EP4027015A1

EP4027015A1 - Scroll compressor

Info

Publication number: EP4027015A1
Application number: EP21216050.1A
Authority: EP
Inventors: Akihiro KANAI; Taichi Tateishi; Takuma YAMASHITA; Yoshiyuki Okada; Emiri UCHIKAWA; Kazuki Takahashi; Yogo Takasu
Original assignee: Mitsubishi Heavy Industries Thermal Systems Ltd
Current assignee: Mitsubishi Heavy Industries Thermal Systems Ltd
Priority date: 2021-01-05
Filing date: 2021-12-20
Publication date: 2022-07-13
Anticipated expiration: 2041-12-20
Also published as: JP2022105791A; EP4027015C0; EP4027015B1; JP7483638B2

Abstract

A scroll compressor (1) includes: a casing (10); a discharge cover (100) dividing a space in the casing into a high-pressure side space (12b) and a low-pressure side space (12a); an orbital scroll (40) positioned in the low-pressure side space and which is eccentrically rotated with respect to the axis; and a fixed scroll (30) positioned between the discharge cover and the orbital scroll, a compression chamber (31) to which refrigerant introduced from the low-pressure side space being formed between the fixed and orbital scrolls. A discharge port (36) through which the refrigerant compressed in the compression chamber is discharged to the high-pressure side space is formed so as to be passed through the fixed scroll and the discharge cover, an annular injection space (S) surrounding the discharge port and a communication path communicating the injection space with the low-pressure side space are formed between the fixed scroll and the discharge cover, and the scroll compressor further includes an injection pipe (130) through which liquid refrigerant is introduced to the injection space from an outside thereof.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure relates to a scroll compressor.

Description of Related Art

Japanese Patent No. 6535153 discloses a scroll compressor that cools a scroll by introducing a liquid refrigerant into a compression chamber from the outside of a housing. According to the scroll compressor, the contact between a scroll lap and an end plate due to thermal expansion that occurs during operation is suppressed.

SUMMARY OF THE INVENTION

Incidentally, in the scroll compressor described in Japanese Patent No. 6535153 , it is difficult to introduce a liquid refrigerant into the center of the compression chamber due to the pressure and it is necessary to introduce the liquid refrigerant to the some extent outside of the compression chamber.
Therefore, the outside of the compression chamber may be cooled and the inside of the fixed scroll having a relatively high temperature during operation may not be sufficiently cooled.
The present disclosure has been made to solve the above-described problems and an object thereof is to provide a scroll compressor capable of effectively cooling the inside of a fixed scroll.
In order to solve the above-described problems, a scroll compressor according to the present disclosure includes: a casing which is extended in a direction of an axis; a discharge cover which is accommodated in the casing and formed so as to divide a space in the casing into a high-pressure side space on one side in the direction of the axis and a low-pressure side space on the other side; an orbital scroll which is positioned in the low-pressure side space and is configured to eccentrically rotate with respect to the axis; and a fixed scroll which is positioned between the discharge cover and the orbital scroll in the low-pressure side space, a compression chamber to which refrigerant introduced from the low-pressure side space being formed between the fixed scroll and the orbital scroll, wherein a discharge port through which the refrigerant compressed in the compression chamber is discharged to the high-pressure side space is formed so as to be passed through the fixed scroll and the discharge cover, an annular injection space surrounding the discharge port and a communication path communicating the injection space with the low-pressure side space are formed between the fixed scroll and the discharge cover, and the scroll compressor further comprises an injection pipe through which liquid refrigerant is introduced to the injection space from an outside thereof.
According to the scroll compressor of the present disclosure, it is possible to effectively cool the inside of the fixed scroll.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view showing a schematic configuration of a scroll compressor according to an embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of a main part of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

(Scroll compressor)

Hereinafter, a scroll compressor 1 according to an embodiment of the present disclosure will be described in detail with reference to FIGS. 1 and 2.
FIG. 1 is a cross-section showing a schematic configuration of a scroll compressor 1 according to an embodiment of the present invention. The scroll compressor 1 of the embodiment compresses a refrigerant flowing in a refrigerant circuit of, for example, a packaged air conditioner.
The scroll compressor 1 according to this embodiment includes a casing 10, an intake pipe 13, a discharge pipe 14, an injection pipe 130, a driving unit 20, a first bearing 50, a second bearing 60, an oil supply pump 140, an orbital scroll 40, a bush assembly 70, a third bearing 80, an oldham ring 90, a fixed scroll 30, and a discharge cover 100.

