JP2010043670A - Wheel-bearing device - Google Patents

Abstract

A wheel bearing device capable of improving the sealing performance of a seal and maintaining the bearing performance for a long period of time.
A base portion 6b of a wheel mounting flange 6 is formed in an arc shape, a metal ring 12 is fitted on the base portion 6b, a seal 8 having side lips 14a, 14b is slidably contacted, and the metal ring 12 is connected to a hub. A cylindrical fitting portion 12a fitted on the shoulder portion 4e of the wheel 4, a curved portion 12b formed in an arc shape corresponding to the shape of the base portion 6b, and a wheel mounting flange extending radially outward therefrom. 6 is provided with a disc portion 12c that is in close contact with the side surface 6c, and an umbrella portion 12d that extends away from the outer diameter portion with respect to the wheel mounting flange 6 in the axial direction. Along the outer periphery of the outer end portion of the umbrella portion 12a, a plurality of discharge holes 15 are equally spaced in the circumferential direction of the umbrella portion 12d, and at least one of them is formed on the road surface. It is arranged at the nearest position.
[Selection] Figure 2

Description

  The present invention relates to a wheel bearing device for rotatably supporting a wheel of an automobile or the like, and more particularly to a wheel bearing device with improved sealing performance.

  2. Description of the Related Art Conventionally, a wheel bearing device for supporting a wheel of an automobile or the like is such that a hub wheel for mounting a wheel is rotatably supported via a rolling bearing, and there are a drive wheel and a driven wheel. For structural reasons, an inner ring rotation method is generally used for driving wheels, and an inner ring rotation method and an outer ring rotation method are generally used for driven wheels. As the wheel bearing device, a double-row angular ball bearing having a desired bearing rigidity, exhibiting durability against misalignment, and having a small rotational torque from the viewpoint of improving fuel efficiency is often used. On the other hand, double row tapered roller bearings are used in vehicles such as off-road cars and trucks that have a heavy vehicle body weight.

  Since these wheel bearing devices are arranged at sites where muddy water or the like is easily applied, a seal device is mounted to seal between the outer member and the inner member. Generally, in a sealing device, a sealing member having a sealing lip is attached to an outer member serving as a stationary member, and the sealing lip is slidably contacted with an outer peripheral surface of the inner member.

  An example of such a wheel bearing device is shown in FIG. The wheel bearing device 50 includes an outer ring member (outer member) 51 that is non-rotatably attached to the vehicle body side, and an inner ring member (inner member) that is rotatably supported by the outer ring member 51 via a ball (not shown). The wheel (not shown) is fixed to the inner ring member 52 and is rotatable with respect to the vehicle body. Since the wheel bearing device 50 is disposed in a place where mud water or the like is easily applied, a sealing device is disposed to seal between the inner ring member 52 and the outer ring member 51.

  This sealing device includes a seal member 53 fitted to the inner periphery of the end of the outer ring member 51 and a metal ring 57 fitted to the base 56 of the wheel mounting flange 55 of the hub ring 54. The seal member 53 includes an annular elastic seal body 58 and a metal core 59 that holds the elastic seal body 58. The elastic seal body 58 has three annular seal lips 58a, 58b, and 58c. The seal lip 58a is on the flange surface 54a of the hub wheel 54, and the seal lip 58b is on the round surface 54b of the hub wheel 54. Further, the seal lip 58c is formed so as to be disposed close to the outer peripheral surface 54c of the shoulder portion of the hub wheel 54, respectively.

  The metal ring 57 includes a fitting portion 57a fitted to the shoulder portion outer peripheral surface 54c of the hub wheel 54, a flange portion 57b closely attached to the flange surface 54a of the hub wheel 54, and an outer peripheral side peripheral edge of the flange portion 57b. And a non-contact portion extending in the axial direction along the chamfered portion 51 a of the outer ring member 51, and a seal mounting portion 57 c formed in a substantially crank shape in a direction away from the flange surface 54 a of the hub wheel 54. And a seal portion 57d. The gap C between the inner peripheral surface of the non-contact seal portion 57d and the chamfered portion 51a and the outer peripheral surface 51b of the outer ring member 51 is set to an extremely narrow dimension.

