CN108779775B

CN108779775B - Scroll compressor

Info

Publication number: CN108779775B
Application number: CN201780016615.5A
Authority: CN
Inventors: 佐藤泰造
Original assignee: Sanden Automotive Conponents Corp
Current assignee: Sanden Corp
Priority date: 2016-03-23
Filing date: 2017-02-24
Publication date: 2020-03-27
Anticipated expiration: 2037-02-24
Also published as: CN108779775A; DE112017001481T5; WO2017163814A1; JP2017172427A

Abstract

Provided is a scroll compressor capable of appropriately lubricating a sliding portion in a scroll unit. A scroll compressor (100) is configured to include: a housing (10) having a suction chamber (H1) and a discharge chamber (H2); a scroll unit (1) that compresses and discharges a refrigerant in a closed space (S) between a fixed scroll (2) and a movable scroll (3); a bearing holding section (30) that holds a bearing (17) that rotatably supports a drive shaft (21) and forms a back pressure chamber (3) between the bearing holding section and the orbiting scroll (3); a back pressure regulating valve (50); a fluid introduction passage (L1) that communicates the suction chamber (H1) with a space (H4) near the outer periphery of the scroll unit (1); a pressure supply passage (L3) that connects the discharge chamber (H2) and the back pressure chamber (H3); and a pressure release passage (L4) that connects the back pressure chamber (H3) and the fluid introduction passage (L1), wherein the back pressure regulating valve (50) is provided at the fluid introduction passage (L1) side opening end of the pressure release passage (L4).

Description

Scroll compressor

Technical Field

The present invention relates to a scroll compressor having a fixed scroll and a movable scroll which are engaged with each other, and compressing a fluid such as a refrigerant flowing into a space between the two scrolls.

Background

Such a scroll type compressor includes a scroll unit having a fixed scroll and an orbiting scroll engaged with each other, and is, for example, incorporated in a refrigerant circuit of a vehicle air conditioner for compressing a refrigerant of the refrigerant circuit. The scroll unit is configured such that a volume of a sealed space between the two scrolls is gradually reduced by orbiting and orbiting of the orbiting scroll around an axis of the fixed scroll via the drive shaft, a fluid such as a refrigerant gas flowing into the suction chamber is compressed in the sealed space, and the compressed fluid is discharged via the discharge chamber.

As such a scroll compressor, for example, a scroll compressor described in patent document 1 is generally known. The scroll compressor described in patent document 1 has a back pressure chamber between the orbiting scroll and a bearing holding portion that rotatably supports an end portion of the driving shaft on the orbiting scroll side. The back pressure chamber is communicated with the discharge chamber and the suction chamber. A back pressure regulating valve is provided in a passage that communicates the back pressure chamber with the suction chamber, and the pressure in the back pressure chamber is regulated to a pressure intermediate between the pressure in the suction chamber and the pressure in the discharge chamber by the back pressure regulating valve. In the scroll compressor described in patent document 1, lubricating oil is supplied into the back pressure chamber for lubricating sliding portions such as the drive shaft in the back pressure chamber. The lubricating oil supplied into the back pressure chamber is directly discharged into the suction chamber through a passage that communicates the back pressure chamber with the suction chamber and a back pressure regulating valve provided in the middle of the passage.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2015-38327

Disclosure of Invention

Technical problem to be solved by the invention

However, in such a scroll compressor, the lubricating oil is not limited to the sliding portion such as the drive shaft in the back pressure chamber, and the lubricating oil is also required in the sliding portion in the scroll unit. A small amount of lubricant may be contained in the refrigerant gas supplied from the suction chamber to the scroll unit, but the lubrication of the sliding portions in the scroll unit may be insufficient with a small amount of lubricant.

In this regard, in the scroll compressor described in patent document 1, since the lubricating oil is supplied only to the back pressure chamber, there is a possibility that the lubrication of the sliding portion in the scroll unit is insufficient.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a scroll compressor which can appropriately lubricate a sliding portion in a scroll unit as well as a sliding portion in a back pressure chamber.

Technical scheme for solving technical problem

A scroll-type compressor of an aspect of the present invention includes: a housing having a suction chamber and a discharge chamber for fluid therein; a scroll unit which is provided in the housing, has a fixed scroll and a movable scroll engaged with each other, and compresses a fluid flowing into the suction chamber in a sealed space between the two scrolls by revolving and revolving the movable scroll around an axis of the fixed scroll via a drive shaft, and discharges the compressed fluid via the discharge chamber; a bearing holding portion provided in the housing, holding a bearing portion that rotatably supports an end portion of the drive shaft on the movable scroll side, and forming a back pressure chamber between the bearing holding portion and the movable scroll; and a back pressure regulating valve for regulating the pressure in the back pressure chamber, wherein the back pressure regulating valve comprises: a fluid introduction passage formed by an inner circumferential surface of a circumferential wall portion of the housing and an outer circumferential surface of the bearing holding portion, the fluid introduction passage communicating the suction chamber with a space in the vicinity of an outer circumferential portion of the scroll unit; a pressure supply passage that communicates the discharge chamber with the back pressure chamber; and a pressure release passage that communicates the back pressure chamber with the fluid introduction passage, wherein the back pressure regulating valve is provided at an opening end of the pressure release passage on the fluid introduction passage side.

