JP2019120335A - Wheel bearing device - Google Patents

Abstract

To provide a wheel bearing device capable of fitting either a cover or a sensor holder by an appropriate removal proof strength.SOLUTION: This invention relates to a wheel bearing device comprising a pilot part 2g fitted to a vehicle body; a vehicle body fixing flange 2f having a larger thickness than that of the pilot part 2g; an outer wheel 2 formed with a plurality of rows of outer rail surfaces 2d and 2e at an inner peripheral surface; an inner member having at least one inner wheel 4 pressed into a small diameter step part 3a of a hub wheel 3 and formed with a plurality of rows of inner rail surfaces 4a opposing the plurality of rows of outer side rail surface at the outer peripheral surface; a plurality of rows of rollers 5a and 5b stored between the rail surfaces of the outer wheel 2 and the inner member; a cover 7 fitted to an inner peripheral surface of the inner side opening 2a of the outer wheel 2. The cover 7 has a fitted part 7a fitted to the outer wheel 2, and at least a part of the fitted part 7a is fitted at a position where it overlaps the vehicle body fixing flange 2f in a radial view.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a bearing device for a wheel.

  2. Description of the Related Art Conventionally, there has been known a wheel bearing device which rotatably supports a wheel in a suspension system of a car or the like. In the wheel bearing device, a hub wheel, which is an inward member connected to a wheel, is rotatably supported via rolling elements. In the bearing device for a wheel, bearing life is shortened due to the occurrence of rust due to leakage of grease enclosed in the internal space thereof or muddy water or the like entering the internal space. For this reason, the wheel bearing device is provided with a seal member which prevents the grease from leaking from the gap between the outer member and the inner member and prevents the entry of muddy water from the outside.

  In such a bearing device for a wheel, a metal cover is fitted to the opening on the inner side of the outer member of the bearing device for a wheel (the side of the vehicle when the bearing device for a wheel is attached to the vehicle) There is something. The wheel bearing device has an opening sealed by a cover. Thereby, it is possible to effectively prevent the entry of muddy water and the like from the outside. For example, it is as described in Patent Document 1.

JP, 2015-68454, A

  In the wheel bearing device described in Patent Document 1, a pilot portion fitted to a knuckle of a vehicle body is formed on the inner side of the outer member. A cover is press-fit fitted on the inner circumferential surface of the pilot portion. Further, the sensor holder may be fitted to the outer side (inner side) of the cover on the inner peripheral surface of the pilot portion. At this time, the pilot portion is pushed outward in the radial direction by the press-fitted cover. In the wheel bearing device, the inner diameter of the portion of the inner peripheral surface of the pilot portion fitted with the sensor holder is larger than that before the fitting due to the fitting of the cover. As a result, in the wheel bearing device, management of the interference in the pilot portion becomes difficult, and there are cases in which it is not possible to appropriately maintain the pullout resistance (holding force) of the cover and the sensor holder.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a bearing device for a wheel capable of fitting a cover with an appropriate pull-out resistance.

  That is, according to the first aspect of the present invention, an outer member formed with a pilot portion fitted to a vehicle body, a vehicle body mounting flange having a larger thickness than the pilot portion, and double rows of outer raceways, A hub wheel having an axially extending small diameter step portion formed thereon, and at least one inner ring press-fit into the small diameter step portion of the hub wheel, and having a double row facing the outer raceway surface of the double row An inner member formed with an inner raceway surface, double rows of rolling elements rollably accommodated between respective raceway surfaces of the outer member and the inner member, and an inner side of the outer member In the bearing device for a wheel including a bottomed cylindrical cover fitted to the inner circumferential surface of the opening, at least a part of the fitting of the cover is viewed in a radial direction relative to the vehicle body mounting flange. It is fitted in the overlapping position.

  A second aspect of the invention is the wheel bearing device, wherein an annular seal member is provided on an outer peripheral surface of the cover, and the seal member is fitted on an inner peripheral surface of the pilot portion.

  In a third aspect of the present invention, the portion of the fitting portion of the cover that presses the inner peripheral surface of the outer member with the largest force is fitted at a position overlapping with the vehicle body mounting flange in a radial direction It is a bearing device for wheels.

