JP2003148364A - Rotary compressor - Google Patents

Abstract

(57) Abstract: In a rotary compressor, reliability and compression efficiency are improved by reducing stress at a contact portion between a vane and a roller. A cylinder (6) forming a working chamber, shielding members (5, 7) for closing both end surfaces of the cylinder (6), a roller (8) fitted to an eccentric part (4a) of a crankshaft (4) in the working chamber, and a roller (8). The compression mechanism 22 is provided with a vane that partitions the working chamber into a low-pressure section 18 and a high-pressure section 19 following the eccentric rotation of the roller 8 while abutting on the outer periphery. Is formed with an arc surface having a different curvature having a small curvature at the center portion and a large curvature at the end portion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary compressor, and more particularly to a rotary compressor used for a refrigerator such as an air conditioner or a cold air application product.

[0002]

2. Description of the Related Art Rotary compressors are widely adopted as compact, lightweight and highly efficient compression systems. The structure is such that an electric motor unit connected by a crankshaft and a compression mechanism unit are housed in a closed container, and the compression mechanism unit includes a cylinder having a working chamber, a shield member closing both end surfaces of the cylinder, and a cylinder. A roller fitted in the eccentric portion of the crankshaft, and a reciprocating motion that follows the eccentric rotation of the roller while contacting the outer circumference of the roller, and a vane that partitions the working chamber into the low pressure side and the high pressure side. , Are provided.

The sliding structure between the vane and the roller of the rotary compressor will be described with reference to FIGS. 10 and 11. FIG. 10 shows a state where the rotation angle is 90 degrees, and FIG. 11 shows a state where the rotation angle is 270 degrees. Vane insertion groove 6b of cylinder 6
The vane 9 that reciprocates inside has a surface 9a that is in contact with the roller.
Is formed on an arc surface having a radius of curvature r. The radius of curvature r is generally set to be approximately the same as the thickness dimension of the vane 9. The circular arc surface 9a is brought into contact with the circular arc surface 8a on the outer periphery of the roller 8 and reciprocates following the eccentric rotation of the roller 8. The radius of curvature R0 of the arcuate surface 8a is much larger than the radius of curvature r of the arcuate surface 9a. As is clear from FIGS. 10 and 11, the contact position of the circular arc surface 9a with respect to the circular arc surface 8a reciprocates while moving within a certain range in accordance with the eccentric rotation of the roller 8 (in the figures, it moves in the left and right ranges). To).

As a document relating to such a conventional rotary compressor, there is JP-A-2001-140782.

[0005]

However, in the conventional rotary compressor, the arc portion 9 of the vane 9 having a large curvature is used.
a and the circular arc portion 8a of the roller 8, and they slide with each other in a state of being substantially linear contact. In this state, in order to prevent the refrigerant gas from leaking from the high pressure side to the low pressure side through the contact portion between the vane 9 and the roller 8, it is necessary to make the pressing force of the vane 9 extremely large. When the pressing force of the vane 9 is increased, the stress at the contact portion increases. Due to this increase in stress, the amount of wear of the line contact portion of the vane 9 increases. As this wear progresses, an acute angle portion is generated at the end of the vane 9, and the roller 8 is caused by this acute angle portion.
May be damaged.

In particular, H which is an alternative refrigerant to the HCFC refrigerant
When the FC type refrigerant is used, it does not contain chlorine atoms having an extreme pressure lubricity unlike the HCFC type refrigerant, so by increasing the pressing force of the vane 9 in the line contact state,
The lubricity of the contact part is significantly reduced. As a result, the wear of the line contact portion of the vane 9 progresses extremely quickly.

Further, when the surface-hardened vane 9 is used (for example, the one described in JP 2001-140782 A), when the stress in the contact portion increases, the surface-hardened layer is worn. The base material is exposed and the base material may damage the roller 8.

