A dynamic test platform for electric propulsion system of tiltable electric aircraft

Abstract

A kind of dynamic test platform of electric propulsion system for tiltable electric aircraft, including transmission shaft, electric propulsion system is arranged at one end of transmission shaft, the other end is coupled with first push-pull force sensor, static torque sensor is arranged on mounting base, mounting base is slidably arranged on first fixed seat, and first push-pull force sensor is arranged on first fixed seat;First fixed seat is arranged on the driving device of rotating assembly, and driving device is arranged on second fixed seat;Second fixed seat is horizontally slidably arranged on X-axis mounting seat, X-axis mounting seat is vertically slidably arranged on Y-axis mounting seat, second push-pull force sensor is arranged on Y-axis mounting seat, and third push-pull force sensor is arranged on X-axis mounting seat.The application can be used for the test and evaluation of system parameters in the process of horizontal, vertical and horizontal to vertical angle dynamic transformation of electric propulsion system;The test platform simulates the mechanical force situation of electric propulsion system on its electric aircraft fixing device under complex stress state.

Description

Technical Field

[0001] This invention belongs to the field of electric propulsion system testing technology for electric aircraft, and specifically relates to a dynamic test platform for an electric propulsion system for a tiltable electric aircraft. Background Technology

[0002] Compared to traditional aircraft, all-electric aircraft have significant advantages in terms of operating costs and noise control, and the development of electric aircraft has been put on the agenda of the aviation industry. The electric propulsion system, which consists of a propeller, a motor drive, and an electric motor, is the core power drive component of an electric aircraft. It uses electricity as its energy source, and the electricity is output to the motor drive, which rotates the motor, which in turn drives the propeller to generate thrust / pull force.

[0003] Common electric aircraft include multi-rotor, fixed-wing, vertical takeoff and landing (VTOL) fixed-wing, eVTOL, and helicopter models. These aircraft utilize electric propulsion systems in three configurations: horizontal, vertical, and rotatable. In the horizontal configuration, the propeller generates horizontal thrust / pull. This configuration is primarily used in fixed-wing electric aircraft, where multiple electric propulsion systems can be arranged side-by-side to increase thrust / pull on a single wing. The symmetrical wing layout allows for safe landing even if one propulsion system fails. The vertical configuration is mainly used in multi-rotor aircraft. By adjusting the rotational speed of each rotor, the vertical thrust / pull of a single rotor can be varied. The combined vertical thrust of several rotors enables the electric aircraft to achieve various attitude changes. Rotatable electric propulsion systems are mainly used in vertical takeoff and landing fixed-wing aircraft. During takeoff, the electric propulsion system generates vertical thrust. After the aircraft reaches a certain altitude, the electric propulsion system gradually rotates automatically towards the nose, generating thrust at a certain angle to the vertical direction. During cruise flight, the electric propulsion system rotates to the horizontal, generating horizontal thrust.

[0004] To achieve more efficient and safer operation of electric propulsion systems across multiple aircraft models, dynamic testing is necessary to enable more precise improvements. The performance parameters for testing and evaluating electric propulsion systems mainly include thrust / pull force, torque, voltage, current, power, efficiency, rotational speed, airspeed, temperature rise, vibration, and noise. Existing electric propulsion system testing technologies are mostly horizontal static tests, which cannot simultaneously meet the testing requirements for horizontal, vertical, or horizontal-to-vertical angular transformation processes. Furthermore, testing equipment for the mechanical stress on the fixed components of electric propulsion systems in electric aircraft has not been developed and applied.

[0005] Therefore, to fill the gap in the existing technical field, it is necessary to design a dynamic test platform for the electric propulsion system of a tiltable electric aircraft. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a dynamic test platform for an electric propulsion system for a tiltable electric aircraft.

