EP4756230A1

EP4756230A1 - Rotary compressor and refrigeration device provided with same

Info

Publication number: EP4756230A1
Application number: EP25855414.6A
Authority: EP
Inventors: Daiki KIKUTAKE; Yohei Nishide; Naoki Masuda; Hiromichi Ueno
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 2024-09-26
Filing date: 2025-09-12
Publication date: 2026-06-10
Also published as: WO2026070457A1; JP2026059587A; JP7869477B2

Abstract

A first cylinder (31) is provided with a first valve housing portion (31j) recessed from the inner peripheral surface toward the outer side and housing a first reed valve (63) and a valve retainer (64). The valve retainer (64) has a first surface (64b) facing the first reed valve (63) and a second surface (64c) opposite to the first surface (64b). A center line (C1) extending in the longitudinal direction of the first reed valve (63) crosses an opening of the first valve housing portion (31j) that is close to the first cylinder chamber (S1). A first edge (31k) that is located on the opening of the first valve housing portion (31j) which is close to the first cylinder chamber (S1) and that is close to the valve attachment surface (31g) is located closer to the second surface (64c) of the valve retainer (64) than the valve attachment surface (31g) in a first direction orthogonal to the valve attachment surface (31g).

Description

TECHNICAL FIELD

The present disclosure relates to a rotary compressor and a refrigeration apparatus including the rotary compressor. The rotary compressor is a compressor that eccentrically rotates a roller in a cylinder to compress gas in a cylinder chamber formed in the cylinder. In general, the rotary compressor has a vane for dividing the cylinder chamber. The rotary compressor includes a so-called rolling-piston-type compressor in which a roller eccentrically rotates while a vane separate from the roller contacts the roller; a so-called swing-type compressor in which a vane integrated with a roller swings as the roller eccentrically rotates; a so-called hinge-vane-type compressor in which a roller eccentrically rotates while the tip end of a vane is rotatably fitted in a recess of the outer peripheral surface of the roller; and the like.

BACKGROUND ART

Patent Document 1 discloses a rotary compressor having an injection flow path. The rotary compressor includes a cylinder provided with a valve housing portion recessed from the inner peripheral surface of a cylinder chamber toward the outer side. The end portion of the valve housing portion that is close to the cylinder chamber extends in the radial direction of the cylinder. On the other hand, part of the valve housing portion that is other than the end portion close to the cylinder chamber is inclined so as to be distant from a cylinder intake port while extending toward the outer side of the cylinder in the radial direction. A reed valve is housed in this part of the valve housing portion that is other than the end portion close to the cylinder chamber. The valve attachment surface of the valve housing portion is provided with an injection opening that is opened and closed by the reed valve.

CITATION LIST

PATENT DOCUMENT

Patent Document 1: Chinese Patent No. 104791251

SUMMARY OF THE INVENTION

TECHNICAL PROBLEM

In Patent Document 1, the center line extending in the longitudinal direction of the reed valve does not cross the opening of the valve housing portion that is close to the cylinder chamber. Therefore, if the pressure of a refrigerant in the cylinder chamber becomes higher than an intermediate pressure, the reed valve is obliquely pressed onto the valve attachment surface by the pressure of a refrigerant in the cylinder chamber, and the reed valve may be cracked easily.
An object of the present disclosure is to suppress cracking of the reed valve caused by the pressure of refrigerant from a cylinder chamber.

SOLUTION TO THE PROBLEM

A first aspect of the technique disclosed herein is directed to a rotary compressor having an injection flow path (61), including: a piston (34, 44); a drive shaft (90) configured to drive the piston (34, 44); a first bearing (56) and a second bearing (50) supporting the drive shaft (90); a cylinder (31, 41) housing the piston (34, 44) and having a cylinder chamber (S1, S2) defined by an inner peripheral surface; a reed valve (63, 66) disposed in the injection flow path (61); and a valve retainer (64, 67) having a first surface (64b) facing the reed valve (63, 66) and a second surface (64c) opposite to the first surface (64b), wherein the cylinder (31, 41) is provided with a valve housing portion (31j, 41j) recessed from the inner peripheral surface toward an outer side and housing the reed valve (63, 66) and the valve retainer (64, 67), a valve attachment surface (31g, 41g), which is a surface of the valve housing portion (31j, 41j) that is close to the first bearing (56) or the second bearing (50), is provided with an injection opening (31b, 41b) that is opened and closed by the reed valve (63, 66), the reed valve (63, 66) is fixed to the valve attachment surface (31g, 41g) of the valve housing portion (31j, 41j) on an outer side of the cylinder (31, 41) in a radial direction than the injection opening (31b, 41b), a center line (C1, C2) extending in a longitudinal direction of the reed valve (63, 66) crosses an opening of the valve housing portion (31j, 41j) that is close to the cylinder chamber (S1, S2), and a first edge (31k) that is located on an opening of the valve housing portion (31j, 41j) which is close to the cylinder chamber (S1, S2) and that is close to the valve attachment surface (31g, 41g) is located closer to the second surface (64c) of the valve retainer (64, 67) than the valve attachment surface (31g, 41g) in a first direction orthogonal to the valve attachment surface (31g, 41g).
In the first aspect, the center line (C1, C2) extending in the longitudinal direction of the reed valve (63, 66) crosses the opening of the valve housing portion (31j, 41j) that is close to the cylinder chamber (S1, S2), and therefore the pressure of a refrigerant from the cylinder chamber (S1, S2) acts in a well-balanced manner on both sides of the center line (C1, C2) of the reed valve (63, 66) compared with when the center line (C1, C2) does not cross the opening of the valve housing portion (31j, 41j). Accordingly, it is possible to suppress cracking of the reed valve (63, 66) caused by the pressure of a refrigerant from the cylinder chamber (S1, S2).
A second aspect of the technique disclosed herein is an embodiment of the first aspect. In the second aspect, the first edge (31k) is located closer to the second surface (64c) of the valve retainer (64, 67) in the first direction than an edge of the first surface (64b) of the valve retainer (64, 67) that is close to the cylinder chamber (S1, S2).
In the second aspect, the refrigerant less likely flows from the cylinder chamber (S1, S2) into the space between the reed valve (63, 66) and the valve attachment surface (31g, 41g). Accordingly, it is possible to reduce formation of a high-pressure portion between the reed valve (63, 66) and the valve attachment surface (31g, 41g), where the high-pressure portion interferes with an operation of closing the reed valve (63, 66).
A third aspect of the technique disclosed herein is an embodiment of the first or second aspect. In the third aspect, an intermediate surface (31m) is formed between the first edge (31k) and the valve attachment surface (31g, 41g), and the intermediate surface (31m) is located closer to the second surface (64c) of the valve retainer (64, 67) in the first direction than the valve attachment surface (31g, 41g).
A fourth aspect of the technique disclosed herein is an embodiment of the third aspect. In the fourth aspect, the intermediate surface (31m) includes a plurality of intermediate surfaces (31m).
In the fourth aspect, it is possible to allow the refrigerant to flow more smoothly from the cylinder chamber (S1, S2) into the space between the reed valve (63, 66) and the valve retainer (64, 67) compared with when only one intermediate surface (31m) is formed.
A fifth aspect of the technique disclosed herein is an embodiment of any one of the third or fourth aspect. In the fifth aspect, a length in the first direction between the intermediate surface (31m) and the valve attachment surface (31g, 41g) is greater than or equal to a thickness of the reed valve (63, 66).
In the fifth aspect, the refrigerant less likely flows from the cylinder chamber (S1, S2) into the space between the reed valve (63, 66) and the valve attachment surface (31g, 41g). Accordingly, it is possible to reduce formation of a high-pressure portion between the reed valve (63, 66) and the valve attachment surface (31g, 41g), where the high-pressure portion interferes with an operation of closing the reed valve (63, 66).
A sixth aspect of the technique disclosed herein is an embodiment of the first or second aspect. In the sixth aspect, an inclined surface (31n) is formed between the first edge (31k) and the valve attachment surface (31g, 41g), and the inclined surface (31n) is inclined toward the valve attachment surface (31g, 41g) in the first direction while extending toward the injection opening (31b, 41b).
In the sixth aspect, it is possible to allow the refrigerant to flow smoothly from the cylinder chamber (S1, S2) into the space between the reed valve (63, 66) and the valve retainer (64, 67) along the inclined surface (31n).
A seventh aspect of the technique disclosed herein is an embodiment of any one of the first to sixth aspects. In the seventh aspect, a refrigerant is CO₂.
In the seventh aspect, CO₂ with a relatively high pressure is employed as a refrigerant, so the reed valve (63, 66) may be cracked easily. However, the center line (C1, C2) extending in the longitudinal direction of the reed valve (63, 66) crosses the opening of the valve housing portion (31j, 41j) that is close to the cylinder chamber (S1, S2), so it is possible to reduce cracking of the reed valve (63, 66).
An eighth aspect of the technique disclosed herein is directed to a refrigeration apparatus (100). The refrigeration apparatus (100) includes the rotary compressor (1) of any one of the first to seventh aspects.

