KR20060116355A - Modulation type multi-stage rotary compressor - Google Patents

Abstract

A multi-stage rotary compressor is provided to realize the variable capacity by realizing a power mode and a saving mode using a relatively low-priced constant speed motor. A multi-stage rotary compressor includes a casing(100), a drive unit(200), a plurality of compression units(300,400), and a guide unit(500). The casing forms a sealed space in the interior thereof. The drive unit is embedded in the casing to produce drive power. The compression units are connected to the drive unit and compresses refrigerant. The guide unit is connected to the compression units to selectively guide the refrigerant discharged from on of the compression units to another compression unit. The control unit allows the compression units to perform compression, guides the refrigerant discharged from the compression unit to another compression unit to be compressed again, or idles some of the compression units.

Description

Multi-stage rotary compressor {MODULATION TYPE MULTI-STAGE ROTARY COMPRESSOR}

1 is a cross-sectional view showing a multistage rotary compressor according to a first embodiment of the present invention;

2 is a cross-sectional view showing the flow of the refrigerant in the power mode of the multi-stage rotary compressor according to the first embodiment of the present invention,

3 is a cross-sectional view showing the flow of the refrigerant in the saving mode of the multi-stage rotary compressor according to the first embodiment of the present invention,

4 is a cross-sectional view showing the flow of the refrigerant in the idle mode of the multi-stage rotary compressor according to the first embodiment of the present invention,

5 is a cross-sectional view showing a multi-stage rotary compressor according to a second embodiment of the present invention.

* Description of the main parts of the drawings *

100: casing 200: drive unit

300: first compression unit 400: second compression unit

500: guide unit 510: second suction pipe

520: chamber 525: first control valve

530: first connection flow path 540: first suction pipe

545: second control valve 550: second branch flow path

555: third control valve 560: second connection passage

570: first quarter euro

The compressor receives power from a power generating device such as an electric motor and compresses the working gas to increase pressure by applying compression work to air, refrigerant, or other special gases, and is widely used throughout the industry. Compressors can be classified into volumetric and turbo type, depending on how the compression is achieved. Positive displacement compressors have a compression method that increases pressure through volume reduction, and a turbo compressor converts gas kinetic energy into pressure energy to achieve compression. Rotary compressors among volumetric compressors are mainly applied to air conditioners such as air conditioners, and in recent years, rotary compressors also require products that can vary in capacity in response to a trend of varying functions of air conditioners.

Rotary compressors have used CFC-based refrigerants until now. However, these refrigerants are regulated because they destroy the ozone layer and cause global warming, and research and development of alternative refrigerants instead of the existing refrigerants are actively performed. Carbon dioxide is expected as an alternative refrigerant. Moreover, the problem of global warming is not just a replacement for refrigerants, but also leads to a task of increasing the energy efficiency of equipment. This is because much of the electrical energy is still obtained using fossil fuels, because the carbon dioxide produced when burning fossil fuels is a major culprit of global warming. In the compressor, which is the heart of the refrigeration system, the natural concern of colostrum is how to apply alternative refrigerants harmless to the global environment to existing compressors without any loss of performance. There is a multi-stage rotary compressor having a plurality of compression units as a compressor that can vary in capacity and can use alternative refrigerants.

Conventional multi-stage rotary compressors each include a plurality of compression units for sucking, compressing and discharging refrigerant, and a driving unit for driving the compression unit in a sealed container. In the compression unit, a plurality of eccentric cams are integrally formed on a rotating shaft that is rotated by the drive unit, and a rolling piston is fitted to the outer circumferential surface of each eccentric cam. The rolling piston is located inside the cylinder and rolls in contact with the inner diameter of the cylinder. Inside the cylinder is divided into an intake chamber and a compression chamber by vanes in contact with the rolling piston. The drive unit is composed of a motor that rotates the rotating shaft and is housed in a closed container together with the compression unit. In such a conventional multistage rotary compressor, the rolling piston is sucked, compressed, and discharged continuously while one point of contact with the inner diameter of the cylinder is performed. If a lot of load is generated and you want to make a large capacity (hereinafter, power mode), each of the compression units is driven. At this time, the capacity of the compressor will be the sum of the refrigerant discharged by each compression unit. If you want to save power while reducing the load (Saving mode), use the inverter motor with the control drive as a drive unit to implement variable capacity of refrigerant through variable speed, or after retracting the vane It is fixed by a piece or the like to remove the compartments of the intake chamber and the compression chamber so that the rolling piston does not compress the refrigerant but idles.

