WO2017163814A1

WO2017163814A1 - Scroll-type compressor

Info

Publication number: WO2017163814A1
Application number: PCT/JP2017/008395
Authority: WO
Inventors: 泰造佐藤
Original assignee: サンデン・オートモーティブコンポーネント株式会社
Priority date: 2016-03-23
Filing date: 2017-02-24
Publication date: 2017-09-28
Also published as: CN108779775A; DE112017001481T5; CN108779775B; JP2017172427A

Abstract

Provided is a scroll-type compressor capable of appropriately lubricating a sliding site inside a scroll unit. The scroll-type compressor 100 includes: a housing 10 having an intake chamber H1 and a discharge chamber H2; a scroll unit 1 that compresses and discharges refrigerant, inside a sealed space S between a fixed scroll 2 and a movable scroll 3; a bearing holding unit 30 holding a bearing 17 that rotatably supports a drive shaft 21 and forming a back pressure chamber H3 between the bearing holding unit 30 and the movable scroll 3; a back pressure adjustment valve 50; a fluid introduction passage L1 that connects the intake chamber H1 and a space H4 in the vicinity of the outer circumferential section 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. The back pressure adjustment valve 50 is configured so as to be provided at an opening end on the fluid introduction passage L1 side of the pressure release passage L4.

Description

Scroll compressor

The present invention relates to a scroll compressor that has a fixed scroll and a movable scroll meshed with each other, and compresses a fluid such as a refrigerant flowing into a space between both scrolls.

This type of scroll compressor includes a scroll unit having a fixed scroll and a movable scroll meshed with each other. For example, the scroll compressor is incorporated in a refrigerant circuit of a vehicle air conditioner and used to compress the refrigerant in the refrigerant circuit. In this scroll unit, the movable scroll is revolved around the axis of the fixed scroll via the drive shaft, thereby gradually reducing the volume of the sealed space between the two scrolls, and the refrigerant gas flowing into the suction chamber Or the like is compressed in a sealed space, and the compressed fluid is discharged through a discharge chamber.
As this type of scroll compressor, for example, a scroll compressor described in Patent Document 1 is generally known. The scroll compressor described in Patent Document 1 includes a back pressure chamber between the movable scroll and a bearing holding portion that rotatably supports the movable scroll side end portion of the drive shaft. The back pressure chamber communicates with the discharge chamber and the suction chamber. A back pressure adjusting valve is provided in the middle of the passage that connects the back pressure chamber and the suction chamber, and the back pressure adjusting valve changes the pressure in the back pressure chamber to a pressure intermediate between the pressure in the suction chamber and the pressure in the discharge chamber. It has been adjusted to be. In the scroll compressor described in Patent Document 1, lubricating oil is supplied into the back pressure chamber in order to lubricate sliding parts such as a drive shaft in the back pressure chamber. The lubricating oil supplied into the back pressure chamber is directly discharged into the suction chamber via a passage communicating the back pressure chamber and the suction chamber and a back pressure adjusting valve provided in the middle of the passage.

Japanese Patent Laying-Open No. 2015-38327

However, in this type of scroll compressor, the lubricating oil is required not only for the sliding part such as the drive shaft in the back pressure chamber but also for the sliding part in the scroll unit. The refrigerant gas supplied from the suction chamber to the scroll unit may contain a small amount of lubricating oil, but there may be insufficient lubrication of the sliding portion in the scroll unit with a small amount of lubricating oil.
In this regard, in the scroll compressor described in Patent Document 1, since the lubricating oil is only supplied to the back pressure chamber, there is a possibility that the sliding portion in the scroll unit may be insufficiently lubricated. .
The present invention has been made paying attention to such a situation, and is not limited to a sliding portion in the back pressure chamber, and is a scroll type compressor capable of appropriately lubricating the sliding portion in the scroll unit. The purpose is to provide.

A scroll compressor according to one aspect of the present invention includes a housing having a fluid suction chamber and a discharge chamber therein, and a fixed scroll and a movable scroll that are provided in the housing and mesh with each other. By revolving around the axis of the fixed scroll via the drive shaft, the fluid flowing into the suction chamber is compressed in a sealed space between the two scrolls, and this compressed fluid is passed through the discharge chamber. And a scroll unit that is disposed in the housing and holds a bearing portion that rotatably supports the movable scroll side end portion of the drive shaft and forms a back pressure chamber between the movable scroll and the scroll unit. In a scroll compressor comprising a holding portion and a back pressure adjusting valve for adjusting pressure in the back pressure chamber, an inner peripheral surface of a peripheral wall portion of the housing A fluid introduction passage formed in cooperation with the outer peripheral surface of the bearing holding portion and communicating the suction chamber and the space near the outer peripheral portion of the scroll unit, and the discharge chamber and the back pressure chamber. A pressure supply passage, and a pressure release passage communicating the back pressure chamber and the fluid introduction passage. The back pressure adjusting valve is provided at the fluid introduction passage side opening end of the pressure release passage.

