WO2008006645A1

WO2008006645A1 - Roller bearing with integrated rotary shaft encoder

Info

Publication number: WO2008006645A1
Application number: PCT/EP2007/055377
Authority: WO
Inventors: Günter Schmid
Original assignee: Schaeffler Kg
Priority date: 2006-07-08
Filing date: 2007-06-01
Publication date: 2008-01-17
Also published as: DE102006031718A1

Abstract

The invention relates to a roller bearing (1) that has at least one first, radially external bearing ring (3) and at least one second, radially internal bearing ring (4a, 4b), at least one series of rolling elements (5a, 5b) guided in tracks between the bearing rings, and at least one rotary shaft encoder (8) to record the angular position and/or the relative rotary speed between the mutually corresponding bearing rings (3, 4a, 4b). The at least one rotary shaft encoder (8) is made of resin-bonded, ferromagnetic material (9), which is/has been accommodated in a ring-shaped recess (10) or groove of a bearing ring (4a), and of at least one sensor (11) assigned to the resin-bonded, ferromagnetic material (9), wherein said sensor (11) is supported by the other bearing ring (3) or by a component adjoining the roller bearing (1).

Description

Name of the invention

Rolling bearings with integrated rotary encoder

Field of the invention

The invention relates to a roller bearing with the features of claim 1.

Background of the invention

For some time now, it has been known to make a rotational speed or angle measurement directly on a roller bearing.

For example, DE 42 07 324 A1 proposes a so-called pulse rolling bearing, which enables the non-contact detection of rotational speeds using magnetic means. Essentially, it is provided that the outer or the inner race of the rolling bearing in the circumferential direction in each case at equal intervals successively arranged areas of different magnetic properties, and on the outer or inner race on a radial radial surface or an axial end face at equal intervals one behind the other the magnetic field shielding substance, such as a film, is arranged. The rotation of the corresponding trained race is converted into electrical signals by means of a sensor which detects the constantly changing magnetic field strengths.

From DE 195 13 669 A1 further a hydrostatic pump or a motor with a drive or output shaft is known, which is mounted in a housing and rotatably connected to a Zählkranz for speed and / or position monitoring. The Zählkranz can be made of a metallic material and be encapsulated with a polymeric material. Likewise, the metering ring can be made of a polymer material and in gleichmä- ßigen intervals be provided with distributed around its circumference metallic deposits. Finally, it is proposed in this document that the Zählkranz is made of different polymeric materials by two-component injection molding, wherein a component has metallic Eigen- shafts.

Object of the invention

The invention has for its object to provide a rolling bearing with at least one angle sensor for detecting the angular position and / or the relative speed between the mutually corresponding bearing rings, which is simple and inexpensive to produce and requires a minimum of space for said angle encoder.

Summary of the invention

Starting from a roller bearing, with at least one first radially outer and at least one second radially inner bearing ring, at least one arranged between them in raceways Wälzkörper- row and at least one angle sensor for detecting the angular position and / or the relative speed between the corresponding bearing rings, the above object is achieved in that the at least one angle encoder on the one hand has a plastic-bonded, ferromagnetic material which is received in an annular recess or groove of a bearing ring, and on the other hand at least one, the plastic-bonded, ferromagnetic material associated sensor, which on another bearing ring or is supported on a component adjacent to the rolling bearing.

Due to the fact that the ferromagnetic material is integrated so to speak in the outer contour of the respective bearing ring, the required Installation space in the warehouse advantageously minimized. Furthermore, material and weight savings as well as savings in the production of the rolling bearing itself are recorded, since the recess or the groove can be produced very easily by means of standard production technologies.

Advantageous developments or refinements of the invention are described in the subclaims.

Thus, the annular recess or groove can be arranged or formed within a lateral surface and / or an end face of the respective bearing ring.

Furthermore, it is proposed that the plastic-bonded, ferromagnetic material, a material and / or positive connection with the respective bearing ring in detail, is introduced into the annular recess or groove by a known injection molding process.

As the invention further provides, the magnetization of the ferromagnetic material is realized during the injection of the same into the recess or groove by means of the injection molding tool or in a separate working step after carrying out the injection process.

Likewise, it may also be advantageous that a plurality of separately manufactured ring sections of ferromagnetic material within the recess or groove material and / or positive locking and / or by means of known mechanical fastening means are fixed. Said separately manufactured ring sections are magnetizable both before and after their assembly.

Further, the ferromagnetic material, forming an angular scale, may be magnetized with a pole pair number "1" or a multiple thereof. It is also proposed that between the plastic-bonded, ferromagnetic material and the respective bearing bearing ring a magnetic coupling between the same reducing coating is provided. This coating can be formed for example by an injectable, thermoplastic plastic layer.

