CN113595350B

CN113595350B - Self-starting three-phase secondary permanent magnet synchronous motor

Info

Publication number: CN113595350B
Application number: CN202110800065.4A
Authority: CN
Inventors: 徐正雄; 朱林希
Original assignee: Taizhou Dengfeng Technology Co ltd
Current assignee: Taizhou Dengfeng Technology Co ltd
Priority date: 2021-07-13
Filing date: 2021-07-13
Publication date: 2023-02-03
Anticipated expiration: 2041-07-13
Also published as: CN113595350A

Abstract

The invention discloses a self-starting three-phase two-stage permanent magnet synchronous motor, which comprises: the stator assembly is fixedly arranged in the accommodating cavity in the machine body and comprises a plurality of stacked stator units, a stator notch is formed in the inner periphery of each stator unit, and stator notches in the plurality of mutually stacked stator units form stator grooves; the rotor assembly comprises a core body, a squirrel cage winding is arranged on the outer layer of the core body, four cavities are formed in the core body, the cavities are used for accommodating magnetic steel pieces, and magnetic isolation gaps are formed between two ends of each magnetic steel piece and two ends of each cavity when each magnetic steel piece is accommodated in each cavity. The invention optimizes the structure of the rotor assembly through optimized design, and improves the running balance of the motor by reducing the stray loss of the motor, thereby increasing the starting traction torque.

Description

Self-starting three-phase two-stage permanent magnet synchronous motor

Technical Field

The invention relates to the technical field of synchronous motors, in particular to a self-starting three-phase two-stage permanent magnet synchronous motor.

Background

In recent years, permanent magnet synchronous motors have been developed more rapidly, and are characterized by high power factor and high efficiency, and the permanent magnet synchronous motors gradually replace the most common alternating current asynchronous motors in many occasions. The permanent magnet synchronous motor is generally composed of a stator, a rotor, an end cover, a machine body and other components, the structure of the stator is generally the same as that of a common induction motor, and a falling-breaking structure is generally adopted to reduce iron loss during the operation of the motor. The rotor core is usually of a solid structure, and can also be formed by lamination. The permanent magnet synchronous motor is different from other motors in the magnetic structure of a rotor, so that the running performance, a control system, a manufacturing process and a use occasion of the permanent magnet synchronous motor are different.

The rotor magnetic circuit structure of the permanent magnet synchronous motor can be divided into a surface type rotor magnetic circuit structure, and the structure is simple in design and manufacturing process, low in cost, wide in application and particularly suitable for rectangular wave permanent magnet synchronous motors. But the rotating surface can not be provided with a starting winding, has no asynchronous starting capability and can not be used for asynchronously starting the permanent magnet synchronous motor; in addition, the permanent magnet rotor comprises a convex permanent magnet rotor, a cage winding permanent magnet rotor, a built-in rotor magnetic circuit structure and the like.

The existing permanent magnet synchronous motor reflects the synchronous rotating speed of the motor according to the number of magnetic poles, the 2-pole synchronous rotating speed is 3000r/min, the 4-pole synchronous rotating speed is 1500r/min, the number of the magnetic poles is the number of the magnetic poles formed after the motor winding is electrified, the magnetic poles are divided into four poles, namely 2 poles, 4 poles, 6 poles, 8 poles and the like, the rotating speeds output at different levels are different, and the rotating speed of the permanent magnet synchronous motor is equal to the frequency (50 Hz) 60/pole logarithm theoretically. Namely 3000 rpm for a 2 pole motor, 1500 rpm for a 4 pole, 1000 rpm for a 6 pole, and 750 rpm for an 8 pole.

If the frequency of the three-phase alternating current is 50Hz, the synchronous rotating speed of the synthetic magnetic field is 50r/s, namely 3000r/min, if the rotating magnetic field of the motor is not only a pair of magnetic poles, the relationship between the synchronous rotating speed n and the magnetic pole pair number p of the magnetic field can be obtained through further analysis: n =60 f/p.f. frequency, in hz.n, in r/min. ns has a strict relation with the frequency (f) of the alternating current and the number (P) of the magnetic pole pairs of the motor, ns = f/P.

Therefore, when selecting the motor, it is necessary to consider how much starting torque is loaded, for example, the torque for starting with a load is larger than the torque for starting without load. However, under the condition of constant power, the larger the rotation speed is, the smaller the torque corresponding to the motor is, so that the existing two-stage permanent magnet synchronous motor can meet more no-load operation requirements, but in the actual use process, after the load is completed, the torque of load starting cannot meet the existing use requirements generally.

Disclosure of Invention

The invention aims to provide a self-starting three-phase two-stage permanent magnet synchronous motor, which is used for solving the technical problems, optimizing the structure of a rotor assembly, and improving the running balance of the motor by reducing the stray loss of the motor so as to increase the starting torque.

