Permanent magnet device for actively loading axial load on transmission shaft

Abstract

The invention discloses a permanent magnet device for actively loading an axial load on a transmission shaft, which comprises a main body assembly, an axially moving stator assembly is arranged in the main body assembly, a rotor assembly rotating along an axis is arranged in the stator assembly, the stator assembly comprises a bearing frame and a stator permanent magnet, the stator permanent magnet is arranged below the bearing frame, and the rotor assembly is arranged below the bearing frame. The rotor assembly comprises a rotor shaft and a rotor permanent magnet, the rotor permanent magnet is arranged above the rotor shaft, the axial projection of the stator permanent magnet is located on the outer side of the axial projection of the rotor permanent magnet, and the stator permanent magnet and the rotor permanent magnet are opposite in the axial magnetic pole direction. The bearing frame is controlled to axially move, so that the rotor permanent magnet bears the axial acting force of the stator permanent magnet, the axial load loaded on the rotor shaft is adjusted by controlling the displacement distance of the stator permanent magnet, the axial load is actively loaded through magnetic force so as to achieve axial load balance when the transmission shaft rotates, and the whole device is compact in structure and convenient to operate. The thrust-weight ratio is large, the axial load adjusting stroke is wide, and the control precision is high.

Description

Technical Field

[0001] The present application belongs to the technical field of unmanned aerial vehicles, and specifically relates to a permanent magnet device for actively applying an axial load to a transmission shaft. Background Art

[0002] Currently, drones are increasingly used. In addition to the common small and micro drones for aerial photography, there are also large and medium-sized unmanned aerial vehicles such as agricultural drones and cargo drones. The maximum take-off weight of these unmanned aerial vehicles ranges from a few hundred grams to a few hundred kilograms or even higher. Most civil unmanned aerial vehicles use a rotor power system. The motor drives the transmission shaft to drive the rotor to rotate. The lift generated by the rotation of the rotor is transmitted to the transmission component through the transmission shaft. The transmission component then transmits the lift to the base or the unmanned aerial vehicle shell that fixes the transmission component. The axial load of the transmission shaft is almost the entire load when the unmanned aerial vehicle takes off. In addition, when the flight attitude and mission of the unmanned aerial vehicle change, the operating power of the unmanned aerial vehicle power system and the axial load of the transmission shaft will also change accordingly.

[0003] The current unmanned aerial vehicles do not use transmission components similar to the gear reducers of helicopters, because the gear reducers are complex in structure and heavy, accounting for about 1 / 7-1 / 9 of the total weight of the helicopter structure. Obviously, this device is not suitable for use in unmanned aerial vehicles. Existing unmanned aerial vehicles use the transmission shaft and the ball bearings in the motor as all transmission components. The transmission shaft not only transmits the torque of the unmanned aerial vehicle power system to the rotor, but also acts as a load-bearing component. The transmission shaft transmits all the forces and torques generated by the rotor to the ball bearing rotor. Through the ball bearing structure, the ball bearing stator then transmits the axial load to the unmanned aerial vehicle body. During the flight of the unmanned aerial vehicle, the high-speed rotating ball bearings are prone to axial overload when the axial load suddenly changes, causing motor failure, resulting in the unmanned aerial vehicle losing control and crashing.

[0004] In order to solve the above problems, it is necessary for the transmission components of the unmanned aerial vehicle to actively balance the axial load on the transmission shaft while rotating at high speed. Summary of the invention

[0005] The purpose of the present application is to provide a permanent magnet device for actively loading an axial load on a transmission shaft, which is a contactless permanent magnet combination structure. The axial load is actively loaded by magnetic force to achieve axial load balance when the transmission shaft rotates. The rotor shaft in the device is mounted on the transmission shaft. The rotor assembly and the stator assembly are contactless and frictionless. The adjustment stroke for loading the axial load is wide, the control accuracy is high, the thrust-to-weight ratio is large, the entire device has a compact structure, and the manufacturing cost is low. It can significantly improve the load-bearing capacity of unmanned aerial vehicles, increase the flight altitude, flight radius and endurance of unmanned aerial vehicles, and reduce the failure rate of motors and ball bearings. It has broad application prospects.

