JP2003293971A - Rotary compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary compressor with increased reliability and compression efficiency of a vane. <P>SOLUTION: In this rotary compressor, an electric element and a rotating compression element driven by the electric element are installed in a closed container. The rotary compressor comprises: a roller 46 fitted to a cylinder 38 for forming the rotating compression element and an eccentric part 42 formed on the rotating shaft of the electric element and eccentrically rotated in the cylinder; the vane 50 allowed to abut on the roller and dividing the inside of the cylinder into a low pressure chamber side and a high pressure chamber side; a guide groove 71 formed in the cylinder to store the vane; and a back pressure chamber 72 formed in the cylinder and communicating with the guide groove to apply a back pressure to the vane. The cross sectional shape of the vane at the tip is formed in an arc shape, and the radius of the arc of the vane on the high pressure chamber side is lowered less than the radius of the arc on the low pressure chamber side. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary compressor provided with an electric element in a closed container and a rotary compression element driven by the electric element, and compressing and discharging a refrigerant gas by the rotary compression element. Is.

[0002]

2. Description of the Related Art A conventional rotary compressor of this type, particularly an internal intermediate pressure type multi-stage compression type rotary compressor, is disclosed in, for example, Japanese Patent Application Laid-Open No. 2-294587 (F04C23 / 0).
0). That is, in such a rotary compressor, the refrigerant gas is sucked into the low pressure chamber side of the cylinder from the suction port of the first rotary compression element, and is compressed by the operation of the roller and the vane to become an intermediate pressure, and the discharge port from the high pressure chamber side of the cylinder, It is discharged into the closed container through the discharge muffling chamber. Then, the intermediate-pressure gas in the closed container is sucked into the low-pressure chamber side of the cylinder from the suction port of the second rotary compression element, and the second stage compression is performed by the operation of the roller and the vane, so that the high-temperature and high-pressure gas is generated. And is discharged from the high pressure chamber side through the discharge port and the discharge muffling chamber.

The gas discharged from the rotary compressor flows into a radiator or the like of the refrigerant circuit, radiates heat, is throttled by an expansion valve and absorbed by an evaporator, and is sucked into a first rotary compression element of the rotary compressor. Repeat the cycle.

When a refrigerant having a large difference in high pressure and low pressure, for example, carbon dioxide (CO ₂ ) is used as the refrigerant in the rotary compressor, the pressure of the discharged refrigerant reaches 12 MPaG in the second rotary compression element which becomes high pressure, while The first rotary compression element on the lower stage side has a pressure of 8 MPaG (intermediate pressure) (the suction pressure of the first rotary compression element is 4 MPa).

[0005]

Generally, the vane attached to the rotary compressor is inserted into a guide groove provided in the radial direction of the cylinder so as to be movable in the radial direction of the cylinder. Since this vane needs to be pressed against the roller side, the structure in which the vane is pressed against the roller by the biasing force of the spring and the back pressure from the back pressure chamber has been adopted in the past. In the second rotary compression element, since the pressure in the cylinder is higher than the intermediate pressure in the closed container, the pressure in the closed container cannot be used as the back pressure of the vane.

Therefore, in the second rotary compression element, the discharge pressure is applied as the back pressure of the vane, but as described above, the difference between the high pressure and the low pressure (in this case, the intermediate pressure) becomes large, so that the vane is increased. The force pressing the tip against the roller (the surface pressure of the tip) increases, and the reliability decreases due to abrasion of the tip. In addition, the force required for the roller to push the vane becomes large, which causes a problem that the compression performance is adversely affected. This is not limited to the above-described multi-stage compression type rotary compressor, and the same applies to a single cylinder type rotary compressor.

Therefore, the present invention has been made in order to solve the above-mentioned conventional technical problems, and an object of the present invention is to provide a rotary compressor having improved reliability and compression efficiency regarding vanes.

