Tiltrotor power transmission system with shared power source and its working method

Abstract

This invention provides a tiltrotor power transmission system with shared power source and its operating method. The power system includes a power source, a clutch, a first-stage input bevel gear shaft, a rotary transmission structure, a tilt transmission structure, and a parallel shaft. The power source is fixed to the frame via a threaded connection. The clutch enables connection and disconnection with the first-stage input bevel gear shaft. The first-stage input bevel gear shaft transmits power to the rotary transmission structure and the tilt transmission structure through meshing pairs. This invention achieves power splitting of a single power source through a coaxial configuration, allowing power to be transmitted separately to the rotary and tilt transmission structures. This enables synchronous control of rotation and tilt, reduces the number of power sources, and improves the overall reliability of the aircraft. Furthermore, the interaction of the clutch and brake enables control of the rotor shaft tilt.

Description

Technical Field

[0001] This invention relates to the field of aircraft power transmission technology, specifically a tiltrotor power transmission system with shared power source and its working method. Background Technology

[0002] As a new generation of operational aircraft, tiltrotor aircraft possess the dual advantages of traditional helicopters and fixed-wing aircraft. They can maintain high flexibility in combat while also responding quickly. In the modern combat environment dominated by information warfare, combat time is particularly important, and the emergence of tiltrotor aircraft will undoubtedly give our side more opportunities to a certain extent.

[0003] Based on the numerous advantages of tiltrotor aircraft, many domestic scholars and enterprises have successively launched related research. Initially, the focus was mainly on the principle verification stage of small and medium-sized prototypes, later shifting towards larger-scale designs. During the principle verification stage, various conceptual configurations and tiltrotor power transmission structures emerged. The overall configuration was primarily based on a fixed-wing fuselage with tiltrotor rotors added to both wings. The tilting structure mainly used motor-driven screw drives, hydraulic rods, worm gears, and differential gear trains, while the rotating structure mainly used bevel gear drives and single-stage or double-stage planetary gear drives. The tilting and rotating structures could respectively use dual motors, motors plus servos, or engines plus hydraulic drives as power sources. As can be seen from the above, in the current configurations, both tilting and rotating require separate power sources. From a design perspective, increasing the number of power sources increases control difficulty and reduces system reliability. To reduce the number of power sources and improve overall reliability, it is necessary to propose a power transmission system that can simultaneously control tilting and rotating using a single power source. Summary of the Invention

[0004] To address the problems of existing technologies, this invention provides a tiltrotor power transmission system with shared power sources and its operating method. By using a coaxial configuration, power distribution from a single power source is achieved, reducing the number of power sources and improving the overall reliability of the aircraft.

[0005] This invention provides a tiltrotor power transmission system with shared power source, including a fuselage and a left tiltrotor power transmission system and a right tiltrotor power transmission system distributed on both sides of the fuselage and synchronized through parallel shafts. The left tiltrotor power transmission system and the right tiltrotor power transmission system have the same structure, both including a power input device, a rotary transmission structure and a tilt transmission structure. The output shaft of the power input device is connected to a first-stage output bevel gear and a first-stage output bevel gear shaft through a meshing pair. The first-stage output bevel gear is connected to the rotary transmission structure, and the first-stage output bevel gear shaft is connected to the tilt transmission structure.

[0006] The rotary transmission structure includes a short transmission shaft, a secondary input bevel gear, a secondary output bevel gear, a rotor shaft, and a propeller. The primary output bevel gear is fixedly connected to the transmission shaft, the short transmission shaft is fixedly connected to the secondary input bevel gear, the secondary input bevel gear transmits power to the secondary output bevel gear through a meshing pair, the secondary output bevel gear is fixedly connected to the rotor shaft, and the rotor and propeller are flexibly connected.

