Instrumented bearing and method of manufacturing such an instrumented bearing

Abstract

An instrumented bearing, which includes an outer race and an inner race between which a rolling chamber is delimited. Rolling bodies are disposed in the rolling chamber. The bearing additionally includes a member isolating the rolling chamber from the outside; and a measuring device including at least one sensor adapted to measure at least one operating parameter of the instrumented bearing. At least one measuring device can be mounted to the member isolating the rolling chamber from the outside.

Claims

1. An instrumented bearing, including: a. an outer race and an inner race between which a rolling chamber is delimited; b. rolling bodies disposed in the rolling chamber; c. a member isolating the rolling chamber from the outside; and d. a measuring device including at least one sensor adapted to measure at least one operating parameter of the instrumented bearing; wherein the measuring device is mounted to the member isolating the rolling chamber from the outside, wherein the measuring device includes active elements sensitive to a physical parameter characteristic of the instrumented bearing, wherein the active elements consist in microcapsules containing molecules designed to produce a detectable effect as a function of the parameter.

2. The instrumented bearing as recited in claim 1, wherein the measuring device is inserted in an opening in the member isolating the rolling chamber so that an inner portion of the measuring device is in contact with the interior of the rolling chamber and an outer portion of the measuring device opens to the exterior of the bearing.

3. The instrumented bearing as recited in claim 2, wherein the measuring device takes the form of a pin, at least one of the inner portion of the pin and the outer portion of the pin having the shape of a head with a diameter greater than a diameter of the opening in the member isolating the rolling chamber.

4. The instrumented bearing as recited in claim 1, wherein the inner portion of the measuring device includes an intermediate portion capable of connecting the rolling chamber and the active elements of the measuring device.

5. The instrumented bearing as recited in claim 1, wherein the microcapsules are designed to emit molecules if the parameter exceeds a limit value.

6. The instrumented bearing as recited in claim 1, the measuring device further comprising a wireless emitter.

7. A method in manufacturing an instrumented bearing, wherein the instrumented bearing includes: an outer race and an inner race between which a rolling chamber is delimited; rolling bodies disposed in the rolling chamber; a member isolating the rolling chamber from the outside; and a measuring device including at least one sensor adapted to measure at least one operating parameter of the instrumented bearing; wherein the measuring device is mounted to the member isolating the rolling chamber from the outside, the method includes the following steps: a) manufacturing the outer race, the inner race and the rolling bodies; b) manufacturing the member isolating the rolling chamber with an opening; c) inserting the measuring device in the opening of the member isolating the rolling chamber; and d) assembling the instrumented bearing, wherein the measuring device includes active elements sensitive to a physical parameter characteristic of the instrumented bearing, wherein the active elements consist in microcapsules containing molecules designed to produce a detectable effect as a function of the parameter.

8. The method as recited in claim 7, wherein the measuring device is inserted in an opening in the member isolating the rolling chamber so that an inner portion of the measuring device is in contact with the interior of the rolling chamber and an outer portion of the measuring device opens to the exterior of the bearing.

9. The method as recited in claim 8, wherein the measuring device takes the form of a pin, at least one of the inner portion of the pin and the outer portion of the pin having the shape of a head with a diameter greater than a diameter of the opening in the member isolating the rolling chamber.

10. The method as recited in claim 8, wherein the outer portion includes a display component for displaying at least one indicator for the measured parameter.

11. The method as recited in claim 7, wherein the inner portion of the measuring device includes an intermediate portion capable of connecting the rolling chamber and the active elements of the measuring device.

12. The method as recited in claim 7, wherein the microcapsules are designed to emit molecules if the parameter exceeds a limit value.

13. The method as recited in claim 7, the measuring device further comprising a wireless emitter.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be better understood after reading the following description given by way of non-limiting example only and with reference to the appended drawings, in which:

(2) FIG. 1 is a perspective view of an instrumented bearing in accordance with the invention; and

(3) FIG. 2 is a section to a larger scale of a detail of the bearing from FIG. 1.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

(4) An instrumented bearing 1 in accordance with the invention is shown in FIGS. 1 and 2.

(5) The bearing 1 includes an outer race 2 and an inner race 3 between which a rolling chamber 4 is delimited. The bearing 1 has a central axis, forming the axis of relative rotation of the races 2 and 3.

(6) The bearing 1 includes rolling bodies (not shown) disposed in the rolling chamber 4 and retained by a bearing cage.

(7) The rolling chamber 4 is isolated from the outside by a member 20 including a metal flange 26 and an overmolded elastomer 28 forming a sealing lip designed to be in sliding contact with the inner race 3. The member 20 is constrained to rotate with the outer face 2.

(8) The bearing 1 also includes a measuring device 10 adapted to measure at last one parameter characteristic of the operation of the bearing 1.

(9) In the context of the invention, the measuring device 10 is mounted to the member 20 isolating the rolling chamber 4, as described in detail hereinafter.

(10) The measuring device 10 is preferably entirely disposed on the member 20 and supported by the latter, as in the example of FIGS. 1 and 2.

