Scroll compressor

Abstract

Provided is a scroll compressor in which it is possible to properly manage gaps in a sliding part in which toothed surfaces of the scroll compressor slide against each other. This scroll compressor comprises: an orbiting scroll that is provided so as to be able to orbit around an axis (O1) at a position eccentric with respect to the axis (O1); a crank pin (5) that is eccentric with respect to the axis (O1) and is provided to a rotary shaft; a drive bush (10) that has a crank pin fitting hole (10B) into which the crank pin (5) is fitted and that drives the orbiting scroll; and a coating film that is provided to toothed surfaces of the orbiting scroll and a fixed scroll. The crank pin fitting hole (10B) is provided with gaps (t1), (t2) that allow the crank pin (5) to move in one direction, and the gaps (t1), (t2) are narrower than the film thickness of the coating film.

Description

Scroll Compressor

[0001] The present disclosure relates to scroll compressors.

[0002] Scroll compressors are widely used in refrigeration and air conditioning compressors to compress refrigerants. Oil is sealed into scroll compressors to lubricate the sliding surfaces of opposing scroll teeth and each bearing, but the oil is discharged along with the refrigerant out of the compressor during operation. The development of a control design to return the discharged oil back to the compressor requires a lot of development time, and oil accumulation in the heat exchanger leads to a decrease in heat exchange efficiency. Therefore, in the development of heat pump systems, the development of scroll compressors with low oil discharge volume is desired.

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

[0004] Japanese Patent Application Laid-Open No. 2020-51406

[0005] When the oil discharge rate from the scroll compressor is reduced as in Patent Document 1, the amount of oil introduced to the compression section is reduced, making it more important to protect the sliding surfaces where the scroll tooth flanks of the scroll compressor slide against each other. To protect the sliding sections, one of the following measures, or a combination of these, is required: (1) reducing the scroll tooth flank load, (2) protecting with a coating, or (3) making the tooth flanks non-contact. Making the tooth flanks non-contact as in (3) above increases the leakage gap, leading to a decrease in compression efficiency, so it is necessary to properly manage the gap between the tooth flanks.

[0006] The present disclosure has been made in consideration of the above circumstances, and aims to provide a scroll compressor that can appropriately manage the gap in the sliding portion where the scroll tooth surfaces slide against each other.

[0007] A scroll compressor according to one aspect of the present disclosure includes a rotating shaft extending along an axis and rotating about the axis, a rotating scroll provided rotatably about the axis at a position eccentric to the axis, a fixed scroll fixed to a housing and meshing with the rotating scroll to form a compression chamber for compressing a refrigerant between the rotating scroll and the fixed scroll, a crankpin provided on the rotating shaft and eccentric to the axis, a drive bushing having a crankpin fitting hole into which the crankpin is fitted and which drives the rotating scroll, and a coating film provided on tooth surfaces of the orbiting scroll and / or the fixed scroll, wherein the crankpin fitting hole has a gap that allows the crankpin to move in one direction, and the gap is less than the thickness of the coating film.

[0008] The clearance at the sliding portion where the tooth surfaces of the scroll compressor slide against each other can be appropriately controlled.

[0009] 1 is a longitudinal sectional view showing a scroll compressor according to an embodiment of the present disclosure; FIG. 2 is a partially enlarged longitudinal sectional view of the seal portion of FIG. 1; FIG. 3 is a plan view of the seal portion of FIG. 1; FIG. 4 is a meshing diagram of a fixed scroll and an orbiting scroll; FIG. 5 is a plan view showing a drive bush and a crank pin; FIG. 6 is a longitudinal sectional view corresponding to FIG. 5; FIG. 7 is a plan view showing a modified drive bush and a crank pin; FIG. 8 is a plan view showing another modified drive bush and a crank pin; FIG. 9 is a plan view showing another modified drive bush and a crank pin;

[0010] 1, a scroll compressor 100 includes a housing 1 that defines the outer shape of the device, a drive unit 3 that is an electric motor provided within the housing 1, a rotating shaft 4 that is driven to rotate by the drive unit 3, a compression unit 2 that compresses a refrigerant by being driven by the rotation of the rotating shaft 4, a main bearing 9A and a sub-bearing 9B that rotatably support the rotating shaft 4, and a seal unit S.

