Rotary expansible chamber devices – Working member has planetary or planetating movement – Helical working member – e.g. – scroll
Reexamination Certificate
2002-12-02
2004-01-06
Denion, Thomas (Department: 3748)
Rotary expansible chamber devices
Working member has planetary or planetating movement
Helical working member, e.g., scroll
Reexamination Certificate
active
06672851
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to scroll-type compressors. In particular, the invention is directed to scroll-type compressors having spiral elements which reduce or suppress a noise associated with an expansion of a compressed refrigerant.
2. Description of Related Art
Referring to
FIG. 4
, a known scroll-type compressor
100
, such as the compressor described in Japanese Patent (unexamined) Publication No. H7-77178, may include a compressor housing
101
, and housing
101
may include a fixed scroll member
103
and an orbiting scroll member
105
. Fixed scroll member
103
may have a first spiral element
102
, and orbiting scroll member
105
may have a second spiral element
104
. Fixed scroll-member
103
and orbiting scroll member
105
are positioned inside housing
101
, such that first spiral element
102
and second spiral element
104
interfit with each other and form a plurality of fluid pockets
106
. Compressor
100
also may include a discharge port
109
formed through about a center of a first end plate of fixed scroll member
103
and a drive shaft
107
which is positioned inside housing
101
and is rotatably supported, by housing
101
via a bearing
120
. Drive shaft
107
also may be connected to orbiting scroll member
105
via a crank mechanism
108
. Compressor
100
further may include a rotation prevention mechanism
121
, and rotation prevention mechanism
121
may include a plurality of balls
130
. Each of balls
130
is positioned between a surface of a second end plate of orbiting scroll member
105
and an axial end surface of housing
101
. Moreover, rotation prevention mechanism
121
is adapted to prevent orbiting scroll member
105
from rotating. Rotation prevention mechanism
121
also is adapted to allow orbiting scroll member
105
to move in an orbital motion with respect to a center of fixed scroll member
103
. Compressor
100
also may include an electromagnetic clutch
122
which is rotatably supported by housing
101
via a bearing
123
.
In operation, when an external power source, e.g., an engine of a vehicle, transfers a driving force to drive shaft
107
via electromagnetic clutch
122
, drives shaft
107
rotates. Because drive shaft
107
is connected to orbiting scroll member
105
via crank mechanism
108
, when drive shaft
107
rotates, drive shaft
107
drives orbiting scroll member
105
to move in an orbital motion. Moreover, when orbiting scroll member
105
moves in the orbital motion, fluid pockets
106
also may move from outer portions of first spiral element
102
and second spiral element
104
to a center portion of first spiral element
102
and second spiral element
104
. Consequently the volume of fluid pockets
106
is reduced, and refrigerant gas, which is in fluid pockets
106
, is compressed. After the refrigerant gas is compressed in the center portion of the spiral elements, the refrigerant gas moves through discharge port
109
, displaces a reed value
124
, and is discharged into an external refrigerant circuit (not shown) via an outlet port (not shown).
Referring to
FIGS. 5
a
-
5
c,
a compression stroke and a discharge stroke of compressor
100
is depicted. Specifically, referring to
FIG. 5
a
, fluid pockets
106
may include a first fluid pocket portion
106
a
and a second fluid pocket portion
106
a
. During the compression stroke, fluid pocket portions
106
a
and
106
a
may move towards the center portion of first spiral element
102
and second spiral element
104
, such that a volume of the fluid pocket portions
106
a
and
106
a
is reduced. Subsequently, as shown in
FIG. 5
b,
fluid pocket portions
106
a
and
106
a
may merge and become a combined fluid pocket
206
located at the center portion of spiral element
102
and spiral element
104
. First fluid pocket portion
106
a
may be scaled at a first pair of seal points a and b, and second fluid pocket portion
106
a
, may be sealed at a second pair of seal points a and b. Moreover, combined-fluid pocket
206
may be seal points a and a. As shown in
FIG. 5
c,
as fluid pocket portions
106
a
and
106
a
′ merge into combined fluid pocket
206
, seal points b and b move towards the center of first spiral element
102
and second spiral element
104
, and seal points a and a disappear.
Referring to
FIG. 7
, one of the examples of a center portion of a spiral element of a known scroll member, a plan view of a spiral element
102
(
104
), is depicted. A center of a curvature
112
of an arc
111
at a tip portion of spiral element
102
(
104
) is positioned on a line from an involute
115
. A center of a curvature
114
of an arc
113
of a fillet is positioned on a line from an involute
116
. A base circle
117
is for making involute
115
and involute
116
. The center of curvature
112
and the center of curvature
114
are positioned on a different line of an involute, in other words, on a different involute angle.
Referring to
FIG. 6
, a fillet
110
may be formed at a base of a wall at a center end portion of first spiral element
102
and second spiral element
104
. Fillet
110
may be adapted to reinforce the wall at the center portion of first spiral element
102
and second spiral element
104
at which the pressure of the refrigerant gas is greatest. Moreover, because fillet
110
is formed at the root of the wall at the center end portion of first spiral element
102
and second spiral element
104
, the wall at the center end portion of first spiral element
102
does not contact the wall at the center end portion of second spiral element
104
. Consequently, as orbiting scroll
105
orbits, seal points a and a disappear, and fillet
110
creates a first space between first spiral element
102
and second spiral element
104
and a second space between first spiral element
102
and second spiral element
104
. Combined fluid pocket
206
may be in fluid communication with first fluid pocket portion
106
a
and second fluid pocket portion
106
′ via the first space and the second space, respectively, and compressed refrigerant may flow from combined fluid pocket
206
to first fluid pocket portion
106
a
and second fluid pocket portion
106
a
′. When the compressed refrigerant flows into first fluid pocket portion
106
a
and second fluid pocket portion
106
a
′, the compressed refrigerant may expand rapidly, which may generate noise.
In order to suppress this noise, in known compressors, each of the scroll members may, include a communication portion, e.g., a notch, a groove, an aperture, or the like, formed adjacent to each of the seal points. Moreover, the communication portion is adapted to relieve pressure from combined fluid pocket
206
and, thereby to suppress the noise associated with the expansion of the refrigerant. Nevertheless, when the refrigerant expands, a portion of the refrigerant flows to an adjacent fluid pocket via the communication portion, which may decrease compression efficiency.
SUMMARY OF THE INVENTION
Therefore, a need has arisen for scroll-type compressors which overcome these and other shortcomings of the related art. A technical advantage of the present invention is that noise associated with the expansion of compressed fluid is reduced.
In an embodiment of the present invention, a scroll-type compressor includes a fixed scroll member having a first spiral element, and an orbiting scroll member having a second spiral element. The first spiral element and thee second spiral element interfit with each other at an angular offset and at a radial offset to form a plurality of fluid pockets which are adapted to compress a fluid. Further, the first spiral element or the second spiral element, or both, include an interior wall surface defined by a first involute curve based on a circle, an exterior wall surface defined by a second involute curve based on the circle, an end wall surface formed at a center end of the spiral element by a first arc, and a fillet formed along a root of the end wall su
Ito Kiyofumi
Ito Shigeru
Baker & Botts L.L.P.
Denion Thomas
Sanden Corporation
Trieu Theresa
LandOfFree
Scroll-type compressors does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Scroll-type compressors, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Scroll-type compressors will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3206899