JP2018115566A - Rotary Compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a compression efficiency of refrigerant.SOLUTION: When a first rotating angle of a piston positioned at a top dead center at a peripheral direction of a cylinder is set at a degree of 360 and the piston is positioned at a third rotating angle of a central value of an angle range formed by the first rotating angle and the second rotating angle where a pressure of a refrigerant in a compression chamber reaches a maximum value, a center of a rotating shaft is eccentrically displaced from a center of an inner diameter of the cylinder toward the side of the third rotating angle along a straight line connecting the center of the inner diameter of the cylinder with the position of the third rotating angle on the inner peripheral surface of the cylinder in such a way that a clearance between a position of the third rotating angle on the inner peripheral surface of the cylinder and the outer peripheral surface of the piston on a plane crossing at a right angle with an axial direction of the rotating shaft may become minimum at a peripheral direction of the cylinder.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a rotary compressor.

  For example, in an air conditioner or a refrigeration apparatus, a compressor is used to compress the refrigerant. As a compressor, a rotary compressor in which a cylinder chamber is divided into a suction chamber and a compression chamber by abutting a vane protruding into the cylinder chamber against an annular piston that rotates eccentrically in the cylinder is known. Yes.

  In this type of rotary compressor, in order for the piston to properly revolve along the inner peripheral surface of the cylinder in the cylinder, the outer peripheral surface of the piston that revolves along the inner peripheral surface of the cylinder and the inner peripheral surface of the cylinder A predetermined gap is provided between them. When the gap is reduced, the inner peripheral surface of the cylinder and the outer peripheral surface of the piston tend to come into contact with each other, and the compression efficiency is reduced by sliding. On the other hand, when the gap is increased, in the refrigerant compression process, from the high pressure compression chamber in the cylinder chamber, through the clearance between the outer peripheral surface of the piston revolving along the inner peripheral surface of the cylinder and the inner peripheral surface of the cylinder, There is a tendency for the amount of refrigerant leaking into the low pressure suction chamber to increase. As described above, the refrigerant leaks from the gap between the sliding portion between the outer peripheral surface of the piston and the inner peripheral surface of the cylinder, thereby causing a reduction in compression efficiency.

  In the related art rotary compressor, the inner peripheral surface of the cylinder is deformed into a predetermined shape that is not a perfect circle, and the rotation angle (crank angle) of the piston located at the top dead center in the circumferential direction of the cylinder is 0. As a degree, when the piston is located near 45 degrees and 225 degrees, a gap that is a separation distance between the outer peripheral surface of the piston and a position near 45 degrees on the inner peripheral surface of the cylinder (gap in the radial direction of the cylinder) And a technology for improving the compression efficiency of the refrigerant by setting the gap between the outer peripheral surface of the piston and a position near 225 degrees on the inner peripheral surface of the cylinder to be minimum in the circumferential direction of the cylinder. It has been.

International Publication No. 2013/179679

  By the way, in an air conditioner, for example, as an index indicating energy saving performance, performance evaluation considering annual energy consumption efficiency (APF: Annual Performance Factor), so-called energy saving operation, is performed. In a rotary compressor, the amount of refrigerant leaking from the gap between the outer peripheral surface of the piston and the inner peripheral surface of the cylinder tends to be larger during refrigerant compression than during refrigerant intake. Even in a configuration in which a gap between the outer peripheral surface and the inner peripheral surface of the cylinder is set, the refrigerant leaking from the gap generated during the compression of the refrigerant cannot be sufficiently suppressed, and the improvement of the refrigerant compression efficiency is insufficient. This is causing a decrease in APF. That is, from the viewpoint of increasing the APF, in the rotary compressor, it is preferable to suppress the amount of refrigerant leaking from the gap between the outer peripheral surface of the piston and the inner peripheral surface of the cylinder during the compression of the refrigerant.

  The disclosed technology has been made in view of the above, and an object thereof is to provide a rotary compressor capable of increasing the compression efficiency of the refrigerant.

  One aspect of the rotary compressor disclosed in the present application is a vertically-placed cylindrical compressor housing that is provided with a refrigerant discharge portion at an upper portion and a refrigerant suction portion at a lower portion, and is sealed, A compression unit that compresses the refrigerant sucked from the suction unit and is discharged from the discharge unit; and a motor that is disposed in the upper part of the compressor housing and drives the compression unit. The part includes an annular cylinder, an end plate that closes the upper side and the lower side of the cylinder, a rotating shaft that has an eccentric part and is rotated by the motor, and is fitted into the eccentric part and is fitted to the eccentric part. An annular piston that revolves along an inner peripheral surface and forms a cylinder chamber in the cylinder, and protrudes into the cylinder chamber from a vane groove provided in the cylinder and contacts the piston to make the cylinder chamber a suction chamber Ward in compression chamber In the rotary compressor having the vane to be operated, the first rotation angle of the piston located at the top dead center in the circumferential direction of the cylinder is 360 degrees, and the pressure of the refrigerant in the compression chamber When the piston is positioned at the third rotation angle that is the median value of the second rotation angle that reaches the maximum value, the inner peripheral surface of the cylinder on a plane that is orthogonal to the axial direction of the rotation shaft The center of the rotation axis is the center of the inner diameter of the cylinder and the center of the cylinder so that the gap between the position of the third rotation angle and the outer peripheral surface of the piston is minimized in the circumferential direction of the cylinder. It is characterized by being eccentric from the center of the inner diameter of the cylinder toward the position of the third rotation angle along a straight line connecting the position of the third rotation angle on the inner peripheral surface.

  According to one aspect of the rotary compressor disclosed in the present application, the compression efficiency of the refrigerant can be increased.

FIG. 1 is a longitudinal sectional view showing a rotary compressor of an embodiment. FIG. 2 is an exploded perspective view illustrating a compression unit of the rotary compressor according to the embodiment. FIG. 3 is a cross-sectional view of the compression portion of the rotary compressor of the embodiment as viewed from above. FIG. 4A is a cross-sectional view for explaining the position of the inner peripheral surface of the cylinder on which the outer peripheral surface of the piston slides when the piston is positioned at an arbitrary rotation angle in the compression section of the rotary compressor of the reference example. is there. FIG. 4B shows the position of the outer peripheral surface of the piston that slides on the inner peripheral surface of the cylinder when the rotation axis is eccentric from the center of the cylinder to the position side of an arbitrary rotation angle in the compression section of the rotary compressor of the embodiment. It is a cross-sectional view for demonstrating. FIG. 5 is a graph for explaining the rotation angle of the piston when the refrigerant pressure reaches the maximum value in the rotary compressor of the embodiment. FIG. 6 is a cross-sectional view for explaining changes in pressure in the compression chamber and the suction chamber in the cylinder chamber in the rotary compressor of the embodiment. FIG. 7 is a graph showing a gap generated in the compression process when the alignment angle is 270 degrees in the rotary compressor of the example. FIG. 8 is a graph showing a gap generated in the compression process in the case of center alignment in the rotary compressor of the reference example. FIG. 9 is a graph showing a gap generated in the compression process when the alignment angle is 225 degrees in the rotary compressor of the reference example. FIG. 10 is a graph showing a gap generated in the compression process when the alignment angle is 315 degrees in the rotary compressor of the reference example. FIG. 11 is a graph showing the relationship between the ratio of APF and the alignment angle of the rotating shaft in the rotary compressors of Examples and Reference Examples. FIG. 12 is a graph for explaining the relationship between the rotation angle of the piston and the compression ratio when the refrigerant pressure in the compression chamber reaches the maximum value in the rotary compressor of the example. FIG. 13 is a graph for explaining the relationship between the rotation angle of the piston and the compression ratio when the refrigerant pressure in the compression chamber reaches the maximum value in the rotary compressor of the example.

