JP2012097574A - Rotary compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly cool a bearing portion (32) for rotatably supporting a drive shaft (40) in the peripheral direction.SOLUTION: This rotary compressor includes a casing (11), a drive mechanism (50) stored in the casing, the drive shaft (40) connected to the drive mechanism (50), a compression mechanism (20) rotatingly driven by the drive shaft (40) to compress fluid, a housing portion (23) having the bearing portion (32) for rotatably supporting the drive shaft (40) and forming a bearing hole (23c) for inserting and fixing the bearing portion (32), and an oil supply mechanism (30) for supplying lubricating oil to a bearing clearance (27) between the drive shaft (40) and the bearing portion (32). Cooling grooves (28, 58, 68) for making the lubricating oil flow from the oil supply mechanism (30), are formed on an inner peripheral surface of the bearing hole (23c) of the housing portion (23) so as to cool the periphery of the bearing portion (32).

Description

  The present invention relates to a rotary compressor, and particularly relates to measures for heat dissipation of a sliding portion between a drive shaft that drives a compression mechanism of the rotary compressor and a bearing portion that supports the drive shaft.

  Conventionally, in a rotary compressor, a structure such as Patent Document 1 is known as a structure for continuously supplying lubricating oil between a drive shaft that drives a compression mechanism and a bearing that supports the drive shaft. Yes. In the drive shaft in Patent Document 1, an oil supply passage that penetrates the drive shaft vertically and a branch passage that extends in the horizontal direction from the oil supply passage are formed. An oil pump is provided at the lower end of the oil supply passage to pump up lubricating oil into the oil supply passage. The lubricating oil pumped up by the oil pump into the oil supply passage passes through the branch passage, and is then supplied to a bearing gap formed between the drive shaft and the bearing. Thus, the lubricating oil supplied to the bearing gap forms an oil film of sufficient thickness between the drive shaft and the bearing portion, so that the sliding portion between the drive shaft and the bearing portion is sufficiently lubricated. The

JP2003-294037

  By the way, in order to improve the compression efficiency of the rotary compressor, it is conceivable to narrow the bearing gap between the drive shaft and the bearing portion. Thereby, since it is suppressed that the axis of a drive shaft inclines with respect to a bearing part, the inclination of the axis of a movable member with respect to the axis of a fixed member can also be suppressed. As a result, it can be avoided that the gap between the movable member and the fixed member is enlarged and the fluid leaks, and the compression efficiency can be improved.

  Moreover, the lubricating oil may be discharged to the outside of the compressor together with the fluid compressed by the compression mechanism. When the lubricating oil discharged to the outside increases in this way, the lubricating oil stored in the compressor becomes insufficient and the oil runs out. As a countermeasure against such oil shortage, it is conceivable to reduce the amount of lubricating oil supplied to the bearing gap.

  However, if the bearing gap is narrowed as described above or the amount of lubricating oil supplied to the bearing gap is reduced, the thickness of the oil film formed in the bearing gap is reduced accordingly. When the thickness of the oil film is reduced, the frictional resistance of the sliding portion between the drive shaft and the bearing portion increases, and as a result, the temperature of the sliding portion increases due to frictional heat. Then, the temperature of the lubricating oil that lubricates the sliding portion also increases. If it becomes so, the viscosity of lubricating oil will fall and the thickness of the oil film of lubricating oil will become still thinner. As described above, when the oil film formed in the bearing gap becomes thinner, the lubrication of the sliding portion between the drive shaft and the bearing portion is further impaired, and the bearing portion is caused by seizure of the sliding portion. The desired performance cannot be obtained.

  On the other hand, by cooling the bearing portion, the lubricating oil flowing through the bearing gap between the bearing portion and the drive shaft is cooled to maintain the oil film thickness of the lubricating oil. It is conceivable to secure However, when only a part of the bearing portion in the circumferential direction is cooled in the bearing portion, a temperature difference in the circumferential direction occurs with respect to the lubricating oil flowing through the bearing gap. As a result, the oil film thickness varies in the circumferential direction of the lubricating oil flowing through the bearing gap, and sufficient lubrication is not performed in the portion where the oil film thickness is thin, and as a result, sufficient sliding performance is obtained for the entire bearing unit. It will not be possible.

  This invention is made | formed in view of this point, The objective is to cool uniformly the bearing part which supports a drive shaft rotatably.

  A first invention is directed to a rotary compressor, and includes a casing (11), a drive mechanism (50) accommodated in the casing, a drive shaft (40) connected to the drive mechanism (50), A compression mechanism (20) that is rotationally driven by the drive shaft (40) and compresses the fluid, and a bearing portion (32) that rotatably supports the drive shaft (40), and the bearing portion (32) is inserted therethrough. An oil supply mechanism that supplies lubricating oil to a housing part (23) in which a fixed bearing hole (23c) is formed and a bearing gap (27) between the drive shaft (40) and the bearing part (32) (30), and on the inner peripheral surface of the bearing hole (23c) of the housing part (23), the oil supply mechanism (30) from the oil supply mechanism (30) is cooled so as to cool the periphery of the bearing part (32). A cooling groove (28, 58, 68) through which the lubricating oil flows is formed.

  In the first aspect of the invention, the lubricating oil is supplied to the bearing gap (27) between the drive shaft (40) and the bearing portion (32) that rotatably supports the drive shaft (40) by the oil supply mechanism (30). As a result, the sliding portion between the drive shaft (40) and the bearing portion (32) is lubricated.

