JP7232914B2 - Multi-stage rotary compressor and refrigeration cycle device - Google Patents

Description

An embodiment of the present invention relates to a multistage rotary compressor and a refrigerating cycle device.
This application claims priority based on Japanese Patent Application No. 2019-141324 filed in Japan on July 31, 2019, the content of which is incorporated herein.

Conventionally, multi-stage rotary compressors that compress working fluid in stages are known. For example, a multi-stage rotary compressor includes a low-stage compression mechanism, a high-stage compression mechanism, and a sealed case. The low-stage compression mechanism section compresses the low-pressure working fluid to an intermediate pressure. The high-stage compression mechanism section compresses the intermediate-pressure working fluid compressed by the low-stage compression mechanism section to a high pressure. A closed case houses the compression element and the drive element. The inside of the sealed case is filled with high-pressure working fluid discharged from the high-stage compression mechanism.

Each compression mechanism has a blade. The blade divides the cylinder chamber into a suction side and a compression side. The blade is biased towards the roller. The roller is mounted on the eccentric portion of the rotating shaft. The pressure inside the sealed case acts on the rear surface of the blade opposite to the tip surface (roller contact surface). This pressure urges the blade toward the roller.
The same case internal pressure acts on the back surface of the blade on both the low stage side and the high stage side. The following pressure acts on the blade tip surface (roller contact surface). That is, a low pressure before compression acts on the low stage side of the blade tip surface. On the high stage side of the blade tip surface, an intermediate pressure after compression acts on the low stage side. The pressure difference on both sides of the low-stage blade in the advancing/retreating direction is greater than the pressure difference on both sides of the high-stage-side blade in the advancing/retreating direction.

The suction volume on the low stage side is larger than the suction volume on the high stage side. The height of the cylinder on the low stage side is greater than the height of the cylinder on the high stage side. The cross-sectional area (pressure-receiving area) of the low-stage blade is larger than the cross-sectional area (pressure-receiving area) of the high-stage blade. The pressing force of the blade is calculated by multiplying the cross-sectional area by the pressure difference. The pressing force on the low stage side is greater than the pressing force on the high stage side.

In a compression element with a rotating eccentric portion, the rotating shaft is likely to bend. Deflection of the rotating shaft leads to tilting of the eccentric portion and rollers. This tilt results in uneven contact of the blade against the roller. An intermediate pressure space (discharge space of the low-stage compression mechanism) may be provided in the partition plate that partitions the low-stage side and the high-stage side. In this case, the thickness of the partition plate is increased. As the thickness of the partition plate increases, the distance between the bearings increases. As the bearing-to-bearing distance increases, the rotation shaft is more likely to flex. If the blade is in uneven contact with the roller due to the bending of the rotating shaft, the following problems arise. That is, at the sliding portion between the blade and the roller, the local contact surface pressure increases and uneven wear occurs. Uneven wear tends to occur on the low stage side where both the cross-sectional area and the pressure difference are large. This uneven wear affects the reliability of the compressor.

Japanese Patent No. 6176782

The problem to be solved by the present invention is to provide a multi-stage rotary compressor and a refrigeration cycle apparatus that can suppress the occurrence of uneven wear in the sliding portion between blades and rollers and improve reliability.

A multi-stage rotary compressor of an embodiment has a rotating shaft, a drive element provided on one axial end side of the rotating shaft, and a compression element provided on the other axial end side of the rotating shaft. The compression element has a low-stage compression mechanism that compresses the working fluid to an intermediate pressure and a high-stage compression mechanism that compresses the intermediate-pressure working fluid to a high pressure. Each of the low-stage compression mechanism and the high-stage compression mechanism includes a cylinder, a roller mounted on an eccentric portion of a rotating shaft, and a blade that advances and retreats from the roller to divide the cylinder chamber into a suction side and a compression side. and have The blades of each compression mechanism are urged toward the rollers by the discharge pressure acting on the back surface thereof. The cross-sectional area of the blade member forming the blade of the low-stage compression mechanism is smaller than the cross-sectional area of the blade member forming the blade of the high-stage compression mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram of a refrigerating-cycle apparatus including sectional drawing of the multistage rotary compressor of embodiment. Sectional drawing of the compression element of the multistage rotary compressor of embodiment. III-III sectional view of FIG.

Hereinafter, a multistage rotary compressor and a refrigeration cycle apparatus according to embodiments will be described with reference to the drawings.
First, the refrigeration cycle device will be explained.
FIG. 1 is a schematic configuration diagram of a refrigeration cycle device including a cross-sectional view of a multistage rotary compressor of an embodiment. A refrigeration cycle apparatus 1 of this embodiment includes a multistage rotary compressor 2 , a radiator 3 , an expansion device (expansion valve) 4 , and an evaporator (heat absorber) 5 . The multistage rotary compressor 2 has a compressor body 11 and an accumulator (gas-liquid separator) 12 . The multi-stage rotary compressor 2 compresses gas refrigerant, which is a working fluid. The radiator 3 is connected to the discharge portion 15 of the compressor main body 11 . The radiator 3 cools the high-temperature, high-pressure gas refrigerant discharged from the compressor main body 11 . The expansion device 4 is connected downstream of the radiator 3 . The expansion device 4 reduces the pressure of the refrigerant. The evaporator 5 is connected between the expansion device 4 and the introduction portion 12 a of the accumulator 12 . The evaporator 5 evaporates the refrigerant. Reference numeral 13 in the drawing denotes an introduction passage extending from the discharge portion 15 of the compressor main body 11 to the introduction portion 12a of the accumulator 12. As shown in FIG.

A lead-out portion 12 b of the accumulator 12 and a suction portion 14 of the compressor main body 11 are connected by a suction pipe 6 . The gas refrigerant separated from gas and liquid in the accumulator 12 is guided through the suction pipe 6 . This gas refrigerant is led to the low-stage compression mechanism portion 37 of the compressor main body 11 .

A refrigeration cycle apparatus 1 shown in FIG. 1 has an intermediate pressure passage 7 . The intermediate pressure passage 7 guides the intermediate pressure gas refrigerant to the intercooler 7a. The gas refrigerant is compressed by the low-stage compression mechanism 37 of the compressor main body 11 to the intermediate pressure. The intermediate-pressure passage 7 guides the intermediate-pressure gas refrigerant to the high-stage compression mechanism portion 38 of the compressor main body 11 . The intermediate pressure passage 7 extends from the second discharge portion 15 a that communicates with the low-stage compression mechanism portion 37 . The intermediate pressure passage 7 extends to the second suction portion 14 a communicating with the high-stage compression mechanism portion 38 .

The refrigeration cycle device 1 has a second accumulator (gas-liquid separator) 8 and a second expansion device (expansion valve) 9 between the expansion device 4 and the evaporator 5 . A bypass passage 8 a is provided between the second accumulator 8 and the second suction portion 14 a of the high-stage compression mechanism portion 38 of the compressor main body 11 . The bypass passage 8 a guides the gas-liquid-separated gas refrigerant in the second accumulator 8 to the high-stage compression mechanism portion 38 . The bypass passage 8a in FIG. 1 merges with the intermediate pressure passage 7 in the middle.

