DE102010008772A1 - Rotary bearing for wheel of e.g. passenger car, has measuring rod facing sensor that is connected with inner ring in torque-proof manner for measuring rotation of wheel of motor vehicle, where sensor is secured in recess in inner ring - Google Patents

Abstract

The bearing has an outer ring rotatable opposite to an inner ring (1), and a bearing inner space formed between the rings. A cassette gasket (2) has a ring-shaped measuring rod (11) connected with the outer ring in a torque-proof manner. The measuring rod faces a sensor (13) that is connected with the inner ring in a torque-proof manner for measuring rotation of a wheel of a motor vehicle. The sensor is secured in a recess (12) in the inner ring. The sensor is designed as a moisture sensor for measuring moisture in the bearing inner space.

Description

Field of the invention

The present invention relates to a bearing for rotatively supporting a wheel of a motor vehicle, in particular a wheel bearing, which is equipped with a sensor for measuring a rotation of the wheel, for example for controlling an antilock brake system of the motor vehicle.

The DE 10 2007 057 962 A1 shows a cassette seal for sealing a wheel bearing for a car or for a truck, which has an angle sheet metal ring which is rotatably connected to a radially inner component. The cassette seal further comprises an annular seal arrangement, which forms a labyrinth seal with the angle sheet ring.

From the DE 199 16 934 A1 a cassette seal for rolling bearings is known, in which a spring-loaded radial sealing lip and an axial sealing lip are fastened together on an L-shaped ring.

The DE 197 39 452 A1 shows a wheel bearing for vehicles with ABS, which has a double-row tapered roller bearing with at least one cassette seal and a pulse wheel attached. The impulse wheel is formed on an L-shaped profiled impulse ring. In this solution, the entire axial space is exploited on the outer ring of a double-row tapered roller bearing.

The EP 0 532 011 A1 shows a cassette seal with an outer ring seal and an inner ring seal, wherein one of the two ring seals forms a unit with a metal plate having recesses of a certain pitch, so that it acts as a scale. The cassette seal further comprises a speed sensor, which is arranged axially adjacent to the metal plate.

From the US 5,085,519 a bearing arrangement is known, in which a speed sensor is integrated. The speed sensor is mounted in a recess in the bearing outer ring and protrudes into a bearing interior, where it faces a fixed to the bearing inner ring coding ring. A disadvantage of this solution is the increased space required for the coding ring in the bearing interior.

The DE 694 16 498 T2 shows a bearing seal with a pulse generator, in particular a wheel bearing with a sensor for measuring the angular velocity of the wheel to control an anti-lock braking system. The bearing comprises a seal on which a coding ring is formed. The coding ring is located in an end face of the wheel bearing, where it faces a arranged outside of the wheel bearing speed sensor. A disadvantage of this solution is that the speed sensor is located near a brake so that it is exposed to high temperatures and therefore has a high probability of failure. Another disadvantage of this solution is that it allows only the measurement of a speed of the wheel.

The object of the present invention is based on the DE 694 16 498 T2 It is to provide a bearing for rotatively supporting a wheel of a motor vehicle, in which a sensor for measuring a rotation of the wheel has a low failure probability and is configurable for measuring further measured variables.

Said object is achieved by a bearing for rotationally bearing a wheel of a motor vehicle according to the appended claim 1.

The bearing according to the invention serves for rotational bearing of a wheel of a motor vehicle and can therefore be referred to briefly as a wheel bearing. The wheel may be, for example, a powered or a non-driven wheel of a passenger car or a truck. The bearing initially comprises a first bearing ring and a second bearing ring rotatable relative to the first bearing ring. Between the first bearing ring and the second bearing ring, a bearing interior is formed, in which preferably rolling elements are arranged. The bearing interior is sealed with a cassette seal against a space outside the bearing interior. The cartridge seal can prevent, for example, water from entering the bearing interior, where it would lead to corrosion and impair the function of the bearing. The cartridge seal comprises a rotationally fixed connected to the second bearing ring annular scale, for example in the form of a coding ring. The cartridge seal and the annular scale are preferably in the bearing interior, particularly preferably on an end face of the bearing interior. Also, the annular scale is preferably arranged coaxially with the second bearing ring. The annular scale is opposite to a rotatably connected to the first bearing ring sensor for measuring a rotation of the wheel. By means of the sensor and the annular scale, it is possible to be able to measure a rotation of the first bearing ring relative to the second bearing ring, ie, a rotation of the wheel, for example for controlling an anti-lock braking system. According to the invention, the sensor is mounted in a recess in the first bearing ring; for example, the fact that the sensor sits partially or completely in the recess. In this case, the sensor preferably opens into the bearing interior. Consequently, the Recess in the first bearing ring preferably in an axial portion of the first bearing ring, which limits the bearing interior. Furthermore, the recess is located in an axial portion of the first bearing ring, in which the cassette seal is arranged. The attachment of the sensor in the recess in the first bearing ring causes the sensor is integrated into the first bearing ring.

