COMPRESSOR AND REFRIGERATION CYCLE DEVICE

Abstract

 A compressor (14) includes a casing (11), a motor (12) housed in the casing, a compression mechanism (13) housed in the casing and configured to be driven by the motor. Inside of the casing is a high-pressure atmosphere filled with a refrigerant compressed by the compression mechanism (13), and the compression mechanism (13) is provided with a gas-liquid separation chamber (Cb) around a compression chamber (Cc), which separates the refrigerant sucked into the compression chamber into a gas refrigerant and a liquid refrigerant. The gas-liquid separation chamber (Cb) is defined at least partially by a component constituting the compression chamber (Cc).

Description

TECHNICAL FIELD

[0001] Embodiments of the present invention relate to a compressor and a refrigeration cycle apparatus.

BACKGROUND

[0002] In a refrigeration cycle apparatus to be applied to an air conditioner, a freezer, and the like, an accumulator is installed adjacent to a compressor. When a refrigerant circulating through piping is introduced into the accumulator before being sucked into the compressor and the refrigerant contains a refrigerant in a liquid state or droplet state (called a "liquid refrigerant"), this liquid refrigerant is separated in the accumulator to prevent the liquid refrigerant from being directly sucked into the compressor.

[0003] The refrigeration cycle apparatus uses a so-called high-pressure compressor in which a motor and a compression mechanism to be driven by the motor are housed in a hermetic casing. Patent Document 1 discloses a high-pressure compressor in which a space for gas-liquid separation of the refrigerant in addition to a chamber for housing the motor and the compression mechanism are provided inside the hermetic casing.

PRIOR ART DOCUMENT

PATENT DOCUMENT

[0004] [Patent Document 1] Japanese Unexamined Utility Model Application Publication No. H04-100077

SUMMARY

PROBLEM TO BE SOLVED BY INVENTION

[0005] In the compressor of Patent Document 1, the inside of the hermetic casing is partitioned by a material called an inner shell into a low pressure section connected to a suction pipe and a high pressure section connected to a discharge pipe. The low pressure section is used for the gas-liquid separation of the refrigerant, and the compression mechanism and the rotor of the motor are disposed in the high pressure section. Thus, it is in a situation where the compression chamber is surrounded by a high-pressure atmosphere filled with the discharged refrigerant subjected to compression and the refrigerant in the low-pressure section is susceptible to heat from the discharged refrigerant. Hence, there is still room for improvement in preventing the compression mechanism, especially the sliding portion of the compression chamber, from overheating. Furthermore, there is a demand for further improvement in efficiency of the gas-liquid separation of the refrigerant.

[0006] Accordingly, an object of the present invention is to provide a compressor and a refrigeration cycle apparatus, which can suppress overheating of its compression mechanism and promote efficient gas-liquid separation of its refrigerant while achieving more efficient layout of the compressor.

MEANS FOR SOLVING PROBLEM

[0007] According to one aspect of the present invention, a compressor includes a casing, a motor housed in the casing, and a compression mechanism housed in the casing and configured to be driven by the motor. Inside of the casing is a high-pressure atmosphere filled with a refrigerant compressed by the compression mechanism, and the compression mechanism is provided with a gas-liquid separation chamber around a compression chamber, the gas-liquid separation chamber being configured to separate the refrigerant sucked into the compression chamber into a gas refrigerant and a liquid refrigerant. The gas-liquid separation chamber is defined at least partially by a component constituting the compression chamber.

[0008] By providing the gas-liquid separation chamber around the compression chamber and defining it at least partially by the component that constitutes the compression chamber, the compressor itself has an accumulator function. This configuration reduces the need for additional space to install a separate accumulator, enabling a more efficient layout of the compressor.

[0009] Furthermore, by providing the gas-liquid separation chamber around the compression chamber, the compression chamber can be cooled by the refrigerant present in the gas-liquid separation chamber, making it possible to prevent excessive heat generation in the sliding parts of the compression mechanism and avoid overheating the refrigerant after compression.

[0010] Then, the heat generated during compression of the refrigerant, in other words the heat transmitted from the compression chamber, accelerates the evaporation of the liquid refrigerant contained in the refrigerant, thereby reducing the amount of liquid refrigerant itself and preventing the liquid refrigerant from being sucked into the compression chamber. This contributes to efficient gas-liquid separation of the refrigerant.

[0011] The compressor may further include a cylindrical cylinder, a rotor rotatably disposed on an inner diameter side of the cylinder, and a vane disposed to be radially movable with respect to the rotor between the cylinder and the rotor, which defines a space between the cylinder and the rotor into a suction chamber and the compression chamber. In this case, the gas-liquid separation chamber is preferably formed outside the compression chamber with respect to a radial direction of the cylinder.

[0012] The compressor can be appropriately realized by providing a cylinder and a rotor and partitioning the suction chamber and the compression chamber with vanes. In this compressor, the gas-liquid separation chamber is formed radially outside the compression chamber, thereby allowing for a reduction in dimensions of the compressor, such as its height when installed vertically.

[0013] The gas-liquid separation chamber is preferably formed in an outer peripheral portion of the cylinder outside the compression chamber with respect to the radial direction.

[0014] By forming the gas-liquid separation chamber in part of the cylinder, specifically, in the outer peripheral portion of the cylinder radially outside the compression chamber, the number of parts in the compressor or compression mechanism can be reduced. This configuration also reduces the number of joints with other parts, thereby making it easier to ensure airtightness of the gas-liquid separation chamber.

[0015] The compressor may further include a pair of end plate portions disposed to be in contact with respective two axial ends of the cylinder. Each of the end plate portions preferably includes an inner diameter portion configured to close a space of the cylinder in which the rotor is housed, and an outer diameter portion configured to close the gas-liquid separation chamber.

[0016] By providing end plate portions that contact the respective axial ends of the cylinder and closing the gas-liquid separation chamber with the outer diameter portion of this end plate portion, there is no need to prepare a separate or dedicated part for sealing the gas-liquid separation chamber, which is cost-effective. Additionally, the inner diameter portion that closes the rotor housing and this outer diameter portion can be finished simultaneously in a single process including polishing, which is also advantageous in terms of processability.

