CN118100496B

CN118100496B - Stator, motor and compressor

Info

Publication number: CN118100496B
Application number: CN202410480470.6A
Authority: CN
Inventors: 邱小华; 李宏涛; 吴帮超; 龚浩文
Original assignee: Guangdong Meizhi Compressor Co Ltd
Current assignee: Guangdong Meizhi Compressor Co Ltd
Priority date: 2024-04-22
Filing date: 2024-04-22
Publication date: 2024-06-21
Anticipated expiration: 2044-04-22
Also published as: CN118100496A

Abstract

The invention discloses a stator, a motor and a compressor, and relates to the technical field of motors, wherein the stator comprises a stator core, insulating pieces and electromagnetic wires, the axial height of the stator core is H, the stator core comprises a yoke part and a plurality of tooth parts which are arranged at intervals along the circumferential direction of the yoke part, winding grooves are formed between the yoke part and any two tooth parts in a surrounding manner, Q winding grooves are formed, and the circumference of each winding groove is Z; the insulating piece is arranged on the wall of the winding slot, and the thickness of the insulating piece is d; the electromagnetic wire is wound on the tooth part, the contact coefficient of the electromagnetic wire and the insulating piece is w, and the relationship between H, Q, Z, d and w is as follows: 0.05< (d x k)/(1000 x u x f x epsilon x Z x H x Q x w) <0.2; u is withstand voltage test voltage, f is power frequency, epsilon is dielectric constant of the insulating member, and k is electrostatic constant. According to the technical scheme, the leakage current of the stator is effectively reduced, the leakage current requirement value of a compressor system is effectively met, and safe and reliable operation of the compressor is ensured.

Description

Stator, motor and compressor

Technical Field

The invention relates to the technical field of motors, in particular to a stator, a motor and a compressor.

Background

At present, in the technical field of high-power compressors, in order to further reduce the cost of the compressor, a ferrite material with lower price is adopted, the remanence and the coercive force of the material are lower, and the axial length of a motor needs to be increased to be matched with a reasonable slot pole to compensate the deficiency. For a high-power motor, the axial length of the motor is too long and the number of slots is too large, so that the leakage current is too large to meet the leakage current requirement value of a compressor system due to the conventional insulation structure in the stator slots.

Disclosure of Invention

The main object of the present invention is to provide a stator aimed at reducing the stator leakage current to meet the compressor system leakage current requirement.

In order to achieve the above purpose, the stator provided by the invention comprises a stator core, an insulating piece and electromagnetic wires, wherein the axial height of the stator core is H, the stator core comprises a yoke part and a plurality of tooth parts which are arranged at intervals along the circumferential direction of the yoke part, winding grooves are formed between the yoke part and any two tooth parts in a surrounding way, Q winding grooves are formed, and the circumference of each winding groove is Z; the insulation piece is arranged on the wall of the winding groove, and the thickness of the insulation piece is d; the electromagnetic wire is wound on the tooth part, the contact coefficient of the electromagnetic wire and the insulating piece is w, and the relation among H, Q, Z, d and w is as follows: 0.05< (d x k)/(1000 x u x f x epsilon x Z x H x Q x w) <0.2; u is withstand voltage test voltage, f is power frequency, epsilon is dielectric constant of the insulating piece, and k is electrostatic constant.

Optionally, the range of w is: w is more than or equal to 0.3 and less than or equal to 0.6.

Optionally, the axial direction height H of the stator core ranges from 85mm to 140mm.

Optionally, the insulating part protrudes towards the end surfaces of the two opposite ends of the stator core, the height of the insulating part protruding towards the end surface of the stator core is h, and the range of h is: h is more than or equal to 3mm and less than or equal to 6mm.

Optionally, the material of the insulating member is PET.

Optionally, the insulator is integrally formed.

Optionally, the insulating piece is clamped with the groove wall of the winding groove.

The invention also provides a motor which comprises a rotor and the stator, wherein the rotor is rotatably arranged in the stator.

