JP6614289B2 - Bearing unit - Google Patents

Description

  The present invention is a wheel support bearing unit for rotatably supporting a wheel of, for example, an automobile with respect to a suspension device, and a cover member such as a resin sensor holder or a resin end cap is provided on an end surface of the outer ring. It is related with the bearing unit formed.

  Various bearing units equipped with a rotation sensor have been proposed to measure the rotational speed of automobile wheels. For example, in the case of a wheel support bearing unit that supports a driven wheel, one that is provided on the inner side of the unit inside the vehicle body is known, and an encoder is fitted to the inner side end of the inner ring that is a rotating wheel. In addition, a resin sensor holder (cover member) is fitted and disposed at the inner side end of the outer ring which is a stationary ring.

  A resin sensor holder is known in which a resin part is molded in an annular shape on an annular core metal. When the resin part is molded on a core metal in this manner, the resin material is subjected to molding shrinkage. The cored bar and the resin part do not adhere to each other, and the airtightness at the abutting surface (butting area) between the axial surface part of the inner side end of the outer ring and the outer axial side part of the resin part of the resin sensor holder May be lowered. If the airtightness of the abutting surface becomes low in this way, foreign matter such as muddy water may enter from the abutting area, and muddy water may reach the inside of the bearing through the surface of the cored bar. .

  Therefore, in order to improve the airtightness between the inner side end portion of the outer ring and the resin sensor holder, as illustrated in FIG. 5, the axial surface portion 101 of the inner side end portion of the outer ring 100 and the resin An O-ring 400 is disposed on the abutting surface (butting region) 300 of the resin portion of the sensor holder 200 with the outer axial surface portion 201, and the O-ring 400 is waterproofed (improves airtightness). (See Patent Document 1).

However, as shown in Patent Document 1, when the O-ring 400 is disposed on the abutting surface (butting region) 300, the O-ring 400 is a component and the axial surface portion 201 on the outer side of the resin portion. There was a problem that the cost increased by the amount that the annular O-ring groove 500 had to be formed.
In addition, since the O-ring 400 is used in a state where it is covered in three directions by an O-ring groove 500 provided in the resin portion, the plasticizer of the rubber material of the O-ring 400 moves to the resin portion and the rubber elasticity is lost. In order to prevent it from becoming hard, it is necessary to select a resin part material that has water resistance and salt-caloric resistance and does not cause absorption of the plasticizer of the rubber. However, there is a problem that the cost becomes high.

JP 2008-256512 A

  The present invention has been made in view of the above-described problems of the prior art, and the object of the present invention is to provide an O-ring that is disposed in the abutting region between the inner end of the stationary ring and the cover member. Provides a bearing unit that can effectively prevent the entry of foreign matter such as water and mud into the bearing without the need to eliminate the inconvenience such as the limitation of compatible materials due to the use of O-rings. There is to plan. It is another object of the present invention to provide a structure capable of quickly discharging foreign matter that has entered the abutting region to the outside.

In order to achieve such a subject, the first invention includes a stationary wheel having a stationary side raceway surface on the peripheral surface,
A rotating wheel that is disposed so as to be relatively rotatable with the stationary wheel, has a rotating side raceway surface on a circumferential surface facing the stationary side raceway surface, and has a wheel support flange for supporting a wheel on the outer circumferential surface;
A plurality of rolling elements incorporated between the stationary side raceway surface and the rotation side raceway surface;
A cover member fitted and sealed to the inner side end of the stationary ring, and a bearing unit including at least
The cover member includes an annular metal core that can be fitted to an inner side end of the stationary ring, and an annular resin portion that is molded integrally with the metal core.
The stationary ring forms a step on the outer diameter side of the inner side end,
The cover member forms an annular radial surface portion that protrudes in the axial direction toward the outer side on the outer diameter side from the axial surface portion on the outer side in the resin portion,
An axial surface portion of the resin portion of the cover member is abutted against an axial surface portion positioned on the inner side of the step on the inner side end portion of the stationary wheel to form a butt region, and the outer diameter side of the butt region In the outer diameter side of the radial surface portion in the step portion of the inner side end portion, the radial surface portion of the cover member is positioned so as to overlap in the radial direction,
The cored bar is fitted and fixed to the inner diameter surface of the stationary ring located on the outer side of the butting region,
A radial surface portion of the step is formed to be recessed radially inward,
The inner diameter surface of the radial surface portion of the cover member is formed in a tapered surface that increases in diameter toward the outer side ,
The radial surface portion of the step portion is formed as a tapered surface having a diameter that increases toward the inner side .