  Hereinafter, embodiments of a rotary compressor disclosed in the present application will be described in detail with reference to the drawings. In addition, the rotary compressor which this application discloses is not limited by the following examples.

(Configuration of rotary compressor)
FIG. 1 is a longitudinal sectional view showing a rotary compressor of an embodiment. FIG. 2 is an exploded perspective view illustrating a compression unit of the rotary compressor according to the embodiment. FIG. 3 is a cross-sectional view of the compression portion of the rotary compressor of the embodiment as viewed from above.

  As shown in FIG. 1, the rotary compressor 1 includes a compression unit 12 disposed at a lower portion in a sealed vertical cylindrical compressor housing 10 and a rotation portion disposed at an upper portion in the compressor housing 10. A motor 11 that drives the compression unit 12 via a shaft 15 and a vertically installed cylindrical accumulator 25 that is fixed and sealed to the outer peripheral surface of the compressor housing 10 are provided.

  The accumulator 25 is connected to the upper cylinder chamber 130T (see FIG. 2) of the upper cylinder 121T via the upper suction pipe 105 and the accumulator upper curved pipe 31T as the suction part, and the lower suction pipe 104 and the lower accumulator curve as the suction part. A lower cylinder chamber 130S (see FIG. 2) is connected to the lower cylinder 121S through a pipe 31S. In the present embodiment, the positions of the upper suction pipe 105 and the lower suction pipe 104 overlap in the circumferential direction of the compressor housing 10 and are located at the same position.

  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 peripheral surface of the compressor housing 10 by shrink fitting or welding. The rotor 112 is fixed to the rotating shaft 15 in a shrink-fitted state.

  The rotary shaft 15 is rotatably supported at the sub-shaft portion 151 below the lower eccentric portion 152S by the sub-bearing portion 161S provided on the lower end plate 160S, and the main shaft portion 153 above the upper eccentric portion 152T is at the upper end. The main bearing portion 161T provided on the plate 160T is rotatably supported. An upper eccentric portion 152T and a lower eccentric portion 152S are provided on the rotary shaft 15 with a phase difference of 180 degrees from each other. The upper piston 125T is supported by the upper eccentric portion 152T, and the lower eccentric portion The lower piston 125S is supported by 152S. As a result, the rotary shaft 15 is rotatably supported with respect to the entire compression section 12, and as shown in FIG. 3, the outer peripheral surface 139T of the upper piston 125T is rotated along the inner peripheral surface 137T of the upper cylinder 121T by rotation. The outer peripheral surface 139S of the lower piston 125S is revolved along the inner peripheral surface 137S of the lower cylinder 121S.

  Inside the compressor housing 10, the lubrication of sliding parts such as the upper cylinder 121T and the upper piston 125T and the lower cylinder 121S and the lower piston 125S sliding in the compression part 12 is secured, and the upper compression chamber 133T (FIG. 2) and the lower compression chamber 133 </ b> S (see FIG. 2) are sealed with a lubricating oil 18 in an amount that substantially immerses the compression portion 12. An attachment leg 310 (see FIG. 1) that fixes a plurality of elastic support members (not shown) that support the entire rotary compressor 1 is fixed to the lower side of the compressor housing 10.

  As shown in FIG. 1, the compression unit 12 compresses the refrigerant sucked from the upper suction pipe 105 and the lower suction pipe 104 and discharges it from a discharge pipe 107 described later. As shown in FIG. 2, the compression portion 12 includes, from above, an upper end plate cover 170 </ b> T having a bulging portion in which a hollow space is formed, an upper end plate 160 </ b> T, an annular upper cylinder 121 </ b> T, an intermediate partition plate 140, The lower cylinder 121S, the lower end plate 160S, and a flat plate-like lower end plate cover 170S are laminated. The entire compression unit 12 is fixed by a plurality of through bolts 174 and 175 and auxiliary bolts 176 arranged substantially concentrically from above and below.

  As shown in FIG. 3, a cylindrical inner peripheral surface 137T is formed in the upper cylinder 121T. An upper piston 125T having an outer diameter smaller than the inner diameter of the inner peripheral surface 137T of the upper cylinder 121T is disposed inside the inner peripheral surface 137T of the upper cylinder 121T. The inner peripheral surface 137T and the upper piston 125T of the upper cylinder 121T are disposed. An upper compression chamber 133T is formed between the outer peripheral surface 139T and the refrigerant. A cylindrical inner peripheral surface 137S is formed on the lower cylinder 121S. A lower piston 125S having an outer diameter smaller than the inner diameter of the inner peripheral surface 137S of the lower cylinder 121S is disposed inside the inner peripheral surface 137S of the lower cylinder 121S. The inner peripheral surface 137S and the lower piston 125S of the lower cylinder 121S are disposed. A lower compression chamber 133S is formed between the outer peripheral surface 139S and the refrigerant.

  As shown in FIGS. 2 and 3, the upper cylinder 121 </ b> T has an upper protrusion 122 </ b> T that protrudes from the circular outer peripheral portion in the radial direction of the cylindrical inner peripheral surface 137 </ b> T. The upper protruding portion 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 in the upper vane groove 128T. The lower cylinder 121S has a lower side protruding portion 122S protruding from the circular outer peripheral portion in the radial direction of the cylindrical inner peripheral surface 137S. The lower side protrusion 122S is provided with a lower vane groove 128S extending radially outward from the lower cylinder chamber 130S. A lower vane 127S is slidably disposed in the lower vane groove 128S.

  The upper protrusion 122T is formed over a predetermined protrusion range along the circumferential direction of the inner peripheral surface 137T of the upper cylinder 121T. The lower side protrusion 122S is formed over a predetermined protrusion range along the circumferential direction of the inner peripheral surface 137S of the lower cylinder 121S. The upper side protruding part 122T and the lower side protruding part 122S are used as chuck holding parts for fixing to the processing jig when the upper cylinder 121T and the lower cylinder 121S are processed.

