WO2020026333A1

WO2020026333A1 - Screw compressor and refrigeration cycle device

Info

Publication number: WO2020026333A1
Application number: PCT/JP2018/028609
Authority: WO
Inventors: 直也光成; 優木庭
Original assignee: 三菱電機株式会社
Priority date: 2018-07-31
Filing date: 2018-07-31
Publication date: 2020-02-06

Abstract

This screw compressor is provided with: a screw rotor axially extending and including a screw groove in the outer peripheral surface; a pair of gate rotors which mesh with the screw groove of the screw rotor; and a pair of slide valves which are disposed at positions that are point-symmetric about the radial center of the screw rotor. A first compression chamber is formed which is closed by one of the pair of gate rotors and one of the pair of slide valves. A second compression chamber is formed which is closed by the other of the pair of gate rotors and the other of the pair of slide valves. The pair of slide valves are provided such that axial positions of ends of respective discharge ports connected to the first compression chamber and the second compression chamber are shifted from each other.

Description

Screw compressor and refrigeration cycle device

The present invention relates to a screw compressor and a refrigeration cycle device including a screw rotor, a pair of gate rotors, and a pair of slide valves.

シングル Single screw compressors are conventionally known as compressors for refrigeration and air conditioning. The single screw compressor includes a screw rotor having a plurality of spiral screw grooves formed on an outer peripheral surface. Further, the single screw compressor includes a gate rotor having a disk shape and having a plurality of teeth formed on an outer peripheral surface along a circumferential direction. The teeth of the gate rotor are meshed with the screw grooves. A space surrounded by the teeth of the gate rotor and the screw grooves is formed in the compression chamber.

In a single screw compressor, a screw rotor and a gate rotor are housed in a casing. In the casing, a low-pressure space into which the low-pressure fluid before compression flows is formed. When the screw rotor is driven to rotate by an electric motor or the like, the gate rotor rotates with the rotation of the screw rotor. Then, the teeth of the gate rotor relatively move from the start end of the suction side end of the spiral screw groove toward the end of the discharge side end.

(4) In the suction stroke in which the low-pressure fluid is sucked into the compression chamber formed by the spiral groove of the screw rotor, the low-pressure fluid flows into the compression chamber from the outer peripheral surface and the end surface of the screw rotor. Thereafter, the compression chamber is partitioned from the low-pressure space by the partition wall of the casing that covers the outer peripheral surface of the screw rotor and the gate rotor that has entered the spiral groove. In the compression stroke in which the fluid in the compression chamber is compressed, the volume of the compression chamber is reduced by relatively moving the gate rotor from the beginning to the end of the spiral groove, and the fluid in the compression chamber is compressed.

Here, a pair of compression chambers are formed at point-symmetric positions with respect to the radial center of the screw rotor. Therefore, there is a first compression chamber having one gate rotor as a component and a second compression chamber having the other gate rotor as a component. In addition, a pair of discharge ports from which the compressed fluid is discharged are formed at point-symmetric positions in the same manner as described above, and each discharge port communicates with each compression chamber.

がある In some single screw compressors, a slide valve is provided so as to form a part of a cylindrical wall of a casing or to serve as one end of a discharge port from which a refrigerant is discharged. The slide valve is a separate component that is movable in the axial direction of the screw rotor, and constitutes an internal volume ratio variable mechanism that varies the internal volume ratio by adjusting the timing of discharge from the compression chamber. . That is, a part of the discharge port is formed by the slide valve. Here, the internal volume ratio indicates the ratio of the volume of the compression chamber at the time of completion of suction, which is the start of compression, to the volume of the compression chamber immediately before discharge.

スライド In addition to the internal volume ratio variable mechanism, the slide valve can also be used as a capacity control mechanism capable of bypassing a part of the refrigerant sucked into the compression chamber to the low pressure space during the compression stroke.

Here, generally, six spiral grooves of the single screw compressor are formed, and are formed at 60 ° pitch positions on a plane perpendicular to the screw axis. As described above, the compression chamber and the discharge port are formed at positions symmetrical with respect to the radial center of the screw rotor, and these are located at the same position in the screw axial direction. For this reason, the timing of discharging the fluid in each compression chamber coincides.

