Guiding device and mechanical system comprising such device

Abstract

The invention relates to a guiding device and a mechanical system comprising such a device. The guide device (10) comprises: a metal assembly (20) in the form of a bushing (21) provided with a friction surface (22) for accommodating a mating part (2) in frictional contact by means of a sliding with a swing; a detection system (30) for detecting wear of the friction surface (22), the detection system (30) comprising one or more sensors (32); a wireless communication system (40) connected to the detection system (30) and configured to transmit information relating to wear of the friction surface to the outside of the guide device (10); characterized in that one or more sensors (32) are provided only on one or two longitudinal sides (29) of the bushing, each longitudinal side (29) being defined on at most two fifths of the length of the annular bushing (21), the friction surface (22) comprising a fixing portion as a lubricant reservoir.

Description

[0001] This application is a divisional application of the Chinese patent application for invention with the application number 202180042349.X and the title "Guiding device and mechanical system comprising such a device", filed on May 28, 2021. TECHNICAL FIELD

[0002] The present invention relates to a guiding device comprising a metallic assembly, a detection device and a wireless communication device. The present invention relates to the field of devices for guiding a moving component in a sliding friction contact. BACKGROUND

[0003] For example, the guiding device according to the invention is of the bush type for guiding a shaft forming an articulation of a construction machine.

[0004] Various devices installed on machines are subjected to high mechanical stresses. Preventive and predictive maintenance programs have been implemented to avoid costly downtime. SUMMARY

[0005] The aim of the present invention is to propose a guiding device that makes it possible to perform a predictive maintenance operation.

[0006] To this end, the subject of the invention relates to a guiding device comprising:

[0007] - a metallic assembly in the form of a bush provided with a friction surface for accommodating a fitting component in a friction contact by sliding with oscillation;

[0008] - a detection system for detecting the wear of the friction surface comprising one or more sensors;

[0009] - a wireless communication system connected to the detection system and configured to send information relating to the wear of the friction surface to the outside of the guiding device;

[0010] characterized in that the one or more sensors are arranged only on one or both longitudinal sides of the bush, each longitudinal side being defined over at most two fifths of the length of the annular bush.

[0011] The invention thus makes it possible for the device to communicate the wear or clearance level of the friction assembly so as to replace it before a serious malfunction occurs. When the device is in operation, mechanical stresses are generally concentrated on the sides of the bush. Since the sensors are arranged on the sides rather than on the central portion, it is possible to improve the detection of wear and increase the probability of performing a predictive maintenance operation before the system suffers a serious malfunction.

[0012] According to other advantageous features of the invention, the following features are taken separately or in combination:

[0013] - each longitudinal side is defined over a length of one third of the annular bushing.

[0014] - the sensor or the plurality of sensors is arranged on only one longitudinal side of the bushing.

[0015] - the sensor or the plurality of sensors is distributed on two longitudinal sides of the bushing.

[0016] - the metallic assembly is formed from an annular bushing having a radial thickness of at least 5 mm.

[0017] - the metallic assembly is formed from an annular bushing having a radial thickness of at most 15 mm.

[0018] - the guiding means comprise a lubricant arranged on the friction surface.

[0019] - the friction surface comprises a fixed portion which is a reservoir for the lubricant.

[0020] - the fixed portion comprises a cavity.

[0021] - the fixed portion comprises a groove.

[0022] - the detection system is configured to detect wear of the friction surface over at least an angular range of 3° around the central axis of the metallic assembly.

[0023] - the detection system is configured to detect wear over 360° around the central axis. In this case, the operator who mounts the guiding means and their counterpart does not need to ensure that the detection system is correctly oriented. Indeed, the region of maximum load is necessarily within the angular detection range. The assembly of the device is thus simplified.

[0024] - the detection system comprises a plurality of sensors distributed around the central axis and ensuring detection of wear over an angular range of at least 120°.

[0025] - the sensors ensure detection of wear over a plurality of angular ranges.

[0026] - the sensors are distributed over a range of 360° around the central axis.

[0027] - the detection system comprises three sensors distributed over a range of 120° around the central axis.