Effects of the invention

According to the scroll compressor of the above aspect, the fluid in the suction chamber can be guided to the space near the outer peripheral portion of the scroll unit via the fluid introduction passage, the fluid in the discharge chamber can be guided to the back pressure chamber via the pressure supply passage, the fluid in the back pressure chamber can be guided to the middle of the fluid introduction passage via the pressure release passage and the back pressure regulating valve, and returned to the scroll unit side following the flow in the fluid introduction passage. Thus, even if the amount of lubricating oil in the fluid flowing from the suction chamber to the fluid introduction passage is small, the lubricating oil is returned to the middle of the fluid introduction passage through the pressure release passage and the back pressure regulating valve, and the lubricating oil from the back pressure chamber is supplied to the scroll unit together with the lubricating oil from the suction chamber.

Thus, a scroll compressor capable of appropriately lubricating a sliding portion of a scroll unit can be provided.

Drawings

Fig. 1 is a schematic sectional view of a scroll compressor according to an embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view for explaining a fastening state of the bearing holding portion of the scroll compressor.

Fig. 3 is a block diagram for explaining the refrigerant flow in the scroll compressor.

Fig. 4 is a main part sectional view showing a main part of the scroll compressor.

Fig. 5 is a view showing a modification of the bearing holding portion and the fixed scroll of the scroll compressor.

Detailed Description

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

Fig. 1 is a schematic cross-sectional view of a scroll compressor according to the present embodiment.

The scroll compressor 100 of the present embodiment is, for example, a component incorporated in a refrigerant circuit of a vehicle air conditioner, and compresses and discharges a refrigerant (fluid) drawn from a low-pressure side of the refrigerant circuit.

The scroll compressor 100 includes: a scroll unit 1; a casing 10 having a refrigerant suction chamber H1 and a refrigerant discharge chamber H2 inside the casing 10; an electric motor 20 as a driving part that drives the scroll unit 1; a bearing holding portion 30 for rotatably supporting one end portion (an upper end portion in fig. 1) of the drive shaft 21 of the electric motor 20; and an inverter 40 for controlling driving of the electric motor 20. In addition, in the present embodiment, CO is used₂The refrigerant is the refrigerant. The scroll compressor 100 is described by taking as an example a so-called inverter-integrated compressor. The scroll unit 1 has a fixed scroll 2 and a movable scroll 3 engaged with each other. The fixed scroll 2 is integrally formed with a wrap 2b on a disk-shaped bottom plate 2 a. The movable scroll 3 is in a circleA scroll wrap 3b is integrally formed on the disc-shaped bottom plate 3 a. Further, a bottom plate 2a of the fixed scroll 2 has a larger diameter than a bottom plate 3a of the movable scroll 3.

The two

scrolls

2, 3 are arranged such that wrap 2b of fixed scroll 2 meshes with wrap 3b of orbiting scroll 3. Specifically, the two

scrolls

2 and 3 are disposed such that a predetermined gap is provided between the end edge of the protruding side of wrap 2b of fixed scroll 2 and bottom plate 3a of movable scroll 3, and a predetermined gap is provided between the end edge of the protruding side of wrap 3b of movable scroll 3 and bottom plate 2a of fixed scroll 2. The gap that fluctuates during the compression operation is maintained within an appropriate range during the compression operation, and the airtightness of a sealed space (compression chamber) S, which will be described later, is appropriately maintained.

Further, the two

scrolls

2 and 3 are disposed so that the side walls of the two

scroll wraps

2b and 3b partially contact each other in a state where the circumferential angles of the two

scroll wraps

2b and 3b are offset from each other. Thereby, a crescent-shaped closed space (compression chamber) S is formed between the two

scroll wraps

2b and 3 b.

The fixed scroll 2 is fixed to a rear housing 12, which will be described later, of the housing 10, and has a groove portion 2a1 opening toward the rear housing 12 at a radial center portion of the fixed scroll 2. Specifically, the groove portion 2a1 is formed on the back surface of the base plate 2a (i.e., the end surface on the opposite side of the orbiting scroll 3).

Orbiting scroll 3 is configured to be capable of orbiting around the axis of fixed scroll 2 via drive shaft 21 in a state where rotation of orbiting scroll 3 is prevented. Thus, the scroll unit 1 moves the sealed space S formed between the two

scrolls

2 and 3, more specifically, between the two

wrap windings

2b and 3b, toward the center portion, so that the volume of the sealed space gradually decreases. As a result, the scroll unit 1 compresses the refrigerant flowing into the sealed space S from the outer end portion side of the

wrap

2b and 3b in the sealed space S.

As shown in fig. 1, the casing 10 mainly includes a front casing 11, and the front casing 11 accommodates the scroll unit 1, the electric motor 20, the bearing holding portion 30, and the inverter 40 therein; a rear housing 12; and an inverter cover 13. These members (11, 12, 13) are integrally fastened by fastening means such as bolts 14, thereby constituting the casing 10 of the scroll compressor 100.