According to the first invention, the step portion is provided on the outer diameter side of the stationary wheel, and the radial surface portion of the resin portion of the cover member is configured to protrude and overlap on the step portion on the outer diameter side of the step portion. For this reason, it is possible to prevent muddy water from being directly applied to the abutting region between the axial surface portion of the inner side end portion of the stationary wheel and the axial surface portion of the resin portion of the cover member.
In addition, since the inner diameter surface of the radial surface portion of the cover member is formed into a tapered surface that increases in diameter toward the outer side, foreign matter that has entered the abutting region is quickly discharged outward along the tapered surface. can do.
Furthermore, since the radial surface portion of the stepped portion is formed with a tapered surface that becomes larger in diameter toward the inner side, together with the tapered surface of the cover member, foreign matter that has entered the abutting region is more quickly outward. Can be discharged.

  According to the present invention, entry of foreign matter such as water and mud into the bearing can be effectively prevented even if the O-ring disposed in the abutting region between the inner side end of the stationary ring and the cover member is eliminated. At the same time, a bearing unit that can eliminate inconveniences such as limitation of compatible materials due to the use of an O-ring has been provided, and significant cost reduction has been achieved. Moreover, the structure which can discharge | emit the foreign material which penetrate | invaded the butt | matching area | region quickly to the outside was able to be provided.

BRIEF DESCRIPTION OF THE DRAWINGS In 1st embodiment of this invention, (a) is a schematic longitudinal cross-sectional view which shows the whole, (b) is the elements on larger scale which expand and show the principal part. In 2nd embodiment of this invention, (a) is a schematic longitudinal cross-sectional view which shows the whole, (b) is the elements on larger scale which expand and show the principal part. In 3rd embodiment of this invention, (a) is a schematic longitudinal cross-sectional view which shows the whole, (b) is the elements on larger scale which expand and show the principal part. In 4th embodiment of this invention, (a) is a schematic longitudinal cross-sectional view which shows the whole, (b) is the elements on larger scale which expand and show the principal part. It is a schematic longitudinal cross-sectional view of a prior art.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In addition, this embodiment is only one embodiment of the present invention, and is not construed as being limited thereto. The design can be changed within the scope of the present invention.

"First embodiment"
FIG. 1 shows an example of a first embodiment of the present invention. In this embodiment, a mounting flange 5 that is fixed to an automobile suspension is provided on the outer peripheral surface, and a double row outer ring raceway (stationary side) is provided on the inner peripheral surface. Hub wheel having outer ring (stationary wheel) 1 having raceway surfaces 7 and 7 and a wheel support flange 20 for supporting the wheel on the outer circumferential surface and an inner ring raceway (rotation side raceway surface) 21 on the outer circumferential surface. (Rotating wheel) 19 and a separate inner ring (rotating wheel) 25 having an inner ring raceway (rotating side raceway surface) 27 that is externally fitted to a small-diameter step portion 23 formed on the outer peripheral surface on the inner side of the hub wheel 19. And a plurality of rolling elements (balls) 29 incorporated between the outer ring raceways 7 and 7 and the inner ring raceways 21 and 27, and a support ring 31 fitted to the shoulder portion of the inner ring 25 in the axial direction. Is fitted to the inner side end 9 of the outer ring 1. And at least a resin sensor holder 43 serving as a cover member that seals the bearing inner space, and a sensor 39 that includes a detection unit 41 that detects the rotation of the encoder 33 and is fixed to the sensor hole 55 of the resin sensor holder 43. A description will be given of an embodiment in which a wheel bearing hub bearing unit with a sensor for a driven wheel is employed.
In the figure, the arrow X indicates the axial direction, and the arrow Y indicates the radial direction.

  The outer ring 1 includes a cylindrical radial surface portion 13 projecting toward the inner side in the axial direction by denting the inner side end portion 9 in the axial direction toward the outer side, and the radial surface portion 13. Further, a short cylindrical recessed portion 11 having an annular axial surface portion 15 formed on the outer side is formed.

  The axial direction surface part 15 which comprises the recessed part 11 is formed in the annular | circular shape by the plane orthogonal to the axial center 17 and a perpendicular direction. On the other hand, the radial surface portion 13 is formed in a tapered surface having a larger diameter from the outer diameter of the axial surface portion 15 toward the inner side.

