JPWO2013080519A1 - Rotary compressor - Google Patents

Abstract

The rotary compressor of the present invention includes a cylinder 30, a shaft eccentric portion 31a, a piston 32, and a vane 33. The vane 33 includes a suction chamber side contact surface 33a, a compression chamber side contact surface 33b, and the like. The lubricant is supplied from the oil reservoir 6 to the suction chamber side contact surface 33a and the compression chamber side contact surface 33b, and the suction chamber is in a state where the pressure difference between the suction chamber 39a and the compression chamber 39b is equal to or lower than a predetermined pressure. By forming a differential pressure generating mechanism in which the pressure applied to the compression chamber side contact surface 33b is larger than the side contact surface 33a, the refrigerant gas and the lubricating oil are sucked into the suction chamber 39a via the gap between the vane 33 and the vane groove 30b. And leakage into the compression chamber 39b.

Description

  The present invention relates to a rotary compressor used for an air conditioner, a refrigerator, a blower, a water heater, and the like.

  Conventionally, in refrigeration equipment and air conditioning equipment, a compressor that sucks in gas refrigerant evaporated in an evaporator, compresses the sucked gas refrigerant to the pressure required to condense, and sends out high-temperature and high-pressure gas refrigerant is used. Has been. A rotary compressor is known as one of such compressors.

In the rotary compressor, the electric motor and the compression mechanism unit are connected by a crankshaft and stored in a sealed container. The compression mechanism unit includes a cylinder, an upper bearing, a lower bearing, and a piston. Both end surfaces of the cylinder are closed by the end plate of the upper bearing and the end plate of the lower bearing. The crankshaft is supported by an upper bearing and a lower bearing. An eccentric portion of the crankshaft is disposed between the upper bearing and the lower bearing. The piston is fitted to the eccentric part of the crankshaft. A compression space is formed by the cylinder, the upper bearing, the lower bearing, and the piston.
A vane groove is formed in the cylinder, and the vane is disposed in the vane groove. The vane reciprocates following the eccentric rotation of the piston, and partitions the compression space into a suction chamber and a compression chamber. The crankshaft is provided with an oil hole in the shaft portion, and an oil supply hole communicating with the oil hole is provided in the wall portion of the crankshaft with respect to the upper bearing and the lower bearing.
An oil supply hole communicating with the oil hole is provided in the wall portion of the eccentric portion, and an oil groove is formed on the outer peripheral surface of the eccentric portion.

On the other hand, the cylinder is provided with a suction port for sucking refrigerant gas in the suction chamber. The upper bearing is provided with a discharge port for discharging refrigerant gas from the compression chamber. The discharge port is formed as a circular hole in plan view that passes through the upper bearing, and a discharge valve that is released when a predetermined pressure is applied is provided on the upper surface of the discharge port. This discharge valve is covered with a cup muffler.
The suction chamber sucks in the refrigerant gas from the suction port by expanding the space, and the compression chamber compresses the refrigerant gas to a predetermined pressure or more by reducing the space. The compressed refrigerant gas opens the discharge valve, flows out from the discharge port, and is discharged into the sealed container through the cup muffler.

The vane groove has a spring hole that houses a spring that presses the vane against the piston when the compressor is started. The spring hole is filled with lubricating oil or high-pressure refrigerant gas. From this spring hole, lubricating oil and high-pressure gas leaked into the suction chamber and the compression chamber through the gap between the vane and the vane groove, and the efficiency was lowered.
In order to reduce this leakage, there is a configuration shown in FIG.
FIG. 11 is a plan view of an essential part showing a cylinder of a conventional rotary compressor.
In FIG. 11, a part of the cylinder 130 and a part of the piston 132 disposed in the cylinder 130 are shown. A vane groove 130 b is formed in the cylinder 130. A vane 133 is disposed in the vane groove 130b.
An oil reservoir groove 133 a is formed in the vane 133. A plurality of oil sump grooves 133a are formed at arbitrary intervals in a direction intersecting the sliding direction of the vane 133. An oil film is sufficiently formed between the vane 133 and the vane groove 130b by the oil sump groove 133a. This oil film exhibits a labyrinth sealing effect and can prevent leakage of lubricating oil, refrigerant gas, or the like (see, for example, Patent Document 1).