  An upper spring hole 124T is provided in the upper protruding portion 122T at a depth that does not penetrate the upper cylinder chamber 130T at a position overlapping the upper vane groove 128T from the outer surface. An upper spring 126T is disposed in the upper spring hole 124T. A lower spring hole 124S is provided in the lower side protrusion 122S at a position that overlaps with the lower vane groove 128S from the outer surface with a depth that does not penetrate the lower cylinder chamber 130S. A lower spring 126S is disposed in the lower spring hole 124S.

  Further, the compressed refrigerant in the compressor housing 10 is introduced into the upper cylinder 121T by communicating the radially outer side of the upper vane groove 128T with the inside of the compressor housing 10 through the opening, and the compressed air in the compressor housing 10 is introduced into the upper vane 127T. An upper pressure introduction path 129T that applies back pressure by the pressure of the refrigerant is formed. Further, the refrigerant compressed in the compressor housing 10 is introduced into the lower cylinder 121S through the radially outer side of the lower vane groove 128S and the compressor housing 10, and the pressure of the refrigerant is applied to the lower vane 127S. Thus, a lower pressure introduction path 129S for applying back pressure is formed.

  An upper suction hole 135T that fits into the upper suction pipe 105 is provided in the upper protruding portion 122T of the upper cylinder 121T. A lower suction hole 135S that fits into the lower suction pipe 104 is provided in the lower side protruding portion 122S of the lower cylinder 121S.

  As shown in FIG. 2, the upper cylinder chamber 130T is closed by an upper end plate 160T and an intermediate partition plate 140 on the upper and lower sides, respectively. The lower cylinder chamber 130S is closed at the top and bottom by an intermediate partition plate 140 and a lower end plate 160S, respectively.

  The upper cylinder chamber 130T is provided in the upper suction chamber 131T communicating with the upper suction hole 135T and the upper end plate 160T by the upper vane 127T being pressed by the upper spring 126T and contacting the outer peripheral surface 139T of the upper piston 125T. The upper compression chamber 133T communicates with the upper discharge hole 190T. The lower cylinder chamber 130S is provided in a lower suction chamber 131S communicating with the lower suction hole 135S and a lower end plate 160S by the lower vane 127S being pressed by the lower spring 126S and coming into contact with the outer peripheral surface 139S of the lower piston 125S. And a lower compression chamber 133S communicating with the lower discharge hole 190S.

  The upper discharge hole 190T is provided in the vicinity of the upper vane groove 128T, and the lower discharge hole 190S is provided in the vicinity of 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.

  As shown in FIG. 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. An upper valve seat (not shown) is formed around the discharge hole 190T. The upper end plate 160T is formed with an upper discharge valve accommodating recess 164T extending in a groove shape from the position of the upper discharge hole 190T toward the outer periphery of the upper end plate 160T.

  The upper discharge valve accommodating recess 164T has a reed valve type upper discharge valve 200T whose rear end is fixed by an upper rivet 202T in the upper discharge valve accommodating recess 164T and whose front end opens and closes the upper discharge hole 190T, and a rear end Is overlapped with the upper discharge valve 200T and fixed in the upper discharge valve housing recess 164T by the upper rivet 202T, and the front end is bent (warped) in the direction in which the upper discharge valve 200T opens, thereby opening the upper discharge valve 200T. The entire upper discharge valve presser 201T to be regulated is accommodated.

  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) extending in a groove shape from the position of the lower discharge hole 190S toward the outer periphery of the lower end plate 160S.

  The lower discharge valve housing recess has a reed valve type lower discharge valve 200S whose rear end is fixed in the lower discharge valve housing recess by a lower rivet 202S and whose front end opens and closes the lower discharge hole 190S. The bottom of the lower discharge valve 200S is superposed on the discharge valve 200S and fixed in the lower discharge valve housing recess by the lower rivet 202S, and the front end is bent (warped) in the opening direction of the lower discharge valve 200S. The entire discharge valve presser 201S is accommodated.

  An upper end plate cover chamber 180T is formed between the upper end plate 160T and the upper end plate cover 170T having a bulging portion that are closely 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 plate-like lower end plate cover 170S which are closely fixed to each other. A refrigerant passage hole 136 that penetrates 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 the lower end plate cover chamber 180S and the upper end plate cover chamber 180T is provided.

  Below, the flow of the refrigerant | coolant by rotation of the rotating shaft 15 is demonstrated. In the upper cylinder chamber 130T, the rotation of the rotation shaft 15 causes the upper piston 125T fitted to the upper eccentric portion 152T of the rotation shaft 15 to revolve along the inner peripheral surface 137T of the upper cylinder 121T. The suction chamber 131T sucks the refrigerant from the upper suction pipe 105 while increasing the volume, the upper compression chamber 133T compresses the refrigerant while reducing the volume, and the pressure of the compressed refrigerant is the upper end plate cover outside the upper discharge valve 200T. When the pressure in the chamber 180T becomes higher, the upper discharge valve 200T is opened, 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 from an upper end plate cover discharge hole 172T (see FIG. 1) provided in the upper end plate cover 170T.

  Further, in the lower cylinder chamber 130S, the rotation of the rotation shaft 15 causes the lower piston 125S fitted to the lower eccentric portion 152S of the rotation shaft 15 to revolve along the inner peripheral surface 137S of the lower cylinder 121S. The lower suction chamber 131S sucks the refrigerant from the lower suction pipe 104 while increasing the volume, and the lower compression chamber 133S compresses the refrigerant while reducing the volume, and the pressure of the compressed refrigerant becomes the lower end outside the lower discharge valve 200S. When the pressure in the plate cover chamber 180S becomes higher, 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 provided in the upper end plate cover 170T. .

  The refrigerant discharged into the compressor housing 10 is notched (not shown) provided on the outer periphery of the stator 111 and communicated with the upper and lower sides, or a gap (not shown) between winding portions of the stator 111, or the stator 111. Is guided to the upper side of the motor 11 through a gap 115 (see FIG. 1) between the rotor 112 and the rotor 112, and is discharged from a discharge pipe 107 serving as a discharge portion disposed on the upper portion of the compressor housing 10.

(Characteristic configuration of rotary compressor)
Next, a characteristic configuration of the rotary compressor 1 of the embodiment will be described. Hereinafter, for convenience of explanation, the upper cylinder 121T and the lower cylinder 121S are referred to as a cylinder 121, the upper piston 125T and the lower piston 125S are referred to as a piston 125, and the upper discharge hole 190T and the lower discharge hole 190S are referred to as a discharge hole 190. Similarly, for convenience of explanation, the upper cylinder chamber 130T and the lower cylinder chamber 130S are the cylinder chamber 130, the upper compression chamber 133T and the lower compression chamber 133S are the compression chamber 133, the upper suction chamber 131T and the lower suction chamber 131S are the suction chamber 131, The eccentric part 152S and the lower eccentric part 152T are referred to as the eccentric part 152. Similarly, for convenience of explanation, the inner peripheral surface 137T of the upper cylinder 121T and the inner peripheral surface 137S of the lower cylinder 121S are replaced with the inner peripheral surface 137 of the cylinder 121, the outer peripheral surface 139T of the upper piston 125T, and the outer peripheral surface 139S of the lower piston 125S. Is referred to as the outer peripheral surface 139 of the piston 125.

