JP5233921B2 - Rotary compressor - Google Patents

Description

  The present invention relates to a rotary compressor that can be incorporated into a refrigerator or an air conditioner.

  12 and 13 are schematic views showing the configuration of a conventional rotary compressor. As shown in FIGS. 12 and 13, in a conventional rotary compressor, an electric motor and a compression mechanism driven by the electric motor are housed in a hermetic container 1. The compression mechanism includes a cylinder 5, an upper bearing 7 and a lower bearing 8 that are fastened to both end surfaces of the cylinder 5 to form a cylinder chamber 6, and a shaft 4 that is positioned between the upper bearing 7 and the lower bearing 8. The piston 9 is fitted in the eccentric portion, and the vane 11 reciprocates in the vane groove 10 formed in the cylinder 5.

  A part of the high-temperature and high-pressure working refrigerant discharged into the hermetic container 1 acts on the back surface of the vane 11 as a back pressure, and the tip of the vane 11 is brought into contact with the outer peripheral surface of the piston 9 to thereby form a cylinder. A suction chamber 12 and a compression chamber 13 partitioned by a vane 11 are formed in the chamber 6.

  The volume of the suction chamber 12 and the compression chamber 13 is changed by the swinging motion of the piston 9 accompanying the rotation of the shaft 4 and the reciprocating motion of the vane 11, and the suction port 14 is sucked into the suction chamber 12 by this volume change. The working refrigerant is compressed to a high temperature and pressure, and the compressed refrigerant is discharged from the compression chamber 13 through the discharge port 15 and the discharge muffler chamber 103 into the sealed container 1.

  By the way, in the rotary compressor of FIGS. 12 and 13, during operation, the vane is pushed up by the pressure difference between the pressure Pc of the compression chamber 13 and the pressure Ps of the suction chamber 12 to cause vane jumping, and volume efficiency is improved. There was a problem of lowering. In order to solve this problem, in the rotary compressor shown in FIG. 14, the tip end portion 11 </ b> A of the vane 11 is processed into an arc shape, and such a tip end portion 11 </ b> A swings on the fitting portion 9 </ b> A formed on the piston 9. Fit and connect freely. Thereby, vane jumping is reliably prevented (see, for example, Patent Document 1).

JP 2000-120572 A

  In the rotary compressor shown in FIG. 14, the arc of the fitting portion 9 </ b> A formed on the piston 9 is prevented so that the piston 9 does not contact the side surface of the vane 11 when the piston 9 swings in the cylinder chamber 6. The curved surface and the outer peripheral surface 9C of the piston 9 are connected via a notch. As a result, since the difference between the width of the inlet 9B of the fitting portion 9A and the diameter of the tip portion 11A of the vane 11 is reduced, the vane jumps when the piston 9 expands greatly compared to the vane 11 during operation. There was a fear. In order to cope with this, the diameter of the tip portion 11A of the vane 11 is increased, and a difference from the width of the fitting portion inlet 9B is ensured to prevent the vane from flying.

However, as shown in FIG. 15, the back surface of the vane 11 communicates with the inside of the closed container 1, and a part of the high-temperature and high-pressure working refrigerant discharged into the closed container 1 is back pressure on the back of the vane 11. Acts as As a result, the tip end portion 11 </ b> A of the vane 11 is in line contact with the outer peripheral surface 9 </ b> C of the piston 9 in the radial direction of the piston 9, that is, for example, at the contact 203. Further, the suction chamber pressure Ps acts on the arc side surface facing the suction chamber 12 and the compression chamber pressure Pc acts on the arc side surface facing the compression chamber 13 at the tip portion 11A of the vane 11 with the contact 203 as a boundary.

