JP2015055198A - Rotary fluid machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce rising of oil by devising the shape of a delivery pipe.SOLUTION: A second delivery pipe (17) extends in a radial direction so as to pass through a trunk (12) of a casing (11), and an inlet side end of the second delivery pipe (17) is bent toward the upper side, thereby allowing the inlet side of the second delivery pipe (17) to be opened upward. The inlet side end of the second delivery pipe (17) is also opened upward at a position overlapping with an axis as viewed from the axial direction of a drive shaft (23), and is located in the vicinity of the central axis of the trunk (12).

Description

  The present invention relates to a rotary fluid machine.

  2. Description of the Related Art Conventionally, rolling piston type and swing piston type rotary fluid machines in which a compression mechanism including a cylinder and a piston that rotates eccentrically with respect to the cylinder are accommodated in a casing are known (for example, patents). Reference 1).

  The rotary fluid machine of Patent Document 1 is a high-pressure dome type compressor in which a space in a casing becomes a high-pressure (discharge pressure). In a high-pressure dome type compressor, after the high-pressure gas compressed by the compression mechanism is filled in the casing and the inside of the casing becomes high-pressure, high-pressure gas is discharged from the discharge pipe connected to the casing to the outside of the machine. The In the rotary fluid machine of Patent Document 1, the discharge pipe is connected so as to penetrate the end plate portion at the upper part of the casing.

  However, if the motor wiring terminal is arranged at the upper part of the casing, the terminal and the discharge pipe may interfere with each other, and the discharge pipe may not be connected to the upper part of the casing. Therefore, it is conceivable to connect the discharge pipe so as to penetrate the body portion of the casing and extend the discharge pipe radially outward (see, for example, Patent Document 2).

JP 2011-074857 A JP 2012-2111569 A

  However, when the discharge pipe is connected so as to penetrate through the body of the casing as in the compressor of Patent Document 2, there is a possibility that oil rise will increase.

  Specifically, mist-like oil stays in the internal space of the casing together with the high-pressure gas. Here, the oil concentration in the high-pressure gas in the internal space is higher in the outer peripheral portion than in the central portion in the casing, and is higher in the lower position than in the upper position of the internal space. In the compressor of Patent Document 2, the end portion on the inlet side of the discharge pipe is located near the center portion in the casing, but the oil staying at the outer peripheral portion in the casing because it opens in the radial direction. A high-pressure gas with a high concentration will be sucked in and the oil rise will increase.

  This invention is made | formed in view of this point, The objective is to make it possible to reduce oil rising by devising the shape of a discharge pipe.

  The present invention provides an electric motor (20) having a stator (21) and a rotor (22) in a casing (11), and a drive shaft (23) connected to the rotor (22) of the electric motor (20). ) And a compression fluid mechanism (60) disposed below the electric motor (20) and compressing fluid as the drive shaft (23) is rotationally driven. The following solution was taken.

That is, in the first invention, the casing (11) communicates with the internal space (S2) above the electric motor (20) and is compressed by the compression mechanism (60) to be compressed into the internal space (S2). ) Is provided with a discharge pipe (17) for discharging the compressed fluid flowing into the casing (11) to the outside,
An end portion on the inlet side of the discharge pipe (17) is open upward at a position overlapping with the axis when viewed from the axial direction of the drive shaft (23).

  In the first invention, the end on the inlet side of the discharge pipe (17) communicating with the internal space (S2) is opened upward at a position overlapping the axis as viewed from the axial direction of the drive shaft (23). Yes. As a result, the compressed fluid having a low oil concentration staying in the center of the internal space (S2) can be sucked from the inlet side end of the discharge pipe (17) and discharged to the outside of the casing (11). , Oil rise can be reduced.

According to a second invention, in the first invention,
The end portion on the inlet side of the discharge pipe (17) is also opened downward at a position overlapping with the axis when viewed from the axial direction of the drive shaft (23).

  In the second invention, the end portion on the inlet side of the discharge pipe (17) is opened upward and downward at a position overlapping the axis when viewed from the axial direction of the drive shaft (23). As a result, oil rise can be reduced, and pressure loss when sucking in the compressed fluid can be reduced as compared with the case where the end portion on the inlet side of the discharge pipe (17) is opened only upward.

  Even when the compression mechanism (60) is stopped in a state where oil has entered the discharge pipe (17), the end of the discharge pipe (17) on the inlet side opens downward. (17) The internal oil is discharged from the downward opening, and the oil can be prevented from accumulating inside the discharge pipe (17).

  According to the present invention, the end on the inlet side of the discharge pipe (17) communicating with the internal space (S2) is opened upward at a position overlapping the axis as viewed from the axial direction of the drive shaft (23). Yes. As a result, the compressed fluid having a low oil concentration staying in the center of the internal space (S2) can be sucked from the inlet side end of the discharge pipe (17) and discharged to the outside of the casing (11). , Oil rise can be reduced.

FIG. 1 is a cross-sectional view illustrating a longitudinal section of the compressor according to the first embodiment. FIG. 2 is a cross-sectional view showing a partially enlarged longitudinal section of the compressor according to the first embodiment. FIG. 3 is a cross-sectional view illustrating a longitudinal section of the compressor unit according to the first embodiment. 4 is a cross-sectional view showing a longitudinal section different from that of FIG. 3 of the compressor section of the first embodiment. FIG. 5 is a cross-sectional view of the first compression mechanism showing the EE cross section of FIG. 3. FIG. 6 is a cross section of the second compression mechanism showing the FF cross section of FIG. 3. FIG. 7 is a cross-sectional view showing a cross section (GG cross section of FIG. 3) of the compressor of the first embodiment. FIG. 8 is a cross-sectional view of the first compression mechanism according to the first embodiment, and shows a state every time the rotation angle of the drive shaft changes by 90 °. FIG. 9 is a view corresponding to FIG. 2 showing a modification of the first embodiment. FIG. 10 is a view corresponding to FIG. 2 showing another modification of the first embodiment. FIG. 11 is a cross-sectional view illustrating a partially enlarged vertical cross section of the compressor according to the second embodiment. FIG. 12 is a view corresponding to FIG. 11 showing a modification of the second embodiment. FIG. 13 is a view corresponding to FIG. 11 showing another modification of the second embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature and is not intended to limit the present invention, its application, or its use.

Embodiment 1
A first embodiment of the present invention will be described. The compressor (10) of the present embodiment, which is a rotary fluid machine, is provided in a refrigerant circuit that performs a refrigeration cycle, and sucks and compresses refrigerant circulating in the refrigerant circuit.

