CN218760410U

CN218760410U - Scroll compressor and air conditioner

Info

Publication number: CN218760410U
Application number: CN202222782665.5U
Authority: CN
Inventors: 冯建伟; 覃凤莲; 康小丽; 刘双来
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2022-10-21
Filing date: 2022-10-21
Publication date: 2023-03-28
Anticipated expiration: 2032-10-21

Abstract

The utility model provides a scroll compressor and air conditioner belongs to the air conditioner field. The scroll compressor comprises a movable scroll and a fixed scroll which are arranged in a compressor shell, wherein the movable scroll and the fixed scroll are mutually meshed to form a compression chamber; the back pressure chamber is configured to provide back pressure to resist the overturning force applied to the movable scroll when the movable scroll rotates; the movable scroll is provided with a first channel and a second channel, and the first channel or the second channel can be selectively communicated with the back pressure chamber according to the running frequency of the compressor so as to adjust the back pressure of the back pressure chamber. The utility model provides a backpressure cavity can change the backpressure of backpressure cavity along with the operating frequency of compressor, can improve the compressor pump body high frequency phenomenon of toppling.

Description

Scroll compressor and air conditioner

Technical Field

The utility model belongs to the air conditioner field especially relates to a scroll compressor and air conditioner.

Background

Scroll compressors are widely used in air conditioning and heat pump systems due to their high efficiency, small size, and smooth operation. Generally, a scroll compressor is composed of a closed tube shell, a movable scroll, a fixed scroll, a frame, a crankshaft, an anti-rotation slip ring, a motor and an oil supply structure device.

The movable and static disc of the scroll compressor is eccentric in the operation process due to the crankshaft and the movable scroll disc, the overturning phenomenon of the movable scroll disc can occur, the clearance between the pump body and the upper bracket is increased due to the overturning, the leakage phenomenon of the pump body is caused, and therefore the cold quantity and the performance of the compressor are influenced

Meanwhile, the pump body overturns, so that the movable scroll plate can not stably run in the running process, and the noise value is increased. Therefore, the back of the movable scroll needs to be provided with axial force, the movable scroll is attached to the fixed scroll, and the phenomena of pump body leakage and unstable operation of the movable scroll are reduced.

The overturning moment of the scroll compressor is increased along with the increase of the frequency in the operation process, the back pressure of the existing pump body is communicated with the compression cavity through the middle pressure hole to supply the back pressure, the axial back pressure provided by the structure cannot be changed along with the frequency, so that the overturning phenomenon of the scroll compressor is further increased along with the increase of the operation frequency of the scroll compressor, and meanwhile, the leakage amount of the scroll compressor is increased.

In view of this, the present invention is provided.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model lies in overcoming the not enough of prior art, provides a scroll compressor and air conditioner.

In order to solve the above technical problem, in one aspect, an embodiment of the present invention provides a scroll compressor, including a movable scroll and a fixed scroll disposed in a compressor housing, where the movable scroll and the fixed scroll are engaged with each other to form a compression chamber;

the back pressure chamber is configured to provide back pressure to resist the overturning force applied to the movable scroll when the movable scroll rotates;

the movable scroll is provided with a first channel and a second channel, and the first channel or the second channel can be selected according to the running frequency of the compressor and is communicated with the back pressure chamber so as to guide different gas pressures at different positions in the compression chamber into the back pressure chamber and provide different back pressures for the movable scroll.

In the technical scheme, a first back pressure hole a close to the center of the movable scroll and a first back pressure hole b far away from the center of the movable scroll are formed in the first channel, the first back pressure hole a is communicated with the compression chamber, and the first back pressure hole b is intermittently communicated with the back pressure chamber in the period that the movable scroll revolves for one circle;

a second back pressure hole a close to the center of the movable scroll and a second back pressure hole b far away from the center of the movable scroll are formed in the second channel, the second back pressure hole a is communicated with the compression chamber, and the second back pressure hole b is intermittently communicated with the back pressure chamber in the period that the movable scroll revolves for one circle;

the second back pressure hole a is disposed close to the center of the orbiting scroll with respect to the first back pressure hole a.

In the above technical solution, the movable scroll is provided with an on-off assembly, and the on-off assembly is configured to change an on-off state of the first channel and an on-off state of the second channel according to an operating frequency of the compressor so as to communicate the back pressure chamber with the first channel or communicate with the second channel.

