This application claims priority to French Patent Application No. 1454790, filed May 27, 2014, the entire content of which is incorporated herein by reference in its entirety.
The technical field of the invention is generally that of aircraft engines, and more particularly that of cooling of different elements, in particular low pressure turbine casings, of the engines considered.
To ensure cooling of some low pressure turbine casings, a cooling device is provided which involves a set of cooling tubes provided outside the casing, most often by surrounding the casing, such that air is sent towards the outer face of the casing considered. The cooling tubes are typically fed by several housings, and for example by two housings or four housings. In the case where the cooling tubes are fed by two housings, the latter are typically provided on either side of the casing considered, such that each housing feeds cooling tubes surrounding the casing considered with air on about one quarter of its side circumference. This is called herein an LPTCC (Low Pressure Turbine Clearance Control) type system. The LPTCC system may be controlled by the FADEC (Full Authority Digital Engine Control); this is called herein an active control, the system then being designated by the acronym LPTACC. When it is not controlled by the FADEC, this is called here a passive control for the LPTCC system. Its main function is to regulate the low pressure turbine clearance by modulating the air flow rate taken off from the bypass flow for cooling the low pressure turbine casing.
Cooling tubes, and in particular those of LPTCC systems, are secured via feed housings with the outer face of the casing they cool. Besides, it is desirable to ensure a proper positioning of the cooling tubes acting on the casing, in particular at the farthest places of the feed housings; to that end, it is provided in the state of the art the use of an attachment metal sheet which consists of a flat metal sheet under which collars are attached, the collars surrounding the cooling tubes, enabling the tubes to be held in position.
a shows a first perspective view of a cooling device 1 for a turbojet casing according to the state of the art.
b shows a second perspective view of the cooling device 1 for a turbojet casing according to the state of the art.
a schematically illustrates an example of proper positioning of a cooling tube 3 of the cooling device 1 for a turbojet casing, with respect to the turbojet casing 2. In this example:
b schematically illustrates a first example of improper positioning of the cooling tube 3 with respect to the turbojet casing 2, wherein the cooling tube 3 is in contact with the casing 2.
An aspect of the present invention relates to a holding device of a cooling tube for a turbojet casing, or several cooling tubes for a turbojet casing.
An aspect of the invention offers a solution to the previously discussed problems, by providing in particular a holding device of a cooling tube for a turbojet casing, the holding device enabling possible axial or side misalignments of the cooling tube with respect to the turbojet engine to be reduced.
An aspect of the invention relates to a holding device of a cooling tube for a turbojet casing, the holding device including:
In the present description, the turbojet casing typically having a casing body and at least one side rim, by “the first plate is arranged in integral contact with the turbojet casing”, it is meant that a not inconsiderable part of the first plate is in contact with the casing body, and the first plate is fixed with respect to the casing. By “not inconsiderable part”, it is meant more than one third of the first plate.
The holding device according to an aspect of the invention beneficially includes, with respect to the state of the art, a restricted number of links, which enables the accumulation of tolerances related to each link to be minimized. Thanks to the first and second spacers of the holding device according to an aspect of the invention, the positioning of the cooling tube with respect to the casing is beneficially controlled and optimized: the first and second spacers define the gap between the first and second plates and allow an optimum tightening, without damaging the cooling tube. The holding device according to an aspect of the invention enables in particular possible axial or radial misalignments of the cooling tube with respect to the casing to be avoided, and thus a compact system to be obtained while ensuring the absence of contact between the cooling tube and the turbojet casing.
Besides the characteristics just discussed in the previous paragraph, the holding device according to an embodiment of the invention may have one or more further characteristics from the following ones, considered alone or according to all the technically possible combinations:
Another aspect of the invention relates to a cooling device for a turbojet casing including:
The cooling device according to an embodiment of the invention may in particular have the following further characteristic:
Another aspect of the invention relates to a turbojet casing including a cooling device according to an aspect of the invention.
The cooling device according to an embodiment of the invention may in particular have the following further characteristic:
The invention and its different applications will be better understood upon reading the description that follows and upon examining the accompanying figures.
