EP4722539A1

EP4722539A1 - Compressor unit

Info

Publication number: EP4722539A1
Application number: EP25812279.5A
Authority: EP
Inventors: Takazo Sotojima; Tomoya KUMAZAKI; Hiromichi Ueno; Arisa KAWAE; Hikaru Wada; Tatsuya Katayama
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 2024-07-29
Filing date: 2025-05-07
Publication date: 2026-04-08
Also published as: WO2026028542A1; JP7832522B2; JP2026020868A

Abstract

A compressor unit includes: a compressor (1) including a first casing (10) with a tubular first barrel (11), an electric motor (20) housed in the first casing (10), a drive shaft (70) configured to be driven by the electric motor (20), and a rotary compression mechanism (15); and an accumulator (2) including a second casing (60) with a tubular second barrel (61) adjacent to the first casing (10) in a horizontal direction, and an outlet pipe (65a, 65b) extending from a lower portion of the second casing (60) and connected to the first barrel (11). A first eigenvalue s1 of the accumulator (2) in a rolling direction does not overlap with a value of n-N (where N is an integer), which is an integer multiple of a maximum number of rotations n of the compressor (1).

Description

TECHNICAL FIELD

The present disclosure relates to a compressor unit.

BACKGROUND ART

There is a refrigeration cycle apparatus having a compressor to which an accumulator is connected. An accumulator described in Patent Document 1 is fixed to a side surface of a casing of a compressor via a bracket.

CITATION LIST

PATENT DOCUMENT

Patent Document 1: Japanese Unexamined Patent Publication No. 2001-317479

SUMMARY OF THE INVENTION

TECHNICAL PROBLEM

When a compressor operates, an accumulator may vibrate and/or generate noise due to resonance. Patent Document 1 aims to reduce vibration and/or noise of the accumulator caused by the operation of the compressor by adjusting the position of the bracket; however, this is not considered sufficient.
An object of the present disclosure is to reduce vibration of an accumulator resulting from operation of a compressor.

SOLUTION TO THE PROBLEM

A first aspect is directed to a compressor unit including: a compressor (1); and an accumulator (2) adjacent to the compressor (1), the compressor (1) including: a first casing (10) including a tubular first barrel (11); an electric motor (20) housed in the first casing (10); a drive shaft (70) configured to be driven by the electric motor (20); and a rotary compression mechanism (15) configured to compress a fluid, the accumulator (2) including: a second casing (60) including a tubular second barrel (61) adjacent to the first casing (10) in a horizontal direction; and an outlet pipe (65a, 65b) extending from a lower portion of the second casing (60) and connected to the first barrel (11). When a direction in which the second barrel (61) moves so as to roll along an outer peripheral surface of the first barrel (11) in a circumferential direction of the first barrel (11) is defined as a rolling direction, a first eigenvalue s1 of the accumulator (2) in the rolling direction does not overlap with a value of n·N (where N is an integer), which is an integer multiple of a maximum number of revolutions n of the compressor (1).
One of modes of vibration of an accumulator caused by the operation of a compressor is a vibration mode in which the accumulator vibrates so as to roll along the outer peripheral surface of a casing of the compressor. It has been found that the vibration of the accumulator increases if this vibration mode overlaps with an integer multiple of the maximum number of revolutions n of the compressor (1). In the first aspect, the first eigenvalue does not overlap with n·N, and therefore, such an increase in vibration can be reduced.
A second aspect is an embodiment of the first aspect. In the second aspect, the first eigenvalue s1 satisfies n·N + n/4 ≤ s1 ≤ n·N + 3n/4.
The closer the first eigenvalue s1 is to an integer multiple of n, the greater the vibration becomes. In the second aspect, however, the first eigenvalue s1 can be adjusted to a value that is relatively far from an integer multiple of n. Accordingly, the effect of vibration reduction can be enhanced.
A third aspect is an embodiment of the first or second aspect. In the third aspect, the compressor unit further includes a first adjustment portion (64) configured to adjust the first eigenvalue s1.
In the third aspect, the first eigenvalue s1 can be set to a target value.
A fourth aspect is an embodiment of the third aspect. In the fourth aspect, the first adjustment portion (64) is a fixing member (64) that has a plate shape and fixes the compressor (1) and the accumulator (2) to each other, the fixing member (64) has a bent portion (64d) formed so that the fixing member (64) is bent between the first barrel (11) and the second barrel (61), and a shape of the bent portion (64d) or a position of the bent portion (64d) in the fixing member (64) is determined such that the first eigenvalue s1 does not overlap with the value of n·N.
In the fourth aspect, the first eigenvalue s1 can be easily adjusted by setting the shape and/or the attachment position of the fixing member (64).
A fifth aspect is an embodiment of any one of the first to fourth aspects. In the fifth aspect, the compression mechanism (15) is a two-cylinder rotary compression mechanism, and the first eigenvalue s1 is greater than 2n.
In the fifth aspect, since the compression mechanism (15) is a two-cylinder rotary compression mechanism, an excitation force at 2n acts. The first eigenvalue s1 is thus adjusted so as not to overlap with the 2n excitation force exerted on the two-cylinder compressor (1), and therefore, an increase in vibration of the accumulator (2) can be reduced.
A sixth aspect is an embodiment of the fifth aspect. In the sixth aspect, the outlet pipe (65a, 65b) includes a first outlet pipe (65a) and a second outlet pipe (65b) that extend side by side from a lower portion of the accumulator (2), a second eigenvalue s2 of the outlet pipe (65a, 65b) is greater than 2n, and a first connecting portion (82a), where the first outlet pipe (65a) and the second casing (60) are connected to each other, and a second connecting portion (82b), where the second outlet pipe (65b) and the second casing (60) are connected to each other, are at positions offset from a central axis of the tubular second casing (60).
In the sixth aspect, the second eigenvalue s2 can be prevented from overlapping with n·N by shifting the first connecting portion (82a) and the second connecting portion (82b) from the central axis of the tubular second casing (60).
A seventh aspect is an embodiment of the sixth aspect. In the seventh aspect, the compressor unit further includes a second adjustment portion (68) configured to adjust the second eigenvalue s2.
In the seventh aspect, the second eigenvalue s2 can be prevented from overlapping with n·N by the second adjustment portion (68).
An eighth aspect is an embodiment of the seventh aspect. In the eighth aspect, the second adjustment portion (68) is a support (68) that supports the outlet pipe (65a, 65b) in the second casing (60).
In the eighth aspect, the second eigenvalue s2 can be easily adjusted by setting the shape and/or the attachment position of the support (68).
A ninth aspect is an embodiment of the seventh aspect. In the ninth aspect, the outlet pipe (65a, 65b) includes a first pipe portion (80a) and a second pipe portion (80b) that have pipe thicknesses different from each other, the first pipe portion (80a) and the second pipe portion (80b) of the outlet pipe (65a, 65b) are continuous with each other, and the second adjustment portion (68) is the first pipe portion (80a) or the second pipe portion (80b).
In the ninth aspect, the eigenvalue of the outlet pipe (65a, 65b) can be adjusted by arranging the outlet pipe (65a, 65b) to be provided with the first pipe portion (80a) and the second pipe portion (80b) that have different pipe thicknesses. That is, the second eigenvalue s2 can be easily adjusted by setting the positions and/or the pipe thicknesses of the first pipe portion (80a) and the second pipe portion (80b) of the outlet pipe (65a, 65b).
A tenth aspect is an embodiment of any one of the first to ninth aspects. In the tenth aspect, the compressor (1) rotates at a number of revolutions of 120 rps or greater.
In the tenth aspect, it is possible to enhance the effect of reducing vibration of the accumulator (2), the vibration of which increases at a number of revolutions of 120 rps or greater, particularly at 150 rps.
An eleventh aspect is directed to a refrigeration apparatus including the compressor unit of any one of the first to tenth aspects.
In the eleventh aspect, it is possible to provide a refrigeration apparatus capable of reducing vibration of the accumulator (2) caused by the operation of the compressor (1).

