CN-114379791-B - Integrated electric propulsion unit

CN114379791BCN 114379791 BCN114379791 BCN 114379791BCN-114379791-B

Abstract

An integrated electric propulsion unit includes a housing, an ac motor, a beta rod, a propeller, a governor, an inverter, and a controller. An ac motor is disposed within the housing and includes a plurality of bearings supported within the housing, a hollow motor shaft rotatably coupled to the housing by the plurality of bearings, a stator supported by the housing, and a rotor mounted to the hollow motor shaft. The beta rod can axially translate inside the hollow motor shaft. The propeller is mechanically coupled to the hollow motor shaft. The propeller comprises propeller blades having an adjustable pitch angle depending on the axial position of the beta rod. The governor is configured to adjust a pitch angle of the propeller blades by actuating an axial translation of the beta rod. An inverter is disposed within the housing and connected to receive dc power for conversion to ac power. A controller is disposed within the housing and configured to control operation of the inverter and to control a pitch angle of the propeller blades.

Inventors

Frederick LaCO
Rice in Ka meter Ya Er J card
Eugene V Suo Luo Raymond Downey gram
Aaron J Kurtz Manchester
PATRICK R. DARMSTADT
Mali E. Beckman
ALEJANDRO SILVA
Nicholas J. SilverI
Esther S. Zidowitzki

Assignees

波音公司

Dates

Publication Date: 20260512
Application Date: 20211014
Priority Date: 20201020

Claims (15)

1. An electric propulsion unit, wherein the electric propulsion unit comprises: A housing; an ac motor disposed within the housing and including a plurality of bearings supported within the housing, a hollow motor shaft rotatably coupled to the housing through the plurality of bearings, a stator supported by the housing, and a rotor mounted to the hollow motor shaft; A beta rod axially translatable inside the hollow motor shaft; A propeller mechanically coupled to the hollow motor shaft, the propeller comprising a propeller blade having an adjustable pitch angle depending on an axial position of the beta rod; A governor configured to adjust the pitch angle of the propeller blades by actuating an axial translation of the beta rod; an inverter disposed within the housing and connected to receive dc power for conversion to ac power; A first cooling passage thermally coupled to the inverter and a second cooling passage thermally coupled to the stator, the second cooling passage in fluid communication with the first cooling passage, and A controller disposed within the housing, and the controller is configured to perform operations comprising: Controlling the operation of the inverter, and Controlling the pitch angle of the propeller blades.
2. The electric propulsion unit of claim 1, further comprising one or more inserts attached inside the hollow motor shaft, and configured to support the beta rod while allowing the beta rod to slide axially.
3. The electric propulsion unit of claim 1, further comprising a thrust bearing/transmission/propeller shaft assembly integrated with a drive end plate of the housing.
4. The electric propulsion unit of claim 1, wherein the governor is integrated with a rear end plate of the housing.
5. The electric propulsion unit of claim 1, wherein the first cooling channel is a cooling plate.
6. The electric propulsion unit of claim 1, wherein the stator includes a stator housing and the second cooling passage is defined in part by the stator housing.
7. The electric propulsion unit of claim 1, wherein the stator includes a stator housing and the inverter is disposed radially outward from the stator housing, the electric propulsion unit further comprising a cooling jacket disposed between the inverter and the stator housing.
8. An electric propulsion system, wherein the electric propulsion system comprises a first battery configured to generate direct current power, a first direct current power input line connected to the first battery, and an electric propulsion unit connected to the first direct current power input line, wherein the electric propulsion unit comprises: A housing; An ac motor disposed within the housing and including a plurality of bearings supported within the housing, a motor shaft rotatably coupled to the housing through the plurality of bearings, a stator supported by the housing, and a rotor mounted to the motor shaft; A first electromagnetic interference filter disposed within the housing and connected to receive direct current power from the first battery via the first direct current input line; A first direct current bus arranged in the shell, and the first dc bus is connected to the first electromagnetic interference filter; a plurality of first inverters disposed within the housing, each of the plurality of first inverters connected to the first dc bus; A first cooling passage thermally coupled to the inverter and a second cooling passage thermally coupled to the stator, the second cooling passage in fluid communication with the first cooling passage, and A controller disposed within the housing and configured to control operation of the plurality of first inverters.
9. The electric propulsion system of claim 8, wherein the first dc bus includes interleaved conductor layers and insulation layers, each conductor layer connected to the first electromagnetic interference filter and to a respective inverter of the plurality of inverters.
10. The electric propulsion system of claim 8, wherein the stator includes a plurality of motor star windings, the electric propulsion system further comprising a plurality of ac bus bars connecting the inverter to the respective motor star windings.
11. The electric propulsion system of claim 8, further comprising a second battery configured to generate dc power and a second dc power input line connected to the second battery, wherein the electric propulsion unit further comprises: A second electromagnetic interference filter disposed within the housing and connected to receive dc power from the second battery via the second dc power input line; A second direct current bus arranged in the shell, and the second dc bus is connected to the second electromagnetic interference filter; and A plurality of second inverters disposed within the housing, each of the plurality of second inverters being connected to the second direct current bus, Wherein the controller is further configured to control operation of the plurality of second inverters.
12. The electric propulsion system of claim 8, further comprising a propeller mechanically coupled to the motor shaft.
13. An electric propulsion unit, wherein the electric propulsion unit comprises: A housing; An ac motor disposed within the housing and including a plurality of bearings supported within the housing, a motor shaft rotatably coupled to the housing through the plurality of bearings and having an axis of rotation, a stator supported by the housing, and a rotor mounted to the motor shaft; A main drive gear mounted to a front end of the motor shaft, the main drive gear having teeth; A propeller comprising a hollow propeller shaft having an axis of rotation, which is offset from the axis of rotation of the motor shaft, and propeller blades having an adjustable pitch angle; a beta rod axially translatable within the hollow propeller shaft; A governor configured to adjust the pitch angle of the propeller blades by actuating an axial translation of the beta rod; a propeller shaft drive gear mounted to the hollow propeller shaft and having teeth intermeshed with the teeth of the main drive gear; A plurality of power modules disposed radially outward from the stator; A first cooling passage thermally coupled to the AC motor and a second cooling passage thermally coupled to the stator, the second cooling passage in fluid communication with the first cooling passage, and A controller disposed within the housing, and the controller is configured to perform operations comprising: controlling operation of the plurality of power modules, and Controlling the pitch angle of the propeller blades.
14. The electric propulsion unit of claim 13, further comprising a cooling jacket disposed between the stator and the power module.
15. An electric propulsion unit, wherein the electric propulsion unit comprises: A housing; a plurality of first bearings and a plurality of second bearings, the plurality of first bearings and the plurality of second bearings being supported within the housing; A main drive train shaft supported by the plurality of first bearings and the plurality of second bearings supported within the housing; a first hollow motor shaft and a second hollow motor shaft surrounding respective segments of the main drive train shaft; A first pair of mechanical coupling means and a second pair of mechanical coupling means, the first and second pairs of mechanical coupling devices selectively couple the first and second hollow motor shafts to the main drive train shaft, respectively; A first rotor and a second rotor mounted to the first hollow motor shaft and the second hollow motor shaft, respectively; a first stator and a second stator supported within the housing, and disposed radially outward of the first rotor and the second rotor, respectively; and A propeller mechanically coupled to the main drive train shaft; a first cooling passage thermally coupled to the electric machine and a second cooling passage thermally coupled to the stator, the second cooling passage in fluid communication with the first cooling passage, and A controller is disposed within the housing and is configured to selectively activate a pair of mechanical linkages to disengage one hollow motor shaft from the main drive train shaft.

