System and method for measuring a clearance between a rotating blade and a casing of a turbomachine

Abstract

System and method for measuring a clearance between a rotating blade and a casing of a turbomachine Measuring system (1) of a clearance between a rotating blade and a casing of a turbomachine, the measuring system (1) comprising a removable fixing device (7) provided with a locking mechanism for maintaining the mounted position of the measuring system (1) on the casing; a retractable stop mechanism (9) provided with a guide (11) and a finger (13) configured to maintain the rotating blade (3) in a measuring position; a remote acquisition device (15) configured to measure at least one clearance between the rotating blade and the casing when the removable fixing device (7) is in the mounted position and the retractable stop mechanism (9) in the deployed position; a plate (17) on which the removable fixing device (7), the retractable stop mechanism (9) and the remote acquisition device (15) are attached. Figure 1

Description

Title of the invention: System and method for measuring a clearance between a rotating blade and a casing of a turbomachine Field of invention

[0001] The present invention relates to a system for measuring a clearance between a rotating blade and a casing of a turbomachine. In particular, the measuring system is suitable for fan blades whose main function is to bring the incoming air to a certain compression level. Prior art

[0002] It is known to check the correct dimensioning of the clearance between a rotating blade and a casing to ensure the conformity of the turbomachine. Typically, for a fan blade, the clearance must correspond to the hundredth of a millimeter to the value planned during design.

[0003] Too much clearance can have a negative impact on engine operability and engine performance. Conversely, too little clearance creates risks of wear and mechanical contact between the rotating blade and the casing.

[0004] One possibility for measuring the correct dimensioning of the clearance is to use shims of known thicknesses which are manually slid between the rotating blade and the casing. This is satisfactory in that the correct dimensioning can be easily observed.

[0005] However, this type of measurement has drawbacks. For the operator responsible for carrying out the measurements, it can be long and tedious to insert the shim at the desired locations, as several blades at different time positions must be tested. The operator also has the constraint of limiting the friction of the shim so as not to damage the rotating blade or the casing.

[0006] This manual measurement also raises the question of the quality of the measurement because it is likely to fluctuate depending on the circumstances, in particular if the operator engages the shim beyond the axial measurement position. By axial, it is understood relative to the rotating axis of the turbomachine.

[0007] Thus, although it is possible to measure the clearance, there remains a problem of repeatability and reproducibility of the measurements.

[0008] The present invention aims to resolve all or part of the drawbacks mentioned above. Statement of the invention

[0009] To this end, the present invention relates to a system for measuring a clearance between a rotating blade and a casing of a turbomachine, the measuring system comprising:

[0010] a removable attachment device shaped to fit by form cooperation to a complementary location of the housing in a mounted position, the removable attachment device being provided with a locking mechanism for maintaining the mounted position of the measuring system on the housing,

[0011] a retractable stop mechanism provided with a guide and a finger adapted to be arranged relative to the guide in a deployed position in which the finger is configured to maintain the rotating blade in a measuring position,

[0012] a remote acquisition device configured to measure at least one clearance between the rotating blade and the casing when the removable fixing device is in the mounted position and the retractable stop mechanism in the deployed position,

[0013] a plate on which the removable fixing device, the retractable stop mechanism and the remote acquisition device are attached.

[0014] Thus, the measuring system is a specific tool with a device for remote acquisition of a measurement which can be removably fixed to the casing and lock the rotating blade in the measuring position.

[0015] For the operator, installation in the mounted position of the measuring system is easy and quick. Positioning the rotating blade is also simple to achieve since the measuring position is reached by stopping on the finger.

[0016] Furthermore, acquiring the measurement remotely eliminates the risk of scratches or damage to the rotating blade or the casing.

[0017] The positioning of the precise measuring system in two stages - mounted position then measuring position - ensures good reproducibility and repeatability of the clearance measurements.

[0018] According to one aspect of the invention, the remote acquisition device comprises at least one sensor configured to measure a clearance corresponding to a minimum distance between the rotating blade and the casing in a corresponding measurement plane of the sensor.

[0019] In other words, the sensor is configured to detect in the measurement plane a point on the rotating blade and a point on the casing having the smallest distance and then to measure this distance.

[0020] This type of measurement is advantageous because it is non-intrusive and avoids any scratching or damage to the rotating blade and / or the casing.

