Rotary compressor

Abstract

To improve sealability of a cylinder in a rotary compressor.SOLUTION: A compression part in a rotary compressor according to an embodiment comprises: an annular cylinder forming a cylinder chamber inside; an upper end plate which is an end plate closing an upper end of the cylinder; a lower end plate which is an end plate closing a lower end of the cylinder; a shaft rotated by a motor; a piston disposed inside the cylinder; and a vane dividing the cylinder chamber into a suction chamber and a compression chamber. In the rotary compressor, when the direction along the rotation axis of the shaft is defined as the axial direction, there are formed in a sliding portion where the end plate and the piston slide, a first region where an axial gap is formed between the end plate and the piston, and a second region in which the axial gap is narrower than that in the first region, and the first region and the second region are continuous in the radial direction around the rotation axis of the shaft.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present disclosure relates to a rotary compressor. [Background technology]

[0002] Conventionally, a rotary compressor has been known that has a compressor main body container, a motor arranged inside the compressor main body container, and a compression section arranged inside the compressor main body container and driven by the rotation of the motor, the compression section comprising an annular cylinder, an upper end plate that is an end plate closing the upper end of the cylinder, a lower end plate that is an end plate closing the lower end of the cylinder, and a piston arranged inside the cylinder to form a cylinder chamber (Patent Document 1).

[0003] In this rotary compressor, the cylinder chamber, which is formed so as to be surrounded by the cylinder, piston, upper end plate, and lower end plate, is divided by the vane into an intake space (low-pressure side) and a discharge space (high-pressure side). In rotary compressors with a divided cylinder chamber in this way, there is a problem that the pressure difference between the low-pressure side and the high-pressure side of the refrigerant easily flows into the intake space (low-pressure side) through the sliding surface between the piston and the end plate.

[0004] A known prior art technique for improving the sealing of the cylinder chamber (i.e., preventing unintended leakage of refrigerant from or into the cylinder chamber) is to form multiple recesses (dimples or grooves) on the end face of the piston (Patent Document 2). Forming multiple recesses on the end face of the piston makes it easier to maintain a film of lubricating oil on the sliding surface between the piston and the end plate. Maintaining an oil film on the sliding surface between the piston and the end plate can prevent refrigerant from leaking from the discharge side space (high-pressure side) of the cylinder chamber to the suction side space (low-pressure side). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-115566 [Patent Document 2] Patent No. 6988932 [Patent Document 3] Japanese Patent Application Publication No. 2019-183768 Summary of the Invention [Problem to be solved by the invention]

[0006] On the other hand, in rotary compressors, in order to supply lubricating oil to the sliding surface between the piston and end plate, a vertical oil feed hole or a horizontal oil feed hole may be provided in the shaft, or a spiral oil feed groove may be provided on the inner circumferential surface of the lower end plate facing the shaft (for example, Patent Document 3).In such cases, it has been found that high-pressure refrigerant compressed in the cylinder chamber and discharged into the compression vessel main body container can enter the sliding surface between the piston and end plate from below inside the container via the oil feed hole or oil feed groove.

[0007] In particular, because the piston and end plate are generally annular with a through-hole (insertion hole) in the center through which the shaft is inserted, high-pressure refrigerant can enter the through-hole (insertion hole) formed in the piston or end plate. In such rotary compressors, when the piston revolves within the cylinder, there is a point at which the distance between the insertion hole in the end plate and the cylinder chamber is shortest at the sliding portion where the piston and end plate slide. In such cases, it can be difficult to sufficiently prevent high-pressure refrigerant that has reached the insertion hole in the piston or end plate via the oil supply hole or oil supply groove from flowing into the cylinder chamber. In particular, because the suction-side space in the cylinder chamber is under low pressure, the pressure difference between the high-pressure side and the suction-side space (low-pressure side) is large, which can lead to unintended high-pressure refrigerant flowing into the suction-side space.

[0008] For example, in the technology described in Patent Document 2, when high-pressure refrigerant enters the space on the inner periphery of the piston, the sliding surfaces on which multiple recesses are arranged cannot sufficiently prevent the refrigerant from short-circuiting from the inner periphery of the piston toward the radial direction of the piston and flowing into the suction-side space (low-pressure side). Furthermore, if the entire gap between the sliding surfaces is narrowed instead of forming dimples or grooves, problems arise such as an insufficient supply of lubricating oil and metal-to-metal contact between components, which makes them more susceptible to wear.

[0009] The present disclosure proposes a technique that enables the sealing performance inside the cylinder of a rotary compressor to be improved. [Means for solving the problem]

[0010] In the rotary compressor of the present disclosure, the compression section includes an annular cylinder that defines a cylinder chamber therein, an upper end plate that closes the upper end of the cylinder, a lower end plate that closes the lower end of the cylinder, a shaft that is rotated by a motor, a piston that is disposed inside the cylinder, and a vane that divides the cylinder chamber into a suction chamber and a compression chamber. When the axial direction of the rotary compressor is defined as the direction along the rotation axis of the shaft, a sliding section where the end plate and the piston slide is formed with a first region where an axial gap is formed between the end plate and the piston, and a second region where the axial gap is narrower than that of the first region, and the first region and the second region are continuous in the radial direction around the rotation axis of the shaft. [Effects of the Invention]

[0011] According to the present disclosure, it is possible to improve the sealing performance inside the cylinder of a rotary compressor. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a vertical cross-sectional view showing a rotary compressor according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view showing a compression unit of the rotary compressor according to the embodiment. [Figure 3]FIG. 3 is a cross-sectional view of the compression unit of the rotary compressor according to the embodiment, viewed from above. [Figure 4] FIG. 4 is a perspective view of a shaft of the rotary compressor according to the embodiment. [Figure 5] FIG. 5 is a plan view of a shaft of the rotary compressor according to the embodiment. [Figure 6] FIG. 6 is a diagram illustrating an oil supply through hole provided in the shaft of the rotary compressor according to the embodiment. [Figure 7] FIG. 7 is a diagram illustrating a lubricating oil supply path in the rotary compressor according to the embodiment. [Figure 8A] FIG. 8A is a vertical cross-sectional view illustrating an oil supply groove of the sub-bearing portion of the rotary compressor according to the embodiment. [Figure 8B] FIG. 8B is a vertical cross-sectional view illustrating an oil supply groove of the sub-bearing portion of the rotary compressor according to the embodiment. [Figure 9] FIG. 9 is a vertical cross-sectional view illustrating a main part of a compression unit of the rotary compressor according to the embodiment. [Figure 10] FIG. 10 is a vertical cross-sectional view illustrating a first modified example of a main part of the compression unit of the rotary compressor according to the embodiment. [Figure 11] FIG. 11 is a vertical cross-sectional view for explaining a second modified example of the main part of the compression unit of the rotary compressor according to the embodiment. [Figure 12] FIG. 12 is a vertical cross-sectional view illustrating a third modified example of a main part of the compression unit of the rotary compressor according to the embodiment. [Figure 13A] FIG. 13A is an explanatory diagram illustrating the range in which the second region is formed. [Figure 13B] FIG. 13B is an explanatory diagram illustrating the range in which the second region is formed. [Figure 14] FIG. 14 is an explanatory diagram illustrating a case where refrigerant leakage occurs in the compression section. [Figure 15] FIG. 15 is an explanatory diagram illustrating a comparative example of period efficiency. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, a rotary compressor according to an embodiment will be described with reference to the drawings. Components having the same functions in the embodiments will be denoted by the same reference numerals, and duplicated descriptions will be omitted. Note that the rotary compressor described in the following embodiment is merely an example and does not limit the embodiment. Furthermore, the following embodiments may be combined as appropriate within a range that does not cause contradiction.

