JP2008014428A - Wheel bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel bearing device having improved bearing rigidity by increasing the number of rollers, and having improved lubricating performance and durability by forming a proper lubricating film between the tapered roller and a cage. <P>SOLUTION: The wheel bearing device comprises the cage 3 having annular portions 3a, 3b, columnar portions 10 held between the annular portions and separated from each other in the circumferential direction, and rectangular pockets 11 formed between the columnar portions 10 for holding the tapered rollers 4, the columnar portions 10 each having an outer peripheral face located radially outward from a pitch circle diameter PCD of the tapered roller 4. An outer diameter D1 of the annular portion 3a on the large diameter side is formed somewhat smaller than a diameter D0 of a circumscribed circle of the tapered roller 4. A maximum number of rollers are stored in an annular space formed between an outward member 2 and an inward member 1. A plurality of parallel lubricating grooves 12 passing through the outer diameter side to the inner diameter side of the cage 3 are formed in the columnar portions in the horizontal direction to communicate the insides of the pockets 11 with the outsides. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wheel bearing device composed of a double row tapered roller bearing that rotatably supports a wheel of an automobile or the like, and more particularly, a wheel that increases bearing rigidity and lubrication performance to improve durability. The present invention relates to a bearing device.

  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. Generally, the rolling bearing has a desired bearing rigidity. A double-row angular contact ball bearing that exhibits durability against misalignment and has low rotational torque is often used from the viewpoint of improving fuel efficiency. 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.

  A typical example of such a wheel bearing device is shown in FIG. This wheel bearing device 50 is integrally provided with a vehicle body mounting flange 51b for mounting to the vehicle body on the outer periphery, and an outer member 51 having tapered double-row outer rolling surfaces 51a, 51a formed on the inner periphery. A wheel mounting flange 52 for mounting a wheel at one end, and one tapered inner rolling surface 53a facing the double row outer rolling surfaces 51a, 51a on the outer periphery, and the inner side A hub wheel 53 having a cylindrical small-diameter step portion 53b extending in the axial direction from the rolling surface 53a, and a small-diameter step portion 53b of the hub wheel 53 are press-fitted to the outer periphery of the double row outer rolling surface 51a, An inner member 55 comprising an inner ring 54 formed with the other tapered inner rolling surface 54a facing 51a, double-row tapered rollers 56, 56 accommodated between both rolling surfaces, and these cones Roller 56 is held so as to roll freely. A lifting device 57, and a sealing ring 58, 59 mounted on both end portions of the outer member 51.

  The inner ring 54 is press-fitted into the small-diameter step portion 53b of the hub ring 53, and the end portion of the small-diameter step portion 53b is plastically deformed radially outward to the hub ring 53 with respect to the hub ring 53. And a so-called self-retained third generation structure that is positioned and fixed in the axial direction.

  Here, the cage 57 is formed in the shape of a partial conical cylinder by injection molding synthetic resin, and the pockets 60 and the column portions 61 are alternately provided in the circumferential direction. Further, the tapered roller 56 is disposed so as to be able to roll in the pocket 60, and the outer peripheral surface of the column portion 61 is located radially outward from the PCD (pitch circle diameter) of the tapered roller 56. The operation of storing the tapered roller 56 in the pocket 60 is performed from the inner diameter side of the cage 57. As shown in FIG. 4, the tapered roller 56 and the cage 57 are temporarily assembled, and the tapered roller 56 is temporarily assembled. 56 passes over the small flange portions 62 and 63, and the hub ring 53 and the inner ring 54 are inserted into the inner diameter side thereof. The tapered rollers 56 and the retainer 57 are held by the small flange portions 62 and 63 so as not to fall off.

  Further, small flange portions 62 and 63 projecting radially outward are formed at the small diameter side ends of the inner rolling surfaces 53a and 54a of the hub ring 53 and the inner ring 54. Therefore, in a state where the tapered rollers 56 are disposed around the inner rolling surfaces 53a and 54a while the cage 57 is elastically deformed, the tapered rollers 56 are not accidentally displaced in the axial direction.

