DE102011084261B4 - Active ring sensor with dowel pins fixed to the bearing - Google Patents

Abstract

Device (6) for fastening a signal receiver (2) of a rotational speed sensor (26) on an axle (10) of a vehicle, comprising a retaining element (34) for supporting the signal transducer (2) and a dowel pin (46) formed on the retaining element (34). a plug connection for merging with a corresponding counterpart of the plug connection on the axle (10), so that the holding element (34) and thus the signal pickup (2) are non-rotatably connected to the axle (10), characterized in that a further dowel pin (48 ), which is firmly connected in the axial direction with a wheel bearing (4) holding the axle (10), and the two dowel pins (46, 48) are integrally formed, the further dowel pin (48) being made of a material, which is softer than the material of the dowel pin (46), and / or wherein between the dowel pins (46, 48) a predetermined breaking point is formed.

Description

Field of the invention

The invention relates to a device for fastening a signal receiver of a speed sensor to an axle of a vehicle.

Background of the invention

In vehicles, speed sensors measure the speed of a wheel relative to the chassis. For this purpose, the speed sensor must be mounted at a location in the vehicle, where it can detect the movement of the wheel relative to the chassis. The speed sensed by the speed sensor is typically used by the anti-lock brake system to detect a wheel locked by the brake, or by advanced vehicle dynamics control, such as traction control, to detect the yaw rate. By means of these, the extended vehicle dynamics control then counteracts understeer or oversteering of the vehicle in good time by means of dedicated brake interventions on the individual axles.

From the DE 697 09 500 T2 It is known to integrate the speed sensor in the wheel bearing. For this purpose, the speed sensor has an encoder fixed to the inner ring, also called pole wheel, and a signal sensor positioned on the outer ring, which is held on the outer ring via a cover.

However, it has been shown that the data cable for forwarding the measurement results of the signal sensor to a vehicle electronics in the DE 697 09 500 T2 can tear.

The DE 10 2010 013 213 A1 discloses a device for mounting a signal receiver. The signal sensor has a holding element, which is designed as a radially enlarged nose.

From the US 5 564 839A a device for fixing a signal sensor is known, which has a formed on the holding element dowel pin. The dowel pin is attached to the axle or the wheel bearing.

In the DE 22 43 331 A an attachment of a signal pickup is described. This attachment provides that a stator of the signal pickup is inserted into a steering knuckle.

Object of the invention

It is an object of the invention to improve the attachment of a speed sensor in a vehicle.

Solution of the task

The object is solved by the features of the independent claims. Further developments of the invention are the subject of the dependent claims.

The invention proposes a device with which the speed sensor can be rotationally fixed to the axle of a vehicle.

The invention is based on the finding that it occurs in a real pivot bearing, such as a rolling bearing, that the rotating bearing partner entrains the actually stationary bearing partner. In the case of the wheel bearing of a vehicle in which a bearing partner is connected to the axle of the vehicle and the other bearing partner to the wheel of the vehicle, the bearing partner connected to the wheel can entrain the bearing partner associated with the axle, for example due to non-optimal lubrication conditions, and with respect to the axle twist.

However, if the signal sensor is held by the bearing partner connected to the axle, the signal sensor also rotates relative to the axle and winds its connection cable to the vehicle electronics around the axle. If, due to the limited length of the cable, the signal receiver can not continue to rotate with the bearing partner connected to the axle, the tensile forces acting on the cable can become so great that it eventually breaks.

Therefore, the invention proposes a device for mounting a signal sensor of a speed sensor on an axle of a vehicle, comprising a holding element for supporting the signal receiver and formed on a holding element connecting element of a connector for merging with a corresponding counterpart of the connector on the axis, so that the Retaining element and thus the signal sensor is rotatably connected to the axis.

The connector can be formed positively and / or non-positively. For this purpose, the connecting element formed on the holding element may have any desired shape, which allows a rotationally fixed merging between the connecting element on the holding element and the corresponding counterpart on the axis.

The specified device reduces the likelihood of premature failure of the speed sensor, as can be effectively avoided by the rotationally fixed connection winding the connection cable to the vehicle electronics about the axis. A device having the vehicle is so more reliable and fail-safe. Furthermore, manufacturing costs can be saved, since the connection cables are hardly exposed to the specified device mechanical tensile loads against which they would be manufacturing technology to protect, for example, by an increased cost of materials.

The formed on the holding device connecting element of the connector may be the male part of a connector, with an outwardly facing dowel pin, or the female part of a connector, with an inwardly facing opening. The connecting element is designed as a dowel pin. This may have any shape to allow a positive connection with the female part on the axis. Thus, the dowel pin may be formed, for example, as a cylindrical pin, taper pin, dowel pin, toggle plug or cylinder plug. Forming the dowel pin on the holding element is particularly favorable, since this is weaker by design, as the axis and would be only weakened even more by the female part.

