Rotary compressor

Abstract

To suppress the effect of lubricating oil foaming in rotary compressors. [Solution] The rotary compressor (1) comprises a casing (16) having a cylindrical body (17) and storing lubricating oil at the bottom, a compression mechanism (15) fixed inside the casing (16) for compressing a refrigerant, and a motor (10) for driving the compression mechanism (15). The compression mechanism (15) comprises rollers (40, 45), cylinders (30, 35) forming cylinder chambers (39, 44) in which the rollers (40, 45) rotate eccentrically, upper plates (20, 50) positioned above the cylinders (30, 35), and lower plates (50, 25) positioned below the cylinders (30, 35). A porous defoaming member (80, 80a, 80c, 80d) is positioned between the casing (16) and the compression mechanism (15).

Description

Technical Field

[0001] The present disclosure relates to a rotary compressor. A rotary compressor is a compressor that compresses gas in a compression chamber formed in a cylinder by eccentrically rotating a roller in the cylinder. A rotary compressor generally has a vane for partitioning the compression chamber. The rotary compressor includes a so-called rolling piston type in which a vane separate from the roller abuts against the roller while the roller rotates eccentrically, a so-called swing type in which a vane integrally formed with the roller swings as the roller rotates eccentrically, a so-called hinge vane type in which the tip of the vane is rotatably fitted into a recess on the outer peripheral surface of the roller and the roller rotates eccentrically, and the like.

Background Art

[0002] In a compressor in which an oil sump for lubricating oil is formed at the lower part of the casing, oil foaming may occur when the compressor is started or the like. Foaming refers to the phenomenon that the refrigerant dissolved in the lubricating oil in the oil sump vaporizes and bubbles are generated in the lubricating oil when the compressor is started or the like.

[0003] Foaming causes oil creep, in which lubricating oil flows out of the compressor. Further, due to foaming, the liquid level of the lubricating oil drops, which may cause problems in oil supply and lead to failure of the compressor.

[0004] In contrast, Patent Document 1 discloses providing a float floating on the lubricating oil in the casing and providing a structure for collecting the lubricating oil contained in the gaseous refrigerant on the float.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the conventional configuration described above, since the float is suspended in the lubricating oil, there is no effect in suppressing foaming below the liquid level of the lubricating oil, and fluctuations in the liquid level can cause the float to collide with components inside the compressor, leading to damage.

[0007] The purpose of this disclosure is to suppress the effect of foaming below the lubricating oil level in a rotary compressor. [Means for solving the problem]

[0008] A first aspect of this disclosure is based on a rotary compressor (1). The rotary compressor (1) comprises a casing (16) having a vertically extending cylindrical body (17) and storing lubricating oil at its bottom, a compression mechanism (15) fixed within the casing (16) for compressing a refrigerant, and a motor (10) for driving the compression mechanism (15). The compression mechanism (15) comprises rollers (40, 45), cylinders (30, 35) forming cylinder chambers (39, 44) in which the rollers (40, 45) rotate eccentrically, upper plates (20, 50) positioned above the cylinders (30, 35), and lower plates (50, 25) positioned below the cylinders (30, 35). A porous defoaming member (80, 80a, 80c, 80d) is positioned between the casing (16) and the compression mechanism (15).

[0009] In the first embodiment, even if foaming occurs in the lubricating oil, the foaming is suppressed by providing defoaming members (80, 80a, 80c, 80d), thereby reducing the effects of foaming.

[0010] A second aspect of this disclosure is the first aspect, wherein the foam members (80, 80a, 80c, 80d) have portions that are positioned below the upper end of the upper plate (20, 50).

[0011] According to the second embodiment, since the liquid level of the lubricating oil is usually located below the lower surface of the front head (upper plate), the defoaming members (80, 80a, 80c, 80d) are located above the liquid level, thereby improving the defoaming effect.

[0012] A third aspect of the present disclosure is, in the first aspect, the space around the motor (10) within the casing (16) is filled with suction refrigerant, the compression mechanism (15) includes a refrigerant inlet (85), and the upper ends of the defoaming members (80, 80a, 80c, 80d) are positioned below the inlet (85).

[0013] According to the third embodiment, even if lubricating oil accumulates on the upper surface of the defoaming members (80, 80a, 80c, 80d), it is possible to prevent the lubricating oil from flowing directly into the suction port (85).