Furthermore, since the wedge angle between the contact surfaces of the vane 9 and the roller 8 becomes large, the oil film pressure due to the lubricating oil present on the curved surfaces of both 9 and 8 becomes small, and the stress at the contact portion increases. Combined with this, there is a possibility that metal contact may occur between the both 9 and 8.

As a result, there is a problem that the reliability of the compressor is deteriorated and the leakage of the refrigerant at the contact portion is increased to deteriorate the compression efficiency.

An object of the present invention is to provide a rotary compressor capable of improving reliability and compression efficiency by reducing stress at a contact portion between a vane and a roller.

[0011]

In order to achieve the above object, the structure of a rotary compressor according to the present invention is such that an electric motor part and a compression mechanism part connected by a crankshaft are housed in a hermetically sealed container, The compression mechanism section includes a cylinder that forms a working chamber, a shielding member that closes both end surfaces of the cylinder, a roller fitted to an eccentric portion of the crankshaft in the cylinder, and an outer periphery of the roller. A vane that reciprocates while following the eccentric rotation of the roller while contacting and partitions the working chamber into a low-pressure side and a high-pressure side, the vane having an arcuate surface on the side contacting the roller with a central curvature Is small and the curvature on the end side is large.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A plurality of embodiments of the present invention will be described below with reference to the drawings. In the drawings including the conventional example, the same reference numerals indicate the same or equivalent parts.

A first embodiment of the present invention will be described with reference to FIGS. 1 to 7.

First, the overall construction of the rotary compressor of the first embodiment will be described with reference to FIGS. 1 and 2. 1 is a vertical sectional view of a rotary compressor according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA of the compression mechanism portion of FIG.

The rotary compressor 20 shown in FIG. 1 has an electric motor part 21 composed of a stator 2 and a rotor 3 in an upper part of a closed container 1 in which a lubricating oil 15 is stored, and in the lower part of the electric motor part 21. A compression mechanism section 22 connected by the crankshaft 4 is housed. The rotary compressor 20 is used to form a part of a refrigeration cycle in a refrigerator such as an air conditioner or a cold air application product. In such a refrigeration cycle, an HFC-based refrigerant that is an alternative refrigerant to the HCFC-based refrigerant is used.

The compression mechanism section 22 has a crankshaft 4, a main bearing 5, a cylinder 6, an auxiliary bearing 7, a roller 8 and a vane 9 as main constituent elements.

The crankshaft 4 has an upper portion fixed to the rotor 3, an eccentric portion 4a formed at the lower portion, and an oil supply hole 4b penetrating the central portion. A refueling piece 14 is attached to the lower end of the crankshaft 4. This refueling piece 1
4, the lower end opening is immersed in the lubricating oil 15 to communicate with it, and the upper part is communicated with the oil supply hole 4b. The lubricating oil 15
Is supplied to each sliding part of the compression mechanism part 22 through the oil supply piece 14 and the oil supply hole 4b.

The main bearing 5 is fixed to the closed container 1 by welding or the like. A crankshaft 3 is rotatably supported on the main bearing 5. A roller 8 is rotatably fitted in the eccentric portion 4a of the crankshaft 4. This roller 8
With the eccentric movement of the eccentric portion 4a, the cylinder 6 rotates eccentrically within the inner peripheral cylindrical surface 6a.

The cylinder 6 is supported by being fastened to the main bearing 5 with bolts. An inner peripheral cylindrical hole 6a (see FIG. 2) is formed in the cylinder 6, and a working chamber is constituted by this.
The main bearing 5 also serves as a shielding member that closes the end surface of the cylinder 6.

The cylinder 6 is formed with a vane insertion groove 6b (see FIG. 2) which penetrates vertically. The vane 9 is horizontally slidably fitted in the vane insertion groove 6b. The vane 9 is pressed against the outer circumference of the roller 8 by the spring 10. The pressing force of this vane 9 is
It is set to match the reciprocating motion of. The vane 9 separates the working chamber into a suction chamber 18 and a compression chamber 19.