[0011] The compression section 2 and the drive section 3 are connected to each other by a rotary shaft 4 extending along an axis O1. That is, rotational energy from the drive section 3 is instantly transmitted to the compression section 2 through the rotary shaft 4. The compression section 2 uses this rotational energy to compress a refrigerant gas (refrigerant) as a working fluid 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 drawing in refrigerant gas as a working fluid from the outside, and a discharge pipe 12 for discharging the refrigerant gas that has been compressed in the compression section 2 and is now in a high-pressure state. Lubricating oil for lubricating the main bearing 9A and the sub-bearing 9B is stored in the lower part of the housing 1. The lubricating oil is supplied to the lower part of the housing 1 via 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 up 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 into the space between the orbiting end plate 71 of the orbiting 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 within the housing 1 by a main bearing 9A and a sub-bearing 9B provided at the end opposite the axial direction 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 a radial load applied to the rotating shaft 4. The main bearing 9A has a disk shape centered on the axis O1. The outer peripheral surface of the main bearing 9A is fixed by welding, interference fit, or the like, in contact with the inner peripheral surface of the housing 1 along its entire circumference. In other words, the main bearing 9A divides the space within the housing 1 into two. The compression unit 2 is housed in the space on one side of the main bearing 9A in the axial direction. The drive unit 3 is housed in the space on the opposite side of the main bearing 9A in the axial direction. The above-mentioned intake pipe 11 communicates with the space (the space in which the compression section 2 is accommodated) on one side of the main bearing 9A in the axial direction.

[0015] The interior space of the housing 1 is divided into two spaces by the main bearing 9A. The space on one axial side of the main bearing 9A within the housing 1 is an intake space V1 that houses the compression section 2. The space on the other axial side of the housing 1, including the main bearing 9A, is a machine space V2 that houses the drive section 3, main bearing 9A, and sub-bearing 9B.

[0016] A crank pin 5 serving as an eccentric shaft is provided at one end of the rotating shaft 4. The crank pin 5 is provided at a position offset (eccentric) from the axis O1. The crank pin 5 is columnar, centered on an eccentric axis O2 that is different from the axis O1. The eccentric axis O2 is parallel to the axis O1. The crank pin 5 is columnar and protrudes from the end of the rotating shaft 4 toward one side in the axial direction (the side where the compression section 2 is located relative to the main bearing 9A). Therefore, when the rotating shaft 4 rotates around the axis O1, the crank pin 5 revolves around the axis O1 of the rotating shaft 4.

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

[0018] An Oldham ring 91 is provided on the main surface (top surface in FIG. 1 : see reference numeral 9S in FIG. 2 ), which is the surface of the main bearing 9A facing the other side in the axial direction. The Oldham ring 91 restricts the rotation of the orbiting scroll 7 (rotation about the eccentric axis O2). Furthermore, a thrust ring 92 is provided on the inner peripheral side of the Oldham ring 91 to support the axial load applied to the rotating shaft 4. When viewed in the axial direction, the thrust ring 92 has an annular shape centered on the axis O1.

[0019] A discharge cover 8 is provided on one side of the compression section 2 in the axial direction. The discharge cover 8 is a generally disk-shaped member that axially divides the suction space V1. Within the suction space V1, the space on one side of the discharge cover 8 in the axial direction is defined as a discharge chamber 67. A discharge port 68 that connects the discharge chamber 67 to the compression section 2 is provided in the center of the discharge cover 8. Furthermore, a flow guide 69 is provided between the discharge cover 8 and the compression section 2, surrounding the discharge port 68 from the outer periphery. The flow guide 69 is cylindrical and centered on the axis O1. High-pressure refrigerant gas flowing out of the compression section 2 is guided by the flow guide 69 and flows into the discharge chamber 67.

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

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

[0022] An outer peripheral wall 63 is formed radially outward from the fixed wrap 62, extending cylindrically along the outer periphery of the fixed end plate 61. That is, the outer peripheral wall 63 extends axially from the fixed end plate 61 to surround the fixed wrap 62 from the radially outer side. Furthermore, an annular flange 64 extending radially outward is provided on the edge of the outer peripheral wall 63 on the other axial side (the side where the drive unit 3 is located relative to the main bearing 9A). The fixed scroll 6 is fixed to the main bearing 9A via the flange 64 with bolts (not shown). A fixed scroll discharge port 65 is formed in the center of the fixed end plate 61, penetrating the fixed end plate 61 in the axial direction. A discharge valve 66 is provided in the fixed scroll discharge port 65 to prevent backflow of refrigerant gas into the compression chamber C. The fixed scroll discharge port 65 communicates with the discharge port 68 via the flow guide 69. Furthermore, a communication hole 63H is formed in a part of the outer peripheral wall 63, penetrating the outer peripheral wall 63 in the radial direction. The communication hole 63H communicates the inside and outside of the compression chamber C. The communication hole 63H is formed directly beside the opening of the suction pipe 11 so that its axial position overlaps with the connection portion between the suction pipe 11 and the housing 1. Refrigerant gas supplied from the suction pipe 11 to the suction space V1 flows into the fixed scroll 6 through the communication hole 63H.

