Compressors and refrigeration equipment

Abstract

To inhibit disturbance of gas flow above a stator of an electric motor and reduce discharge of oil of a compressor.SOLUTION: A compressor (10) is provided with: a compression mechanism (30); a drive shaft (40); and an electrical motor (70) which rotates the drive shaft to drive the compression mechanism. The drive shaft extends in a vertical direction. The electrical motor includes: a rotor (71) coupled to the drive shaft; and a stator (72) disposed on the outer circumferential side of the rotor. The rotor is provided with a first gas passage (75) that penetrates the same in the vertical direction. A lid member (110) and a cylindrical member (103) are arranged above the rotor. The lid member has a plate shape facing an opening end (75a) of the first gas passage at an upper end (71a) of the rotor. The cylindrical member extends downward from the lid member on the outer circumferential side of the first gas passage. A gap (120) extending in a circumferential direction of the cylindrical member is formed between a lower end (103a) of the cylindrical member and the upper end of the rotor. A first space (U) that is surrounded by the upper end of the rotor, the lid member, and the cylindrical member, and that is open on the outer circumferential side through the gap is formed.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a compressor and a refrigeration device. [Background technology]

[0002] The compressor disclosed in Patent Document 1 includes a compression mechanism, a drive shaft, and an electric motor that rotates the drive shaft to drive the compression mechanism. The drive shaft extends in the vertical direction. A gas passage that penetrates the rotor of the electric motor in the vertical direction is provided. In the electric motor, a stator is disposed on the outer circumferential side of the rotor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-017849 Summary of the Invention [Problem to be solved by the invention]

[0004] In the compressor of Patent Document 1, gas flows upward through a gas passage provided in the rotor of the motor. Typically, a plurality of gas passages are arranged side by side at intervals along the circumferential direction of the rotor. The rotor rotates in the circumferential direction. Gas is discharged upward from the open end of the gas passage at the upper end of the rotor.

[0005] In the rotor, regions with gas passages and regions without gas passages are arranged alternately in the circumferential direction. In the regions with gas passages in the rotor, the flow velocity of the gas discharged upward and to the outer periphery toward the space above the stator is relatively high, and in the regions without gas passages in the rotor, the flow velocity of the gas discharged upward and to the outer periphery toward the space above the stator is relatively low.

[0006] When the rotor rotates in this state, the flow of gas in the space above the stator is disturbed by the effect of the flow of gas discharged from the open end of the gas passage at the upper end of the rotor.

[0007] If the gas flow in the space above the stator becomes turbulent, oil rise in the compressor increases, reducing the reliability of the compressor.

[0008] An object of the present disclosure is to reduce oil rise in a compressor by suppressing turbulence in the gas flow in the space above the stator of the electric motor. [Means for solving the problem]

[0009] A first aspect of the present disclosure is directed to a compressor (10). The compressor (10) includes a compression mechanism (30), a drive shaft (40), and an electric motor (70) that rotates the drive shaft (40) to drive the compression mechanism (30), the drive shaft (40) extending in the vertical direction, the electric motor (70) including a rotor (71) coupled to the drive shaft (40) and a stator (72) disposed on the outer circumferential side of the rotor (71), a first gas passage (75) penetrating the rotor (71) in the vertical direction, a cover member (110) and a cylindrical member (103) disposed above the rotor (71), the cover member (110) being configured to cover the first gas passage (75) and the cylindrical member (103) in the vertical direction. The tubular member (103) is plate-shaped and faces the opening end (75a) of the first gas passage (75) at the upper end (71a) of the rotor (71). The tubular member (103) extends downward from the cover member (110) on the outer circumferential side of the first gas passage (75). A gap (120) extending in the circumferential direction of the tubular member (103) is formed between the lower end (103a) of the tubular member (103) and the upper end (71a) of the rotor (71). A first space (U) is formed which is surrounded by the upper end (71a) of the rotor (71), the cover member (110), and the tubular member (103) and opens to the outer circumferential side through the gap (120).

[0010] According to the compressor (10) of the first aspect, gas is discharged upward from the open end (75a) of the first gas passage (75) at the upper end (71a) of the rotor (71) of the electric motor (70) and introduced into the first space (U) surrounded by the upper end (71a) of the rotor (71), the cover member (110), and the tubular member (103). The gas temporarily stays in the first space (U) and is diffused in the circumferential direction. The gas is discharged from the first space (U) to the outer circumferential side through the gap (120) between the lower end (103a) of the tubular member (103) and the upper end (71a) of the rotor (71), toward the space above the stator (72) outside the first space (U).

[0011] Since the gas discharged upward from the first gas passage (75) of the rotor (71) temporarily remains in the first space (U) and is diffused in the circumferential direction, the flow velocity of the gas discharged to the outer circumferential side (R2) through the gap (120) toward the space above the stator (72) outside the first space (U) can be made nearly uniform in the circumferential direction.

[0012] In the compressor (10) of the first aspect, by forming the first space (U) above the rotor (71) of the electric motor (70), it is possible to suppress turbulence of the gas flow in the space above the stator (72) of the electric motor (70), and thus it is possible to suppress oil rise.

[0013] A second aspect of the present disclosure is directed to the compressor (10) according to the first aspect. In this compressor (10), the drive shaft (40) is provided with a balance weight (60) disposed above the cover member (110) and a cover (100) covering an outer periphery (60b) of the balance weight (60), the cover (100) extends downward beyond a lower end (60c) of the balance weight (60), and the tubular member (103) is a portion of the cover (100) that extends downward beyond the lower end (60c) of the balance weight (60).

[0014] In the compressor (10) according to the second aspect, the cylindrical member (103) is formed as a part of the cover (100), thereby making it possible to reduce the number of parts.

[0015] A third aspect of the present disclosure is directed to the compressor (10) according to the second aspect. In this compressor (10), the cover member (110) is fixed to a lower surface (60d) of the balance weight (60).

[0016] According to the compressor (10) of the third aspect, the cover member (110) can be easily disposed below the balance weight (60) and above the rotor (71).

[0017] A fourth aspect of the present disclosure is directed to the compressor (10) according to the first to third aspects. The compressor (10) includes a casing (20) that houses the compression mechanism (30), the drive shaft (40), and the electric motor (70), and a second gas passage (76) extending in the vertical direction is provided between an outer periphery (72c) of the stator (72) and the casing (20).

[0018] According to the compressor (10) of the fourth aspect, it is possible to suppress turbulence in the flow of gas passing through the second gas passage (76) between the outer periphery (72c) of the stator (72) and the casing (20) due to the influence of the flow of gas discharged from the open end (75a) of the first gas passage (75) at the upper end (71a) of the rotor (71), and thus it is possible to suppress oil rise.

[0019] A fifth aspect of the present disclosure is directed to the compressor (10) according to any one of the first to fourth aspects. In the compressor (10), the stator (72) is provided with coils (73) arranged at intervals in a circumferential direction (T) of the stator (72), and third gas passages (77) extending in the vertical direction are provided between adjacent coils (73).

[0020] According to the compressor (10) of the fifth aspect, it is possible to suppress turbulence in the flow of gas discharged from the third gas passage (77) between adjacent coils (73) into the space above the stator (72) due to the influence of the flow of gas discharged from the open end (75a) of the first gas passage (75) at the upper end (71a) of the rotor (71), and thus it is possible to suppress oil rise.

[0021] A sixth aspect of the present disclosure is directed to the compressor (10) according to any one of the first to fifth aspects. In this compressor (10), an outer diameter (D1) of the tubular member (103) is equal to or smaller than an outer diameter (D3) of the rotor (71).