[0017]  The compressor may be vertically installed in such a manner that the motor is located above the compression mechanism. The compressor preferably includes a liquid return passage configured to spatially connect the gas-liquid separation chamber and the compression chamber with each other and to introduce lubricating oil mixed in the gas-liquid separation chamber into the compression chamber. The liquid return passage is preferably defined by a lower end plate portion or is formed on a surface of the lower end plate portion which contacts an end face of the cylinder.

[0018] In a vertically installed compressor, by forming a liquid return passage that connects the gas-liquid separation chamber and the compression chamber, it is possible to prevent a situation where lubricating oil that has entered the compressor together with the refrigerant accumulates in the gas-liquid separation chamber and causes a shortage of space that actually contributes to gas-liquid separation of the refrigerant. Additionally, by forming this liquid return passage on the contact surface with the cylinder in the lower end plate portion or by having it defined by the lower end plate portion, gravity can be utilized to facilitate the flow of lubricating oil into the liquid return passage.

[0019] The compressor may further include a cylindrical cylinder, a rotor rotatably disposed on an inner diameter side of the cylinder, and a vane disposed to be radially movable with respect to the rotor between the cylinder and the rotor and to define a space between the cylinder and the rotor into a suction chamber and the compression chamber. The gas-liquid separation chamber may be formed outside the compression chamber with respect to an axial direction of the cylinder.

[0020] The compressor can be preferably realized by providing a cylinder and a rotor, with vanes partitioning the suction chamber and the compression chamber. In this configuration, the gas-liquid separation chamber is formed axially outside the compression chamber, which reduces the dimensions of the compressor, such as the installation area when placed vertically.

[0021] The compressor may further include a bearing disposed outside the compression chamber with respect to the axial direction. The bearing preferably has a bearing portion that supports a rotating shaft of the rotor, and the gas-liquid separation chamber is preferably formed radially outward from the bearing portion.

[0022] In a compressor with a bearing arranged axially outside the compression chamber, the gas-liquid separation chamber is formed radially outside the bearing portion of this bearing. This configuration efficiently utilizes the space between the motor and the compression mechanism, allowing for the formation of the gas-liquid separation chamber while suppressing an increase in the installation area of the compressor.

[0023] The bearing may include an inner diameter portion configured as the bearing portion to support the rotating shaft of the rotor, an outer diameter portion disposed concentrically with the inner diameter portion and spaced radially outward from the inner diameter portion, and a connection portion configured to connect the inner diameter portion and the outer diameter portion. The gas-liquid separation chamber is preferably formed as a space surrounded by the inner diameter portion, the outer diameter portion, and the connecting portion.

[0024] In addition to the inner diameter portion serving as the bearing portion, an outer diameter portion and a connecting portion are provided on the bearing, and the gas-liquid separation chamber is formed as a space surrounded by the inner diameter portion, the outer diameter portion and the connecting portion. This configuration simplifies sealing of the gas-liquid separation chamber, particularly in relation to the compression chamber.

[0025]  The bearing may further include a communication passage that spatially connects the gas-liquid separation chamber and the compression chamber with each other, and is preferably configured to introduce a gas refrigerant existing in the gas-liquid separation chamber into the compression chamber.

[0026] A communication passage that connects the gas-liquid separation chamber and the compression chamber is formed in the bearing, and the gas refrigerant present in the gas-liquid separation chamber can be introduced into the compression chamber via this communication passage. This configuration eliminates the need for special components to form the communication passage, thereby being economical.

[0027] The compressor may further include an end plate portion disposed to be in contact with a lower end of the cylinder in an axial direction and to close a space of the cylinder for housing the rotor from below, and a tap bolt that penetrates the end plate portion and the cylinder from below in the axial direction to reach the bearing and fixes both the end plate portion and the cylinder to the bearing by co-fastening.

[0028] The cylinder and the end plate portion beneath it are secured together by co-fastening using a pressure bolt that penetrates the cylinder and the end plate portion axially from below and reaches the bearing. This configuration prevents the sealing of the gas-liquid separation chamber from being compromised by the use of fasteners, and mitigates the impact of liquid refrigerant on the bolt axial force if the liquid refrigerant gets mixed into the gas-liquid separation chamber formed in the bearing.

[0029] In another aspect of the present invention, a refrigeration cycle apparatus includes the compressor mentioned above, a condenser, an expansion valve, an evaporator, and refrigerant piping that connects the compressor, the condenser, the expansion valve, and the evaporator and circulates a refrigerant discharged from the compressor through the condenser, the expansion valve, and the evaporator.

EFFECT OF INVENTION

[0030] The present invention can provide a compressor and a refrigeration cycle apparatus, which can suppress overheating of its compression mechanism and promote efficient gas-liquid separation of its refrigerant while achieving more efficient layout of the compressor.

BRIEF DESCRIPTION OF DRAWINGS

[0031] 

Fig. 1 is a schematic diagram illustrating an overall configuration of a refrigeration cycle apparatus according to one embodiment of the present invention.

Fig. 2 is a cross-sectional view taken along a plane including the central axis of a hermetic casing for illustrating an internal configuration of a compressor according to the embodiment.

Fig. 3 is a cross-sectional view taken along the line A-A of Fig. 2.

Fig. 4 is a cross-sectional view taken along a plane including the central axis of the hermetic casing for illustrating the internal structure of the compressor according to another embodiment of the present invention.

Fig. 5 is a cross-sectional view taken along a plane, which includes the central axis of the hermetic casing and is different from that of Fig. 4, for illustrating the internal configuration of the compressor according to the embodiment.

Fig. 6 is a partial cross-sectional view for illustrating a bearing portion of a compression mechanism and its surrounding structure in the compressor according to the embodiment.

Fig. 7 is a partial cross-sectional view for illustrating the bearing portion of the compression mechanism and its surrounding structure in the compressor according to a first modification of the embodiment.

Fig. 8 is a partial cross-sectional view for illustrating the bearing portion of the compression mechanism and its surrounding structure in the compressor according to a second modification of the embodiment.

Fig. 9 is a partial cross-sectional view for illustrating a support structure of the compression mechanism in the compressor according to the embodiment.

DETAILED DESCRIPTION

[0032] Hereinbelow, embodiments of the present invention will be described by referring to the accompanying drawings.

[0033] Fig. 1 is a schematic diagram illustrating an overall configuration of a refrigeration cycle apparatus U according to one embodiment of the present invention.