[0021] According to one aspect of the invention, the measuring system comprises at least one device for adjusting the relative position of the at least one sensor relative to the plate so as to define the positioning of the corresponding measuring plane of the sensor relative to the plate.

[0022] This arrangement contributes to the reliability of the measurement of the clearance by the sensor because the measurement plane can be precisely defined to correspond to the exact location desired measurement distance between the rotating blade and the casing.

[0023] According to one aspect of the invention, the at least one measuring plane is positioned so as to be transverse and in particular normal to the casing at the location of the measured clearance.

[0024] According to one aspect of the invention, the adjustment device comprises a support configured to receive the corresponding sensor, the support being provided with an adjustment pin whose movement makes it possible to modify the position of the sensor relative to the plate.

[0025] Preferably, the adjustment device comprises a clamping element for maintaining the relative position of the support with respect to the plate. In particular, the clamping element comprises two screws configured to cooperate with two corresponding threads of the support. The screws are configured to extend through at least one through opening of the plate to ensure the support is secured to the plate.

[0026] According to one aspect of the invention, the remote acquisition device comprises three sensors configured to measure three clearances corresponding to three minimum distances between the rotating blade and the casing in three corresponding measurement planes.

[0027] Three measuring planes are thus defined to measure three clearances at three different locations between the rotating blade and the casing. These three measurements are quick and reliable. Furthermore, no manipulation is required by the operator once the measuring system is in the mounted position and in the measuring position.

[0028] Each sensor is associated with a corresponding adjustment device of the measuring system. The sensors are arranged so that the three measuring planes are substantially parallel.

[0029] According to one aspect of the invention, the at least one sensor is a laser profilometer adapted to identify two distinct elements and to measure a length of a gap separating said two elements.

[0030] The measuring system is particularly effective by using one or more laser profilometers as a sensor. This type of sensor makes it possible to measure a length remotely by sending a laser beam and receiving a return from said laser beam.

[0031] According to one aspect of the invention, the finger is further adapted to be arranged relative to the guide in a retracted position in which the finger is outside the rotary path of the rotating blade when the measuring system is in the mounted position.

[0032] This arrangement makes it possible to carry out several clearance measurements on several rotating blades without having to move the measuring system from the mounted position. This represents a time saving for carrying out the measurements necessary for checking rotating blades.

[0033] According to one aspect of the invention, the retractable stop mechanism comprises a return element configured to automatically move the finger from the retracted position to the extended position.

[0034] Furthermore, the retractable stop mechanism comprises an actuating handle for manually moving the finger from the extended position to the retracted position. It is thus sufficient to pull the actuating handle when changing the rotating blade.

[0035] According to one aspect of the invention, the removable fixing device is a fixing flange adapted to be removably fixed to a receiving flange of the casing. In particular, the receiving flange is located at a lower location of the casing directly above an axis of rotation of the rotating blade.

[0036] This position corresponds to the six o'clock position.

[0037] Preferably, the fixing flange comprises two rods capable of engaging in two corresponding holes of the housing in the mounted position. Since only one location in the mounted position is provided, it is easy for the operator to arrange the measuring system in the mounted position.

[0038] The locking mechanism comprises two rotary levers capable of being arranged in a locked position for holding the fixing flange on the casing.

[0039] According to one aspect of the invention, the three measurement planes have a direction inclined relative to a vertical plane passing through the axis of rotation of the rotating blade.

[0040] This arrangement facilitates measurement since the rotating blade extends inclined relative to the axis of rotation. The three measuring planes are thus adapted to the measurement of three clearances along the rotating blade.

[0041] According to one aspect of the invention, the guide and the finger of the retractable stop mechanism also extend at an inclination substantially identical to that of the measuring planes relative to the axis of rotation. The measuring system is thus adapted to the inclined profile of the rotating blade.

[0042] According to one aspect of the invention, the plate extends in the mounted position along a mounting axis substantially parallel to the axis of rotation of the rotating blade. Preferably, the three sensors are oriented inclined relative to the mounting axis.

[0043] A recess in the plate allows at least one of the sensors to be mounted set back along the mounting axis so as to allow rotation of the rotating blade when the finger of the retractable stop mechanism is in the retracted position.

[0044] According to one aspect of the invention, the measurement system comprises a data analysis terminal, such as a computer on a mobile cart, and a transmission cable capable of connecting the remote acquisition device to the data analysis terminal.