[0007] The tilting transmission structure includes a two-stage input cylindrical gear shaft, a two-stage output cylindrical gear, a long transmission shaft, a three-stage input cylindrical gear, a three-stage output cylindrical gear, a sun gear shaft, planetary gears, a ring gear, a planetary carrier, and a housing. The short transmission shaft is connected to the two-stage input cylindrical gear shaft via a second clutch and a third clutch. The first-stage output bevel gear shaft is connected to the two-stage input cylindrical gear shaft via a third clutch. The two-stage input cylindrical gear shaft transmits power to the two-stage output cylindrical gear through a meshing pair. The two-stage output cylindrical gear is fixedly connected to the transmission shaft. The transmission shaft is fixedly connected to the three-stage input cylindrical gear. The three-stage input cylindrical gear transmits power to the three-stage output cylindrical gear through a meshing pair. The three-stage output cylindrical gear is fixedly connected to the sun gear shaft. The sun gear shaft transmits power to the planetary carrier through the meshing of the sun gear and planetary gears. One end of the planetary carrier is connected to the planetary gears via bearings, and the other end is fixedly connected to the housing. The housing is connected to the parallel shaft and the frame via rotating pairs.

[0008] In a further improvement, the power input device includes a power source, a first clutch, and a first-stage input bevel gear shaft. The power source is fixed on the frame, and the power output shaft of the power source is connected to and disconnected from the first-stage input bevel gear shaft through the first clutch. The first-stage input bevel gear shaft is connected to a first-stage output bevel gear and a first-stage output bevel gear shaft respectively through meshing pairs.

[0009] In a further improvement, the tilting transmission structure is connected to a brake.

[0010] In a further improvement, the short drive shaft, long drive shaft, and parallel shaft are all single shafts.

[0011] In a further improvement, the short drive shaft, long drive shaft, and parallel shaft are multiple shafts connected by couplings or differential gear trains.

[0012] In a further improvement, the housing has circular holes on both the left and right sides. The inner circular surface of the left hole is connected to the parallel shaft via a bearing, and the outer circular surface is connected to the frame via a bearing. The right hole is connected to the parallel shaft only on the inner circular surface via a bearing. At the same time, the right side wall of the housing is fixedly connected to the planetary carrier.

[0013] The present invention also provides a method for operating a tiltrotor power transmission system with shared power source, comprising the following steps:

[0014] When the tiltrotor aircraft is preparing to take off on the ground, the tilt structure tilts so that the rotor blades rotate parallel to the horizontal plane. At this time, driven by the power source, the power is transmitted to the rotor shaft through the first-stage bevel gear pair and the second-stage bevel gear pair, which drives the rotor to rotate. The left and right rotors rotate in opposite directions. At this time, under the lift generated by the rotation of the rotor, the aircraft rises vertically.

[0015] Once the aircraft has ascended to a suitable altitude, the second clutch is engaged, and power is transmitted through the first-stage bevel gear pair to the second-stage cylindrical gear shaft. At this point, the brake is released, and power is transmitted through the second-stage cylindrical gear pair, the third-stage cylindrical gear pair, and the planetary gear system to the housing, causing the housing, rotor shaft, and propeller to rotate counterclockwise. The rotation range is 0° to 90°. When the angle is set to 90°, it is in level flight mode. To maintain level flight mode, the brake is locked, and then the second clutch is disengaged.

[0016] When the aircraft needs to switch from level flight to vertical takeoff and landing, by engaging the third clutch, disengaging the second clutch, and releasing the brake, power is transmitted through the first-stage bevel gear pair and the third clutch to the second-stage cylindrical gear shaft, and then through the second-stage cylindrical gear pair, the third-stage cylindrical gear pair, and the planetary gear system to the housing, driving the housing, rotor shaft, and propeller to rotate clockwise.

[0017] The beneficial effects of this invention are as follows:

[0018] 1. Power is provided by a single power source, and the power is split through the meshing of two bevel gears, which can transmit the power to the rotary transmission structure and the tilting transmission structure respectively, thus realizing the synchronous control of rotation and tilting.

