JP2012097580A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure reliability of a sliding bearing, even when forming an elastic groove part in a bearing housing, in a scroll compressor having the bearing housing for fixing the sliding bearing.SOLUTION: The bearing housing 1 is formed in a cylindrical shape having a hollow part, and can also dissipate heat of a sliding bearing part 2 fixed to an inner peripheral surface 1b of the bearing housing 1. The bearing housing 1 is provided with an oil draining passage 4 for draining lubricating oil in the elastic groove part to an external part of the bearing housing 1, by penetrating through between an outer surface 7a of the bearing housing 1 and an inner surface of the elastic groove part.

Description

  The present invention relates to a scroll compressor, and more particularly to a technique for improving the reliability of a slide bearing that rotatably supports a drive shaft.

  Conventionally, a scroll compressor including a scroll compression mechanism and an electric motor that drives the scroll compression mechanism is known. Among these scroll compressors, as shown in Patent Document 1, there are those provided with journal bearings (sliding bearings) on which a main shaft (drive shaft) that connects the scroll compression mechanism and the electric motor is rotatably supported. It is disclosed.

  Lubricating oil flows in the bearing gap of the journal bearing (the gap between the inner peripheral surface of the journal bearing and the outer peripheral surface of the main shaft). In the oil film formed in the bearing gap by this lubricating oil, pressure due to the wedge effect is generated as the main shaft rotates. The journal bearing rotatably supports the main shaft by the pressure of the oil film. Further, since the lubricating oil passes through the bearing gap, there is also a cooling effect for cooling the journal bearing.

  In the scroll compressor of Patent Document 1, in order to improve the reliability of the journal bearing described above, a housing (bearing housing) in which the journal bearing is integrally formed has an annular slit groove (elasticity) positioned around the main shaft. Grooves) are formed. The inner peripheral wall of the slit groove is configured to elastically support the main shaft from the radial direction together with the journal bearing.

  As described above, when the slit groove is provided in the housing, even when the main shaft is inclined, the inner peripheral wall of the slit groove is elastically deformed according to the inclination. As a result, the journal bearing is adapted to the inclination of the main shaft, and the contact between the journal bearing and the main shaft can be reduced.

JP 2003-97458 A

  Incidentally, as described above, the elastic groove is formed in the vicinity of the outer periphery of the slide bearing. Therefore, the lubricating oil that has flowed out of the bearing gap of the sliding bearing is likely to flow into the elastic groove.

  If the lubricating oil accumulates in the elastic groove, the elastic groove may be formed so as to surround the outer periphery of the sliding bearing, and this lubricating oil acts as a heat insulating member that inhibits heat dissipation of the sliding bearing. Can be considered. If it becomes like this, heat dissipation of a sliding bearing will not be performed well, but the temperature of a sliding bearing will rise more than needed. This increase in temperature causes a problem in the sliding bearing, which is not preferable.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a scroll compressor having a bearing housing to which a sliding bearing is fixed, even when an elastic groove is formed in the bearing housing. The goal is to ensure reliability.

   The first invention includes a scroll compression mechanism (30) having a movable scroll (35) and a fixed scroll (40), an electric motor (20) for driving the scroll compression mechanism (30), the electric motor (20), and the above-mentioned It is assumed that the scroll compressor includes a drive shaft (23) that connects the movable scroll (35) in the vertical direction and a bearing housing (1) that is fixed to the fixed scroll (40).

  The bearing housing (1) of the scroll compressor is formed in a cylindrical shape having a hollow portion, and is fixed to the inner peripheral surface (1b) of the bearing housing (1) to rotate the drive shaft (23). It consists of a sliding bearing part (2) to be supported, is open to the upper end surface (8f) of the bearing housing (1), and is formed between the drive shaft (23) and the sliding bearing part (2) Between the annular elastic groove (3) located on the outer periphery of the bearing gap (2a) and the outer surface (7a) of the bearing housing (1) and the inner surface (3b, 3c) of the elastic groove (3) And an oil drainage passage (4) through which the lubricating oil in the elastic groove (3) is discharged to the outside of the bearing housing (1).

   In the first aspect of the invention, most of the lubricating oil that has flowed upward from the bearing gap (2a) of the sliding bearing (2) is directed from the radially inner side to the outer side of the drive shaft (23). And flows into the annular elastic groove (3) located on the outer periphery of the bearing gap (2a). The lubricating oil flows through the elastic groove (3) and then is discharged to the outside of the bearing housing (1) through the oil drain passage (4). Thus, by providing the oil drain passage (4), the lubricating oil flows through the elastic groove (3).

