Self-retracting thermocouple for test bench

Abstract

The present invention relates to a test bench (0) for bursting a turbomachine component (1), comprising: - a tank (3) in which a shaft (2) extending along an axis A is rotatably mounted, the shaft (2) being configured to rotate the component (1) when the component (1) is secured in rotation to the shaft (2); - a sensor (7) for measuring a physical parameter of the component (1) intended to be in contact with the component (1), - a device (9) for moving the sensor (7) connected to the sensor (7) and configured so that when the shaft (2) is rotated, the device (9) for moving the sensor (7) moves the sensor (7) so that it is no longer in contact with the component (1). Figure for abstract: Fig. 4

Description

Title of the invention: Self-retracting thermocouple for test bench Technical field

[0001] The present application relates to the control of the conformity of rotating mechanical parts, in particular rotating parts constituting a turbomachine. It relates more specifically to a test bench for such control. STATE OF THE ART

[0002] Checking the conformity of mechanical parts to specifications requires the use of test benches allowing the parts to be subjected to mechanical and physical stresses generally much higher than those of normal operating conditions.

[0003] For example, in the aeronautical field, the design of turbomachines requires increasingly precise prediction of the service life of the parts that compose them. The overspeed resistance of rotating parts of turbines, such as disks, is an important step in the design of new engines. Furthermore, the regulations require the demonstration during tests on a test bench that the parts in question do not burst under the effect of centrifugal loading, and this for speeds generally at least 20% higher than normal operating conditions. These tests aim to evaluate a burst speed and temperature of the rotating disks, by subjecting them to a rotation of increasing speed and to high temperatures, similar to those of real operating conditions, until the disk bursts.

[0004] To achieve these temperatures, the test benches include an integrated oven, which must be calibrated during a static test procedure (without rotation of the disc), using contact thermocouples. The contact thermocouples, placed in contact with the disc, record its temperature but must be removed for the rotation test. Proximity thermocouples are used during the static tests for calibration as well as during the rotation test. However, because of the temperatures required to reproduce real tests, the cooling times of the test bench, which must be respected to safely remove the contact thermocouples, are of the order of several hours. In addition, once the thermocouples have been removed, it is necessary to restore the test temperature inside the test bench, which again represents a significant duration.These delays considerably extend the duration of the tests and the two heating cycles generate substantial energy consumption. Statement of the invention

[0005] An aim of the present application is to remedy the aforementioned drawbacks.

[0006] For this purpose, according to a first aspect of the invention, a test bench is proposed bursting of a turbomachine component, comprising:

[0007] - a tank in which a shaft extending along an axis A is mounted in rotation, the shaft being configured to rotate the component when the component is rotationally secured to the shaft;

[0008] - a sensor for measuring a physical parameter of the component intended to be in contact with the component,

[0009] - a sensor moving device connected to the sensor and configured so that at the rotating the shaft, the sensor displacement device moves the sensor so that it is no longer in contact with the component.

[0010] The test bench according to the invention is advantageously supplemented by the following characteristics, taken alone or in any of their technically possible combinations: - according to a first aspect of the invention, the sensor displacement device comprises:

[0011] - a cable having a first end wound around the shaft, the cable being connected to the sensor, the cable supporting at its second end opposite the first end a counterweight;

[0012] - an arm connected to the tank, the arm supporting a pulley arranged along the arm of so as to define a path for the cable in the tank from its first end to its second end;

[0013] - the test bench being configured so that the rotation of the shaft causes unwinding of the cable from the shaft, the cable being driven by the counterweight which then moves the sensor so that it is no longer in contact with the component;

[0014] - according to a second aspect of the invention, the device for moving the sensor includes:

[0015] - a cable having a first end wound around the shaft, the cable being connected at its second end to a holding element, the holding element being configured to hold the sensor in position;

[0016] - a counterweight connected to the cable between its first and second ends;

[0017] - an arm connected to the tank, the arm supporting at least one pulley arranged along the arm so as to define a path for the cable in the tank from its first end to its second end; the test bench being configured so that rotation of the shaft causes the cable to unwind from the shaft, the cable being driven by the counterweight driving the holding element and thus moving the sensor so that it is no longer in contact with the component;

