Rotary compressor and refrigeration cycle device

Abstract

A rotary compressor capable of improving the performance of supplying lubricating oil to a thrust surface. [Solution] The rotary compressor includes a compression mechanism having a shaft 151 supported for free rotation about a rotation axis O. The compression mechanism includes an end plate having a thrust bearing surface that supports a thrust surface 40 of the shaft 151, and a groove 41 is formed in the thrust surface 40. The groove 41 has a shape that increases the oil pressure of the lubricating oil drawn into the groove 41 as the shaft 151 rotates.

Description

[Technical Field]

[0001] The present invention relates to a rotary compressor and a refrigeration cycle device. [Background technology]

[0002] Conventionally, a rotary compressor has been known that includes a cylinder, a piston (roller) disposed within the cylinder, a shaft having an eccentric portion fitted to the inner periphery of the piston, and a pair of end plates that close the axial ends of the cylinder. In a rotary compressor, the piston revolves within the cylinder as the shaft rotates, compressing the refrigerant within the cylinder. Such rotary compressors are used in refrigeration cycle devices that circulate refrigerant within a refrigerant circuit.

[0003] In a rotary compressor, the thrust bearing that receives the thrust load is formed by the lower surface (thrust surface) of the eccentric part and the upper surface of the lower end plate that closes the lower end of the cylinder. Lubricating oil is supplied between the thrust surface (the lower surface of the eccentric part) and the upper surface of the lower end plate, which form the sliding surfaces of the thrust bearing, to reduce friction on the sliding surfaces of the thrust bearing and cool the sliding surfaces, thereby preventing seizure on the sliding surfaces. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-072365 Summary of the Invention [Problem to be solved by the invention]

[0005] In the invention described in Patent Document 1, the sliding surface of the thrust bearing is provided with a pressure reduction groove that opens toward the inner periphery of the thrust surface to prevent foaming due to frictional forces when lubricating oil containing refrigerant is supplied to the sliding surface. The pressure reduction groove reduces the pressure of the lubricating oil supplied to the pressure reduction groove, causing the gas refrigerant dissolved in the lubricating oil to separate and foam. At this time, the lubricating oil, which has a higher specific gravity than the gas refrigerant, is subjected to centrifugal force and flows out of the pressure reduction groove radially outward, supplying the lubricating oil from which the gas refrigerant has been separated between the sliding surfaces of the thrust bearing (between the thrust surface of the eccentric portion and the upper surface of the lower end plate).

[0006] However, in the invention described in Patent Document 1, the pressure reduction groove reduces the oil pressure of the lubricating oil, so there is a risk that the centrifugal force acting on the reduced-pressure lubricating oil alone may not be enough to supply the lubricating oil to the thrust surface.

[0007] The disclosed technology has been made in view of the above, and aims to provide a rotary compressor and a refrigeration cycle device that can improve the performance of supplying lubricating oil to the thrust surface. [Means for solving the problem]

[0008] One aspect of a rotary compressor disclosed herein includes a compression mechanism having a shaft rotatably supported about a rotation axis. The compression mechanism includes an end plate having a thrust bearing surface. The thrust bearing surface of the end plate supports a thrust surface of the shaft. A groove is formed in the thrust surface of the shaft. The groove in the thrust surface has a shape that increases the oil pressure of lubricating oil drawn into the groove as the shaft rotates. [Effects of the Invention]

[0009] According to one aspect of the rotary compressor disclosed in the present application, the ability to supply lubricating oil to the thrust surface can be improved. [Brief explanation of the drawings]

[0010] [Figure 1]1 is a vertical cross-sectional view showing a rotary compressor of a first embodiment. [Figure 2] 1 is an exploded perspective view showing a compression mechanism of a rotary compressor according to a first embodiment. [Figure 3] 1 is a vertical cross-sectional view illustrating a main part of a compression mechanism of a rotary compressor according to a first embodiment. [Figure 4] FIG. 2 is a perspective view showing a shaft of the rotary compressor of the first embodiment. [Figure 5] FIG. 2 is a vertical cross-sectional view illustrating a shaft of the rotary compressor of the first embodiment. [Figure 6] FIG. 2 is a plan view of the shaft of the rotary compressor of the first embodiment as viewed from below. [Figure 7] FIG. 2 is a plan view for explaining a thrust surface of the rotary compressor of the first embodiment. [Figure 8] FIG. 2 is a plan view of a lower end plate of the rotary compressor of the first embodiment as viewed from above. [Figure 9A] FIG. 2 is a vertical cross-sectional view illustrating a lower end plate of the rotary compressor of the first embodiment. [Figure 9B] FIG. 2 is a vertical cross-sectional view illustrating a lower end plate of the rotary compressor of the first embodiment. [Figure 10] FIG. 10 is a plan view illustrating a thrust surface of a rotary compressor according to a second embodiment. [Figure 11] FIG. 10 is a plan view illustrating a thrust surface of a rotary compressor according to a third embodiment. [Figure 12] FIG. 10 is a plan view illustrating a thrust surface of a rotary compressor according to a fourth embodiment. [Figure 13] FIG. 10 is a plan view illustrating a thrust surface of a rotary compressor according to a fifth embodiment. [Figure 14] FIG. 13 is a plan view for explaining a thrust surface of a rotary compressor according to a sixth embodiment. [Figure 15] FIG. 13 is a plan view illustrating a thrust surface of a rotary compressor according to a seventh embodiment. [Figure 16] FIG. 13 is a plan view illustrating a thrust surface of the rotary compressor of the eighth embodiment. [Figure 17]1 is a conceptual diagram showing a refrigeration cycle device including a rotary compressor according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the rotary compressor disclosed in the present application will be described in detail with reference to the drawings. Note that the rotary compressor disclosed in the present application is not limited to the following embodiment. In the following description, the upward direction on the paper surface of FIG. 1, i.e., the direction from the compression mechanism unit 12 described below toward the discharge pipe 24, is referred to as the upward direction, and the opposite direction is referred to as the downward direction.

[0012] As shown in Fig. 1, the rotary compressor 1 has a sealed, vertically-placed, cylindrical compressor casing 10, a compression mechanism 12 housed within the compressor casing 10 and compressing a gas refrigerant to a high temperature and high pressure, and a motor 11 housed within the compressor casing 10 and supplying driving power to the compression mechanism 12. The high-pressure, high-temperature refrigerant compressed by the compression mechanism 12 is discharged from the inside of the compressor casing 10 through a discharge pipe 24 into the piping of a refrigerant circuit. The rotary compressor 1 is an internal high-pressure hermetic compressor.

[0013] The compression mechanism 12 includes an assembly fixed within the compressor housing 10 and forming an upper cylinder chamber 130T and a lower cylinder chamber 130S, a shaft 15 supported by the assembly so as to be rotatable about a rotation center axis O, and upper pistons 125T and lower pistons 125S housed in the upper cylinder chamber 130T and the lower cylinder chamber 130S and compressing gas refrigerant in the upper cylinder chamber 130T and the lower cylinder chamber 130S in response to rotation of the shaft 15. The shaft 15 mechanically connects the motor 11 and the compression mechanism 12. The motor 11 drives the compression mechanism 12 via the shaft 15.

[0014] The motor 11 includes a cylindrical stator 111 and a cylindrical rotor 112 arranged coaxially on the inner periphery of the stator 111. The stator 111 is fixed to the inner periphery of the compressor housing 10 by shrink fitting. The rotor 112 is also fixed coaxially to the shaft 15 by shrink fitting. When a control signal (electric power) is supplied to the stator 111, a magnetic force is generated in the stator 111. The magnetic force generated in the stator 111 causes the shaft 15 to rotate around the central rotation axis O of the rotor 112.

[0015] The rotary compressor 1 includes a cylindrical accumulator 25 fixed to a side portion of the compressor housing 10. The accumulator 25 includes an accumulator container 26 in which separated liquid refrigerant is stored, an accumulator suction pipe 27 that draws low-pressure, low-temperature refrigerant from the piping of the refrigerant circuit into the accumulator container 26, and a gas-liquid separation pipe 28 that supplies gas refrigerant from the inside of the accumulator container 26 to the compression mechanism unit 12. The gas-liquid separation pipe 28 includes an upper curved pipe 28T that is joined to an upper suction pipe 105 (suction pipe 23) that is connected to the compression mechanism unit 12 and protrudes from the outer surface of the compressor housing 10, and a lower curved pipe 28S that is joined to a lower suction pipe 104 (suction pipe 23) that is connected to the compression mechanism unit 12 and protrudes from the outer surface of the compressor housing 10.

[0016] As shown in FIGS. 1 to 3 , the assembly includes, from top to bottom, an upper end plate cover 170T having a dome-shaped bulge, an upper end plate 160T, an upper cylinder 121T, an intermediate partition plate 140, a lower cylinder 121S, a lower end plate 160S, and a flat lower end plate cover 170S. The assembly is formed as a stack of these components. The upper end plate cover 170T, the upper end plate 160T, the upper cylinder 121T, the intermediate partition plate 140, the lower cylinder 121S, the lower end plate 160S, and the lower end plate cover 170S are fixed together by a plurality of through bolts 174, 175 and auxiliary bolts 176 arranged approximately concentrically. The outer peripheral surface of the upper end plate 160T is fixed to the inner peripheral surface of the compressor housing 10 by welding, thereby fixing the integrated assembly to the compressor housing 10.

[0017] A main bearing 161T that is connected to the main shaft portion 153 of the shaft 15 is formed on the upper end plate 160T. A sub-bearing 161S that is connected to the sub-shaft portion 151 of the shaft 15 is formed on the lower end plate 160S. The main bearing 161T and the sub-bearing 161S position the rotational center axis O of the shaft 15 relative to the compressor casing 10. The main bearing 161T and the sub-bearing 161S support the shaft 15 so that it can rotate freely around the rotational center axis O. The main bearing 161T and the sub-bearing 161S are constituted by slide bearings.

[0018] An upper suction hole 135T is provided in the annular upper cylinder 121T. An upper suction pipe 105 is fitted into the upper suction hole 135T. A lower suction hole 135S is provided in the annular lower cylinder 121S. A lower suction pipe 104 is fitted into the lower suction hole 135S. An upper piston 125T is disposed in the upper cylinder chamber 130T of the upper cylinder 121T. A lower piston 125S is disposed in the lower cylinder chamber 130S of the lower cylinder 121S.