The pressure of the gas refrigerant separated into gas and liquid by the second accumulator 8 is set as follows. The pressure of this gas refrigerant is equivalent to the intermediate pressure of the gas refrigerant compressed by the low-stage compression mechanism 37 of the compressor main body 11 . The multistage rotary compressor 2 may be configured without the intermediate pressure passage 7, the bypass passage 8a, the second accumulator 8 and the second expansion device 9.

The multistage rotary compressor 2 is a so-called rotary compressor. The multi-stage rotary compressor 2 compresses the low-pressure gaseous refrigerant taken inside in two stages to obtain a high-temperature, high-pressure gaseous refrigerant. A specific configuration of the multistage rotary compressor 2 will be described later.

The refrigerant, which is a working fluid, circulates in the refrigeration cycle device 1 while undergoing a phase change between a gas refrigerant and a liquid refrigerant. The refrigerant absorbs heat during the phase change from the liquid refrigerant to the gas refrigerant. This heat absorption is used for freezing and refrigerating. For example, the refrigerant can be an HFC refrigerant such as R410A or R32, an HFO refrigerant such as R1234yf or R1234ze, or a natural refrigerant such as CO2.

The radiator 3 radiates heat from the high-temperature, high-pressure gaseous refrigerant fed from the multistage rotary compressor 2 .
The expansion device 4 reduces the pressure of the high-pressure refrigerant sent from the radiator 3 to convert it into a low-temperature, low-pressure liquid refrigerant.
The evaporator 5 evaporates the low-temperature, low-pressure liquid refrigerant fed from the expansion device 4 into a low-pressure gaseous refrigerant. The evaporator 5 absorbs heat of vaporization from the surroundings when the low-pressure liquid refrigerant is vaporized, thereby cooling the surroundings. The low-pressure gaseous refrigerant that has passed through the evaporator 5 is taken into the multi-stage rotary compressor 2 described above.

In the refrigeration cycle device 1, the intermediate-pressure gas refrigerant separated from gas and liquid by the second accumulator 8 is led as follows. This intermediate-pressure gas refrigerant is guided into the high-stage compression mechanism portion 38 of the compressor main body 11 via the bypass passage 8a. Thereby, the compression performance of the compressor main body 11 is enhanced.

Next, the multistage rotary compressor 2 will be described.
As shown in FIG. 1 , the multistage rotary compressor 2 of this embodiment includes a compressor body 11 and an accumulator 12 .

The accumulator 12 is a so-called gas-liquid separator. The accumulator 12 is provided between the evaporator 5 and the compressor body 11 described above. The accumulator 12 is connected to the compressor body 11 through the suction pipe 6 . The accumulator 12 separates the gaseous refrigerant vaporized by the evaporator 5 and the liquid refrigerant not vaporized by the evaporator 5 . The accumulator 12 supplies only the separated gaseous refrigerant to the compressor body 11 .

The compressor main body 11 includes a rotating shaft 31 , an electric motor (driving element) 32 , a compression element 33 , and a sealed case 34 that houses the rotating shaft 31 , the electric motor 32 and the compression element 33 . The compressor main body 11 is arranged with the axial directions of the rotary shaft 31 and the sealing case 34 as vertical directions. The rotary shaft 31 has its rotation center axis C aligned with the center axis of the sealed case 34 . In the following description, the direction along the central axis C of the rotary shaft 31 and the sealed case 34 is called the axial direction, the direction perpendicular to the axial direction is called the radial direction, and the direction around the axis C is called the circumferential direction.

The sealed case 34 forms a sealed container by closing both ends in the axial direction of the cylindrical body. Inside the sealed case 34, the electric motor 32 is accommodated on the upper side, and the compression element 33 is accommodated on the lower side. These electric motors 32 and compression elements 33 are connected via a rotating shaft 31 . Inside the sealed case 34 , an electric motor 32 is provided on one end side of the rotary shaft 31 , and a compression element 33 is provided on the other end side of the rotary shaft 31 . A frame 34 a is provided between the electric motor 32 and the compression element 33 within the sealed case 34 . The frame 34 a has an annular shape coaxial with the cylindrical body of the closed case 34 . The frame 34 a is fixed to the inner wall surface of the closed case 34 .

Lubricating oil J for lubricating the compression element 33 is stored in the bottom of the sealed case 34 . The bottom of the sealed case 34 constitutes a lubricating oil reservoir 34b in which the lubricating oil J is reserved. A portion of the compression element 33 is immersed in the lubricating oil J. As shown in FIG. A high-pressure gas refrigerant compressed by the high-stage compression mechanism 38 is discharged into the space inside the sealed case 34 .

The electric motor 32 is a so-called inner rotor type DC brushless motor. The electric motor 32 is an electric motor having a stator 35 and a rotor 36 . The stator 35 is fixed to the upper inner wall surface of the sealed case 34 . The rotor 36 is arranged inside the stator 35 with a radial gap therebetween. The rotor 36 is fixed to the top of the rotating shaft 31 .

FIG. 2 is a cross-sectional view of the compression element 33 of the multistage rotary compressor 2. FIG. FIG. 3 is a cross-sectional view along III-III in FIG.
As shown in FIGS. 2 and 3, the compression element 33 is a multi-cylinder compression element having a plurality of cylinders 37a and 38a. For example, the compression element 33 is a two-cylinder (multi-cylinder) compression element. The compression element 33 has a pair (plurality) of cylinders 37a and 38a arranged vertically (axially). The compression element 33 of this embodiment includes a low-stage compression mechanism portion 37 , a high-stage compression mechanism portion 38 , and a partition plate 39 . The low-stage compression mechanism portion 37 is located axially above. The high-stage compression mechanism portion 38 is located axially below. The partition plate 39 partitions the low-stage compression mechanism portion 37 and the high-stage compression mechanism portion 38 in the vertical direction (axial direction). The low-stage compression mechanism portion 37 sucks the low-pressure working fluid from the accumulator 12 . The "low pressure" means relatively low with respect to "intermediate pressure" and "high pressure" which will be described later. The low-stage compression mechanism 37 compresses (increases) the low-pressure working fluid sucked from the accumulator 12 to a relatively high “intermediate pressure”. The high-stage compression mechanism 38 compresses (increases) the "intermediate pressure" working fluid compressed by the low-stage compression mechanism 37 to a relatively high "high pressure".

The low-stage compression mechanism 37 includes a low-stage cylinder 37a. The low-stage cylinder 37a is provided in parallel with the rotating shaft 31 in the axial direction. The low-stage cylinder 37a vertically penetrates the rotating shaft 31. As shown in FIG. The low-stage cylinder 37a forms a circular low-stage cylinder hole 37b. The low-stage cylinder hole 37b is aligned with the rotation center axis C of the rotary shaft 31. As shown in FIG. The low-stage compression mechanism portion 37 includes a first bearing 41 on the upper side of the low-stage cylinder 37a (on the side opposite to the partition plate 39 in the axial direction). The first bearing 41 closes the upper end opening of the low-stage cylinder hole 37b. The first bearing 41 rotatably supports the upper first main shaft 31a of the rotating shaft 31 .