According to the scroll compressor according to the one aspect, the fluid in the suction chamber is guided to the space near the outer peripheral portion of the scroll unit through the fluid introduction passage, and the fluid in the discharge chamber is routed through the pressure supply passage. It is led to the pressure chamber, and the fluid in the back pressure chamber can be guided to the middle of the fluid inlet passage via the pressure release passage and the back pressure regulating valve, and returned to the scroll unit side on the flow in the fluid introduction passage. As a result, even if the amount of lubricating oil in the fluid flowing from the suction chamber to the fluid introducing passage is very small, the lubricating oil is returned to the middle of the fluid introducing passage through the pressure releasing passage and the back pressure adjusting valve. Lubricating oil from the chamber can be supplied to the scroll unit together with lubricating oil from the suction chamber.
In this way, it is possible to provide a scroll compressor that can appropriately lubricate the sliding portion of the scroll unit.

It is a schematic sectional drawing of the scroll compressor by one Embodiment of invention. It is a schematic sectional drawing for demonstrating the fastening state of the bearing holding | maintenance part of the scroll compressor. It is a block diagram for demonstrating the refrigerant | coolant flow in the scroll-type compressor. It is principal part sectional drawing which showed the principal part of the scroll-type compressor. It is the figure which illustrated the modification of the bearing holding | maintenance part and fixed scroll of the scroll-type compressor.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic cross-sectional view of a scroll compressor according to this embodiment.
The scroll compressor 100 according to the present embodiment is incorporated in a refrigerant circuit of a vehicle air conditioner, for example, and compresses and discharges refrigerant (fluid) sucked from the low pressure side of the refrigerant circuit.
The scroll compressor 100 includes a scroll unit 1, a housing 10 having a refrigerant suction chamber H 1 and a discharge chamber H 2 therein, an electric motor 20 as a drive unit that drives the scroll unit 1, and driving of the electric motor 20. A bearing holding portion 30 for rotatably supporting one end portion (upper end portion in FIG. 1) of the shaft 21 and an inverter 40 for driving control of the electric motor 20 are provided. In the present embodiment, it is assumed that a CO ₂ refrigerant is employed as the refrigerant. Further, the scroll compressor 100 will be described by taking a so-called inverter integrated type as an example.
The scroll unit 1 includes a fixed scroll 2 and a movable scroll 3 that are meshed with each other. The fixed scroll 2 is formed by integrally forming a spiral wrap 2b on a disk-shaped bottom plate 2a. The movable scroll 3 is formed by integrally forming a spiral wrap 3b on a disk-shaped bottom plate 3a. The bottom plate 2 a of the fixed scroll 2 has a larger diameter than the bottom plate 3 a of the movable scroll 3.
Both

scrolls

2 and 3 are arranged so that both the

spiral wraps

2b and 3b mesh. Specifically, both the

scrolls

2 and 3 have a predetermined gap between the end edge of the spiral wrap 2b of the fixed scroll 2 and the bottom plate 3a of the movable scroll 3 so that the spiral wrap 3b of the movable scroll 3 protrudes. The side edge is disposed so as to have a predetermined gap with the bottom plate 2 a of the fixed scroll 2. This gap that may fluctuate during the compression operation is maintained in an appropriate range during the compression operation, and the airtightness of the sealed space (compression chamber) S described later is appropriately maintained.
The

scrolls

2 and 3 are arranged so that the side walls of the

spiral wraps

2b and 3b are partially in contact with each other with the circumferential angles of the

spiral wraps

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

spiral wraps

2b and 3b.
The fixed scroll 2 is fixed to a rear housing 12 (to be described later) of the housing 10, and has a groove 2a1 that opens toward the rear housing 12 at the radial center. Specifically, the groove 2a1 is formed on the back surface of the bottom plate 2a (that is, the end surface opposite to the movable scroll 3).
The movable scroll 3 is configured to be capable of revolving orbiting around the axis of the fixed scroll 2 via the drive shaft 21 in a state in which the rotation is prevented. Thereby, the scroll unit 1 moves the sealed space S formed between the