BRIEF DESCRIPTION OF THE DRAWINGS

[FIG. 1] FIG. 1 is a piping system diagram of a refrigeration apparatus according to an embodiment.
[FIG. 2] FIG. 2 is a cut-away vertical sectional view of a compressor unit according to the embodiment.
[FIG. 3] FIGS. 3A and 3B are plan views of a piston of a compression mechanism. FIG. 3A is a plan view of a first compression mechanism. FIG. 3B is a plan view of a second compression mechanism.
[FIG. 4] FIGS. 4A and 4B are views of the shape of a fixing member. FIG. 4A partially shows a state in which a compressor and an accumulator are fixed by the fixing member, as viewed from above. FIG. 4B shows the fixing member, as viewed from the side of its first surface.
[FIG. 5] FIG. 5 shows operation of the compression mechanisms.
[FIG. 6] FIG. 6 is a cut-away vertical sectional view of an accumulator according to a first variation.
[FIG. 7] FIG. 7 is a cut-away vertical sectional view of an accumulator according to a second variation.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention will be described below with reference to the drawings. The following embodiments are merely exemplary ones in nature, and are not intended to limit the scope, application, or uses of the invention. Features of the embodiments, variations, and other examples described below can be combined or partially substituted within the range where the present invention can be embodied.

(1) Compressor Unit

As shown in FIG. 1, a compressor unit (U) of an embodiment is applied to a refrigeration apparatus (100). The refrigeration apparatus (100) is an air conditioner for conditioning air in an indoor space, for example. The refrigeration apparatus (100) includes a refrigerant circuit (9) that performs a refrigeration cycle. The refrigerant circuit (9) includes a refrigerant pipe (9a) through which a refrigerant flows. A compressor (1), an accumulator (2), a four-way switching valve (3), an outdoor heat exchanger (4), an expansion valve (5), and an indoor heat exchanger (6) are connected to the refrigerant pipe (9a). The compressor unit (U) of this embodiment includes the compressor (1) and the accumulator (2).
The four-way switching valve (3) has four ports (P1, P2, P3, P4). The four-way switching valve (3) switches the flow path of the refrigerant circuit (9) between the state indicated by solid lines and the state indicated by broken lines in FIG. 1. Thus, the refrigerant circuit (9) switches between a first refrigeration cycle for cooling the indoor space and a second refrigeration cycle for heating the indoor space.
The outdoor heat exchanger (4) is provided in an outdoor unit (not shown) disposed outdoors. The outdoor heat exchanger (4) exchanges heat between the refrigerant and outdoor air. The outdoor heat exchanger (4) functions as a radiator in the first refrigeration cycle and functions as an evaporator in the second refrigeration cycle.
The expansion valve (5) decompresses the refrigerant in the refrigerant circuit. The expansion valve (5) is, for example, an electronic expansion valve whose opening degree is adjustable.
The indoor heat exchanger (6) is provided in an indoor unit (not shown) disposed indoors. The indoor heat exchanger (6) exchanges heat between the refrigerant and indoor air. The indoor heat exchanger (6) functions as an evaporator in the first refrigeration cycle and functions as a radiator in the second refrigeration cycle.

(2) Compressor

The compressor (1) is a rotary compressor. The compressor (1) compresses the refrigerant flowing through the refrigerant circuit. The refrigerant is an example of a fluid. The compressor (1) includes a first casing (10), an electric motor (20), and a compression mechanism (15). The electric motor (20) and the compression mechanism (15) are housed in the first casing (10). The compressor (1) is configured as a so-called high-pressure dome-shaped compressor where the refrigerant compressed in the compression mechanism (15) is discharged to an internal space of the first casing (10) and the pressure inside the internal space becomes high.

(2-1) First Casing

The first casing (10) is a vertically long closed container made of metal. The first casing (10) includes a cylindrical first barrel (11) extending in an up-down direction, an upper end plate (12) closing the upper end of the first barrel (11), and a lower end plate (13) closing the lower end of the first barrel (11). A discharge pipe (8) is connected to the upper end plate (12). A first suction pipe (14a) and a second suction pipe (14b) are provided at a lower portion of the first barrel (11). The first barrel (11) forms a side surface of the first casing (10).

(2-2) Electric Motor

The electric motor (20) is disposed in an upper portion of the internal space of the first casing (10). The electric motor (20) includes a stator (21) and a rotor (22). The stator (21) is fixed to the first barrel (11). The rotor (22) is attached to a drive shaft (70) of the compression mechanism (15), which will be described later. The drive shaft (70) is disposed to extend in the up-down direction within the first casing (10). The drive shaft (70) is driven by the electric motor (20). An upper portion of the drive shaft (70) is coupled to the rotor (22) of the electric motor (20). The details of the drive shaft (70) will be described later.

