Mechanical variable flux motor

Abstract

The invention discloses a mechanical variable flux motor, and belongs to the technical field. A mechanical variable flux motor comprises a first permanent magnet rotor, a second permanent magnet rotor, an elastic shaft and a limiting mechanism. The elastic shaft is connected with the first permanent magnet rotor and the second permanent magnet rotor to stagger a preset angle; the limiting mechanism is located between the first permanent magnet rotor and the second permanent magnet rotor and limits the included angle between the two within a preset range. The torque output of the motor is adjusted by adjusting the included angle between the two rotors. In an initial state or a working condition requiring a small torque, a preset angle is kept between the two rotors, so that the motor can obtain a small torque and a high maximum rotating speed; when a working condition that the torque is greater than or equal to a rated torque is needed, the included angle between the two rotors is reduced, so that the motor obtains a larger torque, but the maximum rotating speed is correspondingly reduced. According to the motor, the mechanical variable-flux mechanical structure is simplified, the highest rotating speed is obviously higher, the reliability of the motor is improved, and the cost of the motor is reduced.

Description

Technical Field

[0001] The present invention belongs to the field of motors, and more specifically, relates to a mechanical variable-flux motor. Background Art

[0002] Permanent magnet synchronous motors have the characteristics of high power density, mature design methods, and complete control theories, so they have been widely used in various production industries. However, when a permanent magnet synchronous motor needs to operate at a speed higher than or far higher than the rated speed, a field weakening method is required to reduce the excitation magnetic flux of the motor. Common field weakening methods include armature D-axis current field weakening, variable leakage flux field regulation, and mechanical variable-flux methods, etc. Among them, the D-axis current field weakening method needs to apply a field weakening current to the permanent magnet, which will increase the energy consumption of the motor and increase the risk of demagnetization of the permanent magnet, and the field weakening ability is limited; the variable leakage flux field regulation method uses the saturation characteristics of ferromagnetic materials to adjust the magnetic flux, and the field weakening ability is limited; while the mechanical variable-flux method has perfect magnetic flux regulation ability, and the regulation process is well decoupled from the motor control and design methods, and can realize the relatively perfect and fast design and control of the motor. Based on the above advantages, mechanical variable-flux motors are commonly used in application fields with a relatively wide high-speed operation range, a high limit speed, and a large torque requirement within the rated speed.

[0003] Existing mechanical variable-flux motors often add a magnetic flux regulation mechanical mechanism in the axial direction of the motor to change the position or direction of the permanent magnet, so as to adjust the magnetic flux. However, the existing mechanism of mechanical variable-flux is often relatively complex, making it difficult to work under high-speed and high-load conditions for a long time. Summary of the Invention

[0004] Aiming at the defects of the related art, the purpose of the present invention is to provide a mechanical variable-flux motor, aiming to solve the technical problems that the mechanism of mechanical variable-flux is relatively complex and it is difficult to work under high-speed and high-load conditions for a long time.

[0005] To achieve the above purpose, the present invention provides a mechanical variable-flux motor, including: a first permanent magnet rotor, a second permanent magnet rotor, an elastic shaft, and a limiting mechanism;

[0006] The elastic shaft connects the first permanent magnet rotor and the second permanent magnet rotor, and is used to stagger the two by a preset angle;

[0007] The limiting mechanism is located between the first permanent magnet rotor and the second permanent magnet rotor, and is used to limit the included angle between the two within a preset range when the first permanent magnet rotor and the second permanent magnet rotor rotate relative to each other;

[0008] When the motor needs to operate under a condition where the torque is greater than or equal to the rated torque, the second permanent magnet rotor rotates under the action of the electromagnetic torque, overcoming the elastic force of the elastic shaft, and reducing the preset angle of misalignment with the first permanent magnet rotor, so as to increase the magnetic flux of the second permanent magnet rotor and thus increase the total magnetic flux of the motor. The torques generated by the first permanent magnet rotor and the second permanent magnet rotor drive the load of the motor.

[0009] Optionally, the first permanent magnet rotor is a rigid rotor, and the second permanent magnet rotor is an elastic rotor;

[0010] The rotating shaft of the rigid rotor is used for rigidly connecting to an external mechanical shaft; the elastic rotor is connected to the rigid shaft of the rigid rotor through an elastic shaft.