[0014] A fourth aspect of the present disclosure is, in the first aspect, the space around the motor within the casing (16) is filled with an intake refrigerant, the compression mechanism (15) is provided with a refrigerant inlet (85), and the upper ends of the defoaming members (80, 80a, 80c, 80d) are positioned above the inlet (85).

[0015] According to the fourth embodiment, the defoaming effect can be improved by increasing the volume of the defoaming members (80, 80a, 80c, 80d) so that they extend above the suction port (85).

[0016] A fifth aspect of the present disclosure, in the first aspect, includes a lubrication pump (82) for drawing lubricating oil stored at the bottom of the casing (16), and the defoaming member (80, 80a, 80c, 80d) has a portion positioned between the oil intake port (82a) of the lubrication pump (82) and the lower plate (50, 25).

[0017] According to a fifth aspect of this disclosure, the liquid level of the lubricating oil usually fluctuates at a position higher than the oil intake port (82a), so an antifoaming effect can be obtained at such a liquid level.

[0018] In a sixth aspect of the present disclosure, in the first aspect, an oil supply pump (82) for sucking lubricating oil stored at the bottom of the casing (16) is provided, and the defoaming members (80, 80a, 80c, 80d) have a portion disposed at a position lower than the oil suction port (82a) of the oil supply pump.

[0019] According to the sixth aspect of the present disclosure, the presence of the defoaming members (80, 80a, 80c, 80d) at a position lower than the oil suction port (82a) can raise the liquid level of the lubricating oil by its volume, reducing the required amount of lubricating oil.

[0020] In a seventh aspect of the present disclosure, in the first aspect, the defoaming members (80, 80a, 80c) have through holes (80b) penetrating in the vertical direction.

[0021] According to the seventh aspect of the present disclosure, the falling of the lubricating oil carried on the upper surface of the defoaming members (80, 80a, 80c) is promoted by the through holes (80b).

[0022] In an eighth aspect of the present disclosure, in the first aspect, the refrigerant is a hydrocarbon.

[0023] According to the eighth aspect, since hydrocarbons are easily soluble in lubricating oil, the defoaming effect by the defoaming members (80, 80a, 80c) is significantly exerted.

Brief Description of the Drawings

[0024] [Figure 1] FIG. 1 is a diagram schematically showing the configuration of a refrigeration device including a rotary compressor of the present disclosure. [Figure 2] FIG. 2 is a diagram schematically showing a cross section parallel to the drive shaft of the rotary compressor of the present disclosure. [Figure 3] FIG. 3 is a diagram schematically showing a cross section perpendicular to the drive shaft of the rotary compressor of the present disclosure. [Figure 4] FIG. 4 is a diagram for explaining the operation of the compression mechanism of the present disclosure. [Figure 5]Figure 5 shows an example of the arrangement of the defoaming member in this disclosure. [Figure 6] Figure 6 shows an example of the arrangement of the defoaming member in this disclosure. [Figure 7] Figure 7 shows an example of the arrangement of the defoaming member in this disclosure. [Figure 8] Figure 8 shows an example of the arrangement of the defoaming member in this disclosure. [Figure 9] Figure 9 shows an example of the arrangement of the defoaming member in this disclosure. [Figure 10] Figure 10 shows a rotary compressor according to a second embodiment of the present disclosure. [Modes for carrying out the invention]

[0025] Embodiments of the present invention will be described below with reference to the drawings. The following embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or its uses. Furthermore, the embodiments, modifications, and other examples described below can be combined or partially replaced to the extent that the present invention is implementable.

[0026] <First Embodiment> (Refrigeration equipment) As shown in Figure 1, the rotary compressor (1) in this example is applied to a refrigeration system (100). The refrigeration system (100) is, for example, an air conditioning system that provides air conditioning for a room. The refrigeration system (100) has an outdoor unit (7) located outside and an indoor unit (8) located inside. The outdoor unit (7) houses the rotary compressor (1), a four-way switching valve (3), an outdoor heat exchanger (4), and an expansion valve (5). The indoor unit (8) houses an indoor heat exchanger (6).

[0027] The refrigeration system (100) includes a refrigerant circuit (9). A rotary 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 circuit (9). The refrigeration cycle is performed by the flow of refrigerant through the refrigerant circuit (9).

[0028] (Rotary compressor) Figure 2 is a longitudinal cross-sectional view of the rotary compressor (1) in this embodiment. In the rotary compressor (1), the compression mechanism (15) and the electric motor (10) are housed in a casing (16).

