EP3199753B1

EP3199753B1 - Scroll compressor

Info

Publication number: EP3199753B1
Application number: EP17153568.5A
Authority: EP
Inventors: Takuma YAMASHITA; Taichi Tateishi; Akihiro KANAI; Hajime Sato; Yoshiyuki Kimata; Yogo Takasu; Kazuki Takahashi
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 2016-01-29
Filing date: 2017-01-27
Publication date: 2021-01-20
Anticipated expiration: 2037-01-27
Also published as: EP3199753A1; JP6630580B2; JP2017133466A

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a scroll compressor. More particularly, the invention relates to a technology for reducing wear of a wall of a key groove along which a key of an Oldham link provided in a scroll compressor slides.

Description of the Related Art

A scroll compressor is provided with an Oldham link that restricts rotation of an orbiting scroll. The Oldham link has a pair of first keys inserted into a pair of key grooves of the orbiting scroll and a pair of second keys inserted into a pair of key grooves of a shaft bearing, and a direction in which the first keys can slide in the radial direction along the key grooves and a direction in which the second keys can slide in the radial direction along the key grooves are orthogonal to each other.
To reduce wear of the wall of the key groove along which the key of the Oldham link slides, highly wear-resistant hard member is disposed on the wall of the key groove (Japanese Patent Laid-Open No. 8-189480 ), or a coating of a solid lubricant is formed on the wall.
Lubricating oil pumped up from an oil storage part inside a housing through an oil supply path inside a rotating shaft is supplied to sliding parts of the scroll compressor, such as the rotating shaft, orbiting scroll, thrust plate, shaft bearing, and Oldham link. As the amount of lubricating oil supplied is smaller during low-speed operation, it is necessary to secure reliability by reducing wear of the sliding parts.
In particular, it is necessary to reduce wear of the key of the Oldham link and the key groove in which the key slides that are located far away from a connection part of an eccentric pin of the rotating shaft and the orbiting scroll where the lubricating oil is present.
JP 2015-101985 discloses a scroll compressor according to the preamble of claim 1 and JP 2000-274361 discloses a scroll compressor according to the preamble of claim 7. JP 2005-054744 , US 5,516,267 , US 2008/050260 and JP H03-267501 disclose other scroll compressors.
The present invention aims to provide a scroll compressor that can reduce wear of a key of an Oldham link and a key groove in which the key slides.