[0011] Optionally, the mechanical variable magnetic flux motor further includes a stator, and the stator includes a stator core and a stator winding;

[0012] When the mechanical variable magnetic flux motor is a radial mechanical variable magnetic flux motor, the inner side of the stator core has a tooth-slot structure, and the stator winding is distributed in the slots of the tooth-slot structure;

[0013] When the mechanical variable magnetic flux motor is an axial mechanical variable magnetic flux motor, the stator core has a tooth-slot structure on the side close to the rotor and the air gap, and the stator winding is wound and placed in the slots.

[0014] Optionally, the elastic shaft is a thin-walled metal elastic shaft or a spring.

[0015] Optionally, the relationship between the included angle and the torque between the first permanent magnet rotor and the second permanent magnet rotor is:

[0016] T = T1 + T2

[0017] T spring = T2 = k·θ

[0018] wherein, T is the total output torque of the motor, T1 is the torque of the first permanent magnet rotor, T2 is the torque of the second permanent magnet rotor, T spring is the elastic shaft torque, k is the elastic coefficient of the elastic shaft, and θ is the included angle between the two rotors.

[0019] Optionally, the first permanent magnet rotor and the second permanent magnet rotor share the stator;

[0020] The change of the current in the stator winding acts on the first permanent magnet rotor and the second permanent magnet rotor simultaneously.

[0021] Optionally, the permanent magnets of the first permanent magnet rotor and the second permanent magnet rotor are surface-mounted or embedded.

[0022] Optionally, the preset angle is 0 to 90 electrical degrees, and the preset range is 0 to 90 electrical degrees.

[0023] Through the above technical solution conceived by the present invention, compared with the prior art, the following beneficial effects can be achieved:

[0024] 1. The present invention provides a mechanical variable-flux motor. The motor adopts a dual-rotor structure and uses an elastic shaft to connect the two rotors, so that they are staggered by a preset angle in the initial state. When a smaller magnetic flux is required, the two rotors are staggered by a certain angle. When a larger magnetic flux is required, the relative position of the rotors moves, and the preset angle between the two rotors decreases, increasing the magnetic flux of the rotors and thus increasing the total magnetic flux of the motor to drive the load. During this process, the angle between the two rotors can be reduced until the two rotors are aligned. At the same time, the motor in this solution also adopts a limiting mechanism to limit the included angle between the two rotors within a preset range when the two rotors rotate relative to each other. The mechanical structure of the mechanical variable-flux motor in this solution is only composed of an elastic shaft or a spring, with a simple and reliable structure. The motor can reduce the magnetic flux through the elastic shaft at high speeds to reduce the back electromotive force and ensure that the motor has a high maximum speed; the motor can provide a high torque and achieve mechanical field weakening above the rated speed, ensuring that the motor has a high maximum speed. The motor can work under high-speed and high-load conditions for a long time.

[0025] 2. The present invention provides a mechanical variable-flux motor. One of the two rotors is a fixed rigid rotor, and the other is a rotatable elastic rotor. According to the required magnetic flux, the included angle between the elastic rotor and the rigid rotor is controlled to adjust the magnetic flux to provide different torques; the included angle between the two rotors can be continuously adjusted, so that the magnetic flux of the motor can be continuously adjusted. The motor can reduce the magnetic flux through the elastic shaft at any speed to generate a smaller torque and reduce the vibration and noise of the motor. There are two options for the elastic shaft, namely a thin-walled elastic shaft and a spring. The motor can be a radial-flux motor or an axial-flux motor; this solution has a wide range of applications and rich application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a cross-sectional view of a radial-flux elastic-shaft mechanical variable-flux motor;

[0027] Figure 2 is a cross-sectional view of a spring-shaft solution of a radial-flux elastic-shaft mechanical variable-flux motor;

[0028] Figure 3 is a cross-sectional view of an axial-flux elastic-shaft mechanical variable-flux motor;

[0029] Figure 4 is a cross-sectional view of a spring-shaft solution of an axial-flux elastic-shaft mechanical variable-flux motor;

[0030] Figure 5It is a schematic diagram of the initial position of the rotor of a radial flux elastic shaft mechanical variable flux motor;

[0031] Figure 6 It is a schematic diagram of the aligned position of the rotor of a radial flux elastic shaft mechanical variable flux motor;

[0032] Figure 7 It is a schematic diagram of the initial position of the rotor of an axial flux elastic shaft mechanical variable flux motor;

[0033] Figure 8 It is a schematic diagram of the aligned position of the rotor of an axial flux elastic shaft mechanical variable flux motor;

[0034] Figure 9 It is a schematic diagram of the motor starting process.