[0007] The objective of this invention is achieved through the following technical solution. A dynamic test platform for an electric propulsion system of a tiltable electric aircraft, according to this invention, includes a drive shaft rotatably mounted on a mounting base. One end of the drive shaft is equipped with an electric propulsion system, and the other end is coupled to a first push-pull force sensor. The push-pull force direction of the electric propulsion system coincides with the axial direction of the drive shaft. A static torque sensor for measuring the torque of the drive shaft or a fourth push-pull force sensor for indirectly measuring the torque of the drive shaft is mounted on the mounting base. The mounting base is slidably mounted on a first fixed seat, and the sliding direction of the mounting base relative to the first fixed seat is the same as the axial direction of the drive shaft. The first push-pull force sensor is mounted on the first fixed seat. The first fixed seat is mounted on a drive device of a rotating assembly, enabling the rotating assembly to drive the first fixed seat, the mounting base, and the drive shaft to rotate in a vertical plane. The drive device is mounted on a second fixed seat. The second fixed seat is horizontally slidably mounted on an X-axis mounting seat, and the X-axis mounting seat is vertically slidably mounted on a Y-axis mounting seat. A second push-pull force sensor coupled to the X-axis mounting seat is mounted on the Y-axis mounting seat, and a third push-pull force sensor coupled to the second fixed seat is mounted on the X-axis mounting seat.

[0008] Furthermore, the Y-axis mounting base is mounted on a T-shaped support frame.

[0009] Furthermore, the electric propulsion system includes a motor and a propeller. The motor drives the propeller to rotate and is mounted on the drive shaft via a mounting flange seat. The mounting flange seat includes a first flange, a second flange, and bolts. The motor is fixed to the first flange, and the first flange and the second flange are connected by axially arranged bolts. The second flange is located at the end of the drive shaft.

[0010] Furthermore, the first flange is axially centered and fixed to the motor, and the two are detachably connected. The first flange has multiple circumferentially distributed elongated holes that match the fixed position of the motor. The center of the second flange has a self-centering circular hole and a stepped tensioning structure. The stepped tensioning structure is located on the side away from the first flange. The self-centering circular hole passes through the second flange and the stepped tensioning structure. The side wall of the stepped tensioning structure is slotted. The end of the drive shaft connected to the second flange has a stepped hole that mates with the stepped tensioning structure. The bottom of the stepped hole has a threaded hole. The stepped tensioning structure is inserted into the stepped hole. The self-centering circular hole on the second flange and the stepped tensioning structure is fitted with a self-centering screw. The threaded shaft part of the self-centering screw is screwed into the threaded hole. At the same time, the other part of the self-centering screw causes the stepped tensioning structure to expand and be squeezed and fixed in the stepped hole.

[0011] Furthermore, the drive shaft is rotatably mounted on the mounting base via a bearing housing, which contains a double-row angular contact ball bearing and is lubricated with ultra-low viscosity lubricating oil.

[0012] Furthermore, the mounting base is slidably connected to the first fixed seat, the second fixed seat is slidably connected to the X-axis mounting seat, and the X-axis mounting seat is slidably connected to the Y-axis mounting seat via a linear guide rail assembly. The linear guide rail assembly includes a guide rail and a slider slidably mounted on the guide rail. The guide rail and the slider are respectively mounted on different corresponding components.

[0013] Furthermore, ultra-low viscosity lubricating oil is injected into the oil inlet of the slider to lubricate the linear guide rail assembly; the linear guide rail assembly between the mounting base and the first fixed seat, and between the second fixed seat and the X-axis mounting seat has static friction, which is compensated during the test.

[0014] Furthermore, a T-shaped structure is fixedly installed on the drive shaft, and the T-shaped structure rotates with the drive shaft. A U-shaped opening structure is installed on the fourth push-pull force sensor, and the T-shaped structure is nested inside the U-shaped opening structure with a clearance fit between the two. Both the T-shaped structure and the U-shaped opening structure have through holes. After the two are nested, a safety pin is used to pass through the through holes on both the U-shaped opening structure and the T-shaped structure simultaneously, and is in clearance fit with the through holes. The gap between the safety pin and the through hole is ≥1mm.

[0015] Furthermore, the driving device includes a servo motor with a brake and a planetary gear reducer mechanism. Both the servo motor and the planetary gear reducer mechanism are fixedly mounted on a second fixed base. The first fixed base is fixed on the rotating structure of the planetary gear reducer mechanism. The planetary gear reducer mechanism is driven by the servo motor. An electrical origin sensor, an electrical positive limit sensor, an electrical negative limit sensor, a mechanical positive limit device, and a mechanical negative limit device are installed on the planetary gear reducer mechanism.

[0016] Furthermore, the push-pull force values ​​measured by the first and second push-pull force sensors include the weight values ​​of the corresponding components, which are compensated for in the testing software.

