CN104967279B - Axial magnetic gear employing stator permanent magnetism structure at low-speed rotor side - Google Patents

Abstract

The invention discloses an axial magnetic gear, which comprises a low-speed rotor, a high-speed rotor and a stator. The low-speed rotor and the high-speed rotor are arranged coaxially in the axial direction, and both have the same outer diameter; the low-speed rotor is a ring-shaped magnetizer, and the low-speed rotor salient poles are arranged equidistantly on its outer ring; the high-speed rotor includes a high-speed rotor core And the high-speed rotor permanent magnet embedded in the high-speed rotor core; the stator is a ring structure composed of magnetic conductive blocks arranged at equal intervals, and is coaxially fixed outside the high-speed and low-speed rotors, and the two ends of the stator are respectively aligned with the outer end faces of the high-speed and low-speed rotors , permanent magnets need to be filled between adjacent stator magnetic blocks corresponding to the low-speed rotor side. There is an air gap between the stator and the high and low speed rotors, and there is a gap between the high and low speed rotors axially to ensure that the high and low speed rotors can rotate freely. As a magnetic gear that utilizes the coupling effect of the harmonic magnetic field to realize variable-speed transmission, the present invention has the characteristics of high mechanical reliability and convenient processing and manufacturing.

Description

Axial magnetic gear with stator permanent magnet structure on the low-speed rotor side

technical field

The invention relates to an axial magnetic gear suitable for non-contact variable speed drive, belonging to the technical field of variable speed transmission.

Background technique

In industrial applications, many occasions that require variable speed drives are usually realized by mechanical devices such as bulky gearboxes. The use of mechanical gearboxes will inevitably bring about problems such as noise, vibration, friction loss, and regular maintenance, and will significantly increase the size and weight of the transmission system. In addition, mechanical gears do not have overload self-protection capabilities. When the transmitted torque exceeds the bearing capacity of mechanical teeth, safety accidents are prone to occur.

In comparison, magnetic gears use magnetic field coupling to transmit torque. It is a non-contact variable speed transmission device that does not have problems such as noise, vibration, friction loss, and lubrication, and can achieve physical isolation between input and output. , also has overload self-protection ability, high safety and reliability. In recent years, with the development of high-performance NdFeB permanent magnet materials, the exploration of new magnetic gear topology has become a research hotspot of scholars at home and abroad. At present, a type of magnetic gear that has been studied more usually adopts a coaxial structure. This type of coaxial magnetic gear includes low-speed rotors arranged from outside to inside, concentric, a magnetic ring and a high-speed rotor. The high-speed and low-speed rotors are composed of permanent Composed of magnets and iron cores, the permanent magnets rotate with the rotor, which reduces the mechanical reliability of the rotor; the magnetic adjustment ring is a ring-shaped component composed of magnetic conductive blocks and non-magnetic conductive blocks arranged at intervals, and is placed statically between the high and low speed rotors. This makes the processing and fixed installation of the magnetic adjusting ring very difficult. In addition, there are air gaps between the magnetic ring and the high-speed and low-speed rotors respectively, and two air gaps and two rotating parts (high-speed and low-speed rotors) further increase the manufacturing difficulty of the coaxial magnetic gear. The above-mentioned reasons limit the practical application of coaxial magnetic gears to a certain extent. Therefore, the research on the new topological structure of magnetic gears with high mechanical reliability and convenient manufacturing has important theoretical significance and practical engineering value.

Contents of the invention

Technical problem: In order to solve the problems of low mechanical reliability and difficult manufacturing of existing coaxial magnetic gears, the present invention provides a topological structure of axial magnetic gears.

