Permanent magnet axial flux motor rotor structure adopting separated self-locking principle

Abstract

The invention belongs to the technical field of axial magnetic flux motors, and particularly relates to a permanent magnet axial magnetic flux motor rotor structure adopting a separation type self-locking principle, which comprises a magnetic steel mounting plate, a fan-shaped magnetic steel mounting groove is formed in the magnetic steel mounting plate, magnetic steel is fixedly mounted in the magnetic steel mounting groove, and the magnetic steel is in a fan shape matched with the magnetic steel mounting groove in boundary dimension. Two grooves are formed in the positions of two diagonal sides in the fan-shaped diameter direction, the length of each groove in the circumferential direction is the same as the width of each groove conductor on the external stator, installation is convenient, the structural stability is high, the distribution condition of an air-gap magnetic field is improved, higher harmonic and tooth harmonic electromotive force is weakened, and the motor performance is effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of axial flux motors, and in particular relates to a permanent magnet axial flux motor rotor structure adopting a separate self-locking principle. Background Art

[0002] Axial flux motors, also known as disc motors, have the characteristics of compact structure, small size, light weight and high power density. Therefore, compared with traditional radial flux motors, axial flux motors have obvious advantages in certain occasions with thin installation size requirements. At present, axial flux motors are widely used in many fields, especially in new energy vehicles, aerospace, ship propulsion and robotics.

[0003] During the operation of the motor, the rotor needs to rotate while the stator is fixed, so a certain gap needs to be left between the stator and the rotor. This gap is the air gap. Theoretically, the air gap magnetic field should be sinusoidally distributed, but in practical applications, the air gap magnetic field cannot be completely sinusoidally distributed, which causes the motor to generate high-order harmonics and tooth harmonics, increase the noise and vibration of the motor, affect the motor efficiency, and in severe cases cause the motor to burn out due to excessive temperature rise.

[0004] Therefore, how to make the magnetic field distribution in the air gap as close to a sinusoidal distribution as possible is an urgent problem that needs to be solved. Summary of the invention

[0005] The main technical problem to be solved by the present invention is to provide a permanent magnet axial flux motor rotor structure adopting a separate self-locking principle, which improves the distribution of the air gap magnetic field, weakens the high-order harmonics and tooth harmonic electromotive force, and improves the motor performance.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: A permanent magnet axial flux motor rotor structure adopting a separate self-locking principle comprises a magnetic steel mounting plate, on which a fan-shaped magnetic steel mounting groove is arranged, on which a magnetic steel is fixedly mounted, the magnetic steel is a fan-shaped structure adapted to the outer dimensions of the magnetic steel mounting groove, two grooves are arranged at two diagonal sides along the diameter direction of the fan-shaped structure, and the length of the grooves along the circumferential direction is the same as the width of each slot conductor on the external stator.

[0007] The following is a further optimization of the above technical solution by the present invention: The magnetic steel mounting plate comprises an upper magnetic steel mounting plate and a lower magnetic steel mounting plate, and the lower magnetic steel mounting plate has the same structure as the upper magnetic steel mounting plate and is symmetrically arranged.

[0008] Further optimization: the upper magnetic steel mounting plate includes a fixed disk, and a plurality of long strip spokes are fixedly connected to the fixed disk.

[0009] Further optimization: a plurality of spoke plates are evenly spaced along the circumferential direction of the fixed disk, and the magnetic steel mounting groove is enclosed by two adjacent spoke plates.

[0010] Further optimization: A plurality of mounting holes distributed in a circle are arranged on the fixing disk, a fixing component is arranged in the mounting hole, and the upper magnetic steel mounting plate and the lower magnetic steel mounting plate are fixedly connected by the fixing component.

[0011] Further optimization: two protrusions are arranged at positions corresponding to the grooves in the magnetic steel mounting groove, and the two protrusions are fixedly connected to the spokes of the upper magnetic steel mounting plate and the lower magnetic steel mounting plate respectively.

[0012] Further optimization: The bump size is adapted to the groove size.

[0013] Further optimization: A fastening ring is fixedly installed on the outer ring of the magnetic steel mounting plate, and the fastening ring and the magnetic steel mounting plate have an axial interference fit.

[0014] Further optimization: a limiting block is connected to one end of the spoke plate away from the fixed disk to form an axial limit for the fastening ring.

[0015] Further optimization: a heat sink is fixedly connected outside the fastening ring.

[0016] The present invention adopts the above technical solution and has the following beneficial effects: The present invention provides grooves on both sides of the magnetic steel, so that the air gap is enlarged at the position of the magnetic steel groove and remains small at the center of the magnetic steel, so that the air gap magnetic field is closer to a sinusoidal distribution, which is beneficial to weakening the high-order harmonics and tooth harmonic electromotive force and improving the motor performance; The magnetic steel mounting plate of the present invention adopts a split structure, has a simple processing technology, is easy to install, and forms a self-locking structure through the protrusions provided on the magnetic steel mounting plate and the grooves on the magnetic steel, further improving the stability of the overall structure; The fastening ring of the present invention is provided with a heat sink outside. When the rotor rotates, the heat sink drives the surrounding air to flow, so as to dissipate the heat in the internal space of the motor.