[0008]

That is, according to the invention of claim 1, a rotary compression element is constituted in a rotary compressor provided with an electric element in a closed container and a rotary compression element driven by the electric element. And a roller that is fitted to an eccentric portion formed on the rotating shaft of the electric element and rotates eccentrically in the cylinder, and a vane that abuts on the roller and divides the cylinder into a low pressure chamber side and a high pressure chamber side. , A guide groove formed in the cylinder for accommodating the vane, and a back pressure chamber formed in the cylinder and communicating with the guide groove for applying a back pressure to the vane, and the cross-sectional shape of the vane tip is an arc shape. In addition, the radius of the arc on the high pressure chamber side of the vane is smaller than the radius of the arc on the low pressure chamber side.

According to the second aspect of the present invention, in a rotary compressor including an electric element in a closed container and a rotary compression element driven by the electric element, a cylinder for forming the rotary compression element and a rotation of the electric element are rotated. A roller fitted in an eccentric portion formed on the shaft and rotating eccentrically in the cylinder, a vane that abuts on this roller to divide the inside of the cylinder into a low pressure chamber side and a high pressure chamber side, and a vane formed in the cylinder to A guide groove for housing and a back pressure chamber that is formed in the cylinder and communicates with the guide groove for applying back pressure to the vane are provided, and the cross-sectional shape of the tip of the vane is formed in an arc shape, and the center of the arc is formed. It is characterized in that it is offset from the center of the vane to the low pressure chamber side.

According to the third aspect of the present invention, the hermetic container is provided with an electric element and first and second rotary compression elements driven by the electric element, and the refrigerant gas compressed by the first rotary compression element. In a hermetically sealed container and further compresses the discharged intermediate pressure refrigerant gas by a second rotary compression element, in a cylinder and a rotary shaft of an electric element for constituting the second rotary compression element. A roller that is fitted into an eccentric part formed on the cylinder and rotates eccentrically in the cylinder; a vane that abuts on the roller and divides the cylinder into a low pressure chamber side and a high pressure chamber side; And a back pressure chamber that is formed in the cylinder and that communicates with the guide groove for applying back pressure to the vane. The vane tip has an arc-shaped cross section and the high pressure chamber side of the vane. Of the arc Diameter, characterized by being smaller than the radius of the arc of the low-pressure chamber side.

According to the fourth aspect of the present invention, the hermetic container is provided with an electric element and first and second rotary compression elements driven by the electric element, and the refrigerant gas compressed by the first rotary compression element is provided. In a hermetically sealed container and further compresses the discharged intermediate pressure refrigerant gas by a second rotary compression element, in a cylinder and a rotary shaft of an electric element for constituting the second rotary compression element. A roller that is fitted into an eccentric part formed on the cylinder and rotates eccentrically in the cylinder; a vane that abuts on the roller and divides the cylinder into a low pressure chamber side and a high pressure chamber side; And a back pressure chamber that is formed in the cylinder and communicates with the guide groove to apply back pressure to the vane.The vane tip has an arc-shaped cross-section, and the center of the arc is the vane. Center of Ri is characterized in that is displaced toward the low pressure chamber.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a vertical cross-sectional side view of an internal intermediate pressure type multi-stage (two-stage) compression rotary compressor 10 having first and second rotary compression elements as an embodiment of the rotary compressor of the present invention.

In this figure, 10 is carbon dioxide (CO
₂ ) is an internal intermediate pressure type multi-stage compression rotary compressor that uses as a refrigerant. This multi-stage compression rotary compressor 10 is arranged and housed in a cylindrical hermetic container 12 made of steel plate and above the inner space of the hermetic container 12. The first rotary compression element 32 (first stage) and the second rotary compression element 34 (second stage), which are arranged below the electric element 14 and are driven by the rotary shaft 16 of the electric element 14. ) Is composed of the rotary compression mechanism section 18.

The closed container 12 has a bottom as an oil reservoir, and the container body 1 for accommodating the electric element 14 and the rotary compression mechanism 18
2A and a substantially bowl-shaped end cap (lid) 12B that closes the upper opening of the container body 12A, and a circular mounting hole 12D is formed at the center of the upper surface of the end cap 12B. A terminal (wiring is omitted) 20 for supplying electric power to the electric element 14 is attached to the attachment hole 12D.

