also loads the wheel mounting flange 6. Therefore, the durability of the hub wheel 4 is improved. The inner ring 5 and the rolling element 3 are made of high carbon chrome bearing steel such as SUJ2, and are hardened in the range of 58 to 64 HRC to the core portion by quenching.

  The seal 9 is an integrated seal composed of a core metal 11 press-fitted into the inner periphery of the outer side end portion of the outer member 2 through a predetermined shimiro and a seal member 12 joined to the core metal 11. It is configured. The core metal 11 is formed by pressing a cold-rolled steel plate (JIS standard SPCC system or the like).

  On the other hand, the sealing member 12 is made of synthetic rubber such as nitrile rubber and is integrally joined to the core metal 11 by vulcanization adhesion. The seal member 12 is formed to be inclined outward in the radial direction, and is predetermined on a side lip 12a that is slidably brought into contact with the side surface on the inner side of the wheel mounting flange 6 with a predetermined squeeze, and on a base portion 6b that is formed in an arc shape in cross section. The intermediate lip 12b is slidably in contact with the squeeze, and the grease lip 12c is formed to be inclined toward the inner side of the bearing.

  A support ring 13 having an L-shaped cross section is fitted on the inner ring 5. 2, the support ring 13 includes a cylindrical portion 13a that is press-fitted into the outer diameter of the inner ring 5, and a vertical plate portion 13b that extends radially outward from the cylindrical portion 13a. A magnetic encoder 14 is integrally joined to the inner side surface of the plate portion 13b by vulcanization adhesion. In the magnetic encoder 14, magnetic powder such as ferrite is mixed in synthetic rubber, and magnetic poles N and S are magnetized alternately at equal pitches in the circumferential direction.

  The support ring 13 is pressed from a ferromagnetic steel plate, for example, a ferritic stainless steel plate (JIS standard SUS430 or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC or the like). It is formed by processing. As a result, it is possible to prevent the support ring 13 from rusting and to increase the magnetic output of the magnetic encoder 14 to ensure stable detection accuracy.

  The protective cover 10 attached to the inner side end of the outer member 2 is formed by injection molding from a synthetic resin material such as polyamide (PA) 66, PA6 / 12, and further a reinforcing material such as GF (glass fiber). 10 to 50 wt% is added. As a result, the sensing performance of the rotation speed sensor (not shown) is not adversely affected, the corrosion resistance is excellent, the strength and rigidity are increased, and the durability can be maintained over a long period of time. If the addition amount of GF is less than 10 wt%, the reinforcing effect is not exhibited, and if it exceeds 50 wt%, the fiber causes anisotropy and the density increases, and the dimensional stability during injection molding decreases. It is not preferable.

  Here, the cover main body 10 can be exemplified by synthetic resins such as polyphenylene sulfide (PPS), PPA (polyphthalamide), and PBT (polybutylene terephthalate) other than the above-described materials. Moreover, as a fibrous reinforcement, not only GF but CF (carbon fiber), an aramid fiber, a boron fiber, etc. can be illustrated other than this.

  As shown in FIG. 1, the protective cover 10 is formed with a cylindrical fitting portion 10 a that is press-fitted into the inner periphery of the end of the outer member 2, and protrudes radially outward from the fitting portion 10 a. A flange portion 10b closely contacting the inner end face 2c of the side member 2, a disk-shaped shield portion 10c extending radially inward from the flange portion 10b, and an inward portion from the shield portion 10c via the inclined portion 10d And a bottom portion 10e that closes an end portion on the inner side of the member 1. A stepped portion 10f that bulges into the recess 7a of the caulking portion 7 is formed at the center of the bottom portion 10e. A detection unit of a sensor (not shown) is brought close to the shielding unit 10c of the protective cover 10, and the detection unit and the magnetic encoder 14 are arranged to face each other with a predetermined air gap (axial clearance) through the protective cover 10. . In addition, since the protective cover 10 is a non-magnetic material, it does not affect the flow path of the magnetic flux, and there is no problem of a decrease in accuracy of rotation speed detection by the sensor.