[0019] The upper cylinder 121T is provided with an upper vane groove 128T extending radially outward from the upper cylinder chamber 130T, and an upper vane 127T is disposed in the upper vane groove 128T. The lower cylinder 121S is provided with a lower vane groove 128S extending radially outward from the lower cylinder chamber 130S, and a lower vane 127S is disposed in the lower vane groove 128S.

[0020] Upper cylinder 121T has upper spring hole 124T formed in a position overlapping upper vane groove 128T from the outer surface, with a depth that does not penetrate into upper cylinder chamber 130T, and upper spring 126T is disposed in upper spring hole 124T. Lower cylinder 121S has lower spring hole 124S formed in a position overlapping lower vane groove 128S from the outer surface, with a depth that does not penetrate into lower cylinder chamber 130S, and lower spring 126S is disposed in lower spring hole 124S.

[0021] The upper cylinder chamber 130T is closed at its upper side by an upper end plate 160T and at its lower side by the intermediate partition plate 140. The lower cylinder chamber 130S is closed at its upper side by the intermediate partition plate 140 and at its lower side by a lower end plate 160S.

[0022] The upper cylinder chamber 130T is divided into an upper suction chamber 131T connected to the upper suction hole 135T and an upper compression chamber 133T connected to the upper discharge hole 190T provided in the upper end plate 160T when the upper vane 127T is pressed by the upper spring 126T and abuts against the outer peripheral surface of the upper piston 125T. The lower cylinder chamber 130S is divided into a lower suction chamber 131S connected to the lower suction hole 135S and a lower compression chamber 133S connected to the lower discharge hole 190S provided in the lower end plate 160S when the lower vane 127S is pressed by the lower spring 126S and abuts against the outer peripheral surface of the lower piston 125S.

[0023] The upper end plate 160T is provided with an upper discharge hole 190T that penetrates the upper end plate 160T and communicates with the upper compression chamber 133T of the upper cylinder 121T, and an annular upper valve seat (not shown) that surrounds the upper discharge hole 190T is formed on the outlet side of the upper discharge hole 190T. The upper end plate 160T is formed with an upper discharge valve accommodating recess 164T that extends in a groove shape from the position of the upper discharge hole 190T toward the outer periphery of the upper end plate 160T.

[0024] The upper discharge valve accommodating recess 164T accommodates the entire reed valve type upper discharge valve 200T and upper discharge valve holder 201T. The rear end of the upper discharge valve 200T is fixed in the upper discharge valve accommodating recess 164T by an upper rivet 202T, and with the rear part fixed, the front part moves up and down to open and close the upper discharge hole 190T. The rear end of the upper discharge valve holder 201T is overlapped with the upper discharge valve 200T and fixed in the upper discharge valve accommodating recess 164T by the upper rivet 202T, and the front part is curved (warped) in the direction in which the upper discharge valve 200T opens, thereby restricting the opening degree of the upper discharge valve 200T. The upper rivet 202T is fixed to the upper end plate 160T by being inserted into a rivet hole formed in the upper end plate 160T and crimped.

[0025] The lower end plate 160S is provided with a lower discharge hole 190S that penetrates the lower end plate 160S and communicates with the lower compression chamber 133S of the lower cylinder 121S. An annular lower valve seat that surrounds the lower discharge hole 190S is formed on the outlet side of the lower discharge hole 190S in the lower end plate 160S. The lower end plate 160S is formed with a lower discharge valve accommodating recess 164S that extends in a groove-like shape from the position of the lower discharge hole 190S toward the outer periphery of the lower end plate 160S. The upper surface of the lower end plate 160S is formed as a plane perpendicular to the central axis of rotation O.

[0026] The lower discharge valve accommodating recess 164S accommodates a reed valve-type lower discharge valve 200S and a lower discharge valve holder 201S. The rear end of the lower discharge valve 200S is fixed in the lower discharge valve accommodating recess 164S by a lower rivet 202S, and the front part opens and closes the lower discharge hole 190S by moving up and down with the rear part fixed. The rear end of the lower discharge valve holder 201S is overlapped with the lower discharge valve 200S and fixed in the lower discharge valve accommodating recess 164S by the lower rivet 202S, and the front part curves in the direction in which the lower discharge valve 200S opens, restricting the opening degree of the lower discharge valve 200S. The lower rivet 202S is inserted into a rivet hole 168 formed in the lower end plate 160S and crimped, thereby being fixed to the lower end plate 160S.

[0027] An upper end plate cover chamber 180T is formed between the upper end plate 160T and the upper end plate cover 170T, which have a dome-shaped bulge, and are fixed so as to be in close contact with each other. A lower end plate cover chamber 180S is formed between the lower end plate 160S and the flat lower end plate cover 170S, which are also fixed so as to be in close contact with each other. A refrigerant passage hole 136 is provided that passes through the lower end plate 160S, the lower cylinder 121S, the intermediate partition plate 140, the upper end plate 160T, and the upper cylinder 121T, and communicates between the lower end plate cover chamber 180S and the upper end plate cover chamber 180T.

[0028] As shown in FIGS. 1 to 3, the shaft 15 has a main shaft portion 153 connected to a main bearing portion 161T of the assembly, and a counter shaft portion 151 that is coaxial with the main shaft portion 153 and connected to a counter bearing portion 161S of the assembly below the main shaft portion 153. This allows the shaft 15 to be rotatably supported by the fixed assembly. The main shaft portion 153 is fitted into the main bearing portion 161T provided on the upper end plate 160T, thereby providing rotatable support and restricting movement of the main shaft portion 153 in the radial direction of the shaft 15. The counter shaft portion 151 is fitted into the counter bearing portion 161S provided on the lower end plate 160S, thereby providing rotatable support and restricting movement of the counter shaft portion 151 in the radial direction of the shaft 15. Of the two eccentric portions, the eccentric portion on the side of the auxiliary bearing portion 161S arranged at the bottom of the shaft 15 is the lower eccentric portion 152S, and the eccentric portion on the side of the main bearing portion 161T arranged at the top of the shaft 15 is the upper eccentric portion 152T.

[0029] Between the main shaft portion 153 and the counter shaft portion 151, an upper eccentric portion 152T and a lower eccentric portion 152S are formed, which are eccentric with respect to the rotation center axis O, which is the center of rotation of the shaft portion 153 and the counter shaft portion 151. The upper eccentric portion 152T is disposed within the upper cylinder chamber 130T. The lower eccentric portion 152S is disposed within the lower cylinder chamber 130S. The upper eccentric portion 152T and the lower eccentric portion 152S are separated from each other by an intermediate shaft portion 154. The intermediate shaft portion 154 connects the lower eccentric portion 152S and the upper eccentric portion 152T.

[0030] The upper eccentric portion 152T has a cylindrical surface that is eccentric in a first direction perpendicular to the rotational axis O of the main shaft portion 153 and the counter shaft portion 151. The lower eccentric portion 152S has a cylindrical surface that is eccentric in a second direction perpendicular to the rotational axis O of the main shaft portion 153 and the counter shaft portion 151 and opposite to the first direction. The upper eccentric portion 152T and the lower eccentric portion 152S are arranged with a phase difference of 180 degrees from each other. That is, the upper eccentric portion 152T and the lower eccentric portion 152S are disk-shaped portions that protrude in opposite directions from the rotational center (rotational axis O) of the shaft 15. The eccentric amounts of the lower eccentric portion 152S and the upper eccentric portion 152T are equal. An annular upper piston 125T is coaxially attached to the upper eccentric portion 152T. An annular lower piston 125S is coaxially attached to the lower eccentric portion 152S. Rotation of the shaft 15 allows the upper piston 125T to revolve along the inner circumferential surface of the upper cylinder 121T. Similarly, rotation of the shaft 15 allows the lower piston 125S to revolve along the inner circumferential surface of the lower cylinder 121S.

[0031] A thrust surface 40 is formed on the lower eccentric portion 152S. The thrust surface 40 is configured as a plane perpendicular to the central axis of rotation O. The thrust surface 40 is supported in the axial direction of the shaft 15 on the upper surface (thrust bearing surface 50) of the lower end plate 160S. The thrust surface 40 will be described in detail later.

[0032] Lubricating oil 18 is stored inside the compressor housing 10 in an amount that allows a portion of the compression mechanism 12 to be submerged. Note that, since FIG. 1 is a diagram for explaining the overall configuration of the rotary compressor 1, the oil level is not shown. Support legs 310 that support the entire rotary compressor 1 are joined to the lower part of the compressor housing 10. The rotary compressor 1 is fixed to the bottom plate of the outdoor unit via elastic support members (not shown) attached to the support legs 310.

[0033] As shown in FIGS. 4 and 5, the shaft 15 has a vertical oil feed hole 155 and a gas vent hole 158. The vertical oil feed hole 155 is a hollow portion that opens at the lower end side of the shaft 15 and extends along the central axis O of rotation of the shaft 15. The gas vent hole 158 is a hollow portion that opens at the upper end side of the shaft 15 and extends along the central axis O of rotation of the shaft 15. The lower end side of the gas vent hole 158 is connected to the upper end side of the vertical oil feed hole 155, and the vertical oil feed hole 155 communicates with the space above the shaft 15. An oil feed vane 159 shown in FIG. 4 is press-fitted into the vertical oil feed hole 155.

[0034] The horizontal oil-feed hole 156T has an opening at a position on the side surface of the shaft 15 that is positioned above the upper surface 1521T of the upper eccentric portion 152T, and is connected to the vertical oil-feed hole 155. The shaft 15 is also provided with a horizontal oil-feed hole 156S. The horizontal oil-feed hole 156S has an opening at a position on the side surface of the shaft 15 that is positioned below the lower surface 1522S (thrust surface 40) of the lower eccentric portion 152S, and is connected to the vertical oil-feed hole 155.

[0035] The shaft 15 is also provided with a horizontal oil-feed hole 157T. The horizontal oil-feed hole 157T has an opening at a position on a side surface of the shaft 15 facing the upper eccentric portion 152T with the vertical oil-feed hole 155 in between, and is in communication with the vertical oil-feed hole 155. The shaft 15 is also provided with a horizontal oil-feed hole 157S. The horizontal oil-feed hole 157S has an opening at a position on a side surface of the shaft 15 facing the lower eccentric portion 152S with the vertical oil-feed hole 155 in between, and is in communication with the vertical oil-feed hole 155. The horizontal oil-feed hole 157T is provided below the horizontal oil-feed hole 156T. The horizontal oil-feed hole 156S is provided below the horizontal oil-feed hole 157S. The horizontal oil-feed hole 157T and the horizontal oil-feed hole 157S are provided so that their openings face opposite positions across the vertical oil-feed hole 155.

