CN114069902B

CN114069902B - Compressor and air conditioner

Info

Publication number: CN114069902B
Application number: CN202111288808.0A
Authority: CN
Inventors: 张辉; 周博; 陈福; 李晓东
Original assignee: Gree Green Refrigeration Technology Center Co Ltd of Zhuhai
Current assignee: Gree Green Refrigeration Technology Center Co Ltd of Zhuhai
Priority date: 2021-11-02
Filing date: 2021-11-02
Publication date: 2023-02-28
Anticipated expiration: 2041-11-02
Also published as: CN114069902A

Abstract

The invention provides a compressor and an air conditioner, wherein the compressor comprises a motor assembly, the motor assembly comprises a rotor core and a stator core sleeved on the outer circumference side of the rotor core, the stator core is provided with six stator teeth with the same structure, a stator groove is formed between every two adjacent stator teeth, eight magnetic poles are formed on the rotor core in a structure mode, and the eight magnetic poles are uniformly arranged at intervals along the circumferential direction of the rotor core. According to the invention, the stator core is provided with six stator slots, compared with a nine-stator-slot structure in the prior art, the whole slot area of the stator core is larger, and the stator core is provided with eight rotor magnetic poles, and compared with a six-magnetic-pole structure in the prior art, the running current can be further reduced, so that the copper loss of the motor at low frequency is greatly reduced, the iron loss is slightly increased, and the total loss is greatly reduced, thereby greatly improving the motor efficiency of the motor at low frequency and the whole energy efficiency of the compressor.

Description

Compressor and air conditioner

Technical Field

The invention belongs to the technical field of air conditioning, and particularly relates to a compressor and an air conditioner.

Background

The new national standard energy efficiency of the air conditioner is upgraded to require that the compressor has higher energy efficiency, and the working conditions influencing the energy efficiency of the air conditioner in the national standard are mainly concentrated on low frequency, so that the motor of the compressor is required to have higher efficiency at the low frequency. Promote compressor motor's low frequency efficiency, the key lies in reducing the copper loss under the low frequency operating mode, because the motor copper loss accounts for than big during the low frequency, has reduced the copper loss and has just reduced total loss, and compressor motor efficiency is just higher.

At present, a 9S6P (8 stator slot 6 rotor magnetic pole, also called 6 slot 8 pole) structure motor is a basic structure applied to the field of compressors, the structure optimization and development of the motor are basically saturated, and the copper loss is difficult to further reduce, so that the efficiency is improved. According to the motor principle, the effective way of reducing copper loss is to reduce the running current and the winding resistance, so that the running current can be effectively reduced by increasing the number of poles of the motor rotor according to a motor torque formula. The inventor finds that the motor winding is embedded in a stator slot of the motor, the whole slot area of the motor is increased, and the resistance of the motor winding can be reduced.

Disclosure of Invention

Therefore, the invention provides a compressor and an air conditioner, which can overcome the defect that the efficiency of a motor component is low when the motor component operates at low frequency due to large winding resistance, namely large copper consumption, caused by small slot area of a motor stator with a 9S6P structure in the compressor in the prior art.

In order to solve the above problems, the present invention provides a compressor, including a motor assembly, where the motor assembly includes a rotor core and a stator core sleeved on an outer circumference side of the rotor core, the stator core has six stator teeth with the same structure, a stator slot is formed between two adjacent stator teeth, eight magnetic poles are formed on the rotor core, and the eight magnetic poles are uniformly spaced along a circumferential direction of the rotor core.

In some embodiments, the stator core further has a yoke ring, the stator teeth include tooth bodies connected to the yoke ring and tooth shoes at free ends of the tooth bodies, and two points of the tooth shoes which are farthest from each other in the circumferential direction respectively form an included angle de3 with a connecting line with the center of the rotor core, and the included angle de3 is greater than or equal to 45 degrees and less than or equal to 60 degrees.

In some embodiments, two magnetic steels symmetric along a d axis of the magnetic pole are arranged in the same magnetic pole, the two magnetic steels are in a bell mouth structure, a large mouth of the bell mouth faces the outer circumferential side of the rotor core, two points of the two magnetic steels which are farthest from the circumferential direction respectively form an included angle de1 with the center of the rotor core, two points of the two magnetic steels which are farthest from the circumferential direction respectively form a line with the center of the rotor core, an included angle de2 between two points of the side edges of the two circumferential sides of the tooth body which intersect with the tooth shoes respectively form a line with the center of the rotor core is de2, and de2 is not less than de1 and not more than de3.