[0029] The casing (16) is a cylindrical sealed container in an upright position. The casing (16) comprises a cylindrical body (17) extending vertically and a pair of end plates (18, 19) that close off the ends of the body (17). A discharge pipe (13) is attached to the upper end plate (18), and a terminal (not shown) for supplying power to the electric motor (10) is also attached thereto. A first suction pipe (61) and a second suction pipe (62) are provided at the lower part of the body (17).

[0030] An oil reservoir (81) is formed at the bottom of the casing (16). The oil reservoir (81) is composed of the lower end plate (19) and the lower inner wall of the body (17). Lubricating oil (refrigeration oil) for lubricating the sliding parts of the compression mechanism (15) and the drive shaft (70) is stored in the oil reservoir (81).

[0031] The electric motor (10) is located in the upper part of the internal space of the casing (16). The electric motor (10) comprises a stator (11) and a rotor (12) located inside the stator. The stator (11) is fixed to the body (17) of the casing (16). The rotor (12) is attached to the drive shaft (70) of the compression mechanism (15), which will be described later.

[0032] The internal space (S) of the casing (16) is divided into a primary space (S1) below the electric motor (10) and a secondary space (S2) above the electric motor (20).

[0033] The rotary compressor (1) is configured as a so-called high-pressure dome type, in which the refrigerant compressed in the compression mechanism (15) is discharged into the internal space (S) of the casing (16), and the internal space (S) becomes high-pressure.

[0034] (Drive shaft) The drive shaft (70) is a component that drives the rollers (40, 45). The drive shaft (70) comprises a main shaft portion (72), a first eccentric portion (75) arranged from top to bottom, an intermediate connecting portion (78), a second eccentric portion (76), and a sub-shaft portion (74), and is formed integrally (see Figure 2).

[0035] The main shaft (72) and the sub-shaft (74) are columnar or rod-shaped parts with a circular cross-section. The rotor (12) of the electric motor (10) is attached to the upper part of the main shaft (72). The lower part of the main shaft (72) is supported by the main bearing (22) of the front head (20). The sub-shaft (74) is supported by the sub-bearing (27) of the rear head (25). The central axes of the main shaft (72) and the sub-shaft (74) coincide with the rotational axis of the drive shaft (70).

[0036] The drive shaft (70) is provided with an oil supply path (71) for supplying lubricating oil to sliding parts such as the main bearing section (22), the sub-bearing section (27), the first eccentric section (75), and the second eccentric section (76). The lubricating oil stored in the oil reservoir (81) is supplied to the oil supply path (71) by an oil supply pump (82) equipped with an oil suction port (82a) at the bottom of the drive shaft (70), and supplied to each sliding part.

[0037] (Compression mechanism) The compression mechanism (15) is located below the electric motor (10) within the casing (10). In the compression mechanism (15), the front head (20), first cylinder (30), middle plate (50), second cylinder (35), and rear head (25) are arranged in order from top to bottom. These are fastened to each other by multiple bolts (not shown). A drive shaft (70) is also provided in the center of the compression mechanism (15).

[0038] A compression mechanism is configured in the first cylinder (30) and the second cylinder (35), respectively. This is shown in Figure 3. Figure 3 is a schematic diagram showing a cross-section of the rotary compressor (1) at the height of the first cylinder (30) and the second cylinder (35). This cross-section is a plane perpendicular to the axial direction of the drive shaft (70).

[0039] As shown in Figure 3, the cylinders (30, 35) are thick, disc-shaped members housed within the body (17) of the casing (16). Each cylinder (30, 35) comprises a cylinder chamber (39, 44) with a circular cross-section that is closed at the top and bottom. The first cylinder (30) is closed at the top and bottom by a front head (20) and a middle plate (50), while the second cylinder is closed at the top and bottom by a middle plate (50) and a rear head (25).

[0040] Furthermore, the first cylinder (30) has a first vane chamber (32) connected to the first cylinder chamber (39). The first vane chamber (32) is a hole extending radially outward from the first cylinder chamber (39) to the first cylinder (30). The first cylinder chamber (39) houses a cylindrical first roller (40), and the first vane (41), which is integrally formed with the first roller (40), is housed in the first vane chamber (32).

[0041] The first vane chamber (32) is provided with a pair of first bushes (42) that sandwich the first vane (41) from both sides. The first bushes (42) are plate-shaped members with flat front surfaces facing each other and an arc-shaped back surface. The first vane (41) is supported by the first cylinder (30) via the bushes (42) so as to be able to swing and move back and forth.