[0036] The vertical oil feed hole 155 sucks up lubricating oil 18 from the lower end of the shaft 15 by the action of a centrifugal pump, which is generated by centrifugal force when the shaft 15 rotates. The lubricating oil 18 sucked up from the lower end of the vertical oil feed hole 155 passes through horizontal oil feed holes 156S, 157S, and 157T formed in the main shaft portion 153 of the shaft 15, overflows onto the outer circumferential surface of the shaft 15, and flows downward along the outer circumferential surface of the shaft 15, thereby being supplied to the main bearing portion 161T and sliding parts below the main bearing portion 161T. In addition, a spiral groove (not shown) is formed on the inner circumferential surface of the shaft hole 161T1 of the main bearing portion 161T, and this spiral groove is inclined so that its height gradually increases as it approaches the rotational direction R of the shaft 15. Lubricating oil 18 supplied to the outer peripheral surface of shaft 15 through horizontal oil feed hole 156T is sucked up by a spiral groove formed on the inner peripheral surface of shaft hole 161T1 of main bearing portion 161T of upper end plate 160T, and lubricating oil 18 is supplied to the sliding surface between main bearing portion 156T and shaft 15. In addition, the gaseous refrigerant sucked up into vertical oil feed hole 155 is discharged from the upper end of shaft 15 through gas vent hole 158.

[0037] The oil feed vanes 159 are fitted into the inner surface of the vertical oil feed hole 155, which is a hollow portion of the shaft 15. When the shaft 15 rotates, the oil feed vanes 159 rotate and press the lubricating oil 18 against the inner wall of the vertical oil feed hole 155. This makes it easier for the lubricating oil 18 to rise inside the vertical oil feed hole 155 due to centrifugal force. In other words, the vertical oil feed hole 155 can easily pump up the lubricating oil 18.

[0038] As shown in FIGS. 3 and 6, a lower surface 1522S that slides against the upper surface (thrust bearing surface 50) of the lower end plate 160S is formed on the lower end side of the lower eccentric portion 152S. The lower surface 1522S of the lower eccentric portion 152S corresponds to the thrust surface 40 in the first embodiment. The lower surface 1522S as the thrust surface 40 is formed as an end surface located lower than the portion of the lower eccentric portion 152S other than the lower surface 1522S (thrust surface 40). The thrust surface 40 is a plane perpendicular to the central axis of rotation O. In the rotary compressor 1 of this embodiment, the lower surface 1522S (thrust surface 40) of the lower eccentric portion 152S and the upper surface (thrust bearing surface 50) of the lower end plate 160S form a sliding surface that functions as a thrust bearing that supports a thrust load.

[0039] In the first embodiment, the single groove 41 is recessed toward the rotation center axis O (upward) and extends along the circumferential direction of the shaft 15. The groove 41 has a starting end 42 located forward in the rotation direction R of the shaft 15 and a terminal end 43 located rearward in the rotation direction R relative to the starting end 42. The starting end 42 of the groove 41 is connected to the outer peripheral side surface 1523S of the lower eccentric portion 152S on which the thrust surface 40 is formed. In other words, the starting end 42 of the groove 41 is formed as an open end. The terminal end 43 of the groove 41 is not connected to the outer peripheral side surface 1523S of the lower eccentric portion 152S on which the thrust surface 40 is formed. In other words, the terminal end 43 of the groove 41 is formed as a closed portion that is interrupted on the thrust surface 40.

[0040] When viewed from the direction of the rotation center axis O, the groove 41 is formed in an arc shape that convexly extends radially outward from the shaft 15. In Example 1, the groove 41 has an arc line that runs along the center of the width direction of the groove 41 (a direction perpendicular to the extension direction of the groove 41 when viewed from the direction along the rotation center axis O) and that has only a single radius of curvature, and the width of the groove 41 is constant throughout. In addition, when the line connecting the rotation center axis O and the starting end 42 of the groove 41 is defined as a first line L1, the line connecting the rotation center axis O and the terminal end 43 of the groove 41 is defined as a second line L2, and the angle formed by the first line L1 and the second line L2 is defined as an angle θ [rad], θ>π / 3…(Equation 1) In particular, in Example 1, the entire groove 41 is formed along an imaginary circle Ca whose center coincides with the central axis of rotation O. Here, when the length of the arc line Ar that connects the starting end 42 and the ending end 43 of the groove 41 and overlaps with the imaginary circle Ca is C1 [mm] and the circumferential length of this imaginary circle Ca is C2 [mm], C1>(C2) / 6…(Formula 2) It further satisfies the following.

[0041] As shown in FIG. 7, the area of ​​the thrust surface 40 that faces the upper surface (thrust bearing surface 50) of the lower end plate 160S in the direction along the rotation axis O is defined as a sliding area 44, and the area of ​​the thrust surface 40 that does not face the upper surface (thrust bearing surface 50) of the lower end plate 160S in the direction along the rotation axis O is defined as a non-sliding area 45. In this case, in Example 1, the entire groove portion 41 is located on the sliding area 44 of the thrust surface 40. Note that in FIG. 7, the sliding area 44 is defined as the range of the thrust surface 40 that is located outer circumferentially of the annular groove portion 51 of the thrust bearing surface 50 as viewed from the direction of the rotation axis O, and this sliding area 44 is indicated by diagonal lines. The annular groove portion 51 is an annular groove that is recessed downward from the upper surface (thrust bearing surface 50) of the lower end plate 160S, and will be described in detail below. In each embodiment, the annular groove portion 51 is formed at a position where, when viewed from the axial direction, the entire annular groove portion 51 overlaps with the non-slide region 45. In embodiment 1, the annular groove portion 51 is formed near the outer circumferential edge of the non-slide region 45 when viewed from the axial direction.

[0042] In the first embodiment, the groove portion 41 is formed at a position that does not overlap with the annular groove portion 51 on the upper surface (thrust bearing surface 50) of the lower end plate 160S when viewed from the axial direction. Specifically, the entire groove portion 41 is formed at a position that is radially outward of the annular groove portion 51 in the radial direction of the shaft 15 when viewed from the axial direction. Therefore, when the lower surface 1522S (thrust surface 40) of the lower eccentric portion 152S and the upper surface (thrust bearing surface 50) of the lower end plate 160S face each other, the space created by the groove portion 41 on the thrust surface 40 and the space created by the annular groove portion 51 on the upper surface (thrust bearing surface 50) are not integrated.

[0043] 4 to 6, a step 1524S is formed on the lower end side of the lower eccentric portion 152S. The step 1524S is an end surface formed so that the distance from an upper surface 1521S of the lower eccentric portion 152S to the step 1524S in the direction along the rotation central axis O is shorter than the distance from the upper surface 1521S to a lower surface 1522S (thrust surface 40) of the lower eccentric portion 152S. In other words, the lower surface 1522S (thrust surface 40) is formed as the end surface located at the lowest side of the lower eccentric portion 152S, whereas the step 1524S is formed as the end surface located above the lower surface 1522S of the lower eccentric portion 152S. Therefore, the step portion 1524S faces the lower end plate 160S in the direction of the rotation center axis O while being spaced apart from the lower end plate 160S, so that the step portion 1524S and the lower end plate 160S do not slide on each other. Furthermore, the step portion 1524S is disposed in the lower eccentric portion 152S at a position radially outward from the lower surface 1522S in the radial direction centered on the rotation center axis O.

[0044] [Lower end plate] Fig. 8 is a plan view of a lower end plate 160S of the rotary compressor 1 of the first embodiment, as viewed from above. As shown in Fig. 8, an upper surface (thrust bearing surface 50) of the lower end plate 160S is formed with a shaft hole 161S1, a lower discharge hole 190S, rivet holes 168, a refrigerant passage hole 136, a through-bolt hole 138 through which a through-bolt 175 is inserted, and an auxiliary bolt hole 167 through which an auxiliary bolt 176 is inserted. The shaft hole 161S1, the lower discharge hole 190S, the rivet holes 168, the refrigerant passage hole 136, the through-bolt hole 138, and the auxiliary bolt hole 167 all penetrate the lower end plate 160S in the direction of the rotation center axis O.

[0045] The lower end plate 160S has an annular groove 51 formed around the periphery of a shaft hole 161S1 formed in the center of the upper surface (thrust bearing surface 50). The annular groove 51 is a groove recessed downward from the upper surface (thrust bearing surface 50) and formed in an annular shape coaxial with the shaft hole 161S1. This makes the inner peripheral portion of the lower end plate 160S of the annular groove 51 more flexible, thereby elastically supporting the shaft 15. Note that the portion of the upper surface (thrust bearing surface 50) of the lower end plate 160S that is inner than the annular groove 51 is shallower than the portion outer than the annular groove 51, so that the portion inner than the annular groove 51 does not directly slide against the thrust surface 40 of the shaft 15. In other words, the portion of the upper surface (thrust bearing surface 50) of the lower end plate 160S that is outer than the annular groove 51 slides against the sliding region 44 of the thrust surface 40.

[0046] 9A and 9B are longitudinal cross-sectional views of the lower end plate 160S of the rotary compressor 1 of the first embodiment. As shown in FIGS. 9A and 9B, a spiral groove 166 is formed on the inner circumferential surface of the shaft hole 161S1 of the sub-bearing portion 161S, and the spiral groove 166 discharges the lubricating oil 18 from the upper end to the lower end of the shaft hole 161S1. The spiral groove 166 is inclined so that its height gradually decreases toward the rotation direction R of the shaft 15, and extends from the upper end to the lower end of the shaft hole 161S1 in the rotation direction R of the shaft 15. In other words, the spiral groove 166 is formed in a so-called spiral shape around the shaft 15.

[0047] [Driving behavior] Next, the flow of refrigerant caused by the rotation of the shaft 15 during operation of the rotary compressor 1 will be described. As the shaft 15 rotates, the upper piston 125T fitted to the upper eccentric portion 152T of the shaft 15 revolves around the inner circumferential surface of the upper cylinder 121T within the upper cylinder chamber 130T. As a result, the upper suction chamber 131T expands in volume while drawing in refrigerant from the upper suction pipe 105. The upper compression chamber 133T compresses the refrigerant while reducing its volume. When the pressure of the compressed refrigerant exceeds the pressure in the upper end plate cover chamber 180T outside the upper discharge valve 200T, the upper discharge valve 200T opens, and the refrigerant is discharged from the upper compression chamber 133T to the upper end plate cover chamber 180T. The refrigerant discharged into the upper end plate cover chamber 180T is discharged into the compressor housing 10 through the upper end plate cover discharge hole 172T (see FIG. 1) provided in the upper end plate cover 170T.