JP-A-3-185292

As shown in Patent Document 1, by forming an oil sump groove 133a in the vane 133, a labyrinth seal effect is exhibited, leakage of refrigerant gas or the like can be suppressed, and compression efficiency is improved.
However, when the suction chamber and the compression chamber have the same pressure, there is no difference in the pressure applied to the surfaces formed in the thickness direction of the vane 133 (the suction chamber side contact surface 133b and the compression chamber side contact surface 133c). 133 does not tilt toward the suction chamber, the vane 133 does not contact the vane groove 130b, and a gap is formed between the vane 133 and the vane groove 130b.
That is, in Patent Document 1, the labyrinth seal effect can be expected to suppress leakage of lubricating oil, refrigerant gas, etc., but when the suction chamber and the compression chamber are at the same pressure, the gap between the vane 133 and the vane groove 130b is completely eliminated. It cannot be sealed.

  The present invention solves the above-described conventional problem, and in a state where the pressure difference between the suction chamber and the compression chamber is equal to or less than a predetermined pressure, the refrigerant gas and the lubricating oil are passed through the gap between the vane and the vane groove. And it aims at providing the rotary compressor which suppresses leaking into a compression chamber.

  In order to achieve the above object, the present invention provides a cylinder, an eccentric part of a shaft, a piston fitted in the eccentric part, a cylinder fitted in the eccentric part, and following the eccentric rotation of the piston. A vane that reciprocates in a vane groove provided in the cylinder and divides the inside of the cylinder into a suction chamber and a compression chamber, and the vane has a suction chamber side in contact with the vane groove on the suction chamber side. A contact surface and a compression chamber side contact surface that contacts the vane groove on the compression chamber side are formed, and a rotary oil is supplied to the suction chamber side contact surface and the compression chamber side contact surface from an oil reservoir. A differential pressure generating mechanism that is a compressor, wherein a pressure applied to the compression chamber side contact surface is larger than the suction chamber side contact surface when a pressure difference between the suction chamber and the compression chamber is a predetermined pressure or less. Rotor characterized by being formed A compressor. By pressing the vane in the direction of the suction chamber side of the vane groove and providing a differential pressure generating mechanism that communicates with the oil reservoir, the refrigerant gas and lubricating oil are transferred to the vane and vane when the suction chamber and the compression chamber are at the same pressure. Leakage into the suction chamber and the compression chamber can be suppressed through the gap in the groove.

  According to the above configuration, a difference is generated in the pressure applied to the vane thickness direction (suction chamber side contact surface and compression chamber side contact surface) when the suction chamber and the compression chamber are at the same pressure, and the vane is tilted toward the suction chamber. As a result, the vane and the vane groove are brought into contact with each other, so that refrigerant gas and lubricating oil leaking into the suction chamber and the compression chamber can be suppressed, and the efficiency is improved. Furthermore, oil is easily held between the vane and the vane groove, the sliding state is improved, and the vane can be prevented from fluttering in the vane groove, so that the reliability is improved.

The longitudinal cross-sectional view of the rotary compressor in embodiment of this invention The expanded sectional view of the compression mechanism part of the rotary compressor in an embodiment of the invention (A) The principal part top view which shows the cylinder of the rotary compressor compressor in this Embodiment (b) The principal part side view seen from the A direction and B direction shown to the same figure (a) (A) The principal part top view which shows the relationship between the cylinder and vane when the piston of this embodiment is near a vane top dead center, (b) The cylinder when the compression chamber of this embodiment has reached the predetermined pressure, Principal plan view showing vane relationship (A) The principal part top view which shows the cylinder of the rotary compressor of a comparative example, (b) The principal part side view seen from the A direction and B direction shown to the same figure (a) The principal part top view which shows the relationship between the cylinder and vane when the piston of a comparative example is near a vane top dead center, (b) The cylinder and vane when the compression chamber of this embodiment of a comparative example has reached a predetermined pressure Plan view showing the relationship between The graph explaining the efficiency of the contact area ratio difference of the vane and vane groove | channel of the rotary compressor in embodiment of this invention (A) The principal part top view which shows the cylinder of the rotary compressor in other embodiment of this invention (b) The principal part side view seen from the A direction and B direction shown to the same figure (a) The principal part top view which shows the cylinder of the rotary compressor in other embodiment of this invention. (A) The principal part top view which shows the cylinder of the rotary compressor in further another embodiment of this invention (b) The principal part side view seen from the A direction and B direction which are the same figure (a) Plan view of vanes and cylinders in the prior art

