Method for monitoring a failure of a gearbox on a transmission line of a railway vehicle and railway vehicle

Abstract

A method for monitoring a failure of a gearbox in a transmission line of a railway vehicle, the railway vehicle comprising at least one transmission line including one axle and at least one traction motor driving the axle via the gearbox, the gearbox comprising at least two on-board sensors, the monitoring method comprising a check step (E1) of the operating status of the on-board sensors, if the on-board sensors are operational (OK), a monitoring step (E2) of a primary failure (P1) of the gearbox based on measurements from the on-board sensors and if the on-board sensors are not operational (POK), a monitoring step (E3) of a secondary failure (P2) of the gearbox based on at least one auxiliary measurement (AUX) external to the gearbox. Abstract figure: Figure 7

Description

Title of the invention: Method for monitoring a breakdown of a reducer of a transmission line of a railway vehicle and railway vehicle Technical field

[0001] The present invention relates to the field of railway vehicles and, more specifically, to the detection of failures of a reducer connecting a traction motor and an axle of a railway vehicle in a transmission line.

[0002] In a known manner, a railway vehicle comprises several bogies equipped with axles. One or more axles of a bogie are connected to a traction motor in order to form a transmission line for the movement of the railway vehicle. As an example, [fig.l] illustrates a transmission line L comprising a traction motor 1 connecting an axle 2 via a reducer 3. In a known manner, as shown in [fig.2], a reducer 3 comprises several gear shafts 31, 32, guided by internal bearings (not shown), which make it possible to apply a reduction ratio between the traction motor 1 and the axle 2. The gear shafts 31, 32 are housed in a sealed enclosure 33 filled with oil 30 in order to provide lubrication and allow cooling. Such a reducer 3 is known to those skilled in the art and will not be presented in more detail.

[0003] Over time, the gear shafts 31, 32 wear and metal particles degrade the performance of the oil 30, which can lead to a lubrication defect and / or a cooling defect which can cause the reduction gear 3 to break down. The same applies in the event of oil 30 leaking out of the sealed enclosure 33, a maintenance error when replacing the oil 30, etc.

[0004] The failure of a reducer 3 is a critical event for a railway vehicle. In certain cases, the lubrication defect and / or the cooling defect can lead to the destruction of the internal bearings or the gear shafts 31, 32, which blocks the axle 2 and can lead to a derailment of the railway vehicle. When the axle 2 is blocked, the driver must immobilize the railway vehicle on its track and the passengers are forced to get off the railway vehicle. The track is blocked and no longer allows the circulation of other railway vehicles. Such a critical event is very detrimental for a railway operator. In order to avoid such a critical event, it is known to monitor the reducer 3.

[0005] To avoid the occurrence of breakdowns, the reducer 3 undergoes periodic checks of the quality of the components of the reducer 3 and of the oil 30. In addition to these periodic checks periodic, it has also been proposed to carry out on-board monitoring of the reducer 3 by providing several sensors embedded in the reducer 3 in order to detect an abnormal rise in temperature, acoustic signals characteristic of a breakdown, etc. These various on-board sensors are also likely to be defective and, despite the implementation of redundancies, the reducer 3 may be deprived of any on-board monitoring, which prevents any emission of a critical alarm.

[0006] During studies, it was observed that during a breakdown of the reducer 3, the temperature of the reducer 3 rises significantly and leads to the degradation of the on-board sensors. Also, it was proposed to issue a critical alarm when one or more on-board sensors are defective. In practice, each on-board sensor has its own failure modes, which leads to numerous untimely critical alarms (false positives). The driver must then immobilize the railway vehicle even though the reducer 3 is not defective.

[0007] The invention thus aims to eliminate at least some of these drawbacks by proposing a new method for monitoring a failure of a reducer of a transmission line, the reliability of which is improved. PRESENTATION OF THE INVENTION

[0008] The invention relates to a method for monitoring a failure of a reducer of a transmission line of a railway vehicle, the railway vehicle comprising at least one transmission line comprising an axle and at least one traction motor driving the axle via the reducer, the reducer comprising at least two on-board sensors, the monitoring method comprising: • a step of checking the operating state of the on-board sensors, • if the on-board sensors are operational, a step of monitoring a primary failure of the reducer from the measurements of the on-board sensors and • if the on-board sensors are not operational, a step of monitoring a secondary failure of the reducer from at least one auxiliary measurement external to the reducer.

[0009] Thanks to the invention, a primary failure can be detected optimally by the on-board sensors. When the latter are not operational, a secondary failure is not automatically detected as in the prior art. A secondary failure is detected solely on the basis of an auxiliary measurement external to the reducer, which avoids the emission of an untimely alarm. The use of an auxiliary measurement external to the reducer makes it possible to prevent the reducer from disturbing the auxiliary measurement, which improves the overall reliability of the monitoring.

