JP2013079701A - Bearing device for wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing device for a wheel preventing foreign matters from coming between a protecting cover and a rotational speed sensor by regulating the increase of an air gap and enhancing the accuracy and reliability of rotational speed detection.SOLUTION: A protecting cover 10 comprises a core metal 17 formed in a cup-shape from a nonmagnetic steel plate and a nonmagnetic elastic member integrally bonded to the same, the core metal 17 has a cylindrical fitting member 17a fitted in the end part inner peripheral face of an outside member 2 and a shielding part 17b extending inward in a radial direction from the same and forming a bottom part, a rotational speed sensor 16 is placed near the side face of the shielding part 17b or abuts on the same, the rotational speed sensor 16 and a magnetic encoder 14 are oppositely arranged via the protecting cover 10, a part facing the rotational speed sensor is formed in a thin wall thickness by press machining, the wall thickness is set larger than the depth of the site to be pressed, and an elastic member 18 is bonded to the site so as to be substantially flush with the side face of the shielding part 17b.

Description

  The present invention relates to a wheel bearing device equipped with a protective cover for rotatably supporting a wheel of an automobile or the like and sealing the inside of the bearing.

  There is provided a wheel bearing device in which a rotation speed detection device for detecting a rotation speed of a vehicle and controlling an anti-lock brake system (ABS) is incorporated in the bearing while rotatably supporting a vehicle wheel with respect to a suspension device. 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. .

  As an example of such a wheel bearing device, a structure as shown in FIG. 12 is known. The wheel bearing 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. It is formed of a cylindrical fitting portion 62 formed.

  The side surface of the encoder main body 59 that constitutes the encoder 57 is disposed in close proximity to the cover 60, and the detection unit 64 of the sensor 63 is in proximity to or in contact with the side surface of the cover 60. Are opposed to each other through a cover 60. Thus, the presence of the cover 60 prevents water, iron powder, magnetic fragments, etc. from entering between the sensor 63 and the encoder 57, thereby preventing the encoder 57 from being damaged, and the encoder body 59. It is possible to prevent regular and periodic changes in magnetic characteristics from being disturbed or deteriorated (see, for example, Patent Document 1).

JP 2000-249138 A

  However, such conventional wheel bearing devices have the following problems. Since the detection unit 64 of the sensor 63 faces the encoder 57 via the cover 60, not only the plate thickness of the cover 60 but also the interference between the encoder 57 and the cover 60 or between the cover 60 and the sensor 63 must be considered. As compared with the normal specification, the air gap between the encoder 57 and the sensor 63 may become large, and the detection accuracy may decrease.

  Further, when the cover 60 is press-fitted into the outer member 50, as shown in FIG. 13, the closing plate portion 61 of the cover 60 may be deformed by the press-fitting shimoshi between the cover 60 and the outer member 50 (in the drawing). (Indicated by a broken line). In this case, since the sensor 63 interferes after assembly, the amount of deformation of the cover 60 is considered in advance, and the initial air gap must be set large in order to avoid interference between the components.

  The present invention has been made in view of such circumstances, and restricts an increase in the air gap to prevent foreign matter from entering between the protective cover and the rotation speed sensor, and the accuracy and reliability of rotation speed detection. It aims at providing the bearing device for wheels which improved.

  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, A vehicle in which an opening of an annular space formed by the outer member and the inner member is sealed In the bearing device, the protective cover comprises a cored bar formed by pressing from a non-magnetic steel plate and a nonmagnetic elastic member integrally joined to the cored bar, A cylindrical fitting portion that is press-fitted into the inner peripheral surface of the end portion of the outer member, and a shield that extends radially inward from the fitting portion and serves as a bottom portion that closes the inner end portion of the inner member. A rotational speed sensor is brought close to or in contact with the inner side surface of the shielding part, the rotational speed sensor and the magnetic encoder are arranged to face each other with a predetermined air gap through the protective cover, and The elastic member is disposed at a portion of the shielding portion that faces the rotational speed sensor.