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

[0024] Furthermore, the orbiting wraps 72 are arranged to overlap each other in a direction (radial direction) intersecting the axis O1 with respect to the fixed wrap 62. In other words, the fixed wrap 62 and the orbiting wrap 72 are meshed with each other. In this 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. This makes it possible to compress the refrigerant gas.

[0025] The seal portion S seals the fluid flow between the inside and outside of the compression section 2 within the housing 1. In this embodiment, the seal portion S is provided to seal the fluid flow (leakage) between the main bearing 9A and the orbiting scroll 7. Here, "fluid" refers not only to gases such as refrigerant gas compressed in the compression chamber C, but also to liquids such as lubricating oil used in the main bearing 9A. The seal portion S is provided on the outer periphery of the Oldham ring 91. As shown in FIG. 2 , the main surface 9S of the main bearing 9A extends in a plane perpendicular to the axis O1. The main surface 9S faces a bearing-opposing surface 71A, facing the other axial side of the orbiting end plate 71 of the orbiting scroll 7, across a gap G. The seal portion S suppresses leakage of refrigerant gas and oil through 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 seal portion Sa, an outer seal portion Sb, and a grease layer Lg. The inner seal portion Sa is annular and centered on the axis O1. The inner seal portion Sa is located relatively closer to the inner periphery (inside in the radial direction) within the seal portion S. The outer seal portion Sb is annular and centered on the axis O1. The outer seal portion Sb is located relatively closer to the outer periphery (outside in the radial direction) than the inner seal portion Sa. In other words, the radial dimension of the outer seal portion Sb is larger than the radial dimension of the inner seal portion Sa. As a result, the outer seal portion Sb surrounds the inner seal portion Sa from the radial outside.

[0027] The inner seal portion Sa is accommodated in an inner circumferential accommodating groove 9i formed on the main surface 9S. The inner circumferential accommodating groove 9i is recessed from the main surface 9S toward the other axial direction. When viewed from the axial direction, the inner circumferential accommodating groove 9i is formed so as to surround the Oldham ring 91 from the radial outside. The inner circumferential accommodating groove 9i has an annular shape centered on the axis O1. That is, the inner circumferential accommodating groove 9i is formed continuously in the circumferential direction about the axis O1.

[0028] The outer seal portion Sb is accommodated in an outer circumferential accommodating groove 9o formed on the main surface 9S. The outer circumferential accommodating groove 9o is recessed from the main surface 9S toward the other axial side. When viewed from the axial direction, the outer circumferential accommodating groove 9o is formed so as to surround the inner circumferential accommodating groove 9i from the radial outside. The outer circumferential accommodating groove 9o has an annular shape centered on the axis O1. In other words, the outer circumferential accommodating groove 9o is formed continuously in the circumferential direction about the axis O1. The radial dimension of the outer circumferential accommodating groove 9o is greater than the radial dimension of the inner circumferential accommodating groove 9i.

[0029] The inner seal portion Sa has an inner seal portion main body S11 and an inner seal portion elastic portion S21. A portion of the inner seal portion main body S11 is accommodated in the inner seal accommodation groove 9i. The inner seal portion main body S11 is disposed so that a portion of it protrudes from the main surface 9S in the axial direction. This allows the inner seal portion main body S11 to abut against the bearing-opposing surface 71A. The inner seal portion main body S11 has an annular shape centered on the axis O1 (see FIG. 3). The inner seal portion main body S11 is integrally formed from, for example, a resin material such as rubber or a metal material that is relatively resistant to wear.

[0030] The inner elastic portion S21 biases the inner seal portion main body S11 toward the bearing-opposing surface 71A within the inner accommodating groove 9i. The inner elastic portion S21 is made of an elastic material such as silicone rubber. Like the inner seal portion main body S11, the inner elastic portion S21 has an annular shape centered on the axis O1 (see FIG. 3). When biased by the inner elastic portion S21, a portion of the inner seal portion main body S11 protrudes from the inner accommodating groove 9i toward one side in the axial direction (the side toward the bearing-opposing surface 71A).