The high-stage compression mechanism 38 includes a high-stage cylinder 38a. The high-stage cylinder 38a is provided in parallel with the rotating shaft 31 in the axial direction. The high-stage cylinder 38a vertically penetrates the rotating shaft 31. As shown in FIG. The high-stage cylinder 38a forms a circular high-stage cylinder hole 38b. The high-stage cylinder hole 38b is aligned with the center axis of rotation C of the rotating shaft 31 . The high-stage cylinder hole 38b and the low-stage cylinder hole 37b are arranged coaxially with each other. The high-stage cylinder hole 38 b and the low-stage cylinder hole 37 b are arranged coaxially with the rotating shaft 31 . The high-stage compression mechanism portion 38 includes a second bearing 42 on the lower side of the high-stage cylinder 38a (on the side opposite to the partition plate 39 in the axial direction). The second bearing 42 closes the lower end opening of the high-stage cylinder hole 38b. The second bearing 42 rotatably supports the lower third main shaft 31 e of the rotary shaft 31 .

The outer peripheral portion of the low-stage cylinder 37a is fixed to the frame 34a while being in contact with the lower surface of the frame 34a. An outer peripheral portion of the low-stage cylinder 37a is fastened and fixed to the frame 34a by a bolt B1 inserted from below. A first bearing 41 is arranged on the inner peripheral side of the frame 34a. The first bearing 41 is fixed to the low-stage cylinder 37a while being in contact with the upper surface of the low-stage cylinder 37a. The first bearing 41 is fastened and fixed to the low-stage cylinder 37a by a bolt B2 inserted from above. The bolt B2 extends downward through the low-stage cylinder 37a. The bolt B2 penetrates the partition plate 39 and the high-stage cylinder 38a. The bolt B2 is screwed into the screw hole of the second bearing 42 and tightened. The first bearing 41, the low-stage cylinder 37a, the partition plate 39, the high-stage cylinder 38a, and the second bearing 42 are integrally fastened in a layered state. A laminate of the first bearing 41, the low-stage cylinder 37a, the partition plate 39, the high-stage cylinder 38a, and the second bearing 42 is fixed to the frame 34a. The rotating shaft 31 is rotatably supported by a first bearing 41 and a second bearing 42 . The first bearing 41 and the second bearing 42 are fixed to the frame 34a and thus to the sealed case 34. As shown in FIG.

A first bearing 41 closes the upper end opening of the low-stage cylinder hole 37b of the low-stage cylinder 37a. A lower end opening of the low-stage cylinder hole 37b of the low-stage cylinder 37a is closed by a partition plate 39. As shown in FIG. A space defined by the low-stage cylinder 37a, the first bearing 41, and the partition plate 39 serves as a low-stage cylinder chamber 37c.

A lower end opening of the high-stage cylinder hole 38b of the high-stage cylinder 38a is closed by a second bearing 42 . A partition plate 39 closes the upper end opening of the high-stage cylinder hole 38b of the high-stage cylinder 38a. A space defined by the high-stage cylinder 38a, the second bearing 42, and the partition plate 39 serves as a high-stage cylinder chamber 38c.
The low-stage cylinder 37a and the high-stage cylinder 38a face each other with a partition plate 39 interposed therebetween in the axial direction. A specific configuration of the partition plate 39 will be described later.

The rotary shaft 31 has a low-stage eccentric portion 31b at a portion located inside the low-stage cylinder chamber 37c. The low stage side eccentric portion 31b is eccentric to one side in the radial direction with respect to the center axis C. As shown in FIG. The rotary shaft 31 has a high-stage eccentric portion 31d at a portion located within the high-stage cylinder chamber 38c. The high stage side eccentric portion 31d is eccentric to the other side in the radial direction with respect to the center axis C. As shown in FIG.

The rotating shaft 31 has a main shaft extending around the central axis C. As shown in FIG. The main shafts include a first main shaft 31a, a second main shaft 31c, and a third main shaft 31e. The first main shaft 31a extends above the low stage side eccentric portion 31b. The second main shaft 31c extends between the low-stage eccentric portion 31b and the high-stage eccentric portion 31d. The third main shaft 31e extends below the high stage side eccentric portion 31d. The first main shaft 31a is longer in the axial direction than the other main shafts 31c and 31e and extends greatly upward. A rotor 36 of the electric motor 32 is fixed to the first main shaft 31a.

Each of the eccentric portions 31b and 31d has a cylindrical shape with the same diameter. The eccentric portions 31b and 31d are arranged with a phase difference of 180° in the circumferential direction. The eccentric portions 31b and 31d have the same amount of eccentricity with respect to the central axis C. As shown in FIG.

A cylindrical low-stage roller 45 is rotatably fitted to the low-stage eccentric portion 31b. The low-stage roller 45 rotates around the central axis of the low-stage eccentric portion 31b.
A cylindrical high-stage roller 46 is rotatably fitted to the high-stage eccentric portion 31d. The high-stage roller 46 rotates around the center axis of the high-stage eccentric portion 31d.

The first bearing 41 includes a cylindrical tubular portion 41a and a flange portion 41b. The cylindrical portion 41a rotatably supports the first main shaft 31a of the rotating shaft 31. As shown in FIG. The flange portion 41b is formed to have an enlarged diameter on the outer peripheral side of the lower end portion of the cylindrical portion 41a. A first muffler 43 is fixed to the first bearing 41 by, for example, the bolt B2.

The second bearing 42 includes a cylindrical tubular portion 42a and a flange portion 42b. The cylindrical portion 42a rotatably supports the third main shaft 31e of the rotating shaft 31 through it. The flange portion 42b is formed to have an enlarged diameter on the outer peripheral side of the upper end portion of the tubular portion 42a. A second muffler 44 is fixed to the second bearing 42 .

In the first bearing 41 and the second bearing 42, the axial lengths of the sliding portions with respect to the rotary shaft 31 are denoted by L1 and L2. The sliding portion length L1 of the first bearing 41 is longer than the sliding portion length L2 of the second bearing 42 . Since the sliding portion length L1 is long, the deflection of the rotating shaft 31 on the side of the first bearing 41 is small. Since the sliding portion length L1 is long, the inclination of the low stage side eccentric portion 31b and the low stage side roller 45 is small.