[0035] Reference numerals: 21 - stator core; 22 - armature winding; 31 - first permanent magnet rotor permanent magnet; 32 - first permanent magnet rotor yoke; 33 - rigid shaft; 34 - second permanent magnet rotor permanent magnet; 35 - second permanent magnet rotor yoke; 36 - thin - wall flexible shaft; 37 - limiting mechanism second rotor side; 38 - limiting mechanism second rotor side; 39 - elastic shaft; 310 - radial flexible shaft support. Detailed implementation manners

[0036] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] The following describes the content involved in the above - mentioned embodiments in combination with a preferred embodiment.

[0038] As Figure 1 shown, the present invention provides a mechanical variable flux motor, including: a first permanent magnet rotor, a second permanent magnet rotor, an elastic shaft 39 and a limiting mechanism;

[0039] The elastic shaft 39 connects the first permanent magnet rotor and the second permanent magnet rotor and is used to stagger the two by a preset angle;

[0040] The limiting mechanism is located between the first permanent magnet rotor and the second permanent magnet rotor and is used to limit the included angle between the two within a preset range when the first permanent magnet rotor and the second permanent magnet rotor rotate relative to each other;

[0041] When the motor needs to operate under a condition where the torque is greater than or equal to the rated torque, the second permanent magnet rotor rotates under the action of the electromagnetic torque, overcoming the elastic force of the elastic shaft 39, reducing the preset angle of misalignment with the first permanent magnet rotor, so as to increase the magnetic flux of the second permanent magnet rotor and thus increase the total magnetic flux of the motor, enabling the motor to drive the load.

[0042] Among them, the first permanent magnet rotor is composed of the first permanent magnet rotor permanent magnet 31 and the first permanent magnet rotor yoke 32, and the second permanent magnet rotor is composed of the second permanent magnet rotor permanent magnet 34 and the second permanent magnet rotor yoke 35; the permanent magnet 31 of the first permanent magnet rotor is installed on the surface of the rigid rotor yoke 32, and the permanent magnet 34 of the second permanent magnet rotor is installed on the surface of the elastic rotor yoke 35. The second permanent magnet rotor rotates under the action of the electromagnetic torque, overcoming the elastic force of the elastic shaft 39, reducing the preset angle of misalignment with the first permanent magnet rotor, that is, the permanent magnet 39 of the second permanent magnet rotor rotates under the action of the electromagnetic torque, overcoming the elastic force of the elastic shaft 39, reducing the preset angle of misalignment with the permanent magnet 34 of the first permanent magnet rotor.

[0043] The limiting mechanism includes two parts: the flexible side 37 of the limiting mechanism and the rigid side 38 of the limiting mechanism. The volumes of the effective parts of the first permanent magnet rotor and the second permanent magnet rotor are the same, that is, the volumes of the parts used to generate the electromagnetic torque are the same, and such a design has a simple structure.

[0044] Among them, the first permanent magnet rotor is a rigid rotor, and the second permanent magnet rotor is an elastic rotor;

[0045] The rigid shaft 33 of the rigid rotor is rigidly connected to the external mechanical shaft; the elastic rotor is connected to the rigid shaft 33 of the rigid rotor through the elastic shaft 36. In the radial flux mechanical variable flux motor, considering that the elastic shaft 39 is soft, unstable and easy to bend, a radial flexible shaft support 310 is added to ensure that the spring will not bend. Further, the elastic shaft 39 in this solution can be a spring or can be replaced with the form of a thin-walled flexible shaft 36, for example, a thin-walled metal elastic shaft. The thin-walled metal elastic shaft has a small volume and a compact structure, but requires special design and can be used when a smaller volume is needed; the spring elastic shaft has a larger volume, but the spring is a standard part and can be used when the volume requirement is not high but the design time requirement is high.