-Overall configuration of compressor-
As shown in FIG. 1, the compressor (10) includes a sealed container-like casing (11). The casing (11) includes an upright cylindrical body portion (12) and a pair of end plate portions (13) formed in a thick disc shape. In the casing (11), one end plate portion (13) is arranged at each end portion of the trunk portion (12), and the end portion of the trunk portion (12) is closed by the end plate portion (13).

  A terminal (18) is attached to the center position of the upper end plate (13). The terminal (18) includes a terminal pin (18a) for wiring the electric motor (20) and a terminal block (18b) for attaching the terminal pin (18a) to the end plate portion (13).

  Both end portions of the terminal pin (18a) penetrate the upper end plate portion (13) in the vertical direction and project inward and outward of the casing (11), respectively. The end of the terminal pin (18a) on the inner side of the casing (11) is connected to the stator (21) of the electric motor (20) by a lead wire (19). Electrical wiring (not shown) is connected to the end of the terminal pin (18a) on the outer side of the casing (11).

  An electric motor (20) and a compressor unit (30) are accommodated in the casing (11). The compressor part (30) is disposed below the electric motor (20). The electric motor (20) and the compressor unit (30) are connected by a drive shaft (23). The compressor section (30) includes a first compression mechanism (40) on the lower stage side and a second compression mechanism (60) on the higher stage side.

  The body (12) of the casing (11) is provided with a first suction pipe (14), a first discharge pipe (15), a second suction pipe (16), and a second discharge pipe (17). . These suction pipes (14, 16) and discharge pipes (15, 17) pass through the body (12). The first suction pipe (14) and the first discharge pipe (15) are connected to the first compression mechanism (40). The second suction pipe (16) is connected to the second compression mechanism (60). Although not shown, the first discharge pipe (15) and the second suction pipe (16) are connected via a pipe.

  In the compressor (10) of the present embodiment, the refrigerant compressed in the second compression mechanism (60) on the higher stage side is discharged into the internal space of the casing (11), and the casing is passed through the second discharge pipe (17). (11) It is configured to be discharged to the outside. That is, the compressor (10) is a high-pressure dome type compressor in which the pressure in the internal space of the casing (11) is substantially equal to the discharge pressure of the compressor (10).

  As shown in FIG. 2, the second discharge pipe (17) communicates with the secondary space (S2), which is the portion above the electric motor (20) in the internal space of the casing (11). In the secondary space (S2), mist-like oil stays with the high-pressure refrigerant.

  Here, the hatching in the secondary space (S2) in FIG. 2 indicates the distribution of the oil concentration in the high-pressure refrigerant. Specifically, it shows that the oil concentration is higher in the region where the hatching interval is narrower and the oil concentration is lower in the region where the hatching interval is wider. That is, it can be seen that the oil concentration is the lowest in the central portion of the secondary space (S2), and the oil concentration is the highest in the lower position of the outer peripheral portion of the secondary space (S2).

  Therefore, in the present embodiment, the oil discharge can be reduced by devising the shape of the second discharge pipe (17). Specifically, the second discharge pipe (17) extends in the radial direction so as to pass through the body (12) of the casing (11), and the end on the inlet side is bent upward, whereby the second discharge pipe (17) The inlet side of the pipe (17) opens upward.

  Further, the end of the second discharge pipe (17) on the inlet side is opened upward at a position overlapping the axis when viewed from the axial direction of the drive shaft (23), and the central axis of the trunk portion (12) Located in the vicinity.

  With such a configuration, the high pressure refrigerant having a low oil concentration staying in the central portion of the secondary space (S2) is sucked from the end portion on the inlet side of the second discharge pipe (17), and the casing (11) Since the oil can be discharged to the outside, oil rise can be reduced.

  Inside the casing (11), a drive shaft (23) is provided along the axial direction of the body (12). The drive shaft (23) connects the electric motor (20) and the compressor unit (30). In addition, lubricating oil (refrigerating machine oil) for supplying each sliding part of the compressor part (30) is stored in the bottom part of the airtight container-shaped casing (11).

  The drive shaft (23), which is a crankshaft, includes a main shaft portion (24) and two eccentric portions (25, 26). The two eccentric parts (25, 26) are arranged side by side in the axial direction of the main shaft part (24). Among these two eccentric parts (25, 26), the upper part is the upper eccentric part (25), and the lower part is the lower eccentric part (26). Each of these two eccentric portions (25, 26) is formed in a cylindrical shape having a larger diameter than the main shaft portion (24), and the respective shaft centers are eccentric with respect to the shaft center of the main shaft portion (24). Yes. Further, the eccentric direction of the upper eccentric portion (25) and the eccentric direction of the lower eccentric portion (26) are shifted from each other by 180 ° about the axis of the main shaft portion (24).

  An oil suction pipe (28) projects from the lower end of the drive shaft (23). The lower end of the oil suction pipe (28) is immersed in the lubricating oil stored at the bottom of the casing (11). Although not shown, an oil supply passage connected to the oil suction pipe (28) is formed inside the drive shaft (23). The lubricating oil sucked into the oil suction pipe (28) by the centrifugal pump action is supplied to the sliding portion of each compression mechanism (40, 60) through the oil supply passage.

  The electric motor (20) includes a stator (21) and a rotor (22). The stator (21) is fixed to the body (12) of the casing (11). On the other hand, the rotor (22) is arranged inside the stator (21) and is connected to the main shaft portion (24) of the drive shaft (23).

  A core cut (21a) is formed in the stator (21) by cutting out a part of its outer peripheral portion. In the internal space of the casing (11), the upper part and the lower part of the electric motor (20) communicate with each other via the core cut (21a).

  As shown in FIGS. 3 and 7, an oil return guide (85) is provided in the primary space (S1), which is a portion between the compressor section (30) and the electric motor (20), in the internal space of the casing (11). ) And an oil scattering prevention cover (86). Moreover, as shown in FIG. 1, the oil return guide (87) is arrange | positioned in the secondary space (S2) which is a part above an electric motor (20) among the internal space of a casing (11). The oil return guide (85) and oil splash prevention cover (86) in the primary space (S1) and the oil return guide (87) in the secondary space (S2) are both the body (12) of the casing (11). Is attached.

  The oil scattering prevention cover (86) is disposed below the core cut (21a) formed between the stator (21) and the casing (11). The oil scattering prevention cover (86) is a member having a shape covering the inner peripheral surface of the body (12) of the casing (11), and forms an oil passage with the body (12).