In some embodiments, the radial width of the yoke ring is eb, the circumferential width of the stator teeth is bt, and bt/eb is 1.4 ≦ 1.7.

In some embodiments, there is a groove on the rotor core between two adjacent poles.

In some embodiments, the grooves have q-axis symmetry about two adjacent poles.

In some embodiments, the radial depth is greatest at a location where a trough bottom of the groove intersects the q-axis.

In some embodiments, the maximum radial depth of the groove bottom is D, the radial distance between the farthest point of the circumferential distance of the magnetic steel and the outer circumferential wall of the rotor core is h, a side line of the tooth shoe facing one side of the rotor core is provided with an arc line, an air gap formed between the arc line and the outer circumferential wall of the rotor core has a first radial width wa, and wa/2 is greater than or equal to D and less than or equal to h.

In some embodiments, the arc has two V-shaped structures symmetrical about a radial symmetry line of the stator tooth, the V-shaped structures include a first straight line segment and a second straight line segment which are connected, and an opening of the V-shaped structures faces one side of the rotor core.

In some embodiments, an air gap formed between the V-shaped structure and the outer circumferential wall of the rotor core has a second radial width Wb, wb ≦ 1.2Wa; and/or, in the case that the radial symmetry line of the stator tooth coincides with the d-axis of the pole, the V-shaped structure is located on the arc line between the q-axis of the corresponding pole and the extension line of the side edge of the tooth body close to the q-axis.

In some embodiments, a line connecting a sharp corner of the V-shaped structure and the center of the rotor core is a first straight line, and an angle between a q-axis in the groove adjacent to the first straight line and the first straight line is not more than 12 °.

In some embodiments, the rotor core is configured with a magnetic steel slot, the magnetic steel slot adjacent to the groove and the groove forming an elongated channel therebetween; and/or the circumferential width of the tooth shoe is larger than the circumferential width between radial symmetry lines of two grooves on two sides of the same magnetic pole respectively.

In some embodiments, the channels are uniform width channels; and/or, in the case that the radial symmetry line of the stator tooth coincides with the d-axis of the pole, the channel is located in the region between the q-axis of the corresponding pole and the extension line of the side edge of the tooth body close to the q-axis.

The invention also provides an air conditioner comprising a compressor as claimed above.

According to the compressor and the air conditioner, the stator core is provided with six stator slots, compared with a structure with nine stator slots in the prior art, the whole slot area of the stator core is larger, the eight rotor magnetic poles are arranged at the same time, and compared with the structure with six magnetic poles in the prior art, the running current can be further reduced, so that the copper loss of the motor at low frequency is greatly reduced, the iron loss is slightly increased, the total loss is greatly reduced, and the motor efficiency of the motor at low frequency and the whole energy efficiency of the compressor are greatly improved.

Drawings

Fig. 1 is a schematic structural view (a shaft sectional view of a stator and a rotor) of a motor assembly in a compressor according to an embodiment of the present invention;

FIG. 2 is a schematic view of the fit between portions of the stator core and rotor core of FIG. 1;

FIG. 3 is a schematic illustration of the fit between a portion of the stator core and a portion of the rotor core of FIG. 1;

fig. 4 is a partially enlarged schematic view of another embodiment of the motor assembly of fig. 1.

The reference numerals are represented as:

1. a rotor core; 11. a groove; 12. a magnetic steel groove; 2. a stator core; 21. stator teeth; 211. a tooth body; 212. a tooth boot; 213. an arc; 214. a first straight line segment; 215. a second straight line segment; 22. a stator slot; 23. a yoke ring; 3. and (5) magnetic steel.

Detailed Description

Referring to fig. 1 to 4 in combination, according to an embodiment of the present invention, there is provided a compressor, including a motor assembly, where the motor assembly includes a rotor core 1 and a stator core 2 sleeved on an outer circumference side of the rotor core 1, the stator core 2 has six stator teeth 21 with the same structure, a stator slot 22 is formed between two adjacent stator teeth 21, eight magnetic poles are configured on the rotor core 1, and the eight magnetic poles are uniformly spaced along a circumferential direction of the rotor core 1. This technical scheme, stator core 2 has six stator slots 22, for the structure of nine stator slots among the prior art, stator core 2 holistic groove area is bigger, eight rotor magnetic poles have simultaneously, for the structure of six magnetic poles among the prior art, the operating current can further be reduced, make the copper loss greatly reduced of motor when the low frequency, the iron loss increases slightly, total loss greatly reduced, thereby the motor efficiency of motor when the low frequency and the whole energy efficiency of compressor are improved to very big range.