The electric element 14 is a stator 22 mounted in an annular shape along the inner peripheral surface of the upper space of the closed container 12.
And a rotor 24 inserted and installed inside the stator 22 with a slight gap. The rotor 24 is fixed to the rotary shaft 16 that extends vertically through the center.

The stator 22 includes a laminated body 26 in which donut-shaped electromagnetic steel sheets are laminated, and a stator coil 2 wound around the teeth of the laminated body 26 by a direct winding (concentrated winding) method.
Have eight. The rotor 24 is also formed of a laminated body 30 of electromagnetic steel plates, like the stator 22.
It is configured by embedding a permanent magnet MG therein.

An intermediate partition plate 36 is sandwiched between the first rotary compression element 32 and the second rotary compression element 34. That is, the first rotary compression element 3 of the rotary compression mechanism portion 18
2 and the second rotary compression element 34 include an intermediate partition plate 36 and an upper cylinder 3 arranged above and below the intermediate partition plate 36.
8. Upper and lower rollers which are eccentrically rotated in the upper and lower cylinders 38 and 40 by being fitted to the lower cylinder 40 and the upper and lower eccentric portions 42 and 44 provided on the rotary shaft 16 with a phase difference of 180 degrees. 46 and 48, coil springs 76 and 77, and back pressure to urge their tips into contact with the upper and lower rollers 46 and 48, respectively, so that the insides of the upper and lower cylinders 38 and 40 are in the low pressure chamber side LR and the high pressure chamber side HR, respectively. (FIG. 2) upper and lower vanes 50 and 52, and an upper support member as a support member that also serves as a bearing for the rotary shaft 16 by closing the upper opening surface of the cylinder 38 and the lower opening surface of the cylinder 40. 54 and a lower support member 56.

On the other hand, in the upper support member 54 and the lower support member 56, a suction passage 60 communicating with the insides of the upper and lower cylinders 38 and 40 through a suction port 55 (FIG. 2, the lower support member 56 is not shown). (The upper support member 54 is not shown) and a part thereof is recessed, and the recessed portion is covered by the upper cover 66,
Discharge silencing chambers 62 and 64 formed by closing with a lower cover 68 are provided.

The discharge muffler chamber 64 and the inside of the closed container 12 are communicated with each other by a communication passage that penetrates the upper and lower cylinders 38, 40 and the intermediate partition plate 36, and the intermediate discharge pipe 121 is provided at the upper end of the communication passage. Is erected, and the intermediate-pressure refrigerant compressed by the first rotary compression element 32 is discharged from the intermediate discharge pipe 121 into the closed container 12.

In this case, the above-mentioned carbon dioxide (CO ₂ ) which is a natural refrigerant in consideration of flammability and toxicity is used as the refrigerant, and the oil as the lubricating oil is, for example, a mineral oil. (Mineral oil), alkylbenzene oil, ether oil, ester oil, PAG (polyalkyl glycol) and other existing oils are used.

The suction passage 6 of the upper support member 54 and the lower support member 56 is provided on the side surface of the container body 12A of the closed container 12.
0 (upper side not shown), discharge muffling chamber 62, upper cover 66
Of the sleeves 141, 142, 143 and 14 at positions corresponding to the upper side of the (the position substantially corresponding to the lower end of the electric element 14).
4 are fixed by welding. And sleeve 1
One end of a refrigerant introducing pipe 92 for introducing a refrigerant gas into the cylinder 38 is inserted and connected in the cylinder 41.
One end of 2 communicates with a suction passage (not shown) of the cylinder 38. The refrigerant introduction pipe 92 passes through the upper side of the closed container 12 to reach the sleeve 144, and the other end is inserted and connected into the sleeve 144 and communicates with the closed container 12.