The structure and operation method of such a conventional rotary compressor have the following problems.

First, the method of retracting the vane in the saving mode requires a space for mounting a separate part such as a piece, and increases the number of manufacturing processes.

Second, as the piece is repeatedly impacted on the vanes, the surface may be damaged as time passes, and reliability problems such as wear or foreign matters may be caused.

Third, when an inverter motor is used as the drive unit, it is generally expensive, resulting in an increase in manufacturing cost. Therefore, there is a need to realize variable capacity while using a constant speed motor having a relatively low cost.

The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a multi-stage rotary compressor that can implement a variety of capacity change by operating each compression unit independently.

In addition, in the power mode requiring a large capacity to provide a multi-stage rotary compressor that can maximize the compression capacity by using a plurality of compression units.

Multistage rotary compressor of the present invention for achieving the object of the present invention as described above and the casing having a sealed space therein; A driving unit embedded in the casing to produce a driving force; A plurality of compression units receiving a driving force from the drive unit to compress the refrigerant; A guide unit connecting the plurality of compression units to selectively guide the refrigerant discharged from the compression unit to another compression unit; And a control unit mounted to the guide unit to compress each of the plurality of compression units, or the refrigerant discharged from the compression unit is guided to the next compression unit to be recompressed, or idle some of the compression units.

Hereinafter, the multi-stage rotary compressor according to the present invention will be described in detail with reference to an embodiment shown in the accompanying drawings.

1 is a cross-sectional view showing a first embodiment of a multistage rotary compressor of the present invention.

As shown in the drawing, the multi-stage rotary compressor of the present invention includes a casing 100 having a sealed space therein, a driving unit 200 built into the casing 100 to produce a driving force, and the driving unit 200. ) Is connected to the first and second compression units (300, 400) for compressing the refrigerant and the first and second compression units (300, 400) to connect the refrigerant discharged from the first compression unit (300) for the second A guide unit 500 for selectively guiding the compression unit 400; The refrigerant mounted on the guide unit 500 to compress the first and second compression units 300 and 400, respectively, or the refrigerant discharged from the second compression unit 400 is guided to the first compression unit 300 and recompressed. Or a control unit for idling or partially idling the compression unit.

The casing 100 has a predetermined accommodation space therein, and the discharge pipe 110 and the first and second suction pipes 510 and 540 are installed therethrough.

The drive unit 200 is fixed to the inside of the casing 100 to apply power from the outside and the stator 210 is disposed while leaving a predetermined gap inside the stator 210 to rotate while interacting with the stator The rotor 220 and the rotor 220 are formed integrally to transmit a driving force to the compression unit (300, 400) and comprises a rotating shaft 230 having two eccentric parts.

The drive unit 200 is preferably composed of a constant speed motor. Constant speed motors generally have the advantage of being less expensive than inverter motors with control drives.

The compression unit is composed of a first compression unit 300 and the second compression unit 400, the first compression unit 300 is formed in an annular first cylinder 310 to be installed in the casing 100 ), An upper bearing 320 and an intermediate bearing 350 which radially support the rotating shaft 230 while forming the first inner space 330 together by covering both the upper and lower sides of the first cylinder 310, and the The first rolling piston 340 is inserted into the upper eccentric portion of the rotary shaft 230 to compress the refrigerant while turning in the first inner space 330 of the first cylinder 310, and the first rolling piston 340 A first vane configured to be movably coupled to the first cylinder 310 to be pressed against the outer circumferential surface so as to partition the first inner space 330 of the first cylinder 310 into a first suction chamber and a first compression chamber ( Not shown), and the opening and closing at the tip of the first discharge hole 360 formed to communicate with the first compression chamber in the upper bearing 320 The first discharge valve 370 may be configured to be coupled to control the discharge of the refrigerant discharged from the first compression chamber.