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Electric motor 3 Compression mechanism part 30 Cylinder 30b Vane groove 30c Spring hole 31 Crankshaft 31a Eccentric part 32 Piston 33 Vane 34 Upper bearing 35 Lower bearing 36 Discharge valve 37 Cup muffler 38 Discharge port 39 Compression space 39a Suction chamber 39b Compression Chamber 40 Suction port 41 Oil hole 42 Oil supply hole 44 Oil supply hole 45 Oil groove 46 Space 47 Space 60 Counterbore

  According to a first aspect of the present invention, an electric motor and a compression mechanism are connected to each other by a crankshaft and accommodated in a sealed container. Provided on the suction chamber side of the cylinder, the vane for reciprocating in the vane groove provided in the cylinder following the eccentric rotation of the piston, and dividing the inside of the cylinder into a suction chamber and a compression chamber The vane is formed with a suction chamber side contact surface that contacts the vane groove on the suction chamber side and a compression chamber side contact surface that contacts the vane groove on the compression chamber side. A rotary compressor in which lubricating oil is supplied from an oil reservoir to the suction chamber side contact surface and the compression chamber side contact surface, wherein a pressure difference between the suction chamber and the compression chamber is a predetermined pressure or less. , The pressure more than the suction chamber side contact surface A rotary compressor, wherein a pressure applied to the chamber side contact surface to form a larger differential pressure generating mechanism. With this configuration, when the suction chamber and the compression chamber have the same pressure, the vane can be forcibly tilted by generating a difference in the pressure applied in the vane thickness direction (the suction chamber side contact surface and the compression chamber side contact surface). In addition, the sealing property can be improved by bringing the vane and the vane groove into contact, and the refrigerant gas and the lubricating oil can be prevented from leaking into the suction chamber and the compression chamber through the gap between the vane and the vane groove. Further, since the differential pressure generating mechanism communicates with the oil reservoir, the lubricating oil is easily held between the vane and the vane groove, and the reliability is improved.

  In a second aspect of the invention, in particular, in the rotary compressor according to the first aspect of the invention, the differential pressure generating mechanism has a contact area with the vane groove on the suction chamber side contact surface, and the vane on the compression chamber side contact surface. A rotary compressor characterized in that it is larger than the contact area with the groove. With this configuration, since the differential pressure generating mechanism is provided in the vane groove, the retention of the lubricating oil is improved as compared to when the differential pressure generating mechanism is provided in the moving vane.

  In a third aspect of the invention, in particular, in the rotary compressor of the second aspect of the invention, the differential pressure generating mechanism is provided with a counterbore communicating with the vane groove in a direction perpendicular to the vane groove. Machine. With this configuration, it can be easily processed with a drill hole or an end mill.

  In a fourth aspect of the invention, in particular, in the rotary compressor of the third aspect of the invention, the counterbore communicates with a suction chamber side counterbore that communicates with the vane groove on the suction chamber side, and with the vane groove on the compression chamber side. A rotary compressor having a counterbore in the compression chamber. Usually, the height of the cylinder is about 4 to 6 times the width of the vane groove. Considering the general tool life, it is only possible to dig up to a depth of 2 to 3 times the diameter of the drill hole, so the counterbore that communicates with only one side of the vane groove can be penetrated by a single hole drilling in the axial direction. Have difficulty. In the configuration in which the counterbore does not penetrate in the axial direction, the pressure balance in the thickness direction (the suction chamber side contact surface and the compression chamber side contact surface) is lost on the upper shaft side and the lower shaft side of the vane, leading to a decrease in efficiency. In the counterbore communicating with both the suction chamber side and the compression chamber side of the vane groove, the diameter of the drill hole can be made larger than the width of the vane groove, so that it is easy to penetrate in the axial direction by one hole drilling. Further, since the diameter of the drill hole can be increased, the tool life is extended and the workability is improved.