[0017] Compared with existing technologies, the advantages of this invention are as follows: The dynamic test platform for a tiltable electric propulsion system for electric aircraft described in this invention can be used to test and evaluate system parameters during dynamic changes in horizontal, vertical, and horizontal-to-vertical angles of the electric propulsion system for multi-purpose electric aircraft. Through rotating components, it achieves experimental simulation of real-world operating conditions such as single-point or periodic changes in multiple angles of the electric propulsion system, as well as periodic durability dynamic testing and evaluation of the electric propulsion system, which can guide the optimization design of the electric propulsion system. The force of the electric propulsion system is decomposed into independent push-pull forces and torques through the transmission components. These forces and torques are measured separately within the transmission components, enabling the measurement of the characteristic parameters of the electric propulsion system itself. Furthermore, this test platform simulates the mechanical forces exerted by the electric propulsion system on the electric aircraft's mounting device under complex stress conditions. The XY component decomposes the resultant force of the electric propulsion system on the electric aircraft's mounting device into forces in the X and Y directions. By measuring the changes in these two forces, the force exerted by the electric propulsion system on the electric aircraft's mounting device can be easily studied, which helps in the optimization design of the electric propulsion system's mounting device.

[0018] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0019] Figure 1 This is an overall schematic diagram of a dynamic test platform for an electric propulsion system of a tiltable electric aircraft provided in an embodiment of the present invention;

[0020] Figure 2 for Figure 1 An exploded view of the mounting flange seat and the electric propulsion system installed thereon;

[0021] Figure 3 for Figure 1 Exploded view of the central transmission assembly;

[0022] Figure 4 for Figure 1 Exploded view of the rotating component;

[0023] Figure 5 for Figure 1 A schematic diagram of the exploded XY component.

[0024] [Attached image labels]

[0025] 1-T-type support frame, 2-XY assembly, 201-Y-axis mounting base, 202-Second linear guide rail assembly, 203-X-axis mounting base, 204-Third linear guide rail assembly, 205-Second push-pull force sensor, 206-Third push-pull force sensor, 3-Rotating assembly, 301-Servo motor, 302-Disc planetary reduction mechanism, 303-Second fixed base, 4-Transmission assembly, 401-Mounting base, 402-First bearing seat, 403-Second bearing seat, 404-Transmission shaft, 405-First linear guide rail assembly, 406-First fixed base, 407-First push-pull force sensor, 408-Static torque sensor, 5-Mounting flange seat, 501-First flange, 502-Second flange, 50201-Step tensioning structure, 503-Bolt, 6-Motor, 7-Propeller. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] An embodiment of the present invention provides a dynamic test platform for an electric propulsion system for a tiltable electric aircraft, as follows: Figures 1 to 5 As shown, hereinafter referred to as the test platform. The test platform includes a T-shaped support frame 1, an XY assembly 2 fixedly mounted on the T-shaped support frame 1, a rotating assembly 3 movably mounted on the XY assembly 2, a transmission assembly 4 fixedly mounted on the rotating assembly 3, and a mounting flange 5 fixedly mounted on the transmission assembly 4. Figure 1 The orientation shown in the figure is used as an example for explanation, with the extension direction of the transmission shaft in the transmission assembly 4 as the axial direction.

[0028] The mounting flange 5 includes a first flange 501, a second flange 502, and bolts 503. The mounting flange 5 is used to mount the electric propulsion system to be tested, which includes a motor 6 and a propeller 7. The first flange 501 is axially centered and matched according to the fixing method of the motor 6 in the electric propulsion system. The motor 6 is detachably mounted on the first flange 501. The first flange 501 has multiple circumferentially distributed elongated holes that match the motor's fixing position, which can meet the motor installation requirements of the same series of electric propulsion systems. The second flange 502 has a self-centering circular hole at its center and a stepped tensioning structure 50201. The stepped tensioning structure 50201 is located on the side opposite to the first flange 501. The self-centering circular hole penetrates the second flange 502 and the stepped tensioning structure 50201. The side wall of the stepped tensioning structure 50201 is slotted. The first flange 501 and the second flange 502 are connected and fixed by axially arranged bolts 503. The rotation of motor 6 drives propeller 7 to rotate. The rotation of propeller 7 generates torque and push-pull force, which are transmitted to transmission assembly 4 through first flange 501, bolt 503, and second flange 502.