  The hub wheel 19, the separate inner ring 25, the rolling elements 29, the encoder 33, the sensor 39, and the like are not particularly limited and are appropriately selected and applied within the scope of the present invention.

The resin sensor holder (cover member) 43 is formed with a diameter smaller than the radial width of the recessed portion 11 and with a thickness greater than the axial depth of the recessed portion 11, and is formed from the recessed portion 11 toward the inner side. It is arranged in a state of protruding part.
That is, for example, the resin sensor holder 43 according to the present embodiment includes a circular annular disk portion 47 in the vertical direction, and a cylindrical portion (fitting portion) 49 formed continuously from the inner diameter of the disk portion 47 in the axial direction. The cored bar 45, the disk part 47 of the cored bar 45, and at least a part of the cylindrical part 49 are embedded, and the whole circumferential direction of the radial inner diameter surface 51 of the cylindrical part 49 is integrally formed. And a bottomed cylindrical resin portion 53.

  The cylindrical portion 49 of the cored bar is formed with an outer diameter that can be fitted to the inner diameter surface 3 of the outer ring formed continuously from the inner diameter of the recessed portion 11 toward the outer side in the axial direction.

As described above, in the resin portion 53, the sensor hole 55 that houses the sensor 39 is recessed from the inner axial surface portion 57 of the resin portion 53.
Further, the radial surface portion (outer diameter surface) 61 of the resin portion 53 is formed in a tapered surface having a diameter that decreases from the outer side axial surface portion 59 that is abutted against the axial surface portion 15 of the recessed portion 11 toward the inner side. ing.

  Therefore, the resin sensor holder 43 is inserted into the recessed portion 11 formed in the inner side end 9 of the outer ring 1, and the axial surface portion 59 on the outer side of the resin portion 53 in the resin sensor holder 43 is inserted in the axial direction of the recessed portion 11. When the cylindrical portion 49 of the cored bar 45 is fitted and fixed to the surface portion 15 (forms a butt region 63) and the outer ring inner diameter surface 3 at the back of the recessed portion 11 is fixed, the radial surface portion 13 of the recessed portion 11 is Since the resin sensor holder 43 is disposed on the radial surface portion (outer diameter surface) 61 of the resin portion 53 so as to overlap with a predetermined gap 65, the axial direction of the recessed portion 11 of the outer ring 1 is arranged. Muddy water is not directly applied to the abutting region 63 between the surface portion 15 and the axial surface portion 59 of the resin portion 53 of the resin sensor holder 43.

  Further, the radial surface portion 13 of the recessed portion 11 is a tapered surface that increases in diameter toward the inner side, and the radial surface portion (outer diameter surface) 61 of the resin portion 53 of the resin sensor holder 43 is directed toward the inner side. Since the tapered surface has a small diameter, even if muddy water enters the abutting region 63, the muddy water is a radial surface portion 13 that is a tapered surface of the recessed portion 11 or a tapered surface of the resin portion 53 ( The water is quickly drained along the outer surface 61).

  Since such a configuration is adopted, it is possible to improve the sealing performance even if the O-ring disposed in the butt region 63 is omitted as in the prior art. Therefore, in this embodiment, not only the cost can be reduced by eliminating the O-ring, but also the limitation of the compatible material by using the O-ring can be eliminated, so that a great cost reduction effect can be obtained.

"Second embodiment"
FIG. 2 shows an example of the second embodiment of the present invention. In the present embodiment, only the differences from the first embodiment will be described, and the description of the first embodiment will be given for other configurations and effects. Is used.

  In the present embodiment, the recessed portion 11 is formed in the inner side end portion 9 of the outer ring 1, the resin sensor holder 43 is inserted into the recessed portion 11, and the axial side surface portion on the outer side of the resin portion 53 in the resin sensor holder 43. 59 is abutted against the axial surface portion 15 of the recessed portion 11 (to form a butted region 63), and the cylindrical portion 49 of the metal core 45 is fitted and fixed to the inner surface 3 of the outer ring at the back of the recessed portion 11. An embodiment similar to the form is adopted.