A particular advantage of the bearing according to the invention is that the reliability of the sensor is substantially increased by the integration in the first bearing ring. In particular, the sensor is not exposed to increased heat by a brake. Another advantage is that no components for positioning the sensor outside of the bearing are required.

In a preferred embodiment of the bearing according to the invention, the first bearing ring is formed by a bearing inner ring, while the second bearing ring is formed by a bearing outer ring. The bearing outer ring is rotatably connected to a hub of the wheel, wherein the bearing outer ring may be formed as an integral part of the hub. The bearing inner ring is rotatably mounted on a pin. The journal may in particular be a journal bearing the wheel. The bearing is preferably a roller bearing, in particular a double-row tapered roller bearing. The bearing interior is preferably sealed at both axial end faces, each with one of the cassette seals. Of course, in alternative embodiments, the second bearing ring may be formed by the bearing inner ring, while the first bearing ring is formed by the bearing outer ring.

The annular scale is preferably formed on a retaining ring of the cassette seal attached to the bearing outer ring. In this case, the retaining ring is preferably formed as an integral part of the cartridge seal, for example, characterized in that an axial sealing lip and / or a radial sealing lip is attached to this.

The annular scale may be designed in different ways for its function as a scale, for example by an optical and / or magnetic division. The scale is preferably formed by a sheet in which the division is formed by punched out fields.

The scale preferably has the shape of a cylinder jacket, the inside of which faces the sensor. The inner cylinder jacket surface is preferably arranged at a small distance of less than 1 mm from the sensor.

The retaining ring preferably has an L-shaped cross-section in a radially inner region. This cross-section is located in a plane which is perpendicular to the direction of rotation of the retaining ring, d. H. perpendicular to a tangent of the retaining ring, wherein the axis of the bearing lies in this plane. The scale is formed on a parallel to the axis of the bearing arranged leg of the L-shape. This leg is preferably the shorter of the two legs of the L-shape, which can be aligned either in the direction of the bearing interior or direction of a room outside of the bearing interior. The L-shape of the cross-section of the retaining ring may also be modified, for example, in that the long leg of the L-shape has a relation to the axis of the bearing obliquely disposed portion to allow a space-saving arrangement with respect to the axis of the bearing.

In an alternative preferred embodiment of the bearing according to the invention, the retaining ring has a cylinder jacket-shaped inner side, on which the scale is formed. This embodiment is particularly suitable when the retaining ring of sufficient thickness, d. h., Has sufficient axial length to form the scale on the inside can.

In a particularly preferred embodiment of the bearing according to the invention, the sensor is arranged flush with a surface of the bearing inner ring finally in the recess. Consequently, the sensor does not protrude beyond the contour of the bearing inner ring. In this case, the sensor is preferably adjusted in its position in the recess to the outer shape of the bearing inner ring. This design allows a space-saving and reliable arrangement of the sensor.

In an alternative preferred embodiment, the scale has the shape of a truncated cone shell, the inside of which faces the sensor. In this embodiment, the sensor is preferably arranged outstandingly out of the recess in the bearing inner ring. This embodiment allows a particularly space-saving arrangement of the sensor, for example between two sealing lips of the cassette seal.

The bearing inner ring preferably has a channel for the passage of a cable of the sensor. The channel begins in the recess and opens on a facing the pin end face of the bearing inner ring. The cable guided to the pin is - as is known from the prior art - to lead, for example, to the control electronics of an anti-lock brake system and / or for display in a cab. The channel in the bearing inner ring protects the cable of the sensor against mechanical and thermal influences.

A particular advantage of the solution according to the invention is that the arrangement of the sensor allows it to be used for further measuring tasks. For example, it is possible by the inventive solution to measure a distance of the scale from the sensor and / or a tilt of the scale relative to the sensor, whereby a changed position and / or tilting of the second bearing ring is detectable. For this purpose, the sensor is preferably further designed as a distance sensor for measuring a distance to the second bearing ring and / or as a tilt sensor for measuring a tilting of the second bearing ring. In this embodiment of the bearing according to the invention can be drawn using the sensor conclusions about the wear of the bearing, which, for example, an end-of-life detection is possible.