The auxiliary bearing 7 is fastened to the cylinder 6 together with the discharge silencer cover 16 by bolts 17. The auxiliary bearing 7 also serves as a shielding member that closes the end surface of the cylinder 6. A working chamber is defined by a space surrounded by the inner peripheral cylindrical surface 6 a, the main bearing 5, the sub bearing 7, and the roller 8.

The suction pipe 11 is connected to the low-pressure pipe of the external cycle and communicates with the working chamber (suction chamber 18) of the cylinder 6. The discharge pipe 12 communicates with the high-pressure space in the closed container 1 and is connected to the high-pressure pipe of the external cycle.

The rotation of the crankshaft 4 causes the roller 8 to eccentrically rotate within the working chamber of the cylinder 6.
As a result, the refrigerant gas is kept in the low temperature and low pressure state in the suction chamber 18
Is sucked in through the suction pipe 11, and this suction pipe 1
After being compressed in the compression chamber 19 switched from No. 1, it is discharged into the closed container 1 through the discharge silencer cover 16 in a high temperature and high pressure state. The refrigerant gas in the closed container 1 is discharged to the external cycle through the discharge pipe 12.

Next, the contact state between the vane 9 and the roller 8 will be described with reference to FIGS. 3 to 7. FIG. 3 is an explanatory view of one rotation of the compression mechanism portion of FIG. 1, and FIG. 4 is a rotation angle 90 of FIG.
5 is an enlarged view of the contact portion between the vane and the roller at various degrees, FIG. 5 is an enlarged view of the contact portion between the vane and the roller at a rotation angle of 270 degrees in FIG. 3, FIG. 6 is a diagram of a comparative example corresponding to FIG. 3, and FIG. Four
It is a figure of the comparative example corresponding to.

When the crankshaft 4 rotates, as shown in FIG.
The contact state between the vane 9 and the roller 8 changes as shown in (d). When the rotation angle of the crankshaft 4 is 0 degree,
As shown in (a), the vane 9 is in the farthest state from the center of the rotating shaft. In this state, the central portion of the vane 9 comes into contact with the roller 8 and also comes into symmetrical contact with the center of the contact portion as the center. Further, when the rotation angle of the crankshaft 4 advances to 90 degrees, as shown in FIG. 3B, the vane 9 is located at the rightmost end of the contact surface of the vane 9.
Is in contact with the roller 8. In other words, the contact position of the vane 9 with respect to the roller 8 in one rotation is the position farthest from the contact center of the vane 9 to the one side. Further, when the rotation angle of the crankshaft 4 advances to 270 degrees, the vane 9 is in the state of being closest to the center of the rotation shaft, as shown in FIG. In this state,
The central portion of the vane 9 comes into contact with the roller 8 and also comes into contact with the center of the contact portion symmetrically. further,
When the rotation angle of the crankshaft 4 advances to 270 degrees, as shown in FIG. 3D, the vane 9 is in contact with the roller 8 at the leftmost end of the contact surface of the vane 9. In other words, the contact position of the vane 9 with respect to the roller 8 in one rotation is in the contact position farthest from the contact center of the vane 9 to the other side. The state of FIG. 3D is returned to the state of FIG. 3A, and this is repeated thereafter.

The vane 9, as shown in FIGS. 4 and 5,
The arcuate surface 9a on the side abutting the roller 8 is an arcuate surface having different curvatures at the center (in other words, the radius of curvature R is large) and at the end side is large (in other words, the radius of curvature r is small). It is molded. The radius of curvature R of the central portion is set smaller than the radius of curvature r of the conventional example.

Generally, the stress generated at the contact portion between curved surfaces is called Hertzian contact stress. Now, assuming that the radius of curvature of the roller 8 is RO, the ratio of the Hertz contact stress according to this embodiment and the Hertz contact stress according to the conventional example is expressed by the following equation (1).