  As described above, the magnetic encoder that is externally fitted to the inner ring is provided, the seal is attached to the outer end of the outer member, and the protective cover is attached to the inner end of the outer member. In an inner ring rotating type wheel bearing device in which an opening of an annular space formed by a member and an inner member is sealed, a protective cover is formed from a non-magnetic steel plate in a cup shape by pressing, and a metal core A non-magnetic elastic member integrally joined to the cored bar, and the cored bar is press-fitted into the inner peripheral surface of the end of the outer member, and the radial direction from the fitted part A shield portion that extends inward and serves as a bottom portion that closes the inner side end of the inner member, and a rotational speed sensor approaches or abuts on the inner side surface of the shield portion. The rotational speed sensor and the magnetic encoder Through the protective cover. Since the elastic member is arranged at the part of the shield that faces the rotational speed sensor, the bearing cover is subjected to a heavy load or the rotational speed of the protective cover due to tolerance variations of each part. Even if the sensor comes into strong contact, it can be buffered, preventing the occurrence of problems such as the protective cover slipping and the air gap going wrong, restricting the increase of the air gap, and the protective cover and rotational speed sensor It is possible to provide a wheel bearing device in which foreign matter is prevented from entering between them and the accuracy and reliability of rotation speed detection are improved.

  Further, as in the second aspect of the present invention, a portion of the core metal facing the rotation speed sensor is formed thin by pressing, and the thickness is larger than the depth of the pressed portion. If the elastic member is joined to this portion so as to be substantially flush with the side surface of the shielding portion, the cost can be reduced without reducing the strength of the protective cover, and the air gap can be increased. Can be regulated.

  According to a third aspect of the present invention, the mandrel includes a disc-shaped shielding portion that extends radially inward from the fitting portion via the reduced diameter portion, and a bent portion from the shielding portion. If a bottom part extending radially inward is provided, the rigidity of the protective cover increases, and deformation at the time of press-fitting or deformation when a large load is applied can be prevented.

  Further, as in the invention described in claim 4, the diameter of the bent portion of the cored bar is set to be smaller than the diameter of the lowermost part of the speed sensor, and a gap C (radius value) with the rotational speed sensor is set. If it is set in the range of 0.1 mm ≦ C ≦ 1.0 mm, a sufficient space for the shielding portion can be secured, and even if there is a variation in processing accuracy, a heavy load is applied to the bearing portion. Even if the protective cover is deformed, it is possible to prevent the rotation speed sensor and the metal core from interfering with each other.

  Further, as in the invention described in claim 5, if the inclination angle θ1 of the bent portion of the core metal is set in the range of 2 ° ≦ θ1 ≦ 45 °, the metal cover can be secured while ensuring the rigidity of the protective cover. The mold releasability can be improved.

  Further, as in the sixth aspect of the present invention, a portion extending from the shielding portion of the core metal to a substantially central portion of the bent portion is formed thin by pressing, and the elastic member is provided on the side surface of the shielding portion at this portion. If the joint is joined so that it is substantially flush with the inclined surface of the bent part, even if a heavy load is applied to the bearing part and the protective cover is deformed, the rotational speed sensor and the metal core interfere with each other. It can buffer, and it can prevent that a protective cover moves by pressing force and an air gap goes wrong.

  Further, as in the invention described in claim 7, a seal member is integrally joined to the outer peripheral portion of the reduced diameter portion of the core metal by vulcanization adhesion, and the seal member is slightly smaller than the outer diameter of the fitting portion. Provided with a convex portion formed in a large diameter, and if this convex portion is press-fitted into the inner peripheral surface of the end portion of the outer member via a predetermined shimoshiro, the fitting surface of the outer member and the protective cover Airtightness can be increased.

  Further, if the seal member is set so as not to protrude from the side surface on the inner side of the shielding portion as in the invention described in claim 8, a rotation speed sensor is required to avoid interference with the seal member. Thus, it is not necessary to keep away from the magnetic encoder, the air gap can be set to the minimum, and the detection accuracy can be further improved.

  Further, as in the ninth aspect of the present invention, when the elastic member is disposed only in a portion facing the rotational speed sensor, the elastic member is formed by the joining range of the elastic member, that is, the core metal is pressed. The range can be minimized, the strength of the protective cover can be ensured, and the manufacturing cost can be reduced.

  According to a tenth aspect of the present invention, the side surface of the elastic member is set on the inner side with respect to the end surface on the inner side of the outer member, and the convex portion is chamfered on the inner diameter of the end portion of the outer member. If it is pressure-bonded to the portion, the width of the outer member can be reduced to the minimum, and the weight and size can be reduced.