BRIEF DESCRIPTION OF THE DRAWINGS

[FIG. 1] FIG. 1 is a piping system diagram of a refrigeration apparatus including a rotary compressor according to a first embodiment.
[FIG. 2] FIG. 2 is a plan view of the rotary compressor.
[FIG. 3] FIG. 3 is a sectional view taken along line III-III in FIG. 2.
[FIG. 4] FIG. 4 is a sectional view taken along line IV-IV in FIG. 7.
[FIG. 5] FIG. 5 is a sectional view taken along line V-V in FIG. 7.
[FIG. 6] FIG. 6 is a sectional view taken along line VI-VI in FIG. 2.
[FIG. 7] FIG. 7 is an enlarged view of a section VII in FIG. 6.
[FIG. 8] FIG. 8 is a partial sectional view taken along line VIII-VIII in FIG. 2.
[FIG. 9] FIG. 9 is a schematic bottom view of a first cylinder.
[FIG. 10] FIG. 10 is an enlarged view of a section X in FIG. 9.
[FIG. 11] FIG. 11 is a sectional view taken along line XI-XI in FIG. 10.
[FIG. 12] FIG. 12 corresponds to FIG. 11 and shows an enlarged view of the end portion and the surrounding area of a first valve housing portion that is close to the first cylinder chamber, where the first valve housing portion houses a first reed valve and a first valve retainer.
[FIG. 13] FIG. 13 shows operation of a compression mechanism.
[FIG. 14] FIG. 14 shows a second embodiment and corresponds to FIG. 12.
[FIG. 15] FIG. 15 shows a third embodiment and corresponds to FIG. 12.
[FIG. 16] FIG. 16 shows a fourth embodiment and corresponds to FIG. 12.
[FIG. 17] FIG. 17 shows a fifth embodiment and corresponds to FIG. 12.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present disclosure will be described in detail below with reference to the drawings. The present disclosure is not limited to the embodiments shown below, and various changes can be made within the scope without departing from the technical concept of the present disclosure. Since each of the drawings is intended to illustrate the present disclosure conceptually, dimensions, ratios, or numbers may be exaggerated or simplified as necessary for the sake of easy understanding. In the following description, unless otherwise specified, the "axial direction" indicates the direction in which the shaft extends, the "radial direction" indicates the direction which extends radially from the shaft, and the "circumferential direction" indicates the circumferential direction which extends around the shaft. The terms "top" and "bottom" refer to the directions of a rotary compressor (1) in front view. Some drawings may be illustrated without hatching for the sake of easy understanding of the description.

(First Embodiment)

(1) Refrigeration Apparatus

FIG. 1 shows a refrigeration apparatus (100) including a rotary compressor (1) according to a first embodiment. In the following, the rotary compressor (1) may be simply referred to as a compressor (1). The refrigeration apparatus (100) is an air conditioner for conditioning air in an indoor space, for example. The refrigeration apparatus (100) has an outdoor unit (7) disposed outdoors and an indoor unit (8) disposed indoors. The outdoor unit (7) includes the compressor (1), an accumulator (2), a four-way switching valve (3), an outdoor heat exchanger (4a), an economizer heat exchanger (4b), and an expansion valve (5). The indoor unit (8) includes an indoor heat exchanger (6). The outdoor unit (7) and the indoor unit (8) are connected via a connection pipe (9a) to form a refrigerant circuit (9).
The compressor (1) compresses a low-pressure gas refrigerant into a high-pressure gas refrigerant. The compressor (1) is driven by a compressor motor. The compressor (1) is supplied with part of an intermediate-pressure refrigerant flowing from the outdoor heat exchanger (4a) toward the expansion valve (5) in order to perform an intermediate injection. The intermediate pressure is a predetermined pressure between the pressure of gas refrigerant sucked into the compressor (1) (low pressure) and the pressure of gas refrigerant discharged from the compressor (1) (high pressure). The refrigerant is not particularly limited but may be carbon dioxide (CO₂), for example.
The four-way switching valve (3) switches the connection state of internal piping of the outdoor unit (7). When the refrigeration apparatus (100) performs a cooling operation, the four-way switching valve (3) turns to the connection state indicated by the broken lines in FIG. 1. When the refrigeration apparatus (100) performs a heating operation, the four-way switching valve (3) turns to the connection state indicated by the solid lines in FIG. 1.
The outdoor heat exchanger (4a) exchanges heat between the refrigerant circulating in the refrigerant circuit (9) and the outdoor air. The outdoor heat exchanger (4a) has a refrigerant flow path through which a refrigerant flows, and a heat transfer fin which is exposed to the outdoor air. The outdoor heat exchanger (4a) functions as a radiator (a condenser) for a refrigerant during the cooling operation, and functions as an absorber (an evaporator) for a refrigerant during the heating operation.
The expansion valve (5) is an electric valve or an electromagnetic valve of which the opening degree is adjustable. The expansion valve (5) decompresses a refrigerant flowing through the internal piping of the outdoor unit (7). The expansion valve (5) controls the flow rate of a refrigerant flowing through the internal piping of the outdoor unit (7).
The accumulator (2) is disposed in the suction-side piping of the compressor (1). The accumulator (2) separates a gas-liquid mixed refrigerant flowing in the refrigerant circuit into a gas refrigerant and a liquid refrigerant and then stores the liquid refrigerant. The gas refrigerant separated in the accumulator (2) is sent to a suction port of the compressor (1).
The economizer heat exchanger (4b) is disposed between the outdoor heat exchanger (4a) and the expansion valve (5). The economizer heat exchanger (4b) exchanges heat between a refrigerant flowing from the outdoor heat exchanger (4a) toward the expansion valve (5) and a refrigerant flowing through an economizer pipe (9b). The economizer pipe (9b) is a pipe branched from between the economizer heat exchanger (4b) and the expansion valve (5) in the refrigerant circuit (9) and connected to an injection pipe (9c) (described later). An economizer valve (9d) is attached to the economizer pipe (9b). The refrigerant flowing through the economizer pipe (9b) is decompressed by the economizer valve (9d), and then exchanges heat in the economizer heat exchanger (4b) with the refrigerant flowing from the outdoor heat exchanger (4a) toward the expansion valve (5). The refrigerant flowing from the outdoor heat exchanger (4a) toward the expansion valve (5) and the refrigerant having exchanged heat in the economizer heat exchanger (4b) are supplied to the injection pipe (9c) as intermediate-pressure refrigerants.
The refrigeration apparatus (100) includes the refrigerant circuit (9). The compressor (1), the four-way switching valve (3), the outdoor heat exchanger (4a), the expansion valve (5), the indoor heat exchanger (6), and the economizer heat exchanger (4b) are connected to the refrigerant circuit (9). The refrigerant flows through the refrigerant circuit (9) to create a refrigeration cycle.
The refrigeration apparatus (100) performs the heating operation and the cooling operation by switching the four-way switching valve (3). In the cooling operation, a first refrigeration cycle is performed. Specifically, in the connection state indicated by the broken lines in FIG. 1, the indoor heat exchanger (6) functions as an evaporator, and the outdoor heat exchanger (4a) functions as a radiator. In the heating operation, a second refrigeration cycle is performed. Specifically, in the connection state indicated by the solid lines in FIG. 1, the indoor heat exchanger (6) functions as a radiator, and the outdoor heat exchanger (4a) functions as an evaporator.