[0019] 2. The tilting transmission structure has a clutch and a brake, which can control the start, stop and position locking of the tilting when the power source is continuously outputting power.

[0020] 3. The rotary transmission structure and the tilting transmission structure adopt a coaxial design to a certain extent, which improves the utilization rate of limited space.

[0021] 4. The power transmission system is designed in two parts: a tilting section and a non-tilting section. The power source and transmission components are placed in the non-tilting section, which reduces the tilting torque requirements of the tilting section. The tilting rotor power transmission systems on both sides of the fuselage are connected by parallel shafts, which realizes bidirectional power flow. When the power source on one side fails, the aircraft can be rotated and tilted by the power source on the other side. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a detailed structural diagram of the tilting and rotating power transmission system of the present invention;

[0024] Figure 2 This is a detailed structural diagram of the rotary power transmission system of the present invention;

[0025] Figure 3 This is a detailed structural diagram of the tilting power transmission system of the present invention;

[0026] Figure 4 This is a symmetrical distribution diagram of the tilting rotor power transmission system on the left and right sides of the present invention;

[0027] Figure 5 This is a diagram showing the relative positions of the left and right tilt rotor transmission systems and the fuselage of this invention.

[0028] Figure label:

[0029] Power source 1, power output shaft 2, first clutch 3, first-stage input bevel gear shaft 4, first-stage output bevel gear 5, short transmission shaft 6, second-stage input bevel gear 7, second-stage output bevel gear 8, rotor shaft 9, propeller 10, first-stage output bevel gear shaft 11, second clutch 12, brake 13, second-stage input cylindrical gear shaft 14, second-stage output cylindrical gear 15, long transmission shaft 16, third-stage input cylindrical gear 17, third-stage output cylindrical gear 18, sun gear shaft 19, planetary gears 20, ring gear 21, planetary carrier 22, housing 23, parallel shaft 24, tiltable part 25, left tilt rotor power transmission system 26, right tilt rotor power transmission system 27, fuselage 28, left side hole 29, third clutch 30. Detailed Implementation

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] It should be understood that in the description of this application, the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. That is, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Furthermore, unless otherwise stated, "a plurality of" means two or more.

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation of the present invention will be described below with reference to the accompanying drawings.

[0033] See Figures 1 to 5 The tilt rotor power transmission system with shared power source proposed in this invention consists of a power source 1, a first clutch 3, a first-stage input bevel gear shaft 4, a rotary transmission structure, a tilt transmission structure, and a parallel shaft 24. The power source 1 is fixed to the frame by a threaded connection. The first clutch 3 is used to connect and disconnect with the first-stage input bevel gear shaft 4. The first-stage input bevel gear shaft 4 transmits power to the rotary transmission structure and the tilt transmission structure through meshing pairs. The rotary transmission structure realizes the power flow and synchronization between the left tilt rotor transmission system 26 and the right tilt rotor transmission system 27 through the parallel shaft 24.

[0034] The rotary transmission structure consists of a primary output bevel gear 5, a short transmission shaft 6, a secondary input bevel gear 7, a secondary output bevel gear 8, a rotor shaft 9, and a propeller 10. The primary output bevel gear 5 is fixedly connected to the transmission shaft 6, and the transmission shaft 6 is fixedly connected to the secondary input bevel gear 7. The secondary input bevel gear 7 transmits power to the secondary output bevel gear 8 through a meshing pair. The secondary output bevel gear 8 is fixedly connected to the rotor shaft 9. The rotor shaft 9 and the propeller 10 are flexibly connected using known technology.