  Further, as in the invention described in claim 11, the side surface of the elastic member is set on the inner side with respect to the end surface on the inner side of the outer member, and the convex portion is the inner diameter of the end portion of the outer member. Can be made lighter and more compact without increasing the width of the outer member, and the dimensions of the chamfered part will vary. Also, the outer member can be crimped to the inner diameter of the end portion, and the airtightness can be improved.

  Further, as in the invention described in claim 12, if the shift amount B between the convex portion and the chamfered portion is set in a range of 0.1 mm ≦ B ≦ 0.5 mm, the chamfered portion has a variation. However, the outer member can be securely crimped to the inner diameter of the end portion.

  The wheel bearing device according to the present invention integrally has an outer member integrally formed with a double row outer rolling surface on the inner periphery, and a wheel mounting flange for mounting the wheel on one end, and on the outer periphery. A hub ring formed with a small-diameter step portion extending in the axial direction, and at least one inner ring press-fitted into the small-diameter step portion of the hub ring, the inner side of the double row facing the outer rolling surface of the double row on the outer periphery An inner member on which a rolling surface is formed, a double row rolling element that is slidably accommodated between the rolling surfaces of the inner member and the outer member, and the inner ring is externally fitted to the inner ring. A magnetic encoder, 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, and the outer member, the inner member, In the wheel bearing device in which the opening of the annular space formed by is sealed, The protective cover comprises a cored bar formed by pressing from a non-magnetic steel plate and a nonmagnetic elastic member integrally joined to the cored bar, the cored bar of the outer member A cylindrical fitting portion press-fitted into the inner peripheral surface of the end portion, and a shielding portion that extends radially inward from the fitting portion and serves as a bottom portion that closes the inner side end portion of the inner member. A rotational speed sensor is brought close to or in contact with a side surface on the inner side of the part, the rotational speed sensor and the magnetic encoder are arranged to face each other with a predetermined air gap through the protective cover, and the rotational speed of the shielding part Since the elastic member is arranged at the part facing the sensor, even if a heavy load is applied to the bearing or the rotational speed sensor comes into strong contact with the protective cover due to variation in tolerance of each part, etc. Buffer and protective cover This can prevent the occurrence of malfunctions such as the air gap getting out of order, restricting the increase in the air gap, and preventing foreign matter from entering between the protective cover and the rotation speed sensor, and the accuracy of rotation speed detection. It is possible to provide a wheel bearing device with improved reliability.

It is a longitudinal section showing one embodiment of a wheel bearing device concerning the present invention. It is a principal part enlarged view which shows the detection part of FIG. (A) is sectional drawing which shows the protective cover single-piece | unit based on this invention, (b) is a side view of (a). (A) is sectional drawing which shows the modification of the protective cover of FIG. 3, (b) is a side view of (a). (A), (b) is explanatory drawing which shows the relationship between the protective cover of FIG. 4, and a rotational speed sensor. (A) is sectional drawing which shows the modification of the protective cover of FIG. 4, (b) is a side view of (a). (A) is sectional drawing which shows the other modification of the protective cover of FIG. 3, (b) is a side view of (a). It is sectional drawing which shows the other modification of the protective cover of FIG. It is sectional drawing which shows the modification of the protective cover of FIG. It is a principal part enlarged view which shows the state which mounted | wore the protective cover of FIG. It is a principal part enlarged view which shows the modification of FIG. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus. It is a principal part enlarged view which shows the state at the time of the cover press injection of FIG.

