WO2009129708A1

WO2009129708A1 - Direct driving combined type permanent magnet motor

Info

Publication number: WO2009129708A1
Application number: PCT/CN2009/070789
Authority: WO
Inventors: 章跃进; 江建中; 崔巍; 杜世勤; 刘新华; 龚宇; 汪信尧
Original assignee: 许晓华
Priority date: 2008-04-21
Filing date: 2009-03-13
Publication date: 2009-10-29
Also published as: CN101330234A

Abstract

A direct driving combined type permanent magnet motor includes an auto-control type permanent magnet motor and a concentric type magnetic gear. The auto-control type permanent magnet motor and the magnetic gear are integrated by a telescope feed structure or an axial series connection structure. The combined type permanent magnet motor achieves a power transmission between a high speed lower torque and a low speed high torque interiorly and does not require matching a mechanical gear box. The combined type permanent magnet motor may serve as not only an electric motor but also a generator.

Description

Direct drive composite permanent magnet motor

Technical field

The present invention relates to a motor, and more particularly to a direct drive composite permanent magnet motor suitable for low speed and high torque.

Background technique

A conventional motor drive system is a combination of a motor and a mechanical shifting mechanism. However, the daily maintenance of mechanical transmission components (such as gearboxes) and the replacement of wear parts require additional cost, and the cost of regular maintenance for long-distance operating systems (such as wind power, tidal power) will be extremely expensive. The gap and friction loss between mechanical transmission components make high-precision control difficult to achieve, reducing system reliability and efficiency, and generating noise; motor and mechanical shifting devices also require a large installation space.

Summary of the invention

SUMMARY OF THE INVENTION An object of the present invention is to provide a direct drive composite permanent magnet motor which is compact in structure and high in torque density and can be used for low speed and high torque. It discards mechanical transmission components, improves system transmission efficiency, reduces volume, and greatly reduces maintenance costs and noise.

In order to achieve the above object, the concept of the present invention is: a high-performance magnetic gear and a self-controlled permanent magnet motor are assembled by a sleeve structure or an axial series structure to form a composite high torque density suitable for direct drive. The permanent magnet motor has a double stator and double rotor structure, that is, a multi-pole rotor and a low-pole rotor structure, a reluctance stator and an armature stator structure.

According to the above inventive concept, the present invention adopts the following technical solutions:

A direct drive composite permanent magnet motor, comprising a self-controlled permanent magnet motor and a concentric magnetic gear, characterized in that the self-controlled permanent magnet motor and the concentric magnetic gear are concentrically assembled into a double stator double rotor structure, that is, The outer rotor and the outer stator of the magnetic gear and the inner rotor and the inner stator of the permanent magnet motor are assembled in a concentric structure by a sleeve structure.

The outer rotor is a cup rotor, and the cup bottom is fixedly connected with the central rotating shaft; the outer stator is a cylindrical body, one end of which is directly fixedly connected with one end cover of the base, and the other end passes through a radial disk and an inner stator. The inner end is fixedly connected; the inner rotor is also a cup-type rotor, and the two ends are supported by the inner and outer ends of the inner stator through two bearings; the outer end of the inner stator is fixedly connected with an end cover of the base, and the inner end of the inner stator is The central shaft is disposed; one end of the central shaft is supported by the outer end of the inner stator through the bearing, and the other end is supported by the inner hole of the other end cover of the base through the bearing.

The cup body of the inner rotor is circumferentially distributed with a pair of permanent magnets of Pi pair, and the inner wall of the outer rotor cup body is circumferentially uniformly embedded. Install P ₂ pairs of permanent magnets, and! ^ (P ₂ ; The outer stator is a reluctance stator, which has Ns circumferentially uniformly distributed iron core teeth, that is, the cup core is uniformly distributed in the circumferential direction, and the groove is filled with non-magnetic material, which should satisfy 1^=? ₁ +? ₂ or 1^=? ₂ -? _{1 ;} This is composed of an armature winding wound on the inner stator core.

The above-mentioned outer rotor permanent magnet magnetic steel adopts high-performance rare earth permanent magnet material, the outer rotor is surface-mounted structure, and the inner rotor is surface-mounted, or built-in radial type, or built-in tangential type.

The iron core of the outer stator described above is evenly grooved, and the groove is filled with a non-magnetic material.

The inner stator armature winding described above adopts a fractional slot winding structure.