  In this embodiment, since the protective cover 10 is formed of a synthetic resin having a high elastic modulus (compression rate) of the material and is fitted to the outer member 2, the airtightness of the fitting portion is increased, The magnetic encoder 14 is protected from iron powder, magnetic fragments and the like, and is fitted into the end of the outer member 2, and the rigidity of the protective cover 10 is increased by the stepped shape including the flange portion 10b. Deformation due to stepping stones can be suppressed. Furthermore, since the flange portion 10b is press-fitted until it comes into close contact with the inner end face 2c of the outer member 2, the positioning accuracy of the protective cover 10 with respect to the outer member 2 can be increased, and reliability can be improved by accurate air gap adjustment. High speed detection can be performed.

  In the present embodiment, the large end surface 5b of the inner ring 5 is formed to protrude from the inner side end surface 2c of the outer member 2 to the inner side by a predetermined step L1, and the detection surface of the magnetic encoder 14 is outward. The member 2 is disposed so as to protrude from the end surface 2c on the inner side by a. This protrusion amount a is set to a range that is equal to or larger than the step L1 of the inner ring 5 and smaller than the thickness t of the shielding portion 10c of the protective cover 10. Furthermore, the thickness t of the shielding part 10c of the protective cover 10 is set in a range smaller than the thickness b of the flange part 10b (L1 ≦ a <t <b). As a result, the protective cover 10 can be prevented from coming into contact with the inner ring 5, and the air gap can be set small, so that the detection accuracy can be increased.

  FIG. 3 is a longitudinal sectional view showing a second embodiment of the wheel bearing device with a rotational speed detection device according to the present invention, and FIG. 4 is an enlarged view of a main part of FIG. Note that this embodiment is basically different from the above-described embodiment only in the configuration of the protective cover, and the other parts having the same parts or the same functions as those of the above-described embodiment are denoted by the same reference numerals. Detailed description thereof is omitted.

  A protective cover 15 is attached to the inner end of the outer member 2. The protective cover 15 is formed by injection molding from a synthetic resin material such as PA66 and PA6 / 12, and further a reinforcing material made of CF (carbon fiber) is added in an amount of 5 to 50 wt%. As a result, the sensing performance of the rotation speed sensor (not shown) is not adversely affected, the corrosion resistance is excellent, the strength and rigidity are increased, and the durability can be improved over a long period of time. If the addition amount of CF is less than 5 wt%, the reinforcing effect is not exhibited, and if it exceeds 50 wt%, the fiber causes anisotropy and the density increases, and the dimensional stability during injection molding decreases. It is not preferable.

  The protective cover 15 is formed with a cylindrical fitting portion 15a that is press-fitted into the inner periphery of the end portion of the outer member 2, and is formed to protrude radially outward from the fitting portion 15a. A flange portion 15b that is in close contact with the end surface 2c, a disk-shaped shielding portion 10c that extends radially inward from the flange portion 15b, and an inner side end of the inner member 1 from the shielding portion 10c via the inclined portion 10d. And a stepped portion 10f formed at the center of the bottom portion 10e. A detection unit of a sensor (not shown) is brought close to the shielding unit 10c of the protective cover 15, and the detection unit and the magnetic encoder 14 are arranged to face each other with a predetermined air gap through the protective cover 15.

  Here, in the present embodiment, as shown in an enlarged view in FIG. 4, the core metal 16 is insert-molded at the portions of the fitting portion 15 a and the flange portion 15 b of the protective cover 15. The core 16 is formed from a non-magnetic austenitic stainless steel plate (JIS standard SUS304) by press working so as to have a substantially L-shaped cross section. As a result, as in the above-described embodiment, the air tightness of the fitting portion can be improved, and the rigidity of the protective cover 15 can be improved without affecting the flow path of the magnetic flux because the cored bar 16 is nonmagnetic. Can be further increased.

