A motor structure with high axial and bending moment carrying capacity and an aircraft

Abstract

The application relates to the field of motors, in particular to a motor structure with high axial and bending moment bearing capacity and an aircraft, the motor structure comprising a stator, a rotor, a casing, a front end cover, a rear end cover, two angular contact bearings and a bearing baffle; the stator is installed on the casing; the rotor is rotatably installed in the stator; the rotor comprises a rotating shaft and a rotor body, the front end of the rotating shaft penetrates through the front end cover, the middle part of the rotor body along the axial direction of the rotating shaft is assembled with the rotating shaft, and the two ends and the rotating shaft form a spacing space, the angular contact bearings, the first bearing chamber and the bearing baffle are accommodated in the corresponding spacing space; the front end cover and the rear end cover are installed on the axial two ends of the casing; the first bearing chamber is arranged on the rear end cover, the two angular contact bearings are assembled in the first bearing chamber and are assembled with the rear end of the rotating shaft; the two angular contact bearings are back-to-back paired along the axial direction of the rotating shaft; and the bearing baffle is installed on the rear end cover. The motor structure in the application can significantly improve the motor torque density without sacrificing the structural strength and operation reliability.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and more specifically to a motor structure and aircraft with high axial and bending moment load-bearing capacity. Background Technology

[0002] Against the backdrop of rapid development in the low-altitude economy, 2-3 ton class manned or cargo low-altitude vertical takeoff and landing (VTOL) aircraft have become an important development direction in the low-altitude general aviation field. Their propulsion motors (rotor motors) are one of the core components ensuring the stable operation of the aircraft. These motors primarily bear axial forces during operation. For some tiltrotor aircraft, in addition to bearing the aforementioned axial forces, the motors also experience significant bending moments during rotor tilt switching. Furthermore, due to the stringent requirements for motor torque density in aircraft, to balance power performance and lightweight design, the diameter of these motors is typically designed to be 350-500 mm. Their fuselage and end caps are mostly made of lightweight aluminum alloy, with an overall average thickness of only about 3 mm, except for the reinforcing ribs, making them typical thin-walled structural components.

[0003] In the prior art, the housing and end covers of the aforementioned propulsion motor directly bear the axial force and bending moment generated during operation. However, due to the inherent characteristics of the thin-walled structure, its structural strength and load-bearing capacity are limited, making it unable to effectively withstand such loads. This can easily lead to structural failures such as deformation and cracking, affecting the normal operation of the motor.

[0004] The aforementioned structural defects not only limit the space for lightweight design of thin-walled components such as motor housings and end caps, preventing further reduction in their thickness to lower structural weight, but also restrict the improvement of motor torque density. In other words, if the thickness of thin-walled components is forcibly reduced in pursuit of lightweight and high torque density, their load-bearing capacity will be further reduced, resulting in a significant decrease in motor structural strength and operational reliability. This makes it impossible to meet the safe operation requirements of 2-3 ton class low-altitude vertical take-off and landing aircraft, becoming a major bottleneck in the development of motor technology in this field.

[0005] Therefore, in response to the aforementioned problems with the propulsion motors of existing 2-3 ton class low-altitude vertical take-off and landing aircraft, it is urgent to propose a reasonable structural improvement scheme so that thin-walled components such as the fuselage and end caps do not bear the main axial and bending moment loads. This would allow the main structural components such as the fuselage and end caps to be designed to be thinner and lighter, effectively improving the motor torque density while ensuring the structural strength and operational reliability of the motor, and meeting the lightweight and high safety requirements of the aircraft.

[0006] In view of this, how to overcome the shortcomings of the existing technology has become the subject of study and solution of this invention. Summary of the Invention

[0007] The purpose of this invention is to provide a motor structure and an aircraft with high axial and bending moment load-bearing capacity.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A motor structure with high axial and bending moment load-bearing capacity includes a stator, a rotor, a housing, a front cover, a rear cover, two angular contact bearings and bearing baffles;

[0010] The stator is fixedly mounted on the housing;

[0011] The rotor is rotatably mounted inside the stator; the rotor includes a shaft, the front end of which passes through the front end cover and is used for assembly with the aircraft rotor.

[0012] The front end cover and the rear end cover are respectively installed at both axial ends of the housing;

[0013] The rear end cover has a first bearing chamber, and both angular contact bearings are assembled in the first bearing chamber and are assembled with the rear end of the rotating shaft; the two angular contact bearings are arranged back to back along the axial direction of the rotating shaft.

