Bearing structure for motor duct integration and control method

Abstract

The invention belongs to the technical field of motors, and particularly relates to a bearing structure for motor duct integration and a control method. Comprising a duct shell and fan blades. The fan blades are shaftless fan blades and located in the duct space, and the ends, facing the duct shell, of the fan blades are connected with permanent magnet poles. A bearing main body is arranged between the inner wall of the duct shell and the permanent magnet poles; the bearing main body is made of a permanent magnet material; through the magnetic force in the bearing main body, the permanent magnet poles are suspended and fixed in the ducted space and do not deviate; the positions of the permanent magnetic poles are fixed under the action of static magnetic force in the bearing main body, so that the motor is fixed and does not deviate in the working process, the power density of the motor is effectively improved, and the weight of the motor is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of motors, and in particular relates to a bearing structure for motor duct integration and a control method. Background Art

[0002] The successive introduction of low-altitude economic policies has led to the rapid development of low-altitude aircraft with eVTOL (electric vertical take-off and landing aircraft) as the core. Low-altitude aircraft such as eVTOL generally use pure electric propulsion, and the motor, as one of the key technologies, determines the overall performance of the aircraft. For low-altitude aircraft such as eVTOL, the motor needs to have high power density and torque density to improve the thrust-to-weight ratio. At present, direct-drive motors using permanent magnet materials are the main technical route. According to the different flux paths in the motor structure, it can be divided into axial flux motors and radial flux motors. Compared with radial flux motors, axial flux motors have a compact structure, higher power density and efficiency, and are more suitable for aviation fields that require high torque density and high efficiency. The integrated design of axial flux motors and ducts can better improve the overall performance of the motor. But on the one hand, the bearings cannot meet the requirements of high-speed and large-size motors; on the other hand, in a limited space, how the bearing structure can be coordinated with the motor and duct also faces problems. Summary of the invention

[0003] In view of the above problems, the present invention proposes a bearing structure for motor duct integration, comprising a duct housing and a fan blade; the fan blade is a shaftless fan blade, six separate fan blades are located in the duct space, and one end of the fan blade facing the duct housing is connected to a permanent magnetic pole; a bearing body is arranged between the inner wall of the duct housing and the permanent magnetic pole; the bearing body is made of permanent magnetic material;

[0004] Through the magnetic force between the permanent magnetic poles and the duct housing of the bearing body, the permanent magnetic poles are suspended and fixed in the duct space without displacement, and the independent fan blades are also fixed in the duct space through the permanent magnetic poles.

[0005] Furthermore, the bearing body includes bearing No. 1 and bearing No. 2, and the magnetic poles of bearing No. 1 and bearing No. 2 are the same; bearing No. 1 can be fixed to the inner wall of the duct by bolt connection, and bearing No. 2 is fixed to the permanent magnetic pole, and there is a spacing of 0.3-1 mm between bearing No. 1 and bearing No. 2.

[0006] Furthermore, an installation groove is opened on the inner wall of the duct shell, and the cross-sectional shape of the installation groove is "T"-shaped, and one vertical end of the "T"-shaped installation groove is connected to the duct space; two stators are fixedly installed in the two horizontal ends of the "T"-shaped installation groove; the permanent magnet pole is located between the two stators; and the permanent magnet pole corresponds to the cross-sectional shape of the two stators.

[0007] Furthermore, a pole sleeve is fixedly provided on the outer wall of the permanent magnetic pole, and the No. 2 bearing is fixedly installed on the pole sleeve; a connecting structure is provided between the fan blades and the permanent magnetic poles, one end of the connecting structure is fixedly connected to the fan blades, and the other end of the connecting structure is fixedly connected to the permanent magnetic poles, and the connecting structure and the pole sleeve provide installation and fixing positions for the permanent magnetic poles and the fan blades.

[0008] Furthermore, the permanent magnetic poles are annular structures, and are evenly divided into eight pairs of sector structures, with N poles and S poles arranged alternately, and the number of pairs of permanent magnetic poles is determined according to the design power and performance requirements of the motor.