In the single screw compressor configured so that the fluid in the compression chamber is simultaneously discharged from the two discharge ports as described above, the pulsation of the fluid discharged from each discharge port in a predetermined cycle overlaps, and the peak of the pulsation increases. Become. That is, loud noise or vibration is generated.

Therefore, Patent Document 1 discloses a screw compressor in which the number of spiral grooves is set to a value other than an integral multiple of the number of gate rotors, and the timing of discharging fluid from two discharge ports is shifted from each other.

Japanese Patent No. 5125524

However, in the screw compressor of the technology of Patent Literature 1, for example, when the number of spiral grooves of the screw rotor is reduced from six to five, the compression time of the fluid per one spiral groove becomes longer, and the compression time increases. The leakage losses occurring therein increase. When the number of spiral grooves is increased from six to seven, the angle between the spiral groove and the axis of the screw rotor in the developed view of the screw groove becomes smaller. In other words, the area of the discharge port is reduced, and the pressure loss generated when discharging from the compression chamber increases.

The present invention has been made to solve the above problems, and provides a screw compressor and a refrigeration cycle device capable of reducing noise and vibration due to displacement of discharge pulsations and reducing leakage loss and pressure loss. Aim.

The screw compressor according to the present invention is a screw rotor that extends in the axial direction and has a screw groove on the outer peripheral surface, a pair of gate rotors that mesh with the screw groove of the screw rotor, and a radial center of the screw rotor. And a pair of slide valves arranged at point-symmetric positions, and the first compression chamber closed by one of the pair of gate rotors and one of the pair of slide valves. Is formed, and a second compression chamber closed by the other gate rotor of the pair of gate rotors and the other slide valve of the pair of slide valves is formed, and the pair of slide valves is The axial position of one end of the discharge port communicating with the chamber and the second compression chamber is shifted from each other. Is shall.

冷凍 A refrigeration cycle apparatus according to the present invention includes the above screw compressor.

According to the screw compressor and the refrigeration cycle apparatus according to the present invention, the pair of slide valves are provided such that the axial positions of one ends of the discharge ports communicating with the first compression chamber and the second compression chamber are shifted from each other. ing. Accordingly, the timings of discharging the fluid from the first compression chamber and the second compression chamber are shifted from each other. That is, the peak of the discharge pulsation of each compression chamber can be prevented from overlapping, and the noise and vibration can be reduced. In addition, the number of screw grooves is not limited, and the number of screw grooves can be optimized. For this reason, the compression time of the fluid per one screw groove does not become long, and the leakage loss generated during compression can be reduced. Further, the angle between the screw groove and the axis of the screw rotor in the developed view of the screw groove does not become small. That is, the area of the discharge port is not reduced, and the pressure loss generated when the discharge is performed from the first compression chamber and the second compression chamber can be reduced. Therefore, the overlap of the discharge pulsations is shifted, so that noise and vibration can be reduced, and leakage loss and pressure loss can be reduced.

It is a sectional view showing the screw compressor concerning Embodiment 1 of the present invention. It is sectional drawing which expands and shows the B section of FIG. 1 of the screw compressor which concerns on Embodiment 1 of this invention. It is a figure which shows the compression principle 1 of the screw compressor concerning Embodiment 1 of this invention. It is a figure which shows the compression principle 2 of the screw compressor concerning Embodiment 1 of this invention. FIG. 2 is a diagram illustrating a compression principle 3 of the screw compressor according to Embodiment 1 of the present invention. FIG. 2 is a development view showing a first state of the screw rotor, the cylindrical wall, the gate rotor, and the slide valve according to Embodiment 1 of the present invention as viewed from the inside of the cylinder. FIG. 3 is a development view showing a second state of the screw rotor, the cylindrical wall, the gate rotor, and the slide valve according to Embodiment 1 of the present invention, as viewed from the inside of the cylinder. FIG. 4 is a schematic diagram showing a noise level generated by discharging a fluid from each of two discharge ports according to the conventional structure and the first embodiment of the present invention, and a superimposed noise level of the noise levels of the two discharge ports. FIG. 8 is a refrigerant circuit diagram illustrating a refrigeration cycle device to which the screw compressor according to Embodiment 2 of the present invention is applied.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same reference numerals denote the same or corresponding components, which are common throughout the entire specification. In the drawings of the cross-sectional views, hatching is omitted as appropriate in view of visibility. Further, the forms of the components shown in the entire text of the specification are merely examples, and the present invention is not limited to these descriptions. The level of the pressure is not particularly determined in relation to an absolute value, but is relatively determined in a state or operation of a system, an apparatus, or the like.