The figures are presented by way of indicating and in no way limiting purposes of the invention.
a shows a first perspective view of a cooling device for a turbojet casing according to the state of the art.
b shows a second perspective view of the cooling device for a turbojet casing of figure la.
a schematically illustrates an example of proper positioning of a cooling tube of a cooling device for a turbojet casing, with respect to a turbojet casing.
b, 2c and 2d schematically illustrate first, second and third examples of improper positioning of the cooling tube of
a schematically illustrates a perspective view of a holding device of a cooling tube for a turbojet casing according to a first exemplary embodiment of the invention.
b schematically illustrates a cross section view of the holding device of
c schematically illustrates a cross section view of a spacer of the holding device of
d schematically illustrates a cross section view of the spacer of the holding device of
a schematically illustrates a partial perspective view of the holding device of
b schematically illustrates a second partial perspective view of the holding device of
a schematically illustrates a partial perspective view of a holding device of a cooling tube for a turbojet casing according to a second exemplary embodiment of the invention.
b schematically illustrates a second partial perspective view of the device of
a schematically illustrates a perspective view of a holding device of a cooling tube for a turbojet casing according to a third exemplary embodiment of the invention.
b schematically illustrates a second perspective view of the holding device of
a schematically illustrates a perspective view of a turbojet casing including the holding device of a cooling tube of
b schematically illustrates a second perspective view of the turbojet casing of
c schematically illustrates a third perspective view of the turbojet casing of
d schematically illustrates a fourth perspective view of the turbojet casing of
Unless otherwise specified, a same element appearing on different figures has a single reference.
a and 1b on the one hand, and 2a to 2d on the other hand, have been previously described.
a schematically illustrates a perspective view of a holding device 10 of a cooling tube for a turbojet casing according to a first exemplary embodiment of the invention.
a and 3b are described together and show in particular:
Since the casing 20 has a body 21 and a side rim 22, the first plate PL1 is in particular in contact with the body 21 of the casing 20. In the example represented in
b illustrates in particular the first exemplary embodiment, wherein the holding device 10 further includes:
The first connecting device t1L1 of the first type is a controlled tightening element, which passes through the first plate PL1 on the one hand, and at least one part of the first spacer EN1 on the other hand. The second connecting device t1L2 of the first type is a controlled tightening element, which passes through the first plate on the one hand, and at least one part of the second spacer EN2 on the other hand.
In the first exemplary embodiment illustrated in
In the first exemplary embodiment illustrated in
The first connecting device t2L1 of the second type is a controlled tightening element, which passes through the second plate on the one hand, and at least one part of the first spacer EN1 on the other hand. The second connecting device t2L2 of the second type is a controlled tightening element, which passes through the second plate on the one hand, and at least one part of the second spacer EN2 on the other hand.
In the first exemplary embodiment which is particularly represented in
It is noted that in the case where all the cooling tubes have the same diameter, the spacing between two consecutive spacers is constant, irrespective of the pair of consecutive spacers considered.
The following alternatives of the first exemplary embodiment just described in connection with
c schematically illustrates a cross section view of the second spacer EN2 of the holding device 10 according to the first exemplary embodiment, with a first mounting type. According to this first mounting type, the connecting device of the first type of each spacer is snugly fitted to the spacer. Alternatively, the second connecting device of the second type of each spacer may be snugly fitted to the spacer. According to another alternative, for each spacer, the connecting device of the first type and the connecting device of the second type may be snugly fitted to the spacer. The first mounting type with a snug fit enables a stop to be made, along the radial direction Rad, of each connecting device of the first type and/or of the second type. In the particular case of the first mounting type illustrated in
The single fastener includes:
The head TE is partly in contact with the casing 20. The first part Ti1 of the rod Ti passes through the casing 20, the first plate PL1 and a first part of the second spacer EN2. The fitted strut FU enables a tightening to be exerted at the second spacer EN2. The second part Ti2 of the rod Ti passes through a second part of the second spacer EN2, as well as the second plate PL2. The second part Ti2 of the rod Ti is at least partly threaded for screwing the nut EC. The nut EC is partly in contact with the second plate PL2.
d schematically illustrates a cross section view of the second spacer EN2 of the holding device 10 according to the first exemplary embodiment of the invention, with a second mounting type. According to this second mounting type, a circlip AN is arranged at each connecting device of the first type. Alternatively, a circlip may be arranged at each connecting device of the second type. According to another alternative, a circlip may be arranged at each connecting device of the first type and at each connecting device of the second type. The second mounting type with a circlip enables a stop to be made, along the radial direction Rad, of each connecting device of the first type and/or the second type.