As far as the sensor is concerned, it is provided that it is fixed by means of mechanical fastening means known per se and / or by material bonding, preferably by gluing, to the other bearing ring or a component adjacent to the rolling bearing.

Further, the sensor may have a radial or axial scanning direction depending on the selected configuration and arrangement of the recess or groove.

Finally, it is proposed that the annular recess or groove are preferably arranged on the rotating bearing ring and the sensor on the fixed bearing ring of the rolling bearing or on a component adjacent to the rolling bearing.

Brief description of the drawings

The invention will be explained in more detail below with reference to the accompanying drawings of an embodiment. The single FIGURE shows schematically a supported by a shaft inventively designed rolling bearing in an axial section.

Detailed description of the drawings

Accordingly, in the figure, a double-row roller bearing 1 is shown, which is arranged on a shaft 2 and has a radially outer bearing ring 3 and two radially inner bearing rings 4a and 4b. Between these bearing rings 3; 4a, 4b are guided in two rows of rolling elements 5a, 5b balls as rolling elements. The two inner bearing rings 4a, 4b are axially fixed by means of a threaded nut 6 screwed onto the shaft 2 against a rim 7 of the shaft 2.

As already mentioned in the introduction, it may be advantageous to carry out a rotational speed and / or rotational angle measurement directly on the rolling bearing 1. According to the invention, an angle encoder 8 is provided for this purpose, which serves for detecting the angular position and / or the relative rotational speed between the mutually corresponding bearing rings 3, 4a.

This angle transmitter 8 is formed on the one hand by a plastic-bonded, ferromagnetic material 9, which is received in an annular recess 10 of the inner bearing ring 4a. The plastic-bonded, ferromagnetic material 9 can be formed within the recess 10 both as closed or as a multiple, forming individual ring sections, interrupted ring.

On the other hand, this angle encoder 8 comprises a known sensor 11, which is associated with the plastic-bonded, ferromagnetic material 9. This sensor 1 1 is adapted to detect changing magnetic field strengths and to generate suitable electrical signals, and to provide an evaluation device, not shown, but known per se for evaluation.

As the single figure further shows, the annular recess 10 together with the formed ring of plastic-bonded, ferromagnetic material 9 is arranged in an end-side section of the lateral surface of the left bearing ring 4a, whereby a simple and cost-effective production is possible. As a result of this advantageous embodiment of the bearing ring 4a or the arrangement of the formed ring of plastic-bonded, ferromagnetic material 9, the scanning direction of the sensor 11 can be chosen such that either in the radial direction or in the axial direction Detecting the changing in each revolution magnetic field strength is possible.

In contrast, it may also be appropriate, instead of the at least one recess 10, one or more annular grooves for receiving the plastic-bonded, ferromagnetic material 9 in a rotatable bearing ring 4a, 4b provided, which are introduced into the end face or the lateral surface of the bearing ring (not shown in more detail).

Preferably, the plastic-bonded, ferromagnetic material 9 is introduced into the recess 10 or groove according to a known injection molding, whereby a material and / or positive connection between the formed ring of plastic-bonded, ferromagnetic material 9 and the respective bearing ring 4a is extremely easy to produce , However, the invention is not limited to this type of attachment of the formed ring of plastic-bonded, ferromagnetic material 9, but includes any other suitable measure.

Thus, for example, a plurality of separate ring sections can be prepared beforehand and, forming a closed or partially interrupted ring, can be firmly bonded within the recess 10 or groove by, for example, bonding and / or positive locking and / or by means of mechanical fasteners known per se.

Said plastic-bonded, ferromagnetic material 9 can be magnetized with a number of pole pairs "1" or a multiple thereof, the magnet tion is expediently realized during the injection of the same in the recess 10 or groove by means of the selected per se known injection molding tool.

Furthermore, the magnetization can also be carried out after the actual injection process, which is accordingly also covered by the invention.

If, in contrast, prefabricated ring sections are used, then it may also be expedient to assemble the same already in a correspondingly magnetized manner.

As can be seen further from the single figure, it has proved to be particularly advantageous to provide a magnetic coupling between the same reducing coating 12 between the plastic-bonded, ferromagnetic material 9 and the same bearing ring 4a, in order to avoid a falsification of the measurement result.

This coating 12 is preferably formed by a aufspritzbare, thermoplastic see plastic layer, which enters into a material connection with the then plastic-coated, ferromagnetic material 9 then sprayed on it in an advantageous manner. Likewise, film-like coatings 12, paints and the like can be used for this purpose.

