GB2546897A

GB2546897A - Scroll compressor

Info

Publication number: GB2546897A
Application number: GB1701457.2A
Authority: GB
Inventors: Kanzaki Junya
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2014-11-10
Filing date: 2014-11-10
Publication date: 2017-08-02
Anticipated expiration: 2034-11-10
Also published as: GB201701457D0; JPWO2016075731A1; JP6227164B2; GB2546897B; WO2016075731A1

Abstract

A scroll compressor 1 is provided with: an insertion hole 61 formed in the other surface of the base plate 31a of a stationary scroll 31; an injection port 62 having an inner diameter smaller than that of the insertion hole 61 and passing between the bottom 61a of the insertion hole 61 and one surface of the base plate 31a; an injection pipe 60 which passes through a closed container 10, is inserted in the insertion hole 61, and injects fluid into a compression chamber 35 through the injection port 62; and an annular damping member 63 having an outer diameter D11 greater than the inner diameter of the injection port 62 and disposed between the injection pipe 60 and the bottom 61a of the insertion hole 61. The injection pipe 60 is provided with: a large-diameter section 60b1 having an outer diameter D21 greater than the inner diameter D22 of the damping member 63, the large-diameter section 60b1 being in contact with the damping member 63; and a small-diameter section 60b2 having an outer diameter D22 smaller than the outer diameter D21 of the large-diameter section 60b1, the small-diameter section 60b2 being fitted in the damping member 63. The axial dimension L21 of the small-diameter section 60b2 is smaller than the axial dimension L11 of the damping member 63.

Description

DESCRIPTION Title of Invention SCROLL COMPRESSOR Technical Field [0001]

The present invention relates to a scroll compressor.

Background Art [0002]

Patent Literature 1 discloses a scroll compressor including an injection mechanism that injects fluid into a compression chamber. This scroll compressor has an oil injection port disposed in a mirror plate portion of a fixed scroll. An oil injection pipe extending through an upper lid of a sealed container is connected to the oil injection port.

Citation List Patent Literature [0003]

Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2010-121582 (Fig. 8)

Summary of Invention Technical Problem [0004]

Typically, in a scroll compressor including an injection mechanism as described above, a pipe insertion hole coaxial with an injection port and having a diameter greater than the diameter of the injection port is formed on the back surface of a fixed scroll. An annular bottom portion is formed between the pipe insertion hole and the injection port due to the difference between these diameters.

[0005]

In a manufacturing process of such a scroll compressor, an injection pipe is inserted into a pipe insertion hole of a fixed scroll, before a lid part is attached to a body part of a sealed container. Then, the injection pipe with its end portion abutting an annular bottom portion of the pipe insertion hole is arranged to extend through the lid part, and the lid part is attached to the body part. The lid part and the body part are fixed by welding. Then, before the lid part is completely cooled, the injection pipe and the lid part are fixed by brazing. Therefore, after the lid part is completely cooled, the end portion of the injection pipe is pressed against the annular bottom portion due to the difference in thermal contraction. The resulting stress concentrates at a brazed portion between the injection pipe and the lid part, and therefore the injection pipe might be damaged during operation or at other time. Accordingly, the scroll compressor described above has a problem of a reduction in durability.

[0006]

The present invention has been made to solve the above problem, and aims to provide a scroll compressor with improved durability.

Solution to Problem [0007] A scroll compressor according to the present invention includes: a container; a fixed scroll accommodated in the container and including a base plate portion and a spiral wrap formed on one surface of the base plate portion, the fixed scroll and an orbiting scroll forming a compression chamber therebetween; an insertion hole formed on an other surface of the base plate portion; an injection port having an inner diameter less than an inner diameter of the insertion hole, and extending between a bottom portion of the insertion hole and the one surface of the base plate portion; an injection pipe extending through the container and inserted in the insertion hole to inject fluid into the compression chamber through the injection port; and an annular buffer member having an outer diameter greater than the inner diameter of the injection port, and disposed between the injection pipe and the bottom portion of the insertion hole, the injection pipe including a large diameter portion having an outer diameter greater than an inner diameter of the buffer member and abutting on the buffer member, and a small diameter portion having an outer diameter less than the outer diameter of the large diameter portion and fitted in the buffer member, the small diameter portion having an axial dimension less than an axial dimension of the buffer member.