  In a fifth aspect of the invention, in particular, in the rotary compressor of the second aspect, the ratio of the contact area of the compression chamber side contact surface with the vane groove to the contact area of the suction chamber side contact surface with the vane groove. Is a rotary compressor characterized by having 70% or more. With this configuration, when the suction chamber and the compression chamber have the same pressure, the pressure difference applied in the thickness direction of the vane (the suction chamber side contact surface and the compression chamber side contact surface) does not become excessive, so the vane and vane groove suction chamber side The contact force with can be reduced. Further, when the contact force between the vane and the vane groove is maximized, the compression chamber reaches a predetermined pressure, so that the oil reservoir and the compression chamber have substantially the same pressure. For this reason, the gap between the vane and the compression chamber side of the vane groove is almost filled with high pressure, and the differential pressure generation mechanism does not function.Therefore, the pressure distribution is the same as that of a general rotary compressor, and the vane and the vane groove are separated. It does not slide strongly and reliability does not deteriorate.

  In a sixth aspect of the invention, in particular, in the rotary compressors of the first to fifth aspects of the invention, the working fluid is a single refrigerant comprising a refrigerant composed of carbon and a hydrofluoroolefin having a double bond between carbons as a base component, or A mixed refrigerant containing the refrigerant is used. This refrigerant has a low suction density and requires, for example, about 1.7 times the amount of circulation in order to produce the same capacity as R410A, and the difference between high and low pressure becomes large, and the influence of leakage of lubricating oil and refrigerant gas is large. Therefore, the efficiency of the compressor can be improved more effectively. Moreover, since this refrigerant has no ozone destruction and a low global warming potential, it can contribute to the configuration of an air-conditioning cycle that is friendly to the earth.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

FIG. 1 is a longitudinal sectional view of a rotary compressor according to an embodiment of the present invention. FIG. 2 is an enlarged view of the compression mechanism section in the embodiment of the present invention.
As shown in FIGS. 1 and 2, the rotary compressor in the present embodiment is housed in the hermetic container 1 by connecting the electric motor 2 and the compression mechanism 3 with a crankshaft 31. A discharge pipe 5 is provided on the top of the sealed container 1. An oil reservoir 6 is formed in the lower part of the sealed container 1. Since the compressed refrigerant gas is discharged into the sealed container 1, the discharge pressure acts on the oil reservoir 6.

The electric motor 2 includes a stator 22 and a rotor 24.
The compression mechanism unit 3 includes a cylinder 30, an upper bearing 34, a lower bearing 35, and a piston 32. Both end surfaces of the cylinder 30 are closed by the end plate of the upper bearing 34 and the end plate of the lower bearing 35. The crankshaft 31 is supported by an upper bearing 34 and a lower bearing 35. An eccentric portion 31 a of the crankshaft 31 is disposed between the upper bearing 34 and the lower bearing 35. The piston 32 is fitted into the eccentric portion 31 a of the crankshaft 31. A compression space 39 is formed by the cylinder 30, the upper bearing 34, the lower bearing 35, and the piston 32.
A suction port 40 is formed in the cylinder 30.
The crankshaft 31 is provided with an oil hole 41 in the axial direction. Oil supply holes 42, 43 communicating with the oil hole 41 are provided in the wall portion of the crankshaft 31 with respect to the upper bearing 34 and the lower bearing 35. An oil supply hole 44 communicating with the oil hole 41 is provided in the wall portion of the eccentric portion 31a, and an oil groove 45 is formed on the outer peripheral surface of the eccentric portion 31a. Lubricating oil is supplied to the oil hole 41 from the oil reservoir 6.

The discharge port 38 is formed as a circular hole in plan view that passes through the upper bearing 34, and a discharge valve 36 that is released when a predetermined pressure is applied is provided on the upper surface of the discharge port 38. The discharge valve 36 is covered with a cup muffler 37.
The suction chamber 39a sucks the refrigerant gas from the suction port 40 due to the expansion of the space, and the compression chamber 39b compresses the refrigerant gas to a predetermined pressure or more due to the reduction of the space. The compressed refrigerant gas opens the discharge valve 36, flows out from the discharge port 38, and is discharged into the sealed container 1 through the cup muffler 37.