  When the flange portion 57b of the metal ring 57 is brought into close contact with the flange surface 54a of the hub ring 54, and the fitting portion 57a of the metal ring 57 is fitted to the shoulder outer peripheral surface 54c of the hub ring 54, the flange surface 54a. The elastic body 60 is mounted in a seal space formed between the seal mounting portion 57c and the seal mounting portion 57c. A labyrinth is formed by the inner peripheral surface of the non-contact seal portion 57d and the chamfered portion 51a and the outer peripheral surface 51b of the outer ring member 51.

The sealing effect of the elastic body 60 mounted in the seal space prevents muddy water and the like from entering the fitting portion between the metal ring 57 and the hub ring 54, and the inner peripheral surface of the non-contact seal portion 57d and the outer ring member. Due to the effect of the labyrinth formed by the chamfered portion 51 a and the outer peripheral surface 51 b of 51, muddy water or the like can be prevented from entering the sliding contact portion between the seal member 53 and the metal ring 57.
JP 2005-291485 A

  In such a conventional sealing device for a wheel bearing device, the seal member 53 and the metal ring 57 are formed by the labyrinth effect formed by the inner peripheral surface of the non-contact seal portion 57d and the chamfered portion 51a and the outer peripheral surface 51b of the outer ring member 51. It is possible to prevent muddy water from entering the sliding contact portion. However, there is a problem that the muddy water or the like that has once entered from the slight gap C is difficult to be discharged to the outside. Then, muddy water or the like staying on the elastic seal body 58 may adhere to the sliding contact surface of the seal lip 58a and wear the seal lip 58a, and it is difficult to maintain a stable sealing performance for a long period of time. .

  This invention is made | formed in view of such a situation, and aims at the improvement of the sealing performance of a seal | sticker, and it aims at providing the wheel bearing apparatus which can maintain bearing performance over a long period of time. .

  In order to achieve such an object, the invention according to claim 1 of the present invention has a vehicle body mounting flange integrally attached to the suspension on the outer periphery, and a double row outer rolling surface integrally on the inner periphery. A formed outer member and a hub wheel integrally having a wheel mounting flange for mounting a wheel at one end and a small-diameter stepped portion formed on the outer periphery, and an inner ring or a constant speed fitted to the hub ring An inner member comprising an outer joint member of a universal joint and having a double-row inner rolling surface facing the double-row outer rolling surface on the outer periphery, and both the inner member and the outer member. A double-row rolling element accommodated between the running surfaces via a cage, and a seal attached to an opening in an annular space formed between the outer member and the inner member. A base portion on the inner side of the wheel mounting flange is formed in a circular arc shape. A metal ring formed by pressing is fitted, and an outer seal of the seals is joined to a core metal fitted to the inner periphery of the end of the outer member, and the core metal is integrally joined to the core metal. And a seal member having a side lip extending obliquely outward in the radial direction and a grease lip extending inclined toward the inner side of the bearing, and at least the side lip of the seal member is in sliding contact with the metal ring. In the wheel bearing device, the metal ring includes a cylindrical fitting portion that is fitted on a shoulder portion of the hub wheel, a curved portion that is formed in an arc shape corresponding to the shape of the base portion, and A disc portion that extends radially outward from the curved portion and is in close contact with the inner side surface of the wheel mounting flange, and is spaced axially from the outer diameter portion of the disc portion to the wheel mounting flange. An extending umbrella portion, and the umbrella portion is Square along the outer side of the outer circumference of the end portion of the member while being oppositely arranged with a slight annular gap, a plurality of drain holes in the circumferential direction of the umbrella portion is bored.