According to the invention, the specified device comprises a further dowel pin, which is firmly connected to a wheel bearing holding the axle in the axial direction. The fixed connection can be for example a press fit. Alternatively, the dowel pin but cohesively or positively connected to the wheel bearing in the axial direction are firmly connected. In this way, the specified device and thus held on the device Signalaufnehmer can be supplied in a simple manner prefabricated together with the wheel bearing for mounting in the vehicle, which allows a highly accurate positioning of the signal sensor on the wheel bearing. In addition, the device can also be removed simultaneously with the wheel bearing from the vehicle, so that the device and thus the signal sensor are more easily accessible.

According to the dowel pin and the further dowel pin are integrally formed. Due to the one-piece design of the dowel pins, these can be joined together in a simple manner by forming an opening in the retaining element and inserting the dowel pins into the retaining element.

According to the invention, the further dowel pin is made of a material which is softer than the material of the first dowel pin. Between both dowel pins a predetermined breaking point is provided. In this way, shear forces on the dowel pins on the holding element, which arise during rotation of the axle holding ring of the wheel bearing against the axis itself, are collected at a defined location in the specified device. As a result, damage to the specified device at indefinite locations are avoided.

The further dowel pin can also be designed to break off after installation of the wheel bearing with the mounted on the wheel bearing specified device in the vehicle from the holding element. This has the advantage that the specified device remains on the axle even when removing the wheel bearing from the vehicle, so that in this case no connections to the connecting cables between the signal sensor and the vehicle electronics must be solved.

In a preferred development of the invention, the signal receiver is an active signal receiver. An active signal receiver is to be understood below to mean a signal sensor which converts the rotational speed into an electrical variable, such as voltage or current, while consuming energy. Active transducers are particularly beneficial in a vehicle because they provide readings even at low speeds (such as when starting up) because they are more accurate and because they offer additional features such as automatic relative position control between the transducer and the encoder.

The invention also provides a vehicle comprising an axle, a wheel bearing supporting the axle, and a specified device rotationally connected to the axle via the connector.

In a further development of the dowel pin of the connector in the axis is loosely fitted, so that the device can be solved axially, for example, for inspection purposes of the axis without further technical measures.

In a preferred embodiment, the further dowel pin is connected to the wheel bearing by press fitting, so that the wheel bearing can not only be prefabricated with the specified device in the vehicle can be used, it can also be removed during expansion, for example, for inspection purposes together with this.

In a particularly preferred embodiment of the invention, the device overhangs an axial end side of the wheel bearing radially. In this way, the signal receiver can be mounted axially spaced apart from the axial end side. In this position of the signal pickup, the reading distance between the signal pickup and the encoder is least affected by an axial displacement between the wheel bearing and the specified device, so that the probability of the occurrence of so-called ABS errors is further reduced.

Short description of the drawing

Embodiments of the invention are explained below with reference to a drawing. Showing:

1 a first indicated a signal sensor on a wheel bearing specified device in a sectional view according to a first embodiment;

2 the specified device 1 in a front view;

3 a second a signal pickup attached to a wheel bearing specified device in a sectional view according to a second embodiment;

4 the specified device 3 in a front view;

5 a third a signal pickup attached to a wheel bearing specified device in a sectional view according to a third embodiment; and

6 the specified device 5 in a front view.

Detailed description of the drawing

It will open 1 Reference is made to a first a signal receiver 2 at a wheel bearing 4 fixing specified device 6 in a sectional view according to a first embodiment shows.

The wheel bearing 4 stores in a vehicle, not shown, a wheel hub 8th rotatable about an axis 10 , While at the wheel hub 8th about threaded holes 11 of which in 1 only one is shown, a not further shown wheel of a vehicle can be attached, is the axis 10 connected to a chassis of the vehicle, not shown.

The wheel bearing 4 has two in the wheel hub 8th recorded outer rings 12 and two inner rings 14 on where the axis is 10 is held. While the outer rings 12 in the wheel hub 8th are inserted, the inner rings 14 in the outer rings 12 inserted and via a clamping element 16 connected with each other. In a radial gap 20 between the outer rings 12 and the inner rings 14 are tapered rollers 18 arranged over which the outer rings 12 opposite the inner rings 14 can roll off. The tapered rollers 18 be in the radial gap 20 in rolling bearing cages 22 held. The radial gap 20 is also at its axial ends via seals 24 closed so that in the radial gap 20 a lubricant not shown in detail can be maintained, the friction between the tapered rollers 18 and the outer rings 12 or between the tapered rollers 18 and the inner rings 14 reduced. In the present embodiment, the wheel hub 8th looking into the picture plane on the left side a long front side 23 with the threaded hole 11 and on the right side one of the long front side 23 opposite short end 25 on. The short front 25 the wheel hub 8th closes flush with a frontal face 21 the inner rings 14 from.