  In the rotary compressor 1 of the embodiment, as shown in FIG. 3, the center O <b> 1 of the rotating shaft 15 is the center of the inner diameter of the cylinder 121 on a plane parallel to the radial direction of the cylinder 121 (the radial direction of the rotating shaft 15). It is eccentrically provided in a predetermined direction with respect to O2 (center O2 in the radial direction of the cylinder 121).

Specifically, the first rotation angle θ1 of the piston 125 located at the top dead center in the circumferential direction of the cylinder 121 is set to 360 degrees, and the first rotation angle θ1 and the pressure of the refrigerant in the compression chamber 133 are maximum values. The median value of the angle range formed by the second rotation angle θ2 reaching the third rotation angle θ3 is defined as a third rotation angle θ3. When the piston 125 is positioned at the third rotation angle θ3, the position of the third rotation angle θ3 on the inner peripheral surface of the cylinder 121 and the outer peripheral surface 139 of the piston 125 on the plane orthogonal to the axial direction of the rotary shaft 15 The center O1 of the rotary shaft 15 is eccentric from the center O2 of the inner diameter of the cylinder 121 so that the gap D (the gap D, which is a separation distance with respect to the radial direction of the cylinder 121) is minimized in the circumferential direction of the cylinder 121. ing. On the plane orthogonal to the axial direction of the rotating shaft 15, the center O 1 of the rotating shaft 15 is the center O 2 of the inner diameter of the cylinder 121 and the position of the third rotation angle θ 3 on the inner peripheral surface 137 of the cylinder 121 (hereinafter referred to as the first rotation angle). Along a straight line (hereinafter referred to as an eccentric line Le) connecting the three rotation angles θ3) and decentering from the center O2 of the inner diameter of the cylinder 121 toward the position of the third rotation angle θ3. Yes. Although details will be described later, in the present embodiment, for example, the second rotation angle θ2 is 180 degrees, and the center O1 of the rotation shaft 15 extends from the center O2 of the inner diameter of the cylinder 121 on the inner peripheral surface 137 of the cylinder 121. To the position side of 270 degrees that is the third rotation angle θ3, that is, the center O1 of the rotation shaft 15 is eccentric along an eccentric line Le passing through the center O2 of the inner diameter of the cylinder 121 (the position is shifted). ) The third rotation angle θ3 is calculated as follows, for example.
(360 degrees-180 degrees) / 2 = 90 degrees, 180 degrees (second rotation angle θ2) +90 degrees = 270 degrees (third rotation angle θ)

  Here, the gap D generated between the inner peripheral surface 137 of the cylinder 121 and the outer peripheral surface 139 of the piston 125 when the center O1 of the rotating shaft 15 is eccentric will be described. 4A illustrates the position of the inner peripheral surface 137 of the cylinder 121 on which the outer peripheral surface 139 of the piston 125 slides when the piston 125 is positioned at an arbitrary rotation angle in the compression unit 12 of the rotary compressor 1 of the reference example. It is a cross-sectional view for doing. FIG. 4B shows that, in the compression section 12 of the rotary compressor 1 of the embodiment, the rotation shaft 15 is eccentric from the center O2 of the inner diameter of the cylinder 121 to the position side of an arbitrary rotation angle on the inner peripheral surface 137 of the cylinder 121. It is a cross-sectional view for explaining the position of the outer peripheral surface 139 of the piston 125 that slides on the inner peripheral surface 137 of the cylinder 121 when it is eccentric along the top. 4A and 4B, the horizontal direction on the drawings is the X direction, and the vertical direction is the Y direction.

In the reference example shown in FIG. 4A, the center O1 of the rotating shaft 15 and the center O2 of the inner diameter of the cylinder 121 coincide with each other on a plane orthogonal to the axial direction of the rotating shaft 15. As shown in FIG. 4A, when the piston 125 is positioned at an arbitrary rotation angle θa (in FIG. 4A, the angle θa is shown as 60 degrees as an example) on a plane orthogonal to the axial direction of the rotation shaft 15. The coordinates of the position of the inner peripheral surface 137 of the cylinder 121 on which the outer peripheral surface 139 of the piston 125 slides are as follows:
X coordinate: r1 × sin θa (Formula 1)
Y coordinate: r1 × cos θa (Expression 2)
It becomes.

In the reference example shown in FIG. 4A, the center O1 of the rotating shaft 15 and the center O2 of the inner diameter of the cylinder 121 coincide with each other on the plane orthogonal to the axial direction of the rotating shaft 15, so that the piston When the 125 is positioned at an arbitrary rotation angle θa, the coordinates of the position of the inner peripheral surface 137 of the cylinder 121 on which the outer peripheral surface 139 of the piston 125 slides are such that the radius of the outer diameter of the piston 125 is r2, and When the eccentric amount of the center O3 of the eccentric portion 152 with respect to the center O1 is a,
X coordinate: (r2 + a) × sin θa (Expression 3)
Y coordinate: (r2 + a) × cos θa (Expression 4)
It becomes.

In contrast to the reference example shown in FIG. 4A, in the embodiment shown in FIG. 4B, the center O <b> 1 of the rotating shaft 15 is eccentric from the center O <b> 2 of the inner diameter of the cylinder 121. As shown in FIG. 4B, on the plane orthogonal to the axial direction of the rotating shaft 15, the center O1 of the rotating shaft 15 extends along the eccentric line Le from the center O2 of the inner diameter of the cylinder 121 to the position side of an arbitrary rotation angle. As for the coordinates of the position of the inner peripheral surface 137 of the cylinder 121 on which the outer peripheral surface 139 of the piston 125 slides, the eccentric amount of the center O1 of the rotating shaft 15 with respect to the center O2 of the cylinder 121 is b, When the rotation angle formed by the direction in which the rotation shaft 15 is eccentric with respect to the first rotation angle θ1 is θb (in FIG. 4B, the angle θb is shown as 225 degrees as an example),
X coordinate: b × sin θb (Formula 5)
Y coordinate: b × cos θb (Formula 6)
It becomes.

When the center O1 of the rotating shaft 15 is eccentric by an eccentric amount b as shown in FIG. 4A on a plane orthogonal to the axial direction of the rotating shaft 15, the piston 125 is positioned at an arbitrary rotation angle θb. The coordinates of the position of the inner peripheral surface 137 of the cylinder 121 on which the outer peripheral surface 139 of the piston 125 slides are:
X coordinate: (Formula 3) + (Formula 5)
= (R2 + a) × sin θa + (b × sin θb) (Expression 7)
Y coordinate: (Formula 4) + (Formula 6)
= (R2 + a) × cos θa) + (b × cos θb) (Equation 8)
It becomes.

