Apparatus for measuring an aircraft turbine engine shaft

Abstract

The invention relates to an apparatus (22) for measuring a turbine engine shaft (10), which comprises: - a device (20) for measuring dimensions; - a first support member (12) capable of supporting a first longitudinal end (10a) of a shaft (10), and comprising a member (22) for rotating the shaft (10) about a horizontal axis (X); - a second support member (14) capable of supporting a second longitudinal end (10b) of the shaft (10), opposite the first end (10a), this first support member (12) comprising first rollers (26) for guiding the shaft (10) in rotation about the horizontal axis (X); and - a system (32) for adjusting the height of the shaft (10) on the first support member (12), along a vertical axis (Y), this adjustment system (32) being connected to the measurement device (20), which is able to detect a position of the shaft (10) along the vertical axis (Y).

Description

[0001] DESCRIPTION

[0002] TITLE: MEASURING INSTALLATION FOR AN AIRCRAFT TURBOMACHINE SHAFT

[0003] Technical field of the invention

[0004] The present invention relates in particular to a measuring installation for a turbomachine shaft, especially for aircraft.

[0005] Technical background

[0006] The prior art documents JP-B2-3 083 058 and EP-B1-3 317 631 are known.

[0007] A turbomachine shaft, particularly in aircraft, is a mechanical component that generally transmits rotational torque. It is therefore a rotor element designed to rotate around an axis. For example, a low-pressure shaft connects the rotor of a low-pressure compressor to the rotor of a low-pressure turbine. Similarly, a high-pressure shaft connects the rotor of a high-pressure compressor to the rotor of a high-pressure turbine.

[0008] A turbomachine shaft has a generally elongated shape along its axis of rotation and is tubular. The shaft is formed from a single piece and can be relatively long, on the order of 2 meters for example.

[0009] It is important that a turbomachine shaft be free of defects, particularly dimensional or geometric ones. Therefore, after manufacturing, a shaft undergoes a series of measurements to verify, among other things, its cylindricity and concentricity. These measurements are performed using a coordinate measuring machine (CMM). To allow measurement of the shaft's interior, it is proposed to position it horizontally and leave the interior of its two axial ends free so that a sensor can be inserted into the shaft at these ends. The shaft is then positioned on a fixture with two supports capable of holding its two longitudinal ends.

[0010] The quality of the tree measurements depends, in particular, on the accuracy of the tree's positioning within the measurement device's reference frame. It is therefore important that the tree be positioned as precisely as possible so that the device can perform measurements with high accuracy.

[0011] The invention provides a simple, effective and economical solution to this need.

[0012] Summary of the invention

[0013] The invention relates to a measuring installation for a turbomachine shaft, particularly for aircraft, comprising:

[0014] - a device for measuring dimensions,

[0015] - a first support capable of supporting a first longitudinal end of a shaft, this first support comprising a drive element for rotating the shaft around a horizontal axis,

[0016] - a second support capable of supporting a second longitudinal end of the shaft, opposite to said first end, this first support comprising first rollers for guiding the rotation of the shaft around the horizontal axis, and

[0017] - a system for adjusting the height of the shaft on the first support, along a vertical axis, this adjustment system being connected to a measuring device capable of detecting the shaft's position along the vertical axis. The installation thus proposes using one of the installation's supports to adjust the shaft's position. The distinctive feature of the invention lies in the fact that the measuring device, even before measuring the shaft, is used to detect the shaft's position and to adjust the shaft's position accordingly. The installation according to the invention may include one or more of the following features, taken individually or in combination:

[0018] - the first support includes a fixed base carrying two second rotating rollers on which the shaft is able to rest;

[0019] - one of the said second rollers is a guide roller for the shaft, and the other of the said second rollers is a drive roller for rotating the shaft;

[0020] - the fixed base also carries a third rotating roller which is suitable for being applied with a certain pressure on the shaft, this third roller having an axis of rotation which is located in a vertical plane passing through the horizontal axis and between the two second rollers;

[0021] - said adjustment system is located on the first support;

[0022] -- said adjustment system includes a display screen showing the position of the shaft along the vertical axis;

[0023] - said second support includes at least one axial stop capable of cooperating with the second end of the shaft in order to axially position the shaft on the second support;

[0024] -- said axial stop is formed by a ring mounted freely to rotate around a vertical axis, this ring having an external cylindrical bearing surface on the second end of the shaft;

[0025] - said second support includes a tachometer system capable of cooperating with the shaft to measure the number of revolutions made by the shaft around the horizontal axis;

[0026] - the tachometer system includes a U-shaped fork which defines an opening in which the shaft is intended to be housed and rotate;

[0027] - the ring and the U-shaped fork are fixed to a reference part, this reference part being removably mounted on the second support and being specific to a shaft reference;

[0028] -- the first and second supports are fixed on the same reference frame;

[0029] - the measuring device is a Three-Dimensional Measuring Machine. The present invention also relates to an assembly comprising an installation as described above, and a turbomachine shaft, in particular of an aircraft, the shaft being formed of a single tubular piece and comprising a first longitudinal end bearing on the first support, and a second longitudinal end, opposite said first end, bearing on the second support.