The signal receiver 2 is part of a speed sensor 26 which further includes an encoder 28 , also called pole wheel, owns.

The encoder 28 has an annular perforated disc 27 with holes 30 on, with the perforated disc 27 concentric on the short end 25 the wheel hub 8th put on and in an axial gap 29 between the short end 25 the wheel hub 8th and the signal receiver 2 is arranged. The perforated disc 27 is over bent clamping elements 31 at the short end 25 the wheel hub 8th held. The holes 30 of the encoder 28 are in a manner not shown in the same radial distance from the center of the encoder, not shown 28 and arranged at a uniform circumferential distance from each other. Furthermore, there is the perforated disc 27 of the encoder 28 in the present embodiment of a ferromagnetic material, which is suitable, the magnetic properties of the space in the axial gap 29 to change.

The holes 30 the perforated disc 27 are radially at the height of the signal pickup 2 educated. Rotates the encoder 28 together with the wheel hub 8th so pull the holes 30 the perforated disc 27 in the radial gap 29 in regular and by the speed of the wheel hub 8th dependent time intervals before the signal sensor 2 past. This causes the magnetic properties of the space in the axial gap 29 in front of the signal sensor 2 depending on the speed of the wheel hub 8th change in a pulse shape. These pulses are from the signal sensor 2 recorded and as measurement results via a data cable 32 forwarded to the vehicle electronics for evaluation of the speed.

The signal receiver 2 is an active transducer that converts the acquired pulses into an electrical quantity, such as voltage or current, and through the data cable 32 sends to the vehicle electronics. From the point of view of the vehicle electronics, an active signal pickup therefore represents a voltage source. Active signal pickups are also capable of the position of the signal pickup 2 to capture on the axis. If the position deviates from a predetermined position, this generates Vehicle electronics a so-called ABS error. This must then be cleared as part of an inspection, for example, to ensure that the data cable 32 not around the axis 10 wraps and eventually rips.

To prevent the generation of an ABS error from the outset according to the invention a rotational movement of the signal pickup 2 around the axis 10 avoided. This is the signal sensor 2 on the specified device 6 held, the specified device 6 against twisting against the axle 10 is secured.

For this purpose, the specified device 6 a holding element 34 on that in 2 is shown in a front view. The holding element 34 is made in the present embodiment of an annular sheet and has an in 1 shown collar 36 on. To the collar 36 closes a ring area 38 of which at a circumferential position radially a support area 40 protrudes. The ring area 38 and the carrying area 40 are shifted axially to each other. The ring area 38 pierce plug-in elements 42 , It also penetrates the carrying area 40 a window 44 ,

The holding element 34 lies axially on the above-mentioned end face 21 the inner rings 14 on and is axially between the inner rings 14 and the axis 10 trapped. It engages the collar 36 radially under the inner rings 14 , Because the front side 21 of the inner ring 14 flush with the short end 25 the wheel hub 8th concludes, lie the ring area 38 of the holding element 34 and the perforated disc 27 axially on a line. Because of the carrying area 40 axially to the ring area 38 is shifted, it overlaps the perforated disc 27 , In this way, the signal receiver 2 through the window 44 through the encoder 28 influenced magnetic properties of the space in the axial gap 29 and thus detect the pulses in the manner explained above.

Each plug element 42 splits into two dowel pins 46 . 48 on. During the first passport 46 axially from the retaining element 34 into the axis 10 extends into the second dowel pin extends 48 from the holding element 34 in the inner ring 14 into it.

The first passport pin 46 takes over the actual rotation of the device 6 opposite the axis 10 , It is positively in a corresponding not further referenced receiving opening in the axis 10 inserted. However, the form fit itself is not absolutely necessary. It is sufficient if the receiving opening the first dowel pin 46 after a certain rotation of the device 6 opposite the axis 10 provides a stop in the tangential direction, so that further rotation of the device 6 opposite the axis 10 is avoided.

The second dowel pin 48 holds the device 6 axially on the inner ring 14 , Will the wheel bearing 4 and thus the inner ring 14 for example, for maintenance purposes of the axle 10 removed, so does the device 10 thereby automatically removed. This is the second dowel pin 48 pressed in the present embodiment non-positively in a corresponding not further referenced receiving opening in the inner ring. As an alternative to the second dowel pin, the holding device could, for example, also cohesively with the inner ring 14 get connected. An axial force or cohesive connection of the holding element 34 with the inner ring 14 also has the advantage that the specified device 6 on the inner ring 14 preassembled and thus can be placed in a precise position on the axle.