  In this way, the base portion on the inner side of the wheel mounting flange is formed in an arc shape, and a metal ring formed by pressing from a steel plate is fitted to this base portion, and the seal on the outer side is attached to the outer member. Seal member having a metal core fitted to the inner periphery of the end, a side lip integrally joined to the metal core, extending obliquely outward in the radial direction, and a grease lip extending inclined toward the inner side of the bearing In the wheel bearing device in which at least the side lip is slidably contacted with the metal ring among the seal members, the metal ring has a cylindrical fitting portion that is fitted on the shoulder portion of the hub wheel, and a shape of the base portion Corresponding to the curved portion formed in an arc shape, a disk portion extending radially outward from the curved portion and closely contacting the inner side surface of the wheel mounting flange, and an outer diameter portion of the disk portion Away from the wheel mounting flange in the axial direction An umbrella portion extending, and the umbrella portion is disposed opposite to the outer end of the outer member via a slight annular gap, and has a plurality of drain holes in the circumferential direction of the umbrella portion. Therefore, it is possible to prevent muddy water or the like from entering the sliding contact portion between the seal and the metal ring, and even if muddy water or the like enters from the slight annular gap, It is possible to provide a wheel bearing device that can be easily discharged to the outside by centrifugal force accompanying rotation, improve the sealing performance of the seal, and maintain the bearing performance over a long period of time.

  Preferably, as in the invention described in claim 2, when the discharge holes are bored at equal intervals in the circumferential direction and at least one is disposed at a position closest to the road surface, The muddy water or the like that has entered the interior flows downward through the side lip of the seal and is easily discharged to the outside.

  According to a third aspect of the present invention, the size of the inlet opening of the drain hole in the outer peripheral surface of the umbrella portion is smaller than the size of the outlet opening in the inner peripheral surface. If the cross section is formed in a tapered shape, it is difficult for muddy water or the like to enter from the outside, and once muddy water or the like is easily discharged due to the centrifugal force associated with the rotation of the metal ring, A stable sealing property can be maintained.

  According to a fourth aspect of the present invention, the drain hole has an inlet opening in the outer peripheral surface of the umbrella portion smaller in size than an outlet opening in the inner peripheral surface. If it is formed in a two-stage circular hole, it is difficult for muddy water or the like to enter from the outside, and once muddy water or the like has entered, it becomes easy to be discharged to the outside by the centrifugal force accompanying the rotation of the metal ring.

  Further, as in the invention described in claim 5, if the drainage hole is formed in a circular diameter and the diameter is set to 3 mm or less, intrusion of muddy water or the like is caused by the surface tension of the water adhering to the drainage hole. It can be effectively prevented.

  Further, as in the invention described in claim 6, if the annular gap between the umbrella portion of the metal ring and the outer peripheral surface of the outer member is set in the range of 0.05 to 1.0 mm, the metal Even if there is a dimensional variation or eccentricity of the ring or the outer member, it is possible to effectively prevent muddy water or the like from entering without the umbrella part interfering with the outer member.

  Further, as in the invention according to claim 7, if the bent portion is formed so as to protrude radially outward from the umbrella portion, the rigidity of the metal ring is improved and the dimensional and shape accuracy of the metal ring is improved. Can be increased.

  Further, as in the invention described in claim 8, the base is formed on an arc surface having a predetermined radius of curvature r, and the curved portion of the metal ring corresponding to the arc surface has a predetermined radius of curvature R. If the radius of curvature R and r are set so that R ≧ r, the curved portion of the metal ring interferes with the arc surface of the base when the metal ring is fitted to the base. Therefore, it is possible to prevent floating, and it is possible to prevent a gap from being generated between the side surface of the wheel mounting flange and the disk portion of the metal ring. As a result, both can be in close contact with each other to suppress the unevenness of the side lip and to ensure stable sealing.

  Moreover, if the said metal ring is formed with the steel plate which has corrosion resistance like invention of Claim 9, and the surface roughness of the steel plate used as the raw material is set to the range of Ra0.2-0.6. Can prevent rusting over a long period of time, maintain sealing performance, obtain a good seal sliding contact surface, suppress lip wear, and seal even if used in a poor environment The sealing performance can be maintained.