Embodiment 1 FIG.
<Structure of screw compressor 100>
FIG. 1 is a cross-sectional view illustrating a screw compressor 100 according to Embodiment 1 of the present invention. As shown in FIG. 1, the screw compressor 100 includes a casing 1, a screw rotor 3,

gate rotors

6a and 6b, an electric motor 2 for rotating the screw rotor 3, and

slide valves

8a and 8b. The cylindrical casing 1 having the cylindrical wall 1c accommodates the screw rotor 3, the

gate rotors

6a and 6b, the electric motor 2, the

slide valves

8a and 8b, and the like inside the cylinder.

The electric motor 2 includes a stator 2a internally fixed to the casing 1 and a motor rotor 2b disposed inside the stator 2a. The electric motor 2 may be a constant speed machine having a constant drive frequency, or may be an inverter type that is driven so that its capacity can be adjusted by changing the drive frequency.

The screw rotor 3 and the motor rotor 2b are arranged around a screw shaft 4 serving as a rotating shaft, and are fixed to the screw shaft 4. The screw rotor 3 extends in the axial direction of the screw shaft 4. Six spiral screw grooves 12 are formed on the outer peripheral surface of the screw rotor 3. In addition, the number of the screw grooves 12 can be appropriately changed depending on the configuration of the screw compressor 100 to be a product. The screw rotor 3 rotates with the rotation of the motor rotor 2b fixed to the screw shaft 4.

The screw compressor 100 has a pair of

gate rotors

6a and 6b. The pair of

gate rotors

6 a and 6 b are located in a point-symmetric positional relationship with respect to the screw shaft 4, and are disposed on both sides of the screw rotor 3, respectively. The two

gate rotors

6a and 6b have a disk shape, and a plurality of teeth 13 are provided on the outer peripheral surface along the circumferential direction. The teeth 13 of the

gate rotors

6a and 6b are engaged with the screw grooves 12. A space surrounded by the teeth 13 of the

gate rotors

6a and 6b, the screw groove 12, and the inner surface of the casing 1 is a first compression chamber 5a and a second compression chamber 5b.

スライド Inside the casing 1,

slide grooves

1a and 1b extending in the axial direction of the screw shaft 4 of the screw rotor 3 are formed. A slide valve 8a is accommodated in the slide groove 1a so as to be slidable in the axial direction along the slide groove 1a. A slide valve 8b is accommodated in the slide groove 1b so as to be slidable in the axial direction along the slide groove 1b. The slide valve 8a is integrated with the casing 1 to form a first compression chamber 5a together with the casing 1. The slide valve 8b is integrated with the casing 1 to form a second compression chamber 5b together with the casing 1.

The first compression chamber 5a is formed in a space closed by one of the pair of

gate rotors

6a and 6b and one of the pair of

slide valves

8a and 8b. The second compression chamber 5b is formed in a space closed by the other gate rotor 6b of the pair of

gate rotors

6a and 6b and the other slide valve 8b of the pair of

slide valves

8a and 8b. The first compression chamber 5a and the second compression chamber 5b are formed at positions that are point-symmetric with respect to the radial center of the screw rotor 3.

Here, the interior of the screw compressor 100 is partitioned into a low-pressure side, which is a refrigerant suction side, and a high-pressure side, which is a refrigerant discharge side, by a partition wall (not shown). The space on the low pressure side is a low pressure chamber A1 serving as a suction pressure atmosphere. The space on the high pressure side is a high pressure chamber A2 serving as a discharge pressure atmosphere. The slide valve 8a is provided with a discharge port 7a for communicating the high-pressure chamber A2 with the first compression chamber 5a at a position on the high-pressure side of the first compression chamber 5a. The slide valve 8b is provided with a discharge port 7b for communicating the high-pressure chamber A2 with the second compression chamber 5b at a position on the high-pressure side of the second compression chamber 5b.