  A fourth aspect of the invention is the wheel bearing apparatus, wherein a sensor holder is fitted on the inner peripheral surface of the pilot portion and outside the cover.

  The effects of the present invention are as follows.

  That is, in the first invention, since the cover is fitted at a position overlapping the flange for mounting the vehicle body having high rigidity among the outward members, expansion of the inner diameter which is elastic deformation of the pilot portion by the cover is suppressed Be done. As a result, it is possible to control the interference and fit the cover and the sensor holder with an appropriate pull-out resistance.

  According to the second aspect of the invention, the cover is sealed at the outer side of the fitting portion while the cover is fitted at a position overlapping the flange portion for mounting the vehicle body having high rigidity among the outward members. As a result, it is possible to manage the interference and fit the cover and the sensor holder with an appropriate pull-out resistance without impairing the airtightness of the cover.

  The third invention is an elastic deformation of the pilot portion by the cover because the most rigid portion of the fitting portion of the cover is fitted to the flange portion for mounting the vehicle body having high rigidity among the outward members. The expansion of the inner diameter is further suppressed. As a result, it is possible to control the interference and fit the cover and the sensor holder with an appropriate pull-out resistance.

  In the fourth invention, since the sensor holder is fitted to the pilot portion in which the expansion of the inner diameter due to the fitting of the cover is suppressed, the interference margin is managed and the sensor holder is fitted with an appropriate pull-out resistance Can.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view which shows the whole structure of the wheel bearing apparatus. (A) Sectional drawing which shows the whole structure of the bearing apparatus for wheels, (b) A partial expanded sectional view in FIG. 2 (a). The partially expanded sectional view which shows the positional relationship of the vehicle body attachment flange of a bearing apparatus for wheels, and a cover fitting hole. (A) Partially enlarged sectional view schematically showing a reaction force applied to the cover of the bearing apparatus for a wheel, (b) Similar enlarged sectional view schematically showing the reaction force applied to the cover and the sensor holder. (A) Partially enlarged sectional view showing distribution of reaction force applied to a cover fitted to a portion facing the vehicle body mounting flange of the wheel bearing device, (b) Similarly, a portion facing the vehicle body mounting flange and the pilot portion The partial expanded sectional view which shows distribution of the reaction force added to the cover currently fitted over.

  Below, the bearing apparatus 1 for wheels which is one Embodiment of the bearing apparatus for wheels which concerns on this invention is demonstrated using FIGS. 1-3.

  As shown in FIGS. 1 and 2, the wheel bearing device 1 rotatably supports wheels in a suspension system of a vehicle such as a car. The wheel bearing device 1 includes an outer ring 2 as an outer member, a hub ring 3 and an inner ring 4 as an inner member, two inner ball rows 5a, an outer ball row 5b, and a cover 7 as rolling rows. The sensor holder 8, the magnetic sensor 9, and the outer seal member 10 are provided. Here, the inner side represents the vehicle side of the wheel bearing device 1 when attached to the vehicle body, and the outer side represents the wheel side of the wheel bearing device 1 when attached to the vehicle body. Further, the axial direction represents a direction along the rotation axis of the wheel bearing device 1.

  As shown in FIG. 2A, the outer ring 2 supports the hub wheel 3 and the inner ring 4 via the ball rows 5a and 5b. The outer ring 2 is formed in a substantially cylindrical shape. The outer ring 2 is made of, for example, a medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C. The inner side opening 2a of the outer ring 2 is opened so that the cover 7 and the sensor holder 8 can be fitted. Further, a sensor holder fitting hole 2b and a cover fitting hole 2c are formed in the inner side opening 2a. The sensor holder fitting hole 2 b is a fitting portion into which the sensor holder 8 is fitted. The cover fitting hole 2c is a fitting portion into which the cover 7 is fitted.

  On the inner peripheral surface of the outer ring 2, the inner side outer raceway surface 2d formed in an annular shape and the outer side outer raceway surface 2e are formed in parallel in the circumferential direction. A hardened layer having a surface hardness in the range of 58 to 64 HRC is formed, for example, by induction hardening on the inner side outer raceway surface 2d and the outer side outer raceway surface 2e. The outer side opening 2 h of the outer ring 2 is formed so that the outer side sealing member 10 can be fitted.