[0014] Fig. 1 is a vertical cross-sectional view showing a rotary compressor according to an embodiment, Fig. 2 is an exploded perspective view showing a compression unit of the rotary compressor according to an embodiment, and Fig. 3 is a horizontal cross-sectional view of the compression unit of the rotary compressor according to an embodiment as seen from above.

[0015] As shown in FIG. 1, the rotary compressor 1 includes a compression section 12 arranged at the bottom inside a sealed, vertically-placed, cylindrical compressor housing 10, a motor 11 arranged at the top inside the compressor housing 10 and driving the compression section 12 via a shaft 15, and a vertically-placed, cylindrical accumulator 25 fixed to the outer peripheral surface of the compressor housing 10 and sealed.

[0016] The accumulator 25 is connected to an upper cylinder chamber 130T (see FIG. 2) of the upper cylinder 121T via an upper suction pipe 105 as a suction portion and an accumulator upper curved pipe 31T, and is connected to a lower cylinder chamber 130S (see FIG. 2) of the lower cylinder 121S via a lower suction pipe 104 as a suction portion and an accumulator lower curved pipe 31S. In this embodiment, the upper suction pipe 105 and the lower suction pipe 104 overlap each other in the circumferential direction of the compressor casing 10, and are located at the same position.

[0017] The motor 11 includes a stator 111 disposed on the outside and a rotor 112 disposed on the inside. The stator 111 is fixed to the inner circumferential surface of the compressor housing 10 in a shrink-fitted or welded state. The rotor 112 is fixed to the shaft 15 in a shrink-fitted state.

[0018] The shaft 15 has two disk-shaped eccentric portions 152 that protrude perpendicularly to the shaft 15. The eccentric portion on the side of the sub-bearing portion 161S, which is located 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, which is located at the top of the shaft 15, is the upper eccentric portion 152T. The shaft 15 has a countershaft portion 151 located below the lower eccentric portion 152S, a main shaft portion 153 located above the upper eccentric portion 152T, and an intermediate shaft portion 154 sandwiched between the upper eccentric portion 152T and the lower eccentric portion 152S in the vertical direction (see FIG. 4). The countershaft portion 151 below the lower eccentric portion 152S is rotatably fitted and supported by the sub-bearing portion 161S provided on the lower end plate 160S. Furthermore, the shaft 15 is supported by a main shaft portion 153 above the upper eccentric portion 152T rotatably fitted to a main bearing portion 161T provided on an upper end plate 160T. The shaft 15 is provided with an upper eccentric portion 152T and a lower eccentric portion 152S, which are 180 degrees out of phase with each other. That is, the upper eccentric portion 152T and the lower eccentric portion 152S are disks that protrude in opposite directions relative to the shaft 15. The upper piston 125T is supported by the upper eccentric portion 152T, and the lower piston 125S is supported by the lower eccentric portion 152S. As a result, the shaft 15 is supported so as to be rotatable within the fixed compression section 12, and the rotation causes the upper piston 125T to revolve along the inner circumferential surface of the upper cylinder 121T and the lower piston 125S to revolve along the inner circumferential surface of the lower cylinder 121S.

[0019] Lubricating oil 18 is sealed inside compressor housing 10 in an amount that nearly immerses compression section 12. Lubricating oil 18 ensures lubrication of sliding parts, such as upper cylinder 121T and upper piston 125T and lower cylinder 121S and lower piston 125S, that slide in compression section 12, and seals upper cylinder chamber 130T (see FIG. 2) and lower cylinder chamber 130S (see FIG. 2). Mounting legs 310 (see FIG. 1) that engage multiple elastic support members (not shown) that support the entire rotary compressor 1 are fixed to the underside of compressor housing 10.

[0020] As shown in Fig. 1, compression section 12 compresses refrigerant drawn through upper suction pipe 105 and lower suction pipe 104 and discharges the refrigerant from discharge pipe 107, which will be described later. As shown in Fig. 2, compression section 12 is configured by stacking, from top to bottom, upper end plate cover 170T having a bulging portion with a hollow space formed therein, upper end plate 160T, annular upper cylinder 121T, intermediate partition plate 140, annular lower cylinder 121S, lower end plate 160S, and flat lower end plate cover 170S. The entire compression section 12 is fixed by a plurality of through bolts 174, 175 and auxiliary bolts 176 arranged approximately concentrically from above and below.

[0021] As shown in FIG. 3 , the upper cylinder 121T has a cylindrical inner circumferential surface 137T. An upper piston 125T having an outer diameter smaller than the inner diameter of the inner circumferential surface 137T of the upper cylinder 121T is disposed inside the inner circumferential surface 137T of the upper cylinder 121T. An upper cylinder chamber 130T that draws in, compresses, and discharges a refrigerant is formed between the inner circumferential surface 137T of the upper cylinder 121T and an outer circumferential surface 139T of the upper piston 125T. The lower cylinder 121S has a cylindrical inner circumferential surface 137S. A lower piston 125S having an outer diameter smaller than the inner diameter of the inner circumferential surface 137S of the lower cylinder 121S is disposed inside the inner circumferential surface 137S of the lower cylinder 121S. A lower cylinder chamber 130S that draws in, compresses, and discharges a refrigerant is formed between the inner circumferential surface 137S of the lower cylinder 121S and an outer circumferential surface 139S of the lower piston 125S.