[0045] Therefore, the raw data obtained by the sensors are processed so as to obtain the three sets per rotating blade and for several rotating blades.

[0046] The present invention also relates to an intermediate production assembly comprising a casing, a rotating wheel, preferably a fan blade, and a measuring system as described above.

[0047] The present invention also relates to a method for measuring at least one clearance between a rotating blade and a casing of a turbomachine, the rotating blade having an end surface facing an abradable material of the casing covering an interior part of the casing, the measuring method comprising the following steps:

[0048] have a measuring system as described above,

[0049] adapting by form cooperation to the complementary location of the casing the measuring system in the mounted position, then locking the removable fixing device in the mounted position on the casing with the locking mechanism,

[0050] moving the blading comprising the rotating blade around the axis of rotation of the blading relative to the casing to bring the rotating blade into abutment on a dedicated surface of the finger when the finger is in the deployed position so as to maintain the rotating blade in the measuring position,

[0051] measure at least one clearance between the rotating blade in the measuring position and the abradable material of the casing with the remote acquisition device.

[0052] According to one aspect of the invention, following the step of adaptation by shape cooperation, the following steps can be carried out optionally if necessary:

[0053] moving a blade around the rotation axis to bring the rotating blade into the measuring position or close to the measuring position, if necessary by placing the finger of the retractable stop mechanism in the retracted position,

[0054] arrange or ensure that the finger of the retractable stop mechanism is in the deployed position.

[0055] Preferably, following the measurement, the method comprises a step consisting of recording the at least one measurement of the at least one set in a memory of the measurement system.

[0056] Carrying out the measurement method is easy and consists of properly setting up the measurement system so that the remote acquisition device can accurately measure the at least one game.

[0057] The removable fixing device and the retractable stop mechanism make it possible in particular to obtain excellent reproducibility and repeatability of the measurements taken since the relative position of the casing, the rotating blade and the remote acquisition device are strictly identical at each installation and measurement with the measuring system.

[0058] In practice, the measuring method is quick to carry out by the operator responsible for measuring the at least one clearance and the results obtained are reliable.

[0059] According to one aspect of the invention, following the step of measuring at least one clearance between the rotating blade and the abradable material of the casing, the method comprises the following additional steps:

[0060] place the finger of the retractable stop mechanism in the retracted position, then,

[0061] moving the blade around the axis of rotation to bring an additional rotating blade into the measuring position or close to the measuring position,

[0062] place the finger of the retractable stop mechanism in the deployed position, then,

[0063] arranging the additional rotating blade in abutment on the dedicated surface of the finger when the finger is in the deployed position so as to maintain the additional rotating blade in the measuring position,

[0064] measuring at least one additional clearance between the additional rotating blade in the measuring position and the abradable material of the casing with the remote acquisition device,

[0065] recording the measurement of the at least one additional clearance on the memory of the measuring system.

[0066] Advantageously, the measuring system can remain in the mounted position when a measurement of at least one clearance must be carried out on an additional rotating blade.

[0067] It is sufficient to place the finger of the retractable stop mechanism in the retracted position to allow rotation of the blade and to place the additional rotating blade in the measuring position or close to the measuring position.

[0068] By the expression "in proximity", it is understood that the additional rotating blade is brought to a location allowing the deployment of the finger and then an additional rotation of the additional rotating blade makes it possible to bring the latter into abutment against the finger.

[0069] According to one aspect of the invention, the additional steps are repeated a number of times corresponding to a number of additional rotating blades to be measured.

[0070] According to one aspect of the invention, the measuring method comprises a prior step consisting of measuring relief disparities of an internal portion of the abradable material intended to be opposite the blading.

[0071] This arrangement makes it possible to know over 360° the irregularities of the internal portion of the abradable material. Indeed, it is preferable to know the recesses or bumps of the abradable material likely to modify the clearance between the rotating blade and the casing according to the clockwise position of the rotating blade.

[0072] According to one aspect of the invention, the measurement of the disparities is carried out by a regularity control device comprising a base capable of being mounted on a turbomachine rotor intended to receive the blading.

[0073] The assembly of the regularity control device is carried out in the absence of the blading, in particular before the assembly of the blading during manufacturing.