[0048] Furthermore, within the lower cylinder chamber 130S, as the shaft 15 rotates, the lower piston 125S fitted to the lower eccentric portion 152S of the shaft 15 revolves along the inner circumferential surface of the lower cylinder 121S, causing the lower suction chamber 131S to expand in volume and draw in refrigerant from the lower suction pipe 104, and the lower compression chamber 133S to compress the refrigerant while reducing its volume. When the pressure of the compressed refrigerant exceeds the pressure in the lower end plate cover chamber 180S outside the lower discharge valve 200S, the lower discharge valve 200S opens and the refrigerant is discharged from the lower compression chamber 133S to the lower end plate cover chamber 180S. The refrigerant discharged into the lower end plate cover chamber 180S passes through the refrigerant passage hole 136 and the upper end plate cover chamber 180T and is discharged into the compressor housing 10 from the upper end plate cover discharge hole 172T (see FIG. 1) provided in the upper end plate cover 170T.

[0049] The refrigerant discharged into the compressor housing 10 is guided above the motor 11 through a notch (not shown) on the outer periphery of the stator 111 that connects the top and bottom, or a gap (not shown) in the winding part of the stator 111, or a gap 115 (see Figure 1) between the stator 111 and the rotor 112, and is discharged from the discharge pipe 24 at the top of the compressor housing 10.

[0050] [Lubricant flow] Here, we will explain the flow of lubricating oil 18 during operation of rotary compressor 1. When shaft 15 rotates, the rotation of oil feed impeller 159 shown in Figure 4 causes lubricating oil 18 to be pumped up into vertical oil feed hole 155. The centrifugal force acting as a result of the rotation of shaft 15 causes lubricating oil 18 drawn into vertical oil feed hole 155 of shaft 15 to be discharged to the outside of shaft 15 through horizontal oil feed holes 156S, 157S, 156T, and 157T.

[0051] The lubricating oil 18 discharged through the horizontal oil supply holes 156S, 157S, 156T, and 157T enters the gaps between the metal components that make up the compression mechanism 12. Specifically, as shown in FIG. 3 , the lubricating oil 18 is supplied to the gaps between the shaft 15 and the end plates (middle partition plate 140, lower end plate 160S, and upper end plate 160T), the gaps between the shaft 15 and the pistons (lower piston 125S and upper piston 125T), the gaps between the end plates (140, 160S, and 160T) and the pistons (125S and 125T), and the gaps between the end plates (140, 160S, and 160T) and the cylinders (121S and 121T). In this way, the lubricating oil 18 enters the gaps between the metal components that make up the compression mechanism 12, thereby lubricating the components of the compression mechanism 12 and reducing sliding resistance. Furthermore, the compression mechanism 12, which becomes hot due to the sliding of the components of the compression mechanism 12, can be effectively cooled by the lubricating oil 18 that has entered the gaps between the components.

[0052] In particular, the lubricating oil 18 supplied to the gap between the shaft 15 and the lower end plate 160S and the lubricating oil 18 supplied to the gap between the shaft 15 and the lower cylinder 121S is drawn into the groove 41 via a starting end 42 disposed on the front side of the thrust surface 40 in the rotation direction R, as shown in FIGS. 6 and 7 , as the shaft 15 rotates. In the first embodiment, the starting end 42 of the groove 41 is formed to be connected to the outer peripheral side surface 1523S of the lower eccentric portion 152S. Therefore, the lubricating oil 18 present in the space on the outer peripheral side surface 1523S side, which is located on the front side of the lower eccentric portion 152S in the rotation direction R, can be smoothly drawn into the groove 41 from the starting end 42 as the shaft 15 rotates.

[0053] Then, as the shaft 15 rotates, the lubricating oil 18 drawn into the groove 41 moves circumferentially toward a terminal end 43 formed on the rear side in the rotation direction R. In this case, in the first embodiment, the terminal end 43 of the groove 41 is formed closed so as not to connect to the outer peripheral side surface 1523S of the lower eccentric portion 152S. Therefore, while the lubricating oil 18 drawn into the groove 41 moves toward the terminal end 43, the lubricating oil 18 receives a drag force from the inner wall of the groove 41 that is continuous with the terminal end 43 of the groove 41 and a pressure from the lubricating oil 18 newly flowing into the groove 41, and the internal pressure (oil pressure) of the lubricating oil 18 inside the groove 41 is increased. In other words, the oil pressure of the lubricating oil 18 drawn into the groove 41 is increased by the rotation of the shaft 15. Furthermore, the lubricating oil 18, whose oil pressure has been increased by the groove portion 41, seeps out from the groove portion 41 into the gap between the lower surface 1522S (thrust surface 40) of the lower eccentric portion 152S and the upper surface (thrust bearing surface 50) of the lower end plate 160S, thereby improving the performance of supplying the lubricating oil 18 to the sliding surfaces (40, 50) that constitute the thrust bearing.

[0054] Meanwhile, as shown in FIGS. 3 and 9A-9B, the lubricating oil 18 that has entered the gaps between the metal parts that make up the compression mechanism 12 flows under the influence of gravity into the upper end side of the spiral groove 166 in the gap between the inner peripheral surface of the shaft hole 161 in the lower end plate 160S and the outer peripheral surface of the countershaft portion 151 of the shaft 15. As the shaft 15 rotates, the lubricating oil 18 that has flowed into the spiral groove 166 is discharged from the upper end 166b to the lower end 166a of the shaft hole 161S1 along the inside of the spiral groove 166, and is stored in the lower part of the compressor housing 10. By replacing the lubricating oil 18 that lubricates the compression mechanism 12 in this way, the components of the compression mechanism 12 can be effectively cooled.

[0055] [Effects of Example 1] The rotary compressor 1 of the first embodiment includes a compression mechanism 12 having a shaft 15 supported for rotation about a rotation center axis O. The compression mechanism 12 includes an end plate (lower end plate 160S) having a thrust bearing surface 50. The thrust bearing surface 50 supports a thrust surface 40 (lower surface 1522S) formed at the lower end of a lower eccentric portion 152S of the shaft 15. A groove 41 is formed in the thrust surface 40 of the shaft 15. The groove 41 has a shape that increases the oil pressure of the lubricating oil 18 drawn into the groove 41 as the shaft 15 rotates. As a result, the oil pressure of the lubricating oil 18 drawn into the groove 41 increases as the shaft 15 rotates, and the lubricating oil 18 with increased oil pressure seeps out of the groove 41 between the thrust surface 40 and the upper surface (thrust bearing surface 50) of the lower end plate 160S, thereby improving the ability to supply lubricating oil to the sliding surface between the lower eccentric portion 152 and the lower end plate 160S.

[0056] Furthermore, thrust surface 40 is formed as an end surface of eccentric portion 152S on which thrust surface 40 is formed, located lower than the remaining portion of thrust surface 40, and is a flat surface perpendicular to central axis of rotation O. Therefore, planar thrust surface 40 is provided at a position closest to lower end plate 160S, and groove 41 is provided in thrust surface 40, so that thrust surface 40 can bear the thrust load in a distributed manner by the flat surface, and lubricating oil can be supplied by groove 41 between lower surface 1522S (thrust surface 40) of lower eccentric portion 152S and upper surface (thrust bearing surface 50) of lower end plate 160S, where the clearance is small and sliding resistance is likely to increase due to the close proximity of the flat surfaces.

[0057] Furthermore, the groove 41 has a starting end 42 located forward in the rotation direction of the shaft 15 and a terminal end 43 located rearward of the starting end 42 in the rotation direction of the shaft 15, and the lubricating oil 18 is drawn into the groove 41 from the starting end 42. As a result, the lubricating oil 18 drawn in from the starting end 42 moves toward the terminal end 43 due to the rotation of the shaft 15, and the oil pressure of the lubricating oil 18 is increased from the starting end 42 to the terminal end 43. Therefore, the groove 41 can function as a pressure-boosting mechanism that increases the oil pressure of the lubricating oil 18 due to the rotation of the shaft 15.

[0058] Furthermore, the groove 41 has a start end 42 formed as an open end that communicates with the outer peripheral side surface 1523S of the lower eccentric part 152S on which the thrust surface 40 is formed. This allows the lubricating oil 18 present in the space on the outer peripheral side surface 1523S side of the lower eccentric part 152S to be smoothly drawn into the start end 42 of the groove 41 as the shaft 15 rotates.

[0059] Furthermore, the groove 41 has a terminal end 43 formed as a closed portion that does not communicate with the outer peripheral side surface 1523S of the lower eccentric portion 152S on which the thrust surface 40 is formed. This allows the lubricating oil 18 drawn in from the starting end 42 of the groove 41 to be blocked by the terminal end 43. In other words, by forming the terminal end 43 of the groove 41 as a closed portion, it is possible to easily obtain a shape that increases the oil pressure of the lubricating oil 18 drawn into the groove 41 by the rotation of the shaft 15.

[0060] Here, we will explain the difference in ease of supply of lubricating oil 18 to thrust surface 40 depending on the length of groove 41 extending in the circumferential direction. As described above, when lubricating oil 18 is drawn from starting end 42 into groove 41 due to rotation of shaft 15, the oil pressure of this lubricating oil 18 increases. Then, the lubricating oil 18, whose oil pressure has been increased in groove 41, seeps out between thrust surface 40 of lower eccentric portion 152S and the upper surface (thrust bearing surface 50) of lower end plate 160S. In Example 1, starting end 42 of groove 41 is formed to be connected to outer peripheral side surface 1523S of lower eccentric portion 152S. Therefore, the flow path cross-sectional area A1 [m^2] of the inflow portion when lubricating oil 18 is drawn into groove 41 can be roughly approximated to the opening area of ​​the point where starting end 42 is connected to outer peripheral side surface 1523S of lower eccentric portion 152S.