In some embodiments, the stator core 2 further has a yoke ring 23, the stator teeth 21 include a tooth body 211 connected to the yoke ring 23 and tooth shoes 212 at free ends of the tooth body 211, two points of the tooth shoes 212 that are farthest from the circumferential direction respectively form an included angle de3 with a line connecting the center of the rotor core 1, and an included angle de3 is greater than or equal to 45 ° and less than or equal to 60 °, in this technical solution, the width of the tooth shoes is defined, and the stator space angle occupied by the tooth shoes is also defined, so that torque pulsation can be further adjusted. Furthermore, two magnetic steels 3 which are symmetrical along a d axis and are arranged in the same magnetic pole are arranged, the two magnetic steels 3 are in a bell mouth structure, a large mouth of the bell mouth faces the outer circumferential side of the rotor core 1, two points of the two magnetic steels 3 which are farthest in the circumferential direction form an included angle de1 between connecting lines with the center of the rotor core 1, two points of the two side edges of the tooth body 211 which are intersected with the tooth shoes 212 form an included angle de2 between connecting lines with the center of the

rotor core

1, and 2 × de2 is not less than de1 and not more than de3. The air gap field of the motor is the key for energy conversion of the motor, and in order to pursue higher motor performance, the air gap field is required to present a sinusoidal distribution characteristic under each tooth shoe along an air gap, so that the magnetic steel 3 generating the source of the magnetic field can specifically determine the sinusoidal characteristic of air gap flux density for the spatial distribution of the permanent magnet in the rotor and the relative stator teeth 21, the air gap field near the position where the center of the teeth is opposite to is strongest, and gradually decreases towards two sides, and when the relationship is satisfied: when de1 is more than or equal to 2 x de2 and less than or equal to de3, and de3 is more than or equal to 45deg and less than or equal to 60deg, the magnetic field of the magnetic steel can be fully and effectively utilized, so that the air gap magnetic field has good sinusoidal distribution characteristics.

The radial width of the yoke ring 23 is eb, the circumferential width of the stator teeth 21 is bt, and bt/eb is more than or equal to 1.4 and less than or equal to 1.7. Generally, the tooth width (that is, the circumferential width) and the yoke width (that is, the radial width) of a motor determine the magnetic density of the motor, and further determine the iron loss of the motor, in order to reduce the iron loss, the tooth width and the yoke width have a relatively high figure of merit, and simultaneously, the tooth width and the yoke width determine the space of a motor slot, which affects the copper loss of the motor, theoretically, the copper loss and the iron loss can be considered, so that the efficiency of the motor is optimal, in order to pursue higher efficiency, the tooth width bt and the yoke width eb, which are key variables for determining the iron loss and the copper loss of the motor, satisfy that bt/eb is more than or equal to 1.4 and less than or equal to 1.7, the difference between the copper loss and the iron loss of the motor at a low-frequency operating point is within 8%, and the efficiency of the motor at a low frequency is greatly improved.

In some embodiments, there is a groove 11 on the rotor core 1 between two adjacent magnetic poles, and preferably, the groove 11 has q-axis symmetry with respect to two adjacent magnetic poles, and it can be understood that the q-axis is a radial symmetry line of the groove 11. In some embodiments, the radial depth is greatest at the location where the groove bottom of the groove 11 intersects the q-axis. The arrangement of the groove 11 enables the air gap flux density at the position to be reduced and enhances the sine of a magnetic field, and increases the magnetic resistance at the position to enable the cogging effect to be restrained when the tooth shoe rotates and reduce the torque ripple. The depth of the groove 11 is too large, which will affect the circulation path of the magnetic steel fields on both sides, and the value is too small, which has a limited influence on the magnetic fields, and thus the requirement is hard to be met, therefore, in some embodiments, the maximum radial depth of the groove bottom is D, the radial distance between the farthest circumferential distance point of the magnetic steel 3 and the outer circumferential wall of the rotor core 1 is h, the side line of the tooth shoe 212 facing one side of the rotor core 1 has an arc line 213, an air gap formed between the arc line 213 and the outer circumferential wall of the rotor core 1 has a first radial width wa, and wa/2 is not less than D and not more than h.

The six-slot eight-pole motor with the number of slots of the stator core being less than the number of poles has relatively large teeth, large torque pulsation and low-order exciting force, and is easy to vibrate greatly. It is therefore necessary to take measures to reduce the above two effects. Unlike the conventional improved rotor structure, the present invention improves the characteristics of the motor by improving the tooth shoes that most affect the torque ripple and vibration of the motor.