The pair of

slide valves

8a and 8b adjust the discharge timing from the first and

second compression chambers

5a and 5b by moving the screw shaft 4 in the axial direction, and the internal volume ratio is variable so that the internal volume ratio can be changed. Mechanism. Here, the internal volume ratio refers to the ratio of the volumes of the first and

second compression chambers

5a and 5b at the time of completion of suction at the start of compression to the volumes of the first and

second compression chambers

5a and 5b immediately before discharge. It is shown.

Note that, apart from the internal volume ratio variable mechanism, the pair of

slide valves

8a and 8b allow a part of the refrigerant sucked into the first and

second compression chambers

5a and 5b to bypass the low pressure chamber A1 in the middle of the compression stroke. It can also be used as a capacity control mechanism.

The pair of

slide valves

8a and 8b are connected to the slide

valve driving devices

10a and 10b, such as pistons, via the connecting rod 9, respectively. By driving the slide

valve driving devices

10a and 10b, the

slide valves

8a and 8b move in the

slide groove

1a or 1b in the axial direction of the screw shaft 4 of the screw rotor 3, respectively.

The screw compressor 100 performs a control operation of controlling the positions of the pair of

slide valves

8a and 8b to adjust the internal volume ratio. This control operation is performed by sending an instruction to the slide

valve driving devices

10a and 10b from a control device (not shown) as to where to place the pair of

slide valves

8a and 8b so as to adjust the discharge amount of the refrigerant. The slide control of the pair of

slide valves

8a and 8b by the slide

valve driving devices

10a and 10b is controlled at the same timing. Here, each of the slide

valve driving devices

10a and 10b for driving the pair of

slide valves

8a and 8b is driven by a gas pressure, by a hydraulic pressure, by a motor separately from the piston, or the like. The power source is not limited.

<Configuration of

Discharge Ports

7a and 7b>
FIG. 2 is an enlarged cross-sectional view illustrating part B of FIG. 1 of screw compressor 100 according to Embodiment 1 of the present invention. As shown in FIG. 2, a pair of

slide valves

8a and 8b are provided with screw shafts 4 at end faces 11a and 11b which are one ends of

discharge ports

7a and 7b communicating with the first compression chamber 5a and the second compression chamber 5b. Are shifted from each other by a length C. The pair of

slide valves

8a and 8b are the same except that the positions of the end faces 11a and 11b of the

discharge ports

7a and 7b are different.

Accordingly, the timing at which one of the two

outlets

7a and 7b communicates with the first compression chamber 5a and the other of the two

outlets

7a and 7b are connected to the second compression chamber 5b. The timing of communication is shifted.

Specifically, as shown in FIG. 8, which will be described later, the positions of the end faces 11a and 11b are at the middle of the timing when one of the discharge ports 7a sequentially communicates with the first compression chamber 5a, and the position of the other discharge port 7b is the second. The timing for communicating with the compression chamber 5b is set to start. The timing at which the two

discharge ports

7a and 7b communicate with the first compression chamber 5a or the second compression chamber 5b is not limited to being shifted by a half cycle.

<Compression principle>
FIG. 3 is a diagram illustrating a compression principle 1 of the screw compressor 100 according to the first embodiment of the present invention. FIG. 4 is a diagram illustrating a compression principle 2 of the screw compressor 100 according to Embodiment 1 of the present invention. FIG. 5 is a diagram illustrating a compression principle 3 of the screw compressor 100 according to Embodiment 1 of the present invention.

As shown in FIGS. 3 to 5, when the screw rotor 3 is rotated via the screw shaft 4 by the electric motor 2, the teeth 13 of the pair of

gate rotors

6a and 6b are brought into contact with the first and

second compression chambers

5a and 5b. It relatively moves within the screw groove 12 constituting each. At this time, in the first and

second compression chambers

5a and 5b, a suction stroke, a compression stroke, and a discharge stroke are sequentially performed. The cycle is repeated with the suction stroke, the compression stroke, and the discharge stroke as one cycle. Here, each step will be described, focusing on the second compression chamber 5b indicated by dot-shaped hatching in FIGS.

FIG. 3 shows a state where the second compression chamber 5b formed in the screw groove 12 is confined by the casing 1, the screw rotor 3, and the

gate rotors

6a and 6b. The screw rotor 3 is driven by the electric motor 2 and rotates in the direction indicated by the solid arrow.