[0006] The purpose of this application is achieved through the following technical solutions:

[0007] A permanent magnet device for actively loading an axial load on a transmission shaft comprises a main body component, an axially movable stator component is arranged in the main body component, a rotor component is arranged in the stator component and rotates along an axis, the stator component comprises a carrier and a stator permanent magnet, the stator permanent magnet is arranged below the carrier, the rotor component comprises a rotor shaft and a rotor permanent magnet, the rotor permanent magnet is arranged above the rotor shaft, the axial projection of the stator permanent magnet is located outside the axial projection of the rotor permanent magnet, and the stator permanent magnet and the rotor permanent magnet have opposite axial magnetic pole directions.

[0008] Furthermore, the stator assembly also includes a first magnetic conductive ring and a second magnetic conductive ring. A downward recessed portion is provided on the support frame, a first circular hole is provided in the center of the recessed portion, the first magnetic conductive ring is arranged at the bottom of the recessed portion of the support frame, the stator permanent magnet is arranged below the first magnetic conductive ring, and the second magnetic conductive ring is arranged below the stator permanent magnet.

[0009] Furthermore, the outer diameters of the first magnetic ring, the stator permanent magnet and the second magnetic ring are the same, the inner diameters of the first magnetic ring and the second magnetic ring are smaller than the inner diameter of the stator permanent magnet, and the inner diameters of the first magnetic ring and the second magnetic ring are smaller than the diameter of the first circular hole.

[0010] Furthermore, the rotor assembly also includes a fourth magnetic conductive ring and a third magnetic conductive ring, a protrusion is provided on the rotor shaft, the third magnetic conductive ring is arranged above the protrusion, the rotor permanent magnet is arranged above the third magnetic conductive ring, and the fourth magnetic conductive ring is arranged above the rotor permanent magnet.

[0011] Furthermore, the inner diameters of the third magnetic ring, the rotor permanent magnet and the fourth magnetic ring are the same, the outer diameters of the third magnetic ring and the fourth magnetic ring are larger than the outer diameter of the protrusion, and the outer diameters of the third magnetic ring and the fourth magnetic ring are larger than the outer diameter of the rotor permanent magnet.

[0012] Furthermore, the support frame serves as a manual axial moving member of the stator assembly.

[0013] Furthermore, a driving assembly is provided on the main body assembly, and the driving assembly serves as an active axial moving part of the stator assembly.

[0014] Furthermore, the main body base of the main body assembly is provided with an upwardly facing recessed portion, the inner wall of the recessed portion is provided with an internal thread, and the outer wall of the support frame is provided with an external thread, and the external thread is screwed together with the internal thread.

[0015] Furthermore, the driving assembly includes a motor and a gear. The motor is arranged on the main assembly. The output shaft of the motor is provided with a gear. The gear is meshed with an outer gear ring on the outer wall of the supporting frame.

[0016] Furthermore, the stator permanent magnet and the rotor permanent magnet have the same height, and the axial height difference formed by the axial movement of the stator permanent magnet and the rotor permanent magnet ranges from 0 to 2 / 3 of the height of the stator permanent magnet.

[0017] Furthermore, the stator permanent magnets and rotor permanent magnets are both axially magnetized.

[0018] Beneficial effects of this application:

[0019] (1) The axial force is applied to the transmission shaft without mechanical contact, and the axial load is dynamically balanced when the transmission shaft rotates. The active loading of the axial load on the rotor shaft is achieved by actively controlling the axial displacement of the carrier frame. The magnitude of the axial load on the rotor shaft can be adjusted by adjusting the axial displacement distance of the carrier frame.

[0020] (2) The radial load of the rotor assembly is basically unaffected when the stator assembly moves. The stator assembly has a wide displacement adjustment stroke and can perform real-time, reciprocating, high-frequency, and precise axial movement. The axial force acting on the rotor shaft has a smooth follow-up curve and high control accuracy.

[0021] The aforementioned main scheme of the present application and its further options can be freely combined to form multiple schemes, all of which are schemes that can be adopted and claimed for protection in the present application; and in the present application, (non-conflicting options) can also be freely combined with each other and with other options. After understanding the scheme of the present application, those skilled in the art can understand that there are many combinations based on the prior art and common knowledge, all of which are technical schemes to be protected by the present application, and they are not exhaustively listed here. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural cross-sectional view of Example 1 of the present application.