The inventive arrangement of the sensor relative to the bearing interior also allows the measurement of state variables of the bearing interior, for example, a temperature or humidity in the bearing interior. For this purpose, the sensor is preferably also designed as a moisture sensor for measuring moisture in the bearing interior and / or as a temperature sensor for measuring a temperature in the bearing interior. As a result, for example, overheating and / or water ingress into the bearing interior can be detected.

The sensor preferably further comprises an evaluation electronics, so that it forms an active sensor.

Further advantages, details and developments of the invention will become apparent from the following description of preferred embodiments, with reference to the drawing. Show it:

1 a cross-section of a detail of a first preferred embodiment of the bearing according to the invention;

2 a cross section of a detail of a second preferred embodiment of the bearing according to the invention;

3 a cross section of a detail of a third preferred embodiment of the bearing according to the invention;

4 a cross-section of a detail of a fourth preferred embodiment of the bearing according to the invention;

5 : one in 1 shown bearing inner ring in a first sectional view;

6 : the in 5 bearing inner ring shown in a second sectional view; and

7 a modified embodiment of the in 5 shown bearing inner ring.

1 shows a cross section of a detail of a bearing according to the invention, which is designed as a wheel bearing of a motor vehicle. The cross section is located in a plane which is perpendicular to the direction of rotation of the bearing and in which also lies the axis of the bearing. There are in particular a detail of a bearing inner ring 01 and a cassette seal 02 shown. The bearing further comprises a bearing outer ring (not shown) and rolling elements (not shown). The cassette seal 02 includes a retaining ring 03 which is attached to the bearing outer ring. On the retaining ring 03 are several sealing lips 04 . 06 and 07 attached, with one of the sealing lips 06 by an annular spring 08 against the bearing inner ring 01 pressed. Another of the sealing lips 04 is against a shaped ring 09 pressed.

The retaining ring 03 is designed in its radially inner region in its cross-section L-shaped. This cross section is again in a plane perpendicular to the direction of rotation of the retaining ring 03 is. The shorter leg of the L-shape forms in its circumferential extent the shape of a cylinder jacket, which is coaxial with the bearing inner ring 01 is arranged. The cylinder jacket-shaped part of the retaining ring 03 is as a yardstick 11 educated. The retaining ring 03 consists of a metal sheet, which is in the range of scale 11 punched out to form a division.

The scale 11 is located at a distance of less than 1 mm to the bearing inner ring 01 , In which the scale 11 opposite axial portion of the bearing inner ring 01 this has a recess 12 on, in which a sensor 13 is arranged. The sensor 13 is up to the standard 11 opposite, so using the sensor 13 a rotation of the scale 11 and thus a rotation of the retaining ring 03 the bearing outer ring and the stored wheel can be measured. The sensor 13 is flush with a surface of the bearing inner ring 01 finally in the recess 12 arranged.

In the bearing inner ring 01 is still a channel 14 formed, which, starting from the recess 12 to a front side of the bearing inner ring 01 extends. The channel 14 serves to carry a cable 16 to the sensor 13 ,

2 shows a cross section of a detail of a second preferred embodiment of the bearing according to the invention. This embodiment is initially similar to the one in FIG 1 shown embodiment. A modification consists in the shape of the retaining ring 03 which has a modified L-shape in cross-section in its radially inner region. The shorter leg of the L-shape of the retaining ring 03 trained scale 11 is in this embodiment, compared to the longer leg of the L-shape by an angled region 17 offset to minimize the space required in the axial direction.

3 shows a cross section of a detail of a third preferred embodiment of the bearing according to the invention. This embodiment is initially similar to the one in FIG 1 shown embodiment. A modification consists in the shape of the retaining ring 03 in its radially inner region. The retaining ring 03 is straight in the radially inner area, so the scale 11 on the inner circumferential surface of the retaining ring 03 is trained. The sensor 13 is optionally designed to measure moisture so it can be used for a leak indication.

4 shows a cross section of a detail of a fourth preferred embodiment of a bearing according to the invention. This embodiment is initially similar to the one in FIG 1 shown embodiment. A first modification consists in the shape of the retaining ring 03 in its radially inner region. The cross section of the retaining ring 03 has in its radially inner region on a leg which is inclined relative to the axis of the bearing, so that formed in this leg scale 11 has in its circumferential extent the shape of a truncated cone shell. The scale 11 shows in comparison to the in 1 embodiment shown a greater distance from the bearing inner ring 01 on. A second modification in this embodiment is that the sensor 13 partly outstanding from the bearing inner ring 01 is arranged. The sensor 13 is located with its active area between the truncated cone-shaped scale 11 and the bearing inner ring 01 , where the active area of the sensor 13 parallel and near the truncated cone-shaped scale 11 is arranged. The sensor 13 is in the recess 12 attached.

