Sensor arrangement for a driven wheel hub-rolling bearing arrangement with a signal generator, a sensor and a sealing cap

Abstract

An ABS encoder arrangement for a driven wheel bearing unit, with a multi-pole ring, a sensor device with a sensor head, and an annular cap element that has an annular wall portion which shields a cap interior against the exterior. The annular wall section extends through an intermediate region lying between the multi-pole ring and an end face of the sensor head. An extension concentric with the axis of rotation of the multi-pole ring and extending axially over a circumferential area of an articulated shaft head is connected to the annular wall section on a side facing away from the multi-pole ring. In the end portion of the extension facing away from the multi-pole ring and extending over the articulated shaft head, the extension forms a circumferential profile that radially stiffens the extension and forms an annular edge which extends into a circumferential groove of the articulated shaft head and forms a channel cross-section open to the outside.

Claims

1. An ABS encoder system comprising: a multi-pole ring carrying a multi-pole structure; a sensor device having a sensor head for detecting a magnetic field generated by the multi-pole structure; and an annular cap element having an annular wall section sealing off a cap interior toward the outside, the cap interior housing the multi-pole ring; the annular wall section extending through an intermediate area situated between the multi-pole ring and a front surface of the sensor head, an extension concentrical to the circumferential axis of the multi-pole ring being connected to the annular wall section, and axially overlapping in a mounting position a circumferential area of a drive shaft head, the extension, in an end area facing away from the multi-pole ring and surrounding the drive shaft head, forming a circumferential profile radially stiffening the extension; the circumferential profile forming an annular border extending axially away from the multi-pole ring into a circumferential groove of the drive shaft head, and the annular border forms a channel cross-section open to the outside.

2. The ABS encoder system as recited in claim 1 wherein the annular cap element is made of a non-ferromagnetic material.

3. The ABS encoder system as recited in claim 2 wherein the annular cap element is made of a sheet material as a deep-drawn part.

4. The ABS encoder system as recited in claim 2 wherein the annular cap element is made of a plastic material.

5. The ABS encoder system as recited in claim 1 wherein the annular wall section is formed as an annular disk section aligned radially to a bearing shaft.

6. The ABS encoder system as recited in claim 1 wherein the annular border is located axially beyond the multi-pole ring and the sensor device.

7. The ABS encoder system as recited in claim 1 wherein the extension, concentrical to a bearing shaft and adjoining the annular wall section, has an end area facing away from the annular wall section.

8. The ABS encoder system as recited in claim 7 wherein the extension conically tapers to narrow away from the annular wall section.

9. The ABS encoder system as recited in claim 1 wherein the annular cap element has a seat ring section.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further details and features of the present invention are derived from the following description in connection with the drawings.

(2) FIG. 1 shows an axial sectional view of a first specific embodiment of an ABS encoder system according to the present invention; and

(3) FIG. 2 shows an axial sectional view of a second specific embodiment of an ABS encoder system according to the present invention.

DETAILED DESCRIPTION

(4) An ABS encoder system according to the present invention is illustrated in FIG. 1 in the form of a detailed representation of its structure. The ABS encoder unit according to the present invention is incorporated into a wheel bearing. The wheel bearing itself includes a hub carrier 1 having a rolling element track 1a formed directly thereon, a bearing inner ring 2 which likewise forms a rolling element track 2a, as well as rolling elements 3 which are accommodated in a rolling element circumferential space formed between both rolling element tracks 1a and 2a. The rolling bearing formed in hub carrier 1 is only partially represented in this case, and is designed, for example, as an angular ball bearing. Bearing inner ring 2 rests on a hub pin 4. Although not shown in detail here, hub pin 4 is designed as a hollow pin with internal gear teeth. Within this hollow pin sits an externally toothed section of a drive shaft head 5.

(5) The bearing unit accommodated in hub carrier 1 is sealed by a sealing device 6. This sealing device 6 is designed as a cartridge seal and includes a sealing ring 7 which has a ring core 7a and a molded-on elastomer structure 7b. Elastomer structure 7b forms multiple sealing lips 7c, 7d and 7e. These sealing lips 7c, 7d and 7e form a sealing system on angular ring 8. A so-called multi-pole structure 9 is attached to a side of angular ring 8 facing away from sealing lips 7c, 7d and 7e. This multi-pole structure 9 contains magnetized particles. Overall, the magnetization of these particles is coordinated in such a way that the multi-pole structure in the circumferential direction is made up of + and zones. Angular ring 8 and multi-pole structure 9 resting thereon form a so-called multi-pole ring 10. The multi-pole ring rests on a cylindrical section of bearing inner ring 2. Sealing ring 7 rests in a cylindrical inner circumferential surface 1b of hub carrier 1.