   In a second aspect based on the first aspect, the drive shaft (23) has an eccentric portion (25) extending upward from an upper end surface of the sliding bearing portion (2), and the eccentric portion (25 ) Is provided with an oil supply hole (6b) serving as an outflow end of an oil supply passage (27) formed inside the drive shaft (23).

   In the second invention, the oil supply hole (6b) of the eccentric part (25) is located above the upper end opening surface of the bearing gap part (2a) in the sliding bearing part (2). The lubricating oil flowing out from the oil supply hole (6b) flows into the elastic groove (3) together with the lubricating oil flowing out from the bearing gap (2a). Here, since the lubricating oil flowing through the oil supply passage (27) of the drive shaft (23) does not pass through the bearing gap (2a), the lubricating oil flows out from the oil supply hole (6b) of the oil supply passage (27). This temperature is considered to be lower than the temperature of the lubricating oil flowing out from the bearing gap (2a). From this, the temperature of the lubricating oil flowing into the elastic groove (3) can be lowered.

   The third invention is characterized in that, in the first or second invention, the inflow end (4a) of the oil drainage passage (4) is open to the bottom of the elastic groove (3).

   In the third aspect of the invention, the lubricating oil that has flowed into the elastic groove (3) flows out smoothly to the outside of the elastic groove (3). Suppose that the inflow end (4a) of the oil drainage passage (4) opens above the bottom of the elastic groove (3). In this case, the lubricating oil easily accumulates below the inflow end (4a) of the oil discharge passage (4). In the third invention, the retention of the lubricating oil is not preferable because the heat dissipation performance of the bearing housing (1) is deteriorated as described above. In the third invention, it is possible to suppress the retention of the lubricating oil in the elastic groove (3).

   According to a fourth aspect of the present invention, in any one of the first to third aspects, the inner edge portion of the bearing housing (1) has an inner edge portion rather than an outer edge portion of the upper end surface (8f). A stepped portion (8a) is formed so as to be lowered, and an oil reservoir (5) is formed in a space surrounded by the side peripheral surface (8e) of the stepped portion (8a), and the sliding bearing portion (2 ) Bearing clearance (2a) and the elastic groove (3) open toward the oil reservoir (5), and the oil drainage passage (4) is an annular ring formed by the elastic groove (3). It extends in the tangential direction and the rotational direction of the drive shaft (23).

   In the fourth invention, the lubricating oil from the bearing gap (2a) is temporarily stored in the oil reservoir (5) of the bearing housing (1). Further, when the oil supply hole (6a) is formed in the eccentric part (25) of the drive shaft (23), the lubricating oil from the oil supply hole (6a) is also stored in the oil reservoir part of the bearing housing (1). (5) temporarily stored.

   Here, in the oil reservoir (5), when the oil level is above the elastic groove (3), the elastic groove (3) is sealed with the lubricating oil of the oil reservoir (5). It becomes a state. When the drive shaft (23) rotates in this state, a swirling flow is generated in the lubricating oil in the oil reservoir (5) by the eccentric rotational movement of the eccentric portion (25) in the drive shaft (23). This swirl flow is a flow along the rotation direction of the drive shaft (23), and this swirl flow is also generated in the lubricating oil in the elastic groove (3).

   The swirling flow is generated in the lubricating oil in the elastic groove (3), so that the drained oil extends in the tangential direction of the ring formed by the elastic groove (3) and in the rotational direction of the drive shaft (23). Lubricating oil flows smoothly into the passage (4).

   According to a fifth invention, in any one of the first to fourth inventions, the oil discharge passage (4) is formed on the outer surface of the bearing housing (1) from the inner surface (3b, 3c) of the elastic groove portion (3). It is characterized in that it is inclined obliquely downward toward (7a).

   In the fifth aspect of the invention, the oil discharge passage (4) is inclined obliquely downward so that the oil discharge passage (4) has an outflow end below the inflow end (4a). (4b) comes to be located. Thereby, the lubricating oil flowing in from the inflow end (4a) of the oil discharge passage (4) flows smoothly toward the outflow end (4b) of the oil discharge passage (4).

   According to a sixth aspect of the present invention, in any one of the first to fourth aspects, the oil discharge passage (4) extends from the inner surface (3b, 3c) of the elastic groove (3) to the outer surface of the bearing housing (1). It is characterized by extending horizontally and linearly to (7a).

