Motor and vehicle with adjustable magnetic circuit

Abstract

The present invention discloses a motor and vehicle with adjustable magnetic circuit, comprising a housing, a rotor assembly, a stator assembly, and a yoke driving mechanism within the housing. The stator assembly comprises stator slots, stator coils wound around the stator slots, and a rotatable yoke, the stator coils being used to generate a moving magnetic field. The rotatable yoke is disposed circumferentially around the stator slots, and the magnetic resistance of the rotatable yoke is unevenly arranged along the circumferential and radial directions. The yoke driving mechanism comprises an actuator and a controller connected to the actuator, the controller being used to control the movement of the actuator. The actuator is connected to the rotatable yoke and, under the control of the controller, is used to drive the rotatable yoke to rotate to a preset angle along the circumferential direction of the stator slots, thereby adjusting the magnetic resistance of the magnetic circuit between the rotor, stator slots, and rotatable yoke. The present invention can effectively adjust the magnitude of the back electromotive force on the stator coils.

Description

Technical Field

[0001] The invention relates to a motor with adjustable magnetic circuit and a vehicle, belonging to the technical field of motors. Background Art

[0002] When the motor rotates, a back electromotive force is generated on the stator coil. The higher the speed, the higher the back electromotive force. When the back electromotive force is higher than the power supply voltage, the motor cannot work normally in the driving state.

[0003] Modern motor design, especially permanent magnet motors, requires a compromise between torque and speed. While maintaining high torque in the low-speed range, current control methods such as field weakening are generally used in the high-speed range to suppress back EMF. However, field weakening increases motor losses in the high-speed range, so improvements are being made to the motor structure to suppress back EMF.

[0004] Some motors have a rotor that can be controlled to move axially relative to the stator. At low speeds, the rotor and stator are axially aligned. At high speeds, a mechanical device forces the rotor to shift axially, preventing them from completely aligning, thereby reducing back EMF.

[0005] Axially moving a high-speed rotor requires complex mechanical structures and is rarely used in practice. Axially moving a stator connected to a power line can compromise the motor's electrical reliability and lifespan. Summary of the Invention

[0006] The present invention aims to overcome the shortcomings of the prior art and provide a motor and vehicle with an adjustable magnetic circuit, which can effectively adjust the magnitude of the back electromotive force on the stator coil. To achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a motor with adjustable magnetic circuit, comprising a housing, wherein a rotor assembly, a stator assembly and a yoke pushing device are arranged in the housing.

[0008] The rotor assembly includes a rotor and a rotor shaft connected to the rotor, wherein the rotor shaft is connected to the housing through a bearing, and the rotor and the rotor shaft rotate relative to the housing;

[0009] The stator assembly includes a stator slot portion, a stator coil wound around the stator slot portion, and a rotatable yoke portion, wherein the stator coil is used to generate a moving magnetic field; the rotatable yoke portion is arranged at the circumference of the stator slot portion, and the magnetic resistance of the rotatable yoke portion is unevenly arranged in the circumferential direction and the radial direction;

[0010] The yoke pushing device includes an actuator and a controller connected to the actuator, the controller is used to control the movement of the actuator, and the actuator is connected to the rotatable yoke, and is used to push the rotatable yoke to rotate along the circumferential direction of the stator tooth portion to a preset angle under the control of the controller, thereby adjusting the magnetic resistance of the magnetic circuit between the rotor, the stator tooth portion, and the rotatable yoke.

[0011] In combination with the first aspect, optionally, a permanent magnet is provided on the rotor, and the permanent magnet is used to couple with the moving magnetic field generated by the stator coil to drive the rotor to move.

[0012] In combination with the first aspect, optionally, the rotatable yoke is provided with holes or slots along the circumferential direction, for generating magnetic resistance that is unevenly arranged along the circumferential direction and the radial direction.

[0013] In combination with the first aspect, optionally, when the motor with adjustable magnetic circuit is an inner rotor motor, the stator tooth slot portion is arranged outside the rotor circumference, and the rotatable yoke portion is arranged outside the outer circumference of the stator tooth slot portion, located between the stator tooth slot portion and the housing.

