Patent Application
20250012492
The present disclosure relates to a rotary compressor and a refrigeration apparatus.
Japanese Patent No. 5429319 discloses a compressor including a gas guide that forms a gas flow path together with an inner surface of a casing. The gas guide is joined to the casing by spot welding. The gas guide discharges part of a refrigerant compressed by a compression mechanism along the circumferential direction of the casing to separate a lubricant contained in the refrigerant.
A first aspect of the present disclosure is directed a rotary compressor. The rotary compressor includes a casing, a compression mechanism housed inside the casing to compress a refrigerant, a drive shaft configured to drive the compression mechanism, a motor configured to rotate the drive shaft, and a partitioning member housed inside the casing. The partitioning member partitions an interior of the casing into a first space into which the refrigerant compressed by the compression mechanism is discharged, and a second space provided between the partitioning member and the motor. The partitioning member has a discharge flow path through which the refrigerant is discharged from the first space to the second space. The discharge flow path includes an inclined flow path that extends while inclining toward downstream in a direction of rotation of the motor.
As illustrated in
The refrigeration apparatus (1) is an air conditioner. The air conditioner may be a cooling-only apparatus, a heating-only apparatus, or an air conditioner switchable between cooling and heating. In this case, the air conditioner has a switching mechanism (e.g., a four-way switching valve) configured to switch the direction of circulation of the refrigerant. The refrigeration apparatus (1) may be a water heater, a chiller unit, or a cooling apparatus configured to cool air in an internal space. The cooling apparatus cools the air in a refrigerator, a freezer, or a container, for example.
As illustrated in
The motor (30) includes a stator (31) and a rotor (32). The stator (31) is fixed to the inner circumferential surface of the casing (20). The rotor (32) is disposed inside the stator (31). A drive shaft (11) passes through the rotor (32). The rotor (32) is fixed to the drive shaft (11). The drive shaft (11) is provided with a balance weight (18).
The casing (20) has, at its bottom, an oil reservoir (21). The oil reservoir (21) stores a lubricant. A suction pipe (12) is connected to an upper portion of the casing (20). A discharge pipe (13) is connected to a barrel of the casing (20).
A housing (50) serving as a partitioning member is fixed to the casing (20). The housing (50) is made of a casting. The housing (50) is fixed to the inside of the casing (20) by, for example, shrink fitting. The housing (50) is located above the motor (30). The compression mechanism (40) is located above the housing (50). The discharge pipe (13) has an inflow end between the motor (30) and the housing (50).
The interior of the casing (20) has a first space (23) and a second space (24) partitioned by the housing (50). The first space (23) is a space above the housing (50). The high-pressure refrigerant compressed by the compression mechanism (40) is discharged to the first space (23). The second space (24) is a space provided between the housing (50) and the motor (30). As will be described in detail later, the housing (50) has a discharge flow path (80) through which the refrigerant is discharged from the first space (23) toward the second space (24) (see
The housing (50) has a recess (53). The recess (53) is a recessed portion of the upper surface of the housing (50). An upper bearing (51) is located below the recess (53). The upper bearing (51) rotatably supports the drive shaft (11).
The drive shaft (11) extends vertically along the center axis of the casing (20). The drive shaft (11) has a main shaft portion (14) and an eccentric portion (15).
The eccentric portion (15) is provided at an upper end of the main shaft portion (14). The main shaft portion (14) has a lower portion rotatably supported by a lower bearing (22). The lower bearing (22) is fixed to the inner circumferential surface of the casing (20). The lower bearing (22) is provided with a positive-displacement pump (25), for example. The main shaft portion (14) has an upper portion passing through the housing (50) and rotatably supported by the upper bearing (51) of the housing (50).
The compression mechanism (40) includes a fixed scroll (60) and a movable scroll (70). The fixed scroll (60) is fixed to the upper surface of the housing (50). The movable scroll (70) is arranged between the fixed scroll (60) and the housing (50).