[0029] The transmission assembly 4 includes a mounting base 401, a first bearing seat 402, a second bearing seat 403, a transmission shaft 404, a first linear guide rail assembly 405, a first fixed base 406, a first push-pull force sensor 407, and a static torque sensor 408. The transmission shaft is rotatably mounted on the mounting base via the bearing seats. In this embodiment, two bearing seats are provided, namely the first bearing seat 402 and the second bearing seat 403. The first bearing seat 402 and the second bearing seat 403 are axially distributed on the mounting base 401, and the two ends of the transmission shaft 404 are respectively inserted through the first bearing seat 402 and the second bearing seat 403. The left end of the drive shaft 404 is provided with a stepped hole that mates with the stepped tensioning structure 50201. A threaded hole is provided at the bottom of the stepped hole. The stepped tensioning structure 50201 is inserted into the stepped hole. A self-centering screw is passed through the self-centering circular hole on the second flange 502 and the stepped tensioning structure 50201. The threaded shaft part of the self-centering screw is screwed into the threaded hole. At the same time, the other part of the self-centering screw causes the stepped tensioning structure 50201 to expand and be pressed and fixed in the stepped hole, thereby realizing the fixed connection between the stepped tensioning structure 50201 and the drive shaft. Through the cooperation between the stepped tensioning structure 50201 and the stepped hole, the sliding between the second flange 502 and the drive shaft 404 is prevented during the transmission of torque by the electric propulsion system.

[0030] The double-row angular contact ball bearings, model 7005, housed in the first and second bearing housings. These bearings experience static friction torque during operation and require lubrication with ultra-low viscosity lubricating oil. According to a mechanical handbook, the friction coefficient μ of this bearing is 0.0012-0.0020. The maximum design push-pull force of this invention is 200 kg. The static friction torque of the double-row angular contact ball bearing can be calculated using the formula M = μPd / 2 (where M is the bearing friction torque, P is the bearing load, and d is the nominal inner diameter of the bearing). max The static friction torque is no more than 0.05 Nm. When the pushing and pulling force is small, this value can be ignored. In addition, this static friction torque value can also be corrected and compensated in the test software through periodic equipment calibration, so as to meet the test system's requirements for measurement accuracy.

[0031] In other embodiments, the first bearing housing uses a double-row angular contact ball bearing, and the second bearing housing uses a single-row angular contact ball bearing. The first bearing housing can restrict the axial movement of the drive shaft, and this embodiment can still prevent the axial movement of the drive shaft and the mounting base.

[0032] The rear side of the mounting base 401 is slidably connected to the first fixed seat 406 via a first linear guide rail assembly 405. The first linear guide rail assembly 405 includes two parallel guide rails extending axially. Two sliders are slidably mounted on each guide rail, and the sliders are fixed to the mounting base 401. The guide rails are fixed to the first fixed seat 406, allowing the mounting base 401 to slide freely axially relative to the first fixed seat 406. A first push-pull force sensor 407 is fixedly mounted on the first fixed seat 406. The first push-pull force sensor 407 is coupled to the right end of the drive shaft 404 via a first floating joint. The propeller 7 rotates to generate push-pull force, which is transmitted to the first push-pull force sensor 407 through the first flange 501, the second flange 502, the drive shaft 404, and the first floating joint. Because the mounting base 401 can slide freely axially relative to the first fixed seat 406, the drive shaft only transmits push / pull force to the first push-pull force sensor 407, thus enabling the first push-pull force sensor to more accurately measure the push / pull force from the electric propulsion system.

[0033] A static torque sensor 408 is fixedly mounted on the mounting base 401, and the drive shaft 404 can rotate freely relative to the static torque sensor 408. The connection method between the static torque sensor 408 and the drive shaft is the same as that in Embodiment 1 of the prior art CN201510001107 - A mechanical connection structure for detecting dynamic torque using a static torque sensor, and will not be described again here. The double-row angular contact ball bearings in the first and second bearing seats restrict the axial relative movement between the drive shaft 404 and the mounting base 401, so that the static torque sensor is not subjected to any torque in the non-working state, and does not bear any horizontal push / pull force in the working state. Therefore, the drive shaft 404 cannot transmit axial push / pull force to the static torque sensor, but can only transmit torque. Therefore, the static torque sensor can more accurately measure the torque when the electric propulsion system is working.