SUMMARY OF THE INVENTION

An examination made by the present inventors of a state of the wall of a key groove that had worn through the use of the scroll compressor has found that the amount of wear increases gradually, for example, toward the outer peripheral-side end of the key groove, within a range in which the key of the Oldham link shifts relative to the key groove. This means that the key groove wears easily at the side of the open end (outer peripheral-side end), where the key comes in contact with the wall of the key groove in an inclined state.
Once the scroll compressor starts to be used, the surface roughness of the wall of the key groove and the key changes until the sliding surfaces of the key and the wall of the key groove are adapted to each other.
Accordingly, we imparted the shape and the surface roughness simulating the state where the wall has worn through use and the state where the surface is adapted through use to the wall of the key groove before the start of use, and confirmed that wear was thereby reduced.
Having been devised on the basis of this finding, a scroll compressor of the present invention is defined in claim 1 and includes: a fixed scroll fixed to a housing; an orbiting scroll eccentrically connected to a rotating shaft and revolved relative to the fixed scroll; a shaft bearing fixed to the housing and supporting the orbiting scroll; and an Oldham link interposed between the orbiting scroll and the shaft bearing and restricting rotation of the orbiting scroll.
The Oldham link has a first key that slides in a radial direction of the rotating shaft along a wall of a key groove provided in the orbiting scroll, and a second key that slides in the radial direction of the rotating shaft along a wall of another key groove provided in the shaft bearing.
In the present invention, on the assumption of a flat reference surface in the wall of the key groove, the wall has an offset portion that is gradually offset from the reference surface while extending toward at least one of an outer peripheral-side end and an inner peripheral-side end of the key groove.
In the scroll compressor of the present invention, it is preferable that a surface roughness Ra of a sliding surface of the wall including a surface of the offset portion be 0.2 µm or less before the start of use of the Oldham link.
"The surface roughness Ra" according to the present invention is based on JIS B 0601-2001.
In the scroll compressor of the present invention, a part of an inner periphery of the key groove including at least the offset portion, or the entire inner periphery of the key groove, is formed by a liner discrete from a main body that is the orbiting scroll or the shaft bearing.
In the scroll compressor of the present invention, it is preferable that, as the liner is fitted with the main body located on the rear surface side of the liner through engagement between a recess and a protrusion, the liner be positioned in a sliding direction that is a direction in which the first key or the second key slides.
"Engagement fitting" refers to fitting through engagement between a recess and a protrusion.
In the scroll compressor of the present invention, it is preferable that the liner be formed substantially in a U-shape.
In the scroll compressor of the present invention, it is preferable that a liner groove receiving an edge of the liner be formed in a bottom of the key groove.
In the scroll compressor of the present invention, it is preferable that the liner have a liner bottom that forms a bottom surface of the key groove and is pressed into the main body, and a liner wall that stands on the liner bottom and includes the offset portion.
Another scroll compressor of the present invention is defined in claim 7 and includes: a fixed scroll fixed to a housing; an orbiting scroll eccentrically connected to a rotating shaft and revolved relative to the fixed scroll; a shaft bearing fixed to the housing and supporting the orbiting scroll; and an Oldham link interposed between the orbiting scroll and the shaft bearing and restricting rotation of the orbiting scroll, wherein the Oldham link has a first key that slides in a radial direction of the rotating shaft along a wall of a key groove provided in the orbiting scroll, and a second key that slides in the radial direction of the rotating shaft along a wall of another key groove provided in the shaft bearing, and wherein a surface roughness Ra of the wall of the key groove before the start of use of the Oldham link is set to 0.2 µm or less.
In the above configuration, at least a part of an inner periphery of the key groove for which the surface roughness Ra is set, or the entire inner periphery of the key groove, is formed by a liner discrete from a main body that is the orbiting scroll or the shaft bearing.
In the scroll compressor of the present invention, it is preferable that the main body have a liner housing part that houses the liner and allows the liner to shift in a sliding direction that is a direction in which the first key or the second key slides.
In the scroll compressor of the present invention, it is preferable that the liner be swingably supported on the main body located on the rear surface side of the liner.
In the scroll compressor of the present invention, it is preferable that, of the liner and the inner periphery of the key groove, at least the liner have an oil path which communicates with an oil sump present around a connection part of the rotating shaft and the orbiting scroll and through which lubricating oil is supplied from the oil sump to the wall of the key groove.
In the scroll compressor of the present invention, it is preferable that a coating having a lubricating property is applied to the wall of the key groove.
According to the present invention, the offset portion is provided in the wall of the key groove along which the key of the Oldham link slides, and the surface roughness Ra of the wall of the key groove is set to 0.2 µm or less. As will be described later in detail, these features achieve an effect of reducing wear of the key and the key groove by preventing significant wear typically occurring at an initial stage of use.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal sectional view showing a scroll compressor;
FIG. 2 is a partially enlarged view of FIG. 1, showing keys of an Oldham link;
FIG. 3 is an overall perspective view of the Oldham link;
FIG. 4A is a view showing a key groove of an orbiting scroll and the key of the Oldham link;
FIG. 4B is a view showing a key groove of a shaft bearing and the key of the Oldham link;
FIGS. 5A and 5B are views showing a key groove according to a first embodiment, in which FIG. 5A is a perspective view and FIG. 5B is a plan view;
FIG. 6 is a perspective view showing another key groove according to the first embodiment;
FIGS. 7A to 7C are views illustrating a state of wear of a key groove that was checked to determine the shape of a wall of the key groove along which a first key slides, in which FIG. 7A is a schematic view showing the key inclined on the open end side of the key groove, FIG. 7B is a perspective view of the key groove, and FIG. 7C is a graph showing an image of a shape profile of the wall of the key groove in the direction of the arrow of FIG. 7B;
FIG. 8 is a graph showing a relation between a surface roughness and a depth of wear of the wall of the key groove;
FIG. 9A is a view showing an example in which an offset portion is formed on both an outer peripheral-end side and an inner peripheral-end side;
FIG. 9B is a schematic view showing an oil film between the key and the wall of the key groove;
FIGS. 10A to 10C are perspective views showing key grooves according to a second embodiment;
FIG. 11 is a perspective view showing a key groove according to a third embodiment;
FIGS. 12A and 12B are perspective views showing key grooves according to a combination of the second embodiment and the third embodiment;
FIG. 13 is a perspective view showing a key groove according to a combination of the second embodiment and the third embodiment;
FIGS. 14A and 14B are perspective views showing key grooves according to a fourth embodiment;
FIG. 15 is a perspective view showing a key groove according to a fifth embodiment;
FIG. 16 is a perspective view showing a key groove according to a sixth embodiment;
FIGS. 17A and 17B are perspective views showing key grooves according to a seventh embodiment;
FIG. 18 is a plan view showing the key groove according to the seventh embodiment;
FIGS. 19A to 19C are views showing components of a key groove according to an eighth embodiment; and
FIG. 19D is a view showing a modified example of the components.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be described below with reference to the accompanying drawings.
First, a configuration common to the following embodiments will be described with reference to FIG. 1 to FIG. 4.
A scroll compressor 1 shown in FIG. 1 and FIG. 2 includes a fixed scroll 2, an orbiting scroll 3, an Oldham link 10 restricting rotation of the orbiting scroll 3, a motor 4, a rotating shaft 5, shaft bearings 6, 7, and a housing 8.
The scroll compressor 1 constitutes a refrigerator or an air conditioner.
A suction pipe 91 and a discharge pipe 92 provided in the housing 8 are connected to a refrigerant circuit of a refrigerator or an air conditioner.
When drive current is supplied to a stator 4A of the motor 4 by a drive circuit part (not shown), a rotor 4B of the motor 4 rotates and a rotary drive force is output to the rotating shaft 5. The rotating shaft 5 is rotatably supported by the shaft bearings 6, 7 fixed to the housing 8.
When the rotating shaft 5 is rotated, the orbiting scroll 3 connected through a bearing 5B to an eccentric pin 5A provided at the upper end of the rotating shaft 5 is revolved relative to the fixed scroll 2 fixed to the housing 8. Meanwhile, rotation of the orbiting scroll 3 is restricted by the Oldham link 10 (FIG. 3) interposed between the orbiting scroll 3 and the shaft bearing 6.
As the orbiting scroll 3 revolves, a refrigerant inside the housing 8 is suctioned into the gap between the orbiting scroll 3 and the fixed scroll 2. Then, the refrigerant is compressed inside a compression chamber R between the orbiting scroll 3 and the fixed scroll 2, as the orbiting scroll 3 revolves and the volume of the compression chamber R decreases accordingly. A thrust load due to the pressure of the compressed refrigerant is borne by the shaft bearing 6 that supports an end plate 3A of the orbiting scroll 3. The compressed refrigerant is discharged through the discharge pipe 92 to the refrigerant circuit via a discharge port 2P of the fixed scroll 2.
Lubricating oil is stored in the bottom of the housing 8. The lubricating oil is pumped up by a pump 101, provided at the lower end of the rotating shaft 5, through an oil supply path 5C (FIG. 2) inside the rotating shaft 5, and is supplied to sliding parts such as the shaft bearings 6, 7, rotating shaft 5, eccentric pin 5A, orbiting scroll 3, Oldham link 10, and thrust plate (not shown) disposed between the shaft bearing 6 and the orbiting scroll 3.
The Oldham link 10 (also called an Oldham coupling) will be described with reference to FIG. 2 to FIG. 4.
As shown in FIG. 3, the Oldham link 10 includes a pair of first keys 11, 11, a pair of second keys 12, 12, and an annular coupling part 13 coupling together the keys 11, 11, 12, 12.
The first keys 11, 11, the second keys 12, 12, and the coupling part 13 are integrally made of a metal material such as aluminum alloy.
The shaft bearing 6 and the orbiting scroll 3 that slide with the Oldham link 10 are made of a metal material such as aluminum alloy.
The first keys 11, 11 protrude from one surface 131 of the coupling part 13 in an out-of-plane direction, while the second keys 12, 12 protrude from the other surface 132 of the coupling part 13 in an out-of-plane direction.
A direction D1 connecting the first keys 11, 11 to each other and a direction D2 connecting the second keys 12, 12 to each other both extend in the radial direction of the coupling part 13 and are orthogonal to each other.
The first keys 11, 11 are formed in a rectangular parallelepiped shape that is long in the direction D1.
The second keys 12, 12 are formed in a rectangular parallelepiped shape that is long in the direction D2.
As shown in FIG. 2 and FIG. 4A, the first key 11 is fitted into a key groove 20 formed in the end plate 3A of the orbiting scroll 3. In the end plate 3A, a pair of key grooves 20 corresponding to the pair of first keys 11 (FIG. 3) are formed.
The first key 11 slides in the key groove 20 in the radial direction with a predetermined stroke. Hereinafter, unless otherwise mentioned, "the radial direction" refers to the direction of the diameter passing through the centers of the rotating shaft 5 and the shaft bearing 6.
As shown in FIG. 2 and FIG. 4B, the second key 12 is fitted into a key groove 30 formed in a thrust surface 6A of the shaft bearing 6 facing the orbiting scroll 3. In the shaft bearing 6, a pair of key grooves 30 corresponding to the pair of second keys 12 (FIG. 3) are formed.
The second key 12 slides in the key groove 30 in the radial direction with a predetermined stroke.
The direction in which the first key 11 can slide along the key groove 20 (the direction D1 in FIG. 3) and the direction in which the second key 12 can slide along the key groove 30 (the direction D2 in FIG. 3) are orthogonal to each other.
When a rotary force of the rotating shaft 5 (FIG. 2) is transmitted to the orbiting scroll 3 through the eccentric pin 5A, the first key 11 slides along the key groove 20 in the direction D1, while the second key 12 slides along the key groove 30 in the direction D2, causing the Oldham link 10 as a whole sliding in the direction D2. Thus, the orbiting scroll 3 revolves relative to the fixed scroll 2 while tracing a predetermined trajectory without rotating.
FIGS. 5A and 5B show the key groove 20 formed in the end plate 3A of the orbiting scroll 3 as seen from the rear surface side (lower surface side) of the end plate 3A.
The key groove 20 is depressed to a predetermined depth from the rear surface of the end plate 3A of the orbiting scroll 3.
The key groove 20 extends a predetermined distance in the radial direction from an outer peripheral edge 3B of the orbiting scroll 3 toward the center of the scroll. An outer peripheral-side end 20A of the key groove 20 opens to the outside of the orbiting scroll 3. An inner peripheral-side end 20B of the key groove 20 has an arc shape in a plan view.
An inner periphery 201 of the key groove 20 stands vertically on a flat bottom 202 of the key groove 20.
While the orbiting scroll 3 makes one revolution, the first key 11 (indicated by the two-dot dashed line in FIG. 5B) reciprocates in the radial direction along the wall 21 of the key groove 20 by being guided by the key groove 20. As shown in FIG. 4A, the first key 11 shifts in a reciprocating manner within a range Rg1 of the key groove 20 from the outer peripheral-side end 20A to the vicinity of the inner peripheral-side end 20B.
The first key 11 slides along one surface 21 of two opposite surfaces 21, 22 (FIG. 5B) of the key groove 20 that is determined by the direction of rotation of the orbiting scroll 3. The surface along which the first key 11 slides will be referred to as the wall 21 of the key groove 20.
As shown in FIG. 5A, it is preferable that the wall 21 of the key groove 20 be formed by a liner 23 that is discrete (distinct) from the end plate 3A of the orbiting scroll 3.
Since the orbiting scroll 3 that is the base material of the key groove 20 and the liner 23 are discrete, a material different from the base material of the key groove 20, preferably a wear-resistant hard material, can be used for the liner 23. It is preferable that the liner 23 be harder than the base material of the key groove 20, at least at a predetermined thickness from the surface (sliding surface). An appropriate surface processing or surface treatment can increase the surface hardness of the liner 23.
Moreover, since the sliding surface (wall 21) is formed by the liner 23 that is discrete from the base material of the key groove 20, crowning processing or polishing processing, to be described later, can be more easily performed on the liner 23 than on the base material of the key groove.
The above description also applies to a liner 28 (FIG. 6) disposed in the key groove 30.
FIG. 6 shows the key groove 30 formed in the shaft bearing 6. The surface along which the second key 12 (FIG. 2 and FIG. 3) slides will be referred to as a wall 31 of the key groove 30.
The key groove 30 is depressed from the thrust surface 6A of the shaft bearing 6. An outer peripheral-side end 30A and an inner peripheral-side end 30B of the key groove 30 have arc shapes in a plan view.
While the orbiting scroll 3 makes one revolution, the second key 12 (FIG. 2 and FIG. 3) reciprocates in the radial direction along the wall 31 of the key groove 30 by being guided by the key groove 30. The second key 12 shifts in a reciprocating manner within a range Rg2 (FIG. 4B) of the key groove 30 between the inner peripheral-side end 30B and the outer peripheral-side end 30A.
The ranges Rg1, Rg2 (FIG. 4) within which the first key 11 and the second key 12 slide in the key grooves 20, 30 are merely examples, and the ranges of sliding are determined as appropriate along the walls 21, 31 of the key grooves 20, 30.
The ranges Rg1, Rg2 of sliding in the key grooves 20, 30 and whether the outer peripheral-side end of the key groove is opened are determined in connection with the strokes of the first key 11 and the second key 12.