scrolls

2 and 3, more specifically between the

spiral wraps

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

spiral wraps

2b and 3b in the sealed space S.
As shown in FIG. 1, the housing 10 mainly includes a scroll housing 1, an electric motor 20, a bearing holding portion 30, and an inverter 40 inside a front housing 11, a rear housing 12, and an inverter. And a cover 13. These (11, 12, 13) are integrally fastened by fastening means such as bolts 14 to form the housing 10 of the scroll compressor 100.
The front housing 11 has a substantially annular peripheral wall portion 11a and a partition wall portion 11b. The interior space of the front housing 11 is divided into an accommodation space for accommodating the scroll unit 1, the electric motor 20, and the bearing holding portion 30 and an accommodation space for accommodating the inverter 40 by the partition wall portion 11 b. Partitioned. The opening on one end side (upper side in FIG. 1) of the peripheral wall portion 11 a is closed by the rear housing 12. Further, the opening on the other end side (the lower side in FIG. 1) of the peripheral wall portion 11 a is closed by the inverter cover 13. In the partition wall portion 11b, a cylindrical support portion 11b1 that holds a bearing 15 that supports the other end portion (the lower end portion in FIG. 1) of the drive shaft 21 is provided at one end side of the peripheral wall portion 11a. Protrusively facing.
A refrigerant suction port P1 is formed in the peripheral wall portion 11a. 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 in the front housing 11 functions as the suction chamber H1. The electric motor 20 is cooled by circulating the refrigerant around the electric motor 20 in the suction chamber H1. In FIG. 1, the upper space of the electric motor 20 communicates with the lower space of the electric motor 20 and constitutes one suction chamber H <b> 1 together with the lower space of the electric motor 20. In the suction chamber H1, the refrigerant flows as a mixed fluid with a small amount of lubricating oil.
The rear housing 12 is formed in a disk shape having an outer diameter that matches the outer diameter of the peripheral wall portion 11 a of the front housing 11. The peripheral edge of the rear housing 12 is fastened to one end of the peripheral wall 11a (upper end in FIG. 1) by fastening means such as a suitable number of bolts 14 and the like. Close.
In addition, a peripheral edge portion (in other words, a portion surrounding the groove portion 2a1) of the rear surface of the bottom plate 2a of the fixed scroll 2 is in contact with one end surface of the rear housing 12. The one end face of the rear housing 12 and the groove 2a1 of the bottom plate 2a define a refrigerant discharge chamber H2. A compressed refrigerant discharge passage L2 is formed at the center of the bottom plate 2a. In the discharge chamber H2, a one-way valve (a check valve for restricting the flow from the discharge chamber H2 to the scroll unit 1) 16 is provided 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 spiral wraps 2b and 3b is discharged through the discharge passage L2 and the one-way valve 16. The rear housing 12 is formed with a discharge port P2 that 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 illustration is omitted, for example, an appropriate 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 is separated by the oil separator (including the refrigerant in which a small amount of lubricating oil remains) is discharged to the high pressure side of the refrigerant circuit via 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 includes a drive shaft 21, a rotor 22, and a stator core unit 23 disposed on the radially outer side of the rotor 22. For example, a three-phase AC motor is applied. For example, a direct current from a vehicle battery (not shown) is converted into an alternating current by the inverter 40 and supplied to the electric motor 20.
The drive shaft 21 is connected to the movable scroll 3 via a crank mechanism, and transmits the rotational force of the electric motor 20 to the movable scroll 3. One end portion of the drive shaft 21 (that is, 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 inverter 40 side end portion is rotatably supported by a bearing 15 fitted to the support portion 11b1. In the present embodiment, the bearing 17 corresponds to a “bearing portion” according to 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 that is fitted (for example, press-fitted) into a shaft hole formed at the radial center thereof. When a magnetic field is generated in the stator core unit 23 by power feeding from the inverter 40, a rotational force is applied to the rotor 22 and the drive shaft 21 is rotationally driven.
The bearing holding portion 30 is provided in the front housing 11 and holds the bearing 17 as a bearing portion that rotatably supports the end portion of the drive shaft 21 on the movable scroll 3 side. The bearing holding portion 30 is formed in a bottomed cylindrical shape having an outer diameter combined with the outer diameter of the bottom plate 2a of the fixed scroll 2, for example, and includes a cylindrical portion 30a and a bottom wall portion 30b positioned on one end side of the cylindrical portion 30a. And have. The cylindrical portion 30a has a shoulder portion 30a3 that is expanded so that the inner diameter on the opening side is larger than the inner diameter on the bottom wall portion 30b side, and connects between the large-diameter portion 30a1 and the small-diameter portion 30a2. The movable scroll 3 is accommodated in a space defined by the large-diameter portion 30a1 and the shoulder portion 30a3. The opening-side end portion of the cylindrical portion 30a is in contact with the peripheral edge portion of the end surface on the movable scroll 3 side of the bottom plate 2a. Therefore, the opening of the bearing holding portion 30 is closed by the fixed scroll 2. The bearing 17 is fitted into the small diameter portion 30a2 of the cylindrical portion 30a. And the through-hole for making the movable scroll 3 side edge part of the drive shaft 21 penetrate is opened in the radial direction center part of the bottom wall part 30b. An appropriate seal member 18a is provided between the bearing 17 and the bottom wall portion 30b to ensure the airtightness of the back pressure chamber H3 described later.
An annular thrust plate 19 is disposed between the shoulder 30 a 3 of the bearing holder 30 and the bottom plate 3 a of the movable scroll 3. The shoulder 30 a 3 receives a thrust force from the movable scroll 3 through the thrust plate 19. Sealing members 18b are disposed at portions of the shoulder 30a3 and the bottom plate 3a that are in contact with the thrust plate 19, respectively.
Further, a back pressure chamber H3 is defined between the bottom plate 3a and the small diameter portion 30a2 by the