[0034] In the present embodiment, the refrigeration cycle apparatus U is a heat pump type refrigeration cycle apparatus. The refrigeration cycle apparatus U can be applied to an air conditioner, a freezer, a refrigerator, a hot water heater, and the like, and can also be applied to a heat source unit that cools or heats utilization fluid to be circulated between a cooling/heating apparatus or a hot water storage apparatus (not shown) configured as an external apparatus. Although the utilization fluid is generally water, brine can be used as the utilization fluid for the purpose of preventing freezing and the like. The refrigerant to be circulated in the refrigeration cycle apparatus U is, for example, an HFC refrigerant such as R410A and R32, an HFO refrigerant such as R1234yf, or a natural refrigerant such as carbon dioxide (CO₂) and propane.

[0035] The refrigeration cycle apparatus U includes a compressor 1A, a first heat exchanger 2, a second heat exchanger 3, a four-way valve 4, and an expansion valve 5 as its main components. The refrigeration cycle apparatus U further includes refrigerant piping 6 that fluidly connects these components and circulates the refrigerant between these components. In the refrigeration cycle apparatus U, the refrigerant circulates while changing its phase between a gas refrigerant and a liquid refrigerant.

[0036] The compressor 1A is a so-called high-pressure type compressor and is a rotary compressor in the present embodiment. As will be described in more detail below, the compressor 1A includes a high pressure-resistant hermetic casing 11 as its outer body, and a motor 12 and a rotary type compression mechanism 13 to be driven by the motor 12 are housed inside the hermetic casing 11. The compressor 1A may be capable of changing the operating frequency by known inverter control or may be operated at a constant speed by using a commercial frequency.

[0037] The first heat exchanger 2 is installed outdoors and exchanges heat between the outdoor air and the refrigerant. The first heat exchanger 2 is a component of an outdoor unit and is housed in a casing of the outdoor unit together with an outdoor blower (not shown). Heat exchangers applicable to the first heat exchanger 2 include a finned tube heat exchanger.

[0038] The second heat exchanger 3 is installed indoors and exchanges heat between the refrigerant and the indoor air, which is the fluid to be conditioned. The second heat exchanger 3 is a component of an indoor unit and is housed in a casing of the indoor unit together with an indoor blower (not shown). Heat exchangers applicable to the second heat exchanger 3 include a finned tube heat exchanger, similarly to the first heat exchanger 2.

[0039] The four-way valve 4 switches the flow path of the refrigerant discharged from the compressor 1A between cooling operation and heating operation. During the cooling operation, the four-way valve 4 sets the flow path of the refrigerant to a direction from the four-way valve 4 toward the first heat exchanger 2. As a result, the refrigerant having left the four-way valve 4 passes through the first heat exchanger 2 and then flows into the second heat exchanger 3.

[0040] During the heating operation, the flow path of the refrigerant is set to a direction from the four-way valve 4 toward the second heat exchanger 3. As a result, the refrigerant having left the four-way valve 4 passes through the second heat exchanger 3 and then flows into the first heat exchanger 2. The first heat exchanger 2 functions as a condenser during the cooling operation and functions as an evaporator during the heating operation, whereas the second heat exchanger 3 functions as an evaporator during the cooling operation and functions as a condenser during the heating operation. In the condenser, a high-temperature and high-pressure gas refrigerant sent from the compressor 1A changes into a high-pressure liquid refrigerant through heat exchange. In the evaporator, a low-temperature and low-pressure liquid refrigerant sent from the expansion valve 5, which will be described next, changes into a low-pressure gas refrigerant.

[0041] The expansion valve 5 regulates the pressure of the refrigerant having left the condenser (specifically, the first or second heat exchanger 2 or 3 functioning as a condenser) by the action of an orifice, and regulates the pressure of the refrigerant flowing toward the evaporator (specifically, the second or first heat exchanger 3 or 2 functioning as an evaporator) by using flow resistance and thereby generating a pressure drop. Valves applicable to the expansion valve 5 include an electronic expansion valve to be driven by a stepping motor, for example. In the process of regulating the pressure by the expansion valve 5, the high-pressure liquid refrigerant sent from the condenser changes into a low-temperature and low-pressure liquid refrigerant.

[0042] The refrigerant piping 6 connects the compressor 1A, the first heat exchanger 2, the second heat exchanger 3, the four-way valve 4, and the expansion valve 5 such that the refrigerant can flow through them. In the present embodiment, the refrigerant piping 6 is mainly composed of: a first refrigerant pipe 6a connected to the compressor 1A and the four-way valve 4; a second refrigerant pipe 6b connected to the four-way valve 4 and the first heat exchanger 2; a third refrigerant pipe 6c connected to the first heat exchanger 2 and the expansion valve 5; a fourth refrigerant pipe 6d connected to the expansion valve 5 and the second heat exchanger 3; a fifth refrigerant pipe 6e connected to the second heat exchanger 3 and the four-way valve 4; and a sixth refrigerant pipe 6f connected to the four-way valve 4 and the compressor 1A.

[0043] During the cooling operation, the four-way valve 4 connects an inlet port 4a to a first inlet/outlet port 4b and connects a second inlet/outlet port 4c to an outlet port 4d. As a result, the refrigerant discharged from the compressor 1A passes through the four-way valve 4 toward the first heat exchanger 2, then is subjected to the action of the expansion valve 5, then passes through the second heat exchanger 3, and then returns to the compressor 1A through the four-way valve 4.

[0044] During the heating operation, the four-way valve 4 switches the connection destination of the inlet port 4a to the second inlet/outlet port 4c and switches the connection destination of the outlet port 4d to the first inlet/outlet port 4b. As a result, the refrigerant discharged from the compressor 1A passes through the four-way valve 4 toward the second heat exchanger 3, then is subjected to the action of the expansion valve 5, then passes through the first heat exchanger 2, and then returns to the compressor 1A through the four-way valve 4.

[0045] Fig. 2 is a cross-sectional view taken along a plane including the central axis Ax1 of the hermetic casing 11 (hereinafter abbreviated as "the casing 11") for illustrating the internal configuration of the compressor 1A according to the present embodiment. Fig. 3 is a cross-sectional view taken along the line A-A of Fig. 2.

[0046] The compressor 1A includes the casing 11, the motor 12, and the compression mechanism 13.