Specific configurations of the first and second keys 11, 12 and the key grooves 20, 30 will be described below.
The first embodiment mainly features the shape (an offset portion 21A to be described later) of the wall 21 of the key groove 20 and a surface roughness Ra of the key groove 30. Both features are intended to reduce wear of the keys 11, 12 and the key grooves 20, 30.
As described above, the lubricating oil is supplied from the storage part inside the housing 8 to the upper end of the rotating shaft 5, but it is difficult to sufficiently supply the lubricating oil from the upper end of the rotating shaft 5 to the Oldham link 10 through the gaps among the end plate 3A of the orbiting scroll 3, the thrust plate (not shown), the thrust surface 6A of the shaft bearing 6, etc.
In particular, it is difficult to sufficiently form an oil film during low-speed operation, as the velocity of the lubricating oil flowing along the sliding surface is low and thus the pressure of the lubricating oil according to a wedge effect of the lubricating oil is low.
Moreover, as for the key groove 20, the lubricating oil is difficult to retain at the outer peripheral-side end 20A that is open.
Thus, it is important to reduce wear even when the keys 11, 12 of the Oldham link 10 come in contact respectively with the walls 21, 31 of the key grooves 20, 30.
First, a state of wear of a key groove 40 (FIG. 7) that was checked to determine the shape of the wall 21 of the key groove 20 will be described.
A durability test equivalent to a predetermined time of use (operation) was conducted on a scroll compressor that was not used except in trial operation etc. for operation check. FIG. 7C schematically shows the resulting surface shape of a wall 41 of the key groove 40 that has worn from its initial state (before the durability test).
The horizontal axis of FIG. 7C corresponds to the sliding direction indicated by the arrow in FIG. 7B. As shown in FIG. 7C, the depth of wear (amount of wear) of the wall 41 increases from an inner peripheral-side end 40B of the key groove 40 toward an outer peripheral-side end 40A thereof that is open. The broken line shown in FIG. 7C corresponds to the flat surface of the wall 41 in its initial state.
The increase in amount of wear of the wall 41 toward the open end (outer peripheral-side end 40A) of the key groove 40 is mainly attributable to the fact that, at the side of the open end (outer peripheral-side end 40A) of the key groove 40, the first key 11 shifts in a reciprocating manner while being inclined relative to the wall 41 as shown in FIG. 7A.
The amount of wear is largest at the open end (edge) of the key groove 40 at which the inclination angle of the first key 11 is largest.
In this embodiment, as shown in FIG. 5B, a part of the wall 21 is gradually offset from a reference surface 210 on the basis of the profiling data on the surface shape of the wall 41 shown in FIG. 7C. The reference surface 210 is an assumed flat surface in the surface of the wall 21, and corresponds to the flat surface of the wall 41 in its initial state indicated by the broken line in FIG. 7C.
The wall 21 has the offset portion 21A that is further offset from the reference surface 210 while extending toward the outer peripheral-side end 20A. An amount of offset Of of the offset portion 21A from the reference surface 210 is, for example, up to approximately 15 to 20 µm. The offset portion 21A shown in FIG. 5B has an exaggerated amount of offset. The offset portion 21A is not shown in FIG. 5A.
The shaded part in FIG. 5B does not exist. The surface of the offset portion 21A is denoted by reference sign 21S.
The shape of the surface 21S of the offset portion 21A simulates the surface shape (FIG. 7C) of the wall 21 that has worn through use. The offset portion 21A recedes gradually from the reference surface 210 at a smooth and gentle gradient.
As shown in FIG. 5B, the wall 21 including the offset portion 21A is formed by the liner 23 provided in the end plate 3A. The liner 23 has a rectangular plate-like shape, and is disposed in a recess 3C that is formed in the end plate 3A so as to be depressed from the inner periphery 201 of the key groove 20. The surface of the liner 23 and the surface of the inner periphery 201 are flush and continuous with each other. The plate thickness of the liner 23 can be set as appropriate.
Machining such as crowning processing is performed on the liner 23 as a single part to form the offset portion 21A therein, and the liner 23 is disposed in the recess 3C of the end plate 3A. The liner 23 is integrated with the end plate 3A by an appropriate method. The liner 23 can be integrated with the end plate 3A, for example, by casting the end plate 3A with the liner 23 disposed inside a casting mold of the end plate 3A. Alternatively, the liner 23 can be fastened to the end plate 3A.
The effect achieved by forming the offset portion 21A in the wall 21 before the start of use will be described.
As shown in FIG. 5A, when the first key 11 is inclined relative to the wall 21, a side surface 11S of the first key 11 comes in contact with the gently curved offset portion 21A (FIG. 5B). Thus, the first key 11 and the wall 21 (liner 23) of the key groove 20 can come in surface contact with each other, so that sliding friction is suppressed even at the edge of the outer peripheral-side end 20A of the key groove 20.
As a result, significant wear typically occurring at an initial stage of use is prevented and the wall 21 of the key groove 20, and the side surface 11S of the first key 11 are quickly adapted to each other, allowing the first key 11 to slide stably with low friction.
In this embodiment, the surface roughness Ra of the wall 31 of the key groove 30 (FIG. 6) also simulates the surface state of the wall 41 (FIG. 7) that has worn through use, and the surface roughness Ra of the wall 31 of the key groove 30 is 0.2 µm or less.
Since the surface roughness Ra of the existing wall 41 (FIG. 7) exceeds 0.2 µm, when the unused scroll compressor 1 starts to be used, the surface roughness Ra of the wall 41 decreases gradually from its initial state due to sliding friction between the second key 12 and the wall 41. Thereafter, the surface roughness Ra of the wall 41 stabilizes when the wall 41 of the key groove 30 and the side surface of the second key 12 have been adapted to each other. The surface roughness Ra of the wall 41 at this point is 0.2 µm or less.
On the basis of this wear process of the wall 41, the surface roughness Ra of the wall 31 (FIG. 6) of the key groove 30 in this embodiment is set to 0.2 µm or less.
Although setting the surface roughness Ra of the side surface of the key 12 sliding along the wall 31 of the key groove 30 to 0.2 µm or less can also achieve the same effect as setting the surface roughness Ra of the wall 31 to 0.2 µm or less, in view of the processing cost and time, the surface roughness Ra of the wall 31 of the key groove 30 is set to 0.2 µm or less.
It is preferable that the wall 31 be formed by the liner 28 that is discrete from the base material of the key groove 30. Performing polishing processing on the liner 28 as a single part can set the surface roughness (Ra) of the surface (sliding surface) of the liner 28 forming the wall 31 to a predetermined surface roughness.
If the surface roughness Ra of the wall 31 is set to 0.2 µm or less before the start of use of the scroll compressor 1, the wall 31 of the key groove 30 and the side surface of the second key 12 are quickly adapted to each other, so that solid-to-solid contact can be reduced even when the oil film is thin due to the low surface roughness. Thus, significant wear typically occurring at an initial stage is avoided, and the side surface of the second key 12 slides along the wall 31 of the key groove 30 stably with low friction.
As has been described above, wear occurring at an initial stage of use can be suppressed by forming the offset portion 21A for the first key 11 of the Oldham link 10 and the key groove 20, and by setting the surface roughness Ra for the second key 12 and the key groove 30. Accordingly, wear of the keys 11, 12 of the Oldham link 10 and the walls 21, 31 of the key grooves 20, 30 can be reduced, and power loss due to friction can also be suppressed.
According to this embodiment, it is possible to suppress wear of the keys 11, 12 and the key grooves 20, 30, even under severe lubricating conditions, by forming the offset portion 21A and setting the surface roughness Ra. It is therefore possible to remove operational restrictions, such as increasing the rotation speed to prevent a lack of lubricating oil after continuous low-speed operation.
It is preferable that a coating be formed using a solid lubricant on the sliding parts of the Oldham link 10 to which sufficient lubricating oil is difficult to supply and which is thus likely to be subject to sever lubricating conditions.
For example, a solid lubricant obtained by dispersing powder of polytetrafluoroethylene (PTFE) in an epoxy resin or a polyimide resin or the like can be used to form a coating on the side surfaces of the keys 11, 12 and the surfaces (liner surfaces) of the walls 21, 31 of the key grooves 20, 30. The coating is not shown in the drawings.
In the case where a coating of a solid lubricant is formed on the offset portion 21A, it is preferable that the wall 21 be machined to a larger amount of offset than a desired amount of offset with the thickness of the coating taken into account. In that case, the final amount of offset is determined by the surface of the coating of the solid lubricant.
In the case where a coating of a solid lubricant is formed in a portion of the wall 21 for which the surface roughness Ra is set to 0.2 µm or less, the surface roughness Ra of the solid lubricant coating adhering to the surface of the base material is machined to 0.2 µm or less. The solid lubricant coating can be polished, for example, by mechanical polishing with a grinder or by spraying abrasive grains, or by chemical polishing of dissolving the coating using a chemical.
In this embodiment, the presence of the offset portion 21A or the setting of the surface roughness Ra prevents significant wear at an initial stage of use, so that the coatings of a solid lubricant applied on the wall 21 and the wall 31 remain without wearing. These coatings can be maintained to secure wear resistance.
The coating of a solid lubricant can be formed on all the keys 11, 12 and the key grooves 20, 30 or on some of these keys and key grooves selected according to the lubricating conditions etc.
As the Oldham link 10 slides over the end plate 3A and the shaft bearing 6 while restricting rotation of the orbiting scroll 3, a coating of a solid lubricant may be applied on the entire sliding surface of the Oldham link 10 to improve the lubricity of the entire Oldham link 10.

