Double-stator and double-rotor axial flux motor

Abstract

The invention relates to the technical field of axial magnetic flux motors, in particular to a double-stator double-rotor axial magnetic flux motor which comprises a front end cover, a rear end cover, a connecting plate and a photoelectric encoder which are sequentially and axially mounted together on the same central axis, and a motor shaft is rotatably mounted in the front end cover and the rear end cover. The end portion of the motor shaft is detachably connected with the output end of a photoelectric encoder, stators are fixedly installed on the opposite sides in the front end cover and the rear end cover, two rotors located between the two stators are fixedly installed on the motor shaft, and the central axes of the two stators and the central axes of the two rotors coincide. An air gap is formed between one rotor and one adjacent stator; the two stators and the two rotors share the same axis, magnetic flux acts in the two air gaps at the same time while a magnetic circuit is short, power output of two times is achieved within one axial length, and axial magnetic pulling force generated by the two rotors can be offset under the symmetrical condition.

Description

Technical Field

[0001] This invention relates to the field of axial flux motor technology, and more specifically to a dual-stator dual-rotor axial flux motor. Background Technology

[0002] In recent years, axial permanent magnet motors have attracted increasing attention from researchers due to their compact structure, high efficiency, and high power density. Numerous in-depth studies have been conducted on the application of various axial permanent magnet motor structures in small-scale applications. Unlike ordinary motors, their magnetic flux direction is axial, the current-carrying conductor system is placed radially, and the stator and rotor cores have a disc-shaped structure.

[0003] In practical applications, traditional single-stator single-rotor axial flux motors suffer from axial loads on the bearings due to unilateral magnetic pull, which reduces bearing life. At the same time, there is a need to increase the power and torque output per unit volume or unit mass.

[0004] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to design a dual-stator dual-rotor axial flux motor that significantly improves power density and torque density, and whose power and torque output per unit volume or unit mass far exceeds that of traditional radial flux motors and single-stator single-rotor axial flux motors, while reducing the axial load on the bearings, in order to overcome the aforementioned shortcomings in the technology.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a dual-stator dual-rotor axial flux motor, comprising a front end cover, a rear end cover, a connecting plate, and a photoelectric encoder sequentially mounted together on the same central axis. A motor shaft is rotatably mounted inside the front end cover and the rear end cover. The end of the motor shaft is detachably connected to the output end of the photoelectric encoder. Stator is fixedly mounted on opposite sides inside the front end cover and the rear end cover. Two rotors located between the two stators are fixedly mounted on the motor shaft. The central axes of the two stators and the two rotors coincide. An air gap exists between one rotor and an adjacent stator. By sharing the same axis between the two stators and two rotors, the magnetic circuit is short, and the magnetic flux works simultaneously in the two air gaps, achieving twice the power output within one axial length.

[0007] Preferably, the stator includes stator cores fixedly installed on opposite sides inside the front end cover or the rear end cover, and stator coils are installed on both stator cores.

[0008] Preferably, the stator core includes a positioning ring fixedly installed on one side of the front end cover or the rear end cover, and protrusions fixedly installed in a ring array on one side of the two positioning rings, wherein the number and position of the stator coils are matched with the protrusions.

[0009] Preferably, the overall shape of the protrusion is set as an isosceles trapezoid, with one side of the protrusion on the same outer circumferential surface as the outer ring of the positioning ring, and the other side of the protrusion on the same inner circumferential surface as the inner ring of the positioning ring.

[0010] Preferably, the stator coil is mounted on the protrusion using a concentrated flat wire winding.

[0011] Preferably, the positioning ring and the protrusion are an integrated design of disc-type wound stacked sheets.

[0012] Preferably, the two rotors consist of a rotor core fixedly mounted on the motor shaft and a plurality of permanent magnets fixedly mounted on both sides of the rotor core. The permanent magnets on both sides are arranged in a ring array on both sides of the rotor core, and the permanent magnets on both sides of the rotor core are located between the stator coils on the two positioning rings.