[0061] Meanwhile, since the lubricating oil 18 seeps out from the groove 41 between the thrust surface 40 and the thrust bearing surface 50 over the range from the starting end 42 to the terminal end 43 of the groove 41, the flow path cross-sectional area A2 [m^2] of the outflow portion of the lubricating oil 18 drawn into the groove 41 can be approximated to the projected area of ​​the groove 41 projected along the direction of the rotation axis O onto an imaginary plane perpendicular to the rotation axis O. In other words, as the length of the groove 41 extending along the circumferential direction increases, the flow path cross-sectional area A1 [m^2] of the inflow portion to the groove 41 does not change, while the flow path cross-sectional area A2 [m^2] of the outflow portion from the groove 41 increases in accordance with the length of the groove 41 extending along the circumferential direction.

[0062] At this time, assuming that the internal space of groove 41 is the inside of a virtual sealed container, according to Pascal's principle acting on lubricating oil 18 in groove 41, the oil pressure p1 [Pa] of lubricating oil 18 at the inflow portion of groove 41 is equal to the oil pressure p2 [Pa] of lubricating oil 18 at the outflow portion of groove 41, i.e., p1 = p2 = p [Pa]. Furthermore, if the force applied to the inflow portion into groove 41 is F1 [N] and the force applied by lubricating oil 18 to the outflow portion from groove 41 (in other words, the force of lubricating oil 18 exuding from groove 41 to push thrust surface 40 upward in the direction of rotation central axis O) is F2 [N], then F1 = p1 × A1 = p × A1 [N] and F2 = p2 × A2 = p × A2 [N]. Therefore, since F1:F2 = (p × A1):(p × A2) = A1:A2, F1 × A2 = F2 × A1, or in other words, F2 = (A2 / A1) × F1[N].

[0063] In Example 1, the flow path cross-sectional area A2 [m^2] of the outflow portion from the groove 41 can be roughly approximated to the projected area of ​​the groove 41 projected along the rotation axis O onto an imaginary plane perpendicular to the rotation axis O, and the flow path cross-sectional area A1 [m^2] of the inflow portion to the groove 41 can be roughly approximated to the opening area of ​​the point where the starting end 42 connects to the outer peripheral side surface 1523S of the lower eccentric portion 152S. Therefore, A2 > A1 always holds, and (A2 / A1) > 1 is satisfied. Therefore, F2 = (A2 / A1) × F1 [N], and the force F2 of the lubricating oil 18 seeping out of the groove 41 pushing up the thrust surface 40 is amplified by the force F1 applied to the inflow portion of the groove 41 multiplied by (A2 / A1), which is the ratio of the flow path cross-sectional area of ​​the inflow portion to the flow path cross-sectional area of ​​the outflow portion of the groove 41. Therefore, when the force F1 applied to the inlet portion of the groove portion 41 is constant, the force F2 with which the lubricating oil 18 seeping out of the groove portion 41 pushes up the thrust surface 40 increases as the ratio (A2 / A1) of the flow path cross-sectional area of ​​the inlet portion of the groove portion 41 to the flow path cross-sectional area of ​​the outlet portion increases.

[0064] Therefore, in Example 1, in a cross section perpendicular to the rotation center axis O, when a line connecting the rotation center axis O and the starting end 42 of the groove portion 41 is defined as a first line L1, a line connecting the rotation center axis O and the terminal end 43 of the groove portion 41 is defined as a second line L2, and the angle formed by the first line L1 and the second line L2 is defined as an angle θ [rad], θ>π / 3…(Equation 1) is satisfied. This allows the circumferential length of the groove 41 extending from the starting end 42 to the terminal end 43 to be increased by more than a predetermined percentage, thereby increasing the flow path cross-sectional area A2 [m^2] of the outflow portion from the groove 41. As a result, the force F2 [N] with which the lubricating oil 18 flowing through the groove 41 pushes the thrust surface 40 of the lower eccentric portion 152S upward in the direction of the rotation center axis O can be increased. Therefore, the increased force F2 [N] can further expand the gap between the sliding surfaces of the thrust surface 40 and the thrust bearing surface 50. This makes it easier for the lubricating oil 18 to seep out from the groove 41 between the thrust surface 40 and the thrust bearing surface 50, improving the performance of supplying the lubricating oil 18 to the sliding surfaces (40, 50) that constitute the thrust bearing. Furthermore, the expanded gap between the sliding surfaces of the thrust surface 40 and the thrust bearing surface 50 can reduce sliding loss between the thrust surface 40 and the thrust bearing surface 50.

[0065] The inventors of the present invention indirectly measured using a prototype how the amount of lubricating oil 18 supplied to the thrust surface 40 increases depending on the length of extension of the groove 41 along the circumferential direction (the angle θ formed by the first straight line L1 and the second straight line L2), and found that when θ≦π / 3, the performance of supplying the lubricating oil 18 to the sliding surfaces (40, 50) that constitute the thrust bearing does not increase significantly. Therefore, in Example 1, the length of extension of the groove 41 along the circumferential direction is made long so as to satisfy the above-mentioned formula 1, thereby improving the performance of increasing the oil pressure of the lubricating oil 18.

[0066] Furthermore, groove 41 is formed in an arc shape that convexly extends radially outward from rotation axis O in a cross section perpendicular to rotation axis O. This allows lubricating oil 18 drawn into groove 41 from starting end 42 to reach terminal end 43 of groove 41 along the rotation direction as shaft 15 rotates, allowing lubricating oil 18 to be distributed over a wide area of ​​thrust surface 40.

[0067] Furthermore, in a cross section perpendicular to the rotation axis O, the entire groove 41 is formed along an imaginary circle Ca whose center coincides with the rotation axis O. This allows the lubricating oil 18 drawn into the groove 41 to smoothly reach the terminal end 43 of the groove 41 in the rotation direction as the shaft 15 rotates, and allows the lubricating oil 18 to be distributed over a wide area of ​​the thrust surface 40. Furthermore, in the machining process of forming the groove 41 on the thrust surface 40 of the lower eccentric portion 152S, a machining tool (not shown) such as a drill for forming the groove 41 is positioned at a position a distance R (the radius of the imaginary circle Ca) away from the rotation axis O, and the machining tool is rotated while the shaft 15 is rotated along the rotation axis O, thereby easily forming the groove 41.

[0068] Furthermore, the groove 41 has an arc line along the center of the width direction of the groove 41 (a direction perpendicular to the extension direction of the groove 41 when viewed from the direction along the rotation central axis O) formed with only a single radius of curvature, and the width of the groove 41 is constant throughout. As a result, in the machining step of forming the groove 41 on the thrust surface 40 of the lower eccentric part 152S, the groove 41 can be formed simply by moving a machining tool (not shown) such as a drill for forming the groove 41 along an arc with a single radius of curvature.

[0069] In addition, in a cross section perpendicular to the rotation center axis O, when the length of the arc line Ar (the arc line overlapping the imaginary circle Ca) connecting the starting end 42 and the ending end 43 of the groove 41 is C1 [mm] and the circumferential length of the imaginary circle Ca overlapping the arc line Ar is C2 [mm], C1>(C2) / 6…(Formula 2) This satisfies the above formula 1. With the entire groove 41 formed along a virtual circle Ca whose center coincides with the rotation axis O, the length of the groove 41 extending from the end 42 to the terminal end 43 can be increased by a predetermined percentage or more. This makes it possible to more efficiently increase the force F2 [N] with which the lubricating oil 18 flowing through the groove 41 pushes the thrust surface 40 of the lower eccentric portion 152S upward in the direction of the rotation axis O. This makes it easier for the lubricating oil 18 to seep out of the groove 41 between the thrust surface 40 and the thrust bearing surface 50, thereby improving the performance of supplying lubricating oil to the sliding surfaces (40, 50) that constitute the thrust bearing. Furthermore, the increased gap between the thrust surface 40 and the thrust bearing surface 50 reduces sliding loss between the thrust surface 40 and the thrust bearing surface 50.

[0070] Furthermore, when the region of the thrust surface 40 that faces the upper surface (thrust bearing surface 50) of the lower end plate 160S in the direction along the rotation center axis O is defined as the sliding region 44, at least the terminal end 43 of the groove 41 is located in the sliding region 44 of the thrust surface 40. This reduces the distance between the thrust surface 40 and the upper surface (thrust bearing surface 50) of the lower end plate 160S at the position of the terminal end 43 of the groove 41, preventing the space at the terminal end 43 of the groove 41 from becoming large and improving the performance of increasing oil pressure at the terminal end 43 of the groove 41. In the first embodiment, the entire groove 41 is located in the sliding region 44 of the thrust surface 40. This reduces the distance between the thrust surface 40 and the upper surface (thrust bearing surface 50) of the lower end plate 160S over the entire area from the starting end 42 to the terminal end 43 of the groove 41, thereby improving the ability to increase oil pressure over the entire area from the starting end 42 to the terminal end 43 of the groove 41. In other words, the ability to supply lubricating oil 18 to the thrust surface 40 can be improved.

[0071] Furthermore, an annular groove 51 extending circumferentially and forming an elastic bearing on the inner peripheral edge of the shaft hole 161S1 through which the shaft 15 is inserted is formed on the upper surface (thrust bearing surface 50) of the lower end plate 160S of the first embodiment. The groove 41 formed on the thrust surface 40 of the lower eccentric portion 152S is positioned so as not to overlap with the annular groove 51 forming the elastic bearing. Therefore, the groove 41 formed on the thrust surface 40 does not communicate with the annular groove 51 on the upper surface (thrust bearing surface 50) of the lower end plate 160S facing the thrust surface 40. Since the annular groove 51 and the groove 41 do not communicate with each other, it is possible to prevent the annular groove 51 and the groove 41 from connecting to each other and enlarging the groove space through which the lubricating oil 18 passes. This prevents the flow path from suddenly widening and reducing the pressure when the lubricating oil flows into the groove 41. As a result, it is possible to prevent the lubricating oil 18 drawn into the groove 41 from flowing into the annular groove 51 on the upper surface (thrust bearing surface 50) of the lower end plate 160S and being reduced in pressure. That is, even when the annular groove 51 for forming an elastic bearing is formed on the upper surface (thrust bearing surface 50) of the lower end plate 160S, it is possible to prevent the groove 41 on the thrust surface 40 from reducing the effect of increasing the oil pressure of the lubricating oil 18.

[0072] [Example 2] 10 is a plan view illustrating a thrust surface 40 of a rotary compressor 1 of Example 2. The rotary compressor 1 of Example 2 differs from Example 1 in that the length of the groove portion 41 formed on the thrust surface 40 extending along the imaginary circle Ca is shorter than that of Example 1. In Example 2, a description of the contents common to Example 1 will be omitted.