In the above technical solution, the on-off assembly includes a first on-off portion and a second on-off portion that are linked with each other;

the first on-off part is configured to change the on-off state of the first channel according to the running frequency of the compressor, and the second on-off part is configured to change the on-off state of the second channel according to the running frequency of the compressor;

when the compressor runs at different frequencies, the first channel and the second channel always keep one of the channels in a communicated state under the action of the first on-off part and the second on-off part.

In the above technical solution, when the compressor operates at a low frequency, the first on-off part and the second on-off part which are linked with each other are configured to communicate the first passage and close the second passage;

when the compressor operates at high frequency, the first on-off part and the second on-off part which are linked are configured to close the first channel and communicate with each other.

In the above technical solution, the first on-off part and the second on-off part are rotatably disposed on the movable scroll;

when the compressor runs, the first on-off part and the second on-off part can rotate relative to the movable scroll according to the running frequency of the compressor so as to change the on-off state of the first channel and the on-off state of the second channel.

In the above technical solution, the first opening/closing portion and the second opening/closing portion rotate relative to the orbiting scroll under the action of centrifugal force, and when the compressor operates, the centrifugal force applied to the first opening/closing portion is greater than the centrifugal force applied to the second opening/closing portion;

the on-off component also comprises a spring arranged in the second channel, and the spring is connected with the first on-off part so that the first channel is in a closed state and the second channel is in an open state when the compressor runs at low frequency.

In the above technical solution, the first opening/closing portion includes a first channel pin slidably disposed along the first channel and a first guide bar rotatably disposed with the first channel pin;

the second cut-off part comprises a second channel pin arranged along the second channel in a sliding way and a second guide rod arranged with the second channel pin in a rotating way;

the first guide rod and the second guide rod are telescopic rods;

the on-off component further comprises a rotary disc which is rotatably arranged on the movable scroll disc, and the first guide rod and the second guide rod are connected with the rotary disc to enable the first on-off part and the second on-off part to be linked.

In the above technical solution, the density of the first channel pins is smaller than the density of the second channel pins.

In the above technical solution, the length of the first guide bar is smaller than the length of the second guide bar.

In the above technical solution, the movable scroll includes an upper portion and a lower portion, which are tightly combined, the upper portion of the movable scroll is configured to be connected to the crankshaft, and the lower portion of the movable scroll is configured to be connected to the fixed scroll;

the first channel, the second channel and the on-off assembly are arranged on the lower portion of the movable scroll plate.

On the other hand, the embodiment of the present invention further provides an air conditioner, which includes the above-mentioned scroll compressor.

After the technical scheme is adopted, compared with the prior art, the utility model following beneficial effect has:

1. the utility model discloses in through setting up two backpressure passageways, and two backpressure passageways can be according to the running frequency of compressor can be selected with the backpressure cavity intercommunication, can make the pump body open different backpressure passageways under different frequencies, make the back pressure of the pump body change along with the frequency variation of compressor then, improve the phenomenon that the pump body high frequency topples.

2. The utility model provides a backpressure cavity can increase the back pressure along with the operating frequency of compressor increases, makes quiet vortex dish laminating nature more excellent to reduce its high-frequency leakage volume, increase compressor refrigerating output and performance.

3. The utility model provides a backpressure cavity can increase the back pressure along with the operating frequency of compressor increases, makes the vortex dish operation more stable to reduce its high frequency noise total value, increase pump body reliability.

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention, are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention without undue limitation. It is obvious that the drawings in the following description are only some embodiments, and that for a person skilled in the art, other drawings can be derived from them without inventive effort. In the drawings:

FIG. 1 is a sectional view of a scroll compressor according to an embodiment of the present invention;

FIG. 2 is a schematic three-dimensional structure of the orbiting scroll in the embodiment of FIG. 1;

FIG. 3 is a schematic diagram of the exploded structure of the orbiting scroll in the embodiment of FIG. 2;

FIG. 4 is a schematic top view of the lower portion of the orbiting scroll of the embodiment of FIG. 3, illustrating the orbiting scroll at low frequency operation;

FIG. 5 is a top view of the lower portion of the orbiting scroll of the embodiment of FIG. 3, showing one configuration of the orbiting scroll at high frequency operation;