Advantageous Effects of Invention [0008]

According to the present invention, it is possible to prevent a direct contact between an end portion of an injection pipe and a bottom portion of an insertion hole, and thus to reduce damage to the injection pipe. Therefore, according to the present invention, it is possible to improve the durability of a scroll compressor.

Brief Description of Drawings [0009] [Fig. 1] Fig. 1 is a vertical cross-sectional view illustrating the configuration of a scroll compressor 1 according to Embodiment 1 of the present invention.

[Fig. 2] Fig. 2 is a diagram illustrating a connection structure of an injection pipe 60 in the scroll compressor 1 according to Embodiment 1 of the present invention.

[Fig. 3] Fig. 3 is a diagram illustrating a connection structure of an injection pipe 60 in a scroll compressor 1 according to Embodiment 2 of the present invention.

[Fig. 4] Fig. 4 is a diagram illustrating a connection structure of an injection pipe 60 in a scroll compressor 1 according to Embodiment 3 of the present invention. Description of Embodiments [0010]

Embodiment 1 A scroll compressor according to Embodiment 1 of the present invention will be described. Fig. 1 is a vertical cross-sectional view illustrating the configuration of a scroll compressor 1 according to Embodiment 1. The scroll compressor 1 is a fluid machine that compresses and discharges fluid (for example, gaseous refrigerant), and is one of the elements of a refrigeration cycle used for, for example, a refrigerator, a freezer, an automatic vending machine, an air-conditioning apparatus, a refrigeration apparatus, a water heater, and other apparatuses. In the drawings including Fig. 1 to be referred to below, the relative dimensional relationship between the components and the shapes thereof may be different from the actual ones.

[0011]

As illustrated in Fig. 1, the scroll compressor 1 has configuration in which a compression mechanism unit 30 that compresses fluid and a motor unit 20 that drives the compression mechanism unit 30 are accommodated in a sealed container 10.

The sealed container 10 has a configuration in which a body part 10a having a cylindrical shape, a lid part 10b attached to the upper end of the body part 10a, and a bottom part 10c attached to the lower end of the body part 10a are fixed to each other by welding or other methods. An oil reservoir 11 is formed in the bottom part 10c. The oil reservoir 11 stores refrigerating machine oil that lubricates sliding portions. A suction pipe 12 that suctions fluid (for example, low-pressure gaseous refrigerant) into a low-pressure space in the sealed container 10 is connected to the body part 10a. Further, a frame 33 is fixed to an upper portion of the inner peripheral surface of the body part 10a. A motor stator 21 of the motor unit 20 is fixed under the frame 33 on the inner peripheral surface of the body part 10a. A sub-frame 38 is fixed under the motor stator 21 on the inner peripheral surface of the body part 10a. A discharge pipe 13 that discharges compressed fluid (for example, high-pressure gaseous refrigerant) from a discharge space 14 to the outside of the sealed container 10, and an injection pipe 60 (described below in detail) that injects fluid (for example, liquid refrigerant) into a compression chamber in the midway of the compression stroke are connected to the lid part 10b. In this example, only one injection pipe 60 is provided.

