Guide device and mechanical system comprising such a device

Abstract

The present invention relates to a guide device (10) comprising: a metal component (20) having a friction surface (22) for receiving a counter piece (2) in sliding frictional contact; a wear detection system (30) for detecting wear of the friction surface (22) or a gap between the friction surface (22) and the counter piece (2), the detection system (30) comprising one or more sensors (32); and a wireless communication system (40) connected to the detection system (30) and configured to transmit information relating to wear or play outwards from the guide device (10).

Description

[0001] Guiding device and mechanical system including such a device. Technical field.

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

[0003] Previous art

[0004] The guiding devices according to the invention are, for example, of the type of guide bearing for an axis, forming the articulation of a public works machine.

[0005] Devices mounted on machines are subjected to significant mechanical stresses. Preventive and predictive maintenance solutions are implemented to avoid costly downtime.

[0006] Description of the invention

[0007] The aim of the present invention is to provide a guidance device enabling the implementation of predictive maintenance operations.

[0008] To this end, the invention relates to a guidance device, comprising:

[0009] - a metallic component equipped with a friction surface intended to receive an opposing part in contact by sliding friction;

[0010] - a system for detecting wear on the friction surface or play between the friction surface and the opposing part, the system comprising one or more sensors; and

[0011] - a wireless communication system connected to the detection system and configured to transmit information relating to wear or play to the outside of the guiding device.

[0012] Thus, the invention allows the device to communicate the level of wear or play of the metallic friction component, in order to replace it before a critical malfunction.

[0013] According to other advantageous features of the invention, taken individually or in combination:

[0014] - The metallic component is formed by an annular ring having a radial thickness of at least 5 millimeters.

[0015] - The metallic component is formed by an annular ring having a radial thickness of at most 15 millimeters.

[0016] - The guiding device includes a lubricant disposed on the friction surface. - The friction surface includes arrangements that act as a lubricant reservoir.

[0017] - The arrangements include cavities.

[0018] - The arrangements include grooves.

[0019] - The detection system is configured to detect wear on the friction surface at least over an angular range of 3° around a central axis of the metallic component.

[0020] The detection system is configured for 360° wear detection around the central axis. In this case, the operator assembling the guide and its opposing device does not need to ensure the detection system is correctly oriented. This is because the maximum load zone is necessarily within the detection angle range. The device assembly is therefore simplified.

[0021] - The detection system includes several sensors, which are distributed around the central axis and which ensure wear detection over an angular range of at least 120°.

[0022] - The sensors ensure wear detection over several angular ranges.

[0023] - The sensors are distributed 360° around the central axis.

[0024] - The detection system includes three sensors distributed at 120° around the central axis.

[0025] - The detection system includes four sensors distributed at 90° around the central axis.

[0026] The detection system is configured to detect wear over a single angular range of at least 3°, i.e., along a single angular direction. In this case, the operator assembling the guide and its opposing device must ensure that the detection system is correctly oriented, with the detection angular range coinciding with the maximum load zone. The device is simpler and less expensive, but its assembly requires greater precision.

[0027] - The detection system is configured for wear detection over an angular range of at least 60°, preferably at least 120°. This offers a good compromise between device cost, detection accuracy and mounting accuracy.

[0028] - The detection system includes a single sensor, which ensures the detection of wear on the friction surface at least over an angular range of 3°.

[0029] - The detection system includes several sensors ensuring wear detection over an angular range of at least 60°. The sensors can be arranged within this single angular range of 60°, or over a more restricted range.

[0030] - The sensor(s) are arranged exclusively on one longitudinal edge or on two longitudinal edges of the ring, each longitudinal edge being defined on at most two-fifths of the length of the annular ring.

[0031] - Each longitudinal edge is defined over one third of the length of the annular ring.

[0032] - The sensor(s) are arranged exclusively on a longitudinal edge of the ring.

[0033] - The sensor(s) are distributed on the two longitudinal edges of the ring.

[0034] - The sensor or sensors comprise at least one conducting wire having one end arranged at a given depth below the friction surface.

[0035] - The detection system is configured to detect different wear thresholds of the friction surface.

[0036] - The sensor(s) comprise several conductive wires having ends arranged at different depths below the friction surface.

[0037] - Each sensor includes means for indexing its angular position around the central axis.

[0038] - Each sensor includes means for indexing its axial position along the friction surface.

[0039] - Each sensor includes means for indexing its radial position relative to the friction surface.

[0040] - The sensor(s) comprise a cylindrical housing in an orifice through the metallic component between the friction surface and an opposite surface.

[0041] - The radial indexing means include a collar formed on the cylindrical envelope of the sensor.

[0042] - The detection system includes a conductive strip which is arranged in an annular groove formed on a surface of the metallic component opposite the friction surface and which is connected, on one side, to each sensor and, on the other side, to the wireless communication system.

[0043] - The communication system includes a transmitter configured to transmit information through metallic components with a total thickness greater than 10 millimeters.