  On the other hand, a cooling groove (28) through which lubricating oil from the oil supply mechanism (30) flows is formed on the inner peripheral surface of the bearing hole (23c) of the housing portion (23), that is, on the back side of the bearing portion (32). ing. When the drive shaft (40) rotates with respect to the bearing portion (32), frictional heat of relatively high temperature is generated at the sliding portion between the drive shaft (40) and the bearing portion (32). The temperature of the bearing portion (32) rises. The lubricating oil in the cooling groove (28) flows through the cooling groove (28) while cooling the bearing portion (32) whose temperature has increased in this way. Here, in 1st invention, the cooling groove (28) is formed so that the circumference | surroundings of a bearing part (40) may be cooled. That is, the bearing portion (32) is uniformly cooled in the circumferential direction without cooling only a part in the circumferential direction.

  In a second aspect based on the first aspect, the oil supply mechanism (30) includes a main oil passage (44) extending in the axial direction inside the drive shaft (40), and an inflow end of the main oil passage ( 44) and a bearing oil supply passage (45a, 45b) in which the outflow end is connected to the bearing gap (27). One end of the bearing portion (32) is connected to the outflow end of the bearing oil supply passage (45b). And a communication hole (32a) that opens to face the bearing gap (27) at a position that coincides with the axial direction, and that has the other end connected to the cooling groove (28, 58, 68). To do.

  In the second aspect of the invention, the lubricating oil that has flowed through the main oil supply passage (44) and the bearing oil supply passage (45a, 45b) sequentially flows from the outflow end of the bearing oil supply passage (45a, 45b) into the bearing gap (27). Then, the lubricating oil that has flowed into the bearing gap (27) flows through the cooling groove (28, 58, 68) after passing through the communication hole (32a), thereby cooling the bearing portion (32). Here, since the communication hole (32a) is formed at a position coinciding with the outflow end of the bearing oil supply passage (45b) in the axial direction, the bearing oil supply passage (rotating with the rotation of the drive shaft (40) ( When the outflow end of 45b) and the communication hole (32a) coincide in the circumferential direction, the lubricating oil from the bearing oil supply passage (45b) flows directly toward the communication hole (32a). That is, relatively low temperature lubricating oil that does not lubricate between the drive shaft (40) and the bearing portion (32) flows into the communication hole (32a). Thus, since the comparatively low temperature lubricating oil which flowed into the communicating hole (32a) flows through the cooling groove (28, 58, 68), the bearing portion (32) is efficiently cooled.

  In a third aspect based on the first aspect, the oil supply mechanism (30) includes a main oil passage (44) extending in the axial direction inside the drive shaft (40), and an inflow end of the main oil passage ( 44) and a bearing oil supply passage (45a, 45b) in which the outflow end is connected to the bearing gap (27). One end of the bearing portion (32) is connected to the outflow end of the bearing oil supply passage (45a). And a communication hole (32a) that opens to face the bearing gap (27) at a position shifted in the axial direction and the other end is connected to the cooling groove (28, 58, 68). To do.

  In the third aspect of the invention, as in the case of the second aspect of the invention, the lubricating oil that has flowed in order through the main oil supply passage (44) and the bearing oil supply passage (45a, 45b) is discharged from the outflow end of the bearing oil supply passage (45a, 45b). It flows into the bearing gap (27). Then, the lubricating oil flowing into the bearing gap (27) passes through the communication hole (32a) and then flows through the cooling groove (28) to cool the bearing portion (32). Here, in the third invention, unlike the case of the second invention, the communication hole (32a) is formed at a position shifted in the axial direction with respect to the outflow end of the bearing oil supply passage (45a). Then, the lubricating oil after lubricating the sliding portion between the drive shaft (40) and the bearing portion (32) flows into the communication hole (32a). That is, the lubricating oil used for lubricating the sliding portion flows into the cooling groove (28).

  In a fourth aspect based on the third aspect, the drive shaft (40) is disposed so as to extend in a vertical direction, and the drive shaft (40) has a sliding contact portion with respect to the bearing portion (32). An annular oil catching groove (41b) extending in the circumferential direction of the drive shaft (40) is formed in a portion below the outflow end of the bearing oil supply passage (45a) and near the lower end of the sliding contact portion, One end of the communication hole (32a) is open so as to face the oil catching groove (41b).

  In the fourth invention, the lubricating oil that has flowed out of the bearing oil supply passage (45a) into the bearing gap (27) flows downward through the bearing gap (27), so that the drive shaft (40) and the bearing portion (32) Lubricate the sliding part between. Thereafter, the lubricating oil is captured by an annular oil capturing groove (41b) formed in a portion near the lower end of the sliding contact portion of the drive shaft (40) with respect to the bearing portion (32), and then the communication hole (32a). And flows into the cooling groove (28, 58, 68). As described above, in the fourth aspect of the invention, since the lubricating oil that is about to flow downward from the bearing gap (27) is captured by the oil capturing groove (41b), a large amount of lubricating oil is absorbed by the cooling groove (28,58). , 68).

  According to a fifth invention, in any one of the second to fourth inventions, the cooling groove (28, 58, 68) extends in a circumferential direction of an inner peripheral surface of the bearing hole (23c). An annular groove (28a, 58a, 68a) that is formed in an annular shape and that coincides with the communication hole (32a) in the axial direction is included.

  In the fifth invention, the annular groove (28a, 58a, 68a) formed in the inner peripheral surface of the bearing hole (23c) is in a state where the bearing portion (32) is inserted and fixed to the bearing hole (23c). , Is formed at a position communicating with the communication hole (32a). As a result, when the bearing portion (32) is inserted and fixed in the bearing hole (23c) during assembly, the communication hole (32a) does not depend on the position of the communication hole (32a) in the circumferential direction of the bearing portion (32). And the annular groove (28a, 58a, 68a) communicate with each other. That is, the bearing portion (32) can be inserted and fixed in the bearing hole (23c) without aligning the bearing portion (32) in the circumferential direction with respect to the bearing hole (23c).