(2-3) Compression Mechanism

The compression mechanism (15) is a so-called "oscillating-piston, rotary fluid machine." The compression mechanism (15) of this embodiment is a two-cylinder rotary fluid machine having a first compression mechanism (K1) and a second compression mechanism (K2). In the internal space of the first casing (10), the compression mechanism (15) is disposed below the electric motor (20).
The compression mechanism (15) is configured such that a front head (24), a first cylinder (30), an intermediate plate (50), a second cylinder (35), and a rear head (25) are arranged in this order from the top to the bottom.

(2-3-1) Front Head

The front head (24) is a member that covers an end surface of the first cylinder (30), which is closer to the electric motor (20) (i.e., an upper end surface of the first cylinder (30) in FIG. 1). The front head (24) is fixed to the inner surface of the first barrel (11). The front head (24) includes a main bearing portion (23). The main bearing portion (23) constitutes a journal bearing that supports the drive shaft (70) of the compression mechanism (15). The front head (24) is provided with a discharge port (not shown) for discharging the refrigerant from a cylinder chamber (S), which will be described later.

(2-3-2) Rear Head

The rear head (25) is a member that covers an end surface of the second cylinder (35), which is farther from the electric motor (20) (i.e., a lower end surface of the second cylinder (35) in FIG. 1). The rear head (25) includes an auxiliary bearing portion (27). The auxiliary bearing portion (27) constitutes the journal bearing that supports the drive shaft (70) of the compression mechanism (15). The rear head (25) is provided with a discharge port (not shown) for discharging the refrigerant from the cylinder chamber (S), which will be described later.

(2-3-3) Cylinder and Piston

As shown in FIG. 3A, the first compression mechanism (K1) includes the first cylinder (30), a first piston (40), and a first blade (41). The second compression mechanism (K2) includes the second cylinder (35), a second piston (45), and a second blade (46).
Each cylinder (30, 35) is a thick disk-shaped member. The cylinders (30, 35) have the same thickness. Each cylinder (30, 35) has a cylinder bore (31, 36) and a blade housing hole (32, 37).
Each cylinder bore (31, 36) is a circular hole extending through the corresponding cylinder (30, 35) in its thickness direction. Specifically, the first cylinder bore (31) is formed at a central portion of the first cylinder (30). The second cylinder bore (36) is formed at a central portion of the second cylinder (35).
The first cylinder bore (31) houses the first piston (40). The second cylinder bore (36) houses the second piston (45). The inner diameter of the first cylinder bore (31) and the inner diameter of the second cylinder bore (36) are equal to each other.
A first cylinder chamber (S) is formed between the wall surface of the first cylinder bore (31) and the first piston (40). Thus, the first cylinder (30) has the first cylinder chamber (S). A second cylinder chamber (S) is formed between the wall surface of the second cylinder bore (36) and the second piston (45). Thus, the second cylinder (35) has the second cylinder chamber (S).
Each blade housing hole (32, 37) is a hole that houses the corresponding blade (41, 46). Each blade housing hole (32, 37) is formed to extend from the inner peripheral surface of the corresponding cylinder (30, 35) (i.e., from the outer edge of the corresponding cylinder bore (31, 36)) outward in the radial direction of the cylinder (30, 35). Each blade housing hole (32, 37) extends through the corresponding cylinder (30, 35) in its thickness direction. The first blade housing hole (32) is formed in the first cylinder (30). The second blade housing hole (37) is formed in the second cylinder (35).
The first cylinder (30) is provided with a first suction port (33). The second cylinder (35) is provided with a second suction port (38). The first suction pipe (14a) is connected to the first suction port (33). The second suction pipe (14b) is connected to the second suction port (38). Each suction port (33, 38) communicates with a first chamber (S1) of the corresponding cylinder chamber (S). Each suction port (33, 38) is located to the right of the corresponding blade housing hole (32, 37) in a top view of each cylinder (30, 35) shown in FIGS. 3A and 3B. Each discharge port (not shown) is located to the left of the corresponding blade housing hole (32, 37).
The pistons (40, 45) shown in FIGS. 3A and 3B rotate eccentrically in the respective cylinders (30, 35). The first piston (40) and the second piston (45) are members having the same shape, dimensions, and material. Each piston (40, 45) is a moderately thick cylindrical member.
A first eccentric portion (75) of the drive shaft (70) is inserted into the first piston (40). The first piston (40) eccentrically rotates as the first eccentric portion (75) of the drive shaft (70) rotates. A second eccentric portion (76) of the drive shaft (70) is inserted into the second piston (45). The second piston (45) eccentrically rotates as the second eccentric portion (76) of the drive shaft (70) rotates.
Each blade (41, 46) is a moderately thick rectangular flat plate-shaped member. The first blade (41) is formed integrally with the first piston (40). The first blade (41) is disposed in the first blade housing hole (32). The first blade (41) partitions the first cylinder chamber (S) into a first chamber (S1) on the suction side and a second chamber (S2) on the discharge side. The second blade (46) is disposed in the second blade housing hole (37). The second blade (46) partitions the second cylinder chamber (S) into a first chamber (S1) on the suction side and a second chamber (S2) on the discharge side.
Each blade (41, 46) is sandwiched between a pair of bushings (42, 47). Each blade (41, 46) is supported via the corresponding bushings (42, 47) so as to be movable angularly and reciprocally relative to the corresponding cylinder (30, 35).

(2-3-4) Intermediate Plate

The intermediate plate (50) shown in FIG. 2 is disposed so as to be sandwiched between the first cylinder (30) and the second cylinder (35). The intermediate plate (50) is in close contact with the lower end surface of the first cylinder (30) and the upper end surface of the second cylinder (35).
The intermediate plate (50) has, at its central portion, a central hole (51) that extends through the intermediate plate (50) in its thickness direction. An intermediate coupling portion (78) of the drive shaft (70) is inserted into the central hole (51) of the intermediate plate (50).