  From the above, as shown in FIG. 16, the area where the vane 11 receives the compression chamber pressure Pc and the suction chamber pressure Ps increases, and the compression chamber pressure Pc when the vane 11 reciprocates in the vane groove 10. As the reaction force of the force acting on the vane 11 due to the differential pressure Pc−Ps between the suction chamber pressure Ps and the suction chamber pressure Ps, the frictional resistance force between the vane 11 and the vane groove 10 acting on the contact 201 and the contact 202 of the vane groove 10 increases. There is a problem that the sliding loss generated by the reciprocating motion of 11 in the vane groove 10 increases.

  Therefore, an object of the present invention is to provide a rotary compressor that reduces sliding loss caused by reciprocating motion of vanes in the vane groove and has low input loss.

To achieve the above object, the present invention is formed in a cylinder having a cylinder chamber, a piston that swings and moves in the cylinder chamber, a vane that partitions the cylinder chamber into a suction chamber and a compression chamber, and the cylinder. The vane has a vane groove in which the vane reciprocates, and at least a part of the tip of the vane has an arc shape having a diameter larger than the thickness of the vane and is fitted in a swingable manner in a fitting portion formed in the piston. In the rotary compressor configured to be coupled, when the piston oscillates in the cylinder chamber, the arc surface of the fitting portion formed on the piston and the plane on which the outer peripheral surface of the piston is connected or so as not to contact the curved surface, of the vane, a notch is provided on a side surface facing the side surface and the compression chamber facing the suction chamber, provided on a side surface facing the compression chamber of the vane The shape of the notch is formed in the piston at an angular position of 270 degrees in the rotational direction of the shaft when the position of the shaft when the vane is most housed in the vane groove is 0 degree. The arcuate curved surface of the fitting portion and the shape of a flat surface or curved surface to which the outer peripheral surface of the piston is connected substantially coincide .

  According to the above, since the notch provided on the outer peripheral surface of the piston intersecting the arcuate curved surface of the fitting portion formed on the piston can be eliminated and the width of the piston fitting portion inlet can be made small, vane jumping is ensured. The diameter of the tip of the vane can be made smaller than that of a conventional rotary compressor in a state where the difference between the width of the inlet of the fitting portion of the piston necessary to prevent the diameter of the tip of the vane is secured. It becomes possible. Therefore, since the position of the contact point where the tip of the vane contacts the piston can be configured on the radially outer side of the piston, the area where the vane receives the compression chamber pressure and the suction chamber pressure when the vane reciprocates in the vane groove. The force acting on the vane can be reduced by the differential pressure between the compression chamber pressure and the suction chamber pressure. Thereby, the frictional resistance with the vane groove acting on the vane as a reaction force of this force is reduced. Therefore, it is possible to provide a rotary compressor in which the sliding loss generated by the reciprocating motion of the vane in the vane groove is reduced and the input loss is small.

FIG. 3 is a broken sectional view showing a main part of the rotary compressor according to the embodiment of the present invention. FIG. 1 is a cross-sectional view of the rotary compressor of FIG. 1 as viewed from the direction of the arrow along the section AA. The enlarged view which shows the periphery of the front-end | tip part 11A of the vane 11 shown in FIG. First schematic diagram showing the rotation direction of the shaft 4 FIG. 4 is a schematic diagram showing the positional relationship between the side surface of the vane 11, the circular curved surface of the fitting portion 9A, and the curved surface to which the outer peripheral surface 9C is connected at each timing of FIG. Schematic diagram showing the difference X between the width of the fitting portion inlet 9B and the diameter of the tip portion 11A and the width of the fitting portion inlet 9B as Y. Second schematic diagram showing the rotation direction of the shaft 4 Schematic diagram showing the top clearance volume 301 The schematic diagram which shows angle (theta) which the straight line which connected 9C of outer peripheral surfaces and the circular arc center of front-end | tip part 11A makes with the width direction centerline of the vane groove | channel 11 Schematic diagram showing reduction of top clearance volume 301 The schematic diagram which shows the modification of the rotary compressor of FIG. Partial longitudinal sectional view showing a conventional first rotary compressor Cross section of the rotary compressor shown in FIG. Schematic diagram showing a conventional second rotary compressor Schematic diagram showing suction chamber pressure Ps and compression chamber pressure Pc in the rotary compressor of FIG. Schematic showing differential pressure Pc-Ps between compression chamber pressure Pc and suction chamber pressure Ps

  FIG. 1 is a broken sectional view showing a main part of a rotary compressor according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the rotary compressor of FIG. 1 when a cut surface along the plane AA is viewed from the direction of the arrow.