[0022] The compressor (10) according to the sixth aspect is more advantageous in preventing the gas flowing on the outer circumferential side of the rotor (71) from flowing into the first space (U).

[0023] A seventh aspect of the present disclosure is directed to the compressor (10) according to any one of the first to sixth aspects. In the compressor (10), a distance (h) between the cover member (110) and an upper end (71a) of the rotor (71) and a distance (d) between a lower end (103a) of the tubular member (103) and the upper end (71a) of the rotor (71) satisfy the relationship d≦h / 3.

[0024] The compressor (10) according to the seventh aspect is more advantageous in preventing the gas flow from being disturbed in the space above the stator (72).

[0025] An eighth aspect of the present disclosure is directed to the compressor (10) according to any one of the first to seventh aspects. In the compressor (10), a distance (d) between a lower end (103a) of the tubular member (103) and an upper end (71a) of the rotor (71), an inner diameter (D2) of the tubular member (103), a total cross-sectional area (M) of all the first gas passages (75), and pi (π) satisfy the relationship M / (π×D2)≦d.

[0026] The compressor (10) according to the eighth aspect is more advantageous in preventing turbulence in the gas flow in the space above the stator (72).

[0027] A ninth aspect of the present disclosure is directed to the compressor (10) according to any one of the first to eighth aspects. In this compressor (10), the cover member (110) and the tubular member (103) are integral with each other.

[0028] A tenth aspect of the present disclosure is directed to a refrigeration system (1). The refrigeration system (1) includes a compressor (10) according to any one of the first to ninth aspects. [Brief description of the drawings]

[0029] [Figure 1] FIG. 1 shows a refrigeration device (1) according to a first embodiment. [Diagram 2] FIG. 2 shows a front cross-sectional view of the compressor (10) according to the first embodiment. [Diagram 3] FIG. 3 is a front cross-sectional view showing the periphery of the electric motor (70) of the compressor (10) according to the first embodiment. [Figure 4] FIG. 4 is a plan view of the electric motor (70) according to the first embodiment, seen from above. [Diagram 5] FIG. 5 is a front cross-sectional view showing the periphery of a balance weight (60) of the compressor (10) according to the first embodiment. [Figure 6] FIG. 6 is a plan view showing the periphery of the balance weight (60) according to the first embodiment as viewed from below. [Figure 7] FIG. 7 shows the relationship between the expansion ratio (h / d) [-] and the oil rise rate (E) [%] according to the first embodiment. [Figure 8] FIG. 8 is a view corresponding to FIG. 5 according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below, and various modifications are possible within the scope of the technical idea of ​​the present disclosure. Since each drawing is intended to conceptually explain the present disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary for ease of understanding.

[0031] First Embodiment (Refrigeration equipment) A compressor (10) according to a first embodiment will be described. The compressor (10) is applied to a refrigeration device (1). FIG. 1 shows the refrigeration device (1). The refrigeration device (1) includes a refrigerant circuit (1a) through which a refrigerant circulates. The refrigerant circuit (1a) of the refrigeration device (1) includes a compressor (10), a condenser (heat radiator) (2), a pressure reduction mechanism (expansion mechanism) (3), and an evaporator (4). The pressure reduction mechanism (3) is, for example, an expansion valve or a capillary tube. The refrigerant circuit (1a) performs a vapor compression refrigeration cycle. The refrigeration device (1) is applied to, for example, an air conditioner or a chiller.

[0032] (Compressor) 2 shows a front cross-sectional view of the compressor (10). The compressor (10) is a scroll compressor. The compressor (10) includes a casing (20), a compression mechanism (30), a drive shaft (40), a housing (50), a balance weight (60), an electric motor (70), a lower bearing member (80), and an oil pump (90).

[0033] Hereinafter, the direction in which the axis of the drive shaft (40) extends is referred to as the axial direction and is designated as (Z). The direction perpendicular to the axis of the drive shaft (40) is referred to as the radial direction and is designated as (R). The side closer to the axis of the drive shaft (40) in the radial direction is referred to as the inner circumferential side or inward in the radial direction and is designated as (R1). The side farther from the axis of the drive shaft (40) in the radial direction is referred to as the outer circumferential side or outward in the radial direction and is designated as (R2). The direction of rotation of the drive shaft (40) is referred to as the circumferential direction and is designated as (T).

[0034] The axial direction of the drive shaft (40) extends in the vertical direction. The vertical direction is indicated by (Z), just like the axial direction. The upper side in the axial direction (vertical direction) is indicated by (Z1). The lower side in the axial direction (vertical direction) is indicated by (Z2).

[0035] The compressor (10) is disposed vertically. A compression mechanism (30), a housing (50), a balance weight (60), an electric motor (70), a lower bearing member (80), and an oil pump (90) are housed in the casing (20) in this order from top to bottom. The drive shaft (40) extends axially (vertically) within the casing (20).

[0036] (Casing) The casing (20) accommodates a compression mechanism (30), a drive shaft (40), a housing (50), a balance weight (60), an electric motor (70), a lower bearing member (80), and an oil pump (90).

[0037] The casing (20) is a cylindrical sealed container that extends vertically in the axial direction (vertical direction). The casing (20) includes a body (21), an upper lid (22), a lower lid (23), and legs (24). The body (21) is cylindrical with both axial (vertical) ends open. The upper lid (22) closes the upper end of the body (21). The lower lid (23) closes the lower end of the body (21). The legs (24) are provided below the lower lid (23) and support the casing (20) on a foundation.

[0038] A suction pipe (25) is connected to the casing (20). The suction pipe (25) axially passes through the upper cover portion (22) of the casing (20). The suction pipe (25) is connected to the compression mechanism (30). A discharge pipe (26) is connected to the casing (20). The discharge pipe (26) radially passes through the body portion (21) of the casing (20). The discharge pipe (26) opens into the internal space of the casing (20).

[0039] An oil reservoir (27) is provided in the lower bottom (20a) of the casing (20). The oil reservoir (27) stores lubricating oil (L). The lubricating oil (L) serves to lubricate the sliding parts of the compressor (10).

[0040] (Compression mechanism) The compression mechanism (30) is provided in the casing (20). The compression mechanism (30) compresses a refrigerant. The refrigerant is a gas. The compression mechanism (30) has a fixed scroll (31) and a movable scroll (35). The movable scroll (35) is meshed with the fixed scroll (31).

[0041] The fixed scroll (31) includes a fixed end plate portion (32), a fixed side wrap (33), and an outer circumferential wall portion (34). The fixed side end plate portion (32) is disk-shaped. The fixed side wrap (33) is a spiral wall that describes an involute curve and protrudes downward from the lower surface of the fixed side end plate portion (32). The outer circumferential wall portion (34) is formed so as to surround the fixed side wrap (33) from the outer circumferential side and protrudes downward from the lower surface of the fixed side end plate portion (32). The tip surface (lower end surface) of the outer circumferential wall portion (34) is substantially flush with the tip surface (lower end surface) of the fixed side wrap (33).

[0042] The movable scroll (35) is also called an orbiting scroll. The movable scroll (35) is disposed below the fixed scroll (31).

[0043] The movable scroll (35) includes a movable end plate (36), a movable wrap (37), and a boss (38). The movable end plate (36) is disk-shaped. The movable wrap (37) is a spiral wall that describes an involute curve and protrudes upward from the upper surface of the movable end plate (36). The boss (38) is cylindrical and protrudes downward from the center of the lower surface of the movable end plate (36). A bearing (38a) is fitted into the inner periphery of the boss (38).