Optionally, X permanent magnets are arranged on the rotor at intervals, the permanent magnets bend towards the direction away from the center of the stator, and the range of X is more than or equal to 6 and less than or equal to 10.

The invention also provides a compressor comprising the motor.

The stator at least comprises the following beneficial effects:

According to the technical scheme, the stator iron core, the insulating piece and the electromagnetic wire are adopted, the axial height of the stator iron core is H, the stator iron core comprises a yoke part and a plurality of tooth parts which are arranged at intervals along the circumferential direction of the yoke part, winding grooves are formed between the yoke part and any two tooth parts in a surrounding mode, Q winding grooves are formed, and the circumference of each winding groove is Z; the insulation piece is arranged on the wall of the winding groove, and the thickness of the insulation piece is d; the electromagnetic wire is wound on the tooth part, the contact coefficient of the electromagnetic wire and the insulating piece is w, and the relation among H, Q, Z, d and w is as follows: 0.05< (d x k)/(1000 x u x f x epsilon x Z x H x Q x w) <0.2; u is withstand voltage test voltage, f is power frequency, epsilon is dielectric constant of the insulating piece, and k is electrostatic constant. According to the scheme, the numerical value of (d & ltk)/(1000 & ltUf & gtepsilon & ltZ & gtH & ltQ & gtw) is limited to be 0.05-0.2, and the thickness d of different insulating pieces, the axial height H of a stator core, the number Q of winding grooves, the circumference Z of the winding grooves and the contact coefficient w of the electromagnetic wires and the insulating pieces are mutually matched, so that the thickness of the insulating pieces is limited, the excessive number of the winding grooves and the excessive contact area of the electromagnetic wires and the winding grooves are avoided, the leakage current of a stator is effectively reduced, the leakage current requirement value of a compressor system is effectively met, and the safe and reliable operation of the compressor is ensured.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of a stator according to an embodiment of the present invention;

FIG. 2 is an enlarged view of a portion of FIG. 1 at A;

FIG. 3 is a graph showing the leakage current of the motor according to the present invention as a function of Q;

FIG. 4 is a graph showing the leakage current of the motor according to the present invention as a function of d;

Fig. 5 is a graph showing the variation of leakage current with (d k)/(1000 uf zhq w) for an electric machine according to the present invention;

FIG. 6 is a graph showing the leakage current of the motor according to the present invention as a function of H;

Fig. 7 is a schematic diagram showing the variation of the resistance of the motor according to the present invention with h.

Reference numerals illustrate:

100. A stator core; 110. a yoke; 120. a tooth portion; 130. a wire winding groove; 200. an insulating member; 300. an electromagnetic wire; 400. a rotor; 410. permanent magnets.

The achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be noted that all directional indicators (such as up, down, left, right, front, and rear … …) in the embodiments of the present invention are merely used to explain the relative positional relationship, movement, etc. between the components in a particular posture (as shown in the drawings), and if the particular posture is changed, the directional indicator is changed accordingly.

In the present invention, unless specifically stated and limited otherwise, the terms "connected," "affixed," and the like are to be construed broadly, and for example, "affixed" may be a fixed connection, a removable connection, or an integral body; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In addition, if there is a description of "first", "second", etc. in the embodiments of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and/or" as it appears throughout includes three parallel schemes, for example "A and/or B", including the A scheme, or the B scheme, or the scheme where A and B are satisfied simultaneously. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present invention.

The motor includes a rotor 400 and a stator, the rotor 400 being disposed in a mounting port of the stator, the rotor 400 being rotatable relative to the stator.

The invention provides a stator.