[0047] The casing 11 includes a casing main-body 11a, a casing upper-portion 11b, and a casing bottom portion 11c. The casing main-body 11a is opened at its upper end, and the lower end of the casing main-body 11a is integrally formed with the casing bottom portion 11c. The casing main-body 11a has an internal space S for housing the motor 12 and the compression mechanism 13. The casing upper-portion 11b is joined to the upper end portion of the casing main-body 11a, and hermetically closes the opening at the upper end of the casing main-body 11a. Although the casing main-body 11a and the casing bottom portion 11c are integrally formed into a cylindrical shape with a bottom in the present embodiment, the casing main-body 11a and the casing bottom portion 11c can be separately formed and the casing 11 can be composed of three parts including: the casing main-body 11a formed as a cylindrical body penetrating from top to bottom; the casing upper-portion 11b; and the casing bottom portion 11c. In this case, the casing bottom portion 11c is joined to the lower end portion of the casing main-body 11a, and hermetically closes the opening at the lower end of the casing main-body 11a.

[0048] In the present embodiment, the casing upper-portion 11b is formed by a dish-shaped end plate and is joined to the casing main body 11a by an appropriate method such as welding. The compressor 1A is installed vertically such that the central axis Ax1 of the casing 11 stands vertically, i.e., such that the motor 12 and the compression mechanism 13 are stacked one above the other inside the casing 11.

[0049] Inside the casing 11, the motor 12 is housed in the upper half portion of the casing main-body 11a.

[0050] Inside the casing 11, the compression mechanism 13 is housed in the lower half portion of the casing main-body 11a.

[0051] The motor 12 constitutes the driving source of the compression mechanism 13 and includes a stator 121 and a rotor 122. The stator 121 is cylindrical and is fixed to the casing main-body 11a. The rotor 122 is disposed on the inner diameter side of the stator 121 and is rotatably supported with respect to the casing main-body 11a.

[0052] The rotor 122 of the motor 12 is connected to the compression mechanism 13 via a rotating shaft 14. The motor 12 applies electromagnetic attractive force to the rotor 122 by energizing an electromagnetic coil 121a formed on the stator 121 so as to rotate the rotor 122. Further, the motor 12 transmits the rotational driving force generated in the rotor 122 to the compression mechanism 13 via the rotating shaft 14, and thereby drives the compression mechanism 13.

[0053] The power supply to the electromagnetic coil 121a of the stator 121 is performed via a terminal portion 15 provided on the casing upper-portion 11b. The terminal portion 15 is an intermediate element that connects a non-illustrated lead wire (also called a "power line") outside the casing 11 to a lead wire 153 (also called an "output wire 153") inside the casing 11. Here, the non-illustrated lead wire (i.e., power line) extends from a power source such as a commercial AC power source of the motor 12 or a power converter such as an inverter, and the output wire 153 extends from the coil winding of the electromagnetic coil 121a.

[0054] In the present embodiment, the terminal portion 15 includes an installation base 151 and a plurality of terminal pins 152. The installation base 151 is fitted into an insertion hole formed in the casing upper-portion 11b and is fixed to the casing upper-portion 11b. A flat tab terminal is fixed to each terminal pin 152, and each terminal pin 152 is attached to the installation base 151 in the state of penetrating its front and back sides. The power supply to the electromagnetic coil 121a is achieved by joining the terminals of the lead wires outside the casing 11 to the tab terminals of the terminal pins 152. The installation base 151 ensures the insulation distance between the respective terminal pins 152.

[0055] The compression mechanism 13 is driven by the motor 12, compresses the refrigerant sucked in through a suction pipe 1a (hereinafter sometimes referred to as "the suctioned refrigerant"), and discharges the compressed refrigerant (hereinafter sometimes referred to as "the discharge refrigerant) through a discharge pipe 1b. In the present embodiment, the compressor 1A is a sliding vane type compressor, and the compression mechanism 13 includes a cylinder 131, a rotor 132, vanes 133, a main bearing 134, a sub-bearing 135, and a discharge muffler 136.

[0056] The cylinder 131 is cylindrical as a whole and is fixed to the casing main-body 11a coaxially with the rotating shaft 14 and the rotor 122 of the motor 12. In the present embodiment, the cylinder 131 has an accommodation chamber of the rotor 132 in the inner diameter portion, and has a discharge chamber Cd radially outward from the accommodation chamber of the rotor 132. The accommodation chamber of the rotor 132 is connected to the suction pipe 1a and the discharge chamber Cd through a suction port h1 and a discharge port h2 formed on the inner wall of the cylinder 131, respectively. The accommodation chamber of the rotor 132 is approximately annular and is formed eccentrically with respect to the central axis of the cylinder 131 (i.e., the rotating shaft 14).

[0057] The rotor 132 is housed in the inner-diameter side of the cylinder 131, and is connected to the rotor 122 of the motor 12 via the rotating shaft 14 so as to be rotatable together with the rotor 132. The rotor 132 and the rotating shaft 14 are concentric with each other and are rotatably supported with respect to the cylinder 131.

[0058] In the present embodiment, a plurality of grooves g extending radially outward are formed on the rotor 132, these grooves g are opened on the outer circumferential surface of the rotor 132, and the vane 133 is housed in each of the plurality of grooves g. When the compressor 1A is in operation, the vanes 133 are pressed against the inner circumferential surface of the cylinder 131 by the back pressure, and slide against it so as to divide the space between the cylinder 131 and the rotor 132 into a suction chamber Ci and a compression chamber Cc. The suction chamber Ci is spatially connected with the suction port h1, and the compression chamber Cc is spatially connected with he discharge port h2. The compression mechanism 13 sucks in and compresses the refrigerant as the rotor 132 rotates inside the cylinder 131.

[0059]  As shown in Fig. 3, the cylinder 131 has a shape obtained by cutting a part of its outer peripheral portion along a chord connecting two points on the outer periphery, the discharge chamber Cd opened toward the cut surface is formed in the cylinder 131, and the cylinder 131 has a sealing plate 131a that is joined to the cut surface so as to close the discharge chamber Cd. The cylinder 131 further has a discharge valve 131b that blocks the discharge port h2. When the refrigerant in the compression chamber Cc reaches the valve opening pressure of the discharge valve 131b, the discharge valve 131b opens and the refrigerant flows out from the discharge port h2 to the discharge chamber Cd.

[0060] The main bearing 134 is disposed between the motor 12 and the compression mechanism 13, and supports the rotating shaft 14.