[0044] In the compression mechanism (30), a movable wrap (37) of the movable scroll (35) is meshed with a fixed wrap (33) of the fixed scroll (31). A compression chamber (C) is formed in a region surrounded by the fixed end plate portion (32) and the fixed wrap (33) of the fixed scroll (31) and the movable end plate portion (36) and the movable wrap (37) of the movable scroll (35). A refrigerant is compressed in the compression chamber (C).

[0045] A discharge port (P) is formed in the fixed end plate portion (32) of the fixed scroll (31). The discharge port (P) axially penetrates the center of the fixed end plate portion (32). A discharge chamber (Q) is formed in a region between the fixed scroll (31) and the upper cover portion (22) of the casing (20). The discharge chamber (Q) is in communication with the discharge port (P).

[0046] (Drive shaft) The drive shaft (40) extends in the axial direction (vertical direction) within the casing (20). The drive shaft (40) has a main shaft portion (41) and an eccentric shaft portion (42). The eccentric shaft portion (42) is provided at the upper end of the main shaft portion (41). The outer diameter of the eccentric shaft portion (42) is smaller than the outer diameter of the main shaft portion (41). The axis (42a) of the eccentric shaft portion (42) is eccentric with respect to the axis (41a) of the main shaft portion (41) by a predetermined distance.

[0047] The eccentric shaft portion (42) of the drive shaft (40) is rotatably (slidably) supported by the boss portion (38) of the movable scroll (35) through a bearing (38a).

[0048] (housing) The housing (50) accommodates a bearing (52a) disposed on the upper side. The housing (50) is generally cylindrical and extends in the axial direction (vertical direction). The housing (50) is disposed within the casing (20) below the movable scroll (35) and above the balance weight (60). The drive shaft (40) is inserted into the inner periphery of the housing (50). The outer diameter of the upper portion of the housing (50) is larger than the outer diameter of the lower portion of the housing (50). The outer peripheral surface of the upper portion of the housing (50) is fixed to the inner peripheral surface of the body portion (21) of the casing (20).

[0049] A discharge space (A) is formed below the housing (50) within the casing (20). The discharge space (A) is formed in a region between the housing (50) and the electric motor (70). The discharge space (A) communicates with the discharge chamber (Q) through a discharge passage (not shown) formed in the fixed scroll (31) and the housing (50). The discharge space (A) communicates with the discharge pipe (26). The discharge space (A) is filled with high-pressure discharge refrigerant.

[0050] The inner diameter of the upper portion of the housing (50) is larger than the inner diameter of the lower portion of the housing (50). A crank chamber (51) is formed on the inner periphery of the upper portion of the housing (50) by a downwardly recessed portion. The crank chamber (51) accommodates the boss portion (38) of the movable scroll (35).

[0051] A main bearing hole (52) is formed on the inner periphery of the lower part of the housing (50). The main bearing hole (52) penetrates the lower part of the housing (50) in the axial direction (vertical direction) and communicates with the crank chamber (51). A bearing (52a) is fitted into the inner periphery of the main bearing hole (52). The main shaft portion (41) of the drive shaft (40) is rotatably (slidably) supported in the main bearing hole (52) of the housing (50) via the bearing (52a).

[0052] (Balance weight) The balance weight (60) serves to cancel out an unbalanced force generated by the orbital motion of the movable scroll (35) of the compression mechanism (30). The balance weight (60) is provided in the casing (20), below the housing (50) and above the electric motor (70). The balance weight (60) is provided on the main shaft portion (41) of the drive shaft (40). The balance weight (60) rotates integrally with the drive shaft (40).

[0053] The balance weight (60) protrudes radially outward from the drive shaft (40). The balance weight (60) protrudes from the side of the drive shaft (40) opposite to the side where the eccentric shaft portion (42) is eccentric with respect to the main shaft portion (41). The balance weight (60) also extends in the axial direction (up and down direction).

[0054] As will be described in detail later, a cover (100) and a lid member (110) are attached to the balance weight (60).

[0055] (Electric motor) The electric motor (70) will be described with reference to Figs. 3 and 4. Fig. 3 shows a front cross-sectional view of the electric motor (70) and its surroundings in the compressor (10). Fig. 4 shows a plan view of the electric motor (70) as seen from above along arrow IV in Fig. 3. The electric motor (70) is also called a motor. The electric motor (70) is provided in the casing (20) below the balance weight (60) and above the lower bearing member (80). The electric motor (70) drives the compression mechanism (30) by rotating the drive shaft (40).

[0056] The electric motor (70) includes a rotor (71) and a stator (72). The stator (72) is further provided with a plurality of coils (73) and an insulator (74).

[0057] The rotor (71) is also called a rotor. The rotor (71) is made of metal. The rotor (71) is cylindrical and extends in the axial direction (vertical direction). The rotor (71) is coupled to the main shaft portion (41) of the drive shaft (40). The main shaft portion (41) of the drive shaft (40) is inserted and fixed to the inner periphery of the rotor (71). The rotor (71) rotates integrally with the drive shaft (40).

[0058] The rotor (71) is provided with a plurality of first gas passages (75). The first gas passages (75) penetrate the wall of the rotor (71) in the axial direction (vertical direction). In other words, the first gas passages (75) extend in the axial direction (vertical direction) from the upper end to the lower end of the rotor (71). The plurality of first gas passages (75) are arranged side by side at predetermined intervals along the circumferential direction of the rotor (71).

[0059] The stator (72) is also called a stator. The stator (72) is made of metal. The stator (72) is cylindrical and extends in the axial direction (up and down). The stator (72) is fixed to an inner circumferential surface of the body portion (21) of the casing (20). The stator (72) is disposed on the radially outer circumferential side of the rotor (71). The stator (72) is disposed so as to surround the rotor (71) from the radially outer circumferential side. The stator (72) and the rotor (71) are spaced apart from each other by a predetermined distance in the radial direction. The rotor (71) is rotatably inserted into the inner circumferential side of the stator (72).

[0060] The stator (72) includes a back yoke portion (72a) and a plurality of teeth portions (72b). The back yoke portion (72a) is formed in a cylindrical shape extending in the axial direction (up-down direction). The plurality of teeth portions (72b) protrude radially inward from an inner peripheral surface of the back yoke portion (72a). The plurality of teeth portions (72b) are arranged side by side at predetermined intervals from one another in the circumferential direction.

[0061] A plurality of core cuts (72d) are provided on an outer circumferential portion (72c) of the back yoke portion (72a) of the stator (72). The core cuts (72d) extend in the axial direction (vertical direction) from the upper end to the lower end of the stator (72). The core cuts (72d) are grooves that open to the outer circumferential surface of the stator (72) and extend in the axial direction (vertical direction) of the stator (72). The core cuts (72d) are recessed from the outer circumferential surface of the back yoke portion (72a) toward the inner circumferential side in the radial direction. The plurality of core cuts (72d) are arranged side by side at intervals along the circumferential direction of the stator (72).

[0062] A plurality of second gas passages (76) are provided between the outer circumferential portion (72c) of the stator (72) and the inner circumferential surface of the trunk portion (21) of the casing (20). The second gas passages (76) extend in the axial direction (vertical direction) from the upper end to the lower end of the stator (72). The plurality of second gas passages (76) are formed of a plurality of core cuts (72d). The plurality of second gas passages (76) are arranged side by side at intervals along the circumferential direction of the stator (72).

[0063] The coils (73) are fixed to the stator (72). The coils (73) correspond to the teeth (72b). The coils (73) are wound around the teeth (72b) of the stator (72). The coils (73) are arranged side by side at intervals along the circumferential direction of the stator (72).

[0064] A third gas passage (77) is provided between the coils (73) adjacent to each other in the circumferential direction. The third gas passage (77) extends in the axial direction (up-down direction) of the stator (72) from the upper end to the lower end of the stator (72). The third gas passages (77) are arranged side by side at intervals in the circumferential direction of the stator (72).

