An axial magnetic field modulation magnetic gear using a helical permanent magnet and a chamfered modulation ring structure

Abstract

The present invention belongs to the technical field of axial magnetic field modulation magnetic gears, and discloses an axial magnetic field modulation magnetic gear using a helical permanent magnet and a chamfered modulation ring structure, comprising a high-speed helical permanent magnet rotor, a low-speed helical permanent magnet rotor, and a chamfered modulation ring; the chamfered modulation ring is nested and installed between the high-speed helical permanent magnet rotor and the low-speed helical permanent magnet rotor, and two layers of air gaps are left between the three; the chamfered modulation ring is chamfered. The present invention adopts a helical permanent magnet structure to reduce partial magnetic leakage of the permanent magnet, artificially increase the harmonic order to supplement the "concavity" of the torque curve, and make the overall torque more stable and continuous. The modulation ring adopts a chamfered structure, and the four right angles of a single modulation ring are rounded, thereby increasing the modulation area and making the magnetic flux modulation more stable. The present invention adopts helical permanent magnets and a chamfered modulation ring to reduce the torque pulsation generated by the low-speed rotor under the ordinary structure by about 50%.

Description

Technical Field

[0001] The present invention belongs to the technical field of axial magnetic field modulation type magnetic gears, and relates to an axial magnetic field modulation type magnetic gear using a helical permanent magnet and a chamfered modulation ring structure. Background Art

[0002] In recent years, rare earth permanent magnet technology has made significant progress. In the 1980s, high-performance permanent magnet materials, such as neodymium iron boron, were commercialized, significantly enhancing the torque output performance of magnetic gears and laying the foundation for their engineering applications. In 2001, K. Atallah and D. Howe, scholars at the University of Sheffield in the UK, innovatively proposed a concentric magnetic field modulation magnetic gear structure. This structure utilizes a magnetic modulation ring to control the magnetic field harmonics of the inner and outer permanent magnets, significantly improving torque density and permanent magnet efficiency.

[0003] As a contactless transmission device, magnetic gears share the same operating principle as mechanical gears, but utilize the interaction between magnetic poles instead of traditional mechanical meshing. This design eliminates mechanical friction losses, avoiding mechanical fatigue, lubrication requirements, and subsequent maintenance. Its key advantages include the absence of lubrication, low operating noise, and overload protection. These features effectively overcome the wear defects of traditional gear reduction devices, leading to widespread application in new energy vehicles, wind turbines, aerospace, and other fields.

[0004] Optimizing topology is a key approach to reducing torque ripple in axial magnetic gears and expanding their application. Introducing innovative modulation ring structures can significantly improve motor torque performance. For example, in an academic paper presented at the 24th International INFOTEH-JAHORINA Symposium (2025), titled "Impact of Carrier Geometries on the Performance of Coaxial Magnetic Gears," a research team proposed a novel axial magnetic field modulation magnetic gear with a chamfered modulation ring. This innovative structure smoothes the flux coupling process, reducing torque ripple to a certain extent.

[0005] However, a shortcoming of chamfered modulation rings is that they only optimize the chamfered edges and fail to consider the axial distribution differences of the magnetic field itself. This invention, through the introduction of a helical tooth structure, transforms sudden changes in the magnetic field into a gradual process, compensating for the axial distribution differences. This expands the application boundaries of magnetic gears in high-precision, high-dynamic scenarios and provides a new paradigm for the next generation of ultra-low pulsation magnetic transmission systems. Summary of the Invention

[0006] In order to overcome the disadvantage of large torque pulsation in magnetic gears and reduce torque pulsation, the present invention provides an axial magnetic field modulation magnetic gear using a helical permanent magnet and a chamfered modulation ring structure.