  FIG. 5 is a longitudinal sectional view showing a third embodiment of a wheel bearing device with a rotational speed detection device according to the present invention, FIG. 6 is an enlarged view of a main part of FIG. 5, and FIG. 7 is a VII arrow of FIG. FIG. This embodiment is basically the same as the second embodiment described above (FIG. 3) except that the configuration of the protective cover is partially different. Parts are denoted by the same reference numerals, and detailed description thereof is omitted.

  A protective cover 17 is attached to the inner end of the outer member 2. The protective cover 17 is formed by injection molding from a synthetic resin material such as PA66, PA6 / 12, and further, a reinforcing material made of CF is added in an amount of 5 to 50 wt%. As a result, the sensing performance of the rotation speed sensor (not shown) is not adversely affected, the corrosion resistance is excellent, the strength and rigidity are increased, and the durability can be maintained over a long period of time.

  The protective cover 17 is formed with a cylindrical fitting portion 15a that is press-fitted into the inner periphery of the end portion of the outer member 2, and is formed to project radially outward from the fitting portion 15a. A flange portion 15b that is in close contact with the end surface 2c, a disk-shaped shielding portion 17a that extends radially inward from the flange portion 15b, and an inner-side end of the inner member 1 from the shielding portion 17a via the inclined portion 10d. And a stepped portion 10f formed at the center of the bottom portion 10e. Further, in the present embodiment, as shown in an enlarged view in FIG. 6, the cored bar 16 is insert-molded at the fitting portion 15a and the flange portion 15b of the protective cover 17 as in the above-described embodiment.

  Here, as shown in an enlarged view in FIG. 6, an eyebrow-shaped recess 18 is formed in the shielding portion 17 a of the protective cover 17 so as to be close to the magnetic encoder 14 by c. A sensor (not shown) is brought close to the recess 18. Accordingly, it is possible to set the air gap small while maintaining the rigidity of the protective cover 17 and tolerate even if there is an error in the positioning accuracy of the protective cover 17 in the circumferential direction with respect to the sensor. .

  Further, as shown in an enlarged view in FIG. 6, the large end surface 5 b of the inner ring 5 is formed to be substantially flush with the inner end surface 2 c of the outer member 2, and the detection surface of the magnetic encoder 14 is the outer member 2. It protrudes from the end surface 2c on the inner side by a. This protrusion amount a is in a range smaller than the value obtained by subtracting the dent amount c and thickness t of the recess 18 from the thickness b of the flange portion 15b of the protective cover 17 when the thickness of the shielding portion 17a of the protective cover 17 is t. It has been set (a <b-ct). Thereby, while maintaining the rigidity of the protective cover 17 while preventing the protective cover 17 from coming into contact with the inner ring 5, it is possible to prevent the stepping stone or the like from colliding with the protective cover 17 and preventing the deformation, and the air gap. It can be set small, and the detection accuracy can be increased.

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  The wheel bearing device with a rotational speed detection device according to the present invention can be applied to a wheel bearing device on the driven wheel side of the first to third generation structure of the inner ring rotation type.

DESCRIPTION OF SYMBOLS 1 Inner member 2 Outer member 2a Outer rolling surface 2b Car body installation flange 2c Inner side end surface 3 Rolling element 4 Hub wheel 4a, 5a Inner rolling surface 4b Small diameter step part 5 Inner ring 5b Large end surface 6 Wheel mounting flange 6a Hub bolt 6b Inner side base portion 7 Caulking portion 7a Recess 8 Retainer 9 Outer side seal 10, 15, 17 Protective cover 10a, 15a Fitting portion 10b, 15b Gutter portion 10c, 17a Shield portion 10d Inclined portion 10e Bottom portion 10f Step Attached portions 11 and 16 Core 12 Seal member 12a Side lip 12b Intermediate lip 12c Grease lip 13 Support ring 13a Cylindrical portion 13b Standing plate portion 14 Magnetic encoder 18 Recess 50 Outer member 50a Outer rolling surface 50b Car body mounting flange 51 Inward Member 52 Ball 53 Hub wheels 53a, 54a Inner rolling surface 53b Small diameter step portion 53c Clamping portion 54 Inner ring 5 Wheel mounting flange 55a Base 56 Seal ring 57 Encoder 58 Support ring 59 Encoder main body 60 Cover 61 Closing plate part 62 Fitting part 63 Sensor 64 Detection part 65 Knuckle 66 Screw a From the end face of the outer member of the detection surface of the magnetic encoder Protrusion amount b Protective cover collar thickness c Recess dent amount L1 Step between outer member and inner ring t Protective cover shield thickness