During the first passport 46 thus a rotation of the specified device 6 relative to the axle, the second dowel pin allows it 48 the specified device 6 on the inner ring 14 pre-assembled on the axle 10 sit up and both together from the axle 10 to remove again.

It will be on the 3 and 4 Reference is made to the signal receiver 2 at the wheel bearing 4 fixing specified device 6 in a sectional view according to a second embodiment show. In the 3 and 4 become the 1 and 2 the same elements with the same reference numerals and not described again.

In the second embodiment of 3 is the in 1 mentioned front page 21 of the inner ring 14 axially above the short end 25 the wheel hub 8th , In this way, the retaining element 34 the specified device 6 be made of an undeformed, annular and non-metallic sheet.

A window 44 needs in the present embodiment due to the non-metallic property of the device 6 in the carrying area 40 not to be provided.

In addition, the collar 36 of the holding element 34 through an O-ring seal 50 replaced.

It will be on the 5 and 6 Reference is made to the signal receiver 2 at the wheel bearing 4 fixing specified device 6 in a sectional view according to a third embodiment show. In the 5 and 6 become the 1 to 4 the same elements with the same reference numerals and not described again.

The third embodiment of 5 and 6 is based essentially on the first embodiment of the 1 and 2 ,

Unlike in the 1 and 2 has the annular plate of the holding element 34 but no collar 36 on. Therefore, the O-ring seal 50 between the inner rings 14 and the axis 10 arranged.

Furthermore, the plug-in elements 42 formed in two pieces. While the first dowel pins 46 radially on a first line 52 lie down the carrying area 40 of the holding element 34 crosses, lie the second dowel pins 48 radially on a second line 54 that are perpendicular to first line 52 stands.

The advantage of this two-piece design of the plug-in elements 42 that is not just the dowel pins 46 . 48 itself but also your connection with the holding element 34 can be optimally adapted to the necessary mechanical requirements. That means the first dowel pins 46 and their connections to the retaining element 34 should be as shear resistant to a permanent torsional strength of the device 6 against the axis 10 to secure. In contrast, the second dowel pins 48 and your connection to the retaining element 34 tensile strength to be formed with a predetermined breaking point to a one-piece assembly of the device 6 together with the wheel bearing 4 to ensure, but to a break during a twisting of the inner rings 14 against the axis 10 make sure not accidentally the first dowel pins 46 break. One way to do this would be to use the first dowel pins 46 made of a hardened material, as the second dowel pins 48 ,

LIST OF REFERENCE NUMBERS

2

signal sensor

4

Wheel bearings

6

contraption

8th

wheel hub

10

axis

12

outer ring

14

inner ring

16

clamping element

18

Tapered roller

20

radial gap

21

front

22

Rolling bearing cage

23

front

24

poetry

25

front

26

Speed sensor

27

perforated disc

28

encoder

29

gap

30

hole

31

clamping element

32

data cable

34

retaining element

36

collar

38

ring area

40

support area

42

plug-in element

44

window

46

dowel

48

dowel

50

poetry

52

line

54

line

Claims (6)

Contraption ( 6 ) for attaching a signal receiver ( 2 ) a speed sensor ( 26 ) on an axis ( 10 ) of a vehicle, comprising a holding element ( 34 ) for carrying the signal receiver ( 2 ) and one on the holding element ( 34 ) trained dowel pin ( 46 ) a connector for merging with a corresponding counterpart of the connector on the axis ( 10 ), so that the retaining element ( 34 ) and thus the signal sensor ( 2 ) with the axis ( 10 ) are rotatably connected, characterized in that a further dowel pin ( 48 ), with one the axis ( 10 ) holding wheel bearing ( 4 ) is firmly connected in the axial direction, is encompassed and the two dowel pins ( 46 . 48 ) are integrally formed, wherein the further dowel pin ( 48 ) is made of a material that is softer than the material of the dowel pin ( 46 ), and / or wherein between the dowel pins ( 46 . 48 ) A predetermined breaking point is formed. Contraption ( 6 ) according to claim 1, characterized in that the signal receiver ( 2 ) is an active signal receiver. Vehicle comprising an axle ( 10 ), an axis ( 10 ) bearing wheel bearing ( 4 ) and a device ( 6 ) according to one of the preceding claims, with the axis ( 10 ) is rotatably connected via the connector. Vehicle according to claim 3, wherein the dowel pin ( 46 ) of the connector in the axis ( 10 ) is loosely fitted. Vehicle according to claim 3 or 4, wherein the further dowel pin ( 48 ) with the wheel bearing ( 4 ) is connected by press fitting. Vehicle according to one of claims 3 to 5, wherein the device ( 6 ) an axial end side ( 25 ) of the wheel bearing ( 4 ) radially overhangs.

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