[0031] The outer-periphery seal portion Sb has an outer-periphery seal portion main body S12 and an outer-periphery seal portion elastic portion S22. A portion of the outer-periphery seal portion main body S12 is accommodated in the outer-periphery accommodation groove 9o. The outer-periphery seal portion main body S12 is disposed so that a portion thereof protrudes from the main surface 9S in the axial direction. This allows the outer-periphery seal portion main body S12 to abut against the bearing-opposing surface 71A. The outer-periphery seal portion main body S12 has an annular shape centered on the axis O1 (see FIG. 3). The outer-periphery seal portion main body S12 is formed from the same material as the inner-periphery seal portion main body S11. Therefore, the outer-periphery seal portion main body S12 is integrally formed from, for example, a resin material such as rubber or a metal material that is relatively resistant to wear.

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

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

[0034] It should be noted that no grease layer Lg is provided between the inner seal portion main body S11 and the bearing opposing surface 71A of the orbiting scroll 7. It is sufficient that the grease layer Lg is interposed between at least one of the inner seal portion Sa and the outer seal portion Sb arranged closest to the compression chamber C and the orbiting scroll 7.

[0035] 4 shows the meshing between the fixed scroll 6 and the orbiting scroll 7. In the figure, the orbiting scroll 7 is indicated 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 the symbol P. The meshing point P moves sequentially in the spiral direction of each wrap 62, 72 depending on the orbiting angle of the orbiting scroll 7. In this embodiment, the gap between the wraps 62, 72 (between the tooth surfaces) at the meshing point P is adjusted.

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

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

[0038] As shown in Figure 5, the crankpin 5 is fitted into a crankpin fitting hole 10B formed in the drive bushing 10. The flat cutout surface 5A of the crankpin 5 is positioned so as to contact a flat portion 10C of the crankpin fitting hole 10B. This allows the drive bushing 10 to move relative to the crankpin 5 in one direction, which is the extension direction of the cutout surface 5A of the crankpin 5 (the left-right direction in Figure 5).

[0039] In Fig. 5, the counterweight 10A is provided on the opposite side of the eccentric direction (rightward in the figure) in which the eccentric axis O2 is eccentric with respect to the axis O1. Note that, although the counterweight 10A is provided in a substantially semicircular shape on the left side of the axis O1 as shown in Fig. 5, the shape is not limited to this, and it may also be provided at a position rotated a predetermined angle around the axis O1.

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

[0041] The gap t formed between the crankpin fitting hole 10B and the crankpin 5 in one direction (the extension direction of the cutout surface 5A) is set to be less than the total thickness of the coating films provided on the fixed wrap 62 and the orbiting wrap 72. Here, the gap t is set to be the sum of one gap t1 on the left side of the crankpin 5 and the other gap t2 on the right side, as shown in FIG.

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

[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 changes depending on the wear state of the coating film, and as a result, gaps are formed on both sides of the crank pin 5.

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

[0045] The operation of the scroll compressor 100 described above will now be described. When the scroll compressor 100 starts operating, the drive unit 3 first rotates the rotary shaft 4 about the axis O1. As the rotary shaft 4 rotates, the crank pin 5 orbits about the axis O1, and the orbiting scroll 7, which is attached to the rotary shaft 4 via the drive bush 10, orbits around the axis O1 with an orbiting radius ρ. The rotation of the orbiting scroll 7 is restricted by the Oldham ring 91. Therefore, the orbiting scroll 7 performs a circular motion (orbits) around the axis O1 of the rotary shaft 4 along a path traced by the eccentric axis O2. As the orbiting motion progresses, the orbiting wrap 72 of the orbiting scroll 7 repeatedly and continuously moves relative to the fixed wrap 62 of the fixed scroll 6. This relative movement causes the volume of the compression chamber C formed between the fixed wrap 62 and the orbiting wrap 72 to change over time.

[0046] While the orbiting scroll 7 orbits, refrigerant gas as a working fluid is introduced into the compression chamber C through the communication holes 63H formed in the outer peripheral wall 63 of the fixed scroll 6. As the orbiting scroll 7 orbits, the communication holes 63H are closed. This traps the refrigerant gas within the compression chamber C. As the orbiting scroll 7 continues to orbit, the refrigerant gas moves radially inward (i.e., toward the eccentric axis O2). Because the orbiting wrap 72 and the fixed wrap 62 are spiral-shaped, the volume of the compression chamber C formed by them decreases radially inward. This compresses the refrigerant gas. Finally, the refrigerant gas reaches a maximum pressure near the center of the orbiting scroll 7 (or the fixed scroll 6) and is then supplied to an external refrigerant circuit via the fixed scroll discharge port 65, the discharge port 68, and the discharge piping 12.