(2-4) Drive Shaft

As shown in FIGS. 2, 3A, and 3B, the drive shaft (70) is a member that drives the pistons (40, 45). Specifically, the drive shaft (70) includes a main shaft portion (72), the first eccentric portion (75), the intermediate coupling portion (78), the second eccentric portion (76), and an auxiliary shaft portion (74), which are arranged in this order from the top to the bottom. The drive shaft (70) has a rotational center axis (70a), which substantially coincides with the center axes of the cylinder bores (31, 36) of the cylinders (30, 35).
The main shaft portion (72) is attached to the rotor (22) of the electric motor (20) and is supported by the main bearing portion (23) of the front head (24). The auxiliary shaft portion (74) is supported by the auxiliary bearing portion (27) of the rear head (25).
The first eccentric portion (75) and the second eccentric portion (76) are columnar portions each having a larger diameter than that of the main shaft portion (72). The first eccentric portion (75) and the second eccentric portion (76) have the same shape. The center axes of the first eccentric portion (75) and the second eccentric portion (76) are eccentric to the rotational center axis (70a) of the drive shaft (70). The first eccentric portion (75) is eccentric to the side opposite to the second eccentric portion (76) with respect to the rotational center axis (70a) of the drive shaft (70). In other words, the eccentric direction of the first eccentric portion (75) with respect to the rotational center axis (70a) of the drive shaft (70) is different, by 180°, from the eccentric direction of the second eccentric portion (76) with respect to the rotational center axis (70a) of the drive shaft (70).
The intermediate coupling portion (78) is located and couples between the first eccentric portion (75) and the second eccentric portion (76).

(3) Accumulator

The accumulator (2) shown in FIGS. 1 and 2 temporarily stores a refrigerant to be sucked by the compressor (1). The accumulator (2) separates gas and liquid from each other. Specifically, the accumulator (2) separates a liquid refrigerant, refrigerating machine oil, and the like contained in a gaseous refrigerant. The accumulator (2) is disposed adjacent to the compressor (1). The accumulator (2) includes a second casing (60), outlet pipes (65a, 65b), and a fixing member (64).

(3-1) Second Casing

The second casing (60) is a vertically long closed container made of metal. The second casing (60) includes a cylindrical second barrel (61) extending in the up-down direction, an upper lid (81) that covers the upper end of the second barrel (61), and a lower lid (82) that covers the lower end of the second barrel (61). The second casing (60) is adjacent to the first casing (10) in a horizontal direction. Specifically, the second barrel (61) is disposed adjacent to the first barrel (11). The cylindrical axes of the first barrel (11) and the second barrel (61) extend in the same direction. The second barrel (61) forms a side surface of the second casing (60).
The second barrel (61) of this example has an upper barrel (61a) and a lower barrel (61b). The upper barrel (61a) and the upper lid (81) are formed integrally with each other. The lower barrel (61b) and the lower lid (82) are formed integrally with each other. The upper end of the lower barrel (61b) is fitted with the lower end of the upper barrel (61a).
The upper lid (81) has an inlet (81a), which is a hole to which an inlet pipe (7) is connected. The inlet pipe (7) is fixed to the inlet (81a) by welding, for example. The inlet pipe (7) is connected to the refrigerant pipe (9a). The inlet (81a) is formed at the center of the upper lid (81), as viewed from above the second casing (60). In other words, the inlet (81a) is located along the cylindrical axis of the second barrel (61).
The lower lid (82) has connecting portions (82a, 82b), which are holes to which the outlet pipes (65a, 65b) are respectively connected. The connecting portions (82a, 82b) include a first connecting portion (82a) and a second connecting portion (82b). The first connecting portion (82a) and the second connecting portion (82b) open downward. The first connecting portion (82a) and the second connecting portion (82b) are formed at positions offset from the center of the lower lid (82) as viewed from below the second casing (60). In other words, the first connecting portion (82a) and the second connecting portion (82b) are formed at positions that do not coincide with the cylindrical axis of the second barrel (61).

(3-2) Outlet Pipes

The outlet pipes (65a, 65b) are pipes that extend from a lower portion of the second casing (60) and are connected to the side surface of the first casing (10). The outlet pipes (65a, 65b) include a first outlet pipe (65a) and a second outlet pipe (65b) that extend side by side from a lower portion of the accumulator (2).
The first outlet pipe (65a) passes through the first connecting portion (82a). The first outlet pipe (65a) is fixed to the first connecting portion (82a) by welding, for example. The first outlet pipe (65a) extends, toward its one end or upper end, from the first connecting portion (82a) to an upper portion within the second casing (60) in a direction along the cylindrical axis of the second casing (60). The other end of the first outlet pipe (65a) is connected to the first suction pipe (14a). The first outlet pipe (65a) extends downward from the first connecting portion (82a) and then extends in the horizontal direction toward the first suction pipe (14a).
The second outlet pipe (65b) passes through the second connecting portion (82b). The second outlet pipe (65b) is fixed to the second connecting portion (82b) by welding, for example. The second outlet pipe (65b) extends, toward its one end, from the second connecting portion (82b) to an upper portion within the second casing (60) in a direction along the cylindrical axis of the second casing (60). The other end of the second outlet pipe (65b) is connected to the second suction pipe (14b). The second outlet pipe (65b) extends downward from the second connecting portion (82b) and then extends in the horizontal direction toward the second suction port (38). The upper ends of the first outlet pipe (65a) and the second outlet pipe (65b) are approximately at the same height.