It is preferable that the surface roughness Ra of the wall 21 of the key groove 20 be set to 0.2 µm or less in addition to the offset portion 21A (FIG. 5B) being formed in the wall 21.
It is preferable that a durability test with varied surface roughness Ra be conducted to appropriately determine the surface roughness Ra.
In FIG. 8, a relation between the depth of wear (amount of wear) at the end of the key 11 on the outer peripheral side and the surface roughness Ra of the wall 21 after a durability test is plotted with black rhombuses. The depth of wear shown is an average value of a plurality of measured values. The amount of wear and the surface roughness Ra of the wall 21 of the key groove 20 correspond to the amount of wear and the surface roughness Ra of the key 11.
As can be seen from FIG. 8, the lower the surface roughness Ra, the smaller the amount of wear after the durability test.
With variation in measured value of multiple times of the test (measured values of the depth of wear exceeding the average value are indicated by the straight line) taken into account, the surface roughness Ra of the wall 21 needs to be 0.2 µm or less to keep the depth of wear under the allowable value.
It is possible to more sufficiently reduce wear by providing the offset portion 21A in the wall 21 and setting the surface roughness Ra of the wall 21 to 0.2 µm or less before the start of use.
FIG. 9A shows another modified example of the first embodiment.
The wall 21 of the key groove 20 is provided with an offset portion 21B located in the vicinity of the inner peripheral-side end 20B, in addition to the offset portion 21A located at the outer peripheral-side end 20A.
It is preferable that the offset portion 21B be gradually offset from the reference surface 210 while extending toward the inner peripheral-side end 20B.
As with the offset portion 21A, the offset portion 21B shown in FIG. 9A has an exaggerated amount of offset.
The shaded part in FIG. 9A does not exist. The surface of the offset portion 21A is denoted by reference sign 21S and the surface of the offset portion 21B is denoted by reference sign 21S'.
The shapes of the surfaces 21S, 21S' of the offset portions 21A, 21B simulate the surface shape of the wall 21 that has worn through use.
As shown in FIG. 9B, in both an inward path and an outward path of the first key 11 that shifts in a reciprocating manner, an oil film 100 is formed between the first key 11 and the wall 21 by the wedge effect occurring as the lubricating oil flows into the gap between the first key 11 and the wall 21.
Here, at both ends of the wall 21 in the sliding direction, where the shifting velocity of the first key 11 is low and a sufficient wedge effect is therefore difficult to obtain, a sufficient oil film 100 is difficult to form. Then, compared with in a center part of the wall 21, the amount of wear becomes larger at both ends of the wall 21 due to the sliding friction between the wall 21 and the first key 11 inclined relative to the wall 21. Accordingly, the offset portions 21A, 21B are formed in advance at the outer peripheral-side end 20A and in the vicinity of the inner peripheral-side end 20B of the wall 21.
The amount of offset Of of the offset portion 21A from the reference surface 210 corresponds to the amount of wear on the outer peripheral side (radially outer side) of the wall 21, while an amount of offset Of of the offset portion 21B from the reference surface 210 corresponds to the amount of wear on the inner peripheral side (radially inner side) of the wall 21.
In the configuration shown in FIG. 9A, on the basis of the fact that the key groove 20 wears easily especially at the side of the open end (outer peripheral-side end 20A), the amount of offset Of of the offset portion 21A is set to be larger than the amount of offset Of of the offset portion 21B.
According to the configuration shown in FIGS. 9A and 9B, the offset portions 21A, 21B are formed with wear through use taken into account, which makes it possible to reduce wear by preventing significant wear typically occurring at an initial stage.
Forming the offset portion simulating wear before use is also applicable to the wall 31 (FIG. 6) of the key groove 30 along which the second key 12 slides.
The position and the amount of offset of the offset portion formed in the wall 31 can be determined as appropriate on the basis of the stroke and the sliding conditions of the second key 12.
For example, it is possible to form an offset portion in a region of the wall 31 corresponding to the range Rg2 (FIG. 4) of sliding of the second key 12 so as to be symmetrical with respect to the center of the range Rg2.