   In the sixth invention, the oil drainage passage (4) extends horizontally and linearly. For this reason, it is easy to form the oil drainage passage (4) in the bearing housing (1). In addition, the flow rate of the lubricating oil in the oil drainage passage (4) becomes faster than the case where the oil drainage passage (4) extends obliquely upward, and the flow of the lubricating oil in the elastic groove (3) is reduced. Become smooth.

   According to the present invention, by providing the oil drain passage (4), the lubricating oil flows through the elastic groove (3). Accordingly, heat transfer between the lubricating oil and the inner surfaces (3a, 3b) of the elastic groove (3) is promoted as compared with a state where the lubricating oil remains in the elastic groove (3). By promoting the heat transfer, the performance of the bearing housing (1) as a heat radiating member can be enhanced. As mentioned above, the temperature rise of the sliding bearing part (2) can be suppressed, and the reliability of the sliding bearing part (2) can be ensured.

   According to the second aspect of the invention, the oil supply hole (6b) of the oil supply passage (27) is formed on the outer surface of the eccentric part (25), compared with the case where the oil supply hole (6b) is not formed. The temperature of the lubricating oil passing through the elastic groove (3) can be lowered. Thus, by lowering the temperature of the lubricating oil, heat transfer between the lubricating oil and the inner surface (3a, 3b) of the elastic groove (3) is promoted. Thereby, the heat dissipation performance of the bearing housing (1) can be enhanced.

   Further, according to the third aspect of the invention, the inflow end (4a) of the oil drainage passage (4) is opened at the bottom of the elastic groove (3), so that the inflow end (4a) is connected to the elastic groove ( Compared with the case where it is provided above the bottom of 3), the retention of lubricating oil in the elastic groove (3) can be suppressed. A decrease in the heat dissipation performance of the housing due to the retention of the lubricating oil can be suppressed.

   Further, according to the fourth aspect of the invention, the swirling flow is generated in the elastic groove (3), so that the lubricating oil in the elastic groove (3) flows out smoothly into the oil discharge passage (4). As a result, the flow velocity of the lubricating oil in the elastic groove (3) is increased, heat transfer between the lubricating oil and the inner surface (3a, 3b) of the elastic groove (3) is promoted, and the bearing housing (1 ) Heat dissipation performance can be further enhanced.

   Further, according to the fifth aspect of the invention, the oil discharge passage (4) is inclined obliquely downward so that the oil discharge passage (4) is not inclined. The head difference between the outflow end (4b) and the inflow end (4a) can be increased. The larger the head difference in the oil discharge passage (4), the higher the flow rate of the lubricating oil in the oil discharge passage (4) and the smoother the flow of the lubricating oil in the elastic groove (3). As a result, the flow velocity of the lubricating oil in the elastic groove (3) is increased, heat transfer between the lubricating oil and the inner surface (3a, 3b) of the elastic groove (3) is promoted, and the bearing housing (1 ) Can be further improved.

   According to the sixth aspect of the invention, since the oil drain passage (4) extends horizontally and linearly, the oil drain passage (4) is formed relatively easily in the bearing housing (1). be able to. In addition, the flow rate of the lubricating oil in the oil drainage passage (4) becomes faster than when the oil drainage passage (4) extends obliquely upward, and the flow of the lubricating oil in the elastic groove (3) is reduced. It can be smooth. Thereby, heat transfer between the lubricating oil and the inner surface (3a, 3b) of the elastic groove (3) is promoted, and the heat dissipation performance of the bearing housing (1) can be further enhanced.

It is a longitudinal section showing a scroll compressor concerning this embodiment. It is a perspective sectional view of a bearing housing. It is a top view of a bearing housing. It is a longitudinal cross-sectional view of the oil drain passage vicinity in a bearing housing. It is a longitudinal cross-sectional view of the oil drain passage vicinity of the bearing housing which concerns on the modification of embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a scroll compressor (10) according to the present embodiment. The scroll compressor (hereinafter referred to as a compressor) (10) is connected to, for example, a refrigerant circuit that performs a vapor compression refrigeration cycle of an air conditioner. The compressor (10) includes a casing (11), a motor (electric motor) (20), and a scroll compression mechanism (30).

<casing>
The casing (11) is composed of a vertically long cylindrical sealed container closed at both ends, and has a cylindrical body (12) and an upper end plate (13) fixed to the upper end side of the body (12). And a lower end plate (14) fixed to the lower end side of the body (12).