[0073] In the rotary compressor 1 of the second embodiment, the groove 41 is formed such that, in a cross section perpendicular to the rotation axis O, the length of the arc line Ar (the arc line overlapping the imaginary circle Ca) connecting the start end 42 and the end end 43 of the groove 41 is C1 [mm] and the circumferential length of the imaginary circle Ca overlapping the arc line Ar is C2 [mm]. In the groove 41 of the second embodiment, the length C1 of the arc line Ar (in other words, the length of the groove 41 extending from the start end 42 to the end end 43) is short at approximately (C2) / 8. Therefore, the force F2 [N] with which the lubricating oil 18 drawn from the start end 42 into the groove 41 pushes the thrust surface 40 of the lower eccentric portion 152S upward in the direction of the rotation axis O is smaller than that in the first embodiment. However, the processing cost for forming the groove 41 can be reduced.

[0074] The rotary compressor 1 of the second embodiment also includes a compression mechanism 12 having a shaft 15 supported for rotation about a central rotation axis O. The compression mechanism 12 includes an end plate (lower end plate 160S) having a thrust bearing surface 50. The upper surface of the lower end plate 160S, which serves as the thrust bearing surface 50, supports a thrust surface 40 formed on the lower end of a lower eccentric portion 152S of the shaft 15. A groove 41 is formed on the thrust surface 40 of the lower eccentric portion 152S. The groove 41 has a shape that increases the oil pressure of the lubricating oil 18 drawn into the groove 41 as the shaft 15 rotates. As a result, the oil pressure of the lubricating oil 18 drawn into the groove portion 41 increases due to the rotation of the shaft 15, and the lubricating oil 18 with increased oil pressure seeps out from the groove portion 41 between the thrust surface 40 and the upper surface (thrust bearing surface 50) of the lower end plate 160S, thereby allowing sufficient lubricating oil to be supplied to the sliding surface between the lower eccentric portion 152 and the lower end plate 160S.

[0075] [Example 3] 11 is a plan view illustrating a thrust surface 40 of a rotary compressor 1 of a third embodiment. The rotary compressor 1 of the third embodiment differs from the rotary compressor 1 of the first embodiment in that, when viewed from the direction of the central axis of rotation O, grooves 41 formed on the thrust surface 40 are formed along the circumference of an imaginary circle Cb whose center is eccentric from the central axis of rotation O of the shaft 15. In the third embodiment, the grooves 41 are formed along the circumference of an imaginary circle Ca whose center coincides with the central axis of rotation O. In the third embodiment, a description of the same content as in the first embodiment will be omitted.

[0076] In the rotary compressor 1 of the third embodiment, when the distance from the rotation center axis O to the starting end 42 is a [mm] and the distance from the rotation center axis O to the terminal end 43 is b [mm] in a plane perpendicular to the rotation center axis O, a≦b…(Formula 3) is satisfied. As a result, the starting end 42 is located radially inward of the terminal end 43 in the radial direction around the rotation center axis O, and as the lubricating oil 18 drawn from the starting end 42 into the groove 41 flows along the extension direction of the groove 41, centrifugal force acts on the lubricating oil 18. Therefore, the centrifugal force makes it easier for the lubricating oil 18 to seep out to the thrust surface 40, which is located radially outward of the groove 41 in the radial direction around the rotation center axis O. In this way, by satisfying formula 3, in addition to the effect of increasing the oil pressure of the lubricating oil 18 drawn into the groove 41, the effect of the centrifugal force acting on the lubricating oil 18 flowing along the groove 41 can be simultaneously obtained.

[0077] In FIG. 11 , the area of ​​the thrust surface 40 that is located on the outer periphery of the annular groove 51 of the thrust bearing surface 50 as viewed from the direction of the rotation center axis O is designated as a sliding region 44, and this sliding region 44 is indicated by diagonal lines. As shown in FIG. 11 , in the rotary compressor 1 of the third embodiment, when the sliding region 44 is the region of the thrust surface 40 that faces the upper surface (thrust bearing surface 50) of the lower end plate 160S in the direction along the rotation center axis O, at least the terminal end 43 of the groove 41 is positioned so as to overlap with the sliding region 44 of the thrust surface 40 as viewed from the rotation center axis O. This reduces the distance between the thrust surface 40 and the upper surface (thrust bearing surface 50) of the lower end plate 160S at the terminal end 43 of the groove 41, thereby improving the ability to increase hydraulic pressure at the terminal end 43 of the groove 41. That is, the ability to supply lubricating oil 18 to the thrust surface 40 is improved.

[0078] In the rotary compressor 1 of the third embodiment, the start end 42 of the groove 41 is formed at a position overlapping the non-sliding region 45. This allows the lubricating oil 18 to be drawn into the groove 41 from a space on the inner circumferential side of the sliding region 44 by centrifugal force.

[0079] The upper surface (thrust bearing surface 50) of the lower end plate 160S of the third embodiment also has an annular groove 51 that extends circumferentially and forms an elastic bearing on the inner peripheral edge around the shaft hole 161S1 through which the shaft 15 is inserted. On the other hand, the groove 41 formed on the thrust surface 40 faces the annular groove 51 only near the starting end 42, and most of the groove 41 does not face the annular groove 51. This prevents the groove 41 and the annular groove 51 from joining together to form a large space, and prevents the lubricating oil 18 drawn into the groove 41 from being significantly depressurized.

[0080] Furthermore, in the groove 41 of Example 3, an arc line along the center of the width direction of the groove 41 (a direction perpendicular to the extension direction of the groove 41 when viewed from the direction along the rotation central axis O) is formed with only a single radius of curvature, and the width of the groove 41 is constant throughout. As a result, in the machining step of forming the groove 41 on the thrust surface 40 of the lower eccentric part 152S, the groove 41 can be formed simply by moving a machining tool (not shown) such as a drill for forming the groove 41 along an arc with a single radius of curvature.

[0081] Furthermore, in a cross section perpendicular to the rotation axis O, the entire groove 41 is formed along an imaginary circle Cb whose center does not coincide with the rotation axis O. Specifically, in Example 3 shown in FIG. 11 , when the thrust surface 40 is partitioned by a straight line L3 connecting the rotation axis O and the center P of the lower eccentric portion 152S in a cross section perpendicular to the rotation axis O, the center of the imaginary circle Cb is located on a side of the thrust surface 40 partitioned by L3 that is different from the side on which the starting end 42 is formed. This makes it possible to easily realize a structure that satisfies the above-mentioned formula 3 even with a simple manufacturing method in which a machining tool (not shown) such as a drill for forming the groove 41 moves along an arc with a single radius of curvature.

[0082] [Example 4] 12 is a plan view illustrating a thrust surface 40 of a rotary compressor 1 of a fourth embodiment. The rotary compressor 1 of the fourth embodiment differs from the first embodiment in that the groove width W of the groove 41 formed on the thrust surface 40 decreases from a starting end 42 to a terminal end 43 of the groove 41, which is a constant groove width W. Here, the groove width W of the groove 41 in the fourth embodiment refers to the length of the groove 41 along the radial direction of the shaft 15. In the fourth embodiment, a description of the same content as in the first embodiment will be omitted.

[0083] In the rotary compressor 1 of the fourth embodiment, the groove width W of the groove 41 formed on the thrust surface 40 gradually decreases from the starting end 42 to the terminal end 43 of the groove 41. This makes it easy to realize a shape in which the flow path cross-sectional area of ​​the groove 41 gradually decreases. In other words, it is easy to realize a shape in which the groove 41 increases the oil pressure of the lubricating oil 18 as the shaft 15 rotates. Note that the flow path cross-sectional area of ​​the groove 41 here refers to the cross-sectional area of ​​the groove 41 in a cross section perpendicular to the direction in which the groove 41 extends (the circumferential direction).

[0084] [Example 5] 13 is a plan view illustrating the thrust surface 40 of the rotary compressor 1 of the fifth embodiment. The rotary compressor 1 of the fifth embodiment differs from the fourth embodiment in that the terminal end 43 of the groove 41 formed on the thrust surface 40 is connected to the outer peripheral side surface 1523S of the lower eccentric portion 152S (in other words, the terminal end 43 of the groove 41 is not interrupted on the thrust surface 40). In the fifth embodiment, a description of the contents common to the first embodiment will be omitted.

[0085] In the rotary compressor 1 of the fifth embodiment, the groove width W of the groove 41 formed on the thrust surface 40 gradually decreases from the starting end 42 to the terminal end 43 of the groove 41. This makes it easy to realize a shape in which the flow path cross-sectional area of ​​the groove 41 gradually decreases. In other words, it is easy to realize a shape in which the groove 41 increases the oil pressure of the lubricating oil 18 as the shaft 15 rotates. Note that the flow path cross-sectional area of ​​the groove 41 here refers to the cross-sectional area of ​​the groove 41 in a cross section perpendicular to the direction in which the groove 41 extends (the circumferential direction).

[0086] In the rotary compressor 1 of Example 5, the terminal end 43 of the groove 41 formed on the thrust surface 40 is connected to the outer peripheral side surface 1523S of the lower eccentric portion 152S, so the performance of the groove 41 in increasing the oil pressure of the lubricating oil 18 is lower than in Example 4, in which the terminal end 43 is not connected to the outer peripheral side surface 1523S of the lower eccentric portion 152S. On the other hand, the flow path cross-sectional area of ​​the groove 41 gradually decreases from the starting end 42 to the terminal end 43, so the flow path cross-sectional area of ​​the groove 41 at the terminal end 43 is kept smaller than the flow path cross-sectional area of ​​the groove 41 at the starting end 42. Therefore, compared to when the flow path cross-sectional area of ​​the groove 41 is constant, the performance in increasing the oil pressure is prevented from decreasing in Example 4. In addition, in Example 5, the terminal end 43 of the groove portion 41 formed on the thrust surface 40 is connected to the outer peripheral side surface 1523S of the lower eccentric portion 152S, so that the lubricating oil 18 can be supplied over a wide area on the thrust surface 40.

[0087] [Example 6] 14 is a plan view illustrating a thrust surface 40 of a rotary compressor 1 of a sixth embodiment. The rotary compressor 1 of the sixth embodiment differs from the first embodiment in that the groove height H, which is the height of the groove 41 formed on the thrust surface 40, decreases from the starting end 42 to the terminal end 43 of the groove 41. Here, the groove height H of the groove 41 in the sixth embodiment refers to the length of the groove 41 along the central axis O of rotation of the shaft 15. In the sixth embodiment, a description of the same content as in the first embodiment will be omitted.