  Here, the rotor (22) of the electric motor (20) rotates clockwise in FIG. For this reason, in the primary space (S1) and the secondary space (S2), the refrigerant flows so as to rotate in the same direction as the rotation direction of the rotor (22). That is, in the primary space (S1) and the secondary space (S2), a swirl flow having the same direction as the rotation direction of the rotor (22) is generated.

  The oil return guides (85, 87) of the primary space (S1) and the secondary space (S2) are members having a shape that covers the inner peripheral surface of the body (12) of the casing (11). These oil return guides (85, 87) are configured to capture the oil droplets contained in the swirling flow and guide them downward.

−Compressor configuration−
The detailed configuration of the compressor section (30) will be described with reference to FIGS.

  As shown in FIGS. 3 and 4, the compressor section (30) includes a first compression mechanism (40) and a second compression mechanism (60). A middle plate (31) is sandwiched between the compression mechanisms (40, 60). Further, both the compression mechanisms (40, 60) and the middle plate (31) are fixed to the casing (11) via the mounting plate (35).

<First compression mechanism>
As shown in FIGS. 3 and 4, the first compression mechanism (40) includes a rear head (41), a first cylinder (51), a first piston (52), and a first blade (54). ing. The first cylinder (51) is formed integrally with the rear head (41). Further, the first piston (52) rotates eccentrically relative to the first cylinder (51).

  The rear head (41) includes a thick plate-like cylinder side end plate portion (42). A support through hole (43) is formed at the center of the rear head (41). The supporting through hole (43) is a hole having a circular cross section, and penetrates the rear head (41) in the thickness direction (vertical direction in FIG. 3). That is, the support through-hole (43) opens in the front surface (44) (upper surface in FIG. 3) and the rear surface (lower surface in FIG. 3) of the rear head (41).

  A cylindrical bearing metal (47) is press-fitted into the support through hole (43) of the rear head (41). A portion of the main shaft portion (24) of the drive shaft (23) located below the lower eccentric portion (26) is inserted through the bearing metal (47). The rear head (41), which is a bearing member, constitutes a sliding bearing that supports the drive shaft (23).

  An annular protrusion (43a) is formed on the rear head (41). The annular protrusion (43a) is an annular protrusion extending in the circumferential direction of the wall surface of the support through hole (43), and is disposed near the upper end of the support through hole (43). When the upper end of the bearing metal (47) hits the lower end of the annular protrusion (43a), the upward movement of the bearing metal (47) is blocked by the annular protrusion (43a).

  As shown in FIGS. 3 and 4, the rear head (41) has an annular groove (45). The annular groove (45) is an annular groove that opens to the front surface (44) of the rear head (41) and surrounds the opening of the support through hole (43) in the front surface (44) of the rear head (41). Are arranged as follows. The rear head (41) is formed with an oil discharge passage (49a) for discharging the refrigerating machine oil from the annular groove (45).

  A first suction passage (14a) is formed in the rear head (41). One end of the first suction passage (14a) opens on the outer peripheral surface of the cylinder side end plate portion (42), and the other end opens on the front surface (44) of the cylinder side end plate portion (42). A first suction pipe (14) is inserted into one end of the first suction passage (14a). The opening of the first suction passage (14a) in the front surface (44) of the cylinder side end plate portion (42) is a suction port (56). The position of the suction port (56) will be described later.

  A rear side recess (46) is formed in the rear head (41). The back-side recess (46) is a recess that opens to the back surface (lower surface in FIGS. 3 and 4) of the cylinder-side end plate portion (42). The first discharge pipe (15) communicates with the back side recess (46). A bottom plate (34) is attached to the rear head (41). The bottom plate (34) is a disk-shaped member and is provided so as to cover the back surface of the cylinder side end plate portion (42). The back side recess (46) that opens to the back side of the cylinder side end plate part (42) is closed by the bottom plate (34).

  Two discharge passages (15a, 15b) are formed in the rear head (41). Each discharge passage (15a, 15b) is a through-hole penetrating the cylinder side end plate portion (42) in the thickness direction. One end of each discharge passage (15a, 15b) opens to the front surface (44) of the cylinder-side end plate portion (42), and the other end opens to the bottom surface of the back-side recess (46). The opening of the inner discharge passage (15a) in the front surface (44) of the cylinder side end plate portion (42) is an inner discharge port (57a). An opening portion of the outer discharge passage (15b) in the front surface (44) of the cylinder side end plate portion (42) is an outer discharge port (57b). The positions of the inner discharge port (57a) and the outer discharge port (57b) will be described later.

  As shown in FIG. 4, the rear head (41) is provided with two discharge valves (58a, 58b). Each discharge valve (58a, 58b) is a so-called reed valve, and is installed on the bottom surface of the back side recess (46) of the cylinder side end plate part (42). The inner discharge valve (58a) is disposed so as to cover the opening of the inner discharge passage (15a) on the bottom surface of the back side recess (46), and opens and closes the inner discharge passage (15a). The outer discharge valve (58b) is disposed so as to cover the opening of the outer discharge passage (15b) on the bottom surface of the back side recess (46), and opens and closes the outer discharge passage (15b).

  The first cylinder (51) includes an inner cylinder part (51a) and an outer cylinder part (51b). The inner cylinder part (51a) and the outer cylinder part (51b) are formed integrally with the cylinder side end plate part (42) of the rear head (41), and the front side (44) (the upper surface in FIG. 3) of the cylinder side end plate part (42). ) Projecting upward.

  As shown also in FIG. 5, the inner cylinder part (51a) is formed in a short cylindrical shape, and is disposed so as to surround the circumference of the annular groove (45). The outer cylinder part (51b) is disposed so as to surround the inner cylinder part (51a). The inner peripheral surface of the outer cylinder portion (51b) is a cylindrical surface that faces the outer peripheral surface of the inner cylinder portion (51a).

  The first piston (52) includes a piston side end plate portion (52a), a piston main body (52b), and a bearing portion (52c). The bearing portion (52c) is formed in a short cylindrical shape. In the first piston (52), the bearing metal (53) is press-fitted into the bearing portion (52c), and the lower eccentric portion (26) of the drive shaft (23) is inserted through the bearing metal (53). The piston side end plate portion (52a) is a flat plate-like portion continuous with one end portion (the upper end portion in FIG. 3) of the bearing portion (52c), and is formed in a donut plate shape extending outward from the bearing portion (52c). Has been. The piston body (52b) is formed in a short cylindrical shape surrounding the periphery of the bearing portion (52c), and protrudes downward from the front surface (lower surface in FIG. 3) of the piston-side end plate portion (52a).