{(1 / R + 1 / RO) / (1 / r + 1 / RO)} ^1/2 (1) By the way, the radius of curvature R of the present embodiment is about the size used in a normal air conditioner. Is 3 of the radius of curvature r of the conventional example
If set to about double, the Hertzian contact stress can be reduced to about half. Therefore, the Hertzian contact stress can be remarkably reduced by setting the radius of curvature R to about 3 times or more of the radius of curvature r. It is desirable that the upper limit of the radius of curvature R be equal to or less than the radius of curvature R0 of the roller 8 so that the change of the curvature between the circular arc surface on the central side and the circular arc surface on the end side is not abrupt.

As is clear from the equation (1), the larger the radius of curvature R is set, the more the Hertzian contact stress can be reduced. However, when the radius of curvature is simply set large over the entire contact side of the roller 8, As shown in FIGS. 6 and 7, the contact occurs at the acute angle portion 9b on the side surface of the vane 9, and
As a result, the outer peripheral surface 8a of the roller 8 is scraped, and the reliability is significantly impaired.

Therefore, in this embodiment, as described above, the curvature of the end portion side of the roller 8 is formed large, and the corner portion of the side surface of the vane 9 is provided with the arc portion having the larger curvature than the central portion. This makes it possible to prevent contact at sharp corners.

The radius of curvature R'of the circular arc portion on the end side is 1
It is preferable to set it to mm or more. When the radius of curvature R ′ is extremely small as shown in FIG. 8, for example, the lateral load F on the vane 9 becomes large, and the wear on the facing surface side of the vane insertion groove 6b in which the vane 9 is inserted becomes large.
This is because the compressed refrigerant gas leaks from the gap between the vane insertion groove 6b and the vane 9 and the compression performance is deteriorated.

Further, at the contact portion between the vane 9 and the roller 8, since the wedge angle between the curved surfaces 9a, 8a of both 9 and 8 is small and sharp, the oil film pressure due to the lubricating oil present on both curved surfaces 9a, 8a is large. Therefore, there is also an effect of making it difficult for metal contact to occur between the arcuate surfaces 9a and 8a. In particular, vane 9
It is very effective to prevent the high-pressure refrigerant gas from leaking by forming the curvature of the end portion on the high-pressure portion side larger than that of the central portion. Further, by increasing the radius of curvature R, the gas leakage at the contact portion can be reduced, so that the deterioration of the compression performance due to the leakage can be reduced.

The boundary portion continuing from the curvature of the central portion of the vane 9 to the curvature of the end portion is located within the range in which the vane 9 abuts on the roller 8 in the initial state where the rotary compressor 20 starts to operate for the first time. I am letting you. As a result, the range in which the vane 9 comes into contact with the roller 8 is widened from the initial state, and the width of the vane 9 can be effectively used to prevent leakage of the contact portion.

A surface hardening treatment layer is provided on at least the surface of the vane 9 that is in contact with the roller 8, and the depth dimension of the surface hardening treatment layer is a boundary at which the curvature changes from the curvature at the center of the vane to the curvature at the end. If it is made substantially larger than the dimension in the reciprocating direction up to the part, when the wear of the central part progresses, the surface hardening treatment layer of the arc surface of the curvature part on the end side comes into contact, and the base material Exposure can be prevented.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 9 is a vertical sectional view of a rotary compressor according to a second embodiment of the present invention. The second embodiment is different from the first embodiment as described below, and is basically the same as the first embodiment in other points.

In the rotary compressor 20 of the second embodiment, the compression mechanism section 22 is formed by two compression elements having two cylinders 6, two rollers 8 and two vanes (not shown), The two compression elements are arranged in a symmetrical shape rotated by 180 degrees. A partition plate 31 is provided between the two compression elements. Two suction pipes 11 are connected to each compression element. The two suction pipes 11 are connected to an external cycle via a gas-liquid separator 32.

