Rotating containment enclosure for test bench
The test bench addresses safety and integration challenges by enabling rotational energy dissipation in the containment enclosure, using low-hardness materials to manage high-speed fragment impacts, enhancing safety and reducing mass.
Patent Information
- Application Number
- FR2023009653
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-09-13
- Publication Date
- 2025-08-15
- Estimated Expiration
- 2043-09-13
AI Technical Summary
Current test benches for turbomachine components face safety risks due to the removable containment enclosures, which are heavy and require high strength to withstand high-speed fragment impacts, conflicting with the need for reduced mass and integration into existing setups.
A test bench design featuring a sliding member between the containment enclosure and a retention element, allowing the enclosure to rotate relative to the retention element upon impact, reducing energy absorption as deformation and enhancing rotational energy dissipation, enabling the use of low-hardness materials like aluminum for the enclosure.
The design reduces the mass and volume of the containment enclosure, improving safety and ease of handling while preserving fracture surfaces, and allows for realistic testing conditions by simulating high-speed fragment impacts.
Smart Images
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Abstract
Description
Title of the invention: Rotating containment enclosure 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 of the rotating disks, by subjecting them to a rotation of increasing speed but also to high temperatures, similar to those of real operating conditions, until the disk bursts.The analysis being completed by a study of the disc fragments, it is therefore necessary to design a test bench resistant to the projection of heavy metal fragments at high speeds, while preserving the fracture surfaces of these fragments.
[0004] Current test benches for this type of application are thus equipped with a removable containment enclosure, made of a material capable of receiving fragments projected at high speed without excessively damaging them. Metals with low hardness are therefore preferred to allow the study of these fragments.
[0005] However, these structural and material constraints induce a risk for the safety of personnel and installations around the test bench. Indeed, the necessarily removable nature of such a containment enclosure requires an attempt to reduce its mass, while advances in the design of rotating parts impose increasingly high test speeds, which requires strengthening the containment enclosure, in particular by increasing its diameter. To these conflicting requirements are added to the imperative of integrating the enclosure into existing test benches. Statement of the invention
[0006] An aim of the present application is to remedy the aforementioned drawbacks.
[0007] For this purpose, according to a first aspect of the invention, a test bench is proposed. bursting of a turbomachine component, comprising:
[0008] - a shaft extending along an axis, the shaft being rotatable about the axis; the shaft being configured to rotate the component when the component is rotationally secured to the shaft;
[0009] - an annular confinement enclosure arranged coaxially with the shaft,
[0010] - an annular retention element arranged around the containment enclosure and coaxially with the shaft, the retention element being fixed relative to the shaft and the containment enclosure; the test bench comprising a sliding member between the containment enclosure and the retention element configured so as to promote rotation of the containment enclosure relative to the retention element when the containment enclosure is subjected to a torque generated by an impact of a fragment following a bursting of the rotating component in the containment enclosure during a test.
[0011] The test bench according to the invention is advantageously supplemented by the following characteristics, taken alone or in any of their technically possible combinations: - the sliding member is a bearing; - the bearing is a ball bearing, a needle bearing or a hydrodynamic bearing; - the sliding member is a lubricant; - the lubricant is a lubricating oil or grease; - the containment enclosure comprises aluminum; - an oven arranged inside the containment enclosure, the oven being configured to heat the component.
[0012] The invention also relates to a burst testing method for a turbomachine component of a test bench according to the invention, comprising the following steps:
[0013] - rotational securing of the component with the shaft;
[0014] - installation of the containment enclosure inside the retention element and around the shaft, in contact with a sliding member;
[0015] - rotating the component by the shaft until the component bursts;
[0016] - stopping the rotation of the shaft;
[0017] - extraction of the containment enclosure;
[0018] - harvesting fragments of the component resulting from the shattering of the component.
[0019] The method of testing a component is advantageously completed by the following steps, taken alone or in any of their technically possible combinations:
[0020] - placing the oven around the component;
[0021] - heating the oven.
[0022] Advantageously, the component is a turbomachine component, for example a turbomachine disk. DESCRIPTION OF FIGURES
[0023] 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:
[0024] [Fig.l] is a vertical sectional view of a test bench according to the invention;
[0025] [Fig.2] is a schematic horizontal sectional view of a test bench according to a embodiment of the invention;
[0026] [Fig. 3] is a schematic horizontal sectional view of a test bench according to a another embodiment of the invention;
[0027] [Fig.4] is a diagram showing the steps of a method for implementing the invention.