Next, a second embodiment of the present invention will be described with reference to FIGS. 10A to 10C.
The second embodiment to a fifth embodiment feature structures for positioning the liner in the key groove. The second embodiment to the fifth embodiment can be combined as appropriate.
In the following, a liner disposed in the key groove 20 in which the first key 11 slides will be taken as an example, but the configurations described below are also applicable to a liner disposed in the key groove 30 in which the second key 12 slides.
At least one of crowning processing of forming the offset portion 21A or the offset portion 21B and machining of setting the surface roughness to 0.2 µm or less is performed on the surface of a liner 24 that is disposed so as to be flush with the inner periphery 201 of the key groove 20 as shown in FIG. 10A. The offset portion is not shown in FIG. 10.
The above description is also applicable to the liners (to be described later) shown in FIG. 11 to FIG. 16.
In the configuration shown in FIG. 10A, a protrusion 241 provided on the liner 24 is fitted in a recess 211 formed in the inner periphery 201 of the key groove 20. The recess 211 is depressed farther than a surface 3E on which a plate-like main body 240 of the liner 24 is disposed. The protrusion 241 of the liner 24 is fitted between walls 211A, 211B of the recess 211 that are separated from each other in the sliding direction.
In this specification, the direction in which the first key 11 slides along the radial direction of the rotating shaft 5 will be referred to as "the sliding direction". The direction in which the second key 12 slides along the radial direction of the rotating shaft 5 will be also referred to as "the sliding direction".
In the configuration shown in FIG. 10A, the liner 24 and the inner periphery 201 of the key groove 20 are fitted with each other through engagement between the recess 211 and the protrusion 241, and thereby the liner 24 is positioned in the orbiting scroll 3 in the sliding direction. Thus, the liner 24 can be prevented from slipping or detaching in the sliding direction from the inner periphery 201 of the key groove 20.
Other than the configuration shown in FIG. 10A, for example, the configurations shown in FIG. 10B and FIG. 10C can also be used to position the liner 24 in the key groove 20 by engagement fitting.
In FIG. 10B, the protrusion 241 of the liner 24 is located further on the radially outer side than in FIG. 10A. The configuration of FIG. 10B is otherwise the same as that of FIG. 10A.
In FIG. 10C, the recess 212 is formed at the outer peripheral-side end 20A as well as in the vicinity of the inner peripheral-side end 20B of the inner periphery 201 of the key groove 20, and two protrusions 251, 251 protruding from a plate-like main body 250 of a liner 25 toward the rear surface side are fitted inside the recesses 212, 212.
In the configurations shown in FIGS. 10A to 10C, the main bodies 240, 250 of the liners 24, 25 extend to the open end (outer peripheral-side end 20A) of the key groove 20, so that the sliding friction between the first key 11 and the key groove 20 at the edge of the key groove 20 can be reduced.

