Rotary compressor

Abstract

A rotary compressor includes a coil spring to press a vane against a roller, and the contact area between the vane and a vane groove is secured by a simple and inexpensive construction, whereby the compressor size is decreased while the leakage of working fluid is restrained. The rotary compressor includes a closed vessel, a cylinder having a vane groove, which is located in the closed vessel, and a shaft having an eccentric portion. A roller is rotatably fitted on the eccentric portion of the shaft to eccentrically rotate in the cylinder. A vane is provided in the vane groove in the cylinder to reciprocate in the vane groove while a tip end thereof is in contact with the roller, and the coil spring is provided for pressing the vane against the roller. The vane is provided with a spring hole on the side opposite to the side on which the vane is in contact with the roller, and the spring hole contains at least a part of the coil spring.

Description

TECHNICAL FILED

The present invention relates to a rotary compressor used for refrigerators, air conditioners, and the like.

BACKGROUND ART

FIG. 4 is a longitudinal sectional view of a conventional rotary compressor. FIG. 5 is a transverse sectional view of a compression mechanism section of the conventional rotary compressor, FIG. 6 is a transverse sectional view showing dimensions of the compression mechanism section of the conventional rotary compressor, and FIGS. 7 and 8 are perspective views of vanes of the conventional rotary compressor.

The rotary compressor is made up of a closed vessel 1, a compression mechanism section 2 and an electric motor 3, both located in the closed vessel 1. The compression mechanism section 2 includes a cylinder 4 having a cylindrical portion, a shaft 5 rotatable around a center axis L1, a roller 6 which is fitted on an eccentric portion 5a of the shaft 5 to eccentrically rotate in the cylindrical portion of the cylinder 4 along with the rotation of the shaft 5, a vane 7 which reciprocates in a vane groove 4a provided in the cylinder 4 along with the eccentric rotation of the roller 6, a spring mechanism 8, such as a coil spring, which is provided on a back face 7a of the vane 7 to press a tip end 7b of the vane 7 against the roller 6, a first journal bearing 9 at a side near the electric motor 3 and a second journal bearing 10 at a side farther from the electric motor 3, both bearings holding the cylinder 4 from both side and rotatably supporting the shaft 5. The compression mechanism section 2 is fixed to the closed vessel 1 by a support portion 4b formed at the peripheral of the cylinder 4. The electric motor 3 includes a cylindrical stator 11 welded to the internal surface of the closed vessel 1 and a columnar rotor 12 shrink fitted on the shaft 5.

A working fluid is introduced from an intake pipe 13 to a compression chamber 14, which is formed by the cylinder 4, the roller 6, the vane 7, the first journal bearing 9, and the second journal bearing 10, through an suction hole 4c of the cylinder 4. The rotational motion produced by the electric motor 3 eccentrically rotates the roller 6 fitted on the eccentric portion 5a of the shaft 5, and accordingly the volume of the compression chamber 14 changes to compress the working fluid. When a discharge valve (not shown) in a discharge hole 15 is opened, the compressed working fluid is discharged to the outside of the closed vessel 1 through a discharge pipe 16 after passing through the interior of the closed vessel 1 (for example, refer to “Refrigeration and Air Conditioning Handbook”, 5th ed., vol. II Equipment Section, Japanese Association of Refrigeration, 1993, pp. 30-37).

In the steady-state operation of a rotary compressor, the tip end 7b of the vane 7 is pressed against the roller 6 by a force created by a differential pressure between a discharge pressure applied to the back face 7a of the vane 7 and a pressure in the compression chamber 14 applied to the tip end 7b of the vane 7 and a force created by the spring mechanism 8. However, at the start time, there scarcely exists the differential pressure between a discharge pressure applied to the back face 7a of the vane 7 and a pressure in the compression chamber 14 applied to the tip end 7b of the vane 7, so that the tip end 7b of the vane 7 is pressed against the roller 6 by the force created by the spring mechanism 8.

In the conventional rotary compressor, one end of the spring mechanism 8 such as a coil spring is in contact with the back face 7a of the vane 7, and the other end thereof is in contact with a cylindrical internal wall 1a of the closed vessel 1. In the state in which the back face 7a of the vane comes closest to the cylindrical internal wall 1a of the closed vessel 1 when the vane 7 reciprocates along the vane groove 4a, the tip end 7b of the vane 7 is in the state in which it is pushed in to a cylindrical internal wall 4d of the cylinder 4 by the eccentric rotation of the roller 6. At this time, a space larger than the compressed height of the spring mechanism 8 must always be kept between the back face 7a of the vane 7 and the cylindrical internal wall 1a of the closed vessel 1.