In some embodiments, the arc line 213 has two V-shaped structures symmetrical about a radial symmetry line of the stator teeth 21, the V-shaped structure includes a first straight line segment 214 and a second straight line segment 215 connected to each other, and an opening of the V-shaped structure faces one side of the rotor core 1, that is, when an edge line of the tooth shoe 212 facing the rotor side is formed by an arc and a straight line, the arc is located at a position to form a stator inner diameter, an air gap formed by the edge line of the straight line segment and a rotor outer diameter is larger than an air gap formed by the arc line and the rotor outer diameter, and the air gap of the straight line segment is larger than the air gap of the arc line segment, so that energy fluctuation of the air gap of the straight line segment can be reduced, cogging torque can be effectively reduced, the thickness of the tooth shoe of the straight line segment, that is too small, tends to cause magnetic field distribution therein to be too concentrated, resulting in iron loss, so that a maximum air gap length formed in a region of the straight line segment of the stator tooth shoe is not more than 1.2 times the length of the corresponding arc, and an air gap formed between the V-shaped structure and the outer circumferential wall of the rotor core 1 has a second radial width Wb ≤ 2. In some embodiments, in the case where the radial symmetry line of the stator tooth 21 coincides with the d-axis of the pole, the V-shaped structure is on the arc line 213 between the q-axis of the corresponding pole and the line extending from the side of the tooth body 211 close to the q-axis.

The arrangement of the straight segment of the tooth shoe increases the length (i.e. radial width) of the air gap to some extent, and theoretically tends to reduce the efficiency of the motor, and on the basis of this, in order not to reduce the efficiency of the motor too much, the straight segment cannot affect the maximum distribution of the magnetic field near the center of the tooth, and the position of the straight segment is limited, specifically, in some embodiments, the connection line between the sharp corner of the V-shaped structure and the center of the rotor core 1 is a first straight line, and the included angle between the q-axis in the groove 11 adjacent to the first straight line and the first straight line is not more than 12 °. It will be appreciated that the circular arc is smoothly connected to the straight line segment.

In some embodiments, a magnetic steel slot 12 is configured on the rotor core 1, a channel is formed between the magnetic steel slot 12 and the groove 11 adjacent to the groove 11, and in order to further reduce torque ripple, specifically, as shown in fig. 4, the channel is composed of a circumferential channel between the magnetic steel slot 12 and the outer circumferential wall of the rotor core 1 and a radial channel communication between the magnetic steel slot 12 and the groove 11, a thickness of the circumferential channel is not greater than a thickness of the radial channel and a thickness of the radial channel is not greater than a radial width of a stator air gap (before shape modification), a sum of the length of the circumferential channel and the length of the radial channel is greater than three times of the thickness of the circumferential channel, so as to form a long and narrow channel, which has a small width, and easily saturates a magnetic field passing through the channel, thereby limiting the magnetic field passing through the channel, reducing magnetic leakage, and improving magnetic field utilization.

The channels are equal-width channels, so that the process difficulty can be reduced; and/or, under the condition that the radial symmetry line of stator tooth 21 with the d axle coincidence of magnetic pole, the passageway is in corresponding the q axle of magnetic pole with tooth body 211 is close to in the region between the extension line of q axle one side, can avoid influencing the circulation of rotor main magnetic path for reaching the magnetism isolating effect, compromise magnetic leakage and the effective magnetic flux of permanent magnet.

The width of the tooth shoe is larger than that of the tooth body, the motor winding is embedded in the groove, the tooth shoe forms a part of the groove, the winding is bound, the tooth shoe is too small, the binding effect is poor, the width of the tooth shoe cannot be too small, meanwhile, the width of the tooth shoe influences the torque pulsation of the motor, the tooth shoe is wider, the torque pulsation is smaller, and therefore in order to meet the requirements, the circumferential width of the tooth shoe 212 is larger than the circumferential width between radial symmetrical lines of two grooves 11 on two sides of the same magnetic pole respectively.

The invention provides a six-slot motor with tooth width and tooth shoes and rotor poles meeting a certain relation, which can effectively utilize the magnetic field of a permanent magnet, make the air gap magnetic field distributed in a sine mode, reduce the cogging effect, reduce the harmonic magnetic field, improve the motor efficiency, and avoid the problems of low efficiency caused by the pursuit of high efficiency and the pursuit of improvement of the cogging effect in the prior art.