[0028] Throughout the figures, similar elements bear identical references. DETAILED DESCRIPTION OF THE INVENTION
[0029] A test bench aims to obtain the bursting of a component by subjecting it to one or more physical stresses of known amplitude, which are generally increased during the test. Given the significant amplitude of the stresses exerted in many cases, it is necessary to isolate the test bench by a containment enclosure capable of containing the fragments while allowing their analysis. The containment enclosure must therefore be capable of retaining the fragments without damaging the fracture surfaces.
[0030] 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 is conceivable. A shaft 2 configured to drive the component 1 in rotation is placed in the center of the test bench 0 and the component 1 is attached 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 a containment enclosure 3. The containment enclosure 3, generally in the form of a hollow cylinder, is removable and placed for the tests in the center of a retention element 4 of the same shape, so that an outer wall 31 of the containment enclosure confinement faces an inner wall 41 of the retention element 4.
[0031] Throughout the description, 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, inside) and external (respectively, outside), respectively, are used with reference to a radial direction such that the internal part or face of an element is closer to the axis A than the external part or face of the same element.
[0032] The retention element 4 is configured to stop any fragment of the component 1 which would not have been retained by the containment enclosure 3. This retention element 4 is preferably of the same shape and of a greater strength than the containment enclosure 3. For example, the retention element 4 may be a single piece or in several parts in the shape of a hollow cylinder or a ring, coaxial with the axis A and concentric with the containment enclosure 3 of the same shape, and made of materials of a harderness than those used in the containment enclosure 3.
[0033] The containment enclosure 3 is preferably in the form of a ring or a hollow cylinder. The outer wall 31 of the containment enclosure 3 faces the inner wall 41 of the retention element 4. Between the inner wall 41 and the outer wall 31 are placed one or more sliding members 6. The sliding members 6 are configured to reduce the friction between the inner wall 41 and the outer wall 31 so as to facilitate the rotation of the containment enclosure 3 relative to the axis A when a rotational torque is applied to it.
[0034] Indeed, following the bursting of the component 1, fragments of the component 1 are projected onto the retention enclosure 3 with a speed y. During the impact, the speed y is broken down into a radial speed, Vr, and a tangential speed Vt- The latter generates a rotational torque which tends to drive the retention enclosure 3 in rotation.
[0035] Indeed, the energy e of a disc fragment on impact is broken down as the sum of a deformation energy e of the confinement enclosure 3, energy resulting from the radial component of the velocity of the fragment and the rotational energy e of the confinement enclosure 3, energy resulting from the tangential component Vt of the velocity of the fragment y, i.e.:
[0036] ° ^deformation ^rotation
[0037] In a test bench 0 like those of the prior art, the rotational energy erotation is minimal, because the assembly of the confinement enclosure 3 is not designed so that it can be rotated relative to the retention element 4. Thus, it absorbs all the energy e of the impact of the fragment of the component in the form of deformation energy £ deformation*
[0038] The addition of a sliding member 6 allows better dissipation of the energy e by increasing the share of rotational energy erotation at the expense of the share of deformation energy edeformation. This energy is dissipated by the rotation of the entire containment enclosure 3 in the retention element 4 in the form of a rotational torque. It is therefore possible to use a containment enclosure 3 of reduced thickness and therefore mass to stop the projected fragments, which facilitates its handling and makes it possible to reduce the overall volume of the test bench 0, to reduce the time required to set up a test and to increase safety.
[0039] The addition of the sliding members 6 therefore makes it possible to design a containment enclosure 3 made of low-hardness materials, for example aluminum, in order to collect the fragments resulting from the bursting of the component 1 without damaging the fracture surfaces or compromising the safety of the test bench 0, while maintaining a reduced mass, since the containment enclosure 3 will absorb shocks more easily by being rotated during the impact of the fragments.
[0040] In a first illustrated embodiment [Fig.2], the inner wall 41 comprises one or more bearings 6a as sliding members 6. Each bearing 6a is fixedly attached to the inner wall 41 and comprises a movable part in contact with the outer wall 31 so as to allow one to slide over the other.
[0041] There is at least one bearing 6a, but a greater number, such as eight, facilitates the rotation of the containment enclosure 3. A greater number, such as several dozen bearings 6a, can be envisaged. Each bearing 6a may be a ball bearing, a roller bearing, a hydrodynamic bearing or any other suitable device.
[0042] In a second alternative embodiment illustrated [Fig. 3], the inner wall 41 is placed in direct contact, or for example at a distance of less than a centimeter, from the outer wall 31. The inner wall 41 comprises lubricant 6b as sliding member 6. The lubricant 6b may be, for example, a liquid, solid or pasty lubricant. Many oils, greases or any other compound allowing the outer wall 31 to slide on the inner wall 41 while reducing friction may be used.