  The internal space of the casing (11) is vertically divided by a bearing housing (1) joined to the inner peripheral surface of the casing (11). The space above the bearing housing (1) constitutes the upper space portion (15), and the space below the bearing housing (1) constitutes the lower space portion (16). The configuration of the bearing housing (1) will be described later in detail. An oil reservoir (17) is formed at the bottom of the lower space (16) in the casing (11) to store lubricating oil that lubricates the sliding portion of the compressor (10).

  A suction pipe (18) and a discharge pipe (19) are attached to the casing (11). The suction pipe (18) passes through the upper part of the upper end plate (13). One end of the suction pipe (18) is connected to a suction pipe joint (65) of the scroll compression mechanism (30). The discharge pipe (19) passes through the body (12). The end of the discharge pipe (19) opens into the lower space (16) of the casing (11).

<motor>
The motor (20) is accommodated in the lower space (16) of the casing (11). The motor (20) includes a stator (21) and a rotor (22) both formed in a cylindrical shape. The stator (21) is fixed to the body (12) of the casing (11). The rotor (22) is disposed in the hollow portion of the stator (21). A drive shaft (23) is fixed in the hollow portion of the rotor (22) so as to penetrate the rotor (22), and the rotor (22) and the drive shaft (23) rotate integrally. ing.

  The drive shaft (23) has a main shaft portion (24) and an eccentric portion (25) on the upper side of the main shaft portion (24), which are integrally formed. The eccentric portion (25) is formed with a diameter smaller than the maximum diameter of the main shaft portion (24), and the shaft center of the eccentric portion (25) is offset by a predetermined distance with respect to the shaft center of the main shaft portion (24). I have a heart.

  A lower end portion of the main shaft portion (24) of the drive shaft (23) is rotatably supported by a lower bearing portion (28) fixed near the lower end of the body portion (12) of the casing (11). The upper end portion of the main shaft portion (24) is rotatably supported by a first sliding bearing portion (sliding bearing portion) (2) included in the bearing housing (1). The eccentric part (25) is rotatably supported by a second sliding bearing part (29) formed on the inner peripheral surface of a boss part (38) of a movable scroll (35) described later.

  An oil supply pump (26) is provided at the lower end of the drive shaft (23). The suction port of the oil supply pump (26) opens to the oil reservoir (17) of the casing (11). The discharge port of the oil supply pump (26) communicates with an oil supply path (27) provided in the drive shaft (23).

  The oil supply passage (27) has first to third outflow ends (6a, 6b, 6c). The first to third outflow ends (6a, 6b, 6c) constitute first to third oil supply holes (6a, 6b, 6c). The first oil supply hole (6a) opens on the outer peripheral surface of the main shaft portion (24) at a position facing the inner peripheral surface of the first sliding bearing portion (2). The 2nd oil supply hole (6b) is opened in the outer peripheral surface of the said eccentric part (25) in the position which faces the oil reservoir part (5) mentioned later. The third oil supply hole (6c) is formed on the upper end surface of the eccentric portion (25) at a position facing the gap between the upper end surface of the eccentric portion (25) and the boss portion (38) of the movable scroll (35). It is open.

<Scroll compression mechanism>
The scroll compression mechanism (30) includes a movable scroll (35), a fixed scroll (40), and a bearing housing (1). The bearing housing (1) and the fixed scroll (40) are fastened to each other with bolts, and the movable scroll (35) is accommodated in a rotatable manner therebetween.

-Moveable scroll-
The movable scroll (35) has a substantially disc-shaped movable side end plate portion (36). A movable side wrap (37) is erected on the upper surface of the movable side end plate portion (36). The movable side wrap (37) is a wall that spirally extends from the vicinity of the center of the movable side end plate portion (36) outward in the radial direction. A boss portion (38) is provided so as to protrude from the lower surface of the movable side end plate portion (36). Although not shown, an Oldham coupling for preventing the rotation of the movable scroll (35) is disposed between the movable side end plate portion (36) and the bearing housing (1).

-Fixed scroll-
The fixed scroll (40) has a substantially disc-shaped fixed side end plate portion (41). A fixed side wrap (42) is erected on the lower surface of the fixed side end plate portion (41). The fixed side wrap (42) is spirally extended radially outward from the vicinity of the center of the fixed side end plate portion (41), and is formed to mesh with the movable side wrap (37) of the movable scroll (35). Wall. A compression chamber (31) is formed between the fixed side wrap (42) and the movable side wrap (37).

  The fixed scroll (40) has an outer edge portion (43) continuous radially outward from the outermost peripheral wall of the fixed side wrap (42). An opening (44) opening upward is formed in the outer edge (43). A communication hole (34) that communicates the inside of the opening (44) and the outermost peripheral end of the compression chamber (31) is formed in the outer edge (43). This communication hole (34) constitutes a suction port (34). The suction port (34) opens to the suction position of the compression chamber (31). The suction pipe joint (65) described above is connected to the opening (44) of the outer edge (43).