[0034] In other embodiments, the static torque sensor 408 can be replaced with a fourth push-pull force sensor. In this embodiment, a T-shaped structure is fixedly mounted on the drive shaft 404, and the T-shaped structure can rotate with the drive shaft 404. The fourth push-pull force sensor has a U-shaped opening structure, and the T-shaped structure is nested inside the U-shaped opening structure with a clearance fit. Both the T-shaped structure and the U-shaped opening structure have through holes. After nesting, a safety pin passes through the through holes on both the U-shaped opening structure and the T-shaped structure simultaneously, with a clearance fit of ≥1mm. The rotation of the drive shaft drives the T-shaped structure to rotate, thereby transmitting the push-pull force generated by the rotation to the fourth push-pull force sensor through the U-shaped opening structure. The push-pull force measured by the fourth push-pull force sensor is multiplied by the lever arm to obtain the torque, thus measuring the torque transmitted by the propeller. In this embodiment, since the push-pull force measured by the fourth push-pull force sensor is the instantaneous push-pull force when the drive shaft rotates, and it will prevent further rotation of the drive shaft, the processes of the first push-pull force sensor measuring the push-pull force and the fourth push-pull force sensor measuring the push-pull force and obtaining the torque need to be performed separately.

[0035] The test platform can test various parameters of a multi-purpose electric propulsion system. During the test, the motor 6 in the electric propulsion system is installed on the first flange 501. The motor 6 drives the propeller 7 to rotate. When the propeller rotates, it generates push / pull force and torque. The push / pull force and torque act on the first flange 501 and are transferred to the second flange 502 through bolts 503. Through the cooperation of the second flange 501, the stepped tensioning structure 50201, and the drive shaft 404, the push / pull force and torque can be independently transmitted to the corresponding sensors.

[0036] The rotating component 3 includes a drive unit, which comprises a servo motor 301 with a brake and a planetary reducer 302. The servo motor 301 and the planetary reducer 302 are fixedly mounted on a second fixed base 303. The rear side of the first fixed base 406 is fixed to the front end face of the planetary reducer 302. The planetary reducer 302 is driven by the servo motor 301 to achieve stepless rotation of the transmission component 4 and the mounting flange 5 from horizontal (0°) to vertical (90°), thereby driving the electric propulsion system to rotate steplessly from horizontal to vertical, thus testing the torque and thrust of the electric propulsion system at various angles. An electrical origin sensor, an electrical positive limit sensor, an electrical negative limit sensor, a mechanical positive limit device, and a mechanical negative limit device are installed on the planetary reducer 302 to mechanically and electrically limit the rotation of the rotating component 3, thereby improving the safety of the testing process. During the test, the angles of the transmission component 4 and the mounting flange 5 change steplessly from horizontal (0°) to vertical (90°). The test can be performed at any fixed point or dynamically and periodically (0°→90°→0°). The rotation speed can also be changed alternately between uniform speed, acceleration and deceleration as needed to fully simulate the actual working conditions.

[0037] During the angular change of the transmission assembly 4 and mounting flange 5, the push-pull force value collected by the first push-pull force sensor 407 contains the weight components of the four sliders in the first linear guide rail group 405 and all the components connected to them. Therefore, before the electric propulsion system starts working, the transmission assembly 4 and mounting flange 5 automatically move to two positions, horizontal 0° and vertical 90°, driven by the rotating assembly 3. The first push-pull force sensor 407 measures the push-pull force values ​​at the two positions respectively. The difference between the push-pull force values ​​at the horizontal 0° and vertical 90° positions is the sum of the weights of the four sliders in the first linear guide rail group 405 and all the components connected to them. The push-pull force value at the horizontal 0° position is used as the zero-point compensation value of the first push-pull force sensor 407 and is automatically compensated in the test software. During the rotation test of the rotating assembly 3, the test software obtains the rotation angle θ collected by the servo driver used to control the servo motor 301 in the rotating assembly in real time. The first push-pull force sensor 407 collects the weight components of all relevant components in real time, according to the formula G... 分 =G 和 sinθ(G 分 G represents the gravitational component. 和 The weight of the four sliders and all related components connected to them is adjusted in real time by the testing software.