[0022] As shown in FIGS. 2 and 3, the upper cylinder 121T has an upper protrusion 122T that protrudes radially from its circular outer periphery toward a cylindrical inner periphery 137T. The upper protrusion 122T is provided with an upper vane groove 128T that extends radially outward from the upper cylinder chamber 130T. An upper vane 127T is slidably disposed within the upper vane groove 128T. The lower cylinder 121S has a lower protrusion 122S that protrudes radially from its circular outer periphery toward a cylindrical inner periphery 137S. The lower protrusion 122S is provided with a lower vane groove 128S that extends radially outward from the lower cylinder chamber 130S. A lower vane 127S is slidably disposed within the lower vane groove 128S.

[0023] The upper protrusion 122T is formed over a predetermined protruding range along the circumferential direction of the inner circumferential surface 137T of the upper cylinder 121T. The lower protrusion 122S is formed over a predetermined protruding range along the circumferential direction of the inner circumferential surface 137S of the lower cylinder 121S. The upper protrusion 122T and the lower protrusion 122S are used as chuck holders for fixing the upper cylinder 121T and the lower cylinder 121S to a processing jig when processing them.

[0024] An upper spring hole 124T is formed in the upper lateral protrusion 122T at a position overlapping the upper vane groove 128T from the outer surface, with a depth that does not penetrate into the upper cylinder chamber 130T. An upper spring 126T is disposed in the upper spring hole 124T. A lower spring 124S is formed in the lower lateral protrusion 122S at a position overlapping the lower vane groove 128S from the outer surface, with a depth that does not penetrate into the lower cylinder chamber 130S. A lower spring 126S is disposed in the lower spring hole 124S.

[0025] The upper cylinder 121T is also formed with an upper pressure introduction passage 129T that connects the radially outer side of the upper vane groove 128T to the inside of the compressor housing 10 through an opening, introduces compressed refrigerant from the compressor housing 10, and applies back pressure to the upper vanes 127T by the pressure of the refrigerant. The lower cylinder 121S is also formed with a lower pressure introduction passage 129S that connects the radially outer side of the lower vane groove 128S to the inside of the compressor housing 10, introduces compressed refrigerant from the compressor housing 10, and applies back pressure to the lower vanes 127S by the pressure of the refrigerant.

[0026] An upper suction hole 135T that fits with the upper suction pipe 105 is formed in the upper protruding portion 122T of the upper cylinder 121T. A lower suction hole 135S that fits with the lower suction pipe 104 is formed in the lower protruding portion 122S of the lower cylinder 121S.

[0027] 2, the upper cylinder chamber 130T is closed at the top and bottom by an upper end plate 160T and an intermediate partition plate 140. The lower cylinder chamber 130S is closed at the top and bottom by an intermediate partition plate 140 and a lower end plate 160S.

[0028] The upper cylinder chamber 130T is divided into an upper suction chamber 131T communicating with the upper suction hole 135T and an upper compression chamber 133T communicating with an 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 circumferential surface 139T of the upper piston 125T. The lower cylinder chamber 130S is divided into a lower suction chamber 131S communicating with the lower suction hole 135S and a lower compression chamber 133S communicating with a 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 circumferential surface 139S of the lower piston 125S.

[0029] Additionally, the upper discharge hole 190T is provided adjacent to the upper vane groove 128T, and the lower discharge hole 190S is provided adjacent to the lower vane groove 128S. The refrigerant compressed in the upper compression chamber 133T and the lower compression chamber 133S is discharged from the upper compression chamber 133T and the lower compression chamber 133S through the upper discharge hole 190T and the lower discharge hole 190S.

[0030] 2, 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 upper valve seat (not shown) is formed around the upper discharge hole 190T 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.

[0031] The upper discharge valve accommodating recess 164T accommodates a reed valve-type upper discharge valve 200T whose rear end is fixed in the upper discharge valve accommodating recess 164T by an upper rivet 202T and whose front end opens and closes the upper discharge hole 190T, and the entire upper discharge valve retainer 201T whose rear end is overlapped with the upper discharge valve 200T and fixed in the upper discharge valve accommodating recess 164T by an upper rivet 202T and whose front end is curved (warped) in the direction in which the upper discharge valve 200T opens, thereby regulating the opening degree of the upper discharge valve 200T.

[0032] 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. The lower end plate 160S is formed with a lower discharge valve accommodating recess (not shown) that extends in a groove shape from the position of the lower discharge hole 190S toward the outer periphery of the lower end plate 160S.

[0033] The lower discharge valve accommodating recess accommodates the lower discharge valve 200S, which is a reed valve type lower discharge valve whose rear end is fixed in the lower discharge valve accommodating recess by a lower rivet 202S and whose front end opens and closes the lower discharge hole 190S, and the entire lower discharge valve retainer 201S, whose rear end is overlapped with the lower discharge valve 200S and fixed in the lower discharge valve accommodating recess by the lower rivet 202S and whose front end is curved (warped) in the direction in which the lower discharge valve 200S opens, thereby regulating the opening degree of the lower discharge valve 200S.

[0034] An upper end plate cover chamber 180T is formed between the upper end plate 160T and the upper end plate cover 170T having a bulge, which are tightly fixed to each other. A lower end plate cover chamber 180S (see FIG. 1) is formed between the lower end plate 160S and the flat lower end plate cover 170S, which are also tightly fixed to 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.

[0035] Fig. 4 is a perspective view of the shaft 15 of the rotary compressor 1 according to the embodiment. Fig. 5 is a plan view of the shaft 15 of the rotary compressor 1 according to the embodiment. Fig. 6 is a diagram for explaining an oil supply through hole provided in the shaft 15 of the rotary compressor 1 according to the embodiment. Hereinafter, the central axis when the shaft 15 rotates is referred to as a rotation axis O1 of the shaft 15.

[0036] 4 and 6, shaft 15 has hollow portion 155 that opens to the lower end side, and a gas vent hole that has an opening to the upper end side and is connected to hollow portion 155 at the lower end side to communicate hollow portion 155 with the space above shaft 15. An oil supply impeller 159 shown in FIG. 4 is press-fitted into hollow portion 155.

[0037] 4 and 6, the shaft 15 is provided with a horizontal oil-feed hole 156T that has an opening at a location on the side surface of the shaft 15 above an upper end surface 1521T of the upper eccentric portion 152T and is connected to the hollow portion 155. Also, as shown in FIG. 6, the shaft 15 is provided with a horizontal oil-feed hole 156S that has an opening at a location on the side surface of the shaft 15 below a lower end surface 1522S of the lower eccentric portion 152S and is connected to the hollow portion 155.

[0038] The shaft 15 is also provided with a horizontal oil-feed hole 157T that has an opening on a side surface of the shaft 15 facing the upper eccentric portion 152T with the hollow portion 155 interposed therebetween, and is connected to the hollow portion 155. The shaft 15 is also provided with a horizontal oil-feed hole 157S that has an opening on a side surface of the shaft 15 facing the lower eccentric portion 152S with the hollow portion 155 interposed therebetween, and is connected to the hollow portion 155. The horizontal oil-feed hole 157T is provided below the horizontal oil-feed hole 156T. The horizontal oil-feed hole 156S is also provided below the horizontal oil-feed hole 157S. The horizontal oil-feed hole 157T and the horizontal oil-feed hole 157S are provided at opposite positions across the shaft 15.