FIG. 6 is a schematic top view of the lower portion of the orbiting scroll of the embodiment of FIG. 3, showing another schematic configuration of the orbiting scroll at high frequency operation;

in FIGS. 1-6: 1-compressor housing, 2-orbiting scroll, 2 a-orbiting scroll upper part, 2 b-orbiting scroll lower part, 21-first channel, 211-first back pressure hole a, 212-first back pressure hole b, 22-second channel, 221-second back pressure hole a, 222-second back pressure hole b, first 23-on-off assembly, 231-first on-off part, 2311-first channel pin, 2312-first guide bar, 232-second on-off part, 2321-second channel pin, 2322-second guide bar, 3-fixed scroll, 4-compression chamber, 5-upper bracket, 6-back pressure chamber, 7-crankshaft.

It should be noted that the drawings and the description are not intended to limit the scope of the inventive concept in any way, but rather to illustrate the inventive concept by those skilled in the art with reference to specific embodiments.

Detailed Description

In the description of the present invention, it should be noted that the terms "inside", "outside", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted", "connected", "contacting" and "communicating" are to be interpreted broadly, e.g. as either a fixed connection, a detachable connection, or an integral connection; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The overturning moment of the existing scroll compressor is increased along with the increase of the frequency in the operation process, the backpressure of the existing pump body is supplied with backpressure through a medium-pressure hole communicated with a compression cavity, the axial backpressure provided by the structure cannot be changed along with the frequency, the overturning phenomenon of the existing scroll compressor is further increased along with the increase of the operation frequency of the existing scroll compressor, and meanwhile, the leakage amount of the existing scroll compressor is increased. The utility model discloses in through setting up two backpressure passageways, and two backpressure passageways can be according to the running frequency of compressor can be selected with the backpressure cavity intercommunication to make the pump body open different backpressure passageways under different frequencies, make pump body backpressure change along with compressor frequency variation then, improve pump body high frequency phenomenon of toppling.

To further illustrate the technical solution of the present invention, the following specific examples are provided with reference to fig. 1 to 6.

Example 1

Before introducing the embodiment of the present invention, the operation principle of the scroll compressor in the prior art is simply explained: the scroll compressor drives the movable scroll plate to rotate through crankshaft rotation and is meshed with the fixed scroll plate, so that gas compression is carried out, the movable scroll plate can generate an overturning phenomenon in the operation process due to the fact that the center of gravity of the movable scroll plate is not located at the center, the overturning can cause the movable scroll plate to be unstable in operation and generate leakage at the same time, and noise, reliability and performance of the compressor are affected. For solving a series of problems that the driving disk topples and leads to, current scroll compressor adopts the mode that the driving disk set up the middling pressure hole, with the pump body compression chamber in pressure guide movable disk back, the mode that provides pump body backpressure alleviates the phenomenon that moves the vortex dish and topple, nevertheless because it increases along with compressor running frequency to move the vortex dish power of toppling, current structure can't change according to compressor frequency and adjust pump body backpressure size.

In order to solve the above problem, an embodiment of the present invention provides a scroll compressor as shown in fig. 1, which includes a movable scroll 2 and a fixed scroll 3 disposed in a compressor housing 1, wherein the movable scroll 2 and the fixed scroll 3 are engaged with each other to form a compression chamber 4; the compressor further comprises an upper bracket 5 arranged in the compressor shell 1 and used for supporting the movable scroll 2, a back pressure chamber 6 is formed between the upper bracket 5 and the movable scroll 2, the back pressure chamber 6 is configured to provide back pressure to resist the overturning force applied when the movable scroll 2 rotates, a first channel 21 and a second channel 22 are formed on the movable scroll 2, and the first channel 21 or the second channel 22 can be selected to be communicated with the back pressure chamber 6 according to the running frequency of the compressor so as to guide different gas pressures at different positions in the compression chamber 4 to the back pressure chamber 6 to provide different back pressure to the movable scroll 2.

The utility model discloses in through setting up two back pressure passageways, and two back pressure passageways can be according to the running frequency of compressor can be selected with back pressure cavity 6 intercommunication to make the pump body open different back pressure passageways under different frequencies, thereby introduce back pressure cavity 6 with the different pressure of compression cavity 4 different angles, finally provide not equidimension back pressure, make the pump body back pressure change along with compressor frequency change then, improve the phenomenon that the pump body high frequency topples.