[0017] The present invention is further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the rotor of the present invention; Figure 2 An exploded view of the overall structure of the rotor of the present invention; Figure 3 It is a schematic diagram of the structure of the magnetic steel of the present invention; Figure 4 for Figure 1 A local enlarged view of point A; Figure 5It is a cross-sectional view of the magnetic steel mounting plate and the magnetic steel mounting structure of the present invention; Figure 6 It is a schematic diagram of the installation structure of the rotor structure of the present invention in the axial flux motor; Figure 7 for Figure 6 A partial enlarged view of point B; Figure 8 To optimize the front motor back electromotive force waveform; Fig. 9 This is the waveform of the motor back electromotive force after optimization.

[0019] In the figure: 1. magnetic steel mounting plate; 101. upper magnetic steel mounting plate; 102. lower magnetic steel mounting plate; 1011. fixing plate; 1012. spoke plate; 1013. protrusion; 1014. limit block; 2. magnetic steel mounting groove; 3. magnetic steel; 4. groove; 5. fastening ring; 6. heat sink; 7. stator; 8. stator slot; 9. stator winding; 10. stator teeth. DETAILED DESCRIPTION

[0020] like Figure 1-5 As shown, a permanent magnet axial flux motor rotor structure adopting a separate self-locking principle includes an upper magnetic steel mounting plate 101 and a lower magnetic steel mounting plate 102. The upper magnetic steel mounting plate 101 includes a fixed disk 1011, and a plurality of circumferentially distributed mounting holes are arranged on the fixed disk 1011. The lower magnetic steel mounting plate 102 is symmetrically arranged with the upper magnetic steel mounting plate 101 and has the same structure. Such a design can reduce the types of parts, improve production efficiency, and save costs. The upper magnetic steel mounting plate 101 and the lower magnetic steel mounting plate 102 are fixedly connected by inserting a fixing component into the mounting hole to form a magnetic steel mounting plate 1. The contact surfaces of the two need to be finely processed to ensure that they can fit tightly after assembly.

[0021] In this embodiment, the fixing assembly is a combination of bolts and nuts, and the bolts and nuts are used to connect the upper magnetic steel mounting plate 101 and the lower magnetic steel mounting plate 102 into a whole to ensure the stability of the overall structure.

[0022] In addition to this embodiment, the fixing component can also be selected from rivets or elastic cylindrical pins to stably connect the upper magnetic steel mounting plate 101 and the lower magnetic steel mounting plate 102 into a whole.

[0023] A plurality of long strip-shaped spokes 1012 are fixedly connected to the fixed disk 1011 . The plurality of spokes 1012 are evenly spaced along the circumference of the fixed disk 1011 . The fan-shaped notch formed between two adjacent spokes 1012 is a magnetic steel installation groove 2 . A magnetic steel 3 is fixedly installed in the magnetic steel installation groove 2 .

[0024] The magnetic steel 3 is a sector-shaped structure adapted to the outer dimensions of the magnetic steel mounting groove 2, and two grooves 4 are provided at the two diagonal sides along the diameter direction of the sector-shaped structure. Two protrusions 1013 are provided at positions corresponding to the grooves 4 in each magnetic steel mounting groove 2. The two protrusions 1013 are respectively fixedly connected to the spokes 1012 of the upper magnetic steel mounting plate 101 and the lower magnetic steel mounting plate 102, and the size of the protrusions 1013 is adapted to the size of the grooves 4.

[0025] During installation, first place the magnet 3 in the magnet mounting groove 2 of the lower magnet mounting plate 102, and the groove 4 on one side of the magnet 3 is installed in cooperation with the protrusion 1013, and then the upper magnet mounting plate 101 and the lower magnet mounting plate 102 are fastened together through a fixing assembly. During assembly, ensure that the groove 4 on the other side is installed in cooperation with the protrusion 1013 of the upper magnet mounting plate 101, and the axial movement of the magnet 3 is limited by the self-locking principle of the groove 4 and the protrusion 1013. This split structure has simple processing technology, convenient installation, high structural stability, and is conducive to further reducing production costs.

[0026] The outer ring of the magnetic steel mounting plate 1 is fixedly mounted with a fastening ring 5 for limiting the radial sliding movement of the magnetic steel 3. The fastening ring 5 and the magnetic steel mounting plate 1 are axially interference fit, and a hot pressing process is used during installation. Figure 4 As shown, a limiting block 1014 is provided at one end of the spoke plate 1012 away from the fixing disk 1011 , and the limiting block 1014 is used to axially position the fastening ring 5 .

[0027] A plurality of heat sinks 6 are fixedly connected to the outside of the fastening ring 5 , and the plurality of heat sinks 6 are evenly distributed along the circumference of the fastening ring 5 , so that when the rotor rotates, the heat sinks 6 drive the surrounding air to flow, and can dissipate heat from the internal space of the motor.