[0028] - the detection system comprises four sensors distributed over a range of 90° around the central axis.

[0029] - the detection system is configured for detecting wear in a single angular range of at least 3° (i.e. in a single angular direction). In this case, the operator who mounts the guiding device and its counterpart must ensure that the detection system is correctly oriented, with the detection angular range coinciding with the maximum load region. This device is simpler and less costly, but its assembly requires greater precision.

[0030] - the detection system is configured for detecting wear in an angular range of at least 60° (preferably at least 120°). This achieves a good compromise between device cost, detection precision and assembly precision.

[0031] - the detection system comprises a single sensor which ensures detection of wear of the friction surface in an angular range of at least 3°.

[0032] - the detection system comprises a plurality of sensors which ensure detection of wear in an angular range of at least 60°. The sensors can be arranged in this single angular range of 60° or in a more restricted range.

[0033] - the or each sensor comprises at least one wire, one end of which is arranged at a given depth below the friction surface.

[0034] - the detection system is configured to detect different wear thresholds of the friction surface.

[0035] - the or each sensor comprises a number of wires having ends arranged at different depths below the friction surface.

[0036] - each sensor comprises means for indicating its angular position about a central axis.

[0037] - each sensor comprises means for indicating its axial position along the friction surface.

[0038] - each sensor comprises means for indicating its radial position relative to the friction surface.

[0039] - the or each sensor comprises a cylindrical housing housed in an orifice passing through the metal assembly between the friction surface and the opposite surface.

[0040] - the radial indication means comprise a collar formed on the cylindrical housing of the sensor.

[0041] - the detection system comprises an electrically conductive strip arranged in an annular groove formed on the surface of the metal assembly opposite the friction surface, on the one hand, and connected to each sensor and to a wireless communication system, on the other hand.

[0042] - the communication system comprises a transmitter configured to transmit information through a metal assembly having a total thickness greater than 10 millimeters.

[0043] The subject of the application also relates to a mechanical system, characterized in that it comprises at least one guiding device as described above and a cooperating part mounted in sliding friction contact, preferably with oscillating sliding, with the friction surface. BRIEF DESCRIPTION OF DRAWINGS

[0044] The application will be better understood from the following description. The following description is given by way of non-limiting example only and with reference to the drawings. In these drawings:

[0045] Figure 1 is a perspective view of a mechanical system according to the application, comprising a guiding device and a shaft mounted in this device.

[0046] Figure 2 is a side view of the device in the radial direction.

[0047] Figure 3 is a cross-sectional view along the line III-III in Figure 2 .

[0048] Figure 4 is a cross-sectional view along the line IV-IV in Figure 2 .

[0049] Figure 5 is an enlarged view of detail V in Figure 4 .

[0050] Figure 6 is a cross-sectional view similar to that in Figure 4 , showing a variant of the guiding device with sensors on both sides. DETAILED DESCRIPTION

[0051] Figure 1 and Figure 5 shows a mechanical system (1) according to the application, comprising a guiding ring (10) according to the application and a shaft (2) mounted in this device (10). For the sake of simplicity, the shaft (2) is represented by two dashed lines. The device (10) is designed to guide the shaft (2) in sliding friction contact, in particular in oscillating sliding.

[0052] The oscillating movement corresponds to a back-and-forth incomplete rotation around a central axis. The shaft (2) oscillates in the device (10), or the device (10) oscillates around the shaft (2). In both cases, the load applied to the device (10) defines a maximum load zone, corresponding to a particular angular position.

[0053] A lubricant, preferably a grease, is provided at the friction interface between the device (10) and the shaft (2).

[0054] The device (10) comprises a metallic friction assembly (20), a detection system (30) and a wireless communication system (40).

[0055] The metallic assembly (20) is formed by a ring-shaped bushing (21) provided with an inner surface (22) and an outer surface (23) having a cylindrical profile. The inner surface (22) constitutes a friction surface for receiving the shaft (2) in sliding friction contact. Advantageously, the surface (22) can comprise fixed portions that are lubricant reservoirs. These fixed portions can comprise cavities, grooves and / or other types of fixed portions.