Next, the third embodiment of the present invention will be described with reference to FIG. 11.
As shown in FIG. 11, a liner 26 of the third embodiment is formed in a U-shape and disposed along the entire inner periphery 201 of the key groove 20.
The liner 26 has a plate-like part 261 along which the first key 11 slides, a plate-like part 262 facing the plate-like part 261, and a coupling part 263 coupling together the plate- like parts 261, 262 at the inner peripheral-side end 20B of the key groove 20.
In the configuration shown in FIG. 11, the liner 26 is positioned in the key groove 20 without a protrusion or a recess formed in the liner 26 or the key groove 20.
The width of the liner 26 in the direction connecting the plate- like parts 261, 262 to each other is set to be larger than the width of the key groove 20, so that the liner 26 deflects so as to be compressed inside the key groove 20, and is fixed to the key groove 20 by an elastic force.
Thus, the liner 26 can be prevented from slipping from the inner periphery 201 of the key groove 20 in the sliding direction or the width direction of the liner 26, or the liner 26 can be prevented from detaching from the key groove 20.
The second embodiment and the third embodiment can be combined as appropriate.
In FIG. 12A, a protrusion 264 formed on the U-shaped liner 26 is fitted inside the recess 212 formed in the inner periphery 201 of the key groove 20.
In the configuration of FIG. 12B, which is similar to that of FIG. 12A, a protrusion 265 of the liner 26 is fitted inside a recess 213 formed in a region of the inner periphery 201 of the key groove 20 where the first key 11 slides.
In FIG. 13, a protrusion 214 formed on the inner periphery 201 of the key groove 20 is fitted into a recess 266 formed in the U-shaped liner 26.
In the configurations shown in FIGS. 12A, 12B, and 13, it is not necessary to fix the liner 26 inside the key groove 20 by an elastic force or interference fitting. According to the engagement fitting between the U-shaped liner 26 and the inner periphery 201 of the key groove 20, the liner 26 can be prevented from slipping from the inner periphery 201 of the key groove 20 in the sliding direction or the width direction, or the liner 26 can be prevented from detaching from the key groove 20.

Next, the fourth embodiment of the present invention will be described with reference to FIGS. 14A and 14B.
In the configuration shown in FIG. 14A, a liner groove 29 that receives a peripheral edge 271 of a liner 27 is formed in the bottom 202 of the key groove 20.
The entire peripheral edge 271 of the U-shaped liner 27 is fitted inside the U-shaped liner groove 29 that is formed at the root of the inner periphery 201 of the key groove 20.
According to this configuration, the liner 27 is positioned in both the sliding direction and the width direction in the key groove 20 of the orbiting scroll 3 by fitting through engagement between the liner groove 29 (recess) and the peripheral edge 271 (protrusion) of the liner 27.
As shown in FIG. 14B, a J-shaped liner 27' can also be adopted.
The liner 27' has a plate-like part 291 disposed in the region of the inner periphery 201 where the first key 11 slides, and a curved part 292 that continues to the inner peripheral edge of the plate-like part 291 and curves along the arc-shaped inner peripheral-side end 20B.
As the plate-like part 291 is fitted into the straight part of the liner groove 29, the liner 27' is positioned in the key groove 20 in the plate thickness direction, and as the curved part 292 is fitted in the curved part of the liner groove 29, the liner 27' is positioned in the key groove 20 in the sliding direction.
The configuration of the fourth embodiment can also be used to position the liner 28 (FIG. 6) along which the second key 12 slides. In that case, for example, the peripheral edge of the liner 28 is fitted into a liner groove formed in the bottom of the key groove 30. Then, the liner 28 is positioned in both the plate thickness direction and the sliding direction by fitting through engagement between the peripheral edge of the liner 28 and the liner groove.

Next, the fifth embodiment of the present invention will be described with reference to FIG. 15.
A liner 50 shown in FIG. 15 has a bottom 51A disposed on the bottom 202 of the key groove 20, and a U-shaped wall 51B standing on the bottom 51A and disposed on the inner periphery 201 of the key groove 20.
The bottom 51A of the liner 50 has a width larger than the width of the bottom 202 of the key groove 20, and is pressed onto the bottom 202 of the key groove 20 to form the bottom surface of the key groove 20.
At least one of crowning processing for forming an offset portion (not shown) and machining for setting the surface roughness to 0.2 µm or less is performed on the inner surface (sliding surface) of the wall 51B.
The wall 51B may be formed in a J-shape like the liner 27' of FIG. 14B, or may be formed in a plate-like shape like the liner 23 shown in FIG. 5.
As the bottom 51A is pressed and fixed in the key groove 20, the liner 50 can be prevented from slipping from the inner periphery 201 of the key groove 20 in the sliding direction or the width direction, or the liner 50 can be prevented from detaching from the key groove 20.
The configuration of the fifth embodiment can also be used to position the liner 28 (FIG. 6) along which the second key 12 slides.