(2) Rotary Compressor

FIGS. 2 to 8 show the compressor (1). As shown in FIGS. 3 and 6 in particular, the compressor (1) includes a casing (10), an electric motor (20), and a compression mechanism (30). The electric motor (20) and the compression mechanism (30) are housed in the casing (10). The compressor (1) is a so-called high-pressure dome-type compressor where the refrigerant compressed in the compression mechanism (30) is discharged into an internal space (R) of the casing (10) so that the pressure in the internal space (R) becomes high.

(2-1) Rotary Compressor

The casing (10) is vertically long. Specifically, the casing (10) includes a barrel portion (11) formed in a cylindrical shape and extending in the top-bottom direction, an upper lid portion (12) closing the upper end of the barrel portion (11), and a lower lid portion (13) closing the lower end of the barrel portion (11). A discharge pipe (15) is inserted into an upper portion of the barrel portion (11). A suction pipe (14) is disposed in a lower portion of the barrel portion (11).

(2-2) Electric Motor

The electric motor (20) is housed in the casing (10). The electric motor (20) drives the compression mechanism (30). The electric motor (20) is disposed above a mounting plate (54). The electric motor (20) has a stator (21) formed in a tubular shape along the inner peripheral surface of the barrel portion (11), and a rotor (22) disposed inside the stator (21).

(2-3) Shaft

A shaft (90) is disposed so as to extend in the vertical direction in the casing (10). That is, the axial direction of the shaft (90) is the vertical direction. The shaft (90) is driven by the electric motor (20). An upper portion of the shaft (90) is coupled to the rotor (22) of the electric motor (20). The shaft (90) drives a first piston (34) and a second piston (44).
A lower portion of the shaft (90) has an upper shaft portion (90a), a first eccentric portion (91), an intermediate shaft portion (90b), a second eccentric portion (92), and a lower shaft portion (90c) in sequence from top to bottom. The upper shaft portion (90a), the first eccentric portion (91), the intermediate shaft portion (90b), the second eccentric portion (92), and the lower shaft portion (90c) are integrated together.
The first eccentric portion (91) and the second eccentric portion (92) are eccentric with respect to the axis of the shaft (90). The first eccentric portion (91) and the second eccentric portion (92) have larger diameters than those of the upper shaft portion (90a), the intermediate shaft portion (90b), and the lower shaft portion (90c). The eccentric direction of the first eccentric portion (91) with respect to the rotation axis of the shaft (90) is different by 180° from the eccentric direction of the second eccentric portion (92) with respect to the rotation axis of the shaft (90).
The intermediate shaft portion (90b) is disposed between the first eccentric portion (91) and the second eccentric portion (92). The intermediate shaft portion (90b) couples the first eccentric portion (91) and the second eccentric portion (92).

(2-4) Compression Mechanism

The compression mechanism (30) is disposed inside the casing (10). The compression mechanism (30) compresses a sucked refrigerant and discharges a compressed refrigerant to the internal space (R) of the casing (10). The compression mechanism (30) is fixed to the mounting plate (54) fixed to the inner peripheral surface of the barrel portion (11). Specifically, the compression mechanism (30) is disposed on the lower surface of the mounting plate (54). The compression mechanism (30) has two cylinders. The compression mechanism (30) includes the shaft (90) as a drive shaft, a front head (50) as an upper bearing (a second bearing), a first cylinder (31), a first piston (34), a middle plate (55), a second cylinder (41), a second piston (44), and a rear head (56) as a lower bearing (a first bearing).
As shown in FIGS. 6 and 7, an injection flow path (61) is formed in the first cylinder (31), the middle plate (55), the second cylinder (41), and the rear head (56). The injection flow path (61) communicates with the injection pipe (9c). As shown in FIG. 6, the injection pipe (9c) is connected with an injection muffler (80). The lower end of the injection muffler (80) is located lower than the lower end of the front head (50).
As shown in FIG. 7 as an enlarged view, the injection flow path (61) has a first flow path (61a) connected to the injection pipe (9c), a second flow path (61b) branched from the first flow path (61a) and communicating with a first cylinder chamber (S1) (described later), and a third flow path (61c) branched from the first flow path (61a) and communicating with a second cylinder chamber (S2) (described later). The injection pipe (9c) is connected to the first flow path (61a) by being inserted from the outer side in the radial direction. The second flow path (61b) has a fourth flow path (61d) extending in the axial direction of the shaft (90) and penetrating the middle plate (55).