FIG. 4 shows a state in which the second compression chamber 5b confined in FIG. 3 is compressed by the rotation of the screw rotor 3, and the volume of the second compression chamber 5b is continuously reduced.

FIG. 5 shows a state where the fluid compressed in the state shown in FIG. 4 is discharged. When the screw rotor 3 continues to rotate from the state shown in FIG. 4, the second compression chamber 5b communicates with the outside via the discharge port 7b as shown in FIG. Thus, the high-pressure refrigerant gas compressed in the second compression chamber 5b is discharged from the discharge port 7b to the outside. Then, the same compression is performed again in the next tooth space of the screw rotor 3. In the above description, the description has been given focusing on the second compression chamber 5b, but the operation principle of the first compression chamber 5a is the same.

<Rotating operation of screw rotor 3>
FIG. 6 is a developed view showing a first state of the screw rotor 3, the cylindrical wall 1c, the

gate rotors

6a and 6b, and the

slide valves

8a and 8b according to Embodiment 1 of the present invention as viewed from the inside of the cylinder. FIG. 7 is a developed view showing a second state of the screw rotor 3, the cylindrical wall 1c, the

gate rotors

6a and 6b, and the

slide valves

8a and 8b according to Embodiment 1 of the present invention as viewed from the inside of the cylinder.

As shown in FIGS. 6 and 7, for two

slide valves

8 a and 8 b located at point-symmetric positions with respect to the radial center of the screw rotor 3, end surfaces 11 a and 7 b forming a part of the

discharge ports

7 a and 7 b are formed. 11b are different from each other in the axial direction of the screw shaft 4. The six screw grooves 12 forming the screw rotor 3 are formed at 60 ° pitch positions on a plane perpendicular to the screw shaft 4. Here, the end faces 11a and 11b of the

slide valves

8a and 8b are in a positional relationship such that any of the six screw grooves 12 and the other grooves do not simultaneously discharge fluid.

FIG. 6 shows a state in which the screw rotor 3 indicated by the dotted line rotates and the side surface 12a of the screw groove 12 overlaps the end surface 11a of one of the slide valves 8a. That is, FIG. 6 shows a state immediately before the fluid is discharged from the discharge port 7a. FIG. 7 shows a state in which the screw rotor 3 further rotates from the state shown in FIG. 6, and the side surface 12b of the screw groove 12 overlaps the end surface 11b of the other slide valve 8b.

In FIG. 6, while the fluid is just discharged from the discharge port 7a, the fluid is already discharged from the discharge port 7b communicating with the screw groove 12. Further, in FIG. 7, the fluid is just discharged from the discharge port 7b, whereas the fluid is already discharged from the screw groove 12 from the discharge port 7a immediately before the discharge in FIG. 6, from the discharge port 7a. . With the rotation of the screw rotor 3, the above-described discharge is repeated.

<Operation of screw compressor 100>
FIG. 8 is a diagram showing the superposition of the noise level generated by the fluid being discharged from each of the two

discharge ports

7a and 7b and the noise level of the two

discharge ports

7a and 7b according to the conventional structure and the first embodiment of the present invention. FIG. 4 is a schematic diagram illustrating a noise level that has been set.

As shown in FIG. 8, in the present embodiment, the peak of the pulsation of the fluid discharged from the

discharge ports

7a and 7b is shifted, and noise and vibration are reduced as compared with the conventional structure. With this structure, the pulsation cycle of the fluid discharged from each of the

discharge ports

7a and 7b is the same. However, the phase of the wave having the peak of the pulsation is shifted. Due to the shift in the timing at which the fluid is discharged from the

discharge ports

7a and 7b, the pulsation peaks generated when the fluid is discharged from the

respective discharge ports

7a and 7b do not overlap, and the noise and vibration are reduced as compared with the conventional structure. it can.

Further, the above-described structure is different from the conventional structure only in that the shape of the positions of the end faces 11a and 11b of the

slide valves

8a and 8b only needs to be changed, and the screw compressor which can reduce noise and vibration without increasing the number of parts or the assembly process. 100 can be realized.

