Magnetic gear assisted by permanent magnets

Abstract

The invention relates to a magnetic gear assisted by permanent magnets to magnetize, and the gear comprises an outer rotor which comprises an outer rotor iron yoke and a plurality of groups of first permanent magnet pairs, and the plurality of groups of first permanent magnet pairs are uniformly disposed on the inner surface of the side wall of the outer rotor iron yoke; the inner rotor comprises an inner rotor iron yoke which is uniformly provided with a plurality of groups of permanent magnet grooves, a plurality of second permanent magnets which are arranged in parallel are embedded in each group of permanent magnet grooves, the magnetizing directions of the second permanent magnets in the adjacent permanent magnet groove groups are opposite, and the second permanent magnets are made of ferrite materials; the magnetism adjusting ring comprises a circular ring made of a non-magnetic conductive material, and a plurality of magnetic conductive tooth blocks made of silicon steel sheets are uniformly fixed on the circular ring along the circumferential direction; the magnetism adjusting ring is fixed, the inner rotor is rotatably arranged on the inner side of the magnetism adjusting ring magnetic conductive tooth block, and the outer rotor is rotatably arranged on the outer side of the magnetism adjusting ring magnetic conductive tooth block. The cost of the magnetic gear is effectively reduced by adopting the ferrite material, and the transmission performance and reliability of the magnetic gear are ensured through the special design of the second permanent magnet.

Description

Technical Field

[0001] This invention relates to a magnetic gear assisted by a permanent magnet, belonging to the field of magnetic gear transmission technology. Background Technology

[0002] In the field of traditional mechanical transmission, mechanical gear transmission mechanisms are dominant. However, mechanical gears often generate problems such as noise, friction and vibration, and lubrication in practical applications. Magnetic gears can avoid contact with the rotor, do not generate noise caused by mechanical vibration, and have no friction or need for lubrication. They can solve the problems of mechanical gears. Therefore, the development of magnetic gears has gradually become a hot topic in the engineering field.

[0003] Current magnetic gears suffer from high manufacturing costs and relatively weak gear strength. To achieve high torque density, magnetic gears often use neodymium iron boron or samarium cobalt, but these materials are expensive and have complex manufacturing processes. If lower-cost ferrite materials are used, their performance is weak and cannot meet the high-performance transmission requirements of magnetic gears. Therefore, how to control costs while ensuring the transmission performance and reliability of magnetic gears has become an urgent problem to be solved. Summary of the Invention

[0004] The purpose of this invention is to provide a magnetic gear with permanent magnet assistance to solve the problems mentioned in the background art.

[0005] The technical solution of the present invention is as follows: A magnetic gear assisted by a permanent magnet, comprising: The outer rotor includes an outer rotor yoke and multiple sets of first permanent magnet pairs. The multiple sets of first permanent magnet pairs are evenly arranged on the inner surface of the sidewall of the outer rotor yoke. Each first permanent magnet pair consists of two permanent magnets with opposite magnetization directions. The inner rotor includes an inner rotor yoke with multiple sets of permanent magnet slots evenly arranged. Each set of permanent magnet slots is embedded with multiple parallel second permanent magnets, and the second permanent magnets in adjacent sets of permanent magnet slots are magnetized in opposite directions. The second permanent magnets are made of ferrite material. The magnetic ring includes a ring made of a non-magnetic material, with multiple magnetically conductive tooth blocks made of silicon steel sheets uniformly fixed along the circumference of the ring. The magnetic adjusting ring is fixed, the inner rotor is rotatably mounted inside the magnetic guiding tooth block of the magnetic adjusting ring, and the outer rotor is rotatably mounted outside the magnetic guiding tooth block of the magnetic adjusting ring.

[0006] Furthermore, the outer rotor yoke is a concave column, and the first permanent magnet pair consists of an axially magnetized N-pole neodymium iron boron permanent magnet and an axially magnetized S-pole neodymium iron boron permanent magnet. Multiple sets of the first permanent magnet pairs are closely arranged on the inner wall of the outer rotor yoke.

[0007] Furthermore, the magnetic ring is positioned on the inner rotor away from the outer rotor, and the toothed block is inserted into the gap between the outer rotor and the inner rotor. There are air gaps between the magnetic ring guide toothed block and both the outer rotor and the inner rotor.

[0008] Furthermore, the outer rotor yoke, the inner rotor yoke, and the magnetic adjustment ring are respectively provided with a first through hole, a second through hole, and a third through hole. The first through hole, the second through hole, and the third through hole are matched to connect the mounting shaft and the magnetic gear.

[0009] Furthermore, the bottom of the outer rotor is provided with multiple small through holes for heat dissipation around the first through hole ring.

[0010] Furthermore, each of the second permanent magnets has a trapezoidal structure with an open bottom, and the direction of the opening is opposite to the central axis of the inner rotor yoke.

