Scroll compressor

Abstract

To provide a scroll compressor capable of appropriately controlling a gap at a sliding part where tooth surfaces of the scroll compressor slide against each other.SOLUTION: A scroll compressor comprises: a rotating scroll that is rotatable around an axial line O1 at a position eccentric to the axial line O1; a crank pin 5 that is eccentric to the axis O1 and is provided on a rotating shaft; a drive bush 10 that has a crank pin fitting hole 10B into which the crank pin 5 is fitted, and drives the rotating scroll; and a coating film provided on the tooth surfaces of the rotating scroll and a fixed scroll. The crank pin fitting hole 10B has gaps t1, t2 that allow the crank pin 5 to move in one direction, and the gaps t1, t2 are less than the film thickness of the coating film.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a scroll compressor.

Background Art

[0002] In compressors for refrigeration and air conditioning, scroll compressors are widely used as compressors for compressing refrigerant. Oil is enclosed in scroll compressors for lubricating the sliding parts between opposing scroll tooth surfaces and each bearing part, but the oil is discharged together with the refrigerant outside the compressor during operation. Developing a control design to return the oil discharged outside the compressor back to the compressor takes a lot of man-hours, and the oil accumulated in the heat exchanger leads to a decrease in heat exchange efficiency. Therefore, in the development of heat pump systems, the development of a scroll compressor with a small amount of oil discharge is desired.

[0003] In Patent Document 1, a seal part that seals the flow of fluid between the inside and outside of the compression part of a scroll compressor prevents lubricating oil from flowing into the inside of the compression part, reducing the amount of oil discharged from the scroll compressor.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When reducing the amount of oil discharged from a scroll compressor as in Patent Document 1, the amount of oil guided to the compression part decreases, so protecting the sliding surface where the scroll tooth surfaces of the scroll compressor slide against each other becomes more important. To protect the sliding part, any one of or a combination of the following measures is required: (1) reducing the tooth surface load of the scroll, (2) protecting it with a coating, and (3) making the tooth surfaces non-contact. When non-contact is achieved as in (3) above, the leakage gap becomes large, leading to a decrease in compression efficiency. Therefore, it is necessary to appropriately manage the gap between the tooth surfaces.

[0006] The present disclosure has been made in view of such circumstances, and an object thereof is to provide a scroll compressor capable of appropriately managing the gap between the sliding parts where the scroll tooth surfaces slide against each other.

Means for Solving the Problems

[0007] A scroll compressor according to an aspect of the present disclosure includes a rotating shaft that extends along an axis and rotates around the axis, a swash scroll provided so as to be pivotable around the axis at a position eccentric with respect to the axis, a fixed scroll fixed to the housing side, meshed with the swash scroll, and forming a compression chamber for compressing a refrigerant between the fixed scroll and the swash scroll, a crank pin eccentric with respect to the axis and provided on the rotating shaft, a drive bush having a crank pin fitting hole into which the crank pin is fitted and driving the swash scroll, and a coating film provided on the tooth surfaces of the swash scroll and / or the fixed scroll. The crank pin fitting hole is provided with a gap in which the crank pin can move in one direction, and the gap is less than the film thickness of the coating film.

Effects of the Invention

[0008] The gap between the sliding parts where the tooth surfaces of the scroll compressor slide against each other can be appropriately managed.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9A

Figure 9B

Figure 9C

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings. As shown in FIG. 1, the scroll compressor 100 includes a housing 1 forming the outer shape of the device, a drive unit 3 that is an electric motor provided in the housing 1, a rotating shaft 4 that is rotationally driven by the drive unit 3, a compression unit 2 that compresses a refrigerant by being driven by the rotation of the rotating shaft 4, main bearings 9A and sub - bearings 9B that rotatably support the rotating shaft 4, and a seal part S.

[0011] The compression unit 2 and the drive unit 3 are connected to each other by a rotating shaft 4 extending along the axis O1. That is, the rotational energy by the drive unit 3 is immediately transmitted to the compression unit 2 through this rotating shaft 4. The compression unit 2 compresses a refrigerant gas (refrigerant) as a working fluid by this rotational energy and discharges it to the outside in a high - pressure state. The high - pressure refrigerant gas is used as a refrigerant in, for example, air - conditioning equipment.