(Casing)

The casing 10 has a tubular shape extending in a direction of an axis O1 of the driving unit 20 and of which both ends are closed. The casing 10 includes a casing body 11.
The casing body 11 is extended in the direction of the axis O1. The casing body 11 includes a casing inner peripheral surface 11a on the inside thereof and an accommodation space 12 accommodating various parts for compressing a refrigerant is formed inside the casing body 11.
The casing body 11 accommodates the driving unit 20, the first bearing 50, the second bearing 60, the oil supply pump 140, the orbital scroll 40, the bush assembly 70, the third bearing 80, the oldham ring 90, the fixed scroll 30, and the discharge cover 100.
The accommodation space 12 in the casing body 11 is divided into a high-pressure side space 12b and a low-pressure side space 12a with the discharge cover 100 as a boundary.
The high-pressure side space 12b is located on an upper side of the casing body 11 in the direction of the axis O1, which is the downstream side of the refrigerant flow, in relation to the discharge cover 100 in the accommodation space 12. The refrigerant is compressed in the compression chamber 31 and then discharged from the discharge cover 100 to the high-pressure side space 12b.
The low-pressure side space 12a is located on a lower side of the casing body 11 in the direction of the axis O1, which is the upstream side of the refrigerant flow, in relation to the discharge cover 100 in the accommodation space 12. An atmospheric pressure of the low-pressure side space 12a, in which refrigerant to be compressed in the compression chamber 31 exists, is lower than that of the high-pressure side space 12b.
The casing body 11 is provided with an intake pipe 13, a discharge pipe 14, and an injection pipe 130. The intake pipe 13, the discharge pipe 14, and the injection pipe 130 communicate with each other inside and outside the casing body 11 and the refrigerant can flow in each pipe.
The intake pipe 13 supplies a refrigerant from the outside of the casing body 11 to the low-pressure side space 12a in the casing body 11. Most of the refrigerant flowing in the intake pipe 13 is a gas.
The discharge pipe 14 discharges the refrigerant from the high-pressure side space 12b in the casing body 11 to the outside of the casing body 11. The refrigerant discharged from the discharge pipe 14 flows through a refrigerant circuit (not shown), is decompressed and expanded, and then returns to the intake pipe 13. Most of the refrigerant flowing in the discharge pipe 14 is a gas.
The injection pipe 130 supplies a liquid refrigerant from the outside of the casing body 11 into an injection space S formed by the fixed scroll 30 and the discharge cover 100 in the casing body 11. Most of the liquid refrigerant flowing in the injection pipe 130 is a liquid.
The casing body 11 includes a first casing portion 15, a second casing portion 16, and a third casing portion 17.
The first casing portion 15 and the third casing portion 17 define the low-pressure side space 12a together with the discharge cover 100. The first casing portion 15 includes a first inner peripheral surface 15a formed therein and the third casing portion 17 includes a third inner peripheral surface formed therein.
The first casing portion 15 has a cylindrical shape centered on the axis O1 and includes opening end portions on both the upstream side and the downstream side.
The third casing portion 17 is a lid-shaped member and is combined with the first casing portion 15 to close the opening end portion of the first casing portion 15 on the other side of the direction of the axis O1.
The second casing portion 16 defines the high-pressure side space 12b together with the discharge cover 100 and includes a second inner peripheral surface 16a therein.
The second casing portion 16 is a lid-shaped member and the opening end portion of the second casing portion 16 facing the other side of the direction of the axis O1 is combined with the opening end portion of the first casing portion 15 on one side in the direction of the axis O1 through a flange portion 100b of the discharge cover 100. Thus, the airtightness of the high-pressure side space 12b is maintained by the opening end portion of the second casing portion 16, the flange portion 100b, and the opening end portion of the first casing portion 15.
Each of the first inner peripheral surface 15a, the second inner peripheral surface 16a, and the third inner peripheral surface is part of the casing inner peripheral surface 11a of the casing body 11.