[0018] - according to a third aspect of the invention, the device for moving the sensor includes:

[0019] - an actuator connected to the sensor and configured to move the sensor;

[0020] - a member for transmitting the rotational movement of the shaft, the member transmission being fixed to the tank by an arm and configured to transmit the rotational movement of the shaft to the actuator;

[0021] the test bench being configured so that when the shaft is rotated, the actuator actuated by the movement transmission member moves the sensor so that it is no longer in contact with the component;

[0022] thus, according to advantageous and non-limiting characteristics:

[0023] - the member for transmitting the rotational movement of the shaft comprises a dynamoelectric machine configured to generate electrical energy from the rotational movement of the shaft and electrical cables connecting the dynamoelectric machine to the actuator;

[0024] -the actuator comprises an electric cylinder carried by the arm and configured to spread the sensor when powered by the electric cables, the test bench being configured so that when the shaft is rotated, the electric cylinder actuated by the electric cables powered by the dynamoelectric machine moves the sensor so that it is no longer in contact with the component;

[0025] - the member for transmitting the rotational movement of the shaft comprises a compressor configured to pressurize a gas from the rotational movement of the shaft and gas lines connecting the compressor to the actuator,

[0026] - the actuator comprises a pneumatic cylinder carried by the arm and configured to moving the sensor away when it is subjected to the pressurized gases contained by the gas lines, the test bench being configured so that when the shaft is rotated, the pneumatic cylinder actuated by the gases from the gas lines pressurized by the compressor, moves the sensor so that it is no longer in contact with the component.

[0027] - the movement transmission member comprises a belt connected to the shaft and driving a pinion;

[0028] - the actuator comprises a rack configured to be driven in rotation by the pinion, one end of the rack being configured to move the sensor, the test bench being configured so that when the shaft is rotated, the pinion driven in rotation by the belt drives the rack in translation and moves the sensor so that it is no longer in contact with the component;

[0029] - the movement transmission member comprises a belt connected to the shaft and rotating a threaded rod,

[0030] - the actuator comprises a nut configured to be driven in translation by the threaded rod and carrying the sensor, the test bench being configured so that when the shaft is rotated, the threaded rod driven in rotation by the belt drives the nut in translation and moves the sensor so that it is no longer in contact with the component;

[0031] - the turbomachine component is a turbomachine disk.

[0032] The invention also relates to a method for testing a component in a test bench according to the invention, comprising the following steps:

[0033] - securing the rotating component relative to the shaft;

[0034] - placing the oven around the component;

[0035] - heating the oven;

[0036] - rotating the component by the shaft;

[0037] - moving the sensor so as to stop the contact between the sensor and the component.

[0038] - stopping the rotation of the shaft after the component bursts; DESCRIPTION OF FIGURES

[0039] Other characteristics, aims and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting, and which must be read in conjunction with the appended drawings in which:

[0040] [Fig.l] is a vertical sectional view of a prior art test bench;

[0041] [Fig.2] is a graph of temperature versus time during the static and dynamic test procedures of a prior art test bench;

[0042] [Fig. 3] is a graph of temperature versus time during static and dynamic test procedures of a test bench according to one embodiment of the invention;

[0043] [Fig.4] is a vertical sectional view of a test bench during a static test procedure according to a first embodiment of the invention;

[0044] [Fig.5] is a vertical sectional view of a test bench during a dynamic test procedure according to a first embodiment of the invention;

[0045] [Fig.6] is a vertical sectional view of a test bench during a static test procedure according to a second embodiment of the invention;

[0046] [Fig.7] is a vertical sectional view of a test bench during a dynamic test procedure according to a second embodiment of the invention;

[0047] [Fig.8] is a vertical sectional view of a test bench during a static test procedure according to a third embodiment of the invention;

[0048] [Fig.9] is a vertical sectional view of a test bench during a dynamic test procedure according to a third embodiment of the invention;

[0049] [Fig. 10] is a vertical sectional view of a test bench during a static test procedure according to a fourth and a fifth embodiment of the invention;