[0023] Figure 2 It is a structural stereogram of the carrier frame of Example 1 of the present application.

[0024] Figure 3 This is a schematic diagram of the meshing between the outer gear ring of the carrier frame and the gear in Example 1 of the present application.

[0025] Figure 4 This is an axial force cross-sectional view of Example 1 of the present application.

[0026] Figure 5 This is a dynamic simulation diagram of axial force in Example 2 of the present application.

[0027] Figure 6 It is a structural cross-sectional view of Example 3 of the present application.

[0028] Figure 7 This is an axial force cross-sectional view of Example 3 of the present application.

[0029] Figure 8 It is a three-dimensional cross-sectional view of Example 3 of the present application.

[0030] Fig. 9 This is a dynamic simulation diagram of axial force in Example 4 of the present application.

[0031] In the figure: 11-carrying frame; 121-first magnetic conductive ring; 13-stator permanent magnet; 122-second magnetic conductive ring; 14-first retaining ring; 15-external thread; 16-external gear ring; 21-rotor shaft; 221-fourth magnetic conductive ring; 23-rotor permanent magnet; 222-third magnetic conductive ring; 24-second retaining ring; 31-main body base; 32-main body end cover; 33-internal thread; 41-motor; 42-gear. DETAILED DESCRIPTION

[0032] The following non-limiting examples are provided to illustrate the present application.

[0033] In this disclosure, unless otherwise specified, when a component is referred to as being "bonded" or "disposed" on another component, it can be directly or indirectly on the other component. When a component is referred to as being "connected" to another component, it can be directly or indirectly connected to the other component.

[0034] In the description of the present disclosure, it is necessary to understand that, unless otherwise specified, the directional words used, such as "inside" and "outside", refer to the inside and outside of the contour of the corresponding component itself; the orientation or position relationship indicated by the terms "upper" and "lower" etc. is based on the orientation or position relationship shown in the accompanying drawings, and the dimensions or directions referred to by the terms "height" and "depth" are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present disclosure.

[0035] In the description of the present disclosure, it should be noted that, unless otherwise clearly stipulated and limited, the terms "install", "connect", "connect", "set", and "fix" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; for ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to the specific circumstances.

[0036] Example 1

[0037] refer to Figure 1 to Figure 4 As shown, a permanent magnet device for actively applying an axial load to a transmission shaft comprises a main body assembly, a stator assembly, a rotor assembly and a drive assembly.

[0038] The main component serves as the placement basis of the device, realizing the placement of the device itself, and also realizing the accommodation, protection, fixation and installation of other components. An axially movable stator component is provided in the main component. The stator permanent magnet is axially magnetized to provide an axial loading force for the rotor component. Stator components in different positions form axial loads of different sizes on the rotor component. A rotor component that rotates along the axis is provided in the stator component. The rotor permanent magnet is axially magnetized and has the opposite magnetic pole to the stator permanent magnet. The rotor component is connected to the transmission shaft of the drone to withstand the axial force of the rotor, and at the same time withstands the axial loading force of the stator component. The axial loading force of the stator component and the axial force of the rotor on the transmission shaft are opposite in direction on the rotor shaft of the rotor component to offset each other and form a dynamic balance. A drive component is provided on the main component, which serves as the active axial moving part of the stator component to adjust the axial position of the stator component through automation.

[0039] refer to Figure 1 As shown, the stator assembly includes a carrier 11, a first magnetic conductive ring 121, a stator permanent magnet 13, a second magnetic conductive ring 122, a first retaining ring 14, an external thread 15 and an external gear ring 16. The carrier 11 is an annular structure, and a downward recessed portion is provided on the carrier 11, and the recessed portion is used to place the magnetic conductive ring and the permanent magnet of the stator assembly. A first circular hole is provided in the center of the recessed portion to enable the rotor assembly to pass through when the stator assembly moves axially.