According to an embodiment of the present invention, there is also provided an air conditioner including the compressor as set forth in the claims.

It is readily understood by a person skilled in the art that the advantageous ways described above can be freely combined, superimposed without conflict.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention. The above is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the technical principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A compressor comprises a motor assembly, wherein the motor assembly comprises a rotor core (1) and a stator core (2) sleeved on the outer circumferential side of the rotor core (1), the compressor is characterized in that the stator core (2) is provided with six stator teeth (21) with the same structure, a stator slot (22) is formed between every two adjacent stator teeth (21), eight magnetic poles are formed on the rotor core (1) in a constructed mode, and the eight magnetic poles are uniformly arranged at intervals along the circumferential direction of the rotor core (1); the stator core (2) is further provided with a yoke ring (23), the stator teeth (21) comprise tooth bodies (211) connected with the yoke ring (23) and tooth shoes (212) located at free ends of the tooth bodies (211), and two points of the tooth shoes (212) which are farthest in circumferential distance form an included angle de3 between connecting lines with the center of the rotor core (1); the magnetic pole is internally provided with two magnetic steels (3) which are symmetrical along a d axis and are arranged in the magnetic pole, the two magnetic steels (3) are of a horn mouth structure, a large mouth of the horn mouth faces towards the outer circumferential side of the rotor core (1), two points with the farthest circumferential distance of the magnetic steels (3) respectively form an included angle between connecting lines with the center of the rotor core (1) to be de1, two points with the two sides of the tooth body (211) in the circumferential direction and two points with the crossed tooth shoes (212) respectively form an included angle between connecting lines with the center of the rotor core (1) to be de2, and 2 is less than or equal to de1 and less than or equal to de3.

2. The compressor of claim 1, wherein de3 is 45 ° ≦ de3 ≦ 60 °.

3. A compressor according to claim 2, characterized in that the radial width of the yoke ring (23) is eb, the circumferential width of the stator teeth (21) is bt,1.4 ≦ bt/eb ≦ 1.7.

4. Compressor according to claim 1, characterized in that there are grooves (11) on the rotor core (1) between two adjacent poles.

5. A compressor according to claim 4, characterized in that the grooves (11) have q-axis symmetry with respect to the pole between two adjacent poles.

6. A compressor according to claim 5, characterized in that the radial depth is greatest at the location where the groove bottom of the groove (11) intersects the q-axis.

7. The compressor of claim 6, wherein the maximum radial depth of the groove bottom is D, the radial distance between the farthest point of the circumferential distance of the magnetic steel (3) and the outer circumferential wall of the rotor core (1) is h, the edge of the side of the tooth shoe (212) facing the rotor core (1) has an arc line (213), and the air gap formed between the arc line (213) and the outer circumferential wall of the rotor core (1) has a first radial width wa, wa/2 ≦ D ≦ h.

8. The compressor of claim 7, wherein the arc (213) has two V-shaped structures symmetrical about a radial symmetry line of the stator teeth (21), the V-shaped structures comprise a first straight line segment (214) and a second straight line segment (215) which are connected, and an opening of the V-shaped structures faces one side of the rotor core (1).

9. The compressor of claim 8, wherein an air gap formed between the V-shaped structure and the outer circumferential wall of the rotor core (1) has a second radial width Wb ≦ 1.2Wa; and/or, in the case that the radial symmetry line of the stator tooth (21) coincides with the d-axis of the pole, the V-shaped structure is on the arc (213) between the q-axis of the corresponding pole and the extension of the side of the tooth body (211) close to the q-axis.

10. Compressor according to claim 9, characterized in that the line between the tip of the V-shaped structure and the center of the rotor core (1) is a first line, and that the q-axis in the groove (11) adjacent to the first line has an angle of not more than 12 ° with the first line.

11. A compressor according to claim 4, characterized in that the rotor core (1) is configured with a magnet steel slot (12), and a long and narrow channel is formed between the magnet steel slot (12) adjacent to the groove (11) and the groove (11); and/or the circumferential width of the tooth shoe (212) is larger than the circumferential width between radial symmetry lines of two grooves (11) on two sides of the same magnetic pole respectively.

12. The compressor of claim 11, wherein the channel is an equal width channel; and/or, in the case where the radial symmetry line of the stator tooth (21) coincides with the d-axis of the pole, the channel is in the region between the q-axis of the respective pole and the extension of the side of the tooth body (211) close to the q-axis.

13. An air conditioner characterized by comprising the compressor of any one of claims 1 to 12.