  Moreover, the piston main body (52b) is formed in a shape divided at one place in the circumferential direction. A pair of bush holding portions (59) for holding a pair of first swing bushes (55) to be described later are provided at both ends of the dividing portion.

  In the first piston (52), the front surface (lower surface in FIG. 3) of the piston-side end plate portion (52a) faces the front surface (44) of the cylinder-side end plate portion (42), and the piston body (52b) is connected to the inner cylinder portion (51a ) And the outer cylinder part (51b). Further, the first piston (52) is configured such that a portion between the bearing portion (52c) and the piston main body (52b) in the front surface of the piston side end plate portion (52a) is a protruding end surface of the inner cylinder portion (51a) (in FIG. 3). The upper part of the piston side end plate part (52a) and the part outside the piston body (52b) slide with the projecting end face (upper end face in FIG. 3) of the outer cylinder part (51b). The protruding end surface (lower end surface in FIG. 3) of the piston body (52b) slides on the front surface (44) of the cylinder side end plate portion (42) between the inner cylinder portion (51a) and the outer cylinder portion (51b). Move.

  In the first compression mechanism (40), an outer fluid chamber (S11) and an inner fluid chamber (S12) are formed by the first cylinder (51) and the first piston (52). Specifically, in the first compression mechanism (40), an outer fluid chamber (S11) is formed between the piston body (52b) and the outer cylinder part (51b), and the piston body (52b) and the inner cylinder part (51a). An inner fluid chamber (S12) is formed between the two.

  The first blade (54) is a flat plate-like portion extending in the radial direction of the inner cylinder part (51a), and extends from the outer peripheral surface of the inner cylinder part (51a) to the inner peripheral surface of the outer cylinder part (51b). Is formed. The first blade (54) protrudes from the front surface (44) of the cylinder side end plate portion (42). The first blade (54) is formed integrally with the cylinder side end plate part (42), the inner cylinder part (51a), and the outer cylinder part (51b). The first blade (54) enters the dividing portion of the piston body (52b), and the outer fluid chamber (S11) and the inner fluid chamber (S12) are respectively connected to the low pressure chamber (S11L, S12L, S21L, S22L) and the high pressure chamber. Partition (S11H, S12H, S21H, S22H).

  The first compression mechanism (40) includes a pair of first swing bushes (55). The first rocking bush (55) is provided on each of the right and left sides of the first blade (54) in FIG. 5, and the bush holding portions provided at both ends of the dividing portion of the piston body (52b). (59). A curved sliding contact surface is formed on the end surface of the bush holding portion (59).

  Each first swing bush (55) is formed with a flat surface in sliding contact with the first blade (54) and an arc surface located on the opposite side of the flat surface. The arc surface of the first swing bush (55) is in sliding contact with the sliding contact surface of the bush holding portion (59).

  The suction port (56) is disposed on the right side of the first blade (54) in FIG. 5 and communicates with both the outer fluid chamber (S11) and the inner fluid chamber (S12). That is, the suction port (56) communicates with the low pressure chambers (S11L, S12L, S21L, S22L) of the outer fluid chamber (S11) and the inner fluid chamber (S12). On the other hand, the inner discharge port (57a) and the outer discharge port (57b) are arranged on the left side of the first blade (54). The inner discharge port (57a) communicates with the high pressure chamber (S12H) of the inner fluid chamber (S12), and the outer discharge port (57b) communicates with the high pressure chamber (S11H) of the outer fluid chamber (S11).

  In the first compression mechanism (40), the outer peripheral surface of the piston main body (52b) and the inner peripheral surface of the outer cylinder part (51b) are in sliding contact with each other in one circumferential direction, and the inner peripheral surface of the piston main body (52b) The outer peripheral surfaces of the inner cylinder part (51a) are in sliding contact with each other in one circumferential direction. The sliding contact location between the outer peripheral surface of the piston body (52b) and the inner peripheral surface of the outer cylinder portion (51b), and the sliding contact location between the inner peripheral surface of the piston main body (52b) and the outer peripheral surface of the inner cylinder portion (51a) are: It is located on the opposite side across the axis of the main shaft (24).

<Second compression mechanism>
As shown in FIGS. 3 and 4, the second compression mechanism (60) includes a front head (61), a second cylinder (71), a second piston (72), and a second blade (74). I have. The second cylinder (71) is formed integrally with the front head (61). The second piston (72) rotates eccentrically relative to the second cylinder (71).

  The front head (61) includes a thick plate-like cylinder side end plate portion (62). A cylindrical tubular protrusion (62a) is integrally formed on the cylinder side end plate portion (62). The cylindrical protrusion (62a) is disposed at the center of the cylinder side end plate part (62) and protrudes upward from the back surface (upper surface in FIG. 3) of the cylinder side end plate part (62). A support through hole (63) is formed at the center of the front head (61). The supporting through hole (63) is a hole having a circular cross section, and penetrates the front head (61) in the thickness direction (vertical direction in FIG. 3). That is, one end of the support through hole (63) opens to the projecting end surface of the cylindrical projection (62a), and the other end opens to the front surface (64) (lower surface in FIG. 3) of the cylinder side end plate portion (62). To do.

  A cylindrical bearing metal (67) is press-fitted into the support through hole (63) of the front head (61). A portion of the main shaft portion (24) of the drive shaft (23) located above the upper eccentric portion (25) is inserted through the bearing metal (67). The front head (61) that is a bearing member constitutes a sliding bearing that supports the drive shaft (23).

  An annular protrusion (63a) is formed on the front head (61). The annular protrusion (63a) is an annular protrusion extending in the circumferential direction of the wall surface of the support through hole (63), and is disposed near the lower end of the support through hole (63). When the lower end of the bearing metal (67) hits the upper end of the annular protrusion (63a), the downward movement of the bearing metal (67) is prevented by the annular protrusion (63a).

  As shown in FIGS. 3 and 4, the front head (61) is formed with an annular groove (65). The annular groove (65) is an annular groove that opens to the front surface (64) of the front head (61), and is an opening portion of the support through hole (63) in the front surface (64) of the front head (61). It is arranged to surround. Although not shown, the front head (61) is formed with an oil discharge passage for discharging the refrigerating machine oil from the annular groove (65).

  A second suction passage (16a) is formed in the front head (61). One end of the second suction passage (16a) opens in the outer peripheral surface of the cylinder side end plate part (62), and the other end opens in the front surface (64) of the cylinder side end plate part (62). A second suction pipe (16) is inserted into one end of the second suction passage (16a). The opening of the second suction passage (16a) in the front surface (64) of the cylinder side end plate portion (62) is a suction port (76). The position of the suction port (76) will be described later.