The eccentric portion 31b of the low-stage compression mechanism portion 37 is arranged in the low-stage side cylinder chamber 37c as follows. The eccentric portion 31b is arranged to be biased toward the first bearing 41 in the axial direction. In the low-stage compression mechanism portion 37, the axial center position of the eccentric sliding portion (sliding portion between the eccentric portion 31b and the roller 45) is indicated by reference numeral cp1. In the low-stage compression mechanism 37, the axial center position of the low-stage cylinder 37a is denoted by cp2. The axial center position cp1 is arranged closer to the first bearing 41 in the axial direction than the axial center position cp2. This arrangement also reduces the deflection of the rotary shaft 31 on the side of the first bearing 41 .

The low-stage compression mechanism portion 37 includes blades (low-stage side blades) 18 . The blade 18 divides the low-stage cylinder chamber 37 c into the suction chamber 16 and the compression chamber 17 . The blade 18 is held in a blade groove 18c formed in the low-stage cylinder 37a. The blade 18 can move forward and backward with respect to the cylinder chamber 37c. The blade 18 contacts the roller 45 side tip surface (roller contact surface) 18 a against the outer peripheral surface of the roller 45 . The blade 18 maintains a state in which the tip surface 18 a is in contact with the outer peripheral surface of the roller 45 . The blade 18 and the roller 45 divide the inside of the cylinder chamber 37 c into the suction chamber 16 and the compression chamber 17 .

The blade 18 of the low stage compression mechanism 37 is composed of a plurality of blade members (low stage side blade members) 19a and 19b. For example, a plurality of blade members 19a and 19b are provided as a pair vertically overlapping each other in the axial direction. Hereinafter, the upper and lower blade members 19a and 19b may be simply referred to as the blade member 19 in some cases.

The blade 18 (blade member 19 ) is urged toward the roller 45 . The blade 18 has a rear surface 18b on the opposite side of the front end surface 18a in the radial direction (advancing and retreating direction) of the cylinder chamber 37c. The blade 18 receives the case internal pressure (the pressure of the gas refrigerant in the closed case 34, the same shall apply hereinafter) at the rear surface 18b. The blade 18 is urged toward the roller 45 only by receiving the internal pressure of the case on the back surface 18b. An urging member such as a spring is not provided on the back surface 18 b side of the blade 18 . For example, the tip surface 18a of the blade 18 has an arcuate shape when viewed from the axial direction. A tip surface 18a of the blade 18 is subjected to a surface hardening treatment such as DLC coating. For example, the rear surface 18b of the blade 18 has a flat shape perpendicular to the advancing/retreating direction when viewed from the axial direction. Reference numeral 34c in the drawing indicates a communication portion in the case facing the rear surface 18b of the blade 18. As shown in FIG. The case internal pressure acts on the case internal communication portion 34c by communicating with the inside of the closed case 34 .

A blade 18 (a pair of blade members 19a and 19b) is slidably held in the blade groove 18c. The pair of blade members 19a and 19b can individually slide (advance and retreat) along the radial direction with respect to the blade groove 18c.

The blades 18 are urged by the pressure of the high-pressure gaseous refrigerant inside the sealed case 34 (case internal pressure). The blades 18 are urged radially inward (towards the rollers 45). The blade 18 contacts the outer peripheral surface of the roller 45 with the tip surface 18a. The blade 18 maintains a state in which the tip surface 18 a is in contact with the outer peripheral surface of the roller 45 . The blade 18 advances and retreats in the radial direction as the roller 45 rotates eccentrically.
The low-stage compression mechanism 37 compresses the gas refrigerant by the eccentric rotation of the roller 45 and the forward and backward movement of the blade 18 . The low-stage compression mechanism portion 37 compresses the gas refrigerant in the low-pressure side cylinder chamber 37c.

A suction hole 18d is formed in a part of the low-stage cylinder 37a in the circumferential direction. The suction hole 18d radially penetrates the low-stage cylinder 37a. 18 d of suction holes are arrange|positioned as follows in the eccentric rotation direction of the roller 45 (arrow F direction in FIG. 3, also the rotation direction of the rotating shaft 31). The suction hole 18d is arranged downstream of the blade groove 18c (on the left side of the blade groove 18c in FIG. 3). A suction pipe 6 extending from the accumulator 12 is connected to the radially outer side of the suction hole 18d.

Referring to FIG. 2 , the high-stage compression mechanism portion 38 includes blades (high-stage side blades) 21 , similarly to the low-stage compression mechanism portion 37 . The blade 21 divides the cylinder chamber 38 c into the suction chamber 16 and the compression chamber 17 . The blade 21 of the high stage compression mechanism 38 is composed of one blade member (high stage side blade member) 22 . In the drawing, reference numeral 21a indicates the tip surface of the blade 21, and reference numeral 21b indicates the rear surface of the blade 21, respectively. Illustration similar to FIG. 3 of the high-stage compression mechanism 38 is omitted.

The blade member 22 is biased toward the roller 46 by receiving the internal pressure of the case on the rear surface 21b. The blade member 22 is also urged toward the roller 46 by an urging spring 23 (for example, a coil spring) contracted on the back surface 21b side. That is, the high-stage compression mechanism section 38 includes a biasing spring 23 that biases the blade member 22 . The high-stage compression mechanism 38 has the following effects when the multi-stage rotary compressor 2 is started. The high-stage compression mechanism 38 urges the blade member 22 toward the roller 46 even when the internal pressure of the case is low. The high-stage compression mechanism 38 can compress and increase the pressure of the sucked refrigerant even when the internal pressure of the case is low.

The action of the blade 21 composed of one blade member 22 will be described. The blade member 22 of the blade 21 is biased toward the roller 46 by receiving the internal pressure of the case on the rear surface 21b extending over the entire axial direction. The action of the blade 18 composed of a plurality of blade members 19 will be described. Each blade member 19 of the blade 18 is biased by the case internal pressure on the back surface 18b of a part (half) of the blade 18 in the axial direction.
The back side of each blade member 19, 22 is slidably held by cylinders 37a, 38a. The cross-sectional areas of the blade members 19 and 22 on the back side will be described below. The cross-sectional area is a cross-sectional area when each blade member 19, 22 is cut along a cross plane orthogonal to the advancing/retreating direction. The cross-sectional area per blade member 19 is smaller than the cross-sectional area of one blade member 22 .

The biasing force that each blade member 19, 22 receives from the case internal pressure is calculated by multiplying the cross-sectional area of each blade member 19, 22 by the case internal pressure. The biasing force that each of the divided blade members 19 receives from the case internal pressure is smaller than the biasing force that the integral blade member 22 receives from the case internal pressure. The biasing force that each blade member 19 of the low-stage compression mechanism portion 37 receives from the case internal pressure is smaller than the biasing force that the integrated blade member 22 of the high-stage compression mechanism portion 38 receives from the case internal pressure.

The number of blade members 19 in the low-stage compression mechanism portion 37 is greater than the number of blade members 22 in the high-stage compression mechanism portion 38 . The number of blade members 19 of the low-stage compression mechanism portion 37 is not limited to two. For example, the number of blade members 19 of the low-stage compression mechanism portion 37 may be three or more.
The number of blade members 22 of the high-stage compression mechanism portion 38 is not limited to one. For example, the number of blade members 22 of the high-stage compression mechanism portion 38 may be plural. The blade member 22 of the high-stage compression mechanism portion 38 may be divided into a plurality of pieces. The number of blade members 22 in the high-stage compression mechanism portion 38 is smaller than the number of blade members 19 in the low-stage compression mechanism portion 37 .