As shown in fig. 3, the first channel 21 is provided with a first back pressure hole a211 close to the center of the movable scroll 2 and a first back pressure hole b212 far from the center of the movable scroll 2, the first back pressure hole a211 is communicated with the compression chamber 4, and the first back pressure hole b212 is intermittently communicated with the back pressure chamber 6 during the period that the movable scroll 2 rotates for one circle;

the second channel 22 is provided with a second back pressure hole a221 close to the center of the movable scroll 2 and a second back pressure hole b222 far away from the center of the movable scroll 2, the second back pressure hole a221 is communicated with the compression chamber 4, and the second back pressure hole b222 is intermittently communicated with the back pressure chamber 6 during the period that the movable scroll 2 rotates for one circle;

wherein the pressure of the compression chamber 4 led out from the first passage 21 is greater than the pressure of the compression chamber 4 led out from the second passage 22.

Specifically, the second back pressure hole a221 is provided near the center of the orbiting scroll 2 with respect to the first back pressure hole a 211. Since the second back pressure hole a221 is disposed closer to the center of the orbiting scroll 2 than the first back pressure hole a211, the pressure of the gas discharged from the second back pressure hole a221 is greater than the pressure of the gas discharged from the first back pressure hole a 211. Therefore, when the compressor is operated at a high frequency, in order to resist a large overturning force generated by the orbiting scroll 2 at the high frequency operation, the compressed gas in the compression chamber 4 may be discharged from the second back pressure hole a211 to resist the large overturning force received by the orbiting scroll 2. When the compressor operates at low frequency, the overturning force generated by the movable scroll 2 is small, so that the overturning force applied to the movable scroll 2 can be resisted only by discharging the compressed gas in the compression chamber 4 from the first back pressure hole a 211.

And the embodiment of the utility model provides an on moving vortex dish 2 so with two backpressure passageways according to foretell setting mode (being about to relative first backpressure hole a211 in second backpressure hole a221 and being close to in moving vortex dish 2's center setting) can guarantee that the compressor is corresponding when the different frequency moves and opens different backpressure holes (first backpressure hole a211 and second backpressure hole a 221) to the work efficiency of compressor still can not be influenced in the even running of compressor has been guaranteed.

As shown in fig. 3, when the compressor is operated at a low frequency, the first passage 21 is in a communication state, and the second passage 22 is in a closed state, at this time, the compressed gas in the compression chamber 4 can be guided to the back pressure chamber 6 through the first back pressure hole a211, the first passage 21 and the first back pressure hole b212 in sequence, (the high-pressure compressed gas at the center of the compression chamber 4 is not discharged, and thus the working efficiency of the compressor is not affected), so as to resist the overturning force to which the movable scroll 2 is subjected at the low frequency operation, thereby reducing the overturning degree of the movable scroll 2.

As shown in fig. 4, when the compressor operates at high frequency, the first passage 21 is in a closed state, the second passage 22 is in a communicated state, and at this time, the compressed gas in the compression chamber 4 can sequentially pass through the second back pressure hole a221, the second passage 22 and the second back pressure hole b222 to be guided into the back pressure chamber 6, so as to provide a larger back pressure force into the back pressure chamber 6 to resist a larger overturning force suffered by the movable scroll 2 during high frequency operation, thereby reducing the overturning degree of the movable scroll 2, making the compressor operate at high frequency more stably, reducing the leakage amount of the compressor during high frequency operation, increasing the refrigerating capacity and performance of the compressor, and thus ensuring the performance, noise and reliability of the compressor.

The following is a detailed description of how the back pressure of the back pressure chamber 6 is adjusted:

as shown in fig. 2 to 5, an on-off assembly 23 is provided on the movable scroll 2, wherein the on-off assembly 23 is configured to change an on-off state of the first passage 21 and an on-off state of the second passage 22 according to an operating frequency of the compressor to communicate the back pressure chamber 6 with the first passage 21 or with the second passage 22.