(11) The measuring device 10 is produced in the form of a pin inserted in an opening 22 in the member 20 isolating the rolling chamber 4 so that an inner portion 30 of the pin is in contact with the interior of the rolling chamber 4 and an outer portion 32 of the pin is visible from the outside of the bearing 1. An intermediate portion of the pin passing through the opening 22 can provide a channel of communication between the inner portion 30 and the outer portion 32. This communication channel can transmit mechanical, physical, chemical, electrical, magnetic or electromagnetic signals or a combination thereof.

(12) The measuring device 10 includes one or more sensors 11 adapted to detect the parameters chosen by the person skilled in the art in accordance with the circumstances. The sensors may include a temperature sensor, a sensor adapted to detect a conductivity or an acidity or a sensor adapted to detect specific molecules.

(13) In the FIG. 2 example, the inner portion 30 of the pin and the outer portion 32 of the pin take the form of a head with a diameter greater than the diameter of the opening 22 in the member 20 isolating the rolling chamber 4.

(14) In particular, the inner portion 30 includes a chamfer so as to facilitate the insertion of the pin in the opening 22 of the member 20.

(15) The outer portion 32 includes display device for displaying at least one indicator for the measured parameter. These display device include a transparent portion enabling the interior of the head of the pin to be seen and may contain coloring agents or an LED indicator.

(16) As shown in FIG. 1, the bearing 1 may be equipped with a plurality of measuring devices 10 of the type shown in FIG. 2, the various measuring devices 10 including different sensors 11 and/or containing different coloring agents. Moreover, the various sensors 11 could be adapted to measure the same parameter but use different limit values for the display. One of the measuring devices 10 could therefore change color, for example to orange, if the parameter exceeds a first limit value, and another measuring device 10 could change its color, for example to red, if the parameter exceeds a second limit value higher than the first limit value, as in a traffic light system.

(17) The measuring device 10 includes active elements, here a plurality of microcapsules 24 containing molecules designed to produce a detectable and visible effect as a function of the parameter, for example coloring agents released or produced by molecules released if a parameter such as the temperature or the moisture content has exceeded a limit value. This effect is irreversible. Once the molecules have been released, it is impossible or very difficult to reintroduce them into the microcapsules 24. This makes it possible to memorize events in which a parameter has exceeded a limit value.

(18) The microcapsules 24 are arranged in a manner that is visible from the outside of the bearing in a gel or in a transparent body and the release of the molecules results in a change of color of the microcapsules 24 or of their environment. This makes it possible to signal the value of the parameter in a simple manner without using electronic components.

(19) The microcapsules 24 are dispersed inside a transparent body of the measuring device. This makes it possible to render the coloring agents or other phenomena inside the pin visible, notably via the outer part 32.

(20) In one embodiment, the measuring device includes a wireless emitter 36 provided by an RFID tag, for example. This enables remote interrogation. A semiconductor chip of the RFID tag is adapted to measure the parameter either directly or via molecules released by the microcapsules 24. The RFID tag may include a microprocessor for interpreting and processing the data obtained by the sensors 11 of the device.

(21) The inner portion 30 of the pin includes an intermediate portion, such as a porous portion or a membrane, capable of connecting the rolling chamber 4 and the microcapsules 24 of the measuring device 10. The physical parameter to which the microcapsules 24 are sensitive is therefore directly detectable by the microcapsules 24.

(22) The inner portion 30 of the pin includes a feature 34 for isolation of the interior of the pin via the rolling chamber in order to prevent the microcapsules 24, the sensors 11 or electronic components escaping.

(23) In one embodiment, the pin is manufactured directly on the flange 26 of the member by overmolding an RFID tag inserted in the opening 22 of the member 20.

(24) Thanks to the invention, the parameters associated with the instrumented bearing 1 are measured as close as possible to the functional zone of the bearing 1, in the rolling chamber 4, which makes it possible to obtain pertinent and precise measured values. The overall size of the instrumented bearing 1 is optimized, the number of wires is reduced, notably for the supply of power and the transmission of data.

(25) In accordance with one particular application, the invention makes it possible to analyze parameters linked to the lubrication of the bearing 1, even if this bearing 1 is protected by members 20 isolating the rolling chamber 4 from the outside (i.e. is capped bearing).

(26) The invention also concerns a method of manufacturing an instrumented bearing 1. The method includes a step a) consisting in manufacturing the outer race 2, the inner race 3 and the rolling bodies. The method also includes a step b) consisting in manufacturing the member 20 in the form of a metal flange 26 with an opening 22 overmolded with rubber or another elastomer material 28 including a vulcanization step. The method further includes a step c) consisting in inserting the measuring device 10 in the opening 22 of the member 20 isolating the rolling chamber 6. The method finally includes a step d) consisting in assembling the instrumented bearing 1.

(27) The instrumented bearing 1 and notably the measuring device 10 may be formed differently from FIGS. 1 and 2 and the variants referred to hereinabove without departing from the scope of the invention as defined in the claims.

(28) Regardless of the embodiment of the invention, the measuring device 10 includes at least one sensor 11 and is at least partially mounted to the member 20 isolating the rolling chamber 4.

(29) Moreover, some or all of the technical features of the various embodiments and variants referred to hereinabove may be combined with one another. The instrumented bearing 1 can therefore be adapted in terms of cost, functionality, overall size and performance.