[0012]

The motor unit 20 drives an orbiting scroll 32 of the compression mechanism unit 30 via a main shaft 40. The motor unit 20 includes the motor stator 21 fixed to the inner peripheral surface of the sealed container 10, and a motor rotor 22 fixed to the main shaft 40. The motor rotor 22 rotates when energized by the motor stator 21, and rotates the main shaft 40 that transmits a driving force to the orbiting scroll 32. An eccentric shaft portion 40a that rotatably fits in an orbiting bearing 34 of the orbiting scroll 32 is formed at the upper end of the main shaft 40. An oil hole 40c serving as a flow path for the refrigerating machine oil stored in the oil reservoir 11 is provided inside the main shaft 40 to extend from the lower end to the upper end of the main shaft 40. Further, balancers 48 and 49 for balancing the orbiting scroll 32 with respect to the center of rotation of the main shaft 40 are disposed on an upper portion of the main shaft 40 and a lower portion of the motor rotor 22, respectively.

[0013]

The compression mechanism unit 30 includes a fixed scroll 31 and the orbiting scroll 32. The fixed scroll 31 is fixed to the frame 33 that is fixed to the body part 10a. The fixed scroll 31 includes a base plate portion 31a and a spiral wrap 31 b curved in an involute shape and standing upright on one surface (the lower surface in this example) of the base plate portion 31 a. A seal 43 for preventing leakage of fluid is disposed at the tip end of the spiral wrap 31 b. A discharge port 31 c that discharges a compressed fluid (for example, high-pressure gaseous refrigerant) is formed at the center of the fixed scroll 31. A discharge valve 50 having a reed valve structure is disposed at the outlet of the discharge port 31c.

[0014]

The orbiting scroll 32 performs an orbital motion with respect to the fixed scroll 31 without performing a rotational motion. The orbiting scroll 32 includes a base plate portion 32a and a spiral wrap 32b curved in an involute shape and standing upright on one surface (the upper surface in this example) of the base plate portion 32a. A seal 44 for preventing leakage of fluid is disposed at the tip end of the spiral wrap 32b. A thrust plate 42 serving as thrust bearing is disposed on the other surface (a thrust bearing surface) of the base plate portion 32a. The thrust bearing surface of the orbiting scroll 32 is axially supported by the frame 33 via the thrust plate 42. Further, the orbiting bearing 34 having a bottomed cylindrical shape is formed substantially at the center of the other surface of the orbiting scroll 32. A slider 46 that supports the orbiting scroll 32 to cause the orbiting scroll 32 to perform an orbital motion is rotatably stored in the orbiting bearing 34. The eccentric shaft portion 40a is inserted in the slider 46. The eccentric shaft portion 40a is disposed at the upper end of the main shaft 40 to be eccentric to the main shaft 40.

[0015]

The fixed scroll 31 and the orbiting scroll 32 are attached inside the sealed container 10 in a manner such that the spiral wrap 31b and the spiral wrap 32b mesh with each other. A compression chamber 35 is formed between the spiral wrap 31 b and the spiral wrap 32b. Further, an Oldham ring 36 for preventing a rotational motion of the orbiting scroll 32 and allowing an orbital motion thereof is disposed between the orbiting scroll 32 and the frame 33. A key portion 36a formed on the upper surface of the Oldham ring 36 is slidably accommodated in an Oldham groove 45 provided in the orbiting scroll 32. A key portion (not illustrated) formed on the lower surface is slidably accommodated in an Oldham groove (not illustrated) provided in the frame 33.

[0016]

The frame 33 fixes and supports the fixed scroll 31, and supports the orbiting scroll 32 via the thrust plate 42. The frame 33 also supports an upper portion of the main shaft 40 near the eccentric shaft portion 40a, via a main bearing 37 disposed in a through hole at the center. A sleeve 47 for allowing the main shaft 40 to rotate smoothly is rotatably accommodated in the main bearing 37.

[0017]

The sub-frame 38 is dispose under the frame 33 and is fixed to the inner peripheral surface of the sealed container 10. The sub-frame 38 rotatably supports the lower portion of the main shaft 40, via a through hole formed at the center. A bearing housing portion 38a is disposed in the through hole. An outer ring of a ball bearing 39 for rotatably supporting the main shaft 40 is press-fitted in the bearing housing portion 38a.