(2-4-1) Cylinder

FIGS. 9 to 11 show the first cylinder (31). The first cylinder (31) and the second cylinder (41) are thick disk-shaped members. As shown in FIGS. 4 and 5 in particular, the cylinders (31, 41) have cylinder bores (32, 42), respectively. The cylinder bore (32, 42) is a circular hole penetrating in the thickness direction. The cylinder bore (32, 42) is formed in a center portion of the cylinder (31, 41). The first cylinder bore (32) of the first cylinder (31) houses the first piston (34). The second cylinder bore (42) of the second cylinder (41) houses the second piston (44).
The first cylinder (31) has the first cylinder chamber (S1) defined by the inner peripheral surface of the first cylinder (31). The second cylinder (41) has the second cylinder chamber (S2) defined by the inner peripheral surface of the second cylinder (41).
The cylinder (31, 41) has a vane housing hole (33, 43) extending from the inner peripheral surface of the cylinder (31, 41) (i.e., the outer edge of the cylinder bore (32, 42)) toward the outside of the cylinder (31, 41) in the radial direction. The vane housing hole (33, 43) penetrates the cylinder (31, 41) in the thickness direction.
Also as shown in FIG. 3, the first cylinder (31) has a first passage (16a) as part of a suction passage (16). The first passage (16a) is a hole having a bottom and extending in the thickness direction of the first cylinder (31). The first passage (16a) is disposed to the right side of the vane housing hole (33) in FIG. 4. As shown in FIG. 3, the second cylinder (41) has a second passage (16b) as part of the suction passage (16). The second passage (16b) penetrates the second cylinder (41) in the thickness direction. The second passage (16b) is disposed to the right side of the vane housing hole (43) in FIG. 5.
The cylinder (31, 41) has a suction port (17, 18) extending from the suction passage (16) toward the cylinder chamber (S1, S2). The first suction port (17) of the first cylinder (31) extends from the first passage (16a) toward the first cylinder chamber (S1). As shown in FIG. 4, the first suction port (17) of the first cylinder (31) extends at a position distant from the vane housing hole (33) by an angle of 30 degrees or less in the clockwise direction as viewed from above. The second suction port (18) of the second cylinder (41) extends from the second passage (16b) toward the second cylinder chamber (S2). As shown in FIG. 5, the second suction port (18) of the second cylinder (41) extends at a position distant from the vane housing hole (43) by an angle of 30 degrees or less in the clockwise direction as viewed from above. The suction port (17, 18) extends toward the cylinder chamber (S1, S2) to be closer to the vane housing hole (33, 43) than the suction passage (16) is as viewed in the axial direction.
A lower end surface (one of the end surfaces in the axial direction) of the first cylinder (31) has a first recessed portion (31a) formed in an elongated shape in plan view and inclined toward the vane housing hole (33) while extending toward the inner side of the first cylinder (31) in the radial direction. In the first recessed portion (31a), the end portion of a bottom surface (31g) that is on the inner side in the radial direction includes a first injection opening (31b) that is open on one side in the axial direction. In the first recessed portion (31a), the end portion of the bottom surface (31g) that is on the outer side in the radial direction includes a first bolt insertion hole (31c) penetrating in the axial direction. As shown in FIGS. 10 and 11, almost the entire region of around half of the bottom surface (31g) of the first recessed portion (31a) that is on the inner side in the radial direction includes a recess-shaped portion (31h) that is more recessed than the other regions. A valve seat (31i) in an annular shape protrudes from an outer peripheral edge portion of the first injection opening (31b) in the recess-shaped portion (31h).
Between the first recessed portion (31a) of the lower end surface (one of the end surfaces in the axial direction) of the first cylinder (31) and the first cylinder chamber (S1), a first communication groove (31d) narrower than the first recessed portion (31a) is formed so as to extend in the longitudinal direction of the first recessed portion (31a). Accordingly, the first communication groove (31d) is also inclined toward the vane housing hole (33) while extending toward the inner side of the first cylinder (31) in the radial direction. The first recessed portion (31a) and the first communication groove (31d) form a first valve housing portion (31j) recessed from the inner peripheral surface of the first cylinder (31) toward the outer side. In the first communication groove (31d), the end portion of the bottom surface that is opposite to the first cylinder chamber (S1) includes an intermediate surface (31m) set back opposite to the middle plate (55) rather than toward the first cylinder chamber (S1). The intermediate surface (31m) is located closer to the middle plate (55) than the bottom surface (31g) of the first recessed portion (31a). The intermediate surface (31m) is formed between a first edge (31k) of the bottom surface of the first communication groove (31d) that is close to the first cylinder chamber (S1) (the edge that is located at the opening of the first valve housing portion (31j) which is close to the first cylinder chamber (S1) and that is close to the bottom surface (31g)) and the bottom surface (31g) of the first recessed portion (31a). Accordingly, a step (ST1) is formed between the end portion of the bottom surface of the first communication groove (31d) that is close to the first cylinder chamber (S1) and the intermediate surface (31m). A step (ST2) is formed between the intermediate surface (31m) and the bottom surface (31g) of the first recessed portion (31a).
As shown in FIG. 7, the first cylinder (31) includes an upper end portion of the fourth flow path (61d), a first lateral flow path (31e) extending from the upper end of the fourth flow path (61d) to the inner side in the radial direction, and a first coupling path (31f) extending downward from the end portion of the first lateral flow path (31e) that is on the inner side in the radial direction in order to couple the first lateral flow path (31e) and the first injection opening (31b) in the axial direction. The first lateral flow path (31e) and the first coupling path (31f) are part of the second flow path (61b). As shown in FIG. 4, the first lateral flow path (31e) extends at a position distant from the vane housing hole (33) by an angle of 30 degrees or less in the counterclockwise direction (the opposite direction to the first suction port (17)) as viewed from above. The extending directions of the first lateral flow path (31e) and the first recessed portion (31a) are deviated from each other by about 30 degrees. That is, the angle α between the first lateral flow path (31e) and the first recessed portion (31a) is about 30 degrees. By deviating the extending directions of the first lateral flow path (31e) and the first recessed portion (31a) from each other by 5 degrees or more, or in other words, by setting the angle α to 5 degrees or more, it is possible to make the first bolt insertion hole (31c) less likely interfere with the first lateral flow path (31e).
Also as shown in FIG. 12, the first recessed portion (31a) of the first cylinder (31) houses a first reed valve (63) in an elongated shape and a first valve retainer (64) in an elongated shape while their longitudinal directions extend along the longitudinal direction of the first recessed portion (31a). The first reed valve (63) and the first valve retainer (64) have a common shape when viewed in the axial direction of the shaft (90). A fastening hole (63a) is formed to penetrate one end of the first reed valve (63) that is in the longitudinal direction. A fastening hole (64a) is also formed to penetrate a corresponding part of the first valve retainer (64).
The first reed valve (63) is a plate member that is elongated and flat. The first reed valve (63) is made of metal such as spring steel or iron. The first reed valve (63) is flexible.
As shown in FIG. 12, the first valve retainer (64) has a first surface (64b) facing the first reed valve (63) and a second surface (64c) opposite to the first surface (64b). In the first valve retainer (64), the end portion of the first surface (64b) that is on the inner side in the radial direction is inclined (toward the middle plate (55)) so as to be more distant from the bottom surface (31g) of the first recessed portion (31a) as extending more to the inner side in the radial direction.
Then, a bolt (65) is inserted into the first bolt insertion hole (31c) of the first cylinder (31), and the tip end portion of the bolt (65) is fastened to the fastening hole (63a) of the first reed valve (63) and the fastening hole (64a) of the first valve retainer (64), whereby the first reed valve (63) is attached to the first cylinder (31). Part of the bolt (65) that is other than the tip end portion, such as a head portion, of the bolt (65) is housed in the first bolt insertion hole (31c) of the first cylinder (31). In this state, the first reed valve (63) can open and close the first injection opening (31b) by moving up and down one end portion (the end portion opposite to the fastening hole (63a)) in the axial direction of the shaft (90). The bottom surface (31g) of the first recessed portion (31a) (the surface of the first valve housing portion (31j) that is close to the front head (50)) forms a valve attachment surface of the first valve housing portion (31j). In this manner, the first reed valve (63) is provided in the end portion of the injection flow path (61). The first reed valve (63) is fixed to the bottom surface (31g) of the first recessed portion (31a) on the outer side of the first cylinder (31) in the radial direction than the first injection opening (31b).
In this state, as shown in FIG. 10 in particular, a center line (C1) extending in the longitudinal direction of the first reed valve (63) crosses the opening of the first valve housing portion (31j) that is close to the first cylinder chamber (S1). The center line (C1) passes through part of the first reed valve (63) that is fixed to the bottom surface (31g) of the first recessed portion (31a) and part of the first reed valve (63) that faces the first injection opening (31b) in the closed state.
The first edge (31k) that is located at the opening of the first valve housing portion (31j) which is close to the first cylinder chamber (S1) and that is close to the valve attachment surface (or close to the bottom surface (31g) of the first recessed portion (31a)) is located closer to the second surface (64c) of the first valve retainer (64) than the bottom surface (31g) of the first recessed portion (31a) in the first direction orthogonal to the bottom surface (31g) of the first recessed portion (31a) (the axial direction of the shaft (90)).
An upper end surface (one of the end surfaces in the axial direction) of the second cylinder (41) has a second recessed portion (41a) formed in an elongated shape in plan view and inclined toward the vane housing hole (43) while extending toward the inner side of the second cylinder (41) in the radial direction. In the second recessed portion (41a), the end portion of a bottom surface (41g) (see FIG. 8) that is on the inner side in the radial direction includes a second injection opening (41b) that is open on one side in the axial direction. In the second recessed portion (41a), the end portion of the bottom surface (41g) that is on the outer side in the radial direction includes a second bolt insertion hole (41c) penetrating in the axial direction.
Between the second recessed portion (41a) of the lower end surface (one of the end surfaces in the axial direction) of the second cylinder (41) and the second cylinder chamber (S2), a second communication groove (41d) narrower than the second recessed portion (41a) is formed so as to extend in the longitudinal direction of the second recessed portion (41a). Accordingly, the second communication groove (41d) is also inclined toward the vane housing hole (43) while extending toward the inner side of the second cylinder (41) in the radial direction. The second recessed portion (41a) and the second communication groove (41d) form a second valve housing portion (41j) recessed from the inner peripheral surface of the second cylinder (41) toward the outer side. Although not shown, the shapes of the bottom surfaces of the second recessed portion (41a) and the second communication groove (41d) are the same as the shapes of the bottom surfaces of the first recessed portion (31a) and the first communication groove (31d).
As shown in FIG. 7, the second cylinder (41) includes a lower end portion of the fourth flow path (61d), a second lateral flow path (41e) extending from the lower end of the fourth flow path (61d) to the inner side in the radial direction, and a second coupling path (41f) extending upward from the end portion of the second lateral flow path (41e) that is on the inner side in the radial direction in order to couple the second lateral flow path (41e) and the second injection opening (41b) in the axial direction. The second lateral flow path (41e) and the second coupling path (41f) are part of the third flow path (61c). As shown in FIG. 5, the second lateral flow path (41e) extends at a position distant from the vane housing hole (43) by an angle of 30 degrees or less in the counterclockwise direction (the opposite direction to the second suction port (18)) as viewed from above. The extending directions of the second lateral flow path (41e) and the second recessed portion (41a) are deviated from each other by about 30 degrees. That is, the angle β between the second lateral flow path (41e) and the second recessed portion (41a) is about 30 degrees. By deviating the extending directions of the second lateral flow path (41e) and the second recessed portion (41a) from each other by 5 degrees or more, or in other words, by setting the angle β to 5 degrees or more, it is possible to make the second bolt insertion hole (41c) less likely interfere with the second lateral flow path (41e).
The second recessed portion (41a) of the second cylinder (41) houses a second reed valve (66) and a second valve retainer (67) with the same configurations as those of the first reed valve (63) and the first valve retainer (64). The second reed valve (66) and the second valve retainer (67) have a common shape when viewed in the axial direction of the shaft (90).
As shown in FIG. 8, a bolt (68) is inserted into the second bolt insertion hole (41c) of the second cylinder (41), and a tip end portion of the bolt (68) is fastened to a fastening hole (66a) of the second reed valve (66) and a fastening hole (67a) of the second valve retainer (67), whereby the second reed valve (66) and the second valve retainer (67) are attached to the second cylinder (41) in the same way as the first reed valve (63) and the first valve retainer (64) are attached. Part of the bolt (68) that is other than the tip end portion, such as a head portion, of the bolt (68) is housed in the second bolt insertion hole (41c) of the second cylinder (41). In this state, the second reed valve (66) can open and close the second injection opening (41b) by moving up and down one end portion (the end portion opposite to the fastening hole (66a)) in the axial direction of the shaft (90). The bottom surface (41g) of the second recessed portion (41a) (the surface of the second valve housing portion (41j) that is close to the rear head (56)) forms a valve attachment surface of the second valve housing portion (41j). In this manner, the second reed valve (66) is provided in the end portion of the injection flow path (61). The second reed valve (66) is fixed to the bottom surface (41g) of the second recessed portion (41a) on the outer side of the second cylinder (41) in the radial direction than the second injection opening (41b).
In this state, as shown in FIG. 5, a center line (C2) extending in the longitudinal direction of the second reed valve (66) crosses the opening of the second valve housing portion (41j) that is close to the second cylinder chamber (S2). The center line (C2) passes through part of the second reed valve (66) that is fixed to the bottom surface (41g) of the second recessed portion (41a) and part of the second reed valve (66) that faces the second injection opening (41b) in the closed state.
The first edge that is located at the opening of the second valve housing portion (41j) which is close to the second cylinder chamber (S2) and that is close to the valve attachment surface (or close to the bottom surface (41g) of the second recessed portion (41a)) is located closer to the second surface of the second valve retainer (67) (or opposite to the second reed valve (66)) than the bottom surface (41g) of the second recessed portion (41a) in the first direction orthogonal to the bottom surface (41g) of the second recessed portion (41a) (the axial direction of the shaft (90)).