<Sixth Embodiment

Next, a sixth embodiment of the present invention will be described with reference to FIG. 16.
In the sixth embodiment, a liner that is allowed to shift in the sliding direction of the key is interposed between the key and the wall of the key groove.
FIG. 16 shows the key groove 30 in which the second key 12 is disposed.
In the key groove 30, a plate-like liner 52 forming the wall 31 along which the second key 12 slides is disposed.
The liner 52 is housed in a liner housing part 53 formed in the shaft bearing 6.
As the dimension of the liner housing part 53 is larger than the dimension of the liner 52 in the sliding direction, there is a space Sp inside the liner housing part 53 that allows the liner 52 to shift in the sliding direction of the second key 12.
When the second key 12 comes in contact with the liner 52 (wall 31) and shifts in the sliding direction while retaining the liner 52 by a friction force, the liner 52 also shifts inside the liner housing part 53 (see the arrows).
According to the sixth embodiment, the second key 12 shifts in a reciprocating manner along with the liner 52, so that the distance the second key 12 and the liner 52 slide and shift relative to each other can be reduced, and thus wear of the second key 12 and the liner 52 can be reduced.
As the rear surface of the liner 52 slides over an inner periphery 301 of the key groove 30, the friction force is divided into a friction force between the second key 12 and the liner 52 and a friction force between the liner 52 and the inner periphery 301. Thus, wear of each of the second key 12, the liner 52, and the inner periphery 301 (shaft bearing 6) is suppressed.
As shown in FIG. 16, to prevent the key 12 from shifting beyond the ends of the liner 52, the following relation needs to be satisfied: $Ln / 2 - d / 2 > Sp,$
where d is the stroke of the key 12, Ln is the dimension of the liner housing part 53 that is the movable range of the liner 52, and Sp is the length of the space inside the liner housing part 53.
According to this relation, it is possible to shift the liner 52 along with the key 12 while keeping the key 12 between the left end and the right end of the liner 52.
In the sixth embodiment, it is not absolutely necessary to form an offset portion in the liner 52 or set the surface roughness of the liner 52 to 0.2 µm or less. As with the liner 23 etc. described above, at least one of crowning processing for forming the offset portion and machining for setting the surface roughness to 0.2 µm or less performed on the liner 52 can contribute to further wear reduction.

Next, a seventh embodiment of the present invention will be described with reference to FIG. 17 and FIG. 18.
The seventh embodiment is configured so that a liner swings to follow the posture of the key.
FIG. 17A shows the key groove 20 in which the first key 11 is disposed.
In the key groove 20, a plate-like liner 54 forming the wall 21 along which the first key 11 slides is disposed.
The liner 54 is housed in a recess 55 formed in the orbiting scroll 3.
A support portion 551 protruding in an arc shape in a plan view is formed on the wall of the recess 55 located on the rear surface side of the liner 54. The support portion 551 is located in the vicinity of the inner peripheral-side end 20B in the wall of the recess 55. The liner 54 supported by the support portion 551 is swingable within the range of a clearance CL between the liner 54 and the wall of the recess 55.
FIG. 17B shows an example in which a support portion 541 is formed not in the recess 55 but on the rear surface side of the liner 54. The liner 54 supported by the support portion 541 inside the recess 55 is swingable within the range of the clearance CL between the liner 54 and the wall of the recess 55.
As shown in FIG. 18, when the first key 11 shifts in a reciprocating manner, the liner 54 swings (inclines) to an angle following the posture of the first key 11. In both the inward path and the outward path of the first key 11, the liner 54 swings, around the support portion 541 (or 551) as a supporting point, between an angle at which the liner 54 is parallel to the axis of the key groove 20 and an angle at which the outer peripheral-side end of the liner 54 comes in contact with the wall of the recess 55.
As a result, the side surface 11S of the first key 11 comes in surface contact with the liner 54, so that the first key 11 slides over the surface of the liner 54 stably with low friction.
According to the seventh embodiment, the liner 54 swings to follow the posture of the first key 11, so that the sliding friction between the first key 11 and the liner 54 can be suppressed, and thus wear of the first key 11 and the liner 54 can be reduced.
In the seventh embodiment, it is not absolutely necessary to form an offset portion in the liner 54 or set the surface roughness of the liner 54 to 0.2 µm or less. As with the liner 23 etc. described above, at least one of crowning processing for forming an offset portion and machining for setting the surface roughness to 0.2 µm or less performed on the liner 54 can contribute to further wear reduction.

Next, an eighth embodiment of the present invention will be described with reference to FIG. 19.
In the eighth embodiment, the lubricating oil that is supplied to the periphery of the eccentric pin 5A through the oil supply path 5C (FIG. 2) inside the rotating shaft 5 is supplied to the sliding surfaces through the inside of the liner.
As shown in FIG. 2, the eccentric pin 5A is connected to the inside of a boss 3F of the orbiting scroll 3 through the bearing 5B. The eccentric pin 5A, the bearing 5B, and the boss 3F are disposed inside a recess 6C formed around the rotating shaft 5 in the shaft bearing 6.
The inside of the recess 6C serves as an oil sump where the lubricating oil is accumulated. A pressure difference is provided between the atmosphere inside the recess 6C and the atmosphere outside the recess 6C, so that the lubricating oil inside the recess 6C is supplied to the outside of the recess 6C according to the pressure difference.
In the following, a liner disposed in the key groove 20 in which the first key 11 slides will be taken as an example, but the configurations described below are also applicable to the liner disposed in the key groove 30 in which the second key 12 slides.
As shown in FIGS. 19A and 19B, a liner 56 of this embodiment is a member that is attached to the orbiting scroll 3 and constitutes a part of the key groove 20.
Processing for forming an offset portion or processing for setting the surface roughness to 0.2 µm or less is performed on the surface of the liner 56 that forms the wall 21 along which the first key 11 slides.
As shown in FIGS. 19B and 19C, an oil path 57 through which the lubricating oil flows is formed by the key groove 20 and the liner 56.
The oil path 57 has a first path 571 extending in the sliding direction on the rear side of the liner 56, and a plurality of second paths 572 extending from the first path 571 in the plate thickness direction of the liner 56 and reaching the sliding surface (wall 21) of the liner 56.
As shown in FIG. 19B, the first path 571 is formed between a groove 571C formed in the rear surface of the liner 56 and the wall (FIG. 19A) of the recess 3C in which the liner 56 is disposed.
A base end 571A of the first path 571 communicates with the inside of the recess 6C (FIG. 2) where the lubricating oil is accumulated.
The plurality of second paths 572 are disposed at intervals in the sliding direction between the base end 571A and a leading end 571B of the first path 571, and each open in the surface of the liner 56.
During operation of the scroll compressor 1, the lubricating oil inside the recess 6C is forcibly supplied through the oil path 57 to the sliding surfaces of the first key 11 and the key groove 20 (liner 56) on the basis of the pressure difference between the inside and the outside of the recess 6C. Under the pressure of the lubricating oil jetting out of the second paths 572 opening in the surface of the liner 56 along which the first key 11 slides, the first key 11 floats from the surface of the liner 56, and an oil film is formed between the first key 11 and the liner 56.
According to this embodiment, the amount of lubricating oil supplied to the key groove 20 is increased by the lubricating oil flowing through the oil path 57, and a thick oil film is formed between the first key 11, floating on the lubricating oil jetting out of the oil path 57, and the wall 21 of the key groove 20. Thus, solid-to-solid contact is reduced, which can contribute to the reduction of wear of the first key 11 and the wall 21 (liner 56) of the key groove 20.
According to the eighth embodiment, it is possible to sufficiently reduce wear by supplying oil to the sliding surfaces through the oil path 57, in addition to forming an offset portion in the liner 56 or setting the surface roughness of the liner 56 to 0.2 µm or less.
The oil path 57 can be modified as appropriate, provided that the oil path 57 provides communication between the inside of the recess 6C and the wall 21 of the key groove 20.
For example, the groove constituting the first path 571 can also be formed in the wall of the recess 3C located on the rear surface of the liner 56, instead of in the liner 56.
As shown in FIG. 19D, the first path 571 can also be formed inside the liner 56.
The configuration of the oil path 57 in the eighth embodiment is workable without the precondition of processing for forming an offset portion in the liner 56 or processing for setting the surface roughness of the liner 56 to 0.2 µm or less. In other words, supplying oil to the sliding surfaces through the oil path 57 can contribute to wear reduction.
The present invention is not limited to the above embodiments; the configurations presented in the above embodiments can be selectively adopted or changed as appropriate into other configurations within the scope of the appended claims.
The Oldham link according to the present invention can also be applied to devices, other than scroll compressors, that include a mechanism for converting a turning motion of a member, which is eccentrically connected to a rotating shaft and turned along with the rotating shaft, into a revolving motion while restricting rotation of that member.