[0040] The first magnetic conductive ring 121 is fixed at the bottom of the recessed portion of the carrier 11, and the outer diameter of the first magnetic conductive ring 121 is the same as the inner diameter of the recessed portion, and the inner diameter of the first magnetic conductive ring 121 is smaller than the diameter of the first circular hole. The stator permanent magnet 13 is fixed below the first magnetic conductive ring 121, and the inner diameter of the stator permanent magnet 13 is 1 mm larger than the inner diameter of the first magnetic conductive ring 121. The second magnetic conductive ring 122 is fixed below the stator permanent magnet 13, and the inner and outer diameters of the second magnetic conductive ring 122 are the same as those of the first magnetic conductive ring 121.

[0041] The first retaining ring 14 is clamped in the annular groove below the inner side of the recessed portion of the carrier frame 11 to clamp and limit the second magnetic ring 122, thereby limiting the axial displacement of the second magnetic ring 122, the stator permanent magnet 13 and the first magnetic ring 121, and connecting the stator assembly into a whole.

[0042] A stator permanent magnet 13 is provided below the carrier 11, and the carrier 11 is used to form a downward pressure on the stator permanent magnet 13. The stator permanent magnet 13 is axially magnetized, with an S pole at the top and an N pole at the bottom. The first magnetic conductive ring 121 is magnetized by the stator permanent magnet 13, and an S pole is presented at the inner diameter edge of the magnetic conductive ring. The second magnetic conductive ring 122 is magnetized by the stator permanent magnet 13, and an N pole is presented at the inner diameter edge of the magnetic conductive ring.

[0043] The stator permanent magnet 13 is made of rare earth permanent magnet material, and the first and second magnetic rings are made of soft magnetic material. Compared with directly using permanent magnets, the magnetic rings made of soft magnetic material have higher processing and installation accuracy, greater strength, and better force resistance. In this way, the material properties of the magnetic rings are utilized to improve the processing and installation precision of the stator assembly.

[0044] The rotor assembly includes a rotor shaft 21, a third magnetic conductive ring 222, a rotor permanent magnet 23, a fourth magnetic conductive ring 221 and a second retaining ring 24. The rotor shaft 21 is a columnar structure with a central through-hole, and a circular protrusion is provided on the rotor shaft 21. The protrusion and the outer periphery of the rotor shaft 21 realize the placement of the permanent magnet and the magnetic conductive ring of the rotor assembly. The rotor shaft 21 can be connected to the transmission shaft of the UAV power system to achieve common force and synchronous rotation.

[0045] The third magnetic conductive ring 222 is fixed above the protrusion, and the inner diameter of the third magnetic conductive ring 222 is the same as the inner diameter of the protrusion (the outer diameter of the rotor shaft), and the outer diameter of the third magnetic conductive ring 222 is larger than the outer diameter of the protrusion. The rotor permanent magnet 23 is fixed above the third magnetic conductive ring 222, and the inner diameter of the rotor permanent magnet 23 is the same as the inner diameter of the protrusion (the outer diameter of the rotor shaft), and the outer diameter of the rotor permanent magnet 23 is 1 mm smaller than the outer diameter of the third magnetic conductive ring 222. The fourth magnetic conductive ring 221 is fixed above the rotor permanent magnet 23, and the inner and outer diameters of the fourth magnetic conductive ring 221 are the same as the inner and outer diameters of the third magnetic conductive ring 222.

[0046] A rotor permanent magnet 23 is provided above the rotor shaft 21, and the rotor permanent magnet 23 is used to form a downward pressure on the rotor shaft 21. The rotor permanent magnet 23 is axially magnetized, with an N pole at the top and an S pole at the bottom. The third magnetic ring 222 is magnetized by the rotor permanent magnet 23, and an S pole is presented at the outer diameter edge of the magnetic ring. The fourth magnetic ring 221 is magnetized by the rotor permanent magnet 23, and an N pole is presented at the outer diameter edge of the magnetic ring.

[0047] The rotor permanent magnet 23 is made of rare earth permanent magnet material, and the third and fourth magnetic conductive rings are made of soft magnetic material. In this way, the material properties of the magnetic conductive rings are utilized to improve the precision of machining and installation of the rotor assembly, which is beneficial to maintaining the radial air gap spacing between the rotor assembly and the stator assembly.