The front housing 11 has a substantially annular peripheral wall portion 11a and a partition wall portion 11 b. The internal space of front housing 11 is partitioned by partition wall portion 11b into an accommodation space for accommodating scroll unit 1, electric motor 20, and bearing holding portion 30, and an accommodation space for accommodating inverter 40. An opening of one end side (upper side in fig. 1) of the peripheral wall portion 11a is closed by the rear case 12. The opening on the other end side (lower side in fig. 1) of the peripheral wall portion 11a is closed by the inverter cover 13. A cylindrical support portion 11b1 is provided to project toward one end of the peripheral wall portion 11a at the radially central portion of the partition wall portion 11b, the support portion 11b1 holds the bearing 15, and the bearing 15 supports the other end (lower end in fig. 1) of the drive shaft 21.

Further, a refrigerant suction port P1 is formed in the peripheral wall portion 11 a. The refrigerant from the low-pressure side of the refrigerant circuit is sucked into the front housing 11 through the suction port P1. Therefore, the space inside the front housing 11 functions as the suction chamber H1. The refrigerant is configured to flow around the electric motor 20 and the like in the suction chamber H1, thereby cooling the electric motor 20. In fig. 1, the space above the electric motor 20 communicates with the space below the electric motor 20, and constitutes one suction chamber H1 together with the space below the electric motor 20. In the suction chamber H1, the refrigerant flows as a mixed fluid mixed with a small amount of lubricating oil.

The rear case 12 is formed in a disk shape having an outer diameter corresponding to the outer diameter of the peripheral wall portion 11a of the front case 11. The peripheral edge portion of the rear case 12 is fastened to one end side (upper end in fig. 1) of the peripheral wall portion 11a by fastening means such as an appropriate number of bolts 14 so as to close the opening of the one end side of the front case 11.

Further, a peripheral edge portion (in other words, a portion surrounding the groove portion 2a 1) of the back surface of the bottom plate 2a of the fixed scroll 2 abuts against one end surface of the rear housing 12. A refrigerant discharge chamber H2 is defined by one end surface of the rear case 12 and the groove portion 2a1 of the bottom plate 2 a. A discharge passage L2 for compressed refrigerant is formed in the center of the bottom plate 2 a. Further, the discharge chamber H2 is provided with a check valve (check valve for restricting the flow from the discharge chamber H2 to the scroll unit 1 side) 16 so as to cover the opening of the discharge passage L2. In the discharge chamber H2, the refrigerant compressed in the sealed space S formed between the two scroll wraps 2b and 3b is discharged through the discharge passage L2 and the check valve 16. Further, a discharge port P2 is formed in the rear housing 12, and the discharge port P2 communicates the discharge chamber H2 with the outside (the high-pressure side of the refrigerant circuit). The compressed refrigerant in the discharge chamber H2 is discharged to the high-pressure side of the refrigerant circuit through the discharge port P2.

Although not shown, for example, a suitable oil separator for separating the lubricating oil from the compressed refrigerant flowing into the discharge port P2 is provided in the discharge port P2. The refrigerant from which the lubricating oil has been separated by the oil separator (including the refrigerant in which a slight amount of lubricating oil remains) is discharged to the high-pressure side of the refrigerant circuit through the discharge port P2. On the other hand, the lubricating oil separated by the oil separator is guided to a pressure supply passage L3 described later.

The electric motor 20 is configured to include a drive shaft 21, a rotor 22, and a stator core unit 23 arranged radially outward of the rotor 22, and a three-phase ac motor, for example, is applied to the electric motor 20. For example, a direct current from a battery (not shown) of the vehicle is converted into an alternating current by the inverter 40, and the alternating current is supplied to the electric motor 20.

Drive shaft 21 is connected to orbiting scroll 3 via a crank mechanism, and transmits the rotational force of electric motor 20 to orbiting scroll 3. One end portion of the drive shaft 21 (i.e., the end portion on the movable scroll 3 side) is inserted through a through hole formed in the bearing holding portion 30 and is rotatably supported by the bearing 17, and the other end portion of the drive shaft 21 (the end portion on the inverter 40 side) is rotatably supported by the bearing 15 fitted to the support portion 11b 1. In the present embodiment, the bearing 17 corresponds to the "bearing portion" of the present invention.

The rotor 22 is rotatably supported on the radially inner side of the stator core unit 23 via a drive shaft 21 fitted (e.g., press-fitted) to a shaft hole formed in the radial center of the rotor 22. When a magnetic field is generated at stator core unit 23 due to power supply from inverter 40, a rotational force acts on rotor 22 to drive rotation of drive shaft 21.

The bearing holding portion 30 is a member that is provided in the front housing 11 and holds a bearing 17, and the bearing 17 is a bearing portion that rotatably supports the end portion of the drive shaft 21 on the orbiting scroll 3 side. The bearing holding portion 30 is formed in a bottomed cylindrical shape having an outer diameter suitable for the outer diameter of the bottom plate 2a of the fixed scroll 2, for example, and has a cylindrical portion 30a and a bottom wall portion 30b, and the bottom wall portion 30b is located on one end side of the cylindrical portion 30 a. The cylindrical portion 30a has a shoulder portion 30a3 that extends between the large diameter portion 30a1 and the small diameter portion 30a2 of the cylindrical portion 30a, and has an opening side inner diameter larger than the bottom wall portion 30b inner diameter of the cylindrical portion 30 a. Orbiting scroll 3 is housed in a space defined by large diameter portion 30a1 and shoulder portion 30a 3. An opening-side end of the cylindrical portion 30a abuts against a peripheral edge portion of an end surface of the base plate 2a on the movable scroll 3 side. Therefore, the opening of the bearing holding portion 30 is closed by the fixed scroll 2. Further, a bearing 17 is fitted to the small-diameter portion 30a2 of the cylindrical portion 30 a. A through hole through which the end of drive shaft 21 on orbiting scroll 3 side is inserted is formed in the radial center portion of bottom wall portion 30 b. A suitable seal member 18a is provided between the bearing 17 and the bottom wall portion 30b to ensure airtightness of a back pressure chamber H3 described later.

