JP2546073B2 - Scroll compressor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type compressor (hereinafter simply referred to as "compressor"), and more particularly to fixing a fixed scroll and a movable scroll and improving a seal groove in a movable scroll.

[0002]

2. Description of the Related Art A conventional compressor is disclosed in JP-A-61-34379.
No. 6,086,045. As shown in FIG. 7, this compressor has a fixed scroll 5 fixed in a housing 51.
2 and a movable scroll 54 rotatably supported in the housing 51. Fixed scroll 5
2 includes a fixed side plate 521 and a fixed spiral body 522 which is integrally formed on one surface of the fixed side plate 521 and whose inner and outer walls are formed by an involute curve or the like. The movable scroll 54 includes a movable side plate 541 and the movable side plate 541.
Is integrally formed on one surface, the inner and outer walls are formed by an involute curve or the like, and is composed of a fixed spiral body 522 and a movable spiral body 542 that meshes with each other with a 180 ° phase shift. As shown in FIG. 8, the fixed spiral body 522 and the movable spiral body 542 are respectively provided with seal grooves 522a and 542a extending in the increasing direction of the expansion angle θ, and the seal grooves 522a and 542a are formed in the seal grooves 522a and 542a. Chip seals 522b and 522b for sealing the play with the movable side plate 541 or the fixed side plate 521.
42b is accommodated. In this compressor, the seal groove 5
The center line CL ₁ of 22a and 542a is located inside the center line CL _{0 of the} fixed and movable spirals 522 and 542, that is, on the high-pressure side HP.

When this compressor is used in, for example, a vehicle air conditioner, as shown in FIG. 7, the rotation of the drive shaft 59 causes the shaft seal device 57, the bearings 58 and 63, and the counterweight 6 to rotate.
1. The eccentric bush 64 and the rotation prevention mechanism 62 make the orbital movement of the movable scroll 54 through the eccentric pin 60, whereby the compression chamber 56 formed between the solid scroll 52 and the solid scroll 52 is gradually reduced in volume toward the center. To the fixed side plate 52.
It discharges to the discharge chamber 66 through the discharge port 65 formed in 1.

At this time, the tip seal 542 shown in FIG.
In the seal groove 542a (522a), b (522b) is on the high pressure side H closer to the central portion of the fixed side plate 521.
Refrigerant gas is introduced from P to the rear surface to fix the stationary side plate 521.
At the low-pressure side LP far from the central part of the seal groove 542a (5
22a) and the fixed side plate 521 (movable side plate 54) with the lubricating oil in the refrigerant gas interposed.
It is in close contact with 1) and seals the refrigerant gas. In this compressor, the center lines CL ₁ of the seal grooves 522a and 542a are located on the high pressure side HP with respect to the center lines CL ₀ of the fixed and movable scrolls 522 and 542, whereby the respective seal grooves 522 are located.
Since the outer wall thickness t _out is thicker than the inner wall thickness t _in of the a and 542a, the tip seals 522b and 542b are formed.
It is possible to receive the pressing force to the low-pressure side LP with a sufficient strength.

[0005]

However, when the technique described in the above publication is adopted in a compressor having a fixed and movable spiral body which gradually reduces the wall thickness by increasing the expansion angle due to the demand for weight reduction, when the technique described in the above publication is adopted, As shown in FIGS. 9 and 10, for example, A to
As the expansion angle θ increases to G, the movable scroll 5
Inner wall thickness t _in the seal groove 542a in the 4 becomes gradually thinner, the strength of the inner wall is not sufficient. That is, for example, at the expansion angle position G near the end of the movable scroll 54, the refrigerant gas is in the initial stage of compression, and the tip seal 542b is in the seal groove 542a due to the pressure difference between the inside and the outside of the movable scroll 542. The tip seal 542b is dragged by the fixed side plate 521 in the seal groove 542a by the revolving motion of the movable scroll 54, colliding with the outer wall and the inner wall, but is not pressed against the outer wall but does not come into strong contact with the outer wall. The collision and pressing is repeated during the operation of the ongoing i.e. compressor revolving motion of the movable scroll 54, even secured outside the wall thickness t _out, if thin inner wall thickness t _in, in the worst case The inner wall may be damaged by fatigue due to collision / pressing. Fixed scroll 52
The same applies to the seal groove 522a in.