The seal ring 58 is fitted on the end of the outer member 51, and the inner diameter D thereof is set to be larger than the diameter d of the minimum circumscribed circle on the bottom surface side of the tapered roller 56 (see FIG. 3). As a result, even when the outer member 51 having the seal ring 58 fitted and fixed thereto is inserted into the hub ring 53 during assembly, the tapered roller 56 or the retainer 57 does not interfere with the seal ring 58.
JP 2001-10304 A

  Conventionally, in a wheel bearing device composed of double row tapered roller bearings, measures have been taken to increase the number of rollers in order to increase the rigidity of the bearing without reducing the diameter of the tapered roller 56. However, in order to increase the number of rollers, the interval between the pockets 60 of the cage 57 must be reduced. For that purpose, it is necessary to enlarge the PCD of the cage 57 and bring it as close as possible to the outer member 51 side.

  By holding the tapered roller 56 on the outer side in this way, the strength of the column width of the cage 57 can be secured, the number of rollers can be increased, and the bearing rigidity can be increased. If the PCD is increased and brought closer to the outer member 51 side, the amount of grease retained between the tapered rollers 56 becomes extremely small. This may reduce durability due to insufficient lubrication.

  The present invention has been made in view of such circumstances. The number of rollers is increased to increase bearing rigidity, and an appropriate lubricating film is formed between the tapered rollers and the cage to improve the lubricating performance and improve durability. It aims at providing the bearing device for wheels which aimed at improvement of.

  In order to achieve such an object, the invention according to claim 1 of the present invention includes an outer member having a tapered double-row outer rolling surface opened outwardly on the inner periphery, and the compound on the outer periphery. An inner member in which a tapered inner rolling surface facing the outer rolling surface of the row is formed, and a plurality of tapered rollers accommodated so as to be able to roll between the both rolling surfaces via a cage, A seal attached to an opening of an annular space formed between the outer member and the inner member, and the cage includes an annular portion on the large diameter side, an annular portion on the small diameter side, and these annular portions. Between the pillars and a rectangular pocket that holds the tapered rollers, and the outer peripheral surface of the pillar is In the wheel bearing device positioned radially outward from the pitch circle diameter of the tapered roller, an outer portion of the cage is placed on the column portion of the cage. Lubrication groove penetrating from the side to the inner diameter side is formed, and out of the pocket is in communication with.

  Thus, it is composed of a double row tapered roller bearing, and the cage is sandwiched between the annular portion on the large diameter side and the annular portion on the small diameter side, and these annular portions, and is formed in a circumferentially spaced manner. And a rectangular pocket for holding the tapered roller, and the outer peripheral surface of the column portion is located radially outward from the pitch circle diameter of the tapered roller. In this case, a lubrication groove that penetrates from the outer diameter side to the inner diameter side of the cage is formed in the pillar portion of the cage, and the inside and outside of the pocket communicate with each other. Along with the groove, it moves from the outside to the inside of the pocket, and the part overflowing from the lubrication groove adheres to the tapered rollers from both walls of the pillar, and forms an appropriate lubricating film to improve the lubrication performance and improve durability. An improved bearing device for a wheel can be provided.

  Preferably, as in the second aspect of the invention, if a plurality of the lubricating grooves are provided in parallel in the horizontal direction, the lubricating grease is introduced from the outside of the pocket along the lubricating grooves by the centrifugal force of the bearing rotation. Can be moved easily.

  According to a third aspect of the present invention, the outer diameter of the annular portion on the large diameter side of the retainer is slightly smaller than the diameter of the circumscribed circle of the tapered roller, If the maximum number of rollers is accommodated in the annular space formed between the side members, the number of rollers can be increased to increase the bearing rigidity, and the lack of lubrication accompanying the increase in the number of rollers can be solved.