(2-4-2) Piston

The first piston (34) is housed in the first cylinder (31). The first piston (34) eccentrically rotates in the first cylinder chamber (S1). The first piston (34) slides on both the front head (50) and the middle plate (55).
As shown in FIG. 4, the first piston (34) has a first piston body (a roller) (35) and a first vane (36). The first piston body (35) is formed in an annular shape. The first piston body (35) is formed in a cylindrical shape that is slightly thick. The first eccentric portion (91) of the shaft (90) is inserted into and coupled to the first piston body (35). The first piston body (35) turns along the inner peripheral surface of the first cylinder chamber (S1) of the first cylinder (31) as the first eccentric portion (91) rotates.
The first vane (36) is integrated with and protrudes from the outer peripheral surface of the first piston body (35). The first vane (36) is housed in the vane housing hole (33) of the first cylinder (31). The first vane (36) is sandwiched from both sides by a bush (70) fitted in the vane housing hole (33). The first vane (36) is supported by the first cylinder (31) via this bush (70) so as to be freely swingable and freely movable back and forth. The first vane (36) divides the first cylinder chamber (S1) into a first suction space (71) and a first discharge space (72). The first vane (36) restricts the first piston (34) from rotating itself when the first piston (34) turns. Accordingly, the first piston (34) does not rotate but turns along the inner surface of the first cylinder chamber (S1).
The second piston (44) is a member identical in shape, dimension, and material to the first piston (34). The first piston (34) and the second piston (44) are disposed inversely to each other in the top-bottom direction.
The second piston (44) is housed in the second cylinder (41). The second piston (44) eccentrically rotates in the second cylinder chamber (S2). The second piston (44) slides on both the rear head (56) and the middle plate (55).
As shown in FIG. 5, the second piston (44) has a second piston body (a roller) (45) and a second vane (46). The second piston body (45) is formed in an annular shape. The second piston body (45) is formed in a cylindrical shape that is slightly thick. The second eccentric portion (92) of the shaft (90) is inserted into and coupled to the second piston body (45). The second piston body (45) turns along the inner peripheral surface of the second cylinder chamber (S2) of the second cylinder (41) as the second eccentric portion (92) rotates.
The second vane (46) is integrated with and protrudes from the outer peripheral surface of the second piston body (45). The second vane (46) is housed in the vane housing hole (43) of the second cylinder (41). The second vane (46) is sandwiched from both sides by a bush (70) fitted in the vane housing hole (43). The second vane (46) is supported by the second cylinder (41) via this bush (70) so as to be freely swingable and freely movable back and forth. The second vane (46) divides the second cylinder chamber (S2) into a second suction space (75) and a second discharge space (not shown). The second vane (46) restricts the second piston (44) from rotating when the second piston (44) is turning. Accordingly, the second piston (44) does not rotate but turns along the inner surface of the second cylinder chamber (S2).