Further, the cylinder 40 is provided in the sleeve 142.
One end of a refrigerant introduction pipe 94 for introducing a refrigerant gas into the cylinder is inserted and connected, and one end of this refrigerant introduction pipe 94 is connected to the cylinder 40.
Of the suction passage 60. The other end of the refrigerant introducing pipe 94 is connected to an accumulator (not shown). A refrigerant discharge pipe 96 is inserted and connected in the sleeve 143, and one end of the refrigerant introduction pipe 96 communicates with the discharge muffling chamber 62.

Next, the structure around the vane 50 of the second rotary compression element 34 will be described with reference to FIG. The cylinder 38 is formed with a discharge port 70 communicating with the discharge muffling chamber 62 via a discharge valve (not shown) and the suction port 55 described above, and is located between these and extends in the cylinder 38 in the radial direction. A guide groove 71 is formed. The vane 50 is placed in the guide groove 71.
Is slidably stored.

As described above, the vane 50 has its tip abutted against the roller 46 to divide the inside of the cylinder 38 into the low pressure chamber side LR and the high pressure chamber side HR. The suction port 55 opens to the low pressure chamber side LR, and the discharge port 70 to the high pressure chamber side H.
It is open to R.

A back pressure chamber 72 is formed inside the cylinder 38 outside the guide groove 71 (on the closed container 12 side) so as to communicate with the guide groove 71. Here, in the internal intermediate pressure type multi-stage compression rotary compressor 10 of the embodiment, the inside pressure of the hermetic container 12 is an intermediate pressure, and therefore the second rotary compression element 34 cannot use it as the back pressure of the vane 50. Therefore, the back pressure chamber 72 is communicated with the discharge muffling chamber 62, and thereby a high back pressure is applied to the vane 50.

The coil spring 76 is provided in the guide groove 71.
Also, it is stored in a storage portion formed outside the back pressure chamber 72 and formed in the cylinder 38, and abuts on the outside of the vane 50 to constantly urge the tip end of the vane 50 toward the roller 46 side.

That is, the vane 50 is biased toward the roller 46 by the biasing force of the coil spring 76 and the high pressure from the back pressure chamber 72. In this case, the tip 50A of the vane 50 is shown in FIG.
Like this, the cross section has an arc shape. Further, the radius of the arc is different between the low pressure chamber side LR and the high pressure chamber side HR with the center C of the vane 50 as a boundary, as shown in FIG. 3, and the radius R2 of the arc of the high pressure chamber side HR is the low pressure chamber side. It is set smaller than the radius R1 of the arc of LR (R1> R2).

With this configuration, the tip 50A of the vane 50 is
The surface area of is larger in the high pressure chamber side HR than in the center C than in the low pressure chamber side LR. As a result, the pressure (high pressure) on the high pressure chamber side HR in the cylinder 38 is configured to more effectively act on the tip 50A of the vane 50.

Next, the operation of the above configuration will be described. When the stator coil 28 of the electric element 14 is energized via the terminal 20 and wiring (not shown), the electric element 14 is activated and the rotor 24 rotates. Rotation axis 1 by this rotation
The upper and lower rollers 46 and 48 fitted in the upper and lower eccentric portions 42 and 44 provided integrally with the motor 6 rotate eccentrically in the upper and lower cylinders 38 and 40.

As a result, the low-pressure refrigerant sucked into the low-pressure chamber side of the cylinder 40 from the suction port (not shown) via the refrigerant introduction pipe 94 and the suction passage 60 formed in the lower support member 56, the rollers 48 and the vanes. By the operation of 52, it becomes an intermediate pressure and becomes an intermediate pressure from the high pressure chamber side of the cylinder 40 through the communication passage not shown to the intermediate discharge pipe 121 to the closed container 12
Is discharged inside. As a result, the pressure inside the closed container 12 becomes an intermediate pressure.