[0046] The elastic shaft mechanical variable flux motor provided by the present invention is as Figures 1 to 2As shown, permanent magnets are installed on the two rotors of the motor, respectively forming the rotor yokes of the rigid rotor and the elastic rotor. The D-axis of the rigid rotor coincides with the armature magnetomotive force, and can always generate the rated torque or the maximum torque under the armature current, and at the same time generate the rated back electromotive force in the armature, that is, this torque angle is the maximum torque torque angle; when the motor is in the initial position and does not output load, the D-axis of the elastic rotor has a certain included angle with the armature magnetomotive force, generates a smaller torque under this armature current, and at the same time generates a smaller back electromotive force in the armature. At this time, the torque corresponding to the torque angle is not the maximum.

[0047] The torque angle of the rigid rotor is fixed at the position where the torque is the largest. The torque angle of the elastic rotor is equal to the included angle between the elastic rotor and the rigid rotor. When this included angle decreases, the D-axis of the elastic rotor gradually aligns with the direction of the armature magnetomotive force, the torque generated by the elastic rotor gradually increases, and the back electromotive force generated by the elastic rotor also gradually increases.

[0048] In applications where the motor needs to output a torque equal to or greater than the rated torque, the torques generated by the rigid rotor and the elastic rotor are less than the load torque. At this time, the armature current is increased, and the elastic rotor will generate a greater electromagnetic torque. This electromagnetic torque is applied to the elastic shaft, deforming the elastic shaft, reducing the torque angle of the elastic rotor, causing the elastic rotor to generate a greater electromagnetic torque until this electromagnetic torque and the elastic shaft torque are balanced. At the same time, this electromagnetic torque of the elastic rotor is superimposed with the electromagnetic torque of the rigid rotor through the elastic shaft torque and transmitted to the load to achieve an increase in the electromagnetic torque of the motor. Because the included angle of the elastic rotor decreases and the torque angle increases, the magnetic flux of the elastic rotor increases, making the overall motor have a higher magnetic flux. In applications where the motor needs to output a smaller torque, such as less than the rated torque or in the initial state, the elastic rotor can reach the torque at a larger deflection angle. At this time, because the torque angle of the elastic rotor is larger, the elastic rotor will generate a smaller magnetic flux in the armature, and this smaller magnetic flux will allow the motor to operate at a higher speed under the rated voltage.

[0049] Optionally, the mechanical variable-flux motor further includes a stator, and the stator includes a stator core 21 and a stator winding 22;

[0050] When the mechanical variable-flux motor is a radial mechanical variable-flux motor, the inner side of the stator core 21 has a tooth-slot structure, and the stator winding 22 is distributed in the slots of the tooth-slot structure;

[0051] When the mechanical variable-flux motor is an axial mechanical variable-flux motor, the stator core 21 has a tooth-slot structure on the side close to the rotor and the air gap, and the stator winding 22 is wound around and placed in the slots.

[0052] The motor of this solution can be a radial-flux motor or an axial-flux motor; when the mechanical variable-flux motor of this solution is a radial mechanical variable-flux motor, refer to Figures 1 to 2, the motor is composed of a traditional AC armature stator and two permanent magnet rotors. The stator and the rotors are coaxially designed, and the distribution direction of the magnetic field is radial. The stator is composed of a stator core 21 and an armature winding 22, which generates a rotating magnetomotive force; the two rotors are a rigid permanent magnet rotor and an elastic permanent magnet rotor respectively. Among them, the rigid permanent magnet rotor, that is, the first permanent magnet rotor, is obtained by installing the first permanent magnet rotor permanent magnet 31 on the surface of the first permanent magnet rotor yoke 32, and is connected to the load through a rigid shaft 33; the elastic permanent magnet rotor, that is, the second permanent magnet rotor, is obtained by installing the second permanent magnet rotor permanent magnet 34 on the surface of the second permanent magnet rotor yoke 35, and is connected to the first permanent magnet rotor through a thin-walled flexible shaft 36 or a spring 39. In addition, there is a limiting mechanism between the two rotors, which is composed of a flexible side 37 and a rigid side 38 of the limiting mechanism; a radial flexible shaft support 310 for maintaining the shape of the spring is arranged around the spring.

[0053] Figures 5 to 6 Shows the state of the radial mechanical variable-flux motor from the initial state to the maximum rotation angle. As the torque condition of the motor operation continuously increases, the second permanent magnet rotor permanent magnet 39 rotates under the action of the electromagnetic torque, overcoming the elastic force of the elastic shaft, and gradually reducing the preset angle of misalignment with the first permanent magnet rotor permanent magnet 34 until the two are aligned, and at this time the maximum magnetic flux is reached.