(6) The wheel bearing represented is provided with an ABS encoder system. This ABS encoder system includes the previously mentioned multi-pole ring 10, which carries that multi-pole structure 9. Furthermore, the ABS encoder system also includes a sensor device 11 having a sensor 11a for detecting the magnetic field generated on the part of multi-pole structure 9. The ABS encoder system according to the present invention is characterized in that an annular cap element 12 is provided, which has an annular wall section 12a, which seals off a cap interior, housing the multi-pole ring, toward the outside. That annular wall section 12a is designed in such a way that it extends through an intermediate area 13 situated between multi-pole ring 10 and a front surface of sensor 11a. In addition, an essentially cylindrical extension 12b is connected to annular wall section 12a on a side facing away from multi-pole ring 10, concentrical to the circumferential axis of the multi-pole ring, and which axially overlaps in the mounting position a circumferential area of a drive shaft head 5, extension 12b, in its end area facing away from the multi-pole ring and surrounding the drive shaft head, forming a circumferential profile which radially stiffens extension 12b.

(7) The annular cap element in this case is made of a non-ferromagnetic sheet material as a deep-drawn part. The annular wall section 12a extending through intermediate area 13 is designed in this exemplary embodiment as an extending annular disc section aligned essentially radially to the bearing shaft, equidistant over 360 to the multi-pole ring.

(8) An extension 12b concentrical to the bearing shaft is connected to annular wall section 12a on its radially internal inner border area. This extension 12b extends into the area of drive shaft head 5 and there forms an annular border 12c which skirts a passage opening. This annular border 12c extends into a circumferential groove 5a of drive shaft head 5. The clearances are dimensioned in such a way that component contact is reliably avoided, and that a preferably effective shielding of the inner area of that extension 12b is achieved.

(9) By the cross-sectional configuration shown here of annular cap element 12 in the area of the passage opening, there is a sufficiently effective particle protection and also an advantageous stiffening of annular border 12c.

(10) Here, multi-pole ring 10 forms an axial coding structure, i.e., a structure that generates a rising magnetic field across the front face of the multi-pole ring. The sensor head is axially moved towards multi-pole ring 10, but is shielded from it by annular wall section 12a, and is therefore situated outside of the cap interior. The magnetic field generated by multi-pole ring 10 penetrates annular wall section 12a and may therefore be detected by sensor head 11a. Sensor head 11a is protected from any metallic particles revolving with the multi-pole ring by annular wall section 12a.

(11) Annular cap element 12 has a seat ring section 12d and is anchored via this seat ring section 12d to a collar section 1c of hub carrier 1 under a strong press fit. Collar section 1c forms that inner circumferential wall 1b, on which sealing ring 7 rests.

(12) An ABS encoder system according to the present invention is likewise illustrated in FIG. 2 in the form of a detailed representation of its structure according to a second specific embodiment of the present invention. This is similar to the aforementioned encoder system in many features. The ABS encoder unit according to the present invention is again incorporated into a wheel bearing. The wheel bearing itself includes a hub carrier 1 having a rolling element track 1a formed directly thereon, a bearing inner ring 2 which likewise forms a rolling element track 2a, as well as rolling elements 3 which are accommodated in a rolling element circumferential space formed between both rolling element tracks 1a and 2a.

(13) Also in this exemplary embodiment, the rolling bearing formed in hub carrier 1 is only partially represented, and overall is designed as an angular ball bearing. Bearing inner ring 2 rests on a hub pin 4. Hub pin 4 is designed as a hollow pin having interior and front-facing gear teeth. A drive shaft head 5 engages in the hub pin with axial or radial gear teeth.

(14) The bearing unit accommodated in hub carrier 1 is sealed by a sealing device 6. This sealing device 6 is designed as a cartridge seal and includes a sealing ring 7 which has a ring core 7a and a molded-on elastomer structure 7b. Elastomer structure 7b forms multiple sealing lips 7c, 7d and 7e in a manner similar to that in the exemplary embodiment according to FIG. 1. These sealing lips 7c, 7d and 7e form a sealing system toward angular ring 8.