[0010] Preferably, no monitoring of a secondary failure is carried out when the on-board sensors are operational. This makes it possible to avoid any in- tempestive, for example, in the event of slippage.

[0011] Preferably, if the on-board sensors are not operational, the method comprises a step of securing the transmission line so that the axle is in freewheel mode. Thus, no more tractive force is transmitted to the axle via the reducer, which limits the risk of derailment.

[0012] Preferably, at least one auxiliary measurement is a speed measurement carried out on the transmission line outside the reducer, preferably on the axle and / or on the traction motor. Advantageously, the speed of the axle or of the traction motor is modified when the reducer is faulty. A speed measurement on the traction motor is advantageous since the latter generally has integrated speed measuring means. A drop in speed thus makes it possible to detect a secondary fault.

[0013] According to one aspect of the invention, the railway vehicle comprising a bogie comprising at least two transmission lines each comprising an axle and at least one traction motor driving the axle via a reducer, the method comprises, if the on-board sensors are not operational, a step of monitoring a secondary failure of the reducer from speed measurements of each transmission line, preferably of each traction motor.

[0014] A comparative measurement from two independent transmission lines makes it possible to reliably highlight, with low bias, a failure of one of the reducers. Indeed, a faulty reducer induces friction on the traction motor, which is easily observed.

[0015] Preferably, a secondary fault is issued if the difference between the two speeds is greater than a threshold of 15 km / h, preferably 20 km / h. More preferably, a secondary fault is issued if the speed difference is greater than the threshold for a duration greater than 1 second.

[0016] According to one aspect of the invention, if the on-board sensors of a reducer are not operational, the method comprises a step of securing each transmission line so that each axle is in freewheel mode. A difference in speeds is easily observable in freewheel mode, which makes it possible to detect a secondary failure of a reducer in a reactive manner.

[0017] The invention also relates to a railway vehicle comprising at least one transmission line comprising an axle and at least one traction motor driving the axle via the reducer, the reducer comprising at least two on-board sensors, the railway vehicle comprising at least one computer configured to implement the steps of the method as presented previously.

[0018] Preferably, the on-board sensors are selected from temperature sensors, speed sensors, acoustic sensors and oil level sensors. PRESENTATION OF FIGURES

[0019] The invention will be better understood on reading the description which follows, given by way of example, and referring to the following figures, given by way of non-limiting examples, in which identical references are given to similar objects.

[0020] [Fig.l] is a schematic representation of a transmission line of a railway vehicle comprising a reducer.

[0021] [Fig.2] is a schematic representation of a reducer of [Fig.l].

[0022] [Fig. 3] is a schematic representation of two bogies each comprising two transmission lines.

[0023] [Fig.4] is a schematic representation of the transmission lines of [Fig.3].

[0024] [Fig.5] is a schematic representation of a reducer comprising two on-board sensors.

[0025] [Fig.6] is a schematic representation of the transmission of sensor measurements between the bogie computers of [Fig.3].

[0026] [Fig.7] is a schematic diagram of the steps of implementing a method for monitoring the failure of a reducer according to an exemplary implementation of the invention.

[0027] It should be noted that the figures set out the invention in detail to implement the invention, said figures can of course be used to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION

[0028] In this embodiment, with reference to [fig.3], a railway vehicle will be presented comprising two bogies A, B each comprising two transmission lines L-1A, L-2A, L-1B, L-2B. As illustrated in [fig.4], each transmission line L-1A, L-2A, L-1B, L-2B comprises at least one axle 2-1 A, 2-2A, 2-1B, 2-2B associated with at least one traction motor 1-1A, 1-2A, 1-1B, 1-2B via a reducer 3-1A, 3-2A, 3-1B, 3-2B. It goes without saying, however, that the invention also applies to a railway vehicle comprising a single bogie A, B.

[0029] For the sake of clarity and conciseness, the letter X is used to designate a given transmission line.

[0030] In this example, as illustrated in [fig.5], each reducer 3-X comprises several gear shafts 31-X, 32-X, guided by internal bearings (not shown), which make it possible to apply a reduction ratio between the traction motor 1-X and the axle 2-X for the traction line LX. The gear shafts 31-X, 32-X are housed in a sealed enclosure 33-X filled with oil 30-X in order to provide lubrication and allow cooling. In this example, the 3-X reducer has two on-board sensors Cl-X, C2-X which allow the operating status of the 3-X reducer to be monitored.