  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 a wheel bearing device in which an opening of an annular space formed by an inner member is sealed, the protective cover is a core metal formed in a cup shape by pressing from a non-magnetic steel plate, and the core metal A non-magnetic elastic member joined together, and the cored bar is press-fitted into the inner peripheral surface of the end of the outer member, and radially inward from the fitting part A shield portion that extends and closes the inner side end of the inner member, and a rotational speed sensor approaches or abuts on the inner side surface of the shield portion, and the rotational speed sensor and the magnetic encoder are A portion facing the rotation speed sensor of the shielding portion is formed to be thin by pressing, and the thickness is greater than the depth of the portion to be pressed. It will grow Is set to, the elastic member are joined such that a side surface substantially flush with the shield portion to the site.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing an embodiment of a wheel bearing device according to the present invention, FIG. 2 is an enlarged view of a main part showing a detection unit of FIG. 1, and FIG. 3 (a) is a protection according to the present invention. FIG. 4A is a side view of FIG. 4A, FIG. 4A is a cross-sectional view showing a modification of the protective cover of FIG. 3, and FIG. 4B is a side view of FIG. 5A and 5B are explanatory views showing the relationship between the protective cover of FIG. 4 and the rotation speed sensor, FIG. 6A is a cross-sectional view showing a modification of the protective cover of FIG. ) Is a side view of (a), FIG. 7 (a) is a cross-sectional view showing another modification of the protective cover of FIG. 3, (b) is a side view of (a), and FIG. 8 is FIG. FIG. 9 is a cross-sectional view showing another modification of the protective cover of FIG. 8, FIG. 10 is a cross-sectional view showing a modification of the protective cover of FIG. 8, and FIG. 10 is an enlarged view of a main part showing a state where the protective cover of FIG. 11 shows a variation of FIG. Example is an enlarged view showing a. 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 is for a driven wheel referred to as a third generation, and is a double row rolling element housed in a freely rollable manner between the inner member 1, outer member 2, and both members 1,2. (Balls) 3 and 3. 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 the protective cover 10 is attached to the inner opening. Is installed to prevent leakage of lubricating grease sealed inside the bearing and intrusion of rainwater and dust from the outside into the bearing.

  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. As a result, not only the wear resistance of the base portion 6b that becomes the seal land portion of the seal 9 is improved, but also the hub wheel 4 has sufficient mechanical strength against the rotational bending load applied to the wheel mounting flange 6. Improves durability. Moreover, since the crimping part 7 is made into the hardness after a forge process, a crimping process becomes easy and generation | occurrence | production of the micro crack at the time of a process can be prevented. 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.

  In addition, although the wheel bearing apparatus comprised by the double row angular contact ball bearing which used the ball for the rolling element 3 was illustrated here, it is not restricted to this, The double row tapered roller bearing which used the tapered roller for the rolling element 3 It may consist of. 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 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 metal core 11 is formed by pressing an austenitic stainless steel plate (JIS standard SUS304 type or the like) or a cold rolled steel plate (JIS standard SPCC type or the like) in a substantially L-shaped cross section.

  On the other hand, the seal member 12 is made of synthetic rubber such as NBR (acrylonitrile-butadiene 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 formed to be inclined toward the bearing inward side, and side lips 12a and 12b slidably contacting the base 6b having a circular cross section with a predetermined squeeze. Grease lip 12c.

  In addition to the exemplified NBR, the material of the seal member 12 includes, for example, HNBR (hydrogenated acrylonitrile butadiene rubber), EPDM (ethylene propylene rubber), etc., which have excellent heat resistance, and heat resistance and chemical resistance. Examples thereof include ACM (polyacrylic rubber), FKM (fluororubber), and silicon rubber, which are excellent in the above.

  A support ring 13 having an L-shaped cross section is fitted on the inner ring 5. The support ring 13 includes a cylindrical portion 13a that is press-fitted into the outer diameter of the inner ring 5, and a standing plate portion 13b that extends radially outward from the cylindrical portion 13a, and a magnet is formed on the inner side surface of the standing plate portion 13b. The encoder 14 is integrally joined 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 formed by pressing 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. 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 end of the outer member 2 is formed into a generally annular shape in a substantially U-shaped cross section by pressing from a nonmagnetic austenitic stainless steel plate. The protective cover 10 includes a cored bar 17 fitted in the outer member 2 and an elastic member 18 joined to the cored bar 17.

  The cored bar 17 is a cylindrical fitting part 17a that is press-fitted into the inner periphery of the end part of the outer member 2, and extends radially inward from the fitting part 17a. And a shielding portion 17b serving as a bottom portion to be closed. As shown in FIG. 2, the detection portion 16a of the rotation speed sensor 16 fixed to the knuckle (not shown) is brought close to or in contact with the shielding portion 17b of the core metal 17 in the protective cover 10, and the detection portion 16a. And the magnetic encoder 14 are arranged to face each other with a predetermined air gap (axial clearance) through the protective cover 10.