[0009] Furthermore, the pole shield and the connection structure are both made of carbon fiber, which can reduce the overall weight.

[0010] Furthermore, the No. 1 bearing and the No. 2 bearing are composed of a plurality of small bearing blocks, and the size of the permanent magnetic material of the No. 1 bearing and the No. 2 bearing is determined according to the parameters of the motor.

[0011] Furthermore, the No. 1 bearing and the No. 2 bearing each include two groups; the two groups of No. 1 bearings and No. 2 bearings are arranged relative to each other with a tilt, and the specific tilt angle is about 60° with respect to the horizontal direction.

[0012] Furthermore, a fixing block is arranged on the outer wall of the magnetic pole shield, and the cross section of the fixing block is an isosceles trapezoid; the two groups of the No. 2 bearings are fixedly arranged on the two waists of the fixing block.

[0013] The present invention provides a control method for a motor duct integrated bearing structure, which is applied to any one of the motor duct integrated bearing structures described above, and specifically comprises the following steps:

[0014] Energize the stator;

[0015] Detecting the offset value of the actual rotation center line of the permanent magnetic pole relative to the set rotation center line;

[0016] If the offset value is less than the set range, the stator continues to be energized to drive the permanent magnet poles to rotate;

[0017] If the offset value is greater than the set range, stop the machine and adjust the distance between bearing No. 1 and bearing No. 2.

[0018] Beneficial Effects

[0019] The beneficial effects of the present invention compared to the prior art are as follows:

[0020] 1. The present application adopts permanent magnetic material for the bearing body and arranges the bearing body between the duct housing and the permanent magnetic poles. The position of the permanent magnetic poles is fixed by the static magnetic force inside the bearing body, thereby fixing the motor so that the motor does not shift during operation, thereby effectively improving the power density of the motor and reducing the weight of the motor.

[0021] 2. The present application achieves the problem of applying the bearing structure to high-speed and large-size motors by tilting the No. 1 and No. 2 bearings and creating a repulsive force between the permanent magnetic materials in the No. 1 and No. 2 bearings so that the permanent magnetic poles can rotate at high speed around the axis without shifting. This overcomes the problem that the magnetic levitation bearing structure needs to occupy the motor structure and needs to be fixed in position, and the axial flux motor, duct and bearing structure are designed in an integrated manner.

[0022] 3. In the present application, the magnetic pole sheath and the connection structure are made of carbon fiber material. The carbon fiber material can reduce the weight of the overall structure to a certain extent. At the same time, the carbon fiber material also has high strength and can provide an overall higher strength support.

[0023] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 The overall structural diagram of the duct housing, the bearing structure and the motor in an embodiment of the present invention is shown.

[0026] Figure 2 A cross-sectional view of the entire bearing mechanism for a motor in an embodiment of the present invention is shown.

[0027] Figure 3 A schematic structural diagram of a permanent magnetic pole, a bearing body and a magnetic pole sleeve in an embodiment of the present invention is shown.

[0028] Figure 4 A cross-sectional view of a permanent magnetic pole, a bearing body and a pole sleeve in an embodiment of the present invention is shown.

[0029] Figure 5A cross-sectional view of a bearing body and a pole sleeve in an embodiment of the present invention is shown.

[0030] Figure 6 Shows Figure 2 A partial enlarged view of point A in the middle.

[0031] Figure 7 Shows Figure 5 A partial enlarged view of point B in the middle.

[0032] In the figure, 1. duct casing; 2. fan blades; 3. permanent magnet poles; 4. bearing body; 41. No. 1 bearing; 42. No. 2 bearing; 5. mounting groove; 6. stator; 7. pole sleeve; 8. connection structure; 9. fixing block. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0034] The motors of existing low-altitude aircraft need to have high power density and torque density to improve the thrust-to-weight ratio; however, in the limited space, there is a problem of how the bearing structure can be coordinated with the motor and duct.