  The fixed scroll end plate (41) of the fixed scroll (40) is formed with a through hole (32) that is positioned near the center of the fixed wrap (42) and penetrates in the vertical direction. The through hole (32) constitutes the discharge port (32). The lower end of the discharge port (32) opens to the discharge position of the compression chamber (31). The upper end of the discharge port (32) opens into a discharge chamber (46) defined in the upper part of the fixed scroll (40). A discharge reed valve (45) for opening and closing the upper end opening of the discharge port (32) is attached to the bottom surface of the discharge chamber (46). Although not shown, the discharge chamber (46) communicates with the lower space (16) of the casing (11).

−Bearing housing−
As shown in FIG. 2 or FIG. 3, the bearing housing (1) is formed in a cylindrical shape having a hollow portion. The inner peripheral surface facing the hollow portion is provided with the first sliding bearing portion (2) described above over the entire inner peripheral surface, and the bearing housing (1) is provided with the first sliding bearing. It is configured to be able to release the frictional heat generated in the section (2).

  The outer peripheral portion of the bearing housing (1) is formed so that the upper portion has a larger diameter than the lower portion. And the upper part of this outer peripheral part is being fixed to the inner peripheral surface of the said casing (11). Further, the lower portion of the outer peripheral portion has an inclined surface (outer surface) (7a) that is inclined from the radially outer side to the inner side over the entire circumference.

  The lower stepped portion (8a) is formed on the upper end surface (8c, 8d, 8f) of the bearing housing (1) so that the inner edge portion is lower than the outer edge portion of the upper end surface (8c, 8d, 8f). Is formed. The upper stepped portion (8b) has an upper stepped portion (8b) on the upper stepped surface (8c, 8d) so that the inner edge portion is lower than the outer edge portion of the upper stepped surface (8c, 8d). Is formed.

  The lower end surface of the fixed scroll (40) is fixed to the upper step surface (8c) of the upper step portion (8b). The movable side end plate portion (36) of the movable scroll (35) is fitted inside the upper stepped portion (8b). The revolving motion of the movable scroll (35) brings the lower surface of the movable side end plate portion (36) into sliding contact with the lower step surface (8d) of the upper step portion (8b).

(Oil sump)
The space surrounded by the side peripheral surface (8e) of the lower step portion (8a) constitutes an oil reservoir (5). The upper end of the bearing clearance (2a) in the first sliding bearing (2) is opened in the oil reservoir (5). As a result, the lubricating oil from the bearing clearance (2a) of the first sliding bearing (2) flows into the oil reservoir (5).

  The oil reservoir (5) accommodates an eccentric portion (25) of the drive shaft (23) extending from the upper end surface of the first sliding bearing portion (2). Lubricating oil from the second and third oil supply holes (6b, 6c) of the eccentric part (25) flows into the oil reservoir part (5).

  In addition, a through passage (9) penetrating between the side peripheral surface (8e) of the lower stepped portion (8a) and the outer peripheral surface (1a) of the bearing housing (1) is formed. The through passage (9) extends horizontally and linearly. The through passage (9) is an oil discharge passage (9) for discharging the lubricating oil accumulated in the oil reservoir (5) to the outside of the bearing housing (1).

(Elastic groove)
An annular elastic groove (3) that opens to the oil reservoir (5) is formed on the lower step surface (8f) of the lower step portion (8a). The elastic groove (3) is disposed in the vicinity of the outer periphery of the bearing gap (2a) in the first sliding bearing (2). The wall between the inner peripheral surface (inner surface) (3b) of the elastic groove (3) and the inner peripheral surface (1b) of the bearing housing (1) is the inner peripheral wall (3a) of the elastic groove (3). Configure. The inner peripheral wall (3a) elastically supports the drive shaft (23) from the radial direction together with the first sliding bearing portion (2).

  Note that the thickness of the inner peripheral wall (3a) decreases as the position of the elastic groove (3) approaches the inner peripheral surface (1b) of the bearing housing (1) and increases as it moves away from the inner peripheral surface (1b). Become thicker. The thickness of the inner peripheral wall (3a) is set so that the inner peripheral wall (3a) can be elastically deformed. That is, the elastic groove (3) is formed at a position where the inner peripheral wall (3a) can be elastically deformed.