Taking the compressed height of the spring mechanism 8 as l_cvm, the inside diameter of the cylindrical internal wall 1a of the closed vessel 1 as d_mi, the inside diameter of the cylindrical internal wall 4d of the cylinder 4 as d_ci, and the length from the tip end 7b of the vane 7 to the back face 7a thereof as l_vn, an inequality of Formula 1 must hold. (Formula 1) $\begin{array}{cc}\frac{\left(d_{\mathrm{mi}}-d_{\mathrm{ci}}\right)}{2}>1_{\mathrm{vn}}+1_{\mathrm{cvm}}& \mathrm{Formula}1\end{array}$

In the case where the closed vessel 1 of rotary compressor is decreased in size, the left side of Formula 1 decreases, and the compressed height l_cvm of the spring mechanism 8 on the right side is determined by the specifications of the spring mechanism 8.

Therefore, the length l_vn of the vane 7 is shortened, and thus the seal length of a fitting portion of the vane 7 and the vane groove 4a is shortened, so that the sealing ability decreases. As a result, the leakage of working fluid occurs due to a differential pressure between the discharge pressure introduced to the back face 7a side of the vane 7 and the pressure in the compression chamber 14, which decreases the compression efficiency.

Also, in a state in which the vane 7 is projected from the cylindrical internal wall 4d of the cylinder 4 by the eccentric rotation of the roller 6, a difference in pressure between the pressure in the compression process and the pressure in the suction process acts on a side surface 7c of the vane 7 in the compression chamber 14, and thereby the vane 7 is tilted with respect to the vane groove 4a. When the length l_vn of the vane 7 is shortened, the length through which the vane 7 fits in the vane groove 4a becomes insufficient, so that the tilting angle is increased. Therefore, the contact surface pressure between the vane 7 and the vane groove 4a increases, which increases losses due to friction, so that the compressor efficiency decreases.

Further, in the conventional rotary compressor, as shown in FIG. 8, a configuration has been used in which the back face 7a of the vane 7 is recessed to secure a space for containing the spring mechanism 8. However, the vane of this configuration is the same as the vane shown in FIG. 7 in that the substantial length of the vane 7 relating to the sealing ability in the fitting portion of the vane 7 and the vane groove 4a is shortened, so that a decrease in compression efficiency cannot be prevented.

DISCLOSURE OF THE INVENTION

The present invention has been made to solve the above-described conventional problems, and accordingly, an object thereof is to provide a rotary compressor in which the contact area between the vane 7 and a vane groove 4a is secured by a simple and inexpensive construction, that is, by containing a part of a spring mechanism 8 such as a coil spring in a vane 7, whereby the compressor size can be decreased while the leakage of working fluid is restrained.

The 1^st invention of the present invention is a rotary compressor characterized in comprising a closed vessel; a cylinder having a vane groove, said cylinder located in said closed vessel; a shaft having an eccentric portion; a roller which is rotatably fitted on the eccentric portion of said shaft to eccentrically rotate in said cylinder; a vane provided in the vane groove in said cylinder to reciprocate in said vane groove while a tip end thereof is in contact with said roller; and a spring mechanism for pressing said vane against said roller, wherein said vane is provided with a spring hole on the side opposite to the side on which said vane is in contact with said roller, and said spring hole is accommodated in the cross section of said vane perpendicular to the direction of reciprocation of said vane, and contains at least a part of said spring mechanism.

The 2^nd invention of the present invention is the rotary compressor according to the 1^st invention of the present invention, characterized in that a plurality of said spring mechanisms are provided; said vane is provided with said plurality of said spring holes; and at least a part of each of said spring mechanisms is contained in each of said spring holes.

The 3^rd invention of the present invention is the rotary compressor according to the 1^st invention of the present invention, characterized in that said spring mechanism consists of a coil spring.

The 4^th invention of the present invention is the rotary compressor according to the 3^rd invention of the present invention, characterized in that one end of said coil spring is contained in the spring hole in said vane, and a seat with which the other end of said coil spring is in contact is provided with a coil spring guide mechanism.

The 5^th invention of the present invention is the rotary compressor according to the 4^th invention of the present invention, characterized in that said coil spring guide mechanism is provided on the inside side surface of said closed vessel.