The space 46 is surrounded by the eccentric portion 31 a, the upper bearing 34, and the inner peripheral surface of the piston 32. The space 47 is surrounded by the eccentric portion 31 a, the lower bearing 35, and the inner peripheral surface of the piston 32. Lubricating oil leaks into the space 46 from the oil hole 41 through the oil supply hole 42. Lubricating oil leaks into the space 47 from the oil hole 41 through the oil supply hole 43. Accordingly, since the discharge pressure is applied to the spaces 46 and 47, the spaces 46 and 47 are in a state higher than the pressure inside the compression space 39.
The height of the cylinder 30 is set slightly higher than the height of the piston 32 so that the piston 32 can slide inside. As a result, there are gaps between the end face of the piston 32 and the upper bearing 34 and between the end face of the piston 32 and the lower bearing 35. Therefore, the lubricating oil leaks from the spaces 46 and 47 to the compression space 39 through this gap.

3 and 4 show a cylinder of the rotary compressor in the present embodiment.
Fig.3 (a) is a principal part top view which shows the cylinder of the rotary compressor compressor in this Embodiment. FIG.3 (b) is the principal part side view seen from the A direction and B direction shown to the figure (a).
A vane groove 30 b is formed in the cylinder 30. The vane 33 shown in FIGS. 1 and 2 is disposed in the vane groove 30b. The inside of the cylinder 30, that is, the compression space 39 forms a suction chamber 39a and a compression chamber 39b with the vane groove 30b interposed therebetween. The suction port 39 communicates with the suction chamber 39a.
The spring hole 30c is a hole formed from the outer peripheral surface of the cylinder 30, and is formed in the same direction as the vane groove 30b. A spring 30d shown in FIGS. 1 and 2 is disposed in the spring hole 30c. The spring 30 d presses the vane 33 toward the piston 32. The spring hole 30c is filled with high-pressure refrigerant gas and lubricating oil. Accordingly, the refrigerant hole pressure is applied to the spring hole 30c.

FIG. 4A is a main part plan view showing the relationship between the cylinder 30 and the vane 33 when the piston 32 is positioned in the vicinity of the top dead center of the vane 33. FIG. 4B is a main part plan view showing the relationship between the cylinder 30 and the vane 33 when the compression chamber 39b reaches a predetermined pressure.
As shown in FIG. 4, the vane 33 has a suction chamber side contact surface 33a that contacts the vane groove 30c on the suction chamber 39a side, and a compression chamber side contact surface 33b that contacts the vane groove 30c on the compression chamber 39b side. Is formed. Lubricating oil from the oil reservoir 6 is supplied to the suction chamber side contact surface 33a and the compression chamber side contact surface 33b.

Here, before describing the embodiment of the present invention, problems in a cylinder of a rotary compressor as a comparative example will be described with reference to FIGS. 5 and 6.
Fig.5 (a) is a principal part top view which shows the cylinder of the rotary compressor in a comparative example. FIG.5 (b) is the principal part side view seen from the A direction and B direction which are shown to the same figure (a). In addition, the same code | symbol is attached to the member by the same structure as this Embodiment, and description is abbreviate | omitted. FIG. 6A is a main part plan view showing the relationship between the cylinder 130 and the vane 33 when the piston 32 is positioned in the vicinity of the top dead center of the vane 33. FIG. 6B is a principal plan view showing the relationship between the cylinder 130 and the vane 33 when the compression chamber 39b reaches a predetermined pressure.
The spring hole 130c in the comparative example has the same length on the suction chamber 39a side and the compression chamber 39b side.
Therefore, the contact area with the vane groove 30b on the suction chamber side contact surface 33a of the vane 33 is equal to the contact area with the vane groove 30b on the compression chamber side contact surface 33b of the vane 33.

  As shown in FIG. 6A, when the suction chamber 39a and the compression chamber 39b are at the same pressure, that is, when the pressure difference between the suction chamber 39a and the compression chamber 39b is a low pressure equal to or lower than a predetermined pressure, the suction chamber side contact surface 33a and the compression chamber 39a are compressed. No pressure difference is generated between the chamber side contact surface 33b. For this reason, the vane 33 does not tilt toward the suction chamber 39a, there is no contact between the suction chamber side contact surface 33a and the vane groove 30b, and there is no contact between the compression chamber side contact surface 33b and the vane groove 30b. A gap is created. As a result, the high-pressure refrigerant gas and lubricating oil filled in the spring hole 30c leak into the compression space 39 through the left and right gaps of the vane 33, and the efficiency is reduced.