[0074] The regularity control device is thus able to move around the axis of rotation and further comprises at least one comparator intended to measure by contact a relief of the abradable material, the comparator being able to determine a dimension of the relief as well as an hourly position of the relief.

[0075] Preferably, the regularity control device comprises three comparators axially spaced along the axis of rotation.

[0076] According to one aspect of the invention, the measurements of the relief disparities are taken into account to determine, from the clearance measurements made by the measurement system, a real minimum clearance for each rotating blade concerned.

[0077] Preferably, a calculation-determined rotor deflection is also taken into account.

[0078] Thus, the measuring system and method presented above are advantageous in the sense that only one measurement at a six o'clock position is necessary to determine at least a minimum clearance of a rotating blade.

[0079] The different aspects defined above which are not incompatible can be combined. Brief description of the figures

[0080] The invention will be better understood with the aid of the detailed description which is set out below with reference to the appended drawings.

[0081] [Fig-1] is a top view of a measuring system.

[0082] [Fig.2] is a rear view of the measuring system.

[0083] [Fig.3] is a perspective view of the measuring system.

[0084] [Fig.4] is a rear perspective view of the measuring system mounted on a housing of turbomachine.

[0085] [Fig.5] is a detailed perspective view of the measuring system mounted on the housing and a blade comprising a rotating vane.

[0086] [Fig.6] is a schematic view of the measuring system and a portion of the tur machine including the casing and the blades.

[0087] [Fig.7] is a diagram representing the steps of a measurement process.

[0088] [Fig.8] is a side view of a regularity control device. Description with reference to figures

[0089] In the detailed description which follows of the figures defined above, the same elements or the elements fulfilling identical functions may retain the same references so as to simplify the understanding of the invention.

[0090] As illustrated in Figures 1 to 6, a system 1 for measuring a clearance between a rotating blade 3 and a casing 5 of a turbomachine comprises a removable fixing device 7 shaped to adapt by shape cooperation to a complementary location of the casing 5 in a mounted position.

[0091] The removable fixing device 7 is provided with a locking mechanism for maintaining the mounted position of the measuring system 1 on the housing 5.

[0092] The measuring system 1 comprises a retractable stop mechanism 9 provided with a guide 11 and a finger 13 capable of being arranged relative to the guide 11 in a deployed position in which the finger 13 is configured to hold the rotating blade 3 in a measuring position as illustrated in [Fig.5].

[0093] The measuring system 1 comprises a remote acquisition device 15 configured to measure at least one clearance between the rotating blade 3 and the casing 5 when the removable fixing device 7 is in the mounted position and the retractable stop mechanism 9 in the deployed position.

[0094] The measuring system 1 also comprises a plate 17 on which the removable fixing device 7, the retractable stop mechanism 9 and the remote acquisition device 15 are attached.

[0095] Thus, the measuring system 1 is a specific tool with a device 15 for remote acquisition of a measurement which can be removably fixed to the casing 5 and lock the rotating blade 3 in the measuring position.

[0096] The remote acquisition device 15 comprises at least one sensor 19 configured to measure a clearance corresponding to a minimum distance between the rotating blade 3 and the casing 5 in a corresponding measurement plane 21 of the sensor 19. Here, the remote acquisition device 15 comprises three sensors 19.

[0097] In other words, each sensor 19 is configured to detect in the corresponding measurement plane 21 a point on the rotating blade 3 and a point on the casing 5 having the smallest distance and then to measure this distance.

[0098] The measuring system 1 comprises, for each sensor 19, a corresponding adjustment device 23 for the relative position of the sensor 19 with respect to the plate 17 so as to define the positioning of the corresponding measuring plane 21 of the sensor 19 with respect to the plate 17.

[0099] As illustrated in [Fig.5], each measuring plane 21 is positioned so as to be transverse and in particular normal to the casing 5 at the location of the measured clearance.

[0100] Each adjustment device 23 comprises a support 25 configured to receive the corresponding sensor 19, the support 25 being provided with an adjustment pin 27 whose movement makes it possible to modify the position of the sensor 19 relative to the plate 17.

[0101] Each adjustment device 23 comprises a clamping element 29 for maintaining the relative position of the support 25 with respect to the plate 17. In particular, the clamping element 29 comprises two screws configured to cooperate with two corresponding threads of the support 25.