[0012] The housing 1 is provided with a suction pipe 11 for sucking refrigerant gas as a working fluid from the outside, and a discharge pipe 12 for discharging the refrigerant gas that has become high-pressure through compression by the compression unit 2. At the lower part inside the housing 1, lubricating oil for lubricating the main bearing 9A and the sub-bearing 9B is stored. The lubricating oil is supplied to the lower part of the housing 1 through a lubricating oil supply pipe (not shown).

[0013] The lubricating oil LO stored in the lower part of the housing 1 is guided upward by an oil pump 9B1 provided in the sub-bearing 9B. Specifically, the lubricating oil LO is pumped upward in the direction of arrow A1 through an oil flow path (not shown) formed along the axis O1 of the rotating shaft 4, and is guided to the space between the turning end plate 71 of the turning scroll 7 and the main bearing 9A.

[0014] The rotating shaft 4 has a cylindrical shape centered on the axis O1. The rotating shaft 4 is rotatably supported in the housing 1 by the main bearing 9A and the sub-bearing 9B provided at the end on the opposite side of the axial direction when viewed from the main bearing 9A. The main bearing 9A has a main bearing body 9H that rotatably supports the rotating shaft 4. The main bearing body 9H is provided to support the radial load applied to the rotating shaft 4. The main bearing 9A has a disc shape centered on the axis O1. The outer peripheral surface of the main bearing 9A is fixed by welding, interference fitting, etc. in a state of being in contact with the inner peripheral surface of the housing 1 over the entire circumference. That is, the main bearing 9A divides the space inside the housing 1 into two. The compression unit 2 is accommodated in the space on one side of the main bearing 9A in the axial direction. The drive unit 3 is accommodated in the space on the opposite side of the main bearing 9A in the axial direction. The above-mentioned suction pipe 11 communicates with the space on one side of the main bearing 9A in the axial direction (the space in which the compression unit 2 is accommodated).

[0015] The space inside the housing 1 is partitioned into two spaces by the main bearing 9A. The space on one side in the axial direction of the main bearing 9A within the housing 1 is an intake space V1 that houses the compression part 2. The space on the other side in the axial direction within the housing 1 that includes the main bearing 9A is a mechanical space V2 that houses the drive part 3, the main bearing 9A, and the sub-bearing 9B described above.

[0016] At one end of the rotating shaft 4, a crank pin 5 serving as an eccentric shaft is provided. The crank pin 5 is provided at a position offset (eccentric) with respect to the axis O1. The crank pin 5 has a columnar shape centered on an eccentric axis O2 that is different from the axis O1. The eccentric axis O2 is parallel to the axis O1. This crank pin 5 has a columnar shape that protrudes from the end of the rotating shaft 4 toward one side in the axial direction (the side where the compression part 2 is arranged with respect to the main bearing 9A). Therefore, in a state where the rotating shaft 4 is rotating around the axis O1, the crank pin 5 orbits around the axis O1 of the rotating shaft 4.

[0017] The crank pin 5 is fitted and connected to the drive bush 10. The drive bush 10 rotates around the axis O1 together with the crank pin 5, and a counterweight 10A is provided to cancel out the centrifugal force. The drive bush 10 is attached to the boss part 7A of the orbiting scroll 7 and transmits the orbiting motion of the crank pin 5 around the axis O1 to the orbiting scroll 7. The crank pin 5 and the drive bush 10 will be described later.

[0018] An O-ring 91 is provided on the main surface (the upper surface in FIG. 1: see reference numeral 9S in FIG. 2) that faces the other side in the axial direction of the main bearing 9A. The O-ring 91 restricts the rotation of the orbiting scroll 7 (rotation around the eccentric axis O2). Further, on the inner peripheral side of the O-ring 91, a thrust ring 92 for supporting the axial load applied to the rotating shaft 4 is provided. The thrust ring 92 has an annular shape centered on the axis O1 when viewed from the axial direction.

[0019] On one side of the compression part 2 in the axial direction, a discharge cover 8 is provided. The discharge cover 8 is a substantially disk-shaped member that partitions the suction space V1 in the axial direction. In the suction space V1, the space on one side in the axial direction from the discharge cover 8 is the discharge chamber 67. A discharge port 68 that communicates the discharge chamber 67 and the compression part 2 is provided at the central part of the discharge cover 8. Further, a flow guide 69 that surrounds the discharge port 68 from the outer peripheral side is provided between the discharge cover 8 and the compression part 2. The flow guide 69 has a cylindrical shape centered on the axis O1. The high-pressure refrigerant gas flowing out from the compression part 2 is guided by this flow guide 69 and flows into the discharge chamber 67.