[0018]

Further, the sub-frame 38 is provided with a displacement oil pump 41 that supplies refrigerating machine oil to sliding portions. A pump shaft portion 40b is coupled to the oil pump 41. The pump shaft portion 40b is disposed at the lower end of the main shaft 40 to transmit a rotational force to the oil pump 41. The pump shaft portion 40b is integrally molded with the main shaft 40. The oil hole 40c provided at the center of the main shaft 40 communicates, at the lower end side thereof, with the oil pump 41.

[0019]

Fig. 2 is a diagram illustrating a connection structure of the injection pipe 60 in the scroll compressor 1 according to Embodiment 1. As illustrated in Fig. 2, an insertion hole 61 having a depth less than the thickness of the base plate portion 31a is formed on the upper surface of the base plate portion 31a of the fixed scroll 31 in a thickness direction of the base plate portion 31 a. An injection port 62 extending through the base plate portion 31a is formed between a bottom portion 61a of the insertion hole 61 and a compression-chamber-35-side surface of the base plate portion 31a. The fixed scroll 31 of this example is provided with only one injection port 62 for injection. An open end of the injection port 62 at the compression chamber 35 side is located in the midway of the compression stroke in the compression chamber 35. The injection port 62 is formed coaxially with the insertion hole 61, and has an inner diameter less than the inner diameter of the insertion hole 61. Thus, the bottom portion 61 a of the insertion hole 61 has an annular shape surrounding the injection port 62.

[0020]

The injection pipe 60 injects fluid into the compression chamber 35 through the injection port 62. The injection pipe 60 includes a joint part 60a and a pipe part 60b. The joint part 60a extends through a through portion 15 formed in the lid part 10b of the sealed container 10, and is brazed to the lid part 10b. The pipe part 60b is located at the base end side (that is, the injection port 62 side) of the joint part 60a, and is inserted into the insertion hole 61.

[0021]

An annular buffer member 63 is disposed between the injection pipe 60 and the bottom portion 61a of the insertion hole 61. The buffer member 63 has a rectangular cross-sectional shape, for example. The buffer member 63 is made of, for example, an elastic material such as resin or rubber. The outer diameter of the buffer member 63 is D11, and the inner diameter of the buffer member 63 is D12 when the buffer member 63 is inserted (including press-fitted) in the insertion hole 61. The outer diameter D11 of the buffer member 63 is greater than at least the inner diameter of the injection port 62. In this example, the outer diameter D11 of the buffer member 63 is equal to the inner diameter of the insertion hole 61. Thus, the buffer member 63 is disposed on the annular bottom portion 61a in the insertion hole 61. Further, the axial dimension (the vertical thickness in Fig. 2) of the buffer member 63 is L11.

[0022]

The buffer member 63 of this example is made of a material having a smaller Young's modulus (elastic modulus) than the materials of the fixed scroll 31 and the injection pipe 60. For example, the fixed scroll 31 is made of cast iron (Young's modulus 152.3 GPa), and the injection pipe 60 is made of brass (Young's modulus 103 GPa). Meanwhile, the buffer member 63 is made of a material having a Young's modulus sufficiently less than those of the above materials, such as rubber (Young's modulus 0.01 - 0.1 GPa) or polytetrafluoroethylene (Young's modulus 0.5 GPa), for example.

[0023]

The pipe part 60b of the injection pipe 60 includes a large diameter portion 60b1, and a small diameter portion 60b2 located at the base end side of the large diameter portion 60b1. The small diameter portion 60b2 is formed by performing, for example, a cutting operation on the large diameter portion 60b1. A full circumferential groove 65 circumferentially extending around the entire circumference is formed on the outer peripheral surface of the large diameter portion 60b1. An O-ring 64 is accommodated in the full circumferential groove 65. The O-ring 64 hermetically separates the injection port 62 from the discharge space 14.