  The wheel bearing device according to the present invention has an outer member having a tapered double-row outer rolling surface formed outwardly on the inner circumference, and an outer circumference facing the outer rolling surface of the double row. An inner member in which a tapered inner rolling surface is formed, a plurality of tapered rollers which are rotatably accommodated between the both rolling surfaces via a cage, the outer member and the inner member, And a seal attached to the opening of the annular space formed between the large-diameter side annular portion, the small-diameter side annular portion, and the annular portion, and spaced apart in the circumferential direction. And a rectangular pocket that holds the tapered rollers, and the outer peripheral surface of the column is larger in diameter than the pitch circle diameter of the tapered rollers. In the wheel bearing device positioned outward in the direction, the moisture penetrating from the outer diameter side to the inner diameter side of the cage in the pillar portion of the cage. Since a groove is formed and the inside and outside of the pocket communicate with each other, the lubricating grease filled in the bearing moves from the outside of the pocket along the lubricating groove of the column portion to the inside, and also overflows from the lubricating groove. It is possible to provide a wheel bearing device that adheres to the tapered rollers from both walls of the column portion and forms an appropriate lubricating film to improve the lubricating performance and improve the durability.

  An outer member having a tapered double-row outer rolling surface opened outwardly on the inner periphery, and a tapered inner rolling surface facing the outer rolling surface of the double-row is formed on the outer periphery. An inner member, a plurality of tapered rollers that are rotatably accommodated between the rolling surfaces via a cage, and an opening in an annular space formed between the outer member and the inner member The retainer is provided with an annular portion on the large diameter side, an annular portion on the small diameter side, and a column portion formed between the annular portions and spaced apart in the circumferential direction, and A wheel bearing device having a rectangular pocket for holding the tapered roller formed between the column portions, and an outer peripheral surface of the column portion positioned radially outward from a pitch circle diameter of the tapered roller The outer diameter of the large-diameter annular portion of the cage is slightly smaller than the diameter of the circumscribed circle of the tapered roller The maximum number of rollers is accommodated in an annular space formed between the outer member and the inner member, and the lubricating groove penetrates from the outer diameter side to the inner diameter side of the cage in the pillar portion of the cage Are formed, these lubrication grooves are provided in parallel in the horizontal direction, and the inside and outside of the pocket communicate with each other.

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 a sectional view showing a cage according to the present invention, and (b) is a modification of (a). An example is shown.

  This wheel bearing device is for a drive wheel called the third generation, and is accommodated between the inner member 1, the outer member 2, and both members 1, 2 via a cage 3 so as to be capable of rolling. Double-row tapered rollers 4 and 4 are provided. The inner member 1 includes a hub ring 5 and an inner ring 6 press-fitted into the hub ring 5 through a predetermined shimiro.

  The hub wheel 5 integrally has a wheel mounting flange 7 for mounting a wheel (not shown) at an end on the outer side, and one (outer side) tapered inner rolling surface 5a on the outer periphery. A cylindrical small diameter step portion 5b extending in the axial direction from the inner rolling surface 5a is formed. Hub bolts 7a for fixing the wheels are planted at equal intervals in the circumferential direction of the wheel mounting flanges 7. Further, a serration (or spline) 5c for torque transmission is formed on the inner periphery. A large collar 5d for guiding the tapered roller 4 is formed on the large diameter side of the inner rolling surface 5a of the hub wheel 5. On the other hand, a small ridge for holding the tapered roller 4 is not formed on the small diameter side of the inner rolling surface 5a, and the small diameter step portion 5b extends straight from the small diameter side of the inner rolling surface 5a to the shoulder 5e. It is connected to.

  The hub wheel 5 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and includes a base portion of a wheel mounting flange 7 that serves as a seal land for an outer side seal 8 to be described later, including the inner rolling surface 5a. To the small-diameter step portion 5b, the surface hardness is set to a range of 58 to 64HRC by induction hardening.

  The inner ring 6 is formed with the other (inner side) tapered inner rolling surface 6a on the outer periphery, a large collar 6b for guiding the tapered roller 4 on the large diameter side of the inner rolling surface 6a, and a conical on the small diameter side. A gavel 6c for preventing the roller 4 from falling off is formed. Then, the hub wheel 5 is press-fitted and fixed to the small-diameter step portion 5b of the hub wheel 5 through a predetermined shimiro.