Referring to fig. 1 and 2, in an embodiment of the present invention, the stator includes a stator core 100, an insulating member 200 and an electromagnetic wire 300, the axial height of the stator core 100 is H, the stator core 100 includes a yoke 110 and a plurality of teeth 120 circumferentially spaced along the yoke 110, a winding slot 130 is formed between the yoke 110 and any two teeth 120, Q winding slots 130 are provided, and the circumference of the winding slot 130 is Z; the insulating piece 200 is arranged on the groove wall of the wire winding groove 130, and the thickness of the insulating piece 200 is d; the magnet wire 300 is wound around the tooth 120, and the contact coefficients of the magnet wire 300 and the insulator 200 are w, H, Q, Z, d, and w are as follows: 0.05< (d x k)/(1000 x u x f x epsilon x Z x H x Q x w) <0.2; u is the withstand test voltage, f is the power frequency, ε is the dielectric constant of insulator 200, and k is the electrostatic constant.

It is understood that the number Q of the winding slots 130, the dielectric constant of the insulator 200, and the thickness of the insulator 200 can adjust the leakage current of the motor. Referring to fig. 3, fig. 3 is a schematic diagram showing a change of the leakage current of the motor with Q, and as can be seen from fig. 3, the leakage current of the motor gradually increases with an increase of the number of slots Q of the wire winding slot 130. Referring to fig. 4, fig. 4 is a schematic view showing a change of leakage current of the motor with d, and as can be seen from fig. 4, the thickness d of the insulating member 200 is inversely proportional to the leakage current of the motor, and as the thickness d of the insulating member 200 increases, the leakage current of the motor gradually decreases. In this solution, the number of (d x k)/(1000 u x f x Z H x Q x w) is limited between 0.05 and 0.2, and the thickness d of the different insulating members 200, the axial height H of the stator core 100, the number Q of the winding slots 130, the perimeter Z of the winding slots 130, and the contact coefficient w of the electromagnetic wire 300 and the insulating members 200 are designed to be mutually matched, so as to limit the thickness of the insulating members 200, avoid the excessive number of the winding slots 130, and avoid the excessive contact area between the electromagnetic wire 300 and the winding slots 130, thereby effectively reducing the leakage current of the stator, effectively meeting the leakage current requirement value of the compressor system, and ensuring the safe and reliable operation of the compressor.

Referring to fig. 5, fig. 5 is a schematic diagram showing a change of leakage current of the motor with (d_k)/(1000_uf_epsilon_z_h_q_w), and as can be seen from fig. 5, as (d_k)/(1000_uf_epsilon_z_h_q_w) increases, leakage current of the motor gradually decreases, and when (d_k)/(1000_uf_epsilon_zh_q_w) is less than 0.05, leakage current of the motor is above 10mA, which does not meet safety regulations; second, the greater (d k)/(1000 uf epsilon Z Q w), the greater the thickness d of the insulator 200. The greater the thickness d of the insulating member 200, on the one hand, the larger the area of the insulating member 200 occupied the wire winding slot 130, so that the area of the magnet wire 300 is reduced, the resistance is increased, and the motor efficiency is reduced. On the other hand, the heat of the electromagnetic wire 300 cannot be rapidly dissipated, and the operation efficiency of the motor is also affected, and the present scheme limits the value of (d x k)/(1000 x u x f x Z x H x Q x w) to 0.05 to 0.2, which is beneficial to reducing the leakage current of the motor and improving the motor efficiency.

The stator core 100 is formed by stacking a plurality of stator laminations, and the stator laminations are made of silicon steel material. The silicon steel is silicon alloy steel with silicon content of 1.0-4.5% and carbon content of less than 0.08%. Silicon steel has the characteristics of high magnetic permeability, low coercive force, large resistivity and the like, so that hysteresis loss and eddy current loss are relatively small.

The axial height H of the stator core 100 refers to the height of the stator core 100 in the axial direction. The thickness d of the insulator 200 refers to the distance from the side of the insulator 200 facing the slot wall of the wire slot 130 to the slot wall facing away from the wire slot 130. The contact coefficient w of the magnet wire 300 and the insulator 200 refers to the ratio of the contact area of the magnet wire 300 and the insulator 200 to the total area of the insulator 200.