  A wheel bearing device according to the present invention has an outer member integrally formed with a vehicle body mounting flange for mounting to a suspension device on the outer periphery, and an outer member formed integrally with a double row outer rolling surface on the inner periphery, and one end A hub ring integrally having a wheel mounting flange for mounting a wheel on the part, and a outer ring member of an inner ring or a constant velocity universal joint fitted to the hub ring, and a small-diameter stepped portion formed on the outer periphery, 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, and a cage is provided between both rolling surfaces of the inner member and the outer member. A double row rolling element accommodated in a freely rollable manner, and a seal attached to an opening of an annular space formed between the outer member and the inner member, the inner side of the wheel mounting flange The base was formed in an arc shape, and this base was formed by pressing from a steel plate A metal ring is fitted, and an outer seal of the seals is integrally joined to the inner periphery of the end of the outer member, and is integrally joined to the core, and radially outward. In a wheel bearing device comprising a seal member having a side lip extending inclined and a grease lip extending inclined toward the inner side of the bearing, and at least the side lip of the seal member is in sliding contact with the metal ring. A cylindrical fitting portion in which the metal ring is fitted on the shoulder portion of the hub wheel, a curved portion formed in an arc shape corresponding to the shape of the base portion, and a radially outward direction from the curved portion A disc portion that is in close contact with the side surface on the inner side of the wheel mounting flange, and an umbrella portion that extends away from the outer diameter portion of the disc portion in the axial direction with respect to the wheel mounting flange. This umbrella portion is the outer end of the outer member. Since it is arranged oppositely through a slight annular gap along the circumference and a plurality of drainage holes are drilled in the circumferential direction of the umbrella part, mud etc. are in the sliding contact part between the seal and the metal ring. Intrusion can be prevented, and even if muddy water or the like enters through this slight annular gap, it is easily discharged to the outside by the centrifugal force accompanying the rotation of the metal ring, and the sealing performance of the seal is improved. Thus, it is possible to provide a wheel bearing device capable of maintaining the bearing performance over a long period of time.

  An outer member integrally having a vehicle body mounting flange to be attached to the suspension device on the outer periphery, a double row outer rolling surface formed integrally on the inner periphery, and a wheel mounting flange for attaching a wheel to one end And a hub wheel in which an inner rolling surface facing one of the double row outer rolling surfaces and a small-diameter step portion extending in the axial direction from the inner rolling surface are formed on the outer periphery, and the hub An inner member formed of an inner ring that is press-fitted into a ring through a predetermined squeeze and has an inner rolling surface that faces the other of the outer rolling surfaces of the double row on the outer periphery, and the inner member and the outer A seal attached to an opening portion of an annular space formed by a double row rolling element that is rotatably accommodated between both rolling surfaces of the member via a cage, and the outer member and the inner member. And a base portion on the inner side of the wheel mounting flange is formed in an arc shape. A metal ring formed by pressing from a steel plate is fitted on the outer side of the seal, and a core metal fitted to the inner periphery of the end of the outer member, and the core metal The seal member comprises a seal member having a side lip that is integrally joined and extends obliquely outward in the radial direction, and a grease lip that extends obliquely inward of the bearing, and the side lip and the grease lip of the seal member are connected to the metal ring. In the wheel bearing device slidably contacted with each other, the metal ring has a cylindrical fitting portion that is fitted on the shoulder portion of the hub wheel, and a curve formed in an arc shape corresponding to the shape of the base portion. A disk portion that extends radially outward from the curved portion and is in close contact with the inner side surface of the wheel mounting flange, and an axial direction from the outer diameter portion of the disk portion to the wheel mounting flange And an umbrella portion extending apart from Are arranged opposite to each other via a slight annular gap along the outer periphery of the outer side end of the outer member, and a plurality of discharge holes are formed in the circumferential direction of the umbrella part at equal intervals. And at least one is arranged at a position closest to the road surface.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing an embodiment of a wheel bearing device according to the present invention, FIG. 2 (a) is an enlarged view of a main part of FIG. 1, and (b) is a view taken in the direction of arrow II in (a). FIG. 3A is a partial cross-sectional view showing a modification of the metal ring according to the present invention, and FIG. 3B is a partial cross-sectional view showing a modification of (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 called a third generation, and is an outer member 1 and an outer member externally inserted into the inner member 1 through double-row rolling elements (balls) 3. And a member 2. The inner member 1 includes a hub ring 4 and an inner ring 5 fixed to the hub ring 4.