The fixed scroll (60) includes a fixed end plate (61), a fixed wrap (62), and an outer circumferential wall (63). The outer circumferential wall (63) is substantially tubular. The outer circumferential wall (63) is erected at the outer edge of the front surface (the lower surface in
The fixed wrap (62) is spiral. The fixed wrap (62) is erected on a portion of the fixed end plate (61) inside the outer circumferential wall (63).
The fixed end plate (61) is located on the outer circumference and is continuous with the fixed wrap (62). The end surface of the fixed wrap (62) and the end surface of the outer circumferential wall (63) are substantially flush with each other. The fixed scroll (60) is fixed to the housing (50).
As will be described in detail later, the outer circumferential wall (63) of the fixed scroll (60) has a fixed flow path (66) communicating with the discharge flow path (80) of the housing (50) (see
The movable scroll (70) includes a movable end plate (71), a movable wrap (72), and a boss (73). The movable wrap (72) is spiral. The movable wrap (72) is formed on the upper surface of the movable end plate (71). The movable wrap (72) meshes with the fixed wrap (62).
The boss (73) is formed on a central portion of the lower surface of the movable end plate (71). The eccentric portion (15) of the drive shaft (11) is inserted into the boss (73), whereby the boss (73) is connected to the drive shaft (11).
An Oldham coupling (45) is provided at an upper portion of the housing (50). The Oldham coupling (45) blocks the rotation of the movable scroll (70) on its axis. The Oldham coupling (45) is provided with a key (46). The key (46) protrudes toward the lower surface of the movable end plate (71) of the movable scroll (70). The lower surface of the movable end plate (71) of the movable scroll (70) has a keyway (47). The key (46) of the Oldham coupling (45) is slidably fitted to the keyway (47).
Although not shown, a key is provided in a portion of the Oldham coupling (45) toward the housing (50). The key toward the housing (50) is slidably fitted to a keyway (not shown) of the housing (50).
The compression mechanism (40) has a fluid chamber(S) into which the refrigerant flows. The fluid chamber(S) is formed between the fixed scroll (60) and the movable scroll (70). The movable scroll (70) is placed so that the movable wrap (72) meshes with the fixed wrap (62) of the fixed scroll (60). Here, the lower surface of the outer circumferential wall (63) of the fixed scroll (60) serves as a facing surface that faces the movable scroll (70). On the other hand, the upper surface of the movable end plate (71) of the movable scroll (70) serves as a facing surface that faces the fixed scroll (60).
The outer circumferential wall (63) of the fixed scroll (60) has a suction port (64). The suction port (64) is open near the winding end of the fixed wrap (62). A downstream end of the suction pipe (12) is connected to the suction port (64).
The fixed end plate (61) of the fixed scroll (60) has, at its center, an outlet (65). The outlet (65) is open to the upper surface of the fixed end plate (61) of the fixed scroll (60). The high-pressure refrigerant discharged from the outlet (65) is discharged into the first space (23) above the housing (50). The refrigerant discharged into the first space (23) is discharged to the second space (24) through the fixed flow path (66) of the fixed scroll (60) and the discharge flow path (80) of the housing (50) (see
An oil supply passage (16) is formed inside the drive shaft (11). The oil supply passage (16) extends vertically from the lower end to the upper end of the drive shaft (11). The pump (25) is connected to the lower end of the drive shaft (11). A lower end portion of the pump (25) is immersed in the oil reservoir (21). The pump (25) sucks up the lubricant from the oil reservoir (21) as the drive shaft (11) rotates, and transfers the lubricant to the oil supply passage (16). The oil supply passage (16) supplies the lubricant in the oil reservoir (21) to the sliding surfaces between the lower bearing (22) and the drive shaft (11) and the sliding surfaces between the upper bearing (51) and the drive shaft (11), and to the sliding surfaces between the boss (73) and the drive shaft (11). The oil supply passage (16) is open to the upper end surface of the drive shaft (11) and supplies the lubricant to above the drive shaft (11).
The recess (53) of the housing (50) communicates with the oil supply passage (16) of the drive shaft (11) via the inside of the boss (73) of the movable scroll (70). The high-pressure lubricant is supplied to the recess (53), so that a high pressure equivalent to the discharge pressure of the compression mechanism (40) acts on the recess (53). The movable scroll (70) is pressed onto the fixed scroll (60) by the high pressure that acts on the recess (53).
