A rotor propulsion system and its use

Abstract

The application discloses a rotor propulsion system and application thereof, and belongs to the technical field of propulsion systems. The system adopts a double-motor counter-rotating structure, driving torque is superposed and output, and reverse torques are offset to each other, so that no driving reverse torque is generated to an external fuselage, and therefore no balancing device such as a tail rotor is needed. The system realizes unidirectional output through a overrunning clutch, prevents the rotor from generating a power generation effect on the driving device, and significantly improves reliability and safety. The specific structure comprises a shell, a first motor mechanism and a second motor mechanism fixed to the shell, the two are connected through meshing of parallel gears and rotate in opposite directions, a main shaft is axially fixed to the parallel gears, a speed reducer is fixed to the main shaft, and an output end of the speed reducer is connected to the overrunning clutch. The output ports of the first and second motor mechanisms are 180° rotationally symmetrical about the intersection point of the meshing center point and the parallel gear axis.

Description

Technical Field

[0001] This invention relates to the field of aircraft propulsion system technology, specifically a rotor propulsion system and its control method. Background Technology

[0002] In traditional single-rotor aircraft, during the pre-rotation phase, the rotation of the rotor generates a reaction torque on the fuselage. The consequences are: single-rotor helicopters need to balance this reaction torque through a tail rotor or other means; and gyroplanes cannot achieve vertical takeoff and landing or hovering. The tail rotor structure not only consumes additional power but also increases mechanical complexity and flight safety hazards. To overcome these problems, existing technologies generally employ a dual-rotor counter-rotating design for helicopters; alternatively, there are designs with two coaxial motors driving two counter-rotating rotors.

[0003] For example, existing patents (such as CN117302512A) disclose a structure in which two motors are mounted opposite each other to drive one rotor, but they do not solve the problem of synchronous control of speed and torque between the two motors, which can easily lead to fuselage yaw, increased vibration, and power loss. Another type of technology (such as CN112340000A) proposes a structure in which a stator drives two counter-rotating motors, but it lacks a specific closed-loop coordinated control strategy for current and speed, and cannot guarantee that the output torque of the two motors is equal in real time, thus making it difficult to achieve effective cancellation of counter-torque within the shell.

[0004] In summary, while the aforementioned solutions have their respective applications, achieving vertical takeoff and landing (VTOL) is very difficult for single-rotor helicopters, especially autogyros, without a tail rotor or additional lift devices. Therefore, in the nascent stage of the low-altitude economy, autogyros possess unique safety and widespread applicability. Adding VTOL capability would eliminate the need for runways, enabling takeoff and landing anywhere, making it an economically and marketably valuable endeavor. There is an urgent need to develop a rotor propulsion system and its control method capable of achieving precise torque matching between dual motors, self-cancelling of anti-torque, and support for autogyro operating modes, in order to solve existing technical challenges. Summary of the Invention

[0005] The technical problems to be solved by this invention are: the rotor drive of a single-rotor aircraft requires an additional tail rotor to balance the counter-torque; autogyro aircraft cannot achieve vertical take-off and landing by relying on the rotor itself; for electric aircraft, rotor overspeed can easily damage the drive system and affect safety. To solve the above-mentioned technical problems, the present invention provides a rotor propulsion system, comprising: case; The first motor mechanism is mounted on the housing and fixedly connected to the housing by bolts; The second motor mechanism is mounted on the housing and is fixedly connected to the housing by bolts; The second motor mechanism is connected to the first motor mechanism via a parallel gear meshing; The first motor mechanism rotates in the opposite direction to the second motor mechanism; The main shaft is axially fixedly connected to the parallel gear; The speed reducer is fixedly connected to the main shaft; The overrunning clutch is fixedly connected to the output end of the reducer; The center point of engagement between the output ports of the first and second motor mechanisms is 180° rotationally symmetrical with respect to the intersection point of the parallel gear axis.

[0006] The first motor mechanism includes a motor and a pinion; the pinion is fixedly connected to the output end of the motor; the stator of the motor is fixedly connected to the housing; the two motors have the same mechanical and electromagnetic characteristics and rotate in opposite directions.

[0007] The motor is either a DC motor or a BLDC motor.

[0008] The reducer is a planetary reducer, and the reducer output shaft is fixedly connected to the overrunning clutch.

[0009] The present invention also provides a control system applied to the above-mentioned rotor propulsion system, comprising: First motor M1, first driver, second motor M2, second driver, and controller; The first driver drives the first motor M1; the second driver drives the second motor M2. The controller coordinates the first and second drives. The first driver controls and monitors the speed, voltage, and current of the first motor; The second driver controls and monitors the speed, voltage, and current of the second motor.

