Patent Application
20240208663
This disclosure relates generally to an aircraft and, more particularly, to a hybrid propulsion system for the aircraft.
A hybrid propulsion system for an aircraft may include a thermal engine, such as a gas turbine engine, and an electric motor. The thermal engine and the electric motor may be coupled to and may selectively drive rotation of a propeller through a geartrain. Various types and configurations of hybrid aircraft propulsion systems are known in the art. While these known hybrid aircraft propulsion systems have various benefits, there is still room in the art for improvement.
According to an aspect of the present disclosure, an aircraft system is provided that includes a propulsor rotor, a geartrain, a thermal engine, a drivetrain and an electric machine. The geartrain includes a power output, a first power input and a second power input. The power output is coupled to the propulsor rotor. The thermal engine is configured to drive rotation of the propulsor rotor through the geartrain. The thermal engine is coupled to the first power input. The drivetrain includes a first driveshaft and a second driveshaft. The first driveshaft is coupled to and between the second power input and the second driveshaft. The second driveshaft is angularly offset from the first driveshaft. The electric machine is configured to drive rotation of the propulsor rotor through the drivetrain and the geartrain. The second driveshaft is coupled to and between the first driveshaft and the electric machine.
According to another aspect of the present disclosure, another aircraft system is provided that includes a propulsor rotor, a thermal engine, an electric machine and an aircraft wing. The thermal engine is configured to drive rotation of the propulsor rotor. The electric machine is configured to drive rotation of the propulsor rotor. The thermal engine and the electric machine are independently mounted to the aircraft wing.
According to still another aspect of the present disclosure, another aircraft system is provided that includes a propulsor rotor, a thermal engine, an electric machine and an aircraft wing. The thermal engine is configured to drive rotation of the propulsor rotor. The electric machine is configured to drive rotation of the propulsor rotor. The thermal engine is disposed outside of the aircraft wing. The electric machine is at least partially housed within the aircraft wing.
The thermal engine may be disposed outside of the aircraft wing. The electric machine may be at least partially housed within the aircraft wing.
The aircraft system may also include a geartrain and a drivetrain. The geartrain may include a power output, a first power input and a second power input. The power output may be coupled to the propulsor rotor. The first power input may be coupled to the thermal engine. The drivetrain may include a first driveshaft, a second driveshaft and an angle drive coupling the first driveshaft to the second driveshaft. The first driveshaft may be coupled to the second power input. The second driveshaft may be coupled to the electric machine.
The second driveshaft may be angularly offset from the first driveshaft by an acute angle.
The second driveshaft may be angularly offset from the first driveshaft by a right angle.
The drivetrain may also include an angle drive coupled to and between the first driveshaft and the second driveshaft.
The propulsor rotor may be rotatable about a rotational axis. The thermal engine may be located axially between the geartrain and the electric machine along the rotational axis.
The aircraft system may also include an airframe structure. The thermal engine and the electric machine may be independently mounted to the airframe structure.
The airframe structure may be configured as an aircraft wing.
The electric machine may be housed within the aircraft wing at a leading edge of the aircraft wing.
The thermal engine may be disposed outside of the airframe structure. The electric machine may be at least partially housed within the airframe structure.
The electric machine may be vertically below the airframe structure.
The electric machine may be outside of the airframe structure.
The aircraft system may also include a nacelle at least partially housing the thermal engine and the electric machine.
The thermal engine may include an exhaust duct at an aft end of the thermal engine. At least a portion of the electric machine may be disposed aft of the exhaust duct.
The electric machine may be configurable as an electric motor during a motor mode of operation to drive rotation of the propulsor rotor through the drivetrain and the geartrain. The electric machine may also be configurable as an electric generator during a generator mode of operation where the thermal engine is configured to power the electric machine through the geartrain and the drivetrain.
The thermal engine may be configured as a gas turbine engine.
The propulsor rotor may be configured as or otherwise include a propeller rotor.
The present disclosure may include any one or more of the individual features disclosed above and/or below alone or in any combination thereof.
The foregoing features and the operation of the invention will become more apparent in light of the following description and the accompanying drawings.
The propulsor rotor 28 is a bladed rotor mechanically driven by an output shaft 37 or another torque transmission device. This propulsor rotor 28 may be an open rotor such as a propeller rotor 38 for a propeller engine; e.g., a hybrid turboprop engine. The present disclosure, however, is not limited to such an exemplary propulsor rotor. The propulsor rotor 28, for example, may alternatively be configured as a rotor (e.g., a main rotor) for a helicopter engine (e.g., a hybrid turboshaft engine), or a rotor (e.g., a fan rotor, a compressor rotor, etc.) for a turbofan engine or a turbojet engine. However, for ease of description, the propulsor rotor 28 may be described below as the propeller rotor 38.
The thermal engine 30 is configured to convert chemical energy stored within fuel into mechanical power. The thermal engine 30 of
Referring to
The compressor section 42, the combustor section 43, the HPT section 44A and the LPT section 44B are arranged sequentially along a core flowpath 48 within the gas turbine engine 40. This core flowpath 48 extends within the gas turbine engine 40 from an upstream airflow inlet 50 into the gas turbine engine 40 to a downstream combustion products exhaust 52 from the gas turbine engine 40.
Each of the engine sections 42, 43A and 44B includes a respective bladed rotor 54-56. Each of these bladed rotors 54-56 includes a plurality of rotor blades arranged circumferentially around and connected to one or more respective rotor disks. The rotor blades, for example, may be formed integral with or mechanically fastened, welded, brazed, adhered and/or otherwise attached to the respective rotor disk(s).