In the technique described in the above publication, in order to avoid insufficient strength of the inner walls of the seal grooves 522a and 542a, the width W of the seal grooves 522a and 542a is gradually narrowed by increasing the expansion angle θ, that is, Tip seal 52
Although it is conceivable that the widths of 2b and 542b are narrowed as the expansion angle θ is increased, the original sealing of the refrigerant gas becomes insufficient with the chip seal having the narrowed width.

According to the present invention, in a compressor having a fixed and movable spiral body in which the wall thickness is gradually reduced by increasing the expansion angle due to the demand for weight reduction, the strength of the inner and outer walls of each seal groove is sufficiently ensured. In addition, it is an issue to be solved to appropriately seal the refrigerant gas.

[0008]

In order to solve the above-mentioned problems, the compressor of the present invention has the same inner and outer wall thicknesses in the terminal region, and the inner wall thickness is constant regardless of the expansion angle. In addition, a novel means of engraving the seal groove with the same width is adopted.

[0009]

In the compressor of the present invention, the inner and outer wall thicknesses are the same in the end region in the fixed and movable spirals whose wall thickness is gradually reduced by increasing the expansion angle, and the inner wall is independent of the expansion angle. Since the seal groove is engraved with a constant thickness and an equal width, the outer wall of the seal groove is made thicker due to the reduction of the expansion angle, and it depends on the pressure difference between the inner and outer sides of the fixed and movable scroll. While the outer wall of the seal groove secures sufficient strength, the tip seal collides with the inner and outer walls.
Sufficient strength is ensured even at the angle of extension where pressure is applied. Further, at this time, the tip seal has a uniform width regardless of the expansion angle, and the refrigerant gas is sufficiently sealed.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. This compressor, as shown in FIG.
It has a fixed scroll 2 fixed in the housing 1 and a movable scroll 3 rotatably supported in the housing 1. The fixed scroll 2 is a fixed side plate 2.
1 and a fixed spiral body 22 integrally formed on one surface of the fixed side plate 21. The movable scroll 3 includes a movable side plate 31 and a movable spiral body 32 that is integrally formed on one surface of the movable side plate 31 and that meshes with the fixed spiral body 22 with a π (rad) phase offset from each other. In this compressor, the shapes of the fixed scroll 22 of the fixed scroll 2 and the movable scroll 32 of the movable scroll 3 and the shape of the seal grooves 22a, 32a of the fixed scroll 22 and the movable scroll 32 are excluded. Since it is similar to that of No. 7, detailed description of the same configuration and operation will be omitted below.

The fixed spiral body 22 and the movable spiral body 32 are, for example, Japanese Patent Application No. 2-245364 proposed by the applicant of the present application.
It has the shape shown in No. That is, in the movable spiral body 32, as shown by the xy axis in FIG. 2, an involute curve I ₁ is drawn by the basic circle C _S , and the involute curve I ₁ extends from the inflection angle position J to the involute line ₁ on the involute curve I ₁ . The curve of the position X which is reduced at a rate of Bθ ² (B is a constant) in accordance with the increase of the extension angle θ in the direction is defined as the outer wall curve SG ₁ . Then, the position X is moved by the revolution radius R in the direction substantially normal to the position X on the outer wall curve SG ₁ to obtain the movement position Y, and the curve SG ₂ of the movement position Y is set to the center point O of the basic circle C _{S. The} point symmetry curve drawn by the point Z moved to the point symmetry position of _S is defined as the inner wall curve SG ₃ . In this way, the wall thickness of the movable scroll 32 is gradually reduced due to the increase of the expansion angle θ.