[0010] The controller controls and coordinates the first driver and the second driver; the first motor M1 and the second motor M2 have a master-slave relationship: the first motor M1 is the master motor and the second motor M2 is the slave motor.

[0011] The first motor M1 uses a speed closed-loop control strategy to ensure that the rotor speed is maintained at the set value; the second motor M2 uses a current closed-loop control strategy to ensure that the output torque of M1 and M2 is the same.

[0012] The present invention also provides a control method applied to the above-mentioned control system, comprising the following steps: Step 1: The controller starts the first driver and the second driver; the first driver and the second driver control the operation of M1 and M2 respectively.

[0013] Step 2: The controller receives the speed setpoint Vs; Step 3: The controller sends a speed Vr control command to the first driver; Step 4: The controller queries the drive current I1 of the first motor M1 fed back by the first driver; Step 5: The controller sends an Ir control command to the second driver according to I1; the second driver adjusts the power of M2; Step 6: The controller queries the second driver for the current I2 of M2 and compares it with Ir; Step 7: If Ir≠I2, then return to step 5; Step 8: If Ir = I2, proceed to the next step; Step 9: The controller queries the first driver for the rotational speed Vn of the first motor M1 and compares whether Vn=Vr. Step 10: If Vn ≠ Vr, then return to step 3; Step 11: If Vn = Vr, then return to step 2.

[0014] The present invention has the following advantages: the two motors rotate in opposite directions and are coupled by parallel gears, so that the counter-torques generated when the output torques are equal cancel each other out; the master-slave control strategy ensures that the currents of the two motors are consistent, thereby achieving torque synchronization; the overrunning clutch allows the rotor drive device to automatically intervene and disengage in real time; for autogyros, the rotor can passively and freely rotate during level flight; for helicopters, the system has a high degree of integration and can maintain directional stability without a tail rotor.

[0015] Other features and advantages of the present invention will be disclosed in detail in the following detailed description and accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a perspective view of an embodiment of the present invention; Figure 2 This is a perspective view of the interior of the housing in an embodiment of the present invention; Figure 3 This is a front view of the interior of the housing in an embodiment of the present invention; Figure 4 This is a top view of the interior of the housing in an embodiment of the present invention; Figure 5 This is a top view of another dual-motor parallel driving scheme in an embodiment of the present invention; Figure 6 This is a control flowchart in an embodiment of the present invention.

[0017] The figures are labeled as follows: 1. Housing; 2. First motor mechanism; 21. Motor; 22. Pinion; 3. Second motor mechanism; 4. Parallel gear; 5. Main shaft; 6. Reducer; 7. Overrunning clutch. Detailed Implementation

[0018] 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. Example 1

[0019] like Figure 1-6 As shown A first motor mechanism 2 and a second motor mechanism 3 are fixedly connected to the housing 1 by bolts. The first motor mechanism 2 includes a motor 21 and a pinion 22. The output end of the motor 21 is fixedly connected to the pinion 22. The stator of the motor 21 is fixedly connected to the housing 1. The structure of the second motor mechanism 3 is the same as that of the first motor mechanism 2. The rotation directions of the first motor mechanism 2 and the second motor mechanism 3 are opposite. The mechanical and electromagnetic characteristics of the two motors 21 are identical.

[0020] Based on the motor characteristics, under normal operating conditions and without magnetic saturation, its output torque T = K * I; K is the motor's torque constant, which is an inherent constant of the motor. I is the effective operating current = current current - motor no-load current; since the mechanical and electromagnetic characteristics of M1 and M2 are the same, their no-load currents are the same as K; as long as we control the drive current I of M1 and M2 to be consistent, we can ensure that their output torque is consistent.

[0021] The pinion 22 of the first motor mechanism 2 and the pinion 22 of the second motor mechanism 3 simultaneously mesh with the same parallel gear 4. The meshing center point of the output port of the first motor mechanism 2 and the intersection point of the axis of the parallel gear 4 are 180° rotationally symmetrical. The parallel gear 4 is axially fixedly connected to the main shaft 5. The main shaft 5 is fixedly connected to the input shaft of the reducer 6.

[0022] Reducer 6 is a planetary reducer. Planetary reducers have advantages such as small size, compact structure, and high transmission efficiency. They are a mature technology and will not be elaborated on here. The output shaft of reducer 6 is fixedly connected to overrunning clutch 7. The output end of overrunning clutch 7 is used to connect to the rotor system.