[0038] The XY assembly 2 includes a Y-axis mounting base 201, a second linear guide rail assembly 202 fixed on the Y-axis mounting base 201, an X-axis mounting base 203, a third linear guide rail assembly 204 fixed on the X-axis mounting base 203, a second push-pull force sensor 205, and a third push-pull force sensor 206. The Y-axis mounting base 201 is mounted on a T-shaped support frame 1, and the second linear guide rail assembly 202 is disposed on the Y-axis mounting base 201. The second linear guide rail assembly 202 includes two parallel and vertically extending guide rails, which are fixedly disposed on the front side of the Y-axis mounting base 201. Two sliders are slidably disposed on each guide rail, and the rear side of the X-axis mounting base 203 is fixedly disposed on the sliders, so that the X-axis mounting base can slide up and down relative to the Y-axis mounting base, with the sliding direction being the Y-axis direction. A third linear guide rail group 204 is provided on the X-axis mounting base 203. The third linear guide rail group 204 includes two parallel guide rails that extend horizontally to the left and right. The guide rails are fixedly mounted on the front side of the X-axis mounting base 203. Two sliders are slidably mounted on each guide rail. The rear side of the second fixed base 303 is fixedly mounted on the sliders, so that the second fixed base 303 can slide left and right relative to the X-axis mounting base, with the sliding direction being the X-axis direction.

[0039] The second push-pull force sensor 205 is fixedly mounted on the Y-axis mounting base 201 and coupled to the X-axis mounting base 203 via a second floating joint. The third push-pull force sensor 206 is fixedly mounted on the X-axis mounting base 203 and coupled to the second fixed base 303 via a third floating joint.

[0040] The rotating component 3, the transmission component 4 connected to the rotating component, and the mounting flange 5 can move freely in a straight line along the X-axis direction of the XY component via the third linear guide group 204. The third floating joint transmits the push / pull force generated in the X-axis direction by the rotating component 3 and its connected components during operation to the third push / pull force sensor 206. The X-axis mounting base 203 can move freely in a straight line along the Y-axis direction of the XY component via the second linear guide group 202, thereby enabling the rotating component 3, the transmission component 4 connected to the rotating component, and the mounting flange 5 to move freely in a straight line along the Y-axis direction of the XY component via the second linear guide group 202. The second floating joint transmits the push / pull force generated in the Y-axis direction by the rotating component 3 and its connected components during operation to the second push / pull force sensor 205.

[0041] The base of the disc planetary reduction mechanism 302 is fixed to the front side of the second fixed seat 303. The rear side of the second fixed seat 303 is fixed on the four sliders of the third linear guide rail group 204. The second fixed seat 303 can slide freely on the third linear guide rail group 204. The third push-pull force sensor 206 is coupled to the second fixed seat 303 through the third floating joint, thereby testing the push-pull force of the electric propulsion system acting on the X-axis of the electric aircraft.

[0042] The third linear guide rail assembly 204 is mounted on the X-axis mounting base 203. The rear side of the X-axis mounting base 203 is fixed to the four sliders of the second linear guide rail assembly 202. The X-axis mounting base 203 can slide freely up and down on the second linear guide rail assembly 202. The second push-pull force sensor 205 is coupled to the X-axis mounting base 203 through the second floating joint, thereby testing the push-pull force of the electric propulsion system acting on the electric aircraft in the Y-axis direction.

[0043] The push-pull force value measured by the second push-pull force sensor 202 includes the sum of the weights of the four sliders of the second linear guide rail assembly 202 and all related components. This sum of weights also varies with the weight of the electric propulsion system, but for the same electric propulsion system, this sum of weights is a constant and can be accurately calculated. In the test software, the measured value of the second push-pull force sensor can be compensated.

[0044] The first linear guide rail assembly 405 experiences static friction during operation and requires lubrication with ultra-low viscosity lubricating oil injected through the oil inlets of its four sliders. Medium- or high-viscosity lubricating oils or greases should not be used, as this will increase static friction during measurement. To improve measurement accuracy, static friction can be dynamically compensated in the test program according to the static friction formula, enabling real-time correction during the test. Specifically, during horizontal movement, the upper surface of the first linear guide rail assembly bears the weight of the electric propulsion system, the mounting base 401, and all its components. At this time, the normal pressure on the first linear guide rail assembly 405 is at its maximum, i.e., the static friction is also at its maximum. When the disc planetary reduction mechanism 302 causes the transmission component 4 and the mounting flange 5 to rotate counterclockwise, the static friction on the first linear guide rail assembly 405 gradually decreases, reaching zero when it moves to the vertical direction.