Description

Integrated electric propulsion unit Technical Field The present disclosure relates generally to an electric propulsion unit for an aircraft. Some aircraft have electric propulsion systems (hereinafter referred to as "electric aircraft"). In such aircraft, the electric motor converts electrical power to mechanical power for use by the propulsion system. For example, the motor may rotate one or more propellers on the aircraft to provide thrust. Electric aircraft may take various forms. For example, the electric aircraft may be an aircraft, a rotorcraft, a helicopter, a four-axis aircraft, a drone, or some other suitable type of aircraft. Background Typical electric propulsion solutions rely on discrete joint components that are assembled together to form an electric propulsion system. As used herein, the modifier "associated" when applied to components of an assembly means that the components are designed independently of one another. The motor and inverter are combined components requiring special mechanical structures, special cooling circuits, and complex electrical and control interfaces. The inverter needs to be in close proximity to the motor in the cabin environment. Mechanical installation of the inverter and motor is a challenging task due to the small size of the nacelle and the installation constraints of the cooling channels, heat exchanger/air ducts, wiring of the electrical and control lines. The traditional solutions are mainly separate inverters, motors and transmission elements with a large number of electrical and cooling interfaces in between. Most of the electric propulsion components are separate entities-electric motors, power electronics, transmissions and batteries-packaged very much like conventional turbine propulsion systems. Attempting to integrate a single electrified drivetrain component is complex, expensive, and time consuming. An electric propulsion system is a complex system that creates serious integration problems within the cabin and the aircraft fuselage. Developing an optimized integration solution that mechanically integrates the components within the nacelle would reduce weight and cost. Disclosure of Invention The subject matter disclosed in detail below relates to an integrated electric propulsion unit having reduced weight and cost compared to an aircraft propulsion system comprised of joined components. The system comprises a simplified cooling system with a single circuit for all the components (motor, inverter, thrust bearing, governor, etc.) housed inside the nacelle. The system design enables simplified integration of electrical components, a reasonable number of electrical connections, simplified electromagnetic interference (EMI) filtering, simplified electrical wiring harnesses, and reduced number of distribution boards. Propulsion control systems are also integrated to reduce the number of controllers and simplify control harness design. In the context of the fluid delivery system described below, the term "channel" refers to a hollow body comprising a conduit for guiding the flow of fluid from one opening at one end of the conduit to another opening at the other end of the conduit. The opening through which fluid enters the conduit is referred to herein as the "inlet" and the opening through which fluid exits the conduit is referred to herein as the "outlet". Examples of the channels disclosed herein include pipes, tubes, cooling plates, cooling jackets, and internal channels in solids. In the context of the motor controller described below, the term "channel" refers to an inverter consisting of a set of power switches controlled by the inverter controller. For example, a motor controller having three inverters that provide phase-controlled ac power to the same motor is described as having three channels. Although various embodiments of an integrated electric propulsion unit for an aircraft will be described in considerable detail below, one or more of those embodiments may feature one or more of the following aspects. One aspect of the subject matter disclosed in detail below is an electric propulsion unit including a housing, an ac motor disposed within the housing and including a plurality of bearings supported within the housing, a hollow motor shaft rotatably coupled to the housing by the plurality of bearings, a stator supported by the housing, and a rotor mounted to the hollow motor shaft, a beta rod axially translatable within the hollow motor shaft, a propeller mechanically coupled to the hollow motor shaft, the propeller including a propeller blade having an adjustable pitch angle depending on an axial position of the beta rod, a speed governor configured to adjust the pitch angle of the propeller blade by actuating the axial translation of the beta rod, an inverter disposed within the housing and connected to receive dc power for conversion to ac power, and a controller disposed within the housing. The controller is configured to perform operati