Specifically, the on-off assembly 23 includes a first on-off portion 231 and a second on-off portion 232 which are linked with each other, wherein the first on-off portion 231 is configured to change the on-off state of the first channel 21 according to the operation frequency of the compressor, the second on-off portion 232 is configured to change the on-off state of the second channel 22 according to the operation frequency of the compressor, when the compressor operates at different frequencies, one of the channels can be always kept in the connected state by the first on-off portion 231 and the second on-off portion 232 of the first channel 21 and the second channel 22, and therefore smooth operation of the compressor can be ensured no matter the compressor operates at low frequency or high frequency.

More specifically, when the compressor is operated at a low frequency, the first opening/closing part 231 and the second opening/closing part 232 are coupled to each other such that the first passage 21 is connected and the second passage 22 is closed, that is, the first passage 21 is opened by the first opening/closing part 231 and the second passage 22 is closed by the second opening/closing part 232. The compressed gas (having a small pressure) discharged from the first passage 21 is discharged into the back pressure chamber 6 to resist the overturning force (having a relatively small overturning force) of the orbiting scroll 2.

When the compressor operates at a high frequency, the first opening/closing part 231 and the second opening/closing part 232 are interlocked and arranged such that the first passage 21 is closed and the second passage 22 is communicated, that is, the first passage is closed by the first opening/closing part 231 and the second passage 22 is opened by the second opening/closing part 232. The compressed gas (having a large pressure) discharged from the two back pressure passages 22 is discharged into the back pressure chamber 6 to resist the overturning force (relatively large overturning force) of the orbiting scroll 2.

Further, as shown in fig. 4 and 5, the first opening/closing portion 231 and the second opening/closing portion 232 are rotatably provided on the orbiting scroll 2, and when the compressor is operated, the first opening/closing portion 231 and the second opening/closing portion 232 may rotate relative to the orbiting scroll 2 according to an operation frequency of the compressor to change an opening/closing state of the first passage 21 and an opening/closing state of the second passage 22.

When the compressor operates, the first opening/closing portion 231 and the second opening/closing portion 232 rotate relative to the movable scroll 2 under the action of centrifugal force, and when the compressor operates, the centrifugal force applied to the first opening/closing portion 231 is greater than the centrifugal force applied to the second opening/closing portion 232, wherein the opening/closing assembly 23 further includes a spring 233 disposed in the second passage, and the spring 233 is connected to the first opening/closing portion 231 so that when the compressor operates at a low frequency, the spring 233 drives the first opening/closing portion 231 to return to enable the first passage 21 to be in a closed state and the second passage 22 to be in an open state.

Still further, as shown in fig. 3 to 5, the first opening/closing portion 231 includes a first passage pin 2311 slidably disposed along the first passage 21 and a first guide bar 2312 rotatably disposed with the first passage pin 2311, and in particular, the first guide bar 2312 is hinged to the first passage pin 2311.

The second cut-off portion 232 includes a second channel pin 2321 slidably disposed along the second channel 22 and a second guide bar 2322 rotatably disposed with the second channel pin 2321, and in particular, the second guide bar 2322 is hinged to the second channel pin 2321.

Wherein, the passage pins (the first passage pin 2311 and the second passage pin 2321) are cylindrical pin bodies with through holes in the middle, and the first guide bar 2312 and the second guide bar 2322 are telescopic rod-shaped bodies;

in addition, the opening/closing assembly 23 further includes a rotating plate 234 rotatably disposed on the movable scroll 2, and the first and

second guide rods

2312 and 2322 are fixedly connected to the rotating plate 234 to link the first and second opening/closing

parts

231 and 232.

When the compressor is operated, the first opening/closing portion 231 and the second opening/closing portion 232 of the orbiting scroll 2 are subjected to a centrifugal force and rotate relative to the orbiting scroll 2 with the turntable 234 as a rotation center, and since the centrifugal force applied to the first opening/closing portion 231 is greater than that applied to the second opening/closing portion 232, when the orbiting scroll 2 rotates, the first passage pin 2311 located in the first passage 21 generates a movement tendency toward the edge of the orbiting scroll 2.

Specifically, when the compressor is operated at a low frequency, the spring 233 located in the first passage 21 has a larger elastic force than the centrifugal force to which the first opening/closing part 231 is subjected, and therefore, the spring 233 is in an uncompressed state at this time, and the first opening/closing part 231 and the second opening/closing part 232 do not rotate with respect to the movable scroll 2. As shown in fig. 4, at this time, the first passage pin 2311 of the first opening/closing portion 231 does not block the first back pressure hole b, and the second passage pin 2321 of the second opening/closing portion 232 blocks the second back pressure hole b222, so that the first passage 21 is in a communicating state and the second passage 22 is in a closed state.