[0054] When the mechanical variable-flux motor in this solution is an axial mechanical variable-flux motor, refer to Figures 3 to 4 , the motor is composed of an AC armature stator located at the center and two permanent magnet rotors located at both ends. The stator and the rotors are coaxially designed, and the distribution direction of the magnetic field is axial. The stator is composed of a stator core 21 and an armature winding 22, which generates a rotating magnetomotive force; the two rotors are a rigid permanent magnet rotor and an elastic permanent magnet rotor respectively. Among them, the rigid permanent magnet rotor, that is, the first permanent magnet rotor, is obtained by installing the first permanent magnet rotor permanent magnet 31 on the surface of the first permanent magnet rotor yoke 32, and is connected to the load through a rigid shaft 33; the elastic permanent magnet rotor, that is, the second permanent magnet rotor, is obtained by installing the second permanent magnet rotor permanent magnet 34 on the surface of the second permanent magnet rotor yoke 35, and is connected to the first permanent magnet rotor through a thin-walled flexible shaft 36 or a spring 39. In addition, there is a limiting mechanism between the two rotors, which is composed of a flexible side 37 and a rigid side 38 of the limiting mechanism.

[0055] Figures 7 to 8 Shows the state of the axial mechanical variable-flux motor from the initial state to the maximum rotation angle. As the torque condition of the motor operation continuously increases, the second permanent magnet rotor rotates under the action of the electromagnetic torque, overcoming the elastic force of the elastic shaft, and gradually reducing the preset angle of misalignment with the first permanent magnet rotor until the two are aligned, and at this time the maximum magnetic flux is reached.

[0056] Optionally, the relationship between the included angle and the torque between the first permanent magnet rotor and the second permanent magnet rotor is:

[0057]

[0058] Among them, T is the total output torque of the motor, T1 is the torque of the first permanent magnet rotor, T2 is the torque of the second permanent magnet rotor, and T spring is the elastic shaft torque, k is the elastic coefficient of the elastic shaft, and θ is the angle between the two rotors.

[0059] The electromagnetic torque formulas of the two rotors are as follows:

[0060]

[0061] Among them, θ1 is the torque angle of the rigid rotor, θ2 is the torque angle of the elastic rotor, and f is the torque angle characteristic curve. During the control process of the motor, it is necessary to control the torque angles θ1 and θ2 of the rigid rotor and the elastic rotor to make them conform to the equations (1) and (2).

[0062] The deflection process of the elastic rotor during the motor startup process is as Figure 9 shown.

[0063] At the initial moment of startup, the elastic rotor is located at a relatively large initial deflection angle θ0, and the driver applies a current I0 to the motor; at this time, the combined torque T of the rigid rotor T1 and the elastic rotor torque T2 is less than the target torque, and the current is increased; after the current is increased, both T1 and T2 increase; after T2 increases and is greater than the spring torque, the deflection angles of the elastic rotor and the spring decrease, the magnetic flux of the elastic rotor increases, and T2 increases at a faster speed. At this time, the increasing speed of T2 is greater than that of T1; at the operating point moment, the total torque of T1 and T2 is equal to the target torque, and the elastic rotor reaches the operating angle θ s , and the startup of the motor is completed.

[0064] Optionally, the first permanent magnet rotor and the second permanent magnet rotor share the stator;

[0065] The change of the current in the stator winding acts on the first permanent magnet rotor and the second permanent magnet rotor simultaneously.

[0066] Referring to Figure 2 , the two rotors face the same stator winding axially and are affected by a stator winding at the same time.

[0067] Optionally, the permanent magnets of the first permanent magnet rotor and the second permanent magnet rotor are surface-mounted or embedded.

[0068] The surface-mounted structure is relatively simple in design and installation, with a lower cost, but a lower power density; the embedded structure is more complex in design and installation, with a higher cost, but a higher power density.

[0069] Optionally, the preset angle is 0 to 90 electrical degrees, and the preset range is 0 to 90 electrical degrees.

[0070] The preset angle includes the minimum to maximum range of the torque angle of the permanent magnet motor, and can achieve continuous adjustment of the second permanent magnet rotor within all torque ranges.