[0011] The present invention has the following beneficial effects: The permanent magnets on the outer rotor are made of neodymium iron boron, while those on the inner rotor are made of ferrite. This combination effectively reduces the cost of the magnetic gear. The inner rotor yoke has permanent magnet slots into which the permanent magnets are embedded. The ferrite core is then wrapped and reinforced by the yoke, ensuring stable placement within the yoke at high speeds and guaranteeing the transmission performance of the magnetic gear. The inner rotor permanent magnets have a trapezoidal structure with an open bottom, increasing the heat dissipation area and preventing overheating from affecting the ferrite's magnetism. Simultaneously, the parallel arrangement of ferrite cores within the slots defines the magnetic field direction, ensuring stable operation of the magnetic gear and improving its reliability. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a cross-sectional schematic diagram of the present invention.

[0013] The reference numerals in the figure are as follows: 1. Outer rotor; 11. Outer rotor yoke; 12. First permanent magnet; 13. First permanent magnet pair; 14. First through hole; 15. Small through hole; 2. Inner rotor; 21. Inner rotor yoke; 22. Second permanent magnet; 23. Second through hole; 3. Adjusting ring; 31. Circular ring; 32. Adjusting gear block; 33. Third through hole. Detailed Implementation

[0014] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Reference Figures 1 to 2 A magnetic gear assisted by a permanent magnet includes: a magnetic gear assisted by a permanent magnet, comprising: The outer rotor 1 is a column with its end face concave inward. It includes an outer rotor yoke 11 and multiple sets of first permanent magnet pairs 13. The multiple sets of first permanent magnet pairs 13 are evenly and closely arranged on the inner surface of the side wall of the outer rotor yoke 11. Each first permanent magnet pair 13 is composed of two first permanent magnets 12 with opposite magnetization directions.

[0015] The inner rotor 2, in the form of a cylinder, is coaxially disposed inside the outer rotor 1. The inner rotor 2 includes an inner rotor yoke 21 and second permanent magnets 22. The inner rotor yoke 21 is provided with multiple sets of permanent magnet slots, specifically four sets of permanent magnet slots. The four sets of permanent magnet slots are distributed along the circumferential direction of the cross-section of the inner rotor yoke 21. Each set of permanent magnet slots specifically includes three parallel permanent magnet slots, and each permanent magnet slot extends along the central axis of the inner rotor yoke 21. Multiple second permanent magnets 22 are arranged in parallel on each set of permanent magnet slots. Specifically, there are three parallel second permanent magnets 22. Each second permanent magnet 22 has a trapezoidal structure with an open bottom. The opening direction is opposite to the central axis of the inner rotor yoke 21. This is to increase the heat dissipation area of ​​the second permanent magnet 22 and prevent the second permanent magnet 22 from being affected by overheating. The size of the three second permanent magnets 22 gradually decreases outward along the radial direction of the column. The second permanent magnets 22 in the same permanent magnet slot group have the same magnetization direction, while the second permanent magnets 22 in adjacent permanent magnet slot groups have opposite magnetization directions.

[0016] The magnetic adjustment ring 3 includes a circular ring 31 made of non-magnetic material and magnetic adjustment teeth 32 made of silicon steel sheet. The magnetic adjustment teeth 32 are evenly arranged along the circumference of the circular ring 31.

[0017] Among them, the magnetic adjustment ring 3 is fixed, the outer rotor 1 is rotatably set on the outside of the magnetic guide tooth block 32 on the magnetic adjustment ring 3, and the inner rotor 2 is rotatably set on the inside of the magnetic guide tooth block 32 on the magnetic adjustment ring 3. There is an external air gap between the magnetic guide tooth block 32 and the outer rotor 1, and there is an internal air gap between the magnetic guide tooth block 32 and the inner rotor 2.

[0018] The outer rotor yoke 11, the inner rotor yoke 21, and the magnetic ring 3 are respectively provided with a first through hole 14, a second through hole 23, and a third through hole 33. The first through hole 14, the second through hole 23, and the third through hole 33 are matched to connect the mounting shaft and the magnetic gear.

[0019] The modulation principle of the tuning ring 3 is as follows: After the magnetic field generated by the second permanent magnet 22 on the inner rotor 2 is modulated by the magnetic adjustment ring 3, a new harmonic magnetic field is generated in the outer air gap. The number of magnetic poles of this harmonic magnetic field is the same as the number of magnetic poles of the magnetic field generated by the permanent magnet of the outer rotor 1 in the outer air gap. After the magnetic field generated by the first permanent magnet 12 on the outer rotor 1 is modulated by the magnetic adjustment ring 3, a harmonic magnetic field coupled with the magnetic field of the inner rotor 2 is generated in the inner air gap, so that the magnetic gear runs stably.