[0048] The second retaining ring 24 is clamped in the annular groove above the rotor shaft 21 to clamp and limit the fourth magnetic ring 221, thereby limiting the axial displacement of the fourth magnetic ring 221, the rotor permanent magnet 23 and the third magnetic ring 222, so that the rotor assembly is connected as a whole.

[0049] The axial projection of the stator permanent magnet 13 is located outside the axial projection of the rotor permanent magnet 23. Similarly, the axial projections of the first and second magnetic conductive rings are also located outside the axial projections of the third and fourth magnetic conductive rings. When the stator assembly moves axially, there is a radial air gap between the two to avoid mutual interference. Preferably, when the stator permanent magnet and the rotor permanent magnet are horizontal in a direction perpendicular to the axis, the radial air gap between the magnetic conductive rings is 0.5 mm.

[0050] The main body assembly includes a main body base 31, a main body end cover 32 and an internal thread 33. The main body base 31 is fixed on the body or the outer shell of the power system. There is a concave portion in the center of the bottom of the main body base 31, and a second circular hole is provided in the center of the concave portion for the rotor shaft 21 to pass through. The main body end cover 32 is fixed on the main body base 31. To facilitate installation and disassembly, the main body end cover 32 can be fixed by screws or threads. There is a third circular hole in the center of the main body end cover 32 for the rotor shaft 21 to pass through. A cylindrical cavity for accommodating various components is formed between the main body base 31 and the main body end cover 32. The support frame 11, the rotor shaft 21, the main body base 31, and the main body end cover 32 are all made of non-magnetic materials to avoid affecting the magnetic field of the permanent magnet.

[0051] refer to Figure 1 and Figure 2 As shown, the main body base 31 is provided with an upwardly facing concave portion, and the inner wall of the concave portion is provided with an internal thread 33, and the thread depth is consistent with the axial movement distance of the stator assembly. The outer wall of the carrier 11 is provided with an external thread 15 below, and the external thread 15 and the internal thread 33 are screwed together. Through the screwing of the internal and external threads, the carrier 11 is rotated to adjust the axial position of its stator assembly, and at the same time, the axial magnetic force received by the carrier 11 is transmitted to the main body base 31 through the thread pair.

[0052] refer to Figure 1 and Figure 3As shown, the driving assembly includes a motor 41 and a gear 42. The motor 41 is fixed to the main body end cover 32 of the main body assembly. The motor 41 can be fixed by welding or mounting brackets. The main body end cover 32 has a small hole that allows the output shaft to pass through. The output shaft of the motor 41 extends into the main body assembly and is provided with a gear 42. The length of the output shaft meets the axial movement distance requirements of the carrier frame 11. The outer gear ring 16 above the outer wall of the carrier frame 11 is meshed with the gear 42.

[0053] The outer thread 15 of the carrier protrudes from the outer edge of the tooth surface of the outer gear ring 16, and there is a gap of more than 1mm between the outer edge of the tooth surface of the outer gear ring 16 and the outer edge of the thread of the inner thread 33 to prevent the axial movement of the stator assembly from being affected. The torque of the motor 41 can be calculated according to the formula: T = kdF / r; where: T is the motor torque, unit: Nm; k is the torque coefficient (related to the friction between the threads and the pitch); d is the diameter of the outer thread of the carrier, unit: meter; F is the maximum axial force generated by the rotation of the carrier on the permanent magnet of the rotor, unit: N; r is the gear ratio of the gear ring to the gear.

[0054] The motor 41 is controlled by the aircraft power system controller signal and executes its instructions: forward and reverse rotation, speed, number of revolutions, and lock. The motor 41 drives the gear 42 to drive the outer gear ring 16 of the carrier 11 to rotate, and the outer thread 15 of the carrier 11 and the inner thread 33 of the main base 31 that are screwed together cause the stator assembly to move axially.