[0030] The assembly according to the invention may comprise one or more of the following features, taken individually or in combination with each other:

[0031] -- the second end has a frustoconical shape and includes a radially external annular flange,

[0032] -- the tree has a length measured along the horizontal axis, greater than 1 meter.

[0033] Brief description of the figures

[0034] Other features and advantages will become apparent from the following description of a non-limiting embodiment of the invention with reference to the accompanying drawings in which:

[0035] [Fig. 1] Figure 1 is a perspective view of an installation according to the invention for measuring a turbomachine shaft, in particular an aircraft shaft, [Fig. 2] Figure 2 is a highly simplified view of the installation of Figure 1, [Fig. 3] Figure 3 is a schematic view of a step in measuring a shaft, [Fig. 4] Figure 4 is a larger-scale view of part of the installation of Figure 1, and shows a first support for a first end of the shaft,

[0036] [Fig. 5] Figure 5 is a schematic perspective view of the first support of the installation in Figure 1.

[0037] [Fig. 6] Figure 6 is a larger-scale view of part of the installation in Figure 1, and shows an intermediate support for a middle section of the tree. [Fig. 7] Figure 7 is a larger-scale view of part of the installation in Figure 1, and shows a second support for a second end of the tree.

[0038] [Fig.8] Figure 8 is a schematic perspective view of the second support of the installation in Figure 1.

[0039] [Fig.9] Figure 9 is a larger scale view of part of the second support and the second end of the tree.

[0040] Detailed description of the invention

[0041] Figure 1 shows a shaft 10 of a turbomachine, in particular of an aircraft, placed on supports 12, 14, 16 of an installation 22 according to the invention.

[0042] Tree 10 has an elongated shape along an X-axis, which is shown here horizontally. Tree 10 is tubular and formed from a single piece. It can be longer than 1 meter, or even 2 meters for example.

[0043] In the example shown, installation 22 includes three supports 12, 14, 16 but it could include only two.

[0044] A first support 12 is suitable for supporting a first longitudinal end 10a of the shaft 10.

[0045] A second support 14 is suitable for supporting a second longitudinal end 10b of the shaft 10. The two ends 10a and 10b are opposite.

[0046] An optional intermediate support 16 is located between the first and second supports 12 and 14 and is suitable for supporting a mid-section 10c of the shaft 10. It is important that the shaft 10 be perfectly positioned on the supports 12, 14, and 16 so that the shaft 10 is aligned with the X-axis along its entire length. This means that any cross-section of the shaft 10 along its X-axis must have its center located on the X-axis.

[0047] This position of the shaft 10 is important when its dimensions are measured after manufacturing. The shaft 10 undergoes a series of measurements to verify, in particular, its cylindricity and concentricity. Figure 2 schematically shows a shaft 10 in axial section, this shaft 10 having an internal axial bore 18 that opens at both ends 10a, 10b of the shaft 10.

[0048] In the example shown, the second end 10b of the shaft 10 has a frustoconical shape and includes a radially external annular flange 10b1.

[0049] Figure 3 shows that a measuring device 20, for example of the CMM type, is used to measure dimensions of the shaft 10. In the example shown, the device 20 includes at least one sensor or probe which is engaged in the bore 18 and which takes measurements from inside the shaft 10.

[0050] The measuring device 20 can also measure the external diameter of the shaft 10 at a particular position along the X-axis and then determine the precise position of the center of this diameter in a vertical position. The position of the center can be measured relative to the ground, in a vertical direction, or relative to the X-axis, for example.

[0051] Advantageously, this measurement is carried out at both ends 10a, 10b of the tree 10 so as to define reference points A and B (figure 2).

[0052] Point A is located at the end 10a. At this point A, the external diameter Dext_A of the shaft 10 is measured, as well as the position or height of the center CA of this diameter.

[0053] Point B is located at the end 10b. At this point B, the external diameter Dext_B of the shaft 10 is measured, as well as the position or height of the center CB of this diameter.