[0007] The technical solution of the present invention:

[0008] An axial magnetic field modulation type magnetic gear using a helical permanent magnet and chamfered modulation ring structure, comprising a high-speed helical permanent magnet rotor, a low-speed helical permanent magnet rotor and a chamfered modulation ring;

[0009] The chamfered modulation ring is nested and installed between the high-speed helical-tooth permanent magnet rotor and the low-speed helical-tooth permanent magnet rotor, and two layers of air gaps are left between the three; the chamfered modulation ring is chamfered, and the air gap between the high-speed helical-tooth permanent magnet rotor and the chamfered modulation ring, and the air gap between the low-speed helical-tooth permanent magnet rotor and the chamfered modulation ring are both 2mm.

[0010] The high-speed helical-tooth permanent magnet rotor includes a high-speed rotor N-pole helical-tooth permanent magnet, a high-speed rotor S-pole helical-tooth permanent magnet and a high-speed rotor yoke; the high-speed rotor N-pole helical-tooth permanent magnet and the high-speed rotor S-pole helical-tooth permanent magnet are arranged alternately, and the high-speed rotor yoke is located between the high-speed rotor N-pole helical-tooth permanent magnet and the high-speed rotor S-pole helical-tooth permanent magnet; wherein, the high-speed rotor N-pole helical-tooth permanent magnet includes 4n N-pole tile-type NdFeB permanent magnets, and every 4 N-pole tile-type NdFeB permanent magnets form an N-pole helical-tooth NdFeB permanent magnet, and the 4 N-pole tile-type NdFeB permanent magnets in an N-pole helical-tooth NdFeB permanent magnet are arranged from the inside to the outside. The circumferential direction is offset by 0.5 degrees in one direction in sequence; the high-speed rotor S-pole helical tooth permanent magnet includes 4n S-pole tile-type NdFeB permanent magnets, and every 4 S-pole tile-type NdFeB permanent magnets constitute an S-pole helical tooth NdFeB permanent magnet. The 4 S-pole tile-type NdFeB permanent magnets in one S-pole helical tooth NdFeB permanent magnet are offset by 0.5 degrees in one direction in sequence from the inside to the outside in the circumferential direction; the high-speed rotor yoke includes 8n tile-type rotor yokes, and every 4 tile-type rotor yokes constitute a rotor yoke. The 4 tile-type rotor yokes in one rotor yoke are offset by 0.5 degrees in one direction in sequence from the inside to the outside in the circumferential direction;

[0011] The low-speed helical-tooth permanent magnet rotor includes a low-speed rotor N-pole helical-tooth permanent magnet, a low-speed rotor S-pole helical-tooth permanent magnet and a low-speed rotor yoke. The low-speed rotor N-pole helical-tooth permanent magnet and the low-speed rotor S-pole helical-tooth permanent magnet are arranged alternately, and the low-speed rotor yoke is located between the low-speed rotor N-pole helical-tooth permanent magnet and the low-speed rotor S-pole helical-tooth permanent magnet. Among them, the low-speed rotor S-pole helical-tooth permanent magnet includes 12n S-pole tile-type NdFeB permanent magnets, and every 4 S-pole tile-type NdFeB permanent magnets form an S-pole helical-tooth NdFeB permanent magnet. The 4 S-pole tile-type NdFeB permanent magnets in an S-pole helical-tooth NdFeB permanent magnet are arranged from the inside to the outside. The low-speed rotor N-pole helical tooth permanent magnet includes 12n N-pole tile-type NdFeB permanent magnets, and every 4 N-pole tile-type NdFeB permanent magnets constitute an N-pole helical tooth NdFeB permanent magnet. The 4 N-pole tile-type NdFeB permanent magnets in an S-pole helical tooth NdFeB permanent magnet are sequentially shifted by 0.5 degrees in one direction from the inside to the outside in the circumferential direction; the low-speed rotor yoke includes 24n tile-type rotor yokes, and every 4 tile-type rotor yokes constitute a rotor yoke. The 4 tile-type rotor yokes in a rotor yoke are sequentially shifted by 0.5 degrees in one direction from the inside to the outside in the circumferential direction;

[0012] The chamfered modulation ring includes alternating magnetic modulation pole pieces and non-magnetic composite material pole pieces;

[0013] Furthermore, the chamfered modulation ring includes 25 chamfered No. 10 steel magnetic modulation pole pieces and 25 non-magnetic composite material pole pieces that are alternately arranged.