[0014] The bearing baffle is installed on the rear end cover and is used to cooperate with the first bearing chamber along the axial direction of the rotating shaft to limit the two angular contact bearings.

[0015] The rotor further includes a rotor body. Along the axial direction of the rotating shaft, the middle part of the rotor body is assembled with the rotating shaft, and both ends of the rotor body form a space between them and the rotating shaft. The angular contact bearing, the first bearing chamber, and the bearing baffle are all accommodated in the corresponding space.

[0016] The motor structure is configured to have a first operating state and a second operating state:

[0017] In the first working state, the axial force generated by the aircraft rotor is transmitted to the rotating shaft, then from the rotating shaft to the two angular contact bearings, and then to the first bearing housing and the bearing baffle.

[0018] In the second operating state, the force generated by the aircraft rotor during pitching or tilting will act radially on the shaft to generate bending stress, and gradually be transmitted to the two angular contact bearings and the first bearing chamber.

[0019] In this application, axial direction refers to the axis of rotation, radial direction refers to the radial direction of rotation, and outward direction refers to the direction upward from the center of rotation.

[0020] The rotor body refers to the part of the rotor other than the shaft, such as the rotor core, which is well known to those skilled in the art and will not be described in detail here. The assembly method of the rotor body and the shaft is also a conventional method.

[0021] The shaft has a shaft extension end that extends out of the housing (through the front cover), which serves as the rotor mounting end for assembly with the aircraft rotor.

[0022] During operation, the axial force (or lift, axial tension) generated by the aircraft rotor is transmitted to the shaft, then from the shaft to the two angular contact bearings, and then to the first bearing housing (or the bearing housing area on the rear end cover) and the bearing baffle. Finally, it can be transmitted to the aircraft's wings or other structural components through the flange structure described below (explained here for understanding; see the description below for details). In other words, the axial force is concentrated only on these structures (or areas), which can be considered as forming load-bearing areas (including the mounting interfaces and flange structures described below). This means that certain areas on the fuselage, front end cover, and rear end cover (or the area surrounding the bearing housing area, understood as thin-walled sections) do not need to bear axial force, thus allowing for lightweight design by ignoring axial force. For example, lightweight aluminum alloy materials can be used, and the average wall thickness can be 3-4 mm.

[0023] Furthermore, when the aircraft performs pitch or tilt operations, the rotor generates a bending moment on the rotor shaft. Specifically, the force generated during pitch or tilting acts radially on the shaft extension, causing bending stress on the shaft, which is gradually transmitted to the first bearing housing. Ultimately, this stress can also be transmitted to the aircraft's wings or other structural components through the mounting interface (with a flange structure). This means that some areas on the fuselage, front cover, and rear cover do not need to bear bending moments, thus allowing for negligible bending moment effects and lightweight design.

[0024] Understandably, all structures within the load-bearing area can be reinforced (considered reinforced design areas). For example, bearing baffles (which can be steel plates) and bearing housing areas can be made of steel. These structures do not require lightweight design to ensure high load-bearing capacity against axial forces and bending moments. Specifically, reinforced design areas can be made of high-strength alloy steel; if further weight reduction is required, TC4 titanium alloy can also be used.

[0025] It should be noted that back-to-back (DB) paired angular contact bearings can withstand bidirectional axial forces and bending moment loads, and facilitate bearing preload, improving rotational accuracy. An example of DB pairing is as follows: the outer ring wide end faces of the two DB paired angular contact bearings face each other, with the contact angle bisectors diverging outwards. This significantly increases the effective support point spacing of the bearings. From a mechanical perspective, a larger support span enhances the bearing's resistance to bending moments. The overturning moment generated under bending moment can be effectively offset by the support reaction forces of the two bearings, thereby effectively suppressing the bending deformation of the main shaft (rotating shaft).

[0026] In summary, the motor structure in this application decouples the load transmission path by setting up a dedicated load-bearing area that independently bears axial force and bending moment. This eliminates the need for certain areas of the fuselage, front cover, and rear cover to share the axial force and bending moment. Under this design, certain areas of the fuselage, front cover, and rear cover can utilize thinner walls for weight reduction. Simultaneously, critical loads are independently borne by the dedicated load-bearing area, significantly improving motor torque density without sacrificing structural strength and operational reliability. This structurally better meets the requirements of (2-3 ton class) low-altitude vertical takeoff and landing aircraft for lightweight, highly reliable, and high-power-density propulsion motors.