The intermediate pressure refrigerant gas in the hermetic container 12 exits from the sleeve 144, passes through the refrigerant introduction pipe 92 and the suction passage (not shown) formed in the upper support member 54, and from the suction port 55 to the cylinder. 38 is sucked into the low pressure chamber side LR. The sucked intermediate-pressure refrigerant gas is transferred to the roller 46.
The second stage compression is performed by the operation of the vane 50 and the vane 50 to become a high-temperature and high-pressure refrigerant gas, and the discharge silencer chamber 6 formed in the upper support member 54 from the high pressure chamber side HR through the discharge port 70.
2. It flows into the external gas cooler (not shown) via the refrigerant discharge pipe 96. After radiating the heat of the refrigerant in this gas cooler, it is decompressed by a decompression device (not shown) or the like and also flows into an evaporator (not shown).

Then, the refrigerant evaporates, and then the cycle in which the refrigerant is sucked into the first rotary compression element 32 from the refrigerant introduction pipe 94 through the accumulator is repeated.

In this case, in the compression operation by the second rotary compression element 34, in the present invention, the surface area of the tip 50A of the vane 50, which is pressed against the roller 46 as described above, is located on the low pressure chamber side LR in the cylinder 38. Since the portion located on the high pressure chamber side HR is made larger than the portion, the pressure on the high pressure chamber side HR in the cylinder 38 is controlled by the vane 50.
Effectively acts on the front end 50A of the above, and the vane pressing force against the roller 46 due to the pressure from the back pressure chamber 72 is relaxed.

As a result, the vane 50 is pressed against the roller 46 more strongly than necessary, and the surface pressure is prevented from becoming abnormally high, and the reliability of the tip 50A of the vane 50 can be improved. Since the roller 46 also reduces the work of pushing the vane 50 into the guide groove 71 side,
The compression efficiency is also improved.

Further, since the tip 50A of the vane 50 has an arc shape (having different radii) on both the low pressure chamber side LR and the high pressure chamber side HR, there is no occurrence of biting phenomenon in which the tip 50A of the vane 50 bites into the roller 46.

Here, FIG. 4 shows the shape of the tip 50A of the vane 50 of another embodiment of the present invention. In this case, the tip 50 </ b> A of the vane 50 has a circular cross section with a radius R as a whole, but the center O of this arc is the vane 50.
Is deviated to the low pressure chamber side LR by the dimension S from the center C of. With this configuration as well, the surface area of the tip end 50A of the vane 50 is larger at the high pressure chamber side HR than at the center C than at the low pressure chamber side LR, as described above. As a result, the pressure (high pressure) on the high pressure chamber side HR in the cylinder 38 acts on the tip 50A of the vane 50 more effectively,
The same effect as described above is achieved.

Particularly, in this case, since the arc radius of the vane 50 is uniform, the vane 50 can be easily machined.

In the embodiment, the present invention is applied to the internal intermediate pressure type multi-stage compression type rotary compressor, but the present invention is not limited to this, and the present invention is also effective for a single cylinder rotary compressor. Further, the refrigerant to be used is not limited to carbon dioxide (CO ₂ ) in claims 1 to 4.

[0039]

As described above in detail, according to the present invention, the surface area of the tip of the vane pressed against the roller is larger in the portion located in the high pressure chamber side than in the portion located in the low pressure chamber side in the cylinder. As a result, the pressure on the high pressure chamber side in the cylinder can be effectively applied to the tip of the vane, and the vane pressing force on the roller due to the pressure from the back pressure chamber can be mitigated to improve the reliability of the vane tip. In addition, the compression efficiency can be improved.

Further, since the vane tip is arcuate on both the low-pressure chamber side and the high-pressure chamber side, the so-called roller biting phenomenon does not occur. Particularly, in the second rotary compression element of the internal intermediate pressure type multi-stage compression type rotary compressor as in claims 3 and 4, a high pressure is applied to the back pressure chamber, so the present invention is extremely effective. . Further, when compressing the CO ₂ refrigerant in which the high-low pressure difference becomes large as in claim 5,
The effect becomes more remarkable.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an internal intermediate pressure type multi-stage compression rotary compressor according to an embodiment of the present invention.