[0014] Furthermore, the chamfered modulation ring is chamfered to a depth of 0.3-0.7 mm, preferably 0.5 mm. The chamfered modulation ring is chamfered, and non-magnetic conductive material is used to connect the chamfered modulation rings. The magnetic flux is more stable during modulation by the chamfered modulation rings, and the use of non-magnetic conductive material to connect the rings reduces the overall mass of the magnetic gear, thereby improving the torque density per unit mass to a certain extent.

[0015] The magnetic circuit of the magnetic gear starts from the four N-pole tile-type NdFeB permanent magnets in the high-speed rotor N-pole helical permanent magnets, which are staggered by 0.5 degrees, and passes through the high-speed rotor yoke, high-speed air gap, chamfered modulation ring, low-speed air gap, low-speed rotor yoke, and reaches the four S-pole tile-type NdFeB permanent magnets in the low-speed rotor S-pole helical permanent magnets, which are staggered by 0.5 degrees. The number of permanent magnet pole pairs of the high-speed helical permanent magnet rotor is P. h , the number of permanent magnet pole pairs of the low-speed helical gear permanent magnet rotor is P l , the number of magnetic pole pieces of the chamfered modulation ring is N s To maximize torque transmission, the pole pair relationship between the rotor and stator is P h +P l =N s , the permanent magnet is magnetized along the entire circumferential direction.

[0016] A single permanent magnet, when not rotated, will generate radial magnetic flux leakage on both the inner and outer sides. However, for every 0.5-degree rotation of a tile-type NdFeB permanent magnet, the radially protruding portion of the permanent magnet mates with the yoke. Therefore, the magnetic flux leakage from the inner and outer sides of a helical permanent magnet is partially transferred through the yoke to the air gap after three rotations (four tile-type permanent magnets make up one helical permanent magnet, so only three rotations are required). Therefore, helical permanent magnets can reduce some of this magnetic flux leakage.

[0017] The beneficial effects of the present invention are as follows: (1) The use of a helical permanent magnet structure can reduce partial magnetic flux leakage from the permanent magnets, artificially increase the harmonic order to compensate for the "sag" in the torque curve, and make the overall torque more stable and continuous. (2) The modulation ring adopts a chamfered structure, and the four right angles of a single modulation ring are rounded, which increases the modulation area and makes the flux modulation more stable. (3) The use of helical permanent magnets and chamfered modulation rings can reduce the torque pulsation generated by the low-speed rotor under the ordinary structure by about 50%. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is an exploded view of an axial magnetic field modulation type magnetic gear with helical permanent magnets and a chamfered modulation ring structure in an embodiment of the present invention.

[0019] Figure 2 2 is a schematic diagram of the chamfer modulation ring structure in an embodiment of the present invention.

[0020] Figure 3 It is a partial schematic diagram of the chamfered modulation ring structure in an embodiment of the present invention.

[0021] Figure 4 It is a three-dimensional diagram of the low-speed rotor helical tooth permanent magnet in an embodiment of the present invention.

[0022] Figure 5 It is a three-dimensional diagram of a low-speed rotor yoke in an embodiment of the present invention.

[0023] Figure 6 It is a three-dimensional diagram of the high-speed rotor helical gear permanent magnet in an embodiment of the present invention.

[0024] Figure 7 It is a three-dimensional diagram of a high-speed rotor yoke in an embodiment of the present invention.

[0025] Figure 8 1 is a low-speed rotor torque diagram in an embodiment of the present invention without using helical-tooth permanent magnets.

[0026] Figure 9 1 is a low-speed rotor torque diagram using helical-tooth permanent magnets in an embodiment of the present invention.