(Driving unit)

The driving unit 20 includes a rotating shaft 21, a rotor 22, a coil 160, and an eccentric shaft 23.
The rotating shaft 21 is a member having a columnar shape centered on the axis O1. The rotating shaft 21 extends in the direction of the axis O1 at the substantial center in the low-pressure side space 12a. The rotating shaft 21 rotates integrally with the rotor 22 around the axis O1 due to the rotation of the rotor 22.
The rotor 22 is integrally formed to cover part of the rotating shaft 21 along the axis O1. The rotor 22 rotates under the influence of the electromagnetic force generated by the coil 160 that covers the rotor 22 from the radial outside of the axis O1.
The eccentric shaft 23 is provided on the first end surface 21a of the rotating shaft 21 facing the downstream side. The eccentric shaft 23 is bonded to the first end surface 21a of the rotating shaft 21 while an end surface 23a of the eccentric shaft 23 on the upstream side of the low-pressure side space 12a faces the first end surface 21a of the rotating shaft 21. The eccentric shaft 23 extends in the direction of the axis O1 with the eccentric axis O2 eccentric with respect to the axis O1 as the center axis. The eccentric shaft 23 is a member having a cylindrical shape smaller than the rotating shaft 21. Thus, the eccentric shaft 23 revolves in an orbital manner around the axis O1 integrally with the rotating shaft 21 when the rotating shaft 21 rotates around the axis O1.

(First bearing)

The first bearing 50 is accommodated in the casing body 11. The first bearing 50 is fixed to the first inner peripheral surface 15a. The first bearing 50 is disposed between the compression chamber 31 and the connection position between the first casing portion 15 and the intake pipe 13.
The first bearing 50 extends in the direction of the axis O1 and rotatably supports a first end portion 21b of the rotating shaft 21 on the side of the compression chamber 31.

(Second bearing)

The second bearing 60 is fixed to the first inner peripheral surface 15a of the first casing portion 15 in the vicinity of the third casing portion 17. The second bearing 60 rotatably supports a second end portion 21c of the rotating shaft 21 on the side of the third casing portion 17.

(Oil supply pump)

The oil supply pump 140 supplies lubricating oil to the sliding portions of the first bearing 50, the second bearing 60, and the third bearing 80 through an oil supply path (not shown). The oil supply pump 140 is provided on the side of the third casing portion 17 of the second bearing 60.

(Orbital scroll)

The orbital scroll 40 is disposed between the first bearing 50 and the second casing portion 16. The orbital scroll 40 includes an orbital end plate 41, an orbital spiral-lap 42, and a boss portion 43.
The orbital end plate 41 has a disk shape with the direction of the axis O1 as a plate thickness direction and includes a first surface 41a and a second surface 41b.
The first surface 41a and the second surface 41b are orthogonal to the axis O1. The first surface 41a faces the fixed scroll 30 in the direction of the axis O1 and constitutes part of the compression chamber 31. The second surface 41b is a surface disposed on the side opposite to the first surface 41a. The second surface 41b faces the first bearing 50.
The orbital spiral-lap 42 is provided on the first surface 41a of the orbital end plate 41 and is erected toward one side in the direction of the axis O1. Similarly to a fixed spiral-lap 33, the orbital spiral-lap 42 is a wall body formed in a spiral shape when viewed from one side in the direction of the axis O1. The orbital spiral-lap 42 is preferably formed in an involute curve centered on the eccentric axis O2 when viewed from the direction of the eccentric axis O2.
The orbital spiral-lap 42 with the above-described configuration is disposed to mesh with the fixed spiral-lap 33 of the fixed scroll 30 which faces the orbital spiral-lap in the direction of the axis O1. Accordingly, the compression chamber 31 which is a space for introducing the refrigerant from the low-pressure side space 12a and compressing the refrigerant is formed between the orbital spiral-lap 42 and the fixed spiral-lap 33. Then, when the orbital spiral-lap 42 revolves in an orbital manner with respect to the fixed spiral-lap 33, the volume in the compression chamber 31 is changed and the refrigerant in the compression chamber 31 is compressed. Thus, the orbital scroll 40 is provided in the low-pressure side space 12a and rotates eccentrically with respect to the axis O1.
The boss portion 43 is provided in an annular shape in the vicinity of the center of the second surface 41b of the orbital end plate 41. The boss portion 43 is a cylindrical member and protrudes from the second surface 41b of the orbital end plate 41 toward the other side of the direction of the axis O1. The boss portion 43 is disposed to surround the outer peripheral surface of the eccentric shaft 23.