The 6^th invention of the present invention is the rotary compressor according to the 3^rd invention of the present invention, characterized in that the width of said vane is set so as to be not smaller than 3.0 mm and not larger than 3.5 mm; the stroke of reciprocation of said vane is set so as to be not shorter than 3.0 mm and not longer than 5.0 mm; the diameter of said coil spring is set so as to be not smaller than 2.0 mm and smaller than the width of said vane; and the free length of said coil spring is set so as to be not larger than five times the diameter thereof.

The 7^th invention of the present invention is the rotary compressor according to the 1^st invention of the present invention, characterized in that a working fluid is carbon dioxide.

According to the rotary compressor of the present invention, there can be provided a rotary compressor in which the contact area between the vane and the vane groove is secured by a simple and inexpensive construction, whereby the compressor size can be decreased while the leakage of working fluid is restrained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a vane of a rotary compressor in accordance with a first embodiment of the present invention;

FIG. 2 is a transverse sectional view of a portion near a vane groove of a compression mechanism section of a rotary compressor in accordance with a first embodiment of the present invention;

FIG. 3 is a transverse sectional view of a portion near a vane groove of a compression mechanism section of a rotary compressor in accordance with a second embodiment of the present invention;

FIG. 4 is a longitudinal sectional view of a conventional rotary compressor;

FIG. 5 is a transverse sectional view of a compression mechanism section of a conventional rotary compressor;

FIG. 6 is a transverse sectional view showing dimensions of a compression mechanism section of a conventional rotary compressor;

FIG. 7 is a perspective view of a vane of a conventional rotary compressor; and

FIG. 8 is a perspective view of a vane of a conventional rotary compressor.

(Description of Symbols)

• 1 closed vessel
• 1a cylindrical internal wall of closed vessel
• 1b coil spring guide mechanism
• 2 compression mechanism section
• 3 electric motor
• 4 cylinder
• 4a vane groove
• 4b support portion
• 4c suction hole
• 4d cylindrical internal wall of cylinder
• 5 shaft
• 5a eccentric shaft
• 6 roller
• 7 vane
• 7a back face
• 7b tip end
• 7c side surface
• 7d spring hole
• 8 spring mechanism
• 9 first journal bearing
• 10 second journal bearing
• 11 stator
• 12 rotor
• 13 suction pipe
• 14 compression chamber
• 15 discharge hole
• 16 discharge pipe
• 20 coil spring

BEST MODE FOR CARRYING OUT THE INVENTION

Some embodiments of the present invention will now be described with reference to FIGS. 1, 2 and 3. The following description is given of examples of the present invention, and does not limit the appended claims.

For the rotary compressors in accordance with some embodiments of the present invention, the construction of rotary compressors excluding a cylinder 4, a vane 7, and a spring mechanism 8 is the same as that of the conventional rotary compressor shown in FIGS. 4 to 8, and thus the same reference numerals as applied to elements of the conventional rotary compressor will be applied to when elements are the same as those of the conventional rotary compressor. Also, the explanation of the same construction and operation as those of the conventional example is omitted.

(First Embodiment)

FIG. 1 is a perspective view of a vane of a rotary compressor in accordance with a first embodiment of the present invention. FIG. 2 is a transverse sectional view of a portion near a vane groove of a compression mechanism section of the rotary compressor in accordance with the first embodiment of the present invention. FIG. 2 shows a state in which a tip end 7b of the vane 7 is pushed in to a cylindrical internal wall 4d of the cylinder 4.

In this embodiment, as shown in FIG. 1, as the spring mechanism 8, coil springs 20 having an inside diameter dimension smaller than the width and height of a back face 7a of the vane 7 is provided. In the back face 7a of the vane 7, two spring holes 7d having a depth l_vna are provided in the direction in which the vane 7 reciprocates, each of the spring holes 7d having a diameter larger than the outside diameter of the coil spring 20 and smaller than the width and height of the vane 7. One end of the coil spring 20 is contained in each of the two spring holes 7d, and the other end thereof on the opposite side to the vane 7 is brought into contact with a cylindrical internal wall 1a of a closed vessel 1. Also, the length l_vn of the vane 7 is set so as to be a length such that in a state in which the tip end 7b of the vane 7 is pushed in to the surface of the cylindrical internal wall 4d of the cylinder 4 by the eccentric rotation of a roller 6, a minimum clearance 1_cr is provided between the back face 7a of the vane 7 and the cylindrical internal wall 1a of the closed vessel 1.