(2-4-3) Front Head

The front head (50) is disposed on part of the first cylinder (31) that is opposite to the middle plate (55). The front head (50) closes an end portion of the first cylinder (31) in the axial direction. Specifically, the front head (50) closes the upper end surface of the first cylinder (31) (the surface close to the electric motor (20)). The front head (50) includes a first body portion (50a) and an upper bearing portion (50b). The first body portion (50a) and the upper bearing portion (50b) are integrated together.
The first body portion (50a) is formed in a thick plate shape that is substantially circular. The lower surface of the first body portion (50a) is in close contact with the upper end surface of the first cylinder (31). The upper bearing portion (50b) is formed in a cylindrical shape extending from the first body portion (50a) toward the electric motor (20) (or toward the upper side in FIG. 3). The upper bearing portion (50b) is disposed in a center portion of the first body portion (50a). The upper bearing portion (50b) rotatably supports the upper shaft portion (90a) of the shaft (90).
As shown in FIG. 8, the first body portion (50a) has a first discharge port (51). The first discharge port (51) penetrates the first body portion (50a) in the thickness direction. The first discharge port (51) allows the internal space (R) and the first discharge space (72) to communicate with each other.
Part of the first body portion (50a) that is around the first discharge port (51) is a first thin portion (52) that is thinner in the axial direction than the other part of the first body portion (50a).
The first discharge port (51) is provided with a first discharge valve (53) as a reed valve. The first discharge valve (53) is disposed so as to cover the first discharge port (51). The first discharge valve (53) is released from the first discharge port (51) if the pressure of a refrigerant in the first discharge space (72) of the first cylinder chamber (S1) is more than or equal to a predetermined value. The refrigerant is discharged from the first discharge space (72) of the first cylinder chamber (S1) to the internal space (R) through the first discharge port (51) when the first discharge valve (53) is released from the first discharge port (51). The first discharge valve (53) covers the first discharge port (51) again after the refrigerant is discharged to the internal space (R).

(2-4-4) Middle Plate

The middle plate (55) is disposed between the first cylinder (31) and the second cylinder (41). The middle plate (55) closes an end portion of the first cylinder (31) in the axial direction and an end portion of the second cylinder (41) in the axial direction. Specifically, the middle plate (55) closes the lower end surface of the first cylinder (31) and the upper end surface of the second cylinder (41).
A center hole penetrating the middle plate (55) in the axial direction is formed in a center portion of the middle plate (55). The intermediate shaft portion (90b) of the shaft (90) is inserted into the center hole.
As shown in FIG. 3, the middle plate (55) has an intermediate passage (16c) as part of the suction passage (16). The intermediate passage (16c) penetrates the middle plate (55) in the axial direction. The intermediate passage (16c) allows the first passage (16a) and the second passage (16b) to communicate with each other.
In the second flow path (61b) of the injection flow path (61), the fourth flow path (61d) extending in the axial direction penetrates the middle plate (55).

(2-4-5) Rear Head

The rear head (56) is disposed on part of the second cylinder (41) that is opposite to the middle plate (55). The rear head (56) closes an end portion of the second cylinder (41) in the axial direction. Specifically, the rear head (56) closes the lower end surface of the second cylinder (41) (the surface opposite to the electric motor (20)).
The upper surface of the rear head (56) is in close contact with the lower end surface of the second cylinder (41). The rear head (56) rotatably supports the lower shaft portion (90c) of the shaft (90).
The rear head (56) has a first insertion hole (19) into which the suction pipe (14) is inserted and a second insertion hole (60) into which the injection pipe (9c) is inserted. The first insertion hole (19) and the second insertion hole (60) each extend in the radial direction.
A lower passage (16d) as part of the suction passage (16) extends from the first insertion hole (19). The lower passage (16d) extends upward in the axial direction from the end of the first insertion hole (19). An upper end portion of the lower passage (16d) communicates with the second passage (16b).
The injection flow path (61) extends from the second insertion hole (60). The rear head (56) includes part of the first flow path (61a) of the injection flow path (61).
As shown in FIGS. 7 and 8, the rear head (56) has a second discharge port (57). The second discharge port (57) penetrates the rear head (56) in the thickness direction. The second discharge port (57) allows the internal space (R) and a second discharge space (not shown) to communicate with each other.
Part of the rear head (56) that is around the second discharge port (57) is a second thin portion (58) that is thinner in the axial direction than the other part of the rear head (56).
The second discharge port (57) is provided with a second discharge valve (59). The second discharge valve (59) is disposed so as to cover the second discharge port (57). The second discharge valve (59) is released from the second discharge port (57) if the pressure of a refrigerant in the second discharge space (not shown) is more than or equal to a predetermined value. The refrigerant is discharged from the second discharge space (not shown) to the internal space (R) through the second discharge port (57) when the second discharge valve (59) is released from the second discharge port (57). The second discharge valve (59) covers the second discharge port (57) again after the refrigerant is discharged to the internal space (R).