[0061] The sub-bearing 135 is disposed on the side opposite to the main bearing 134 with respect to the compression mechanism 13, and supports the rotating shaft 14 together with the main bearing 134.

[0062] The discharge muffler 136 is disposed concentrically with the main bearing 134 and forms a muffler chamber between itself and the main bearing 134.

[0063]  After being compressed, the refrigerant discharged from the compression chamber Cc to the discharge chamber Cd flows into the discharge muffler 136 through a communication passage p2 that is formed so as to penetrate the cylinder 131 and the main bearing 134. On the inner diameter side of the discharge muffler 136, an annular communication port h3 is formed between the discharge muffler 136 and the main bearing 134, and the refrigerant flows out to the inside of the casing 11 through the communication port h3.

[0064] Afterward, the refrigerant reaches the discharge pipe 1b through: the gap between the stator 121 of the motor 12 and the inner peripheral surface of the casing 11; a communication passage (not shown) formed in the rotor 122; and the like, and then the refrigerant flows out of the compressor 1A through the discharge pipe 1b.

[0065] Furthermore, lubricating oil is sealed in the casing bottom portion 11c and the lower half portion of the casing main-body 11a, and the compression mechanism 13 is immersed in this lubricating oil.

[0066] In addition to the above, the compressor 1A has a gas-liquid separation chamber Cb inside the casing 11.

[0067] The gas-liquid separation chamber Cb is provided around the compression chamber Cc of the compression mechanism 13, and at least part of the gas-liquid separation chamber Cb is partitioned by components constituting the compression chamber Cc. The components constituting the compression chamber Cc are, for example, the cylinder 131, the rotor 132, the main bearing 134, and the sub-bearing 135, and in the present embodiment, the cylinder 131, the main bearing 134, and the sub-bearing 135 are adopted. The gas-liquid separation chamber Cb is also called a buffer chamber, is located between the suction pipe 1a and the suction port h1, receives the refrigerant from the suction pipe 1a, and separates the liquid refrigerant if it contains any liquid refrigerant.

[0068] In the present embodiment, the gas-liquid separation chamber Cb is formed outside the compression chamber Cc in the radial direction of the cylinder 131. Specifically, in the cylinder 131, the outer peripheral portion, radially outside the compression chamber Cc, is where the gas-liquid separation chamber Cb is formed. In other words, in the present embodiment, the gas-liquid separation chamber Cb is formed in the cylinder 131 itself, and in the cross-section shown in Fig. 3, the entire gas-liquid separation chamber Cb is partitioned by the inner wall surface of the cylinder 131. In the radial direction of the cylinder 131, the gas-liquid separation chamber Cb is separated from the space outside the cylinder 131 by the peripheral portion of the cylinder 131. Furthermore, in the circumferential direction centered on the central axis Ax1 of the casing 11, the gas-liquid separation chamber Cb is formed over the entire outer peripheral portion except the discharge chamber Cd.

[0069] Further, in the present embodiment, each of the end plate portion 134a of the main bearing 134 and the end plate portion 135a of the sub-bearing 135 extends radially outward to the peripheral portion of the cylinder 131. The end plate portion 134a of the main bearing 134 contacts one of the axial end faces of the cylinder 131 so as to close the accommodation chamber of the rotor 132 and close the gas-liquid separation chamber Cb, and the end plate portion 135a of the sub-bearing 135 contacts the other axial end face of the cylinder 131 so as to close the accommodation chamber of the rotor 132 and close the gas-liquid separation chamber Cb. In each of the main bearing 134 and the sub-bearing 135, "the end plate portion" refers to the disk-shaped portion extending radially outward from the cylindrical bearing portion that faces and supports the rotating shaft 14. In other words, each of the end plate portion 134a of the main bearing 134 and the end plate portion 135a of the sub-bearing 135 has an inner circumferential portion for closing the accommodation chamber of the rotor 132 and an outer circumferential portion for closing the gas-liquid separation chamber Cb.

[0070] In the sub-bearing 135, a liquid return passage p1 is formed in the end plate portion 135a in contact with the lower axial end face of the cylinder 131 so as to straddle the inner wall portion of the cylinder 131 that partitions the suction chamber Ci. In the present embodiment, the liquid return passage p1 is in the form of a groove drilled in the joint surface of the end plate portion 135a, spatially connects the bottom of the gas-liquid separation chamber Cb and the bottom of the compression chamber Cc with each other, and thereby allows the lubricating oil mixed in the gas-liquid separation chamber Cb to be introduced into the compression chamber Cc.

[0071] The liquid return passage p1 can be formed not only as a groove but also as a hole. For example, a hole is formed through the inner wall portion of the cylinder 131 partitioning the gas-liquid separation chamber Cb and the compression chamber Cc, and the gas-liquid separation chamber Cb and the compression chamber Cc are spatially connected with each other through this hole.

[0072] The refrigeration cycle apparatus U and the compressor 1A according to the present embodiment have the above-described configuration, and the effects to be obtained by the present embodiment will be described below.

[0073] Firstly, though the accumulator is generally disposed outside the hermetic casing, the functions of the accumulator are given to the compressor 1A itself and the gas-liquid separation chamber Cb is formed inside the casing 11, specifically, formed around the compression chamber Cc. This configuration can reduce the space required for individually installing the accumulator and allows the compressor 1A to be disposed more efficiently.

[0074] Inside the casing 11, the gas-liquid separation chamber Cb is formed around the compression chamber Cc. Hence, the refrigerant existing in the gas-liquid separation chamber Cb cools the compression chamber Cc, especially the sliding portions such as the tips of the vanes 133, and this can prevent excessive heat generation in the sliding portions and avoid overheating the refrigerant after compression.

[0075] Moreover, by using the heat generated during compression, i.e., the heat transmitted from the compression chamber Cc to promote the evaporation of a liquid refrigerant contained in the refrigerant and reduce the amount of the liquid refrigerant itself, the gas-liquid separation can be promoted and the intake of the liquid refrigerant into the compression chamber Cc can be suppressed. Further, promoting the evaporation of the liquid refrigerant can secure the amount of the refrigerant to be supplied to the compression chamber Cc and prevent malfunctions caused by the liquid refrigerant being sucked into the compression chamber Cc or by an insufficient amount of the refrigerant to be sucked into the compression chamber Cc.