[0088] In the rotary compressor 1 of the sixth embodiment, the groove height H of the groove 41 formed on the thrust surface 40 gradually decreases from the starting end 42 to the terminal end 43 of the groove 41. This makes it easy to realize a shape in which the flow path cross-sectional area of ​​the groove 41 gradually decreases. In other words, it is easy to realize a shape in which the groove 41 increases the oil pressure of the lubricating oil 18 as the shaft 15 rotates. Note that the flow path cross-sectional area of ​​the groove 41 here refers to the cross-sectional area of ​​the groove 41 in a cross section perpendicular to the direction in which the groove 41 extends (the circumferential direction).

[0089] [Example 7] 15 is a plan view illustrating the thrust surface 40 of the rotary compressor 1 of the seventh embodiment. The rotary compressor 1 of the seventh embodiment has a plurality of grooves 41 formed on the thrust surface 40, which is different from the rotary compressor 1 of the first embodiment that has only one groove 41. Here, in the seventh embodiment, a description of the contents common to the first embodiment will be omitted.

[0090] In the rotary compressor 1 of the seventh embodiment, a plurality of grooves 41 having different starting ends 42 are formed on the thrust surface 40. Specifically, the grooves 41 in the seventh embodiment include four grooves 41A, 41B, 41C, and 41D.

[0091] The first groove 41A in Example 7 is formed similarly to the groove 41 in Example 2. That is, in a cross section perpendicular to the central axis of rotation O, the first groove 41A is formed such that C1≈(C2) / 8, where C1 [mm] is the length of the arc line Ar connecting the starting end 42A and the ending end 43A of the first groove 41A (the arc line overlapping the imaginary circle Ca) and C2 [mm] is the circumferential length of the imaginary circle Ca overlapping the arc line Ar. The first groove portion 41A has a short length C1 of the arc line Ar (in other words, the length C1 of the first groove portion 41A extending from the starting end 42A toward the terminal end 43A), which is approximately C1≈((C2) / 8. Therefore, the force F2 [N] with which the lubricating oil 18 drawn from the starting end 42A into the first groove portion 41A pushes the thrust surface 40 of the lower eccentric portion 152S upward in the direction of the rotation central axis O is weaker than in Example 1. Therefore, Example 7 further includes, in addition to the above-described first groove portion 41A, a second groove portion 41B, a third groove portion 41C, and a fourth groove portion 41D whose starting ends 42 are different from one another.

[0092] For example, in a plane perpendicular to the rotation axis O, when the distance from the rotation axis O to the starting end 42B is a [mm] and the distance from the rotation axis O to the terminal end 43B is b [mm], the second groove portion 41B has the following dimensions: a≦b…(Formula 3) As a result, the starting end 42B of the second groove 41B is located radially inward of the ending end 43B in the radial direction around the rotation axis O. Therefore, centrifugal force acts on the lubricating oil 18 as the lubricating oil 18 drawn from the starting end 42B into the groove 41B flows along the extension direction of the groove 41B. Therefore, the centrifugal force makes it easier for the lubricating oil 18 to seep out to the thrust surface 40, which is located radially outward of the groove 41B in the radial direction around the rotation axis O. In this way, by satisfying Equation 3, in addition to the effect of increasing the oil pressure of the lubricating oil 18 drawn into the groove 41B, the effect of the centrifugal force acting on the lubricating oil 18 flowing along the groove 41B can be simultaneously obtained. Similar effects can be obtained for the third groove 41C and the fourth groove 41D.

[0093] Furthermore, when the region of thrust surface 40 that faces the upper surface (thrust bearing surface 50) of lower end plate 160S in the axial direction along rotation center axis O is defined as sliding region 44, terminal end 43B of groove 41B is positioned so as to overlap sliding region 44 when viewed from rotation center axis O. This reduces the distance between thrust surface 40 and the upper surface (thrust bearing surface 50) of lower end plate 160S at the position of terminal end 43B of groove 41B, thereby improving the ability to increase oil pressure at terminal end 43B of groove 41B and, as a result, improving the ability to supply lubricating oil 18 to thrust surface 40.

[0094] [Example 8] 16 is a plan view illustrating a thrust surface 40 of a rotary compressor 1 of an eighth embodiment. The rotary compressor 1 of the eighth embodiment differs from the seventh embodiment in that, among the plurality of grooves 41 formed on the thrust surface 40 in the seventh embodiment, the first groove 41A connected to the outer peripheral side surface 1523S of the eccentric portion 152S is replaced with two grooves that are not connected to the outer peripheral side surface 1523S of the eccentric portion 152S. Here, a description of the contents of the eighth embodiment that are common to the first and seventh embodiments will be omitted.

[0095] In the rotary compressor 1 of the eighth embodiment, a plurality of grooves 41 having different starting ends 42 are formed on the thrust surface 40. Specifically, the grooves 41 in the eighth embodiment include five grooves 41A, 41B, 41C, 41D, and 41E. The starting ends 42 of the five grooves 41A, 41B, 41C, 41D, and 41E are not connected to the outer peripheral side surface 1523S of the eccentric portion 152S, and therefore the ability to draw the lubricating oil 18 into each groove 41 is weaker than in the first embodiment. However, because centrifugal force acts on the lubricating oil 18 drawn into each groove 41, in addition to the effect of increasing the hydraulic pressure of the lubricating oil 18 drawn into each groove 41, the effect of the centrifugal force acting on the lubricating oil 18 flowing along each groove 41 can be simultaneously obtained.

[0096] [Refrigeration cycle equipment] Figure 17 is a refrigerant circuit diagram showing a refrigeration cycle apparatus equipped with a rotary compressor 1 of the present invention. In this embodiment, the refrigeration cycle apparatus is applied to an air conditioner 2 that cools and heats a room. The air conditioner 2 includes an outdoor unit 3 and an indoor unit 4. The outdoor unit 3 includes a compressor (rotary compressor 1), flow path switching means (four-way valve 5), an outdoor heat exchanger 6, pressure reduction means (expansion valve 7), an outdoor blower 31, and an outdoor unit control unit 32. The indoor unit 4 includes an indoor heat exchanger 8, an indoor blower 35, and an indoor unit control unit 36. The outdoor unit 3 and the indoor unit 4 are connected to each other by refrigerant piping 9 (pipes 9a, 9b, 9c, 9d, 9e) to form a refrigerant circuit.

[0097] The rotary compressor 1 includes a discharge pipe 24 as a discharge portion, a suction pipe 23 as a suction portion, and an accumulator 25. The accumulator 25 separates the refrigerant sucked through an accumulator suction pipe 27 into gas and liquid refrigerants, and supplies the gaseous refrigerant to the suction pipe 23 via a gas-liquid separation pipe 28. The rotary compressor 1 is controlled by the outdoor unit control unit 32 to compress the refrigerant supplied via the four-way valve 5 and the suction pipe 23, and supplies the compressed refrigerant to the four-way valve 5 via the discharge pipe 24.

[0098] The four-way valve 5 is a switching valve (flow path switching means) that switches the flow direction of the refrigerant circulating through the refrigerant circuit, and has four ports a, b, c, and d. Port a is connected to the discharge pipe 24 of the rotary compressor 1 via pipe 9a. Port b is connected to one refrigerant inlet / outlet side of the outdoor heat exchanger 6 via pipe 9b. Port c is connected to the accumulator suction pipe 27 of the accumulator 25 via pipe 9c. Port d is connected to one refrigerant inlet / outlet side of the indoor heat exchanger 8 via pipe 9d. The four-way valve 5 switches the refrigerant flow direction by the outdoor unit control unit 32 when the air conditioner 2 is operating in heating mode or cooling mode. The four-way valve 5 is controlled by the outdoor unit control unit 32 to switch the air conditioner 2 between heating mode and cooling mode.

[0099] When switched to the cooling mode, the four-way valve 5 supplies the refrigerant discharged from the rotary compressor 1 to the outdoor heat exchanger 6 via the discharge pipe 24, and supplies the refrigerant flowing out from the indoor heat exchanger 8 to the rotary compressor 1 via the suction pipe 23. When switched to the heating mode, the four-way valve 5 supplies the refrigerant discharged from the rotary compressor 1 to the indoor heat exchanger 8 via the discharge pipe 24, and supplies the refrigerant flowing out from the outdoor heat exchanger 6 to the rotary compressor 1 via the suction pipe 23.

[0100] The outdoor heat exchanger 6 is connected to the expansion valve 7 via a refrigerant pipe 9b. An outdoor blower 31 is disposed near the outdoor heat exchanger 6. The outdoor blower 31 is driven by a motor (not shown) to take in outside air into the outdoor unit 3 and release the outside air that has exchanged heat with the refrigerant in the outdoor heat exchanger 6 to the outside of the outdoor unit 3. The outdoor heat exchanger 6 functions as a condenser in the cooling mode and as an evaporator in the heating mode. In the cooling mode, the outdoor heat exchanger 6 exchanges heat between the refrigerant supplied from the four-way valve 5 and the outside air taken into the outdoor unit 3, and supplies the refrigerant after this heat exchange to the expansion valve 7. In the heating mode, the outdoor heat exchanger 6 exchanges heat between the refrigerant supplied from the expansion valve 7 and the outside air taken into the outdoor unit 3, and supplies the refrigerant after this heat exchange to the four-way valve 5.

[0101] The expansion valve 7 is connected to the indoor heat exchanger 8 via a refrigerant pipe 9. In the cooling mode, the expansion valve 7 reduces the pressure of the refrigerant supplied from the outdoor heat exchanger 6 by adiabatic expansion, and supplies the low-temperature, low-pressure two-phase refrigerant to the indoor heat exchanger 8. In the heating mode, the expansion valve 7 reduces the pressure of the refrigerant supplied from the indoor heat exchanger 8 by adiabatic expansion, and supplies the low-temperature, low-pressure two-phase refrigerant to the outdoor heat exchanger 6. Furthermore, the opening degree of the expansion valve 7 is adjusted by control of the outdoor unit control unit 32. In the cooling mode, the expansion valve 7 adjusts the flow rate of refrigerant supplied from the outdoor heat exchanger 6 to the indoor heat exchanger 8. In the heating mode, the expansion valve 7 adjusts the flow rate of refrigerant supplied from the indoor heat exchanger 8 to the outdoor heat exchanger 6.