[0102] As illustrated in [Fig.5], the screws are configured to extend through at least one through opening 31 of the plate 17 to ensure the securing of the support 25 on the plate 17.

[0103] Here, the remote acquisition device 15 comprises three sensors 19 configured to measure three clearances corresponding to three minimum distances between the rotating blade 3 and the casing 5 in three corresponding measurement planes 21.

[0104] The sensors 19 are arranged so that the three measuring planes 21 are substantially parallel.

[0105] Each sensor 19 is a laser profilometer adapted to identify two distinct elements and to measure a length of a gap separating said two elements. This type of sensor makes it possible to measure a length remotely by sending a laser beam and receiving a return from said laser beam.

[0106] Regarding the retractable stop mechanism 9, the finger 13 is further capable of being arranged relative to the guide 11 in a retracted position in which the finger 13 is outside the rotary path of the rotating blade 3 when the measuring system 1 is in the mounted position.

[0107] The retractable stop mechanism 9 comprises a return element configured to automatically move the finger 13 from the retracted position to the deployed position.

[0108] Furthermore, the retractable stop mechanism 9 comprises an actuating handle 33 for manually moving the finger 13 from the deployed position to the retracted position. It is thus sufficient to pull the actuating handle 33 when changing the rotating blade 3.

[0109] The removable fixing device 7 is a fixing flange adapted to be fixed in a removably manner to a receiving flange of the casing 5. In particular, the receiving flange is located at a lower location of the casing 5 directly above an axis of rotation 35 of the rotating blade 3. This position corresponds to the six o'clock position.

[0110] The fixing flange comprises two rods 37 capable of engaging in two corresponding holes of the casing 5 in the mounted position. Since only one location in the mounted position is provided, it is easy for the operator to arrange the measuring system 1 in the mounted position.

[0111] The locking mechanism comprises two rotary levers 39 capable of being arranged in a locked position for holding the fixing flange on the casing 5.

[0112] The three measurement planes 21 have a direction inclined relative to a vertical plane passing through the axis of rotation 35 of the rotating blade 3. This arrangement facilitates the measurement since the rotating blade 3 extends in an inclined manner relative to the axis of rotation 35.

[0113] The guide 11 and the finger 13 of the retractable stop mechanism 9 also extend at an inclination substantially identical to that of the measuring planes 21 relative to the axis of rotation 35. The measuring system 1 is thus adapted to the inclined profile of the rotating blade 3.

[0114] The plate 17 extends in the mounted position along a mounting axis 41 substantially parallel to the axis of rotation 35 of the rotating blade 3. The three sensors 19 are oriented inclined relative to the mounting axis 41.

[0115] A recess 43 of the plate 17 makes it possible to mount one of the sensors 19 set back along the mounting axis 41 so as to allow rotation of the rotating blade 3 when the finger 13 of the retractable stop mechanism 9 is in the retracted position.

[0116] As illustrated in [Fig.6], the measurement system 1 comprises a data analysis terminal 45, such as a computer on a mobile cart, and a transmission cable 47 capable of connecting the remote acquisition device 15 to the data analysis terminal 45.

[0117] Consequently, the raw data obtained by the sensors 19 are processed so as to obtain the three sets per rotating blade 3 and for several rotating blades 3.

[0118] [Fig. 6] schematically represents an intermediate production assembly 49 comprising a casing 5, a rotating wheel, preferably a fan blade comprising a plurality of rotating blades 3, and a measuring system 1 as described above.

[0119] [Fig.7] represents a method for measuring at least one clearance between a rotating blade 3 and a casing 5 of a turbomachine, the rotating blade 3 having an end surface 51 facing an abradable material 53 of the casing 5 covering an interior part of the casing 5.

[0120] A step E1 consists of having a measuring system 1 as described above.

[0121] A step E2 consists of adapting by shape cooperation to the completed location housing 5 the measuring system 1 in the mounted position, then lock the removable fixing device 7 in the mounted position on the housing 5 with the locking mechanism.

[0122] A step E2', carried out optionally if necessary, consists of moving the blading around the rotation axis 35 to bring the rotating blade 3 into the measurement position or close to the measurement position, if necessary by placing the finger 13 of the retractable stop mechanism 9 in the retracted position.

[0123] A step E2”, carried out optionally if necessary, consists of arranging or ensuring that the finger 13 of the retractable stop mechanism 9 is in the deployed position.