Annular thrust plate 19 is disposed between shoulder portion 30a3 of bearing holding portion 30 and base plate 3a of orbiting scroll 3. Shoulder 30a3 receives thrust from orbiting scroll 3 via thrust plate 19. The seal members 18b are disposed at the shoulder portion 30a3 and the bottom plate 3a at portions that abut against the thrust plate 19.

Further, a back pressure chamber H3 is defined between the bottom plate 3a and the small diameter portion 30a2 by the

seal members

18a, 18 b. That is, a back pressure chamber H3 is formed between bearing holder 30 and orbiting scroll 3. A fluid introduction passage L1 is formed between the inner peripheral surface of the peripheral wall portion 11a of the front housing 11 and the outer peripheral surface of the cylindrical portion 30a of the bearing holding portion 30, and the fluid introduction passage L1 is used to communicate between the suction chamber H1 and a space H4 near the outer peripheral portions of the two scroll wraps 2b and 3b of the scroll unit 1, and to introduce a refrigerant (specifically, a mixed fluid in which the refrigerant and a small amount of lubricating oil are mixed) from the suction chamber H1 into the space H4. That is, in the present embodiment, the fluid introduction passage L1 that communicates the suction chamber H1 with the space H4 is formed by the inner peripheral surface of the peripheral wall portion 11a of the front housing 11 and the outer peripheral surface of the cylindrical portion 30a of the bearing holding portion 30. Therefore, the pressure in the space H4 is equal to the pressure in the suction chamber H1.

In the present embodiment, the crank mechanism includes: a cylindrical boss portion 24, the boss portion 24 being formed to protrude from the back surface (end surface on the back pressure chamber H3 side) of the bottom plate 3 a; an eccentric bush 26, the eccentric bush 26 being mounted in an eccentric state to a crank 25 provided at an end of the drive shaft 21 on the orbiting scroll 3 side; and a sliding bearing 27, wherein the sliding bearing 27 is fitted to the boss portion 24. The eccentric bush 26 is rotatably supported in the boss portion 24 via a slide bearing 27. Further, a balance weight 28 is attached to the end of drive shaft 21 on orbiting scroll 3 side to oppose the centrifugal force generated when orbiting scroll 3 operates. Although not shown, a rotation preventing mechanism for preventing rotation of orbiting scroll 3 can be provided as appropriate. Accordingly, orbiting scroll 3 is configured to be capable of orbiting and revolving around the axis of fixed scroll 2 via the crank mechanism in a state where the rotation of orbiting scroll 3 is prevented.

Fig. 2 is a schematic cross-sectional view for explaining a fastened state of the bearing holding portion 30, which is shown at a cross-sectional position of the bearing holding portion 30 including the fastening bolt 14.

In the present embodiment, as shown in fig. 2, the bearing holding portion 30 is fastened to the fixed scroll 2 and the rear housing 12 by the fastening bolt 14 in a state where the fixed scroll 2 is sandwiched between the rear housing 12 and the bearing holding portion.

Specifically, the fixed scroll 2 has a peripheral portion of the rear surface of the bottom plate 2a in contact with one end surface of the rear housing 12, and has a peripheral portion of the end surface of the bottom plate 2a on the movable scroll 3 side in contact with the opening-side end portion of the cylindrical portion 30a of the bearing holding portion 30 so as to be sandwiched between the rear housing 12 and the bearing holding portion 30. The bearing holding portion 30 and the fixed scroll 2 have through holes 14a, the through holes 14a being formed at a plurality of circumferentially spaced positions of the bearing holding portion 30 and the peripheral portion of the fixed scroll 2 (in detail, the cylindrical portion 30a and the peripheral portion of the bottom plate 2 a) so as to extend in the extending direction of the drive shaft 21, and the through holes 14a through which bolts 14 for fastening the fixed scroll 2 and the rear housing 12 are inserted. Further, a female screw portion is formed on one end surface side of the rear housing 12 corresponding to the opening position of the through hole. The bolt 14 is inserted through the through hole 14a of the cylindrical portion 30a and the bottom plate 2a, and is screwed with the female screw portion of the rear housing 12. In this way, the bearing holding portion 30 is fastened to the fixed scroll 2 and the rear housing 12.

In the present embodiment, the fluid introduction passage L1 extends along a recessed portion 30c (see fig. 1 and fig. 4 described later), which recessed portion 30c extends in the extending direction of the drive shaft 21 between the formation locations of the through holes 14a in the peripheral edge portion (i.e., the cylindrical portion 30a) of the bearing holding portion 30. That is, the fluid introduction passage L1 is partitioned mainly by a portion (the concave portion 30c) of the cylindrical portion 30a that is recessed toward the drive shaft 21 side as appropriate for weight reduction at a portion avoiding the formation portion of the through hole 14a and a corresponding portion of the inner peripheral surface of the peripheral wall portion 11a that faces this portion. One end of the fluid introduction passage L1 opens into the suction chamber H1, and the other end of the fluid introduction passage L1 penetrates the end of the cylindrical portion 30a and opens into the space H4.