(Oil drainage passage)
The bearing housing (1) includes a through-passage (4) extending between the inclined surface (outer surface) (7a) of the bearing housing (1) and the outer peripheral surface (inner surface) (3c) of the elastic groove (3). ) Are formed. These through passages (4) constitute an oil discharge passage (4) for discharging the lubricating oil accumulated in the elastic groove (3) to the outside of the bearing housing (1).

  As shown in FIG. 4, these oil drain passages (4) have an inflow end (4a) opened at the bottom of the outer peripheral surface (3c) of the elastic groove (3), and an outflow end (4b) of the bearing. It opens to the inclined surface (7a) located at the lower part of the outer surface of the housing (1). These oil drain passages (4) extend in the tangential direction of the ring formed by the elastic groove (3) and in the rotational direction of the drive shaft (23). These oil drain passages (4) are inclined obliquely downward from the outer peripheral surface (3c) of the elastic groove (3) toward the outer peripheral surface (1a) of the bearing housing (1).

-Driving action-
Next, the operation of the compressor (10) described above will be described.

  When the motor (20) of the compressor (10) is energized, the drive shaft (23) rotates with the rotor (22), and the movable scroll (35) turns. Due to the orbiting movement of the movable scroll (35), the volume of the compression chamber (31) is periodically increased and decreased. The refrigerant sucked into the compression chamber (31) from the suction pipe (18) by the increase in the volume of the compression chamber (31) is compressed by the decrease in the volume of the compression chamber. When the refrigerant reaches a predetermined pressure, it is discharged from the compression chamber (31) to the outside of the casing (11) through the discharge pipe (19).

  Next, the flow of lubricating oil in the compressor (10) will be described.

  By the rotation of the drive shaft (23), the oil supply pump (26) of the drive shaft (23) sucks up the lubricating oil in the oil reservoir (17) in the casing (11). After passing through the oil supply passage (27) of the drive shaft (23), the lubricating oil flows out from the first to third oil supply holes (6a, 6b, 6c) of the oil supply passage (27).

  The lubricating oil flowing out from the first oil supply hole (6a) is supplied to the bearing clearance (2a) of the first sliding bearing (2). In the oil film formed in the bearing gap (2a) by this lubricating oil, pressure due to the wedge effect is generated as the drive shaft (23) rotates. The drive shaft (23) is rotationally supported by the pressure of the oil film.

  Of the lubricating oil flowing into the bearing clearance (2a) of the first sliding bearing (2), one flows downward through the bearing clearance (2a) and the other is the bearing clearance (2a). ) Flowing upward. The lubricating oil flowing downward flows out from the lower end of the first sliding bearing portion (2) while receiving frictional heat generated in the first sliding bearing portion (2).

  On the other hand, the lubricating oil flowing upward flows out from the upper end of the first sliding bearing portion (2) while receiving frictional heat generated in the first sliding bearing portion (2). The lubricating oil flowing out from the upper end of the first sliding bearing portion (2) flows into the oil reservoir (5) of the bearing housing (1).

  The lubricating oil that has flowed out of the second oil supply hole (6b) flows into the oil reservoir (5). Here, since the lubricating oil from the second oil supply hole (6b) is directly supplied from the oil reservoir (17) of the casing (11), the bearing of the first sliding bearing (2) The temperature is lower than the lubricating oil that has flowed out of the gap (2a). As a result, the temperature of the lubricating oil accumulated in the oil reservoir (5) is lowered, and the temperature of the lubricating oil flowing into the elastic groove (3) is lowered.

  The lubricating oil flowing out from the third oil supply hole (6c) flows out from the lower end of the bearing clearance (29a) after passing through the bearing clearance (29a) of the second sliding bearing (29). To do. This lubricating oil flows into the oil reservoir (5).

  Of the lubricating oil flowing into the oil reservoir (5), a part of the lubricating oil flows into the elastic groove (3) and passes through the elastic groove (3). Through the bearing housing (1). Thus, by providing the oil drain passage (4), the lubricating oil flows through the elastic groove (3). On the other hand, the lubricating oil that has not flowed into the elastic groove (3) is discharged to the outside of the bearing housing (1) through the oil drain passage (9) of the bearing housing (1).

  The lubricating oil discharged to the outside of the bearing housing (1) through the oil drainage passage (4) and the oil drainage passage (9) passes through the lower space (16) of the casing (11) and passes through the oil. Return to reservoir (17). The lubricating oil in the oil reservoir (17) is sucked up again by the oil pump (26) of the drive shaft (23). Then, after passing through the oil supply passage (27) of the drive shaft (23), the lubricating oil flows out from the first to third oil supply holes (6a, 6b, 6c) of the oil supply passage (27). Such circulation of the lubricating oil is repeated in the casing (11).