[0023] The control system includes a first motor M1 (i.e., motor 21), a first driver, a second motor M2 (i.e., the motor of the second motor mechanism 3), a second driver, and a controller. The first driver drives the first motor M1. The second driver drives the second motor M2. The controller controls and coordinates the first and second drivers. The first driver controls and monitors the speed, voltage, and current of the first motor. The second driver controls and monitors the speed, voltage, and current of the second motor.

[0024] The controller coordinates the first and second drives. The first motor M1 and the second motor M2 have a master-slave relationship: the first motor M1 is the master motor, and the second motor M2 is the slave motor. The first motor M1 employs a speed closed-loop control strategy to ensure the rotor speed is maintained at the set value. The second motor M2 employs a current closed-loop control strategy, using the drive current of the first motor M1 as a reference to ensure that the drive current of the second motor M2 is consistent with that of the first motor M1.

[0025] The control method steps are as follows: Step 1: The controller starts the first driver and the second driver; the first driver and the second driver control the operation of M1 and M2 respectively.

[0026] Step 2: The controller receives the speed setpoint Vs; Step 3: The controller sends a speed Vr control command to the first driver; Step 4: The controller queries the drive current I1 of the first motor M1 fed back by the first driver; Step 5: The controller sends an Ir control command to the second driver according to I1; the second driver adjusts the power of M2; Step 6: The controller queries the second driver for the current I2 of M2 and compares it with Ir; Step 7: If Ir≠I2, then return to step 5; Step 8: If Ir = I2, proceed to the next step; Step 9: The controller queries the first driver for the rotational speed Vn of the first motor M1 and compares whether Vn=Vr. Step 10: If Vn ≠ Vr, then return to step 3; Step 11: If Vn = Vr, then return to step 2.

[0027] During operation, the first motor M1 and the second motor M2 rotate in opposite directions, one clockwise and the other counterclockwise; their power is combined through the parallel gear 4. When the output torques of the two motors are equal, the counter-torques applied to the housing 1 are equal in magnitude and opposite in direction, thus canceling each other out. The overrunning clutch 7 transmits power to the rotor during vertical takeoff and landing; during level flight, when the rotor speed exceeds the output shaft speed of the overrunning clutch 7, the overrunning clutch 7 automatically disengages, allowing the rotor to rotate freely.

[0028] Example 2 like Figure 5 As shown The difference between this embodiment and Embodiment 1 lies in the arrangement of the parallel gears.

[0029] Two parallel turning gears 4 are fixedly connected to the main shaft 5, and the two parallel turning gears 4 are arranged at intervals along the axis of the main shaft 5. The pinion 22 of the first motor mechanism 2 meshes with one of the parallel turning gears 4. The pinion 22 of the second motor mechanism 3 meshes with the other parallel turning gear 4. The first motor mechanism 2 and the second motor mechanism 3 are mounted side by side on the housing 1.

[0030] The two parallel gears 4 have the same number of teeth and module. The first motor mechanism 2 and the second motor mechanism 3 rotate in opposite directions. When the output torque of the two motors is equal, it is transmitted to the main shaft 5 through the two parallel gears 4, and the power is combined and input to the reducer 6. Since the two motors rotate in opposite directions and have equal torque, the counter-torque generated on the main shaft 5 cancels each other out on the housing.

[0031] The remaining structures in this embodiment (reducer 6, overrunning clutch 7, control system and control method) are the same as in embodiment one.

[0032] The feature of this embodiment is that the two motors are installed side by side, resulting in a more compact overall volume.

[0033] According to the above technical solution of the present invention, the working principle is as follows: The two motors (Motor M1 and Motor M2) rotate in opposite directions and are meshed with a parallel gear via pinions of the same number of teeth. The two motors have identical mechanical and electromagnetic characteristics. When the controller receives the speed setpoint, Motor M1, acting as the master motor, uses closed-loop speed control to maintain the target rotor speed; Motor M2, acting as the slave motor, uses closed-loop current control to ensure its drive current is equal to that of Motor M1 in real time. Since the motor output torque is proportional to the drive current, the output torques of the two motors are equal.

[0034] Based on the motor characteristics, under normal operating conditions and without magnetic saturation, its output torque T = K * I; K is the motor's torque constant, which is an inherent constant of the motor. I is the effective operating current = current current - motor no-load current; since the mechanical and electromagnetic characteristics of M1 and M2 are the same, their no-load current and K are the same; as long as we control the drive current I of M1 and M2 to be consistent, we can ensure that their output torque is consistent.