(3-3) Fixing Member

As shown in FIGS. 2 and 4A, the fixing member (64) fixes the compressor (1) and the accumulator (2) to each other. The fixing member (64) is provided between the first casing (10) and the second casing (60). Specifically, the fixing member (64) is provided between the first barrel (11) and the second barrel (61). The fixing member (64) is a plate-shaped member.
The fixing member (64) includes: a first fixing portion (64a) fixed to the outer peripheral surface of the second barrel (61); two second fixing portions (64b) fixed to the outer peripheral surface of the first barrel (11); and extending portions (64c) extending from the first fixing portion (64a) to the second fixing portions (64b).
The first fixing portion (64a) is formed to be curved along the outer peripheral surface of the second barrel (61). A surface of the first fixing portion (64a) that faces the second barrel (61) is in contact with the outer peripheral surface of the second barrel (61).
The extending portions (64c) connect the first fixing portion (64a) and the second fixing portions (64b) to each other. The extending portions (64c) are provided so as to extend from both ends of the first fixing portion (64a) in the circumferential direction of the second barrel (61) toward the outer peripheral surface of the first barrel (11). Each extending portion (64c) includes a bent portion (64d). The bent portions (64d) are formed to extend from both ends of the first fixing portion (64a) and to be bent toward the outer peripheral surface of the first barrel (11). A predetermined bending radius R is set at the bent portions (64d). Thus, the fixing member (64) includes the bent portions (64d). Each bent portion (64d) is formed so as to allow the plate to bend between the first barrel (11) and the second barrel (61).
The second fixing portions (64b) extend from the respective end portions of the extending portions (64c) along the circumferential direction of the first barrel (11). A surface of each second fixing portion (64b) that faces the first barrel (11) is in contact with the outer peripheral surface of the first barrel (11) . Thus, the second fixing portions (64b) are fixed to the first barrel (11) such that the two second fixing portions (64b) hold the first barrel (11).
The first fixing portion (64a) is provided with protrusions (66) for welding (see FIG. 4B). In this embodiment, four protrusions (66) are formed on the surface of the first fixing portion (64a) that faces the second barrel (61). By welding these protrusions (66), the first fixing portion (64a) is fixed to the second barrel (61). The number of the protrusions (66) provided on the first fixing portion (64a) may be two.

(3-4) Support

As shown in FIG. 2, a support (68) supports the outlet pipes (65a, 65b) within the second casing (60). The support (68) is fixed within the second casing (60). The support (68) is in contact with upper portions of the first outlet pipe (65a) and the second outlet pipe (65b). Thus, the first outlet pipe (65a) is fixed within the second casing (60) by the first connecting portion (82a) and the support (68). The second outlet pipe (65b) is fixed within the second casing (60) by the second connecting portion (82b) and the support (68).

(4) Operation of Compressor

The operation of the compressor (1) will be described with reference to FIG. 5. When the electric motor (20) drives the drive shaft (70), the pistons (40, 45) of the compression mechanism (15) are driven by the drive shaft (70). Each piston (40, 45) is displaced periodically in the corresponding cylinder (30, 35) for every revolution of the drive shaft (70). In two-cylinder rotary compressors, processes of sucking, compressing, and discharging a refrigerant are performed in each of the first compression mechanism (K1) and the second compression mechanism (K2).
In each cylinder (30, 35), the volumes of the first chamber (S1) and the second chamber (S2) of the corresponding cylinder chamber (S, S) change with the displacement of the corresponding piston (40, 45). In each cylinder (30, 35), the following processes are performed: a suction phase in which a refrigerant is sucked into the cylinder chamber (S, S) through the corresponding suction port (33, 38); a compression phase in which the refrigerant sucked into the cylinder chamber (S, S) is compressed; and a discharge phase in which the compressed refrigerant is discharged to the outside of the cylinder chamber (S, S) through the discharge port.
The angles indicated in FIG. 5 are on the premise that: the rotational angle of the drive shaft (70) at the position where the first blade (41) of the first compression mechanism (K1) is most retracted from the first cylinder (30) is 0°; and the rotational angle of the drive shaft (70) at the position where the first blade (41) of the first compression mechanism (K1) is most advanced into the first cylinder (30) is 180°.
Since the eccentric direction of the first piston (40) with respect to the rotational center axis (70a) of the drive shaft (70) is different from the eccentric direction of the second piston (45) with respect to the rotational center axis (70a) of the drive shaft (70) by 180°, the displacement cycle of the first piston (40) and the displacement cycle of the second piston (45) are shifted from each other by 180° (i.e., a half cycle). Hereinafter, the operation of the first compression mechanism (K1) is described, and the description of the operation of the second compression mechanism (K2) is omitted.

(5) Operation of First Compression Mechanism

(5-1) Suction Phase

When the drive shaft (70) slightly rotates in the clockwise direction in FIG. 5 from the state where the rotational angle of the drive shaft (70) is 0°, the contact position between the first piston (40) and the first cylinder (30) passes beyond the first suction port (33). At this time, suction of the refrigerant into the first chamber (S1) of the first cylinder (30) is started.
As the rotational angle of the drive shaft (70) increases, the volume of the first chamber (S1) increases accordingly, and the amount of refrigerant sucked into the first chamber (S1) increases. The refrigerant suction phase continues until the rotational angle of the drive shaft (70) reaches 360°, and then shifts to the discharge phase.

(5-2) Discharge Phase

When the drive shaft (70) slightly rotates from the state where the rotational angle is 0°, the contact position between the first piston (40) and the first cylinder (30) passes beyond the first suction port (33) again. At this time, the sealing of the refrigerant within the first chamber (S1) is completed, and the first chamber (S1), which has been in communication with the first suction port (33), becomes the second chamber (S2), which is now in communication only with the discharge port.
In this state, the compression of the refrigerant in the second chamber (S2) is started. As the rotational angle of the drive shaft (70) increases, the volume of the second chamber (S2) decreases, and the pressure in the second chamber (S2) increases. When the pressure in the second chamber (S2) exceeds a predetermined value, a discharge valve opens. At this time, the refrigerant in the second chamber (S2) is discharged to the outside of the compression mechanism (15) through the discharge port.
The refrigerant discharge phase continues until the rotational angle of the drive shaft (70) reaches 360°, and then shifts to the suction phase. In this manner, the suction phase and the discharge phase are alternately repeated in the first compression mechanism (K1), whereby the refrigerant compression operation is continuously performed.

(6) Vibration Problem Caused by Operation of Compressor

In a compressor unit including a compressor and an accumulator, the accumulator has a plurality of vibration modes. Specifically, the vibration modes include: a first mode in which an upper portion of the accumulator vibrates; a second mode in which a lower portion of the accumulator vibrates; and a third mode in which the accumulator moves in a direction in which the accumulator rolls along the outer peripheral surface of the compressor in the circumferential direction of the compressor. The eigenvalues of the accumulator in the first mode and the second mode are approximately in the range of 500 Hz to 2000 Hz, while the eigenvalue in the third mode is often in the range of 200 Hz to 300 Hz. When the compressor operates, not only is noise generated due to the vibrations in the first mode and the second mode, but the accumulator also vibrates in the third mode, which may lead to damage to a refrigerant pipe and/or an outlet pipe.
In addition, the vibration mode of the outlet pipe of the accumulator may also have an eigenvalue in the same frequency band as the third mode. Accordingly, if the vibration mode of the outlet pipe and the third vibration mode overlap with each other, the vibration of the accumulator increases.
Furthermore, in the case where the compressor is a rotary compressor having two cylinders, an excitation force at 2n (n: the number of revolutions of the compressor) is exerted on the compressor due to torque fluctuations or vibration of the drive shaft caused by the rotation of the drive shaft. Particularly in a small-sized high-speed compressor, the eigenvalue of the drive shaft is lower due to the smaller diameter of the drive shaft. It has been thus found that if the number of revolutions of the compressor reaches 120 rps or more, particularly 150 rps, the frequency bands of the 2n excitation force, the third mode, and the vibration mode of the outlet pipe become close to each other, increasing the vibration of the accumulator. Based on the above findings, a first adjustment portion (64) and a second adjustment portion (68) for adjusting eigenvalues are provided for the compressor unit (U) of this embodiment.