(15) Angular ring 8 carries an annular cylinder section 8a. A multi-pole structure 9 is attached to an outer circumferential surface of annular cylinder section 8a. This multi-pole structure 9 again contains magnetized particles. The magnetization of these particles is coordinated in such a way that the multi-pole structure in the circumferential direction is made up of + and zones. Angular ring 8 and multi-pole structure 9 resting thereon form a multi-pole ring 10. Multi-pole ring 10 rests via an inner ring section 8b with moderate press fit on a cylindrical section of bearing inner ring 2. Sealing ring 7 rests on a cylindrical inner circumferential surface 1b of hub carrier 1.

(16) The wheel bearing represented is again provided with an ABS encoder system. This ABS encoder system includes the previously mentioned multi-pole ring 10, which carries that multi-pole structure 9. Furthermore, the ABS encoder system also includes a sensor device 11 having a sensor head 11a for detecting the magnetic field generated on the part of multi-pole structure 9. The ABS encoder system according to the present invention is again characterized in that an annular cap element 12 is provided, which has an annular wall section 12a, which seals off a cap interior, housing the multi-pole ring, toward the outside. That annular wall section 12a is designed in such a way that it extends through an intermediate area 13 situated between multi-pole ring 10 and a front surface of sensor head 11a. In addition, here an essentially truncated, conically tapering extension 12b is connected to the annular wall section 12a on a side facing away from multi-pole ring 10, concentrical to the circumferential axis of the multi-pole ring 10, and which axially overlaps in the mounting position a circumferential area of a drive shaft head 5, extension 12b, in its end area facing away from the multi-pole ring and surrounding the drive shaft head, forming a circumferential profile which radially stiffens extension 12b.

(17) Annular cap element 12 is made of a non-ferromagnetic sheet material, as a deep-drawn part, in a manner similar to the exemplary embodiment according to FIG. 1. The annular wall section 12a extending through intermediate area 13 is designed in this exemplary embodiment as a cylinder jacket section aligned essentially coaxially to the bearing shaft.

(18) An extension 12b concentrical to the bearing shaft is connected to annular wall section 12a on its side facing away from hub carrier 1. This extension 12b extends into the area of drive shaft head 5 and there forms an annular border 12c that skirts a passage opening. The extent of the gap remaining between the inner wall of annular border 12c and the outer wall of drive shaft head 5 is dimensioned in such a way that component contact is reliably avoided, and a preferably effective shielding of the inner area of that extension 12b is achieved.

(19) Here, multi-pole ring 10 forms a radial coding structure, i.e., a structure which generates a radially rising magnetic field across the outer circumferential surface of the multi-pole ring 10. The sensor head is radially moved toward multi-pole ring 10, but is shielded from it by annular wall section 12a. The radially emitted magnetic field generated by multi-pole ring 10 penetrates annular wall section 12a and may therefore be detected by sensor head 11a. Annular wall section 12a extends over the entire circumferential area of the multi-pole ring.

(20) Annular cap element 12 has a seat ring section 12d and is anchored via this seat ring section 12d to a collar section 1c of hub carrier 1 under a strong press fit. Collar section 1c forms that inner circumferential wall 1b, in which sealing ring 7 rests as in the exemplary embodiment according to FIG. 1.

(21) Although not shown here, it is possible to form a support structure on annular cap element 12, e.g., in the form of a socket section, to secure sensor head 11a directly to annular cap element 12.

LIST OF REFERENCE NUMERALS

(22) 1 hub carrier 1a rolling element track 1b inner circumferential surface 1c collar section 2 bearing inner ring 2a rolling element track 3 rolling element 4 hub pin 5 drive shaft head 5a circumferential groove 6 sealing device 7 sealing ring 7a ring core 7b elastomer structure 7c sealing lip 7d sealing lip 7e sealing lip 8 angular ring 8a annular cylinder section 8b inner ring section 9 multi-pole structure 10 multi-pole ring 11 sensor device 11a sensor head 12 annular cap element 12a annular wall section 12b extension 12c annular border 12d seat ring section 13 intermediate area