(Bush assembly)

The bush assembly 70 connects the orbital scroll 40 and the rotating shaft 21 and includes a bush 71 provided between the eccentric shaft 23 and the boss portion 43. The bush assembly 70 is provided between the orbital scroll 40 and the rotating shaft 21.

(Third bearing)

The third bearing 80 is disposed between the outer peripheral surface of the bush 71 and the inner peripheral surface of the boss portion 43. The third bearing 80 extends in the direction of the axis O1 and supports the eccentric shaft 23 through the bush 71.

(Oldham ring)

The oldham ring 90 is provided between the orbital end plate 41 and the first bearing 50. The oldham ring 90 includes a key which is fitted into a key groove formed in the orbital end plate 41. The oldham ring 90 is a joint member that converts the rotation motion of the rotating shaft 21 into the revolution motion of the orbital scroll 40 while suppressing the orbital scroll 40 from rotating around the eccentric axis O2 in accordance with the rotation of the rotating shaft 21.
Next, the fixed scroll 30 and the discharge cover 100 will be described with reference to FIG. 2. FIG. 2 is an enlarged cross-sectional view of a main part of FIG. 1.

(Fixed scroll)

The fixed scroll 30 is provided between the discharge cover 100 and the orbital scroll 40 in the low-pressure side space 12a. The fixed scroll 30 includes a fastening portion 37, a fixed end plate 32, the fixed spiral-lap 33, and an annular protruded portion 35.
The fastening portion 37 is a flange-shaped member that is fastened to the first bearing 50 by a bolt 150 at the outer end portion of the fixed scroll 30 in the radial direction of the axis O1. The fastening portion 37 is provided at a plurality of positions at intervals in the circumferential direction of the axis O1 along the first inner peripheral surface 15a. Accordingly, the fixed scroll 30 is positioned into the casing 10 not to be movable.
A gap is formed between the first inner peripheral surface 15a and the outer peripheral surface of the fastening portion 37 between the fastening portions 37 adjacent to each other in the circumferential direction.
The fixed end plate 32 is formed in a disk shape with the direction of the axis O1 as the plate thickness direction and includes a back surface 32b, a front surface 32a, a fixed scroll side discharge hole 36a, and a discharge valve 34.
The back surface 32b and the front surface 32a are surfaces orthogonal to the axis O1. The back surface 32b faces the discharge cover 100 in the direction of the axis O1. The back surface 32b is exposed to the low-pressure side space 12a. The front surface 32a is disposed on the side opposite to the back surface 32b. The front surface 32a faces the orbital scroll 40 in the direction of the axis O1 and constitutes part of the compression chamber 31.
The fixed scroll side discharge hole 36a is formed to pass through the center of the fixed end plate 32 in the direction of the axis O1. The fixed scroll side discharge hole 36a extends in the direction of the axis O1 from the front surface 32a toward the back surface 32b. The fixed scroll side discharge hole 36a is a flow path for discharging the refrigerant compressed in the compression chamber 31 to the high-pressure side space 12b through the discharge valve 34, a discharge space 36b, and a discharge cover side discharge hole 36c.
The discharge valve 34 is provided in the discharge space 36b. The discharge valve 34 has a function as a valve for opening and closing the outlet of the fixed scroll side discharge hole 36a for the purpose of preventing the refrigerant from flowing back from the high-pressure side space 12b to the compression chamber 31 in the discharge space 36b.
The discharge space 36b is formed between the fixed scroll 30 and the discharge cover 100, the refrigerant discharged from the fixed scroll side discharge hole 36a is passed through the discharge space 36b. The refrigerant passing through the discharge space 36b enters the discharge cover side discharge hole 36c of the subsequent discharge cover 100 and escapes to the high-pressure side space 12b.
The fixed spiral-lap 33 is provided on the front surface 32a of the fixed end plate 32 and is erected on the other side of the direction of the axis O1. The fixed spiral-lap 33 is a wall body which is formed in a spiral shape when viewed from the direction of the axis O1. As an example, the fixed spiral-lap 33 preferably forms an involute curve centered on the axis O1 when viewed from the direction of the axis O1.
The annular protruded portion 35 is a cylindrical member that is provided on the back surface 32b and is provided on the outer peripheral side of the fixed scroll side discharge hole 36a to be protruded toward one side in the direction of the axis O1. The annular protruded portion 35 is disposed on the outer peripheral side of the fixed scroll side discharge hole 36a and the discharge space 36b to surround the fixed scroll side discharge hole 36a and the discharge space 36b.