Therefore, when the piston 125 is positioned at an arbitrary rotation angle θa, the gap D generated between the outer peripheral surface 139 of the piston 125 and the inner peripheral surface 137 of the cylinder 121 can be expressed as follows.
X coordinate: (Formula 1)-(Formula 7) (Formula 9)
Y coordinate: (Formula 2)-(Formula 8) (Formula 10)
Therefore, the dimension of the gap D is approximately √ [(Equation 9) ² + (Equation 10) ² ] (Equation 11).
Sought by.

  Here, as an example, the center O2 of the inner diameter of the cylinder 121 and the center O1 of the rotating shaft 15 are made to coincide with each other, and the gap D between the inner peripheral surface 137 of the cylinder 121 and the outer peripheral surface 139 of the piston 125 is The amount of eccentricity of the rotary shaft 15 in the embodiment will be described in comparison with the configuration of the reference example that is uniformly set to 30 [μm] over the entire circumferential direction of the inner peripheral surface 137. In the present embodiment, as an example, the eccentric amount of the rotating shaft 15 is set to 10 [μm].

  As shown in FIG. 3, when the centering O1 of the rotating shaft 15 is brought closer to the position of the rotational angle of 270 degrees by 10 [μm] as in the above-described embodiment, the rotational angle is 270, as shown in FIG. The clearance D between the outer peripheral surface 139 of the piston 125 positioned at a degree and the position of 270 degrees on the inner peripheral surface 137 of the cylinder 121 is 30 [μm] to 20 [μm] (= 30 [μm] −10 [μm). ]). Therefore, the minimum value of the gap D in the circumferential direction of the inner peripheral surface 137 of the cylinder 121 is 20 [μm]. In addition, the gap D between the outer peripheral surface 139 of the piston 125 positioned at a rotation angle of 90 degrees and the 90-degree position on the inner peripheral surface 137 of the cylinder 121 is 30 [μm] to 40 [μm] (= 30 [ μm] +10 [μm]). Therefore, the gap D at the position of 270 degrees on the inner peripheral surface 137 of the cylinder 121 is ½ of the gap D at the position of 90 degrees.

  Note that the minimum value of the gap D between the outer peripheral surface 139 of the piston 125 positioned at a rotational angle of 270 degrees and the position of 270 degrees on the inner peripheral surface 137 of the cylinder 121 is 10 [μm] or more and 40 [μm]. The following is preferred. When the gap D exceeds 40 [μm], the effect of suppressing the refrigerant leaking from the gap D between the inner peripheral surface 137 of the cylinder 121 and the outer peripheral surface 139 of the piston 125 is not preferable. When the gap D is less than 10 [μm], there is a high possibility that the inner peripheral surface 137 of the cylinder 121 and the outer peripheral surface 139 of the piston 125 are worn, which is not preferable.

  Further, in the embodiment, each gap D between the outer peripheral surface 139 of the piston 125 and the inner peripheral surface 137 of the cylinder 121 that is located at each rotation angle of 180 degrees and 360 degrees (0 degrees) is 30 [μm]. There is no change compared to the configuration of the reference example in which the center O2 of the inner diameter of the cylinder 121 and the center O1 of the rotating shaft 15 coincide. When the piston 125 is positioned at each of the rotation angles of 315 degrees and 225 degrees that are shifted by 45 degrees with respect to 270 degrees, the outer peripheral surface 139 of the piston 125 and the position of 315 degrees on the inner peripheral surface 137 of the cylinder 121 The clearance D and the clearance D between the outer peripheral surface 139 of the piston 125 and the position of 225 degrees on the inner peripheral surface 137 of the cylinder 121 are from 20 [μm] (270 degrees) to 30 [μm] (180 degrees, 360 [deg.] (0 [deg.]), Which is an intermediate value that gradually changes to 25 [[mu] m]. In addition, when the piston 125 is positioned at 45 degrees and 135 degrees rotated by 45 degrees with respect to 90 degrees, the position of 45 degrees on the outer peripheral surface 139 of the piston 125 and the inner peripheral surface 137 of the cylinder 121 The gap D between the outer peripheral surface 139 of the piston 125 and the position of 135 degrees on the inner peripheral surface 137 of the cylinder 121 is 40 [μm] (90 degrees) to 30 [μm] (0 35 [μm] because it is the middle gradually changing to degrees (360 degrees) and 180 degrees).

  Thus, in the embodiment, when the piston 125 is positioned at a rotation angle of 270 degrees, the gap D between the outer peripheral surface 139 of the piston 125 and the position of 270 degrees on the inner peripheral surface 137 of the cylinder 121 is When the piston 125 is positioned at a rotation angle of 90 degrees in the circumferential direction of the inner circumferential surface 137, the gap between the outer circumferential surface 139 of the piston 125 and the 90-degree position on the inner circumferential surface 137 of the cylinder 121 D is the maximum value. In the embodiment, 20 [μm] that is the minimum value of the gap D in the circumferential direction of the cylinder 121 is set to ½ of 40 [μm] that is the maximum value of the gap D, and is set to 2/3 or less. It is preferable to do. Further, the gap D at the position of 270 degrees as the third rotation angle θ3 is 20 [μm], and the gap D at the position of 360 degrees as the first rotation angle θ1 and 180 degrees as the second rotation angle θ2 is 30. [Μm]. That is, the gap D at the position of 270 degrees is set to 2/3 of the gap D at the positions of 360 degrees and 180 degrees, and is preferably set to 4/5 or less.

  In addition, as a result of aligning the center O1 of the rotating shaft 15 so that the gap D between the outer peripheral surface 139 of the piston 125 and the position of 270 degrees on the inner peripheral surface 137 of the cylinder 121 becomes the minimum value as described above, The gap D becomes relatively large in the angle range where the rotation angle of 125 is 0 to 180 degrees. However, in the compression process in this angular range, since the pressure of the refrigerant in the compression chamber 133 is relatively low, the amount of refrigerant leaking from the gap D is relatively small, and there is no inconvenience due to the gap D becoming large. .

  Here, as an example, when a rotary compressor having a compression ratio of about twice is used with an air conditioner, a rotation angle at which the refrigerant pressure reaches a maximum value, that is, a rotation angle when the refrigerant compression is completed will be described. FIG. 5 is a graph for explaining the rotation angle of the piston 125 when the refrigerant pressure reaches the maximum value in the rotary compressor 1 of the embodiment. In FIG. 5, the vertical axis indicates the refrigerant pressure [MPaG] (gauge pressure) in the compression chamber 133, and the horizontal axis indicates the rotation angle [deg] of the piston 125 in the circumferential direction of the inner peripheral surface 137 of the cylinder 121. .

  Here, the use state in the air conditioner is classified into refrigerant rating, cooling middle, heating rating, and heating middle, and changes in refrigerant pressure in the rotary compressor 1 are shown. The cooling rating and the heating rating refer to a state where the air conditioner is used at a rated output. The cooling middle and the heating middle indicate a state in which the air conditioner is used at an output almost half of the rated output. In FIG. 5, the curve connecting the square marks indicates the cooling rating, and the curve connecting the triangle marks indicates the middle of the cooling. Similarly, in FIG. 5, the curve connecting the cross marks indicates the heating rating, and the curve connecting the diamond marks Indicates intermediate heating.