[0031] The on-board sensors Cl-X, C2-X are configured to detect a primary failure PI (see [fig.7]) of the reducer 3-X, that is to say, directly. For example, the on-board sensors Cl-X, C2-X can be in the form of temperature sensors, speed sensors, acoustic sensors, oil level sensors, etc. In this example, the speed sensors Cl-X, C2-X determine the rotation speed by counting the passage time of each tooth of a gear shaft 31-X, 32-X. To be able to detect the teeth, each of the speed sensors Cl-X, C2-X is positioned as close as possible to the teeth of the gear shaft 31-X, 32-X. Such on-board sensors Cl-X, C2-X are known to those skilled in the art and make it possible to quickly detect a failure of the 3-X reducer in the event of a rise in temperature, an abnormal drop in speed, an abnormal acoustic signal, a drop in oil level, etc.As long as the on-board sensors Cl-X, C2-X are operational, the 3-X reducer is optimally monitored and a primary PI failure can be detected.

[0032] In this example, with reference to [fig.5], two speed sensors C1-X, C2-X are positioned in the reducer 3-X in order to monitor the speed of the gear shafts 31-X, 32-X in the reducer 3-X. Such speed sensors C1-X, C2-X are efficient but may be defective when the temperature rises or for other various reasons independent of the temperature of the reducer 3-X.

[0033] In this example, with reference to [fig.3], each bogie A, B further comprises a computer 5A, 5B for receiving the measurements from the on-board sensors C1-X, C2-X, here speed measurements.

[0034] With reference to [fig.6], the first reducer 3-1A of the first bogie A sends a first speed measurement V1-1A to the first computer 5A and a second speed measurement V2-1A to the second computer 5B. Similarly, the second reducer 3-2A of the first bogie A sends a first speed measurement V1-2A to the first computer 5A and a second speed measurement V2-2A to the second computer 5B.

[0035] Similarly, the first reducer 3-1B of the second bogie B sends a first speed measurement V1-1B to the first computer 5A and a second speed measurement V2-1B to the second computer 5B. Similarly, the second reducer 3-2B of the second bogie B sends a first speed measurement V1-2B to the first computer 5A and a second speed measurement V2-2B to the second computer 5B.

[0036] For the sake of clarity and conciseness, only the processing of the measurements will be presented. speed measurements VI-1 A, V2-1A, V1-2A, V2-2A of the first bogie A. The processing of speed measurements VI-IB, V2-1B, V1-2B, V2-2B of the second bogie B are similar and will not be presented in detail.

[0037] As shown in [fig.6], the first computer 5A processes the speed measurements VI-1 A, V1-2A in order to monitor a transmission break RT-A of the reducer 3-1A and the speed measurements V1-1B, V1-2B in order to monitor a non-rotation of an axle NRE-B of the reducer 3-1B. In order to ensure cross-redundancy, the first computer 5A monitors a transmission break RT-A of the first bogie A and a non-rotation of an axle NRE-B of the second bogie B. Similarly, the second computer 5B monitors a transmission break RT-B of the second bogie B and a non-rotation of an axle NRE-A of the first bogie A.

[0038] Furthermore, each computer 5A, 5B transmits EX ([fig.6]) to the other computer 5A, 5B the operating status of the speed sensors C1-X, C2-X. Thus, the second computer 5B continuously informs the first computer 5A of the operating status of the speed sensors C2-1A, C2-2A which provide the speed measurements V2-1A, V2-2A. Thus, in the event of failure of the speed sensors C1-1A, C2-1A, the first computer 5A signals a simultaneous loss of RT-A and NRE-A monitoring of the axle 2-1 A. The same applies to the other axles.

[0039] As presented previously, the RT-A and NRE-A monitoring losses are not necessarily synonymous with a failure of the 3-1A reducer of this 2-1 A axle. Indeed, the speed sensors C1-1A, C2-1A can be simultaneously faulty. According to feedback, for a fleet of 100 railway vehicles, a simultaneous failure of the speed sensors C1-1A, C2-1A can occur up to 10 times per year without the 3-1A reducer actually being faulty.

[0040] As an example, with reference to [fig.7], an example of implementation of a method for monitoring a failure of the reducer 3-1A of the first axle 2-1A of the first bogie A will now be presented. In this example, the monitoring is implemented by the first computer 5A but it goes without saying that other calculation means could be suitable.

[0041] First of all, the method comprises a first step E1 of checking the operating state of the on-board sensors C1-1A, C2-1A of the first axle IA. As explained previously, a communication EX exists between the two computers 5A, 5B of the bogies A, B, which allows the first computer 5A to know the operating state of the on-board sensors C1-1A, C2-1A of the first axle IA directly or indirectly.