[0035] The present application provides a bearing structure for motor duct integration, referring to Figure 1 and Figure 2 , Figure 2 The overall installation diagram between the motor and the bearing structure is shown, including a duct housing 1 and a fan blade 2; the fan blade 2 is a shaftless fan blade, the fan blade 2 is located in the duct space, and the end of the fan blade 2 facing the duct housing 1 is connected to a permanent magnetic pole 3; a bearing body 4 is arranged between the inner wall of the duct housing 1 and the permanent magnetic pole 3; the bearing body 4 is made of permanent magnetic material;

[0036] Through the magnetic force inside the bearing body 4, the permanent magnetic pole 3 is suspended and fixed in the duct space without deviation.

[0037] In one embodiment of the present invention, reference Figure 6 and Figure 7 The bearing body 4 includes a No. 1 bearing 41 and a No. 2 bearing 42, and the magnetic poles of the No. 1 bearing 41 and the No. 2 bearing 42 are the same; the No. 1 bearing 41 is fixed on the inner wall of the duct, and the No. 2 bearing 42 is fixed on the permanent magnetic pole 3, and there is a distance between the No. 1 bearing 41 and the No. 2 bearing 42.

[0038] By arranging the bearing body 4 between the duct housing 1 and the permanent magnet pole 3, and utilizing the repulsive magnetic force between the permanent magnet materials inside the No. 1 bearing 41 and the No. 2 bearing 42, the magnetic force between the permanent magnet materials acts on the axial flux motor, so that the axial flux motor can be suspended and fixed in a limited space, so that the motor does not shift during operation. The bearing body 4 also meets the requirements of high-speed large-size motors and has a compact structure, thereby improving the overall performance of the motor.

[0039] During the implementation process, the positions of the permanent magnetic poles 3 and the fan blades 2 are fixed by the static magnetic force between the No. 1 bearing 41 and the No. 2 bearing 42 made of permanent magnetic materials; by energizing the stator 6, the permanent magnetic poles 3 start to rotate due to the magnetic field effect between the magnetic field generated by the stator 6 and the permanent magnetic poles 3, and the permanent magnetic poles 3 drive the No. 2 bearing 42 and the fan blades 2 to rotate at high speed, thereby realizing the operation of the motor on the low-altitude aircraft.

[0040] The present application adopts permanent magnetic material for the bearing body 4 and arranges the bearing body 4 between the duct housing 1 and the permanent magnetic pole 3. The static magnetic force inside the bearing body 4 is used to fix the position of the permanent magnetic pole 3, thereby fixing the motor so that the motor does not shift during operation, thereby effectively improving the power density of the motor and reducing the weight of the motor.

[0041] In one embodiment of the present invention, reference Figure 2 and Figure 6 The inner wall of the duct housing 1 is provided with a mounting groove 5, the cross-sectional shape of the mounting groove 5 is "T"-shaped, and one vertical end of the "T"-shaped is connected to the duct space; two stators 6 are fixedly installed in the two horizontal ends of the "T"-shaped mounting groove 5; the permanent magnet pole 3 is located between the two stators 6.

[0042] The motor in the present application is an axial flux rim motor with a double stator 6 and a single rotor; the two stators 6 can provide a larger line load, can generate a larger torque under the same volume, and improve the material and space utilization of the motor; stator teeth and windings are distributed on the stator 6;

[0043] The middle vertical direction of the "T"-shaped mounting groove 5 is connected to the duct space, providing an installation and connection space for the permanent magnet pole 3 to drive the fan blade 2 to rotate; installing the two stators 6 inside the mounting groove 5 can improve the stability of the installation on the one hand, and on the other hand, can further make the overall structure more compact and lighter; after the stator 6 is energized to drive the permanent magnet pole 3 to rotate, the permanent magnet pole 3 rotates at high speed in the mounting groove 5, driving the fan blade 2 to rotate synchronously at high speed.