  As described above, the oil drainage passage (4) extending from the elastic groove (3) has an inflow end (4a) on the elastic groove (3) side of the outer peripheral surface (3c) of the elastic groove (3). Open to the bottom. Suppose that the inflow end (4a) of the oil discharge passage (4) is open above the outer peripheral surface (3c). In this case, the lubricating oil easily accumulates below the inflow end (4a) of the oil discharge passage (4). In this way, by retaining the inflow end (4a) of the oil discharge passage (4) below the outer peripheral surface (3c), the retention of the lubricating oil in the elastic groove (3) can be suppressed.

  Here, in the oil reservoir (5) of the bearing housing (1), when there is an oil level above the elastic groove (3), the elastic groove (3) is connected to the oil reservoir (5). It will be in the state sealed with lubricating oil. When the drive shaft (23) rotates in this state, a swirling flow is generated in the lubricating oil in the oil reservoir (5) by the eccentric rotational movement of the eccentric portion (25) in the drive shaft (23). This swirl flow is a flow along the rotation direction of the drive shaft (23), and this swirl flow is also generated in the lubricating oil of the elastic groove (3).

  Then, when a swirling flow is generated in the elastic groove (3), the oil drainage passage (4) extending in the tangential direction of the ring formed by the elastic groove (3) and in the rotation direction of the drive shaft (23). ) So that the lubricating oil flows smoothly.

-Effect of the embodiment-
According to this embodiment, by providing the oil drainage passage (4), the lubricating oil flows through the elastic groove (3). Accordingly, heat transfer between the lubricating oil and the inner surfaces (3a, 3b) of the elastic groove (3) is promoted as compared with a state where the lubricating oil remains in the elastic groove (3). By promoting the heat transfer, the performance of the bearing housing (1) as a heat radiating member can be enhanced. As described above, the temperature increase of the first sliding bearing portion (2) can be suppressed, and the reliability of the first sliding bearing portion (2) can be ensured.

  Further, according to the present embodiment, by forming the oil supply hole (6b) of the oil supply passage (27) on the outer surface of the eccentric part (25), compared to the case where the oil supply hole (6b) is not formed, The temperature of the lubricating oil passing through the elastic groove (3) can be lowered. Thus, by lowering the temperature of the lubricating oil, heat transfer between the lubricating oil and the inner surface (3a, 3b) of the elastic groove (3) is promoted. Thereby, the heat dissipation performance of the bearing housing (1) can be enhanced.

  Further, according to the present embodiment, the inflow end (4a) of the oil drainage passage (4) is opened at the bottom of the elastic groove (3), so that the inflow end (4a) is opened in the elastic groove (3). Compared with the case where it is provided on the upper side of the bottom part, the retention of lubricating oil in the elastic groove (3) can be suppressed. Thereby, the fall of the thermal radiation performance of the bearing housing (1) resulting from this retention of lubricating oil can be suppressed.

  Further, according to the present embodiment, the eccentric rotational motion of the eccentric portion (25) causes a swirling flow to occur in the lubricating oil in the elastic groove portion (3), whereby the lubricating oil in the elastic groove portion (3) is produced. Smoothly flows into the oil drainage passage (4). As a result, the flow velocity of the lubricating oil in the elastic groove (3) is increased, heat transfer between the lubricating oil and the inner surface (3a, 3b) of the elastic groove (3) is promoted, and the bearing housing (1 ) Heat dissipation performance can be further enhanced.

  In addition, according to the present embodiment, the oil discharge passage (4) is inclined downward and the outflow in the oil discharge passage (4) is made smaller than when the oil discharge passage (4) is not inclined. The head difference between the end (4b) and the inflow end (4a) can be increased. The larger the head difference in the oil discharge passage (4), the higher the flow rate of the lubricating oil in the oil discharge passage (4) and the smoother the flow of the lubricating oil in the elastic groove (3). As a result, the flow velocity of the lubricating oil in the elastic groove (3) is increased, heat transfer between the lubricating oil and the inner surface (3a, 3b) of the elastic groove (3) is promoted, and the bearing housing (1 ) Can be further improved.