[0065] A gap (air gap) formed between the rotor (71) and the stator (72) constitutes a fourth gas passage (78). The fourth gas passage (78) extends in the axial direction (vertical direction) from the upper end to the lower end of the rotor (71) and the stator (72). The fourth gas passage (78) has an annular shape when viewed in the axial direction (vertical direction). The fourth gas passage (78) is located radially inner than the third gas passage (77). The fourth gas passage (78) is located radially outer than the outer periphery (71b) of the rotor (71). The outer periphery (71b) of the rotor (71) is the outer periphery surface of the rotor (71). The outer periphery surface of the rotor (71) faces the outer periphery in the radial direction.

[0066] The insulator (74) is made of resin. There are two insulators (74). The insulators (74) are disposed above and below the stator (72). The insulators (74) insulate the stator (72) from the coils (73).

[0067] (Lower bearing member) The lower bearing member (80) accommodates a bearing (81a) disposed below. The lower bearing member (80) has a generally cylindrical shape extending in the axial direction (vertical direction). The lower bearing member (80) is provided in the casing (20) between the electric motor (70) and the oil reservoir (27) (the lower bottom portion (20a) of the casing (20)). The lower bearing member (80) includes a cylindrical portion (81), a protruding portion (82), and an oil separation plate (83).

[0068] The cylindrical portion (81) is cylindrical. The cylindrical portion (81) accommodates the main shaft portion (41) of the drive shaft (40). A bearing (81a) is fitted into the inner periphery of the cylindrical portion (81). The main shaft portion (41) of the drive shaft (40) is rotatably (slidably) supported by the cylindrical portion (81) of the lower bearing member (80) via the bearing (81a).

[0069] The protrusion (82) protrudes radially outward from the cylindrical portion (81) and is fixed to the inner circumferential surface of the body portion (21) of the casing (20).

[0070] The oil separation plate (83) is fixed to the cylindrical portion (81) and extends in the radial and circumferential directions. The oil separation plate (83) faces the oil reservoir (27). The gas refrigerant flowing through the internal space of the casing (20) contains mist-like lubricating oil (L). When the gas refrigerant containing the mist-like lubricating oil (L) hits the oil separation plate (83), the gas refrigerant and a portion of the lubricating oil (L) are separated, and the separated lubricating oil (L) drops into the oil reservoir (27).

[0071] (Oil pump) The oil pump (90) includes a pump portion (91) and a nozzle portion (92). The pump portion (91) is provided at the lower end of the main shaft portion (41) of the drive shaft (40). The pump portion (91) rotates and reciprocates in synchronization with the drive shaft (40). The nozzle portion (92) is fixed to the lower end of the cylindrical portion (81) of the lower bearing member (80). The nozzle portion (92) is immersed in the lubricating oil (L) stored in the oil storage portion (27) in the lower bottom portion (20a) of the casing (20).

[0072] The oil pump (90) draws up the lubricating oil (L) from the oil reservoir (27). The lubricating oil (L) is supplied to each sliding part of the compressor (10) through an oil passage (not shown) provided inside the drive shaft (40).

[0073] Sliding parts in the compressor (10) include between the bearing (38a) of the boss portion (38) of the movable scroll (35) and the eccentric shaft portion (42) of the drive shaft (40), between the bearing (52a) of the main bearing hole (52) of the housing (50) and the main shaft portion (41) of the drive shaft (40), between the bearing (81a) of the cylindrical portion (81) of the lower bearing member (80) and the main shaft portion (41) of the drive shaft (40), and between the lower surface of the movable scroll (35) and the upper surface of the housing (50).

[0074] (Cover, tubular member) Fig. 5 is a front cross-sectional view of the periphery of the balance weight (60) of the compressor (10). Fig. 6 is a plan view of the periphery of the balance weight (60) as seen from below, as viewed from the direction of arrow VI in Fig. 5. For simplicity, the coil (73) and the insulator (74) are not shown in Fig. 5.

[0075] As described above, the balance weight (60) is disposed above the electric motor (70). The balance weight (60) is provided on the main shaft portion (41) of the drive shaft (40). The balance weight (60) rotates integrally with the drive shaft (40).

[0076] The balance weight (60) extends over approximately half the circumference in the circumferential direction and protrudes radially outward from the drive shaft (40). The balance weight (60) also extends in the axial direction (up and down direction).

[0077] The cover (100) is provided on the main shaft portion (41) of the drive shaft (40). More specifically, the cover (100) is attached to the balance weight (60) provided on the drive shaft (40). The cover (100) is formed in a cylindrical shape with a bottom that opens downward. The cover (100) is intended to suppress agitation of gas caused by rotation of the balance weight (60). The cover (100) rotates integrally with the drive shaft (40). The cover (100) includes an upper cover portion (101) and an outer circumferential cover portion (102).

[0078] The upper cover portion (101) of the cover (100) is disposed above the balance weight (60). The upper cover portion (101) is in the form of a circular plate. The upper cover portion (101) covers the upper end (60a) of the balance weight (60) from above.

[0079] The outer periphery (60b) of the balance weight (60) is located radially outward of the first gas passage (75) of the rotor (71) of the electric motor (70). The outer periphery (60b) of the balance weight (60) is a portion of the balance weight (60) facing the radially outer periphery. The outer periphery of the upper cover portion (101) is located radially outward of the outer periphery (60b) of the balance weight (60). The outer periphery of the upper cover portion (101) is located radially outward of the first gas passage (75) of the rotor (71) of the electric motor (70).

[0080] An outer circumferential portion (60b) of the balance weight (60) is located radially inward of an outer circumferential portion (71b) of the rotor (71) of the electric motor (70). An upper cover portion (101) of the cover (100) is fixed to an upper end (60a) of the balance weight (60) by a fastener (61) (e.g., a bolt or the like).

[0081] The outer circumferential cover portion (102) of the cover (100) is disposed radially outward of the balance weight (60). The outer circumferential cover portion (102) is in the shape of a circular tube. The outer circumferential cover portion (102) extends downward from the outer circumferential portion of the upper cover portion (101). The upper cover portion (101) and the outer circumferential cover portion (102) are integral with each other.

[0082] The outer periphery cover portion (102) of the cover (100) covers the outer periphery of the outer periphery (60b) of the balance weight (60).

[0083] The inner circumferential surface of the outer circumferential cover portion (102) is located radially outer than the first gas passage (75) of the rotor (71) of the electric motor (70). The outer circumferential cover portion (102) extends downward from the outer circumferential portion of the upper cover portion (101) radially outer than the first gas passage (75) of the rotor (71).

[0084] The outer circumferential cover portion (102) is located radially inward of the outer circumferential portion (71b) of the rotor (71) of the electric motor (70). The outer circumferential cover portion (102) extends downward from the outer circumferential portion of the upper cover portion (101) radially inward of the outer circumferential portion (71b) of the rotor (71) of the electric motor (70).

[0085] The outer circumferential cover portion (102) of the cover (100) extends downward beyond the lower end (60c) of the balance weight (60). Hereinafter, the portion of the outer circumferential cover portion (102) of the cover (100) that extends downward beyond the lower end (60c) of the balance weight (60) is referred to as a tubular member (103).

[0086] The tubular member (103) is a part of the outer circumferential cover portion (102) of the cover (100). The tubular member (103) is disposed above the upper end (71a) of the rotor (71) of the electric motor (70). The upper end (71a) of the rotor (71) also forms the upper surface of the rotor (71). The upper surface of the rotor (71) faces upward. The tubular member (103) has a circular tubular shape. The tubular member (103) rotates integrally with the drive shaft (40).