[0050] [Fig. 11] is a vertical sectional view of a test bench during a dynamic test procedure according to a fourth and a fifth embodiment of the invention;

[0051] [Fig. 12] is a vertical sectional view of a test bench during a static test procedure according to a sixth embodiment of the invention;

[0052] [Fig. 13] is a vertical sectional view of a test bench during a dynamic test procedure according to a sixth embodiment of the invention;

[0053] [Fig. 14] is a vertical sectional view of a test bench during a static test procedure according to a seventh embodiment of the invention;

[0054] [Fig. 15] is a vertical sectional view of a test bench during a dynamic test procedure according to a seventh embodiment of the invention;

[0055] [Fig. 16] is a diagram showing the steps of a method for implementing an embodiment of the invention.

[0056] Throughout the figures, similar elements bear identical references. DETAILED DESCRIPTION OF THE INVENTION

[0057] In the following, as illustrated in [Fig.l], we are more particularly in the context of a burst test bench 0 in which the component 1 is a turbomachine disk, but any other component 1 is conceivable. A shaft 2 configured to rotate the component 1 is placed in the center of the test bench 0 and the component 1 is attached thereto by means adapted so that its center is aligned with the axis of rotation A of the shaft 2. The shaft 2 and the component 1 are surrounded by an inductive or radiative furnace 8. The shaft 2, the component 1 and the furnace 8 are contained in a tank 3 isolating the test bench 0 from its environment.

[0058] The axial direction corresponds to the direction of the axis A and a radial direction is a direction perpendicular to this axis and passing through it. Furthermore, the circumferential (or lateral) direction corresponds to a direction perpendicular to the axis A and not passing through it. Unless otherwise specified, internal (respectively, interior) and external (respectively, exterior), respectively, are used in reference to a radial direction so that the inner part or face of an element is closer to the axis A than the outer part or face of the same element.

[0059] One or more sensors 7 are placed inside the tank 3, in order to measure one or more physical parameters of the component 1. Some sensors, for example contact thermocouples, must be moved away. To move such a sensor away when the dynamic test begins, the invention proposes a device 9 for moving the sensor 7 which is automatically actuated at the start of the dynamic test, that is to say that when the shaft 2 is rotated, the device 9 for moving the sensor 7 moves the sensor 7 so that the sensor 7 is no longer in contact with the component 1. Preferably, such sensors 7 are flexible probes, spherical in shape or in the shape of a pin formed by two wires.

[0060] First embodiment

[0061] In a first embodiment illustrated in [Fig.4], the sensor 7 is placed in a bore of the component 1, the bore being an axial cylindrical recess in the center of the component 1, that is to say aligned with the axis A. The displacement device 9 of the sensor 7 comprises a cable 4, a first end of which is wound around the shaft 2 and a second is linked to a counterweight 60. The cable 4 is resistant to high temperatures, of the order of several hundred degrees at least. The winding around the shaft 2 of the cable 4 is carried out in such a way that the first end is stationary as long as the shaft 2 is not rotating. On the contrary, rotating the shaft 2 unwinds the cable 4 and releases the first end. The sensor 7, mounted on an arm which can freely pivot or translate from one end fixed to the bottom of the tank 3, or which has its own flexibility, is connected to the cable 4 between the first and second ends.An arm 50 fixed to a wall of the tank 3 supports at least one pulley 51 arranged so as to define a path for the cable 4 in the tank 3 from its first end to its second end, that is to say that the pulley(s) 51 hold the cable 4 in a position where it immobilizes the sensor 7 in contact with the component 1 under the effect of the tension induced by the counterweight 60. The arm 50 is for example a mechanically welded structure.

[0062] Thus, as illustrated in [Fig.5], the rotation of the shaft 2 causes the cable 4 to unwind which, driven by the counterweight 60, moves the sensor 7 along an axis imposed by the arm 50 and the pulley(s) 51 so that the sensor 7 is no longer in contact with the component 1. The length of the cable 4 is judiciously chosen, in particular between the second end linked to the counterweight 60 and the part linked to the sensor 7, so that once the cable 4 is untied from the shaft 2 the sensor 7 is placed, under the effect of the weight of the counterweight 60, at a sufficient distance from the component 1.