  In a sixth aspect based on the fifth aspect, the cooling groove (28, 58) includes a plurality of branches extending from the annular groove (28a, 58a) toward the axial end of the bearing hole (23c). It further includes a groove (28b, 58b).

  In the sixth invention, since the plurality of branch grooves (28b, 58b) are branched from the annular groove (28a, 58a), the lubricating oil flowing into the annular groove (28a, 58a) from the communication hole (32a) The plurality of branch grooves (28b, 58b) flow in parallel. Thus, for example, the plurality of branch grooves (28b, 58b) are formed in comparison with the case where a spiral cooling groove is formed on the back side of the bearing part (32) so as to cool the periphery of the bearing part (32). The temperature change in the axial direction of the flowing lubricating oil is small. As a result, the temperature distribution in the axial direction of the bearing portion (32) is easily made uniform.

  As described above, according to the first aspect of the invention, the cooling oil flows from the oil supply mechanism (30) so as to cool the periphery of the bearing portion (32) on the back side of the bearing portion (32). Grooves (28, 58, 68) were provided. Thereby, a bearing part (32) can be cooled uniformly in the circumferential direction.

  Further, according to the second aspect of the invention, since one end of the communication hole (32a) is provided at a position that coincides with the axial direction with respect to the outflow end of the bearing oil supply passage (45b), the bearing portion (32) is still lubricated. Unused lubricating oil can flow into the cooling grooves (28, 58, 68). Therefore, the bearing portion (32) can be efficiently cooled by the relatively low temperature lubricating oil.

  According to the third aspect of the invention, since one end of the communication hole (32a) is provided at a position shifted in the axial direction with respect to the outflow end of the bearing oil supply passage (45a), lubrication from the bearing oil supply passage (45a) is achieved. The oil can flow into the cooling groove (28, 58, 68) after passing through the bearing gap (27) between the drive shaft (40) and the bearing portion (32). That is, the lubricating oil from the bearing oil supply passage (45a) can be used for lubrication of the sliding contact portion of the bearing portion (32) and cooling from the back side of the bearing portion (32).

  According to the fourth aspect of the invention, in the sliding contact portion of the drive shaft (40), the oil catching groove (41b) is formed below the outflow end of the bearing oil supply passage (45a) and closer to the lower end portion of the sliding contact portion. ) Is provided, it is possible to flow the lubricating oil into the cooling grooves (28, 58, 68) while capturing the lubricating oil that is about to flow out from the bearing gap (27). That is, since a large amount of lubricating oil can flow into the cooling grooves (28, 58, 68), the bearing portion (32) can be efficiently cooled.

  According to the fifth aspect of the invention, since the annular groove (28a, 58a, 68a) is provided on the inner peripheral surface of the bearing hole (23c) at a position coinciding with the communication hole (32a) in the axial direction, The work efficiency when inserting and fixing (32) into the bearing hole (23c) can be improved.

  According to the sixth aspect of the invention, since the plurality of branch grooves (28b, 58b) extending from the annular grooves (28a, 58a) are provided, the lubricating oil can flow in parallel on the back side of the bearing portion (32). Thereby, since the temperature distribution in the axial direction of the lubricating oil flowing through the plurality of branch grooves (28b, 58b) can be made uniform, the bearing portion (32) can be cooled uniformly in the axial direction.

FIG. 1 is a longitudinal sectional view of a scroll compressor according to the present embodiment. FIG. 2 is a cross-sectional view showing a main part of the scroll compressor according to the present embodiment. FIG. 3 is a longitudinal sectional view of the housing portion in the present embodiment, and is a view showing the shape of the cooling groove formed on the inner peripheral surface of the bearing hole of the housing portion. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a diagram corresponding to FIG. 2 in a modified example of the embodiment. FIG. 6 is a view corresponding to FIG. 3 in another embodiment. FIG. 7 is a view corresponding to FIG. 3 in another embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or its use.

  The scroll compressor (10) (rotary compressor) of this embodiment is provided in a refrigerant circuit that performs a vapor compression refrigeration cycle of an air conditioner, for example, and compresses the refrigerant.

-Overall configuration-
As shown in FIGS. 1 and 2, the scroll compressor (10) of the present embodiment is formed in a vertical type, and has a casing (11) that is slightly elongated in the vertical direction, and the casing (11). An electric motor (50) (driving mechanism) provided at a lower position inside, a driving shaft (40) extending from the electric motor (50) in the vertical direction, and being driven by the driving shaft (40) to compress the refrigerant A compression mechanism (20) and an oil supply mechanism (30).

  A suction pipe (12) is attached through the top of the casing (11). The suction pipe (12) has a terminal end connected to the compression mechanism (20). A discharge pipe (13) is attached through the body of the casing (11). The discharge pipe (13) is open at the end between the compression mechanism (20) and the electric motor (50) in the casing (11). Lubricating oil is stored in the bottom (11a) of the casing (11).

  The electric motor (50) includes a substantially cylindrical stator (51) fixed to the inner wall of the casing (11), and a cylindrical rotor (52) rotatable in the stator (51). . A through hole through which the drive shaft (40) can be inserted is formed at the center of the rotor (52).