[0013] Preferably, when the N pole of the permanent magnet on one side of the rotor core is fixedly connected to the rotor core, the S pole of the adjacent permanent magnet on the same side is fixedly connected to the rotor core, and the S pole of the permanent magnet on the same axis on the other side is fixedly connected to the rotor core.

[0014] Preferably, the gap between two adjacent permanent magnets forms a centrifugal channel, the front end cover has multiple air inlets near the central axis, the rotor core has multiple through holes near the central axis, and the rear end cover has an exhaust port away from the central axis.

[0015] Preferably, the outer diameter of the circle formed by the plurality of permanent magnets arranged in a ring array is smaller than the outer diameter of the circle formed by the plurality of stator coils.

[0016] The technical effects and advantages provided by the present invention in the above technical solution are as follows: This invention has extremely high power density and torque density. By having two stators and two rotors share the same axis, the axial magnetic circuit is shorter, effectively utilizing radial space. The magnetic flux works simultaneously in the two air gaps, which is equivalent to realizing the power output of "two motors" within one axial length. This significantly improves the power and torque output per unit volume or per unit mass, far exceeding traditional radial flux motors and single-stator single-rotor axial flux motors. This invention has excellent heat dissipation performance. Heat transfer and heat dissipation are achieved through direct contact between the two stators and the front and rear covers. The large contact area results in good heat dissipation. Furthermore, when the permanent magnet rotates, it draws in external media through the air inlet and then discharges it through the exhaust outlet, carrying away heat and further improving the heat dissipation effect of the motor. This allows the motor to withstand higher current densities and increase power density. Meanwhile, this invention can counteract axial magnetic pull. By designing the layout of the permanent magnets, the axial magnetic pull generated by the two rotors can cancel each other out in a symmetrical manner. This greatly reduces the axial load on the bearing, reduces bearing wear, improves bearing life and system reliability, and simplifies the design of the mechanical support structure. Compared to existing motors, this invention features a compact, flat design with a short axial length and a large radial length, making it ideal for installation in space-constrained applications with minimal diameter limitations, such as electric vehicle hub motors, certain aircraft propulsion systems, and integration within equipment flanges. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 This is a perspective view of the present invention; Figure 3 This is a hidden view of the front cover of the present invention; Figure 4 This is a schematic diagram showing the connection between the rotor and the rear end cover of the present invention; Figure 5 This is an exploded view of the present invention; Figure 6 This is a first schematic diagram of the rotor and stator connection of the present invention; Figure 7 This is a second schematic diagram showing the connection between the rotor and stator of the present invention; Figure 8 This is a schematic diagram of the stator disassembly of the present invention; Figure 9 This is a schematic diagram of the connection between the rotor and the motor shaft of the present invention.