2 is an enlarged plan sectional view of a vane portion of the second rotary compression element of FIG. 1. FIG.

3 is an enlarged view of the vane tip portion of FIG. 2. FIG.

FIG. 4 is an enlarged view of a vane tip portion according to another embodiment of the present invention.

[Explanation of symbols]

10 Multi-stage compression rotary compressor 32 First rotary compression element 34 Second rotary compression element 38 cylinders 42 Eccentric part 46 Laura 50 vanes 71 guide groove 72 Back pressure chamber

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takashi Sato             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. (72) Inventor Hiroyuki Matsumori             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. (72) Inventor Dai Matsuura             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd.

Claims (5)

[Claims] 1. A rotary compressor provided with an electric element in a closed container and a rotary compression element driven by the electric element, wherein a cylinder for constituting the rotary compression element and a rotary shaft of the electric element are formed. A roller that is fitted into the eccentric portion and rotates eccentrically in the cylinder; a vane that abuts the roller to divide the inside of the cylinder into a low pressure chamber side and a high pressure chamber side; and a vane formed in the cylinder. And a back pressure chamber that is formed in the cylinder and that communicates with the guide groove to apply back pressure to the vane, and the vane tip has an arc-shaped cross-sectional shape. A rotary compressor characterized in that a radius of an arc of the vane on the high-pressure chamber side is smaller than a radius of an arc on the low-pressure chamber side. 2. A rotary compressor comprising an electric element and a rotary compression element driven by the electric element in a closed container, wherein a cylinder for constituting the rotary compression element and a rotary shaft of the electric element are formed. A roller that is fitted into the eccentric portion and rotates eccentrically in the cylinder; a vane that abuts the roller to divide the inside of the cylinder into a low pressure chamber side and a high pressure chamber side; and a vane formed in the cylinder. And a back pressure chamber that is formed in the cylinder and that communicates with the guide groove to apply back pressure to the vane, and the vane tip has an arc-shaped cross-sectional shape. A rotary compressor characterized in that the center of an arc is deviated from the center of a vane to the low-pressure chamber side. 3. An airtight container comprising an electric element and first and second rotary compression elements driven by the electric element, wherein the refrigerant gas compressed by the first rotary compression element is contained in the airtight container. A rotary compressor that discharges into the interior of the rotary compressor and further compresses the discharged intermediate-pressure refrigerant gas by the second rotary compression element, wherein a cylinder for configuring the second rotary compression element and a rotary shaft of the electric element A roller fitted to an eccentric part formed in the cylinder and rotating eccentrically in the cylinder; a vane that abuts the roller to divide the cylinder into a low pressure chamber side and a high pressure chamber side; A guide groove for accommodating the vane; and a back pressure chamber formed in the cylinder and communicating with the guide groove for applying a back pressure to the vane. The vane tip has an arc-shaped cross-section. , Rotary compressor, characterized in that the radius of the high-pressure chamber side arc of the vane, is smaller than the radius of the arc of the low-pressure chamber side. 4. A hermetic container provided with an electric element and first and second rotary compression elements driven by the electric element in a hermetic container, wherein the refrigerant gas compressed by the first rotary compression element is contained in the hermetic container. A rotary compressor that discharges into the interior of the rotary compressor and further compresses the discharged intermediate-pressure refrigerant gas by the second rotary compression element, wherein a cylinder for configuring the second rotary compression element and a rotary shaft of the electric element A roller fitted to an eccentric part formed in the cylinder and rotating eccentrically in the cylinder; a vane that abuts the roller to divide the cylinder into a low pressure chamber side and a high pressure chamber side; A guide groove for accommodating the vane; and a back pressure chamber formed in the cylinder and communicating with the guide groove for applying a back pressure to the vane. The vane tip has an arc-shaped cross-section. , Rotary compressor is characterized in that the center of the arc is offset from the center of the vane in the low pressure chamber side. 5. The rotary compressor according to claim 1, 2, 3, or 4, wherein the rotary compression element compresses CO ₂ refrigerant.