seal members

18a and 18b. That is, the bearing holding part 30 forms a back pressure chamber H <b> 3 with the movable scroll 3. Further, between the inner peripheral surface of the peripheral wall portion 11 a of the front housing 11 and the outer peripheral surface of the cylindrical portion 30 a of the bearing holding portion 30, there is a vicinity of the outer peripheral portion of the spiral wraps 2 b and 3 b of the suction chamber H 1 and the scroll unit 1. A fluid introduction passage L1 is formed in communication with the space H4 and for introducing a refrigerant (specifically, a mixed fluid of a refrigerant and a small amount of lubricating oil) from the suction chamber H1 to the space H4. That is, in this embodiment, the fluid introduction passage L1 that communicates the suction chamber H1 and the space H4 cooperates with 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. Formed. For this reason, 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 projectingly formed on the back surface (the end surface on the back pressure chamber H3 side) of the bottom plate 3a, and a crank 25 provided on the movable scroll 3 side end portion of the drive shaft 21. And an eccentric bush 26 attached in an eccentric state, and a sliding bearing 27 fitted to the boss portion 24. The eccentric bush 26 is rotatably supported in the boss portion 24 via a slide bearing 27. A balancer weight 28 is attached to the end of the drive shaft 21 on the side of the movable scroll 3 so as to face the centrifugal force during the operation of the movable scroll 3. Although not shown, a rotation prevention mechanism for preventing the rotation of the movable scroll 3 is appropriately provided. Thus, the movable scroll 3 is configured to be capable of revolving around the axis of the fixed scroll 2 via the crank mechanism in a state in which the rotation is prevented.
FIG. 2 is a schematic cross-sectional view for explaining a fastening state of the bearing holding portion 30, and shows a cross-sectional position including the fastening bolt 14 of the bearing holding portion 30.
In the present embodiment, as shown in FIG. 2, the bearing holding portion 30 is integrated with the fixed scroll 2 and the rear housing 12 by fastening bolts 14 with the fixed scroll 2 sandwiched between the bearing holding portion 30 and the rear housing 12. Has been concluded.
Specifically, the fixed scroll 2 causes the peripheral portion of the back surface of the bottom plate 2a to abut one end surface of the rear housing 12, and the peripheral portion of the end surface of the bottom plate 2a on the movable scroll 3 side is used as a bearing holding portion. It is made to contact | abut to the opening side edge part of the cylindrical part 30a of 30, and is pinched | interposed between the rear housing 12 and the bearing holding part 30. The bearing holding portion 30 and the fixed scroll 2 are opened so as to extend in the extending direction of the drive shaft 21 at a plurality of locations spaced in the circumferential direction of the peripheral portion (specifically, the peripheral portion of the cylindrical portion 30a and the bottom plate 2a). It has a through hole 14a through which a bolt 14 for fastening with the fixed scroll 2 and the rear housing 12 is inserted. A female screw portion is formed on one end face side of the rear housing 12 in accordance with the opening position of the through hole. The bolt 14 is inserted into the cylindrical portion 30 a and the through hole 14 a of the bottom plate 2 a and is screwed into the female screw portion of the rear housing 12. In this way, the bearing holder 30 is fastened integrally with the fixed scroll 2 and the rear housing 12.
In the present embodiment, the fluid introduction passage L1 is a recess 30c (FIG. 1) extending in the extending direction of the drive shaft 21 between the portions where the through holes 14a are formed in the peripheral edge portion (that is, the cylindrical portion 30a) of the bearing holding portion 30. And (see FIG. 4 described later). That is, the fluid introduction passage L1 includes a portion (concave portion 30c) that is appropriately recessed toward the drive shaft 21 in order to reduce weight at a portion of the cylindrical portion 30a that avoids the formation portion of the through hole 14a, and this portion. It is mainly partitioned by the corresponding part of the inner peripheral surface of the peripheral wall portion 11a facing each other. One end of the fluid introduction passage L1 opens into the suction chamber H1, and the other end of the fluid introduction passage L1 passes through the end of the cylindrical portion 30a and opens into the space H4.
FIG. 3 is a block diagram for explaining the refrigerant flow 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 guided to the space H4 near the outer end of the scroll unit 1 through the fluid introduction passage L1. And the refrigerant | coolant in the space H4 is taken in in the sealed space S between both the spiral wraps 2b and 3b, and is compressed in this sealed space S. The compressed refrigerant is discharged to the discharge chamber H2 via the discharge passage L2 and the one-way valve 16, and then discharged from the discharge chamber H2 to the high pressure side of the refrigerant circuit via the discharge port P2. In this way, the scroll unit 1 that compresses the refrigerant flowing into the suction chamber H1 in the sealed space S and discharges the compressed refrigerant through the discharge chamber H2 is configured.
Here, referring back to FIG. 1, the scroll compressor 100 according to the present embodiment further includes a back pressure adjusting valve 50 for adjusting the pressure in the back pressure chamber H3.
