Guide Device And Mechanical System Comprising Such A Device

Abstract

A guide device includes: a metal component provided with a friction surface intended to receive a mating part in sliding frictional contact; and a detection sensing system of a wear of the friction surface or of a clearance between the friction surface and the mating part. The detection system includes one or more sensors; and a wireless communication system is connected to the detection system and configured to transmit information relating to wear or clearance out of the guide device.

Claims

1. A guide device comprising: a metal component provided with a friction surface intended to receive a mating part in sliding frictional contact; a detection system of a wear of the friction surface or of a clearance between the friction surface, and the mating part the detection system comprising one or more sensors; and a wireless communication system connected to the detection system and configured to transmit information relating to wear or clearance out of the guide device.

2. The guide device as claimed in claim 1, comprising a lubricant disposed on the friction surface.

3. The guide device as claimed in claim 1, claim 1, characterized in that the friction surface comprises workings acting as a reservoir for lubricant.

4. The guide device as claimed in claim 1, characterized in that the detection system is configured for the detection of wear of the friction surface over an angular range of at least 3° about a central axis of the metal component.

5. The guide device as claimed in claim 4, characterized in that the detection system comprises a single sensor which ensures the detection of wear of the friction surface over an angular range of at least 3°.

6. The guide device as claimed in claim 4, characterized in that the detection system comprises a plurality of sensors which are distributed about the central axis of the metal component and which ensure the detection of wear over at least an angular range of 60°.

7. The guide device as claimed in claim 1, characterized in that the sensor or sensors are disposed exclusively on one longitudinal side or on two longitudinal sides of the metal component each longitudinal side being defined over at most two fifths of the length of the annular bush.

8. The guide device as claimed in claim 1, characterized in that the metal component is formed by an annular bush having a radial thickness of at least 5 millimeters.

9. The guide device as claimed in claim 1, characterized in that the metal component is formed by an annular bush having a radial thickness of at most 15 millimeters.

10. A mechanical system comprising at least one guide device as claimed in claim 1, and a mating part mounted in sliding frictional contact with the friction surface.

11. The guide device as claimed in claim 4, characterized in that the detection system comprises a plurality of sensors which are distributed about the central axis of the metal component and which ensure the detection of wear over an angular range of 360°.

12. A mechanical system of claim 10, wherein the mating part is mounted in sliding frictional contact with oscillation with the friction surface.

Description

DESCRIPTION OF THE FIGURES

[0043] The invention will be better understood from the following description, which is given solely by way of non-limiting example and is made with reference to the accompanying drawings, in which:

[0044] FIG. 1 is a perspective view of a mechanical system in accordance with the invention, comprising a guide device and an axle mounted in the device.

[0045] FIG. 2 is a side view of the device in a radial direction.

[0046] FIG. 3 is a section along the line III-III in FIG. 2.

[0047] FIG. 4 is a section along the line IV-IV in FIG. 2.

[0048] FIG. 5 is a larger scale view of detail V in FIG. 4.

[0049] FIG. 6 is a section similar to FIG. 4, showing a variation of the guide device with sensors on both sides.

DETAILED DESCRIPTION OF THE INVENTION

[0050] FIGS. 1 and 5 show a mechanical system 1 in accordance with the invention, comprising a guide bush (10) in accordance with the invention, and an axle (2) mounted in the device (10). For the purposes of simplification, the axle (2) is represented by two dashed lines. The device (10) is designed to guide the axle (2) in sliding frictional contact, in particular in sliding with oscillation.

[0051] The oscillatory movement corresponds to an incomplete rotation, backwards and forwards, about the central axis. Either the axle (2) oscillates in the device (10), or the device (10) oscillates about the axle (2). In both cases, the loads exerted on the device (10) define a zone of maximum load, corresponding to a particular angular position.

[0052] A lubricant, preferably grease, is disposed at the frictional interface between the device (10) and the axle (2).

[0053] The device (10) comprises a metal friction component (20), a detection system (30), and a wireless communication system (40).

[0054] The metal component (20) is formed by an annular bush (21) provided with an inner surface (22) and an outer surface (23) with cylindrical profiles. The inner surface (22) constitutes a friction surface intended to receive the axle (2) in sliding frictional contact. Advantageously, the surface (22) may comprise workings acting as a reservoir for lubricant. The workings may comprise cavities, grooves and/or other types of workings.

[0055] The surfaces (22, 23) comprise annular grooves (24, 25) in the central portion, connected via orifices (26) passing through the bush (21). The elements (24, 25, 26) constitute means for lubricating the surface (22). In a variation, for example in the case of lubrication by the axle or by the side, the bush (21) may be devoid of elements (24, 25, 26). The means for lubricating the surface (22) may be of any type adapted to the intended application.

[0056] The surface (23) comprising an annular groove (27) formed on one side of the groove (25). The surfaces (22, 23) are connected via orifices (28) passing through the bush (21) at the border of the groove (27). The elements (27, 28) constitute means for receiving the detection system (30). In a variation, if the bush (21) is devoid of elements (24, 25, 26), the elements (27, 28) may be disposed centrally.