  The outer member 2 integrally has a vehicle body mounting flange 2b attached to a suspension device (not shown) on the outer periphery, and has a tapered shape that opens outward facing the inner rolling surfaces 5a and 6a on the inner periphery. Double row outer rolling surfaces 2a, 2a are formed. This outer member 2 is made of medium carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C, and at least the double row outer rolling surfaces 2a and 2a have a surface hardness in the range of 58 to 64HRC by induction hardening. Is cured. The inner ring 6 and the tapered roller 4 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 part by quenching. Seals 8 and 9 are attached to the opening of the annular space formed between the outer member 2 and the inner member 1, leakage of the lubricating grease enclosed in the bearing to the outside, and rainwater from the outside Prevents foreign matter such as dust and dust from entering the bearing.

  In this embodiment, the cage 3 is formed by injection molding a material containing an appropriate amount of reinforcing material such as GF (glass fiber) based on a thermoplastic synthetic resin such as PA (polyamide) 66. . As shown in FIG. 2A, the retainer 3 includes a large-diameter-side annular portion 3a, a small-diameter-side annular portion 3b, and a column portion 10 that is sandwiched between the annular portions 3a and 3b and spaced apart in the circumferential direction. Is formed. A rectangular pocket 11 is formed between the pillars 10 and 10. The tapered rollers 4 are held in these pockets 11 so as to freely roll.

  The outer peripheral surface of the column portion 10 is positioned radially outward from the pitch circle diameter PCD of the tapered roller 4, and the outer diameter D 1 of the annular portion 3 a on the large diameter side is a circumscribed circle on the large end surface side of the tapered roller 4. The diameter is slightly smaller than the diameter D0. As a result, conventionally, only one or two tapered rollers less than the maximum number of rollers that can be accommodated without a cage could be arranged, but the maximum number of rollers corresponding to the total number of rollers could be accommodated, increasing bearing rigidity. Can be planned.

  Here, a plurality of lubricating grooves 12 penetrating from the outer diameter side to the inner diameter side of the cage 3 are formed in the column portion 10 of the cage 3. The lubrication grooves 12 are provided in parallel in the horizontal direction, and communicate the inside and outside of the pocket 11. As a result, as indicated by arrow A, the lubricating grease filled in the bearing is internally fed from the outside of the pocket 11 along the lubricating groove 12 of the column portion 10 by the centrifugal force of the bearing rotation (from the left side to the right side in the figure). Since the portion overflowing from the lubricating groove 12 adheres to the tapered roller 4 from both walls of the column portion 10, the metal contact portions of the column portion 10 and the tapered roller 4 and the respective rolling surfaces and the tapered roller 4 etc. A proper lubricating film is formed. By adopting such a cage 3, the number of rollers is increased to increase bearing rigidity, and at least a proper lubricating film is formed between the tapered roller 4 and the cage 3, and the lubrication is insufficient due to the increase in the number of rollers. Can be eliminated. Therefore, it is possible to provide a wheel bearing device with improved lubrication performance and improved durability.

  FIG. 2B shows a modification of the cage 3 in FIG. The retainer 13 has a large-diameter side annular portion 3a, a small-diameter side annular portion 3b, and a column portion 14 that is sandwiched between the annular portions 3a and 3b and spaced apart in the circumferential direction. Yes. A rectangular pocket 11 is formed between the pillar portions 14 and 14. The tapered rollers 4 are held in these pockets 11 so as to freely roll.