[0056] The surfaces (22, 23) comprise a ring-shaped groove (24, 25) within the central portion, connected via an aperture (26) passing through the bushing (21). The elements (24, 25, 26) constitute means for lubricating the surface (22). In a variant, for example in the case of lubrication by shaft or side, the bushing (21) can be devoid of elements (24, 25, 26). The means for lubricating the surface (22) can be of any type adapted to the intended application.

[0057] The surface (23) comprises a ring-shaped groove (27) formed on one side of the groove (25). The surfaces (22, 23) are connected via an aperture (28) passing through the bushing (21) at the boundary of the groove (27). The elements (27, 28) constitute means for receiving the detection system (30). In a variant, if the bushing (21) is devoid of elements (24, 25, 26), the elements (27, 28) can be provided in the center.

[0058] According to a further variant, the groove (27) can be provided within the central portion, while the aperture (28) is provided in the side portion (29).

[0059] In the longitudinal direction of the bushing (21), a central portion and two longitudinal side portions (29) surrounding the central portion can be distinguished. Each longitudinal side portion (29) is defined over at most two-fifths of the length of the bushing (21). Preferably, each longitudinal side portion (29) is defined over one-third of the length of the bushing (21).

[0060] The thickness of the bushing (21) depends on the envisaged application. The thickness of the bushing (21) can be in the range of 5 to 15 millimeters or more. This thickness is defined within the functional range of the friction surface (22), excluding any shoulder formed on the side portion (29).

[0061] The detection system (30) is configured to detect the wear of the friction surface (22). As an alternative, the detection system (30) can be configured to detect the gap between the friction surface (22) and the surface of the shaft (2).

[0062] The detection system (30) comprises an electrically conductive strip (31), a plurality of sensors (32) connected to the electrically conductive strip (31) via wires (33) and a connector (34) adapted to connect the system (30) to the system (40). The electrically conductive strip (31) is made of a wire layer incorporating the wires (33). The connector (34) can comprise an electronic chip configured to convert the information on the power loss into wear depth information. As an alternative, the connector (34) can comprise simple wires belonging to the electrically conductive strip (31).

[0063] The electrically conductive strip (31) is arranged in an annular groove (27) formed on the outer surface (23) of the metallic assembly (20). The electrically conductive strip (31) is connected to each sensor (32) via the wires (33) on the one hand and to the wireless communication system (40) via the connector (34) on the other hand.

[0064] In the example of the attached figures, the detection system (30) comprises four sensors (32) distributed in a range of 90° around the central axis (X20) of the assembly (20). Thus, the detection system (30) ensures the detection of the wear around the central axis (X20) in an angular range of 360°.

[0065] According to the invention, it is advantageous that the sensors (32) are arranged only on the longitudinal side portions (29) of the bushing (21) and do not protrude onto the central portion. Indeed, mechanical stresses are generally concentrated on the side portions (29) of the bushing (21) when the mechanical system (1) is in operation.

[0066] Thanks to the arrangement of the sensors (32) on the side portions (29) and not on the central portion, it is possible to improve the wear detection and increase the probability of performing a preventive maintenance operation before the system (1) suffers from a serious malfunction.

[0067] Each sensor (32) comprises a plurality of wires (35, 36, 37), one end of each wire being arranged at a given depth below the friction surface (22). The wear of the wires (35, 36, 37) depends on the wear of the surface (22). The ends of the wires (35, 36, 37) are arranged at different depths below the friction surface (22). Depending on different thresholds, the successive wear of the wires (35, 36, 37) is associated with a progressive wear of the friction surface (22). Thus, the detection system (30) is configured to detect different wear thresholds of the friction surface (22).

[0068] Each sensor (32) comprises a cylindrical housing (38) housed in a bore (28) passing through the metal assembly (20) between the friction surface (22) and the outer surface (23). This housing (38) constitutes a means for indicating the angular and axial position of the sensor (32). Other solutions for forming the angular and / or axial indicating means can be envisaged. The advantage of the housing (38) housed in the bore (28) is that it is a relatively simple solution to implement.