[0124] A step E3 consists of moving the blading comprising the rotating blade 3 around an axis of rotation 35 of the blading relative to the casing 5 to bring the rotating blade 3 into abutment on a dedicated surface of the finger 13 when the finger 13 is in the deployed position so as to maintain the rotating blade 3 in the measurement position.

[0125] A step E4 consists of measuring at least one clearance between the rotating blade 3 in the measuring position and the abradable material 53 of the casing 5 with the remote acquisition device 15.

[0126] A step E4' consists of recording the at least one measurement of the at least one set on a memory of the measurement system 1. This memory is included in the data analysis terminal 45.

[0127] Following the step E4 of measuring at least one clearance between the rotating blade 3 and the abradable material 53 of the casing 5, the method may comprise the additional steps described below.

[0128] A step E5 consists of placing the finger 13 of the retractable stop mechanism 9 in the retracted position.

[0129] A step E6 then consists of moving the blading around the rotation axis 35 to bring an additional rotating blade 3' into the measurement position or close to the measurement position,

[0130] A step E7 consists of placing the finger 13 of the retractable stop mechanism 9 in the deployed position.

[0131] A step E8 consists of placing the additional rotating blade 3' in abutment on the dedicated surface of the finger 13 when the finger 13 is in the deployed position so as to maintain the additional rotating blade 3' in the measurement position.

[0132] A step E9 consists of measuring at least one additional clearance between the additional rotating blade 3' in the measurement position and the abradable material 53 of the casing 5 with the remote acquisition device 15.

[0133] A step E10 consists of recording the measurement of the at least one additional set in the memory of the measurement system 1.

[0134] Advantageously, the measuring system 1 can remain in the mounted position when a measurement of at least one clearance must be carried out on the additional rotating blade 3'.

[0135] It is sufficient to place the finger 13 of the retractable stop mechanism 9 in the retracted position to allow rotation of the blade and to place the additional rotating blade 3' in the measuring position or close to the measuring position.

[0136] By the expression "in proximity", it is understood that the additional rotating blade 3' is brought to a location allowing the deployment of the finger 13 then an additional rotation of the additional rotating blade 3' makes it possible to bring the latter into abutment against the finger 13.

[0137] The additional steps E5 to E10 are repeated a number of times corresponding to a number of additional rotating blades 3' to be measured.

[0138] Furthermore, the measurement method may also comprise a prior step E0 consisting of measuring relief disparities of an internal portion of the abradable material 53 intended to be opposite the blading.

[0139] This arrangement makes it possible to know over 360° the lack of regularity of the internal portion of the abradable material 53. Indeed, it is preferable to know the recesses or bumps of the abradable material 53 likely to modify the clearance between the rotating blade 3 and the casing 5 according to the clockwise position of the rotating blade 3.

[0140] As illustrated in [Fig.8], the measurement of the disparities is carried out by a regularity control device 55 comprising a base 57 capable of being mounted on a turbomachine rotor intended to receive the blading.

[0141] The assembly of the regularity control device 55 is carried out in the absence of the blading, in particular before the assembly of the blading during manufacture.

[0142] The regularity control device 55 is thus able to move around the rotation axis 35 and further comprises at least one comparator 59 intended to measure by contact a relief of the abradable material 53, the comparator 59 being able to determine a dimension of the relief as well as a time position of the relief.

[0143] Here, the regularity control device 55 comprises three comparators 59 axially spaced along the axis of rotation 35.

[0144] The measurements of the relief disparities are taken into account to determine, from the clearance measurements made by the measuring system 1, a real minimum clearance for each rotating blade 3 concerned.

[0145] Preferably, a calculation-determined rotor deflection is also taken into account.

[0146] Thus, the measuring system and method presented above are advantageous in the sense that only one measurement at a six o'clock position is necessary to determine at least a minimum clearance of a rotating blade 3.

[0147] For the operator, the installation in the mounted position of the measuring system 1 is easy and quick. The positioning of the rotating blade 3 is also simple to achieve since the measuring position is reached by stopping on the finger 13.

[0148] Furthermore, the acquisition of the remote measurement eliminates the risks of scratches or damage to the rotating blade 3 or the casing 5.

[0149] As goes without saying, the invention is not limited to the single embodiment described above as an example; on the contrary, it encompasses all variant embodiments.