[0020] The compression part 2 includes a stationary scroll 6 and an orbiting scroll 7 made of metal such as iron-based or aluminum alloy. The stationary scroll 6 is a substantially disk-shaped member fixed on one side in the axial direction of the main bearing 9A inside the housing 1. The stationary scroll 6 faces the orbiting scroll 7 from the side opposite to the main bearing 9A in the axial direction, thereby forming a compression chamber C between the two.

[0021] More specifically, the stationary scroll 6 has a disk-shaped stationary end plate 61 and a stationary wrap 62 erected in the axial direction from the other surface of the stationary end plate 61. The stationary end plate 61 extends along a plane orthogonal to the axis O1. The stationary wrap 62 is a wall body formed in a spiral shape when viewed from the axial direction. More specifically, the stationary wrap 62 is formed of a plate-shaped member wound around the center of the stationary end plate 61. As an example, it is desirable that the stationary wrap 62 is configured to form an involute curve centered on the axis O1 when viewed from the axial direction.

[0022] On the radially outer side of the fixed wrap 62, an outer peripheral wall 63 extending cylindrically along the outer periphery of the fixed end plate 61 is formed. That is, the outer peripheral wall 63 extends axially from the fixed end plate 61 so as to surround the fixed wrap 62 from the radially outer side. Further, an annular flange portion 64 that expands from the radially inner side toward the outer side is provided at the edge on the other axial side of the outer peripheral wall 63 (the side where the drive unit 3 is arranged with respect to the main bearing 9A). The fixed scroll 6 is fixed to the main bearing 9A by bolts or the like (not shown) via the flange portion 64. A fixed scroll discharge port 65 penetrating the fixed end plate 61 in the axial direction is formed at the central portion of the fixed end plate 61. A discharge valve 66 for preventing the backflow of the refrigerant gas into the compression chamber C is provided at the fixed scroll discharge port 65. The fixed scroll discharge port 65 communicates with the discharge port 68 via the above-described flow guide 69. Further, a communication hole 63H penetrating the outer peripheral wall 63 in the radial direction is formed in a part of the outer peripheral wall 63. The communication hole 63H communicates the inside and outside of the compression chamber C. The communication hole 63H is formed right beside the opening of the suction pipe 11 so that the axial position thereof overlaps with the connection portion between the suction pipe 11 and the housing 1. Through this communication hole 63H, the refrigerant gas supplied from the above-described suction pipe 11 to the suction space V1 flows into the fixed scroll 6.

[0023] The orbiting scroll 7 has a disk-shaped orbiting end plate 71 and a spiral orbiting wrap 72 provided on the surface on the other axial side of the orbiting end plate 71. It is desirable that this orbiting wrap 72 is also configured to form an involute curve centered on the eccentric axis O2.

[0024] Further, the orbiting wrap 72 is arranged so as to overlap with the fixed wrap 62 in a direction (radial direction) intersecting the axis O1. In other words, the fixed wrap 62 and the orbiting wrap 72 mesh with each other. In such a meshed state, a certain space (compression chamber C) is formed between the fixed wrap 62 and the orbiting wrap 72. The volume of the compression chamber C changes as the orbiting wrap 72 orbits. Thereby, it is possible to compress the refrigerant gas.

[0025] The seal portion S seals the fluid flow between the inside and the outside of the compression portion 2 within the housing 1. The seal portion S of the present embodiment is provided to seal the fluid flow (leakage) between the main bearing 9A and the orbiting scroll 7. Here, the fluid includes not only gases such as the refrigerant gas compressed in the compression chamber C but also liquids such as the lubricating oil used in the main bearing 9A and the like. The seal portion S is provided on the outer peripheral side of the O-ring 91. As shown in FIG. 2, the main surface 9S of the main bearing 9A extends in a plane orthogonal to the axis O1. The main surface 9S faces the bearing opposing surface 71A on the other axial side of the orbiting end plate 71 of the orbiting scroll 7 with a gap G therebetween. The seal portion S suppresses the leakage of the refrigerant gas and oil in the gap G in the axial direction between the main surface 9S and the bearing opposing surface 71A.