[0055] refer to Figure 4 As shown, after the carrier 11 moves axially downward, the third magnetic ring 222 (S magnetic pole) is subjected to the axial downward suction force F1a of the second magnetic ring 122 (N magnetic pole), and the fourth magnetic ring 221 (N magnetic pole) is subjected to the axial downward suction force F1b of the first magnetic ring 121 (S magnetic pole). The third magnetic ring 222 (S magnetic pole) is also subjected to the axial downward repulsive force F1c of the first magnetic ring 121 (S magnetic pole). The rotor assembly is subjected to the axial downward thrust force F1=F1a+F1b+F1c, and the axial lift F2 on the transmission shaft of the aircraft power system is upward. By adjusting F1 to be equal to F2 in the opposite direction and adjusting the speed change rate of the motor 41 to be the same as the axial load change rate of the rotor assembly, the dynamic balance of the axial load when the rotor is rotated is achieved.

[0056] Example 2

[0057] A permanent magnet device for actively applying an axial load to a transmission shaft, in some optional embodiments, the stator permanent magnet 13 and the rotor permanent magnet 23 have the same height, and the axial height difference formed by the axial movement of the stator permanent magnet 13 and the rotor permanent magnet 23 ranges from 0 to 2 / 3 of the stator permanent magnet height. Others are the same as in Embodiment 1.

[0058] refer to Figure 5As shown, the axial height of the permanent magnet (rotor and stator) is 30mm, the total mass of the permanent magnet (rotor and stator) is 7135g, and the axial displacement distance of the stator permanent magnet 13 is adjusted within 2 / 3 of the axial height of a single permanent magnet. It can be seen that when the axial displacement of the stator permanent magnet 13 is 19.9mm, the maximum axial magnetic force on the rotor permanent magnet 23 is 3483N, and the thrust-to-weight ratio of the permanent magnet is 49: 1. By changing the axial movement position of the stator assembly, the axial loading force can be adjusted from zero to maximum.

[0059] Example 3

[0060] A permanent magnet device for actively loading an axial load on a transmission shaft, another exemplary embodiment of the present application, referring to Figure 6 As shown, it includes a main body component, a stator component and a rotor component, and is consistent with the basic technical principle shown in Example 1. The difference is that the main body end cover 32 shown in this embodiment is an integrated structure with the carrier frame 11, and the carrier frame 11 serves as a manual axial moving part of the stator assembly. There is no drive component 40, and the structure is simpler.

[0061] refer to Figure 7 As shown, before the power system is operated, preload is performed, and the carrier 11 is manually rotated to a predetermined position and locked. The locking can be performed by a stop pin or other methods. The carrier 11 moves axially, and the rotor permanent magnet 23 is subjected to the magnetic field force of the stator permanent magnet 13 after axial movement, which generates an axial force on the rotor in the same direction as the movement of the carrier 11. After the power system is turned off, the locking mechanism is opened, and the carrier 11 is manually rotated until the stator permanent magnet 13 and the rotor permanent magnet 23 are horizontal in the direction perpendicular to the axis. For a three-dimensional cross-sectional view of this embodiment, please refer to Figure 8 shown.

[0062] Example 4

[0063] A permanent magnet device for actively applying an axial load to a transmission shaft, in some optional embodiments, the stator permanent magnet 13 and the rotor permanent magnet 23 have the same height, and the axial height difference formed by the axial movement of the stator permanent magnet 13 and the rotor permanent magnet 23 ranges from 0 to 2 / 3 of the stator permanent magnet height. Others are the same as in Embodiment 3.

[0064] refer to Fig. 9 As shown, the axial height of the permanent magnet (rotor and stator) is 10 mm, the total mass of the permanent magnet (rotor and stator) is 263 g, the axial displacement distance of the stator permanent magnet 13 is adjusted within 2 / 3 of the axial height of a single permanent magnet, and when the axial displacement of the stator permanent magnet 13 reaches 6.6 mm, the maximum axial magnetic force on the rotor permanent magnet 23 is 371 N, and the thrust-to-weight ratio of the permanent magnet is 143: 1. By changing the axial movement position of the stator assembly, the axial loading force can be adjusted from zero to maximum.

[0065] The aforementioned basic examples and their further selected examples can be freely combined to form multiple embodiments, all of which are embodiments that can be adopted and claimed for protection in this application. In the scheme of this application, each selected example can be arbitrarily combined with any other basic examples and selected examples.