Claims

Claims

1. A system (1) for measuring a clearance between a rotating blade (3) and a casing (5) of a turbomachine, the measuring system (1) comprising: - a removable fixing device (7) shaped to fit by shape cooperation to a complementary location of the casing (5) in a mounted position, the removable fixing device (7) being provided with a locking mechanism for maintaining the mounted position of the measuring system (1) on the casing (5), - a retractable stop mechanism (9) provided with a guide (11) and a finger (13) capable of being arranged relative to the guide (11) in a deployed position in which the finger (13) is configured to maintain the rotating blade (3) in a measuring position,- a remote acquisition device (15) configured to measure at least one clearance between the rotating blade (3) and the casing (5) when the removable fixing device (7) is in the mounted position and the retractable stop mechanism (9) in the deployed position, - a plate (17) on which the removable fixing device (7), the retractable stop mechanism (9) and the remote acquisition device (15) are attached.,

2. Measuring system (1) according to claim 1, wherein the remote acquisition device (15) comprises at least one sensor (19) configured to measure a clearance corresponding to a minimum distance between the rotating blade (3) and the casing (5) in a corresponding measuring plane (21) of the sensor (19).

3. Measuring system (1) according to claim 2, comprising at least one device (23) for adjusting the relative position of the at least one sensor (19) relative to the plate (17) so as to define the positioning of the corresponding measuring plane (21) of the sensor (19) relative to the plate (17).

4. Measuring system (1) according to one of claims 2 or 3, wherein the remote acquisition device (15) comprises three sensors (19) configured to measure three sets corresponding to three minimum distances between the rotating blade (3) and the casing (5) in three corresponding measuring planes (21).

5. Measuring system (1) according to one of claims 2 to 4, in which the at least one sensor (19) is a laser profilometer adapted to identify two distinct elements and to measure a length of a gap separating said two elements.

6. Measuring system (1) according to one of claims 1 to 5, wherein the finger (13) is further adapted to be arranged relative to the guide (11) in a retracted position in which the finger (13) is outside the rotary path of the rotating blade (3) when the measuring system (1) is in the mounted position.

7. Measuring system (1) according to one of claims 1 to 6, wherein the removable fixing device (7) is a fixing flange adapted to be fixed in a removably manner to a receiving flange of the housing (5).

8. Method for measuring at least one clearance between a rotating blade (3) and a casing (5) of a turbomachine, the rotating blade (3) having an end surface (51) facing an abradable material (53) of the casing (5) covering an inner part of the casing (5), the measuring method comprising the following steps: - (E1) providing a measuring system (1) according to one of claims 1 to 7, - (E2) adapting by shape cooperation to the complementary location of the casing (5) the measuring system (1) in the mounted position, then locking the removable fixing device (7) in the mounted position on the casing (5) with the locking mechanism,- (E3) moving the blading comprising the rotating blade (3) around the axis of rotation (35) of the blading relative to the casing (5) to bring the rotating blade (3) into abutment on a dedicated surface of the finger (13) when the finger (13) is in the deployed position so as to maintain the rotating blade (3) in the measurement position, - (E4) measuring at least one clearance between the rotating blade (3) in the measurement position and the abradable material (53) of the casing (5) with the remote acquisition device (15).,

9. A measuring method according to claim 8, wherein, following step measuring (E4) at least one clearance between the rotating blade (3) and the abradable material (53) of the casing (5), the method comprises the following additional steps: - (E5) placing the finger (13) of the retractable stop mechanism (9) in the retracted position, then, - (E6) moving the blade around the axis of rotation (35) to bring an additional rotating blade (3') into the measuring position or close to the measuring position, - (E7) placing the finger (13) of the retractable stop mechanism (9) in the deployed position, then, - (E8) placing the additional rotating blade (3') in abutment on the dedicated surface of the finger (13) when the finger (13) is in the deployed position so as to maintain the additional rotating blade (3') in the measuring position, - (E9) measuring at least one additional clearance between the additional rotating blade (3') in the measuring position and the abradable material (53) of the casing (5) with the remote acquisition device (15),- (E10) record the measurement of at least one additional set in the memory of the measuring system (1).,

10. Measuring method according to one of claims 8 or 9, comprising a prior step (E0) consisting of measuring relief disparities of an internal portion of the abradable material (53) intended to be opposite the blading.

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