The blade members 19 and 22 of the low-stage compression mechanism portion 37 and the high-stage compression mechanism portion 38 are not limited to being divided in the axial direction. The blade members 19 and 22 of the low-stage compression mechanism portion 37 and the high-stage compression mechanism portion 38 may be divided in the circumferential direction.

Each of the blades 18, 21 of the low-stage compression mechanism portion 37 and the high-stage compression mechanism portion 38 is composed of at least one blade member 19, 22, respectively. The cross-sectional area of each of the blade members 19 and 22 when cut along a cross plane perpendicular to the advancing/retreating direction will be described below. The cross-sectional area per low-stage blade member 19 is smaller than the cross-sectional area per high-stage blade member 19 . The roller pressing force per low-stage blade member 22 is kept lower than the roller pressing force per high-stage blade member 19 .

Each of the compression mechanisms 37 and 38 exerts the following actions by the eccentric rotation of the rollers 45 and 46. As shown in FIG. Each of the compression mechanisms 37 and 38 performs a suction operation of sucking the gaseous refrigerant into the suction chamber 16 and a compression operation of compressing the gaseous refrigerant in the compression chamber 17 .
In the low-stage compression mechanism portion 37, the low-pressure gas refrigerant is sucked from the accumulator 12 by the suction operation. In the low-stage compression mechanism 37, the sucked gas refrigerant is compressed by the compression operation and raised to an intermediate pressure. The gas refrigerant pressurized by the low stage compression mechanism portion 37 is discharged into the intermediate pressure chamber 39c of the partition plate 39 . The gas refrigerant pressurized by the low stage compression mechanism portion 37 is discharged into the intermediate pressure chamber 39c through the discharge hole 47a. The discharge hole 47 a is provided in the partition plate 39 .

In the high-stage compression mechanism portion 38, the intermediate-pressure gas refrigerant is sucked from the intermediate-pressure chamber 39c by the suction operation. In the high-stage compression mechanism 38, the sucked gas refrigerant is further compressed by the compression operation described above to raise the pressure to a high pressure. The gas refrigerant pressurized by the high-stage compression mechanism 38 is discharged outside the cylinder chamber 38c (inside the closed case 34). The gas refrigerant pressurized by the high-stage compression mechanism 38 is discharged into the sealed case 34 through the discharge hole 49a. The discharge hole 49 a is provided in the flange portion 42 b of the second bearing 42 .

The partition plate 39 is formed in an annular shape centered on the axis C. As shown in FIG. The partition plate 39 is axially divided into a plurality of partition plate members 39a and 39b (a pair of upper and lower members in this embodiment). Each partition plate member 39a, 39b has a concave cross-sectional shape with the other side concave. Each of the partition plate members 39a and 39b has the concave cross-sectional shape and extends annularly. The partition plate members 39a and 39b are connected to each other with the open side of the concave cross-sectional shape facing the other side. Inside the partition plate 39, an intermediate pressure space (intermediate pressure chamber) 39c is formed by the concave cross-sectional shape. The partition plate 39 is divided into a pair of partition plate members 39a and 39b to facilitate formation of the intermediate pressure space 39c. The partition plate 39 is divided into a pair of partition plate members 39a and 39b to facilitate installation of a discharge valve device 47, which will be described later, on the partition plate 39. As shown in FIG.

By providing the intermediate pressure space 39c in the partition plate 39, the volume of the intermediate pressure space 39c is ensured. By ensuring the volume of the intermediate pressure space 39c, the discharge pulsation of the gas refrigerant from the low-stage compression mechanism portion 37 is suppressed. By securing the volume of the intermediate pressure space 39c, the suction pulsation of the gas refrigerant to the high-stage compression mechanism portion 38 is suppressed.
A discharge valve device 47 is provided on the end face of the partition plate 39 on the low-stage compression mechanism portion 37 side. The discharge valve device 47 can discharge the intermediate-pressure gas refrigerant compressed by the low-stage compression mechanism portion 37 into the intermediate-pressure space 39c.

The intermediate-pressure gas refrigerant discharged from the low-stage compression mechanism portion 37 into the intermediate-pressure space 39c is guided to the second suction portion 14a. The second suction portion 14 a communicates with the high-stage compression mechanism portion 38 via the intermediate pressure passage 7 . The intermediate-pressure gas refrigerant guided through the intermediate-pressure passage 7 is cooled by an intercooler 7a in the middle of the intermediate-pressure passage 7. As shown in FIG. The cooled intermediate-pressure gas refrigerant is guided to the high-stage compression mechanism portion 38 . The intermediate-pressure gas refrigerant separated from gas and liquid in the second accumulator 8 is guided to the high-stage compression mechanism 38 via the bypass passage 8a. The bypass passage 8a merges with the intermediate pressure passage 7 in the middle. The intermediate-pressure gas refrigerant introduced to the second suction portion 14 a is compressed by the high-stage compression mechanism portion 38 .

In the multistage rotary compressor 2, the gas refrigerant compressed in the low-stage compression mechanism 37 has a predetermined intermediate pressure. When the gas refrigerant reaches the intermediate pressure in the low stage compression mechanism portion 37, the discharge valve device 47 of the partition plate 39 opens. When the discharge valve device 47 of the partition plate 39 is opened, intermediate pressure gas refrigerant is discharged into the intermediate pressure space 39c. This gas refrigerant is guided into the cylinder chamber 38 c of the high-stage compression mechanism portion 38 . The intermediate-pressure gas refrigerant introduced into the cylinder chamber 38 c is compressed to a high pressure by the compression operation of the high-stage compression mechanism 38 .

A high-stage discharge valve device 49 is provided on the flange portion 42 b of the second bearing 42 . The high-stage discharge valve device 49 enables the high-pressure gas refrigerant compressed by the high-stage compression mechanism 38 to be discharged outside the cylinder chamber 38c.
The high-stage compression mechanism section 38 compresses the gas refrigerant to a predetermined high pressure. When the gas refrigerant becomes high pressure in the high-stage compression mechanism portion 38, the high-stage side discharge valve device 49 of the second bearing 42 opens. When the high-stage discharge valve device 49 is opened, high-pressure gas refrigerant is discharged outside the cylinder chamber 38c. This gas refrigerant is discharged into the space in the second muffler 44 (second muffler chamber 44a). After that, the gas refrigerant is appropriately discharged into the sealed case 34 .