[0069] Preferably, each sensor (32) comprises a means for indicating its radial position relative to the friction surface (22). As an example, the radial indicating means comprise a collar (39) formed on the cylindrical housing (38) of the sensor (32). Other solutions for forming the radial indicating means can be envisaged, which can ensure that the wires (35, 36, 37) are positioned at the correct depth relative to the surface (22).

[0070] A wireless communication system (40) is connected to the detection system (30) and is configured for sending information relating to wear or clearance from the guide device (10).

[0071] The system (40) comprises a transmitter (42) which sends radio signals in all directions. If the device (40) is set up in an enclosed environment, the transmitter (42) can be configured to send information through a metal assembly with a total thickness greater than 10 mm. In practice, the signal can be sent along the axis through various parts of its environment to an external reader set up in the vicinity of the bushing (21).

[0072] According to one particular embodiment, the transmitter (42) can be constituted by an RFID chip. Other technologies can be employed without departing from the scope of the application.

[0073] Furthermore, the communication system (40) can comprise an energy source for powering the detection system (30).

[0074] Figure 6 A variant of the guide device (10) is shown, comprising sensors (32) set up on both longitudinal sides (29) but not in the central portion. This device (10) can advantageously be installed in both directions, without requiring the operator to pay attention to its orientation. This configuration is also beneficial in the case of an asymmetric 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 sensors (32) and the transmitters (42) and ensures that the transmitters (42) are always close to an external reader set up in the vicinity of the device (10).

[0075] Moreover, the device (10) can have different configurations without departing from the scope of the application as defined in the claims Figures 1 to 6 Furthermore, the technical features of the various embodiments and variants described above can be combined, in whole or only in part. The device (10) can thus be adapted in terms of cost, functionality and performance.

Claims

1. A guiding device (10) comprising: - a metal assembly (20) in the form of a bushing (21) provided with a friction surface (22) for accommodating a fitting component (2) in frictional contact by sliding with oscillation; - a detection system (30) for detecting wear of the friction surface (22), the detection system (30) comprising one or more sensors (32); - a wireless communication system (40) connected to the detection system (30) and configured to send information relating to wear of the friction surface (22) to the outside of the guiding device (10); characterized in that the one or more sensors (32) are provided only on one or both longitudinal sides (29) of the bushing (21), each longitudinal side (29) being defined over at most two fifths of the length of the annular bushing (21), the friction surface (22) comprising a fixed portion as a reservoir for lubricant.

2. The guiding device (10) according to claim 1, characterized in that Each longitudinal side (29) is defined over one third of the length of the annular bushing (21).

3. Guide device (10) according to any one of the preceding claims, characterized in that The sensor or each sensor (32) comprises at least one wire (35, 36, 37) provided at one end at a given depth below the friction surface (22).

4. Guide device (10) according to any one of the preceding claims, characterized in that The detection system (30) is configured to detect different wear thresholds of the friction surface (22).

5. The guiding device (10) according to claim 4, characterized in that The sensor or each sensor (32) comprises a plurality of wires (35, 36, 37) having ends provided at different depths below the friction surface (22).

6. Guide device (10) according to any one of the preceding claims, characterized in that The sensor or each sensor (32) comprises a cylindrical housing (38) housed in an orifice (28) passing through the metal assembly (20) between the friction surface (22) and an opposite surface (23).

7. Guide device (10) according to any one of the preceding claims, characterized in that The detection system (30) comprises an electrically conductive strip (31) provided in an annular groove (27) formed on the surface (23) of the metal assembly (20) opposite the friction surface (22), and connected to each sensor (32) on the one hand and to the wireless communication system (40) on the other hand.

8. Guide device (10) according to any one of the preceding claims, characterized in that The detection system (30) comprises four sensors (32) distributed at 90° around a central axis (X20) of the metal assembly (20).

9. Guide device (10) according to any one of the preceding claims, characterized in that The wireless communication system (40) comprises a transmitter (42) configured to send information through a metal assembly with a total thickness greater than 10 millimeters.

10. A mechanical system (1) characterized by, The mechanical system comprises at least one guiding device (10) according to any one of claims 1 to 9, and a fitting component (2) mounted against the friction surface (22) in frictional contact by sliding with oscillation.

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