[0027] In the figure: 1 high-speed rotor N-pole helical tooth permanent magnet; 2 high-speed rotor S-pole helical tooth permanent magnet; 3 high-speed rotor yoke; 4 chamfered modulation ring; 5 low-speed rotor yoke; 6 low-speed rotor S-pole helical tooth permanent magnet; 7 low-speed rotor N-pole helical tooth permanent magnet. DETAILED DESCRIPTION

[0028] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and technical solutions.

[0029] The axial magnetic field modulation type magnetic gear of the helical-tooth permanent magnet and chamfered modulation ring structure of the present invention comprises a high-speed helical-tooth permanent magnet rotor, a stator disk and a low-speed helical-tooth permanent magnet rotor.

[0030] Combine Figure 1 The high-speed helical-tooth permanent magnet rotor includes a high-speed rotor N-pole helical-tooth permanent magnet 1, a high-speed rotor S-pole helical-tooth permanent magnet 2 and a high-speed rotor yoke 3, the stator disk includes a chamfered modulation ring 4, and the low-speed helical-tooth permanent magnet rotor includes a low-speed rotor yoke 5, a low-speed rotor S-pole helical-tooth permanent magnet 6 and a low-speed rotor N-pole helical-tooth permanent magnet 7.

[0031] Combine Figure 2 、 Figure 3 The chamfered modulation ring 4 is nested and installed between the high-speed helical permanent magnet rotor and the low-speed helical permanent magnet rotor, and two layers of air gaps are left between the three. The air gap between the high-speed helical permanent magnet rotor and the chamfered modulation ring 4, and the air gap between the low-speed helical permanent magnet rotor and the chamfered modulation ring 4 are both 2mm. The chamfered modulation ring 4 includes 25 No. 10 steel magnetic modulation pole pieces and 25 non-magnetic composite material pole pieces, which are alternately composed of No. 10 steel pole pieces and non-magnetic material pole pieces. The chamfered modulation ring is chamfered by 0.3-0.7mm, preferably by 0.5mm. The chamfered modulation ring is chamfered, and the chamfered modulation rings are connected by non-magnetic materials; the magnetic flux is more stable when modulated by the chamfered modulation ring, and the connection of non-magnetic materials reduces the overall mass of the magnetic gear and improves the torque density per unit mass to a certain extent.

[0032] Combine Figure 4 、 Figure 5The low-speed helical-tooth permanent magnet rotor includes a low-speed rotor N-pole helical-tooth permanent magnet 7, a low-speed rotor S-pole helical-tooth permanent magnet 6 and a low-speed rotor yoke 5. The low-speed rotor N-pole helical-tooth permanent magnet 7 and the low-speed rotor S-pole helical-tooth permanent magnet 6 are arranged alternately, and the low-speed rotor yoke 5 is located between the low-speed rotor N-pole helical-tooth permanent magnet 7 and the low-speed rotor S-pole helical-tooth permanent magnet 6; wherein, the low-speed rotor S-pole helical-tooth permanent magnet 6 includes 76 S-pole tile-type NdFeB permanent magnets, and every 4 S-pole tile-type NdFeB permanent magnets constitute an S-pole helical-tooth NdFeB permanent magnet. The 4 S-pole tile-type NdFeB permanent magnets in an S-pole helical-tooth NdFeB permanent magnet are composed of The circumferential direction from inside to outside is shifted by 0.5 degrees in one direction in sequence; the low-speed rotor N-pole helical tooth permanent magnet 7 includes 76 N-pole tile-type NdFeB permanent magnets, and every 4 N-pole tile-type NdFeB permanent magnets constitute an N-pole helical tooth NdFeB permanent magnet, and the 4 N-pole tile-type NdFeB permanent magnets in an S-pole helical tooth NdFeB permanent magnet are shifted by 0.5 degrees in one direction in sequence from inside to outside; the low-speed rotor yoke 5 includes 152 tile-type rotor yokes, and every 4 tile-type rotor yokes constitute a rotor yoke, and the 4 tile-type rotor yokes in a rotor yoke are shifted by 0.5 degrees in one direction in sequence from inside to outside.