[0063] Second embodiment

[0064] A second embodiment of the device 9 for moving the sensor 7, illustrated in Figures 6 and 7, is similar to the first embodiment and comprises the same elements arranged for the same purpose, except that the sensor 7 is not placed in a bore of the component 1 and that one end of the sensor 7 is fixed on an inner wall of the tank 3, so that it extends radially towards the component 1 and that the cable 4 wound around the shaft 2 exerts an axial tension under the effect of the weight of the counterweight 60. This arrangement simplifies the arrangement of the arm 50 and the pulleys 51.

[0065] Alternatively, if the mass of the sensor 7 allows it, it is possible to remove the counterweight 60, the sensor 7 moving away from the component 1 under the effect of its own weight when the tension exerted by the cable 4 ceases when the shaft 2 begins to rotate, in a manner analogous to the first embodiment.

[0066] Third embodiment

[0067] A third embodiment of the device 9 for moving the sensor 7, illustrated in Figures 8 and 9, is similar to the first embodiment and comprises the same elements, except that the sensor 7 is placed on a support 62 and held in a fixed position by a holding element 61. The cable 4 is connected by a first end to the shaft 2 in a manner similar to the previous embodiments and a counterweight 60 is attached along the length of the cable 4. The holding element 61 is connected by a second end of the cable 4 to the counterweight 60. As long as the shaft 2 is stationary, the cable 4, guided by an arm 50 and pulleys 51, supports the weight of the counterweight 60. When the rotation of the shaft 2 unties the cable 4, the counterweight 60 exerts a force on the holding element 61, which moves to move the sensor 7 into a position without contact with the component 1.

[0068] The holding element 61 is for example a pin configured to be driven out by the traction of the counterweight 60, the traction axis being produced by the arm 50 and the pulleys 51.

[0069] Alternatively, two cables may be used, a first wound at one end around the shaft 2 and linked at the other end to the counterweight 60 and a second linked at one end to the counterweight 60 and at the other end to the holding element 61.

[0070] In the embodiments which follow, with reference to figures 10 to 15, the device 9 for moving the sensor 7 can be broken down on the one hand into an actuator 6 connected to the sensor 7 and configured to move the sensor 7, and on the other hand into a transmission member 5 for the rotational movement of the shaft 2, the transmission member 5 being fixed to the tank 3 by an arm 52 and configured to transmit the rotational movement of the shaft 2 to the actuator 6.

[0071] Fourth and fifth embodiments

[0072] Thus, as illustrated by figures 10 and 11, the transmission member 5 of the rotational movement of the shaft 2 is in a fourth embodiment a dynamoelectric machine 42 configured to generate electrical energy from the rotational movement of the shaft 2 associated with electric cables 53 connecting the dynamoelectric machine 42 to the actuator 6. The actuator 6 is an electric jack 63 carried by the arm 52 which, when it is powered by the electric cables 53, that is to say when the shaft 2 is rotating, extends and thus moves the sensor 7.

[0073] Alternatively, in a fifth embodiment, the transmission member 5 is a compressor 43 driven by the shaft 2 and associated with gas pipes 54 connected to the actuator 6. The rotation of the shaft 2 causes the gas pipes 54 to be pressurized, which extends a pneumatic cylinder 64 of the actuator 6. The pneumatic cylinder 64 carried by the arm 52 thus moves the sensor 7 away from the component 1.

[0074] Sixth embodiment

[0075] In a sixth embodiment of the device 9 for moving the sensor 7, illustrated in [Fig. 12] and 13, the member 5 for transmitting the rotational movement of the shaft 2 is an assembly comprising a belt 44, the internal face of which is in contact with the shaft 2 and a wheel 45, thus transmitting the rotational movement of the axis 2 to the wheel 45. The wheel 45 drives a pinion 54 in rotation via a shaft 55. The pinion 54 drives the actuator 6 in translation, which preferably comprises a rack 65.