5 shows the in 1 shown bearing inner ring 01 in a first sectional view. The cut lies in a plane in which the axis of the bearing is located. The bearing inner ring 01 has a tread 21 for the rolling elements (not shown). The bearing inner ring 01 also has a one-sided recess 22 on, which serves as a rotation against the pin (not shown), on which the bearing with its bearing inner ring 01 to assemble.

6 shows a second sectional view of the in 5 shown bearing inner ring 01 , The cut lies in a plane which is perpendicular to the axis of the bearing. In this view is a cylindrical recess 23 recognizable, which serves to receive the pin. Furthermore, the one-sided recess 22 recognizable, which serves as a rotation against the pin.

7 shows a modified embodiment of the in 6 shown bearing inner ring 01 , This embodiment of the bearing inner ring 01 is similar to the one in 6 shown embodiment. A modification is that the in 7 shown bearing inner ring 01 no recess 22 (shown in 6 ) has as anti-rotation. In the modified embodiment, a center hole is used 24 as anti-rotation, in which an anchoring pin (not shown) of the pin is to be introduced. Another opening 26 serves as the conclusion of the channel 14 (shown in 1 ), through which the cable 16 (shown in 1 ) is to lead.

LIST OF REFERENCE NUMBERS

01

Bearing inner ring

02

cassette seal

03

retaining ring

04

sealing lip

05

06

sealing lip

07

sealing lip

08

annular spring

09

shaped ring

10

11

scale

12

recess

13

sensor

14

channel

15

16

electric wire

17

angled area

18

19

20

21

tread

22

one-sided recess

23

cylindrical recess

24

centering

25

26

opening

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102007057962 A1 [0002]
• DE 19916934 A1 [0003]
• DE 19739452 A1 [0004]
• EP 0532011 A1 [0005]
• US 5085519 [0006]
• DE 69416498 T2 [0007, 0008]

Claims (10)

Bearing for rotary bearing of a wheel of a motor vehicle, comprising a first bearing ring ( 01 ) and one opposite the first bearing ring ( 01 ) rotatable second bearing ring, wherein between the first bearing ring ( 01 ) and the second bearing ring, a bearing interior is formed, which with a cassette seal ( 02 ) is sealed off from a space outside the bearing interior, the cartridge seal ( 02 ) a rotatably connected to the second bearing ring annular scale ( 11 ), which rotatably with the first bearing ring ( 01 ) connected sensor ( 13 ) for measuring a rotation of the wheel, characterized in that the sensor ( 13 ) in a recess ( 12 ) in the first bearing ring ( 01 ) is attached. Bearing according to claim 1, characterized in that the first bearing ring by a bearing inner ring ( 01 ), and that the second bearing ring is formed by a bearing outer ring, wherein the bearing outer ring rotatably connected to a hub of the wheel is connectable, and wherein the bearing inner ring ( 01 ) is rotatably mounted on a pin mountable. Bearing according to claim 2, characterized in that the annular scale ( 11 ) on a retaining ring attached to the bearing outer ring ( 03 ) of the cassette seal ( 02 ) is trained. Bearing according to claim 3, characterized in that on the retaining ring ( 03 ) further comprises an axial sealing lip ( 06 ; 07 ) and / or a radial sealing lip ( 04 ) is attached. Bearing according to one of claims 2 to 4, characterized in that the scale ( 11 ) has the shape of a cylinder jacket, the inside of the sensor ( 13 ) faces. Bearing according to one of claims 2 to 5, characterized in that the sensor ( 13 ) flush with a surface of the bearing inner ring ( 01 ) finally in the recess ( 12 ) is arranged. Bearing according to one of claims 2 to 4, characterized in that the scale ( 11 ) has the shape of a truncated cone whose inside the sensor ( 13 ), the sensor ( 13 ) from the recess ( 12 ) in the bearing inner ring ( 01 ) is arranged outstanding. Bearing according to one of claims 2 to 7, characterized in that the bearing inner ring ( 01 ) one in the recess ( 12 ) beginning channel ( 14 ) for carrying a cable ( 16 ) of the sensor ( 13 ), which faces on a pin facing end face of the bearing inner ring ( 01 ) opens. Bearing according to one of claims 1 to 8, characterized in that the sensor ( 13 ) is further designed as a distance sensor for measuring a distance to the second bearing ring and / or as a tilt sensor for measuring a tilting of the second bearing ring. Bearing according to one of claims 1 to 9, characterized in that the sensor ( 13 ) is further designed as a moisture sensor for measuring moisture in the bearing interior and / or as a temperature sensor for measuring a temperature in the bearing interior.

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