[0042] With reference to [fig.7], if the on-board sensors C1-1A, C2-1A of the first axle 2-1A are operational OK, a monitoring step E2 is carried out for a primary failure PI of the reducer 3-1A of the first axle 2-1A. Such a monitoring step direct is known to those skilled in the art and will not be presented in more detail. In this example, an abnormal drop in speed is monitored by the speed sensors C1-1A, C2-1A and allows the conclusion to be drawn that there is a primary PI failure. It goes without saying that the step of monitoring a primary PI failure depends on the nature of the on-board sensors C1-1A, C2-1A.

[0043] In this example, when the on-board sensors C1-1A, C2-1A of the first axle 2-1A are not operational POK, the method comprises a safety step E4 (optional) during which the transmission lines L-1A and L-2A of the first bogie A are put out of service. In particular, the transmission lines L-1A and L-2A no longer control traction or braking. This is relevant given that the monitoring functions RT-A and NRE-A can no longer be ensured. The loss of RT-A monitoring no longer makes it possible to ensure safe traction force for the motor and the loss of NRE-A monitoring no longer makes it possible to perform braking without the risk of jamming. The axles 2-1 A, 2-2A are in freewheel (ERRE).

[0044] In this example, when the on-board sensors C1-1A, C2-1A of the first axle IA are not operational POK, the method comprises a maintenance warning step E5 (optional) to warn the maintenance services that the on-board sensors C1-1A, C2-1A must be replaced / repaired.

[0045] If the on-board sensors C1-1A, C2-1A of the first axle IA are not operational POK, a monitoring step E3 is carried out for a secondary failure P2 of the reducer 3-1A of the first axle 2-1 A. Such an indirect monitoring step is carried out from one or more auxiliary measurements AUX which are external to the reducer 3-1 A.

[0046] The terms primary failure Pl / secondary failure P2 aim to determine distinct monitoring levels for the same failure.

[0047] Preferably, the auxiliary measurement(s) AUX comprise at least one measurement from one or more transmission lines L-1A, L-2A of the first bogie A, for example, a measurement on the traction motor 1-1A or the axle 2-1A.

[0048] In this example, the auxiliary measurement AUX is in the form of a speed measurement of the traction motor 1-1 A. Several solutions are possible for determining the speed of said traction motor 1-1A: using a speed sensor installed on a rotating part (rotor) of the traction motor 1-1 A, using the measurement of the electrical quantities (voltage and / or current) of the traction motor 1-1 A, etc. Such an auxiliary measurement AUX is external to the reducer 3-1A and is thus not impacted in the event of a temperature rise. Advantageously, as the traction motor 1-1A is mechanically linked to the reducer 3-1A in the transmission line L-1A, the speed of the traction motor 1-1A is directly linked to the rotation speed gears of the 3-1 A reducer. Thus, a failure of the 3-1A reducer causes a drop in the speed of the 1-1 A traction motor.

[0049] According to a first aspect, in order to practically determine a suspicious drop in speed, the speed of the traction motor 1-1A is compared with the speed of the first bogie A, i.e., the reference speed of the railway vehicle. If the speed difference exceeds a predetermined threshold, for example 20 km / h, for a determined period, for example 1 second, a secondary fault P2 is detected.

[0050] In order to obtain improved discrimination, the speed of the traction motor 1-1A is compared to the speed of the traction motor 1-2A of the same bogie A. Such a comparison is practical given that the computer 5A has direct access to these measurements, which increases responsiveness and reliability. In fact, a difference of at least 15 km / h, preferably at least 20 km / h for at least 1 second allows a secondary fault P2 to be concluded. Such a monitoring strategy is particularly relevant when the traction motors 1-1A, 1-2A of said bogie A are in freewheel (safety). The difference in speed between the traction motors 1-1A, 1-2A thus results from a fault in a reducer 3-1A, 3-2A.

[0051] Advantageously, a secondary failure P2 is only monitored when the on-board sensors C1-1A, C2-1A of the first axle 2-1A are not operational POK. This makes it possible to avoid numerous false alarms, in particular, in the event of slippage.

[0052] If the auxiliary measurement AUX is compliant with CONF, we deduce that the reducer 3-1A is not in secondary failure N-P2. Conversely, if the auxiliary measurement AUX is not compliant with NCONF, we deduce a secondary failure P2 of the reducer 3-1 A.