[0035] The tilting transmission structure consists of a first-stage output bevel gear shaft 11, a second clutch 12, a third clutch 30, a brake 13, a second-stage input cylindrical gear shaft 14, a second-stage output cylindrical gear 15, a long transmission shaft 16, a third-stage input cylindrical gear 17, a third-stage output cylindrical gear 18, a sun gear shaft 19, planetary gears 20, a ring gear 21, a planet carrier 22, and a housing 23. The short transmission shaft 6 and the first-stage output bevel gear shaft 11 are connected by the third clutch 30, the second clutch 12, and the second-stage input cylindrical gear shaft 14, respectively. The second-stage input cylindrical gear shaft 14 is connected to the second-stage output cylindrical gear shaft 15 through a meshing pair. The spur gear 15 transmits power. The second-stage output spur gear 15 is fixedly connected to the drive shaft 16. The drive shaft 16 is fixedly connected to the third-stage input spur gear 17. The third-stage input spur gear 17 transmits power to the third-stage output spur gear 18 through a meshing pair. The third-stage output spur gear 18 is fixedly connected to the sun gear shaft 19. The sun gear shaft 19 transmits power to the planet carrier 22 through the meshing of the sun gear and planet gears 20. The gear ring 21 is fixed. One end of the planet carrier 22 is connected to the planet gears 20 through a bearing, and the other end is fixedly connected to the housing 23. The housing 23 is connected to the parallel shaft 24 and the frame through a rotating pair.

[0036] Optionally, the braking of the tilting transmission structure can be achieved using a brake 13.

[0037] Optionally, the connection between the first-stage output bevel gear 5, the second-stage input bevel gear 7, the second-stage output bevel gear 8 and the short transmission shaft 6, the parallel shaft 24, and the rotor shaft 9 can be achieved using other similar techniques such as spline connection, welding, or integral casting.

[0038] Optionally, the secondary output cylindrical gear 15, the tertiary input cylindrical gear 17, and the tertiary output cylindrical gear 18 can be spur gears or helical gears, and their connection with the long transmission shaft 16 and the sun gear shaft 19 can be achieved by spline connection, welding, or integral casting or other similar technologies.

[0039] Optionally, the short drive shaft 6, the long drive shaft 16, and the parallel shaft 24 can be a single shaft or multiple shafts, connected by couplings or differential gear trains.

[0040] Optionally, the short drive shaft 6, long drive shaft 16, first-stage input bevel gear shaft 4, first-stage output bevel gear shaft 11, second-stage input cylindrical gear shaft 14, sun gear shaft 19, and parallel shaft 24 are all hollow shafts and can all be connected to the frame via bearings. The short drive shaft 6 can be nested inside the second-stage output bevel gear shaft 11 and the second-stage input cylindrical gear shaft 14, and the parallel shaft 24 can be nested inside the sun gear shaft 19. The inner shaft short drive shaft 6 and parallel shaft 24 are positioned and connected to the outer shaft first-stage output bevel gear shaft 11, second-stage input cylindrical gear shaft 14, and sun gear shaft 19 through intermediate bearings.

[0041] Optionally, the housing 23 can rotate around the axis of the parallel shaft 24 under the drive of the power source 1, so as to realize the tilting of the rotor. The housing 23 has round holes on the left and right sides. The inner surface of the left hole 29 is connected to the parallel shaft 24 through a bearing, and the outer surface is connected to the frame through a bearing. The right hole is only connected to the parallel shaft 24 through a bearing on the inner surface, and the right side wall is fixedly connected to the planetary carrier 22.

[0042] Optionally, the tilt rotor power transmission system with shared power source is divided into a tiltable part 25 and a non-tiltable part. The tiltable part 25 includes a two-stage output bevel gear 8, a rotor shaft 9, a propeller 10 and a housing 23, while the non-tiltable part includes a power source 1 and a power transmission structure.

[0043] Optionally, the tiltrotor power transmission system, which shares the power source, can be symmetrically distributed on both sides of the fuselage 26, and fixed to both ends of the wing respectively.