-Modification of the embodiment-
In the above embodiment, the oil drainage passage (4) of the bearing housing (1) is inclined obliquely downward, but in this modified example, as shown in FIG. It extends linearly. Thus, the oil drainage passage (4) can be formed in the bearing housing (1) relatively easily. Further, for example, the flow of the lubricating oil in the elastic groove (3) can be made smoother than in the case where the oil discharge passage (4) is inclined obliquely upward, and the lubrication in the elastic groove (3) can be performed. Increases oil flow rate. Thereby, heat transfer between the lubricating oil and the inner surface (3a, 3b) of the elastic groove (3) is promoted, and the heat dissipation performance of the bearing housing (1) can be reliably improved.

<< Other Embodiments >>
About the said embodiment, it is good also as the following structures.

  In the above-described embodiment, the oil discharge passage (4) is inclined obliquely downward. However, the present invention is not limited to this. For example, the oil discharge passage (4) is formed from the bottom surface of the elastic groove (3). It may extend vertically downward toward the lower end surface of the bearing housing (1). Even in this case, the lubricating oil flows through the elastic groove (3), and the same effect as in the above embodiment can be obtained.

  In the above embodiment, each of the plurality of oil drain passages (4) extends in the tangential direction of the ring formed by the elastic groove portion (3) and in the rotational direction of the drive shaft (23), but is not limited thereto. For example, each of the plurality of oil drain passages (4) may extend radially. Even in this case, the lubricating oil flows through the elastic groove (3), and the same effect as in the above embodiment can be obtained.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or its use.

  As described above, the present invention relates to a scroll compressor, and is particularly useful for a technique for improving the reliability of a sliding bearing that rotatably supports a drive shaft.

1 Bearing housing
1a Outer surface
1b Inner peripheral surface
2 Sliding bearing (first sliding bearing)
2a Bearing clearance
3 Elastic groove
3a Inner wall
3b Inner surface
3c Outer peripheral surface
4 Oil drainage passage
4a Inlet end
4b Outflow end
5 Oil reservoir
8a Lower step (step)
8b Upper step
8c Upper surface of the lower step
8d Lower step surface of the lower step
8e Side surface of the lower step
8f Lower step surface (upper end surface) of upper step
9 Oil drain
10 Scroll compressor
20 Motor (electric motor)
30 Scroll compression mechanism

Claims (6)

A scroll compression mechanism (30) having a movable scroll (35) and a fixed scroll (40), an electric motor (20) for driving the scroll compression mechanism (30), the electric motor (20), and the movable scroll (35) A scroll compressor including a drive shaft (23) that is connected in the vertical direction and a bearing housing (1) fixed to the fixed scroll (40),
The bearing housing (1) is formed in a cylindrical shape having a hollow portion, and is fixed to the inner peripheral surface (1b) of the bearing housing (1) to rotationally support the drive shaft (23) ( 2)
The bearing housing (1) is open at the upper end surface (8f) and is located on the outer periphery of the bearing clearance (2a) formed between the drive shaft (23) and the sliding bearing (2). An annular elastic groove (3);
Lubricating oil in the elastic groove (3) passes between the outer surface (7a) of the bearing housing (1) and the inner surface (3b, 3c) of the elastic groove (3). A scroll compressor comprising an oil discharge passage (4) for discharging to the outside. In claim 1,
The drive shaft (23) has an eccentric part (25) extending upward from the upper end surface of the sliding bearing part (2),
Scroll compression characterized in that an oil supply hole (6b) serving as an outflow end of an oil supply passage (27) formed inside the drive shaft (23) is opened on the outer surface of the eccentric part (25). Machine. In claim 1 or 2,
The scroll compressor characterized in that the inflow end (4a) of the oil drainage passage (4) opens at the bottom of the elastic groove (3). In any one of Claims 1-3,
A stepped portion (8a) is formed on the upper end surface (8f) of the bearing housing (1) so that the inner edge portion is lower than the outer edge portion of the upper end surface (8f),
An oil sump part (5) is formed in a space surrounded by the side peripheral surface (8e) of the step part (8a), and the bearing gap part (2a) and the elastic groove part (2) of the sliding bearing part (2) 3) opens toward the oil reservoir (5),
The scroll compressor characterized in that the oil drainage passage (4) extends in the tangential direction of the ring formed by the elastic groove (3) and in the rotational direction of the drive shaft (23). In any one of Claims 1-4,
The oil drain passage (4) is inclined obliquely downward from the inner surface (3b, 3c) of the elastic groove (3) toward the outer surface (7a) of the bearing housing (1). Compressor. In any one of Claims 1-4,
The oil compression passage (4) extends horizontally and linearly from the inner surface (3b, 3c) of the elastic groove (3) to the outer surface (7a) of the bearing housing (1). Machine.

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