[0057] In accordance with another variation, the groove (27) may be disposed in the central portion. In accordance with a further variation, the groove (27) may be disposed in the central portion, while the orifices (28) are disposed on a side (29).

[0058] In the longitudinal direction of the bush (21), a central portion and two longitudinal sides (29) surrounding the central portion can be distinguished. Each longitudinal side (29) is defined over at most two fifths of the length of the bush (21). Preferably, each longitudinal side (29) is defined over a third of the length of the bush (21).

[0059] The thickness of the bush (21) depends on the envisaged application. The bush (21) may have a thickness in the range 5 to 15 millimeters, or more. This thickness is defined over the functional range of the friction surface (22), excluding any shoulder formed on a side (29).

[0060] The detection system (30) is configured in order to detect wear of the friction surface (22). As an alternative, the detection system (30) could be configured in order to detect the clearance between the friction surface (22) and the surface of the axle (2).

[0061] The detection system (30) includes a conductive strip (31), a plurality of sensors (32) connected to the strip (31) via conductive wires (33), and a connector (34) adapted to connect the system (30) to the system (40). The strip (31) is constituted by a layer of conducting wires incorporating the wires (33). The connector (34) may include an electronic chip configured to transform information concerning power loss into wear depth information. As an alternative, the connector (34) may comprise simple wires belonging to the strip (31).

[0062] The conductive strip (31) is disposed in the annular groove (27) formed on the outer surface (23) of the metal component (20). The conductive strip (31) is on the one hand connected to each sensor (32) via the conductive wires (33) and on the other hand to the wireless communication system (40) via the connector (34).

[0063] In the example of the figures, the detection system (30) comprises four sensors (32) distributed over 90° about the central axis (X20) of the component (20). Thus, the detection system (30) ensures the detection of wear over an angular range of 360° about the central axis (X20).

[0064] Advantageously, the sensors (32) are disposed exclusively on a longitudinal side (29) of the bush (21), without jutting out over the central portion. In fact, when the mechanical system (1) is in operation, the mechanical stresses are generally concentrated on the sides (29) of the bush (21).

[0065] Disposing the sensors (32) on a side (29) rather than in the central portion makes it possible to improve the detection of wear and the chances of carrying out a predictive maintenance operation before the system (1) suffers a critical malfunction.

[0066] Each sensor (32) comprises a plurality of conductive wires (35, 36, 37), each having one end disposed at a given depth below the friction surface (22). The wear of the conductive wire (35, 36, 37) is a function of the wear of the surface (22). The ends of the conductive wires (35, 36, 37) are disposed at different depths below the friction surface (22). The successive wear of the conductive wires (35, 36, 37) is linked to the progressive wear of the friction surface (22), in accordance with different thresholds. Thus, the detection system (30) is configured to detect different wear thresholds of the friction surface (22).

[0067] Each sensor (32) comprises a cylindrical envelope (38) housed in an orifice (28) passing through the metal component (20) between the friction surface (22) and the outer surface (23). This envelope (38) constitutes a means for indexing the angular and axial position of the sensor (32). Other solutions for forming angular and/or axial indexing means may be envisaged. The envelope (38) housed in an orifice (28) has the advantage of being a simple solution to implement.

[0068] Preferably, each sensor (32) comprises means for indexing its radial position with respect to the friction surface (22). As an example, the radial indexing means may comprise a collar (39) formed on the cylindrical envelope (38) of the sensor (32). Other solutions for forming the radial indexing means may be envisaged, which make it possible to ensure that the wires (35, 36, 37) are positioned at the right depth with respect to the surface (22).

[0069] The wireless communication system (40) is connected to the sensing system (30) and configured for transmitting information relating to wear or clearance out of the guide device (10).

[0070] The system (40) comprises a transmitter (42) which sends radio signals in all directions. If the device (40) is disposed in a closed environment, the transmitter (42) may be configured in order to transmit information through metal components having a total thickness of more than 10 millimeters. In practice, the signals can be transmitted in an axial direction to an external reader disposed in the vicinity of the bush (21), through the parts of its environment.

[0071] In accordance with a particular embodiment, the transmitter (42) may be constituted by an RFID chip. Other technologies may be employed without departing from the scope of the invention.

[0072] In addition, the communication system (40) may include an energy source for powering the detection system (30).

[0073] FIG. 6 shows a variation of the guide device (10), comprising sensors (32) disposed on the two longitudinal sides (29), but not in the central portion. The device (10) may advantageously be mounted in two directions, without the operator being forced to pay attention to its orientation. This configuration is also useful in the event of asymmetry in the distribution of mechanical stresses between the two sides (29). Preferably, the communication system (40) comprises two transmitters (42), one on each side. This facilitates the connection between the sensor (32) and the emitters (42), and ensures that an emitter (42) is always close to the external reader disposed in the vicinity of the device (10).

[0074] Furthermore, the device (1) may have a different conformation to that of FIGS. 1 to 6 without departing from the scope of the invention which is defined in the claims. Furthermore, the technical features of the various embodiments and variations mentioned above may be combined in their entirety or only in part. Thus, the device (10) can be adapted in terms of cost, functions and performance.