[0054] The positions of the centers CA and CB allow us to define the exact position of the X axis which passes through these centers CA, CB.

[0055] The supports 12, 14, 16 and the measuring device 20 are part of a measuring installation 22, one embodiment of which is shown in figures 1 and 4 and following.

[0056] According to the invention, the measuring installation 22 further comprises a system 32 for adjusting the height of the shaft 10 on the first support 12, along a vertical axis Y1. The adjustment system 32 is connected to the measuring device 20 which is capable of detecting a position of the shaft 10 along the vertical axis Y1.

[0057] The first support 12 is more clearly visible in figures 4 and 5.

[0058] The first support 12 of the measuring installation 22 is suitable for supporting the first longitudinal end 10a of the shaft 10.

[0059] The first support 12 includes a drive element 24 (such as an electric motor) for rotating the shaft 10 around the X axis.

[0060] In the example shown, the first support 12 includes a fixed base 26 carrying two rotating rollers 28 on which the shaft 10, and in particular its end 10a, is able to bear.

[0061] One of these rollers 28a is a guide roller for the shaft 10, and the other of these rollers 28b is a drive roller for rotating the shaft 10. The roller 28b is then connected to the component 28. For example, the output shaft of the component 28 can directly drive the roller 28b in rotation.

[0062] The base 26 can also support a third rotating roller 28c, which is capable of being applied with a certain pressure to the shaft 10. In the example, this third roller 28c has a rotation axis Z1 located in a vertical plane passing through the horizontal axis X and between the two rollers 28a and 28b. The roller 28c is applied to the shaft by a mechanism 30 with an articulated arm located on one side of the shaft 10.

[0063] The aforementioned adjustment system 32 is preferably located on the first support 12. This adjustment system 32 may include a display screen 34 showing the position of the shaft 10 along the vertical axis Y1.

[0064] The intermediate support 16 is more clearly visible in figure 6.

[0065] The intermediate support 16 is located between the first and second supports 12, 14 and is suitable for supporting the middle part 10c of the shaft 10. The intermediate support 16 has rollers 36 for guiding the rotation of the shaft 10 around the X axis. These second rollers 36 are preferably mounted to rotate freely around axes parallel to the X axis.

[0066] The intermediate support 16 may include a system 38 for adjusting the height of the second rollers 36 so that they are more or less close to and pressed against the middle part 10c of the shaft 10.

[0067] In the example shown, the intermediate support 16 comprises:

[0068] - a fixed 40 base, and

[0069] - an element 42 which carries the second rollers 36 and which is movable relative to the base 40 along a vertical axis Y2.

[0070] The adjustment system 38 may include a lever 42 which allows the element 42 and therefore the rollers 36 to be moved along the vertical axis Y2 between a high position and a low position (figure 6), and vice versa.

[0071] In the example shown, the lever 42 is able to pivot in a vertical plane passing through the vertical axis Y. It is articulated on a horizontal axis Z2 carried by the base 40.

[0072] The second support 14 is more clearly visible in figures 7 to 9.

[0073] The second support 14 is suitable for supporting the second longitudinal end 10b of the shaft 10 and this second support includes rollers 43 for guiding the shaft 10 in rotation around the X axis. These rollers 43 are preferably mounted free to rotate around axes parallel to the X axis.

[0074] The second support 14 preferably includes at least one axial stop 46 capable of cooperating with the second end 10b of the shaft 10 in order to axially position the shaft 10 on the second support.

[0075] This axial stop 44 can be formed by a ring 44a mounted to rotate freely about a vertical axis Y3. This ring 44a has an external cylindrical bearing surface on the second end 10b of the shaft 10, and in particular on one side of its flange 10b1. The second support 14 can include a tachometer system 46 adapted to cooperate with the shaft 10 to measure the number of revolutions made by the shaft 10 about the horizontal axis X.

[0076] In the example shown, the tachometer system 46 includes a U-shaped fork 48 which defines an opening 48a in which the shaft 10 is intended to be housed and rotate. In particular, it is the flange 10b1 of the shaft 10 which has its periphery which is able to rotate in the opening 48 of the fork 48.

[0077] The tachometer system 46 can be either magnetic or electromagnetic. A magnet 49 is then fixed to the shaft 10, specifically to the side of its flange 10b1. The system 46 is then able to detect the passage of the magnet 49 each time through the opening 48 of the fork 48, and thus to count the number of revolutions made by the shaft 10.

[0078] The ring 44a and the fork 48 are preferably fixed on a reference part 50. This reference part 50 is removably mounted on the second support 14 and is specific to a shaft reference.