(7) First Adjustment Portion and Second Adjustment Portion

The first adjustment portion (64) adjusts a first eigenvalue s1 that is an eigenvalue of the accumulator (2) in a rolling direction. The rolling direction is a direction in which the second casing (60) moves so as to roll along the outer peripheral surface of the first casing (10) in its circumferential direction. The first adjustment portion (64) in this embodiment is the fixing member (64). The fixing member (64) adjusts the first eigenvalue s1 so as not to be equal to a value of n·N (where N is an integer), which is an integer multiple of the maximum number of rotations n of the compressor (1). Since the compressor in this embodiment is a two-cylinder rotary compressor, N = 2. Therefore, the fixing member (64) adjusts the first eigenvalue s1 so as to be greater than 2n.
Specifically, the fixing member (64) adjusts the first eigenvalue s1 such that the first eigenvalue s1 lies within a target range. The target range of the first eigenvalue s1 is n·N + n/4 ≤ s1 ≤ n·N + 3n/4 (N ≥ 2). The fixing member (64) is designed such that the first eigenvalue s1 falls within the target range. The fixing member (64) is formed through processing of bending a single metal plate. In this process, the shape or position of the bent portions (64d) is determined such that the first eigenvalue s1 falls within the target range. For example, the bending radius R of the bent portions (64d) is set such that the first eigenvalue s1 lies within the target range. Alternatively, the bent portions (64d) are formed at positions in the fixing member (64) such that the first eigenvalue s1 lies within the target range. Thus, when manufacturing the compressor unit (U), the fixing member (64) is formed such that the first eigenvalue s1 lies within the target range. Accordingly, a compressor unit (U) capable of reducing vibration can be easily manufactured. It should be noted that the determination of natural frequencies or vibration measurement can be made using a known test method or a known measurement method.
The second adjustment portion (68) adjusts a second eigenvalue s2, which is an eigenvalue of the outlet pipes (65a, 65b). The second eigenvalue s2 is the eigenvalue of the first outlet pipe (65a) and the second outlet pipe (65b). The second adjustment portion (68) in this embodiment is the support (68). The second eigenvalue s2 can be adjusted by adjusting the positions at which the support (68) supports the first outlet pipe (65a) and the second outlet pipe (65b). The support (68) supports the first outlet pipe (65a) and the second outlet pipe (65b) at the same height. In other words, the height positions where the first outlet pipe (65a) and the second outlet pipe (65b) are supported by the support (68) are the same.
Specifically, the support (68) supports the first outlet pipe (65a) and the second outlet pipe (65b) within the second casing (60) such that the second eigenvalue s2 does not overlap with n·N. The support (68) in this embodiment supports the first outlet pipe (65a) and the second outlet pipe (65b) such that the second eigenvalue s2 does not overlap with 2n. Thus, when manufacturing the compressor unit (U), the support (68) is provided in the second casing (60) such that the second eigenvalue s2 does not overlap with 2n. Accordingly, a compressor unit (U) capable of reducing vibration can be easily manufactured.

(8) Features

(8-1) Feature 1

In the compressor unit (U) of this embodiment, the first eigenvalue s1 of the accumulator (2) in the rolling direction does not overlap with a value of n·N (where N is an integer), which is an integer multiple of the maximum number of rotations n of the compressor (1). Due to this, the third vibration mode and the 2n excitation do not overlap with each other, and thus the vibration of the accumulator can be reduced. As a result, it is possible to reduce noise generated from the refrigeration apparatus (100) due to the operation of the compressor (1), and to reduce damage to pipes connected to the accumulator (2), and thus reduce failure of the refrigeration apparatus (100).

(8-2) Feature 2

The first eigenvalue s1 in this embodiment satisfies n·N + n/4 ≤ s1 ≤ n·N + 3n/4. Though an excitation force is exerted on the compressor (1) at an integer multiple of the maximum number of revolutions n of the compressor (1), the first eigenvalue s1 lies in the range farthest from the integer multiple of n, and therefore, the effect of reducing vibration of the accumulator (2) can be enhanced.

(8-3) Feature 3

The compressor unit (U) in this embodiment includes the first adjustment portion (64) that adjusts the first eigenvalue s1. This enables the first eigenvalue s1 to be adjusted to a target value, and therefore, vibration of the accumulator can be reduced easily without considering the shape, size, location, and the like of the accumulator (2).

(8-4) Feature 4

The first adjustment portion (64) in this embodiment includes the fixing member (64) having the bent portions (64d) formed so as to allow a plate to bend between the first barrel (11) and the second barrel (61). The shape of the bent portions (64d) or the position of the bent portions (64d) in the fixing member (64) is determined such that the first eigenvalue s1 does not overlap with n·N.
Thus, the first eigenvalue s1 can be easily adjusted by setting the shape and/or the attachment position of the fixing member (64).

(8-5) Feature 5

The compression mechanism in this embodiment is a two-cylinder rotary compression mechanism, and the first eigenvalue s1 is greater than 2n. Since the compression mechanism (15) is a rotary compression mechanism with two cylinders, an excitation force at 2n acts. The first eigenvalue s1 is thus adjusted so as not to overlap with the 2n excitation force exerted on the two-cylinder compressor (1), and therefore, an increase in vibration of the accumulator (2) can be reduced.