The high-pressure gas refrigerant discharged into the second muffler chamber 44 a passes through the discharge passage 33 a within the compression element 33 . This gas refrigerant reaches the space in the first muffler 43 (first muffler chamber 43a). For example, the discharge passage 33a is formed so as to axially penetrate the outer peripheral sides of the second bearing 42, the low-stage cylinder 37a, the partition plate 39, the high-stage cylinder 38a, and the first bearing 41. As shown in FIG. The gas refrigerant reaching the first muffler chamber 43 a is discharged into the sealed case 34 through a discharge hole appropriately provided in the first muffler 43 .

A lower end portion of the rotating shaft 31 is immersed in the lubricating oil J stored in the bottom portion of the sealed case 34 . The lower end of the rotating shaft 31 is immersed in the lubricating oil J together with the second muffler 44 .
An oil supply path is formed in the rotating shaft 31 . The oil supply path supplies lubricating oil J to each sliding portion of the compression element 33 . The sliding portions of the compression element 33 are between the eccentric portions 31b, 31d and the rollers 45, 46, between the rotating shaft 31 and the bearings 41, 42, between the rollers 45, 46 and the blades 18, 21, etc.

The oil supply path of the rotating shaft 31 includes an axial flow path 95 and a first radial flow path 96 and a second radial flow path 97 . The axial flow path 95 extends coaxially with the axis C. As shown in FIG. A first radial channel 96 and a second radial channel 97 each extend radially from the axial channel 95 .
The axial flow path 95 opens downward at the lower end of the rotary shaft 31 at its lower end. An upper end portion of the axial flow path 95 terminates within the first main shaft 31a above the low-stage cylinder 37a. Lubricating oil J in the closed case 34 can flow into the axial flow path 95 .

The first radial flow path 96 is formed at a connecting portion between the first main portion 88 and the eccentric portion 31b of the rotating shaft 31 . A radially inner end of the first radial channel 96 opens into the axial channel 95 . A radially outer end of the first radial flow path 96 is open radially outward on the outer peripheral surface of the rotating shaft 31 (in the figure, inside an oil groove extending in the circumferential direction).
The second radial flow path 97 is formed at a connecting portion of the rotating shaft 31 between the third main shaft 31e and the eccentric portion 31d. A radially inner end of the second radial channel 97 opens into the axial channel 95 . A radially outer end of the second radial flow path 97 is open radially outward on the outer peripheral surface of the rotating shaft 31 (in the figure, inside an oil groove extending in the circumferential direction).

When the compression element 33 is driven, the internal pressure of the case increases. When the case internal pressure rises, the lubricating oil J is pushed up into the axial flow path 95 from the lower end of the rotating shaft 31 . This lubricating oil J receives centrifugal force due to the rotation of the rotating shaft 31 . This centrifugal force distributes and feeds the lubricating oil J from the axial flow path 95 to the radial flow paths 96 and 97 . The lubricating oil J that has reached the radial flow paths 96 and 97 flows out on the outer peripheral surface of the rotating shaft 31 . The lubricating oil J flowing out to the outer peripheral surface of the rotating shaft 31 is appropriately supplied to the sliding portion of the compression element 33 . The lubricating oil J flows back to the bottom of the sealed case 34 . The lubricating oil J that has returned to the bottom of the closed case 34 is again supplied to the sliding portion of the compression element 33 .

Next, operation of the multistage rotary compressor 2 will be described.
When the multistage rotary compressor 2 is started, power is supplied to the stator 35 of the electric motor 32 . When power is supplied to the stator 35 , the rotating shaft 31 rotates around the axis C together with the rotor 36 . When the rotary shaft 31 rotates, the eccentric portions 31b, 31d and the rollers 45, 46 of the compression mechanisms 37, 38 rotate eccentrically within the cylinder chambers 37c, 38c.

The rollers 45, 46 of both compression mechanisms 37, 38 are in rolling contact with the inner peripheral surfaces of the cylinder holes 37b, 38b. Each blade 18, 21 operates as follows. The blade 21 of the high-stage compression mechanism 38 is brought into sliding contact with the roller 46 by the biasing force of the biasing spring 23 . When the internal pressure of the case is low, the blade 18 of the low-stage compression mechanism 37 stays in the blade groove 18c. When the multi-stage rotary compressor 2 is started, only the cylinder chamber 38c of the high-stage compression mechanism section 38 compresses the gas refrigerant. A cylinder chamber 38c of the high-stage compression mechanism portion 38 is divided into a suction side and a compression side even when the multi-stage rotary compressor 2 is started. As a result, the gas refrigerant is compressed in the high-stage compression mechanism section 38 .

After the multistage rotary compressor 2 is started, when the sealed case 34 is filled with the high-pressure gas refrigerant discharged from the high-stage compression mechanism 38, the following effects occur. That is, the blade 18 of the low-stage compression mechanism 37 is urged toward the roller 45 by the internal pressure of the case, and begins sliding contact with the roller 45 . When the blade 18 slides on the roller 45, the cylinder chamber 37c of the low-stage compression mechanism 37 is divided into a suction side and a compression side. As a result, the compression of the gas refrigerant is started in the low-stage compression mechanism portion 37 .

The low-pressure gas refrigerant separated from gas and liquid in the accumulator 12 flows through the suction pipe 6 . This gas refrigerant is guided into the cylinder chamber 37 c of the low-stage compression mechanism portion 37 via the suction pipe 6 . The low-pressure gas refrigerant introduced into the cylinder chamber 37c is compressed in the low-stage compression mechanism 37 to a predetermined intermediate pressure. When the gas refrigerant reaches a predetermined intermediate pressure, the discharge valve device 47 of the partition plate 39 opens. The intermediate pressure gas refrigerant is discharged into the intermediate pressure space 39 c of the partition plate 39 through the discharge valve device 47 .

The gas refrigerant discharged into the intermediate pressure space 39 c is sucked into the high stage compression mechanism portion 38 via the intermediate pressure passage 7 .
The gas refrigerant sucked into the high-stage compression mechanism portion 38 is boosted from intermediate pressure to a predetermined high pressure. When the gas refrigerant reaches a predetermined high pressure, the high stage side discharge valve device 49 of the second bearing 42 opens. Through this high stage side discharge valve device 49, high pressure gas refrigerant is discharged into the second muffler chamber 44a. The gas refrigerant discharged into the second muffler chamber 44a reaches the first muffler chamber 43a through the discharge passage 33a. This gas refrigerant is appropriately discharged into the sealed case 34 .

The high-pressure gas refrigerant discharged into the closed case 34 circulates through the radiator 3, the expansion device 4, the evaporator 5, etc., and returns to the low-pressure gas refrigerant. The gas refrigerant that has returned to the low pressure is introduced again into the cylinder chamber 37c of the low-stage compression mechanism portion 37, and repeats the above-described process.

The inside of the cylinder chamber 37 c of the low-stage compression mechanism portion 37 is partitioned into a suction side and a compression side by the blade 18 . The inside of the cylinder chamber 38 c of the high-stage compression mechanism portion 38 is partitioned into a suction side and a compression side by the blade 21 . Each blade 18, 21 is urged toward the rollers 45, 46 by the internal pressure of the case. The pressure difference on both sides of the low-stage blade 18 in the advancing/retreating direction is greater than the pressure difference on both sides of the high-stage blade 21 in the advancing/retreating direction. The pressing force of the blade 18 on the low stage side is greater than the pressing force of the blade 21 on the high stage side.