  In FIG. 1, the rotary compressor is generally arranged in a substantially cylindrical sealed container 1, an electric motor 102 disposed on the upper side of the sealed container 1, and a lower side of the electric motor 102. And a compression mechanism 101 driven by the electric motor unit 102.

  The electric motor 102 includes a stator 2 that is annularly attached along the inner peripheral surface on the upper side of the hermetic container 1, and a rotor 3 that is inserted inside the stator 2 with a slight gap therebetween. Is fixed to the shaft 4 in the vertical direction at its center.

  As shown in FIGS. 1 and 2, the compression mechanism 101 includes a cylinder 5, an upper bearing 7 and a lower bearing 8 that are fastened to both end surfaces of the cylinder 5 to form a cylinder chamber 6, and the upper bearing 7 A piston 9 fitted to an eccentric portion of the shaft 4 positioned between the lower bearing 8 and a vane 11 that reciprocates in a vane groove 10 formed in the cylinder 5 is included.

  Specifically, the vane 11 includes a front end portion 11A and a main body portion 11B that reciprocates in the vane groove 10. The tip portion 11A is formed in an arc shape having a diameter larger than the thickness of the main body portion 11B, and is slidably fitted and connected to a fitting portion formed on the piston 9, so that the vane 11 is placed in the cylinder chamber 6. Thus, a suction chamber 12 and a compression chamber 13 are formed.

  Here, FIG. 3 is an enlarged view showing the periphery of the tip portion 11A of the vane 11 shown in FIG. In FIG. 3, notches 11 c and 11 d are provided in the vane 11 on the side facing the suction chamber 12 and the side facing the compression chamber 13, and the piston 9 performs suction by swinging in the cylinder chamber 6. When the volume of the chamber 12 and the compression chamber 13 changes, the curved surface portion where the arcuate curved surface of the fitting portion 9A formed on the piston 9 and the outer peripheral surface 9C of the piston 9 are connected does not come into contact with the vane 11. It is configured.

In the conventional rotary compressor, as shown in FIG. 14, the piston 9 has a notch that connects the arcuate curved surface of the fitting portion 9 </ b> A formed on the piston 9 and the outer peripheral surface 9 </ b> C of the piston 9. . On the other hand, in the example of FIG. 3, the notches 11c and 11d are formed on the vane 11 side, and the notches on the piston 9 side are substantially eliminated, so that the width of the inlet 9B of the fitting portion of the piston 9 can be reduced. . In other words, it is possible to reduce the diameter of the tip 11A of the vane 11 as compared with the conventional rotary compressor. As a result, the contact point at which the tip portion 11A of the vane 11 contacts the piston 9 can be positioned on the radially outer side of the piston 9 as compared with the related art. Thereby, when the vane 11 reciprocates in the vane groove 10, the area where the vane 11 receives the compression chamber pressure Pc and the suction chamber pressure Ps becomes small, and the pressure difference Pc−Ps between the compression chamber pressure and the suction chamber pressure. Thus, the force acting on the vane 11 can also be reduced. Therefore, since the frictional resistance force with the vane groove 10 acting on the vane 11 is reduced as a reaction force of this force, the sliding loss caused by the reciprocating motion of the vane 11 in the vane groove 10 can be reduced. . Further, since the difference between the width of the fitting portion inlet 9B of the piston 9 and the diameter of the tip end portion 11A of the vane 11 can be ensured to the same extent as that of the conventional rotary compressor, vane jumping can be surely prevented and the reliability is improved. Will not drop.