[0087] The tubular member (103) is located outer circumferentially of the first gas passage (75) of the rotor (71) of the electric motor (70) and extends downward from an outer circumferential portion (110a) of the cover member (110) described later (more specifically, from a position slightly outer circumferentially of the outer circumferential portion (110a)).

[0088] The tubular member (103) is located on the inner peripheral side of the outer peripheral portion (71b) of the rotor (71) of the electric motor (70) and extends downward from the outer peripheral portion (110a) of the cover member (110) described later (more specifically, from a position slightly outer peripheral than the outer peripheral portion (110a)).

[0089] The outer diameter (D1) of the tubular member (103) is equal to or smaller than the outer diameter (D3) of the rotor (71) of the electric motor (70). More specifically, the outer diameter (D1) of the tubular member (103) is smaller than the outer diameter (D3) of the rotor (71) of the electric motor (70). The inner diameter (D2) of the tubular member (103) is smaller than the outer diameter (D3) of the rotor (71) of the electric motor (70).

[0090] A gap (120) is formed between the lower end (103a) of the tubular member (103) and the upper end (71a) of the rotor (71) of the electric motor (70). The lower end (103a) of the tubular member (103) also forms the lower end of the outer circumferential cover portion (102) of the cover (100). The gap (120) extends circumferentially around the entire periphery of the tubular member (103).

[0091] (Covering material) 5 and 6, the cover member (110) is in the form of a plate formed in an annular shape. The cover member (110) extends in the radial and circumferential directions. The main shaft portion (41) of the drive shaft (40) is inserted into the annular cover member (110). The cover member (110) is disposed above the upper end (71a) of the rotor (71) of the electric motor (70). The cover member (110) is disposed below the balance weight (60). In other words, the balance weight (60) is disposed above the cover member (110).

[0092] The lid member (110) covers the lower end (60c) of the balance weight (60) from below. The lid member (110) divides the space inside the cover (100) into upper and lower sections. The outer diameter of the lid member (110) is slightly smaller than the inner diameter (D2) of the cylindrical member (103). The lid member (110) is disposed coaxially with the main shaft portion (41) of the drive shaft (40). In this example, the lower end (60c) of the balance weight (60) is also the lower surface (60d) of the balance weight (60). The lower surface (60d) of the balance weight (60) faces downward.

[0093] The cover member (110) is fixed to the lower surface (60d) of the balance weight (60). More specifically, the cover member (110) is fixed to the lower surface (60d) of the balance weight (60) by a fastener (62) (e.g., a bolt or the like). The cover member (110) rotates integrally with the drive shaft (40).

[0094] The outer periphery (110a) of the cover member (110) is located radially outward of the first gas passage (75) of the rotor (71) of the electric motor (70). The cover member (110) faces an open end (75a) of the first gas passage (75) at the upper end (71a) of the rotor (71) of the electric motor (70). The open end (75a) of the first gas passage (75) is an outlet of the first gas passage (75).

[0095] As described above, the tubular member (103) extends downward from the outer circumferential portion (110a) of the cover member (110) (more specifically, at a position slightly outer circumferential than the outer circumferential portion (110a)) on the outer circumferential side of the first gas passage (75) of the rotor (71). The cover member (110) and the tubular member (103) are not integral with each other but are separate bodies. A small radial gap is provided between the cover member (110) and the tubular member (103). To favorably form a first space (U) described below, it is preferable that the radial gap between the cover member (110) and the tubular member (103) be as small as possible.

[0096] (1st space) A first space (U) is formed between the upper end (71a) of the rotor (71) of the electric motor (70) and the lower end (60c) of the balance weight (60). The first space (U) is a space surrounded by the upper end (71a) of the rotor (71) of the electric motor (70), the cover member (110), and the tubular member (103). The first space (U) faces an open end (75a) of a first gas passage (75) at the upper end (71a) of the rotor (71) of the electric motor (70). The first space (U) opens to the outer periphery toward the stator (72) through a gap (120) formed between the lower end (103a) of the tubular member (103) and the upper end (71a) of the rotor (71).

[0097] The lower end of the first space (U) coincides with the upper end (71a) of the rotor (71). The upper end of the first space (U) coincides with the lower surface of the cover member (110). The outer periphery of the first space (U) coincides with the inner periphery of the tubular member (103). A gap (120) is defined at the lower part and outer periphery of the first space (U). The first space (U) is located below the discharge pipe (26).

[0098] It is preferable that the relationship between the distance (h) between the lower surface of the cover member (110) and the upper end (71a) of the rotor (71) and the distance (d) between the lower end (103a) of the tubular member (103) and the upper end (71a) of the rotor (71) satisfies d≦h / 3. Note that the distance (d) corresponds to the vertical dimension of the gap (120).

[0099] It is preferable that the relationship between the distance (d) between the lower end (103a) of the tubular member (103) and the upper end (71a) of the rotor (71), the inner diameter (D2) of the tubular member (103), the total cross-sectional area (M) of all the first gas passages (75), and pi (π) satisfy M / (π×D2)≦d.

[0100] The total cross-sectional area (M) is the sum of the cross-sectional areas of all the first gas passages (75). The total cross-sectional area (M) of all the first gas passages (75) is expressed as M=n×B, where n is the number of first gas passages (75) and B is the cross-sectional area of ​​each first gas passage (75).

[0101] The cross-sectional area (S) of the gap (120) between the lower end (103a) of the tubular member (103) and the upper end (71a) of the rotor (71) is expressed as S=π×D2×d using the distance (d) between the lower end (103a) of the tubular member (103) and the upper end (71a) of the rotor (71), the inner diameter (D2) of the tubular member (103), and pi (π). Applying S=π×D2×d to M / (π×D2)≦d gives M≦S.

[0102] (Compressor operation) The operation of the compressor (10) will be described. When the electric motor (70) is driven, the drive shaft (40) rotates, thereby driving the movable scroll (35) of the compression mechanism (30). The movable scroll (35) revolves around the axis (41a) of the main shaft portion (41) of the drive shaft (40) while its rotation is restricted.

[0103] The low-pressure gas refrigerant is drawn through the suction pipe (25) into the compression chamber (C) of the compression mechanism (30) in the casing (20) and compressed to become high-pressure gas refrigerant. The high-pressure gas refrigerant is discharged from the compression chamber (C) through the discharge port (P) of the fixed scroll (31) to the discharge chamber (Q). The high-pressure gas refrigerant flows from the discharge chamber (Q) through a discharge passage (not shown) formed in the fixed scroll (31) and the housing (50) to a discharge space (A) located below the housing (50). The high-pressure gas refrigerant is discharged from the discharge space (A) through the discharge pipe (26) to the outside of the casing (20) (for example, the condenser (2) of the refrigerant circuit (1a)).

[0104] (Flow of discharge gas inside the compressor) The flow of the discharge gas (G) flowing inside the compressor (10) will be described with reference to Fig. 3. The discharge gas (G) is gas that is compressed in the compression chamber (C) of the compression mechanism (30) until it is discharged to the outside of the casing (20). The discharge gas (G) contains mist-like lubricating oil (L). The discharge gas (G) compressed in the compression chamber (C) of the compression mechanism (30) passes through a discharge port (P) and is guided to a plurality of second gas passages (76) formed of a plurality of core cuts (72d) via a passage (not shown) and a guide member (not shown) formed in the compression mechanism (30).

[0105] As described above, the second gas passage (76) formed by the core cut (72d) is provided between the outer circumferential portion (72c) of the stator (72) of the motor (70) and the inner circumferential surface of the body portion (21) of the casing (20). In the second gas passage (76), the discharge gas (G) flows downward.