[0014] In combination with the first aspect, optionally, when the motor with adjustable magnetic circuit is an outer rotor motor, the stator tooth slot portion is arranged inside the rotor circumference, and the rotatable yoke portion is arranged on the inner side of the inner circumference of the stator tooth slot portion.

[0015] In combination with the first aspect, optionally, the yoke pushing device further includes a reset device connected to the controller, and the reset device is used to push the rotatable yoke to return to an initial position under the control of the controller.

[0016] In combination with the first aspect, optionally, a limiting structure is provided on the rotatable yoke to limit the maximum angle of rotation of the rotatable yoke relative to the stator tooth slot portion.

[0017] In combination with the first aspect, optionally, the stator tooth slot portion is connected to the housing via a tooth slot portion fixing rod.

[0018] In combination with the first aspect, optionally, a fixed yoke portion is further included, wherein the fixed yoke portion is provided between the stator tooth portion and the rotatable yoke portion and is connected to the stator tooth portion.

[0019] The second invention provides a vehicle that is driven by the motor with adjustable magnetic circuit as described in the first aspect.

[0020] Compared with the prior art, the motor with adjustable magnetic circuit provided by the embodiment of the present invention has the following beneficial effects:

[0021] The present invention includes a shell, in which a rotor assembly, a stator assembly and a yoke pushing device are arranged, the rotor assembly includes a rotor and a rotor shaft connected to the rotor, the rotor shaft is connected to the shell through a bearing, and the rotor and the rotor shaft rotate relative to the shell; the stator assembly includes a stator tooth slot portion, a stator coil wound around the stator tooth slot portion and a rotatable yoke, the stator coil is used to generate a moving magnetic field; the rotatable yoke is provided at the circumference of the stator tooth slot portion, and the magnetic resistance of the rotatable yoke is unevenly arranged along the circumferential direction and the radial direction; the yoke pushing device includes an actuator and a controller connected to the actuator, the controller is used to control the movement of the actuator, the actuator is connected to the rotatable yoke, and is used to push the rotatable yoke to rotate along the circumferential direction of the stator tooth slot portion to a preset angle under the control of the controller, so as to adjust the magnetic resistance of the magnetic circuit between the rotor, the stator tooth slot portion and the rotatable yoke. The present invention is a method for effectively adjusting the magnitude of the back electromotive force on the stator coil by placing the rotatable yoke in a position where the magnetic circuit formed by the rotatable yoke and the stator tooth slots is conducive to the passage of magnetic lines of force when the motor rotates at a low speed; and placing the rotatable yoke in a position where the magnetic circuit formed by the rotatable yoke and the stator tooth slots is not conducive to the passage of magnetic lines of force when the motor rotates at a high speed.

[0022] The present invention eliminates the need for axial movement of the high-speed rotating rotor or the stator, which requires power, resulting in a simple structure and high reliability. By adjusting the offset position of the stator yoke, the back electromotive force can be effectively adjusted, increasing the motor speed and reducing system energy consumption, especially at high speeds. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic structural diagram of a motor with adjustable magnetic circuit provided in the first embodiment of the present invention;

[0024] Figure 2 The rotatable yoke of a motor with adjustable magnetic circuit provided in the first embodiment of the present invention is located in a position that is conducive to the passage of magnetic lines of force;

[0025] Figure 3 The rotatable yoke of a motor with adjustable magnetic circuit provided in the first embodiment of the present invention is located at a position that is not conducive to the passage of magnetic lines of force.