[0028] like Figure 6-7 As shown, the application of a permanent magnet axial flux motor rotor structure adopting a separate self-locking principle in a double-stator single-rotor axial flux motor according to the present invention is shown. It can be seen from the figure that the stator 7 is coaxially arranged with the rotor and symmetrically installed on both sides of the rotor. The stator 7 includes a plurality of stator teeth 10. The gap between two adjacent stator teeth 10 is a stator slot 8. The wire wound in the stator slot 8 is a stator winding 9. The circumferential distance occupied by the wire in each stator slot 8, that is, the center distance between the free ends of two adjacent stator teeth 10, is the conductor width per slot.

[0029] The arrangement of the magnetic steel 3 and the stator winding 9 is adapted, and each phase belt corresponds to a magnetic steel 3, please refer to Figure 7 The length of the groove 4 on the magnetic steel 3 along the circumferential direction is the same as the width of each slot conductor. In this design, the air gap between the stator 7 and the rotor will increase at the position of the groove 4 of the magnetic steel 3 and remain smaller at the center position of the magnetic steel 3.

[0030] like Figure 8-9As shown, after adopting the rotor structure described in the present invention, the back electromotive force waveform in the motor is closer to the sinusoidal distribution, that is, the air gap magnetic field is closer to the sinusoidal distribution, which is beneficial to weaken the high-order harmonics and tooth harmonic electromotive force and improve the motor performance.

[0031] For those skilled in the art, according to the teachings of the present invention, without departing from the principles and spirit of the present invention, changes, modifications, substitutions and variations made to the implementation methods are still within the protection scope of the present invention.

Claims

1. A permanent magnet axial flux motor rotor structure using a separate self-locking principle, comprising a magnetic steel mounting plate (1), characterized in that: A fan-shaped magnetic steel installation groove (2) is provided on the magnetic steel installation plate (1), and a magnetic steel (3) is fixedly installed on the magnetic steel installation groove (2). The magnetic steel (3) is fan-shaped and adapted to the outer dimensions of the magnetic steel installation groove (2), and two grooves (4) are provided at two diagonal sides along the diameter direction of the fan-shaped. The length of the groove (4) along the circumferential direction is the same as the width of each groove conductor on the external stator (7).

2. According to claim 1, a permanent magnet axial flux motor rotor structure using a separate self-locking principle is characterized in that: The magnetic steel mounting plate (1) comprises an upper magnetic steel mounting plate (101) and a lower magnetic steel mounting plate (102); the lower magnetic steel mounting plate (102) has the same structure as the upper magnetic steel mounting plate (101) and is symmetrically arranged.

3. The permanent magnet axial flux motor rotor structure using the separate self-locking principle according to claim 2 is characterized in that: The upper magnetic steel mounting plate (101) comprises a fixed disk (1011), to which a plurality of long strip-shaped spokes (1012) are fixedly connected.

4. The permanent magnet axial flux motor rotor structure using the separate self-locking principle according to claim 3 is characterized in that: A plurality of spokes (1012) are evenly spaced apart along the circumferential direction of the fixed disk (1011), and the magnetic steel installation groove (2) is formed by enclosing two adjacent spokes (1012).

5. The permanent magnet axial flux motor rotor structure using the separate self-locking principle according to claim 4 is characterized in that: The fixing plate (1011) is provided with a plurality of mounting holes distributed in a circumference, and a fixing assembly is arranged in the mounting hole. The upper magnetic steel mounting plate (101) and the lower magnetic steel mounting plate (102) are fixedly connected via the fixing assembly.

6. The permanent magnet axial flux motor rotor structure using the separate self-locking principle according to claim 5 is characterized in that: Two protrusions (1013) are arranged at positions corresponding to the grooves (4) in the magnetic steel installation groove (2), and the two protrusions (1013) are fixedly connected to the spokes (1012) of the upper magnetic steel installation plate (101) and the lower magnetic steel installation plate (102), respectively.

7. The permanent magnet axial flux motor rotor structure using the separate self-locking principle according to claim 6 is characterized in that: The size of the protrusion (1013) is adapted to the size of the groove (4).

8. The permanent magnet axial flux motor rotor structure using the separate self-locking principle according to claim 7 is characterized in that: A fastening ring (5) is fixedly mounted on the outer ring of the magnetic steel mounting plate (1), and the fastening ring (5) is axially interference fit with the magnetic steel mounting plate (1).

9. The permanent magnet axial flux motor rotor structure using the separate self-locking principle according to claim 8 is characterized in that: One end of the spoke plate (1012) away from the fixed disk (1011) is connected to a limiting block (1014) to form an axial limit for the fastening ring (5).

10. The permanent magnet axial flux motor rotor structure using the separate self-locking principle according to claim 9, characterized in that: A heat sink (6) is fixedly connected to the outside of the fastening ring (5).

Images