  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 has one (outer side) inner rolling surface 4a on the outer periphery and the inner rolling surface. A small diameter step 4b extending in the axial direction from the surface 4a is formed. Hub bolts 6a are planted on the wheel mounting flange 6 at equal intervals in the circumferential direction. The inner ring 5 is formed with the other (inner side) inner rolling surface 5a on the outer periphery, and is press-fitted into the small-diameter step portion 4b of the hub wheel 4 through a predetermined shimiro, and the end portion of the small-diameter step portion 4b is radially outward. It is fixed to the hub wheel 4 in the axial direction in a state where a predetermined bearing preload is applied by a caulking portion 4c formed by plastic deformation in the direction.

  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 base 6b on the inner side of the wheel mounting flange 6 to the small diameter step 4b via the step 4d. The surface hardness is set to a range of 58 to 64 HRC by induction hardening. The caulking portion 4c is an unquenched portion while maintaining the surface hardness after forging. This has sufficient mechanical strength against the rotational bending load applied to the wheel mounting flange 6, improves the fretting resistance of the small-diameter stepped portion 4b serving as the fitting portion of the inner ring 5, and performs caulking. It is possible to prevent micro cracks and the like from occurring in the crimped portion 4c due to processing.

  The outer member 2 integrally has a vehicle body mounting flange 2b to be attached to a knuckle (not shown) on the outer periphery, and faces the double row inner rolling surfaces 4a and 5a of the inner member 1 on the inner periphery. Double row outer rolling surfaces 2a, 2a are integrally formed. The outer member 2 is formed of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and at least the double row outer rolling surfaces 2a and 2a have a surface hardness of 58 to 64 HRC by induction hardening. Hardened to range. On the other hand, the inner ring 5 and the rolling element 3 are made of high carbon chrome steel such as SUJ2, and are hardened in the range of 58 to 64 HRC up to the core portion by quenching. And the double row rolling elements 3 and 3 are accommodated between both rolling surfaces of the outer member 2 and the inner member 1, and are held by the cages 7 and 7 so as to roll freely. A ball bearing is configured.

  Further, seals 8 and 9 are attached to the opening of the annular space formed between the outer member 2 and the inner member 1. These seals 8 and 9 prevent the grease sealed inside the bearing from leaking outside and preventing rainwater, dust, and the like from entering the bearing from the outside. The inner side seal 9 constitutes a so-called pack seal composed of an annular seal plate 10 and a slinger 11 which are substantially L-shaped in cross section and arranged to face each other.

  Here, in the present embodiment, the metal ring 12 is fitted to the inner side base portion 6 b of the wheel mounting flange 6, and the outer side seal 8 is disposed so as to be in sliding contact with the metal ring 12. 2A, the seal 8 is integrally formed with a core metal 13 fitted to the inner periphery of the outer side end of the outer member 2, and the core metal 13 by vulcanization adhesion or the like. The seal member 14 is joined. The core 13 has a substantially U-shaped cross section when it is pressed from an austenitic stainless steel plate (JIS standard SUS304 type or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC type or the like). It is formed in a shape.

  On the other hand, the seal member 14 is joined to the outer peripheral portion of the cored bar 13 and joined to the pair of side lips 14a and 14b extending obliquely outward in the radial direction and the inner edge part of the cored bar 13, and to the bearing inner side. And a grease lip 14c extending in an inclined manner. These side lips 14 b and 14 b and the grease lip 14 c are in sliding contact with the metal ring 12 fitted to the base 6 b on the inner side of the wheel mounting flange 6. A seal member 14 is wrapped around and joined to the outer portion of the core bar 13 to prevent foreign matter such as muddy water from entering the bearing from the fitting portion between the outer member 2 and the core bar 13. Yes.