The second compression unit 400 is formed in an annular shape and is positioned below the first cylinder 310 and is in contact with the intermediate bearing 350 and on the upper surface of the second cylinder 410. A lower bearing 450 supporting the rotation shaft 230 in a radial direction and an axial direction while being coupled to form a second inner space 430, and rotatably coupled to a lower eccentric portion of the rotation shaft 230. Compression of the second rolling piston 440 located in the second inner space 430 of the second cylinder 410, and the radial direction to the second cylinder 410 to be in pressure contact with the outer peripheral surface of the second rolling piston 440 A second vane (not shown) which is movably coupled to each other and divides the second internal space 430 of the second cylinder 410 into a second suction chamber and a second compression chamber, and one side of the lower bearing 450. A second discharge coupled to the front end of a second discharge hole 460 formed to communicate with the second compression chamber Consists of a valve 470. As a variant of the invention, the second compression unit in which the refrigerant is first compressed may be formed, but a plurality of first compression units in which the refrigerant is recompressed may be formed.

The volume of the first internal space 330 of the first cylinder 310 and the volume of the second internal space 430 of the second cylinder 410 may be the same, but different from each other for more careful capacity change. It is preferable to form.

The guide unit 500 includes a first suction pipe 540 for guiding the refrigerant to the first compression unit 300, a second suction pipe 510 for guiding the refrigerant to the second compression unit 400, and the second suction pipe 510. A chamber 520 for temporarily storing the refrigerant discharged from the second compression unit 400 by covering the second discharge valve 470 of the compression unit 400, and the first compression unit 300 in the chamber 520. And a first connection passage 530 for guiding the refrigerant to the refrigerant passage, and a second connection passage 560 respectively connected to the first suction pipe and the second suction tube in the chamber 520.

The suction side of the first suction pipe 540 and the second suction pipe 510 is connected to the accumulator 130 for separating the gas liquid of the refrigerant.

The chamber 520 is installed in the lower portion of the second compression unit 400 (more precisely, the lower portion of the lower bearing 450) to maintain the airtightness so that the refrigerant does not leak, and to provide low noise during operation of the compressor. muffler) can also be used at the same time.

The first connection passage 530 extends in the radial direction of the first cylinder 310 by axially penetrating the lower bearing 450, the second cylinder 410, and the intermediate bearing 450 to form a first cylinder ( It is connected to the first internal space 330 of 310.

The first connection passage 530 may be formed inside the bearing and the cylinder as in the present embodiment, but may be configured by exposing a part of the first connection passage 530 to the outside of the compressor. For example, a pipe connected to the chamber 520 is partially exposed to the outside through the casing 100, and then radially penetrates the side surfaces of the casing 100 and the first cylinder 310 in the first cylinder ( It may be connected to the first internal space 330 of 310.

The second connection passage 560 is installed through the casing 100 to communicate with the chamber 620, the first suction tube 540, and the second suction tube 510, and the second connection passage 560 is provided. The first branch passage 570 is branched and connected to the first suction pipe 540, and the second branch passage 550 is connected to the second suction pipe 510.

The control unit is installed on the first suction pipe 540 and the first control valve 525 to regulate the flow of the refrigerant, and the second branch flow path 570 disposed on the second to regulate the flow of the refrigerant And a control valve 545 and a third control valve 555 disposed on the second branch passage 550 to control the flow of the refrigerant.

The first control valve 525 is preferably a check valve.

Preferably, the second and third control valves 545 are 2-way valves.

Referring to Figures 2, 3, 4 the effect of the multi-stage rotary compressor of the present invention as described above are as follows.

First, a case in which a power mode with a large amount of refrigerant is required will be described with reference to FIG. 2. The first control valve 525 is opened to allow suction refrigerant to flow into the first compression unit 300. At the same time, the second and third control valves 545 and 555 are closed to prevent the refrigerant from flowing into the first branch passage 570 and the second branch passage 550.