[0044] The invention also relates to a mechanical system, characterized in that it comprises at least one guiding device as described above, and an opposing part mounted in contact by sliding friction with the friction surface, preferably sliding friction with oscillation.

[0045] Description of the figures

[0046] The invention will be better understood upon reading the following description, given solely by way of non-limiting example and made with reference to the accompanying drawings in which:

[0047] [Fig. 1] is a perspective view of a mechanical system according to the invention, comprising a guiding device and an axis mounted in the device.

[0048] [Fig. 2] is a side view of the device, along a radial direction.

[0049] [Fig. 3] is a section along line lll-lll in figure 2. [Fig. 4] is a section along line IV-IV in figure 2.

[0050] [Fig. 5] is a larger scale view of detail V in figure 4.

[0051] [Fig. 6] is a cross-section analogous to figure 4, showing a variant of the guidance device, with sensors on both edges.

[0052] Detailed description of the invention

[0053] Figures 1 to 5 show a mechanical system (1) according to the invention, comprising a guiding device (10) according to the invention, and a shaft (2) mounted in the device (10). The shaft (2) is represented by two dashed lines for the sake of simplicity. The device (10) is designed to guide the shaft (2) through frictional contact by sliding, in particular sliding with oscillation.

[0054] The oscillatory motion corresponds to an incomplete rotation around the central axis, in a back-and-forth motion. Either the axis (2) oscillates within the device (10), or the device (10) oscillates around the axis (2). In both cases, the loads exerted on the device (10) define a zone of maximum load, corresponding to a particular angular position.

[0055] A lubricant, preferably grease, is placed at the friction interface between the device (10) and the shaft (2).

[0056] The device (10) includes a metallic friction component (20), a detection system (30) and a wireless communication system (40).

[0057] The metallic component (20) is formed by an annular ring (21) having an inner surface (22) and an outer surface (23) of cylindrical profiles. The inner surface (22) provides a friction surface for receiving the shaft (2) in sliding friction contact. Advantageously, the surface (22) may include features that serve as lubricant reservoirs. These features may include cavities, grooves, and / or other types of arrangements.

[0058] The surfaces (22, 23) have annular grooves (24, 25) in their central portion, connected by orifices (26) passing through the ring (21). The elements (24, 25, 26) constitute means for lubricating the surface (22). Alternatively, for example in the case of lubrication via the shaft or the side, the ring (21) may be without elements (24, 25, 26). The means for lubricating the surface (22) may be of any type suitable for the intended application.

[0059] The surface (23) has an annular groove (27) formed on one side of the groove (25).

[0060] The surfaces (22, 23) are connected by openings (28) passing through the ring (21) at the edge of the groove (27). The elements (27, 28) constitute receiving means for the detection system (30). Alternatively, if the ring (21) is devoid of elements (24, 25, 26), the elements (27, 28) can be arranged in the central part. According to another embodiment, the groove (27) can be arranged in the central part, while the openings (28) are arranged on an edge (29).

[0061] Along the longitudinal direction of the ring (21), a central portion and two longitudinal edges (29) framing the central portion are distinguished. Each longitudinal edge (29) is defined over at most two-fifths of the length of the ring (21). Preferably, each longitudinal edge (29) is defined over one-third of the length of the ring (21).

[0062] The thickness of the ring (21) depends on the intended application. The ring (21) can have a thickness between 5 and 15 millimeters, or greater. This thickness is defined over the functional area of ​​the friction surface (22), excluding any shoulder formed on an edge (29).

[0063] The detection system (30) is configured to detect wear on the friction surface (22). Alternatively, the detection system (30) could be configured to detect play between the friction surface (22) and the surface of the shaft (2).

[0064] The detection system (30) comprises a conductive strip (31), several sensors (32) connected to the strip (31) via conductive wires (33), and a connector (34) designed to connect the system (30) to the system (40). The strip (31) consists of a ribbon of conductive wires, incorporating the wires (33). The connector (34) may include an electronic chip configured to convert information about current loss into information about wear depth. Alternatively, the connector (34) may simply consist of wires belonging to the strip (31).

[0065] The conductive strip (31) is arranged in the annular groove (27) formed on the external surface (23) of the metallic component (20). The conductive strip (31) is connected, on the one hand, to each sensor (32) via the conductive wires (33) and, on the other hand, to the wireless communication system (40) via the connector (34).

[0066] As illustrated in the figures, the detection system (30) comprises four sensors (32) distributed at 90° around the central axis (X20) of the component (20). Thus, the detection system (30) ensures wear detection over an angular range of 360° around the central axis (X20).

[0067] Advantageously, the sensors (32) are arranged exclusively on a longitudinal edge (29) of the ring (21), without extending into the central part. Indeed, when the mechanical system (1) is in operation, the mechanical stresses are generally concentrated on the edges (29) of the ring (21). Arranging the sensors (32) on an edge (29) rather than in the central part improves wear detection and the chances of implementing predictive maintenance before a critical malfunction of the system (1).