[0076] Since the gas-liquid separation chamber Cb is provided around the compression chamber Cc and both the gas-liquid separation chamber Cb and the compression chamber Cc are located close to each other, this encourages the active use of the heat generated during compression.

[0077] Secondly, the gas-liquid separation chamber Cb is formed outside the compression chamber Cc with respect to the radial direction of the cylinder 131, and thus, the dimensions of the compressor 1A, such as the height in the case of vertically installing the compressor 1A, can be reduced.

[0078] Thirdly, the gas-liquid separation chamber Cb is formed on the outer peripheral portion of the cylinder 131, and this configuration can reduce the number of parts in the compressor 1A or the compression mechanism 13 and the number of joints with other parts and can improve sealability of the gas-liquid separation chamber Cb.

[0079] Since the gas-liquid separation chamber Cb is located on the outer peripheral portion of the cylinder 131, this configuration can effectively cool the compression chamber Cc formed on the inner diameter side of the cylinder 131, especially the sliding portions, which are between the vanes 133 and the inner circumferential portion of the cylinder 131 and are susceptible to frictional force, in the case of the sliding vane type compressor 1A.

[0080] Fourthly, the gas-liquid separation chamber Cb is closed by the pair of end plate portions 134a and 135a that close the axial end faces of the cylinder 131, which eliminates the need to prepare separate or dedicated parts for closing the gas-liquid separation chamber Cb, making it economical. Under this configuration, of the end plate portions 134a and 135a, both the inner diameter portion closing the accommodation portion of the rotor 132 and the outer diameter portion closing the gas-liquid separation chamber Cb can be simultaneously finished in a single process including polishing and the like, and it is also advantageous in terms of workability.

[0081] Fifthly, the lubricating oil mixed in the gas-liquid separation chamber Cb is introduced into the compression chamber Cc through the liquid return passage p1, and this can suppress a situation where the lubricating oil is accumulated in the gas-liquid separation chamber Cb so as to lead to a shortage of a space substantially contributing to the gas-liquid separation of the refrigerant.

[0082] Since the liquid return passage p1 is formed in the lower end plate portion 135a or is partitioned by the lower end plate portion 135a, the inflow of the lubricating oil into the liquid return passage p1 can be promoted by gravity in the case of vertically installing the compressor 1A.

[0083] Other embodiments of the present invention will be described below.

[0084] Fig. 4 is a cross-sectional view taken along a plane including the central axis Ax1 of the hermetic casing 11 for illustrating an internal configuration of a compressor 1B according to another embodiment of the present invention. Fig. 5 is a cross-sectional view taken along a plane, which includes the central axis Ax1 of the hermetic casing 11 and is different from that of Fig. 4, for illustrating the internal configuration of the compressor 1B. In Fig. 4 and Fig. 5, the components corresponding to those in the compressor 1A according to the above-described embodiment are denoted by the same reference signs as in Fig. 2, and duplicate descriptions are omitted. The compressor 1B according to the present embodiment can be applied to the refrigeration cycle apparatus U having a configuration similar to that shown in Fig. 1.

[0085] Fig. 6 is a partial cross-sectional view for illustrating a main bearing 137 of the compression mechanism 13 and its surrounding structure in the compressor 1B according to the present embodiment.

[0086] The compressor 1B according to the present embodiment will be described below by referring to Fig. 6 as appropriate, focusing on the differences from the compressor 1A according to the above-described embodiment.

[0087] The compressor 1B differs from the compressor 1A of the previous embodiment mainly in configuration of the gas-liquid separation chamber Cb.

[0088] The gas-liquid separation chamber Cb is provided around the compression chamber Cc of the compression mechanism 13 similarly to the previous embodiment, and at least part of the gas-liquid separation chamber Cb is partitioned by the components constituting the compression chamber Cc. In the present embodiment, outside the compression chamber Cc with respect to the axial direction of the cylinder 131, the gas-liquid separation chamber Cb is formed radially outside with respect to the bearing portion of the main bearing 137 that supports the rotating shaft 14 of the rotor 132.

[0089] The main bearing 137 includes: an inner diameter portion 137a configured to support the rotating shaft 14; an outer diameter portion 137b that is concentric with the inner diameter portion 137a and spaced radially outward from the inner diameter portion 137a; and a disk-shaped connection portion 137c that connects the inner diameter portion 137a and the outer diameter portion 137b. The gas-liquid separation chamber Cb is formed as a space surrounded by the inner diameter portion 137a, the outer diameter portion 137b, and the connection portion 137c. In other words, the radially inner and outer sides and the lower side of the gas-liquid separation chamber Cb are shielded by these components 137a, 137b, and 137c of the main bearing 137, and the gas-liquid separation chamber Cb is formed so as to surround the inner diameter portion 137a over its entire circumference.

[0090] The inner diameter portion 137a corresponds to the bearing portion of the main bearing 137, and the connection portion 137c contacts one of the axial end faces of the cylinder 131 and functions as an end plate portion that closes the accommodation chamber of the rotor 132. In other words, in the present embodiment, the accommodation chamber of the rotor 132 is sealed in the axial direction by the connection portion 137c of the main bearing 137 and the end plate portion 135a of the sub-bearing 135.

[0091] The main bearing 137 has an opening in the outer diameter portion 137b, and the suction pipe 1a is connected to this opening in such a manner that the refrigerant is received from the suction pipe 1a into the gas-liquid separation chamber Cb.

[0092] With respect to the main bearing 137, an end plate member 138 is attached to its shaft end face opened upward. The gas-liquid separation chamber Cb is closed from above with this end plate member 138.

[0093] In addition to the above, in the present embodiment, a communication passage p3 configured to spatially connect the gas-liquid separation chamber Cb and the suction port h1 with each other is formed in the outer diameter portion 137b of the main bearing 137. In the inner wall portion of the main bearing 137 partitioning the communication passage p3, a communication port h4 passing through this inner wall portion and spatially connecting the gas-liquid separation chamber Cb and the communication passage p3 with each other is formed.

[0094] The communication passage p3 is formed as a cylindrical space extending in a direction parallel to the axial direction of the cylinder 131, terminates near the axial end portion of the main bearing 137, and forms a small gap g1 between itself and the end plate member 138. The flow resistance or fluid loss of the refrigerant from the gas-liquid separation chamber Cb to the suction port h1 can be adjusted by the opening area of this gap g1. Extending the communication passage p3 close to the end plate member 138 without excessively increasing the flow resistance can increase the storable amount of the liquid refrigerant and promote the evaporation of the liquid refrigerant in combination with the effect of heat from the compression chamber Cc.