In the present embodiment, the radial surface portion 13 of the recessed portion 11 is a cylindrical surface having a constant inner diameter with respect to the axial direction, and the radial surface portion (outer diameter surface) 61 of the resin portion 53 is the radial direction of the recessed portion 11. A dome-shaped protrusion (annular protrusion) 67 is formed in a cross-sectional view having a predetermined fastening margin between the surface section 13 and the surface section 13.
According to this embodiment, while exhibiting the same effect as 1st embodiment, the protrusion 67 of the radial direction surface part (outer diameter surface) 61 of the resin part 53 is on the outer diameter side of the said protrusion 67. As shown in FIG. Since the contact seal area 69 is configured by being press-fitted with the radial surface section 13 of the recessed section 11 positioned, it is possible to prevent further muddy water from entering the butt area 63.

Further, in the present embodiment, the radial surface portion (outer diameter surface) 61 of the resin portion 53 is formed on the dome-shaped protrusion 67 in a cross-sectional view, but is not limited to the protruding shape. As long as it is formed with a predetermined interference with the radial surface portion 13 of the insertion portion 11, the design can be appropriately changed such as a triangular shape or a polygonal shape in a cross-sectional view. Although the present embodiment has been described with a form formed in series in the circumferential direction, it may be a form formed in two or three in the axial direction. It is also within the scope of the present invention to improve the sealing performance.
Moreover, in this embodiment, even if it is the structure which forms the radial direction surface part 13 of the recessed part 11 in the taper surface which becomes gradually large diameter as it goes to an inner side, it is applicable, and within the scope of the present invention. The design can be changed as appropriate.

"Third embodiment"
FIG. 3 shows an example of the third embodiment of the present invention. In this embodiment, only the differences from the first and second embodiments will be described, and other configurations and functions and effects will be described in the first embodiment. The description of the form is used.

  In the present embodiment, unlike the first and second embodiments, a step portion 71 is formed on the outer diameter of the inner side end portion 9 of the outer ring 1, and the resin sensor holder 43 is formed on the outer diameter side of the step portion 71. An embodiment is adopted in which the radial surface portion 61 of the resin portion 53 is arranged so as to overlap with a predetermined gap 85 in the radial direction.

The step portion 71 is formed in a concave shape on the outer diameter of the inner side end portion 9 of the outer ring 1.
The stepped portion 71 is continuously formed so as to have a first wall surface 73 continuously formed in the vertical direction from the outer diameter surface 2 toward the axial center 17 direction, and to have a smaller diameter from the first wall surface 73 toward the inner side. The formed tapered surface 75, the cylindrical portion 77 formed continuously from the tapered surface 75 toward the inner side in the axial direction, and continuously formed from the cylindrical portion 77 in the vertical direction. The second wall surface 79 is formed to have a smaller diameter than the outer wall surface 79, and the second wall surface 79 is formed from the second wall surface 79 toward the inner side in the axial direction.

  The resin sensor holder 43 protrudes in the axial direction toward the outer side on the outer diameter side of the outer side axial surface portion 59 in the resin portion 53 in a state of being fitted to the inner side end portion 9 of the outer ring 1. An annular radial surface portion (also referred to as a flange portion) 61 is formed in a hook shape, and the flange-shaped radial surface portion 61 is larger than the opposed surface portion 81 of the stepped portion 71 so as to protrude to the outer diameter side. In addition to being formed in a diameter, it is positioned on the outer diameter side of the facing surface portion 81 of the stepped portion 71 formed at the inner side end portion 9 of the outer ring 1 so as to overlap with a predetermined gap 85.

The radial surface portion 61 is formed with such a length as to reach the cylindrical portion 77 slightly beyond the facing surface portion 81 of the step portion 71 toward the outer side.
The inner diameter surface of the radial surface portion 61 is formed on the tapered surface 83 so as to increase in diameter toward the outer side.

Then, the axial surface portion 59 on the outer side of the resin portion 53 in the resin sensor holder 43 is abutted against the axial surface portion 15 of the inner side end portion 9 of the outer ring 1 (a butt region 63 is formed), and the axial surface portion. When the cylindrical portion 49 of the cored bar 45 is fitted and fixed to the inner ring surface 3 of the outer ring 15, the bowl-shaped radial surface portion 61 of the resin portion 53 of the resin sensor holder 43 is stepped at the inner side end portion 9 of the outer ring 1. On the opposite surface portion 81 on the outer diameter side of the portion 71, they are arranged so as to overlap with a predetermined gap 85.
In this embodiment, a drainage groove 87 is formed between the flange-shaped radial surface portion 61 of the resin portion 53 and the step portion 71 of the outer ring 1.