[0106] The discharged gas (G) that has passed through the second gas passage (76) hits the oil separation plate (83) of the lower bearing member (80) and is bounced back. At this time, a part of the mist-like lubricating oil (L) contained in the discharged gas (G) is separated from the discharged gas (G) by the oil separation plate (83) and falls into the oil reservoir (27) in the lower bottom part (20a) of the casing (20).

[0107] A part of the discharged gas (G) that is bounced off the oil separation plate (83) flows from below into the first gas passage (75) of the rotor (71) of the electric motor (70). In the first gas passage (75), the discharged gas (G) flows upward. Having passed through the first gas passage (75), the discharged gas (G) is discharged upward from an open end (75a) of the first gas passage (75) at the upper end (71a) of the rotor (71).

[0108] The discharged gas (G) discharged upward from the first gas passage (75) flows out from the first space (U) through the gap (120), as will be described in detail later.

[0109] The other part of the discharge gas (G) bounced off the oil separation plate (83) flows from below into a third gas passage (77) between circumferentially adjacent coils (73) of the electric motor (70) and into a fourth gas passage (78) between the rotor (71) and the stator (72). In the third gas passage (77) and the fourth gas passage (78), the discharge gas (G) flows upward. The discharge gas (G) that has passed through the third gas passage (77) and the fourth gas passage (78) is discharged into a space (V) above an upper end (72e) of the stator (72).

[0110] Hereinafter, for the sake of simplicity, the space (V) above the upper end (72e) of the stator (72) may be referred to as the space (V) above the stator (72). The space (V) above the stator (72) is the portion directly above the upper end (72e) of the stator (72) in the discharge space (A) formed in the region between the housing (50) and the motor (70).

[0111] (Gas flow disturbance) In Figure 4, the flow of the discharge gas (G) discharged from the opening end (75a) of the first gas passage (75) at the upper end (71a) of the rotor (71) of the electric motor (70) when the first space (U) is not formed is shown diagrammatically by a dotted line.

[0112] As described above, the first gas passages (75) are arranged side by side at predetermined intervals along the circumferential direction of the rotor (71) of the electric motor (70). The discharge gas (G) is discharged upward and toward the outer periphery from the open ends (75a) of the first gas passages (75) at the upper end (71a) of the rotor (71) of the electric motor (70). In the rotor (71), passage-containing regions (I) in which the first gas passages (75) are present and passage-free regions (J) in which the first gas passages (75) are not present are arranged alternately in the circumferential direction.

[0113] In the passage-containing region (I) of the rotor (71), the flow velocity of the discharge gas (G) discharged upward and radially outward toward the space (V) above the stator (72) is relatively high, while in the passage-free region (J) of the rotor (71), the flow velocity of the discharge gas (G) discharged upward and radially outward toward the space (V) above the stator (72) is relatively low.

[0114] When the rotor (71) rotates in this state, the flow of the discharge gas (G) discharged from the opening end (75a) of the first gas passage (75) at the upper end (71a) of the rotor (71) disturbs the flow of the discharge gas (G) in the space (V) above the stator (72).

[0115] Specifically, when the rotor (71) is viewed from any point (W) in the circumferential direction on the upper side of the stator (72), the passage-containing region (I) of the rotor (71) and the passage-less region (J) of the rotor (71) pass by alternately, so that the flow velocity of the discharged gas (G) from the rotor (71) side to the stator (72) side varies from moment to moment, and the flow velocity of the discharged gas (G) from the rotor (71) side to the stator (72) side increases or decreases.

[0116] The discharge gas (G) discharged from the third gas passage (77) and the fourth gas passage (78) to the space (V) above the stator (72) is subject to fluctuations in the flow rate of the discharge gas (G) from the rotor (71) side to the stator (72) side, and therefore the upward flow is obstructed and disturbed.

[0117] If the discharged gas (G) discharged from the third gas passage (77) and the fourth gas passage (78) to the space (V) above the stator (72) becomes turbulent, the downward flow of the discharged gas (G) passing through the second gas passage (76) (core cut (72d)) between the outer circumferential portion (72c) of the stator (72) and the inner circumferential surface of the body portion (21) of the casing (20) will be obstructed.

[0118] In this manner, if the flow of the discharge gas (G) discharged from the opening end (75a) of the first gas passage (75) at the upper end (71a) of the rotor (71) becomes disturbed in the space (V) above the stator (72), the flow of the discharge gas (G) flowing inside the compressor (10) will be obstructed, and it will not be possible to obtain a sufficient effect of reducing oil rise.

[0119] Oil rise is a phenomenon in which the lubricating oil (L) in the casing (20) of the compressor (10) is discharged together with the discharge gas (G) through the discharge pipe (26) to the outside of the casing (20) (for example, to the condenser (2) of the refrigerant circuit (1a)). Oil rise is undesirable because it reduces the amount of lubricating oil (L) for lubricating the sliding parts of the compressor (10).

[0120] In the compressor (10) according to this embodiment, by forming the above-mentioned first space (U) above the rotor (71), it is possible to suppress turbulence in the flow of the discharge gas (G) in the space (V) above the stator (72) due to the influence of the flow of the discharge gas (G) discharged from the open end (75a) of the first gas passage (75) at the upper end (71a) of the rotor (71). Furthermore, in the compressor (10) according to this embodiment, it is possible to improve oil rise by suppressing turbulence in the flow of the discharge gas (G) in the space (V) above the stator (72).

[0121] (The role of the first space) The role of the first space (U) will be described. The first space (U) is formed between the upper end (71a) of the rotor (71) and the lower end (60c) of the balance weight (60) and is surrounded by the upper end (71a) of the rotor (71), the cover member (110), and the cylindrical member (103). The first space (U) opens to the outer periphery toward the stator (72) through a gap (120) formed between the lower end (103a) of the cylindrical member (103) and the upper end (71a) of the rotor (71).

[0122] The discharge gas (G) is discharged upward from the open end (75a) of the first gas passage (75) at the upper end (71a) of the rotor (71) and introduced into the first space (U). In the first space (U), the discharge gas (G) hits the cover member (110) and is restricted from moving upward. In the first space (U), the discharge gas (G) hits the cylindrical member (103) and is restricted from moving radially outward.

[0123] The discharge gas (G) temporarily stays in the first space (U) and is diffused over the entire circumference in the circumferential direction. The discharge gas (G) is discharged from the first space (U) to the outer circumferential side through the gap (120) between the lower end (103a) of the tubular member (103) and the upper end (71a) of the rotor (71) almost evenly over the entire circumference in the circumferential direction toward the space (V) above the stator (72) outside the first space (U).

[0124] As described above, the gap (120) extends around the entire circumference of the tubular member (103). Therefore, the flow velocity of the discharge gas (G) flowing out of the first space (U) through the gap (120) is uniform in the circumferential direction of the tubular member (103). Therefore, the effect of the flow of the discharge gas (G) flowing out of the first gas passage (75) on the flow of the discharge gas (G) discharged upward from the third gas passage (77) and the fourth gas passage (78) is reduced compared to the conventional technique. As a result, turbulence in the flow of the discharge gas (G) in the space (V) above the stator (72) of the electric motor (70) is reduced.

[0125] (Relationship between expansion ratio and oil rise rate) As described above, by temporarily retaining the discharge gas (G) discharged upward from the first gas passage (75) of the rotor (71) in the first space (U), disturbance of the flow of the discharge gas (G) in the space (V) above the stator (72) is suppressed, and thereby disturbance of the flow of the discharge gas (G) flowing inside the compressor (10) is suppressed, and the oil rise rate of the compressor (10) is improved. Fig. 7 shows the relationship between the expansion ratio (h / d) [-] and the oil rise rate (E) [%].