[0095] In the present embodiment, as shown in Fig. 6, a volume portion connected to the suction port h1, i.e., a suction chamber Cs is formed on the outer peripheral portion of the cylinder 131, and the communication passage p3 of the main bearing 137 is connected to this suction chamber Cs. As a result, the refrigerant (especially the gas refrigerant after gas-liquid separation) having flowed from the gas-liquid separation chamber Cb into the communication passage p3 is introduced into the suction chamber Cs, and is sucked in from the suction chamber Cs through the suction port h1 into the suction chamber Ci between the cylinder 131 and the rotor 132. In Fig. 6, the flow of the refrigerant flowing from the suction pipe 1a into the gas-liquid separation chamber Cb is indicated by the arrow a1, the flow of the refrigerant flowing from the gas-liquid separation chamber Cb into the communication passage p3 is indicated by the arrow a2, the flow of the refrigerant flowing from the communication passage p3 into the suction chamber Cs is indicated by the arrow a3, and the flow of the refrigerant flowing from the suction chamber Cs through the suction port h1 into the suction chamber Ci is indicated by the arrow a4.

[0096] The communication hole h4 forms the liquid return passage, and allows the liquid refrigerant subjected to the gas-liquid separation and the lubricating oil mixed in the gas-liquid separation chamber Cb to escape to the communication passage p3 and be introduced into the compression chamber Cc. In Fig. 6, the flow of the lubricating oil and the liquid refrigerant flowing from the gas-liquid separation chamber Cb through the communication hole h4 into the communication passage p3 is indicated by the arrow a5.

[0097] Fig. 9 is a partial cross-sectional view for illustrating a support structure of the compression mechanism 13 in the compressor 1B according to the present embodiment.

[0098] In the present embodiment, tap bolts 140 are used as fasteners for the compression mechanism 13. Specifically, through holes are formed so as to penetrate both the cylinder 131 and the end plate portion 135a of the sub-bearing 135 from below and reach the connection portion 137c of the main bearing 137, and female screws are formed around the inner circumference of the respective holes of the connection portion 137c. Each tap bolt 140 is inserted from below into the end plate portion 135a and the cylinder 131 in this order, and is screwed into the female screw of the connection portion 137c. In this manner, the cylinder 131 and the sub-bearing 135 are fastened together to the main bearing 137 and fixed. Since the main bearing 137 is fixed to the casing 11, the entire compression mechanism 13 can be fixed to the casing 11.

[0099] The gas-liquid separation chamber Cb is formed outside the compression chamber Cc with respect to the axial direction of the cylinder 131 in this manner, and this configuration can reduce the dimensions of the compressor 1B, for example, the installation area required for the case of vertically installing the compressor 1B.

[0100] The gas-liquid separation chamber Cb is formed radially outward from the bearing portion for supporting the rotating shaft 14 of the rotor 132, specifically, with respect to the inner diameter portion 137a of the main bearing 137. Although this may result in extension of the length dimension of the rotating shaft 14, the space between the motor 12 and the compression mechanism 13 can be effectively utilized and the gas-liquid separation chamber Cb can be formed without increasing the installation area of the compressor 1B. In other words, the space required for forming the gas-liquid separation chamber Cb can be readily secured.

[0101] Since the inner diameter portion 137a, the outer diameter portion 137b, and the connection portion 137c are formed in the main bearing 137 and the gas-liquid separation chamber Cb is formed as a space surrounded by the inner diameter portion 137a, the outer diameter portion 137b, and the connection portion 137c, sealability of the gas-liquid separation chamber Cb, especially the sealability for the compression chamber Cc can be readily ensured.

[0102] The refrigerant existing in the gas-liquid separation chamber Cb can be introduced into the compression chamber Cc through the communication passage p3. Since the communication passage p3 is formed in the main bearing 137, specifically, in its outer diameter portion 137b, it is not necessary to prepare a special member for forming the communication passage p3, making it economical, and this configuration can ensure resistance to thermal shock when the liquid refrigerant is mixed into the gas-liquid separation chamber Cb.

[0103] Since the cylinder 131 and the sub-bearing 135 are fastened together to the main bearing 137 by the tap bolts 140, the use of fasteners can prevent the sealability of the gas-liquid separation chamber Cb from being impaired, and can also suppress the influence on the bolt axial force when the liquid refrigerant is mixed into the gas-liquid separation chamber Cb.

[0104] In the present embodiment, the communication passage p3 of the main bearing 137 for connecting the gas-liquid separation chamber Cb and the suction port h1 is formed by the inner wall portion of the main bearing 137 (Fig. 6). The formation of the communication passage p3 is not limited to this aspect, and it can also be formed by using a dedicated member.

[0105] Fig. 7 is a partial cross-sectional view for illustrating the main bearing 137 of the compression mechanism 13 and its surrounding structure in the compressor according to a first modification of the present embodiment.

[0106] In the first modification, a cylindrical member 139 separate from the main bearing 137 is adopted and embedded in the outer diameter portion 137b of the main bearing 137 so as to form the communication passage p3. The cylindrical member 139 terminates near the axial end portion of the main bearing 137, and forms a small gap g2 between itself and the end plate member 138. Further, a through hole h5 is formed in the tubular wall portion of the cylindrical member 139 so as to penetrate the tubular wall portion in the radial direction, and thereby, the gas-liquid separation chamber Cb and the inside of the cylindrical member 139, i.e., the communication passage p3, are spatially connected with each other. In other words, the through hole h5 replaces the communication hole h4 in the previous embodiment and forms the liquid return passage. In Fig. 7, the flow of the lubricating oil and the liquid refrigerant flowing from the gas-liquid separation chamber Cb through the through hole h5 into the communication passage p3 is indicated by the arrow a6. In Fig. 7, the other arrows a1 to a4 indicate the same flows as in Fig. 6.

[0107] Since the communication passage p3 is formed from a member separate from the main bearing 137 in this manner, the dimensions of the communication passage p3 can be appropriately changed depending on the flow rate of the refrigerant, the required amount of the liquid refrigerant to be stored, and the like. In particular, the fluid loss in the communication passage p3 can be optimized or minimized by individual adjustment of the cylindrical member 139, and thereby, the adverse effect of the formation of the gas-liquid separation chamber Cb on the operating performance of the compressor can be minimized.