[0026] Specifically, the seal portion S has an inner peripheral side seal portion Sa, an outer peripheral side seal portion Sb, and a grease layer Lg. The inner peripheral side seal portion Sa has an annular shape centered on the axis O1. The inner peripheral side seal portion Sa is relatively located on the inner peripheral side (inner side in the radial direction) within the seal portion S. The outer peripheral side seal portion Sb has an annular shape centered on the axis O1. The outer peripheral side seal portion Sb is relatively located on the outer peripheral side (outer side in the radial direction) with respect to the inner peripheral side seal portion Sa. That is, the dimension of the outer peripheral side seal portion Sb in the radial direction is larger than the dimension of the inner peripheral side seal portion Sa in the radial direction. Thereby, the outer peripheral side seal portion Sb surrounds the inner peripheral side seal portion Sa from the outer side in the radial direction.

[0027] The inner peripheral side seal portion Sa is housed in an inner peripheral side housing groove 9i formed on the main surface 9S. The inner peripheral side housing groove 9i is recessed from the main surface 9S toward the other axial side. The inner peripheral side housing groove 9i is formed so as to surround the O-ring 91 from the outer side in the radial direction when viewed in the axial direction. The inner peripheral side housing groove 9i has an annular shape centered on the axis O1. That is, the inner peripheral side housing groove 9i is continuously formed in the circumferential direction with respect to the axis O1.

[0028] The outer peripheral seal portion Sb is housed in an outer peripheral accommodation groove 9o formed on the main surface 9S. The outer peripheral accommodation groove 9o is recessed from the main surface 9S toward the other side in the axial direction. The outer peripheral accommodation groove 9o is formed so as to surround the inner peripheral accommodation groove 9i from the outer side in the radial direction when viewed from the axial direction. The outer peripheral accommodation groove 9o has an annular shape centered on the axis O1. That is, the outer peripheral accommodation groove 9o is continuously formed in the circumferential direction with respect to the axis O1. The dimension of the outer peripheral accommodation groove 9o in the radial direction is larger than the dimension of the inner peripheral accommodation groove 9i in the radial direction.

[0029] The inner peripheral seal portion Sa has an inner peripheral seal portion main body S11 and an inner peripheral elastic portion S21. A part of the inner peripheral seal portion main body S11 is housed in the inner peripheral accommodation groove 9i. A part of the inner peripheral seal portion main body S11 is arranged so as to protrude from the main surface 9S in the axial direction. Thereby, the inner peripheral seal portion main body S11 can be brought into contact with the bearing opposing surface 71A. The inner peripheral seal portion main body S11 has an annular shape centered on the axis O1 (see FIG. 3). The inner peripheral seal portion main body S11 is integrally formed of, for example, a resin material such as rubber or a metal material that is relatively resistant to wear.

[0030] The inner peripheral elastic portion S21 biases the inner peripheral seal portion main body S11 toward the bearing opposing surface 71A within the inner peripheral accommodation groove 9i. It is formed of an elastic material such as silicon rubber, for example. The inner peripheral elastic portion S21 has an annular shape centered on the axis O1, similar to the inner peripheral seal portion main body S11 (see FIG. 3). In a state biased by the inner peripheral elastic portion S21, a part of the inner peripheral seal portion main body S11 protrudes from the inner peripheral accommodation groove 9i toward one side in the axial direction (the bearing opposing surface 71A side).

[0031] The outer peripheral seal portion Sb has an outer peripheral seal portion main body S12 and an outer peripheral elastic portion S22. A part of the outer peripheral seal portion main body S12 is accommodated in the outer peripheral accommodation groove 9o. A part of the outer peripheral seal portion main body S12 is arranged so as to protrude axially from the main surface 9S. Thereby, the outer peripheral seal portion main body S12 can be brought into contact with the bearing opposing surface 71A. The outer peripheral seal portion main body S12 has an annular shape centered on the axis O1 (see FIG. 3). The outer peripheral seal portion main body S12 is formed of the same material as the inner peripheral seal portion main body S11. Therefore, the outer peripheral seal portion main body S12 is integrally formed of a resin material such as rubber or a metal material that is relatively resistant to wear.

[0032] The outer peripheral elastic portion S22 biases the outer peripheral seal portion main body S12 toward the bearing opposing surface 71A within the outer peripheral accommodation groove 9o. The outer peripheral elastic portion S22 is formed of an elastic material such as silicone rubber. The outer peripheral elastic portion S22 has an annular shape centered on the axis O1, similar to the outer peripheral seal portion main body S12 (see FIG. 3). In the state biased by the outer peripheral elastic portion S22, a part of the outer peripheral seal portion main body S12 protrudes from the outer peripheral accommodation groove 9o toward one side in the axial direction (the bearing opposing surface 71A side).