  Next, the diameter required for the tip portion 11A will be described from the positional relationship between the side surface of the vane 11, the circular curved surface of the fitting portion 9A formed on the piston 9, and the curved surface to which the outer peripheral surface 9C of the piston 9 is connected. .

  When the angle position of the shaft 4 at the time when the vane 11 is stored most in the vane groove 10 is 0 degree, when the shaft 4 is rotated in the rotation direction in the order of 0 degree, 90 degrees, 180 degrees, and 270 degrees, As shown in FIG. 4, the positions of the vane 11 and the piston 9 change in the order of (A), (B), (C), and (D). In the case of the conventional rotary compressor, the positional relationship between the side surface of the vane 11, the circular curved surface of the fitting portion 9A formed on the piston 9 and the curved surface to which the outer peripheral surface 9C of the piston 9 is connected at each timing. Is as shown in FIG. As shown in FIG. 5, the arc curved surface of the fitting portion 9A formed on the piston 9 and the piston at the timing of (B) or (D), that is, at an angular position of 90 degrees or 270 degrees in the rotation direction of the shaft 4. 9 is the closest to the side surface of the vane 11, so that the curved surface of the fitting portion 9A formed on the piston 9 does not come into contact with the side surface of the vane 11 at these angular positions. A notch is provided between the intersecting piston 9 and the outer peripheral surface 9C. Therefore, as shown in FIG. 6, the difference X between the width of the fitting portion inlet 9 </ b> B of the piston 9 and the diameter of the tip portion 11 </ b> A of the vane 11 necessary for reliably preventing vane jumping, and the fitting portion of the piston 9. Assuming that the width of the inlet 9B is Y, the diameter DV required for the tip portion 11A of the vane 11 is expressed by Formula A.

DV ≧ X + Y Formula A
On the other hand, according to the present embodiment, the vane 11 is provided with a notch on the side facing the suction chamber and the side facing the compression chamber, and the fitting formed on the piston 9 in the conventional rotary compressor Since the width Y of the inlet 9B of the fitting portion of the piston 9 can be reduced by eliminating the notch provided in the outer peripheral surface 9C of the piston 9 that intersects the arcuate curved surface of the portion 9A, the conventional rotary compressor is obtained from the equation A. As compared with the above, it is possible to reduce the diameter DV required for the tip portion 11A of the vane 11.

Moreover, on the side surface of the vane 11 facing the compression chamber 13, when the position of the shaft 4 when the vane 11 is most housed in the vane groove 10 is 0 degree, the angular position of 270 degrees in the rotation direction of the shaft 4. Thus, a notch substantially matching the shape of the curved surface to which the arcuate curved surface of the fitting portion 9A formed on the piston 9 and the outer peripheral surface 9C of the piston 9 are connected is provided. As a result, the top clearance volume formed by the side surface of the vane 11 facing the compression chamber 13, the circular curved surface of the fitting portion 9 </ b> A formed on the piston 9, and the curved surface to which the outer peripheral surface 9 </ b> C of the piston 9 is connected is reduced. be able to. Thereby, it becomes possible to provide a rotary compressor with a small input loss, without reducing volumetric efficiency. That is, the positional relationship between the side surface of the vane 11, the arcuate curved surface of the fitting portion 9 </ b> A formed on the piston 9 and the curved surface to which the outer peripheral surface 9 </ b> C of the piston 9 is connected is that the vane 11 is stored most in the vane groove 10. When the angle position of the shaft 4 at that time is 0 degree, when the shaft 4 is rotated in order of 0 degree, 90 degrees, 180 degrees, and 270 degrees in the rotation direction of the shaft 4, as shown in FIG. It changes as (B), (C), (D). As shown in FIG. 8, the top clearance volume 301 where the working refrigerant remains without being discharged is a fitting portion formed on the piston 9 shown in FIG. 7D at an angular position of 270 degrees in the rotation direction of the shaft 4. 9A
This is formed by a notch provided on the side surface of the vane 11 facing the compression chamber 13 so as not to come into contact with the curved surface to which the circular arc curved surface and the outer peripheral surface 9C of the piston 9 are connected. In this way, at the angular position of 270 degrees in the rotation direction of the shaft 4, the above-described notch shape is a curved surface where the circular curved surface of the fitting portion 9 </ b> A formed on the piston 9 and the outer peripheral surface 9 </ b> C of the piston 9 are connected. The side surface of the vane 11 that faces the compression chamber 13, the curved surface of the fitting portion 9 </ b> A formed on the piston 9, and the curved surface to which the outer peripheral surface 9 </ b> C of the piston 9 is connected are configured. Thus, it is possible to reduce the top clearance volume formed.