Fig. 3 is a block diagram for explaining the flow of refrigerant in the scroll compressor 100.

The refrigerant from the low-pressure side of the refrigerant circuit is introduced into the suction chamber H1 through the suction port P1, and then introduced into the space H4 near the outer end of the scroll unit 1 through the fluid introduction passage L1. Then, the refrigerant in the space H4 is sucked into the sealed space S between the scroll wrap 2b and the scroll wrap 3b, and is compressed in the sealed space S. The compressed refrigerant is discharged to the discharge chamber H2 through the discharge passage L2 and the check valve 16, and then discharged from the discharge chamber H2 to the high-pressure side of the refrigerant circuit through the discharge port P2. In this way, the scroll unit 1 is configured such that the scroll unit 1 compresses the refrigerant flowing into the suction chamber H1 in the closed space S and discharges the compressed refrigerant through the discharge chamber H2.

Here, returning to fig. 1, the scroll compressor 100 of the present embodiment further includes a back pressure regulating valve 50 for regulating the pressure in the back pressure chamber H3.

In the present embodiment, the back pressure regulating valve 50 is a differential pressure operated check valve, and is operated in the valve opening direction when the differential pressure between the pressure in the back pressure chamber H3 and the pressure in the suction chamber H1 is greater than a predetermined differential pressure, and is operated in the valve closing direction when the differential pressure is equal to or less than the predetermined differential pressure, so that the pressure in the back pressure chamber H3 is regulated to a predetermined pressure (intermediate pressure) between the pressure (high pressure) in the discharge chamber H2 and the pressure (low pressure) in the suction chamber H1. The arrangement position, structure, and back pressure adjusting operation of the back pressure adjusting valve 50 will be described in detail later.

In the present embodiment, as shown in fig. 1 to 3, the scroll compressor 100 includes a pressure supply passage L3 and a pressure release passage L4 in addition to a fluid introduction passage L1 and a discharge passage L2.

The pressure supply passage L3 is a passage for communicating the discharge chamber H2 with the back pressure chamber H3. The lubricating oil separated from the compressed refrigerant in the discharge port P2 by an oil separator (not shown) is guided into the back pressure chamber H3 through the pressure supply passage L3 and used for lubricating the sliding portions in the back pressure chamber H3. Further, the pressure in the back pressure chamber H3 is increased by the discharge chamber H2 and the back pressure chamber H3 communicating with each other through the pressure supply passage L3.

In the present embodiment, specifically, the pressure supply passage L3 includes: a passage formed in the rear housing 12, one end of which opens into the discharge chamber H2 via the discharge port P2 and the other end of which opens into a portion abutting against the bottom plate 2 a; a passage connected to the passage and penetrating the bottom plate 2 a; and a passage connected to the passage penetrating the bottom plate 2a, penetrating the cylindrical portion 30a, and opening into the back pressure chamber H3. An orifice OL is provided in the middle of the pressure supply passage L3. Therefore, the lubricating oil or the like separated from the compressed refrigerant in the discharge chamber H2 is appropriately decompressed by the port OL and supplied into the back pressure chamber H3 through the pressure supply passage L3.

The pressure release passage L4 is a passage for communicating the back pressure chamber H3 and the suction chamber H1.

In the present embodiment, specifically, the pressure release passage L4 penetrates the small-diameter portion 30a2 of the cylindrical portion 30a and extends in a direction orthogonal to the drive shaft 21. One end of the pressure release passage L4 opens into the back pressure chamber H3, and the other end of the pressure release passage L4 opens into the fluid introduction passage L1.

Next, the arrangement position and the structure of the back pressure regulating valve 50 according to the present embodiment will be described in detail with reference to fig. 1 and 4. Fig. 4 is an enlarged sectional view of a main portion including the back pressure regulating valve 50, which shows an open state.

The back pressure regulating valve 50 includes a valve housing 51, a valve seat housing 52, a valve body 53, and a biasing member 54, and the back pressure regulating valve 50 is provided at an opening end of the pressure release passage L4 on the fluid introduction passage L1 side and constitutes a part of the pressure release passage L4.

The valve housing 51 has a cylindrical portion 51a and a bottom wall portion 51b, the bottom wall portion 51b closes one end of the cylindrical portion 51a, and the valve housing 51 is formed in a bottomed tubular shape as a whole and has a valve chamber 51c therein.

The cylindrical portion 51a and the bottom wall portion 51b are formed with outlet holes 55, respectively, and the outlet holes 55 are opened to the fluid introduction passage L1. In the present embodiment, two outlet holes 55 are opened in the cylindrical portion 51a, and one outlet hole is opened in the bottom wall portion 51 b. The outlet hole 55 communicates the space in the fluid introduction passage L1 with the valve chamber 51c in the valve housing 51.

Specifically, as shown in fig. 4, of the outlet holes 55, two cylindrical portion outlet holes 55a that open in the cylindrical portion 51a are partially located in the fluid introduction passage L1. On the other hand, as shown in fig. 4, the entire bottom wall portion outlet hole 55b, which is opened in the bottom wall portion 51b, of the outlet holes 55 is located in the fluid introduction passage L1. As described above, in the present embodiment, the pressure regulating valve 50 is disposed such that at least a part of the outlet hole 55 is located in the fluid introduction passage L1. That is, at least one of the plurality of outlet holes 55 (bottom wall portion outlet hole 55b) is located entirely within the fluid introduction passage L1, and with respect to the cylindrical portion outlet hole 55a, is located partially within the fluid introduction passage L1.