As far as the sensor 1 1 is concerned, it is fixed on the outer bearing ring 3 by means of mechanical fastening means known per se, in the present case by means of one or more screw connections 13. The actual scanning head 1 1 a of the sensor 1 1 is in the embodiment shown radially through a through hole in the outer bearing ring 3 passes led, and aligned to the plastic-bonded ferromagnetic material 9 of the inner bearing ring 4a. Certainly, a variety of other arrangements of the sensor 1 1 is possible. For example, it may also be fastened to the bearing ring 3 in such a way that it is mounted axially, ie, aligned with the end face of the bearing ring 4a or on its plastic-bonded, ferromagnetic material 9.

The illustrated embodiment is based on an angle encoder 8, the plastic-bonded, ferromagnetic material 9 on an inner bearing ring 4a or 4b and the sensor 1 1 are fixedly disposed on an outer bearing ring 3. Also possible is an arrangement, not shown, according to which the plastic-bonded, ferromagnetic material 9 on a radially outer bearing ring 3 and the sensor 1 1 are fixedly arranged on a radially inner bearing ring 4a or 4b. Furthermore, it is detected by the invention that the sensor 1 1 can be fixed to a component adjacent to the rolling bearing 1.

It is further considered appropriate if the annular recess 10 or groove on the rotating bearing ring 4a, in this case connected to a rotating shaft 2 inner bearing ring 4a, and the sensor 1 1 on fixed bearing ring 3, in this case the outer bearing ring 3 of the rolling bearing. 1 or on a not shown in detail, adjacent to the rolling bearing 1 arranged component, such as a load-bearing component, are fixed, as a simple electrical connection between the sensor 11 and an evaluation unit can be realized. reference numeral

1 rolling bearing

2 wave

3 bearing ring (outside)

4a bearing ring (inside)

4b bearing ring (inside)

5a rolling element row

5b rolling element row

6 threaded nut

7 board

8 angle encoder

9 ferromagnetic material

10 recess

11 sensor

11 a readhead

12 coating

13 screw connection

Claims

claims

1. rolling bearing (1), with at least one first radially outer bearing ring (3) and at least one second radially inner bearing ring

(4a, 4b), with at least one rolling element row (5a, 5b) guided between them in raceways and at least one angle transmitter (8) for detecting the angular position and / or the relative rotational speed between the mutually corresponding bearing rings (3; 4a, 4b) , wherein the at least one angle encoder (8) on the one hand a plastic-bonded, ferromagnetic material (9) which is received in an annular recess (10) or groove of a bearing ring (4a), and on the other at least one, the plastic-bonded, ferromagnetic material (9) associated sensor (1 1), which is supported on the other bearing ring (3) or on a rolling bearing (1) adjacent component.

2. Rolling bearing according to claim 1, characterized in that the annular recess (10) or groove within a lateral surface and / or an end face of the respective bearing ring (4a) is arranged.

3. Rolling bearing according to claim 1 or 2, characterized in that the plastic-bonded, ferromagnetic material (9), a material and / or positive connection with the respective bearing ring (4a) in detail, in an injection molding in the annular recess (10) or

Groove is introduced.

4. Rolling bearing according to claim 3, characterized in that the magnetization of the plastic-bonded, ferromagnetic material (9) during the injection thereof into the recess (10) or groove by means of the injection molding tool or in a separate step after performing the injection process is performed.

5. Rolling bearing according to claim 1 or 2, characterized in that a plurality of previously separately manufactured ring sections of ferromagnetic material (9) within the recess (10) or groove material and / or positive fit and / or by means of known mechanical Fasteners are fixed.

6. Rolling bearing according to claim 5, characterized in that the separately manufactured ring sections are magnetizable before or after their assembly.

7. Rolling bearing according to at least one of claims 1 to 6, characterized in that the ferromagnetic material (9), forming an angular scale, with a pole pair number "1" or a multiple thereof is magnetized.

8. Rolling bearing according to at least one of claims 1 to 7, characterized in that between the plastic-bonded ferromagnetic see material (9) and the same bearing bearing ring (4a), a magnetic coupling between the same reducing coating (12) is provided.

9. Rolling bearing according to claim 8, characterized in that the coating (12) is formed by an injectable, thermoplastic plastic layer.

10. Rolling bearing according to at least one of claims 1 to 9, characterized in that the sensor (11) by means of mechanical fastening means and / or cohesively, for example by gluing, on the other bearing ring (3) or on a rolling bearing (1) adjacent Component is set.

11. Rolling bearing according to at least one of claims 1 to 10, characterized in that the sensor (11) in dependence on the selected configuration and arrangement of the recess (10) or groove has a radial or axial scanning direction.

12. Rolling bearing according to at least one of claims 1 to 1 1, characterized in that the annular recess (10) or groove on the rotating bearing ring (4a) and the sensor (1 1) on the stationary bearing ring

(3) of the rolling bearing (1) or on a rolling bearing (1) adjacent component are arranged, or vice versa.