[0053] Speed ​​measurements have been presented on one or more traction motors 1-1 A, 1-2A, but the same applies to one or more speed measurements of axles 2-1 A, 2-2A. Indeed, even if an axle 2-1A is no longer driven (freewheel), a loss of speed of the axle 2-1A is observed induced by friction exerted by the reducer 3-1A when it suffers a breakdown. Indeed, since the wheel / rail adhesion is relatively low, the forces exerted in a broken reducer 3-1A are sufficiently significant to generate speed losses of the axle 2-1A relative to the speed of the train (also called jamming).

[0054] In this example, on-board sensors C1-X, C2-X have been presented in the form of speed sensors but these could be in a different form. Preferably, two on-board sensors C1-X, C2-X are present on each 3-X reducer but it goes without saying that their number could be higher.

[0055] Advantageously, a primary failure PI of a 3-X reducer is detected in a reactive and relevant manner by on-board sensors C1-X, C2-X of said 3-X reducer. Thanks to the invention, in the event of failure of the on-board sensors C1-X, C2-X, AUX auxiliary measurements allow the detection of a secondary P2 failure of the 3-X reducer. The use of AUX auxiliary measurements, external to the 3-X reducer, reduces the risk of false positives while being reliable and discriminating. Such AUX auxiliary measurements are advantageously not impacted by an increase in the temperature of the 3-X reducer. This avoids the unwanted issuance of a critical alarm, which is beneficial for the railway operator.

Claims

Claims

1. Method for monitoring a failure of a reducer (3-1A) of a transmission line (L-1A) of a railway vehicle, the railway vehicle comprising at least one transmission line (L-1A) comprising an axle (2-1 A) and at least one traction motor (1-1 A) driving the axle (2-1A) via the reducer (3-1A), the reducer (3-1A) comprising at least two on-board sensors (C1-1A, C2-1A), the monitoring method comprising: • a step of checking (El) the operating state of the on-board sensors (C1-1A, C2-1A), • if the on-board sensors (C1-1A, C2-1A) are operational (OK), a step of monitoring (E2) a primary failure (PI) of the reducer (3-1 A) from the measurements of the on-board sensors (C1-1A, C2-1A) and • if the on-board sensors (C1-1A, C2-1A) are not operational (POK),a step of monitoring (E3) a secondary failure (P2) of the reducer (3-1 A) from at least one auxiliary measurement (AUX) external to the reducer (3-1 A).,

2. A monitoring method according to claim 1, wherein no monitoring of a secondary fault is performed when the on-board sensors (C1-1A, C2-1A) are operational.

3. Monitoring method according to one of claims 1 to 2, comprising, if the on-board sensors (C1-1A, C2-1A) are not operational (POK), a step of securing (E4) the transmission line (L-1A) so that the axle (2-1 A) is in freewheel mode.

4. Monitoring method according to one of claims 1 to 3, wherein at least one auxiliary measurement (AUX) is a speed measurement carried out on the transmission line (L-1A) outside the reducer (3-1A), preferably on the axle (2-1A) and / or on the traction motor (1-1A).

5. Monitoring method according to one of claims 1 to 4, wherein the railway vehicle comprising a bogie (A) comprising at least two transmission lines (L-1A, L-2A) each comprising an axle (2-1A, 2-2A) and at least one traction motor (1-1A, 1-2A) driving the axle (2-1A, 2-2A) via a reducer (3-1A, 3-2A), the method comprises, if the on-board sensors (C1-1A, C2-1A) are not operational (POK), a step of monitoring (E3) a secondary failure (P2) of the reducer (3-1 A) from speed measurements (AUX) of each transmission line, preferably of each traction motor (1-1 A, 1-2A).

6. Monitoring method according to the preceding claim, in which a secondary fault (P2) is issued if the difference between the two speeds is greater than a threshold of 15km / h, preferably 20km / h.

7. Monitoring method according to the preceding claim, in which a secondary fault (P2) is issued if the speed difference is greater than the threshold for a duration greater than 1 second.

8. Monitoring method according to one of claims 5 to 7, comprising, if the on-board sensors (C1-1A, C2-1A) of a reducer (3-1 A, 3-2A) are not operational (POK), a step of securing (E4) each transmission line (L-1A) so that each axle (2-1 A, 2-2A) is in freewheel mode.

9. Railway vehicle comprising at least one transmission line (L-1A) comprising an axle (2-1 A) and at least one traction motor (1-1A) driving the axle (2-1A) via the reducer (3-1 A), the reducer (3-1 A) comprising at least two on-board sensors (C1-1A, C2-1A), the railway vehicle comprising at least one computer (5A, 5B) configured to implement the steps of the method according to one of claims 1 to 8.

10. Rail vehicle according to claim 9 wherein the on-board sensors (C1-1A, C2-1A) are chosen from temperature sensors, speed sensors, acoustic sensors and oil level sensors.

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