More specifically, the back pressure regulating valve 50 is disposed such that the cylindrical outlet hole 55a opens at a position on the side closer to the pressure release passage L4 in the fluid introduction passage L1. Specifically, the cylindrical outlet hole 55a is positioned so as to extend across the boundary between the fluid introduction passage L1 and the pressure release passage L4.

Further, the cylindrical portion outlet hole 55a opens in a direction parallel to the extending direction of the fluid introduction passage L1 (in other words, a direction parallel to the flow of the refrigerant flowing through the fluid introduction passage L1 indicated by an open arrow in fig. 4) at the opening end side (the valve seat housing 52 side) of the cylindrical portion 51 a. On the other hand, the bottom wall outlet hole 55b opens in a direction perpendicular to the fluid introduction passage L1. As described above, in the present embodiment, at least a part of the plurality of outlet holes 55 (the cylindrical outlet hole 55a) is opened in a direction parallel to the extending direction of the fluid introduction passage L1.

The seat case 52 constitutes one end portion of the back pressure regulating valve 50, and is fitted to an opening end portion of the pressure release passage L4 on the fluid introduction passage L1 side. The valve seat housing 52 is formed in a bottomed cylindrical shape having an outer diameter corresponding to the inner diameter of the pressure release passage L4, for example, and has a cylindrical portion 52a and a bottom wall portion 52b located on one end side of the cylindrical portion 52a, and the other end side of the cylindrical portion 52a is fixed to the open end side of the valve housing 51. A valve seat portion 52c is formed at a portion of the cylindrical portion 52a on the bottom wall portion 52b side, and the valve seat portion 52c has a conical surface that is in contact with and separated from the valve body 53. The valve seat housing 52 has an inlet hole 52d, and the inlet hole 52d is formed through a bottom wall portion 52b of the valve seat housing 52 and opens toward the back pressure chamber H3 side of the pressure release passage L4. One end of the inlet port 52d is opened to the valve seat portion 52c, and the other end is opened to a space on the back pressure chamber H3 side of the relief passage L4.

The valve body 53 is a member for opening and closing the inlet hole 52d, is formed in a bead shape, and is biased toward the valve seat portion 52c by the biasing element 54.

The biasing member 54 includes: a coil spring 54a, one end of the coil spring 54a abutting against the bottom wall 51b of the valve housing 51; and an urging rod 54b, the urging rod 54b being connected to the other end of the coil spring 54a and urging the valve body 53 in the valve closing direction, and the urging element 54 being disposed in the valve chamber 51c of the valve housing 51.

In the present embodiment, the back pressure regulating valve 5 is configured to include: a valve housing 51; a valve seat housing 52; an inlet hole 52d, the inlet hole 52d being open to the back pressure chamber H3 side of the relief passage L4; a valve body 53, the valve body 53 opening and closing the inlet hole 52 d; a force application element 54; and an outlet hole 55(55a, 55b) that opens into the fluid introduction passage L1, and that moves the valve body 53 in the valve opening direction when the differential pressure between the pressure in the back pressure chamber H3 and the pressure in the suction chamber H1 is greater than a predetermined differential pressure, and that moves the valve body 53 in the valve closing direction when the differential pressure is equal to or less than the predetermined differential pressure.

Next, the operation of adjusting the pressure in the back pressure chamber by the back pressure adjusting valve 50 having the above-described configuration in the scroll compressor 100 will be schematically described. In the following, a case will be described in which the back pressure regulating valve 50 is in a closed state, the back pressure chamber H3 communicates with the discharge chamber H2 via the pressure supply passage L3 and the orifice OL, and the pressure in the back pressure chamber H3 is increased by lubricating oil or the like.

First, the back pressure regulating valve 50 presses the valve body 53 against the valve seat portion 52c by the biasing member 54 to close the inlet hole 52 d. At this time, the biasing force of the coil spring 54a of the biasing element 54 and the pressure in the suction chamber H1 transmitted through the fluid introduction passage L1 and the outlet hole 55 act on the valve body 53. In this state, the pressure in the back pressure chamber H3 gradually increases, and when the differential pressure between the pressure in the back pressure chamber H3 and the pressure in the suction chamber H1 is larger than a predetermined differential pressure determined by the biasing force of the biasing element 54, the valve body 53 moves in the valve opening direction against the biasing force of the biasing element 54. Thereby, the back pressure regulating valve 50 reduces the pressure in the back pressure chamber H3. The lubricating oil or the like guided to the middle of the fluid introduction passage L1 through the back pressure adjustment valve 50 follows the flow in the fluid introduction passage L1 and returns to the scroll unit 1 side (space H4 side). When the differential pressure is smaller than the predetermined differential pressure, the valve body 53 moves in the valve closing direction by the urging force of the urging element 54. Thereby, the back pressure regulating valve 50 increases the pressure in the back pressure chamber H3.