[0042] With this pair of bushes (42) and the first vane (41), the first roller (40) is configured as a swing-type piston that oscillates and revolves along the inner wall surface of the first cylinder (30) in conjunction with the rotation of the drive shaft (70).

[0043] These components constitute the first cylinder of the compression mechanism.

[0044] A second vane chamber (32) is provided in the second cylinder (35). A second roller (45) is housed in the second cylinder chamber (44), and a second vane (46) is housed in the second vane chamber (37). Furthermore, a pair of second bushes (47) are provided in the second vane chamber (37). Thus, a second cylinder similar to the first cylinder is constructed.

[0045] (Front head) As shown in Figure 2, the front head (20) closes the end face of the first cylinder (30) on the motor (10) side (the upper end face of the first cylinder (30) in Figure 2). The front head (20) comprises a body portion (21), a main bearing portion (22), and an outer peripheral wall portion (23) which are formed integrally.

[0046] The main body (21) is formed in a generally circular, thick plate shape and is positioned to cover the end face of the first cylinder (30). The lower surface of the main body (21) is in close contact with the first cylinder (30). The main bearing portion (22) is formed in a cylindrical shape extending from the main body (21) toward the electric motor (10) side (upper side in Figure 1). The main bearing portion (22) is positioned in the center of the main body (21) and supports the drive shaft (70) of the compression mechanism (15). The outer peripheral wall portion (23) is a thick, annular portion formed continuously with the outer peripheral edge of the main body (21).

[0047] A first discharge port (24) is formed in the front head (20). The first discharge port (24) penetrates the main body (21) of the front head (20) in the thickness direction. In Figure 3, the first discharge port (24) is located on the left side (high pressure side) of the first vane chamber (32). A discharge valve (not shown) for opening and closing the first discharge port (24) is provided in the main body (21) of the front head (20).

[0048] (Rear head) The rear head (25) closes the end face of the second cylinder (35) on the side opposite to the electric motor (10) (the lower end face of the second cylinder (35) in Figure 2). The rear head (25) comprises a body portion (26), a sub-bearing portion (27), and an outer peripheral wall portion (28) which are formed integrally.

[0049] The main body (26) is formed in a generally circular, thick plate shape and is positioned to cover the end face of the second cylinder (35). The upper surface of the main body (26) is in close contact with the second cylinder (35). The sub-bearing portion (27) is formed in a cylindrical shape extending from the main body (26) to the side opposite to the second cylinder (35) (the lower side in Figure 2) and is positioned in the center of the main body (26). The sub-bearing portion (27) supports the drive shaft (70) of the compression mechanism (15). The outer peripheral wall portion (28) is formed in a cylindrical shape extending from the outer peripheral edge of the main body (26) to the side opposite to the second cylinder (35).

[0050] A second discharge port (29) is formed in the rear head (25). The second discharge port (29) penetrates the main body (26) of the rear head (25) in the direction of its thickness. In Figure 3, the second discharge port (29) is located on the left side (high pressure side) of the second vane chamber (37). A discharge valve (not shown) for opening and closing the second discharge port (29) is provided in the main body (26) of the rear head (25).

[0051] The middle plate (50) is positioned 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).

[0052] A central hole (51) is formed in the center of the middle plate (50), penetrating the middle plate (50) in the thickness direction. The intermediate connecting portion (78) of the drive shaft (70) is inserted through the central hole (51) of the middle plate (50).

[0053] (Compressor operation) The basic operation of the rotary compressor (1) will be explained with reference to Figures 2 and 4. Figure 4 is a diagram illustrating the operation of the compression mechanism using the first cylinder, which is composed of the first cylinder (30). The basic operation of the second cylinder (35) is the same.

[0054] When power is supplied from the terminal to the electric motor (10), the electric motor (10) operates and the drive shaft (70) is rotated. The first eccentric part (75) of the drive shaft (70) rotates eccentrically, and the first roller (40) performs an oscillating motion in conjunction with this.

[0055] As shown in Figure 4, in the compression mechanism (15), the outer surface of the first roller (40) makes line contact with the inner surface of the first cylinder chamber (39) via an oil film, forming a seal. When the first roller (40) oscillates inside the first cylinder chamber (39), the seal between the first roller (40) and the first cylinder (30) is displaced along the inner surface of the first cylinder chamber (39), and the volumes of the low-pressure chamber (40a) and the high-pressure chamber (40b) change. At this time, the first vane (41) moves back and forth inside the first vane chamber (32) and oscillates in accordance with the oscillating motion of the first roller (40).