As illustrated in
As illustrated also in
The discharge flow path (80) includes an inclined flow path (81). The inclined flow path (81) extends while inclining toward downstream in the direction of rotation of the motor (30). In the example illustrated in
In the example illustrated in
The high-pressure refrigerant discharged from the outlet (65) of the compression mechanism (40) into the first space (23) is discharged into the second space (24) via the fixed flow path (66) of the fixed scroll (60) and the discharge flow path (80) of the housing (50). The refrigerant passing through the discharge flow path (80) flows along the direction of inclination of the inclined flow path (81). Thus, when discharged into the second space (24), the refrigerant flows toward downstream in the direction of rotation of the motor (30).
The housing (50) is made of a casting. The housing (50) made of a casting is subjected to surface finishing by machining. At this time, a casting surface is left in at least part of the discharge flow path (80).
Increasing the surface area by leaving the casting surface in at least part of the discharge flow path (80) makes the lubricant contained in the refrigerant more likely to come into contact with the casting surface and form drops of oil, which makes it possible to improve the efficiency of separation of the lubricant.
The results of simulation of the flow of the refrigerant in the second space (24) will be described below. First, a comparative example in which a discharge flow path (80) does not incline and extends along the axial direction will be described with reference to
As illustrated in
As illustrated in
In contrast, in this embodiment, as illustrated in
As illustrated also in
According to a feature of this embodiment, the housing (50) serving as the partitioning member has the discharge flow path (80) through which the refrigerant is discharged from the first space (23) into the second space (24). The discharge flow path (80) includes the inclined flow path (81) that extends while inclining toward downstream in the direction of rotation of the motor (30).
Thus, making the refrigerant flow along the inclined flow path (81) generates the flow of the refrigerant swirling along the circumferential direction of the casing (20) in the second space (24), which makes it possible to separate the lubricant contained in the refrigerant. Separation of the lubricant from the refrigerant can reduce oil loss.
It is possible to generate the flow of the refrigerant swirling along the circumferential direction of the casing (20) by simply providing the discharge flow path (80) in the housing (50). This eliminates the need to provide a gas guide separately, which is necessary in known art. The component cost can thus be reduced. In addition, a process of spot-welding a gas guide to the casing (20) is not needed, resulting in a reduction in the number of operation processes.
The absence of a gas guide in the second space (24) prevents interference of the gas guide with the flow of the refrigerant, making it possible for the refrigerant to swirl smoothly along the circumferential direction of the casing (20).
According to a feature of this embodiment, increasing the surface area by leaving the casting surface in at least part of the discharge flow path (80) makes the lubricant contained in the refrigerant more likely to come into contact with the casting surface and form drops of oil, which makes it possible to improve the efficiency of separation of the lubricant.
According to a feature of this embodiment, the refrigeration apparatus (1) includes the rotary compressor (10) and the refrigerant circuit (1a) through which the refrigerant compressed by the rotary compressor (10) flows. A refrigeration apparatus including the rotary compressor (10) can thus be provided.
In the following description, the same reference characters designate the same components as those of the first embodiment, and the description is focused only on the difference.
As illustrated in
In the example illustrated in
Thus, the upstream end of the inclined flow path (81) is positioned lower than in the case of the first embodiment by the length of the axial flow path (82) of the discharge flow path (80), which makes the angle of inclination of the inclined flow path (81) acute.
Thus, the refrigerant that has flowed from the first space (23) and passed through the axial flow path (82) and the inclined flow path (81) of the discharge flow path (80) flows toward downstream in the direction of rotation of the motor (30) at an angle at which the refrigerant is less likely to collide with the motor (30) when discharged into the second space (24).
According to a feature of this embodiment, providing the inclined flow path (81) to be continuous with the axial flow path (82) makes it possible for the inclined flow path (81) to have an acute angle of inclination as compared to a case where no axial flow path (82) is provided. Thus, the refrigerant can swirl along the circumferential direction of the casing (20) in the second space (24) easily.