[0019] Explanation of reference numerals in the attached figures: 1. Front cover; 2. Rear cover; 3. Connecting plate; 4. Photoelectric encoder; 5. Motor shaft; 6. Stator; 6a. Stator core; 6a1. Positioning ring; 6a2. Protrusion; 6b. Stator coil; 7. Rotor; 7a. Rotor core; 7b. Permanent magnet; 8. Air gap; 9. Centrifugal channel; 10. Air inlet; 11. Through hole; 12. Exhaust hole. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0022] This invention provides, for example Figure 1-9 The illustrated dual-stator dual-rotor axial flux motor includes a front cover 1, a rear cover 2, a connecting plate 3, and a photoelectric encoder 4, which are axially mounted sequentially on the same central axis, as is common in the prior art. A motor shaft 5 is rotatably mounted inside the front cover 1 and the rear cover 2. The end of the motor shaft 5 is detachably connected to the output end of the photoelectric encoder 4. Positioning rings 6a1 are fixedly installed inside both the front cover 1 and the rear cover 2. Multiple protrusions 6a2 arranged in a circular array are fixedly installed on opposite sides of the two positioning rings 6a1. The overall shape of the protrusions 6a2 is an isosceles trapezoid. One side of each protrusion 6a2 is connected to the positioning ring. The outer ring of 6a1 is on the same outer circumferential surface, and the other side of the protrusion 6a2 is on the same inner circumferential surface as the inner ring of the positioning ring 6a1. The positioning ring 6a1 and the protrusion 6a2 are integrated into a disc-type wound lamination design to form the stator core 6a. A stator coil 6b is installed on each protrusion 6a2, which is installed using a concentrated flat wire winding method. The stator coil 6b and the stator core 6a constitute the stator 6 of the motor. When the stator core 6a and the stator coil 6b generate heat, they can directly transfer heat to dissipate heat through contact with the front cover 1 and the rear cover 2. The contact area is large and the heat dissipation effect is good. Between the two stators 6, there are two rotors 7 mounted on the motor shaft 5. There is an air gap 8 between one rotor 7 and the adjacent stator 6. The two rotors 7 consist of a rotor core 7 fixedly mounted on the motor shaft 5 and multiple permanent magnets 7b fixedly mounted on both sides of the rotor core 7a. The permanent magnets 7b on both sides are arranged in a ring array on both sides of the rotor core 7a. The permanent magnets 7b on both sides of the rotor core 7a are located between the stator coils 6b on the two positioning rings 6a1. The two stators 6 and the two rotors 7 share the same axis, and the magnetic circuit with a shorter axial length is more efficient in utilizing the radial space. The magnetic flux works simultaneously in the two air gaps 8, which is equivalent to realizing the power output of "two motors" within one axial length. This significantly improves the power and torque output per unit volume or unit mass, far exceeding that of traditional radial flux motors and single stator 6 single rotor 7 axial flux motors. Furthermore, when the N pole of the permanent magnet 7b on one side of the rotor core 7a is fixedly connected to the rotor core 7a, the S pole of the adjacent permanent magnet 7b on the same side is fixedly connected to the rotor core 7a, and the S pole of the permanent magnet 7b on the same axis on the other side is fixedly connected to the rotor core 7a. In this way, the axial magnetic pull generated by the two rotors 7 can cancel each other out in a symmetrical case. This greatly reduces the axial load on the bearing, reduces bearing wear, improves bearing life and system reliability, and simplifies the design of the mechanical support structure. Meanwhile, the gap between two adjacent permanent magnets 7b forms a centrifugal channel 9. Multiple air inlets 10 are opened on the front cover 1 near the central axis, multiple through holes 11 are opened on the rotor core 7a near the central axis, and an exhaust hole 12 is opened on the rear cover 2 away from the central axis. This allows the permanent magnets 7b to rotate when the motor shaft 5 drives the permanent magnets 7b to rotate at high speed around the central axis of the motor shaft 5. During this process, the permanent magnets 7b will use centrifugal force to throw the medium in the centrifugal channel 9 towards the inner circumference of the front cover 1 and the rear cover 2. At this time, the part near the central axis will form a low-pressure zone, which will draw in the external medium from the air inlet and enter the low-pressure zone through the through holes 11. The part away from the central axis will form a high-pressure zone, which will discharge the medium into the exhaust hole 12. This medium can be gas or liquid for motors, achieving the purpose of air cooling and liquid cooling, further improving the heat dissipation effect of the motor, allowing the motor to withstand higher current density and increase power density. When the product is working, the photoelectric encoder 4 drives the motor shaft 5 to rotate, the motor shaft 5 drives the rotor core 7a to rotate, and the rotor core 7a drives the permanent magnet 7b to rotate. When the permanent magnet 7b rotates, the magnetic flux works simultaneously in the two air gaps 8, which is equivalent to realizing the power output of "two motors" within one axial length. At the same time, when the permanent magnet 7b rotates, it draws outside air into the motor through the air inlet 10 and then discharges it through the exhaust port 12, carrying away heat.