  Therefore, according to the present embodiment, the stepped portion 71 has a tapered surface 75 having a large diameter toward the outer side, and protrudes like a bowl on the stepped portion 71 on the outer diameter side of the stepped portion 71. Even if muddy water enters the stepped portion 71 by having a tapered surface 83 having a large diameter toward the outer side on the inner diameter surface of the radial surface portion 61 of the resin portion 53 positioned and providing the drainage groove 87. Since the muddy water that has entered can be quickly drained from the drainage groove 87 by the both tapered surfaces 75 and 83, the axial surface portion 15 of the inner side end portion 9 of the outer ring 1 and the resin portion of the resin sensor holder 43. It is possible to prevent muddy water from directly hitting the abutting region 63 with the 53 axial surface portion 59.

"Fourth embodiment"
FIG. 4 shows an example of the fourth embodiment of the present invention. In this embodiment, only the differences from the first to third embodiments will be described, and other configurations and functions and effects will be described in the first embodiment. The description of the form is used.

In the present embodiment, unlike the third embodiment, the protruding amount (overhang amount) of the radial surface portion 61 protruding in a bowl shape of the resin portion 53 is increased to cover the drainage groove 87, and the first wall surface 73 of the step portion 71. This is an example of an embodiment in which a predetermined labyrinth 89 is formed up to immediately before.
In this case, since the outer ring 1 and the resin sensor holder 43 are both stationary members, an extremely narrow labyrinth can be set.
Further, the stepped portion 71 of the present embodiment forms a tapered surface 91 so as to continuously increase in diameter from the inner diameter of the first wall surface 73 toward the inner side.
In the case where the labyrinth 89 is narrow and the muddy water is poorly drained, it is possible to provide a water drain hole (not shown) in the radial direction surface portion 61 of the resin portion 53 of the resin sensor holder 43. The design can be changed.

  The present invention is also applicable to a bearing unit including a resin end cap as a cover member. The present invention is also applicable to hub bearing unit configurations other than those shown in this specification.

1 stationary wheel (outer ring)
7 Outer ring raceway (stationary raceway surface)
9 Inner side end 11 Recessed portion 13 Cylindrical radial surface portion 15 Annular axial surface portion 19 Rotating wheel (hub wheel)
21 Inner ring raceway (rotation side raceway surface)
25 Rotating wheel (separate inner ring)
27 Inner ring raceway (rotation side raceway surface)
29 Rolling body 43 Cover member (resin sensor holder)
45 Core metal 53 Resin portion 59 Outer side axial surface portion 61 Radial surface portion 63 Abutting region

Claims (1)

A stationary wheel having a stationary raceway surface on the circumferential surface;
A rotating wheel that is disposed so as to be relatively rotatable with the stationary wheel, has a rotating side raceway surface on a circumferential surface facing the stationary side raceway surface, and has a wheel support flange for supporting a wheel on the outer circumferential surface;
A plurality of rolling elements incorporated between the stationary side raceway surface and the rotation side raceway surface;
A cover member fitted and sealed to the inner side end of the stationary ring, and a bearing unit including at least
The cover member includes an annular metal core that can be fitted to an inner side end of the stationary ring, and an annular resin portion that is molded integrally with the metal core.
The stationary ring forms a step on the outer diameter side of the inner side end,
The cover member forms an annular radial surface portion that protrudes in the axial direction toward the outer side on the outer diameter side from the axial surface portion on the outer side in the resin portion,
An axial surface portion of the resin portion of the cover member is abutted against an axial surface portion positioned on the inner side of the step on the inner side end portion of the stationary wheel to form a butt region, and the outer diameter side of the butt region In the outer diameter side of the radial surface portion in the step portion of the inner side end portion, the radial surface portion of the cover member is positioned so as to overlap in the radial direction,
The cored bar is fitted and fixed to the inner diameter surface of the stationary ring located on the outer side of the butting region,
A radial surface portion of the step is formed to be recessed radially inward,
The inner diameter surface of the radial surface portion of the cover member is formed in a tapered surface that increases in diameter toward the outer side ,
The bearing unit according to claim 1, wherein the radial surface portion of the step portion is formed into a tapered surface having a diameter that increases toward the inner side .

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