Claims

A scroll compressor (1) comprising:
a fixed scroll (2) fixed to a housing (8);

an orbiting scroll (3) eccentrically connected to a rotating shaft (5) and revolved relative to the fixed scroll (2);

a shaft bearing (6) fixed to the housing (8) and supporting the orbiting scroll (3); and

an Oldham link (10) interposed between the orbiting scroll (3) and the shaft bearing (6) and restricting rotation of the orbiting scroll (3), wherein

the Oldham link (10) has a first key (11) that slides in a radial direction (D1) of the rotating shaft (5) along a wall (21) of a key groove (20) provided in the orbiting scroll (3), and a second key (12) that slides in the radial direction (D2) of the rotating shaft (5) along a wall (31) of another key groove (30) provided in the shaft bearing (6), and

on the assumption of a flat reference surface (210) in the wall (21) of the key groove (20), the wall (21) has an offset portion (21A) that is gradually offset from the reference surface (210) while extending toward at least one of an outer peripheral-side end (20A) and an inner peripheral-side end (20B) of the key groove (20),

characterized in that a part of an inner periphery of the key groove (20) including at least the offset portion (21A), or the entire inner periphery of the key groove (20), is formed by a liner (23, 24, 25, 26, 27, 27', 28, 50, 52, 54, 56) discrete from a main body that is the orbiting scroll (3) or the shaft bearing (6).
The scroll compressor (1) according to claim 1, wherein a surface roughness Ra of a sliding surface of the wall (21) including a surface (21S) of the offset portion (21A) is 0.2 µm or less before the start of use of the Oldham link.
The scroll compressor (1) according to claim 1 or 2, wherein, as the liner (24, 25, 26, 27, 27') is fitted with the main body (3, 6) located on the rear surface side of the liner through engagement between a recess (211, 212, 213, 266) and a protrusion (241, 251, 264, 265, 214), the liner is positioned in a sliding direction that is a direction in which the first key or the second key slides.
The scroll compressor (1) according to any one of claims 1 to 3, wherein the liner (26, 27, 50) is formed substantially in a U-shape.
The scroll compressor (1) according to any one of claims 1 to 4, wherein a liner groove (29) receiving an edge (271) of the liner (27) is formed in a bottom of the key groove (20).
The scroll compressor (1) according to any one of claims 1 to 5, wherein the liner (50) has a liner bottom (51A) that forms a bottom surface of the key groove and is pressed into the main body, and a liner wall (51B) that stands on the liner bottom (51A) and includes the offset portion (21A).
A scroll compressor (1) comprising:
a fixed scroll (2) fixed to a housing (8);

an orbiting scroll (3) eccentrically connected to a rotating shaft (5) and revolved relative to the fixed scroll (2);

a shaft bearing (6) fixed to the housing (8) and supporting the orbiting scroll (3); and

an Oldham link (10) interposed between the orbiting scroll (3) and the shaft bearing (6) and restricting rotation of the orbiting scroll (3), wherein

the Oldham link (10) has a first key (11) that slides in a radial direction (D1) of the rotating shaft (5) along a wall (21) of a key groove (20) provided in the orbiting scroll (3), and a second key (12) that slides in the radial direction (D2) of the rotating shaft (5) along a wall (31) of another key groove (30) provided in the shaft bearing (6), characterized in that

a surface roughness Ra of the wall (31) of the key groove (30) before the start of use of the Oldham link (10) is set to 0.2 µm or less and in that at least a part of an inner periphery of the key groove (30) for which the surface roughness Ra is set, or the entire inner periphery of the key groove, is formed by a liner (28) discrete from a main body that is the orbiting scroll (3) or the shaft bearing (6).
The scroll compressor (1) according to any one of claims 1 to 7, wherein the main body has a liner housing part (53) that houses the liner (52) and allows the liner (52) to shift in a sliding direction that is a direction in which the first key (11) or the second key (12) slides.
The scroll compressor (1) according to any one of claims 1 to 8, wherein the liner (54) is swingably supported on the main body located on the rear surface side of the liner.
The scroll compressor (1) according to any one of claims 1 to 9, wherein, of the liner (56) and the inner periphery of the key groove, at least the liner (56) has an oil path (57) which communicates with an oil sump (6C) present around a connection part of the rotating shaft (5) and the orbiting scroll (3), and configured so that lubricating oil can be supplied from the oil sump (6C) to the wall (21) of the key groove (20) through the oil path (57).