[0027] Furthermore, the space between the two ends of the rotor body and the shaft can be considered as a hollow design for the rotor, with the rear end cover extending into this hollow area (i.e., the space). The middle area of ​​the rotor body is not limited, as long as the angular contact bearing, the first bearing housing, and the bearing baffle are all accommodated in the corresponding (adjacent) space. In this case, on the one hand, these structures do not protrude outward relative to the shaft in the axial direction, and the degree of outward protrusion of the rear end cover can also be limited, which can shorten the axial dimension of the motor structure and achieve compactness and weight reduction of the motor structure; on the other hand, by increasing the installation spacing of the angular contact bearing, the support arm can be extended, thereby further improving the bending moment resistance.

[0028] It should be noted that the motor structure in this application includes, but is not limited to, applications in 2-3 ton vertical take-off and landing aircraft, and can be extended to the field of wheel-side motors that need to withstand large bending moment loads. The rated power of the motor is about 200kW, the peak torque is greater than 1800Nm, the speed does not exceed 2000rpm, and the maximum outer diameter does not exceed 500mm.

[0029] A further technical solution also includes a bearing structure, wherein a second bearing chamber is provided on the front end cover, the bearing structure is assembled in the second bearing chamber, and is assembled with the front end of the rotating shaft;

[0030] The bearing structure is a roller bearing or a deep groove ball bearing;

[0031] Both the bearing structure and the second bearing chamber are housed in corresponding space intervals, further achieving a compact and lightweight motor structure.

[0032] Taking a roller bearing (preferably with strong radial load capacity) as an example, although this roller bearing cannot assist in bearing axial loads, it has a strong radial load-bearing capacity, which can provide auxiliary support for the shaft (involving bending moment). After the front cover is designed to be lightweight, although it cannot withstand large axial loads, the part of the front cover that extends into the gap space can withstand radial loads.

[0033] To elaborate further, when a bending moment is applied to a shaft system (rotating shaft), it will cause the shaft to bend and deform. This can be regarded as one side of the shaft being compressed and the other side being stretched. The half-circle roller of the roller bearing will bear the concentrated load. The bending moment is converted into contact stress through the line contact between the roller and the raceway, and then transmitted outward (such as by setting up a bearing housing structure to transmit it to it).

[0034] A further technical solution is that the rear end cover is provided with an installation interface, and the installation interface is provided with a flange structure. The rear end cover can be connected to the wing or other structural components of the aircraft through the flange structure at the installation interface, so as to transmit the lift or thrust generated by the rotor to the wing or other structural components of the aircraft.

[0035] The rear end cover is the end cover facing away from the rotor mounting side. The corresponding flange stop and bearing housing are both formed on the rear end cover. This integrated design can better ensure the realization of high axial and bending moment load-bearing capacity.

[0036] It should be noted that the mechanical mounting interface of the motor of a low-altitude vertical take-off and landing aircraft is generally located on the rear cover (the front cover has rotors on the outside, making it difficult to design a mounting interface). In addition, due to the high power density requirements, the shell needs to be made thin, so the front cover is not suitable for bearing axial force (the axial force of the aircraft motor is very large during the take-off and landing phase because the aircraft motor needs to take off and land vertically).

[0037] A further technical solution involves a portion of the flange structure extending into the corresponding interval space. It is understood that the length of the flange structure can be extended to improve its ability to withstand axial forces and bending moments, while avoiding an increase in the axial dimensions of the motor structure because it can extend into the corresponding interval space.

[0038] In a further technical solution, along the radial direction of the rotating shaft, the maximum outer contour dimension of the mounting interface is greater than the maximum outer contour dimension of the spacing space.

[0039] The mounting interface may be an irregular structure, therefore, it is described using the maximum outer contour dimension. This application describes it as having both the mounting interface and the spacer having cylindrical outer contours; in this case, the radial dimension of the mounting interface can be considered larger than the radial dimension of the spacer. Based on this, the flange structure can be considered thicker to further improve its ability to withstand axial forces and bending moments.

[0040] A further technical solution is that, along the radial direction of the rotating shaft, the maximum outer contour dimension of the mounting interface is less than or equal to half of the maximum outer contour dimension of the rear end cover, in order to balance the high load-bearing capacity requirement of the flange structure and the lightweight requirement of the motor structure.