  On the outer peripheral surface of the outer ring 2, a vehicle mounting flange 2f for mounting on the knuckle 100 (see FIG. 3) on the vehicle body side is integrally formed. A cylindrical pilot portion 2g fitted to the knuckle 100 of the vehicle body is formed on the inner side of the vehicle body mounting flange 2f. The portion of the outer ring 2 on which the vehicle body mounting flange 2f is formed has an outer diameter larger than that of the pilot portion 2g and a large thickness. That is, the portion of the outer ring 2 on which the vehicle body mounting flange 2f is formed is high in rigidity as compared with the pilot portion 2g, so that elastic deformation hardly occurs.

  The centers of the sensor holder fitting hole 2b and the cover fitting hole 2c are disposed on the same axial center of the inner opening 2a. The sensor holder fitting hole 2 b is a hole into which the sensor holder fitting portion 8 a of the sensor holder 8 is fitted. The cover fitting hole 2 c is a hole into which the fitting portion 7 a of the cover 7 is fitted. The cover fitting hole 2c is formed as a hole having an inner diameter smaller than the inner diameter of the sensor holder fitting hole 2b. That is, on the inner peripheral surface of the inner side opening 2a of the outer ring 2, the sensor holder fitting hole 2b on the large diameter side and the cover fitting hole 2c on the small diameter side are formed sequentially from the outer side (inner side).

  As shown in FIG. 3, the cover fitting hole 2c is formed at a position where at least a portion thereof overlaps with the vehicle body mounting flange 2f in the radial direction. That is, the cover fitting hole 2c constitutes a range Ar (thin ink portion) opposed to the vehicle body mounting flange 2f. In the present embodiment, the cover fitting hole 2c constitutes the range Ar so that the whole of the fitting portion 7a of the cover 7 overlaps with the vehicle body mounting flange 2f in the radial direction.

  As shown in FIG. 2A, the hub wheel 3 rotatably supports wheels of a vehicle (not shown). The hub wheel 3 is formed in a cylindrical shape. The hub wheel 3 is made of, for example, a medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C. At the inner side end of the hub wheel 3, a small diameter step 3a whose diameter is reduced on the outer peripheral surface is formed. At the outer end of the hub wheel 3, a wheel mounting flange 3b for mounting the wheel is integrally formed. The wheel mounting flange 3b is provided with hub bolts 3e at circumferentially equidistant positions. On the hub wheel 3, an outer side inner raceway surface 3 c is formed to face the outer side outer raceway surface 2 e of the outer ring 2. Further, on the hub wheel 3, a lip sliding surface 3 d of the outer side sealing member 10 is formed on the base side of the wheel mounting flange 3 b. In the hub wheel 3, an inner ring 4 is provided in the small diameter step portion 3 a.

  The inner ring 4 is a rolling train, and applies a preload to the inner ball array 5a disposed on the inner side when mounted on the vehicle and the outer ball array 5b disposed on the outer side when mounted on the vehicle. The inner ring 4 is made of, for example, a high carbon chromium bearing steel such as SUJ 2 and is hardened in the range of 58 to 64 HRC up to the core portion by zubb hardening. An annular inner raceway surface 4 a is formed on the outer peripheral surface of the inner ring 4 in the circumferential direction. The inner ring 4 is fixed to the small diameter step 3 a of the hub wheel 3 by press fitting. That is, on the inner side of the hub wheel 3, the inner raceway surface 4 a is formed by the inner ring 4. In the hub ring 3, the inner raceway surface 4a of the inner ring 4 at the inner side end faces the outer raceway surface 2d on the inner side of the outer ring 2, and the inner raceway surface 3c on the outer side is the outer raceway surface 2e on the outer side of the outer race 2. It is arranged to face the.