[0056] As the first roller (40) oscillates (rotation angle = 0° → 90° → 180° → 270°), the volume of the low-pressure chamber (40a) gradually increases, and the fluid (refrigerant) flowing through the first suction pipe (61) is drawn into the low-pressure chamber (40a) from the first suction port (30a). Next, when this low-pressure chamber (40a) is blocked from the first suction port (30a), the blocked space forms a high-pressure chamber (40b) (rotation angle = 90°). Next, as the volume of this high-pressure chamber (40b) gradually decreases (rotation angle = 90° → 180° → 270°), the internal pressure of the high-pressure chamber (40b) increases. When the internal pressure of the high-pressure chamber (40b) becomes greater than the pressure in the internal space of the compressor (1), the discharge stroke is performed. In other words, during the discharge stroke, the reed valve of the discharge port (24) is opened, and the refrigerant in the high-pressure chamber (40b) flows out of the compression mechanism (15) through the discharge port (24). This high-pressure refrigerant flows upward through the internal space of the casing (16) and passes through the core cut (not shown) of the electric motor (20). The high-pressure refrigerant that has flowed out above the electric motor (10) is sent to the refrigerant circuit from the discharge pipe (13).

[0057] (Measures to address lubricant foaming) When starting up the rotary compressor (1), foaming of the lubricating oil may occur. Foaming is a phenomenon in which dissolved refrigerant vaporizes in the lubricating oil stored in the oil reservoir (81), causing bubbles to form in the lubricating oil. In particular, when the refrigerant is a hydrocarbon refrigerant, the refrigerant dissolves easily into the lubricating oil, making foaming more likely to occur during startup.

[0058] When foaming occurs, the lubricating oil level drops, making it impossible to properly supply lubricating oil and causing the rotary compressor (1) to fail. In addition, in the case of a high-pressure dome-type rotary compressor (1) as shown in Figure 2, when the lubricating oil foam rises to the primary space, it is agitated and escapes from the rotary compressor (1) along with the discharge gas, increasing oil buildup.

[0059] To suppress such foaming, the rotary compressor (1) of the present disclosure includes a porous defoaming member (80) between the casing (16) and the compression mechanism (15).

[0060] By providing the defoaming member (80), foaming occurs in the lubricating oil in the oil reservoir (81) but is quickly eliminated. Therefore, problems such as poor lubricating oil supply and increased oil leakage are suppressed.

[0061] The defoaming member (80) may be formed, for example, at a height above the lower end of the rear head (25) and below the upper end of the front head (20), as shown in Figure 2. This allows the entire range in which the defoaming member (80) is provided to come into contact with the lubricating oil in the vertical direction. As a result, the defoaming effect is maintained even if the liquid level of the lubricating oil fluctuates up and down. Also, since the liquid level is usually located below the lower end of the front head (20), positioning the defoaming member (80) within the aforementioned range allows for effective defoaming at the liquid surface.

[0062] Furthermore, as shown in Figure 3, the defoaming member (80) may be formed to surround the entire perimeter of the compression mechanism (15) (in Figure 3, the cylinders (30, 35)). In this way, the defoaming effect is exerted over the entire perimeter of the compression mechanism (15). However, this is not essential; the defoaming effect can be obtained by forming the defoaming member (80) on at least a part of the casing (16) and the compression mechanism (15).

[0063] The defoaming member (80) is a porous member, and may be, for example, a sintered metal member, steel wool, or a mesh member. Such a member has a large contact area with the lubricating oil and therefore has a high defoaming effect.

[0064] Furthermore, the defoaming member (80) occupies a certain volume relative to the casing (16) and the compression mechanism (15). Therefore, even with the same amount of lubricating oil, the liquid level will be higher, thus reducing the amount of lubricating oil required to reach the desired level. Reducing the amount of lubricating oil used contributes to cost reduction. Moreover, it is preferable because a smaller amount of lubricating oil means a smaller amount of refrigerant dissolves into the lubricating oil.

[0065] In particular, when a hydrocarbon is used as a refrigerant, the effect of the rotary compressor (15) of this disclosure is significantly demonstrated because the refrigerant dissolves easily in the lubricating oil. Examples of hydrocarbons used as refrigerants include propane, butane, isobutane, etc.