(Discharge cover)

The discharge cover 100 is provided between the fixed scroll 30 and the second casing portion 16 and divides the accommodation space 12 in the casing 10 into the high-pressure side space 12b on one side in the direction of the axis O1 and the low-pressure side space 12a on the other side of the direction of the axis O1. The discharge cover 100 includes the flange portion 100b, the discharge cover side discharge hole 36c, an inner peripheral surface 100a, an annular recessed portion 101, and a seal portion 120.
The flange portion 100b is fastened and held to the first casing portion 15 and the second casing portion 16 by a bolt (not shown) and the like to be sandwiched between the end portion of the first casing portion 15 and the end portion of the second casing portion 16 in the circumferential direction. Accordingly, the discharge cover 100 is positioned in the casing 10 not to be movable and divides the accommodation space 12 into the high-pressure side space 12b and the low-pressure side space 12a.
The discharge cover side discharge hole 36c is formed to pass through the substantial center of the discharge cover 100 in the direction of the axis O1. The discharge cover side discharge hole 36c extends in the direction of the axis O1 from the inner peripheral surface 100a facing the other side of the discharge cover 100 in the direction of the axis O1 toward the high-pressure side space 12b. The discharge cover side discharge hole 36c is a flow path for discharging the refrigerant introduced from the discharge space 36b toward the high-pressure side space 12b.
The fixed scroll side discharge hole 36a, the discharge space 36b, and the discharge cover side discharge hole 36c constitute a discharge port 36 which communicates the compression chamber 31 and the high-pressure side space 12b with each other. That is, each of the fixed scroll side discharge hole 36a, the discharge space 36b, and the discharge cover side discharge hole 36c is a part of the discharge port 36.
The annular recessed portion 101 is a recessed portion which is provided on the inner peripheral surface 100a and is formed on the outer peripheral side of the discharge cover side discharge hole 36c to be recessed in an annular shape toward one side in the direction of the axis O1. The annular recessed portion 101 is formed so that the annular protruded portion 35 enters the annular recessed portion.
The injection space S which is formed in an annular shape surrounding the discharge cover side discharge hole 36c is formed between a front end surface 35a of the annular protruded portion 35 of the fixed scroll 30 and a bottom surface 101a of the annular recessed portion 101 of the discharge cover 100.
A liquid refrigerant is introduced into the injection space S from the outside through the injection pipe 130 and the liquid refrigerant is filled into the injection space S. As the liquid refrigerant, for example, an R32 refrigerant is used.
No pass-through portion such as a hole which communicates the injection space S and the compression chamber 31 with each other is formed in the front end surface 35a of the annular protruded portion 35. Therefore the liquid refrigerant cannot be directly introduced from the injection space S into the compression chamber 31 through the pass-through portion.
The seal portion 120 is installed between an inward peripheral surface of the annular protruded portion 35 and an inside wall surface of the annular recessed portion 101 so as to separate the injection space S from the discharge port 36 so that the liquid refrigerant cannot flow between them.
The seal portion 120 is formed of a groove and a seal member. The groove is a recessed portion which is formed on the inside wall surface of the annular recessed portion 101 to be recessed toward the discharge cover side discharge hole 36c and the seal member is embedded in the groove. For example, an O-ring is used as the seal member.
A communication path 110 is formed between an outward peripheral surface of the annular protruded portion 35 and an outside wall surface of the annular recessed portion 101 so as to be over the entire circumferential area of the annular protruded portion 35centered around the axis O1. That is, the injection space S is communicated with the low-pressure side space 12a through the communication path 110 formed between the fixed scroll 30 and the discharge cover 100.
The liquid refrigerant in the injection space S passes through the communication path 110 from the injection space S and the liquid refrigerant having passed through the communication path 110 flows outward in the radial direction of the axis O1 in a radial shape on the back surface 32b of the fixed end plate 32 which is the outer surface of the fixed scroll 30.
The liquid refrigerant that has flowed on the outer surface of the fixed scroll 30 flows out from a gap between the first inner peripheral surface 15a and the outer peripheral surface of the fastening portion 37 in the fastening portions 37 which are adjacent to each other in the circumferential direction toward the other side of the direction of the axis O1 in relation to the fixed scroll 30. The liquid refrigerant that has flowed out of the gap approached the orbital scroll 40 driven in an orbital motion and is sucked to the compression chamber 31. Thus the liquid refrigerant is also compressed similarly to the gas refrigerant.