[0024]

The outer diameter of the large diameter portion 60b1 is D21. The outer diameter of the small diameter portion 60b2 is D22, which is less than the outer diameter D21 of the large diameter portion 60b1. The outer diameter D21 of the large diameter portion 60b1 is equal to less than the inner diameter of the insertion hole 61, and is greater than the inner diameter D12 of the buffer member 63. The lower end of the large diameter portion 60b1 is in contact with the buffer member 63. Accordingly, the buffer member 63 is held between the lower end of the large diameter portion 60b1 and the bottom portion 61a of the insertion hole 61.

[0025]

The small diameter portion 60b2 is fitted (including press-fitted) in the buffer member 63. That is, the outer diameter D22 of the small diameter portion 60b2 is substantially equal to or less than the inner diameter D12 of the buffer member 63.

In this example, the outer diameter D22 of the small diameter portion 60b2 is greater than the inner diameter of the injection port 62. However, the outer diameter D22 of the small diameter portion 60b2 may be less than the inner diameter of the injection port 62. The axial dimension (the vertical thickness in Fig. 2) of the small diameter portion 60b2 is L21. The axial dimension L21 of the small diameter portion 60b2 is less than the axial dimension L11 of the buffer member 63. Accordingly, the lower end of the small diameter portion 60b2 and the bottom portion 61a of the insertion hole 61 face each other with a space 66 therebetween, without being in contact with each other.

[0026]

Next, the operation of the scroll compressor of Embodiment 1 will be described with reference to Fig. 1. When an electric power is supplied to the motor stator 21, the motor rotor 22 rotates together with the main shaft 40. A rotational driving force of the main shaft 40 is transmitted to the orbiting scroll 32 via the slider 46. The orbiting scroll 32 with the rotational driving force transmitted thereto performs an orbital motion with respect to the fixed scroll 31 while a rotational motion is restricted by the Oldham ring 36. Thus, the volume of the compression chamber 35 formed between the fixed scroll 31 and the orbiting scroll 32 changes.

[0027]

Along with the orbital motion of the orbiting scroll 32, fluid (for example, low-pressure gaseous refrigerant) is suctioned from the suction pipe 12 into a low-pressure space in the sealed container 10, and is introduced into the compression chamber 35 to be compressed therein. The compressed fluid passes through the discharge port 31c, pushes up the discharge valve 50 to be discharged into the discharge space 14, and is discharged to the outside from the discharge pipe 13.

[0028]

In the case of using an injection mechanism, fluid (for example, liquid refrigerant) having a higher pressure than the inside of the compression chamber 35 is guided into the injection pipe 60, and is caused to flow into the compression chamber 35 in the midway of the compression stroke. Thus, the amount of fluid in the compression chamber 35 increases, and the inside of the compression chamber 35 is cooled. The compressed fluid is discharged to the outside from the discharge pipe 13 through the discharge port 31c, the discharge valve 50, and the discharge space 14, in the same manner as described above.

[0029]

Next, an example of a manufacturing process of the scroll compressor 1 according to Embodiment 1 will be described. First, the compression mechanism unit 30 and the motor unit 20 manufactured by a predetermined process is fixed to the inner peripheral surface of the body part 10a by shrinkage fitting or other methods. Then, the buffer member 63 is disposed on the bottom portion 61a of the insertion hole 61 of the fixed scroll 31 (buffer member disposing step). Then, the injection pipe 60 is inserted into the insertion hole 61 (injection pipe insertion step). In the injection pipe insertion step, the small diameter portion 60b2 of the injection pipe 60 is fitted into the buffer member 63 such that the lower end of the large diameter portion 60b1 abuts the buffer member 63. Note that in the buffer member disposing step, in place of disposing the buffer member 63 on the bottom portion 61a of the insertion hole 61, the buffer member 63 may be fitted on the small diameter portion 60b2 of the injection pipe 60 before insertion.

