Rotary expansible chamber devices – Helical working member
Reexamination Certificate
2003-02-06
2003-12-16
Denion, Thomas (Department: 3748)
Rotary expansible chamber devices
Helical working member
Reexamination Certificate
active
06663369
ABSTRACT:
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-241523, filed Aug. 9, 2000, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fluid compressor of helical-blade type that constitutes, for example, the refrigeration cycle of an air conditioner.
2. Description of the Related Art
Reciprocating compressors and rotary compressors are known as compressors for use in, for example, refrigeration cycles of air conditioners. These compressors may become debased in sealing property or may be complicated in structure.
Recently, it is proposed that helical-blade type compressors be used in place of reciprocating compressors or rotary compressors. This is because helical-blade type compressors are relatively simple in structure, has improved sealing property and can compress fluid with high efficiency. In addition, the components of a helical-blade type compressor are easy to manufacture and assemble.
FIG. 11
shows a part of a helical type compressor. In this helical-blade type compressor, the roller
102
is eccentrically arranged in the fixed cylinder
101
and has a helical groove
103
in its outer circumferential surface. A blade
104
is fitted in the groove
103
such that it can move in the depth direction of the groove
104
.
As the roller
102
revolves, the blade
104
divides the space between the cylinder
101
and the roller
102
into a plurality of compression chambers
105
. Each compression chamber has a smaller volume than the immediately adjacent chamber that is more close to one end of the roller
102
. The coolant gas introduced into the compression chamber
105
at that end of the roller
102
is gradually compressed to a high pressure until it is forced out of the compression chamber
105
provided at the other end of the roller
102
.
As
FIG. 12
shows, the helical groove
103
and the blade
104
have a rectangular cross section, taken along a line extending at right angles to their axes. Having a rectangular cross section, the helical groove
103
is easy to cut in the outer circumferential surface of the roller
102
.
The blade
104
has a width a little smaller than the width of the helical groove
103
. In other words, the widths of the groove
103
and blade
104
are predetermined so that the blade
104
can move in the depth direction of the helical groove
103
.
Since the helical groove
103
and the blade
104
have a rectangular cross section, the blade
103
remains in contact with both sides of the helical groove
103
even when it completely lies within the helical groove
103
.
Hence, the bottom space
106
defined between the lower surface of the blade
104
and the bottom of the helical groove
103
cannot sufficiently communicate with the high-pressure compression chamber
105
A.
Consequently, the pressure of the coolant gas in the bottom space
106
, which lies at the bottom of the helical groove
103
, is lower than the pressure in the high-pressure compression chamber
105
A. The coolant gas is inevitably forced out at a low pressure. Thus, the coolant gas cannot gain an optimal pressure rise. This may result in a decrease of compression efficiency.
When the blade
104
protrudes from the helical groove
103
to a maximum degree, it receives the highest possible pressure. At this time, the blade
104
is most deformed and cannot smoothly move with respect to the helical groove
103
. This may degrade the sealing property of the compressor.
In the process of assembling the compression mechanism unit, the blade
104
having a rectangular cross section must be fitted into the helical groove
103
having a rectangular cross section. This work is extremely cumbersome, lowering the efficiency of assembling the compression mechanism unit.
An object of the present invention is to provide a fluid compressor in which the bottom space lying at the bottom of the helical groove can easily communicate with the high-pressure compression chamber to enhance the compression efficiency, and the blade can smoothly move with respect to the helical groove to improve the sealing property.
BRIEF SUMMARY OF THE INVENTION
A fluid compressor according to the present invention comprises:
a hollow cylinder;
a roller provided in the cylinder, with an axis deviated from the axis of the cylinder, and having a helical groove made in an outer circumferential surface and having turns arranged at a pitch that gradually increases from one end to the other end;
a blade fitted in the helical groove of the roller and being movable with respect to the helical groove; and
a plurality of compression chambers provided between the cylinder and the roller, defined by the blade and designed to compress the fluid to a high pressure gradually as the fluid flows in an axial direction of the roller, from one end to the other end of the roller,
wherein the helical groove has one side positioned at a high-pressure compression chamber and another side positioned at a low-pressure compression chamber, and the one side and the another side are inclined at the same angle such that the groove gradually opens toward the outer circumferential surface of the roller, an opening angle &thgr; defined by the one side and another side is:
0°<&thgr;≦20°,
the blade has one side positioned at a high-pressure compression chamber and another side positioned at a low-pressure compression chamber, and both sides of the blade are inclined at substantially the same angle as both sides of the helical groove.”
The helical groove has one side positioned at a high-pressure compression chamber and another side positioned at a low-pressure compression chamber, and the one side is inclined to the another side such that the groove gradually opens toward the outer circumferential surface of the roller.
Thus, a gap develops between one side of the helical groove and one side of the blade, which opposes the side of the groove, when the blade moves, protruding from the helical groove. The space lying at the bottom of the helical groove therefore reliably communicates with the high-pressure compression chamber.
REFERENCES:
patent: 4872820 (1989-10-01), Iida et al.
patent: 5332377 (1994-07-01), Hirayama et al.
patent: 2/99283 (1990-08-01), None
patent: 7-107391 (1995-11-01), None
patent: 8-82295 (1996-03-01), None
patent: 2602869 (1997-01-01), None
Denion Thomas
Pillsbury & Winthrop LLP
Toshiba Carrier Corporation
Trieu Theresa
LandOfFree
Fluid compressor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fluid compressor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fluid compressor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3115770