Further, in this movable spiral body 32, the basic circle C
_SPoint Q with arbitrary small expansion angle β ₁Take point Q₁To
Tangent line drawn_FourOuter wall curve SG₁Can be extended to
The intersection is point S₁And This outer wall curve SG₁Upper point S₁To
Outer wall side inscribed arc H of radius r₁To provide. Also, the outer wall curve
SG₁Upper point S₁To the outside normal l_Five, Point S₁To
Normal l_FiveCurve SG by moving by the revolution radius R in the direction₂Up
At point S₂And this point S₂The basic circle C_SCenter point O_S
Inner wall curve SG obtained by moving to the point symmetric position of₃Upper point S
₃Inscribed arc H of inner wall side with radius (r + R)₃To provide. So
Then, the outer wall side and inner wall side inscribed arc H₁, H₃And these
Outer wall side and inner wall side inscribed arc H₁, H₃Common tangent line H of_FourWhen
By connecting the start end 321 with a thick wall
Thus, the starting end portion 321 maintains a sufficient strength.

Thus, the outer wall curve SG ₁ and the inner wall curve SG
_The movable spiral body 32 is obtained by ₃ and the starting end portion 321.
The outer wall curve, the inner wall curve, and the starting end portion of the fixed spiral body 22 are the same except that the phase is shifted from the movable spiral body 32 by π. Therefore, the weight of the compressor is reduced as a whole.

As shown in FIG. 3, a seal groove 32a extending in the increasing direction of the expansion angle θ is formed on the tip of the movable scroll 32. As the most characteristic configuration of the compressor of the present embodiment, the seal groove 32a of the movable scroll 32 is as shown in FIG.
3 shows a sectional view taken along the line AA of FIG. 3, and FIG.
FIG. 6 is a cross-sectional view, and FIG. 6 shows the relationship between the expansion angle positions A to G and the wall thickness t _{in FIG} . equal to the outer wall thickness t _out, the inside of the wall thickness t _in regardless involute angle θ is engraved on constant and equal width W. The same applies to the seal groove 22a of the fixed scroll 22.

Each seal groove 32a (22a) accommodates chip seals 32b and 22b for sealing a clearance with the fixed side plate 21 or the movable side plate 31. As the tip seals 32b and 22b, the seal grooves 32a (22
The one with a uniform width is adopted regardless of the extension angle θ that conforms to a). In this compressor, as shown in FIG. 1, the rotation of the drive shaft 4 is revolved around the movable scroll 3 via the eccentric bush 7 and the rotation preventing mechanism 8. At this time, the movable spiral body 32 substantially constantly contacts the fixed spiral body 22 and maintains a constant compression efficiency. The orbital movement of the orbiting scroll 3 causes the plurality of compression chambers 5 formed between the compression scroll 5 and the fixed scroll 2 to move toward the center while sequentially reducing the volume, and then the discharge port 9 provided in the fixed side plate 21. The compressed fluid is discharged from the discharge chamber 6 into the discharge chamber 6.

At this time, in the tip seal 32b (22b) shown in FIGS. 4 and 5, the refrigerant gas is introduced into the rear surface from the inside which is the high pressure side HP in the seal groove 32a (22a), and the low pressure side LP. Seal groove 32a (22
While abutting on the wall surface of a) and in contact with the fixed side plate 21 (movable side plate 31) with the lubricating oil in the refrigerant gas interposed, the refrigerant gas is sealed.

In this case, in this compressor, the wall thickness t _in inside the seal groove 32a (22a) is irrespective of the expansion angle θ.
Is constant, the seal groove 32a (2
Tip seal 32b between the inner and outer walls of 2a)
Even if (22b) collides, sufficient strength can be secured.