[0033] Combine Figure 6 、 Figure 7 The high-speed helical-tooth permanent magnet rotor includes a high-speed rotor N-pole helical-tooth permanent magnet 1, a high-speed rotor S-pole helical-tooth permanent magnet 2 and a high-speed rotor yoke 3; the high-speed rotor N-pole helical-tooth permanent magnet 1 and the high-speed rotor S-pole helical-tooth permanent magnet 2 are arranged alternately, and the high-speed rotor yoke 3 is located between the high-speed rotor N-pole helical-tooth permanent magnet 1 and the high-speed rotor S-pole helical-tooth permanent magnet 2; wherein, the high-speed rotor N-pole helical-tooth permanent magnet 1 includes 24 N-pole tile-type NdFeB permanent magnets, and every 4 N-pole tile-type NdFeB permanent magnets form an N-pole helical-tooth NdFeB permanent magnet, and the 4 N-pole tile-type NdFeB permanent magnets in an N-pole helical-tooth NdFeB permanent magnet From the inside to the outside, the circumference is offset by 0.5 degrees in one direction in sequence; the high-speed rotor S-pole helical tooth permanent magnet 2 includes 24 S-pole tile-type NdFeB permanent magnets, and every 4 S-pole tile-type NdFeB permanent magnets constitute an S-pole helical tooth NdFeB permanent magnet. The 4 S-pole tile-type NdFeB permanent magnets in an S-pole helical tooth NdFeB permanent magnet are offset by 0.5 degrees in one direction from the inside to the outside in the circumference; the high-speed rotor yoke includes 48 tile-type rotor yokes, and every 4 tile-type rotor yokes constitute a rotor yoke. The 4 tile-type rotor yokes in a rotor yoke are offset by 0.5 degrees in one direction from the inside to the outside in the circumference.

[0034] The magnetic circuit of the magnetic gear starts from the four N-pole tile-type NdFeB permanent magnets in the high-speed rotor N-pole helical permanent magnets, which are staggered by 0.5 degrees, and passes through the high-speed rotor yoke, high-speed air gap, chamfered modulation ring, low-speed air gap, low-speed rotor yoke, and reaches the four S-pole tile-type NdFeB permanent magnets in the low-speed rotor S-pole helical permanent magnets, which are staggered by 0.5 degrees. The number of permanent magnet pole pairs of the high-speed helical permanent magnet rotor is P. h , the number of permanent magnet pole pairs of the low-speed helical gear permanent magnet rotor is P l , the number of magnetic pole pieces of the chamfered modulation ring is N s To maximize torque transmission, the pole pair relationship between the rotor and stator is P h +P l =N s , the permanent magnet is magnetized along the entire circumferential direction.

[0035] A single permanent magnet, when not rotated, will generate radial magnetic flux leakage on both the inner and outer sides. However, for every 0.5-degree rotation of a tile-type NdFeB permanent magnet, the radially protruding portion of the permanent magnet mates with the yoke. Therefore, the magnetic flux leakage from the inner and outer sides of a helical permanent magnet is partially transferred through the yoke to the air gap after three rotations (four tile-type permanent magnets make up one helical permanent magnet, so only three rotations are required). Therefore, helical permanent magnets can reduce some of this magnetic flux leakage.