According to the scroll compressor 100 of the present embodiment, the refrigerant in the suction chamber H1 is guided to the space H4 near the outer periphery of the scroll unit 1 through the fluid introduction passage L1, the lubricating oil contained in the refrigerant in the discharge chamber H2 is mainly guided to the back pressure chamber H3 through the pressure supply passage L3, and the lubricating oil and the like in the back pressure chamber H3 is guided to the middle of the fluid introduction passage L1 through the pressure release passage L4 and the back pressure adjustment valve 50, and is returned to the scroll unit 1 side following the flow in the fluid introduction passage L1. Accordingly, even if the amount of lubricant in the refrigerant flowing from the suction chamber H1 to the fluid introduction passage L1 is small, the lubricant oil and the like is returned to the middle of the fluid introduction passage L1 via the pressure release passage L4 and the back pressure adjustment valve 50, and the lubricant oil and the like from the back pressure chamber H3 is supplied to the scroll unit 1 together with the refrigerant containing the small amount of lubricant oil from the suction chamber H1.

Thus, the scroll compressor 100 can be provided which can appropriately lubricate the sliding portion of the scroll unit 1.

In the present embodiment, the inflow introduction passage L1 is formed by the inner peripheral surface of the peripheral wall portion 11a of the front housing 11 and the outer peripheral surface of the bearing holding portion 30 (specifically, the inner surface of the recess 30 c). This makes it easy to form the fluid introduction passage L1.

In the present embodiment, the back pressure regulating valve 50 is a so-called differential pressure operation type check valve including: an inlet hole 52d, the inlet hole 52d being open to the back pressure chamber H3 side of the relief passage L4; a valve body 53, the valve body 53 opening and closing the inlet hole 52 d; and an outlet hole 55 that opens into the fluid introduction passage L1, and that moves the valve body 53 in the valve opening direction when a differential pressure between the pressure in the back pressure chamber H3 and the pressure in the suction chamber H1 is greater than a predetermined differential pressure, and that moves the valve body 53 in the valve closing direction when the differential pressure is equal to or less than the predetermined differential pressure. This makes it possible to provide the back pressure regulating valve 50 capable of autonomously regulating the pressure in the back pressure chamber H3 by sensing the differential pressure without using electricity.

Here, when the back pressure regulating valve 50 is of the differential pressure operation type, if an obstacle that impedes the flow of the fluid flowing out of the outlet port 55 approaches the vicinity of the outlet port 55, the pressure loss on the downstream side of the valve body 53 becomes excessively large. At this time, the back pressure regulating valve 50 may not be normally operated.

In this regard, in the present embodiment, the cylindrical outlet hole 55a of the outlet holes 55 is opened at a position on the side close to the pressure release passage L4 in the fluid introduction passage L1. That is, the back pressure regulating valve 50 is disposed such that the cylindrical outlet hole 55a (at least a part of the outlet hole) is opened at a position in the fluid introduction passage L1 on the side close to the pressure release passage L4. This enables at least a part (55a) of the outlet hole 55 to be opened in a large space without any obstacle. As a result, the pressure loss on the downstream side of the valve body 53 can be reduced, and the back pressure regulating valve 50 can be operated appropriately. Thus, it is possible to provide the back pressure regulating valve 50 using CO as in the present embodiment₂The refrigerant can be operated appropriately according to a predetermined differential pressure even when the differential pressure between the pressure in the back pressure chamber H3 and the pressure in the suction chamber H1 is larger than the conventional differential pressure and high controllability is required for the back pressure regulating valve 50.

In the present embodiment, at least a part of the plurality of outlet holes 55 (the cylindrical outlet hole 55a) is opened in a direction parallel to the extending direction of the fluid introduction passage L1. This allows the lubricating oil or the like guided to the middle of the fluid introduction passage L1 via the pressure release passage L4 and the back pressure adjustment valve 50 to reliably follow the flow of the fluid introduction passage L1, and therefore allows the lubricating oil or the like to be more reliably returned to the scroll unit 1 side.

In addition, in the present embodiment, the following structure is provided: the fluid introduction passage L1 extends along a recessed portion 30c extending in the extending direction of the drive shaft 21 between the formation locations of the through holes 14a in the peripheral edge portion (i.e., the cylindrical portion 30a) of the bearing holding portion 30, through which the fastening bolts 14 are inserted. That is, in the present embodiment, the fluid introduction passage L1 is formed by the concave portion 30c, and the concave portion 30c is a portion recessed for reducing the weight of the front housing 11. This can reduce the weight of the front housing 11 and facilitate the formation of the fluid introduction passage L1.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications and changes can be made based on the technical idea of the present invention.

For example, in the present embodiment, the orbiting scroll 3 is housed in the bearing holding portion 30 (specifically, the large diameter portion 30a1), but the present invention is not limited to this, and may be configured to be housed in the fixed scroll 2 as shown in fig. 5. In this case, a large diameter portion 2a3 protruding toward the bearing holding portion 30 is formed in the peripheral edge portion of the bottom plate 2a of the fixed scroll 2, and the movable scroll 3 is accommodated in the large diameter portion 2a3 of the fixed scroll 2. The bearing holding portion 30 may have a cylindrical portion 30a provided with a small-diameter portion 30a2 into which the bearing 17 is fitted. In the case of the above modification, the fluid introduction passage L1 is formed by the inner surface of the peripheral wall portion 11a of the front housing 11, the outer peripheral surface of the bearing holding portion 30 (the inner surface of the recess 30c), and the outer peripheral surface of the fixed scroll 2 (the inner surface of the recess 2c extending in communication with the recess 30 c).