[0102] The indoor unit 4 has an indoor heat exchanger 8, an indoor fan 35, and an indoor unit control unit 36. The indoor fan 35 is disposed near the indoor heat exchanger 8, and is driven to rotate by a motor (not shown), thereby drawing indoor air into the indoor unit 4 and releasing the indoor air that has exchanged heat with the refrigerant in the indoor heat exchanger 8 into the room.

[0103] The indoor heat exchanger 8 is connected to the four-way valve 5 via piping 9d and to the expansion valve 7 of the outdoor unit 3 via piping 9e. The indoor heat exchanger 8 functions as an evaporator in cooling mode and as a condenser in heating mode. That is, in cooling mode, the indoor heat exchanger 8 exchanges heat between the low-temperature, low-pressure two-phase refrigerant supplied from the expansion valve 7 and the indoor air taken into the indoor unit 4, releases the heat-exchanged indoor air into the room, and supplies the heat-exchanged refrigerant to the four-way valve 5. In heating mode, the indoor heat exchanger 8 exchanges heat between the refrigerant supplied from the four-way valve 5 and the indoor air taken into the indoor unit 4, releases the heat-exchanged indoor air into the room, and supplies the heat-exchanged refrigerant to the expansion valve 7.

[0104] In the air conditioner 2, which is a refrigeration cycle apparatus of the present invention, the compression mechanism 12 of the rotary compressor 1 is provided with an end plate (lower end plate 160S) having a thrust bearing surface 50. The thrust bearing surface 50 supports a thrust surface 40 (lower surface 1522S) formed at the lower end of a lower eccentric portion 152S of a shaft 15, and a groove 41 is formed in the thrust surface 40. The groove 41 has a shape that increases the oil pressure of the lubricating oil 18 drawn into the groove 41 as the shaft 15 rotates. As a result, the oil pressure of the lubricating oil 18 drawn into the groove 41 increases as the shaft 15 rotates, and the lubricating oil 18 with increased oil pressure seeps out of the groove 41 between the thrust surface 40 and the upper surface (thrust bearing surface 50) of the lower end plate 160S, thereby improving the ability to supply the lubricating oil 18 to the sliding surface between the lower eccentric portion 152 and the lower end plate 160S. Therefore, it is possible to eliminate the shortage of lubricating oil 18 to the thrust bearings, particularly when the air conditioning device 2 is operated in a low outdoor temperature environment where the wear resistance of the thrust bearings (40, 50) is required to be high, or when the rotary compressor 1 is operated at a low rotation speed, which makes it difficult to supply lubricating oil 18 to the thrust bearings.

[0105] Although the rotary compressor 1 in this embodiment is a so-called two-cylinder rotary compressor having two cylinders, it may also be applied to a one-cylinder rotary compressor. Also, although the rotary compressor 1 in this embodiment is a so-called rolling piston type rotary compressor in which the piston 125 (upper piston 125T or lower piston 125S) and the vane 127 (upper vane 127T or lower vane 127S) are formed separately, it may also be applied to a rotary compressor in which the piston 125 and the vane 127 are formed integrally. [Explanation of symbols]

[0106] 1 Rotary compressor 2. Air conditioning equipment 3 Outdoor unit 4 Indoor unit 5. Four-way valve (flow path switching means) 6 Outdoor heat exchanger 7 Expansion valve (pressure reducing means) 8 Indoor heat exchanger 9 Refrigerant piping 10 Compressor housing 11 Motor 12 Compression mechanism 15 shaft 18 Lubricating oil 23 Suction pipe 24 Discharge pipe 27 Accumulator suction pipe 28 Gas-liquid separation tube 31 Outdoor blower 32 Outdoor unit control unit 35 Indoor fan 36 Indoor unit control unit 40 Thrust surface 41 Groove 42 Starting end 43 Termination 44 Sliding Area 45 Non-sliding area 50 Upper surface (thrust bearing surface) 51 Annular groove 104 Lower suction pipe 105 Upper suction pipe 111 Stator 112 rotor 121S Lower Cylinder 121T upper cylinder 124S Lower spring hole 124T upper spring hole 125S Lower Piston (Piston) 125T upper piston 126S Lower spring 126T upper spring 127S Lower Vane 127T Upper vane 128S Lower vane groove 128T Upper vane groove 130S Lower cylinder chamber 130T Upper cylinder chamber 131S Lower suction chamber 131T upper suction chamber 133S Lower Compression Chamber 133T upper compression chamber 135S Lower suction hole 135T upper suction hole 136 Refrigerant passage hole 138 Bolt holes 140 Intermediate partition plate (end plate) 151 Secondary shaft part 152S lower eccentric part 1521S top surface 1522S bottom side 1523S outer circumferential side 152T upper eccentric part 153 Main shaft section 154 Intermediate shaft 155 Hollow part 159 Refueling vane 160S Lower end plate (end plate) 160T Upper end plate (end plate) 161S Secondary bearing part 161S1 Shaft hole 161T Main bearing part 164S Lower discharge valve housing recess 164T Upper discharge valve accommodation recess 166 Spiral groove 167 Auxiliary bolt hole 168 rivet holes 170S Lower end plate cover 170T Upper end plate cover 174, 175 through bolt 176 Auxiliary bolt 180S Lower end plate cover chamber 180T Upper end plate cover chamber 190S lower discharge hole 190T upper discharge hole 200S Lower Discharge Valve 200T upper discharge valve 201S Lower discharge valve holder 201T Upper discharge valve holder 202S Lower rivet 202T Upper rivet 310 Mounting leg a, b, c, d ports Ca, Cb virtual circle O Rotational axis (rotation axis)

Claims

1. a compression mechanism having a shaft supported rotatably about a rotation axis; the compression mechanism portion includes an end plate having a thrust bearing surface that supports a thrust surface of the shaft, a groove is formed on the thrust surface; the groove portion has a shape that increases the oil pressure of the lubricating oil drawn into the groove portion by rotation of the shaft, The groove portion has a start end portion located on the front side in the rotation direction of the shaft and a terminal end portion located on the rear side of the start end in the rotation direction of the shaft, and lubricating oil is drawn from the start end portion into the groove portion by rotation of the shaft, The groove portion has a starting end formed as an open end connected to the outer peripheral side surface of the eccentric portion on which the thrust surface is formed. Rotary compressor.

2. the thrust surface is formed as an end surface of the eccentric portion on which the thrust surface is formed, the end surface being located lower than a portion other than the thrust surface, and is a plane perpendicular to the rotation axis.

2. The rotary compressor according to claim 1, wherein:

3. the terminal end of the groove is not connected to the outer peripheral side surface of the eccentric portion on which the thrust surface is formed; 2. The rotary compressor according to claim 1, wherein:

4. In a cross section perpendicular to the rotation axis, a line connecting the rotation axis and the starting end of the groove portion is defined as a first line L1, a line connecting the rotation axis and the terminal end of the groove portion is defined as a second line L2, and the angle formed by the first line L1 and the second line L2 is defined as an angle θ [rad]. θ>π / 3 (Equation 1) 2. The rotary compressor according to claim 1, wherein the following is satisfied:

5. In a cross section perpendicular to the rotation shaft, the groove portion is formed in an arc shape that is convex outward in the radial direction of the rotation shaft.

2. The rotary compressor according to claim 1, wherein:

6. In a cross section perpendicular to the rotation axis, the groove portion is formed so that the entire groove portion is formed along a virtual circle whose center coincides with the rotation axis.

2. The rotary compressor according to claim 1, wherein:

7. In a cross section perpendicular to the rotation axis, an arc line passing through the center of the groove in the width direction has a single radius of curvature, and the width of the groove is constant throughout.

2. The rotary compressor according to claim 1, wherein:

8. In a cross section perpendicular to the rotation axis, when the length of the arc line connecting the starting end and the ending end of the groove portion is C1 [mm] and the circumferential length of a virtual circle overlapping the arc line is C2 [mm], C1>(C2) / 6...(Formula 2) 8. The rotary compressor according to claim 7, wherein the following is satisfied:

9. a compression mechanism having a shaft supported rotatably about a rotation axis; the compression mechanism portion includes an end plate having a thrust bearing surface that supports a thrust surface of the shaft, a groove is formed on the thrust surface; the groove portion has a shape that increases the oil pressure of the lubricating oil drawn into the groove portion by rotation of the shaft, The groove portion has a start end portion located on the front side in the rotation direction of the shaft and a terminal end portion located on the rear side of the start end in the rotation direction of the shaft, and lubricating oil is drawn from the start end portion into the groove portion by rotation of the shaft, When a region of the thrust surface that faces the upper surface of the end plate in the axial direction along the rotation axis is defined as a sliding region, the thrust surface has a non-sliding region that does not overlap with the sliding region in an axial direction along the rotation axis, When viewed from the rotation axis, at least the terminal end of the groove is disposed at a position overlapping the sliding region, The starting end of the groove portion is formed in the non-sliding region located radially inward of the sliding region of the shaft. Rotary compressor.

10. When viewed from the rotation shaft, the entire groove is located in the sliding region.

10. The rotary compressor according to claim 9, wherein the rotary compressor comprises:

11. In a plane perpendicular to the central axis, when the distance from the central axis to the starting end is a [mm] and the distance from the central axis to the terminal end is b [mm], a≦b…(Formula 3) 10. The rotary compressor according to claim 9, wherein the following is satisfied:

12. The groove width W, which is the length of the groove along the radial direction of the shaft, becomes smaller from the starting end to the terminal end.

10. The rotary compressor according to claim 9, wherein the rotary compressor comprises:

13. a groove depth H of the groove, which is the length of the groove along the rotation axis direction, decreases from the starting end toward the terminal end; 10. The rotary compressor according to claim 9, wherein the rotary compressor comprises:

14. The groove portion includes a plurality of groove portions each having a starting end portion at a different position from one another.

10. The rotary compressor according to claim 9, wherein the rotary compressor comprises:

15. An annular groove portion is formed on the upper surface of the end plate around the shaft hole through which the shaft is inserted, the annular groove portion extending in a circumferential direction and forming an elastic bearing, the entire groove portion is formed at a position where it does not overlap with the annular groove portion in the axial direction along the rotation shaft, 10. The rotary compressor according to claim 9, wherein the rotary compressor comprises:

16. A refrigeration cycle apparatus comprising a refrigerant circuit in which the rotary compressor according to any one of claims 1 to 15, a condenser, a pressure reducing means, and an evaporator are connected in sequence by refrigerant piping.

Images