<Effect of First Embodiment>
According to Embodiment 1, the screw compressor 100 includes the screw rotor 3 extending in the axial direction and having the screw groove 12 on the outer peripheral surface. The screw compressor 100 includes a pair of

gate rotors

6a and 6b that mesh with the screw grooves 12 of the screw rotor 3. The screw compressor 100 includes a pair of

slide valves

8a and 8b arranged at positions symmetrical with respect to the center of the screw rotor 3 in the radial direction. A first compression chamber 5a closed by one of the pair of

gate rotors

6a and 6b and one of the pair of

slide valves

8a and 8b is formed. A second compression chamber 5b is formed which is closed by the other gate rotor 6b of the pair of

gate rotors

6a and 6b and the other slide valve 8b of the pair of

slide valves

8a and 8b. The pair of

slide valves

8a and 8b are provided such that axial positions of end faces 11a and 11b, which are one ends of

discharge ports

7a and 7b communicating with the first compression chamber 5a and the second compression chamber 5b, are shifted from each other. I have.

According to this configuration, the timings of discharging the fluid in the first compression chamber 5a and the second compression chamber 5b to the two

discharge ports

7a and 7b are shifted from each other. That is, the peak of the discharge pulsation of each of the first and

second compression chambers

5a and 5b can be prevented from overlapping, and noise and vibration can be reduced. In addition, there is no limitation on the number of screw grooves 12, and the number of screw grooves 12 can be optimized to be six here. For this reason, the compression time of the fluid per one screw groove 12 does not become long, and the leakage loss generated during compression can be reduced. Further, the angle formed between the screw groove 12 and the screw shaft 4 of the screw rotor 3 in the developed view of the screw groove 12 does not become small. That is, the areas of the

discharge ports

7a and 7b are not reduced, and the pressure loss generated when the discharge is performed from the first compression chamber 5a and the second compression chamber 5b can be reduced. Therefore, the overlap of the discharge pulsations is shifted, so that noise and vibration can be reduced, and leakage loss and pressure loss can be reduced.

According to the first embodiment, the timing at which one of the two

outlets

7a and 7b are at the second timing. The timing of communication with the second compression chamber 5b is shifted.

discharge ports

second compression chambers

5a and 5b can be prevented from overlapping, and the noise and vibration can be reduced.

According to the first embodiment, the timing at which one of the two

outlets

7a and 7b communicates with the first compression chamber 5a and the one of the two

outlets

7a and 7b are set to the following timing. The timing at which the other one of the two

outlets

7a and 7b communicates with the second compression chamber 5b is started at an intermediate point of the timing at which it communicates with the first compression chamber 5a.

According to this configuration, the peak of the discharge pulsation of each of the first and

second compression chambers

5a and 5b is shifted by a half cycle, and the discharge pulsation from the two

discharge ports

7a and 7b can be most flattened, thereby further reducing noise and vibration. it can.

According to the first embodiment, the slide control of the pair of

slide valves

8a and 8b is controlled at the same timing.

According to this configuration, the slide control of the pair of

slide valves

8a and 8b does not require special control, simple control can be performed at the same timing, control is easy, and cost reduction can be achieved.

According to the first embodiment, the number of the screw grooves 12 is six.

According to this configuration, the number of screw grooves 12 can be optimized. For this reason, the compression time of the fluid per one screw groove 12 does not become long, and the leakage loss generated during compression can be reduced. Further, the angle formed between the screw groove 12 and the screw shaft 4 of the screw rotor 3 in the developed view of the screw groove 12 does not become small. That is, the areas of the

discharge ports

7a and 7b are not reduced, and the pressure loss generated when the discharge is performed from the first compression chamber 5a and the second compression chamber 5b can be reduced.

According to the first embodiment, the pair of

slide valves

8a and 8b adjusts the timing of communication from the first compression chamber 5a or the second compression chamber 5b to each of the two

discharge ports

7a and 7b, and changes the internal volume ratio. This is a variable internal volume ratio mechanism.

According to this configuration, the discharge timing from the first compression chamber 5a and the second compression chamber 5b can be adjusted, and the internal volume ratio can be changed.

According to the first embodiment, the pair of

slide valves

8a and 8b is a capacity control mechanism that bypasses a part of the refrigerant sucked into the first compression chamber 5a or the second compression chamber 5b to the low-pressure space during the compression stroke. is there.