The tooth 120 includes a tooth body and two tooth shoes, where the two tooth shoes are respectively disposed at free ends of the tooth body and respectively extend toward the circumferential direction of the punching body, and the slot wall of the winding slot 130 includes a yoke slot wall located at the yoke 110, a tooth slot wall located at the tooth body, and a shoe slot wall located at the tooth shoes and connected to the tooth slot wall, where the shoe slot wall is opposite to the yoke slot wall. The circumference Z of the wire slot 130 refers to the circumference of a single wire slot 130, not the sum of the circumferences of all wire slots 130, and the circumference Z of the wire slot 130 is equal to the sum of the length of the yoke slot wall, the two tooth slot walls, and the two shoe slot walls.

Next, k is the electrostatic constant 8.987551 x 10 ⁹N.m²/C².

The insulator 200 is provided on the wall of the wire slot 130, that is, the insulator 200 is disposed against the wall defining the wire slot 130 to prevent a short circuit between the magnet wire 300 and the yoke 110 of the stator, thereby achieving the purpose of insulating the motor core and the magnet wire 300 from each other.

During operation of the motor, current is regularly supplied to the magnet wire 300 to generate an excitation magnetic field, and the rotor 400 rotates under the action of the excitation magnetic field. The insulator 200 is disposed in the winding slot 130, and the insulator 200 is disposed between the magnet wire 300 and the stator core 100, and the insulator 200 can prevent the magnet wire 300 from contacting the stator core 100 to damage the insulation film on the surface of the magnet wire 300 while playing an insulating role, thereby effectively protecting the magnet wire 300 from damage.

The dielectric constant and the thickness of the insulating member 200 in the invention meet certain requirements, and the insulating capability of the motor can be effectively improved, the reliability of the motor can be improved, and the problem of leakage current of the motor with the stator can be solved by the insulating member 200. It should be noted that, the leakage current is mainly a current generated by the capacitor formed by the electromagnetic wire 300 and the stator core 100 under the action of voltage.

The electromagnetic wire 300 is a copper wire, although in other embodiments, the electromagnetic wire 300 may be other wires.

Further, the dielectric constant of the insulator 200 is between 2.5 and 4.5.

In this embodiment, by making the dielectric constant of the insulating member 200 satisfy the above range, the motor insulation performance can be effectively improved, the reliability of the motor can be improved, and the cost can be reduced. On the basis, the motor performance and the power density of the motor can be improved.

In the present embodiment, the dielectric constant of the insulator 200 is 3.2.

It is noted that the dielectric constant, also known as permittivity or relative permittivity, is an important datum characterizing the electrical properties of dielectrics or insulating materials. The dielectric constant is the product of the relative permittivity and the absolute permittivity in vacuum, and if a material with a high permittivity is placed in an electric field, the strength of the electric field will drop considerably in the dielectric. The polarity of the polymer material can be determined according to the dielectric constant of the substance. In general, a substance having a relative dielectric constant of more than 3.6 is a polar substance, a substance having a relative dielectric constant in the range of 2.8 to 3.6 is a weak polar substance, and a substance having a relative dielectric constant of less than 2.8 is a nonpolar substance.

Optionally, w ranges from: the electromagnetic wire of the compressor is generally circular enameled wires, gaps exist between contact points of different electromagnetic wires and insulating materials in a stator slot, when the capacitance discharge area is calculated equivalently, the capacitance discharge area needs to be multiplied by a contact coefficient w, and the size of the contact coefficient w is related to the full slot rate and the wire diameter of copper wires. The contact coefficient w of the embodiment 18 wire winding grooves 130 is 0.429, the contact coefficient w of the 36 wire winding grooves 130 is 0.434, and the contact coefficient w of the 48 wire winding grooves 130 is 0.5.

Further, the range of the axial direction height H of the stator core 100 is 85mm less than or equal to H less than or equal to 140mm, referring to fig. 6, fig. 6 is a schematic diagram showing the change of the leakage current of the motor along with the axial direction height H, referring to fig. 6, it can be known that the leakage current of the motor gradually increases along with the increase of the axial direction height H, and the effect of the axial direction height H of the stator core 100 on the leakage current of the motor can be reduced by limiting the axial direction height H of the stator core 100 between 85mm and 140 mm.