When the compressor is operated at a high frequency, at this time, the elastic force of the spring 233 is smaller than the centrifugal force applied to the first opening/closing part 231, the spring 233 is compressed, the first passage pin 2311 of the first opening/closing part 231 moves along the opening path of the first passage 21 toward the edge of the movable scroll 2, the first guide bar 2312 of the first opening/closing part 231 rotates, the second guide bar 2322 of the second opening/closing part 232 linked with the first opening/closing part 231 also rotates accordingly, the second passage pin 2321 of the second guide bar 2322 rotates and moves along the opening path of the second back pressure path 22 toward the center of the movable scroll 2, at this time, the first passage pin 2311 of the first opening/closing part 231 blocks the first back pressure hole b212, and the second passage pin 2321 of the second opening/closing part 232 does not block the second hole b222, so that the first passage 21 is closed and the second passage 22 is in a connected state. Since the second back pressure hole b222 is disposed closer to the center of the orbiting scroll 2, the second back pressure hole b222 is located where the pressure of the compression chamber 4 is greater, and when the second passage 22 is communicated, a greater back pressure can be provided to the back pressure chamber 6 at the back of the orbiting scroll 2 to resist a greater tilting phenomenon of the orbiting scroll 2 with increasing frequency.

As described above, the centrifugal force applied to the first opening/closing part 231 during the operation of the compressor is greater than the centrifugal force applied to the second opening/closing part 232 during the operation of the compressor. Specifically, the reason why the centrifugal force of the first opening/closing part 231 is greater than the centrifugal force of the second opening/closing part 232 is because the density of the first passage pins 2311 in the first opening/closing part 231 is less than the density of the second passage pins 2321 in the second opening/closing part 232, so that the centrifugal force of the first opening/closing part 231 is greater than the centrifugal force of the second opening/closing part 232.

It should be noted that, in some alternative embodiments, as shown in fig. 6, the length of the first guide rod 2312 in the first opening/closing part 231 may be set to be smaller than the length of the second guide rod 2322 in the second opening/closing part 232, and the centrifugal force applied to the first opening/closing part 231 may also be greater than the centrifugal force applied to the second opening/closing part 232 during the operation of the compressor.

It should be further noted that the above-mentioned orbiting scroll 2 is composed of two parts, and includes an upper orbiting scroll part 2a and a lower orbiting scroll part 2b which are tightly combined, the upper orbiting scroll part 2a is configured to be connected to the crankshaft 7, the lower orbiting scroll part 2b is configured to be connected to the fixed scroll 3, and the first passage 21, the second passage 22 and the on-off assembly 23 are disposed on the lower orbiting scroll part 2b.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and although the present invention has been disclosed with reference to the preferred embodiment, it is not intended to limit the present invention, and any person skilled in the art can make some changes or modifications to equivalent embodiments without departing from the scope of the present invention, and any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention will still fall within the scope of the present invention.

Claims

1. A scroll compressor is characterized by comprising a movable scroll (2) and a fixed scroll (3) which are arranged in a compressor shell (1), wherein the movable scroll (2) and the fixed scroll (3) are meshed with each other to form a compression chamber (4);

the compressor further comprises an upper bracket (5) arranged in the compressor shell (1) and used for supporting the movable scroll (2), a back pressure chamber (6) is formed between the upper bracket (5) and the movable scroll (2), and the back pressure chamber (6) is configured to provide back pressure to resist the overturning force applied when the movable scroll (2) rotates;

the movable scroll (2) is provided with a first channel (21) and a second channel (22), and the first channel (21) or the second channel (22) can be selectively communicated with the back pressure chamber (6) according to the running frequency of the compressor so as to guide different gas pressures at different positions in the compression chamber (4) to the back pressure chamber (6) to provide different back pressures for the movable scroll (2).