[0039] Furthermore, the shaft 15 is provided with an inclined oil-feed hole 158T that has an opening in an upper end surface 1521T of the upper eccentric portion 152T and penetrates the upper eccentric portion 152T to connect to the hollow portion 155. The inclined oil-feed hole 158T is a path that connects the opening provided in the upper end surface 1521T of the upper eccentric portion 152T with an opening provided in the hollow portion 155, and is a path that is inclined with respect to the rotation axis O1 of the shaft 15. Here, a hole that is inclined with respect to the rotation axis is referred to as an "inclined hole." As shown in FIG. 5, the opening of the inclined oil-feed hole 158T in the upper end surface 1521T is located near the outer circumferential edge of the upper end surface 1521T of the upper eccentric portion 152T. The opening of the inclined oil-feed hole 158T may be located anywhere on the upper end surface 1521T of the upper eccentric portion 152T, but is preferably located near the outer periphery in the eccentric direction of the upper end surface 1521T. The eccentric direction of the upper end surface 1521T is the radial direction of the rotation axis O1 of the shaft 15, and is the direction in which the outer wall of the upper eccentric portion 152T is located at the farthest position from the shaft 15. The opening of the inclined oil-feed hole 158T on the hollow portion 155 side is located below the lower end surface 1522T of the upper eccentric portion 152T, as shown in FIG. 6.

[0040] The shaft 15 is also provided with an inclined oil-feed hole 158S that has an opening in an upper end surface 1521S of the lower eccentric portion 152S and penetrates the lower eccentric portion 152S to connect to the hollow portion 155. The inclined oil-feed hole 158S is a path that connects the opening in the upper end surface 1521S of the lower eccentric portion 152S with an opening in the hollow portion 155, and is inclined with respect to the hollow portion 155. In other words, the inclined oil-feed hole 158S is a path that connects the opening in the upper end surface 1521S of the lower eccentric portion 152S with an opening in the hollow portion 155, and is inclined with respect to the rotation axis O1 of the shaft 15. As shown in FIG. 5 , the opening of the inclined oil-feed hole 158S in the upper end surface 1521S is located near the outer circumferential end of the upper end surface 1521S of the lower eccentric portion 152S. The opening of the inclined oil-feed hole 158S may be located anywhere on the upper end surface 1521S of the lower eccentric portion 152S, but is preferably located near the outer periphery of the upper end surface 1521S in the eccentric direction. The eccentric direction of the upper end surface 1521S is the radial direction of the rotation axis O1 of the shaft 15, and is the direction in which the outer wall of the lower eccentric portion 152S is located at the farthest position from the shaft 15. The opening of the inclined oil-feed hole 158S on the hollow portion 155 side is located below the lower end surface 1522S of the lower eccentric portion 152S, as shown in FIG. 6.

[0041] Here, the flow of the lubricating oil 18 will be described with reference to Fig. 7. Fig. 7 is a diagram showing a supply path of the lubricating oil 18 in the rotary compressor 1 according to the embodiment. In Fig. 7, the flow of the lubricating oil 18 is indicated by arrows.

[0042] The lubricating oil 18 in the hollow portion 155 of the shaft 15 is discharged to the outside of the shaft 15 through the horizontal oil-feed holes 156S, 157S, 156T, 157T and the oblique oil-feed holes 158S, 158T by centrifugal force acting when the shaft 15 rotates. The horizontal oil-feed hole 156T and the horizontal oil-feed hole 156S are provided in the same direction relative to the rotation axis O1 of the shaft 15. The horizontal oil-feed hole 157T and the horizontal oil-feed hole 157S are provided in opposite directions relative to the rotation axis O1 of the shaft 15. The horizontal oil-feed hole 156T is provided at a higher position than the horizontal oil-feed hole 157T. The horizontal oil-feed hole 156S is provided at a lower position than the horizontal oil-feed hole 157S.

[0043] The positions of the openings of the inclined oil-feed hole 158S and the inclined oil-feed hole 158T through which the lubricating oil 18 is discharged are farther in the radial direction of the rotation axis O1 of the shaft 15 than the horizontal oil-feed holes 156S, 157S, 156T, and 157T. Therefore, the lubricating oil 18 discharged from the inclined oil-feed hole 158S and the inclined oil-feed hole 158T is subjected to a stronger centrifugal force than the lubricating oil 18 discharged from the horizontal oil-feed holes 156S, 157S, 156T, and 157T. As a result, the lubricating oil 18 is pushed away from the shaft 15 by a stronger force from the inclined oil-feed hole 158S and the inclined oil-feed hole 158T than from the horizontal oil-feed holes 156S, 157S, 156T, and 157T, and more of the lubricating oil 18 is discharged. By discharging more lubricating oil 18, the lubricating oil 18 can reach the ends of the upper eccentric portion 152T and the lower eccentric portion 152S sufficiently, and the space outside the upper eccentric portion 152T and the lower eccentric portion 152S can be filled with lubricating oil 18.

[0044] The lubricating oil 18 discharged to the outside from each opening is supplied to the sliding surface between the sub-bearing portion 161S and the sub-shaft portion 151 of the shaft 15, the sliding surface between the main bearing portion 161T and the main shaft portion 153 of the shaft 15, the sliding surface between the lower eccentric portion 152S of the shaft 15 and the lower piston 125S, and the sliding surface between the upper eccentric portion 152T and the upper piston 125T, thereby lubricating each of the sliding surfaces.

[0045] In particular, the lubricating oil 18 discharged from the inclined oil-feed hole 158S spreads over the upper end surface 1521S of the lower eccentric portion 152S and is carried by centrifugal force to the outer periphery of the lower eccentric portion 152S in the eccentric direction. The lubricating oil 18 carried to the vicinity of the outer periphery of the lower eccentric portion 152S is then supplied to the upper end surface of the lower piston 125S. Furthermore, the lubricating oil 18 supplied to the upper end surface 1521S passes through a groove (not shown) that penetrates part of the outer periphery of the lower eccentric portion in the vertical direction and moves downward by gravity, thereby being supplied to the lower end surface of the lower piston 125S.

