WHEEL BEARING UNIT

Abstract

The invention relates to a wheel bearing unit including a wheel hub. The wheel hub has an integrally formed wheel flange at one end and an inner ring which can be rotated together with the wheel hub. The inner ring is secured on the wheel hub by a rolling rivet connection in order to pretension a row of rolling elements relative to an outer ring. The wheel bearing unit also has an encoder, which is provided on the inner ring and extends radially in the direction of the outer ring, and a protective cover which is secured to the outer ring in order to close and seal annular openings that are formed between the outer ring and the wheel hub. A cylindrical mounting section of the protective cover is pressed into a cylindrical press-in portion of the outer ring, and a shielding section extends from the cylindrical assembly portion inwards in a radial direction (R1). A base section is provided which adjoins the shielding section in order to cover an inner-side end of the wheel hub, and a sealing element is provided on a circumferential surface, which faces away from the outer ring, of the cylindrical assembly portion. The sealing element is formed such that a part of the sealing element protrudes from the mounting section in the axial direction (R2) in order to form a sealing lip which is pressed axially onto a section of the outer ring in order to sealingly rest against this section.

Claims

1. A wheel bearing unit comprising a wheel hub having on one end thereof, an integral wheel flange, an outer ring, a row of rolling bodies, an inner ring that rotates together with the wheel hub, the inner ring is mounted by a rolling rivet collar on the wheel hub and pre-tensions the row of rolling bodies relative to the outer ring, an encoder on the inner ring that extends radially in a direction of the outer ring, a protective cover that is fixed on the outer ring in order to close and seal ring-shaped openings that are formed between the outer ring and the wheel hub, wherein the protective cover is pressed with a cylindrical mounting section in a cylindrical press-in section of the outer ring and a shielding section of the protective cover extends inward in a radial direction (R1) from the cylindrical mounting section, a base section that connects to the shielding section in order to cover an inner end of the wheel hub, a sealing element provided on a circumferential surface facing away from the outer ring in the cylindrical mounting section, the sealing element is constructed such that a part of the sealing element projects in an axial direction (R2) from the mounting section in order to form a sealing lip that is shifted axially onto a section of the outer ring, in order to form a sealing contact with said section.

2. The wheel bearing unit according to claim 1, wherein the section of the outer ring that contacts the sealing lip of the sealing element has a tapered construction.

3. The wheel bearing unit according to claim 1, wherein the protective cover is formed from a non-ferromagnetic material.

4. The wheel bearing unit according to claim 1, wherein the sealing element is formed from an elastomer vulcanized on the mounting section.

5. The wheel bearing unit according to claim 1, wherein the sealing element extends along the protective cover.

6. The wheel bearing unit according to claim 1, wherein the shielding section connects to the base section via a cylindrical section.

7. The wheel bearing unit according to claim 1, wherein the protective cover is pressed with the cylindrical mounting section on an inner circumference of the outer ring.

8. The wheel bearing unit according to claim 1, wherein the protective cover is pressed with the cylindrical mounting section on an outer circumference of the outer ring.

9. The wheel bearing unit according to claim 1, wherein the protective cover is shell-shaped design and is constructed by pressing.

10. The wheel bearing unit according to claim 1, further comprising a rotational speed sensor that detects a rotational speed of the wheel hub, the rotational speed sensor and the encoder are arranged opposite each other with a predetermined air gap in the axial direction by the shielding section.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Two embodiments of the invention are described below with reference to three figures. Shown are:

[0017] FIG. 1 a longitudinal section through a wheel bearing unit according to the invention according to a first embodiment,

[0018] FIG. 2 an enlarged representation of detail I shown in FIG. 1,

[0019] FIG. 3 a longitudinal section through a wheel bearing unit according to the invention according to a second embodiment, and

[0020] FIG. 4 an enlarged representation of the pressed-in protective cover according to a third embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] FIG. 1 shows a wheel bearing unit 1 according to a first embodiment that is allocated to a not-shown vehicle wheel. The wheel bearing unit 1 comprises a wheel hub 2 that has, on its one end, a radially oriented wheel flange 3 with a one-piece construction. The wheel bearing arrangement further has two axially spaced apart rows 4, 5 of roller bodies, with these roller bodies being guided on the outside in an outer ring 6. On the inside, the roller bodies of the row 4 of roller bodies are guided directly in a raceway of a wheel hub 2 and the wheel bodies of the row 5 of roller bodies are guided in an inner ring 7 fixed on the wheel hub 2.