Technical solution: The axial magnetic gear of the present invention includes a stator, a low-speed rotor, a low-speed shaft, a high-speed rotor, a high-speed shaft and a housing; The salient poles of the low-speed rotor are arranged equidistantly; the high-speed rotor is fixedly arranged on the high-speed shaft, and the high-speed rotor is a ring structure, including a high-speed rotor core and a spoke-type high-speed rotor permanent magnet embedded in the high-speed rotor core. The permanent magnets of the high-speed rotor are magnetized tangentially along the circumference, and the magnetization directions of adjacent permanent magnets are opposite; the low-speed rotor and the high-speed rotor are arranged axially and coaxially with a gap between them, and the outer diameters of the two are the same; The stator is a ring structure composed of stator magnetic blocks arranged at equal intervals along the circumferential direction, and is fixedly installed on the outside of the low-speed rotor and the high-speed rotor concentrically. Stator permanent magnets are filled between them, and there is no need to fill any material between the stator magnetic permeable blocks corresponding to the stator side of the high-speed rotor. The stator permanent magnets are magnetized tangentially along the circumference, and the adjacent permanent magnets are magnetized in opposite directions; The shell is an aluminum ring-shaped part, which is tightly surrounded by the outside of the stator and is used to fix the stator; there is an air gap between the stator and the salient poles of the low-speed rotor and the outer surface of the high-speed rotor. Alignment of the outer end faces.

In the present invention, the number N _l of the salient poles of the low-speed rotor, the number N _s of the stator magnetic conductive blocks, and the number of pole pairs P _h of the high-speed rotor permanent magnets satisfy the following relationship: N _s =2×(N _l -P _h ), the achievable gear transmission ratio G _r is: G _r =N _l :P _h .

In the present invention, the axial length L _l of the low-speed rotor, the axial length L _h of the high-speed rotor, the axial length L _s of the stator magnetic block, the axial length L _sm of the corresponding stator permanent magnet on the low-speed rotor side, and the low-speed The axial gap distance L _g between the rotor and the high-speed rotor satisfies the following relationship: L _s =L _l +L _g +L _h , L _sm =L _l .

Beneficial effects: the present invention provides a brand-new axial magnetic gear structure, which has the following advantages compared with traditional coaxial magnetic gears:

1. The structure of the traditional coaxial magnetic gear includes high and low speed rotors rotating coaxially and a magnetic adjustment ring fixed between them. The magnetic adjustment ring is an annular component composed of scattered magnetic conductive blocks. The magnetic adjustment ring itself It is very difficult to manufacture and fix the installation. In addition, the two-layer air gap and two rotating parts make this kind of coaxial magnetic gear can only be fixed by unilateral support, which increases the difficulty of assembly and processing cost, and the concentricity of high and low speed rotors and magnetic rings is also difficult. ensure;

The magnetic gear of the present invention adopts an axial structure, and the high-speed and low-speed rotors arranged axially and coaxially are respectively arranged on both sides inside the stator. The production plan is processed, the assembly process is simple, and the manufacturing cost is low; on the other hand, the high-speed and low-speed rotor shafts can be easily drawn out on both sides, and the fixed installation is very convenient;

2. The high and low-speed rotors of traditional coaxial magnetic gears are composed of iron cores and permanent magnets, and the structural integrity is poor, which reduces the mechanical bearing capacity of the rotor to a certain extent, and during the rotation of the rotor, the surface-mounted permanent magnets It is easy to fall off and also reduces the mechanical reliability of the rotor;

The axial magnetic gear of the present invention adopts a stator permanent magnet structure on the low-speed rotor side, and the low-speed rotor is only a salient pole structure composed of a magnetic conductor, which is not only convenient to manufacture, low in processing cost, but also can improve the ability of the rotor to withstand large torque impacts , which improves the mechanical reliability of the low-speed rotor; in addition, the high-speed rotor adopts the arrangement of permanent magnets embedded in the spokes, so that when the high-speed rotor rotates at a higher speed, it is not easy for the permanent magnet to fall off, and the mechanical reliability of the high-speed rotor is further improved. reliability;

3. The permanent magnetic field of the high and low speed rotors of the traditional coaxial magnetic gear is modulated by the magnetic field of the magnetic ring, and the torque is transmitted by the coupling of the harmonic magnetic field. The magnetic field needs to pass through the inner and outer air gaps. To a certain extent, the utilization rate of permanent magnets and the torque transmission capacity of magnetic gears are reduced;

The permanent magnetic field produced by the stator permanent magnet on the low-speed rotor side of the axial magnetic gear of the present invention is modulated by the salient pole structure of the low-speed rotor. The coupling effect of the magnetic field realizes the transmission of torque, which will further improve the utilization rate of the permanent magnet and the torque transmission capacity of the magnetic gear.