Alternatively, the insulating member 200 may extend outward of the winding slot 130 to protrude from the end surfaces of the opposite ends of the stator core 100, that is, the insulating member 200 may have an axial length greater than that of the stator core 100, and a portion of the insulating member 200 protruding from the axial end surface of the stator core 100 may be bent and attached to the axial end surface of the stator core 100, thereby enabling further realization of good insulation between the stator core 100 and the electromagnetic wire 300. In addition, by increasing the axial length of the insulator 200, the creepage distance can also be increased. It should be noted that the creepage distance may be obtained by referring to the following steps: determining an effective value or a direct current value of the working voltage; determining material group, determining contamination level, determining insulation type, etc.

Alternatively, the height of the insulating member 200 protruding from the end surface of the stator core 100 is h in the range of: h is more than or equal to 3mm and less than or equal to 6mm, the height h of the end surface of the insulating piece 200 protruding out of the stator core 100 is limited to be between 3mm and 6mm, the creepage distance between the electromagnetic wire 300 and the stator core can meet the requirement, and the safety of the motor can be improved. If h > 6mm, the insulator 200 is made to protrude too high, thereby increasing the resistance and decreasing the motor efficiency.

Referring to fig. 7, fig. 7 is a schematic diagram showing the change of the resistance with h, as shown in fig. 7, along with the increase of the height h of the insulating member 200 protruding from the end surface of the stator core 100, the resistance is gradually increased, when the height h of the insulating member 200 protruding from the end surface of the stator core 100 is greater than 6mm, the resistance is greater than 0.72Ω, and along with the increase of the height h of the insulating member 200 protruding from the end surface of the stator core 100, the resistance is gradually increased, so that the range of h is limited between 3mm and 6mm, which is beneficial to reducing the resistance and improving the motor efficiency while satisfying the creepage distance between the electromagnetic wire 300 and the stator core.

The insulator 200 is in the form of a flexible mylar film, the flexible nature of the insulator 200 being such that after insertion into the wire slot 130 and cutting of the insulator 200, the insulator 200 may be pressed against each wall of the wire slot 130.

In this first embodiment, the material of the insulator 200 is PET (polyethylene terephthalate). In other embodiments, the material of the insulator 200 may also be PA (polyamide) or PPS (polyphenylene sulfide) material.

The thickness of the insulator 200 is in the range of 0.25mm to 0.4mm, for example, about 0.3mm. In this embodiment, by making the thickness of the insulating member 200 satisfy the above range, that is, the thickness of the insulating member 200 is small, it is possible to achieve an increase in the space for accommodating the magnet wire 300 in the wire winding groove 130, and thus it is possible to improve the motor performance and the power density of the motor.

Alternatively, the insulator 200 is integrally formed. This is because the integrally formed product has a high structural rigidity, good integrity, strong stability, and less breakage, the strength of the insulating member 200 can be improved by using the integrally forming process, and the integrally formed manufacturing process and mounting process are more convenient and faster, so that the production efficiency of the insulating member 200 can be improved.

The insulating member 200 is matched with the stator core 100 in shape, and is tightly connected with the stator core 100 through an integrated structure of die opening and injection, so that the insulating member can not run up and down during operation, the working efficiency is improved, the space in the winding slot 130 can be utilized to the maximum extent, and when the number of coils is large, the phenomenon that the coils wound in the back side slide out to the periphery due to the tension can be avoided.