  The drive shaft (40) includes a main shaft portion (41) formed in an elongated bar shape extending in the vertical direction, and an eccentric pin (42) erected on the upper end of the main shaft portion (41). The drive shaft (40) is inserted and fixed in a through hole formed in the rotor (52) of the electric motor (50), and is driven to rotate by driving of the electric motor (50). The upper part of the main shaft part (41) is constituted by an upper end part (41a) having a slightly larger diameter than the lower part. The eccentric pin (42) has a substantially cylindrical shape having a smaller diameter than the main shaft portion (41), and is eccentric by a predetermined distance from the axis of the main shaft portion (41).

  The drive shaft (40) is formed with a main oil supply passage (44) penetrating the drive shaft (40) vertically and a branch passage (45a, 45b, 45c) branched from the main oil supply passage (44). Yes. The branch passages (45a, 45b, 45c) are connected to two main bearing oil supply passages (45a, 45b) (bearing oil supply passages) formed in the upper end portion (41a) of the main shaft portion (41) and the eccentric pin (42). It is comprised with the formed eccentric bearing oil supply path (45c). The eccentric bearing oil supply passage (45c) extends horizontally from the main oil supply passage (44) and opens radially outward from the outer peripheral surface of the eccentric pin (42). The flow path in the vicinity of the outflow end of the eccentric bearing oil supply path (45c) is formed so as to gradually increase in diameter radially outward.

  The two main bearing oil supply passages (45a, 45b) include a first main bearing oil supply passage (45a) formed substantially at the center in the axial direction at the upper end portion (41a) and a lower end in the axial direction at the upper end portion (41a). And a second main bearing oil supply passage (45b) formed in the vicinity of the portion. The second main bearing oil supply passage (45b) is formed to have a smaller channel cross-sectional area than the first main bearing oil supply passage (45a). These main bearing oil supply passages (45a, 45b) extend in the horizontal direction from the main oil supply passage (44) and open radially outward from the outer peripheral surface of the main shaft portion (41). The flow path in the vicinity is formed so as to gradually expand toward the radially outer side.

  The compression mechanism (20) includes a fixed scroll (21), a movable scroll (22) meshing with the fixed scroll (21) and capable of rotating eccentrically with respect to the fixed scroll (21), and the fixed scroll (21). And a housing portion (23) for fixing and supporting the housing.

  The entire circumference of the housing part (23) is joined to the inner wall of the casing (11). The housing part (23) includes an upper stage part (23a) and a lower stage part (23b). The upper step portion (23a) and the lower step portion (23b) are successively formed from top to bottom. The upper step (23a) has a recess formed in the center of the upper surface thereof. The space covered by the recess constitutes the crank chamber (24). The lower step (23b) is formed in a substantially cylindrical shape having a smaller diameter than the upper step (23a), and projects downward from the lower surface of the upper step (23a). A bearing hole (23c) penetrating in the axial direction is formed in the lower end (23b). Further, between the upper step portion (23a) and the lower step portion (23b) of the housing portion (23), the exhaust extends horizontally from the vicinity of the bottom surface of the crank chamber (24) and extends toward the inner wall of the casing (11). An oil passage (25) is formed.

  A cylindrical main bearing metal (32) (bearing portion) that rotatably supports the drive shaft (40) is inserted and fixed in the bearing hole (23c). The drive shaft (40) is inserted through the main bearing metal (32). The inner diameter of the main bearing metal (32) is formed to be slightly larger than the outer diameter of the drive shaft (40), so that the outer peripheral surface of the drive shaft (40) and the main bearing metal (32) A main bearing gap (27) (bearing gap) is formed between the two. Further, a communication hole (32a) penetrating in the radial direction is formed near the lower end of the main bearing metal (32). The communication hole (32a) is formed at a height position that coincides with the outflow end of the second main bearing oil supply passage (45b) formed in the drive shaft (40) in the axial direction. Moreover, this communication hole (32a) is formed in the round hole shape of the same magnitude | size as the outflow end of the said 2nd main bearing oil supply path (45b).

  A groove-like cooling groove (28) is formed on the inner peripheral surface of the bearing hole (23c). The shape and action of the cooling groove (28) will be described later in detail.

  The fixed scroll (21) includes a fixed side end plate portion (21a), a fixed side wrap (21b), and an edge portion (21c). The fixed side end plate portion (21a) of the fixed scroll (21) is formed in a substantially disc shape. The fixed side wrap (21b) is erected on the lower surface of the fixed side end plate part (21a) and is integrally formed with the fixed side end plate part (21a). The fixed side wrap (21b) is formed in a spiral wall shape having a constant height. The edge portion (21c) is formed in a wall shape extending downward from the outer peripheral edge portion of the fixed-side end plate portion (21a). The lower end portion of the edge portion (21c) projects outward over the entire circumference, and is fixed to the upper surface of the upper step portion (23a) of the housing portion (23).

  A suction port (39) connected to the end of the suction pipe (12) is formed on the outer peripheral side of the fixed scroll (21). The suction port (39) is configured to intermittently communicate with the compression chamber (24) as the movable scroll (22) rotates eccentrically. A cover (37) is attached to the fixed side end plate portion (21a) of the fixed scroll (21) to cover the upper side. A discharge chamber (38) as a discharge space is formed between the cover (37) and the fixed side end plate portion (21a). A discharge port (35) that opens to the discharge chamber (38) is formed in the center of the fixed-side end plate portion (21a) of the fixed scroll (21). The discharge port (35) is configured to intermittently communicate with the compression chamber (24) with the eccentric rotational movement of the movable scroll (22). In addition, a reed valve (36) that covers the opening of the discharge port (35) is provided on the upper surface of the fixed side end plate (21a) of the fixed scroll (21). The reed valve (36) opens and closes according to the pressure difference between the pressure in the compression chamber (24) and the discharge chamber (38). In the compression mechanism (20), the gas refrigerant discharged into the discharge chamber (38) is introduced into a space below the housing (23) through a gas passage (not shown), and is discharged from the discharge pipe (13) to the casing (11 ) It is configured to be discharged outside.