  In the rotary compressor 1, after the pressure of the refrigerant in the compression chamber 133 rises and reaches a predetermined maximum value, the refrigerant in the compression chamber 133 starts to be gradually discharged from the compression chamber 133 through the discharge hole 190. The refrigerant pressure in the chamber 133 becomes a substantially constant value, and the discharge of the refrigerant is completed while keeping the refrigerant pressure at a constant value. Therefore, in FIG. 5, after the refrigerant pressure increases, the rotation angle at which the refrigerant pressure changes constant is the rotation angle at which the refrigerant pressure in the compression chamber 133 reaches the maximum value (second rotation angle θ2). Thus, it can be said that the compression completion angle at which the compression of the refrigerant in the compression chamber 133 is substantially completed.

  Therefore, as shown in FIG. 5, the rotation angle of the piston 125 (hereinafter also referred to as the compression completion angle) when the refrigerant pressure in the compression chamber 133 reaches the maximum value is about 205 degrees in the case of the cooling rating. Yes, in the middle of cooling, it is about 160 degrees. Similarly, the rotation angle of the piston 125 when the pressure of the refrigerant in the compression chamber 133 reaches the maximum value is about 205 degrees in the case of heating rating, and about 180 degrees in the middle of heating.

  Based on the compression completion angles in these four use states, from the viewpoint of the year-round energy consumption efficiency (APF) of the air conditioner, when used throughout the year, representative of the compression completion angles in the rotary compressor 1 Calculate the value. For example, when calculating APF in Japan, the ratio of each usage time in the four usage states to the total usage time of the air conditioner is roughly 5% for the cooling rating, 20% for the cooling middle, and the heating rating. It is calculated as 20% and heating middle is 55%.

  Therefore, when the representative value of the rotation angle (compression completion angle) at which the pressure of the refrigerant in the compression chamber 133 reaches the maximum value is calculated based on the ratio of each use time in the four use states, the representative value is the cooling rating. (205 degrees x 5%), cooling middle (160 degrees x 20%), heating rating (205 degrees x 20%), and heating middle (180 degrees x 55%). That is, the typical value of the compression completion angle is (205 degrees × 5%) + (160 degrees × 20%) + (205 degrees × 20%) + (180 degrees × 55%) = 182.55 degrees≈180 degrees. Become. In addition, since the usage time during heating is the largest proportion of the total usage time of the air conditioner, and the compression completion angle during heating is 180 degrees, the typical compression completion angle is 180 degrees. Can be considered.

  As described above, the change in the refrigerant pressure in the cylinder chamber 130 of the rotary compressor 1 will be described in the case where the rotation angle at which the refrigerant pressure in the compression chamber 133 reaches the maximum value is 180 degrees. FIG. 6 is a cross-sectional view for explaining changes in pressure in the compression chamber 133 and the suction chamber 131 in the cylinder chamber 130 in the rotary compressor 1 of the embodiment. FIG. 6 shows a state in which the rotation angle of the piston 125 sequentially changes to 0 degree, 45 degrees, 90 degrees, 135 degrees, 180 degrees, 225 degrees, 270 degrees, 315 degrees, and 360 degrees (0 degrees).

  As shown in FIG. 6, in the cylinder chamber 130 of the rotary compressor 1, when the rotation angle of the piston 125 in the circumferential direction of the cylinder 121 is in the angle range of 0 degrees (360 degrees) to 45 degrees, the refrigerant in the compression chamber 133 The pressure is relatively low. Subsequently, when the rotation angle of the piston 125 is in an angle range of about 90 degrees to about 135 degrees, the refrigerant pressure in the compression chamber 133 gradually increases, but the refrigerant pressure in the compression chamber 133 and the suction chamber 131 are increased. Since the difference from the pressure of the internal refrigerant is relatively small, the refrigerant in the compression chamber 133 does not leak into the suction chamber 131.

  Next, when the rotation angle of the piston 125 reaches about 180 degrees, the pressure of the refrigerant in the compression chamber 133 reaches the maximum compression angle as described above, and the pressure of the refrigerant in the compression chamber 133 and the suction chamber The difference with the pressure of the refrigerant in 131 becomes relatively large. For this reason, the refrigerant in the compression chamber 133 tends to leak into the suction chamber 131 through the gap D between the outer peripheral surface 139 of the piston 125 and the inner peripheral surface 137 of the cylinder 121. Thus, the tendency for the refrigerant to leak from the gap D between the outer peripheral surface 139 of the piston 125 and the inner peripheral surface 137 of the cylinder 121 is that the pressure of the refrigerant in the compression chamber 133 is maintained at the maximum value after the compression completion angle. The rotation angle of the piston 125 occurs over an angle range of about 180 degrees to 360 degrees.

  Here, the center O1 of the rotating shaft 15 is set along a decentered line Le from the center O2 of the inner diameter of the cylinder 121 on the inner peripheral surface 137 of the cylinder 121 (hereinafter also referred to as an alignment angle). The average value of the gap D generated between the inner peripheral surface 137 of the cylinder 121 and the outer peripheral surface 139 of the piston 125 (hereinafter, referred to as “decentered”) An example and a reference example are compared and demonstrated. Further, as a reference example, alignment (hereinafter referred to as center alignment) is shown in which the center O2 of the inner diameter of the cylinder 121 and the center O1 of the rotating shaft 15 coincide with each other.

  FIG. 7 is a graph showing the gap D generated in the compression process when the alignment angle is 270 degrees in the rotary compressor 1 of the embodiment. FIG. 8 is a graph showing the gap D generated in the compression process in the case of center alignment in the rotary compressor of the reference example. FIG. 9 is a graph showing a gap D generated in the compression process when the alignment angle is 225 degrees in the rotary compressor of the reference example. FIG. 10 is a graph showing a gap D generated in the compression process when the alignment angle is 315 degrees in the rotary compressor of the reference example. 7, 8, 9, and 10, the vertical axis indicates the gap D [μm] between the inner peripheral surface 137 of the cylinder 121 and the outer peripheral surface 139 of the piston 125, and the horizontal axis indicates the rotation angle of the piston 125. Indicates. On the horizontal axis of FIGS. 7, 8, 9 and 10, the angle range where the rotation angle of the piston 125 is 180 degrees to 360 degrees is indicated by an arrow, and this angle range is after the completion of the compression of the refrigerant in the compression chamber 133. To the compression process until the discharge of the refrigerant in the compression chamber 133 is completed.