In the present embodiment, the back pressure adjustment valve 50 is a differential pressure actuated check valve, 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, When the differential pressure is less than or equal to the predetermined differential pressure, the valve operates in the valve closing direction, and the pressure in the back pressure chamber H3 is changed between the pressure (high pressure) in the discharge chamber H2 and the suction chamber H1. The pressure is adjusted to be a predetermined pressure (intermediate pressure) intermediate to the pressure (low pressure). The arrangement position, structure, and back pressure adjustment operation of the back pressure adjustment valve 50 will be described in detail later.
In the present embodiment, the scroll compressor 100 includes a pressure supply passage L3 and a pressure release passage L4 in addition to the fluid introduction passage L1 and the discharge passage L2, as shown in FIGS.
The pressure supply passage L3 is a passage for communicating the discharge chamber H2 and the back pressure chamber H3. The lubricating oil separated from the compressed refrigerant in the discharge port P2 by the oil separator (not shown) is guided into the back pressure chamber H3 through the pressure supply passage L3, and each sliding portion in the back pressure chamber H3. Used for lubrication. Further, the discharge chamber H2 and the back pressure chamber H3 communicate with each other via the pressure supply passage L3, whereby the pressure in the back pressure chamber H3 increases.
In the present embodiment, the pressure supply passage L3 is specifically a passage formed in the rear housing 12, and one end opens to the discharge chamber H2 via the discharge port P2 and the other end contacts the bottom plate 2a. A passage that opens to the contact portion, a passage that is connected to this passage and penetrates the bottom plate 2a, and a passage that is connected to a passage that penetrates the bottom plate 2a and opens to the back pressure chamber H3 through the cylindrical portion 30a And comprising. 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 orifice OL and supplied into the back pressure chamber H3 through the pressure supply passage L3.
The pressure relief passage L4 is a passage for communicating between the back pressure chamber H3 and the suction chamber H1.
In the present embodiment, specifically, the pressure release passage L4 passes through 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 relief passage L4 opens to the back pressure chamber H3, and the other end of the pressure relief passage L4 opens to the fluid introduction passage L1.
Next, the arrangement position and structure of the back pressure regulating valve 50 in this embodiment will be described in detail with reference to FIGS. FIG. 4 is an enlarged cross-sectional view of the main part including the back pressure regulating valve 50 and shows a valve open state.
The back pressure adjusting valve 50 includes a valve housing 51, a valve seat housing 52, a valve body 53, and an urging means 54, and is provided at the opening end of the pressure release passage L4 on the fluid introduction passage L1 side. Part of L4.
The valve housing 51 has a cylindrical portion 51a and a bottom wall portion 51b that closes one end of the cylindrical portion 51a, is formed in a bottomed cylindrical shape as a whole, and has a valve chamber 51c inside.
The cylindrical portion 51a and the bottom wall portion 51b are respectively formed with outlet holes 55 that open 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 55 is opened in the bottom wall portion 51b. The outlet hole 55 communicates the space in the fluid introduction passage L <b> 1 and the valve chamber 51 c in the valve housing 51.
Specifically, as for the two cylindrical part exit holes 55a opened in the cylindrical part 51a of the outlet holes 55, a part of each is located in the fluid introduction passage L1, as shown in FIG. On the other hand, as shown in FIG. 4, the bottom wall part outlet hole 55b opened in the bottom wall part 51b of the outlet hole 55 is entirely located in the fluid introduction passage L1. Thus, in this embodiment, the pressure regulating valve 50 is disposed so 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 (the bottom wall part outlet hole 55b) is entirely located in the fluid introduction passage L1, and the cylindrical part outlet hole 55a is partially located in the fluid introduction passage L1. Yes.
More specifically, the back pressure adjusting valve 50 is disposed so that the cylindrical portion outlet hole 55a opens at a position close to the pressure release passage L4 side in the fluid introduction passage L1. Specifically, the cylindrical portion outlet hole 55a is positioned so as to straddle the boundary between the fluid introduction passage L1 and the pressure release passage L4.
Further, the cylindrical portion outlet hole 55a is formed on the opening end side (valve seat housing 52 side) of the cylindrical portion 51a in a direction parallel to the extending direction of the fluid introduction passage L1 (in other words, a fluid indicated by a white arrow in FIG. 4). It opens toward the direction parallel to the flow of the refrigerant flowing in the introduction passage L1. On the other hand, the bottom wall portion outlet hole 55b opens in a direction orthogonal to the fluid introduction passage L1. Thus, in the present embodiment, at least a part of the plurality of outlet holes 55 (cylindrical part outlet holes 55a) is open in a direction parallel to the extending direction of the fluid introduction passage L1.