  More preferably, the arc center of the tip 11A of the vane 11 is configured closer to the compression chamber than the center of the vane 11 in the thickness direction. Thereby, the top clearance volume formed by the side surface of the vane 11 facing the compression chamber 13, the circular curved surface of the fitting portion 9 </ b> A formed on the piston 9, and the curved surface to which the outer peripheral surface 9 </ b> C of the piston 9 is connected is further reduced. can do. That is, as shown in FIG. 9, when the position of the shaft 4 when the vane 11 is most housed in the vane groove 10 is 0 degree, the piston 9 is at an angular position of 270 degrees in the rotational direction of the shaft 4. If the angle formed by the straight line connecting the center of the outer peripheral surface 9C of the vane 11 and the arc center of the tip 11A of the vane 11 with the center line in the width direction of the vane groove 11 is θ, the arc center of the tip 11A of the vane 11 As shown in FIG. 9, the θ angle is reduced by the configuration from the thickness direction center of 11 to the compression chamber side, that is, the angle at which the piston 9 swings around the arc center of the tip portion 11A of the vane 11. The range becomes smaller. Further, the center of the arc of the tip portion 11A of the vane 11 is formed on the compression chamber side from the center in the thickness direction of the vane 11, and the arc curved surface of the fitting portion 9A formed on the piston 9 and the outer peripheral surface 9C of the piston 9 are The portion where the curved surface to be connected interferes with the side surface of the vane 11 facing the compression chamber 13 can be reduced. Accordingly, as shown extremely in FIG. 10, the notch provided on the side surface of the vane 11 that faces the compression chamber 13 is reduced, and the side surface of the vane 11 that faces the compression chamber 13 and the fitting portion formed on the piston 9. It is possible to further reduce the top clearance volume 301 formed by the circular curved surface of 9A and the curved surface to which the outer peripheral surface 9C of the piston 9 is connected.

  FIG. 11 is a diagram showing a modification of the above-described embodiment. In the example of FIG. 11, the width direction center L of the vane groove 10 is configured to be positioned closer to the compression chamber 13 than the inner peripheral surface center C of the cylinder 5. Further, when the position of the shaft 4 at the time when the vane 11 is stored most in the vane groove 10 is set to 0 degree on the side surface facing the compression chamber 13 of the vane 11, the angular position of 270 degrees in the rotation direction of the shaft 4 Thus, a notch substantially matching the shape of the curved surface to which the arcuate curved surface of the fitting portion 9A formed on the piston 9 and the outer peripheral surface 9C of the piston 9 are connected is provided. As a result, the top clearance volume formed by the side surface of the vane 11 facing the compression chamber 13, the arcuate curved surface of the fitting portion 9 </ b> A formed on the piston 9, and the curved surface to which the outer peripheral surface 9 </ b> C of the piston 9 is connected is reduced. It becomes possible. That is, as shown in FIG. 11, when the position of the shaft 4 when the vane 11 is most housed in the vane groove 10 is 0 degree, the piston 9 is at an angular position of 270 degrees in the rotational direction of the shaft 4. If the angle between the straight line connecting the center of the outer peripheral surface of the vane 11 and the arc center of the tip 11A of the vane 11 and the center line in the width direction of the vane groove 10 is θ ′, the center L in the width direction of the vane groove 10 is The inner peripheral surface center C is configured on the compression chamber side. As a result, as shown in FIG. 11, the θ ′ angle is reduced, that is, the angle range in which the piston 9 swings around the center of the arc of the tip end portion 11 </ b> A of the vane 11 is reduced. Since the curved surface to which the arcuate curved surface of the fitting portion 9A and the outer peripheral surface 9C of the piston 9 are connected can interfere with the side surface of the vane 11 facing the compression chamber 13, the cut provided on the side surface of the vane 11 facing the compression chamber 13 A top clearance volume formed by a side face of the vane 11 facing the compression chamber 13, a circular curved surface of the fitting portion 9 </ b> A formed on the piston 9, and a curved surface connected to the outer peripheral surface 9 </ b> C of the piston 9. Can be reduced.