  In the inner ball row 5a and the outer ball row 5b, a plurality of balls, which are rolling elements, are annularly held by a cage. The inner side ball row 5a and the outer side ball row 5b are made of, for example, high carbon chromium bearing steel such as SUJ2, and are hardened in the range of 62 to 67 HRC up to the core portion by the zubu hardening. The inner ball row 5 a is rollably interposed between the inner raceway surface 4 a of the inner ring 4 and the outer raceway surface 2 d on the inner side of the outer ring 2. The outer ball row 5 b is rollably interposed between the inner raceway surface 3 c of the hub wheel 3 and the outer raceway surface 2 e on the outer side of the outer ring 2. That is, the inner ball row 5 a and the outer ball row 5 b rotatably support the hub wheel 3 and the inner ring 4 with respect to the outer ring 2.

  In the wheel bearing device 1, a double-row angular contact ball bearing is configured by the outer ring 2, the hub wheel 3, the inner ring 4, the inner ball row 5 a and the outer ball row 5 b. In addition, in this embodiment, although the double row angular contact ball bearing is comprised by the bearing apparatus 1 for wheels, you may be comprised by bearings, such as a double row conical roller bearing.

  In the encoder ring 6 (thin ink portion), synthetic rubber mixed with magnetic powder such as ferrite is annularly formed, and magnetized in the magnetic pole N and the magnetic pole S at an equal pitch in the circumferential direction. The encoder ring 6 is supported on the outer diameter surface of the inner ring 4 via a support ring 6a. The support ring 6a is a cylindrical member having a bent portion in which one side end is bent radially inward. The encoder ring 6 is integrally joined to the bent portion of the support ring 6a by vulcanization bonding. The inner ring 4 is press-fitted to the other end of the support ring 6a. That is, the encoder ring 6 is disposed inside the inner opening 2 a of the outer ring 2 and at a position facing the end face 4 b of the inner ring 4. Thus, the encoder ring 6 is configured to be rotatable integrally with the inner ring 4.

  As shown in FIG. 2 (b), the cover 7 blocks the inner opening 2a (see FIG. 2 (a)) of the outer ring 2 to prevent the entry of foreign matter such as muddy water from the outside and protects the encoder ring 6 It is The cover 7 is formed in a cylindrical shape by press processing. The cover 7 is open only on the outer side in the axial direction. That is, the bottom surface is formed on the inner side in the axial direction of the cover 7. The cover 7 is made of, for example, a ferritic stainless steel plate (SUS430 series etc. according to JIS standard) or an austenitic stainless steel plate (SUS304 series etc. according to JIS standard), or a cold-rolled steel plate subjected to rust prevention treatment (SPCC series etc. according to JIS standard) It consists of The cover 7 is one in which the fitting portion 7a, the step portion 7b, the seal support portion 7c, the shielding portion 7d and the bottom portion 7e are integrally connected. The seal support portion 7c is provided with an annular inner seal member 7f.

  In the cylindrical portion of the cover 7, the fitting portion 7 a and the seal support portion 7 c are formed on the same axial center. The fitting portion 7 a is a portion fitted to the cover fitting hole 2 c of the outer ring 2. The fitting portion 7 a is formed at the open end of the cover 7. The fitting portion 7a is formed to have an outer diameter smaller than the inner diameter of the sensor holder fitting hole 2b of the outer ring 2 and larger than the inner diameter of the cover fitting hole 2c. That is, the fitting portion 7a has an outer diameter and an axial length which can be press-fit into the cover fitting hole 2c without contacting the sensor holder fitting hole 2b.

  The seal support portion 7c is a portion that supports the inner side seal member 7f. The outer peripheral surface of the seal support portion 7 c is formed to be parallel to the inner peripheral surface of the sensor holder fitting hole 2 b of the outer ring 2. The seal support portion 7c is disposed adjacent to the inner side of the fitting portion 7a via the step 7b. The stepped portion 7 b is formed in a tapered shape inward in the radial direction from the inner end portion of the fitting portion 7 a. That is, the cover 7 has the seal support portion 7c having an outer diameter smaller than that of the fitting portion 7a on the inner side in the axial direction from an arbitrary position on the outer peripheral surface. Thus, the seal support portion 7c forms a space in which the inner seal member 7f can be disposed between the seal support portion 7c and the inner peripheral surface of the cover fitting hole 2c. The shield 7 d and the bottom 7 e constitute the bottom of the cover 7 that covers the inner opening 2 a of the outer ring 2. The shield 7d is formed in an annular shape extending radially inward from the inner end of the seal support 7c, and faces the encoder ring 6 with a slight axial clearance. The bottom portion 7 e covers the inner opening 2 a of the outer ring 2 while projecting to the inner side from the inner peripheral edge of the shielding portion 7 d.