[0047] In the initial stage of operation of the scroll compressor 100, the coating films formed on the fixed wrap 62 and the orbiting wrap 72 are not worn and have their initial thickness, so that the crankpin 5 in the crankpin fitting hole 10B is operated in a state in which gaps t1 and t2 remain on both sides of the crankpin 5, as shown in Figures 5 and 6. Note that initial operation may also be performed in a state in which the other gap t2 on the right side in Figure 5 is zero. However, the gaps t1 and t2 are appropriately formed to accommodate the component precision and assembly precision 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 Figures 7 and 8 is reached. In Figures 7 and 8, the one-side gap t1 on the left side of the crankpin 5 becomes zero, and only the other-side gap t2 on the right side remains. In this state, movement of the crankpin fitting hole 10B to the right in Figure 7 is restricted. This state means that movement of the orbiting scroll 7 driven by the drive bushing 10 in the centrifugal direction (toward the fixed wrap 62) is restricted, and this is the limit to which the orbiting wrap 72 can approach the fixed wrap 62.

[0049] During operation of the scroll compressor 100, the seal portion S seals the flow of fluid between the main surface 9S of the main bearing 9A and the bearing-opposing surface 71A of the orbiting scroll 7. This reduces the possibility of lubricating oil flowing into the compression chamber C.

[0050] The effects of the present embodiment described above are as follows. The crankpin 5 is allowed to move in one direction relative to the drive bushing 10 by the gap t provided in the crankpin fitting hole 10B. This gap t allows the orbiting scroll 7 to move in one direction via the drive bushing 10, 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. Even if the coating film wears and the crankpin 5 moves relative to the drive bushing 10, the crankpin fitting hole 10B restricts movement of the drive bushing 10 and the crankpin 5 because the gap t is less than the thickness of the coating film (see FIGS. 7 and 8 ). As a result, even if the coating film wears, the crankpin fitting hole 10B can restrict movement of the drive bushing 10 and, ultimately, the orbiting scroll 7. This ensures that the coating film is maintained at the meshing point P (see FIG. 4 ) between the wraps 62, 72, allowing for appropriate gap management between the wraps 62, 72 (between the tooth surfaces).

[0051] The gap t between the crankpin fitting hole 10B and the crankpin 5 determines the distance between the wraps 62, 72 of the orbiting scroll 7 and the fixed scroll 6. This distance between the wraps 62, 72 must be equal to or greater than the thickness of the coating film to ensure sealing at the meshing point P (see FIG. 4 ) between the wraps 62, 72. However, the thickness of the coating film formed on each wrap 62, 72 varies from the design value in the spiral direction of the scrolls 6, 7 due to manufacturing variations. Therefore, by setting the gap t to be equal to or greater than the minimum thickness of the coating film, sealing at the meshing point P can be ensured even at the position (orbiting position) of the coating film with the minimum thickness.

[0052] By providing a coating film on both the orbiting scroll 7 and the fixed scroll 6, a larger film thickness can be achieved compared to when the same film thickness is provided on only one of the scrolls 6, 7. This allows the gap between the crankpin fitting hole 10B and the crankpin 5 to be set larger, making gap management easier.

[0053] A seal portion S is provided between the orbiting end plate 71 of the orbiting scroll 7 and the main bearing 9A, minimizing the amount of lubricating oil passing through the orbiting end plate 71 and the main bearing 9A. As a result, even if the amount of oil introduced between the wraps 62, 72 of the orbiting scroll 7 and the fixed scroll 6 is minimized, the gap t between the crankpin fitting hole 10B and the crankpin 5 as described above can maintain the sealing properties of the wrap surfaces provided by the coating film.

[0054] This embodiment can be modified as follows: As shown in Fig. 9A, flat cutout surfaces 5A may be provided on both sides of the crank pin 5. This allows the crank pin 5 to more reliably move relative to one side.

[0055] 9B, the cross section of the crank pin 5 may be triangular. By forming one side of the triangle as a notched surface 5A, the relative movement of the crank pin 5 in one direction is restricted.