(Operation and effect)

In the scroll compressor 1 according to the embodiment of the present disclosure, the annular injection space S which surrounds the discharge port 36 and the communication path 110 which communicates the injection space S with the low-pressure side space 12a are formed between the fixed scroll 30 and the discharge cover 100. Further, the casing 10 is provided with the injection pipe 130 which introduces the liquid refrigerant into the injection space S from the outside.
Accordingly, the liquid refrigerant introduced into the injection space S cools the outer surface on the inside of the fixed scroll 30. Further, since the liquid refrigerant passes through the communication path 110 from the injection space S and flows out to the low-pressure side space 12a, a new liquid refrigerant can be continuously supplied from the injection pipe 130 to the injection space S. Thus, it is possible to effectively cool the refrigerant in the discharge port 36 and the inside of the scroll having a relatively high temperature during operation.
Further, according to the above-described configuration, the communication path 110 which communicates the injection space S with the low-pressure side space 12a is formed over the entire circumferential area of the axis O1.
Accordingly, since the liquid refrigerant flows on the entire area of the outer surface of the fixed scroll 30, the outer surface of the fixed scroll 30 can be evenly cooled. Thus, the thermal distribution of the scroll can be optimized.
Further, according to the above-described configuration, the discharge cover 100 includes the annular recessed portion 101 which is formed on the outer peripheral side of the discharge port 36 and the fixed scroll 30 includes the annular protruded portion 35 which is entered into the annular recessed portion 101. Further, the injection space S is formed between the bottom surface 101a of the annular recessed portion 101 and the front end surface 35a of the annular protruded portion 35 and the communication path 110 is formed between the outward peripheral surface of the annular protruded portion 35 and the outside wall surface of the annular recessed portion 101 in the circumferential direction. Further, the seal portion 120 is provided between the inward peripheral surface of the annular protruded portion 35 and the inside wall surface of the annular recessed portion 101 so as to separate the injection space S and the discharge port 36 from each other.
Accordingly, since the communication path 110 connects the front end surface 35a and the back surface 32b as a step portion, the surface area cooled by the liquid refrigerant increases and the refrigerant in the discharge port 36 and the fixed scroll 30 can be more effectively cooled. Thus, the above-described effect can be further improved.
Further, in the above-described configuration, no pass-through portion which communicates the injection space S and the compression chamber 31 with each other is formed in the fixed scroll 30.
Accordingly, a dead volume (an increase in space that does not contribute to compression due to communication) does not occur during refrigerant compression. Thus, since no extra energy is input during compression, the scroll compressor 1 can be operated efficiently.