[0041] A further technical solution is that, along the radial direction of the rotating shaft, the projection of the rear end of the rotating shaft is covered by the projection of the flange structure. At this time, the rear end of the rotating shaft does not protrude outward, thus avoiding extending the axial dimension of the motor structure and avoiding interference with the assembly of the flange structure and the aircraft wing structure.

[0042] A further technical solution also includes a bearing housing, through which the angular contact bearing is assembled in the first bearing chamber. The bearing housing can achieve precise positioning and reliable support of the angular contact bearing, improve assembly accuracy and load-bearing capacity, and facilitate disassembly and maintenance. In particular, it can distribute the load of the angular contact bearing and improve load-bearing stability.

[0043] In a further technical solution, the bearing baffle is fixedly installed on one end face of the first bearing chamber through multiple threaded structures. It can be regarded as the bearing baffle and the first bearing chamber forming an integral part, ensuring that it and the first bearing chamber bear axial force together, thereby improving the ability to withstand axial force.

[0044] In some implementations, the bearing housings and mounting interfaces are reinforced, such as by installing reinforcing ribs on their walls.

[0045] In some embodiments, the axial displacement of the inner rings of each bearing is limited by a locking nut mounted on the shaft, and the outer rings of the bearings are limited by a bearing baffle.

[0046] An aircraft is also provided herein, which includes the motor structure of any of the above embodiments.

[0047] Due to the application of the above-mentioned solution, the technical solution of this application has the following advantages and effects compared with the prior art:

[0048] During operation, the axial force generated by the aircraft rotor is transmitted to the shaft, then from the shaft to the two angular contact bearings, and then to the first bearing housing and bearing baffle. Finally, it can be transmitted to the aircraft's wings or other structural components. In other words, the axial force is concentrated only on these structures, which can be considered as forming load-bearing areas. This means that some areas on the fuselage, front cover, and rear cover do not need to bear axial force, thus allowing for the neglect of axial force and enabling lightweight design.

[0049] Furthermore, when the aircraft performs pitch or tilt operations, the rotor generates a bending moment on the rotor shaft. Specifically, the force generated during pitch or tilting acts radially on the shaft extension, causing bending stress on the shaft, which is gradually transmitted to the first bearing housing and ultimately to the aircraft's wings or other structural components. This means that some areas on the fuselage, front cover, and rear cover do not need to bear bending moments, thus allowing for negligible bending moment effects and lightweight design.

[0050] Meanwhile, back-to-back (DB) paired angular contact bearings can withstand bidirectional axial forces and bending moment loads, and facilitate bearing preload, improving rotational accuracy. An example of DB pairing is as follows: the outer ring wide end faces of the two DB-paired angular contact bearings face each other, with the contact angle bisectors diverging outwards. This significantly increases the effective support point spacing of the bearings. From a mechanical perspective, a larger support span enhances the bearing's resistance to bending moments. The overturning moment generated under bending moment can be effectively offset by the support reaction forces of the two bearings, thereby effectively suppressing the bending deformation of the main shaft (rotating shaft).

[0051] In summary, the motor structure in this application decouples the load transmission path by setting up a dedicated load-bearing area that independently bears axial force and bending moment. This eliminates the need for certain areas of the fuselage, front cover, and rear cover to share the axial force and bending moment. Under this design, certain areas of the fuselage, front cover, and rear cover can utilize thinner walls for weight reduction. Simultaneously, critical loads are independently borne by the dedicated load-bearing area, significantly improving motor torque density without sacrificing structural strength and operational reliability. This structurally better meets the requirements of (2-3 ton class) low-altitude vertical takeoff and landing aircraft for lightweight, highly reliable, and high-power-density propulsion motors.

[0052] Furthermore, the space between the two ends of the rotor body and the shaft can be considered as a hollow design for the rotor, with the rear end cover extending into this hollow area. In this design, on the one hand, none of these structures protrude outward relative to the shaft in the axial direction, and the degree of outward protrusion of the rear end cover can be limited, thus shortening the axial dimension of the motor structure and achieving a compact and lightweight design. On the other hand, by increasing the installation spacing of the angular contact bearings, the support lever arm can be extended, thereby further improving the bending moment resistance. Attached Figure Description

[0053] Figure 1 This is a partial cross-sectional view of the motor structure according to an embodiment of the present invention.