[0079] There are several tree references, and installation 22 is capable of accommodating these different references. Tree references may differ from one another in one or more characteristics, such as dimensions, material, etc.

[0080] It is therefore understood that shafts with the same reference number are theoretically identical from a dimensional and material standpoint. A single turbomachine can have several shaft reference numbers, such as, for example, a low-pressure shaft and a high-pressure shaft.

[0081] According to the invention, for each shaft reference there is associated a reference part 50 which may differ from the other reference parts for example by the position of the ring 44a and the fork 50, their respective dimensions, etc.

[0082] The second support 14 may include a system 52 for adjusting the position of the reference part 50, for example along an axis Z3 parallel to the horizontal axis X. Figures 1, 4, 6 and 7 further show that the supports 12, 14, 16 are preferably fixed on the same reference frame 54. This reference frame 54 may be a "surface plate" which determines a positioning reference for the supports 12, 14, 16 and the installation 22 as a whole.

[0083] The reference frame 54 may include at least one first flat and horizontal reference surface 54a on which the supports 12, 14, 16 bear in the vertical direction. All the supports 12, 14, 16 are preferably supported on a single surface 54a.

[0084] The reference frame 54 may include a second flat, vertical reference surface 54b on which the supports 12, 14, 16 bear in the horizontal direction. Preferably, all supports 12, 14, 16 bear on a single surface 54b.

[0085] The supports 12, 16 can have fixed respective positions on the reference frame 44. On the contrary, the support 14 can be mounted movable along the X axis on the reference frame, for example by means of a rail-slide system 56 (figures 1 and 7).

[0086] The second support 14, and in particular the tachometer system 46, can be connected to the first support 12 and in particular to its adjustment system 32 by an electrical cable 58. The adjustment system 32 can then form a common console for commanding and controlling all the functions of the installation 22, including those of the measuring device 20.

Claims

DEMANDS 1. Measuring installation (22) for a shaft (10) of a turbomachine, in particular an aircraft, comprising: - a dimension measuring device (20), - a first support (12) capable of supporting a first longitudinal end (10a) of a shaft (10), this first support (12) comprising a drive element (22) for rotating the shaft (10) around a horizontal axis (X), - a second support (14) capable of supporting a second longitudinal end (10b) of the shaft (10), opposite said first end (10a), this second support (12) comprising first rollers (26) for guiding the rotation of the shaft (10) around the horizontal axis (X), and - a system (32) for adjusting the height of the shaft (10) on the first support (12), along a vertical axis (Y), this adjustment system (32) being connected to the measuring device (20) which is capable of detecting a position of the shaft (10) along the vertical axis (Y).

2. Installation (22) according to claim 1, wherein the first support (12) comprises a fixed base (26) carrying two second rotating rollers (28) on which the shaft (10) is able to bear.

3. Installation (22) according to claim 2, wherein one of said second rollers (28a) is a guide roller for the shaft (10), and the other of said second rollers (28b) is a drive roller for rotating the shaft (10).

4. Installation (22) according to claim 2 or 3, wherein the fixed base (26) further carries a third rotating roller (28c) which is suitable for being applied with a certain pressure on the shaft (10), this third roller (28c) having an axis of rotation (Z) which is located in a vertical plane passing through the horizontal axis (X) and between the two second rollers (28).

5. Installation (22) according to any one of the preceding claims, wherein said adjustment system (32) is located on the first support (12).

6. Installation (22) according to any one of the preceding claims, wherein said second support (14) comprises at least one axial stop (44) capable of cooperating with the second end of the shaft (10) in order to axially position the shaft (10) on the second support (14).

7. Installation (22) according to any one of the preceding claims, wherein said second support (14) includes a tachometer system (46) capable of cooperating with the shaft (10) to measure the number of revolutions made by the shaft (10) around the horizontal axis (X).

8. Installation (22) according to claim 7, wherein the tachometer system (46) includes a U-shaped fork (48) which defines an opening (48a) in which the shaft (10) is intended to be housed and rotated.

9. Installation (22) according to claim 8, wherein the U-shaped fork (48) is fixed on a reference piece (50), this reference piece (50) being removably mounted on the second support (14) and being specific to a shaft reference.

10. Installation (22) according to any one of the preceding claims, wherein the measuring device (20) is a Three-Dimensional Measuring Machine.

11. Assembly comprising an installation (22) according to any one of the preceding claims, and a turbomachine shaft (10), in particular an aircraft shaft, the shaft (10) being formed of a single tubular piece and comprising a first longitudinal end (10a) bearing on the first support (12), and a second longitudinal end (10b), opposite said first end (10a), bearing on the second support (14).

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