[0044] Figure 1 This diagram illustrates the structure and relative positions of the tiltrotor drive system of a tiltrotor aircraft in level flight. When the tiltrotor aircraft is preparing for takeoff on the ground, the tiltrotor should be in a position where it has rotated 90° clockwise around the parallel shaft 24 axis, based on the position shown in the diagram. Figure 1 (Looking to the left), at this point, driven by the power source, power is transmitted through the first-stage bevel gear pair (first-stage input bevel gear shaft 4, first-stage output bevel gear 5) and the second-stage bevel gear pair (second-stage input bevel gear 7, second-stage output bevel gear 8) to the rotor shaft 9, driving the propeller 10 to rotate. The left and right propellers rotate in opposite directions. At this time, under the lift generated by the rotation of the propeller 10, the aircraft rises vertically. When it rises to a suitable height, the second clutch 12 is engaged, and ... The power is transmitted from the input bevel gear shaft 4 and the first-stage output bevel gear shaft 11 to the second-stage cylindrical gear shaft 14. At this time, the brake 13 is released, and the power is transmitted through the second-stage cylindrical gear pair (second-stage input cylindrical gear shaft 14 and second-stage output cylindrical gear 15), the third-stage cylindrical gear pair (third-stage input cylindrical gear 17 and third-stage output cylindrical gear 18), and the planetary gear train (sun gear shaft 19, planet gears 20, ring gear 21, planet carrier 22) to the housing 23, driving the housing, rotor shaft, and propeller to rotate counterclockwise. Figure 1 (Looking left), the rotation range is 0°~90°. When the angle is set to 90°, the position of the propeller relative to the transmission system is as follows: Figure 1 As shown, the position relative to the fuselage is as follows Figure 5As shown, this is the level flight attitude. To maintain the level flight attitude, brake 13 can be locked first, and then the second clutch 12 can be disengaged. When the aircraft needs to change from the level flight attitude to the vertical takeoff and landing attitude, the third clutch 30 can be engaged, the second clutch 12 can be disengaged, and brake 13 can be released. Power is transmitted through the first-stage bevel gear pair 4, 5, and the third clutch 30 to the second-stage cylindrical gear shaft 14, and then through the second-stage cylindrical gear pair (second-stage input cylindrical gear shaft 14, second-stage output cylindrical gear 15), the third-stage cylindrical gear pair (third-stage input cylindrical gear 17, third-stage output cylindrical gear 18), and the planetary gear train (sun gear shaft 19, planet gears 20, ring gear 21, planet carrier 22) to the housing 23, driving the housing, rotor shaft, and propeller to rotate clockwise. Figure 1 (Looking left).

[0045] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. In particular, for the device embodiments, the above descriptions are merely preferred embodiments of the present invention. Since they are fundamentally similar to the method embodiments, the descriptions are relatively simple, and relevant parts can be referred to the descriptions of the method embodiments. The above descriptions are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention, without departing from the principle of the present invention, should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A tiltrotor power transmission system with shared power source, characterized in that: The system includes a fuselage and two power transmission systems, a left tiltrotor and a right tiltrotor, located on both sides of the fuselage and synchronized via parallel shafts. The left tiltrotor and right tiltrotor power transmission systems have the same structure, each including a power input device, a rotary transmission structure, and a tilt transmission structure. The output shaft of the power input device is connected to a first-stage output bevel gear and a first-stage output bevel gear shaft via meshing pairs. The first-stage output bevel gear is connected to the rotary transmission structure, and the first-stage output bevel gear shaft is connected to the tilt transmission structure. The rotary transmission structure includes a short transmission shaft, a secondary input bevel gear, a secondary output bevel gear, a rotor shaft, and a propeller. The primary output bevel gear is fixedly connected to the short transmission shaft, and the short transmission shaft is fixedly connected to the secondary input bevel gear. The secondary input bevel gear transmits power to the secondary output bevel gear through a meshing pair. The secondary output bevel gear is fixedly connected to the rotor shaft, and the rotor and propeller are flexibly connected. The tilting transmission structure includes a two-stage input cylindrical gear shaft, a two-stage output cylindrical gear, a long transmission shaft, a three-stage input cylindrical gear, a three-stage output cylindrical gear, a sun gear shaft, planetary gears, a ring gear, a planetary carrier, and a housing. The short transmission shaft is connected to the two-stage input cylindrical gear shaft via a second clutch and a third clutch. The first-stage output bevel gear shaft is connected to the two-stage input cylindrical gear shaft via a third clutch. The two-stage input cylindrical gear shaft transmits power to the two-stage output cylindrical gear through a meshing pair. The two-stage output cylindrical gear is fixedly connected to the transmission shaft. The transmission shaft is fixedly connected to the three-stage input cylindrical gear. The three-stage input cylindrical gear transmits power to the three-stage output cylindrical gear through a meshing pair. The three-stage output cylindrical gear is fixedly connected to the sun gear shaft. The sun gear shaft transmits power to the planetary carrier through the meshing of the sun gear and planetary gears. One end of the planetary carrier is connected to the planetary gears via bearings, and the other end is fixedly connected to the housing. The housing is connected to the parallel shaft and the frame via rotating pairs.