[0033] A grease layer Lg is interposed between the outer peripheral seal portion main body S12 and the bearing opposing surface 71A. The grease layer Lg is a thin film layer formed of a grease (grease) that is incompatible with the refrigerant. That is, even when in contact with the refrigerant gas, the grease layer Lg does not dissolve in the refrigerant gas.

[0034] Note that the grease layer Lg is not provided between the inner peripheral seal portion main body S11 and the bearing opposing surface 71A of the orbiting scroll 7. The grease layer Lg only needs to be interposed between at least one of the inner peripheral seal portion Sa and the outer peripheral seal portion Sb arranged at the position closest to the compression chamber C and the orbiting scroll 7.

[0035] Figure 4 shows the meshing of the fixed scroll 6 and the orbiting scroll 7. In the figure, the orbiting scroll 7 is shown by hatching. The meshing point between the fixed wrap 62 of the fixed scroll 6 and the orbiting wrap 72 of the orbiting scroll 7 is indicated by reference numeral P. The meshing point P sequentially moves in the spiral direction of each wrap 62, 72 according to the orbiting angle of the orbiting scroll 7. In the present embodiment, the clearance between the wraps 62, 72 (between the tooth surfaces) at the meshing point P is adjusted.

[0036] A soft coating such as a PTFE (Polytetrafluoroethylene) - based coating is applied to substantially the entire fixed wrap 62 of the fixed scroll 6. The film thickness is, for example, about several tens of μm.

[0037] A soft coating such as a PTFE (Polytetrafluoroethylene) - based coating is applied to substantially the entire orbiting wrap 72 of the orbiting scroll 7 in the same manner as the fixed scroll 6. The film thickness is, for example, about several tens of μm.

[0038] As shown in Figure 5, the crank pin 5 is fitted into a crank pin fitting hole 10B formed in the drive bush 10. The planar notch surface 5A of the crank pin 5 is positioned so as to contact the planar portion 10C of the crank pin fitting hole 10B. Thereby, the drive bush 10 relatively moves in one direction which is the extending direction of the notch surface 5A of the crank pin 5 (the left - right direction in Figure 5) with respect to the crank pin 5.

[0039] The counterweight 10A is provided on the side opposite to the eccentric direction (the right direction in the figure) in which the eccentric axis O2 is eccentric with respect to the axis O1 in Figure 5. Note that the counterweight 10A is provided in a substantially semi - circular shape on the left side with respect to the axis O1 as shown in Figure 5, but is not limited to this shape, and may be provided at a position rotated by a predetermined angle around the axis O1.

[0040] The side surfaces on both sides of the flat surface 10C of the crank pin fitting hole 10B are curved surfaces corresponding to the arc shape of the crank pin 5.

[0041] The gap t in one direction (the extending direction of the notch surface 5A) formed between the crank pin fitting hole 10B and the crank pin 5 is less than the total film thickness of the coating films provided on the fixed wrap 62 and the swivel wrap 72. Here, as shown in FIG. 7, the gap t is the sum of one gap t1 on the left side and the other gap t2 on the right side of the crank pin 5.

[0042] Also, the gap t is equal to or greater than the minimum film thickness of the coating films formed on the fixed wrap 62 and the swivel wrap 72. The minimum film thickness means the film thickness at which the total film thickness at the meshing point P (see FIG. 4) is the smallest in the spiral direction.

[0043] As shown in FIGS. 5 and 6, the relative position of the crank pin 5 with respect to the crank pin fitting hole 10B is displaced according to the wear state of the coating film, and thereby gaps are formed on both sides of the crank pin 5.

[0044] As the wear of the coating film progresses, one gap t1 on the left side of the crank pin 5 becomes smaller, and finally, as shown in FIGS. 7 and 8, one gap t1 becomes zero, and only the other gap t2 on the right side remains. This will be described later.