The invention can obtain ideal running performance, is beneficial to simplify the manufacturing process, reduce the processing cost, improve the mechanical reliability and improve the torque transmission capacity of the magnetic gear.

Description of drawings

Fig. 1 is the cross-sectional structure of the axial magnetic gear low-speed rotor side of the present invention;

Fig. 2 is the side cross-sectional structure of the axial magnetic gear high-speed rotor of the present invention;

Fig. 3 is a cross-sectional structure of a traditional coaxial magnetic gear.

In the figure, there are: stator 1, stator magnetic block 11, stator permanent magnet 12, low-speed rotor 2, low-speed rotor salient pole 21, low-speed rotor permanent magnet 22, air gap 3, casing 4, low-speed shaft 5, high-speed rotor 6, high-speed Rotor iron core 61, high-speed rotor permanent magnet 62, high-speed rotating shaft 7, magnetic modulation ring 8, magnetic-conductive block 81 of magnetic-modulation ring, non-magnetic-conductive block 82 of magnetic modulation ring, outer air gap 91, and inner air gap 92. The arrow in the figure represents the magnetization direction of the permanent magnet.

detailed description

The axial magnetic gear of the present invention comprises a stator 1, a low-speed rotor 2, a low-speed rotating shaft 5, a high-speed rotor 6, a high-speed rotating shaft 7 and a casing 4; the low-speed rotor 2 is fixedly arranged on the low-speed rotating shaft 5, and the low-speed rotor 2 is an annular guide The magnet has low-speed rotor salient poles 21 arranged equidistantly on its outer ring; the high-speed rotor 6 is fixed on the high-speed rotating shaft 7, and the high-speed rotor 6 is a ring structure, including a high-speed rotor core 61 and a spoke-type embedded high-speed The high-speed rotor permanent magnet 62 of the rotor core 61, the high-speed rotor permanent magnet 62 is magnetized tangentially along the circumference, and the magnetization direction of adjacent permanent magnets is opposite; the low-speed rotor 2 and the high-speed rotor 6 are arranged axially, coaxially There is a gap between them, and the outer diameters of the two are the same; the stator 1 is a ring structure composed of stator magnetic blocks 11 arranged at equal intervals along the circumferential direction, and is fixedly installed on the low-speed rotor 2 and the high-speed rotor 6 concentrically. , wherein the stator permanent magnets 12 are filled between the adjacent stator magnetic permeable blocks 11 on the stator side corresponding to the low-speed rotor 2, and there is no need to fill any stator magnetic permeable blocks 11 on the stator side corresponding to the high-speed rotor 6 material, the stator permanent magnet 12 is magnetized tangentially along the circumference, and the magnetization direction of adjacent permanent magnets is opposite; the shell 4 is an aluminum annular part, which is tightly surrounded by the outside of the stator 1 and is used to fix the stator 1; the stator 1 and the salient poles 21 of the low-speed rotor and the outer surface of the high-speed rotor 6 are provided with an air gap 3, and the end faces on both sides of the stator 1 are aligned with the outer end faces of the low-speed rotor 2 and the high-speed rotor 6 respectively.

In the present invention, the number N _l of the salient poles 21 of the low-speed rotor, the number N _s of the stator magnetic conductive blocks 11, and the number of pole pairs _Ph of the high-speed rotor permanent magnet 62 satisfy the following relationship: N _s =2×(N _l -P _h ), the achievable gear transmission ratio G _r is: G _r =N _l :P _h .

In the present invention, the axial length L _l of the low-speed rotor 2, the axial length L _h of the high-speed rotor 6, the axial length L _s of the stator magnetic block 11, and the axial length of the corresponding stator permanent magnet 12 on the low-speed rotor side L _sm , the axial gap distance L _g between the low-speed rotor 2 and the high-speed rotor 6 satisfy the following relationship: L _s =L _l +L _g +L _h , L _sm =L _l .

The present invention will be further described below in conjunction with the accompanying drawings.

The low-speed rotor 2 of the present invention needs to adopt a salient pole structure to modulate the permanent magnetic field generated by the stator permanent magnet 12 corresponding to the low-speed rotor side. Coefficients need to be optimally designed.