The technical problem solved by the invention can be realized by adopting the following technical scheme:

a self-starting three-phase two-stage permanent magnet synchronous motor comprising: the stator assembly is fixedly arranged in the accommodating cavity in the machine body and comprises a plurality of stacked stator units, a stator notch is formed in the inner periphery of each stator unit, stator notches in the plurality of stacked stator units form stator grooves, conducting wires are wound in the stator grooves to form stator coils, the stator coils are used for limiting electric phases, and the stator coils are wound to form winding units which are axially arranged at two sides of the stacked stator units; the rotor assembly rotates around an axis X and comprises a core body, a squirrel cage winding is arranged on the outer layer of the core body, the core body is provided with four cavities, the cavities are used for accommodating magnetic steel pieces, and when the magnetic steel pieces are accommodated in the cavities, magnetic isolation gaps are formed between two ends of the magnetic steel pieces and two ends of the cavities; four cavities are arranged at intervals along four sides of the diamond, magnetic steel pieces in the cavities on opposite surfaces are respectively arranged by adopting N poles and S poles, two poles are distributed, and a magnetic isolation bridge is arranged between the two cavities on the same pole.

The squirrel-cage winding comprises a rotor unit, a rotor groove is formed in the periphery of the rotor unit, and the groove ratio of the stator groove to the rotor groove is 24 grooves/22 grooves.

The thickness dimension of the magnetic isolation bridge is 0.8mm to 1.2mm.

The rotor groove comprises a port groove and an inner cavity groove, the caliber size of the port groove is 0.8mm-1.2mm, the caliber of the inner cavity groove is gradually reduced from outside to inside, and a guide strip portion is filled in the rotor groove.

And two sides of the squirrel cage winding axially extend outwards to form squirrel cage end rings, and the area size of each squirrel cage end ring is 3 to 4 times of a standard reference value.

The included angle between two adjacent cavities for filling the N-pole magnetic steel pieces is 95-100 degrees, and the included angle between two adjacent cavities for respectively filling the N-pole magnetic steel pieces and the S-pole magnetic steel pieces is 80-85 degrees.

The size of the magnetic isolation gap is 0.8mm to 1.2mm.

The number of the magnetic steel pieces in a single cavity is 1-5, the magnetic steel pieces are arranged in the same polarity, and the magnetic steel pieces are made of neodymium iron boron magnetic steel materials.

The integrative rotatory assembly of core is on the motor shaft, and the motor shaft is along extending the setting around axis X, be equipped with front bearing and rear bearing between motor shaft and the organism, the motor shaft extends to the outside.

And one end of the motor shaft is provided with a cooling wind wheel in a matching way, the cooling wind wheel is covered with a fan cover, and the fan cover is used for being installed in a matching way with the machine body.

Compared with the prior art, the invention has the following outstanding advantages and effects: the invention optimizes the structure of the rotor assembly through optimized design, and improves the running balance of the motor by reducing the stray loss of the motor, thereby increasing the starting traction torque.

The features of the present invention will be apparent from the accompanying drawings and from the detailed description of the preferred embodiments which follows.

Drawings

FIG. 1 is a schematic overall sectional view of the present invention;

FIG. 2 is a first schematic view of a rotor assembly according to the present invention;

FIG. 3 is a second schematic structural view of a rotor assembly according to the present invention;

FIG. 4 is a schematic view of a rotor groove configuration of the present invention;

FIG. 5 is a schematic structural diagram of a stator unit according to the present invention;

wherein, 1, the body; 2. a stator assembly; 21. a stator unit; 22. a winding unit; 23. a stator recess; 3. a fan housing; 4. cooling the wind wheel; 5. a motor shaft; 6. a rotor assembly; 61. a core body; 62. a magnetic steel member; 63. a squirrel cage winding; 631. a squirrel cage end ring; 632. a bar guiding part; 64. a rotor unit; 65. a cavity; 66. a rotor groove; 661. a port slot; 662. an inner cavity groove; 67. a magnetic isolation gap; 68. and a magnetic isolation bridge.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further explained below by combining the specific drawings.

Referring to fig. 1 to 5, the self-starting three-phase two-stage permanent magnet synchronous motor provided in this embodiment includes: the machine body 1 is internally provided with a cavity for installing the stator assembly 2 and the rotor assembly 6; the rotor assembly 6 is integrally and rotatably assembled on the motor shaft 5, the motor shaft 5 extends along the axis X, a front bearing and a rear bearing are arranged in front of the motor shaft 5 and the machine body 1 and used for realizing rotation, and the motor shaft 5 extends to the outside; one end of the motor shaft 5 is provided with a cooling wind wheel 4 in a matching way, the cooling wind wheel 4 is covered with a fan cover 3, and the fan cover 3 is used for being installed in a matching way with the machine body 1.