[0076] Seventh embodiment

[0077] In a seventh embodiment of the device 9 for moving the sensor 7, illustrated in figures 14 and 15, the member 5 for transmitting the rotational movement of the shaft 2 is an assembly comprising a belt 44, the internal face of which is in contact with the shaft 2 and a wheel 45, thus transmitting the rotational movement of the axis 2 to the wheel 45. The wheel 45 is driven in rotation by means of a threaded rod 56. The threaded rod 56 drives the actuator 6 in translation, which is a nut 66 on which the sensor 7 is mounted.

[0078] Of course, any other transmission member 5 capable of transmitting the rotational movement of the shaft 2 can be adapted to move the actuator 6. Similarly, the actuator 6 can be any other means capable of moving the sensor 7. The counterweight 60 can be a spring stretched from the frame.

[0079] Method

[0080] The invention also relates to a method for testing a component 1 in a test bench 0. A step of securing (step E1) the component 1 in rotation with respect to the shaft 2 is first carried out, before the installation (step E2) of the furnace 8 around the component 1. The furnace 8 is then heated (step E3). Then, the shaft 2 and consequently the component 1 are set in rotation (step E4), which triggers, thanks to the displacement device 9 of the sensor 7 according to one of the embodiments previously described, the movement of the sensor 7 and stops the contact with the component 1 (step E5). The test then continues until the rotation of the shaft 2 stops after the bursting of the component 1 (step E6).

[0081] A test bench 0 comprising a device 9 for moving the sensor 7 according to one of the preceding embodiments allows a shorter test procedure requiring less handling, since no opening of the bench is necessary to remove the sensors 7 in contact with the component 1, which increases the safety of the user. In addition, a long step of cooling the oven 8 then a second step of heating the oven 8 once the sensors 7 have been removed are saved, and therefore a significant energy expenditure is avoided. With reference to [Fig. 2], which shows the evolution of the temperature acquired by a sensor 7 in a bench of the state of the art, a first peak is observed corresponding to the static test procedure during which a temperature setpoint 100 is applied while measurements at the contact 101 and in the vicinity 102 of the component 1 are carried out.Then, the dynamic test procedure requires the removal of the sensor(s) 7, which requires cooling of the test bench. In comparison, in [Fig. 3], the test bench 0 according to the invention allowing the automatic movement of the sensor 7 (step E5) when the shaft 2 is rotated (step E4), the static and dynamic test procedures take place successively, without reducing the temperature. The test bench 0 according to the invention is therefore more energy-efficient and allows faster tests than current test benches. In addition, the displacement device 9 of the sensor 7 uses a minimal fraction of the rotational torque of the shaft 2 and is therefore easily and at a lower energy cost integrated into a test bench 0.

Claims

Claims

1. Test bench (0) for bursting a turbomachine component (1), comprising a tank (3) in which a shaft (2) extending along an axis A is rotatably mounted, the shaft (2) being configured to rotate the component (1) when the component (1) is secured in rotation to the shaft (2), characterized in that it further comprises: - a sensor (7) for measuring a physical parameter of the component (1) intended to be in contact with the component (1), - a device (9) for moving the sensor (7) connected to the sensor (7) and configured so that when the shaft (2) is rotated, the device (9) for moving the sensor (7) moves the sensor (7) so that it is no longer in contact with the component (1).

2. Test bench (0) according to claim 1, wherein the device (9) for moving the sensor (7) comprises: - a cable (4) having a first end wound around the shaft (2), the cable (4) being connected to the sensor (7), the cable (4) supporting at its second end opposite the first end a counterweight (60); - an arm (50) connected to the tank (3), the arm (50) supporting a pulley (51) arranged along the arm (50) so as to define a path for the cable (4) in the tank (3) from its first end to its second end; - the test bench being configured so that the rotation of the shaft (2) causes the cable (4) to unwind from the shaft (2), the cable (4) being driven by the counterweight (60) which then moves the sensor (7) so that it is no longer in contact with the component (1).