[0046] Similarly, the lubricating oil 18 discharged from the inclined oil feed hole 158T spreads over the upper end surface 1521T of the upper eccentric portion 152T and is carried by centrifugal force to the outer periphery of the upper eccentric portion 152T in the eccentric direction. The lubricating oil 18 carried to the vicinity of the outer periphery of the upper eccentric portion 152T is then supplied to the upper end surface of the upper piston 125T. Furthermore, the lubricating oil 18 supplied to the upper end surface 1521T passes through a groove (not shown) that penetrates part of the outer periphery of the upper eccentric portion in the vertical direction, and moves downward by gravity, to be supplied to the lower end surface of the upper piston 125T.

[0047] Oil supply impeller 159 is sandwiched by hollow portion 155 of shaft 15, and rotates as shaft 15 rotates, pressing lubricating oil 18 against the inner wall of hollow portion 155. This makes lubricating oil 18 more susceptible to centrifugal force due to the rotation of hollow portion 155, making it easier for hollow portion 155 to pump up lubricating oil 18. Oil supply impeller 159 also serves to supply lubricating oil 18 to the sliding surfaces even when lubricating oil 18 is discharged from compressor housing 10 together with the refrigerant and the oil level becomes low.

[0048] 8A and 8B are vertical cross-sectional views illustrating the oil supply groove of the sub-bearing portion 161S of the rotary compressor 1 according to the embodiment.

[0049] 8A and 8B, a spiral oil supply groove 166 is formed on the inner peripheral surface of the shaft hole 161S1 of the sub-bearing portion 161S, which sucks up and supplies lubricating oil 18 from the lower end 161Sa to the upper end 161Sb of the shaft hole 161S1. When the shaft 15 rotates in the rotational direction R, the sub-bearing portion 161S appears to rotate relatively in the opposite direction to the rotational direction R of the shaft 15. Here, when viewed using the rotational direction R of the shaft 15 as the reference, rather than the rotational direction of the sub-bearing portion 161S, the inclination direction of the oil supply groove 166 with respect to the rotational direction R will be described.

[0050] Oil groove 166 is inclined with respect to rotation direction R of shaft 15, and extends from lower end 161Sa to upper end 161Sb of axial hole 161S1 in rotation direction R of shaft 15. In other words, oil groove 166 is formed in a so-called spiral shape around shaft 15. Lubricating oil 18 in oil groove 166 is sucked up along the inside of oil groove 166 from lower end 161Sa to upper end 161Sb of axial hole 161S1 by the action of a viscous pump that utilizes the viscosity of lubricating oil 18 generated in oil groove 166.

[0051] Fig. 9 is a vertical cross-sectional view illustrating a main part of the compression unit 12 of the rotary compressor 1 according to the embodiment. In Fig. 9, the vertical direction is the axial direction along the rotation axis O1 of the shaft 15, and the horizontal direction is the radial direction around the rotation axis O1 of the shaft 15 (the right direction is the radially outward direction). In Fig. 9, the arrows pointing from the shaft 15 to the cylinder chambers 130 (upper cylinder chamber 130T, lower cylinder chamber 130S) illustrate an example of a path along which high-pressure refrigerant (and lubricating oil) flows from a space (high-pressure side space) on the inner circumferential side of the piston 125 (upper piston 125T, lower piston 125S) to the cylinder chambers 130 (low-pressure side space), which is a space on the outer circumferential side of the piston 125, so as to short-circuit in the radial direction of the piston 125.

[0052] 9, in the compression section 12 of the rotary compressor 1 according to the embodiment, the upper piston 125T slides on a sliding portion 300T that extends radially from the inside around the rotation axis O1 of the shaft 15 on the intermediate partition plate upper surface 140T of the intermediate partition plate 140 due to rotation of the shaft 15. In this sliding portion 300T, an axial gap is formed between the upper piston 125T and the intermediate partition plate upper surface 140T of the intermediate partition plate 140, large enough to allow the lubricating oil 18 to enter.

[0053] The gap in the sliding part 300T varies in the radial direction around the rotation axis O1 of the shaft 15. Specifically, the intermediate partition plate 140 is formed so that the thickness (height in the axial direction) of the intermediate partition plate 140 increases as it moves from the radial direction toward the inside around the rotation axis O1 of the shaft 15. That is, the intermediate partition plate upper surface 140T is formed in a tapered shape with a higher axial height (thickness) on the inside around the rotation axis O1 of the shaft 15. In contrast, the thickness (height in the axial direction) of the upper piston 125T is constant. Therefore, the sliding part 300T has a first region 301T formed radially, and a second region 302T formed continuous with the first region 301T and having a narrower gap than the first region 301T, radially inward around the rotation axis than the first region 301T.

[0054] In this way, in the sliding portion 300T between the intermediate partition plate 140 (end plate) and the upper piston 125Ta, a first region 301T in which an axial gap is formed between the intermediate partition plate 140 (end plate) and the upper piston 125Ta, and a second region 302T in which the axial gap is narrower than that of the first region 301T are formed toward the center of the intermediate partition plate 140 (toward the radially inner side around the rotation axis), and the first region 301T and the second region 302T are formed continuously in the radial direction. As a result, in the rotary compressor 1 of the embodiment, it is possible to suppress the inflow of refrigerant in a path (indicated by an arrow in the figure) from the inner periphery side of the upper piston 125T in the radial direction, thereby reducing refrigerant leakage. In particular, as will be described in detail later, the first region 301T and the second region 302T, which has a narrower axial gap than the first region 301T, are formed continuously in the radial direction, which reduces refrigerant leakage more than simply narrowing the gap of the entire sliding part 300T uniformly (for example, when the gap of the entire sliding part 300T is set to the size of the gap of the second region 302T).

[0055] Furthermore, in the rotary compressor 1 of the embodiment, the gap in a part of the second region 302T in the sliding part 300T is narrowed, while the gap in the first region 301T in the sliding part 300T is wider than the gap in the second region 302 (the gap in the entire sliding part 300T is not narrowed uniformly), so that the lubricating oil 18 can be sufficiently supplied to the sliding part 300T. Therefore, it is possible to suppress the occurrence of a problem in which members come into metal contact with each other and become more susceptible to wear.

[0056] The second region 302T is formed over the entire circumferential direction around the rotation shaft (details will be described later). Therefore, in the rotary compressor 1, even when the upper piston 125T revolves, it is possible to reduce refrigerant leakage.

[0057] Similarly, due to the rotation of the shaft 15 described above, the lower piston 125S slides on a sliding portion 300S that extends radially from the inside around the rotation axis O1 of the shaft 15 on the lower surface 140S of the intermediate partition plate 140. In this sliding portion 300S, an axial gap is formed between the lower piston 125S and the lower surface 140S of the intermediate partition plate 140, large enough to allow the lubricating oil 18 to enter.