[0054] In the attached diagrams above:

[0055] 1. Stator;

[0056] 2. Rotor; 21. Shaft; 22. Rotor body;

[0057] 3. Housing;

[0058] 4. Front cover; 41. Second bearing chamber;

[0059] 5. Rear end cover; 51. First bearing chamber; 52. Mounting interface;

[0060] 6. Angular contact bearing; 7. Bearing baffle; 8. Spacer; 9. Bearing structure. Detailed Implementation

[0061] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0062] The terms "first," "second," etc., used in this article do not specifically refer to order or sequence, nor are they intended to limit this case; they are merely used to distinguish components or operations described using the same technical terms.

[0063] The terms "connection" or "positioning" as used in this article can refer to two or more components or devices making direct physical contact with each other, or making indirect physical contact with each other, or to two or more components or devices operating or moving with each other.

[0064] The terms “include,” “including,” and “have” used in this article are all open-ended, meaning they include but are not limited to.

[0065] Unless otherwise specified, the terms used herein generally have their ordinary meaning in the context of the art, the subject matter, and the specific context. Certain terms used to describe this case will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in describing this case.

[0066] The terms “front,” “back,” “up,” “down,” “left,” and “right” used in this article are directional terms. In this case, they are only used to describe the positional relationship between the structures and are not intended to limit the specific direction of the protection scheme or its actual implementation.

[0067] The terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the scope of this work. Singular forms such as “a,” “this,” “this,” “the,” and “the” as used herein also include plural forms.

[0068] See Figure 1 A motor structure with high axial and bending moment bearing capacity includes a stator 1, a rotor 2, a housing 3, a front cover 4, a rear cover 5, two angular contact bearings 6 and a bearing baffle 7.

[0069] The stator 1 is fixedly installed on the housing 3;

[0070] The rotor 2 is rotatably mounted inside the stator 1; the rotor 2 includes a shaft 21, the front end of which passes through the front end cover 4;

[0071] The front cover 4 and the rear cover 5 are respectively installed at both axial ends of the housing 3;

[0072] The rear end cover 5 has a first bearing chamber 51, and both of the two angular contact bearings 6 are assembled in the first bearing chamber 51 and are assembled with the rear end of the rotating shaft 21; the two angular contact bearings 6 are arranged back to back along the axial direction of the rotating shaft 21.

[0073] The bearing baffle 7 is installed on the rear end cover 5 and is used to cooperate with the first bearing chamber 51 along the axial direction of the rotating shaft 21 to limit the two angular contact bearings 6.

[0074] In this embodiment, the axial direction refers to the axial direction of the rotating shaft 21, the radial direction refers to the radial direction of the rotating shaft 21, and the outward direction refers to the direction of the axial direction away from the middle of the rotating shaft 21.

[0075] The pivot 21 has a shaft extension end that extends out of the housing 3 (through the front cover 4), which serves as a rotor mounting end for assembly with the aircraft rotor.

[0076] During operation, the axial force (or lift, axial tension) generated by the aircraft rotor is transmitted to the shaft 21, then from the shaft 21 to the two angular contact bearings 6, and then to the first bearing housing 51 (or the bearing housing area on the rear end cover 5) and the bearing baffle 7. Finally, it can be transmitted to the aircraft wing or other structural components through the flange structure described below (explained here for understanding; see the description below for details). That is, the axial force is concentrated only on these structures (or areas), which can be regarded as forming a load-bearing area (which may include the mounting interface 52 and the flange structure described below). This means that some areas on the housing 3, the front end cover 4, and the rear end cover 5 (or the area surrounding the bearing housing area, understood as thin-walled parts) do not need to bear the axial force, thus the axial force can be ignored for lightweight design. For example, it can be made of lightweight aluminum alloy material, and the average wall thickness can be 3-4 mm.

[0077] Furthermore, when the aircraft performs pitch or tilt operations, the rotor will exert a bending moment on the shaft 21. Specifically, the force generated during pitch or tilt will act radially on the shaft extension end of the shaft 21, causing bending stress in the shaft 21, which is gradually transmitted to the first bearing housing 51. Ultimately, it can also be transmitted to the aircraft's wings or other structural components through the mounting interface end (with a flange structure). This means that some areas on the fuselage 3, front cover 4, and rear cover 5 do not need to bear bending moment, thus allowing for negligible bending moment effects and lightweight design.