This two-cylinder type rotary compressor 2
In 0, since the two cylinders 6 and the intermediate partition plate 31 are arranged in the height direction, the height dimension of the compression mechanism portion 22 is necessarily increased. As a measure to secure the same cylinder volume and reduce the height dimension, the height dimension of each cylinder 6 is reduced to increase the eccentric amount of the roller 8. However, in the first embodiment. By adopting the contact structure between the vane 9 and the roller 8 described in this second embodiment, it is much more effective to reduce the stress at the contact portion between the vane and the roller.

[0038]

As described in detail above, according to the present invention, the rotary compressor capable of improving the reliability and the compression efficiency by reducing the stress at the contact portion between the vane and the roller is provided. Obtainable.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a rotary compressor according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of the compression mechanism section in FIG.

FIG. 3 is an operation explanatory diagram of one rotation of the compression mechanism portion of FIG.

4 is an enlarged view of a contact portion between a vane and a roller at a rotation angle of 90 degrees in FIG.

5 is an enlarged view of a contact portion between a vane and a roller at a rotation angle of 270 degrees in FIG.

6 is an explanatory diagram of a comparative example corresponding to FIG.

7 is an explanatory diagram of a comparative example corresponding to FIG.

FIG. 8 is a local enlarged view for explaining the influence of the vane corner portion shape.

FIG. 9 is a vertical sectional view of a rotary compressor according to a second embodiment of the present invention.

FIG. 10 is a plan view of a main part of a contact portion between a vane and a roller at a rotation angle of 90 degrees in a conventional rotary compressor.

FIG. 11 is a plan view of a main part of a contact portion between a vane and a roller at a rotation angle of 270 degrees of a conventional rotary compressor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Airtight container, 2 ... Stator, 3 ... Rotor, 4 ... Crankshaft, 4a ... Eccentric part, 4b ... Oil supply hole, 5 ... Main bearing, 6 ... Cylinder, 6a ... Inner peripheral cylindrical surface, 6b ... Vane insertion Groove, 7 ...
Secondary bearing, 8 ... Roller, 8a ... Roller arc surface, 9 ... Vane, 9a ... Vane arc surface, 9b ... Acute angle portion, 10 ... Spring,
11 ... Suction pipe, 12 ... Discharge pipe, 14 ... Oil supply piece, 15 ... Lubricating oil, 16 ... Discharge silencer cover, 1
7 ... Bolt, 18 ... Suction chamber, 19 ... Compression chamber, 20 ... Rotary compressor, 21 ... Electric motor part, 22 ... Compression mechanism part, 31
... a partition plate, 32 ... a gas-liquid separator.

Claims (5)

[Claims] 1. An electric motor section connected by a crankshaft and a compression mechanism section are housed in a closed container, the compression mechanism section forming a working chamber, and a shielding member closing both end surfaces of the cylinder. And a roller fitted in the eccentric portion of the crankshaft in the cylinder, and reciprocates while following the eccentric rotation of the roller while contacting the outer periphery of the roller, and reciprocates in the working chamber to a high pressure side and a high pressure side. And a vane for partitioning the vane, wherein the vane is formed by forming an arcuate surface on the side abutting on the roller into arcuate surfaces having different curvatures with a small central curvature and a large end curvature. Rotary compressor. 2. The refrigerant to be compressed according to claim 1, wherein the refrigerant is HFC.
A rotary compressor characterized by using a system refrigerant. 3. The rotary compressor according to claim 1, wherein the radius of curvature of the central portion of the vane is set to about three times or more the vane plate thickness. 4. The rotary compressor according to claim 1, wherein a curvature of at least an end portion of the vane on a high pressure portion side is larger than a curvature of a central portion. 5. The rotary compressor according to claim 1, wherein the curvature on the end side of the vane is set to 1 mm or more.