[0126] The horizontal axis represents the expansion ratio (h / d), which is obtained by dividing the distance (h) between the lower surface of the cover member (110) and the upper end (71a) of the rotor (71) by the distance (d) between the lower end (103a) of the tubular member (103) and the upper end (71a) of the rotor (71).

[0127] The vertical axis represents the oil rise rate (E) [%]. The oil rise rate (E) is the ratio of the lubricating oil (L) to the mixture of the discharge gas (G) and the lubricating oil (L) discharged outside the casing (20) through the discharge pipe (26), expressed in mass percent.

[0128] The numerical values ​​used as the basis for creating the graph of Fig. 7 are shown below. The numerical values ​​below are merely examples, and are not necessarily limited to the numerical values ​​below. Note that, in the compressor (10) according to this embodiment, even if the specific numerical values ​​differ from those shown below, the ratios between the numerical values ​​will often have a similar tendency to those shown below.

[0129] The distance (h) between the lower surface of the cover member (110) and the upper end (71a) of the rotor (71) was set to 15.4 mm. The inner diameter (D2) of the cylindrical member (103) was set to 76 mm. The number (n) of the first gas passages (75) was set to 6. The cross-sectional area (B) of each of the first gas passages (75) was set to 22.0 mm. 2 The total cross-sectional area (M) of all the first gas passages (75) was 132.0 mm 2 ] (M = n × B).

[0130] The conditions of the discharge gas (G) and the lubricating oil (L) when the graph in Figure 7 was created are shown below. Note that the following conditions are merely examples and are not necessarily limited to the following conditions. R410A was used as the discharge gas (G). A lubricating oil (L) containing polyvinyl ether-based synthetic base oil as the main component was used.

[0131] The distance (d) between the lower end (103a) of the tubular member (103) and the upper end (71a) of the rotor (71) was changed, and the oil rise rate (E) was measured for various expansion ratios (h / d).

[0132] It is said that the higher the oil rise rate (E), the worse the oil rise rate. A high (bad) oil rise rate (E) is caused by turbulence in the flow of the discharge gas (G) flowing inside the compressor (10).

[0133] As shown in Figure 7, in the range where the expansion ratio (h / d) is 5 or less, the oil rise rate (E) decreases as the expansion ratio (h / d) increases. For example, when the expansion ratio (h / d) is 1 (h=d), the oil rise rate (E) is about 6%. When the expansion ratio (h / d) is 3, the oil rise rate (E) is about 2.1%. When the expansion ratio (h / d) is 5, the oil rise rate (E) is about 1.5%.

[0134] When the expansion ratio (h / d) is in the range of 5 to 29.8, the oil rise rate (E) remains almost unchanged at about 1.5%.

[0135] In the range where the expansion ratio (h / d) is 29.8 or more, the oil rise rate (E) increases as the expansion ratio (h / d) increases. For example, when the expansion ratio (h / d) is about 29.8, the oil rise rate (E) is about 1.5%. When the expansion ratio (h / d) is 31, the oil rise rate (E) is about 2%. When the expansion ratio (h / d) is 32, the oil rise rate (E) is about 4%.

[0136] According to Fig. 7, when the expansion ratio (h / d) is 3 or more, the oil rise rate (E) improves. 3≦h / d corresponds to d≦h / 3. When the expansion ratio (h / d) is 5 or more, the oil rise rate (E) is particularly improved. 5≦h / d corresponds to d≦h / 5.

[0137] According to Figure 7, it can be seen that the oil rise rate (E) improves when the expansion ratio (h / d) is 31 or less. It can be seen that the oil rise rate (E) is particularly improved when the expansion ratio (h / d) is 29.8 or less. h / d≦29.8 roughly corresponds to M / (π×D2)≦d. Specifically, M / (π×D2)=132 / (π×76)=0.55285. When M / (π×D2)=d, h / d=15.4 / 0.55285=27.855. h / d is a value close to 29.8.

[0138] According to the test results shown in FIG. 7, the expansion ratio (h / d) is preferably 3 or more and 31 or less, and more preferably 5 or more and 29.8 or less.

[0139] (Action and effect) According to the compressor (10) of this embodiment, the discharge gas (G) is discharged from the open end (75a) of the first gas passage (75) at the upper end (71a) of the rotor (71) of the electric motor (70) and introduced into the first space (U) surrounded by the upper end (71a) of the rotor (71), the cover member (110), and the tubular member (103). The discharge gas (G) temporarily stays in the first space (U) and is diffused over the entire circumference in the circumferential direction. The discharge gas (G) is discharged from the first space (U) to the outer periphery side toward the space (V) above the stator (72) located outside the first space (U) through the gap (120) between the lower end (103a) of the tubular member (103) and the upper end (71a) of the rotor (71).

[0140] The discharge gas (G) discharged upward from the first gas passage (75) of the rotor (71) temporarily stays in the first space (U) and is diffused all around in the circumferential direction. Therefore, the flow velocity of the discharge gas (G) discharged to the outer periphery through the gap (120) toward the space (V) above the stator (72) outside the first space (U) can be made nearly uniform in the circumferential direction (T).

[0141] According to the compressor (10) of this embodiment, by forming a first space (U) above the rotor (71) of the electric motor (70), it is possible to suppress turbulence of the flow of the discharge gas (G) in the space (V) above the stator (72) of the electric motor (70), and thus it is possible to suppress oil rise.

[0142] Specifically, disturbance in the flow of the discharge gas (G) discharged from the third gas passage (77) between adjacent coils (73) and the fourth gas passage (78) between the rotor (71) and the stator (72) to the space (V) above the stator (72) can be suppressed, and thus oil rise in the compressor (10) can be suppressed.

[0143] This can prevent the flow of the discharge gas (G) passing through the second gas passage (76) (core cut (72d)) between the outer periphery (72c) of the stator (72) and the casing (20) from being disturbed, thereby preventing oil leakage in the compressor (10).

[0144] If the distance (d) between the lower end (103a) of the tubular member (103) and the upper end (71a) of the rotor (71) (the vertical dimension of the gap (120)) is too large, the discharge gas (G) introduced into the first space (U) from the first gas passage (75) of the rotor (71) will be excessively discharged to the outside of the first space (U) through the gap (120). The discharge gas (G) will be less likely to remain in the first space (U) and less likely to diffuse in the circumferential direction.

[0145] According to the compressor (10) of this embodiment, the distance (d) between the lower end (103a) of the tubular member (103) and the upper end (71a) of the rotor (71) (the vertical dimension of the gap (120)) is set to a predetermined value or less (d≦h / 3). The discharge gas (G) introduced into the first space (U) from the first gas passage (75) of the rotor (71) is not excessively discharged to the outside of the first space (U) through the gap (120). The discharge gas (G) is likely to remain in the first space (U) and to be diffused in the circumferential direction. This is more advantageous in suppressing turbulence in the flow of the discharge gas (G) in the space (V) above the stator (72).

[0146] If the distance (d) between the lower end (103a) of the tubular member (103) and the upper end (71a) of the rotor (71) (the vertical dimension of the gap (120)) is too small, the discharge gas (G) introduced into the first space (U) from the first gas passage (75) of the rotor (71) is difficult to be discharged to the outside of the first space (U) through the gap (120). In this case, the flow of the discharge gas (G) through the first gas passage (75) of the rotor (71) is hindered, so that the amount of the discharge gas (G) from which part of the mist of lubricating oil (L) is separated while passing through the lower space of the electric motor (70) decreases, and the oil rise rate (E) increases.