The refrigerant flowing along the axial flow path (82) collides with the inclined flow path (81), which causes the lubricant contained in the refrigerant to be separated in the inclined flow path (81) and then the refrigerant to flow down along the inclined flow path (81). This facilitates the separation of the refrigerant and the lubricant from each other.
According to a feature of this embodiment, the joint portion between the axial flow path (82) and the inclined flow path (81) is curved. Thus, the refrigerant flowing from the axial flow path (82) to the inclined flow path (81) can flow smoothly along the curved flow path.
As illustrated in
The branch flow path (85) is continuous with the downstream side of the axial flow path (82), and extends along the axial direction of the motor (30). The branch flow path (85) branches toward the motor (30). The flow path cross-sectional area of the inclined flow path (81) is larger than the flow path cross-sectional area of the branch flow path (85).
As can be seen, the discharge flow path (80) is branched into the inclined flow path (81) and the branch flow path (85) on the downstream side of the axial flow path (82). The refrigerant flowing from the first space (23) and passing through the axial flow path (82) of the discharge flow path (80) is divided into the inclined flow path (81) and the branch flow path (85). The refrigerant flowing through the inclined flow path (81) swirls in the circumferential direction in the second space (24) along the inner circumferential surface of the casing (20). The refrigerant flowing through the branch flow path (85) is discharged toward the motor (30) in the second space (24) to cool the motor (30).
According to a feature of this embodiment, the refrigerant flowing through the branch flow path (85) toward the motor (30) can cool the motor (30).
According to a feature of this embodiment, the flow path cross-sectional area of the inclined flow path (81) is larger than the flow path cross-sectional area of the branch flow path (85). Setting the amount of the refrigerant flowing through the inclined flow path (81) to be larger than the amount of the refrigerant flowing through the branch flow path (85) makes it possible to cool the motor (30) while ensuring sufficient flow of the refrigerant swirling along the circumferential direction of the casing (20).
As illustrated in
The inclined flow path (81) has a first surface (81a) and a second surface (81b). The first surface (81a) is a surface with which the refrigerant that has flowed from the first space (23) collides and guides the refrigerant toward the second space (24). The second surface (81b) faces the first surface (81a).
The inclined flow path (81) includes a first flow path (83) and a second flow path (84). The first flow path (83) has a substantially constant flow path width between the first surface (81a) and the second surface (81b). Here, the downstream end of the first flow path (83) on the first surface (81a) is referred to as a “downstream end (P3).” The second flow path (84) is continuous with the downstream side of the first flow path (83). The flow path width of the second flow path (84) is greater than the flow path width of the first flow path (83).
It is preferable that the flow path cross-sectional area of the inclined flow path (81) is largest at the downstream end of the second flow path (84), but is not limited thereto. For example, an intermediate portion of the second flow path (84) may have the largest flow path cross-sectional area. In this case, it is preferable that the flow path cross-sectional area of the downstream end of the second flow path (84) is larger than or equal to the flow path cross-sectional area of the first flow path (83).
The downstream end (P1) of the first surface (81a) is closer to the second space (24) than the downstream end (P4) of the second surface (81b) as viewed in the axial direction of the motor (30).
Here, the angle formed between a phantom plane (91) passing through any point (P) on the first surface (81a) and extending along the first surface (81a) and a reference phantom plane (95) orthogonal to the axial direction of the motor (30) is referred to as an “angle α.”
The angle formed between a phantom plane (91) passing through the downstream end (P1) of the first surface (81a) and extending along the first surface (81a) and a reference phantom plane (95) orthogonal to the axial direction of the motor (30), i.e., the angle α at the point (P) located at the downstream end (P1) of the first surface (81a), is referred to as a “first angle α1.”
The angle formed between a phantom plane (91) passing through the upstream end (P2) of the first surface (81a) and extending along the first surface (81a) and a reference phantom plane (95) orthogonal to the axial direction of the motor (30), i.e., the angle α at the point (P) located at the upstream end (P2) of the first surface (81a), is referred to as a “second angle α2.”