The coil spring 20 is not allowed to have a length not larger than a compressed height l_cvm even in a state of being compressed to a maximum, and must have a length not larger than a free length l_cvf (not shown) in order for the coil spring 20 to press the vane 7 against the roller 6 even in a state in which the vane 7 projects from the cylindrical internal wall 4d of the cylinder 4 to a maximum. For this reason, taking the stroke of reciprocation of the vane 7 caused by the eccentric rotation of the roller 6 as 1_st, the spring hole 7d is formed so as to have a depth l_vna that establishes an inequality of Formula 2.

(Formula 2)
l_cvm−l_cr<l_vna<l_cvf−l_st−l_cr  Formula 2

Next, the effects of the above configuration will be explained.

In the rotary compressor of this embodiment, because a part of the coil spring 20 can be contained in the spring hole 7d in the vane 7, a clearance l_cr smaller than the compressed height l_cvm of the coil spring 20 can be provided between the back face 7a of the vane 7 and the cylindrical internal wall 1a of the closed vessel 1 in a state in which the tip end 7b of the vane 7 is pushed in to the surface of the cylindrical internal wall 4d of the cylinder 4 by the eccentric rotation of the roller 6. Therefore, Formula 1 is expressed by Formula 3.
(Formula 3 ) $\begin{array}{cc}\frac{\left(d_{\mathrm{mi}}-d_{\mathrm{ci}}\right)}{2}>1_{\mathrm{vn}}+1_{\mathrm{cr}}& \mathrm{Formula}3\end{array}$

wherein, as explained in Background Art, d_mi is the inside diameter of the cylindrical internal wall 1a of the closed vessel 1, d_ci is the inside diameter of the cylindrical internal wall 4d of the cylinder 4, and l_vn is a length from the tip end 7b of the vane 7 to the back face 7a thereof.

In the conventional rotary compressor, when the size of the closed vessel 1 is decreased, the sealing ability in a fitting portion of the vane 7 and the vane groove 4a decreases by such amount as the length l_vn of the vane 7 is shortened. Whereas, in the rotary compressor of this embodiment, even if the radius of the closed vessel 1 is decreased by a difference between the compressed height l_cvm of the coil spring 20 and the clearance l_cr, the length l_vn of the vane 7 is unchanged as compared with the length l_vn at the time before the size of the closed vessel 1 is decreased. Further, since the outside diameter of the spring hole 7d is smaller than the width and height of the vane 7, no fracture is produced on the side surface of the vane 7, and the length of fitting portion of the vane 7 and the vane groove 4a is not impaired, so that the sealing ability in the fitting portion of the vane 7 and the vane groove 4a can be maintained.

Since a part of the coil spring 20 can be contained in the spring hole 7d in the vane 7, even if the rotary compressor is decreased in size, the length of the vane 7 can be increased as compared with the conventional rotary compressor. Therefore, the sealing ability in the fitting portion of the vane 7 and the vane groove 4a can be maintained more firmly than that of the conventional rotary compressor.

Also, in the rotary compressor of this embodiment, even when the radius of the closed vessel 1 is decreased by more than the difference between the compressed height l_cvm of the coil spring 20 and the clearance l_cr, the length l_vn of the vane 7 is longer in comparison with the case where the closed vessel 1 of the conventional rotary compressor is decreased in size. Therefore, it is a matter of course that a decrease in sealing ability in a fitting portion of the vane 7 and the vane groove 4a is alleviated.

Also, since the length of the fitting portion of the vane 7 and the vane groove 4a is increased as compared with the conventional rotary compressor, an angle through which the vane 7 tilts with respect to the vane groove 4a decreases. Therefore, the contact surface pressure between the vane 7 and the vane groove 4a decreases, and thus an oil film can be maintained easily, which improves there liability of sliding surface. Also, the decrease in contact surface pressure between the vane 7 and the vane groove 4a decreases the frictional pressure loss, which improves the machine efficiency.