  Here, a non-magnetic elastic member 18 such as FKM or silicon rubber is integrally joined to the portion of the shielding portion 17b of the protective cover 10 facing the rotational speed sensor 16 by vulcanization adhesion. As shown in FIG. 3A, the protective cover 10 has a portion of the shielding portion 17b facing the rotational speed sensor 16 formed thin by pressing, and this thickness T1 is the depth of the pressed portion. It is set to be larger than T2. And the elastic member 18 is joined to this part so that it may become substantially flush with the side surface of the shielding part 17b.

  As a result, the cost can be reduced without reducing the strength of the protective cover 10, and a large load is applied to the bearing, or the rotational speed sensor 16 comes into strong contact with the protective cover 10 due to variations in tolerances of each part. Even if it is buffered, it is possible to prevent the occurrence of a malfunction such that the protective cover 10 is displaced and the air gap is distorted. Accordingly, there is provided a wheel bearing device that restricts an increase in the air gap and prevents foreign matter from entering between the protective cover 10 and the rotation speed sensor 16 and improves the accuracy and reliability of rotation speed detection. be able to. The term “substantially equal” as used herein means, for example, a design target value that is substantially free of steps, that is, a step caused by a processing error or the like should be allowed.

  The elastic member 18 may be coated with, for example, a synthetic resin such as a fluorine-based resin, or a thermoplastic synthetic resin such as (polyamide) 66, in addition to vulcanizing and bonding such synthetic rubber. You may make it join integrally by injection molding. Other synthetic resins include thermoplastic synthetic resins called so-called engineering plastics such as PPA (polyphthalamide) and PBT (polybutylene terephthalate), polyphenylene sulfide (PPS), and polyether ether ketone (PEEK). ), Thermoplastic synthetic resins called super engineering plastics such as polyamideimide (PAI), or thermosetting synthetic resins such as phenolic resin (PF), epoxy resin (EP), polyimide resin (PI), etc. It may be.

  FIG. 4 is a modification of the above-described protective cover 10 (FIG. 3). In addition, the same code | symbol is attached | subjected to the site | part which has the same site | part and the same function as embodiment mentioned above, and detailed description is abbreviate | omitted. The protective cover 19 includes a cored bar 20 and an elastic member 21 joined to the cored bar 20. The core metal 20 has a diameter through a cylindrical fitting portion 20a that is press-fitted into an inner periphery of an end of an outer member (not shown), and a reduced diameter portion 20b that is tapered from the fitting portion 20a. And a shielding portion 20c extending inward in the direction.

  In this embodiment, the seal member 21 made of an elastic member is fixed from the outer peripheral portion of the reduced diameter portion 20b to the outer diameter portion of the shielding portion 20c. The seal member 21 is made of synthetic rubber such as NBR, and is integrally joined to the protective cover 19 by vulcanization adhesion, and includes a convex portion 21a and an annular portion 21b. The convex portion 21a is formed to have a slightly larger diameter than the outer diameter of the fitting portion 20a of the core metal 20, and is press-fitted into the inner peripheral surface of the end portion of the outer member via a predetermined squeeze. Thereby, the airtightness of the fitting surface between the outer member and the protective cover 19 can be enhanced over a long period of time. In addition, the rotational speed sensor 16 is arranged on the annular portion 21b so as to come into contact with or close to the annular portion 21b, so that a large load is applied to the bearing or the tolerance of each part varies. Even if the rotation speed sensor 16 comes into strong contact, it is buffered. Examples of the material of the sealing member 21 include HNBR, EPDM, ACM, FKM, or silicon rubber having excellent heat resistance in addition to the exemplified NBR.

  As shown in FIGS. 5 (a) and 5 (b), it is slightly different depending on the specification and posture of the rotational speed sensor 16 disposed to face the protective cover 19, but it is joined to a part of the shielding portion 20c facing the rotational speed sensor 16. It is preferable that the annular portion 21b of the sealing member 21 is joined to a range that covers the detection range of the detection unit 16a. Thereby, stable detection accuracy can be ensured without adversely affecting the magnetic characteristics.