[0030]

Subsequently, while maintaining a state in which the small diameter portion 60b2 is fitted in the buffer member 63 and the lower end of the large diameter portion 60b1 abuts the buffer member 63, the injection pipe 60 is arranged to extend through the through portion 15 of the lid part 10b, and the lid part 10b is mounted on the body part 10a (lid mounting step). Then, the lid part 10b and the body part 10a are welded around the entire circumference (welding step). Then, before the lid part 10b having heated in the welding step is cooled to room temperature, the injection pipe 60 and the lid part 10b are brazed (brazing step). In the brazing step, the injection pipe 60 and the lid part 10b are joined with a brazed portion 15a. With the above steps, the scroll compressor 1 is manufactured.

[0031]

As described above, the scroll compressor 1 according to Embodiment 1 includes: the sealed container 10; the fixed scroll 31 accommodated in the sealed container 10 and including the base plate portion 31a and the spiral wrap 31b formed on one surface of the base plate portion 31a, the fixed scroll 31 and the orbiting scroll 32 forming the compression chamber 35 therebetween; the insertion hole 61 formed on the other surface of the base plate portion 31a; the injection port 62 having an inner diameter less than the inner diameter of the insertion hole 61, and extending between the bottom portion 61a of the insertion hole 61 and the one surface of the base plate portion 31a; the injection pipe 60 extending through the sealed container 10 and inserted in the insertion hole 61 to inject fluid into the compression chamber 35 through the injection port 62; and the annular buffer member 63 having the outer diameter D11 greater than the inner diameter of the injection port 62, and disposed between the injection pipe 60 and the bottom portion 61a of the insertion hole 61.

The injection pipe 60 includes the large diameter portion 60b1 having the outer diameter D21 greater than the inner diameter D12 of the buffer member 63 and abutting on the buffer member 63, and the small diameter portion 60b2 having the outer diameter D22 less than the outer diameter D21 of the large diameter portion 60b1 and fitted in the buffer member 63. The axial dimension L21 of the small diameter portion 60b2 is less than the axial dimension L11 of the buffer member 63.

[0032]

With this configuration, the buffer member 63 can be held between the injection pipe 60 and the bottom portion 61 a of the insertion hole 61. That is, in the axial direction of the injection pipe 60, the buffer member 63 can be disposed between the lower end of the large diameter portion 60b1 and the bottom portion 61a of the insertion hole 61, and the space 66 can be formed between the lower end of the small diameter portion 60b2 and the bottom portion 61a of the insertion hole 61.

Therefore, even if the lid part 10b is cooled to room temperature after completion of the brazing step and the injection pipe 60 is pressed toward the injection port 62 due to the difference in thermal contraction, it is possible to prevent a direct contact between the injection pipe 60 and the bottom portion 61a of the insertion hole 61.

This can reduce stress concentrated on the brazed portion 15a, and prevent damage to the injection pipe 60. Therefore, according to Embodiment 1, it is possible to improve the durability of the scroll compressor 1.

[0033]

Embodiment 2 A scroll compressor according to Embodiment 2 of the present invention will be described. Fig. 3 is a diagram illustrating a connection structure of an injection pipe 60 in a scroll compressor 1 according to Embodiment 2. As illustrated in Fig. 3, in Embodiment 2, an O-ring 63a made of rubber is used as a buffer member disposed between the injection pipe 60 and a bottom portion 61a of an insertion hole 61. The other configurations, operations, and manufacturing process are the same as those of Embodiment 1, and the description thereof will be omitted.

[0034]

According to Embodiment 2, the same advantages as those of Embodiment 1 can be obtained. Further, according to Embodiment 2, by using the O-ring 63a as a buffer member, it is possible to simplify the structure of the scroll compressor 1, and to reduce the manufacturing cost. Further, in the case where the required air tightness is achieved by the O-ring 63a, it is not necessary to form the full circumferential groove 65 or attach the O-ring 64.