[0045] The operation of the scroll compressor 100 described above will be explained. When starting the operation of the scroll compressor 100, first, the drive unit 3 rotationally drives the rotary shaft 4 around the axis O1. As the rotary shaft 4 rotates, the crank pin 5 revolves around the axis O1, and the orbiting scroll 7 attached thereto via the drive bush 10 orbits around the axis O1 with an orbital radius ρ. Here, the rotation of the orbiting scroll 7 is restricted by the oldham ring 91. Therefore, the orbiting scroll 7 performs a circular motion (orbiting) along the locus described by the eccentric axis O2 around the axis O1 of the rotary shaft 4. Along with this orbiting, the orbiting wrap 72 of the orbiting scroll 7 repeatedly makes continuous relative movement with respect to the fixed wrap 62 of the fixed scroll 6. Due to this relative movement, the volume of the compression chamber C formed between the fixed wrap 62 and the orbiting wrap 72 changes with time.

[0046] During the orbiting of the orbiting scroll 7, refrigerant gas as the working fluid is introduced into the compression chamber C from the communication hole 63H formed in the outer peripheral wall 63 of the fixed scroll 6. As the orbiting scroll 7 orbits, the communication hole 63H is closed. Thereby, the refrigerant gas is confined within the compression chamber C. Subsequently, still due to the orbiting of the orbiting scroll 7, the refrigerant gas moves toward the inner side in the radial direction (i.e., the eccentric axis O2 side). At this time, since the orbiting wrap 72 and the fixed wrap 62 are in a spiral shape, the volume of the compression chamber C formed by both of them decreases as it goes toward the inner side in the radial direction. Thereby, the refrigerant gas is compressed. Finally, near the central portion of the orbiting scroll 7 (or the fixed scroll 6), after the refrigerant gas reaches the highest pressure, it is supplied to the external refrigerant circuit through the fixed scroll discharge port 65, the discharge port 68, and the discharge pipe 12.

[0047] At the initial stage of operation of the scroll compressor 100, since the coating films formed on the fixed wrap 62 and the orbiting wrap 72 have their initial thickness without being worn, the gap t between the crank pin 5 in the crank pin fitting hole 10B is operated with gaps t1 and t2 left on both sides of the crank pin 5 as shown in FIGS. 5 and 6. Note that there may be a case where the initial operation is performed with the other gap t2 on the right side in FIG. 5 being zero. However, the gaps t1 and t2 are appropriately formed so as to absorb the component accuracy and assembly accuracy of the scroll compressor 100.

[0048] As the operation of the scroll compressor 100 progresses and the wear of the coating film progresses, the state shown in FIGS. 7 and 8 is reached. In FIGS. 7 and 8, one gap t1 on the left side of the crank pin 5 becomes zero, and only the other gap t2 on the right side remains. In this state, the movement of the crank pin fitting hole 10B to the right in FIG. 7 is restricted. This state means that the movement of the orbiting scroll 7 driven by the drive bush 10 in the centrifugal direction (toward the fixed wrap 62) is restricted, and the orbiting wrap 72 reaches the limit of approaching the fixed wrap 62.

[0049] During the operation of the scroll compressor 100, due to the provision of the seal portion S, the fluid flow between the main surface 9S of the main bearing 9A and the bearing opposing surface 71A of the orbiting scroll 7 is sealed. Thereby, the possibility of the lubricating oil flowing into the compression chamber C can be reduced.

[0050] The functions and effects of the present embodiment described above are as follows. The crank pin 5 is movable in one direction with respect to the drive bush 10 by a clearance t provided in the crank pin fitting hole 10B. Due to this clearance t, even if the coating film wears at the sliding portion between the wraps 62, 72 of the fixed scroll 6 and the orbiting scroll 7, the orbiting scroll 7 can move in one direction via the drive bush 10. And even if the wear of the coating film progresses and the crank pin 5 moves with respect to the drive bush 10, since the clearance t is less than the film thickness of the coating film, the movement of the drive bush 10 and the crank pin 5 is restricted by the crank pin fitting hole 10B (see FIGS. 7 and 8). Thereby, even if the wear of the coating film progresses, the movement of the drive bush 10 and thus the orbiting scroll 7 can be restricted by the crank pin fitting hole 10B, so that the coating film can be secured at the meshing point P (see FIG. 4) between the wraps 62, 72, and appropriate clearance management between the wraps 62, 72 (between the tooth surfaces) can be performed.