A direct drive composite permanent magnet motor, comprising a self-controlled permanent magnet motor and a concentric magnetic gear, characterized in that the permanent magnet motor and the magnetic gear adopt an axial series structure assembly, that is, a permanent magnet double rotor and a reluctance stator The high-performance magnetic gear is coaxially connected to the self-controlled permanent magnet motor.

Compared with the prior art, the present invention has the following outstanding substantive features and significant advantages:

1. The permanent magnet motor and the magnetic gear are integrated into one body, which eliminates the noise, vibration and corresponding loss of mechanical contact;

2. Greatly reduced maintenance workload and cost, and improved reliability;

3. Inherent overload protection characteristics;

4. Compact structure with high torque density and high power factor.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view showing the structure of an embodiment of the present invention.

Figure 2 is a cross-sectional view taken along line A-A of Figure 1.

Figure 3 is a schematic view of the internal rotor structure of the built-in magnetic steel.

Figure 4 is a schematic view showing the structure of a tangential magnetic steel inner rotor.

Figure 5 is a schematic view showing the structure of another embodiment of the present invention.

detailed description

Embodiment 1: Referring to FIG. 1 and FIG. 2, the direct drive composite permanent magnet motor comprises a self-controlled permanent magnet motor and a concentric magnetic gear, and the self-controlled permanent magnet motor and the concentric magnetic gear are assembled into a double rotor structure, that is, The outer rotor 3 and the outer stator 7 of the magnetic gear and the inner rotor 8 and the inner stator 12 of the permanent magnet motor are constructed in a concentric structure by a sleeve-like structure assembly.

The outer rotor 3 is a cup-type rotor, and the cup-shaped bottom is fixedly connected with the central rotating shaft 11; the outer stator Ί is a cylindrical body, one end of which is directly fixedly connected with one end cover 2b of the machine base 1, and the other end passes through a diameter The disk 6 is fixedly connected to the inner end of the inner stator 12; the inner rotor 8 is also a cup-type rotor, and the two ends thereof are supported by the inner and outer parts of the inner stator through two bearings. The outer end of the inner stator 12 is fixedly connected with an end cover 2b of the base 1, and the central rotating shaft 11 is disposed in the central hole of the inner stator 12. One end of the central rotating shaft 11 is supported by the outer end of the inner stator 12 through a bearing, and One end is supported by a bearing in the inner hole of the other end cover 2a of the base 1.

The stator 10 of the permanent magnet motor is a slotted armature core, and a plurality of symmetrical armature windings 9 are embedded in the slot. The multi-phase armature winding is symmetrical current, generates a rotating magnetic field in the inner air gap, and interacts with the magnetic field of the permanent magnet inner rotor 8 to generate electromagnetic torque to realize energy transmission. The inner rotor permanent magnet has the number of pole pairs. The inner surface of the outer rotor 3 is provided with a permanent magnet steel 4 having a pole pair number P ₂ and Ρ ₂ . Therefore, the inner rotor 8 is a high speed rotor and the outer rotor 3 is a low speed rotor. Between the inner rotor 8 and the outer rotor 3 is a reluctance outer stator 7, and the reluctance stator has 1^ uniformly distributed iron core teeth 5, that is, a circumferential uniform groove, and no conductor in the groove, in order to increase The strength of the stator 7 is filled with a non-magnetic material. The two rotors and the outer stator 7 form a high performance magnetic gear. The distribution of the cogging of the outer stator 7 causes a cyclical change in the air gap flux around the circumference, thereby modulating the permanent magnetic air gap magnetic field on the inner and outer sides of the outer stator 7. The pole pair number Pi of the inner rotor 8 and the pole pair number P _{2 of the} outer rotor 3 and the number of teeth poles N _{s of the} outer stator 7 need to satisfy a certain relationship: N _S = P _{1 +} P ₂ (or N _s = P _{2 -} Pi Therefore, the two rotor spatial air gap magnetic field modulation fundamental waves are the same, and the torque and the rotational speed are transmitted through the coupling effect of the permanent magnet magnetic field of the inner and outer rotors. The magnetic gear ratio is G=P ₂ /P _{1 (} >

In the permanent magnet motor, the inner rotor 8 is not only a part of the magnetic gear but also constitutes a self-controlled permanent magnet motor with the inner stator 10. The inner rotor 8 can take many forms, such as a surface type, a built-in radial type, and a built-in tangential type (see Figures 3 and 4).