The height of the cylinder on the low stage side is greater than the height of the cylinder on the high stage side. The cross-sectional area of the blade 18 on the low stage side is larger than the cross-sectional area of the blade 21 on the high stage side. The pressing force of the blade 18 on the low stage side is greater than the pressing force of the blade 21 on the high stage side.

When the eccentric portions 31b and 31d rotate, the rotary shaft 31 bends. When the rotary shaft 31 bends, the blades 18 and 21 are likely to come into contact with the rollers 45 and 46 in an uneven manner. When the blades 18 and 21 come into contact with each other, uneven wear occurs in the sliding portions between the blades 18 and 21 and the rollers 45 and 46 . On the low stage side where both the cross-sectional area of the blade 18 and the pressure difference are large, uneven wear of the sliding portion is likely to occur.

In the multi-stage rotary compressor 2 of this embodiment, the low-stage blade 18 is divided into a plurality of blade members 19 . The blade 21 on the high stage side is composed of a single blade member 22 . The cross-sectional area of each blade member 19, 22 is set as follows. That is, the cross-sectional area of the blade member 19 of the low-stage compression mechanism portion 37 is smaller than the cross-sectional area of the blade member 22 of the high-stage compression mechanism portion 38 .

With this configuration, the cross-sectional area per blade member 19 in the low-stage compression mechanism portion 37 is reduced. In the low-stage compression mechanism portion 37, the pressure difference on both sides of the blade 18 in the advancing/retreating direction increases. In the low-stage compression mechanism portion 37, the roller pressing force per blade member 19 is relaxed. As a result, the influence of uneven contact between the sliding portion between the roller 45 and the blade 18 due to deflection of the rotating shaft 31 or the like can be suppressed. That is, the roller pressing force of the blade member 19 is relaxed, and uneven wear of the sliding portion between the roller 45 and the blade 18 is suppressed. Therefore, a highly reliable multistage rotary compressor 2 can be provided.

In the multi-stage rotary compressor 2 of the present embodiment, the number of blade members 19 in the low-stage compression mechanism section 37 is greater than the number of blade members 22 in the high-stage compression mechanism section 38 .
With this configuration, the cross-sectional area of each blade member 19 of the low-stage compression mechanism 37 can be easily reduced. Therefore, uneven wear at the sliding portion between the roller 45 and the blade 18 can be suppressed.

In the multi-stage rotary compressor 2 of this embodiment, the plurality of blade members 19 of the low-stage compression mechanism portion 37 are arranged in the axial direction of the rotating shaft 31 .
With this configuration, the cross-sectional area of each blade member 19 of the low-stage compression mechanism 37 can be easily reduced. Since the cross-sectional area of the blade member 19 is small, the blade 18 as a whole easily follows the deflection of the rotating shaft 31 . Therefore, uneven wear at the sliding portion between the roller 45 and the blade 18 can be suppressed.

In the multi-stage rotary compressor 2 of the present embodiment, the blades 21 of the high-stage compression mechanism section 38 are formed of a single blade member 22 . The high-stage compression mechanism 38 has a biasing spring 23 that biases the single blade member 22 toward the roller 46 .
In this configuration, the single blade member 22 and the biasing spring 23 are provided in the high-stage compression mechanism portion 38 . A single blade member 22 is used in the high-stage compression mechanism portion 38 in which both the cross-sectional area and the pressure difference are smaller than those of the low-stage compression mechanism portion 37 . Therefore, the influence on the manufacturability and cost of the high-stage compression mechanism 38 can be suppressed.

For example, when a biasing member is provided on the low-stage blade 18 composed of a plurality of blade members 19, the following configuration is preferable. That is, it is preferable to provide a plurality of urging members for each blade member 19 . However, this configuration may lead to deterioration in manufacturability and increase in cost. The blades 18 of the low-stage compression mechanism portion 37 have a larger cross-sectional area and pressure difference than those of the high-stage compression mechanism portion 38 . The blade 18 of the low-stage compression mechanism 37 can obtain a sufficient pressing force against the roller 45 without providing an urging member. Therefore, the biasing member can be omitted from the low-stage compression mechanism 37 . Therefore, compared to the case where each of the plurality of blade members 19 is provided with an urging member, it is possible to suppress the impact on manufacturability and cost.
When the multistage rotary compressor 2 is started, for example, the internal pressure of the case is not acting (low). In this state, the high-stage compression mechanism section 38 compresses the working fluid to increase the internal pressure of the case. By eliminating the biasing member of the blade 18, the low-stage compression mechanism 37 reduces the roller pressing force corresponding to the biasing force of the biasing member.

In the multi-stage rotary compressor 2 of the present embodiment, one of the low-stage side and the high-stage side (high-stage compression mechanism portion 38) is provided with an urging member that urges the blade member. In the high-stage compression mechanism 38, the blade 21 functions even if the pressure inside the case is low. That is, the high-stage blade member 22 is urged toward the roller 46 even when the case internal pressure is not acting, such as when the multi-stage rotary compressor 2 is started. Therefore, even when the case internal pressure is not acting, the high-stage compression mechanism 38 can compress and pressurize the working fluid. That is, even if the pressure inside the case is low, the pressure inside the case can be increased by driving the high-stage compression mechanism 38 .
When the pressure inside the case rises, the blade 18 of the low-stage compression mechanism 37 also functions, and the low-stage compression mechanism 37 starts compressing the working fluid. Therefore, the working fluid can be compressed step by step by both compression mechanism portions 37 and 38 .

In the multi-stage rotary compressor 2 of this embodiment, the low-stage compression mechanism portion 37 and the high-stage compression mechanism portion 38 are provided with a first bearing 41 and a second bearing 42, respectively. The first bearing 41 and the second bearing 42 each support the rotating shaft 31 . The first bearing 41 and the second bearing 42 are provided on the opposite side of the partition plate 39 in the axial direction of the rotary shaft 31 . The axial length L1 of the first bearing 41 on the low-stage compression mechanism portion 37 side is longer than the axial length L2 of the second bearing 42 on the high-stage compression mechanism portion 38 side. The axial center position cp1 of the sliding portion in the low-stage compression mechanism portion 37 is closer to the first bearing 41 than the axial center position cp2 of the cylinder 37a in the low-stage compression mechanism portion 37 .

In this configuration, the eccentric portion 31b of the low-stage compression mechanism portion 37 approaches the first bearing 41 having a long shaft support portion. When the eccentric portion 31b approaches the first bearing 41, the tilt amount of the eccentric portion 31b (and thus the roller 45) of the low-stage compression mechanism portion 37 due to the bending of the rotating shaft 31 is suppressed. When the inclination of the roller 45 is suppressed, uneven contact at the sliding portion between the roller 45 and the blade 18 of the low-stage compression mechanism portion 37 is suppressed. Therefore, uneven wear of the sliding portion can be suppressed.