The valve seat housing 52 constitutes one end of the back pressure regulating valve 50 and is fitted to the opening end of the pressure release passage L4 on the fluid introduction passage L1 side. The valve seat housing 52 is formed, for example, in a bottomed cylindrical shape having an outer diameter that matches the inner diameter of the pressure release passage L4, and has a cylindrical portion 52a and a bottom wall portion 52b that is located on one end side of the cylindrical portion 52a. The other end side of the cylindrical portion 52 a is fixed to the opening end side of the valve housing 51. A valve seat 52c having a conical surface is formed by contacting and separating the valve body 53 at a portion on the bottom wall 52b side of the cylindrical portion 52a. The valve seat housing 52 has an inlet hole 52d that is formed through the bottom wall portion 52b and opens to the back pressure chamber H3 side of the pressure release passage L4. One end of the inlet hole 52d opens to the valve seat 52c, and the other end opens to the space on the back pressure chamber H3 side of the pressure release passage L4.
The valve body 53 opens and closes the inlet hole 52d, is formed in a ball shape, and is urged toward the valve seat 52c by the urging means 54.
The biasing means 54 is connected to the coil spring 54a whose one end is in contact with the bottom wall 51b of the valve housing 51 and the other end of the coil spring 54a and biases the valve body 53 in the valve closing direction. And a force rod 54b, which is disposed in the valve chamber 51c of the valve housing 51.
In this embodiment, the back pressure regulating valve 50 includes a valve housing 51, a valve seat housing 52, an inlet hole 52d that opens to the back pressure chamber H3 side of the pressure release passage L4, and a valve body 53 that opens and closes the inlet hole 52d. And an urging means 54 and outlet holes 55 (55a, 55b) that open to the fluid introduction passage L1, and the pressure difference between the pressure in the back pressure chamber H3 and the pressure in the suction chamber H1 is a predetermined difference. When the pressure is greater than the pressure, the valve body 53 is moved in the valve opening direction, and when the differential pressure is equal to or less than the predetermined differential pressure, the valve body 53 is moved in the valve closing direction.
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. The back pressure adjusting valve 50 is in a closed state, and the back pressure chamber H3 is communicated 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 reduced by lubricating oil or the like. It will be described below as it is becoming higher.
First, it is assumed that the back pressure regulating valve 50 closes the inlet hole 52d by pressing the valve body 53 against the valve seat portion 52c by the urging means 54. At this time, the urging force by the coil spring 54a of the urging means 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 a predetermined differential pressure in which the differential pressure between the pressure in the back pressure chamber H3 and the pressure in the suction chamber H1 is determined based on the biasing force of the biasing means 54. When it becomes larger, the valve body 53 moves in the valve opening direction against the urging force of the urging means 54. Thereby, the back pressure adjusting valve 50 reduces the pressure in the back pressure chamber H3. Lubricating oil or the like guided along the fluid introduction passage L1 through the back pressure adjusting valve 50 is returned to the scroll unit 1 side (space H4 side) along the flow in the fluid introduction passage L1. When the differential pressure becomes smaller than the predetermined differential pressure, the valve body 53 moves in the valve closing direction by the urging force of the urging means 54. Thereby, the back pressure regulating valve 50 increases the pressure in the back pressure chamber H3.
According to the scroll compressor 100 according to the present embodiment, the refrigerant in the suction chamber H1 is guided to the space H4 near the outer peripheral portion of the scroll unit 1 via the fluid introduction passage L1, and via the pressure supply passage L3. The lubricating oil mainly contained in the refrigerant in the discharge chamber H2 is guided to the back pressure chamber H3, and the lubricating oil and the like in the back pressure chamber H3 are fluidized through the pressure release passage L4 and the back pressure adjustment valve 50. In addition to being guided in the middle of L1, it can be returned to the scroll unit 1 side on the flow in the fluid introduction passage L1. As a result, even if the amount of lubricating oil in the refrigerant flowing from the suction chamber H1 to the fluid introduction passage L1 is very small, the lubricating oil or the like enters the fluid introduction passage L1 via the pressure release passage L4 and the back pressure adjustment valve 50. , And the lubricating oil or the like from the back pressure chamber H3 can be supplied to the scroll unit 1 together with the refrigerant containing a small amount of lubricating oil from the suction chamber H1.
In this way, it is possible to provide the scroll compressor 100 that can appropriately lubricate the sliding portion of the scroll unit 1.
In the present embodiment, the fluid introduction passage L1 is formed in cooperation with 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 concave portion 30c). It was. Thereby, the fluid introduction passage L1 can be easily formed.
In the present embodiment, the back pressure adjusting valve 50 opens to the inlet hole 52d that opens to the back pressure chamber H3 side of the pressure release passage L4, the valve body 53 that opens and closes the inlet hole 52d, and the fluid introduction passage L1. An outlet hole 55, 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, the valve body 53 is moved in the valve opening direction, and the differential pressure A so-called differential pressure actuated check valve that moves the valve body 53 in the valve closing direction when the pressure is not more than the predetermined differential pressure is employed. As a result, it is possible to provide the back pressure adjusting valve 50 that does not require electric power and that can autonomously adjust the pressure in the back pressure chamber H3 by simply sensing the differential pressure.