  The annular inner seal member 7 f closes the gap between the outer ring 2 and the cover 7. The inner seal member 7 f is bonded by vulcanization to the outer peripheral surface of the seal support portion 7 c of the cover 7. That is, the inner seal member 7f is provided adjacent to the fitting portion 7a. The inner side sealing member 7f is made of, for example, NBR (acrylonitrile-butadiene rubber), HNBR (hydrogenated acrylonitrile butadiene rubber) excellent in heat resistance, EPDM (ethylene propylene rubber), ACM (polyamide excellent in heat resistance and chemical resistance) It is made of synthetic rubber such as acrylic rubber), FKM (fluorinated rubber), or silicone rubber.

  The inner seal member 7 f is formed to have an outer diameter larger than the inner diameter of the sensor holder fitting hole 2 b of the outer ring 2. The inner seal member 7 f has a predetermined axial width range (e.g., a range of 0.1 mm to 2 mm) of the outer peripheral surface that protrudes radially outward (e.g., 0. 0. 0. 10. 1 mm to 2 mm protruding). That is, the inner side sealing member 7 f has a projection that protrudes outward in the radial direction than the outer diameter of the cover fitting portion 7 a. The inner seal member 7 f further includes a seal lip 7 g on the inner side of the protrusion. The seal lip 7g extends from the inner side portion of the inner side seal member 7f toward the inner side and radially outward. The seal lip 7g protrudes more than the outer diameter of the cover fitting portion 7a.

  The inner seal member 7 f is configured to be in close contact with the inner peripheral surface of the sensor holder fitting hole 2 b when the fitting portion 7 a of the cover 7 is fitted in the cover fitting hole 2 c of the outer ring 2. The fitting portion 7a of the cover 7 is fitted in the cover fitting hole 2c without contacting the inner peripheral surface of the sensor holder fitting hole 2b which is larger than the cover fitting hole 2c. Further, when the inner seal member 7f is fitted, the projection of the seal member 7f and the seal lip 7g are elastically deformed and crimped to the sensor holder fitting hole 2b, thereby closing the gap between the outer ring 2 and the cover 7. It is. The inner seal member 7f is configured to be in close contact with the inner peripheral surface of the sensor holder fitting hole 2b, but may be configured to be in close contact with the inner peripheral surface of the cover fitting hole 2c.

  The sensor holder 8 holds the magnetic sensor 9 at the inner side opening 2 a of the outer ring 2. The sensor holder 8 is formed in a cylindrical shape having a bottom by pressing. The sensor holder 8 is, for example, a ferritic stainless steel plate (SUS430 series etc. according to JIS standard) or an austenitic stainless steel plate (SUS304 series etc. according to JIS standard), or a cold-rolled steel plate subjected to rust prevention treatment (SPCC series etc. according to JIS standard It consists of).

  The sensor holder 8 is formed of a sensor holder fitting portion 8 a and a disc-like bottom portion 8 c partially protruding. On the side of the bottom portion 8c of the sensor holder fitting portion 8a, an annular flange portion 8b protruding outward in the radial direction is formed. The sensor holder 8 is formed to have an outer diameter larger than the inner diameter of the sensor holder fitting hole 2b. That is, the sensor holder fitting portion 8a is configured as a cylinder having an outer diameter and an axial length which can be press-fit into the sensor holder fitting hole 2b.

  The sensor holder 8 is fitted in the sensor holder fitting hole 2 b of the inner opening 2 a of the outer ring 2. At this time, the sensor holder 8 is fitted in a state where the flange 8 b is in contact with one side end of the outer ring 2. That is, the sensor holder 8 is fitted to the pilot portion 2 g of the outer ring 2 so as to cover the cover 7 on the outer side (inner side) than the cover 7 fitted to the inner circumferential surface of the inner opening 2 a of the outer ring 2 It is done. Thus, the sensor holder 8 closes the inner opening 2 a of the outer ring 2 and the axial position of the sensor holder 8 is determined. Accordingly, the sensor holder 8 can hold the magnetic sensor 9 attached to the bottom 8 c at an appropriate position with respect to the encoder ring 6.