In the multi-stage rotary compressor 2 of the present embodiment, the intermediate-pressure gas refrigerant in the intermediate-pressure chamber 39 c is guided to the high-stage compression mechanism section 38 via the intermediate-pressure passage 7 . In addition, embodiment is not restricted to this structure. For example, the intermediate-pressure gas refrigerant may be directly sucked into the high-stage compression mechanism portion 38 from the intermediate-pressure chamber 39c. For example, a suction port may be formed on the end face of the partition plate 39 on the side of the high-stage compression mechanism 38 . This suction port draws the gas refrigerant in the intermediate pressure chamber 39 c into the cylinder chamber 38 c of the high-stage compression mechanism 38 .

The refrigeration cycle apparatus 1 of the present embodiment includes the multistage rotary compressor 2 described above, a radiator 3 connected to a discharge portion 15 of the multistage rotary compressor, and an expansion device connected downstream of the radiator 3. 4 and an evaporator 5 connected between the downstream side of the expansion device 4 and the inlet of the multistage rotary compressor 2 .
In this configuration, the refrigeration cycle apparatus 1 is provided with the multistage rotary compressor 2 described above, so that the following effects can be obtained. That is, it is possible to provide the refrigeration cycle apparatus 1 capable of improving operational reliability and compression performance over a long period of time.

According to at least one embodiment described above, the multi-stage rotary compressor 2 includes the low-stage compression mechanism 37 that compresses the working fluid to an intermediate pressure and the high-stage compression mechanism that compresses the intermediate-pressure working fluid to a high pressure. It has a part 38 and . Each of the low-stage compression mechanism portion 37 and the high-stage compression mechanism portion 38 has blades 18 and 21 that divide the cylinder chamber into a suction side and a compression side. The blade 18 of the low stage compression mechanism portion 37 has a plurality of blade members 19 . The blade 21 of the high-stage compression mechanism section 38 has one blade member 22 . The cross-sectional area of each blade member 19 is smaller than the cross-sectional area of one blade member 22 . As a result, the roller pressing force per blade member 19 of the low-stage compression mechanism 37 is relaxed. Also, uneven wear at the sliding portion between the roller 45 and the blade 18 is suppressed. Therefore, a highly reliable multistage rotary compressor 2 and refrigeration cycle apparatus 1 can be provided.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 1... Refrigeration cycle apparatus, 2... Multi-stage rotary compressor, 3... Radiator, 4... Expansion device, 5... Evaporator, 18... Low stage side blade, 18a... Roller contact surface (tip surface), 18b... Back surface , 19... Low stage side blade member 21... High stage side blade 21a... Roller contact surface (tip surface) 21b... Back surface 22... High stage side blade member 23... Biasing spring (biasing member) 31 Rotating shaft 31b Low-stage eccentric portion 31d High-stage eccentric portion 32 Electric motor (driving element) 33 Compression element 34 Closed case (case) 37 Low-stage compression mechanism , 37a low-stage cylinder, 37c low-stage cylinder chamber, cp2 axial center position, 38 high-stage compression mechanism, 38a high-stage cylinder, 38c high-stage cylinder chamber, 39 partition plate , 41... First bearing, L1... Axial length, 42... Second bearing, L2... Axial length, 45... Low stage side roller, cp1... Axial center position, 46... High stage side roller

Claims (6)

a case;
a rotating shaft housed inside the case;
a drive element housed inside the case and provided at one end in the axial direction of the rotating shaft;
a low-stage compression mechanism housed inside the case and provided on the other end in the axial direction of the rotating shaft for compressing a low-pressure working fluid to an intermediate pressure; and an intermediate pressure compressed by the low-stage compression mechanism. a compression element comprising: a high-stage compression mechanism that compresses the working fluid to a high pressure; and a partition plate that partitions between the low-stage compression mechanism and the high-stage compression mechanism;
with
The high-stage compression mechanism portion is disposed closer to the other axial end than the low-stage compression mechanism portion,
The low-stage compression mechanism section is
a low-stage cylinder that forms a low-stage cylinder chamber;
a low-stage roller mounted on a low-stage eccentric portion of the rotating shaft and eccentrically rotatable in the low-stage cylinder chamber;
The front end surface abuts on the outer peripheral surface of the low-stage side roller, and the pressure in the case acts on the back surface of the low-stage roller . a step-side blade;
The high-stage compression mechanism section includes:
a high-stage cylinder that forms a high-stage cylinder chamber;
a high-stage roller mounted on the high-stage eccentric portion of the rotary shaft and eccentrically rotatable in the high-stage cylinder chamber;
The front end surface abuts on the outer peripheral surface of the high-stage side roller, and the pressure in the case acts on the back surface of the high-stage side roller so that it can advance and retreat into the high-stage side cylinder chamber, and is composed of at least one high-stage side blade member. and a high-stage side blade,
A working fluid compressed by the high-stage compression mechanism is discharged into the internal space of the case,
In a cross section obtained by cutting the low-stage side blade member and the high-stage side blade member in a plane perpendicular to the advancing/retracting direction of each of the low-stage side blade members, the cross-sectional area per one of the low-stage side blade members is one of the high-stage side blade members. A multi-stage rotary compressor with a smaller cross-sectional area per piece. 2. The multi-stage rotary compressor according to claim 1, wherein the number of said low stage side blade members is greater than the number of said high stage side blade members. the number of the low stage side blade members is plural,
3. The multi-stage rotary compressor according to claim 1, wherein said plurality of low-stage blade members are arranged in the axial direction of said rotating shaft. the number of the low stage side blade members is plural,
The number of the high stage side blade members is one,
The high-stage compression mechanism includes a biasing member that biases the high-stage blade member toward the high-stage roller,
4. The multi-stage rotary type according to any one of claims 1 to 3, wherein the low-stage compression mechanism does not include an urging member that urges the low-stage blade member toward the low-stage roller. compressor. A first bearing and a second bearing supporting the rotating shaft are provided on opposite sides of the partition plate of the low-stage compression mechanism portion and the high-stage compression mechanism portion, respectively,
The axial length of the portion of the first bearing on the low-stage compression mechanism side that slides with the rotating shaft is the axial length of the portion that slides on the rotating shaft of the second bearing on the high-stage compression mechanism side. longer than length
The axial center position of the sliding portion between the low-stage side eccentric portion and the low-stage side roller of the low-stage compression mechanism section is the same as the axial center position of the low-stage cylinder of the low-stage compression mechanism section. 5. A multi-stage rotary compressor according to any one of claims 1 to 4, close to the first bearing. A multistage rotary compressor according to any one of claims 1 to 5, a radiator connected to a discharge portion of the multistage rotary compressor, and an expansion device connected downstream of the radiator. and an evaporator connected between a downstream side of the expansion device and an inlet of the multistage rotary compressor.

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