[0044] In one embodiment of the present invention, reference Figure 3 , Figure 4 and Figure 5The outer wall of the permanent magnetic pole 3 is fixedly provided with a pole sleeve 7, and the second bearing 42 is fixedly installed on the pole sleeve 7.

[0045] By setting a pole sheath 7 on the permanent magnet pole 3, the setting of the pole sheath 7 fixes the permanent magnet pole 3 and provides a fixed installation position for the second bearing 42; the pole sheath 7 can be formed by winding on the outside of the permanent magnet pole 3; the pole sheath 7 can also be fixed on the permanent magnet pole 3 by paving the outer wall of the permanent magnet pole 3.

[0046] In one embodiment of the present invention, reference Figure 3 The permanent magnetic pole 3 is a ring-shaped structure, and the permanent magnetic pole 3 is evenly divided into a plurality of pairs of fan-shaped structures, which are arranged alternately with N poles and S poles.

[0047] In one embodiment of the present invention, reference Figure 2 , Figure 3 and Figure 6 A connecting structure 8 is provided between the fan blade 2 and the permanent magnetic pole 3 , one end of the connecting structure 8 is fixedly connected to the fan blade 2 , and the other end of the connecting structure 8 is fixedly connected to the permanent magnetic pole 3 .

[0048] The connection structure 8 can be integrally formed with the fan blade 2 , and the connection structure 8 provides a fixed installation position for the permanent magnetic pole 3 and the fan blade 2 .

[0049] In one embodiment of the present invention, the magnetic pole sheath 7 and the connecting structure 8 are both made of carbon fiber. The present application is used for aircraft, and the use of carbon fiber material can reduce the weight of the overall structure to a certain extent. At the same time, the carbon fiber material also has high strength and can provide an overall higher strength support.

[0050] In one embodiment of the present invention, the first bearing 41 and the second bearing 42 are composed of a plurality of small bearing blocks. Since the first bearing 41 and the second bearing 42 are relatively large in size during processing, the first bearing 41 and the second bearing 42 are evenly divided to facilitate processing and manufacturing.

[0051] In one embodiment of the present invention, reference Figure 6 and Figure 7 The No. 1 bearing 41 and the No. 2 bearing 42 each include two groups; the two groups of No. 1 bearing 41 and No. 2 bearing 42 are arranged obliquely relative to each other.

[0052] In one embodiment of the present invention, a fixing block 9 is disposed on the outer wall of the magnetic pole sheath 7 , and the cross section of the fixing block 9 is an isosceles trapezoid; two groups of the No. 2 bearings 42 are fixedly disposed on the two waists of the fixing block 9 .

[0053] During the implementation process, by tilting the No. 1 bearing 41 and the No. 2 bearing 42, the repulsive force between the permanent magnetic materials in the No. 1 bearing 41 and the No. 2 bearing 42 allows the permanent magnetic pole 3 to rotate around the axial direction at high speed without displacement, thereby realizing the problem of applying the bearing structure to high-speed large-size motors. At the same time, it overcomes the problem that the magnetic levitation bearing structure needs to occupy the motor structure and needs to be fixed in position, and the axial flux motor, duct and bearing structure are designed in an integrated manner.

[0054] During the implementation process, the distance between the No. 1 bearing 41 and the No. 2 bearing 42 is 0.5 mm, and the relative area of ​​the permanent magnetic material of the No. 1 bearing 41 and the No. 2 bearing 42 is 62000 mm. 2 , thickness is 10mm, and the size of the fan blade 2 is 1000mm. In this application, the entire bearing structure can provide a force of about 20000N, that is, 2 tons, which can provide support for low-altitude economical electric propulsion aircraft. The specific design can also be optimized according to the actual situation of the motor to further improve the support force provided by the bearing structure.