[0045] The third linear guide assembly 204 experiences static friction during operation and requires lubrication with ultra-low viscosity lubricating oil injected through the oil inlets of its four sliders. Medium- or high-viscosity lubricating oils or greases should not be used, as this would increase the static friction during measurement. This static friction is a fixed value related to the gravity of the electric propulsion system and can be compensated for in the test program using the static friction formula. Specifically, the upper surface of the second linear guide assembly 204 bears the combined weight of the electric propulsion system, rotating components, and all related connected parts. This is also the maximum normal pressure exerted on the upper surface of the second linear guide assembly 204. This static friction value can be calculated using the static friction formula and ultimately corrected by the test software.

[0046] Under ideal conditions, the second linear guide group 202 is not subjected to normal pressure during operation, so its static friction is negligible. It only needs to be lubricated by injecting ultra-low viscosity lubricating oil into its four sliders.

[0047] For the first linear guide rail group 405, the second linear guide rail group 202, and the third linear guide rail group 204, mechanical safety blocks are arranged at the mounting ends of the push-pull force sensors corresponding to these three linear guide rail groups to limit the slider and its connected components, so as to prevent safety accidents caused by the failure of the push-pull force sensors.

[0048] The present invention discloses a dynamic test platform for a tiltable electric propulsion system for electric aircraft. This platform can be used to test and evaluate system parameters during dynamic changes in horizontal, vertical, and horizontal-to-vertical angles of the electric propulsion system for multi-purpose electric aircraft. The rotating component 3 simulates real-world operating conditions such as single-point or periodic changes in multiple angles of the electric propulsion system, enabling periodic durability dynamic testing and evaluation, and guiding the optimized design of the electric propulsion system. The force of the electric propulsion system is decomposed into independent push-pull forces and torques through the drive shaft and bearing housing. These forces and torques are measured separately in the transmission component 4, allowing for the measurement of the electric propulsion system's characteristic parameters. Furthermore, the test platform simulates the mechanical forces exerted by the electric propulsion system on the electric aircraft's mounting device under complex stress conditions. The XY component 2 decomposes the resultant force of the electric propulsion system on the mounting device into forces in the X and Y directions. By measuring the changes in these two forces, the force exerted by the electric propulsion system on the mounting device can be easily studied, contributing to the optimized design of the electric propulsion system's mounting device.

[0049] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dynamic test platform for an electric propulsion system of a tiltable electric aircraft, characterized in that: The system includes a drive shaft, which is rotatably mounted on a mounting base via a bearing housing. The bearing housing contains a double-row angular contact ball bearing to limit the relative axial movement between the drive shaft and the mounting base. One end of the drive shaft is equipped with an electric propulsion system, and the other end is coupled to a first push-pull force sensor via a first floating joint. The push-pull force direction of the electric propulsion system coincides with the axial direction of the drive shaft. The mounting base is equipped with either a static torque sensor for measuring the drive shaft torque or a fourth push-pull force sensor for indirectly measuring the drive shaft torque. The static torque sensor or the fourth push-pull force sensor transmits torque but not axial push-pull force. The mounting base is slidably mounted on a first fixed seat, with the sliding direction of the mounting base relative to the first fixed seat being the same as the axial direction of the drive shaft. The first push-pull force sensor is mounted on the first fixed seat so that the drive shaft transmits push-pull force only to the first push-pull force sensor. The first fixed seat is located on the drive of the rotating assembly. The device enables the rotating component to drive the first fixed seat, mounting base, and drive shaft to rotate in the vertical plane. The drive device is mounted on the second fixed seat. The second fixed seat is horizontally slidably mounted on the X-axis mounting seat, and the X-axis mounting seat is vertically slidably mounted on the Y-axis mounting seat. A second push-pull force sensor coupled to the X-axis mounting seat is mounted on the Y-axis mounting seat, and a third push-pull force sensor coupled to the second fixed seat is mounted on the X-axis mounting seat. The push-pull force values ​​measured by the first and second push-pull force sensors include the weight values ​​of the corresponding components, which are compensated for in the testing software. For the first push-pull force sensor, before testing, the first fixed seat is driven to two positions: 0° and 90°. The difference between the push-pull force values ​​at the two positions is the sum of the weights of the corresponding components. During the test, the testing software acquires the rotation angle θ in real time, and the first push-pull force sensor collects the weight components of the corresponding components in real time, according to formula G. 分 =G 和 sinθ, G 分 G represents the gravitational component. 和 The sum of the gravity of the corresponding components is corrected in real time in the testing software. For the second push-pull force sensor, the sum of the gravity of the corresponding components is constant during the testing process and is directly compensated in the testing software.