Claims (12)

An outer member in which a double row outer rolling surface is integrally formed on the inner periphery;
From a hub wheel integrally having a wheel mounting flange for mounting a wheel at one end and having a small-diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small-diameter step portion of the hub ring An inner member in which a double-row inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery,
A double row rolling element housed movably between the rolling surfaces of the inner member and the outer member;
A magnetic encoder fitted on the inner ring,
A seal is attached to the outer end of the outer member,
In the wheel bearing device with a rotational speed detecting device, a protective cover is attached to an inner side end of the outer member, and an opening of an annular space formed by the outer member and the inner member is sealed.
The inner ring is axially fixed to the hub ring in a state where a predetermined bearing preload is applied by a caulking portion formed by plastically deforming an end portion of the small-diameter step portion of the hub ring,
The protective cover is formed of a non-magnetic synthetic resin in a cup shape by injection molding, and is formed by a cylindrical fitting portion fitted into the outer member and projecting radially outward from the fitting portion. A flange portion that is in close contact with the inner side end surface of the outer member, a disk-shaped shielding portion that extends radially inward from the collar portion, and in which the sensor is close to the inner side surface, and the shielding portion. And a bottom portion that closes an inner end of the inner member through an inclined portion.   The wheel bearing with a rotation speed detecting device according to claim 1, wherein a cored bar formed into a substantially L-shaped cross section by press working from a steel plate is insert-molded at a fitting portion and a flange portion of the protective cover. apparatus.   The wheel bearing device with a rotation speed detecting device according to claim 2, wherein the core metal is formed of a non-magnetic austenitic stainless steel plate.   The wheel bearing device with a rotational speed detection device according to any one of claims 1 to 3, wherein a stepped portion that bulges into a recess of the caulking portion is formed at a central portion of the bottom portion of the protective cover.   The wheel bearing device with a rotational speed detection device according to claim 4, wherein the stepped portion is formed in a substantially rectangular cross section along the shape of the recess of the caulking portion.   The detection surface of the magnetic encoder is disposed so as to protrude from the inner end surface of the outer member by a, and the protrusion amount a is set smaller than the thickness t of the shielding portion of the protective cover (a <t). The wheel bearing device with a rotational speed detection device according to claim 1.   The wheel bearing device with a rotational speed detecting device according to any one of claims 1 to 6, wherein a concave portion is formed in the shielding portion of the protective cover so as to be close to the magnetic encoder, and a sensor is disposed in the concave portion.   The wheel bearing device with a rotation speed detecting device according to claim 7, wherein a concave amount c of the concave portion is set smaller than a thickness b of the flange portion of the protective cover (c <b).   The wheel bearing device with a rotation speed detection device according to claim 7 or 8, wherein the concave portion is formed in an eyebrow shape.   The wheel bearing device with a rotation speed detection device according to any one of claims 1 to 9, wherein a reinforcing material made of GF is added to the protective cover in an amount of 10 to 50 wt%.   The wheel bearing device with a rotation speed detection device according to any one of claims 1 to 9, wherein a reinforcing material made of CF is added to the protective cover in an amount of 5 to 50 wt%.   The wheel bearing device with a rotation speed detection device according to any one of claims 1 to 11, wherein the protective cover is made of one of polyamide 66, polyamide 6/12, and polyphenylene sulfide.

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