[0066] (Other shapes, arrangements, etc. of the defoaming components) Regarding the defoaming member (80), other examples of its shape, arrangement, etc., will be described.

[0067] Figure 5 is a magnified view of the lower part of the rotary compressor (1). However, this figure is intended to explain the configuration of the defoaming members (80, 80a), and some detailed illustrations have been omitted. The suction pipes (61, 62) have also been omitted.

[0068] In the example shown in Figure 5, in addition to the defoaming member (80) provided in the range above the lower end of the rear head (25) and below the upper end of the front head (20), similar to Figure 2, there is further a defoaming member (80a) located below the lower end of the rear head (25). Furthermore, an oil intake port (82a) for the oil supply pump (82) is provided at the lower part of the drive shaft (70), and the defoaming member (80a) has a portion that extends below the oil intake port (82a).

[0069] By providing the defoaming member (80a) in this position, the volume of the defoaming member (80a) can raise the liquid level of the lubricating oil, thereby reducing the amount of lubricating oil required to raise the liquid level above the oil intake port (82a). Furthermore, since the liquid level of the lubricating oil usually fluctuates at a position higher than the oil intake port (82a), the defoaming effect can be obtained at such a liquid level.

[0070] Next, Figure 6 shows another example of the defoaming member (80), similar to Figure 5.

[0071] In Figure 6, the defoaming member (80) has a through hole (80b) that penetrates vertically. Since the defoaming member is a porous material, even if the lubricating oil rises above the defoaming member (80), it will gradually fall back down. By providing the through hole (80b), the movement of the lubricating oil can be facilitated.

[0072] Furthermore, as shown in Figure 7, the upper surface of the defoaming member (80) may be angled. This allows the lubricating oil to flow more easily over the upper surface, promoting the dripping of the lubricating oil.

[0073] While steel wool can also be used as the defoaming member (80), Figure 8 shows an example in which a defoaming member (80) made of a sintered metal member and steel wool (80c) are used in combination. Compared to the example in Figure 5, a defoaming member (80) with a narrower radial width of the casing (16) is used, and steel wool (80c) is placed between the defoaming member (80) and the casing (16). Steel wool (80c) allows lubricating oil to pass through more easily than a defoaming member (80) made of a sintered metal member, thus promoting the dripping of lubricating oil. It is also possible to use only steel wool (80c) as the defoaming member (80).

[0074] Furthermore, Figure 9 shows a configuration in which a return oil path (20a) is provided in the front head (20), and an anti-foaming member (80d) is placed in the return oil path (20a). The return oil path (20a) is a path for returning the lubricating oil that has moved onto the front head (20) to the oil reservoir (81) at the bottom of the casing (16). By placing the anti-foaming member (80d) in the return oil path (20a), an anti-foaming effect is also achieved at that location.

[0075] Furthermore, the configurations of the defoaming members (80, 80a, 80c, 80d) shown in Figures 5 to 9 can be combined.

[0076] <Second Embodiment> In the first embodiment, an example of a high-pressure dome-type compressor was described in which the compressed refrigerant is discharged into the internal space (S). However, the present disclosure is also applicable to a low-pressure dome-type compressor (1) in which the refrigerant before compression fills the internal space (S).

[0077] Figure 10 shows a magnified view of the area around the compression mechanism (15) of a low-pressure dome-type rotary compressor (1). Note that the compression mechanism (15) is housed together with the electric motor (10) within a casing (16) comprising a body section (17), and the rotary compressor (1) is connected to a refrigerant circuit (9) for use, as in the first embodiment.

[0078] Furthermore, the compression mechanism (15) is also equipped with a front head (20), a first cylinder (30), a middle plate (50), a second cylinder (35), and a rear head (25), as in the first embodiment, and these are fastened together by through bolts (83). Other components similar to those of the rotary compressor (1) shown in Figure 2 are given the same reference numerals, and detailed explanations are omitted. The differences will be explained below.

[0079] In the low-pressure dome-shaped rotary compressor (1) shown in Figure 10, a refrigerant suction pipe (84) is provided above the compression mechanism (15) in the body (17). The refrigerant is introduced into the internal space (S) through the suction pipe (84).