In the example illustrated in
Specifically, in the example illustrated in
The flow path width of the second flow path (84) increases downstream of the downstream end (P3) of the first flow path (83) on the first surface (81a). Thus, the angle α at the point (P) on the first surface (81a) is greater than the second angle α2. Then the angle α decreases gradually in the section up to the downstream end (P1) of the first surface (81a), and eventually becomes substantially constant at the first angle α1 that is smaller than the second angle α2.
According to a feature of this embodiment, the shape of the inclined flow path (81) is determined so that the first angle α1 and the second angle α2 satisfy the above-described condition. Thus, the refrigerant flowing along the inclined flow path (81) is blown out easily in the direction orthogonal to the axial direction of the motor (30) in the second space (24). It is thus possible to promote the flow of the refrigerant in the second space (24) in the direction in which the refrigerant swirls easily along the circumferential direction of the casing (20).
According to a feature of this embodiment, increasing the flow path width of a downstream portion of the inclined flow path (81) allows the refrigerant to flow smoothly from the inclined flow path (81) toward the second space (24).
As illustrated in
The inclined flow path (81) has a first surface (81a) and a second surface (81b). The first surface (81a) is a surface with which the refrigerant that has flowed from the first space (23) collides and guides the refrigerant toward the second space (24). The second surface (81b) faces the first surface (81a).
The inclined flow path (81) includes a first flow path (83) and a second flow path (84). The first flow path (83) has a substantially constant flow path width between the first surface (81a) and the second surface (81b). The second flow path (84) is continuous with the downstream side of the first flow path (83). The flow path width of the second flow path (84) is greater than the flow path width of the first flow path (83).
The downstream end (P3) of the first flow path (83) on the first surface (81a) is closer to the first space (23) than the downstream end (P4) of the second surface (81b) as viewed in the axial direction of the motor (30).
The downstream end (P1) of the first surface (81a) is closer to the second space (24) than the downstream end (P4) of the second surface (81b) as viewed in the axial direction of the motor (30).
Here, the angle formed between a phantom plane (91) passing through any point (P) on the first surface (81a) and extending along the first surface (81a) and a reference phantom plane (95) orthogonal to the axial direction of the motor (30) is referred to as an “angle α.”
The angle formed between a phantom plane (91) passing through the downstream end (P1) of the first surface (81a) and extending along the first surface (81a) and a reference phantom plane (95) orthogonal to the axial direction of the motor (30), i.e., the angle α at the point (P) located at the downstream end (P1) of the first surface (81a), is referred to as a “first angle α1.”
The angle formed between a phantom plane (91) passing through the upstream end (P2) of the first surface (81a) and extending along the first surface (81a) and a reference phantom plane (95) orthogonal to the axial direction of the motor (30), i.e., the angle α at the point (P) located at the upstream end (P2) of the first surface (81a), is referred to as a “second angle α2.”
In the example illustrated in
According to a feature of this embodiment, expanding the portion where the flow path width of the inclined flow path (81) is increased allows the refrigerant to flow smoothly from the inclined flow path (81) toward the second space (24).
The above-described embodiments may be modified as follows.
In the description of the embodiments, the discharge flow path (80) is provided in the housing (50), but is not limited thereto. For example, as illustrated in
In the description of the embodiments, the discharge flow path (80) is formed between a recessed portion of the side surface of the housing (50) and the inner peripheral surface of the casing (20), but is not limited thereto. For example, as illustrated in
It will be understood that the embodiments and variations described above can be modified with various changes in form and details without departing from the spirit and scope of the claims. The elements according to embodiments, the variations thereof, and the other embodiments may be combined and replaced with each other. In addition, the expressions of “first,” “second,” “third,” . . . , in the specification and claims are used to distinguish the terms to which these expressions are given, and do not limit the number and order of the terms.
As can be seen from the foregoing description, the present disclosure is useful for a rotary compressor and a refrigeration apparatus.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-045283 | Mar 2022 | JP | national |
This is a continuation of International Application No. PCT/JP2023/008585 filed on Mar. 7, 2023, which claims priority to Japanese Patent Application No. 2022-045283, filed on Mar. 22, 2022. The entire disclosures of these applications are incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2023/008585 | Mar 2023 | WO |
| Child | 18887900 | US |