2. The dynamic test platform for an electric propulsion system of a tiltable electric aircraft according to claim 1, characterized in that: The Y-axis mounting base is mounted on a T-shaped support frame.

3. The dynamic test platform for an electric propulsion system of a tiltable electric aircraft according to claim 1, characterized in that: The electric propulsion system includes a motor and a propeller. The motor drives the propeller to rotate and is mounted on the drive shaft via a mounting flange seat. The mounting flange seat includes a first flange, a second flange, and bolts. The motor is fixed to the first flange, and the first flange and the second flange are connected by axially arranged bolts. The second flange is located at the end of the drive shaft.

4. The dynamic test platform for an electric propulsion system of a tiltable electric aircraft according to claim 3, characterized in that: The first flange is axially centered and fixed to the motor, and the two can be detached and connected. The first flange has multiple circumferentially distributed elongated holes that match the fixed position of the motor. The center of the second flange has a self-centering circular hole and a stepped tensioning structure. The stepped tensioning structure is located on the side away from the first flange. The self-centering circular hole passes through the second flange and the stepped tensioning structure. The side wall of the stepped tensioning structure is slotted. The end of the drive shaft connected to the second flange has a stepped hole that mates with the stepped tensioning structure. The bottom of the stepped hole has a threaded hole. The stepped tensioning structure is inserted into the stepped hole. The self-centering circular hole on the second flange and the stepped tensioning structure is fitted with a self-centering screw. The threaded shaft part of the self-centering screw is screwed into the threaded hole. At the same time, the other part of the self-centering screw causes the stepped tensioning structure to expand and be squeezed and fixed in the stepped hole.

5. The dynamic test platform for an electric propulsion system of a tiltable electric aircraft according to claim 1, characterized in that: The bearing housing is equipped with a double-row angular contact ball bearing, and the bearing housing is lubricated with ultra-low viscosity lubricating oil; the static friction torque value of the double-row angular contact ball bearing is corrected and compensated in the testing software through periodic equipment calibration.

6. The dynamic test platform for an electric propulsion system of a tiltable electric aircraft according to claim 1, characterized in that: The mounting base is slidably connected to the first fixed base, the second fixed base to the X-axis mounting base, and the X-axis mounting base to the Y-axis mounting base via linear guide rail assemblies. The linear guide rail assembly includes guide rails and sliders slidably mounted on the guide rails. The guide rails and sliders are respectively mounted on different corresponding components.

7. A dynamic test platform for an electric propulsion system for a tiltable electric aircraft according to claim 6, characterized in that: The slider's oil inlet injects ultra-low viscosity lubricating oil to lubricate the linear guide rail assembly; the linear guide rail assembly between the mounting base and the first fixed seat, and between the second fixed seat and the X-axis mounting seat has static friction, which is compensated during the test. During the test, the test software dynamically compensates and corrects the force in real time based on the tilt angle.

8. The dynamic test platform for an electric propulsion system of a tiltable electric aircraft according to claim 1, characterized in that: A T-shaped structure is fixedly installed on the drive shaft, and the T-shaped structure rotates with the drive shaft. A U-shaped opening structure is installed on the fourth push-pull force sensor, and the T-shaped structure is nested inside the U-shaped opening structure with a clearance fit. Both the T-shaped structure and the U-shaped opening structure have through holes. After they are nested, a safety pin passes through the through holes on both the U-shaped opening structure and the T-shaped structure simultaneously, and is in clearance fit with the through holes. The clearance between the safety pin and the through hole is ≥1mm. The rotation of the drive shaft drives the T-shaped structure to rotate, thereby transmitting the push-pull force generated by the rotation to the fourth push-pull force sensor through the U-shaped opening structure. The push-pull force measured by the fourth push-pull force sensor is multiplied by the lever arm to obtain the torque.

9. A dynamic test platform for an electric propulsion system for a tiltable electric aircraft according to claim 1, characterized in that: The drive device includes a servo motor with a brake and a planetary reducer mechanism. Both the servo motor and the planetary reducer mechanism are fixedly mounted on a second fixed base. The first fixed base is fixed on the rotating structure of the planetary reducer mechanism. The planetary reducer mechanism is driven by the servo motor. An electrical origin sensor, an electrical positive limit sensor, an electrical negative limit sensor, a mechanical positive limit device, and a mechanical negative limit device are installed on the planetary reducer mechanism.

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