  The metal ring 12 can be pressed from a corrosion-resistant steel plate, such as an austenitic stainless steel plate (JIS standard SUS304 type or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC type or the like). A cylindrical fitting portion 12a that is externally fitted to the shoulder portion 4e of the hub wheel 4, a curved portion 12b that is formed in an arc shape corresponding to the base portion 6b that is formed in an arc shape, and this curve A disk part 12c that extends radially outward from the part 12b and is in close contact with the inner side surface 6c of the wheel mounting flange 6, and from the outer diameter part of the disk part 12c to the wheel mounting flange 6 in the axial direction. A cylindrical umbrella portion 12d that extends in a spaced manner and a bent portion 12e that protrudes radially outward from the umbrella portion 12d are provided. The bent portion 12e is provided in order to improve the rigidity of the metal ring 12, and can improve the dimensional and shape accuracy of the metal ring 12.

  In addition, as for this metal ring 12, the surface roughness of the steel plate used as a raw material is set to the range of Ra0.2-0.6. Thereby, a favorable seal sliding contact surface can be obtained, lip wear can be suppressed, and the sealing performance of the seal 8 can be maintained even when used in a poor environment. Note that Ra is one of JIS roughness shape parameters (JIS B0601-1994), and is an arithmetic average roughness, which means an average value of absolute value deviations from an average line.

  The base portion 6 b is formed in an arc surface having a predetermined radius of curvature r at a corner portion between the shoulder portion 4 e of the hub wheel 4 and the wheel mounting flange 6. Corresponding to the arc surface, the curved portion 12b of the metal ring 12 is formed of an arc surface having a predetermined radius of curvature R, and the respective curvature radii R and r are set such that R ≧ r. Thereby, when the metal ring 12 is fitted to the base portion 6b, the curved portion 12b of the metal ring 12 is prevented from interfering with the arc surface of the base portion 6b and rising. Therefore, a gap is prevented from being generated between the side surface 6c of the wheel mounting flange 6 and the disk portion 12c of the metal ring 12, and the both are brought into close contact with each other, and the stable sealing is achieved by suppressing variations in the side lips 14a and 14b. Sex can be secured.

  Although not shown, an elastic lip may be mounted between the side surface 6 c of the wheel mounting flange 6 and the metal ring 12. This prevents foreign matter from entering from between the side surface 6c of the wheel mounting flange 6 and the disc portion 12c of the metal ring 12, and rusting of the mounting portion of the base portion 6b and the metal ring 12 over a long period of time. Can be prevented.

  In the present embodiment, the umbrella portion 12d of the metal ring 12 is disposed so as to face the outer peripheral end portion of the outer member 2 via a slight annular gap A, thereby forming a labyrinth seal. The annular gap A is set in a range of 0.05 to 1.0 mm (diameter). A plurality of drain holes 15 are formed in the circumferential direction of the umbrella portion 12d. If the gap A is less than 0.05 mm, the umbrella 12d may interfere with the outer member 2 due to dimensional variation or eccentricity of the metal ring 12 or the outer member 2, and if it exceeds 1.0 mm, muddy water Etc. is not preferable because it easily enters.

  As described above, the labyrinth effect formed by the inner peripheral surface of the umbrella portion 12d and the outer peripheral surface of the outer member 2 prevents muddy water or the like from entering the sliding contact portion between the seal 8 and the metal ring 12. Even if muddy water or the like enters the inside of the metal ring 12 from this slight annular gap A, it is discharged by the centrifugal force accompanying the rotation of the metal ring 12 as shown by the arrows in the figure, The drain hole 15 formed in the umbrella part 12d is easily discharged to the outside and does not stay on the side lip 14a. Therefore, muddy water or the like can be prevented from adhering to the sliding contact surface of the side lip 14a and being worn, and a stable sealing performance can be maintained over a long period of time.

  As shown in (b), the drain hole 15 is formed in a circular diameter, and the diameter d is set to 3 mm or less. When the size of the drain hole 15 is increased, mud water or the like entering the inside tends to be discharged, but mud water or the like enters the inside from the outside through the drain hole 15, so the surface tension of water generated by suppressing the diameter to 3 mm or less Infiltration of muddy water and the like can be prevented.