In the particular case of the second mounting type illustrated in
More generally, the second plate PL2 has a plurality of oblong holes TO1 to TO(n+1) for mounting the plurality of spacers EN1 to EN(n+1) of the holding device 10.
The oblong holes enable mounting the connecting devices of the second type to be facilitated, by allowing different mounting angles for the connecting devices of the second type.
a schematically illustrates a partial perspective view of the cooling device including the holding device 10 according to the first exemplary embodiment of the invention.
a and 5b are described together.
a shows in particular that, according to the first exemplary embodiment:
According to one alternative of the first exemplary embodiment, the first plate PL1 includes the first runner RG1, or the second plate PL2 includes the second runner RG2.
It will be appreciated that, in the case where the cooling device includes a plurality n of cooling tubes TU1 to TUn, the holding device 10 according to the first exemplary embodiment of the invention is such that:
a and 5b show in particular that the cooling device of the turbojet casing 20 includes, according to a first mode of the first exemplary embodiment, a sheath GA suitable for dampening the contact between the cooling tube TU1 on the one hand, and the first and second plates PL1 and PL2 on the other hand, the sheath GA surrounding a part of the cooling tube TU1.
In the first mode, the sheath GA enables wear of the cooling tube TU1 to be restricted. Indeed, the sheath GA enables a direct contact between the cooling tube TU1 and the first and second plates PL1 and PL2 to be avoided. The sheath GA also enables wear of the first and second plates PL1 and PL2 to be restricted. The material of the sheath GA is indeed selected such that during a contact or friction between the sheath GA and the first and second plates PL1 and PL2, it is the sheath GA that wears out, preserving the first and second plates PL1 and PL2. Finally, the sheath GA enables a possible movement of the cooling tube TU1 to be restricted or slowed down.
In the case where the cooling device includes a plurality of cooling tubes, the cooling device includes a dampening sheath GA for each cooling tube of the plurality of cooling tubes.
In the first mode of the first exemplary embodiment which is particularly represented in
In this particular case, the dampening sheath GA is in contact with the first runner RG1 of the first plate PL1 on the one hand, and with the second runner RG2 of the second plate PL2 on the other hand.
a schematically illustrates a partial perspective view of a cooling device including a holding device 11 according to a second mode of the first exemplary embodiment of the invention.
a and 6b show in particular that the holding device 11 according to the second mode of the first exemplary embodiment includes a pad suitable for dampening the contact between the cooling tube TU1 on the one hand, and the first plate PL1 and/or the second plate PL2 on the other hand. To do this, the pad comprises:
In the second mode of the first exemplary embodiment which is particularly illustrated in
In this particular case, the first part TA1 of the dampening pad is arranged in the first runner RG1 of the first plate PL1, and the second part TA2 of the dampening pad is arranged in the second runner RG2 of the second plate PL2.
The first and second modes may be combined into a third mode, wherein the holding device includes the dampening pad TA and the cooling device includes the dampening sheath GA.
According to a fourth embodiment of the first exemplary embodiment, the holding device may be without a dampening pad, and the cooling device may be at the same time without a dampening sheath.
A holding device according to a second embodiment will now be described, wherein the first and second plates PL1 and PL2 do not include a positioning runner. This second exemplary embodiment corresponds to a simplified and economical operation, and is in particular compatible with the first, second, third and fourth modes which have been previously described in connection with the first exemplary embodiment.
a schematically illustrates a perspective view of a holding device 12 of a cooling tube for a turbojet casing according to a third exemplary embodiment of the invention.
According to the third exemplary embodiment represented in
The first side tab OL1 including the first positioning pin PO1, and the second side tab OL2 including the second positioning pin PO2 enable positioning of the first plate PL1 on the casing 20 to be facilitated and improved.
a schematically illustrates a perspective view of the turbojet casing 20, equipped with the cooling device including the holding device 12 according to the third exemplary embodiment of the invention.
a to 8d thus show the casing 20, to which is mounted the cooling device, including the cooling tube TU1 and the holding device 12 of the cooling tube TU1 according to the third exemplary embodiment of the invention. In the particular case illustrated herein, the first plate PL1 includes:
The casing 20 includes in turn:
Number | Date | Country | Kind |
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1454790 | May 2014 | FR | national |