(3) Operation

Next, operation of the compressor (1) will be described with reference to FIG. 13. The operation of compressing a refrigerant by the first cylinder (31) and the first piston (34) and the operation of compressing a refrigerant by the second cylinder (41) and the second piston (44) are basically the same except that the phases are different by 180°. In the following, the operation of compressing a refrigerant by the first cylinder (31) and the first piston (34) will be described in detail, and the operation of compressing a refrigerant by the second cylinder (41) and the second piston (44) will not be described.
In the compressor (1), when the electric motor (20) is started to rotate the rotor (22), the shaft (90) rotates and the first eccentric portion (91) rotates eccentrically. Then, as the first eccentric portion (91) rotates eccentrically, the first piston (34), which is restricted from rotating, turns along the inner peripheral surface of the first cylinder (31).
A suction phase of sucking a refrigerant into the first cylinder chamber (S1) will be described. When the shaft (90) slightly rotates from the state in which the rotational angle is 0° (the state (A) in FIG. 13), the position at which the first piston (34) and the first cylinder (31) contact each other passes the inner peripheral end of the first suction port (17). At this time, suction of a refrigerant into the first suction space (71) begins.
The refrigerant is sucked from the suction pipe (14) through the suction passage (16) and the first suction port (17). Then, as the rotational angle of the shaft (90) increases, the volume of the first suction space (71) gradually increases, and then the amount of the refrigerant sucked into the first suction space (71) increases (the states (B) to (H) in FIG. 13). This suction phase of sucking the refrigerant continues until the rotational angle of the shaft (90) reaches 360°, and then it shifts to a discharge phase.
The discharge phase of compressing and discharging a refrigerant in the first cylinder chamber (S1) will be described. When the shaft (90) slightly rotates from the state in which the rotational angle is 0° (the state (A) in FIG. 13), the position at which the first piston (34) and the first cylinder (31) contact each other passes the inner peripheral end of the first suction port (17) again. At this time, confinement of the refrigerant in the first suction space (71) is completed.
The first suction space (71) connected to the first suction port (17) turns into the first discharge space (72) connected only to the first discharge port (51). From this state, compression of the refrigerant in the first discharge space (72) begins. As the rotational angle of the shaft (90) increases, the volume of the first discharge space (72) decreases and the pressure of the first discharge space (72) increases. If the pressure of the first discharge space (72) exceeds a predetermined pressure, the first discharge valve (53) opens.
When the first discharge valve (53) opens, the refrigerant in the first discharge space (72) is discharged from the first discharge port (51), flows into the internal space (R) of the casing (10), and then is discharged to the outside of the compressor (1) through the discharge pipe (15). This discharge phase of discharging the refrigerant continues until the rotational angle of the shaft (90) reaches 360°, and then it shifts to the suction phase.
In this manner, the suction phase and the discharge phase are repeated alternately in the first cylinder chamber (S1). In the second cylinder chamber (S2), the suction phase and the discharge phase are repeated alternately with the phase different by 180° from the phase of the first cylinder chamber (S1). Accordingly, the compressor (1) can continuously perform operation of compressing a refrigerant.
Here, the intermediate-pressure refrigerant, or carbon dioxide (CO₂), is injected from the injection flow path (61) into the first cylinder chamber (S1) and the second cylinder chamber (S2) during the compression. Specifically, if the pressure in the injection flow path (61) is higher than in the first cylinder chamber (S1), the intermediate-pressure refrigerant is injected from the injection flow path (61) into the first cylinder chamber (S1). On the other hand, if the pressure in the first cylinder chamber (S1) increases so that the pressure becomes higher in the first cylinder chamber (S1) than in the injection flow path (61), the refrigerant flows from the first cylinder chamber (S1) into the first valve housing portion (31j). The direction in which the refrigerant flows is the direction indicated by the arrow X in FIG. 12, or the radially outward direction opposite to the middle plate (55). At this time, the first edge (31k) of the bottom surface of the first communication groove (31d) that is close to the first cylinder chamber (S1) is located closer to the middle plate (55) than the bottom surface (31g) of the first recessed portion (31a). Accordingly, the refrigerant is less likely to flow into the space between the first reed valve (63) and the bottom surface (31g) of the first recessed portion (31a) than when the first edge (31k) is located at the same height in the axial direction as the bottom surface (31g) of the first recessed portion (31a). Accordingly, it is possible to reduce formation of a high-pressure portion between the first reed valve (63) and the bottom surface (31g) of the first recessed portion (31a), where the high-pressure portion interferes with an operation of closing the first reed valve (63). Then, the end portion of the first reed valve (63) that is provided in the injection flow path (61) and that is opposite to the fastening hole (63a) is pressed onto the peripheral edge portion (the valve seat (31i)) of the first injection opening (31b) in order to close the injection flow path (61), whereby supply of the intermediate-pressure refrigerant is stopped. At this time, since the center line (C1) extending in the longitudinal direction of the first reed valve (63) crosses the opening of the first valve housing portion (31j) that is close to the first cylinder chamber (S1), the pressure of a refrigerant from the first cylinder chamber (S1) acts in a well-balanced manner on both sides of the center line (C1) of the first reed valve (63) compared with when the center line (C1) does not cross the opening of the first valve housing portion (31j). Accordingly, it is possible to suppress cracking of the first reed valve (63) caused by the pressure of a refrigerant from the first cylinder chamber (S1). In the first embodiment, CO₂ with a relatively high pressure is employed as a refrigerant, so the first reed valve (63) may be cracked easily. However, as described above, the center line (C1) extending in the longitudinal direction of the first reed valve (63) crosses the opening of the first valve housing portion (31j) that is close to the first cylinder chamber (S1), so it is possible to suppress cracking of the first reed valve (63).
Similarly, if the pressure in the injection flow path (61) is higher than in the second cylinder chamber (S2), the intermediate-pressure refrigerant is injected from the injection flow path (61) into the second cylinder chamber (S2). On the other hand, if the pressure in the second cylinder chamber (S2) increases so that the pressure becomes higher in the second cylinder chamber (S2) than in the injection flow path (61), the end portion of the second reed valve (66) that is provided in the injection flow path (61) and that is opposite to the fastening hole (66a) is pressed onto the peripheral edge portion of the second injection opening (41b) in order to close the injection flow path (61), whereby supply of the intermediate-pressure refrigerant is stopped. At this time, similarly to the first reed valve (63) described above, it is possible to reduce formation of a high-pressure portion between the second reed valve (66) and the bottom surface (41g) of the second recessed portion (41a), where the high-pressure portion interferes with an operation of closing the second reed valve (66). In addition, it is possible to reduce cracking of the second reed valve (66). In this manner, the rotary compressor (1) increases the efficiency of compression by injecting the intermediate-pressure refrigerant.

(Second Embodiment)

FIG. 14 shows a second embodiment and corresponds to FIG. 12. In the second embodiment, the first edge (31k) of the bottom surface of the first communication groove (31d) that is close to the first cylinder chamber (S1) is located closer to the second surface (64c) of the first valve retainer (64) than the edge of the first surface (64b) of the first valve retainer (64) that is close to the first cylinder chamber (S1) in the first direction orthogonal to the bottom surface (31g) (the valve attachment surface) of the first recessed portion (31a) (the axial direction of the shaft (90)). As shown in FIG. 14, the length H1 in the first direction between the first edge (31k) and the first injection opening (31b) is longer than the length H2 in the first direction between the edge of the first surface (64b) of the first valve retainer (64) that is close to the first cylinder chamber (S1) and the first injection opening (31b). The same applies to the second cylinder (41).
The other configurations are the same as those of the first embodiment, and thus the detailed description thereof will be omitted.
According to the second embodiment, the refrigerant less likely flows from the first cylinder chamber (S1) into the space between the first reed valve (63) and the bottom surface (31g) of the first recessed portion (31a). Accordingly, it is possible to reduce formation of a high-pressure portion between the first reed valve (63) and the bottom surface (31g) of the first recessed portion (31a), where the high-pressure portion interferes with an operation of closing the first reed valve (63). The same applies to the second cylinder (41).