  FIG. 6 shows a modification of the protective cover 19 described above. The protective cover 22 basically differs from the protective cover 19 described above only in the configuration of the elastic member, and the same components are denoted by the same reference numerals and detailed description thereof is omitted. The protective cover 22 includes a cored bar 23 and an elastic member 24 joined to the cored bar 23. The core metal 23 has a diameter through a cylindrical fitting portion 20a that is press-fitted into an inner periphery of an end of an outer member (not shown), and a reduced diameter portion 20b that is tapered from the fitting portion 20a. And a shielding portion 23a extending inward in the direction.

  The sealing member 24 is made of a synthetic rubber such as NBR, and is integrally joined to the core metal 23 by vulcanization adhesion, and a convex portion 21a joined to the outer peripheral portion of the reduced diameter portion 20b of the core metal 23, and an outer portion of the shielding portion 23a. The rotation speed sensor (not shown) of a diameter part consists of the contact part 24a fixed to the part which opposes. Thereby, the joining range of the seal member 24, that is, the range formed by press working can be minimized, and the strength of the protective cover 22 can be ensured and the manufacturing cost can be reduced. Examples of the material of the seal member 24 include HNBR, EPDM, ACM, FKM, or silicon rubber having excellent heat resistance in addition to the exemplified NBR.

  A protective cover 25 shown in FIG. 7 is a modification of the protective cover 10 described above. The protective cover 24 is basically different from the above-described protective cover 10 only in the configuration of the elastic member, and the same reference numerals are given to the other same parts, and detailed description thereof is omitted.

  The protective cover 25 includes a cored bar 26 and an elastic member 27 joined to the cored bar 26. The cored bar 26 includes a cylindrical fitting portion 10a and a shielding portion 26a extending radially inward from the fitting portion 10a, and a rotational speed sensor (not shown) of an outer diameter portion of the shielding portion 26a. The elastic member 27 is fixed to a portion facing each other.

  The elastic member 27 is made of synthetic rubber such as NBR, and is integrally joined to the cored bar 26 by vulcanization adhesion, and is fixed to a portion where the rotation speed sensor (not shown) of the outer diameter portion of the shielding portion 26a faces. . Accordingly, as in the above-described embodiment, the joining range of the elastic member 27, that is, the range formed by pressing can be minimized, and the strength of the protective cover 25 is ensured and the manufacturing cost is reduced. Can do.

  A protective cover 28 shown in FIG. 8 is a modification of the protective cover 19 described above. The protective cover 28 basically differs from the protective cover 19 described above only in the shape of the cored bar, and the same components are denoted by the same reference numerals and detailed description thereof is omitted.

  The protective cover 28 includes a cored bar 29 and an elastic member 21 joined to the cored bar 29. The core metal 29 includes a cylindrical fitting portion 20a, a disc-shaped shielding portion 29a extending inward in the radial direction from the fitting portion 20a via the reduced diameter portion 20b, and a bending portion 29b from the shielding portion 29a. And a bottom portion 29c extending inward in the radial direction. And the recessed part 29d dented on the outer side is formed in the center part of this bottom part 29c. By making the core metal 29 into such a stepped shape, the rigidity of the protective cover 28 is increased, and deformation at the time of press-fitting or deformation when a large load is applied can be prevented.

  Further, the portion of the shielding portion 29a facing the rotational speed sensor 16 is formed thin by pressing, and the thickness T1 is set to be larger than the depth T2 of the pressed portion (T1>). T2). And the elastic member 21 is joined to this part so that it may become substantially flush with the side surface of the shielding part 29a.

  Here, the diameter D1 of the bent portion 29b of the metal core 29 is set to a smaller diameter (D1 <D2) than the lowermost diameter D2 of the rotational speed sensor 16, and the gap C (radius value) with the rotational speed sensor 16 is , Larger than 0.1 mm and smaller than 1.0 mm (0.1 mm ≦ C ≦ 1.0 mm). As a result, a sufficient space for the shielding portion 29a can be secured, and even if there is a variation in processing accuracy, or even if a large load is applied to the bearing portion and the protective cover 28 is deformed, the rotational speed sensor 16 Interference with the cored bar 29 can be prevented.

  Further, the inclination angle θ1 of the bent portion 29b is set to 2 ° or more, preferably 2 ° ≦ θ1 ≦ 45 °. Thereby, the mold release property can be improved while securing the rigidity of the protective cover 28.