Also, since two spring holes 7d are provided in the back face 7a of the vane 7 and at least a part of the coil spring 20 is contained in each of the two spring holes 7d, the vane 7 can be pressed against the roller 6 by using the two springs, so that the coil springs 20 can be designed so as to have a small spring constant. Therefore, the diameter of the coil spring 20 can be decreased, and the above-described effects can be achieved without an excessive thickness of the vane 7. Further, the spring force of the coil spring 20 can be caused to work at distributed positions on the back face 7a of the vane 7, so that the tip end 7b of the vane 7 can be pressed against the roller 6 uniformly. Therefore, one-side hitting of the tip end 7b of the vane 7 with the roller 6 is eliminated, which improves the reliability of the tip end portion of the vane 7. Although in this embodiment, explanation has been given of the case where two spring holes 7d and two coil springs 20 are used, the number of spring holes 7d and coil springs 20 is not limited to two. Three or more spring holes 7d and coil springs 20 may be used. In the configuration in which three or more spring holes 7d and coil springs 20 are used, it is a matter of course that diameter of the coil spring 8 can be decreased, and the tip end 7b of the vane 7 can be pressed against the roller 6 uniformly.

Also, the configuration may be such that the end portion of the coil spring 20 on the opposite side to the vane 7 is not brought into contact with the cylindrical internal wall 1a of the closed vessel 1, but the end portion of the coil spring 20 on the opposite side to the vane 7 is brought into contact with a bottom portion provided on the cylindrical internal wall 1d side of the closed vessel 1 in the portion of the vane groove 4a. This configuration can also achieve the same effects as described above.

Also, since the inexpensive coil spring 20 having a simple shape is used as the spring mechanism 8, the assembling work can be performed easily at a low cost.

Although the coil spring 20 is used as the spring mechanism 8 in this embodiment, it is a matter of course that even an elastic body such as a resin or gas can achieve the same effects as described above.

Although two spring holes 7d and two coil springs 20 are used in this embodiment, the number of these elements is not limited to two. One spring hole 7d and one coil spring 20 may be used.

Also, this embodiment can be realized easily by simply providing the spring holes 7d having a depth l_vna expressed by the inequality of Formula 2 in the back face 7a of the vane 7. Therefore, the above-described effects can be achieved at a low cost.

(Second Embodiment)

A second embodiment of the present invention will now be described with reference to the accompanying drawing.

FIG. 3 is a transverse sectional view of a portion near a vane groove of a compression mechanism section of a rotary compressor in accordance with the second embodiment of the present invention. FIG. 3 shows a state in which a tip end of the vane is pushed in to a cylindrical internal wall surface of the cylinder.

The rotary compressor of this embodiment differs from that of the first embodiment in that a coil spring guide mechanism 1b is provided on the cylindrical internal wall 1a of the closed vessel 1 with which the end portion of the coil spring 20 is in contact in the first embodiment. The coil spring guide mechanism 1b is formed by a columnar convex portion having a diameter smaller than the inside diameter of the coil spring 20, which is provided on the cylindrical internal wall 1a of the closed vessel 1. As is apparent from FIG. 3, the columnar convex portion, which is the coil spring guide mechanism 1b, penetrates in the coil spring 20.

Also, the length of the coil spring guide mechanism 1b on the cylindrical internal wall 1a of the closed vessel 1 is set so as to be shorter than the depth l_vna of the spring hole 7d in the vane 7.

The construction of the second embodiment is the same as that of the first embodiment except the above-described construction, and it is a matter of course that the same effects as those of the first embodiment can be achieved by such a construction.

Next, effects achieved by the construction of the second embodiment will be explained.

The motion of both end portions of the coil spring 20 other than the motion in the extension-and-contraction direction is restricted by the spring hole 7d in the vane 7 and the coil spring guide mechanism 1b on the cylindrical internal wall 1a of the closed vessel 1. Therefore, when the coil spring 20 is extended and contracted repeatedly, the coil spring 20 is prevented from being caught by the inlet of the spring hole 7d on the back face 7a of the vane 7, so that a failure caused by coming-off or bending of the coil spring 20 can be prevented, which can ensure the reliability of the rotary compressor. The inlet portion of the spring hole 7d may be rounded. By rounding the inlet portion of the spring hole 7d as described above, a trouble such that the coil spring 20 is caught by the inlet of the spring hole 7d on the back face 7a of the vane 7 can further be prevented.

Also, by setting the length of the coil spring guide mechanism 1b on the cylindrical internal wall 1a of the closed vessel 1 so as to be shorter than the depth l_vna of the spring hole 7d in the vane 7, a collision of the tip end portion of the coil spring guide mechanism 1b with the bottom portion of the spring hole 7d can be prevented even when the back face 7a of the vane 7 comes close to the cylindrical internal wall la of the closed vessel 1. Therefore, the clearance l_cr between the back face 7a of the vane 7 and the cylindrical internal wall 1a of the closed vessel 1 can be set at a minimum, so that this embodiment achieves the effects of the first embodiment of the present invention to a maximum.