[0035]

Embodiment 3 A scroll compressor according to Embodiment 3 of the present invention will be described. Fig. 4 is a diagram illustrating a connection structure of an injection pipe 60 in a scroll compressor 1 according to Embodiment 3. As illustrated in Fig. 4, in Embodiment 3, a buffer member 63b at least whose surface is made of (PTFE) is used as a buffer member disposed between the injection pipe 60 and a bottom portion 61 a of an insertion hole 61. The other configurations, operations, and manufacturing process are the same as those of Embodiment 1, and the description thereof will be omitted.

[0036]

The entire buffer member 63b may be made of PTFE, or only the surface of the buffer member 63b may be made of PTFE. Alternatively, the buffer member 63b may be a rubber O-ring having a surface coated with PTFE. PTFE is characterized by high sealing and sliding performances, and low dusting properties.

[0037]

According to Embodiment 3, the same advantages as those of Embodiment 1 can be obtained. Further, according to Embodiment 3, since the sliding performance of the buffer member 63b can be enhanced, it is possible to further improve the pipe assemblability in the injection pipe insertion step. Further, according to Embodiment 3, since the dusting properties of the buffer member 63b can be reduced, it is possible to prevent the scroll compressor 1 from failing due to entry of foreign matter.

[0038]

Other Embodiments

The present invention is not limited to the foregoing embodiments, and various modifications may be made.

For example, in the foregoing embodiments, the scroll compressor 1 has been illustrated. However, the prevent invention may also be applied to a horizontal scroll compressor.

Reference Signs List [0039] 1 scroll compressor 10 sealed container 10a body part 10b lid part 10c bottom part 11 oil reservoir 12 suction pipe 13 discharge pipe 14 discharge space 15 through portion 15a brazed portion 20 motor unit 21 motor stator 22 motor rotor 30 compression mechanism unit 31 fixed scroll 31a base plate portion 31b spiral wrap 31c discharge port 32 orbiting scroll 32a base plate portion 32b spiral wrap 33 frame 34 orbiting bearing 35 compression chamber 36 Oldham ring 36a key portion 37 main bearing 38 sub-frame 38a bearing housing portion 39 ball bearing 40 main shaft 40a eccentric shaft portion 40b pump shaft portion 40c oil hole 41 oil pump 42 thrust plate 43, 44 seal 45 Oldham groove 46 slider 47 sleeve 48,49 balancer 50 discharge valve 60 injection pipe 60a joint part 60b pipe part 60b1 large diameter portion 60b2 small diameter portion 61 insertion hole 61a bottom portion 62 injection port 63,63b buffer member 63a O-ring 64 O-ring 65 full circumferential groove 66 space

Claims

CLAIMS [Claim 1] A scroll compressor comprising: a container; a fixed scroll accommodated in the container and including a base plate portion and a spiral wrap formed on one surface of the base plate portion, the fixed scroll and an orbiting scroll forming a compression chamber therebetween; an insertion hole formed on an other surface of the base plate portion; an injection port having an inner diameter less than an inner diameter of the insertion hole, and extending between a bottom portion of the insertion hole and the one surface of the base plate portion; an injection pipe extending through the container and inserted in the insertion hole to inject fluid into the compression chamber through the injection port; and an annular buffer member having an outer diameter greater than the inner diameter of the injection port, and disposed between the injection pipe and the bottom portion of the insertion hole, the injection pipe including a large diameter portion having an outer diameter greater than an inner diameter of the buffer member and abutting on the buffer member, and a small diameter portion having an outer diameter less than the outer diameter of the large diameter portion and fitted in the buffer member, the small diameter portion having an axial dimension less than an axial dimension of the buffer member. [Claim 2] The scroll compressor of claim 1, wherein the buffer member is an O-ring. [Claim 3] The scroll compressor of claim 1 or 2, wherein at least a surface of the buffer member is formed of PTFE.