  A protective cover 30 shown in FIG. 9 is a modification of the protective cover 28 described above. The protective cover 30 basically differs from the protective cover 28 described above only in the configuration of the cored bar and the elastic member, and the same components are denoted by the same reference numerals and detailed description thereof is omitted. .

  The protective cover 30 includes a cored bar 31 and a seal member 32 joined to the cored bar 31. The metal core 31 includes a cylindrical fitting portion 20a, a disc-shaped shielding portion 31a extending radially inward from the fitting portion 20a via the reduced diameter portion 20b, and a bending portion 31b from the shielding portion 31a. And a bottom portion 29c extending inward in the radial direction. And the recessed part 29d dented on the outer side is formed in the center part of this bottom part 29c.

  Here, the seal member 32 has a convex portion 21a joined to the outer periphery of the reduced diameter portion 20b, and a portion extending from the shielding portion 31a of the metal core 31 to the substantially central portion of the bent portion 31b is thinned by press working. The contact portion 32a is joined to this portion so as to be substantially flush with the side surface of the shielding portion 31a and the inclined surface of the bent portion 31b. As a result, even if a large load is applied to the bearing portion and the protective cover 30 is deformed and the rotational speed sensor 16 and the cored bar 31 interfere with each other, the impact can be buffered. It is possible to prevent the air gap from going wrong by moving.

  FIG. 10 shows a state in which the protective cover 28 (FIG. 8) described above is attached to the outer member 2. In this embodiment, the elastic member 21 includes a convex portion 21a joined to the outer peripheral portion of the reduced diameter portion 20b of the core metal 29, and a contact portion 21b joined to the shielding portion a. The side surface is set to the inner side by A with respect to the inner side end surface 2 c of the outer member 2 (A> 0), and the convex portion 21 a is pressure-bonded to the chamfered portion 2 d of the inner diameter of the outer member 2. Thereby, the width | variety of the outer member 2 can be made into the minimum, and lightweight and compactization can be achieved.

  FIG. 11 shows a modification of FIG. 10 described above. In this embodiment, the protective cover 28 is basically the same as the above-described embodiment, but the positional relationship with respect to the outer member 2 is different. In other words, the elastic member 21 includes a convex portion 21a joined to the outer peripheral portion of the reduced diameter portion 20b of the core metal 29, and a contact portion 21b joined to the shielding portion a. In addition to being set on the inner side of the inner side end surface 2c of the side member 2, the convex portion 21a is crimped to the inner diameter of the end portion of the outer member 2, and only B is disposed on the outer side of the chamfered portion 2d. The shift amount B is set to 0.1 mm or more, preferably 0.1 mm ≦ B ≦ 0.5 mm. Accordingly, it is possible to reduce the weight and size of the outer member 2 without increasing the width of the outer member 2, and to press the outer member 2 on the inner diameter of the end portion of the outer member 2 even if the chamfered portion 2 d is not uniform. And airtightness can be improved.

  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, and various modifications can be made without departing from the scope of the present invention. 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 according to the present invention is applied to the wheel bearing device on the driven wheel side of the first to third generation structures of the inner ring rotation type in which the protective cover is attached to the inner side end of the outer member. Can do.

DESCRIPTION OF SYMBOLS 1 Inner member 2 Outer member 2a Outer rolling surface 2b Car body mounting flange 2c End side 2d of outer member Inner end surface 2d Chamfered portion of inner diameter of outer member 3 Rolling element 4 Hub wheels 4a, 5a Inner rolling surface 4b Small diameter step portion 5 Inner ring 5b Large end surface 6 Wheel mounting flange 6a Hub bolt 6b Inner side base 7 Clamping portion 8 Cage 9 Outer side seals 10, 19, 22, 25, 28, 30 Protective covers 10a, 17a, 20a Fitting portion 11, 17, 20, 23, 26, 29, 31 Core 12 Seal member 12a, 12b Side lip 12c Grease lip 13 Support ring 13a Cylindrical portion 13b Standing plate portion 14 Magnetic encoder 16 Rotational speed sensor 16a Detection portion 17b , 20c, 23a, 26a, 29a, 31a Shielding portion 18, 27 Elastic member 20b Reduced diameter portion 21, 24, 32 Seal member 21a Convex 21b Annular parts 24a, 32a Contact parts 29b, 31b Bent part 29c Bottom part 29d Recess 50 Outer member 50a Outer rolling surface 50b Car body mounting flange 51 Inner member 52 Ball 53 Hub wheels 53a, 54a Inner rolling surface 53b Small diameter step Portion 53c caulking portion 54 inner ring 55 wheel mounting flange 55a base 56 seal ring 57 encoder 58 support ring 59 encoder body 60 cover 61 closing plate portion 62 fitting portion 63 sensor 64 detecting portion 65 knuckle 66 screw A from end surface of outer member Distance B from the side of the contact portion Distance C from the chamfered portion of the outer member to the convex portion C Gap with the rotation speed sensor D1 Diameter D2 of the bent portion of the core metal Diameter T1 of the lowermost portion of the rotation speed sensor Thin wall of the core metal Plate thickness T2 Depth of the pressed part of the core