[0068] Each sensor (32) comprises several conductive wires (35, 36, 37), each with one end positioned at a specific depth below the friction surface (22). The wear of the conductive wires (35, 36, 37) is a function of the wear of the surface (22). The ends of the conductive wires (35, 36, 37) are positioned 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), according to different thresholds. Thus, the detection system (30) is configured to detect different wear thresholds of the friction surface (22).

[0069] Each sensor (32) comprises a cylindrical housing (38) housed in an orifice (28) passing through the metallic component (20) between the friction surface (22) and the external surface (23). This housing (38) constitutes a means of indexing the angular and axial position of the sensor (32). Other solutions are conceivable for forming angular and / or axial indexing means. The housing (38) housed in an orifice (28) has the advantage of being a simple solution to implement.

[0070] Preferably, each sensor (32) includes means for indexing its radial position relative to the friction surface (22). For example, the radial indexing means may include a collar (39) formed on the cylindrical casing (38) of the sensor (32). Other solutions are conceivable for forming the radial indexing means, which ensure that the wires (35, 36, 37) are positioned at the correct depth relative to the surface (22).

[0071] The wireless communication system (40) is connected to the detection system (30) and configured to transmit information relating to wear or play to the outside of the guiding device (10).

[0072] The system (40) includes a transmitter (42) that sends radio signals in all directions. If the device (40) is located in an enclosed environment, the transmitter (42) can be configured to transmit information through metallic components with a total thickness greater than 10 millimeters. In practice, the signals can be transmitted along an axial direction to an external reader located near the ring (21), through the surrounding components.

[0073] In one particular embodiment, the transmitter (42) may be an RFID chip. Other technologies may be used without departing from the scope of the invention. Furthermore, the communication system (40) may include a power source for supplying power to the detection system (30).

[0074] Figure 6 shows a variant of the guidance device (10), comprising sensors (32) arranged on the two longitudinal edges (29), but not in the central part. The device (10) can advantageously be mounted in either direction without the operator having to pay attention to its orientation. This configuration is also useful in cases of asymmetry in the distribution of mechanical stresses between the two edges (29). Preferably, the communication system (40) has two transmitters (42), one on each side. This facilitates communication between the sensor (32) and the transmitters (42), and ensures that one transmitter (42) is always close to the external reader located near the device (10).

[0075] Furthermore, the device (10) can be configured differently from Figures 1 to 6 without departing from the scope of the invention, which is defined by the claims. In addition, the technical features of the various embodiments and variants mentioned above can be combined, in whole or in part. Thus, the device (10) can be adapted in terms of cost, functionality, and performance.

Claims

A guide device (10) comprising:- a metal component (20) provided with a friction surface (22) intended to receive a mating part (2) in sliding frictional contact;- a detection system (30) of a wear of the friction surface (22) or of a clearance between the friction surface (22) and the mating part (2), the detection system (30) comprising one or more sensors (32); each sensor comprises at least one conductive wire having one end disposed at a given depth below the friction surface, and each sensor comprises a cylindrical envelope housed in an orifice passing through the metal component between the friction surface and an opposing surface, and- a wireless communication system (40) connected to the detection system (30) and configured to transmit information relating to wear or clearance out of the guide device (10). The guide device (10) as claimed in claim 1, characterized in that it comprises a lubricant disposed on the friction surface (22). The guide device (10) as claimed in claim 1, characterized in that the friction surface (22) comprises workings acting as a reservoir for lubricant. The guide device (10) as claimed in claim 1, characterized in that the detection system (30) is configured for the detection of wear of the friction surface (22) over an angular range of at least 3° about a central axis (X20) of the metal component (20). The guide device (10) as claimed in claim 4, characterized in that the detection system (30) comprises a single sensor (32) which ensures the detection of wear of the friction surface (22) over an angular range of at least 3°. The guide device (10) as claimed in claim 4, characterized in that the detection system (30) comprises a plurality of sensors (32) which are distributed about the central axis (X20) of the metal component (20) and which ensure the detection of wear over at least an angular range of 60°. The guide device (10) as claimed in claim 1, characterized in that the sensor or sensors (32) are disposed exclusively on one longitudinal side (29) or on two longitudinal sides (29) of the metal component (20), each longitudinal side (29) being defined over at most two fifths of the length of the annular bush (21). The guide device (10) as claimed in claim 1, characterized in that the metal component (20) is formed by an annular bush (21) having a radial thickness of at least 5 millimetres. The guide device (10) as claimed in claim 1, characterized in that the metal component (20) is formed by an annular bush (21) having a radial thickness of at most 15 millimetres. A mechanical system (1), characterized in that it comprises at least one guide device (10) as claimed in one of claims 1 to 9, and a mating part (2) mounted in sliding frictional contact with the friction surface (22). 

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