  The front head (61) is formed with a back side recess (66). The back-side recess (66) is a recess that opens to the back surface (upper surface in FIG. 4) of the cylinder-side end plate portion (62). The back side recess (66) is closed by a mounting plate (35) installed so as to cover the back side of the cylinder side end plate part (62). The mounting plate (35) will be described later.

  Two discharge passages (17a, 17b) are formed in the front head (61). Each discharge passage (17a, 17b) is a through-hole penetrating the cylinder side end plate portion (62) in the thickness direction. One end of each discharge passage (17a, 17b) opens to the front surface (64) of the cylinder-side end plate portion (62), and the other end opens to the bottom surface of the back-side recess (66). The opening of the inner discharge passage (17a) in the front surface (64) of the cylinder side end plate portion (62) is an inner discharge port (77a). An opening of the outer discharge passage (17b) in the front surface (64) of the cylinder side end plate portion (62) is an outer discharge port (77b). The positions of the inner discharge port (77a) and the outer discharge port (77b) will be described later.

  The front head (61) is provided with two discharge valves (78a, 78b). Each discharge valve (78a, 78b) is a so-called reed valve, and is installed on the bottom surface of the back side recess (66) of the cylinder side end plate part (62). The inner discharge valve (78a) is disposed so as to cover the opening of the inner discharge passage (17a) on the bottom surface of the back side recess (66), and opens and closes the inner discharge passage (17a). The outer discharge valve (78b) is disposed so as to cover the opening of the outer discharge passage (17b) on the bottom surface of the back side recess (66), and opens and closes the outer discharge passage (17b).

  The second cylinder (71) is composed of an inner cylinder part (71a) and an outer cylinder part (71b). The inner cylinder part (71a) and the outer cylinder part (71b) are formed integrally with the cylinder side end plate part (62) of the front head (61) and project downward from the front surface (64) of the cylinder side end plate part (62). ing.

  As shown also in FIG. 6, the inner cylinder part (71a) is formed in a short cylindrical shape and is disposed so as to surround the circumference of the annular groove (65). The outer cylinder portion (71b) is disposed so as to surround the inner cylinder portion (71a). The inner peripheral surface of the outer cylinder portion (71b) is a cylindrical surface that faces the outer peripheral surface of the inner cylinder portion (71a).

  The second piston (72) includes a piston side end plate portion (72a), a piston main body (72b), and a bearing portion (72c). The bearing portion (72c) is formed in a short cylindrical shape. In the second piston (72), the bearing metal (73) is press-fitted into the bearing portion (72c), and the upper eccentric portion (25) of the drive shaft (23) is inserted into the bearing metal (73). The piston side end plate portion (72a) is a flat plate-like portion continuous to one end portion (lower end portion in FIG. 3) of the bearing portion (72c), and is formed in a donut plate shape extending outward from the bearing portion (72c). Has been. The piston main body (72b) is formed in a short cylindrical shape surrounding the bearing portion (72c), and protrudes upward from the front surface (upper surface in FIG. 3) of the piston side end plate portion (72a).

  Moreover, the piston main body (72b) is formed in the shape divided at one place in the circumferential direction. A pair of bush holding portions (79) for holding a pair of second swing bushes (75) to be described later are provided at both ends of the dividing portion.

  A concave groove (72e) is formed on the protruding end surface (upper surface in FIG. 3) of the piston main body (72b). The concave groove (72e) is an arc-shaped groove extending in the circumferential direction of the piston body (72b). The concave groove (72e) is disposed at the center in the width direction (radial direction) of the protruding end surface of the piston main body (72b). Most of the concave groove (72e) is located on the right side in FIG. 6 of the protruding end surface of the piston main body (72b). Even if the second piston (72) moves, one end of the groove (72e) always communicates with the suction port (76).

  In the second piston (72), the front surface (upper surface in FIG. 3) of the piston side end plate portion (72a) faces the front surface (64) of the cylinder side end plate portion (62), and the piston main body (72b) is connected to the inner cylinder portion (71a). ) And the outer cylinder (71b). Further, the second piston (72) is configured such that the portion between the bearing portion (72c) and the piston body (72b) in the front surface of the piston side end plate portion (72a) is the protruding end surface of the inner cylinder portion (71a) (in FIG. 3). The lower end surface of the piston side end plate portion (72a) slides on the outer surface of the piston body (72b) with the protruding end surface (lower end surface in FIG. 3) of the outer cylinder portion (71b). The protruding end surface (upper end surface in FIG. 3) of the piston body (72b) slides on the portion between the inner cylinder portion (71a) and the outer cylinder portion (71b) of the front surface (64) of the cylinder side end plate portion (62). Move.

  In the second compression mechanism (60), an outer fluid chamber (S21) and an inner fluid chamber (S22) are formed by the second cylinder (71) and the second piston (72). Specifically, in the second compression mechanism (60), an outer fluid chamber (S21) is formed between the piston body (72b) and the outer cylinder part (71b), and the piston body (72b) and the inner cylinder part (71a). An inner fluid chamber (S22) is formed between the two.

  The second blade (74) is a flat plate-like portion extending in the radial direction of the inner cylinder portion (71a), and extends from the outer peripheral surface of the inner cylinder portion (71a) to the inner peripheral surface of the outer cylinder portion (71b). Is formed. The second blade (74) protrudes from the front surface (64) of the cylinder side end plate portion (62). The second blade (74) is formed integrally with the cylinder side end plate part (62), the inner cylinder part (71a), and the outer cylinder part (71b). The second blade (74) enters the dividing portion of the piston main body (72b), and separates the outer fluid chamber (S21) and the inner fluid chamber (S22) into the low pressure chamber (S21L, S22L) and the high pressure chamber (S21H, S22H). ).

  The second compression mechanism (60) includes a pair of second swing bushes (75). One second swing bush (75) is provided on each of the right and left sides of the second blade (74) in FIG. 6, and the bush holding portions are provided at both ends of the dividing portion of the piston body (72b). (79). A curved sliding contact surface is formed on the end surface of the bush holding portion (79).

 Each second swing bush (75) is formed with a flat surface that is in sliding contact with the second blade (74) and an arc surface located on the opposite side of the flat surface. The arc surface of the second swing bush (75) is in sliding contact with the sliding contact surface of the bush holding portion (79).