[0051] The clearance t between the crank pin fitting hole 10B and the crank pin 5 defines the approaching distance between the wraps 62, 72 of the orbiting scroll 7 and the fixed scroll 6. This approaching distance between the wraps 62, 72 needs to be equal to or greater than the thickness of the coating film in order to ensure the sealing performance at the meshing point P (see FIG. 4) between the wraps 62, 72. On the other hand, the film thickness of the coating film formed on each of the wraps 62, 72 varies from the design value due to variations during manufacturing in the spiral direction of the scrolls 6, 7. Therefore, by setting the clearance t to be equal to or greater than the minimum film thickness of the coating film, the sealing performance at the meshing point P can be ensured even at the position (orbiting position) of the coating film with the minimum film thickness.

[0052] By providing the coating film on both the orbiting scroll 7 and the fixed scroll 6, a larger film thickness can be achieved compared to the case where the same film thickness is provided on one of the scrolls 6, 7. Thereby, the clearance between the crank pin fitting hole 10B and the crank pin 5 can be set larger, and clearance management becomes easier.

[0053] A seal portion S is provided between the turning end plate 71 of the turning scroll 7 and the main bearing 9A, and the lubricating oil passing through the turning end plate 71 and the main bearing 9A is minimized. Thereby, even if the oil guided between the laps 62 and 72 of the turning scroll 7 and the fixed scroll 6 is minimized, the sealing performance of the lap surface by the coating film can be maintained by the gap t between the crank pin fitting hole 10B and the crank pin 5 as described above.

[0054] Note that the present embodiment can be modified as follows. As shown in Fig. 9A, planar notch surfaces 5A may be provided on both sides of the crank pin 5. Thereby, the relative movement of the crank pin 5 in one direction can be more reliably performed.

[0055] As shown in Fig. 9B, the cross section of the crank pin 5 may be triangular. By setting one side of the triangular shape as the notch surface 5A, the relative movement of the crank pin 5 in one direction is defined.

[0056] As shown in Fig. 9C, the cross section of the crank pin 5 may be rectangular. By setting the two opposing sides of the rectangular shape as the notch surfaces 5A, the relative movement of the crank pin 5 in one direction can be more reliably performed.

[0057] Also, in the above-described embodiment, the suction pipe 11 is provided in the suction space V1 above the main bearing 9A, but the present disclosure is not limited thereto, and it may be provided in the machine space V2 below the main bearing 9A.

[0058] In the above-described embodiment, the coating film is provided on both the fixed lap 62 and the turning lap 72, but the coating film may be provided on either the fixed lap 62 or the turning lap 72.

[0059] In the above-described embodiment, the seal portion S is provided so that the lubricating oil hardly flows to the laps 62 and 72 side, but the seal portion S may be omitted.

[0060] The scroll compressor described in the above embodiment can be understood as follows, for example.

[0061] The scroll compressor (100) according to the first aspect of the present disclosure includes a rotating shaft (4) that extends along an axis (O1) and rotates around the axis, a swash scroll (7) provided so as to be pivotable around the axis at a position eccentric with respect to the axis, a fixed scroll (6) that is fixed to the housing (1) side, meshes with the swash scroll, and forms a compression chamber (C) for compressing refrigerant between the fixed scroll and the swash scroll, a crank pin (5) that is eccentric with respect to the axis and provided on the rotating shaft, a drive bush (10) that has a crank pin fitting hole (10B) into which the crank pin is fitted and drives the swash scroll, and a coating film provided on the tooth surfaces (62, 72) of the swash scroll and / or the fixed scroll. The crank pin fitting hole is provided with a gap (t) through which the crank pin can move in one direction, and the gap is less than the film thickness of the coating film.

[0062] The crank pin is movable in one direction with respect to the drive bush due to the gap provided in the crank pin fitting hole. Due to this gap, even if the coating film wears on the sliding portion (lap surface) between the tooth surfaces of the fixed scroll and the swash scroll, the swash scroll can move in one direction via the drive bush. And even if the wear of the coating film progresses and the crank pin moves with respect to the drive bush, since the gap is less than the film thickness of the coating film, the movement of the drive bush and the crank pin is restricted by the crank pin fitting hole. Thereby, even if the wear of the coating film progresses, the movement of the drive bush and thus the swash scroll can be restricted by the crank pin fitting hole, so that the coating film can be secured on the lap surface and appropriate gap management of the lap surface can be performed. As the coating film, a soft material such as a PTFE (Polytetrafluoroethylene) - based material is preferable.