[0078] Understandably, all structures within the load-bearing area can be reinforced (considered reinforced design areas). For example, the bearing baffle 7 (which can be a steel plate) and the bearing housing area can be made of steel. These structures do not require lightweight design to ensure high load-bearing capacity against axial forces and bending moments. Specifically, the reinforced design areas can be made of high-strength alloy steel; if further weight reduction is required, TC4 titanium alloy can also be used.

[0079] It should be noted that the back-to-back (DB) paired angular contact bearings 6 can withstand bidirectional axial forces and bending moment loads, and facilitate bearing preload, thereby improving rotational accuracy. An example of DB pairing is as follows: the outer ring wide end faces of the two DB paired angular contact bearings 6 face each other, and the contact angle bisectors diverge outwards, significantly increasing the effective support point spacing of the bearings. From a mechanical perspective, a larger support span enhances the bearing's resistance to bending moments. The overturning moment generated under bending moment can be effectively offset by the support reaction forces of the two bearings, thus effectively suppressing the bending deformation of the main shaft (rotating shaft 21).

[0080] In summary, the motor structure actually has a first operating state and a second operating state (it can be in only one state or in both states at the same time during operation):

[0081] In the first working state, the axial force generated by the aircraft rotor is transmitted to the rotating shaft 21, and then from the rotating shaft 21 to the two angular contact bearings 6, and then to the first bearing chamber 51 and the bearing baffle 7.

[0082] In the second operating state, the force generated by the aircraft rotor during pitching or tilting will act radially on the shaft 21 to generate bending stress, and gradually transmit it to the two angular contact bearings 6 and the first bearing chamber 51.

[0083] In summary, the motor structure in this application decouples the load transmission path by setting up a dedicated load-bearing area that independently bears the axial force and bending moment. This eliminates the need for certain areas of the fuselage 3, front cover 4, and rear cover 5 to share the axial force and bending moment. Under this design, certain areas of the fuselage 3, front cover 4, and rear cover 5 can utilize thinner walls for weight reduction. Simultaneously, critical loads are independently borne by the dedicated load-bearing area, which neither sacrifices structural strength nor operational reliability, but also significantly improves the motor torque density. This structurally better meets the requirements of (2-3 ton class) low-altitude vertical takeoff and landing aircraft for lightweight, high-reliability, and high-power-density propulsion motors.

[0084] It should be noted that the motor structure in this application includes, but is not limited to, applications in 2-3 ton vertical take-off and landing aircraft, and can be extended to the field of wheel-side motors that need to withstand large bending moment loads. The rated power of the motor is about 200kW, the peak torque is greater than 1800Nm, the speed does not exceed 2000rpm, and the maximum outer diameter does not exceed 500mm.

[0085] In one embodiment of this application, the rotor 2 includes a rotor body 22 along the axial direction of the rotating shaft 21. The middle part of the rotor body 22 is assembled with the rotating shaft 21, and both ends of the rotor body 22 form a space 8 between it and the rotating shaft 21. The angular contact bearing 6, the first bearing chamber 51 and the bearing baffle 7 are all accommodated in the corresponding space 8.

[0086] The rotor body 22 refers to the part of the rotor 2 other than the shaft 21, such as the rotor core. This is well known to those skilled in the art and will not be described in detail here. The assembly method of the rotor body 22 and the shaft 21 is also a conventional method.

[0087] The rotor body 22 has a space 8 between its two ends and the shaft 21, which can be regarded as a hollow design of the rotor 2. The rear end cover 5 extends into the hollow area (i.e., the space 8).

[0088] The central region of the rotor body 22 is not limited, as long as the angular contact bearing 6, the first bearing chamber 51 and the bearing baffle 7 are all accommodated in the corresponding (adjacent) space 8. In this case, on the one hand, these structures do not protrude outward relative to the shaft 21 in the axial direction, and the degree of outward protrusion of the rear end cover 5 can also be limited, which can shorten the axial dimension of the motor structure and achieve compactness and lightweighting of the motor structure; on the other hand, by increasing the installation spacing of the angular contact bearing 6, the support arm can be extended, thereby improving the bending moment resistance.

[0089] In one embodiment of this application, a bearing structure 9 is further included. A second bearing chamber 41 is provided on the front end cover 4. The bearing structure 9 is assembled in the second bearing chamber 41 and is assembled with the front end of the rotating shaft 21.