The low-speed rotor 2, the stator magnetic block 11, and the high-speed rotor core 61 are made of silicon steel laminations or other magnetic materials, which are the same manufacturing process as the stator and rotor cores of ordinary permanent magnet synchronous motors.

The high-speed rotor 6 is arranged with permanent magnets embedded in spokes, which can produce a certain magnetic concentration effect, which is beneficial to improve the torque transmission capacity of the magnetic gear. Certainly, in the present invention, the high-speed rotor can also adopt other forms of rotor structures, as long as the high-speed rotor can generate effective N-S magnetic poles. But no matter which structural form is adopted, it is within the protection scope of the present invention.

The stator 1 is an annular component composed of stator magnetic permeable blocks 11 arranged at equal intervals along the circumference, and a stator permanent magnet 12 is arranged between the stator magnetic permeable blocks corresponding to the low-speed rotor side, and the stator 1 is fixed and installed coaxially on the The low-speed rotor 2 and the high-speed rotor 6 are outside, and the low-speed rotor 2 and the high-speed rotor 6 are respectively located on both sides inside the stator 1, and the end surfaces on both sides are aligned with each other. The low-speed rotor 2 and the high-speed rotor 6 have the same outer diameter, and they are coaxially arranged with a certain axial gap between them. At the same time, an air gap 3 is provided between the stator 1, the low-speed rotor 2 and the high-speed rotor 6, so that Ensure the normal rotation of high and low speed rotors.

In the present invention, the low-speed rotating shaft 5 (high-speed rotating shaft 7 ) is connected to an external power input device or a power output device to play the role of input or output power. Therefore, the low-speed rotating shaft 5 (high-speed rotating shaft 7) can be an independent part with the low-speed rotor 2 (high-speed rotor 6), and the low-speed rotor 2 (high-speed rotor 6) is fixedly arranged on the outer circumference of the low-speed rotating shaft 5 (high-speed rotating shaft 7); The rotating shaft 5 (high-speed rotating shaft 7) can also be an integrated part with the low-speed rotor 2 (high-speed rotor 6), so that the low-speed rotating shaft 5 (high-speed rotating shaft 7) can be regarded as the structure of the low-speed rotor 2 (high-speed rotor 6). part of the axis. But no matter which structural form is adopted, it is within the protection scope of the present invention.

The low-speed rotating shaft 5 and the high-speed rotating shaft 7 are made of steel or other non-magnetic materials, and the manufacturing process is the same as that of ordinary permanent magnet synchronous motors.

The casing 4 is tightly surrounded by the outside of the stator 1 for fixed installation of the stator 1. The casing 4 is made of aluminum or other non-magnetic materials, which is the same as the manufacturing process of the casing of a common permanent magnet synchronous motor.

The stator permanent magnet 12 and the high-speed rotor permanent magnet 62 are made of rare earth NdFeB or other permanent magnet materials.

The stator permanent magnets 12 corresponding to the low-speed rotor side are magnetized tangentially along the circumference, and the magnetization directions of adjacent permanent magnets are opposite, forming an N-S magnetic pole structure.

The high-speed rotor permanent magnets 62 constituting the high-speed rotor are magnetized tangentially along the circumference, and the magnetization directions of adjacent permanent magnets are opposite, forming a magnetism-concentrating N-S magnetic pole structure.

The magnetic field modulation function of the salient poles 21 of the low-speed rotor can modulate a series of space harmonic magnetic fields at the air gap 3 from the permanent magnetic field generated by the stator permanent magnet 12 corresponding to the low-speed rotor side. When the low-speed rotor 2 rotates, the corresponding harmonic magnetic field rotates accordingly. When the number of pole pairs of the high-speed rotor permanent magnet 62 of the axial magnetic gear is equal to the number of pole pairs of any one of the rotating harmonic magnetic fields, through the coupling effect of the magnetic field, the high-speed and low-speed rotors of the axial magnetic gear can rotate stably, realizing transmission of torque. Therefore, the high-speed rotor 6 has various structural forms, and it only needs to ensure that the effective NS magnetic pole and harmonic magnetic field coupling effect can be produced. In order to achieve the effect of variable speed transmission, it must be required that the number of pole pairs of the selected harmonic rotating magnetic field cannot be equal to the number of salient poles 21 of the low-speed rotor. At this time, when the number of pole pairs of the selected harmonic magnetic field is equal to the difference between the number of low-speed rotor salient poles 21 and the number of pole pairs of the stator permanent magnets 12 on the low-speed rotor side, the harmonic rotating magnetic field with the largest amplitude is used. Axial magnetic gears enable optimum torque transfer capability. That is, the number N _l of the low-speed rotor salient poles 21 of the axial magnetic gear, the number N _s of the stator magnetic conductive blocks 11, and the number of pole pairs _Ph of the high-speed rotor permanent magnet 62 should satisfy the following relationship:

N _s =2×(N _l -P _h ) (1)

At this time, the rotational speed ratio of the high and low speed rotors of the axial magnetic gear satisfies:

Ω _h :Ω _l ＝N _l :P _h (2)

Ω _h , Ω _l are the rotational speeds of the high and low speed rotors of the axial magnetic gear respectively.

Correspondingly, the transmission ratio G _r that can be realized by the axial magnetic gear is:

G _r =N _l :P _h (3)

The novel axial magnetic gear with stator permanent magnet structure on the low-speed rotor side involved in the present invention can not only achieve higher torque transmission capacity, but also has a more reasonable structural design. The overall outer stator and inner rotor structure of the magnetic gear and the low-speed rotor The adopted stator permanent magnet structure makes the axial magnetic gear have obvious advantages in simplifying the manufacturing process, reducing the processing cost and improving the mechanical reliability.

Claims (3)

1. a kind of low speed rotor side uses the axial magnetic gear of stator permanent magnetic type structure, it is characterised in that the magnetic gear includes fixed Sub (1), low speed rotor (2), low speed rotating shaft (5), high speed rotor (6), high speed rotating shaft (7) and shell (4)；

The low speed rotor (2) is fixedly installed in low speed rotating shaft (5), and low speed rotor (2) is annular magnetizer, on its outer shroud It is provided with the low speed rotor salient pole (21) of equidistant arrangement；

The high speed rotor (6) is fixedly installed on high speed rotating shaft (7), and high speed rotor (6) is loop configuration, including high speed rotor The high speed rotor permanent magnet (62) of iron core (61) and spoke type insertion high speed rotor iron core (61), the high speed rotor permanent magnet (62) circumferentially cutting orientation magnetizing, adjacent permanent magnet magnetizing direction is opposite；

The low speed rotor (2) and high speed rotor (6) are axially aligned, are coaxially disposed, between there is gap, and the two external diameter It is identical；

The stator (1) be by stator magnetic inductive block (11) loop configuration that along the circumferential direction equi-spaced apart is rearranged, it is concentric Be fixedly mounted on the outside of low speed rotor (2) and high speed rotor (6), wherein, stator (1) side corresponding with low speed rotor (2) Adjacent stators magnetic inductive block (11) between need filling stator permanent magnet (12), and stator (1) side corresponding with high speed rotor (6) Stator magnetic inductive block (11) between need not then fill any material, the stator permanent magnet (12) circumferentially cutting orientation magnetizing is adjacent Permanent magnet magnetizing direction is opposite；

The shell (4) is aluminum annular element, stator (1) outside is closely enclosed in, for fixed stator (1)；

Air gap (3) is provided between the stator (1) and low speed rotor salient pole (21), high speed rotor (6) outer surface；Stator (1) End face outside of the both sides end face respectively with low speed rotor (2), high speed rotor (6) is alignd.

2. a kind of axial magnetic gear according to claim 1, it is characterised in that the number of the low speed rotor salient pole (21) N_l, stator magnetic inductive block (11) number N_s, high speed rotor permanent magnet (62) number of pole-pairs P_hMeet following relation：N_s=2 × (N_l- P_h), the gear shift gearratio G that can be realized_rFor：G_r=N_l:P_h。

3. a kind of axial magnetic gear according to claim 1, it is characterised in that the axial length of the low speed rotor (2) L_l, high speed rotor (6) axial length L_h, stator magnetic inductive block (11) axial length L_s, low speed rotor side correspondence stator permanent magnet (12) axial length L_sm, axial gap between low speed rotor (2) and high speed rotor (6) is apart from L_gBetween meet with ShiShimonoseki System：L_s=L_l+L_g+L_h, L_sm=L_l。