[0108] Furthermore, the liquid return passage can be formed not only in the separate member or the inner wall portion of the main bearing 137 forming the communication passage p3 but also in the connection portion 137c or the end plate portion.

[0109] Fig. 8 is a partial cross-sectional view for illustrating the main bearing 137 of the compression mechanism 13 and its surrounding structure in the compressor according to a second modification of the present embodiment.

[0110] In the second modification, a through hole p4 is formed as the liquid return passage so as to penetrate the connection portion 137c of the main bearing 137 from top to bottom, and the gas-liquid separation chamber Cb and the suction port h1 or the suction chamber Cs are spatially connected with each other via this through hole p4.

[0111] Since the through hole p4 is formed in the connection portion 137c of the main bearing 137 and the gas-liquid separation chamber Cb is spatially connected with the suction port h1 or the suction chamber Cs in this manner, the negative pressure to be generated in the suction chamber Ci can be more directly transmitted to the gas-liquid separation chamber Cb, and the lubricating oil and the liquid refrigerant accumulated in the gas-liquid separation chamber Cb can be more actively discharged from the gas-liquid separation chamber Cb. In Fig. 8, the flow of the lubricating oil and the liquid refrigerant flowing from the gas-liquid separation chamber Cb through the through hole p4 into the suction chamber Cs is indicated by the arrow a7.

[0112] Although the compressors 1A and 1B are sliding vane type compressors in the above description, the compressors that can be applied to the embodiments are not limited to such a type and may be a rolling piston type compressor.

[0113] While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.

REFERENCE SIGNS LIST

[0114] 

U

refrigeration cycle apparatus

1A, 1B

compressor

1a

suction pipe

1b

discharge pipe

11

hermetic casing

12

motor

121

stator

122

rotor

13

compression mechanism

131

cylinder

132

rotor

133

vane

134

main bearing

135

sub-bearing

136

discharge muffler

14

rotating shaft

2

first heat exchanger

3

second heat exchanger

4

four-way valve

5

expansion valve

6 (6a to 6f)

refrigerant piping

h1

suction port

h2

discharge port

Ci

suction chamber

Cc

compression chamber

Cb

gas-liquid separation chamber

S

space inside the casing

Claims

1. A compressor comprising:

a casing;

a motor housed in the casing; and

a compression mechanism housed in the casing and configured to be driven by the motor, wherein:

inside of the casing is a high-pressure atmosphere filled with a refrigerant compressed by the compression mechanism;

the compression mechanism is provided with a gas-liquid separation chamber around a compression chamber, the gas-liquid separation chamber being configured to separate the refrigerant sucked into the compression chamber into a gas refrigerant and a liquid refrigerant; and

the gas-liquid separation chamber is defined at least partially by a component constituting the compression chamber.

2. The compressor according to claim 1, further comprising:

a cylindrical cylinder;

a rotor rotatably disposed on an inner diameter side of the cylinder; and

a vane disposed to be radially movable with respect to the rotor between the cylinder and the rotor, the vane defining a space between the cylinder and the rotor into a suction chamber and the compression chamber,

wherein the gas-liquid separation chamber is formed outside the compression chamber with respect to a radial direction of the cylinder.

3. The compressor according to claim 2, wherein the gas-liquid separation chamber is formed in an outer peripheral portion of the cylinder outside the compression chamber with respect to the radial direction.

4. The compressor according to claim 3, further comprising a pair of end plate portions disposed to be in contact with respective two axial ends of the cylinder,
wherein each of the end plate portions includes:

an inner diameter portion configured to close a space of the cylinder in which the rotor is housed; and

an outer diameter portion configured to close the gas-liquid separation chamber.

5. The compressor according to claim 4 vertically installed in such a manner that the motor is located above the compression mechanism, the compressor further comprising a liquid return passage configured to spatially connect the gas-liquid separation chamber and the compression chamber with each other and to introduce lubricating oil mixed in the gas-liquid separation chamber into the compression chamber, wherein:
the liquid return passage is defined by a lower end plate portion or is formed on a surface of the lower end plate portion, the surface of the lower end plate portion being in contact with an end face of the cylinder.

6. The compressor according to claim 1, further comprising:

a cylindrical cylinder;

a rotor rotatably disposed on an inner diameter side of the cylinder; and

a vane disposed to be radially movable with respect to the rotor between the cylinder and the rotor, the vane defining a space between the cylinder and the rotor into a suction chamber and the compression chamber,

wherein the gas-liquid separation chamber is formed outside the compression chamber with respect to an axial direction of the cylinder.

7. The compressor according to claim 6, further comprising a bearing disposed outside the compression chamber with respect to the axial direction, wherein:

the bearing has a bearing portion configured to support a rotating shaft of the rotor; and

the gas-liquid separation chamber is formed radially outward from the bearing portion.

8. The compressor according to claim 7, wherein:

the bearing includes

an inner diameter portion configured as the bearing portion to support the rotating shaft of the rotor,

an outer diameter portion disposed concentrically with the inner diameter portion and spaced radially outward from the inner diameter portion, and

a connection portion configured to connect the inner diameter portion and the outer diameter portion; and

the gas-liquid separation chamber is formed as a space surrounded by the inner diameter portion, the outer diameter portion, and the connecting portion.

9. The compressor according to claim 8, wherein the bearing further includes a communication passage configured to spatially connect the gas-liquid separation chamber and the compression chamber with each other and to introduce a gas refrigerant existing in the gas-liquid separation chamber into the compression chamber.

10. The compressor according to claim 7, further comprising:

an end plate portion disposed to be in contact with a lower end of the cylinder in an axial direction and to close a space of the cylinder for housing the rotor from below; and

a tap bolt that penetrates the end plate portion and the cylinder from below in the axial direction to reach the bearing and fixes both the end plate portion and the cylinder to the bearing by co-fastening.

11. A refrigeration cycle apparatus comprising:

the compressor according to any one of claim 1 to claim 10;

a condenser;

an expansion valve;

an evaporator; and

refrigerant piping that connects the compressor, the condenser, the expansion valve, and the evaporator and circulates a refrigerant discharged from the compressor through the condenser, the expansion valve, and the evaporator.

Drawing