[0026] In the picture:

[0027] 1. Rolling device; 2. Rotatable yoke; 3. Stator slot; 4. Stator coil;

[0028] 5. Yoke pusher; 6. Permanent magnet; 7. Tooth groove fixing rod; 8. Rotor; 9. Rotor shaft;

[0029] 10. Limiting structure; 11. Housing; 12. Fixed yoke. Implementation Method

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

[0031] In the description of the present invention, it should be noted that the terms "upper / lower end," "inner," "outer," "front end," "rear end," "both ends," "one end," "the other end," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "set / mounted," "sleeved," "connected," etc., should be understood in a broad sense. For example, "connected" may refer to a fixed connection, a detachable connection, or an integral connection; it may refer to a mechanical connection or an electrical connection; it may refer to a direct connection or an indirect connection through an intermediate medium; it may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances. Example 1

[0033] This embodiment provides a motor with adjustable magnetic circuit, including a housing 11 , in which a rotor 8 assembly, a stator assembly and a yoke pushing device 5 are arranged.

[0034] like Figure 1 As shown, the rotor 8 assembly includes a rotor 8 and a rotor shaft 9 connected to the rotor 8. The rotor shaft 9 is connected to the housing 11 through a bearing, and the rotor 8 and the rotor shaft 9 rotate relative to the housing 11.

[0035] like Figure 1 As shown, the stator assembly includes stator slots 3, stator coils 4 wound around the stator slots 3, and a rotatable yoke 2. The stator slots 3 are connected to the housing 11 via slot fixing rods 7. The stator assembly also includes a fixed yoke 12, which is disposed between the stator slots 3 and the rotatable yoke 2 and connected to the stator slots 3. This facilitates securing the stator slots 3, enhances the mechanical strength of the stator slots 3, and provides initial magnetic resistance.

[0036] The stator coil 4 is used to generate a moving magnetic field. The rotor 8 is equipped with permanent magnets 6, which couple with the moving magnetic field generated by the stator coil 4 to propel the rotor 8. The rotatable yoke 2 is located around the circumference of the stator tooth slots 3. The rotatable yoke 2 is provided with holes or slots along the circumference to generate uneven magnetic resistance in the circumferential and radial directions.

[0037] In this embodiment, the rotatable yoke 2 is connected to the housing 11 via a rolling device 1 , which is a roller or a bearing.

[0038] The yoke propulsion device 5 includes an actuator and a controller connected to the actuator. The controller controls the movement of the actuator, which is connected to the rotatable yoke 2. Under the control of the controller, the actuator propels the rotatable yoke 2 to rotate to a preset angle along the circumference of the stator tooth slots 3, thereby adjusting the magnetic resistance of the magnetic circuit between the rotor 8, the stator tooth slots 3, and the rotatable yoke 2.

[0039] In this embodiment, the actuator is any one of a hydraulic device, an electromagnetic device, and a cam device, preferably a hydraulic device.

[0040] The yoke pushing device 5 further includes a reset device connected to the controller, and the reset device is used to push the rotatable yoke 2 to return to the initial position under the control of the controller.

[0041] A limiting structure 10 is provided on the rotatable yoke 2 for limiting the maximum angle of rotation of the rotatable yoke 2 relative to the stator tooth slot 3 .

[0042] In this embodiment, when the motor with adjustable magnetic circuit is an inner rotor 8 motor, the stator slots 3 are disposed outside the circumference of the rotor 8, and the rotatable yoke 2 is disposed outside the outer circumference of the stator slots 3, located between the stator slots 3 and the housing 11. The concave-convex fit between the inner side of the rotatable yoke 2 and the outer side of the stator slots 3 forms a limiting structure 10, and / or the concave-convex fit between the outer side of the rotatable yoke 2 and the inner side of the housing 11 forms a limiting structure 10.

[0043] exist Figure 1 In the embodiment, the inner side of the rotatable yoke 2 and the outer side of the fixed yoke 12 are matched with each other to form a limiting structure 10.

[0044] In this embodiment, the reset device is an elastic device such as a spring, a spring, a hydraulic device, or a pneumatic device.

[0045] like Figure 2 、 Figure 3 As shown, the elliptical dotted line illustrates the magnetic field loop from the rotor 8 - stator tooth portion 3 - rotatable yoke 2 - stator tooth portion 3 - rotor 8. The dotted box portion illustrates the change in the magnetic circuit between the rotatable yoke 2 and the stator tooth portion 3 when the rotatable yoke 2 rotates a certain angle.