(8-6) Feature 6

In this embodiment, the second eigenvalue s2 is greater than 2n, and the first connecting portion (82a), where the first outlet pipe (65a) and the second casing (60) are connected to each other, and the second connecting portion (82b), where the second outlet pipe (65b) and the second casing (60) are connected to each other, are at positions offset from the central axis of the tubular second casing (60). The second eigenvalue s2 can be prevented from overlapping with n·N, which is an integer multiple of n, by shifting the first connecting portion (82a) and the second connecting portion (82b) from the central axis of the tubular second casing (60) in this manner.

(8-7) Feature 7

The compressor unit (U) in this embodiment further includes the second adjustment portion (68) that adjusts the second eigenvalue s2. The second eigenvalue s2 can be prevented from overlapping with n·N by the second adjustment portion (68).

(8-8) Feature 8

The second adjustment portion (68) in this embodiment is the support (68) that supports the first outlet pipe (65a) and the second outlet pipe (65b) in the second casing (60). Thus, the second eigenvalue s2 can be easily adjusted by setting the shape and/or the attachment position of the support (68).

(8-9) Feature 9

The compressor (1) in this embodiment rotates at a number of revolutions of 120 rps or greater. It is possible to enhance the effect of reducing vibration of the accumulator (2), the vibration of which increases at a number of revolutions of 120 rps or greater, particularly at 150 rps.

(10) Variations

Variations of the compressor unit (U) of the above-described embodiment will be described. The following describes only the configurations different from that of the compressor unit (U) of the above-described embodiment, and the description of the other configurations is omitted.

(10-1) First Variation

As shown in FIG. 6, each outlet pipe (65a, 65b) of the compressor unit (U) of the first variation has a first pipe portion (80a) and a second pipe portion (80b) that have different pipe thicknesses. The first pipe portion (80a) and the second pipe portion (80b) of each outlet pipe (65a, 65b) are continuous with each other. The first pipe portion (80a) and the second pipe portion (80b) are included in each of the first outlet pipe (65a) and the second outlet pipe (65b). Each of the first outlet pipe (65a) and the second outlet pipe (65b) in this variation is constituted by the first pipe portion (80a) and the second pipe portion (80b). The lower end of the first pipe portion (80a) is connected to the upper end of the second pipe portion (80b). Thus, a refrigerant in the accumulator (2) flows from the first pipe portion (80a) to the second pipe portion (80b).
The pipe thickness is the difference between the outer radius and the inner radius of a pipe. The pipe thickness of the first pipe portion (80a) is smaller than the pipe thickness of the second pipe portion (80b). In this variation, the inner diameters of the first pipe portion (80a) and the second pipe portion (80b) are the same, while the outer diameter of the second pipe portion (80b) is larger than the outer diameter of the first pipe portion (80a). Thus, each of the first outlet pipe (65a) and the second outlet pipe (65b) is formed such that the pipe thickness varies along the direction in which the pipe extends. In this variation, a transition portion (90), where the pipe thickness varies, includes a step portion (91) that increases the outer diameter. The transition portion (90) and the step portion (91) are formed at the upper end of each second pipe portion (80b). The transition portion (90) and the step portion (91) are provided within the second casing (60). The transition portion (90) and the step portion (91) are located below the center in height in the second casing (60).
The second adjustment portion (68) in this variation is each second pipe portion (80b). The second eigenvalue s2 can be adjusted by designing the first outlet pipe and the second outlet pipe (65b) with varying pipe thicknesses. Specifically, by adjusting the positions of the transition portion (90) and the step portion (91) of each pipe and/or adjusting the pipe thickness of each second pipe portion (80b), the second eigenvalue s2 can be prevented from overlapping with n·N.

(10-2) Second Variation

As shown in FIG. 7, the shape of the outlet pipes (65a, 65b) of the compressor unit (U) of the second variation is different from the shape of the outlet pipes (65a, 65b) in the first variation described above. Specifically, each outlet pipe (65a, 65b) has an upper pipe portion (92) and a lower pipe portion (93). The upper pipe portion (92) is formed in a straight shape. The lower pipe portion (93) has a straight portion and a curved portion. Each outlet pipe (65a, 65b) is formed by coupling the upper pipe portion (92) and the lower pipe portion (93) to each other such that the upper pipe portion (92) is located above the lower pipe portion (93) in the second casing (60). Specifically, the outer diameter of the upper pipe portion (92) is approximately the same as the inner diameter of the second outlet pipe (65b). This allows a lower portion of the upper pipe portion (92) to be inserted into and fixed to an upper portion of the lower pipe portion (93), and as a result, the upper pipe portion (92) and the lower pipe portion (93) are connected to each other. The upper pipe portion (92) and the lower pipe portion (93) may be fixed to each other by press-fitting or welding.
A portion of each outlet pipe (65a, 65b) in this variation, where the upper pipe portion (92) is fitted into the lower pipe portion (93) has a larger thickness. In other words, the pipe thickness of the portion where the upper pipe portion (92) is in contact with the lower pipe portion (93) is larger than that of the other portion. Accordingly, in this variation, the second pipe portion (80b) corresponds to the portion where the upper pipe portion (92) and the lower pipe portion (93) are in contact with each other. The first pipe portion (80a) corresponds to: a portion of the upper pipe portion (92) that is not in contact with the lower pipe portion (93); and a portion of the lower pipe portion (93) that is not in contact with the upper pipe portion (92). The second adjustment portion (68) in this variation is each second pipe portion (80b). In this variation, the transition portion (90) and the step portion (91) are formed both at the lower end of the upper pipe portion (92) and at the upper end of the lower pipe portion (93).