  The suction port (76) is disposed on the right side of the second blade (74) in FIG. 6 and communicates with both the outer fluid chamber (S21) and the inner fluid chamber (S22). That is, the suction port (76) communicates with the low pressure chambers (S21L, S22L) of the outer fluid chamber (S21) and the inner fluid chamber (S22). On the other hand, the inner discharge port (77a) and the outer discharge port (77b) are arranged on the left side of the second blade (74). The inner discharge port (77a) communicates with the high pressure chamber (S22H) of the inner fluid chamber (S22), and the outer discharge port (77b) communicates with the high pressure chamber (S21H) of the outer fluid chamber (S21).

  In the second compression mechanism (60), the outer peripheral surface of the piston main body (72b) and the inner peripheral surface of the outer cylinder part (71b) are in sliding contact with each other in one circumferential direction, and the inner peripheral surface of the piston main body (72b) The outer peripheral surfaces of the inner cylinder part (71a) are in sliding contact with each other in one circumferential direction. The sliding contact points between the outer peripheral surface of the piston main body (72b) and the inner peripheral surface of the outer cylinder part (71b), and the sliding contact points between the inner peripheral surface of the piston main body (72b) and the outer peripheral surface of the inner cylinder part (71a) are: It is located on the opposite side across the axis of the main shaft (24).

<Middle plate>
As shown in FIG. 3, the middle plate (31) includes a disk-shaped flat plate portion (31b) and a cylindrical tube portion (31a) formed so as to surround the flat plate portion (31b). ing.

  The cylinder portion (31a) is sandwiched between an outer cylinder portion (51b) integral with the rear head (41) and an outer cylinder portion (71b) integral with the front head (61). That is, in FIG. 3, the lower end surface of the cylindrical portion (31a) is in close contact with the protruding end surface of the outer cylinder portion (51b), and the upper end surface of the cylindrical portion (31a) is in close contact with the protruding end surface of the outer cylinder portion (71b).

  The flat plate portion (31b) is sandwiched between the piston side end plate portion (52a) of the first piston (52) and the piston side end plate portion (72a) of the second piston (72). The lower surface in FIG. 3 faces the back surface of the piston-side end plate portion (52a) of the first piston (52), and the upper surface in FIG. 3 is the piston-side end plate portion (72a) of the second piston (72). ) Face the back. A through hole (31c) that penetrates the flat plate portion (31b) in the thickness direction is formed in the central portion of the flat plate portion (31b). A portion between the upper eccentric portion (25) and the lower eccentric portion (26) of the drive shaft (23) is inserted through the through hole (31c).

  The flat plate portion (31b) of the middle plate (31) is provided with a first seal ring (32a) and a second seal ring (32b) on a surface on the first piston (52) side, and on the second piston (72) side. A third seal ring (32c) is provided on the surface. These seal rings (32a to 32c) are arranged so as to surround the periphery of the through hole (31c), and are fitted into an annular groove formed in the flat plate portion (31b). The first seal ring (32a) is disposed so as to surround the second seal ring (32b). The first seal ring (32a) and the second seal ring (32b) are in contact with the back surface of the piston side end plate portion (52a) of the first piston (52). The third seal ring (32c) is in contact with the back surface of the piston side end plate portion (72a) of the second piston (72).

<Mounting plate>
As shown in FIGS. 3 and 7, the mounting plate (35) is a dish-like member having a disc part (36) and a peripheral part (37). The disc part (36) is formed in a flat disc shape. The peripheral part (37) is a cylindrical part formed continuously from the peripheral part of the disc part (36). The outer peripheral surface of the peripheral edge portion (37) is in close contact with the inner peripheral surface of the trunk portion (12) of the casing (11). Moreover, the peripheral part (37) of the mounting plate (35) is joined to the body part (12) of the casing (11) by welding.

  The first compression mechanism (40), the second compression mechanism (60), the middle plate (31), and the bottom plate (34) are fastened to the mounting plate (35) by three bolts (80). Has been. As shown in FIG. 7, these three bolts (80) are arranged at substantially equal angular intervals in the circumferential direction of the disc portion (36) of the mounting plate (35). Each bolt (80) includes a disc part (36) of the mounting plate (35), a cylinder side end part (62) of the front head (61), a flat part (31b) of the middle plate (31), and a rear head. It penetrates through the cylinder end plate (42) of (41). Further, the male thread portion of each bolt (80) meshes with the female thread formed on the bottom plate (34). The number of bolts (80) shown here is merely an example.

  As shown in FIG. 4, the mounting plate (35) has a communication through hole (36 a) formed at the center of the disc part (36). The communication through hole (36a) is a relatively large-diameter hole that penetrates the disk portion (36) in the thickness direction. The cylindrical projection (62a) of the front head (61) is inserted through the communication through hole (36a). The diameter of the communication through hole (36a) is larger than the outer diameter of the cylindrical protrusion (62a). Accordingly, a gap is formed between the peripheral edge of the communication through hole (36a) and the cylindrical protrusion (62a), and the back side recess (66) of the front head (61) is connected to the mounting plate ( It communicates with the space above the disc part (36) of 35).

<Demister material>
As shown in FIGS. 3 and 4, the demister member (81) is placed on the disc portion (36) of the mounting plate (35). The demister member (81) is fixed to the mounting plate (35) by a fixing member (82).

  The demister member (81) is a member obtained by molding a metal mesh into a cylindrical shape, and is disposed so as to surround the communication through hole (36a) of the disk portion (36). As shown in FIG. 7, the fixing member (82) includes a lid (82a) that covers the upper surface of the demister member (81) and three legs (82b) that extend downward from the periphery of the lid (82a). ). The three legs (82b) are arranged at substantially equal angular intervals in the circumferential direction of the lid (82a). In the fixing member (82), the lower end portion of each leg portion (82b) is fixed to the disc portion (36) of the mounting plate (35). The drive shaft (23) passes through the central portion of the lid portion (82a) of the fixing member (82).

-Driving action-
The operation of the compressor (10) will be described.

  First, the overall operation of the compressor (10) will be described with reference to FIG. When the electric motor (20) is energized, the drive shaft (23) rotates and the pistons (52, 72) of the compression mechanism (40, 60) are driven by the drive shaft (23).

  The refrigerant evaporated by the evaporator of the refrigerant circuit is drawn into the first suction pipe (14) of the compressor (10). The low pressure refrigerant flowing into the first suction pipe (14) is sucked into the outer fluid chamber (S11) and the inner fluid chamber (S12) of the first compression mechanism (40) and compressed. The refrigerant compressed in each fluid chamber (S11, S12) is discharged to the back side recess (46) formed in the rear head (41). The refrigerant discharged from the first compression mechanism (40) once flows out of the casing (11) through the first discharge pipe (15), and is mixed with the intermediate pressure refrigerant supplied from the injection pipe (not shown). Then, it flows into the second suction passage (16a) through the second suction pipe (16).