The permanent magnet motor can be operated as a motor or generator. When operating as a motor, the inner stator armature winding 9 is powered by the inverter and is determined to be turned on and off based on the position signal of the inner rotor 8. If the Hall position signal is used, the motor operates as a permanent magnet brushless DC motor; if a high-precision position encoder is used, the motor can operate as a permanent magnet synchronous servo motor. The high rotational speed of the inner rotor 8 is advantageous for increasing the power density of the motor. Through the magnetic field coupling effect of the inner rotor 8 and the outer rotor 3, the torque and the rotational speed are transmitted, and the outer rotor 3 is output at a low rotational speed and a large torque. When operating as a generator, the outer rotor 3 is driven by the prime mover, and the inner rotor 8 is rotated by the magnetic field coupling effect, and the permanent magnet magnetic field of the inner rotor 8 induces an electromotive force in the armature winding 9 of the stator 10 to generate an alternating current.

Embodiment 2: Referring to FIG. 5, the direct drive of the composite permanent magnet motor is formed in an axial series, which is equivalent to a self-controlled permanent magnet motor coaxially connected with a magnetic gear. The self-controlled permanent magnet motor is in the form of an inner rotor, that is, the inner rotor 8 of the above example is divided into two rotors: a self-controlled permanent magnet motor rotor 8a and a magnetic gear inner rotor 8b, and the self-controlled permanent magnet motor rotor 8a has a large space. The form is more flexible and easy to make a wide-speed permanent magnet motor.

Claims

A direct drive composite permanent magnet motor comprising a self-controlled permanent magnet motor and a concentric magnetic gear, characterized in that the self-controlled permanent magnet motor and the concentric magnetic gear are concentrically assembled into a double stator double rotor structure That is, the outer rotor (3) and the outer stator (2) of the magnetic gear and the inner rotor (8) and the inner stator (12) of the permanent magnet motor adopt a sleeve structure to form a concentric structure.

2. The direct drive composite permanent magnet motor according to claim 1, wherein the outer rotor (3) is a cup rotor, and the cup bottom is fixedly connected to the central shaft (11); the outer stator (7) ) is a cylindrical body, one end of which is directly fixedly connected to one end cover (2b) of the base (1), and the other end is fixedly connected to the inner end of the inner stator (12) through a radial disk (6); 8) is also a cup rotor, the two ends of which are supported by the inner and outer ends of the inner stator through two bearings; the outer end of the inner stator (12) is fixedly connected with an end cover (2b) of the base (1), the inner stator A central rotating shaft (11) is disposed in the center hole of (12); one end of the central rotating shaft (11) is supported by the outer end of the inner stator (12) through the bearing, and the other end is supported by the other end cover of the base (1) through the bearing. Inside the inner hole of (2a).

3. The direct drive composite permanent magnet motor according to claim 2, characterized in that the cup body of the inner rotor (8) is circumferentially uniformly distributed with _P1 pairs of permanent magnets, and the outer rotor (3) cup type of body The inner wall is circumferentially evenly fitted with P ₂ pairs of permanent magnets (4), and! ^ (P ₂ ; The outer stator (7) is a reluctance stator with Ns circumferentially uniformly distributed core teeth, that is, the cup core is uniformly distributed in the circumferential direction, and the groove is filled with non-magnetic material, which should satisfy 1 ^=? ₁ +? ₂ or 1^=? ₂ -? _{1 ;} inner stator

(12) The armature winding (9) is wound from the inner stator core (10).

4. The direct drive composite permanent magnet motor according to claim 3, wherein the outer rotor (3) permanent magnet magnetic steel (4) is made of a high performance rare earth permanent magnet material, and the outer rotor (3) is surface mounted. Structure, inner rotor (8) is surface mounted, or built-in radial, or built-in tangential.

The direct drive composite permanent magnet motor according to claim 3, characterized in that the core of the outer stator (7) is uniformly grooved, and the groove is filled with a non-magnetic material.

6. The direct drive composite permanent magnet motor according to claim 3, wherein the inner stator armature winding (9) adopts a fractional slot winding structure.

7. A direct drive composite permanent magnet motor comprising a self-controlled permanent magnet motor and a concentric magnetic gear, characterized in that the permanent magnet motor and the magnetic gear adopt an axial series structure, that is, a permanent magnet double rotor and a magnetoresistive The high-performance magnetic gear composed of the stator is coaxially connected with the self-controlled permanent magnet motor.