  Further, when the vehicle is stopped, muddy water or the like entering the inside of the metal ring 12 flows downward through the side lip 14a of the seal 8, and is a drainage hole drilled below the umbrella portion 12d closest to the road surface. 15 is discharged. Therefore, it is preferable that a plurality of drain holes 15 are disposed at a position closest to the road surface, and a plurality of drain holes 15 are perforated in the circumferential direction from the surface of the drainage effect. However, if the number is too large, muddy water or the like may enter from the outside, so it is appropriate to set the number in the range of 6 to 12.

  Here, the third generation structure on the driven wheel side is exemplified as the wheel bearing device, but the wheel bearing device according to the present invention is not limited to this, and the second generation or the fourth generation is applicable as long as the structure is applicable. It may be a generation. Furthermore, in the present embodiment, an example of a double-row angular contact ball bearing using balls as the rolling elements 3 is illustrated, but it is not limited to this, and a double-row tapered roller bearing using tapered rollers as the rolling elements is used. It may be configured.

  Next, a modification of the drain hole according to the present invention is shown in FIG. A plurality of drain holes 16 shown in (a) are formed in the umbrella portion 17a of the metal ring 17 at equal intervals in the circumferential direction, and the diameter d of the inlet 16a that opens to the outer peripheral surface of the umbrella portion 17a is formed on the inner peripheral surface. The cross section is formed in a tapered shape so as to be smaller than the diameter d1 of the opening 16b that opens (d <d1). This makes it difficult for muddy water or the like to enter from the outside, and the muddy water or the like that has once entered is easily discharged to the outside by the centrifugal force associated with the rotation of the metal ring 17, and maintains a more stable sealing property over a long period of time. be able to.

  Further, a plurality of discharge holes 18 shown in (b) are formed in the umbrella portion 19a of the metal ring 19 in a circumferentially equidistant manner. A two-stage circular hole is formed (d <d1) so as to be smaller than the diameter d1 of the discharge port 18b opened in the surface. Accordingly, it is difficult for muddy water or the like to enter from the outside, and the muddy water or the like that has entered once is easily discharged to the outside by the centrifugal force accompanying the rotation of the metal ring 19. In addition, although the drain hole was illustrated here as a circular hole, it is not necessarily limited to a circular hole but may be an ellipse or a rectangle.

  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 can be applied to all generations of wheel bearing devices regardless of whether they are for driving wheels or driven wheels.

It is a longitudinal section showing one embodiment of a wheel bearing device concerning the present invention. (A) is a principal part enlarged view of FIG. (B) is the II arrow directional view of (a). (A) is a fragmentary sectional view which shows the modification of the metal ring which concerns on this invention. (B) is a fragmentary sectional view showing a modification of (a). It is a principal part enlarged view which shows the sealing device of the conventional wheel bearing apparatus.

Explanation of symbols

1 ... Inner member 2 ... Outer member 2a ... Outer rolling surface 2b ... ··· Body mounting flange 3 ········· Rolling element 4 ························· Hub wheels 4a, 5a Surface 4b ··· Small diameter step 4c ··· Clamping portion 4d ··· Step portion 4e ··· ... Shoulder 5 ... Inner ring 6 ... Wheel mounting flange 6a ... Hub bolt 6b ... ······ Base 6c ··· Side surface 7 on the inner side ······································ Outer side Seal 9 ··········· Seal 10 on the inner side ········ Seal 11 ... Slinger 12, 17, 19 ... Metal ring 12a ... Fitting part 12b ... Bending part 12c・ ・ ・ ・ ・ ・ ・ ・ Disk parts 12d, 17a, 19a ・ Umbrella part 12e ・ ・ ・ ・ ・ ・ ・ ・ Folded part 13 …… Core 14 ・ ・ ・······ Seal members 14a and 14b ··· Side lip 14c ········· Grease lips 15, 16, and 18 ··· Drain holes 16a and 18a ··· Dipping Inlet 16b, 18b ··· Discharge port 50 ··· Wheel bearing device 51 ··· Outer ring member 51a ··· Chamfer Part 51b ... Outer peripheral surface 52 ... Inner ring member 53 ... Seal member 54 ... Hub wheel 4a ··········· Flange surface 54b ······· Rear surface 54c ································ Wheel Mounting flange 56 ... Base 57 ... Metal ring 57a ... Fitting part 57b ... Collar portion 57c... Seal mounting portion 57d... Non-contact seal portion 58... Elastic seal bodies 58a, 58b and 58c. Lip 59 ... Core 60 ... Elastic body A ... Annular gap C ... ······························· Diameter of the inlet port d1 ·········· Diameter of the outlet port