Specifically, the stator assembly 2 is fixedly installed in the cavity inside the machine body 1 and comprises a plurality of stacked stator units 21, a stator notch 23 is formed in the inner periphery of each stator unit 21, stator notches 23 in the plurality of stacked stator units 21 form stator grooves, conducting wires are wound in the stator grooves to form stator coils, the stator coils are used for limiting electric phases, and the stator coils are wound on winding units 22 which are axially arranged on two sides of the stacked stator units 21; wherein the stator units 21 are generally made of sheet metal, the stator units 21 are stacked axially to form a whole, stator teeth are arranged in the stator units, the adjacent stator teeth form corresponding stator recesses 23, and the opening direction of the stator recesses 23 faces to the position of the axis X.

In order to form a stator coil, a winding unit is formed, a plurality of phases are usually formed by winding coils around adjacent stator teeth, each coil is formed by a conducting wire covered by an electrically insulating material, and an enameled wire is usually used.

Specifically, the permanent magnet motor also comprises a rotor assembly 6 which rotates around an axis X and is matched with the stator assembly 2 to form a permanent magnet motor with an inner rotor type structure; the magnetic steel rotor comprises a core body 61, a squirrel cage winding 63 is arranged on the outer layer of the core body 61, the core body is provided with four cavities 65, the cavities 65 are used for accommodating magnetic steel pieces 62, a built-in rotor magnetic circuit structure design is adopted, the magnetic steel pieces 62 are positioned in a rotor, pole shoes made of ferromagnetic substances are arranged between the outer surfaces of the magnetic steel pieces 62 and a stator assembly 1, the pole shoes are arranged by the squirrel cage winding 63, and preferably, cast aluminum cages are adopted; the structure plays a role in damping or starting, particularly increases starting and steady-state effects, adopts the structural design of a built-in magnetic steel piece 62, is protected by a pole shoe formed by a squirrel-cage winding 63 arranged outside, and contributes to improving the power density of the motor due to the reluctance torque generated by the asymmetry of a rotor magnetic circuit structure.

Specifically, when the magnetic steel piece 62 is accommodated in the cavity 65, magnetic isolation gaps 67 are formed between two ends of the magnetic steel piece 62 and two ends of the cavity 65, and the size of the magnetic isolation gap 67 is 0.8mm to 1.2mm, preferably 1.0mm; the four cavities 65 are arranged along the four sides of the rhombus, the magnetic steel pieces 62 in the cavities 65 positioned on the opposite sides are respectively arranged by adopting an N pole and an S pole and form two-pole distribution, a magnetic isolation bridge 68 is arranged between the two cavities 65 positioned on the same pole, and the thickness dimension of the magnetic isolation bridge 68 is 0.8mm to 1.2mm, preferably 1.0mm; the design of the magnetic isolation bridge 68 and the magnetic isolation gap 67 is optimally adopted, and a good magnetic isolation effect is realized.

Preferably, the included angle between two adjacent cavities for filling the N-pole magnetic steel pieces is 95-100 degrees, preferably 98 degrees, and the included angle between two adjacent cavities for respectively filling the N-pole magnetic steel pieces and the S-pole magnetic steel pieces is 80-85 degrees, preferably 82 degrees; preferably, the design structure of the included angle is adopted, and a stator-rotor slot ratio structure is combined, wherein the rotor slot on the corresponding outer side between the cavities filled with the N-pole magnetic steel part and the S-pole magnetic steel part is an invalid slot group, so that the maximum range value of the valid slot group corresponding to the cavity filled with the N-pole magnetic steel part is pi-pi/N, and N is the number of the rotor slots, and the design of the maximum magnetic pole can be realized.

Preferably, the cage winding 63 comprises a rotor unit 64, the rotor unit 64 is provided with rotor grooves 66 on the outer circumference, and the stator grooves and the rotor grooves 66 have a groove ratio of 24 grooves/22 grooves.

Preferably, the rotor groove 66 comprises a port groove 661 and an inner cavity groove 662, the caliber size of the port groove 661 is 0.8mm to 1.2mm, preferably 1.0mm, the caliber of the inner cavity groove 662 is gradually reduced from outside to inside, a guide strip portion 632 is filled in the rotor groove 66, both sides of the squirrel-cage winding 63 are axially and outwardly extended to be provided with squirrel-cage end rings 631, and the area size of the squirrel-cage end rings 631 is 3 to 4 times of a standard reference value, preferably 3.5 times; in the existing design, the area of a squirrel cage end ring 631 depends on two parameter values, namely the axial thickness of the port and the radial length of the end ring, usually the radial length of the end ring is usually larger than the groove depth of a rotor groove 66 by 5mm to 10mm, and in addition, the axial thickness of the port and the like are obtained according to the conventional design and then used as standard reference values, and unique doubling design is carried out on the basis.