[0046] like Figure 2 As shown, when the motor rotor 8 is in a stationary state or the motor output is in a low speed and high torque state, the back electromotive force generated by the rotation of the motor rotor is lower than the driving voltage or preset voltage applied to the stator coil, and the rotatable yoke 2 is in a position where the magnetic circuit formed with the stator tooth groove portion 3 is conducive to the passage of magnetic lines of force, which is conducive to reducing the magnetic resistance of the elliptical magnetic field loop.

[0047] like Figure 3 As shown, when the motor rotor 8 rotates at high speed, the back electromotive force generated by the motor rotor's rotation is higher than the drive voltage or preset voltage applied to the stator coil. Based on the speed of the rotor 8, the rotatable yoke 2, under the action of the yoke pushing device 5, changes its angle relative to the stator tooth slot 3, placing the rotatable yoke 2 in a position that is conducive to increasing the magnetic resistance of the elliptical magnetic field circuit. The higher the back electromotive force generated by the motor rotor's rotation is than the drive voltage or preset voltage applied to the stator coil, the more conducive the rotatable yoke 2 is to increasing the magnetic resistance of the elliptical magnetic field circuit.

[0048] like Figure 3 In the dotted box shown, the magnetic circuit between the rotatable yoke 2 and the stator tooth slot 3 becomes narrower. Although the magnetic circuit on the left side of the magnetic field loop becomes wider, according to the barrel principle, the magnetic resistance of the entire closed magnetic field loop still increases, thereby reducing the magnetic induction intensity B in Lenz's law E=BLV, and also reducing the magnetic flux E, where L is the effective length of the conductor and V is the speed of the conductor.

[0049] Specifically, the motor is in a low speed state when the motor speed does not exceed 50% of the rated speed, and the motor is in a high speed state when the motor speed exceeds 50% of the rated speed.

[0050] This embodiment eliminates the need for axial movement of the high-speed rotating rotor 8 or the stator, which requires power, resulting in a simple structure and high reliability. By adjusting the offset position of the stator yoke, the back electromotive force can be effectively adjusted, increasing the motor speed and reducing system energy consumption, especially at high speeds. Example 2

[0051] This embodiment provides a motor with adjustable magnetic circuit similar to the first embodiment, including a housing 11, in which a rotor 8 assembly, a stator assembly and a yoke pushing device 5 are arranged. The difference is that the motor with adjustable magnetic circuit in this embodiment is an outer rotor 8 motor.

[0052] The rotor shaft 9 is connected to the housing 11 via a bearing, and the rotor 8 and the rotor shaft 9 rotate relative to the housing 11. The stator assembly includes a stator tooth slot 3, a stator coil 4 wound around the stator tooth slot 3, and a rotatable yoke 2. The stator tooth slot 3 is connected to the housing 11 via a tooth slot fixing rod 7. The stator assembly also includes a fixed yoke 12, which is arranged between the stator tooth slot 3 and the rotatable yoke 2 and is connected to the stator tooth slot 3 to facilitate fixing the stator tooth slot 3 and enhance the mechanical strength of the stator tooth slot 3. It also provides an initial magnetic resistance. Furthermore, the initial magnetic resistance can also be unevenly arranged in the circumferential and radial directions.

[0053] A limiting structure 10 is provided on the rotatable yoke 2 for limiting the maximum angle of rotation of the rotatable yoke 2 relative to the stator tooth slot 3 .

[0054] The stator tooth slots 3 are disposed within the circumference of the rotor 8, and the rotatable yoke 2 is disposed inside the inner circumference of the stator tooth slots 3. A concave-convex fit between the inner side of the rotatable yoke 2 and the outer side of the housing 11 forms a retaining structure 10, and / or a concave-convex fit between the outer side of the rotatable yoke 2 and the inner side of the stator tooth slots 3 forms a retaining structure 10.