  As shown in FIG. 2A, the magnetic sensor 9 detects the magnetism of the encoder ring 6. The magnetic sensor 9 is provided on the outer ring 2 such that the sensor holder 8 makes its detection surface face the encoder ring 6. The magnetic sensor 9 is held by the sensor holder 8 so as to have a predetermined air gap (axial clearance) from the encoder ring 6. The magnetic sensor 9 detects the passage time of each magnetism of the encoder ring 6 alternately passing through the detection surface by rotating integrally with the hub wheel 3.

  The outer side seal member 10 closes a gap between the outer ring 2 and the hub wheel 3. In the outer seal member 10, a plurality of seal lips made of synthetic rubber such as NBR (acrylonitrile-butadiene rubber) are bonded by vulcanization to a substantially cylindrical core metal. The outer seal member 10 has a cylindrical portion fitted in the outer opening 2 h of the outer ring 2. The outer seal member 10 is configured to be slidable with respect to the hub wheel 3 by a plurality of seal lips contacting or approaching the lip sliding surface 3 d of the hub wheel 3 via an oil film. Thereby, the outer seal member 10 prevents the leakage of the lubricating grease from the outer opening 2 h of the outer ring 2 and the entry of foreign matter such as rain water and dust from the outside. In addition, the outer side sealing member 10 has various specifications, and is not limited to the specifications of the present embodiment. In the inner seal member 7f of the cover 7 and the outer seal member 10, a lip or the like is bonded by vulcanization to a core metal or the like. However, other bonding methods may be used.

  In the wheel bearing device 1 configured as described above, the hub wheel 3 and the inner ring 4 are rotatably supported by the outer ring 2 via the inner ball row 5a and the outer ball row 5b. Further, in the wheel bearing device 1, the gap between the inner opening 2 a of the outer ring 2 and the inner ring 4 is closed by the cover 7, and the gap between the outer opening 2 h of the outer ring 2 and the hub wheel 3 is sealed on the outer side It is closed by a member 10. Thus, in the wheel bearing device 1, the hub wheel 3 and the inner ring 4 supported by the outer ring 2 rotate while preventing leakage of lubricating grease from the inside and intrusion of rain water and dust from the outside.

  Next, with reference to FIG. 4, the fitting state of the outer ring 2, the cover 7, and the sensor holder 8 in the wheel bearing device 1 will be specifically described.

  As shown in FIG. 4A, in the cover fitting hole 2c of the inner opening 2a of the outer ring 2, a predetermined range of the fitting portion 7a of the cover 7 is a vehicle mounting flange 2f and a radial view. It is fitted in the range Ar which is the overlapping range. The outer peripheral surface of the fitting portion 7a, which is press-fitted and fitted, is pressed against the inner peripheral surface of the cover fitting hole 2c. That is, the inner peripheral surface of the cover fitting hole 2c is radially pressed outward on the entire circumference by the fitting portion 7a which is press-fitted. On the outer peripheral surface of the fitting portion 7a, a reaction force (fitting force) directed radially inward from the inner peripheral surface of the cover fitting hole 2c corresponds to the amount of elastic deformation of the cover fitting hole 2c and the fitting portion 7a. Add (see black arrow).

  In the outer ring 2, a part of the pressing force from the fitting portion 7a is applied to the portion of the vehicle body mounting flange 2f having high rigidity, so that elastic deformation in which the inner diameter of the cover fitting hole 2c is enlarged by press fitting of the cover 7 is suppressed. Be done. That is, a reaction force mainly corresponding to the amount of elastic deformation of the fitting portion 7a is applied to the outer peripheral surface of the fitting portion 7a. Therefore, the wheel bearing device 1 facilitates management of the interference of the fitting portion 7a with respect to the cover fitting hole 2c. Thereby, the bearing apparatus 1 for wheels adjusts the reaction force which arises in the fitting part 7a by the interference of the fitting part 7a with respect to the cover fitting hole 2c, and covers 7 in the cover fitting hole 2c with a suitable falling off resistance. It can be fitted.