Claims (9)

An outer member integrally having a vehicle body mounting flange to be attached to the suspension device on the outer periphery, and an outer rolling surface of a double row integrally formed on the inner periphery;
It consists of a hub ring that has a wheel mounting flange for mounting a wheel at one end and a small-diameter step formed on the outer periphery, and an outer ring member of an inner ring or constant velocity universal joint fitted to this hub ring. An inner member in which a double row inner rolling surface facing the double row outer rolling surface is formed on the outer periphery;
A double row rolling element housed between the rolling surfaces of the inner member and the outer member so as to be freely rollable via a cage;
A seal attached to an opening of an annular space formed between the outer member and the inner member;
The base portion on the inner side of the wheel mounting flange is formed in an arc shape, and a metal ring formed by pressing from a steel plate is fitted to the base portion,
Outer seal among the seals is a core metal fitted to the inner periphery of the end portion of the outer member, a side lip that is integrally joined to the core metal and extends obliquely outward in the radial direction, and a bearing In a wheel bearing device comprising a seal member having a grease lip extending inclining inwardly, and at least a side lip of the seal member is in sliding contact with the metal ring,
A cylindrical fitting portion in which the metal ring is fitted on the shoulder portion of the hub wheel, a curved portion formed in an arc shape corresponding to the shape of the base portion, and a radially outward direction from the curved portion A disc portion that is in close contact with the inner side surface of the wheel mounting flange, and an umbrella portion that extends away from the outer diameter portion of the disc portion in the axial direction with respect to the wheel mounting flange. The umbrella portion is disposed so as to be opposed to the outer member along the outer periphery of the outer side through a slight annular gap, and a plurality of drain holes are formed in the circumferential direction of the umbrella portion. A wheel bearing device characterized by that.   The wheel bearing device according to claim 1, wherein the discharge holes are formed at equal intervals in the circumferential direction, and at least one of the discharge holes is disposed at a position closest to the road surface.   2. The cross section is formed in a tapered shape so that the drain hole has a smaller inlet opening in the outer peripheral surface of the umbrella portion than the outlet opening in the inner peripheral surface. 2. A wheel bearing device according to 2.   The drain hole is formed in a two-stage circular hole so that the size of the inlet opening in the outer peripheral surface of the umbrella portion is smaller than the size of the outlet opening in the inner peripheral surface. Or the wheel bearing apparatus of 2.   The wheel bearing device according to any one of claims 1 to 4, wherein the drain hole is formed to have a circular diameter, and the diameter is set to 3 mm or less.   The wheel bearing device according to any one of claims 1 to 5, wherein an annular gap between the umbrella portion of the metal ring and the outer peripheral surface of the outer member is set in a range of 0.05 to 1.0 mm.   The wheel bearing device according to any one of claims 1 to 6, wherein a bent portion is formed so as to protrude radially outward from the umbrella portion.   The base is formed on an arc surface having a predetermined radius of curvature r, and the curved portion of the metal ring is formed on an arc surface having a predetermined radius of curvature R corresponding to the arc surface. , R is set so that R ≧ r, the wheel bearing device according to claim 1.   The wheel bearing device according to any one of claims 1 to 8, wherein the metal ring is formed of a steel plate having corrosion resistance, and a surface roughness of the steel plate as a raw material is set in a range of Ra 0.2 to 0.6. .

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