Claims

1. An axial magnetic field modulation type magnetic gear using a helical permanent magnet and a chamfered modulation ring structure, characterized in that: The axial magnetic field modulation type magnetic gear comprises a high-speed helical gear permanent magnet rotor, a low-speed helical gear permanent magnet rotor and a chamfered modulation ring; The chamfered modulation ring is nested between the high-speed helical-tooth permanent magnet rotor and the low-speed helical-tooth permanent magnet rotor, with two layers of air gaps left between the three. Chamfering modulation ring is chamfered; The high-speed helical-tooth permanent magnet rotor includes a high-speed rotor N-pole helical-tooth permanent magnet, a high-speed rotor S-pole helical-tooth permanent magnet and a high-speed rotor yoke; the high-speed rotor N-pole helical-tooth permanent magnet and the high-speed rotor S-pole helical-tooth permanent magnet are arranged alternately, and the high-speed rotor yoke is located between the high-speed rotor N-pole helical-tooth permanent magnet and the high-speed rotor S-pole helical-tooth permanent magnet; wherein, the high-speed rotor N-pole helical-tooth permanent magnet includes 4n N-pole tile-type NdFeB permanent magnets, and every 4 N-pole tile-type NdFeB permanent magnets form an N-pole helical-tooth NdFeB permanent magnet, and the 4 N-pole tile-type NdFeB permanent magnets in an N-pole helical-tooth NdFeB permanent magnet are arranged from the inside to the outside. The circumferential direction is offset by 0.5 degrees in one direction in sequence; the high-speed rotor S-pole helical tooth permanent magnet includes 4n S-pole tile-type NdFeB permanent magnets, and every 4 S-pole tile-type NdFeB permanent magnets constitute an S-pole helical tooth NdFeB permanent magnet. The 4 S-pole tile-type NdFeB permanent magnets in one S-pole helical tooth NdFeB permanent magnet are offset by 0.5 degrees in one direction in sequence from the inside to the outside in the circumferential direction; the high-speed rotor yoke includes 8n tile-type rotor yokes, and every 4 tile-type rotor yokes constitute a rotor yoke. The 4 tile-type rotor yokes in one rotor yoke are offset by 0.5 degrees in one direction in sequence from the inside to the outside in the circumferential direction; The low-speed helical-tooth permanent magnet rotor includes a low-speed rotor N-pole helical-tooth permanent magnet, a low-speed rotor S-pole helical-tooth permanent magnet and a low-speed rotor yoke. The low-speed rotor N-pole helical-tooth permanent magnet and the low-speed rotor S-pole helical-tooth permanent magnet are arranged alternately, and the low-speed rotor yoke is located between the low-speed rotor N-pole helical-tooth permanent magnet and the low-speed rotor S-pole helical-tooth permanent magnet. Among them, the low-speed rotor S-pole helical-tooth permanent magnet includes 12n S-pole tile-type NdFeB permanent magnets, and every 4 S-pole tile-type NdFeB permanent magnets form an S-pole helical-tooth NdFeB permanent magnet. The 4 S-pole tile-type NdFeB permanent magnets in an S-pole helical-tooth NdFeB permanent magnet are arranged from the inside to the outside. The low-speed rotor N-pole helical tooth permanent magnets include 12n N-pole tile-type NdFeB permanent magnets, and every four N-pole tile-type NdFeB permanent magnets constitute an N-pole helical tooth NdFeB permanent magnet. The four N-pole tile-type NdFeB permanent magnets in an S-pole helical tooth NdFeB permanent magnet are shifted 0.5 degrees in one direction from the inside to the outside circumferentially. The low-speed rotor yoke includes 24n tile-type rotor yokes, and every four tile-type rotor yokes constitute a rotor yoke. The four tile-type rotor yokes in a rotor yoke are shifted 0.5 degrees in one direction from the inside to the outside circumferentially.

2. The axial magnetic field modulation type magnetic gear according to claim 1, characterized in that: The chamfered modulation ring includes magnetic modulation pole pieces and non-magnetic composite material pole pieces that are alternately arranged.

3. The axial magnetic field modulation type magnetic gear according to claim 1, characterized in that: The chamfered modulation ring is chamfered to 0.3-0.7mm.

4. The axial magnetic field modulation type magnetic gear according to claim 1, characterized in that: The air gap between the high-speed helical-tooth permanent magnet rotor and the chamfered modulation ring, and the air gap between the low-speed helical-tooth permanent magnet rotor and the chamfered modulation ring are both 2 mm.

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