Optionally, the insulator 200 is engaged with the slot wall of the winding slot 130. The mounting mode of the clamping connection is convenient to mount and dismount, so that the tool-free dismounting can be realized, and additional materials such as screw fasteners are not required to be matched in the mounting process. Moreover, the installation process of the clamping connection is very simple, only the insulating piece 200 needs to be pushed into the winding groove 130, the interface of the insulating piece 200 is clamped on the groove wall of the winding groove 130, the work of rotary motion or product positioning before installation is not needed, and the installation efficiency of the insulating piece 200 can be improved quickly and simply. More specifically, each insulator 200 is inserted in the wire winding slot 130, existing between the magnet wire 300 and the slot wall of the wire winding slot 130.

The invention also provides a motor, which comprises a rotor 400 and the stator, wherein the rotor 400 is rotatably arranged in the stator. Further, the rotor 400 includes a rotor 400 core, a magnet slot provided on the rotor 400 core, and a permanent magnet 410 inserted in the magnet slot.

Optionally, the rotor 400 is provided with X permanent magnets 410 at intervals, the permanent magnets 410 bend towards the direction away from the center of the stator, and X is more than or equal to 6 and less than or equal to 10; specifically, the polarities of any two adjacent permanent magnets 410 are opposite, and the X permanent magnets 410 are alternately distributed along the circumferential direction of the rotor 400 core according to the N-pole and S-pole.

The material of the permanent magnet 410 is a low remanence material, specifically, a material with a smaller remanence, such as a ferrite sintered magnet, a ferrite bonded magnet, or the like. This is because the rare earth magnets are expensive, and ferrite magnets are relatively more expensive, which reduces the cost of the rotor 400.

The present solution limits the number X of permanent magnets 410 on the rotor 400 to between 6 and 10, which can make the electrical frequency higher, thereby increasing the counter potential of the motor.

The invention also provides a compressor, which comprises a motor, wherein the specific structure of the motor refers to the embodiment, and as the compressor adopts all the technical schemes of all the embodiments, the compressor at least has all the beneficial effects brought by the technical schemes of the embodiments, and the description is omitted herein.

The foregoing description is only of the optional embodiments of the present invention, and is not intended to limit the scope of the invention, and all the equivalent structural changes made by the description of the present invention and the accompanying drawings or the direct/indirect application in other related technical fields are included in the scope of the invention.

Claims

1. A stator, comprising:

the stator iron core comprises yoke parts and a plurality of tooth parts which are arranged at intervals along the circumferential direction of the yoke parts, wherein Q winding grooves are formed between the yoke parts and any two tooth parts in a surrounding mode, and the circumference of each winding groove is Z;

the insulation piece is arranged on the groove wall of the winding groove, and the thickness of the insulation piece is d;

The electromagnetic wire is wound on the tooth part, the ratio of the contact area of the electromagnetic wire and the insulating piece to the total area of the insulating piece is w, and the relation among H, Q, Z, d and w is as follows: 0.05< (d x k)/(1000 x u x f x epsilon x Z x H x Q x w) <0.2;

U is withstand voltage test voltage, f is power frequency, epsilon is dielectric constant of the insulating piece, and k is electrostatic constant.

2. The stator of claim 1, wherein w ranges from: w is more than or equal to 0.3 and less than or equal to 0.6.

3. The stator according to claim 1, wherein the axial direction height H of the stator core ranges from 85 mm.ltoreq.h.ltoreq.140 mm.

4. A stator according to claim 3, wherein said insulating members project toward end surfaces of opposite ends of said stator core, and wherein a height of said insulating members projecting toward said end surfaces of said stator core is h, said h ranging from: h is more than or equal to 3mm and less than or equal to 6mm.

5. The stator of claim 1 wherein the material of the insulator is PET.

6. The stator of claim 5, wherein the insulator is integrally formed.

7. The stator of claim 6, wherein the insulator is snapped into a slot wall of the winding slot.

8. An electric machine comprising a rotor and a stator as claimed in any one of claims 1 to 7, the rotor being rotatably arranged within the stator.

9. The motor of claim 8, wherein the rotor is provided with X permanent magnets at intervals, the permanent magnets are bent in a direction away from the center of the stator, and the range of X is 6-10.

10. A compressor comprising a motor as claimed in claim 8 or 9.