The differential pressure generating mechanism in the present embodiment will be described below.
As shown in FIG. 3, the differential pressure generating mechanism in the present embodiment makes the compression chamber side spring hole 30e located on the compression chamber 39b side longer than the suction chamber side spring hole 30f located on the suction chamber 39a side. ing. Thereby, the contact area with the vane groove 30b in the suction chamber side contact surface 33a of the vane 33 becomes larger than the contact area with the vane groove 30b in the compression chamber side contact surface 33b of the vane 33. A region indicated by hatching in FIG. 3B is a contact surface between the vane 33 and the vane groove 30b.

  As shown in FIG. 4A, when the suction chamber 39a and the compression chamber 39b have the same pressure, that is, when the pressure difference between the suction chamber 39a and the compression chamber 39b is a low pressure equal to or lower than a predetermined pressure, the discharge pressure is applied to the spring hole 30c. ing. Therefore, by making the contact area of the suction chamber side contact surface 33a with the vane groove 30b larger than the contact area of the compression chamber side contact surface 33b with the vane groove 30b, the suction chamber side contact surface 33a is closer to the compression chamber side. The pressure applied to the contact surface 33b increases, and the vane 33 can be tilted by this pressure difference. Thereby, the vane 33 and the vane groove 30b are brought into contact with each other to improve the sealing performance, and refrigerant gas and lubricating oil are prevented from leaking from the suction chamber side contact surface 33a and the compression chamber side contact surface 33b of the vane 33 to the compression space 39. it can.

  Further, the lubricating oil is easily held between the vane 33 and the vane groove 30b, and the reliability is improved. On the other hand, when the contact force between the suction chamber side contact surface 33a of the vane 33 and the surface of the vane groove 30b on the suction chamber 39a side is maximized, the compression chamber 39b reaches a predetermined pressure. Therefore, the oil reservoir 6 and the compression chamber 39b have substantially the same pressure. Therefore, the gap between the compression chamber side contact surface 33b of the vane 33 and the surface of the vane groove 30b on the compression chamber 39b side is filled with substantially high pressure. Since this is equivalent to the pressure distribution (see FIG. 6) of the vane 33 and the vane groove 30b of a general rotary compressor, the vane 33 and the vane groove 30b do not slide strongly, and the reliability deteriorates. do not do.

  Although not shown, in the above configuration, the same effect can be obtained by providing counterbore or the like on the vane 33 side and introducing lubricating oil.

Next, FIG. 7 shows the compression chamber side contact surface 33b of the vane 33 and the compression chamber 39b of the vane groove 30b with respect to the contact area between the suction chamber side contact surface 33a of the vane 33 and the surface of the vane groove 30b on the suction chamber 39a side. It is a graph which shows the relationship between the ratio of the contact area with the side surface, and efficiency.
As shown in FIG. 7, when the ratio of the contact area of the compression chamber side contact surface 33b with the vane groove 30b to the contact area of the suction chamber side contact surface 33a with the vane groove 30b is 70% or more, the suction chamber 39a and the compression chamber 39b. Are the same pressure, that is, when the pressure difference between the suction chamber 39a and the compression chamber 39b is a low pressure equal to or lower than a predetermined pressure, the pressure difference applied to the suction chamber side contact surface 33a and the compression chamber side contact surface 33b does not become excessive. Therefore, while reducing the contact force between the suction chamber side contact surface 33a and the surface of the vane groove 30b on the suction chamber 39a side, the lubricating oil from the gap between the vane 33 and the vane groove 30b to the suction chamber 39a and the compression chamber 39b. And the leakage of the refrigerant gas is suppressed, and the efficiency is improved.
As described above, the ratio of the contact area of the compression chamber side contact surface 33b with the vane groove 30b to the contact area of the suction chamber side contact surface 33a with the vane groove 30b is preferably 70% or more.