  The movable scroll (22) includes a movable side end plate portion (22a), a movable side wrap (22b), a boss portion (22c), and an eccentric bearing metal (22d). The movable end plate portion (22a) is formed in a substantially disk shape and is located above the upper step portion (23a) of the housing portion (23). The movable side wrap (22b) is erected on the upper surface of the movable side end plate part (22a), and is integrally formed with the movable side end plate part (22a). The movable wrap (22b) is formed in a spiral wall shape having a constant height, and is configured to mesh with the fixed wrap (21b) of the fixed scroll (21). The boss portion (22c) is integrally formed with the movable side end plate portion (22a) so as to protrude from the lower surface of the movable side end plate portion (22a). The boss portion (22c) is accommodated in a crank chamber (24) formed in the housing portion (23). The eccentric bearing metal (22d) is made of metal formed in a cylindrical shape, and is inserted and fixed to the inner peripheral surface of the boss portion (22c). An eccentric pin (42) of the drive shaft (40) is inserted through the eccentric bearing metal (22d). The inner diameter of the eccentric bearing metal (22d) is formed to be larger than the outer diameter of the eccentric pin (42), so that there is no eccentricity between the eccentric pin (42) and the eccentric bearing metal (22d). A bearing gap (47) is formed.

  The oil supply mechanism (30) includes a pump section (31), and a main oil supply passage (44) and a branch passage (45a, 45b, 45c) formed in the drive shaft (40). This pump part (31) is comprised, for example with the centrifugal pump. The pump part (31) is provided at the lower end of the drive shaft (40) and is immersed in the lubricating oil stored in the bottom part (11a) of the casing (11). The pump section (31) is configured to pump the lubricating oil to the main oil supply passage (44) and the branch passages (45a, 45b, 45c).

-Cooling groove shape-
As described above, the cooling groove (28) is formed in a groove shape on the inner peripheral surface of the bearing hole (23c) of the housing portion (23). As shown in FIGS. 3 and 4, the cooling groove (28) includes an annular groove (28a) and a plurality of branch grooves (28b, 28b,...).

  The annular groove (28a) has a semicircular cross section, and is formed so as to extend annularly in the circumferential direction near the lower end of the inner peripheral surface of the bearing hole (23c). The annular groove (28a) is formed at a height position that coincides with the communication hole (32a) formed in the main bearing metal (32) inserted and fixed to the inner peripheral surface of the bearing hole (23c) and in the axial direction. Yes. That is, the annular groove (28a) and the communication hole (32a) communicate with each other. Thus, by forming the annular groove (28a) at a height position that coincides with the communication hole (32a) of the main bearing metal (32) in the axial direction, the communication hole ( The communication hole (32a) and the annular groove (28a) communicate with each other without aligning 32a) in the circumferential direction. Thereby, the work efficiency at the time of inserting and fixing the main bearing metal (32) with respect to the bearing hole (23c) can be improved.

  The branch groove (28b) is formed to extend upward from the annular groove (28a) to the upper end of the bearing hole (23c) in the vertical direction. The channel cross section of the branch groove (28b) is also formed in a semicircular shape, like the annular groove (28a). As shown in FIG. 4, eight branch grooves (28b) are formed, and are arranged at a predetermined distance so as to be equidistant from each other in the circumferential direction. Specifically, the branch grooves (28b) are arranged at an angle of 45 degrees with respect to the axis of the main bearing metal (32).

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

  When the scroll compressor (10) is started, the electric motor (50) is driven to rotate the drive shaft (40), and at the same time, the pump unit (31) is also driven.

-Refrigerant compression operation by compression mechanism-
When the drive shaft (40) rotates, the movable scroll (22) is eccentrically rotated with respect to the fixed scroll (21). As a result, the refrigerant in the suction port (39) is sucked into the compression chamber (24), and gradually moves to the center of the compression chamber (24) while being compressed. When the compression chamber (24) communicates with the discharge port (35), the refrigerant compressed in the compression chamber (24) is discharged into the discharge chamber (38). The refrigerant in the discharge chamber (38) returns from the internal space of the casing (11) to the refrigerant circuit through the discharge pipe (13).

-Lubricating oil supply operation by oil transfer mechanism-
When the pump part (31) is driven, the lubricating oil stored in the bottom part (11a) of the casing (11) is pumped upward by the pump part (31). This lubricating oil rises in the main oil supply passage (44). And it flows out of the drive shaft (40) from the upper end of the main oil supply passage (44) as it is, or the first main bearing oil supply passage (45a), the second main bearing oil supply passage (45b) or the eccentric bearing oil supply passage. It flows out from the drive shaft (40) radially outward through (45c).

  The lubricating oil that has flowed out from the upper end of the main oil supply passage (44) flows radially outward at the upper end of the eccentric pin (42), and then flows downward through the eccentric bearing gap (47) with the eccentric pin (42). The sliding portion between the eccentric bearing metal (22d) is lubricated and flows downward from the eccentric bearing gap (47). The lubricating oil that has flowed out of the eccentric shaft oil supply passage (45c) lubricates the sliding portion between the eccentric pin (42) and the eccentric bearing metal (22d) while flowing through the eccentric bearing gap (47). Out of the eccentric bearing gap (47). Thus, the lubricating oil that has flowed downward flows into the crank chamber (24), then travels down the inner wall of the casing (11) through the oil discharge passage (25), and returns to the bottom (11a) of the casing (11). It is.