[0080] Furthermore, the front head (20) is provided with an intake port (85) for drawing low-pressure refrigerant from the internal space (S) into the compression mechanism (15). The drawn-in refrigerant is compressed in the compression mechanism (15) in the same manner as in the first embodiment and discharged from the compression mechanism (15) through the rear muffler (86) and discharge pipe (not shown).

[0081] In the low-pressure dome-type compressor (1) described above, an anti-foaming member (80) is provided between the casing (16) and the compression mechanism (15). This allows for an anti-foaming effect to be obtained when foaming of the lubricating oil occurs, similar to the first embodiment. Furthermore, various configurations and combinations of the anti-foaming members (80, 80a, 80c, 80d) shown in Figures 5 to 9 of the first embodiment are also applicable. Figure 10 shows an example in which an anti-foaming member (80d) is also provided in the oil return path (20a) of the front head (20).

[0082] If the upper end of the defoaming member (80) is positioned below the suction port (85), even if lubricating oil accumulates on the defoaming member (80), it has the effect of preventing such lubricating oil from flowing into the suction port (85). On the other hand, if the upper end of the defoaming member (80) is above the suction port (85), the defoaming effect can be enhanced by increasing the volume of the defoaming member (80).

[0083] Although embodiments and modifications have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. Furthermore, elements of the above embodiments, modifications, and other embodiments may be combined or substituted as appropriate.

[0084] The designations such as "First," "Second," and "Third" mentioned above are used to distinguish between the terms to which these designations are attached, and do not limit the number or order of those terms. [Industrial applicability]

[0085] As explained above, this disclosure is useful for rotary compressors. [Explanation of Symbols]

[0086] 1. Rotary Compressor 10. Electric motor 15 Compression mechanism 16 Casing 17 Torso 20 Front head (top plate) 25 Rear head (lower plate) 39. First cylinder chamber (cylinder chamber) 40. The First Laura (Laura) 44. Second cylinder chamber (cylinder chamber) 45. The Second Laura (Laura) 50 Middle Plate (Bottom Plate, Top Plate) 80, 80a, 80c, 80d Antifoaming material 80b through hole 82 Fuel pump 82a Oil intake port 85 Inlet

Claims

1. A casing (16) having a cylindrical body (17) extending in the vertical direction and a bottom portion where lubricating oil is stored, A compression mechanism (15) fixed within the casing (16) for compressing the refrigerant, The system includes a motor (10) that drives the compression mechanism (15), The compression mechanism (15) is Laura (40, 45) and The cylinders (30, 35) form cylinder chambers (39, 44) in which the rollers (40, 45) rotate eccentrically, The upper plates (20, 50) are positioned above the cylinders (30, 35), The system comprises a lower plate (50, 25) positioned below the cylinder (30, 35), A rotary compressor (1) is provided with a porous defoaming member (80, 80a, 80c, 80d) positioned between the casing (16) and the compression mechanism (15).

2. In claim 1, The defoaming members (80, 80a, 80c, 80d) are located in a rotary compressor (1) with portions positioned below the upper ends of the upper plates (20, 50).

3. In claim 1, The space around the motor (10) within the casing (16) is filled with suction refrigerant. The compression mechanism (15) is equipped with a refrigerant inlet (85), The upper ends of the defoaming members (80, 80a, 80c, 80d) are positioned below the suction port (85) of the rotary compressor (1).

4. In claim 1, The space around the motor within the casing (16) is filled with the intake refrigerant. The compression mechanism (15) is equipped with a refrigerant inlet (85), The upper ends of the defoaming members (80, 80a, 80c, 80d) are positioned above the suction port (85) of the rotary compressor (1).

5. In claim 1, The casing (16) is equipped with an oil supply pump (82) for sucking up the lubricating oil stored at the bottom, The defoaming members (80, 80a, 80c, 80d) are located in a rotary compressor (1) with a portion positioned between the oil suction port (82a) of the oil supply pump (82) and the lower plates (50, 25).

6. In claim 1, The casing (16) is equipped with an oil supply pump (82) for sucking up the lubricating oil stored at the bottom, The defoaming members (80, 80a, 80c, 80d) are located in a rotary compressor (1) with a portion positioned lower than the oil suction port (82a) of the oil supply pump.

7. In claim 1, The defoaming members (80, 80a, 80c) are part of a rotary compressor (1) having a through hole (80b) that penetrates in the vertical direction.

8. In claim 1, The refrigerant is a hydrocarbon, and the rotary compressor (1) is also a hydrocarbon.

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