[0055] The present application provides a control method for a motor duct integrated bearing structure, which is applied to a motor duct integrated bearing structure as described in any one of the above, and specifically comprises the following steps:

[0056] Energize the stator 6;

[0057] Detecting the offset value of the actual rotation center line of the permanent magnetic pole 3 relative to the set rotation center line;

[0058] If the offset value is less than the set range, the stator 6 continues to be energized to drive the permanent magnetic pole 3 to rotate;

[0059] If the offset value is greater than the set range, the machine is stopped to adjust the distance between the first bearing 41 and the second bearing 41 .

[0060] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A bearing structure for motor duct integration, characterized in that: The invention comprises a duct housing (1) and a fan blade (2); the fan blade (2) is a shaftless fan blade, the fan blade (2) is located in the duct space, and one end of the fan blade (2) facing the duct housing (1) is connected to a permanent magnetic pole (3); a bearing body (4) is arranged between the inner wall of the duct housing (1) and the permanent magnetic pole (3), and a stator (6) is installed on the inner wall of the duct housing (1); the bearing body (4) is made of permanent magnetic material; The permanent magnetic pole (3) is suspended and fixed in the duct space through the magnetic force inside the bearing body (4) without being deviated.

2. The motor duct integrated bearing structure according to claim 1, characterized in that: The bearing body (4) comprises a first bearing (41) and a second bearing (42), and the first bearing (41) and the second bearing (42) have the same magnetic poles; the first bearing (41) is fixed on the inner wall of the duct, and the second bearing (42) is fixed on the permanent magnetic pole (3), and there is a distance between the first bearing (41) and the second bearing (42).

3. The motor duct integrated bearing structure according to claim 1, characterized in that: The inner wall of the duct housing (1) is provided with a mounting groove (5), the cross-sectional shape of the mounting groove (5) is "T"-shaped, and one vertical end of the "T"-shaped is connected to the duct space; two stators (6) are fixedly mounted in the two horizontal ends of the "T"-shaped mounting groove (5); and the permanent magnetic pole (3) is located between the two stators (6).

4. The motor duct integrated bearing structure according to claim 2, characterized in that: A magnetic pole sleeve (7) is fixedly provided on the outer wall of the permanent magnetic pole (3), and the second bearing (42) is fixedly mounted on the magnetic pole sleeve (7); a connecting structure (8) is provided between the fan blade (2) and the permanent magnetic pole (3), one end of the connecting structure (8) is fixedly connected to the fan blade (2), and the other end of the connecting structure (8) is fixedly connected to the permanent magnetic pole (3).

5. The motor duct integrated bearing structure according to claim 1, characterized in that: The permanent magnetic poles (3) are annular structures, and are evenly divided into a plurality of pairs of fan-shaped structures, which are arranged alternately with N poles and S poles.

6. The motor duct integrated bearing structure according to claim 4, characterized in that: The magnetic pole sheath (7) and the connecting structure (8) are both made of carbon fiber material.

7. The motor duct integrated bearing structure according to claim 2, characterized in that: The first bearing (41) and the second bearing (42) are composed of a plurality of small bearing blocks.

8. The motor duct integrated bearing structure according to claim 2, characterized in that: The No. 1 bearing (41) and the No. 2 bearing (42) each include two groups; the two groups of the No. 1 bearing (41) and the No. 2 bearing (42) are arranged obliquely relative to each other.

9. The motor duct integrated bearing structure according to claim 6, characterized in that: The outer wall of the magnetic pole shield (7) is provided with a fixing block (9), the cross section of the fixing block (9) is an isosceles trapezoid; the two groups of the second bearings (42) are fixedly arranged on the two waists of the fixing block (9).

10. A control method for a motor duct integrated bearing structure, applied to a motor duct integrated bearing structure as claimed in any one of claims 2 to 9, characterized in that: The specific steps include: Applying electricity to the stator (6); Detecting the offset value of the actual rotation center line of the permanent magnetic pole (3) relative to the set rotation center line; If the offset value is smaller than the set range, the stator (6) continues to be energized to drive the permanent magnetic pole (3) to rotate; If the offset value is greater than the set range, the machine is stopped to adjust the distance between the first bearing (41) and the second bearing (41).

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