  In the wheel bearing device 1, the inner seal member 7 f is fitted in the sensor holder fitting hole 2 b having a larger inside diameter than the cover fitting hole 2 c. That is, the bearing device 1 for wheels is the inner peripheral surface of the sensor holder fitting hole 2b outside the cover fitting hole 2c even if a fitting flaw or the like occurs in the cover fitting hole 2c due to the press fitting of the cover 7. Since the gap between the cover 7 and the cover 7 is sealed, the airtightness between the outer ring 2 and the cover 7 is not impaired.

  As shown in FIG. 4 (b), the sensor holder fitting portion 8 a of the sensor holder 8 is further press-fitted into the sensor holder fitting hole 2 b formed in the pilot portion 2 g of the outer ring 2. The outer peripheral surface of the sensor holder fitting portion 8a which is press-fitted and pressed is pressed against the inner peripheral surface of the sensor holder fitting hole 2b. That is, the entire circumference of the inner peripheral surface of the sensor holder fitting hole 2b is pressed radially outward by the sensor holder fitting portion 8a which is press-fitted. A reaction force directed radially inward from the inner circumferential surface of the sensor holder fitting hole 2b is applied to the outer circumferential surface of the sensor holder fitting portion 8a according to the amount of elastic deformation of the sensor holder fitting hole 2b (see white painted arrow ).

  In the outer ring 2, the portion of the vehicle mounting flange 2 f having high rigidity receives a part of the pressing force from the fitting portion 7 a of the cover 7, thereby enlarging the inner diameter of the cover fitting hole 2 c by press fitting the cover 7. Elastic deformation is suppressed. Along with this, the elastic deformation in which the inner diameter of the sensor holder fitting hole 2b formed on the outer side (inner side) of the cover fitting hole 2c is suppressed. That is, a reaction force mainly corresponding to the amount of elastic deformation of the sensor holder fitting portion 8a is applied to the outer peripheral surface of the sensor holder fitting portion 8a. Therefore, the wheel bearing device 1 facilitates management of the interference of the sensor holder fitting portion 8a with respect to the sensor holder fitting hole 2b. As a result, the wheel bearing device 1 can adjust the reaction force by the interference of the sensor holder fitting portion 8a with respect to the sensor holder fitting hole 2b, and can fit the sensor holder 8 with an appropriate pullout resistance.

  Next, with reference to FIG. 5, the reaction force F (fitting force) generated in the cover 7 press-fit fitted to the outer ring 2 in the wheel bearing device 1 will be specifically described. The reaction force F generated in the fitting portion 7a of the cover 7 by the press fitting is determined by the amount of elastic deformation of the cover fitting hole 2c of the outer ring 2 and the amount of elastic deformation of the fitting portion 7a.

  As shown in FIG. 5A, when the entire range of the fitting portion 7a of the cover 7 is fitted in the range Ar of the cover fitting hole 2c overlapping with the vehicle body mounting flange 2f in radial direction, the cover The radial rigidity of the fitting hole 2c is substantially equal in the range where the outer peripheral surface of the fitting portion 7a is in contact. Therefore, the reaction force F generated in the fitting portion 7a of the cover 7 is determined in accordance with the amount of elastic deformation of the fitting portion 7a due to the press fitting. The radial rigidity of the fitting portion 7a becomes higher as it goes from the opening side to the inner side. As a result, the reaction force F generated in the fitting portion 7a becomes larger as it goes from the opening side of the fitting portion 7a to the inner side (see thin ink portion). The reaction force F generated in the fitting portion 7a is maximum at the inner end of the fitting portion 7a.

  As shown in FIG. 5B, the fitting portion 7a extends over a range Ar which is a portion overlapping with the vehicle body mounting flange 2f in the radial direction as viewed in the radial direction of the cover fitting hole 2c and a portion overlapping with the pilot portion 2g. When the fitting portion 7a is fitted, the radial rigidity of the cover fitting hole 2c in the portion in which the fitting portion 7a is fitted is different in the range Ar and the portion overlapping the pilot portion 2g. The reaction force F generated in the fitting portion 7a of the cover 7 is determined according to the amount of elastic deformation of the cover fitting hole 2c and the amount of elastic deformation of the fitting portion 7a. Thereby, in the range Ar, the reaction force F generated in the fitting portion 7a becomes larger as it goes from the opening side of the fitting portion 7a to the inner side (see thin ink portion).