[0058] The gap in the sliding part 300S varies in the radial direction around the rotation axis O1 of the shaft 15. Specifically, the intermediate partition plate 140 is formed so that its thickness (axial direction) increases as it moves from the radial direction toward the inside around the rotation axis O1 of the shaft 15. That is, the lower surface 140S of the intermediate partition plate is formed in a tapered shape such that the height (thickness) in the axial direction increases toward the inside around the rotation axis O1 of the shaft 15. In contrast, the thickness (axial direction) of the lower piston 125S is constant. Therefore, the sliding part 300S has a first region 301S formed radially, and a second region 302S formed continuous with the first region 301S and having a narrower gap than the first region 301S, radially inward around the rotation axis than the first region 301S.

[0059] In this way, the second region 302S that narrows the gap between the first region 301 and the lower piston 125S is formed to be aligned radially toward the center (toward the radially inner side around the rotation axis) of the intermediate partition plate 140, thereby suppressing the inflow of refrigerant (indicated by the arrow in the figure) from the inner circumferential side of the lower piston 125S in the radial direction, thereby reducing refrigerant leakage in the rotary compressor 1. Furthermore, since the rotary compressor 1 is configured to narrow the gap in part of the second region 302S in the sliding part 300S (rather than narrowing the entire gap), problems such as an insufficient supply of lubricating oil 18 or metal-to-metal contact between members that easily causes wear are less likely to occur.

[0060] The second region 302S is formed over the entire circumferential direction around the rotation shaft (details will be described later). Therefore, in the rotary compressor 1, even when the lower piston 125S revolves, it is possible to reduce refrigerant leakage.

[0061] Fig. 10 is a vertical cross-sectional view illustrating a first modified example of the main parts of the compression unit 12 of the rotary compressor 1 according to the embodiment. In Fig. 10, the up-down direction is the axial direction along the rotation axis O1 of the shaft 15, and the rightward direction is the radial direction around the rotation axis O1 of the shaft 15. In Fig. 10, arrows pointing from the shaft 15 to the upper cylinder chambers 130T, 130S illustrate paths through which high-pressure refrigerant flows into the suction-side spaces (low-pressure sides) of the upper cylinder chambers 130T, 130S, short-circuiting from the inner circumferential sides of the upper pistons 125Ta and 125Sa toward the radial direction of the upper pistons 125Ta and 125Sa.

[0062] As shown in FIG. 10, the first modified example uses an upper piston 125Ta and a lower piston 125Sa whose thickness (axial direction) varies radially around the rotation axis O1 of the shaft 15, and an intermediate partition plate 140A whose thickness (axial direction) is constant.

[0063] Specifically, the upper piston 125Ta is formed so that its thickness (axial direction) increases as it moves radially from the inside around the rotation axis O1 of the shaft 15. That is, the sliding surface 125Taa of the upper piston 125Ta that slides on the intermediate partition plate upper surface 140T is formed in a tapered shape around the rotation axis O1 of the shaft 15 such that the height (thickness) in the axial direction is greater in the radial direction.

[0064] Similarly, the lower piston 125Sa is formed so that its thickness (axial direction) increases as it moves radially from the inside around the rotation axis O1 of the shaft 15. That is, the sliding surface 125Saa of the lower piston 125Sa that slides on the lower surface 140S of the intermediate partition plate is formed in a tapered shape around the rotation axis O1 of the shaft 15 such that the height (thickness) in the axial direction is greater in the radial direction.

[0065] As a result, also in the first modified example, a second region 302T is formed in the sliding portion 300T between the intermediate partition plate 140A and the upper piston 125Ta, the second region 302T being continuous with the first region 301T and having a gap narrower than the first region 301T. Also, a second region 302S is formed in the sliding portion 300S between the intermediate partition plate 140A and the lower piston 125Sa, the second region 302S being continuous with the first region 301S and having a gap narrower than the first region 301S. As a result, in the rotary compressor 1, the inflow of refrigerant (indicated by the arrows in the figure) in the radial direction from the inner circumferential sides of the upper piston 125Ta and the lower piston 125Sa can be suppressed, thereby reducing refrigerant leakage.

[0066] Fig. 11 is a vertical cross-sectional view illustrating a second modified example of the main parts of the compression unit 12 of the rotary compressor 1 according to the embodiment. In Fig. 11, the up-down direction is the axial direction along the rotation axis O1 of the shaft 15, and the rightward direction is the radial direction around the rotation axis O1 of the shaft 15. In Fig. 11, the arrow pointing from the shaft 15 to the upper cylinder chamber 130T illustrates an example of a path through which high-pressure refrigerant flows into the suction-side space (low-pressure side) of the upper cylinder chamber 130T, short-circuiting from the inner circumferential side of the upper piston 125T toward the radial direction of the upper piston 125T.

[0067] As shown in Figure 11, the second variant uses 125T and lower piston 125S with a constant thickness (axial direction), and an intermediate partition plate 140B with step portions 140BT and 140BS with increased thickness (axial direction) formed on the inner side around the rotation axis O1 of shaft 15.

[0068] As a result, in the second modified example, the sliding portion 300T between the intermediate partition plate 140B and the upper piston 125T has the second region 302T at the portion where the step portion 140BT is formed. Similarly, the sliding portion 300S between the intermediate partition plate 140B and the lower piston 125S has the second region 302S at the portion where the step portion 140BS is formed. Therefore, in the rotary compressor 1, the flow of refrigerant through the path from the inner circumferential side of the upper piston 125T and the lower piston 125S toward the radial direction is suppressed by the second regions 302T and 302S corresponding to the step portions 140BT and 140BS, thereby reducing refrigerant leakage.

[0069] Fig. 12 is a vertical cross-sectional view illustrating a third modified example of the main parts of the compression unit 12 of the rotary compressor 1 according to the embodiment. In Fig. 12, the up-down direction is the axial direction along the rotation axis O1 of the shaft 15, and the rightward direction is the radial direction around the rotation axis O1 of the shaft 15. In Fig. 12, arrows pointing from the shaft 15 to the upper cylinder chambers 130T, 130S illustrate paths through which high-pressure refrigerant flows into the suction-side spaces (low-pressure sides) of the upper cylinder chambers 130T, 130S, short-circuiting from the inner circumferential sides of the upper pistons 125Tb and 125Sb toward the radial direction of the upper pistons 125Tb and 125Sb.

[0070] As shown in Figure 12, the third modified example uses an intermediate partition plate 140A with a constant thickness (axial direction), and upper piston 125Tb and lower piston 125Sb with step portions 125Tba and 125Sba formed at the tip portions with increased thickness (axial direction).

