Patent Application
20190112946
The present disclosure relates to a communication passage for a gas turbine engine and, more particularly, to a service tube with an annular airflow passage.
Gas turbine engines, such as those that power modern commercial and military aircraft, generally include a compressor section to pressurize an airflow, a combustor section to burn a hydrocarbon fuel in the presence of the pressurized air, and a turbine section to extract energy from the resultant combustion gases.
A Mid Turbine Frame (MTF), sometimes referred to as an inter-turbine frame, is located generally between a high pressure turbine stage and a low pressure turbine stage to support one or more bearings, and to transfer bearing loads to an outer engine case structure.
The MTF typically includes a plurality of hollow vanes arranged in a ring-vane-ring structure. The rings define inner and outer boundaries of a core flow path while the vanes are disposed across the flow path. Struts extend through the hollow vanes to interconnect an engine mount ring and a bearing compartment. Both oil and buffer air are supplied to the bearing compartments for the bearings, seals, and buffer air systems through a multiple of conduits, lines, and other passages within one or more of the hollow struts.
A service tube for a gas turbine engine according to one disclosed non-limiting embodiment of the present disclosure includes an entry end fitting; an exit end fitting; an oil tube; and a housing that interconnects the entry end fitting and the exit end fitting to define an annulus for the oil tube.
A further aspect of the present disclosure includes that the service tube is located within a mid-turbine frame (MTF).
A further aspect of the present disclosure includes that the service tube is located at least partially within a vane.
A further aspect of the present disclosure includes that the housing is insulated.
A further aspect of the present disclosure includes that the housing is triangular in cross-section.
A further aspect of the present disclosure includes that the entry end fitting includes an oil tube entry stub and an inlet to the annulus.
A further aspect of the present disclosure includes that the oil tube entry stub is transverse to the inlet.
A further aspect of the present disclosure includes that the exit end fitting includes an oil tube exit stub and an exit from the annulus.
A further aspect of the present disclosure includes that the exit is displaced from, and generally parallel to, the supply tube exit stub.
A gas turbine engine frame that defines a hollow vane according to one disclosed non-limiting embodiment of the present disclosure includes a service tube within the hollow vane, the service tube provides a communication path for buffer air, and a communication path for oil, the communication path for buffer air surrounding the communication path for oil.
A further aspect of the present disclosure includes that the gas turbine engine frame is a mid-turbine frame (MTF).
A further aspect of the present disclosure includes that the service tube is insulated.
A further aspect of the present disclosure includes that the communication path for buffer air and the communication path for oil communicate with a bearing compartment.
A further aspect of the present disclosure includes that the communication path for buffer air is an annulus.
A further aspect of the present disclosure includes that the communication path for buffer air is triangular in cross-section.
A method for communicating fluids though a hollow vane of a gas turbine engine frame according to one disclosed non-limiting embodiment of the present disclosure includes communicating oil through a service tube within the hollow vane; and communicating buffer air through the service tube within the hollow vane, the buffer air surrounding the oil within the service tube.
A further aspect of the present disclosure includes insulating the service tube.
A further aspect of the present disclosure includes communicating the oil and buffer air to a bearing compartment through the service tube.
A further aspect of the present disclosure includes communicating the buffer air through an annulus.
A further aspect of the present disclosure includes that the annulus is formed by the service tube.
The foregoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated otherwise. These features and elements as well as the operation of the invention will become more apparent in light of the following description and the accompanying drawings. It should be appreciated, however, the following description and drawings are intended to be exemplary in nature and non-limiting.
Various features will become apparent to those skilled in the art from the following detailed description of the disclosed non-limiting embodiment. The drawings that accompany the detailed description can be briefly described as follows:
The engine 20 generally includes a low spool 30 and a high spool 32 mounted for rotation around an engine central longitudinal axis A relative to an engine static structure 36 via several bearing compartments 38. The low spool 30 generally includes an inner shaft 40 that interconnects a fan 42, a low pressure compressor 44 (“LPC”) and a low pressure turbine 46 (“LPT”). The inner shaft 40 drives the fan 42 directly or through a geared architecture 48 to drive the fan 42 at a lower speed than the low spool 30. An exemplary reduction transmission is an epicyclic transmission, namely a planetary or star gear system. The high spool 32 includes an outer shaft 50 that interconnects a high pressure compressor 52 (“HPC”) and high pressure turbine 54 (“HPT”). A combustor 56 is arranged between the HPC 52 and the HPT 54. The inner shaft 40 and the outer shaft 50 are concentric and rotate around the engine central longitudinal axis A which is collinear with their longitudinal axes.
Core airflow is compressed by the LPC 44 then the HPC 52, mixed with fuel and burned in the combustor 56, then expanded over the HPT 54 and the LPT 46. The turbines 54, 46 rotationally drive the respective low spool 30 and high spool 32 in response to the expansion. The main engine shafts 40, 50 are supported at a plurality of points by the bearing compartments 38. It should be appreciated that various bearing compartments 38 at various locations may alternatively or additionally be provided.
With reference to
With reference to
With reference to
One or more of the other vanes 84 may alternatively or additionally be provide a service path for buffer air and oil communication to a bearing compartment 38. The bearing compartment 38 may be, for example, a mid-bearing compartment that is typically subjected to higher temperatures due to proximity to the turbine section.
With reference to
With reference to
The entry end fitting 122 includes an oil tube entry stub 132, and an inlet 134 for the annulus 130. In one example, the oil tube entry stub 132 is transverse to the inlet 134.
The exit end fitting 124 includes an oil tube exit stub 136 and an exit 138 from the annulus 130. In one example, the exit 138 is displaced from, and generally parallel to, the supply tube exit stub 136 (
The oil tube entry stub 132 and the oil tube exit stub 136 are interconnected by an oil tube section 140 of the oil tube 128. The entry end fitting 122 and the exit end fitting 124 are interconnected by the housing 126.
The housing 126 may be insulated to minimize thermal transfer of heat from the turbine section to the buffer air within the annulus 130. In one example, the housing 126 has a generally triangular cross-section (
Although the different non-limiting embodiments have specific illustrated components, the embodiments of this invention are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments.
It should be appreciated that relative positional terms such as “forward,” “aft,” “upper,” “lower,” “above,” “below,” and the like are with reference to the normal operational attitude of the vehicle and should not be considered otherwise limiting.
It should be appreciated that like reference numerals identify corresponding or similar elements throughout the several drawings. It should also be appreciated that although a particular component arrangement is disclosed in the illustrated embodiment, other arrangements will benefit herefrom.
Although particular step sequences are shown, described, and claimed, it should be appreciated that steps may be performed in any order, separated or combined unless otherwise indicated and will still benefit from the present disclosure.
The foregoing description is exemplary rather than defined by the limitations within. Various non-limiting embodiments are disclosed herein, however, one of ordinary skill in the art would recognize that various modifications and variations in light of the above teachings will fall within the scope of the appended claims. It is therefore to be appreciated that within the scope of the appended claims, the disclosure may be practiced other than as specifically described. For that reason the appended claims should be studied to determine true scope and content.
