Rotary expansible chamber devices – Working member has planetary or planetating movement – Helical working member – e.g. – scroll
Reexamination Certificate
2000-06-07
2003-02-04
Denion, Thomas (Department: 3748)
Rotary expansible chamber devices
Working member has planetary or planetating movement
Helical working member, e.g., scroll
C418S055500, C418S057000, C418S102000, C464S102000
Reexamination Certificate
active
06514059
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a scroll compressor, and in particular to a scroll compressor suitable for a vapor compression refrigerating cycle that uses a refrigerant in the supercritical region of carbon dioxide (CO
2
), for example.
2. Description of the Related Art
Recently, a refrigeration cycle using carbon dioxide (referred to hereinbelow as a “carbon dioxide cycle”) as a working gas (refrigerant gas) has been proposed, for example, in Japanese Examined Patent Application, Second Publication, No. Hei 7-18602, as one measure for eliminating the use of Freon (dichlorofluoromethane) as a refrigerant in the vapor compression-type refrigerating cycle. This carbon dioxide cycle is identical to the conventional vapor compression-type refrigerating cycle that uses Freon. That is, as shown by A-B-C-D-A in
FIG. 8
, which shows a carbon dioxide Mollier chart, the carbon dioxide in the gaseous phase is compressed by a compressor (A-B), and this gas-phase carbon dioxide that has been compressed to a high temperature is cooled in a radiator, such as a gas cooler (B-C). Next, the carbon dioxide is decompressed using a decompressor (C-D), the carbon dioxide that has changed to a liquid phase is vaporized (D-A), and an external fluid such as air is cooled by removing its latent heat of vaporization.
However, the critical temperature of carbon dioxide is about 31°, which is low compared to the critical temperature of Freon, the conventional refrigerant. When the external temperature is high, during summer, for example, the temperature of carbon dioxide on the radiator side is higher than its critical temperature. This means that the carbon dioxide does not condense at the radiator outlet side. In
FIG. 8
, this is shown by the fact that the line BC does not cross the saturated liquid line SL. In addition, the state on the radiator output side (point C) is determined by the discharge pressure of the compressor and the temperature of the carbon dioxide at the radiator outlet side. Moreover, the temperature of the carbon dioxide at the radiator outlet side is determined by the radiating capacity of the radiator and the temperature of the uncontrollable external air. Due to this, the temperature at the radiator outlet cannot be substantially controlled. Therefore, the state of the radiator outlet side (point C) can be controlled by the discharge pressure of the compressor, that is, the pressure on the radiator outlet side. This means that in order to guarantee sufficient refrigerating capacity (difference in enthalpy) when the temperature of the external air is high, during summer, for example, as shown by E-F-G-H-E, the pressure on the radiator output side must be high. In order to attain this, the operating pressure of the compressor must be high in comparison to the refrigeration cycle used with conventional Freon. In the case of an air conditioning device for an automobile, for example, the operating pressure of the compressor when using Freon (Trademark R134) is about 3 kg/cm
2
, while in contrast, this pressure must be raised to about 40 kg/cm
2
for carbon dioxide. In addition, the operation stopping pressure when using Freon (Trademark R134) is about 15 kg/cm
2
, while in contrast it must be raised to about 100 kg/cm
2
for carbon dioxide.
Below, for example, a common scroll compressor disclosed in Japanese Unexamined Patent Application, First Publication, No. Hei 4-234502, will be explained using FIG.
9
. As shown in
FIG. 9
, in the casing
100
, a fixed scroll member
101
, an orbiting scroll member
102
, and an Oldham ring
105
, which is an anti-rotation device, are provided.
The fixed scroll member
101
is formed by a fixed side end plate
101
a,
an involute wrap
101
b
provided on one face of this fixed side end plate
101
a,
and a discharge port
104
provided approximately at the center part of this fixed end plate
101
a.
The orbiting scroll member
102
is formed by an orbiting side end plate
102
a
and an involute wrap
102
b
provided on one face of the orbiting side end plate
102
a.
This orbiting scroll member
102
is driven so as to revolve eccentrically with respect to the fixed scroll member
101
. The orbiting scroll member
102
relatively rotating with respect to the fixed scroll member
101
forms an involute pressure chamber
103
between the involute wrap
102
b
of the orbiting scroll member
102
and the involute wrap
101
b
of the fixed scroll member
101
. The Oldham ring
105
allows rotation of the orbiting scroll member
102
with respect to the fixed scroll member
101
while preventing autorotation of the orbiting scroll member
102
. Furthermore, by adjusting the precision of the Oldham ring
105
, the phase of the orbiting scroll member
102
and the fixed scroll member
101
can be adjusted.
However, in this conventional scroll compressor, the Oldham ring
105
is provided on the backside of the orbiting scroll member
102
. Due to this, the position of the orbiting scroll member
102
is easily displaced with respect to the fixed scroll member
101
, the phases of orbiting scroll member
102
and the fixed scroll member
101
easily shift, resulting in the problems that the assembly precision and the reliability are low.
In addition, for example, in a scroll compressor using carbon dioxide as the working gas and having a high operating pressure, when using an Oldham ring
105
having a long connection wrap
106
, which is the part in contact with the fixed scroll member
101
, an excessive load is applied to the base of the engagement projection
106
, which causes fatigue damage, and thus, there is a concern that thereby the reliability will deteriorate.
In consideration of the above described problems with conventional technology, it is an object of the present invention to provide a scroll compressor that increases the assembly precision of the orbiting scroll member and the fixed scroll member, whose engagement projection is difficult to damage even when a large force is applied to the Oldham joint during operation, and therefore, has a high reliability.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention, the present invention provides a scroll compressor furnished with a fixed scroll member including a first end plate and a first involute wrap provided on one face of the first end plate, the fixed scroll being movably supported in the axial direction of the fixed scroll member, and an orbiting scroll member including a second end plate and a second involute wrap provided on one face of the second end plate, which form a plurality of compression chambers in combination with the first involute wrap of the fixed scroll member, wherein a mechanism that prevents rotation of the orbiting scroll member with respect to the fixed scroll member is provided between the orbiting scroll member and the fixed scroll member.
The present invention also provides a scroll compressor including: a fixed scroll member comprising a first end plate and a first involute wrap provided on one face of the first end plate; a flat spring member disposed so as to support the fixed scroll member, the flat spring member allowing the fixed scroll member to move in the axial direction of the fixed scroll member; and an orbiting scroll member comprising a second end plate and a second involute wrap provided on one face of the second end plate, and which form a plurality of compression chambers in combination with the first involute wrap of the fixed scroll member, wherein a mechanism that prevents rotation of the orbiting scroll member with respect to the fixed scroll member is provided between the orbiting scroll member and the fixed scroll member.
According to this scroll compressor, because the mechanism that prevents the rotation of the orbiting scroll member with respect to the fixed scroll member is provided between the fixed scroll member and the orbiting scroll member, and the fixed scroll member is movably supported in the axial direction thereof, by placing the fixed scro
Miura Shigeki
Takeuchi Makoto
Denion Thomas
Mitsubishi Heavy Industries Ltd.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Trieu Theresa
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