[0056] 9C, the cross section of the crank pin 5 may be rectangular. By forming two opposing sides of the rectangle as cutout surfaces 5A, the crank pin 5 can be more reliably moved relative to one side.

[0057] In addition, in the above-described embodiment, the intake pipe 11 is provided in the intake space V1 above the main bearing 9A, but the present disclosure is not limited to this, and the intake pipe 11 may also 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 wrap 62 and the orbiting wrap 72, but the coating film may be provided on either the fixed wrap 62 or the orbiting wrap 72 alone.

[0059] In the above-described embodiment, the seal portion S is provided to prevent the lubricating oil from flowing toward the wraps 62, 72, but the seal portion S may be omitted.

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

[0061] A scroll compressor (100) according to a first aspect of the present disclosure includes: a rotating shaft (4) extending along an axis (O1) and rotating about the axis; an orbiting scroll (7) provided rotatably about the axis at a position eccentric to the axis; a fixed scroll (6) fixed to a housing (1) and meshing with the orbiting scroll to form a compression chamber (C) for compressing a refrigerant between the orbiting scroll and the fixed scroll; a crankpin (5) eccentric to the axis and provided on the rotating shaft; a drive bush (10) having a crankpin fitting hole (10B) into which the crankpin is fitted and which drives the orbiting scroll; and a coating film provided on tooth surfaces (62, 72) of the orbiting scroll and / or the fixed scroll, wherein the crankpin fitting hole has a gap (t) that allows the crankpin to move in one direction, and the gap is less than a thickness of the coating film.

[0062] The crankpin is allowed to move in one direction relative to the drive bushing through a gap provided in the crankpin fitting hole. This gap allows the orbiting scroll to move in one direction via the drive bushing even if the coating film wears at the sliding portion (wrap surface) between the tooth flanks of the fixed scroll and the orbiting scroll. Even if the coating film wears and the crankpin moves relative to the drive bushing, the gap is less than the thickness of the coating film, so the crankpin fitting hole restricts movement between the drive bushing and the crankpin. This allows the crankpin fitting hole to restrict movement of the drive bushing and, ultimately, the orbiting scroll, even if the coating film wears, thereby ensuring a coating film on the wrap surface and enabling appropriate clearance management on the wrap surface. A soft material, such as PTFE (polytetrafluoroethylene), is preferred for the coating film.

[0063] A scroll compressor according to a second aspect of the present disclosure is the scroll compressor of the first aspect, wherein the gap is 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 clearance between the crankpin and the crankpin hole determines the distance between the orbiting scroll and the fixed scroll at the wrap surfaces. This distance must be equal to or greater than the thickness of the coating film to ensure sealing of the wrap surfaces. However, the thickness of the coating film formed on the scroll tooth surface varies from the design value in the scroll spiral direction due to manufacturing variations. Therefore, by setting the clearance equal to or greater than the minimum coating film thickness, sealing of the wrap surfaces is ensured even at the position of the coating film with the minimum thickness (orbiting position).

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

[0066] By providing a coating film on both the orbiting scroll and the fixed scroll, a larger film thickness can be achieved compared to providing the same film thickness on only one scroll. This allows for a larger gap to be set between the crankpin fitting hole and the crankpin, making gap management easier.

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

[0068] A seal is provided between the end plate of the orbiting scroll and the bearing to minimize the amount of oil passing through the end plate of the orbiting scroll and the bearing. As a result, even if the amount of oil introduced to the wrap surfaces of the orbiting scroll and the fixed scroll is minimized, the gap between the crankpin fitting hole and the crankpin as described above can maintain the sealing properties of the wrap surfaces provided by the coating film.

[0069] DESCRIPTION OF SYMBOLS 1: Housing 2: Compression section 3: Drive section 4: Rotating shaft 5: Crank pin 5A: Notched 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 wrap 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 opposing surface 72: Orbiting wrap 91: Oldham ring 92: Thrust ring 100: Scroll compressor C: Compression chamber G: Clearance Lg: Grease layer LO: Lubricating oil O1: Axis O2: Eccentric axis P: Engagement point S: Seal portion S11: Inner seal portion main body S12: Outer seal portion main body S21: Inner elastic portion S22: Outer elastic portion Sa: Inner seal portion Sb: Outer seal portion V1: Intake space V2: Machine space t: Clearance ρ: Orbiting radius

Claims

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

2. The scroll compressor according to claim 1, wherein the gap is not less 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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