Also, since the coil spring guide mechanism 1b is provided on the internal wall 1a of the closed vessel 1, a support portion for fixing the coil spring guide mechanism 1b to the closed vessel 1 can be constructed without interference with the coil spring 20 and the vane 7. Therefore, the seal surface of the vane 7 can be lengthened as compared with the case where the support portion is provided on the cylinder 4.

In a small rotary compressor, the vane 7 with a width not smaller than 3.0 mm and not larger than 3.5 mm is generally used, and the stroke of the vane 7 is not shorter than 3.0 mm and not longer than 5.0 mm. In such a small rotary compressor, the coil spring 20 with a free length not smaller than 10.0 mm is used considering the compressed height of the coil spring 20. For the coil spring 20 generally formed of a steel or piano wire, there is less danger of developing buckling under a condition that both ends thereof are fixed and that the aspect ratio obtained by dividing the free length of coil spring by the average diameter of coil spring is not higher than 5. Therefore, by rendering the diameter of the coil spring 20 not smaller than 2.0 mm and smaller than the width of the vane 7, the reliability of rotary compressor can be ensured.

Carbon dioxide used as a working fluid has a higher pressure than other working fluids such as chlorofluorocarbon, alternatives for chlorofluorocarbon, hydrocarbon, and ammonia, so that the leakage of working fluid between the vane groove 4a and the vane 7 increases. However, the leakage of working fluid can be decreased by increasing the length of the vane 7 as compared with the conventional example by using the embodiments of the present invention.

Also, carbon dioxide used as a working fluid has a high density, and thus the cylinder volume is smaller than the case where any other working fluid is used. The cylinder volume is decreased by the use of carbon dioxide as a working fluid and the use of the present invention can further decrease the size of the compression mechanism section 2 and realize a smaller-sized rotary compressor.

As described above, according to the above-described embodiments, as is apparent from the above description, the present invention has an advantage of providing a small-sized and high-efficiency rotary compressor with a simple construction because at least a part of the coil spring 20 is contained in the spring hole 7d in the back face 7a of the vane 7, by which a space larger than the compressed height of the coil spring 20, which space has been needed conventionally between the vane 7 and the closed vessel 1, is not needed, and the length of seal between the vane 7 and the vane groove 7a can be increased.

Industrial Applicability

The compressor in accordance with the present invention, having a function of compressing and conveying a working fluid, is useful for a refrigerant heat pump for a refrigerator, an air conditioner, and the like. Also, this compressor can be applied to an application of a vacuum pump and the like.

Claims

1. A rotary compressor characterized in comprising, a closed vessel; a cylinder having a vane groove, said cylinder located in said closed vessel; a shaft having an eccentric portion; a roller which is rotatably fitted on the eccentric portion of said shaft to eccentrically rotate in said cylinder; a vane provided in the vane groove in said cylinder to reciprocate in said vane groove while a tip end thereof is in contact with said roller; and a spring mechanism or spring mechanisms for pressing said vane against said roller, wherein said vane is provided with a spring hole or spring holes on a side opposite to a side on which said vane is in contact with said roller, and said spring hole or said spring holes is accommodated in a cross section of said vane perpendicular to a direction of reciprocation of said vane, and contains at least a part of said spring mechanism.

2. The rotary compressor according to claim 1, characterized in that a plurality of spring mechanisms are provided; said vane is provided with a plurality of spring holes in the same number as said spring mechanisms; and at least a part of each of said spring mechanisms is contained in each of said spring holes.

3. The rotary compressor according to claim 1, characterized in that said spring mechanism consists of a coil spring.

4. The rotary compressor according to claim 3, characterized in that one end of said coil spring is contained in the spring hole in said vane, and a seat with which the other end of said coil spring is in contact is provided with a coil spring guide mechanism.

5. The rotary compressor according to claim 4, characterized in that said coil spring guide mechanism is provided on an inside side surface of said closed vessel.

6. The rotary compressor according to claim 3, characterized in that a width of said vane is set so as to be not smaller than 3.0 mm and not larger than 3.5 mm; a stroke of reciprocation of said vane is set so as to be not shorter than 3.0 mm and not longer than 5.0 mm; a diameter of said coil spring is set so as to be not smaller than 2.0 mm and smaller than the width of said vane; and a free length of said coil spring is set so as to be not larger than five times the diameter thereof.

7. The rotary compressor according to claim 1, characterized in that a working fluid is carbon dioxide.