[0055] The yoke propulsion device 5 includes an actuator and a controller connected to the actuator. The controller controls the movement of the actuator, which is connected to the rotatable yoke 2. Under the control of the controller, the actuator propels the rotatable yoke 2 to rotate to a preset angle along the circumference of the stator tooth slots 3, thereby adjusting the magnetic resistance of the magnetic circuit between the rotor 8, the stator tooth slots 3, and the rotatable yoke 2.

[0056] This embodiment eliminates the need for axial movement of the high-speed rotating rotor 8 or the stator, which requires power, resulting in a simple structure and high reliability. By adjusting the offset position of the stator yoke, the back electromotive force can be effectively adjusted, increasing the motor speed and reducing system energy consumption, especially at high speeds. Example 3

[0057] This embodiment provides a vehicle that is driven by a motor with adjustable magnetic circuit as described in the first or second embodiment.

[0058] In the description of the present invention, unless otherwise specified, "plurality" means two or more; terms such as "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," and "tail" indicate positions or relationships based on those shown in the accompanying drawings. These terms are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, terms such as "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0059] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integral connection; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0060] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A motor with adjustable magnetic circuit, characterized in that: It includes a housing, in which a rotor assembly, a stator assembly and a yoke pushing device are arranged. The rotor assembly includes a rotor and a rotor shaft connected to the rotor, wherein the rotor shaft is connected to the housing through a bearing, and the rotor and the rotor shaft rotate relative to the housing; The stator assembly includes a stator slot portion, a stator coil wound around the stator slot portion, and a rotatable yoke portion, wherein the stator coil is used to generate a moving magnetic field; the rotatable yoke portion is arranged at the circumference of the stator slot portion, and the magnetic resistance of the rotatable yoke portion is unevenly arranged in the circumferential direction and the radial direction; The yoke pushing device includes an actuator and a controller connected to the actuator, the controller is used to control the movement of the actuator, and the actuator is connected to the rotatable yoke, and is used to push the rotatable yoke to rotate along the circumferential direction of the stator tooth portion to a preset angle under the control of the controller, thereby adjusting the magnetic resistance of the magnetic circuit between the rotor, the stator tooth portion, and the rotatable yoke.

2. The motor with adjustable magnetic circuit according to claim 1, characterized in that: The rotor is provided with a permanent magnet, which is used to couple with the moving magnetic field generated by the stator coil to drive the rotor to move.

3. The motor with adjustable magnetic circuit according to claim 1, characterized in that: The rotatable yoke is provided with holes or slots along the circumferential direction for generating magnetic resistance that is unevenly arranged along the circumferential direction and the radial direction.

4. The motor with adjustable magnetic circuit according to claim 1, characterized in that: When the motor with adjustable magnetic circuit is an inner rotor motor, the stator slot portion is arranged outside the rotor circumference, and the rotatable yoke portion is arranged outside the outer circumference of the stator slot portion and is located between the stator slot portion and the housing.

5. The motor with adjustable magnetic circuit according to claim 1, characterized in that: When the motor with adjustable magnetic circuit is an outer rotor motor, the stator tooth slot portion is arranged inside the circumference of the rotor, and the rotatable yoke portion is arranged inside the inner circumference of the stator tooth slot portion.

6. The motor with adjustable magnetic circuit according to claim 1, characterized in that: The yoke pushing device further includes a reset device connected to the controller, and the reset device is used to push the rotatable yoke to return to an initial position under the control of the controller.

7. The motor with adjustable magnetic circuit according to claim 1, characterized in that: The rotatable yoke is provided with a limiting structure for limiting the maximum angle of rotation of the rotatable yoke relative to the stator tooth slot portion.

8. The motor with adjustable magnetic circuit according to claim 1, characterized in that: The stator tooth slot portion is connected to the housing via a tooth slot portion fixing rod.

9. The motor with adjustable magnetic circuit according to claim 1, characterized in that: It also includes a fixed yoke portion, which is arranged between the stator tooth portion and the rotatable yoke portion and is connected to the stator tooth portion.

10. A vehicle, characterized in that: It is driven by the motor with adjustable magnetic circuit according to any one of claims 1 to 9.

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