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 extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small-diameter step 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,
An annular space is formed by the outer member and the inner member having a seal attached to the outer end portion of the outer member and a protective cover attached to the inner end portion of the outer member. In the wheel bearing device in which the opening of
The protective cover includes a cored bar formed by pressing from a non-magnetic steel plate and a nonmagnetic elastic member integrally joined to the cored bar, the cored bar being the outer member A cylindrical fitting portion that is press-fitted into the inner circumferential surface of the end portion, and a shielding portion that extends radially inward from the fitting portion and serves as a bottom portion that closes the inner side end portion of the inner member. A rotational speed sensor is brought close to or in contact with the inner side surface of the shielding part, and the rotational speed sensor and the magnetic encoder are arranged to face each other with a predetermined air gap through the protective cover, and the rotation of the shielding part A wheel bearing device, wherein the elastic member is disposed at a portion facing the speed sensor.   A portion of the core metal facing the rotational speed sensor is formed thin by pressing, and the thickness is set to be greater than the depth of the pressed portion. The wheel bearing device according to claim 1, wherein the wheel bearing device is joined so as to be substantially flush with a side surface of the wheel.   The metal core includes a disk-shaped shielding portion extending radially inward from the fitting portion via a reduced diameter portion, and a bottom portion extending radially inward from the shielding portion via a bent portion. The wheel bearing device according to claim 1 or 2.   The diameter of the bent portion of the metal core is set to be smaller than the diameter of the lowermost part of the speed sensor, and the gap C with respect to the rotational speed sensor is set in a range of 0.1 mm ≦ C ≦ 1.0 mm. The wheel bearing device according to claim 3.   The wheel bearing device according to claim 3 or 4, wherein an inclination angle θ1 of the bent portion of the metal core is set in a range of 2 ° ≤ θ1 ≤ 45 °.   A portion extending from the shielding portion of the metal core to a substantially central portion of the bent portion is formed thin by pressing, and the elastic member is substantially flush with the side surface of the shielding portion and the inclined surface of the bent portion. The wheel bearing device according to any one of claims 3 to 5, which is joined.   A seal member is integrally joined to the outer peripheral portion of the reduced diameter portion of the core metal by vulcanization adhesion, and the seal member includes a convex portion formed slightly larger in diameter than the outer diameter of the fitting portion. The wheel bearing device according to claim 3, wherein the convex portion is press-fitted into the inner peripheral surface of the end portion of the outer member via a predetermined shimoshiro.   The wheel bearing device according to claim 7, wherein the seal member is set so as not to protrude from an inner side surface of the shielding portion.   The wheel bearing device according to claim 1, wherein the elastic member is disposed only at a portion facing the rotation speed sensor.   The wheel according to claim 1, wherein a side surface of the elastic member is set on an inner side with respect to an end surface on an inner side of the outer member, and the convex portion is crimped to a chamfered portion of an inner diameter of an end portion of the outer member. Bearing device.   The side surface of the elastic member is set on the inner side of the end surface on the inner side of the outer member, and the convex portion is crimped to the inner diameter of the end portion of the outer member, and is disposed on the outer side of the chamfered portion. The wheel bearing device according to claim 1.   The wheel bearing device according to claim 11, wherein a shift amount B between the convex portion and the chamfered portion is set in a range of 0.1 mm ≦ B ≦ 0.5 mm.

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