(Third Embodiment)

FIG. 15 shows a third embodiment and corresponds to FIG. 12. In the third embodiment, two intermediate surfaces (31m) are formed between the first edge (31k) of the bottom surface of the first communication groove (31d) that is close to the first cylinder chamber (S1) (the edge that is located at the opening of the first valve housing portion (31j) which is close to the first cylinder chamber (S1) and that is close to the bottom surface (31g)) and the bottom surface (31g) of the first recessed portion (31a). The step (ST3) is formed between these intermediate surfaces (31m). The length H3 in the first direction between the intermediate surface (31m) adjacent to the bottom surface (31g) of the first recessed portion (31a) and the bottom surface (31g) of the first recessed portion (31a) (the first injection opening (31b)) is greater than or equal to the thickness of the first reed valve (63). The same applies to the second cylinder (41).
The other configurations are the same as those of the first embodiment, and thus the detailed description thereof will be omitted.
According to the third embodiment, the refrigerant less likely flows from the first cylinder chamber (S1) into the space between the first reed valve (63) and the bottom surface (31g) of the first recessed portion (31a) compared with when the length H3 is less than thickness of the first reed valve (63). Accordingly, it is possible to reduce formation of a high-pressure portion between the first reed valve (63) and the bottom surface (31g) of the first recessed portion (31a), where the high-pressure portion interferes with an operation of closing the first reed valve (63).
Further, since the plurality of intermediate surfaces (31m) are formed, it is possible to allow the refrigerant to flow more smoothly from the first cylinder chamber (S1) into the space between the first reed valve (63) and the first valve retainer (64) compared with when only one intermediate surface (31m) is formed. The same applies to the second cylinder (41).

(Fourth Embodiment)

FIG. 16 shows a fourth embodiment and corresponds to FIG. 12. In the fourth embodiment, an inclined surface (31n) is formed between the first edge (31k) of the bottom surface of the first communication groove (31d) that is close to the first cylinder chamber (S1) (the edge that is located at the opening of the first valve housing portion (31j) which is close to the first cylinder chamber (S1) and that is close to the bottom surface (31g)) and the bottom surface (31g) of the first recessed portion (31a). The inclined surface (31n) is inclined toward the attachment surface in the first direction (or toward the bottom surface (31g) of the first recessed portion (31a)) while extending toward the first injection opening (31b). The same applies to the second cylinder (41).
The other configurations are the same as those of the first embodiment, and thus the detailed description thereof will be omitted.
According to the fourth embodiment, it is possible to allow the refrigerant to flow smoothly from the first cylinder chamber (S1) into the space between the first reed valve (63) and the first valve retainer (64) along the inclined surface (31n). The same applies to the second cylinder (41).

(Fifth Embodiment)

FIG. 17 shows a fifth embodiment and corresponds to FIG. 12. In the first to fourth embodiments, the first valve housing portion (31j) consists of the first recessed portion (31a) and the first communication groove (31d) that opens in the axial direction of the shaft (90). However, in the fifth embodiment, the first valve housing portion (31j) consists of the first recessed portion (31a) and a first communication hole (31p) that does not open in the axial direction of the shaft (90).
Although not shown, the same applies to the second valve housing portion (41j).
The other configurations are the same as those of the first embodiment, and thus the detailed description thereof will be omitted.

The piston (34, 44) and the vane (36, 46) are not necessarily integrated together. The piston (34, 44) and the vane (36, 46) may be connected by a hinge.
In the first to fifth embodiments of the present disclosure, the rotary compressor (1) with the two cylinders (31, 41) is employed, but the rotary compressor (1) with only one cylinder may be employed.
It will be understood that the embodiments and variations described above can be modified with various changes in form and details without departing from the spirit and scope of the claims. The embodiments, the variations thereof, and the other embodiments may be combined and replaced with each other without deteriorating intended functions of the present disclosure.
The expressions such as "first", "second", "third", . . . , described above are used to distinguish the terms to which these expressions are given, and do not limit the number and order of the terms.

INDUSTRIAL APPLICABILITY

As described above, the present disclosure is useful for a rotary compressor and a refrigeration apparatus including the rotary compressor.

DESCRIPTION OF REFERENCE CHARACTERS

1: Rotary Compressor
S1: First Cylinder Chamber
S2: Second Cylinder Chamber
31: First Cylinder
31b: First Injection Opening
31g: Bottom Surface (Valve Attachment Surface)
31j: First Valve Housing Portion
31k: First Edge
31m: Intermediate Surface
31n: Inclined Surface
34: First Piston
41: Second Cylinder
41b: Second Injection Opening
41g: Bottom Surface (Valve Attachment Surface)
41j: Second Valve Housing Portion
44: Second Piston
50: Front Head (Second Bearing)
56: Rear Head (First Bearing)
61: Injection Flow Path
63: First Reed Valve
64: First Valve Retainer
64b: First Surface
64c: Second Surface
66: Second Reed Valve
67: Second Valve Retainer
90: Shaft (Drive Shaft)
100: Refrigeration Apparatus
C1, C2: Center Line

Claims

A rotary compressor having an injection flow path (61), comprising:
a piston (34, 44);

a drive shaft (90) configured to drive the piston (34, 44);

a first bearing (56) and a second bearing (50) supporting the drive shaft (90);

a cylinder (31, 41) housing the piston (34, 44) and having a cylinder chamber (S1, S2) defined by an inner peripheral surface;

a reed valve (63, 66) disposed in the injection flow path (61); and

a valve retainer (64, 67) having a first surface (64b) facing the reed valve (63, 66) and a second surface (64c) opposite to the first surface (64b),

wherein

the cylinder (31, 41) is provided with a valve housing portion (31j, 41j) recessed from the inner peripheral surface toward an outer side and housing the reed valve (63, 66) and the valve retainer (64, 67),

a valve attachment surface (31g, 41g), which is a surface of the valve housing portion (31j, 41j) that is close to the first bearing (56) or the second bearing (50), is provided with an injection opening (31b, 41b) that is opened and closed by the reed valve (63, 66),

the reed valve (63, 66) is fixed to the valve attachment surface (31g, 41g) of the valve housing portion (31j, 41j) on an outer side of the cylinder (31, 41) in a radial direction than the injection opening (31b, 41b),

a center line (C1, C2) extending in a longitudinal direction of the reed valve (63, 66) crosses an opening of the valve housing portion (31j, 41j) that is close to the cylinder chamber (S1, S2), and

a first edge (31k) that is located on an opening of the valve housing portion (31j, 41j) which is close to the cylinder chamber (S1, S2) and that is close to the valve attachment surface (31g, 41g) is located closer to the second surface (64c) of the valve retainer (64, 67) than the valve attachment surface (31g, 41g) in a first direction orthogonal to the valve attachment surface (31g, 41g).
The rotary compressor of claim 1, wherein
the first edge (31k) is located closer to the second surface (64c) of the valve retainer (64, 67) in the first direction than an edge of the first surface (64b) of the valve retainer (64, 67) that is close to the cylinder chamber (S1, S2).
The rotary compressor of claim 1, wherein
an intermediate surface (31m) is formed between the first edge (31k) and the valve attachment surface (31g, 41g), and

the intermediate surface (31m) is located closer to the second surface (64c) of the valve retainer (64, 67) in the first direction than the valve attachment surface (31g, 41g).
The rotary compressor of claim 3, wherein
the intermediate surface (31m) includes a plurality of intermediate surfaces (31m).
The rotary compressor of claim 3 or 4, wherein
a length in the first direction between the intermediate surface (31m) and the valve attachment surface (31g, 41g) is greater than or equal to a thickness of the reed valve (63, 66).
The rotary compressor of claim 1 or 2, wherein
an inclined surface (31n) is formed between the first edge (31k) and the valve attachment surface (31g, 41g), and

the inclined surface (31n) is inclined toward the valve attachment surface (31g, 41g) in the first direction while extending toward the injection opening (31b, 41b).
The rotary compressor of any one of claims 1 to 6, wherein
a refrigerant is CO₂.
A refrigeration apparatus comprising: the rotary compressor of any one of claims 1 to 7.