[0020] When the harmonic source is the permanent magnet magnetic field of the outer rotor 1, the harmonic order in the inner air gap is:

[0021]

[0022]

[0023] Wherein, the spatial harmonic order of the permanent magnet magnetic field of the outer rotor 1 is defined, where m is a positive odd number and k is the harmonic order generated by the modulation of the magnetic ring 3. Let be the number of permanent magnet pole pairs of the outer rotor 1. To adjust the number of pole pairs of magnetic ring 3; The air gap magnetic flux density in the outer air gap contains multiple harmonics, and the rotational speed of the outer rotor 1 is:

[0024] in, Let be the rotational speed of the outer rotor 1; To adjust the rotational speed of magnetic ring 3, The spatial harmonic order is the modulation function of the tuning ring 3.

[0025] When the harmonic source is the permanent magnet magnetic field of the inner rotor 2, the harmonic order in the outer air gap is:

[0026] Where m and k are the same as defined above. The number of permanent magnet pole pairs in the inner rotor; The rotational speed of the inner rotor 2 is:

[0027] in, Let be the rotational speed of the inner rotor 2. and The above definitions are the same.

[0028] From the above formula, we can see that when k=0, = ,in The rotor speed, which serves as the magnetic field source, is equal to the harmonic rotation speed. Therefore, to achieve variable speed motion, k should be set to ≠ 0. When k ≠ 0, the magnetic field generated by any permanent magnet in the magnetic gear, after being modulated by the magnetic ring 3, changes the rotation speed of the spatial harmonics compared to the unmodulated magnetic field, thus achieving variable speed magnetic field.

[0029] To maximize the torque transmitted by the outer rotor, it is essential to ensure that the number of poles of the magnetic field of outer rotor 1 matches the number of poles of the harmonic magnetic field with the largest amplitude. When both have the same number of poles, the interaction between the magnetic fields reaches its optimal state, thus maximizing the torque. Choosing the combination of m=1 and k=-1 yields the maximum harmonic amplitude, resulting in the maximum torque. When the adjusting magnetic ring 3 is stationary, i.e. When =0, the outer rotor is the high-speed output terminal, and its number of pole pairs is Choosing m=1 and k=-1, the transmission ratio of the magnetic gear is: .

[0030] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A permanent magnet assisted magnetic gear, characterized by, The application relates to a magnetic gear, which comprises the following parts: an outer rotor comprising an outer rotor yoke and a plurality of first permanent magnet pairs, the first permanent magnet pairs being evenly arranged on the inner surface of the side wall of the outer rotor yoke, and each first permanent magnet pair being composed of two permanent magnets with opposite magnetization directions; an inner rotor comprising an inner rotor yoke with a plurality of permanent magnet grooves, each permanent magnet groove being embedded with a plurality of second permanent magnets arranged in parallel, and the second permanent magnets in adjacent permanent magnet groove groups being oppositely magnetized, and the second permanent magnets being made of ferrite material; a magnet adjusting ring comprising a circular ring made of non-magnetic material, and a plurality of magnetic teeth blocks made of silicon steel sheet being evenly fixed on the circular ring along the circumferential direction; wherein the magnet adjusting ring is fixed, the inner rotor is rotatably arranged on the inner side of the magnetic teeth blocks of the magnet adjusting ring, and the outer rotor is rotatably arranged on the outer side of the magnetic teeth blocks of the magnet adjusting ring.

2. A permanent magnet assisted magnetic gear as claimed in claim 1, characterized in that: The outer rotor yoke is a column with an inward recess, each first permanent magnet pair is composed of an N-pole iron-boron permanent magnet with axial magnetization and an S-pole iron-boron permanent magnet with axial magnetization, and the plurality of first permanent magnet pairs are closely arranged on the inner wall of the outer rotor yoke.

3. A magnetic gear with permanent magnet assistance as described in claim 1, characterized in that: The circular ring of the magnet adjusting ring is arranged on the side of the inner rotor away from the outer rotor, the magnetic teeth blocks are inserted into the gap between the outer rotor and the inner rotor, and there are air gaps between the magnetic teeth blocks of the magnet adjusting ring and the outer rotor and the inner rotor respectively.

4. A permanent magnet assisted magnetic gear as claimed in claim 1, wherein: First through holes, second through holes and third through holes are arranged on the outer rotor yoke, the inner rotor yoke and the circular ring of the magnet adjusting ring respectively, the first through holes, the second through holes and the third through holes are matched, and are used for connecting and installing a shaft and a magnetic gear.

5. A permanent magnet assisted magnetic gear as claimed in claim 4, characterized in that: A plurality of small through holes for heat dissipation are arranged around the first through holes on the bottom of the outer rotor.

6. A permanent magnet assisted magnetic gear as claimed in claim 4, characterized in that: Each second permanent magnet is in a trapezoidal structure with an open lower bottom, and the open direction of the trapezoidal structure is opposite to the central axis of the inner rotor yoke.

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