Further, in the rotary compressor of the present embodiment, when CO ₂ is used as the working refrigerant, when the vane 11 reciprocates in the vane groove 10, in particular, the compression chamber pressure Pc and the suction chamber pressure Ps.
Since the frictional resistance force with the vane groove 10 acting on the vane 11 is large as a reaction force of the force acting on the vane 11 due to the high differential pressure, the vane 11 is reciprocated in the vane groove 10 more effectively. Sliding loss can be reduced.

  Further, in the rotary compressor of the present embodiment, when a refrigerant mixed with hydrofluoroolefin having a double bond between carbon and carbon as a base component and mixed with hydrofluorocarbon having no double bond is used as a working refrigerant. In particular, since the lubricity deteriorates with a decrease in chemical stability at a high temperature, the sliding loss caused by the reciprocating motion of the vane 11 in the vane groove 10 is more effectively reduced. be able to.

  INDUSTRIAL APPLICABILITY The rotary compressor according to the present invention has an effect that input loss can be reduced, and can be applied to a hot water compressor and an air compression application.

5 Cylinder 9 Piston 11 Vane 10 Vane groove 9A Fitting part 11c, 11d Notch

Claims (5)

A cylinder having a cylinder chamber, a piston that swings in the cylinder chamber, a vane that divides the cylinder chamber into a suction chamber and a compression chamber, and a vane groove that is formed in the cylinder and in which the vane reciprocates, In the rotary compressor configured such that at least a part of the tip end portion of the vane has an arc shape having a diameter larger than the thickness of the vane and is swingably fitted to a fitting portion formed on the piston. When the piston swings in the cylinder chamber, the vane of the vane does not come into contact with the arcuate curved surface of the fitting portion formed on the piston and the plane or curved surface to which the outer peripheral surface of the piston is connected. a notch on the side facing the side surface and the compression chamber facing the suction chamber is provided, the notch shape provided on the side facing the compression chamber of the vane, the vane is a base When the position of the shaft when it is most housed in the groove is set to 0 degree, the circular curved surface of the fitting portion formed on the piston and the piston at an angular position of 270 degrees in the rotation direction of the shaft. A rotary compressor characterized in that the outer peripheral surface substantially coincides with the shape of a plane or curved surface to which it is connected . The arc center of the distal end portion of the vane, rotary compressor according to claim 1, wherein configured to the compression chamber side of the thickness direction center of the vane. Wherein the widthwise center of the vane groove, the rotary compressor according to claim 1, wherein configured to the compression chamber side of the inner circumferential surface center of the cylinder. The rotary compressor according to any one of claims 1 to 3 , wherein CO ₂ is used as a working refrigerant. The hydrofluoroolefin having double bond between carbon and carbon as the working refrigerant and base component, any one of claim 1, wherein the third for using the refrigerant mixed with no hydrofluorocarbon double bond 1 The rotary compressor according to item.

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