  Here, a plurality of lubricating grooves 15 penetrating from the outer diameter side to the inner diameter side of the cage 13 are formed in the column portion 14 of the cage 13. The lubricating groove 15 is provided substantially perpendicular to the axial center of the tapered roller 4 and communicates the inside and outside of the pocket 11. As a result, the lubricating grease filled in the bearing is moved from the outside of the pocket 11 along the lubricating groove 15 as indicated by the arrow B as the tapered roller 4 rolls (from the upper side to the lower side in the figure). Since the portion overflowing from the lubrication groove 15 is attached to the tapered roller 4 from both walls of the column portion 14, the metal contact portions of the column portion 14 and the tapered roller 4 and the respective rolling surfaces and the tapered roller 4 etc. A proper lubricating film is formed. In addition, although the synthetic resin was illustrated as a material of the cage | baskets 3 and 13 here, it does not restrict to this, For example, the steel plate which consists of cold rolled steel plates (JIS standard SPCC system etc.) etc. is formed by press work. It may be made of a steel plate.

  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 composed of, for example, a double-row tapered roller bearing, and increases the PCD of the cage to the outer member side to increase the number of rollers and increase the bearing rigidity. It can be applied to a bearing device.

It is a longitudinal section showing one embodiment of a wheel bearing device concerning the present invention. (A) is sectional drawing of the holder | retainer single-piece | unit based on this invention. (B) shows the modification of (a). It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus. It is explanatory drawing which shows an assembly method same as the above.

Explanation of symbols

1 .... Inner member 2 ... Outer member 2a ... Outer rolling surface 2b ... ··· Body mounting flanges 3 and 13 ············· Retainer 3a ······· Large diameter side annular portion 3b ··· Annular part 4 on the small diameter side ..... Tapered roller 5 ..... Hub wheel 5a, 6a ..... Inner rolling surface 5b ... ······ Small diameter step portion 5c ··· Serrations 5d and 6b ········· Large 5e ········ Shoulder portion 6 ···・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner ring 6c ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Small 7 ・ ・ ・ ・ ・ ・ ・ ・ Wheel mounting flange 7a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・Hub bolts 8, 9 ... Seals 10, 14, ... Column 11 ...・ ・ ・ ・ Pockets 12, 15 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Lubricated groove 50 ・ ・ ・ ・ ・ ・ Bearing bearing device 51 ・ ・ ・ ・ ・ ・ External member 51a ····· Outside rolling surface 51b ·········································· 53a, 54a ... Inner rolling surface 53b ... Small diameter step 53c ... Caulking part 54 ... Inner ring 55 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner member 56 ・ ・ ・ ・ ・ Conical roller 57 ・ ・ ・ ・ ・ Retainer 58, 59 ・ ・ ・ ・ ・ ・Seal ring 60 ································································ 62 .... Diameter D of the minimum circumscribed circle of the tapered roller ······························· Diameter of the seal ring D0 ······ D1 of the circumscribed circle on the large end face side of the tapered roller Outer diameter PCD of the annular part ・ ・ ・ ・ ・ ・ ・ ・ Pitch circle diameter of tapered roller

Claims (3)

An outer member having a tapered double row outer rolling surface formed outwardly on the inner periphery;
An inner member formed with a tapered inner rolling surface facing the outer rolling surface of the double row on the outer periphery;
A plurality of tapered rollers accommodated so as to roll freely between the rolling surfaces via a cage;
A seal attached to an opening of an annular space formed between the outer member and the inner member;
The retainer is formed between the large-diameter annular portion, the small-diameter-side annular portion, and the annular portions that are sandwiched between the annular portions and spaced apart in the circumferential direction. In the wheel bearing device, the outer peripheral surface of the column portion is located radially outward from the pitch circle diameter of the tapered roller,
A bearing device for a wheel, wherein a lubrication groove penetrating from an outer diameter side to an inner diameter side of the cage is formed in a pillar portion of the cage, and the inside and outside of the pocket communicate with each other.   The wheel bearing device according to claim 1, wherein a plurality of the lubricating grooves are provided in parallel in the horizontal direction.   The outer diameter of the large-diameter annular portion of the cage is formed to be slightly smaller than the diameter of the circumscribed circle of the tapered roller, and the largest roller in the annular space formed between the outer member and the inner member. The wheel bearing device according to claim 1 or 2, wherein the number is accommodated.

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