When the power is applied to the drive unit 200, the rotating shaft 230 rotates and the first rolling piston 340 and the second rolling piston 440 is pivoting in the inner space (330, 430) of each cylinder A volume is formed between the first vane (not shown) and the second vane (not shown) to suck the refrigerant. Some of the refrigerant via the accumulator 130 is sucked into the first compression unit 300 through the first suction pipe 540 and is compressed and discharged into the casing 100 through the first discharge hole 360. The remaining refrigerant via the accumulator 130 is sucked into the second compression unit 400 through the second suction pipe 510 and is compressed and discharged into the chamber 520 through the second discharge hole 460. The refrigerant discharged into the chamber 520 is discharged into the casing 100 through the first connection passage 530. The refrigerant discharged from the first compression unit 300 and the second compression unit 400, respectively, saturates the inside of the casing 100 and repeats the process of being discharged to the outside of the casing 100 through the discharge tube.

As described above, in the power mode, the first and second compression units are connected in parallel, respectively, are compressed and discharged, are combined in the casing 100, and then moved to the outside of the compressor through the discharge pipe. Compared with the discharge amount of the refrigerant.

Next, a saving mode with a smaller amount of refrigerant will be described with reference to FIG. 3.

By closing the first control valve 525 (off) to prevent the suction refrigerant passing through the accumulator 130 from entering the first compression unit 300, the second control valve 545 is controlled to control the first suction pipe ( 540 and the first branch flow path 570 are in communication. At this time, the third control valve 555 is closed to prevent the refrigerant from flowing into the second branch passage 550. The refrigerant passing through the accumulator 130 is sucked and compressed into the second compression unit 400 through the second suction pipe 730 and then discharged into the chamber 520 through the second discharge hole 460. The refrigerant temporarily stored in the chamber 520 is sucked into the first compression unit 300 through the first branch passage 570 and the first suction pipe 540 of the second connection passage 560 and is recompressed. The refrigerant is discharged into the casing 100 through the first discharge hole 360 and guided to the external refrigeration system through the discharge tube.

As such, in the saving mode, the refrigerant once compressed in the second compression unit 400 is moved back to the first compression unit 300 and recompressed. That is, since the compression units are connected in series and the refrigerant is discharged while passing through the second compression unit 400 and the first compression unit 300 sequentially, the discharge amount of the refrigerant is relatively small, but a high compression ratio can be obtained. In addition, in order to obtain an appropriate discharge pressure, a two-stage compression process is performed. Particularly, in the case of the first compression unit 300, the refrigerant compressed to some extent by the second compression unit 400 is sucked, so that the required power It costs less. In the saving mode, the sum of the required powers of the first and second compression units is smaller than in the power mode, thereby achieving a power saving effect.

In addition, the present invention has the effect of lowering the manufacturing cost because it is possible to realize the variable capacity by implementing the power mode and the saving mode by using a relatively low-cost constant speed motor without using an expensive inverter motor with a control unit.

Next, the idle mode with a small amount of refrigerant required will be described with reference to FIG. 4.

By opening the first control valve 525 (on), the suction refrigerant via the accumulator 130 flows into the first compression unit 300, and simultaneously closes the second control valve 545 (off) and the third The control valve 555 is opened to allow the second branch passage 550 to communicate with the chamber 520.

Some of the refrigerant via the accumulator 130 is sucked into the first compression unit 300 through the first suction pipe 540 and is compressed and discharged into the casing 100 through the first discharge hole 360. The remaining refrigerant via the accumulator 130 should be sucked into the second compression unit 400 through the second suction pipe 510 and compressed to be discharged into the chamber 520 through the second discharge hole 460. When the refrigerant having a suction pressure flows into the chamber 520 through the second branch passage. Therefore, the second discharge valve 470 is opened early so that the compression of the refrigerant does not occur in the second compression unit 400. That is, since the inside of the chamber 520 is made of suction pressure, the pressure difference between the second inner space 430 and the chamber 520 is not large, and thus the refrigerant that is not compressed through the second discharge valve 470 is discharged. Therefore, the second compression unit 400 is to be idle.

As described above, since the compression does not occur in the second compression unit 400 and the compression proceeds only in the first compression unit 300, the discharge amount of the compressed refrigerant is reduced.