[0071] As a result, in the third modified example, the sliding portion 300T between the intermediate partition plate 140A and the upper piston 125Tb has the second region 302T at the portion where the step portion 125Tba is formed. Similarly, the sliding portion 300S between the intermediate partition plate 140A and the lower piston 125Sb has the second region 302S at the portion where the step portion 125Sba is formed. Therefore, in the rotary compressor 1, the second regions 302T and 302S corresponding to the step portions 125Tba and 125Sba suppress the flow of refrigerant through the paths extending radially from the inner peripheries of the upper piston 125Tb and the lower piston 125Sb, thereby reducing refrigerant leakage.

[0072] Next, the range of second regions 302S, 302T (hereinafter referred to as "302" when not distinguished) formed over the entire circumferential direction around the rotation axis will be described with reference to Figures 13A and 13B. Figures 13A and 13B are explanatory diagrams illustrating the range in which second region 302 is formed.

[0073] As shown in FIG. 13A, the distance from the center O1 to the outer periphery of the cylinder 121 is r c1 The distance from the center O1 to the inner circumferential surface 137 is r c2 The outer diameter d of the cylinder 121 c1 is d c1 =2r c1 3, the center O1 of the cylinder coincides with the rotation axis O1 of the shaft 15.

[0074] As shown in FIG. 13A, the distance from the center O1 to the outer periphery of the intermediate partition plate 140 is r e1 The distance from the center O1 to the edge of the opening 141 through which the shaft 15 passes is r e2 The inner diameter d of the opening 141 in the intermediate partition plate 140 is e2 is d e2 =2r e2 The center O1 of the intermediate partition plate 140 coincides with the rotation axis O1 of the shaft 15, similar to the center O1 of the cylinder.

[0075] As shown in FIG. 13A, in the piston 125, the distance from the center O2, which is the center of the piston, to the outer circumferential surface 139 is r p1 The distance from the center O2 to the inner circumferential surface of the piston 125 is r p2 The outer diameter of the piston 125 is d p1 =2r p1 is.

[0076] As shown in Figure 13B, the magnitude of deviation (eccentricity) between the center O2 of the piston 125 that revolves in contact with the tip of the vane 127 and the center O1 that is the rotation axis of the shaft 15 is set to p. This p is expressed as p=r c2 -r p1 is.

[0077] The second region 302 is formed over the entire circumferential direction around the rotation shaft, and is formed so that at least a portion of the second region 302 is located in a range where the stationary end plates (upper end plate 160S, lower end plate 160T, intermediate partition plate 140) and the revolving piston 125 face each other in the axial direction of the rotation shaft. In other words, when viewed from the axial direction of the rotation shaft, the distance from the center O1 is defined as S, and the second region 302 is formed in at least a part of a range where the distance S satisfies the following formulas (1) and (2). r e2 <S…(1) S <r p1 -p=r p1 -(r c2 -r p1 )=2r p1 -r c2 …(2)

[0078] Fig. 14 is an explanatory diagram illustrating cases where refrigerant leakage occurs in compression section 12. In Fig. 14, cases C1 to C4 exemplify states where piston 125 has rotated 90° from top dead center.

[0079] As shown by the arrows in cases C1 to C4, refrigerant leakage from the shaft 15 side to the cylinder chamber 130 side is likely to occur when the distance between the shaft 15 side and the cylinder chamber 130 side during the revolution of the piston 125 is shortest.

[0080] For example, in cases C1, C3, and C4, the distance to the suction side space (low pressure side) of cylinder chamber 130 is shortest, so refrigerant leakage is likely to occur from shaft 15 to suction chamber 131. In case C2, the distance to the intermediate pressure (space during compression) is shortest, so refrigerant leakage is likely to occur to compression chamber 133, which is an intermediate pressure space.

[0081] In this embodiment, by forming the second region 302 within the above range, in the rotary compressor 1, even when the piston 125 revolves around the rotation axis (cases C1 to C4), the flow of refrigerant from the shaft 15 side into the cylinder chamber 130 in a radial direction is suppressed by the first region 301 and the second region 302 being continuous in the radial direction, thereby reducing refrigerant leakage.

[0082] Fig. 15 is an explanatory diagram illustrating comparative examples of periodic efficiency. In Fig. 14, No. 5 is an example in which the rotary compressor 1 according to the embodiment is actually driven. The comparative examples (Nos. 1 to 4) are examples in which the intermediate partition plate 140, which is an end plate closing the lower cylinder chamber 130S and the upper cylinder chamber 130T, and the like are flat partition plates. The vertical axis in Fig. 15 indicates the power (periodic efficiency) of the compression section 12 measured over a predetermined period, and the values ​​are converted using the periodic efficiency of No. 3 as the reference (100%).

[0083] As shown in Fig. 15, in Comparative Examples (No. 1) to (No. 4), the overall clearance (gap) between the intermediate partition plate 140 and the lower piston 125S and between the intermediate partition plate 140 and the upper piston 125T is changed. Specifically, in the comparative examples, the clearance size is changed in stages from Comparative Example (No. 1), which has the smallest overall clearance (gap), to Comparative Example (No. 4), which has the largest overall clearance (gap). In this way, even when the overall clearance is changed, Comparative Example (No. 3) has the highest period efficiency.

[0084] In contrast, in Example (No. 5) in which the rotary compressor 1 according to the embodiment was actually driven, the seasonal efficiency was higher than that of Comparative Example (No. 3). From this, it can be seen that in the rotary compressor 1 according to the embodiment, the first region 301T and the second region 302T, which has an axial gap narrower than that of the first region 301T, are formed continuously in the radial direction, thereby reducing refrigerant leakage compared to simply narrowing the gap of the entire sliding part 300T uniformly. In other words, in the rotary compressor 1 according to the embodiment, the operating efficiency can be improved by improving the sealing performance inside the cylinder.

[0085] Here, we consider why the rotary compressor 1 (No. 5) of the embodiment is able to suppress refrigerant leakage more effectively than the comparative examples (Nos. 1 to 4). When the first region 301T and the second region 302T, which has a narrower axial gap than the first region 301T, are formed continuously in the radial direction, as in the embodiment, lubricating oil for enhancing sealing performance enters the first region 301T, which has a wider gap, and this is thought to suppress the inflow of refrigerant into the cylinder chamber 130 through the sliding part 300T. Furthermore, in the second region 301T, which has a narrower gap than the first region 301T, the dynamic pressure in the gap increases, acting as a force that moves the end plate (140, 160) and the piston 125 away from each other. This prevents local contact between the end plate (140, 160) and the piston 125, while also preventing the inflow of refrigerant into the cylinder chamber 130 due to the narrow gap. As a result, it is estimated that the rotary compressor 1 of the embodiment (No. 5) is most effective in suppressing the flow of refrigerant into the cylinder chamber 130 compared to simply widening the gap of the entire sliding part 300T (e.g., No. 4) or narrowing the gap of the entire sliding part 300T (e.g., No. 1).