  The refrigerant flowing into the second suction passage (16a) is sucked into the outer fluid chamber (S21) and the inner fluid chamber (S22) of the second compression mechanism (60) and further compressed. The refrigerant compressed in each fluid chamber (S21, S22) is discharged to the back side recess (66) of the front head (61). The refrigerant discharged from the second compression mechanism (60) sequentially passes through the primary space (S1) and the secondary space (S2) in the casing (11), and then passes through the second discharge pipe (17) to the casing. (11) will flow out.

  When the drive shaft (23) rotates, the lubricating oil stored in the bottom of the casing (11) is sucked into the oil suction pipe (28) and passes through the oil supply passage formed inside the drive shaft (23). And supplied to the sliding portion of the compressor section (30).

  Next, the operation of the compressor section (30) will be described with reference to FIG. Although the operation of the first compression mechanism (40) will be described here, the operation of the second compression mechanism (60) is basically the same as that of the first compression mechanism (40). In FIG. 8, the bearing metal (47) is not shown.

  In the first compression mechanism (40), the piston body (52b) of the first piston (52) reciprocates along the first blade (54) and swings. In the first compression mechanism (40), the piston body (52b) revolves while swinging with respect to the outer cylinder part (51b) and the inner cylinder part (51a), and the refrigerant is transferred to the fluid chambers (S11, S12). Inhaled and compressed.

  Specifically, the drive shaft (23) rotates clockwise from the state of FIG. 8 (A), and the contact position between the outer peripheral surface of the piston main body (52b) and the inner peripheral surface of the outer cylinder portion (51b) is determined. After passing through the suction port (56), low-pressure refrigerant starts to be sucked from the suction port (56) into the low-pressure chamber (S11L) of the outer fluid chamber (S11). Thereafter, when the drive shaft (23) rotates, the volume of the low-pressure chamber (S11L) increases (see FIGS. 8B, 8C, and 8D) and returns to the state of FIG. And the volume of the low pressure chamber (S11L) is maximized. While the volume of the low pressure chamber (S11L) is increasing, the low pressure refrigerant continues to be sucked from the suction port (56) into the low pressure chamber (S11L).

  On the other hand, the drive shaft (23) rotates in the clockwise direction in FIG. 8 (A), and the contact position between the outer peripheral surface of the piston body (52b) and the inner peripheral surface of the outer cylinder portion (51b) is the inlet. When passing through (56), the high pressure chamber (S11H) of the outer fluid chamber (S11) becomes a closed space blocked from the first suction passage (14a). Thereafter, when the drive shaft (23) rotates, the volume of the high pressure chamber (S11H) decreases (see FIGS. 8B, 8C, and 8D), and the refrigerant in the high pressure chamber (S11H) As a result, the refrigerant pressure in the high pressure chamber (S11H) rises.

  When the refrigerant pressure in the high pressure chamber (S11H) becomes slightly higher than the pressure in the back side recess (46), the outer discharge valve (58b) opens, and the refrigerant in the high pressure chamber (S11H) opens the outer discharge port (57b). It flows out to the back side recess (46). For example, if the outer discharge valve (58b) is opened in the state of FIG. 8C, then the refrigerant in the high pressure chamber (S11H) flows out through the outer discharge port (57b). Then, when returning to the state of FIG. 8A, the discharge of the refrigerant from the high pressure chamber (S11H) is completed.

  Further, the drive shaft (23) rotates in the clockwise direction in FIG. 8C from the state shown in FIG. 8C, and the contact position between the inner peripheral surface of the piston body (52b) and the outer peripheral surface of the inner cylinder part (51a) is the suction port. After passing (56), the low-pressure refrigerant starts to be sucked from the suction port (56) into the low-pressure chamber (S12L) of the inner fluid chamber (S12). Thereafter, when the drive shaft (23) rotates, the volume of the low-pressure chamber (S12L) increases (see FIGS. 8D, 8A, and 8B) and returns to the state of FIG. And the volume of the low pressure chamber (S12L) is maximized. While the volume of the low pressure chamber (S12L) is increasing, the low pressure refrigerant continues to be sucked from the suction port (56) into the low pressure chamber (S12L).

  On the other hand, the drive shaft (23) rotates in the clockwise direction in FIG. 8C, and the contact position between the inner peripheral surface of the piston main body (52b) and the outer peripheral surface of the inner cylinder portion (51a) is the suction port. When passing through (56), the high-pressure chamber (S12H) of the inner fluid chamber (S12) becomes a closed space blocked from the first suction passage (14a). Thereafter, when the drive shaft (23) rotates, the volume of the high pressure chamber (S12H) decreases (see FIGS. 8D, 8A, and 8B), and the refrigerant in the high pressure chamber (S12H) The refrigerant pressure in the high pressure chamber (S12H) rises as it is compressed.

  When the refrigerant pressure in the high-pressure chamber (S12H) becomes somewhat higher than the pressure in the back-side recess (46), the inner discharge valve (58a) opens and the refrigerant in the high-pressure chamber (S12H) passes through the inner discharge port (57a). It flows out to the back side recess (46). For example, if the inner discharge valve (58a) is opened in the state of FIG. 8B, then the refrigerant in the high pressure chamber (S12H) flows out through the inner discharge port (57a). Then, when returning to the state of FIG. 8C, the discharge of the refrigerant from the high pressure chamber (S12H) is completed.

  As described above, the operation of the second compression mechanism (60) is basically the same as that of the first compression mechanism (40). However, the eccentric directions of the upper eccentric portion (25) and the lower eccentric portion (26) of the drive shaft (23) are opposite to each other. Therefore, the rotational motion of the second piston (72) in the second compression mechanism (60) and the rotational motion of the first piston (52) in the first compression mechanism (40) are shifted from each other by 180 °. Yes. Accordingly, when the position of the first piston (52) of the first compression mechanism (40) is the position shown in FIG. 8 (A), the position of the second piston (72) of the second compression mechanism (60) is not illustrated. The position shown in FIG.

-Effect of Embodiment 1-
In the compressor (10) of the first embodiment, the end on the inlet side of the second discharge pipe (17) communicating with the secondary space (S2) is centered when viewed from the axial direction of the drive shaft (23). It is opened upward at the overlapping position. As a result, the high-pressure refrigerant with low oil concentration staying in the center of the secondary space (S2) is sucked from the end of the inlet side of the second discharge pipe (17) and discharged to the outside of the casing (11). Therefore, oil rise can be reduced.