[0063] In the scroll compressor according to the second aspect of the present disclosure, in the above first aspect, the gap is set to be equal to or greater than the minimum film thickness of the coating film formed on the orbiting scroll and / or the fixed scroll.

[0064] The gap between the crankpin fitting hole and the crankpin defines the approaching distance on the lap surface between the orbiting scroll and the fixed scroll. In order to ensure the sealing performance of this lap surface, the approaching distance on this lap surface needs to be equal to or greater than the thickness of the coating film. On the other hand, the film thickness of the coating film formed on the tooth surface of the scroll varies from the design value due to manufacturing variations in the spiral direction of the scroll. Therefore, by setting the gap to be equal to or greater than the minimum film thickness of the coating film, it is ensured that the sealing performance of the lap surface is maintained even at the position (orbiting position) of the coating film with the minimum film thickness.

[0065] In the scroll compressor according to the third aspect of the present disclosure, in the above first aspect or the above second aspect, the coating film is provided on both the orbiting scroll and the fixed scroll.

[0066] By providing the coating film on both the orbiting scroll and the fixed scroll, a larger film thickness can be achieved compared to the case where the same film thickness is provided on one scroll. As a result, the gap between the crankpin fitting hole and the crankpin can be set larger, facilitating gap management.

[0067] In the scroll compressor according to the fourth aspect of the present disclosure, in any one of the above first aspect to the above third aspect, a seal portion (S) is provided between the end plate of the orbiting scroll and the bearing (9A) that supports the end plate (71).

[0068] A seal portion is provided between the end plate of the orbiting scroll and the bearing to minimize the oil passing through the end plate of the orbiting scroll and the bearing. As a result, even if the oil guided to the lap surfaces of the orbiting scroll and the fixed scroll is minimized, the sealing performance of the lap surfaces by the coating film can be maintained by the gap between the crank pin fitting hole and the crank pin as described above.

Explanation of Signs

[0069] 1: Housing 2: Compression section 3: Drive section 4: Rotating shaft 5: Crank pin 5A: Notch surface 6: Fixed scroll 7: Orbiting scroll 7A: Boss section 8: Discharge cover 9A: Main bearing 9B: Sub bearing 9B1: Oil pump 9H: Main bearing body 9S: Main surface 9i: Inner peripheral side accommodation groove 9o: Outer peripheral side accommodation groove 10: Drive bush 10A: Counterweight 11: Suction pipe 12: Discharge pipe 61: Fixed end plate 62: Fixed lap 63: Outer peripheral wall 63H: Communication hole 64: Flange section 65: Fixed scroll discharge port 66: Discharge valve 67: Discharge chamber 68: Discharge port 69: Flow guide 71: Orbiting end plate 71A: Bearing facing surface 72: Orbiting lap 91: O-ring 92: Thrust ring 100: Scroll compressor C: Compression chamber G: Clearance Lg: Grease layer LO: Lubricating oil O1: Axis O2: Eccentric axis P: Meshing point S: Seal part S11: Inner peripheral side seal part body S12: Outer peripheral side seal part body S21: Inner peripheral side elastic part S22: Outer peripheral side elastic part Sa: Inner peripheral side seal part Sb: Outer peripheral side seal part V1: Suction space V2: Machine space t: Clearance ρ: Swivel radius

Claims

1. a rotating shaft extending along an axis and rotating about the axis, a swivel scroll provided at a position eccentric with respect to the axis and capable of swiveling about the axis, a fixed scroll fixed to the housing side, meshed with the swivel scroll, and forming a compression chamber for compressing refrigerant between the fixed scroll and the swivel scroll, a crank pin eccentric with respect to the axis and provided on the rotating shaft, a drive bush having a crank pin fitting hole into which the crank pin is fitted and driving the swivel scroll, a coating film provided on the tooth surfaces of the swivel scroll and / or the fixed scroll, comprising, the crank pin fitting hole is provided with a gap through which the crank pin can move in one direction, the scroll compressor in which the gap is less than the film thickness of the coating film.

2. The scroll compressor according to claim 1, wherein the gap is equal to or greater than the minimum film thickness of the coating film formed on the swivel scroll and / or the fixed scroll.

3. The scroll compressor according to claim 1 or 2, wherein the coating film is provided on both the swivel scroll and the fixed scroll.

4. The scroll compressor according to claim 1, wherein a seal portion is provided between an end plate of the swivel scroll and a bearing supporting the end plate.

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