[0090] The bearing structure 9 is constructed as a roller bearing or a deep groove ball bearing;

[0091] Both the bearing structure 9 and the second bearing chamber 41 are accommodated in the corresponding space 8, further realizing the compactness and lightweight of the motor structure.

[0092] Taking the bearing structure 9 as an example, which is constructed as a roller bearing (preferably with strong radial load capacity), although this roller bearing cannot assist in bearing axial loads, it has a strong radial load bearing capacity, which can provide auxiliary support for the shaft 21 (involving bending moment). After the front cover 4 is designed to be lightweight, although it cannot bear large axial loads, the part of the front cover 4 that extends into the gap space 8 can bear radial loads.

[0093] To elaborate further, when a bending moment is applied to the shaft system (shaft 21), it will cause the shaft to bend and deform. This can be regarded as one side of the shaft being compressed and the other side being stretched. The half-circle roller of the roller bearing will bear the concentrated load. The bending moment is converted into contact stress through the line contact between the roller and the raceway, and then transmitted outward (such as by setting up a bearing housing structure to transmit it to it).

[0094] In one embodiment of this application, the rear end cover 5 is provided with an installation interface 52, and the installation interface 52 is provided with a flange structure (not shown in the figure). The rear end cover 5 can be connected to the wing or other structural components of the aircraft through the flange structure at the installation interface 52, so as to transmit the lift or pull generated by the rotor to the wing or other structural components of the aircraft.

[0095] The rear end cover 5 is the end cover facing away from the rotor mounting side. The corresponding flange stop and bearing housing are both formed on the rear end cover 5. This integrated design can better ensure the realization of high axial and bending moment bearing capacity.

[0096] It should be noted that the mechanical mounting interface 52 of the motor of the low-altitude vertical take-off and landing aircraft is generally located on the rear cover 5 (the front cover 4 has rotors on the outside, making it difficult to design the mounting interface 52). In addition, due to the high power density requirements, the shell needs to be made thin, so the front cover 4 is not suitable to bear axial force (the axial force of the aircraft motor is very large during the take-off and landing phase because it needs to take off and land vertically).

[0097] In one embodiment of this application, a portion of the flange structure extends into the corresponding interval space 8. It is understood that the length of the flange structure can be extended to improve its ability to withstand axial forces and bending moments, while avoiding an increase in the axial dimension of the motor structure because it can extend into the corresponding interval space 8.

[0098] In one embodiment of this application, the maximum outer contour dimension of the mounting interface 52 is greater than the maximum outer contour dimension of the spacing space 8 along the radial direction of the rotating shaft 21.

[0099] The mounting interface 52 may be an irregular structure; therefore, it will be described using the maximum outer contour dimension. In this embodiment, both the mounting interface 52 and the spacer 8 are cylindrical in shape. In this case, the radial dimension of the mounting interface 52 can be considered larger than the radial dimension of the spacer 8. The dimensions of the flange structure are limited by the dimensions of the mounting interface 52, and the flange structure is generally adapted to the dimensions of the mounting interface 52. Based on this, the flange structure can be considered relatively thick to further improve its ability to withstand axial forces and bending moments.

[0100] In one embodiment of this application, the maximum outer contour dimension of the mounting interface 52 along the radial direction of the rotating shaft 21 is less than or equal to half of the maximum outer contour dimension of the rear end cover 5, so as to balance the high load-bearing capacity requirement of the flange structure and the lightweight requirement of the motor structure.

[0101] In one embodiment of this application, along the radial direction of the rotating shaft 21, the projection of the rear end of the rotating shaft 21 is covered by the projection of the flange structure. At this time, the rear end of the rotating shaft 21 does not protrude outward, thus avoiding extending the axial dimension of the motor structure and avoiding interference with the assembly of the flange structure and the aircraft wing structure.

[0102] In one embodiment of this application, a bearing housing (not shown in the figure) is also included. The angular contact bearing 6 is assembled in the first bearing chamber 51 through the bearing housing. The bearing housing can achieve precise positioning and reliable support of the angular contact bearing 6, improve assembly accuracy and load-bearing capacity, and facilitate disassembly and maintenance. In particular, it can distribute the load of the angular contact bearing 6 and improve load-bearing stability.

[0103] In one embodiment of this application, the bearing baffle 7 is fixedly installed on one end face of the first bearing chamber 51 by multiple threaded structures. It can be regarded as the bearing baffle 7 and the first bearing chamber 51 forming an integral part, ensuring that it and the first bearing chamber 51 bear axial force together, thereby improving the ability to withstand axial force.