  The lubricating oil that has flowed out of the first main bearing oil supply passage (45a) flows into the main bearing gap (27) and flows upward or downward through the main bearing gap (27), while driving the drive shaft (40) and the main bearing metal. Lubricate the sliding part between (32). The lubricating oil that has flowed above the main bearing gap (27) is returned to the bottom (11a) of the casing (11) through the oil drainage passage (25). On the other hand, some of the lubricating oil that flows downward from the main bearing gap (27) is discharged downward from the lower end of the main bearing gap (27), but has reached the vicinity of the communication hole (32a). Is pushed outward in the radial direction by the centrifugal force of the rotating drive shaft (40), and therefore flows into the annular groove (28a) of the cooling groove (28) through the communication hole (32a).

  The lubricating oil that has flowed out from the second main bearing oil supply passage (45b) flows into the main bearing gap (27) in the same manner as the lubricating oil that has flowed out from the first main bearing oil supply passage (45a). Here, a part of the lubricating oil lubricates the sliding portion while flowing through the main bearing gap (27). However, the remaining portion does not lubricate the sliding portion, and flows directly into the cooling groove (28) through the communication hole (32a). Specifically, when the height position of the outflow end of the second main bearing oil supply passage (45b) rotating with the drive shaft (40) matches the height position of the communication hole (32a), the second main bearing oil supply is performed. The lubricating oil discharged from the outflow end of the passage (45b) flows directly into the annular groove (28a) of the cooling groove (28) through the communication hole (32a).

  As described above, the lubricating oil flowing into the annular groove (28a) of the cooling groove (28) is the annular groove (28a) and a plurality of branch grooves (28b, 28b,...) Extending from the annular groove (28a). Flowing. At this time, the lubricating oil takes away the heat of the main bearing metal (32) whose temperature has been increased by the frictional heat generated at the sliding portion between the drive shaft (40) and the bearing metal (32), while Flows upward in the grooves (28b, 28b, ...). The lubricating oil flows into the crank chamber (24) from the outflow end of the branch groove (28b), and then returns to the bottom (11a) of the casing (11) through the oil discharge passage (25).

  Here, since the plurality of branch grooves (28b, 28b,...) Are arranged at equal intervals in the circumferential direction, the main bearing metal (32) includes the branch grooves (28b, 28b,...). It is cooled uniformly in the circumferential direction by the lubricating oil flowing through. Then, the lubricating oil flowing between the main bearing metal (32) and the drive shaft (40) is also cooled uniformly in the circumferential direction, so that the oil film thickness in the circumferential direction of the lubricating oil is kept uniform. As a result, the sliding portion between the drive shaft (40) and the main bearing metal (32) is uniformly lubricated in the circumferential direction.

  These branch grooves (28b, 28b,...) Extend from an annular groove (28a) formed at the lower end in the axial direction of the bearing hole (23c) to the upper end of the bearing hole (23c). Thereby, since lubricating oil flows from the lower end part vicinity of the main bearing metal (32) to the upper end of the main bearing metal (32), the main bearing metal (32) can be cooled over a wide range in the axial direction.

  Furthermore, since the branch grooves (28b, 28b,...) Are formed in a plurality from the annular groove (28a), the lubricating oil flowing into the annular groove (28a) is separated from the plurality of branch grooves ( 28b, 28b, ...) flow in parallel. Thereby, for example, the temperature change in the axial direction of the lubricating oil flowing through the branch grooves (28b, 28b,...) Can be reduced compared to the case where the branch grooves are formed in a spiral shape. Therefore, the temperature distribution in the axial direction of the main bearing metal (32) can be made uniform, and as a result, the main bearing metal (32) can be cooled uniformly in the axial direction. Moreover, since the branch groove (28b) extends in the vertical direction, for example, the flow path of the branch groove (28b) becomes shorter than in the case where the branch groove extends with an inclination with respect to the vertical direction. As a result, the distance through which the lubricating oil flows is shortened, so that an increase in the temperature of the lubricating oil in the vicinity of the outflow end of the branch groove (28b) can be suppressed. Thereby, the main bearing metal (32) can be cooled more uniformly in the axial direction.

  In addition, at the inflow end of the cooling groove (28), not only the lubricating oil that lubricated the sliding portion between the drive shaft (40) and the main bearing metal (32) but also the rotation of the drive shaft (40). Lubricating oil flows when the outflow end of the second main bearing oil supply passage (45b) that rotates and the communication hole (32a) coincide. Since this lubricating oil does not lubricate the sliding portion and has a relatively low temperature, the relatively low temperature lubricating oil flows through the cooling groove (28). Thereby, the main bearing metal (32) can be cooled efficiently.

  Further, the lubricating oil that has flowed through the cooling groove (28) and cooled the main bearing metal (32) as described above is returned to the bottom (11a) of the casing (11) through the oil discharge passage (25). Then, the lubricating oil is conveyed again to the cooling groove (28) by the oil conveying mechanism (30). That is, the lubricating oil used for cooling the main bearing metal (32) can be used by being circulated in the casing (11).

-Effect of the embodiment-
As described above, according to the present embodiment, the annular groove (28a) and the annular groove on the back side of the main bearing metal (32) that rotatably supports the drive shaft (40) that drives the compression mechanism (20). A cooling groove (28) that extends upward in the vertical direction from (28a) and has a plurality of branch grooves (28b, 28b,...) Arranged at equal intervals in the circumferential direction and through which lubricating oil flows. Provided. As described above, since the plurality of branch grooves (28b, 28b,...) Through which the lubricating oil flows are arranged at equal intervals in the circumferential direction, the main bearing metal (32) can be uniformly cooled in the circumferential direction. it can. As a result, the oil film thickness in the circumferential direction of the lubricating oil flowing through the main bearing gap (27) becomes uniform, so that the sliding portion between the drive shaft (40) and the main bearing metal (32) Can be evenly lubricated.