[0023] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible (e.g., changes in the size, dimensions, structure, shape and proportion of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), installation arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application.

Claims

1. A dual-stator dual-rotor axial flux motor, comprising a front end cover (1), a rear end cover (2), a connecting plate (3), and a photoelectric encoder (4) sequentially mounted axially on the same central axis, wherein a motor shaft (5) is rotatably mounted inside the front end cover (1) and the rear end cover (2), and the end of the motor shaft (5) is detachably connected to the output end of the photoelectric encoder (4), characterized in that: Stator (6) is fixedly installed on the opposite side of the front end cover (1) and the rear end cover (2). Two rotors (7) are fixedly installed on the motor shaft (5) between the two stators (6). The central axes of the two stators (6) and the two rotors (7) coincide. There is an air gap (8) between one rotor (7) and an adjacent stator (6). By sharing the same axis with two stators (6) and two rotors (7), the magnetic circuit is short while the magnetic flux works simultaneously in the two air gaps (8), achieving twice the power output within one axial length.

2. The dual-stator dual-rotor axial flux motor according to claim 1, characterized in that: The stator (6) includes a stator core (6a) fixedly installed on one side of the front end cover (1) or the rear end cover (2), and stator coils (6b) are installed on both stator cores (6a).

3. The dual-stator dual-rotor axial flux motor according to claim 2, characterized in that: The stator core (6a) includes a positioning ring (6a1) fixedly installed on one side of the front end cover (1) or the rear end cover (2), and protrusions (6a2) fixedly installed in a ring array on one side of the two positioning rings (6a1). The number and position of the stator coils (6b) are matched with the protrusions (6a2).

4. A dual-stator, dual-rotor axial flux motor according to claim 3, characterized in that: The overall shape of the protrusion (6a2) is set as an isosceles trapezoid. One side of the protrusion (6a2) is on the same outer circumferential surface as the outer ring of the positioning ring (6a1), and the other side of the protrusion (6a2) is on the same inner circumferential surface as the inner ring of the positioning ring (6a1).

5. A dual-stator, dual-rotor axial flux motor according to claim 3, characterized in that: The stator coil (6b) is mounted on the bump (6a2) using a concentrated flat wire winding.

6. A dual-stator, dual-rotor axial flux motor according to claim 3, characterized in that: The positioning ring (6a1) and the protrusion (6a2) are integrated designs of disc-type winding and stacking.

7. A dual-stator, dual-rotor axial flux motor according to claim 3, characterized in that: The two rotors (7) consist of a rotor (7) core fixedly mounted on the motor shaft (5) and a plurality of permanent magnets (7b) fixedly mounted on both sides of the rotor core (7a). The permanent magnets (7b) on both sides are arranged in a ring array on both sides of the rotor core (7a). The permanent magnets (7b) on both sides of the rotor core (7a) are located between the stator coils (6b) on the two positioning rings (6a1).

8. A dual-stator, dual-rotor axial flux motor according to claim 7, characterized in that: When the N pole of the permanent magnet (7b) on one side of the rotor core (7a) is fixedly connected to the rotor core (7a), the S pole of the adjacent permanent magnet (7b) on the same side is fixedly connected to the rotor core (7a), and the S pole of the permanent magnet (7b) on the same axis on the other side is fixedly connected to the rotor core (7a).

9. A dual-stator, dual-rotor axial flux motor according to claim 7, characterized in that: The gap between two adjacent permanent magnets (7b) forms a centrifugal channel (9). Multiple air inlets (10) are opened on the front end cover (1) near the central axis. Multiple through holes (11) are opened on the rotor core (7a) near the central axis. An exhaust hole (12) is opened on the rear end cover (2) away from the central axis.

10. A dual-stator, dual-rotor axial flux motor according to claim 7, characterized in that: The outer diameter of the circle formed by the multiple permanent magnets (7b) arranged in a ring array is smaller than the outer diameter of the circle formed by the multiple stator coils (6b).

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