[0043] On the other hand, in order to improve the realism of the tests carried out with the test bench 0, it is possible to integrate means for controlling the temperature of the test environment, for example an oven 5. Such an oven 5, arranged around the component 1, makes it possible, for example, to raise the temperature of the component 1 to simulate the real physical constraints to which the part is subjected in operation in a turbomachine. The oven 5 is for single use since it will inevitably be destroyed by the fragments of the component 1.
[0044] In certain existing test benches 0, the shaft 2, the furnace 5 and the component 1 are supported by a cover 7, movable in translation along the axis A to be positioned in height in order to facilitate the assembly of component 1, containment enclosure 3 and possibly furnace 5. Cover 7 is positioned lower during testing, in order to place component 1 in the area confined by containment enclosure 3.
[0045] A method of testing the bursting of a component 1 using the test bench 0 described above is described below in relation to [Fig. 4].
[0046] The implementation of the test bench 0 requires firstly carrying out a step E0 consisting of putting, if present, the cover 7 of the bench in the high position, then a step E1 of securing in rotation the component 1 with the shaft 2 then driving the shaft 2 in rotation. The next step is step E2 of placing the containment enclosure 3 in contact with the sliding member(s) 6, followed by a step of placing the cover 7 in the low position. The actual test can then begin with a step E5 consisting of rotating the component 1 by the rotation drive shaft 2, the rotation speed following a pre-established protocol, which generally includes a progressive acceleration of the speed of the shaft 2 until the component 1 bursts. A step E6 of stopping the rotation after the component 1 bursts and possibly lifting the cover 7 is followed by a step E7 of extracting the containment enclosure 3.During the final step E8, the fragments of test piece 1 contained in containment enclosure 3 are collected for examination.
[0047] If the test bench 0 comprises a furnace 5, it is necessary to place the furnace 5 around the component 1 during a step E3, then to heat it during a step E4 located before, simultaneously with or after the step E5 of rotating the component by the shaft 2. In this configuration, the temperature of the furnace 5 can be modified during the test, for example by gradually increasing it until the component 1 bursts, in order to test the thermal properties of the component 1.
Claims
Claims
1. Test bench (0) for bursting a turbomachine component (1), comprising: - a shaft (2) extending along an axis A, the shaft (2) being rotatable about the axis A; the shaft (2) being configured to rotate the component (1) when the component (1) is rotationally secured to the shaft (2); - an annular containment enclosure (3) arranged coaxially with the shaft (2), - an annular retention element (4) arranged around the containment enclosure (3) and coaxially with the shaft (2), the retention element (4) being fixed relative to the shaft (2) and the containment enclosure (3);the test bench (0) comprising a sliding member (6) between the containment enclosure (3) and the retention element (4) configured so as to promote a rotation of the containment enclosure (3) relative to the retention element (4) when the containment enclosure (3) is subjected to a torque generated by an impact of a fragment following a bursting of the component (1) rotating in the containment enclosure (3) during a test.;
2. Test bench (0) for bursting a turbomachine component (1) according to claim 1, in which the sliding member (6) is a bearing (6a).
3. Test bench (0) for bursting a turbomachine component (1) according to claim 2, in which the bearing (6a) is a ball bearing, a needle bearing or a hydrodynamic bearing.
4. Test bench (0) for bursting a turbomachine component (1) according to claim 1, in which the sliding member (6) is a lubricant (6b).
5. Test bench (0) for bursting a turbomachine component (1) according to claim 4, in which the lubricant (6b) is a lubricating oil or grease.
6. Test bench (0) for bursting a turbomachine component (1) according to one of claims 1 to 5, in which the containment enclosure (3) comprises aluminum.
7. Burst test bench for a turbomachine component (1) according to one of claims 1 to 6, comprising a furnace (5) arranged at inside the containment enclosure (3), the furnace (5) being configured to heat the component (1).
8. A burst test method for a turbomachine component (1) of a test bench (0) according to any one of claims 1 to 7, comprising the following steps: - E1 rotational securing of the component (1) with the shaft (2); - E2 positioning of the containment enclosure (3) inside the retention element (4) and around the shaft (2), in contact with a sliding member (6); - E5 rotation of the component (1) by the shaft (2) until the component (1) bursts; - E6 stopping the rotation of the shaft (2); - E7 extraction of the containment enclosure (3); - E8 collection of fragments of the component (1) resulting from the bursting of the component (1).
9. Burst testing method according to claim 8, comprising between steps E2 and E5, the following steps: - E3 placing the furnace (5) around the component (1); - E4 heating the furnace (5).
10. A burst test bench for a turbomachine component (1) according to any one of claims 1 to 7 or a burst test method according to claim 8 or 9, wherein the turbomachine component (1) is a turbomachine disc.