(Other embodiments)

Although the embodiment of the present disclosure has been described in detail with reference to the drawings, the specific configuration is not limited to the configuration of the embodiment, and the configuration can be added, omitted, replaced, or changed into other forms without departing from the gist of the present disclosure. Further, the present disclosure is not limited by the embodiment, but is limited only by the claims.
Additionally, the front end surface 35a of the annular protruded portion 35 may be provided with a recessed portion which is recessed toward the other side of the direction of the axis O1. Accordingly, since the surface area inside the fixed scroll 30 contacting the liquid refrigerant increases, the inside of the scroll can be more effectively cooled.
Further, the seal portion 120 may be provided in the annular protruded portion 35 or may be provided in both the annular recessed portion 101 and the annular protruded portion 35.
Further, in the description of this embodiment, the figure of the so-called stationary scroll compressor as the position component of the refrigerant circuit of the packaged air conditioner or the like is used, but the configuration of this embodiment may be used as the scroll compressor used in an in-vehicle car air conditioner, a refrigerating device, or the like.

The scroll compressor 1 described in the embodiment is understood, for example, as follows.
(1) The scroll compressor 1 according to a first aspect includes: the casing 10 which is extended in a direction of an axis O1; the discharge cover 100 which is accommodated in the casing 10 and formed so as to divide a space in the casing 10 into the high-pressure side space 12b on one side in the direction of the axis O1 and the low-pressure side space 12a on the other side; the orbital scroll 40 which is positioned in the low-pressure side space 12a and is configured to eccentrically rotated with respect to the axis O1; and the fixed scroll 30 which is positioned between the discharge cover 100 and the orbital scroll 40 in the low-pressure side space 12a, the compression chamber 31 to which refrigerant introduced from the low-pressure side space 12a being formed between the fixed scroll 30 and the orbital scroll 40, wherein the discharge port 36 through which the refrigerant compressed in the compression chamber 31 is discharged to the high-pressure side space 12b is formed so as to be passed through the fixed scroll 30 and the discharge cover 100, an annular injection space S surrounding the discharge port 36 and the communication path 110 communicating the injection space S with the low-pressure side space 12a are formed between the fixed scroll 30and the discharge cover 100, and the scroll compressor 1 further comprises an injection pipe 130 through which liquid refrigerant is introduced to the injection space S from an outside thereof.
Accordingly, the liquid refrigerant introduced into the injection space S cools the outer surface on the inside of the fixed scroll 30. Further, since the liquid refrigerant passes through the communication path 110 from the injection space S and flows out to the low-pressure side space 12a, a new liquid refrigerant can be continuously supplied from the injection pipe 130 to the injection space S.
(2) The scroll compressor 1 according to a second aspect is the scroll compressor 1 of the above (1), the communication path 110 may be formed between the fixed scroll 30 and the discharge cover 100 so as to be over the entire circumferential area thereof centered around the axis O1.
Accordingly, since the liquid refrigerant flows in the entire area of the outer surface of the fixed scroll 30, the outer surface of the fixed scroll 30 can be cooled evenly.
(3) The scroll compressor 1 according to a third aspect is the scroll compressor 1 of the above (1) or (2), the discharge cover 100 may be provided with the annular recessed portion 101 which is formed on the outer peripheral side of the discharge port 36 to be recessed in an annular shape toward one side in the direction of the axis O1, the fixed scroll 30 may be provided with the annular protruded portion 35 which is formed on the outer peripheral side of the discharge port 36 to be protruded in an annular shape toward one side in the direction of the axis O1, the annular protruded portion 35 being entered into the annular recessed portion 101, the injection space S may be formed between the bottom surface 101a of the annular recessed portion 101 and the front end surface 35a of the annular protruded portion 35, the communication path 110 may be formed between the outward peripheral surface of the annular protruded portion 35 and the outside wall surface of the annular recessed portion 101, and the scroll compressor 1 may further comprise the seal portion 120 which is installed between the inward peripheral surface 100a of the annular protruded portion 35 and the inside wall surface of the annular recessed portion 101 so as to separate the injection space S from the discharge port 36.
Accordingly, since the communication path 110 connects the front end surface 35a and the back surface 32b as a step portion, the surface area cooled by the liquid refrigerant increases and the refrigerant in the discharge port 36 and the inside of the fixed scroll 30 can be more effectively cooled.
(4) The scroll compressor 1 according to a fourth aspect is the scroll compressor 1 of any one of the above (1) to (3), no pass-through portion communicating the injection space S with the compression chamber 31 may be formed in the fixed scroll 30.
Accordingly, since a dead volume (an increase in space that does not contribute to compression due to communication) does not occur during refrigerant compression, the scroll compressor 1 can be operated efficiently.