According to this configuration, part of the refrigerant sucked into the first compression chamber 5a or the second compression chamber 5b is bypassed to the low-pressure space during the compression stroke.

Embodiment 2 FIG.
<Refrigeration cycle device 101>
FIG. 9 is a refrigerant circuit diagram showing a refrigeration cycle apparatus 101 to which the screw compressor 100 according to Embodiment 2 of the present invention is applied.

As shown in FIG. 9, the refrigeration cycle apparatus 101 includes a screw compressor 100, a condenser 102, an expansion valve 103, and an evaporator 104. The screw compressor 100, the condenser 102, the expansion valve 103, and the evaporator 104 are connected by a refrigerant pipe to form a refrigeration cycle circuit. Then, the refrigerant flowing out of the evaporator 104 is drawn into the screw compressor 100 and becomes high temperature and high pressure. The high-temperature and high-pressure refrigerant is condensed in the condenser 102 to become a liquid. The liquid refrigerant is decompressed and expanded by the expansion valve 103 to become a low-temperature low-pressure gas-liquid two-phase, and the gas-liquid two-phase refrigerant is heat-exchanged in the evaporator 104.

The screw compressor 100 according to the first embodiment can be applied to such a refrigeration cycle apparatus 101. In addition, as the refrigerating cycle device 101, for example, an air conditioner, a refrigerating device, a water heater, or the like can be given.

<Effect of Embodiment 2>
According to the second embodiment, a refrigeration cycle apparatus 101 includes the screw compressor 100 according to the first embodiment.

According to this configuration, in the screw compressor 100 according to the first embodiment provided in the refrigeration cycle apparatus 101, the overlap of the discharge pulsations is shifted, so that noise and vibration can be reduced, and leakage loss and pressure loss can be reduced.

1 casing, 1a, 1b slide groove, 1c cylindrical wall, 2 motor, 2a stator, 2b motor rotor, 3 screw rotor, 4 screw shaft, 5a first compression chamber, 5b second compression chamber, 6a, 6b gate rotor, 7a, 7b discharge port, 8a, 8b slide valve, 9 connection rod, 10a, 10b slide valve drive device, 11a, 11b end surface, 12 screw groove, 12a, 12b side surface, 13 tooth, 100 screw compressor, 101 refrigeration cycle device, 102 Condenser, 103 expansion valve, 104 evaporator.

Claims

A screw rotor extending in the axial direction and having a screw groove on the outer peripheral surface,
A pair of gate rotors that mesh with the screw grooves of the screw rotor,
A pair of slide valves arranged at a point symmetrical position with respect to the radial center of the screw rotor,
With
A first compression chamber closed by one of the pair of gate rotors and one of the pair of slide valves is formed,
A second compression chamber closed by the other gate rotor of the pair of gate rotors and the other slide valve of the pair of slide valves is formed,
A screw compressor in which the pair of slide valves are provided such that axial positions of one ends of discharge ports communicating with the first compression chamber and the second compression chamber are shifted from each other.
The timing at which one of the two discharge ports communicates with the first compression chamber, and the timing at which the other one of the two discharge ports communicates with the second compression chamber, The screw compressor according to claim 1, which is shifted.
An intermediate point between a timing at which one of the two discharge ports communicates with the first compression chamber and a timing at which one of the two discharge ports communicates with the next first compression chamber. 3. The screw compressor according to claim 2, wherein a timing at which the other one of the two discharge ports communicates with the second compression chamber is started.
The screw compressor according to any one of claims 1 to 3, wherein the slide control of the pair of slide valves is controlled at the same timing.
スクリュー The screw compressor according to any one of claims 1 to 4, wherein the number of the screw grooves is six.
The internal volume ratio variable mechanism, wherein the pair of slide valves adjusts the timing of communication from the first compression chamber or the second compression chamber to each of the two discharge ports, and allows the internal volume ratio to be changed. 6. The screw compressor according to any one of 1 to 5.
The capacity control mechanism according to any one of claims 1 to 5, wherein the pair of slide valves is a capacity control mechanism that bypasses a part of the refrigerant sucked into the first compression chamber or the second compression chamber to a low-pressure space in the middle of a compression stroke. Item 7. The screw compressor according to item 1.
冷凍 A refrigeration cycle apparatus comprising the screw compressor according to any one of claims 1 to 7.