The area size of the squirrel cage end ring is preferably designed to be 3 to 4 times of a standard reference value, and the purpose is to further reduce the resistance of the end ring and increase traction torque during starting so as to realize loaded starting.

The design basis of the existing motor tends to be standardized design, the design flow of the motor usually determines the main size, then completes the magnetic circuit calculation, then realizes the parameter calculation, completes the performance calculation, and can complete the shaping of the final scheme only by carrying out multiple times of cyclic adjustment in the period.

Preferably, the number of the magnetic steel pieces 62 in a single cavity 65 is 1 to 5, preferably 2 to 4, and the magnetic steel pieces are arranged in the same polarity, and the magnetic steel pieces 62 are made of neodymium iron boron magnetic steel, namely permanent magnets.

The invention optimizes the structure of the rotor assembly through optimized design, and improves the running balance of the motor by reducing the stray loss of the motor, thereby increasing the starting traction torque.

Based on the content part of the embodiment, specific design parameter values of the self-starting three-phase two-stage permanent magnet synchronous motor with the power of 400W are provided.

Based on the parameters, the three-phase two-stage permanent magnet synchronous motor can enable the traction torque to be larger than the output torque when starting, so that the driving of the load is realized.

It will be appreciated by those skilled in the art that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The embodiments disclosed above are therefore to be considered in all respects as illustrative and not restrictive. All changes which come within the scope of or are equivalent to the scope of the invention are intended to be embraced therein.

Claims

1. A self-starting three-phase two-stage permanent magnet synchronous motor comprising: organism, inside has the appearance chamber for installation stator module and rotor subassembly, its characterized in that:

the stator assembly is fixedly arranged in a cavity in the machine body and comprises a plurality of stacked stator units, a stator notch is formed in the inner periphery of each stator unit, stator notches in the plurality of stacked stator units form a stator groove, a conducting wire is wound in the stator groove to form a stator coil, the stator coil is used for limiting an electric phase, and the stator coil is wound on winding units which are axially arranged on two sides of the stacked stator units;

the rotor assembly rotates around an axis X and comprises a core body, a squirrel cage winding is arranged on the outer layer of the core body, squirrel cage end rings axially and outwardly extend from two sides of the squirrel cage winding, the area size of each squirrel cage end ring is 3-4 times of a standard reference value, each squirrel cage winding comprises a rotor unit, a rotor groove is formed in the periphery of each rotor unit, the groove ratio of the stator groove to the rotor groove is 24 grooves/22 grooves, the radial length of each end ring is 5 mm-10mm larger than the groove depth of the rotor groove, the core body is provided with four cavities for accommodating magnetic steel pieces, and when the magnetic steel pieces are accommodated in the cavities, magnetic isolation gaps are formed between two ends of each magnetic steel piece and two ends of each cavity; the four cavities are distributed at intervals along four sides of the rhombus, magnetic steel pieces in the cavities on opposite sides are respectively distributed by adopting N poles and S poles, two poles are distributed, and a magnetic isolation bridge is arranged between the two cavities on the same pole; the included angle between two adjacent cavities for filling the N-pole magnetic steel pieces is 95-100 degrees, and the included angle between two adjacent cavities for respectively filling the N-pole magnetic steel pieces and the S-pole magnetic steel pieces is 80-85 degrees.

2. The self-starting three-phase two-stage permanent magnet synchronous motor according to claim 1, wherein: the thickness dimension of the magnetic isolation bridge is 0.8mm to 1.2mm.

3. The self-starting three-phase two-stage permanent magnet synchronous motor according to claim 1, wherein: the rotor groove comprises a port groove and an inner cavity groove, the caliber size of the port groove is 0.8mm-1.2mm, the caliber of the inner cavity groove is gradually reduced from outside to inside, and a guide strip portion is filled in the rotor groove.

4. The self-starting three-phase two-stage permanent magnet synchronous motor according to claim 1, wherein: the size of the magnetic isolation gap is 0.8mm to 1.2mm.

5. A self-starting three-phase two-stage permanent magnet synchronous machine according to any one of claims 1 to 4, characterized in that: the number of the magnetic steel pieces in a single cavity is 1-5, the magnetic steel pieces are arranged in the same polarity, and the magnetic steel pieces are made of neodymium iron boron magnetic steel materials.

6. The self-starting three-phase two-stage permanent magnet synchronous motor according to claim 1, wherein: the integrative rotatory assembly of core is on the motor shaft, and the motor shaft is along extending the setting around axis X, be equipped with front bearing and rear bearing between motor shaft and the organism, the motor shaft extends to the outside.

7. The self-starting three-phase two-stage permanent magnet synchronous motor according to claim 6, wherein: and one end of the motor shaft is provided with a cooling wind wheel in a matching way, the cooling wind wheel is covered with a fan cover, and the fan cover is used for being installed in a matching way with the machine body.