FIG. 8 shows a cylinder of a rotary compressor according to another embodiment of the present invention. Only differences from the above embodiment will be described, and description of the same configuration as that of the above embodiment will be omitted.
FIG. 8A is a main part plan view showing a cylinder of a rotary compressor according to another embodiment of the present invention, and FIG. 8B is seen from the A direction and the B direction shown in FIG. It is a principal part side view.
As shown in FIG. 8, as a differential pressure generating mechanism, a counterbore 60 communicating with the vane groove 30b may be provided in a direction orthogonal to the vane groove 30b. Thus, the contact area between the suction chamber side contact surface 33a of the vane 33 and the surface of the vane groove 30b on the suction chamber 39a side, and the compression chamber side contact surface 33b of the vane 33 and the surface of the vane groove 30b on the compression chamber 39b side. The contact area of can be changed. That is, as shown in FIG. 8B, by providing a counterbore 60 as a differential pressure generating mechanism, the contact area of the vane 33 with the vane groove 30b on the suction chamber side contact surface 33a is reduced. It becomes larger than the contact area with the vane groove | channel 30b in the surface 33b. A region indicated by hatching in FIG. 8B is a contact surface between the vane 33 and the vane groove 30b.

In the embodiment shown in FIG. 8, instead of the differential pressure generating mechanism that makes the compression chamber side spring hole 30e located on the compression chamber 39b side longer than the suction chamber side spring hole 30f located on the suction chamber 39a side. A differential pressure generating mechanism using counterbore 60 was provided. However, a differential pressure generating mechanism using a counterbore 60 is provided together with a differential pressure generating mechanism that makes the compression chamber side spring hole 30e positioned on the compression chamber 39b side longer than the suction chamber side spring hole 30f positioned on the suction chamber 39a side. Also good.
The counterbore 60 can be easily processed using a drill or an end mill.

FIG. 9 shows a cylinder of a rotary compressor according to still another embodiment of the present invention. Only differences from the above embodiment will be described, and description of the same configuration as that of the above embodiment will be omitted.
As shown in FIG. 9, when the center of the counterbore 60 is configured outside the vane groove 30b, the intersection (edge part) of the counterbore 60 and the vane groove 30b becomes an acute angle, so that the lubricity of the oil is deteriorated. Therefore, it is preferable that the center of the counterbore 60 is positioned in the vane groove 30b, and the intersection of the counterbore 60 and the vane groove 30b is an obtuse angle (see FIG. 8).

FIG. 10 shows a cylinder of a rotary compressor according to still another embodiment of the present invention. Only differences from the above embodiment will be described, and description of the same configuration as that of the above embodiment will be omitted.
10 (a) is a plan view of a main part showing a cylinder of a rotary compressor according to still another embodiment of the present invention, and FIG. 10 (b) is a view from the A direction and the B direction shown in FIG. 10 (a). FIG.
As shown in FIG. 10, as the counterbore 60, a suction chamber side counterbore 60a communicating with the vane groove 30b on the suction chamber 39a side and a compression chamber side counterbore 60b communicating with the vane groove 30b on the compression chamber 39b side may be provided. .
Usually, the height of the cylinder 30 is about 4 to 6 times the width of the vane groove 30b. Considering the general tool life, since it can only dig up to a depth of 2 to 3 times the diameter of the drill hole, the counterbore 60 communicating with only one side of the vane groove 30b penetrates with a single hole drilling in the axial direction. It is difficult to do.

  In the configuration in which the counterbore 60 does not penetrate in the axial direction, the pressure balance in the thickness direction is lost between the upper shaft side 34a and the lower shaft side 35a of the vane 33, leading to a decrease in efficiency. By providing the suction chamber side counterbore 60a and the compression chamber side counterbore 60b as the counterbore 60, the diameter of the drill hole can be made larger than the width of the vane groove 30b, so that it is easy to penetrate in the axial direction by one hole drilling. Become. Further, since the diameter of the drill hole can be increased, the tool life is extended and the workability is improved.