[0035] When the two motors rotate in opposite directions and have equal torque, the driving torque applied by their respective rotors to the parallel gear is in the same direction. After paralleling, the output torque is twice the output torque of a single motor. At the same time, the counter-torques generated by the stators of the two motors are equal in magnitude and opposite in direction, and cancel each other out through the shell. Therefore, there is no net counter-torque outside the shell, and the aircraft can maintain a stable heading without a tail rotor.

[0036] Power is transmitted from the main shaft to the planetary reducer, where it is reduced in speed and increased in torque before being transmitted to the overrunning clutch via the output shaft. During vertical takeoff and landing or hovering, the overrunning clutch engages, driving the rotor to rotate. During level flight, when the aircraft's airspeed reaches its autorotation sustaining speed, the controller cuts off the motor power supply, gradually reducing the output shaft speed until it stops rotating. As the rotor continues to rotate under the influence of airflow and its speed exceeds the output shaft speed, the overrunning clutch automatically disengages, and the rotor enters a free-rotation state. The motor and reducer stop rotating to reduce drag. When a vertical landing is required again, the controller starts the motor and accelerates it to synchronize with the rotor's real-time speed. The overrunning clutch automatically re-engages, resuming drive.

[0037] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0038] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A rotor propulsion system, characterized in that, include: case; A first motor mechanism is mounted on the housing and is fixedly connected to the housing by bolts; The second motor mechanism is mounted on the housing and is fixedly connected to the housing by bolts. The second motor mechanism is meshed with the first motor mechanism by a parallel gear. The rotation directions of the first motor mechanism and the second motor mechanism are opposite. Main shaft, which is axially fixedly connected to the parallel gear; A speed reducer is fixedly connected to the main shaft, and an overrunning clutch is fixedly connected to the output end of the speed reducer. The meshing center point of the output ports of the first motor mechanism and the second motor mechanism is 180° symmetrical with respect to the intersection point of the parallel gear axis.

2. The rotor propulsion system according to claim 1, characterized in that, The first motor mechanism includes: a motor and a pinion; The pinion is fixedly connected to the output end of the motor, and the stator of the motor is fixedly connected to the housing; the two motors have the same mechanical and electromagnetic characteristics and rotate in opposite directions.

3. A rotor propulsion system according to claim 2, characterized in that, The motor is a DC motor.

4. A rotor propulsion system according to claim 2, characterized in that, The motor is a BLDC motor.

5. A rotor propulsion system according to claim 1, characterized in that, The reducer is a planetary reducer; the output shaft of the reducer is fixedly connected to the overrunning clutch.

6. A control system applied to any one of the rotor propulsion systems described in claims 1-5, characterized in that, include: First motor M1, first driver, second motor M2, second driver, and controller; The first driver drives the first motor M1; The second driver drives the second motor M2; The controller coordinates the first driver and the second driver; The first driver controls and monitors the speed, voltage, and current of the first motor; the second driver controls and monitors the speed, voltage, and current of the second motor.

7. The control system of a rotor propulsion system according to claim 6, characterized in that, The controller controls and coordinates the first driver and the second driver. The first motor M1 and the second motor M2 have a master-slave relationship: the first motor M1 is the master motor and the second motor M2 is the slave motor.

8. The control system of the rotor propulsion system according to claim 7, wherein the first motor M1 adopts a speed closed-loop control strategy to ensure that the rotor speed is maintained at a set value; and the second motor M2 adopts a current closed-loop control strategy to ensure that the output torque of the first motor M1 and the second motor M2 is the same.

9. A control method applied to the control system of a rotor propulsion system according to any one of claims 6-8, characterized in that, Includes the following steps: Step 1: The controller starts the first driver and the second driver; the first driver and the second driver control the operation of the first motor M1 and the second motor M2 respectively; Step 2: The controller receives the speed setpoint Vs; Step 3: The controller sends a speed Vr control command to the first driver; Step 4: The controller queries the drive current I1 of the first motor M1 fed back by the first driver; Step 5: The controller sends an Ir control command to the second driver according to I1; the second driver adjusts the power of M2; Step 6: The controller queries the second driver for the current I2 of M2 and compares it with Ir; Step 7: If Ir≠I2, then return to step 5; Step 8: If Ir = I2, proceed to the next step; Step 9: The controller queries the first driver for the rotational speed Vn of the first motor M1 and compares whether Vn=Vr. Step 10: If Vn ≠ Vr, then return to step 3; Step 11: If Vn = Vr, then return to step 2.

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