Here, when the back pressure adjusting valve 50 is of the differential pressure operation type, if an obstruction that obstructs the flow of the fluid flowing out from the outlet hole 55 is in the vicinity of the outlet hole 55, the downstream of the valve body 53 Pressure loss on the side may be excessive. In this case, the back pressure adjustment valve 50 may not operate normally.
Regarding this point, in the present embodiment, the cylindrical portion outlet hole 55a of the outlet holes 55 opens at a position close to the pressure release passage L4 side in the fluid introduction passage L1. That is, the back pressure adjusting valve 50 is disposed so that the cylindrical portion outlet hole 55a (at least a part of the outlet hole) opens at a position close to the pressure release passage L4 side in the fluid introduction passage L1. Thereby, at least a part (55a) of the outlet holes 55 can be opened in a wide space free of obstructions. 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. Therefore, as in the present embodiment, CO ₂ refrigerant is employed as the refrigerant, and the differential pressure between the pressure in the back pressure chamber H3 and the pressure in the suction chamber H1 is higher than the conventional pressure, and is higher in the back pressure adjustment valve 50. Even when controllability is required, it is possible to provide a back pressure regulating valve 50 that can be appropriately operated according to a predetermined differential pressure.
In the present embodiment, at least a part (cylindrical portion outlet hole 55a) of the plurality of outlet holes 55 is open in a direction parallel to the extending direction of the fluid introduction passage L1. As a result, 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 can be reliably put in the flow of the fluid introduction passage L1, so that the lubricating oil or the like is scrolled. It can be reliably returned by the unit 1 side.
In the present embodiment, the fluid introduction passage L1 has a drive shaft between the formation portions of the through holes 14a through which the fastening bolts 14 are inserted in the peripheral edge portion (that is, the cylindrical portion 30a) of the bearing holding portion 30. It was set as the structure extended along the recessed part 30c extended in the extending | stretching direction of 21. That is, in the present embodiment, the fluid introduction passage L1 is formed by using the concave portion 30c that is a concave portion for reducing the weight of the front housing 11. Thus, the fluid introduction passage L1 can be easily formed while reducing the weight of the front housing 11.
As mentioned above, although preferable embodiment of this invention was described, this invention is not restrict | limited to the said embodiment, A various deformation | transformation and change are possible based on the technical idea of this invention.
For example, in the present embodiment, the movable scroll 3 is accommodated in the bearing holding portion 30 (specifically, the large-diameter portion 30a1). However, the present invention is not limited to this, and as shown in FIG. It is good also as a structure accommodated. In this case, the peripheral portion of the bottom plate 2 a of the fixed scroll 2 is formed with a large diameter portion 2 a 3 that protrudes toward the bearing holding portion 30, and the movable scroll 3 is accommodated in the large diameter portion 2 a 3 of the fixed scroll 2. Configure. Moreover, the bearing holding | maintenance part 30 should just be provided with the small diameter part 30a2 which fits the bearing 17 in the cylindrical part 30a. In the case of this modification, the fluid introduction passage L1 communicates with 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 concave portion 30c), and the outer peripheral surface of the fixed scroll 2 (the concave portion 30c). And the inner surface of the recess 2c extending in this manner.
Further, the number of the outlet holes 55 of the back pressure adjusting valve 50, the opening position and the opening direction, and the formation position of the fluid introduction passage L1 can be set as appropriate.
For example, the number of the outlet holes 55 is three, but may be one, two, or four or more. In the present embodiment, the cylindrical portion outlet hole 55a has been described as an example of the case where the cylindrical portion outlet hole 55a is positioned so as to straddle the boundary between the fluid introduction passage L1 and the pressure release passage L4. The entirety may be located in the fluid introduction passage L1. If the cylindrical portion outlet hole 55a is opened at a position close to the pressure release passage L4 in the fluid introduction passage L1, pressure loss on the downstream side of the valve body 53 can be effectively reduced, The pressure regulating valve 50 can be appropriately operated. Further, if the back pressure adjusting valve 50 is provided at the opening end of the pressure release passage L4 on the fluid introduction passage side, the lubricant in the back pressure chamber H3 is slid on the scroll unit 1 through the fluid introduction passage L1. Can be returned to the site.
Further, in the present embodiment, the scroll compressor 100 has been described by taking a so-called inverter-integrated case as an example. However, the present invention is not limited to this, and the scroll compressor 100 may be separate from the inverter 40. In this case, the housing 10 only needs to include the front housing 11 and the rear housing 12.
Further, in the present embodiment, the refrigerant has been assumed to be CO ₂ refrigerant is not limited to this, it is possible to apply the appropriate refrigerant.