[0086] Generally, in the case of a two-cylinder rotary compressor 1 as in the embodiment, the diameter d of the through-hole formed at the center of the intermediate partition plate 140 is larger than the diameter of the through-hole formed at the center of the upper end plate 160T or the center of the lower end plate 160S. e2The eccentric portion 152 of the shaft 15 must pass through the through-hole at the center of the intermediate partition plate 140 when the shaft 15 is inserted into the cylinder 121. As a result, there is a problem in that the radial length of the sliding surface formed between the inner peripheral edge of the through-hole at the center of the intermediate partition plate 140 and the outer peripheral surface of the piston becomes shorter when viewed from the axial direction. For these reasons, the present invention is particularly effective in a two-cylinder rotary compressor 1.

[0087] In the rotary compressor 1 according to the above embodiment, a so-called two-rotor type compression section 12 is exemplified, which includes a lower cylinder chamber 130S in which the refrigerant is compressed by a lower piston 125S and an upper cylinder chamber 130T in which the refrigerant is compressed by an upper piston 125T. However, the compression section 12 may be configured to include only one cylinder chamber 130.

[0088] Furthermore, in the rotary compressor 1 according to the above embodiment, a rotary compressor in which the piston 125 and the vane 127 are formed as separate bodies has been exemplified, but the rotary compressor may also be a so-called oscillating piston type rotary compressor in which the piston 125 and the vane 127 are formed integrally. [Explanation of symbols]

[0089] 1...Rotary compressor 10...Compressor housing 11...Motor 12...Compression section 15...shaft 18...Lubricating oil 25...Accumulator 31S...Accumulator lower curved pipe 31T...Accumulator upper curved pipe 104…Lower suction pipe 105...Upper suction pipe 107...Discharge pipe 111...Stator 112...Rotor 121...Cylinder 121S...Lower cylinder 121T...Upper cylinder 122S…lower lateral protrusion 122T…Upper side protrusion 124S...Lower spring hole 124T...Upper spring hole 125...Piston 125S, 125Sa, 125Sb...lower piston 125Saa, 125Taa…Sliding surface 125Sba, 125Tba, 140BS, 140BT...Stepped area 125T, 125Ta, 125Tb...Upper piston 126S...Lower spring 126T...Upper spring 127...Vane 127S...lower vane 127T...Upper vane 128S...Lower vane groove 128T...Upper vane groove 129S...lower pressure introduction passage 129T...Upper pressure introduction passage 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…Top suction hole 136...refrigerant passage hole 137, 137S, 137T…Inner peripheral surface 139, 139S, 139T...outer surface 140, 140A, 140B...Intermediate partition plate (end plate) 140S…lower surface of intermediate partition plate 140T...Top of intermediate partition board 141...Opening 151…Subshaft part 152S…Lower eccentric part 152T…Upper eccentric part 153...Spindle part 155...Hollow part 156S~157T...Horizontal fuel hole 158S, 158T...Oil supply diagonal hole 159...Fueling vane 160S…Lower end plate (end plate) 160T…Top end plate (end plate) 161S…Sub bearing part 161S1...shaft hole 161Sa…lower end 161Sb…Top end 161T…Main bearing part 164T...Upper discharge valve accommodating recess 166...Oil groove 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, 200S…Lower discharge hole 190T, 200T…Top discharge hole 201S...Lower discharge valve holder 201T...Upper discharge valve holder 202S...Lower rivet 202T...Upper rivet 300S, 300T...sliding part 301S, 301T…First area 302, 302S, 302S, 302T…Second area 310...Mounting leg 1521S, 1521T…Top end surface 1522S, 1522T…Bottom end surface C1~C4...Cases O…Center R...Rotation direction

Claims

1. a compressor main body container; a motor disposed inside the compressor main body container; a compression unit disposed inside the compressor main body container, The compression section an annular cylinder that defines a cylinder chamber therein; an upper end plate that closes the upper end of the cylinder; a lower end plate that closes the lower end of the cylinder; a shaft rotated by the motor; a piston disposed inside the cylinder; a vane that divides the cylinder chamber into a suction chamber and a compression chamber; Equipped with When the direction along the rotation axis of the shaft is defined as the axial direction, a sliding portion where the end plate and the piston slide against each other is formed with a first region where a gap in the axial direction is formed between the end plate and the piston, and a second region where the gap in the axial direction is narrower than that in the first region, and the first region and the second region are continuous in a radial direction around the rotation axis. Rotary compressor.

2. The second region is formed over the entire circumferential direction around the rotation axis.

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

3. In the first region, the thickness of the end plate and the piston is constant, and in the second region, the thickness of one of the end plate and the piston varies.

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

4. In the second region, the thickness of the end plate varies in a radial direction around the rotation axis.

4. The rotary compressor according to claim 3, wherein:

5. In the second region, the thickness of the piston varies in a radial direction around the rotation axis.

4. The rotary compressor according to claim 3, wherein:

6. In the second region, a change in thickness is formed by a tapered portion provided on the end plate or the piston.

4. The rotary compressor according to claim 3, wherein:

7. In the second region, a thickness change is formed by a step portion provided on the end plate or the piston.

4. The rotary compressor according to claim 3, wherein:

8. In a sliding portion between the end plate and the piston, the second region is formed closer to the inside in the radial direction around the rotation axis than the first region.

4. The rotary compressor according to claim 3, wherein:

9. In the second region, the thickness of the end plate varies so as to become thinner from the inner side to the outer side in the radial direction around the rotation axis.

9. The rotary compressor according to claim 8, wherein:

10. In a sliding portion between the end plate and the piston, the first region is formed closer to the inside in the radial direction around the rotation axis than the second region.

4. The rotary compressor according to claim 3, wherein:

11. In the second region, the thickness of the piston changes so as to become thicker from the inner side toward the outer side in the radial direction of the central axis.

11. The rotary compressor according to claim 10.

12. A through hole through which the shaft is inserted is formed in the center of the end plate, the second region is formed at a position located outside an inner peripheral edge of the through hole in a radial direction around the rotation axis and inside an outer peripheral edge of the piston in a radial direction around the rotation axis when the piston revolves.

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

13. The annular cylinder includes two cylinders, a first cylinder and a second cylinder, The end plate is an intermediate partition plate sandwiched between the first cylinder and the second cylinder.

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

14. An oil supply hole is formed in the shaft to supply lubricating oil to the sliding portion.

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

15. A through hole through which the shaft is inserted is formed in the center of the lower end plate, An oil supply groove is formed on the inner circumferential surface of the through hole to supply lubricating oil to the sliding portion.

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

Images