  A rotary compressor composed of a vane that is coupled to the outer peripheral portion of the piston in a projecting manner and divides the compression chamber into a low pressure side and a high pressure side, and a swinging bush that supports the vane so that it can swing back and forth. Even in the case, the same effect as the above can be obtained. The same effect as described above can also be obtained in a rotary compressor constituted by a vane that is connected to a piston and a tip portion so as to freely swing.

  Further, a single refrigerant composed of a refrigerant having a base component of hydrofluoroolefin having a double bond between carbon and carbon or a mixed refrigerant containing the refrigerant is used as a working fluid. This refrigerant has a low suction density and requires, for example, a circulation amount of about 1.7 times to produce the same capacity as R410A. Accordingly, there is a characteristic that the difference between high and low pressures in the compression becomes large and the influence of leakage of the lubricating oil and the refrigerant gas becomes large, so that the efficiency of the compressor can be improved more effectively. Moreover, since this refrigerant has no ozone destruction and a low global warming potential, it can contribute to the configuration of an air-conditioning cycle that is friendly to the earth.

Alternatively, a mixed refrigerant in which the hydrofluoroolefin is tetrafluoropropene (HFO1234yf) and the hydrofluorocarbon is difluoromethane (HFC32) may be used as the working refrigerant.
Alternatively, a mixed refrigerant in which the hydrofluoroolefin is tetrafluoropropene (HFO1234yf) and the hydrofluorocarbon is pentafluoroethane (HFC125) may be used as the working refrigerant.
Alternatively, a three-component mixed refrigerant in which the hydrofluoroolefin is tetrafluoropropene (HFO1234yf) and the hydrofluorocarbon is pentafluoroethane (HFC125) and difluoromethane (HFC32) may be used as the working refrigerant.

  In the above embodiment, a single-piston rotary compressor with one cylinder has been described as an example. However, a rotary compressor having a plurality of cylinders 30 may be used.

  As described above, the rotary compressor of the present invention is provided with the differential pressure generating mechanism that presses the vane toward the suction chamber side of the vane groove and communicates with the oil reservoir. This makes it possible to reduce the leakage of lubricating oil and refrigerant gas from the gap between the vane and the vane groove when the suction chamber and the compression chamber are at the same pressure without deteriorating reliability, greatly improving the efficiency of the compressor. To do. Therefore, in addition to the compressor for an air conditioner using an HFC refrigerant or an HCFC refrigerant, the present invention can be applied to an application such as an air conditioner using a natural refrigerant CO2 or a heat pump water heater.

Claims (6)

A cylinder,
An eccentric portion of a shaft disposed in the cylinder;
A piston fitted to the eccentric part;
Reciprocating in a vane groove provided in the cylinder following the eccentric rotation of the piston, and having a vane for dividing the inside of the cylinder into a suction chamber and a compression chamber;
The vane is formed with a suction chamber side contact surface that contacts the vane groove on the suction chamber side, and a compression chamber side contact surface that contacts the vane groove on the compression chamber side,
A rotary compressor in which lubricating oil is supplied from an oil reservoir to the suction chamber side contact surface and the compression chamber side contact surface;
A differential pressure generating mechanism is formed in which a pressure applied to the compression chamber side contact surface is larger than the suction chamber side contact surface when a pressure difference between the suction chamber and the compression chamber is a predetermined pressure or less. Rotary compressor.   2. The differential pressure generating mechanism according to claim 1, wherein a contact area with the vane groove on the suction chamber side contact surface is larger than a contact area with the vane groove on the compression chamber side contact surface. Rotary compressor.   3. The rotary compressor according to claim 2, wherein the differential pressure generating mechanism is provided with counterbore communicating with the vane groove in a direction perpendicular to the vane groove.   4. The counterbore according to claim 3, wherein the counterbore includes a suction chamber side counterbore communicating with the vane groove on the suction chamber side and a compression chamber side counterbore communicating with the vane groove on the compression chamber side. Rotary compressor.   The rotary according to claim 2, wherein a ratio of a contact area with the vane groove on the compression chamber side contact surface to a contact area with the vane groove on the suction chamber side contact surface is 70% or more. Compressor.   6. The working fluid is a single refrigerant composed of a refrigerant composed of carbon and a hydrofluoroolefin having a double bond between carbons as a base component or a mixed refrigerant containing the refrigerant. A rotary compressor according to any one of the above.