2. The tilt rotor power transmission system with shared power source according to claim 1, characterized in that: The power input device includes a power source, a first clutch, and a first-stage input bevel gear shaft. The power source is fixed on the frame. The power output shaft of the power source is connected to and disconnected from the first-stage input bevel gear shaft through the first clutch. The first-stage input bevel gear shaft is connected to a first-stage output bevel gear and a first-stage output bevel gear shaft through meshing pairs.

3. The tilt rotor power transmission system with shared power source according to claim 1, characterized in that: The tilting transmission structure is connected to a brake.

4. The tilt rotor power transmission system with shared power source according to claim 1, characterized in that: The short drive shaft, long drive shaft, and parallel shaft are all single shafts.

5. The tilt rotor power transmission system with shared power source according to claim 1, characterized in that: The short drive shaft, long drive shaft, and parallel shaft are multiple shafts connected by couplings or differential gear trains.

6. The tilt rotor power transmission system with shared power source according to claim 1, characterized in that: The housing has circular holes on both the left and right sides. The inner circular surface of the left hole is connected to the parallel shaft through a bearing, and the outer circular surface is connected to the frame through a bearing. The right hole is connected to the parallel shaft only on the inner circular surface through a bearing. At the same time, the right side wall of the housing is fixedly connected to the planetary carrier.

7. A method for operating a tiltrotor power transmission system with shared power source as described in claim 1, characterized in that... Includes the following steps: When the tiltrotor aircraft is preparing to take off on the ground, the tilt structure tilts so that the rotor blades rotate parallel to the horizontal plane. At this time, driven by the power source, the power is transmitted to the rotor shaft through the first-stage bevel gear pair and the second-stage bevel gear pair, which drives the rotor to rotate. The left and right rotors rotate in opposite directions. At this time, under the lift generated by the rotation of the rotor, the aircraft rises vertically. Once the aircraft has ascended to a suitable altitude, the second clutch is engaged, and power is transmitted through the first-stage bevel gear pair to the second-stage cylindrical gear shaft. At this point, the brake is released, and power is transmitted through the second-stage cylindrical gear pair, the third-stage cylindrical gear pair, and the planetary gear system to the housing, causing the housing, rotor shaft, and propeller to rotate counterclockwise. The rotation range is 0° to 90°. When the angle is set to 90°, it is in level flight mode. To maintain level flight mode, the brake is locked, and then the second clutch is disengaged. When the aircraft needs to switch from level flight to vertical takeoff and landing, by engaging the third clutch, disengaging the second clutch, and releasing the brake, power is transmitted through the first-stage bevel gear pair and the third clutch to the second-stage cylindrical gear shaft, and then through the second-stage cylindrical gear pair, the third-stage cylindrical gear pair, and the planetary gear system to the housing, driving the housing, rotor shaft, and propeller to rotate clockwise.

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