[0022] The inner ring 7 is mounted axially on the wheel hub 2 by a roller rivet collar 8, whereby the row 5 of roller bodies is pretensioned relative to the outer ring 6.

[0023] As can be seen further from FIG. 1, an encoder 9 is arranged on an outer circumference of the inner ring 7. The encoder 9 is provided on a carrier 10 by which the encoder 9 is connected to the outer circumference of the inner ring 7. The encoder 9 is formed of an elastomer material, filled with magnetic particles, and is connected integrally to the carrier 10 by a vulcanization process. In addition to the elastomer material, the encoder 9 can also be formed from a plastic or a hard rubber.

[0024] For sealing an opening between the outer ring 6 and the wheel hub 2 there is a protective cap 11 that is press formed from a non-ferromagnetic material. The protective cap 11 is pressed with a cylindrical mounting section 12 onto a cylindrical press-in section 13, the inner circumference of the outer ring 6. A shielding section 14 connects to the cylindrical section 12 inward in a radial direction R1. A base section 16 connects to the shielding section 14 via a cylindrical section 15.

[0025] FIG. 2 shows an enlarged representation of detail I shown in FIG. 1, namely an enlarged view of the protective cap 11. As can be seen, the mounting section 12 has a sealing element 17. The sealing element 17 is provided on a circumferential area 18 of the mounting section 12 facing away from the outer ring 6. The sealing element 17 is formed as an elastomer that is vulcanized onto the section.

[0026] The sealing element 17 is further constructed such that a part of the sealing element projects in an axial direction R2 from the mounting section 12, in order to form a sealing lip 19. When the mounting section 12 is pressed into the cylindrical section 13, only the area of the sealing lip 19 is pushed axially onto a section 20 of the outer ring 6, in order to form a sealing contact on this section 20. The area of the sealing element 17 that is vulcanized onto the mounting section 12 remains untouched, i.e., it is not elastically deformed.

[0027] The section 20 of the outer ring 6 contacting the sealing lip 19 has an inclined construction and connects directly to the press-in section 13.

[0028] FIGS. 3 and 4 show the protective cap 11 according to a second and third embodiment. Matching components are provided with identical reference symbols. The following description is therefore largely limited to features that are different.

[0029] The protective cap 11 shown in FIG. 3 corresponds in its construction to the protective cap 11 described in FIGS. 1 and 2. In addition to the provision of the sealing element 17 on the mounting section 12, a sealing element 21 extends along the complete end side 22 of the protective cap 11. The end side 22 is the side that is turned away from the wheel bearing unit 1. Furthermore, the sealing element 21 has multiple sealing lips 23.

[0030] FIG. 4 shows an enlarged representation of the pressed-in protective cap 11. The wheel bearing unit 1 basically corresponds to the wheel bearing unit 1 shown in FIG. 3. The shielding section 14 of the protective cap 11 has multiple recesses 24 distributed around the circumference. These recesses 24 can be constructed, for example, as elongated holes. In addition, the recess 24 is covered with the sealing element 21 or is closed by this sealing element. Alternatively, it is also possible to leave the area of the recess 24 with the sealing element 21 open.

LIST OF REFERENCE NUMBERS

[0031] 1 Wheel bearing unit [0032] 2 Wheel hub [0033] 3 Wheel flange [0034] 4 Row of rolling bodies [0035] 5 Row of rolling bodies [0036] 6 Outer ring [0037] 7 Inner ring [0038] 8 Rolling rivet collar [0039] 9 Encoder [0040] 10 Carrier [0041] 11 Protective cover [0042] 12 Cylindrical mounting section [0043] 13 Press-in section [0044] 14 Shielding section [0045] 15 Cylindrical section [0046] 16 Base section [0047] 17 Sealing element [0048] 18 Circumferential surface [0049] 19 Sealing lip [0050] 20 Section of the outer ring [0051] 21 Sealing element [0052] 22 End side [0053] 23 Sealing lip [0054] 24 Recess [0055] R1 Radial direction [0056] R2 Axial direction