[0066] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A permanent magnet device for actively applying an axial load to a transmission shaft, comprising a main body component, Features: The main body component is provided with a stator component that moves axially, and the stator component is provided with a rotor component that rotates along an axis. The stator component comprises a carrier (11) and a stator permanent magnet (13). The stator permanent magnet (13) is provided below the carrier (11). The rotor component comprises a rotor shaft (21) and a rotor permanent magnet (23). The rotor permanent magnet (23) is provided above the rotor shaft (21). The axial projection of the stator permanent magnet (13) is located outside the axial projection of the rotor permanent magnet (23). The stator permanent magnet (13) and the rotor permanent magnet (23) have opposite axial magnetic pole directions.

2. The permanent magnet device for actively applying axial load to the transmission shaft according to claim 1, Features: The stator assembly further comprises a first magnetic conductive ring (121) and a second magnetic conductive ring (122); a downwardly facing recessed portion is provided on the support frame (11); a first circular hole is provided at the center of the recessed portion; the first magnetic conductive ring (121) is arranged at the bottom of the recessed portion of the support frame (11); the stator permanent magnet (13) is arranged below the first magnetic conductive ring (121); and the second magnetic conductive ring (122) is arranged below the stator permanent magnet (13).

3. The permanent magnet device for actively applying axial load to the transmission shaft according to claim 2, Features: The outer diameters of the first magnetic conductive ring (121), the stator permanent magnet (13) and the second magnetic conductive ring (122) are all the same, the inner diameters of the first magnetic conductive ring (121) and the second magnetic conductive ring (122) are both smaller than the inner diameter of the stator permanent magnet (13), and the inner diameters of the first magnetic conductive ring (121) and the second magnetic conductive ring (122) are both smaller than the diameter of the first circular hole.

4. The permanent magnet device for actively applying axial load to a transmission shaft according to claim 1 or 2, Features: The rotor assembly further comprises a fourth magnetic conductive ring (221) and a third magnetic conductive ring (222); a protrusion is provided on the rotor shaft (21); the third magnetic conductive ring (222) is arranged above the protrusion; the rotor permanent magnet (23) is arranged above the third magnetic conductive ring (222); and the fourth magnetic conductive ring (221) is arranged above the rotor permanent magnet (23).

5. The permanent magnet device for actively applying axial load to the transmission shaft according to claim 4, Features: The inner diameters of the third magnetic conductive ring (222), the rotor permanent magnet (23) and the fourth magnetic conductive ring (221) are all the same, the outer diameters of the third magnetic conductive ring (222) and the fourth magnetic conductive ring (221) are both larger than the outer diameter of the protrusion, and the outer diameters of the third magnetic conductive ring (222) and the fourth magnetic conductive ring (221) are both larger than the outer diameter of the rotor permanent magnet (23).

6. The permanent magnet device for actively applying axial load to the transmission shaft according to claim 1, Features: The support frame (11) serves as a manual axial moving member of the stator assembly; or, a driving assembly is provided on the main assembly, and the driving assembly serves as an active axial moving member of the stator assembly.

7. The permanent magnet device for actively applying axial load to a transmission shaft according to claim 1 or 6, Features: The main body base (31) of the main body assembly is provided with an upwardly facing recessed portion, the inner wall of the recessed portion is provided with an internal thread (33), the outer wall of the support frame (11) is provided with an external thread (15), and the external thread (15) is screwed together with the internal thread (33).

8. The permanent magnet device for actively applying axial load to the transmission shaft according to claim 7, Features: The driving assembly comprises a motor (41) and a gear (42). The motor (41) is arranged on the main assembly. The output shaft of the motor (41) is provided with a gear (42). The gear (42) meshes with an outer gear ring (16) on the outer wall of the carrier frame (11).

9. The permanent magnet device for actively applying axial load to a transmission shaft according to claim 1, Features: The stator permanent magnet (13) and the rotor permanent magnet (23) have the same height, and the axial height difference formed by the axial movement of the stator permanent magnet (13) and the rotor permanent magnet (23) ranges from 0 to 2 / 3 of the height of the stator permanent magnet.

10. The permanent magnet device for actively applying axial load to a transmission shaft according to claim 1 or 9, Features: The stator permanent magnet (13) and the rotor permanent magnet (23) are both axially magnetized.

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