  Further, in the cooling groove (28), the lubricating oil that has lubricated the sliding portion between the drive shaft (40) and the main bearing metal (32) and the lubricating oil that has flowed out of the second main bearing oil supply passage (45b). Flows directly. Since this lubricating oil does not lubricate the sliding portion and has a relatively low temperature, the main bearing metal (32) can be efficiently cooled.

  In addition, as described above, since a plurality of branch grooves (28b, 28b,...) Branch from the annular groove (28a) are formed, the lubricating oil can flow in parallel on the back side of the main bearing metal (32). . Thereby, since the temperature rise of the lubricating oil which flows near the upper end part in the back surface of the main bearing metal (32) can be reduced, the main bearing metal (32) can be uniformly cooled in the axial direction. Furthermore, since the branch groove (28b) is formed to extend in the vertical direction, the flow path of the branch groove (28b) can be shortened. Thereby, since the temperature rise of the lubricating oil flowing near the upper end portion on the back surface of the main bearing metal (32) can be reduced, the main bearing metal (32) can be cooled more uniformly in the axial direction.

  In addition, the cooling groove (28) is formed so as to extend from the vicinity of the lower end portion of the bearing hole (23c) to the upper end portion of the bearing hole (23c), so that the main bearing metal (32) extends in a wide range in the axial direction. It can cool over.

  In addition, the annular groove (28a) is formed at a height that communicates with the communication hole (32a) with the main bearing metal (32) inserted and fixed in the bearing hole (23c). The communication hole (32a) can be communicated with the annular groove (28a) as the inflow end of the cooling groove (28) without positioning in the circumferential direction. Thereby, the work efficiency at the time of inserting and fixing the main bearing metal (32) in the bearing hole (23c) can be improved.

  In addition, the lubricating oil that has flowed through the cooling groove (28) is returned to the bottom (11a) of the casing (11) through the oil drainage passage (25) and then supplied to the cooling groove (28) again. Lubricating oil for cooling (32) can be circulated in the casing (11).

<< Modification of Embodiment >>
The scroll compressor (10) according to the modification of the embodiment is different from the above embodiment only in the shape of the drive shaft (40), and the other configurations are the same. Therefore, only the different parts will be described below. Further, only the lubricating oil flow in the main bearing gap (27) is different in the operation operation of the compressor, so only that portion will be described.

  As shown in FIG. 5, the drive shaft (40) in the modification of the present embodiment is different from the drive shaft (40) in the above embodiment in which two main bearing oil supply passages (45a, 45b) are formed. One main bearing oil supply passage (45a) is formed. The shape and position of the main bearing oil supply passage (45a) in the modification of the present embodiment are the same as the shape and position of the first main bearing oil supply passage (45a) in the first embodiment.

  In addition, an oil catching groove (41b) is formed in the drive shaft (40) in the modified example of the present embodiment. The oil catching groove (41b) is formed to extend annularly in the circumferential direction of the drive shaft (40) in the vicinity of the lower end portion of the upper end portion (41a) of the main shaft portion (41) of the drive shaft (40). . The oil catching groove (41b) is formed at a height position that coincides with the communication hole (32a) formed in the main bearing metal (32) in the axial direction.

  In the scroll compressor (40) having the drive shaft (40) configured as described above, the lubricating oil flowing out from the main bearing oil supply passage (45a) flows into the main bearing gap (27), and the drive shaft ( 40) Lubricate the sliding part while flowing upward or downward through the main bearing gap (27) between the main bearing metal (32). The lubricating oil that has flowed upward through the main bearing gap (27) flows back to the oil drainage passage (25) and then returns to the bottom (11a) of the casing (11), as in the first embodiment.

  On the other hand, the lubricating oil flowing downward through the main bearing gap (27) is collected by the oil catching groove (41b) and then pushed outward in the radial direction by the centrifugal force of the rotating drive shaft (40). It flows into the cooling groove (28) through (32a). The lubricating oil flows through the annular groove (28a) and the plurality of branch grooves (28b), thereby cooling the main bearing metal (32) uniformly in the circumferential direction.

  As described above, since the lubricating oil that flows downward from the main bearing gap (27) is collected by the oil catching groove (28), the amount of lubricating oil that flows downward from the bearing gap can be reduced. it can. Thereby, it is possible to prevent the lubricating oil from being discharged together with the refrigerant in the casing (11) to the refrigerant circuit through the discharge pipe (13). Moreover, since the lubricating oil efficiently captured by the oil capturing groove (41b) flows into the cooling groove (28), a large amount of lubricating oil can flow into the cooling groove (28). Further, as described above, the lubricating oil that has lubricated the sliding portion between the drive shaft (40) and the main bearing metal (32) flows into the cooling groove (28). That is, the lubricating oil that lubricated the sliding portion can also be used for cooling the main bearing metal (32).

-Other embodiments-
About the said embodiment, you may make it the following structures.

  In the above embodiment, the shape of the branch groove (28b) is a shape extending in the vertical direction from the annular groove (28a). However, the present invention is not limited to this, for example, as shown in FIG. You may arrange | position so that it may mutually cross | intersect a grid | lattice form. Thereby, since the lubricating oil can flow through the plurality of branch grooves (58b) communicating with each other, the temperature of the lubricating oil flowing through the branch grooves (58b) tends to be uniform as a whole. As a result, the main bearing metal (32) can be uniformly cooled as a whole.