  First, in the rotary compressor 1 of the embodiment, when the alignment angle of the rotary shaft 15 is 270 degrees, as shown in FIG. 7, the average gap is 24 in the angle range where the rotation angle of the piston 125 is 180 degrees to 360 degrees. .8 [μm]. On the other hand, in the reference example, when the rotation shaft 15 is centered, as shown in FIG. 8, the average clearance in the angle range of the piston 125 from 180 degrees to 360 degrees was 30 [μm]. In the reference example, when the alignment angle of the rotary shaft 15 is 225 degrees, as shown in FIG. 9, the average gap is 26.5 [μm] in the angle range where the rotation angle of the piston 125 is 180 degrees to 360 degrees. Met. Further, in the reference example, when the alignment angle of the rotation shaft 15 is 315 degrees, as shown in FIG. 10, the average gap in the angle range where the rotation angle of the piston 125 is 180 degrees to 360 degrees is 26.5 [μm]. Met. Therefore, in the example, by setting the alignment angle of the rotating shaft 15 to 270 degrees, the average gap in the angle range where the rotation angle of the piston 125 is 180 degrees to 360 degrees can be reduced.

  FIG. 11 is a graph showing the relationship between the APF ratio and the alignment angle of the rotating shaft 15 in the rotary compressors of the example and the reference example. In FIG. 11, the vertical axis indicates the ratio to the APF value of the configuration in which the alignment angle is 225 degrees, and the horizontal axis indicates the alignment angle (deg) of the rotating shaft 15. Here, the ratio of the APF value when the rotary compressor is used together with an air conditioner having an output of 4.0 [kW] is shown.

  As shown in FIG. 11, the ratio of the APF of the reference example in which the alignment angle of the rotating shaft 15 is 225 degrees is 100%, and the ratio of the APF of the reference example in which the alignment angle is 180 degrees is 99.4%. As compared with the reference example in which the alignment angle is 225 degrees, it was lowered. In addition, the ratio of the APF in the reference example in which the alignment angle is 315 degrees is about 100.1%, which is slightly higher than that in the reference example in which the alignment angle is 225 degrees.

  On the other hand, the ratio of the AFP in the example in which the alignment angle is 270 degrees is about 100.4%, which is higher than the reference examples in which the alignment angle is 225 degrees and other reference examples. Therefore, from the comparison result shown in FIG. 11, in the rotary compressor 1, it is possible to increase the APF by setting the alignment angle of the rotating shaft 15 to 270 degrees.

In this embodiment, as an example, by setting the compression completion angle to 180 degrees, the alignment angle of the rotating shaft 15 is set to 270 degrees. However, as described in other embodiments described later, the adjustment angle is adjusted. The core angle is not limited. Further, in the embodiment, the alignment angle is set from the viewpoint of increasing the APF in the usage state of the air conditioner throughout the year. For example, the alignment is performed so as to maximize the efficiency in the usage state of the heating rating. An angle may be set. In this case, since the compression completion angle at the heating rating is 205 degrees, the third rotation angle θ3 that is the alignment angle of the rotating shaft 15 is calculated as follows, for example.
(360 degrees-205 degrees) /2=77.5 degrees, 205 degrees (second rotation angle θ2) +77.5 degrees = 282.5 degrees (third rotation angle θ)

(Rotating shaft alignment process)
In the rotary compressor 1 configured as described above, for example, the rotation shaft 15 is supported by the main bearing portion 161T (sub-bearing portion 161S) and the position of the rotation shaft 15 is fixed. The radial position of the cylinder 121 is adjusted with respect to the direction. As a result, the position of the center O1 of the rotary shaft 15 is relatively adjusted with respect to the center O2 of the inner diameter of the cylinder 121, and the rotary shaft 15 is positioned while being eccentric with a desired eccentric amount. Thus, the alignment process is completed by fixing the cylinder 121 positioned with respect to the rotating shaft 15 fixed by the main bearing portion 161T (sub-bearing portion 161S) to the upper end plate 160T (lower end plate 160S). . In the two-cylinder rotary compressor 1, the rotation shaft 15 is eccentric by a desired eccentric amount by adjusting the center O2 of the upper cylinder 121T and the lower cylinder 121S with respect to the center O1 of the rotation shaft 15, respectively. ing. In addition, although the present Example was applied to the 2-cylinder type rotary compressor, it is not limited to a 2-cylinder type, and may be applied to a 1-cylinder type rotary compressor.

  Further, the cylindrical inner peripheral surface 137 of the cylinder 121 and the cylindrical outer peripheral surface 139 of the cylindrical piston 125 are processed in advance into a perfect circle with, for example, a circularity with a dimensional accuracy of the order of several [μm]. . For this reason, even when the minimum value of the gap D between the inner peripheral surface 137 of the cylinder 121 and the outer peripheral surface 139 of the piston 125 is set to about 20 [μm], the inner peripheral surface 137 of the cylinder 121 and the piston 125 A decrease in compression efficiency due to wear with the outer peripheral surface 139 or the like is suppressed.

  In the rotary compressor 1 of the embodiment, the first rotation angle θ1 of 360 degrees and the third rotation of the median value of the angle range formed by the second rotation angle θ2 at which the refrigerant pressure in the compression chamber 133 reaches the maximum value. When the piston 125 is positioned at the angle θ 3, the gap between the position of the third rotation angle θ 3 on the inner peripheral surface 137 of the cylinder 121 and the outer peripheral surface 139 of the piston 125 is minimized in the circumferential direction of the cylinder 121. The center O1 of the rotation shaft 15 is eccentric along the eccentric line Le from the center O2 of the inner diameter of the cylinder 121 toward the position of the third rotation angle θ3. Thereby, the compression process (for example, an angle of 180 degrees to 360 degrees) from the second rotation angle θ2 after completion of the compression of the refrigerant in the compression chamber 133 to the first rotation angle θ1 at which the refrigerant discharge of the compression chamber 133 is completed. (Range), the refrigerant can be prevented from leaking from the compression chamber 133 to the suction chamber 131. For this reason, the compression efficiency of the refrigerant in the compression chamber 133 can be increased.

  Further, in the rotary compressor 1 of the embodiment, in the circumferential direction of the cylinder 121, the minimum value of the gap D between the inner peripheral surface 137 of the cylinder 121 and the outer peripheral surface 139 of the piston 125 is 2/3 of the maximum value of the gap D. It is as follows. Thereby, it is possible to appropriately prevent the refrigerant from leaking from the compression chamber 133 to the suction chamber 131 in the second half of the compression process, that is, in the angle range of 180 degrees to 360 degrees. Further, it is possible to avoid the gap D from becoming too large in the first half of the refrigerant suction process and the compression process, that is, in the angle range of 0 to 180 degrees. Thereby, the clearance D between the inner peripheral surface 137 of the cylinder 121 and the outer peripheral surface 139 of the piston 125 can be appropriately ensured. Therefore, the refrigerant can be appropriately prevented from leaking from the compression chamber 133 to the suction chamber 131, and the compression efficiency of the refrigerant can be increased.

  Further, in the rotary compressor 1 of the embodiment, the gap D between the inner peripheral surface 137 of the cylinder 121 and the outer peripheral surface 139 of the piston 125 at the third rotation angle θ3 is set at the first rotation angle θ1 and the second rotation angle θ2. It is 4/5 or less of the gap D. Thereby, the clearance D between the inner peripheral surface 137 of the cylinder 121 and the outer peripheral surface 139 of the piston 125 can be appropriately ensured. Therefore, the refrigerant can be appropriately prevented from leaking from the compression chamber 133 to the suction chamber 131, and the compression efficiency of the refrigerant can be increased.