[0104] In some embodiments, each bearing chamber and mounting interface 52 is reinforced, such as by installing reinforcing ribs on its walls (not shown in the figure).

[0105] In some embodiments, the axial displacement of the inner rings of each bearing is limited by a locking nut (not shown in the figure) installed on the shaft 21, and the outer rings of the bearings are limited by the bearing baffle 7.

[0106] An aircraft is also provided herein, which includes the motor structure of any of the above embodiments.

[0107] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A motor structure with high axial and bending moment bearing capacity, characterized in that: It includes a stator (1), a rotor (2), a housing (3), a front cover (4), a rear cover (5), two angular contact bearings (6) and a bearing baffle (7); The stator (1) is fixedly installed on the housing (3); The rotor (2) is rotatably mounted inside the stator (1); the rotor (2) includes a shaft (21), the front end of which passes through the front end cover (4) and is used for assembly with the aircraft rotor. The front end cover (4) and the rear end cover (5) are respectively installed at both axial ends of the housing (3); The rear end cover (5) is provided with a first bearing chamber (51), and the two angular contact bearings (6) are both assembled in the first bearing chamber (51) and are both assembled with the rear end of the rotating shaft (21); the two angular contact bearings (6) are arranged back to back along the axial direction of the rotating shaft (21). The bearing baffle (7) is installed on the rear end cover (5) and is used to limit the two angular contact bearings (6) by cooperating with the first bearing chamber (51) along the axial direction of the rotating shaft (21). The rotor (2) further includes a rotor body (22). Along the axial direction of the rotating shaft (21), the middle part of the rotor body (22) is assembled with the rotating shaft (21). Both ends of the rotor body (22) form a space (8) between it and the rotating shaft (21). The angular contact bearing (6), the first bearing chamber (51) and the bearing baffle (7) are all accommodated in the corresponding space (8). The motor structure is configured to have a first operating state and a second operating state: In the first working state, the axial force generated by the rotor of the aircraft is transmitted to the rotating shaft (21), and then from the rotating shaft (21) to the two angular contact bearings (6), and then to the first bearing chamber (51) and the bearing baffle (7); In the second operating state, the force generated by the aircraft rotor during pitching or tilting will act radially on the shaft (21) to generate bending stress, and gradually transmit it to the two angular contact bearings (6) and the first bearing chamber (51).

2. The motor structure with high axial and bending moment bearing capacity according to claim 1, characterized in that: It also includes a bearing structure (9), on which a second bearing chamber (41) is provided, the bearing structure (9) is assembled in the second bearing chamber (41) and is assembled with the front end of the rotating shaft (21); The bearing structure (9) is constructed as a roller bearing or a deep groove ball bearing; The bearing structure (9) and the second bearing chamber (41) are both housed in the corresponding space (8).

3. The motor structure with high axial and bending moment bearing capacity according to claim 1, characterized in that: The rear cover (5) is provided with an installation interface (52), and a flange structure is provided at the installation interface (52).

4. The motor structure with high axial and bending moment bearing capacity according to claim 3, characterized in that: Part of the flange structure extends into the corresponding interval space (8).

5. A motor structure with high axial and bending moment bearing capacity according to claim 4, characterized in that: Along the radial direction of the pivot (21), the maximum outer contour dimension of the mounting interface (52) is greater than the maximum outer contour dimension of the space (8).

6. The motor structure with high axial and bending moment bearing capacity according to claim 5, characterized in that: Along the radial direction of the pivot (21), the maximum outer contour dimension of the mounting interface (52) is less than or equal to half the maximum outer contour dimension of the rear end cover (5).

7. The motor structure with high axial and bending moment bearing capacity according to claim 3, characterized in that: Along the radial direction of the shaft (21), the projection of the rear end of the shaft (21) is covered by the projection of the flange structure.

8. A motor structure with high axial and bending moment bearing capacity according to any one of claims 1-7, characterized in that: It also includes a bearing housing, through which the angular contact bearing (6) is assembled to the first bearing chamber (51).

9. A motor structure with high axial and bending moment bearing capacity according to any one of claims 1-7, characterized in that: The bearing baffle (7) is fixedly installed on one end face of the first bearing chamber (51) by multiple threaded structures.

10. An aircraft, characterized in that: The invention comprises a motor structure having high axial and bending moment bearing capacity as described in any one of claims 1-9.

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