-Modification of Embodiment 1-
In the first embodiment, the second discharge pipe (17) is extended in the radial direction so as to pass through the body (12) of the casing (11), but is not particularly limited to this form. That is, since the end on the inlet side of the second discharge pipe (17) only needs to open upward at a position overlapping the axial center when viewed from the axial direction of the drive shaft (23), the second discharge pipe ( The shape from the end on the inlet side to the end on the outlet side in 17) is not particularly limited.

  For example, as shown in FIG. 9, the second discharge pipe (17) is penetrated through the body (12) of the casing (11) while being inclined obliquely upward, and at the inlet side of the second discharge pipe (17). The end of the second discharge pipe (17) may be opened upward at a position that overlaps the axial center when viewed from the axial direction of the drive shaft (23).

  Further, as shown in FIG. 10, the second discharge pipe (17) extends vertically so as to penetrate the upper end plate (13) of the casing (11), and the end on the inlet side faces upward. By bending and forming in a J shape, the end on the inlet side of the second discharge pipe (17) may be opened upward at a position overlapping the axis as viewed from the axial direction of the drive shaft (23). . In this case, the terminal (18) is disposed at a position radially away from the center position of the end plate (13) of the casing (11), so that the second discharge pipe (17) and the terminal ( 18) should not interfere.

<< Embodiment 2 >>
FIG. 11 is a cross-sectional view illustrating a partially enlarged vertical cross section of the compressor according to the second embodiment. Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals, and only differences will be described.

  As shown in FIG. 11, the second discharge pipe (17) extends in the radial direction so as to pass through the body (12) of the casing (11) and extends in the vertical direction at the end on the inlet side. In this way, the inlet side of the second discharge pipe (17) opens upward and downward.

  In addition, the end portion on the inlet side of the second discharge pipe (17) opens upward and downward at a position overlapping with the axis when viewed from the axial direction of the drive shaft (23), and the trunk portion (12) It is located near the central axis.

-Effect of Embodiment 2-
In the compressor (10) of the second embodiment, the end on the inlet side of the second discharge pipe (17) communicating with the secondary space (S2) is centered when viewed from the axial direction of the drive shaft (23). Opening is performed upward and downward at overlapping positions. As a result, the high-pressure refrigerant with low oil concentration staying in the center of the secondary space (S2) is sucked from the end of the inlet side of the second discharge pipe (17) and discharged to the outside of the casing (11). Therefore, oil rise can be reduced. Moreover, pressure loss when sucking in the high-pressure refrigerant can be reduced as compared with the case where the end portion on the inlet side of the second discharge pipe (17) is opened only in the upward direction.

  Even when the compression mechanism (60) is stopped in a state where oil has entered the second discharge pipe (17), the inlet side end of the second discharge pipe (17) opens downward. Therefore, the oil inside the second discharge pipe (17) is discharged from the downward opening, and the oil can be prevented from collecting inside the second discharge pipe (17).

-Modification of Embodiment 2-
In the second embodiment, the second discharge pipe (17) is extended in the radial direction so as to pass through the body (12) of the casing (11). However, the present invention is not particularly limited to this form. In other words, the end portion on the inlet side of the second discharge pipe (17) only needs to open upward and downward at a position overlapping with the axis when viewed from the axial direction of the drive shaft (23). The shape from the end on the inlet side to the end on the outlet side of the discharge pipe (17) is not particularly limited.

  For example, as shown in FIG. 12, the second discharge pipe (17) is allowed to pass through the body (12) of the casing (11) while being inclined obliquely upward, and the inlet side of the second discharge pipe (17). By providing a cylindrical body extending in the vertical direction at the end portion of the second discharge pipe (17), the end portion on the inlet side of the second discharge pipe (17) is directed upward and at a position overlapping the axial center when viewed from the axial direction of the drive shaft (23). It may be opened downward.

  Further, as shown in FIG. 13, the second discharge pipe (17) is extended in the vertical direction so as to penetrate the upper end plate (13) of the casing (11) and the lower end is directed radially inward. The end of the second discharge pipe (17) on the inlet side at a position overlapping with the axis when viewed from the axial direction of the drive shaft (23) by providing a cylindrical body extending in the vertical direction at the end on the inlet side. The part may be opened upward and downward. In this case, the terminal (18) is disposed at a position radially away from the center position of the end plate (13) of the casing (11), so that the second discharge pipe (17) and the terminal ( 18) should not interfere.

<< Other Embodiments >>
The compressor (10) of each of the above embodiments is a two-stage compressor including two compression mechanisms (40, 60), but a single-stage compressor including only one compression mechanism is a rotary fluid according to the present invention. You may comprise with a machine.

  In each of the above embodiments, the compressor is constituted by the rotary fluid machine of the present invention, but the use of the rotary fluid machine is not limited to the compressor. That is, you may comprise the expander which generates motive power by expansion | swelling of a fluid with the rotary fluid machine of this invention.

  The compressor of each of the above embodiments is a general rotary fluid machine in which a cylindrical piston moves eccentrically (for example, a rolling piston type rotary fluid machine in which a piston and a blade are formed separately, a piston And a swinging piston type rotary fluid machine in which blades are integrally formed.

  As described above, the present invention is extremely useful and has industrial applicability because it has a highly practical effect that oil rise can be reduced by devising the shape of the discharge pipe. high.

10 Compressor (Rotary fluid machine)
11 Casing
17 Second discharge pipe
20 Electric motor
21 Stator
22 Rotor
23 Drive shaft
60 Second compression mechanism
S2 Secondary space (internal space)

Claims (2)

An electric motor (20) having a stator (21) and a rotor (22) in a casing (11), a drive shaft (23) connected to the rotor (22) of the electric motor (20), A rotary fluid machine disposed below the electric motor (20) and containing a compression mechanism (60) that compresses fluid in accordance with the rotational drive of the drive shaft (23);
The casing (11) communicates with the internal space (S2) above the electric motor (20), and is compressed by the compression mechanism (60) and flows into the internal space (S2). The casing (11) is provided with a discharge pipe (17) for discharging to the outside,
The rotary fluid machine is characterized in that the inlet side end of the discharge pipe (17) opens upward at a position overlapping the axis as viewed from the axial direction of the drive shaft (23). In claim 1,
The rotary fluid machine is characterized in that the inlet side end of the discharge pipe (17) is also opened downward at a position overlapping the axial center when viewed from the axial direction of the drive shaft (23).

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