That is, there is an effect that the discharge amount of the refrigerant can be changed while using only the constant speed motor without using an expensive inverter motor.

5 is a sectional view showing a second embodiment according to the present invention.

As shown in the drawing, the control unit includes a fourth control valve 580 installed at a point where the first branch passage 555 and the second branch passage 550 branch to control the flow of the refrigerant. It is preferred to be configured.

The fourth control valve 580 is preferably a three-way valve or a four-way valve.

The second embodiment is configured such that the fourth control valve 580 performs the flow of the refrigerant that was performed by the second and third control valves 545 and 555 in the first embodiment, and the power mode, the saving mode, and the idling mode. Since the flow of the refrigerant is the same as in the first embodiment, a detailed operation thereof will be omitted.

The present invention has the effect of varying the discharge amount of the refrigerant in a variety of modes, such as power mode, saving mode and idle mode according to the operating conditions of the compressor.

In addition, the present invention has the effect of lowering the production cost because the control unit is provided to implement the power mode and the saving mode by using a relatively low-cost constant speed motor without using an expensive inverter motor to realize the capacity change .

In the present invention, since the refrigerant once compressed is recompressed again, a high discharge pressure can be achieved, and the volumetric efficiency is improved. In addition, since the refrigerant once compressed is used during recompression, leakage into the casing, which is the discharge pressure, may be reduced, and the amount of heat transferred to the low temperature refrigerant at the suction side may be greatly reduced.

In addition, the present invention does not require a separate component and mounting space, compared to the method of retracting the vane in the saving mode, the manufacturing process is simple. In addition, since a piece for retreating and fixing the vane is not required, wear and foreign matters are not generated, thereby improving reliability.

In addition, since the plurality of compression units are used in the saving mode, the efficiency of the motor and the compressor is improved. In addition, since the refrigerant is compressed once again compared to the power mode, the required power is reduced, thereby saving power.

Claims (10)

A casing having a sealed space formed therein; A driving unit embedded in the casing to produce a driving force; A plurality of compression units connected to the drive unit to compress the refrigerant; A guide unit connecting the plurality of compression units to selectively guide the refrigerant discharged from the compression unit to another compression unit; And a control unit mounted to the guide unit so as to compress the plurality of compression units, respectively, or the refrigerant discharged from the compression unit is guided to the next compression unit to be recompressed, or idling some compression units. Multi-stage rotary compressor. The method of claim 1, The compression unit is composed of a first compression unit and a second compression unit, The guide unit includes a first suction pipe for guiding a refrigerant to the first compression unit; A second suction pipe for guiding a refrigerant to the second compression unit; A chamber for covering the discharge valve installed in the second compression unit to temporarily store the refrigerant discharged from the second compression unit; A first connection channel for guiding the refrigerant from the chamber to the first compression unit; And a second connection passage connected to the first suction pipe and the second suction pipe in the chamber, respectively. The method of claim 2, The second connection channel extends from the chamber, A first branch passage connected to the first suction pipe; And a second branch passage connected to the second suction pipe. The method of claim 3, wherein The control unit includes a first control valve installed on the first suction pipe to regulate the flow of the refrigerant; A second control valve disposed on the first branch passage to control a flow of the refrigerant; And a third control valve disposed on the second branch passage to control the flow of the refrigerant. The method of claim 4, wherein The first control valve is a multi-stage rotary compressor, characterized in that the check valve. The method of claim 4, wherein The second and third control valve is a multi-stage rotary compressor, characterized in that the two-way valve (2-way valve). The method of claim 3, wherein The control unit includes a first control valve installed on the first suction pipe to regulate the flow of the refrigerant; And a fourth control valve installed at a point at which the first branch channel and the second branch channel diverge to control the flow of the refrigerant. The method of claim 7, wherein The first control valve is a multi-stage rotary compressor, characterized in that the check valve. The method of claim 7, wherein The fourth control valve is a three-way valve (3-way valve) or a four-way valve (4-way valve), characterized in that the multi-stage rotary compressor. The method of claim 1, The drive unit is a multi-stage rotary compressor, characterized in that consisting of a constant speed motor.

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