The number, opening position, opening direction, and formation position of the fluid introduction passage L1 of the outlet holes 55 of the back pressure adjustment valve 50 can be set as appropriate.

For example, the number of outlet holes 55 is three, but one or two or four or more may be provided. In addition, in the present embodiment, the case where the cylindrical outlet hole 55a is positioned so as to extend over the boundary between the fluid introduction passage L1 and the pressure release passage L4 is described as an example, but the present invention is not limited to this, and the entire cylindrical outlet hole 55a may be positioned in the fluid introduction passage L1, so long as the cylindrical outlet hole 55a is opened in the fluid introduction passage L1 at a position close to the pressure release passage L1 side, the pressure loss on the downstream side of the valve body 53 can be effectively reduced, and the back pressure regulating valve 50 can be operated appropriately. Further, if the back pressure adjusting valve 50 is provided at the fluid introduction passage side opening end of the pressure release passage L4, the lubricating oil and the like in the back pressure chamber H3 can be returned to the sliding portion of the scroll unit 1 through the fluid introduction passage L1.

In the present embodiment, the description has been given by taking an example in which the scroll compressor 100 is a so-called inverter-integrated compressor, but the present invention is not limited to this, and the scroll compressor 100 may be separate from the inverter 40. At this time, it is sufficient that the housing 10 includes the front housing 11 and the rear housing 12.

In the present embodiment, CO is used as the refrigerant₂The refrigerant is not limited to this, and an appropriate refrigerant can be applied.

(symbol description)

1 … … scroll unit;

2 … … fixed scroll;

3 … … orbiting scroll;

10 … … a housing;

11a … … peripheral wall portion;

14 … … bolt;

14a … … through holes;

17 … … bearing (bearing portion);

21 … … drive shaft;

30 … … bearing holding part;

30a … … cylindrical portion (peripheral edge portion);

30c … … recess;

50 … … back pressure regulating valve;

52d … … inlet aperture;

55 … … an outlet aperture;

a 53 … … valve cartridge;

55a … … cylindrical portion outlet hole (outlet hole);

55b … … bottom wall portion outlet hole (outlet hole);

100 … … scroll type compressor;

h1 … … suction chamber;

h2 … … discharge chamber;

h3 … … back pressure chamber;

h4 … … space;

an L1 … … fluid introduction path;

an L3 … … pressure supply path;

l4 … … pressure relief path;

s … … sealing the space.

Claims

1. A scroll-type compressor comprising:

a housing having a suction chamber and a discharge chamber for fluid therein;

a scroll unit provided in the housing, having a fixed scroll and an orbiting scroll engaged with each other, compressing a fluid flowing into the suction chamber in a sealed space between the two scrolls by orbiting and orbiting the orbiting scroll around an axis of the fixed scroll via a driving shaft, and discharging the compressed fluid via the discharge chamber;

a bearing holding portion provided in the housing, holding a bearing portion that rotatably supports an end portion of the drive shaft on the movable scroll side, and forming a back pressure chamber between the bearing holding portion and the movable scroll; and

a back pressure regulating valve for regulating the pressure in the back pressure chamber,

it is characterized by comprising:

a fluid introduction passage that communicates the suction chamber with a space near an outer peripheral portion of the scroll unit;

a pressure supply passage that communicates the discharge chamber with the back pressure chamber; and

a pressure release passage that communicates the back pressure chamber with the fluid introduction passage, one end portion of the pressure release passage being open to the back pressure chamber, the other end portion of the pressure release passage being open to the fluid introduction passage,

the back pressure regulating valve is provided at an opening end of the pressure release passage on the fluid introduction passage side,

through holes extending in the extending direction of the drive shaft are opened at a plurality of circumferentially spaced locations of the peripheral edge portion of the bearing holding portion, the through holes being through which bolts for fastening the fixed scroll and the housing to the bearing holding portion are inserted,

the fluid introduction passage extends along a recess portion, which is a portion recessed toward the drive shaft side, between formation portions of the through hole in the peripheral edge portion of the bearing holding portion in the housing, the recess portion extending in an extending direction of the drive shaft.

2. A scroll compressor according to claim 1,

the fluid introduction passage is formed by an inner peripheral surface of the peripheral wall portion of the housing and an outer peripheral surface of the bearing holding portion.

3. Scroll compressor according to claim 1 or 2,

the back pressure regulating valve has:

an inlet hole that opens toward a back pressure chamber side of the pressure release passage; a valve body which opens and closes the inlet hole; and an outlet hole that opens toward the fluid introduction passage,

moving the valve body in a valve opening direction when a differential pressure between a pressure in the back pressure chamber and a pressure in the suction chamber is larger than a predetermined differential pressure,

and moving the valve body in a valve closing direction when the differential pressure is equal to or less than the predetermined differential pressure.

4. A scroll compressor according to claim 3,

the back pressure regulating valve is configured to open at least a portion of the outlet hole at a position within the fluid introduction passage on a side close to the pressure release passage.

5. A scroll compressor according to claim 4,

at least a part of the outlet hole is opened toward a direction parallel to an extending direction of the fluid introduction passage.