In this compressor, the outer wall thickness t _out of the seal groove 32a (22a) gradually increases as the expansion angle θ decreases, so that the pressure difference between the inner side and the outer side shown in FIG. At the very large inflection angle position A, the outer wall thickness t _out is very large, so that the tip seal 32b
The pressing force of (22b) on the low-pressure side LP can be received with sufficient strength. That is, the wall on the outer side of the seal groove 32a (22a) secures sufficient strength according to the pressure difference between the inner side and the outer side of the fixed spiral body 21 and the movable spiral body 31.

In this compressor, since the tip seal 32b (22b) has a uniform width regardless of the expansion angle θ during this period, the refrigerant gas can be sufficiently sealed. In this compressor, as shown in FIG. 6, the center line CL ₁ of the seal groove 32a (22a) is always higher than the center line CL ₀ of the fixed and movable spiral body 32 (22) on the high pressure side HP.
It is not located inside.

[0020]

As described in detail above, in the compressor of the present invention, the inner and outer wall thicknesses are equal in the terminal region, and the inner wall thickness is constant and equal in width regardless of the expansion angle. Since it is engraved, the strength of the inner and outer walls of each seal groove is sufficient in a compressor with a fixed and movable scroll that gradually reduces the wall thickness by increasing the expansion angle due to the demand for weight reduction. It can be ensured, and the refrigerant gas can be suitably sealed.

Therefore, in this compressor, the durability of the inner and outer walls of the seal groove can be improved, and excellent fluid compression performance can be maintained for a long period of time.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a compressor according to an embodiment.

FIG. 2 is a curve diagram showing an outer wall curve, an inner wall curve and a starting end portion which form a movable scroll in the compressor of the embodiment.

FIG. 3 is a plan view of a movable scroll in the compressor of the embodiment.

FIG. 4 is a sectional view taken along the line AA of FIG. 3 in the compressor of the embodiment.

5 is a cross-sectional view taken along the line GG of FIG. 3 in the compressor of the embodiment.

FIG. 6 is a spread angle position A to FIG. 3 of the compressor of the embodiment.
It is a graph which shows the relationship between G and wall thickness.

FIG. 7 is a vertical sectional view of a conventional compressor.

FIG. 8 is a longitudinal sectional view of a main part of a conventional compressor.

FIG. 9 is a plan view of a movable scroll in a conventional compressor.

FIG. 10 is a spread angle position A to FIG. 9 of a conventional compressor.
It is a graph which shows the relationship between G and wall thickness.

[Explanation of symbols]

2 ... Fixed scroll 21 ... Fixed side plate 22
... Fixed scroll 3 ... Movable scroll 31 ... Movable side plate 32
... Movable spirals 22a, 32a ... Seal grooves 22b, 32b ...
Tip seal 5 ... Compression chamber θ ... Spread angle A ~
G ... Extension angle position t _in ... Inner wall thickness t _out ... Outer wall thickness W ...
Seal groove width

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuo Yoshida 2-1-1 Toyota-cho, Kariya city, Aichi Inside Toyota Industries Corporation (56) References JP-A-61-34379 (JP, A) 63-196493 (JP, U)

Claims (1)

(57) [Claims] 1. A fixed scroll composed of a fixed side plate and a fixed spiral body whose wall thickness is gradually reduced by increasing the expansion angle, and a movable side plate and a movable spiral body whose wall thickness is gradually reduced by increasing the expansion angle. And a movable scroll composed of the movable scroll and the fixed scroll body and the movable scroll body are provided with a seal groove extending in the direction of increasing the expansion angle on the tip end surfaces thereof. A chip seal that seals a clearance with the fixed side plate is housed, and the movable scroll is orbitally driven while meshing with the fixed scroll in a state in which its rotation is restricted, so that the fixed scroll and the movable scroll are In the scroll type compressor in which the compression chamber formed by the above-mentioned gradually reduces the volume and compresses the fluid in the compression chamber, the seal groove has the same inner and outer wall thicknesses in the terminal region, and the seal groove has the same expansion angle. Scroll compressor, characterized in that the wall thickness of the inner side is engraved with constant and equal width.