  In the rotary compressor 1 of the embodiment, the minimum value of the gap D between the inner peripheral surface 137 of the cylinder 121 and the outer peripheral surface 139 of the piston 125 is set to about 20 [μm]. It is not limited to about 20 [μm], and the minimum value of the gap D may be 10 [μm] or more and 40 [μm] or less. As a result, the leakage of the refrigerant from the gap D between the inner peripheral surface 137 of the cylinder 121 and the outer peripheral surface 139 of the piston 125 is suppressed, and wear and breakage between the inner peripheral surface 137 of the cylinder 121 and the outer peripheral surface 139 of the piston 125 are prevented. It becomes possible to suppress.

  Other embodiments will be described below with reference to the drawings. In other embodiments, the same components as those in the embodiments are denoted by the same reference numerals as those in the embodiments, and the description thereof is omitted.

(Other examples)
12 and 13 show the relationship between the rotation angle of the piston 125 (compression completion angle) and the compression ratio when the refrigerant pressure in the compression chamber 133 reaches the maximum value in the rotary compressor 1 of the embodiment. It is a graph for demonstrating. In FIG. 12, the vertical axis represents the pressure [MPaG], and the horizontal axis represents the rotation angle [deg] of the piston 125. Moreover, in FIG. 12, the curve which shows the change of the pressure in each of pressure ratio 2 times-8 times is accumulated and shown. In FIG. 13, the vertical axis represents the compression completion angle [deg], and the horizontal axis represents the refrigerant compression ratio. In FIG. 13, the change in the compression completion angle with respect to the compression ratio is indicated by a solid line, and the alignment angle of the rotation shaft 15 with respect to the compression ratio (the third O 1 that decenters the center O1 of the rotation shaft 15 from the center O2 of the inner diameter of the cylinder 121). The change in the rotation angle θ3) is indicated by a broken line.

  As shown by the solid lines in FIGS. 12 and 13, the compression completion angle tends to gradually increase as the compression ratio increases. Since the compression completion angle increases in this way, the alignment angle of the rotating shaft 15 gradually increases as the compression ratio increases, as indicated by the broken line in FIG.

Therefore, as in the above-described embodiment, when the compression ratio is double, the compression completion angle that is the second rotation angle θ2 is regarded as 180 degrees, and the center O1 of the rotation shaft 15 is Although it is preferable to decenter along the eccentric line Le from the center O2 of the inner diameter toward the position side of about 270 degrees which is the third rotation angle θ3 (alignment angle of the rotation shaft 15), the third rotation angle θ3 is set to 270. It is not limited to degrees. As indicated by a broken line in FIG. 13, as the third rotation angle θ3, for example, when the pressure ratio is 5 times, the center O1 of the rotation shaft 15 has a rotation angle of 300 degrees from the center O2 of the inner diameter of the cylinder 121. It is preferable to decenter along the eccentric line Le toward the position side. Generally, the pressure ratio of a rotary compressor used in an air conditioner for Japan is set to about 2 to 3 times. For example, a rotary compressor used in a water heater for hot water using CO ₂ as a refrigerant. And the pressure ratio of the rotary compressor used in the plant is set to 4 times or more. That is, the third rotation angle θ3 for eccentrically rotating the rotary shaft 15 is appropriately set according to the pressure ratio of the rotary compressor.

  Although this embodiment is applied to the two-cylinder rotary compressor 1, it may be applied to a one-cylinder rotary compressor, and the same effect as that of the two-cylinder type can be obtained in the one-cylinder type. Can do.

DESCRIPTION OF SYMBOLS 1 Rotary compressor 10 Compressor housing | casing 11 Motor 12 Compression part 15 Rotating shaft 105 Upper suction pipe (suction part)
104 Lower suction pipe (suction part)
107 Discharge pipe (discharge section)
121 cylinder 121T upper cylinder 121S lower cylinder 125 piston 125T upper piston 125S lower piston 127T upper vane 127S lower vane 128T upper vane groove 128S lower vane groove 130 cylinder chamber 130T upper cylinder chamber 130S lower cylinder chamber 131 suction chamber 131T upper suction chamber 131S lower Suction chamber 133 Compression chamber 133T Upper compression chamber 133S Lower compression chamber 137T, 137S Inner peripheral surface 139T, 139S Outer peripheral surface 140 Intermediate partition plate (end plate)
160T Top plate (end plate)
160S Bottom plate (end plate)
θ1 First rotation angle θ2 Second rotation angle θ3 Third rotation angle D Gap O1 Center of rotation axis O2 Center of inner diameter of cylinder

Claims (5)

A vertically-placed cylindrical compressor casing that is provided with a refrigerant discharge section at the top and a refrigerant suction section at the bottom and sealed, and a refrigerant that is disposed at the bottom of the compressor casing and is sucked from the suction section A compression unit that compresses and discharges from the discharge unit, and a motor that is disposed at an upper part in the compressor housing and drives the compression unit,
The compression portion is fitted into the annular cylinder, an end plate that closes the upper side and the lower side of the cylinder, a rotating shaft that has an eccentric portion and is rotated by the motor, and the eccentric portion. An annular piston that revolves along the inner peripheral surface of the cylinder and forms a cylinder chamber in the cylinder, and projects from the vane groove provided in the cylinder into the cylinder chamber and abuts on the piston to suck the cylinder chamber A vane that divides the chamber and the compression chamber;
In a rotary compressor having
The first rotation angle of the piston located at the top dead center in the circumferential direction of the cylinder is 360 degrees, and the first rotation angle and the second rotation angle at which the pressure of the refrigerant in the compression chamber reaches the maximum value are A position of the third rotation angle on the inner peripheral surface of the cylinder on a plane orthogonal to the axial direction of the rotation shaft when the piston is positioned at a third rotation angle that is the median value of the angle range formed; The center of the rotating shaft is the center of the inner diameter of the cylinder and the third rotation angle on the inner peripheral surface of the cylinder so that the gap with the outer peripheral surface of the piston is minimized in the circumferential direction of the cylinder. A rotary compressor characterized by being eccentric from the center of the inner diameter of the cylinder toward the position of the third rotation angle along a straight line connecting the positions. In the circumferential direction of the cylinder, the minimum value of the gap is 2/3 or less of the maximum value of the gap.
The rotary compressor according to claim 1. The gap at the position of the third rotation angle is 4/5 or less of the gap at each of the first rotation angle and the second rotation angle.
The rotary compressor according to claim 1 or 2. The minimum value of the gap is 10 [μm] or more and 40 [μm] or less.
The rotary compressor according to any one of claims 1 to 3. The third rotation angle is 270 degrees;
The rotary compressor according to any one of claims 1 to 4.

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