2. The scroll compressor according to claim 1, wherein the first passage (21) is opened with a first back pressure hole a (211) near a central position of the orbiting scroll (2) and a first back pressure hole b (212) far from the central position of the orbiting scroll (2), the first back pressure hole a (211) communicates with the compression chamber (4), and the first back pressure hole b (212) intermittently communicates with the back pressure chamber (6) during one revolution of the orbiting scroll (2);

a second back pressure hole a (221) close to the center of the movable scroll (2) and a second back pressure hole b (222) far away from the center of the movable scroll (2) are formed in the second channel (22), the second back pressure hole a (221) is communicated with the compression chamber (4), and the second back pressure hole b (222) is intermittently communicated with the back pressure chamber (6) in the period that the movable scroll (2) rotates for one circle;

the second back pressure hole a (221) is disposed close to the center of the orbiting scroll (2) with respect to the first back pressure hole a (211).

3. The scroll compressor according to claim 2, wherein an on-off assembly (23) is provided on the orbiting scroll (2), the on-off assembly (23) being configured to change an on-off state of the first passage (21) and an on-off state of the second passage (22) according to an operating frequency of the compressor to communicate the back pressure chamber (6) with the first passage (21) or with the second passage (22).

4. The scroll compressor of claim 3, wherein the on-off assembly (23) includes a first on-off portion (231) and a second on-off portion (232) in linkage;

the first on-off part (231) is configured to change an on-off state of the first channel (21) according to an operating frequency of the compressor, and the second on-off part (232) is configured to change an on-off state of the second channel (22) according to an operating frequency of the compressor;

when the compressor runs at different frequencies, the first channel (21) and the second channel (22) are always kept in a communicated state under the action of the first on-off part (231) and the second on-off part (232).

5. The scroll compressor according to claim 4, wherein the first and second communicating portions (231, 232) are configured to communicate with each other and to close the first passage (21) and the second passage (22) when the compressor operates at a low frequency;

when the compressor operates at high frequency, the first opening and closing part (231) and the second opening and closing part (232) which are linked are configured to close the first channel (21) and communicate with the second channel (22).

6. The scroll compressor according to claim 5, wherein the first opening/closing portion (231) and the second opening/closing portion (232) are rotatably provided on the orbiting scroll (2);

when the compressor operates, the first opening and closing part (231) and the second opening and closing part (232) can rotate relative to the movable scroll (2) according to the operating frequency of the compressor so as to change the opening and closing states of the first channel (21) and the second channel (22).

7. The scroll compressor according to claim 6, wherein the first opening/closing portion (231) and the second opening/closing portion (232) are rotated relative to the movable scroll (2) by a centrifugal force, and the centrifugal force to which the first opening/closing portion (231) is subjected is larger than the centrifugal force to which the second opening/closing portion (232) is subjected when the compressor is operated;

the on-off component (23) further comprises a spring (233) arranged in the second channel, and the spring (233) is connected with the first on-off part (231) so that the first channel (21) is in a closed state and the second channel (22) is in an open state when the compressor operates at low frequency.

8. The scroll compressor according to claim 7, wherein the first opening/closing portion (231) includes a first passage pin (2311) slidably provided along the first passage (21) and a first guide bar (2312) rotatably provided with the first passage pin (2311);

the second cut-off part (232) comprises a second channel pin (2321) arranged along a second channel (22) in a sliding manner and a second guide rod (2322) arranged in a rotating manner with the second channel pin (2321);

the first guide bar (2312) and the second guide bar (2322) are telescopic bars;

the on-off component (23) further comprises a rotating disc (234) rotatably arranged on the movable scroll (2), and the first guide rod (2312) and the second guide rod (2322) are connected with the rotating disc (234) to enable the first on-off part (231) and the second on-off part (232) to be linked.

9. The scroll compressor according to claim 8, wherein a density of the first passage pin (2311) is less than a density of the second passage pin (2321).

10. The scroll compressor of claim 8, wherein a length of the first guide bar (2312) is less than a length of the second guide bar (2322).

11. The scroll compressor according to claim 1, wherein the orbiting scroll (2) includes an upper orbiting scroll part (2 a) and a lower orbiting scroll part (2 b) which are closely combined, the upper orbiting scroll part (2 a) being configured to be connected with a crankshaft (7), the lower orbiting scroll part (2 b) being configured to be connected with the fixed scroll (3);

the first channel (21), the second channel (22) and the on-off assembly (23) are arranged on the lower portion (2 b) of the movable scroll.

12. An air conditioner characterized by comprising the scroll compressor of any one of claims 1 to 11.