The compressor rotor 54 is connected to the HPT rotor 55 through a high speed shaft 58. At least the compressor rotor 54, the HPT rotor 55 and the high speed shaft 58 may collectively form a high speed rotating structure 60 of the gas turbine engine 40. The LPT rotor 56 is connected to a low speed shaft 62, which low speed shaft 62 may extend axially through a bore of the high speed rotating structure 60 and its high speed shaft 58. At least the LPT rotor 56 and the low speed shaft 62 may collectively form a low speed rotating structure 64 of the gas turbine engine 40. Each of the rotating structures 60, 64 of
During gas turbine engine operation, air enters the core flowpath 48 through the airflow inlet 50 and is directed into the compressor section 42. The air within the core flowpath 48 may be referred to as “core air”. This core air is compressed by the compressor rotor 54 and directed into a combustion chamber 68 of a combustor within the combustor section 43. The fuel is injected into the combustion chamber 68 by one or more fuel injectors and mixed with the compressed air to provide a fuel-air mixture. This fuel-air mixture is ignited and combustion products thereof flow through and sequentially cause the HPT rotor 55 and the LPT rotor 56 to rotate. The rotation of the HPT rotor 55 drives rotation of the compressor rotor 54 and, thus, compression of the air received from the airflow inlet 50. The rotation of the LPT rotor 56 and, more generally, the low speed rotating structure 64 provides mechanical power for driving (e.g., rotating) the propulsor rotor 28 of
Referring to
The electric machine 32 of
Referring to
The geartrain 76 of
The drivetrain 78 of
The first driveshaft 86 is rotatable about a first driveshaft rotational axis 90, which rotational axis 90 may be parallel with and/or (e.g., vertically) offset from the centerline 66. This first driveshaft 86 extends axially along its rotational axis 90 between (e.g., and to) the geartrain 76 and the angle drive 88. A first end of the first driveshaft 86 may be coupled to and rotatable with the machine power transfer element 82 (e.g., a shaft, a gear such as a bevel gear, a carrier, a coupler, etc.) of the geartrain 76. A second end of the first driveshaft 86 may be coupled to and rotatable with a power transfer element 92 of the angle drive 88.
The second driveshaft 87 is rotatable about a second driveshaft rotational axis 94, which rotational axis 94 is angularly offset from (e.g., non-parallel with) the first driveshaft rotational axis 90 (and the centerline 66) by an offset angle 96. The offset angle 96 may be a (e.g., non-zero) acute angle or a right angle. The offset angle 96, for example, may be between fifteen degrees (15°) and forty-five degrees (45°), between forty-five degrees (45°) and seventy-five degrees (75°), or between seventy-five degrees (75°) and ninety degrees (90°) depending on a location of the electric machine 32; see also
With the foregoing arrangement, the first driveshaft 86 is coupled to, arranged between and operatively connects the geartrain 76 and the angle drive 88. The angle drive 88 is coupled to, arranged between and operatively connects the first driveshaft 86 and the second driveshaft 87. The second driveshaft 87 is coupled to, arranged between and operatively connects the angle drive 88 and the electric machine 32. Thus, the electric machine rotor 70 is rotatably coupled to the machine power transfer element 82 of the geartrain 76 sequentially through the drivetrain members 87, 88 and 86.
By including the drivetrain 78 and canting (e.g., angularly offsets) the second driveshaft 87 relative to the first driveshaft 86, the electric machine 32 may be remotely located from the geartrain 76 and/or the thermal engine 30. The electric machine 32 of
The thermal engine 30 and the electric machine 32 may be independently mounted to the airframe structure 22. The thermal engine 30, for example, may be mounted to the airframe structure 22 through a pylon structure 102 (schematically shown). The electric machine 32 may be mounted (e.g., directly) to one or more internal supports 104 (schematically shown) of the airframe structure 22. Thus, the electric machine 32 is not connected to the airframe structure 22 though the thermal engine 30, and the thermal engine 30 is not connected to the airframe structure 22 through the electric machine 32. However, it is contemplated that the thermal engine 30 and the electric machine 32 may be mounted to the airframe structure 22 through a common mounting structure (e.g., a pylon or otherwise) where, for example, the thermal engine 30 and the electric machine 32 are still independently supported; e.g., not connected to the airframe structure 30 through one another.
The aircraft propulsion system components 28, 30, 76 and 86 may be arranged outside of (e.g., external to) the airframe structure 22. The electric machine 32 (e.g., and the drivetrain members 87 and 88), however, may be at least partially (or completely) housed within the airframe structure 22. The drivetrain members 87 and 88 of
In some embodiments, referring to
The airframe structure 22 is described above as the aircraft wing 24 for ease of description. It is contemplated, however, the airframe structure 22 may alternatively be configured as part of an aircraft fuselage where, for example, the aircraft propulsion system 26 is mounted to the aircraft fuselage and/or the aircraft is configured as a helicopter.
While various embodiments of the present disclosure have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the disclosure. For example, the present disclosure as described herein includes several aspects and embodiments that include particular features. Although these features may be described individually, it is within the scope of the present disclosure that some or all of these features may be combined with any one of the aspects and remain within the scope of the disclosure. Accordingly, the present disclosure is not to be restricted except in light of the attached claims and their equivalents.