3. Test bench (0) according to claim 1, wherein the device (9) for moving the sensor (7) comprises: - a cable (4) having a first end wound around the shaft (2), the cable (4) being connected at its second end to a holding element (61), the holding element (61) being configured to hold the sensor (7) in position; - a counterweight (60) connected to the cable (4) between its first and second ends; - an arm (50) connected to the tank (3), the arm (50) supporting at least one pulley (51) arranged along the arm (50) so as to define a path for the cable (4) in the tank (3) from its first end to its second end; the test bench being configured so that rotating the shaft (2) causes the cable (4) to unwind from the shaft (2), the cable (4) being driven by the counterweight (60) driving the holding element (61) and thus moving the sensor (7) so that it is no longer in contact with the component (1).

4. Test bench (0) according to claim 1, wherein the device (9) for moving the sensor (1) comprises: - an actuator (6) connected to the sensor (7) and configured to move the sensor (7); - a member (5) for transmitting the rotational movement of the shaft (2), the transmission member (5) being fixed to the tank (3) by an arm (52) and configured to transmit the rotational movement of the shaft (2) to the actuator (6); the test bench being configured so that when the shaft (2) is rotated, the actuator (6) actuated by the movement transmission member (5) moves the sensor (7) so that it is no longer in contact with the component (1).

5. Test bench (0) for bursting a component (1) according to claim 4, wherein: - the transmission member (5) of the rotational movement of the shaft (2) comprises a dynamoelectric machine (42) configured to generate electrical energy from the rotational movement of the shaft (2) and the electrical cables (53) connecting the dynamoelectric machine (42) to the actuator (6); - the actuator (6) comprises an electric cylinder (63) carried by the arm (52) and configured to move the sensor (7) apart when it is powered by the electrical cables (53), the test bench being configured so that when the shaft (2) is rotated, the electric cylinder (63) actuated by the electrical cables (53) powered by the dynamoelectric machine (42), moves the sensor (7) so that it is no longer in contact with the component (1).

6. Test bench (0) for bursting a component (1) according to claim 4, in which: - the transmission member (5) of the rotational movement of the shaft (2) comprises a compressor (43) configured to pressurize a gas from the rotational movement of the shaft (2) and gas lines (54) connecting the compressor (43) to the actuator (6), - the actuator (6) comprises a pneumatic cylinder (64) carried by the arm (52) and configured to move the sensor (7) away when it is subjected to the pressurized gases contained by the gas lines (54), the test bench being configured so that when the shaft (2) is rotated, the pneumatic cylinder (64) actuated by the gases from the gas lines (54) pressurized by the compressor (43), moves the sensor (7) so that it is no longer in contact with the component (1).

7. Test bench (0) for bursting a component (1) according to claim 4, wherein: - the movement transmission member (5) comprises a belt (44) connected to the shaft (2) and driving a pinion (54); - the actuator (6) comprises a rack (65) configured to be driven in rotation by the pinion (54), one end of the rack (65) being configured to move the sensor (7), the test bench being configured so that when the shaft (2) is rotated, the pinion (54) driven in rotation by the belt (44) drives the rack (65) in translation and moves the sensor (7) so that it is no longer in contact with the component (1).

8. Test bench (0) for bursting a component (1) according to claim 4, wherein: - the movement transmission member (5) comprises a belt (44) connected to the shaft (2) and rotating a threaded rod (56), - the actuator (6) comprises a nut (66) configured to be driven in translation by the threaded rod (56) and carrying the sensor (7), the test bench being configured so that when the shaft (2) is rotated, the threaded rod (56) driven in rotation by the belt (44) drives the nut (66) in translation and moves the sensor (7) so that it is no longer in contact with the component (1).

9. Method for testing a component (1) in a test bench (0) according to any one of claims 1 to 8, comprising the following steps: - securing (El) the component (1) in rotation relative to the shaft (2); - rotating (E4) the component (1) by the shaft (2);

10. - movement (E5) of the sensor (7) so as to stop the contact between the sensor (7) and the component (1). - stopping the rotation (E6) of the shaft (2) after the component (1) bursts; Test bench (0) for bursting a component (1) according to any one of claims 1 to 8, in which the turbomachine component (1) is a turbomachine disk.

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