[0071] In the embodiment of the present invention, the motor adopts a dual-rotor structure, and an elastic shaft is used to connect the two rotors, so that they are staggered by a preset angle in the initial state. When a smaller magnetic flux is required, the two rotors are staggered by a certain angle. When a larger magnetic flux is required, the relative position of the rotors moves, and the preset angle between the two rotors decreases, increasing the magnetic flux of the rotors and thus increasing the total magnetic flux of the motor, so as to drive the load by the motor. During this process, the angle between the two rotors can be reduced until the two rotors are aligned. The mechanical structure is only composed of an elastic shaft or a spring, with a simple and reliable structure. It solves the technical problem that the mechanism for mechanically changing the magnetic flux is relatively complex and difficult to work under high-speed and high-load conditions for a long time. It realizes changing the magnetic flux of the motor through a simple mechanical structure, can reduce the magnetic flux through the elastic shaft at any rotational speed to generate a smaller torque, and reduce the vibration and noise of the motor; it can reduce the magnetic flux through the elastic shaft at high rotational speeds to reduce the back electromotive force and ensure that the motor has a higher maximum rotational speed.

[0072] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A mechanical variable flux motor, characterized in that: include: A first permanent magnet rotor, a second permanent magnet rotor, an elastic shaft and a limiting mechanism; The elastic shaft connects the first permanent magnet rotor and the second permanent magnet rotor to stagger the two by a preset angle; The limiting mechanism is located between the first permanent magnet rotor and the second permanent magnet rotor, and is used to limit the angle between the first permanent magnet rotor and the second permanent magnet rotor to a preset range when the first permanent magnet rotor and the second permanent magnet rotor rotate relative to each other; When the motor needs to operate at a torque greater than or equal to the rated torque, the second permanent magnet rotor overcomes the elastic force of the elastic shaft and rotates under the action of the electromagnetic torque, reducing the preset angle of misalignment with the first permanent magnet rotor to increase the magnetic flux of the second permanent magnet rotor and thus increase the total magnetic flux of the motor. The torque generated by the first permanent magnet rotor and the second permanent magnet rotor enables the motor to drive the load.

2. The mechanical variable flux motor according to claim 1, characterized in that: The first permanent magnet rotor is a rigid rotor, and the second permanent magnet rotor is an elastic rotor; The rotating shaft of the rigid rotor is used for rigidly connecting to an external mechanical shaft; the elastic rotor is connected to the rigid shaft of the rigid rotor via an elastic shaft.

3. The mechanical variable flux motor according to claim 1, characterized in that: The mechanical variable flux motor further comprises a stator, wherein the stator comprises a stator core and a stator winding; When the mechanical variable flux motor is a radial mechanical variable flux motor, the inner side of the stator core has a slot structure, and the stator winding is distributed in the slots of the slot structure; When the mechanical variable flux motor is an axial mechanical variable flux motor, the stator core has a tooth slot structure on a side close to the rotor and the air gap, and the stator winding is placed in the slot in a surrounding manner.

4. The mechanical variable flux motor according to claim 1, characterized in that: The elastic shaft is a thin-walled metal elastic shaft or a spring.

5. The mechanical variable flux motor according to claim 1, characterized in that: The relationship between the angle and torque between the first permanent magnet rotor and the second permanent magnet rotor is: T=T1+T2 T spring =T2=k·θ Where T is the total output torque of the motor, T1 is the torque of the first permanent magnet rotor, T2 is the torque of the second permanent magnet rotor, and T spring is the elastic shaft torque, k is the elastic coefficient of the elastic shaft, and θ is the angle between the two rotors.

6. The mechanical variable flux motor according to claim 3, characterized in that: The first permanent magnet rotor and the second permanent magnet rotor share the stator; The change of the current in the stator winding acts on the first permanent magnet rotor and the second permanent magnet rotor at the same time.

7. The mechanical variable flux motor according to claim 1, characterized in that: The permanent magnets of the first permanent magnet rotor and the second permanent magnet rotor are mounted in a surface-mounted or embedded manner.

8. The mechanical variable flux motor according to claim 1, characterized in that: The preset angle is 0 to 90 electrical degrees, and the preset range is 0 to 90 electrical degrees.

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