DESCRIPTION OF SYMBOLS 1 ... Scroll unit 2 ... Fixed scroll 3 ... Movable scroll 10 ... Housing 11a ... Perimeter wall part 14 ... Bolt 14a ... Through-hole 17- ... Bearings (bearing parts)
21 ··· Drive shaft 30 ··· Bearing holding portion 30a · · · Cylindrical portion (peripheral portion)
30c ... Recess 50 ... Back pressure regulating valve 52d ... Inlet hole 55 ... Outlet hole 53 ... Valve body 55a ... Cylindrical part outlet hole (outlet hole)
55b ... Bottom wall exit hole (exit hole)
DESCRIPTION OF SYMBOLS 100 ... Scroll type compressor H1 ... Suction chamber H2 ... Discharge chamber H3 ... Back pressure chamber H4 ... Space L1 ... Fluid introduction passage L3 ... Pressure Supply passage L4 ... Pressure release passage S ... Sealed space

Claims

A housing having therein a fluid suction chamber and a discharge chamber;
A fixed scroll and a movable scroll which are provided in the housing and mesh with each other. The movable scroll is revolved around the axis of the fixed scroll via a drive shaft and flows into the suction chamber. A scroll unit that compresses the fluid in a sealed space between the scrolls and discharges the compressed fluid through the discharge chamber;
A bearing holding portion that is provided in the housing and holds a bearing portion that rotatably supports the movable scroll side end portion of the drive shaft and forms a back pressure chamber between the movable scroll and the movable scroll;
A back pressure adjusting valve for adjusting the pressure in the back pressure chamber;
In a scroll compressor comprising:
A fluid introduction passage communicating the suction chamber and a space near the outer periphery of the scroll unit;
A pressure supply passage communicating the discharge chamber and the back pressure chamber;
A pressure release passage communicating the back pressure chamber and the fluid introduction passage;
Including
The back pressure regulating valve is a scroll compressor provided at a fluid introduction passage side opening end of the pressure release passage.
2. The scroll compressor according to claim 1, wherein the fluid introduction passage is formed in cooperation with an inner peripheral surface of a peripheral wall portion of the housing and an outer peripheral surface of the bearing holding portion.
The back pressure adjusting valve has an inlet hole that opens to the back pressure chamber side of the pressure release passage, a valve body that opens and closes the inlet hole, and an outlet hole that opens to the fluid introduction passage. When the differential pressure between the pressure in the pressure chamber and the pressure in the suction chamber is greater than a predetermined differential pressure, the valve body is moved in the valve opening direction, and when the differential pressure is equal to or less than the predetermined differential pressure, the valve body The scroll compressor according to claim 1 or 2, wherein the compressor is moved in a valve closing direction.
4. The scroll compressor according to claim 3, wherein the back pressure adjusting valve is disposed so that at least a part of the outlet hole is opened at a position close to the pressure release passage side in the fluid introduction passage.
The scroll compressor according to claim 4, wherein at least a part of the outlet hole is opened in a direction parallel to an extending direction of the fluid introduction passage.
The bearing holding portion is a through hole that is opened so as to extend in the extending direction of the drive shaft at a plurality of locations that are spaced apart in the circumferential direction of the peripheral portion thereof, and is used for fastening with the fixed scroll and the housing. Having a through hole through which the bolt is inserted,
The scroll according to any one of claims 1 to 5, wherein the fluid introduction passage extends along a recess extending in a direction in which the drive shaft extends between the through-hole formation portions of the peripheral portion. Mold compressor.