(11) Other Embodiments

The above-described embodiments may be modified as follows.
The compressor unit (U) may be modified to include the first adjustment portion (64) or the second adjustment portion (68).
The compressor (1) may be a single-cylinder rotary compressor. In this case, N is an integer of 1 or greater. Furthermore, the number of outlet pipes (65a, 65b) connected to the accumulator (2) is one. Also in this case, the connecting portion (82a, 82b) for the outlet pipe (65a, 65b) is formed at a position offset from the central axis of the tubular second barrel (61).
In an embodiment, the first adjustment portion (64) may include a structure other than the fixing member (64). The second adjustment portion (68) may include a structure other than the support (68).
In an embodiment, the accumulator (2) may be fixed to the compressor (1) using a belt. Specifically, the belt is attached so as to be wound around the second casing (60) of the accumulator (2) in the circumferential direction. The belt is thus in contact with the peripheral surface of the second casing (60), and whereby the accumulator is fixed to the compressor (1). In this case, the first adjustment portion (64) may be the belt. The first eigenvalue s1 can be prevented from overlapping with n·N by adjusting the position where the belt is provided on the second casing and/or by adjusting the size of the belt, for example.
In an embodiment, the outlet pipe (65a, 65b) does not have to be connected to a pipe coupling such as the suction pipes (14a, 14b). For example, the outlet pipe (65a, 65b) may be connected to the first barrel (11) by welding.
In a variation, since the second eigenvalue s2 can be adjusted by varying the pipe thickness of each outlet pipe (65a, 65b), the second adjustment portion (68) may be the first pipe portion (80a). Each outlet pipe (65a, 65b) is merely required to have a transition portion where the pipe thickness varies. The step portion (91) in the first variation may be formed inside each outlet pipe (65a, 65b). That is, each outlet pipe (65a, 65b) may be formed such that the inner diameter thereof changes along the direction in which the pipe extends with its outer diameter unchanged. Furthermore, in the first variation, two or more transition portions (90) may be formed. For example, first pipe portions (80a) and second pipe portions (80b) may be provided alternately and continuously with each other.
In an embodiment, the first adjustment portion (64) may be the extending portions (64c) of the fixing member (64). In this case, the shape of the extending portions (64c) and/or the length of the extending portions (64c) from the first fixing portion (64a) to the second fixing portions (64b) is/are set such that the first eigenvalue s1 does not overlap with n·N.
In an embodiment, the first fixing portion (64a) may be fixed to the outer peripheral surface of the second barrel (61) by brazing. Furthermore, the fixing member (64) may be provided in the compressor unit (U) such that the first fixing portion (64a) is fixed to the first barrel (11) and the second fixing portions (64b) are fixed to the second barrel (61).
In an embodiment, the first adjustment portion (64) may be a bent portion that connects each extending portion (64c) and the corresponding second fixing portion (64b).
While the embodiments and variations thereof have been described above, it will be understood that various changes in form and details may be made without departing from the spirit and scope of the claims. The foregoing embodiments and variations thereof may be combined and replaced with each other without deteriorating the intended functions of the present disclosure. The expressions of "first," "second," ... 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 can be seen from the foregoing description, the present disclosure is useful for a compressor unit and a refrigeration apparatus.

DESCRIPTION OF REFERENCE CHARACTERS

1: Compressor
2: Accumulator
10: First Casing
11: First Barrel
15: Compression Mechanism
20: Electric Motor
60: Second Casing
61: Second Barrel
64: Fixing Member (First Adjustment Portion)
64d: Bent Portion
65a: First Outlet Pipe
65a, 65b: Outlet Pipe
65b: Second Outlet Pipe
68: Support (Second Adjustment Portion)
70: Drive Shaft
80a: First Pipe Portion
80b: Second Pipe Portion
82a: First Connecting Portion
82a, 82b: Connecting Portion
82b: Second Connecting Portion
100: Refrigeration Apparatus
U: Compressor Unit

Claims

A compressor unit comprising:
a compressor (1); and

an accumulator (2) adjacent to the compressor (1),

the compressor (1) including:
a first casing (10) including a tubular first barrel (11);

an electric motor (20) housed in the first casing (10);

a drive shaft (70) configured to be driven by the electric motor (20); and

a rotary compression mechanism (15) configured to compress a fluid,

the accumulator (2) including:
a second casing (60) including a tubular second barrel (61) adjacent to the first casing (10) in a horizontal direction; and

an outlet pipe (65a, 65b) extending from a lower portion of the second casing (60) and connected to the first barrel (11),

when a direction in which the second barrel (61) moves so as to roll along an outer peripheral surface of the first barrel (11) in a circumferential direction of the first barrel (11) is defined as a rolling direction,

a first eigenvalue s1 of the accumulator (2) in the rolling direction does not overlap with a value of n·N (where N is an integer), which is an integer multiple of a maximum number of rotations n of the compressor (1).
The compressor unit of claim 1, wherein the first eigenvalue s1 satisfies n·N + n/4 ≤ s1 ≤ n·N + 3n/4.
The compressor unit of claim 1 or 2, further comprising a first adjustment portion (64) configured to adjust the first eigenvalue s1.
The compressor unit of claim 3, wherein
the first adjustment portion (64) is a fixing member (64) that has a plate shape and fixes the compressor (1) and the accumulator (2) to each other,

the fixing member (64) has a bent portion (64d) formed so that the fixing member (64) is bent between the first barrel (11) and the second barrel (61), and

a shape of the bent portion (64d) or a position of the bent portion (64d) in the fixing member (64) is determined such that the first eigenvalue s1 does not overlap with the value of n·N.
The compressor unit of any one of claims 1 to 4, wherein
the compression mechanism (15) is a two-cylinder rotary compression mechanism, and

the first eigenvalue s1 is greater than 2n.
The compressor unit of any one of claims 1 to 5, wherein
the outlet pipe (65a, 65b) includes a first outlet pipe (65a) and a second outlet pipe (65b) that extend side by side from a lower portion of the accumulator (2),

a second eigenvalue s2 of the outlet pipe (65a, 65b) is greater than 2n, and

a first connecting portion (82a), where the first outlet pipe (65a) and the second casing (60) are connected to each other, and a second connecting portion (82b), where the second outlet pipe (65b) and the second casing (60) are connected to each other, are at positions offset from a central axis of the tubular second casing (60).
The compressor unit of claim 6, further comprising
a second adjustment portion (68) configured to adjust the second eigenvalue s2.
The compressor unit of claim 7, wherein
the second adjustment portion (68) is a support (68) that supports the outlet pipe (65a, 65b) in the second casing (60).
The compressor unit of claim 8, wherein
the outlet pipe (65a, 65b) includes a first pipe portion (80a) and a second pipe portion (80b) that have pipe thicknesses different from each other,

the first pipe portion (80a) and the second pipe portion (80b) of the outlet pipe (65a, 65b) are continuous with each other, and

the second adjustment portion (68) is the first pipe portion (80a) or the second pipe portion (80b).
The compressor unit of any one of claims 1 to 9, wherein
the compressor (1) rotates at a number of revolutions of 120 rps or greater.
A refrigeration apparatus comprising the compressor unit of any one of claims 1 to 10.