EXPLANATION OF REFERENCES

1: Scroll compressor
10: Casing
11: Casing body
11a: Casing inner peripheral surface
12: Accommodation space
12a: Low-pressure side space
12b: High-pressure side space
13: Intake pipe
14: Discharge pipe
15: First casing portion
15a: First inner peripheral surface
16: Second casing portion
16a: Second inner peripheral surface
17: Third casing portion
20: Driving unit
21: Rotating shaft
21a: First end surface
21b: First end portion
21c: Second end portion
22: Rotor
23: Eccentric shaft
23a: End surface
30: Fixed scroll
31: Compression chamber
32: Fixed end plate
32a: Front surface
32b: Back surface
33: Fixed spiral-lap
34: Discharge valve
35: Annular protruded portion
35a: Front end surface
36: Discharge port
36a: Fixed scroll side discharge hole
36b: Discharge space
36c: Discharge cover side discharge hole
37: Fastening portion
40: Orbital scroll
41: Orbital end plate
41a: First surface
41b: Second surface
42: Orbital spiral-lap
43: Boss portion
50: First bearing
60: Second bearing
70: Bush assembly
71: Bush
80: Third bearing
90: Oldham ring
100: Discharge cover
100a: Inner peripheral surface
100b: Flange portion
101: Annular recessed portion
101a: Bottom surface
110: Communication path
120: Seal portion
130: Injection pipe
140: Oil supply pump
150: Bolt
160: Coil
O1: Axis
O2: Eccentric axis
S: Injection space

Claims

A scroll compressor (1) comprising:
a casing (10) which is extended in a direction of an axis;

a discharge cover (100) which is accommodated in the casing and formed so as to divide a space in the casing into a high-pressure side space (12b) on one side in the direction of the axis and a low-pressure side space (12a) on the other side;

an orbital scroll (40) which is positioned in the low-pressure side space and is configured to eccentrically rotate with respect to the axis; and

a fixed scroll (30) which is positioned between the discharge cover (100) and the orbital scroll (40) in the low-pressure side space (12a), a compression chamber (31) to which refrigerant introduced from the low-pressure side space being formed between the fixed scroll and the orbital scroll,

wherein a discharge port (36) through which the refrigerant compressed in the compression chamber is discharged to the high-pressure side space is formed so as to be passed through the fixed scroll and the discharge cover,

an annular injection space (S) surrounding the discharge port and a communication path (110) communicating the injection space with the low-pressure side space are formed between the fixed scroll and the discharge cover, and

the scroll compressor further comprises an injection pipe (130) through which liquid refrigerant is introduced to the injection space from an outside thereof.
The scroll compressor according to claim 1,
wherein the communication path (110) is formed between the fixed scroll (30) and the discharge cover (100) so as to be over the entire circumferential area thereof centered around the axis.
The scroll compressor according to claim 1 or 2,
wherein the discharge cover (100) is provided with an annular recessed portion (101) which is formed on an outer peripheral side of the discharge port to be recessed in an annular shape toward one side in the direction of the axis,

the fixed scroll (30) is provided with an annular protruded portion (35) which is formed on the outer peripheral side of the discharge port to be protruded in an annular shape toward one side in the direction of the axis, the annular protruded portion being entered into the annular recessed portion,

the injection space (S) is formed between a bottom surface of the annular recessed portion and a front end surface of the annular protruded portion,

the communication path (110) is formed between an outward peripheral surface of the annular protruded portion and an outside wall surface of the annular recessed portion, and

the scroll compressor further comprises a seal portion (120) which is installed between an inward peripheral surface of the annular protruded portion and an inside wall surface of the annular recessed portion so as to separate the injection space from the discharge port.
The scroll compressor according to any one of claims 1 to 3,
wherein no pass-through portion communicating the injection space (S) with the compression chamber (110) is formed in the fixed scroll.