  On the other hand, in a portion overlapping the pilot portion 2g in the radial direction, the reaction force F generated in the fitting portion 7a decreases as the elastic deformation amount of the pilot portion 2g increases toward the outer side (inner side) and toward the outer side. Of the amount of elastic deformation of the fitting portion 7a, the amount of elastic deformation is determined according to the amount of elastic deformation of the pilot portion 2g which has a large influence. Therefore, in a portion overlapping with the pilot portion 2g, the reaction force F generated in the fitting portion 7a decreases toward the outer side (see thin ink portion).

  By configuring in this manner, the wheel bearing device 1 performs the cover fitting with the part where the largest reaction force F is generated among the fitting parts 7a of the cover 7, that is, the largest force among the fitting parts 7a. A portion for pressing the inner peripheral surface of the hole 2c is fitted in a range Ar overlapping with the vehicle body mounting flange 2f in the radial direction. Therefore, in the wheel bearing device 1, the enlargement of the inner diameter of the cover fitting hole 2c and the pilot portion 2g is further suppressed. As a result, the wheel bearing device 1 can control the interference and fit the cover 7 and the sensor holder 8 with an appropriate pull-out resistance.

  The wheel bearing device 1 in the present application includes a hub wheel 3 to which one inner ring 4 is fitted as an inner member, and an outer ring 2 which is an outer member having a mounting flange and an inner ring 4 which is an inner member. The third generation structure of the inner ring 4 rotation specification configured by the fitting body of the hub wheel 3 and the hub wheel 3 is not limited thereto. The first generation structure configured by the outer ring 2 as the outer member and the pair of inner rings 4 as the inner member, and the outer ring 2 as the outer member having the mounting flange and the pair of inner rings as the inner member And the second generation structure of the inner ring 4 rotation specification in which the pair of inner rings 4 are fitted to the outer periphery of the hub wheel 3. In addition, although the wheel bearing device 1 has been described as a wheel bearing device for a driven wheel, it may be a wheel bearing device for a driving wheel.

  Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments in any way, and is merely an example, and various modifications can be made without departing from the scope of the present invention. The scope of the present invention is, of course, indicated by the description of the claims, and the meaning of equivalents described in the claims, and all modifications within the scope. Including.

1 Wheel bearing device 2 Outer ring 2a Inner opening 2c Cover fitting hole 2d, 2e Outer raceway surface 3 Hub ring 3a Small diameter step 4 Inner ring 5a Inner ball row 5b Outer ball row 7 Cover 7a Cover fitting 8 Sensor holder 10 Outer seal member

Claims (4)

An outer member formed with a pilot portion fitted to a vehicle body, a vehicle body mounting flange having a larger thickness than the pilot portion, and a double row outer raceway surface;
A hub ring having a small diameter step portion extending in the axial direction formed on the outer peripheral surface, and at least one inner ring press-fit into the small diameter step portion of the hub ring, and facing the outer race surface of the double row on the outer peripheral surface An inner member having a double row of inner raceway surfaces formed,
Double rows of rolling elements rollably received between the outer raceway surface and the inner raceway surface;
In the wheel bearing device, provided with a bottomed cylindrical cover fitted to the inner peripheral surface of the inner side opening of the outer member.
The cover has a fitting portion to be fitted to the outward member, and at least a part of the fitting portion is fitted to a position where the at least a portion overlaps with the vehicle body mounting flange in a radial direction. Bearing equipment.   The portion according to claim 1, wherein a portion of the fitting portion of the cover that presses the inner circumferential surface of the outward member with the largest force is fitted at a position overlapping the vehicle body mounting flange in a radial direction. Wheel bearing device.   The wheel bearing device according to claim 1 or 2, wherein a sensor holder is fitted on the inner peripheral surface of the pilot portion and on the inner side of the cover. A seal member is provided on the outer peripheral surface of the cover,
The wheel bearing device according to any one of claims 1 to 3, wherein the seal member is fitted to an inner circumferential surface of the pilot portion.

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