  Further, as shown in FIG. 7, the cooling groove (68) includes an annular groove (68a) formed near the lower end of the bearing hole (23c), and an upper end of the bearing hole (23c) from the annular groove (68a). You may comprise by the spiral groove (68b) formed in the spiral shape extended to a part. Thus, by forming the groove branched from the annular groove (68a) in a spiral shape, the periphery of the main bearing metal (32) can be cooled with a single groove. Therefore, it is not necessary to form a plurality of grooves branched from the annular groove (68a), and the processing of the housing part (23) is facilitated accordingly. In addition, the cooling groove may be composed only of a spiral groove. Furthermore, the shape of the cooling groove may be any shape as long as the periphery of the main bearing metal can be cooled.

  Moreover, in the said embodiment, although each branch groove (28b) was arranged so that it might become equidistant mutually, it is not restricted to this, The space | interval of adjacent branch grooves does not need to be equidistant. Furthermore, in the above-described embodiment, eight branch grooves (28b) are provided. However, the number is not limited to this, and may be two or three as long as the periphery of the main bearing metal (32) can be cooled.

  In the above embodiment, the cooling groove (28) extends from the vicinity of the lower end portion of the bearing hole (23c) to the upper end portion, but is not limited thereto, and may extend over any range.

  In the above embodiment, the inflow end of the cooling groove (28) is provided in the vicinity of the lower end of the bearing hole (23c). However, the present invention is not limited to this. For example, the central portion in the axial direction of the bearing hole (23c) It may be provided in the vicinity. If it carries out like this, since a branching groove can be extended to an upper direction and a downward direction, the flow path of each branching groove can be shortened. Thereby, since the temperature rise of the lubricating oil at the outflow end of the branch groove can be suppressed, the main bearing metal (32) can be cooled more uniformly in the axial direction.

  Moreover, in the said embodiment, although the scroll compressor is made into object as a rotary compressor, a rotary compressor and a screw compressor can also be made into object.

  As described above, the present invention is particularly useful for a so-called vertical scroll compressor in which a drive shaft for driving a compression mechanism is arranged to extend in the vertical direction.

10 Scroll type compressor (rotary compressor)
11 Casing 20 Compression mechanism 23 Housing portion 23c Bearing hole 27 Main bearing gap (bearing gap)
28, 58, 68 Cooling groove 28a, 58a, 68a Annular groove 28b, 58b Branch groove 30 Oil supply mechanism 32 Main bearing metal (bearing part)
32a Communication hole 40 Drive shaft 41b Oil catching groove 44 Main oil supply passage 45a Main bearing oil supply passage, first main bearing oil supply passage (bearing oil supply passage)
45b Second main bearing oil supply passage (bearing oil supply passage)
50 Electric motor (drive mechanism)
68b Spiral groove

Claims (6)

A casing (11),
A drive mechanism (50) housed in the casing;
A drive shaft (40) coupled to the drive mechanism (50);
A compression mechanism (20) that is rotationally driven by the drive shaft (40) and compresses the fluid;
A housing portion (23) having a bearing portion (32) for rotatably supporting the drive shaft (40), and having a bearing hole (23c) through which the bearing portion (32) is inserted and fixed;
An oil supply mechanism (30) for supplying lubricating oil to a bearing gap (27) between the drive shaft (40) and the bearing portion (32),
On the inner peripheral surface of the bearing hole (23c) of the housing part (23), a cooling groove (28) through which lubricating oil from the oil supply mechanism (30) flows so as to cool the periphery of the bearing part (32) , 58, 68) is formed. In claim 1,
The oil supply mechanism (30)
A main oil supply passage (44) extending in the axial direction inside the drive shaft (40) and a bearing oil supply passage (45a, 45) in which an inflow end is connected to the main oil supply passage (44) and an outflow end is connected to the bearing gap (27). 45b)
The bearing portion (32) has one end opened so as to face the bearing gap (27) at a position coincident with the outflow end of the bearing oil supply passage (45b) in the axial direction, and the other end is the cooling groove. A rotary compressor characterized in that a communication hole (32a) connected to (28, 58, 68) is formed. In claim 1,
The oil supply mechanism (30)
A main oil supply passage (44) extending in the axial direction inside the drive shaft (40) and a bearing oil supply passage (45a, 45) in which an inflow end is connected to the main oil supply passage (44) and an outflow end is connected to the bearing gap (27). 45b)
The bearing portion (32) has one end opened so as to face the bearing gap (27) at a position shifted in the axial direction with respect to the outflow end of the bearing oil supply passage (45a), and the other end is the cooling groove. A rotary compressor characterized in that a communication hole (32a) connected to (28, 58, 68) is formed. In claim 3,
The drive shaft (40) is arranged to extend in the vertical direction,
The drive shaft (40) includes a drive shaft at a position below the outflow end of the bearing oil supply passage (45a) and closer to the lower end of the slide contact portion at the slide contact portion with respect to the bearing portion (32). An annular oil catching groove (41b) extending in the circumferential direction of (40) is formed,
One end of the communication hole (32a) is opened so as to face the oil catching groove (41b). In any one of claims 2 to 4,
The cooling groove (28, 58, 68) is formed in an annular shape extending in the circumferential direction of the inner peripheral surface of the bearing hole (23c), and the annular groove (28a, 58a, 68a), a rotary compressor. In claim 5,
The cooling groove (28, 58) further includes a plurality of branch grooves (28b, 58b) extending from the annular groove (28a, 58a) toward the axial end of the bearing hole (23c). And rotary compressor.

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