[0147] According to the compressor (10) of this embodiment, the distance (d) between the lower end (103a) of the tubular member (103) and the upper end (71a) of the rotor (71) (the vertical dimension of the gap (120)) is set to a predetermined value or more (M / (π×D2)≦d). This makes it possible to prevent the flow of the discharge gas (G) passing through the first gas passage (75) of the rotor (71) from being obstructed. This is more advantageous in preventing the flow of the discharge gas (G) from being disturbed in the space (V) above the stator (72).

[0148] The cover (100) can suppress agitation of the discharge gas (G) caused by rotation of the balance weight (60). By forming the cylindrical member (103) as a part of the cover (100), the number of parts can be reduced.

[0149] By fixing the cover member (110) to the lower surface (60d) of the balance weight (60), the cover member (110) can be easily disposed below the balance weight (60) and above the rotor (71).

[0150] The outer diameter (D1) of the tubular member (103) is equal to or smaller than the outer diameter (D3) of the rotor (71), which is more advantageous in preventing the discharge gas (G) flowing on the outer circumferential side of the rotor (71) (for example, the discharge gas (G) discharged from the third gas passage (77) and the fourth gas passage (78) to the space (V) above the stator (72)) from flowing into the first space (U).

[0151] <Second embodiment> A compressor (10) according to the second embodiment will be described below. Fig. 8 is a view corresponding to Fig. 5 according to the second embodiment.

[0152] In this embodiment, the cylindrical member (103) is configured as a separate piece, not integral with, the outer peripheral cover portion (102) of the cover (100). The outer peripheral cover portion (102) of the cover (100) extends only to the lower end (60c) of the balance weight (60).

[0153] The cover member (110) and the tubular member (103) are integral with each other. The upper end of the tubular member (103) is fixed to the outer periphery (110a) of the cover member (110). The tubular member (103) extends downward from the outer periphery (110a) of the cover member (110).

[0154] <Other embodiments> The tubular member (103) may extend downward from a position on the inner circumferential side of the outer circumferential portion (110a) of the cover member (110).

[0155] The compressor (10) does not have to be applied to the refrigeration system (1) and may be used, for example, to compress a fluid other than a refrigerant, such as air.

[0156] Although the embodiments have been described above, it will be understood that various modifications of form and details are possible without departing from the spirit and scope of the claims. Elements of the above-mentioned embodiments, modifications, and other embodiments may be appropriately combined or substituted. [Explanation of symbols]

[0157] Z-axis direction (vertical direction) Z1 upper Z2 downward R Radial direction R1 Inner circumference R2 outer circumference side T circumferential direction L Lubricating oil G Exhaust gas U 1st space V space d Distance h distance D1 Outer diameter D2 Inner diameter D3 Outer diameter π pi S cross-sectional area M total cross-sectional area n Number B cross-sectional area h / d expansion ratio E Oil rise rate 1 Refrigeration equipment 10 Compressor 20 Casing 20a lower bottom 26 Discharge pipe 27 Oil Reservoir 30 Compression Mechanism 31 Fixed Scroll 35 Movable Scroll 40 Drive shaft 41 Main shaft section 42 Eccentric shaft part 50 Housing 60 Balance weight 60b outer periphery 60c bottom end 60d bottom 70 Electric motor 71 Rotor 71a top end 71b Outer periphery 72 Stator 72c outer periphery 72d Core Cut 72e top end 73 Coil 75 First Gas Passage 75a Open end 76 Second Gas Passage 77 Third Gas Passage 78 4th Gas Passage 80 Lower bearing member 83 Oil separation plate 90 Oil Pump 100 Cover 101 Upper cover part 102 Outer cover part 103 Cylinder member 103a Bottom end 110 Lid member 120 Gap

Claims

1. A compression mechanism (30); A drive shaft (40); an electric motor (70) that rotates the drive shaft (40) to drive the compression mechanism (30); The drive shaft (40) extends in the vertical direction, The electric motor (70) includes a rotor (71) coupled to the drive shaft (40) and a stator (72) arranged radially outward of the rotor (71), The rotor (71) is provided with a first gas passageway (75) extending therethrough in the vertical direction, A cover member (110) and a cylindrical member (103) are disposed above the rotor (71), The cover member (110) has a plate shape facing an open end (75a) of the first gas passage (75) at an upper end (71a) of the rotor (71), the cylindrical member (103) extends downward from the cover member (110) on a more outer circumferential side than the first gas passage (75), a gap (120) extending in the circumferential direction of the cylindrical member (103) is formed between a lower end (103a) of the cylindrical member (103) and an upper end (71a) of the rotor (71); a first space (U) is formed which is surrounded by an upper end (71a) of the rotor (71), the cover member (110), and the cylindrical member (103) and which opens to an outer circumferential side through the gap (120), The drive shaft (40) is provided with a balance weight (60) and a cover (100) that covers an outer periphery (60b) of the balance weight (60), the cover (100) extends below a lower end (60c) of the balance weight (60), the tubular member (103) is a portion of the cover (100) that extends downward below a lower end (60c) of the balance weight (60), The cover member (110) is disposed below the balance weight (60), The lid member (110) divides the space inside the cover (100) in the vertical direction. Compressor.

2. A compression mechanism (30), A drive shaft (40); an electric motor (70) that rotates the drive shaft (40) to drive the compression mechanism (30); The drive shaft (40) extends in the vertical direction, The electric motor (70) includes a rotor (71) coupled to the drive shaft (40) and a stator (72) arranged radially outward of the rotor (71), The rotor (71) is provided with a first gas passageway (75) extending therethrough in the vertical direction, A cover member (110) and a cylindrical member (103) are disposed above the rotor (71), The cover member (110) has a plate shape facing an open end (75a) of the first gas passage (75) at an upper end (71a) of the rotor (71), the cylindrical member (103) extends downward from the cover member (110) on a more outer circumferential side than the first gas passage (75), a gap (120) extending in the circumferential direction of the cylindrical member (103) is formed between a lower end (103a) of the cylindrical member (103) and an upper end (71a) of the rotor (71); a first space (U) is formed which is surrounded by an upper end (71a) of the rotor (71), the cover member (110), and the cylindrical member (103) and which opens to an outer circumferential side through the gap (120), The drive shaft (40) is provided with a balance weight (60), The cover member (110) is disposed below the balance weight (60), the cover member (110) and the tubular member (103) are integral with each other; Compressor.

3. The cover member (110) is fixed to a lower surface (60d) of the balance weight (60). The compressor according to claim 1 or 2.

4. a casing (20) that houses the compression mechanism (30), the drive shaft (40), and the electric motor (70), A second gas passage (76) extending in the vertical direction is provided between an outer circumferential portion (72c) of the stator (72) and the casing (20). The compressor according to claim 1 or 2.

5. The stator (72) is provided with coils (73) arranged at intervals along the circumferential direction of the stator (72), A third gas passage (77) extending in the vertical direction is provided between the adjacent coils (73). The compressor according to claim 1 or 2.

6. an outer diameter (D1) of the cylindrical member (103) is equal to or smaller than an outer diameter (D3) of the rotor (71); The compressor according to claim 1 or 2.

7. a distance (h) between the cover member (110) and an upper end (71a) of the rotor (71) and a distance (d) between a lower end (103a) of the tubular member (103) and the upper end (71a) of the rotor (71) satisfy a relationship of d≦h / 3. The compressor according to claim 1 or 2.

8. a distance (d) between a lower end (103a) of the tubular member (103) and an upper end (71a) of the rotor (71), an inner diameter (D2) of the tubular member (103), a total cross-sectional area (M) of all the first gas passages (75), and pi (π) satisfy the relationship M / (π×D2)≦d. The compressor according to claim 1 or 2.

9. A refrigeration system comprising a compressor (10) according to claim 1 or 2.

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