Rotary expansible chamber devices – Working member has planetary or planetating movement – Helical working member – e.g. – scroll
Reexamination Certificate
1999-12-03
2001-08-28
Denion, Thomas (Department: 3748)
Rotary expansible chamber devices
Working member has planetary or planetating movement
Helical working member, e.g., scroll
C418S057000, C418S107000, C418S108000, C029S888022
Reexamination Certificate
active
06280165
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a scroll type fluid machine which processes coolant, air or other compressible gas, and in particular to a scroll type fluid machine characterized by the provision of a positioning means for a single unorbiting scroll member which is movable in the direction of a substantially straight line passing through a substantial center of the scroll lap of the unorbiting scroll member but unmovable in a direction substantially orthogonal to the above-mentioned substantially straight line, and which is rotatable, and an unorbiting scroll fixing member, and adapted to appropriately mesh the unorbiting scroll member with an orbiting scroll member so as to aim at ensuring a high degree of energy efficiency.
2. Related Art
Scroll type fluid machines have been widely used as compressors in refrigerators, air-conditioners, and others in various fields. In comparison with other compressors having other configurations, such fluid machines may have preferences such as a high degree of efficiency, a high degree of reliability, stillness and the like, and accordingly, they have been prosperously developed and studied.
Brief explanation will be made of one of the arrangements of these scroll type fluid machines. The basic components of the compression part thereof are a stationary scroll, an orbiting scroll and a frame, the frame being fixed to a closed container, and is also fixed to the stationary scroll with the use of vacant holes in the stationary scroll, fixing thread parts of the frame, and a fixing bolts. The basic components of the stationary scroll are a lap, a mirror plate, a lap bottom, a lap tip and a discharge port, and those of the orbiting scroll are a lap, and a mirror plate, a lap bottom and a lap tip.
The basic components of the drive part of the compressor, for driving the orbiting scroll in order to orbit the latter, are a stator and a rotor in a motor, a crank shaft, an Oldham's ring which is a main component of a mechanism for preventing the orbiting scroll from rotating around its axis, a support member of the crank shaft, for rotatably engaging the frame and the crank shaft with each other, and a support part of the orbiting scroll, for engaging the orbiting scroll and an eccentric pin part of the crankshaft with each other so as to be movable in a thrust direction which is a rotating axis direction and rotatable.
Next, referring to
FIG. 10
, brief explanation will be made of the compressing operation of the scroll type fluid machine.
FIG. 10
shows compression chambers
4
a
1
,
4
a
2
,
4
b
1
,
4
b
2
which are defined by the lap
2
a
of the stationary scroll
2
and the lap
3
a
of the orbiting scroll
3
, which are meshed with each other. The compression chambers
4
a
1
,
4
a
2
,
4
b
1
,
4
b
2
shown in this figure are those during compression stroke, and the compressing operation is carried out in such a way that the orbiting scroll carries out orbiting motion so as to reduce the volumes of the compression chambers. During compressing operation, working fluid is sucked into the compression chamber
4
by way of a suction port
5
and a suction space
15
in association with the orbiting motion of the orbiting scroll
3
. The sucked working fluid is discharged by way of a discharge space and a discharge port at the time when the compression chamber reaches a position where it is communicated with a discharge port
2
e
of the stationary scroll after the volume of the compression chamber is successively decreased as indicated by
4
a
1
,
4
a
2
,
4
b
1
and
4
b
2
. During the orbiting motion of the stationary scroll
2
and the orbiting scroll
3
which are meshed with each other, there is required sufficient gas-tightness in order to prevent occurrence of leakage of the working fluid between the suction space
15
and the compression chambers
4
a
1
,
4
b
1
, between the compression chambers
4
a
1
,
4
a
2
,
4
b
1
,
4
b
2
, and between the compression chambers
4
a
2
,
4
b
2
and the discharge port
2
e,
as far as possible.
Next, brief explanation will be made of an example of a fixing structure between the stationary scroll
2
and the frame
7
with reference to
FIG. 11
which is a schematic view illustrating an example of the stationary structure. The purpose of fixing the stationary scroll
2
and the frame
7
with each other is to isolate under pressure a space defined between the frame
7
and the stationary scroll
2
from the discharge space or the suction space in order to carry out appropriate compressing operation. In the example of the fixing structure shown in
FIG. 11
, the stationary scroll
2
and the frame
7
are fixed together by using a vacant hole
2
f
in the stationary scroll
2
, a fixing thread part
7
b
in the frame
7
and a fixing bolt
20
. In order to isolate the space from the discharge space and the suction space under pressure, as shown in
FIG. 10
, a plurality of vacant holes
2
f
in the stationary scroll arranged in a ring-like shape. Further, the diameter of the vacant holes
2
f
is dimensioned so as to allow the fixing bolts
20
to smoothly be inserted there-through in order to facilitate the assembly of the fluid machine.
An example of the positioning means for the stationary scroll, is disclosed in Japanese Laid-open patent No. H5-332267, and is shown in FIG.
12
. In this example, a stationary scroll
100
is composed of a first base plate
100
a,
a first spiral member
100
b,
and two reference holes
100
c,
100
d,
and with the use of the two reference holes
100
c,
100
d,
the stationary scroll is positioned so that the phases of the spiral bodies of the stationary scroll
100
and the orbiting scroll are precisely shifted from each other by an angle of 180 deg. In
FIG. 12
, the reference hole
100
d
is elongated. However, it is should not be limited to such an elongated hole. The elongated hole can facilitate the assembly even though there would be errors in pitch accuracy between the reference holes while the clearances between the engaging pin and the reference holes can be minimized, and the phase relationship between both scrolls can be precisely set.
The fixing structure between the stationary structure and the frame, as mentioned above offers problems in view of obtaining an appropriate engaging condition between the orbiting scroll and the stationary scroll in order to ensure a high degree of energy efficiency. As shown in
FIG. 10
, in consideration with the meshing between the orbiting scroll lap
3
a
and the stationary scroll lap
2
a,
no gaps are theoretically present between the side surfaces of the laps
2
a,
3
a
at positions where the side surfaces are made into contact with each other, and accordingly, the stationary scroll
2
and the orbiting scroll
3
can be directly meshed with each other. However, since machining tolerances are inevitably present, in fact, in machined components including the stationary scroll
2
and the orbiting scroll
3
, small gaps are, in general, defined between the side surfaces of the laps
2
a,
3
a
so as to prevent interference between the orbiting scroll lap
3
a
and the stationary scroll lap
2
a
during the assembly of the fluid machine and the orbiting motion thereof. Thus, even with scroll type fluid machines with identical specifications, deviation are inevitably caused among the gaps between the side surfaces of the laps
2
a,
3
a
within the range of machining tolerances.
Further, in the example of the fixing structure between the stationary scroll
2
and the frame
7
, shown in
FIG. 11
, it is frequent that a relatively large gap
21
is defined between the vacant hole
2
f
in the stationary scroll and the fixing bolt
20
as shown in
FIG. 11
in order to enable the fixing bolt
20
to be smoothly inserted through the vacant hole
2
f
in the stationary scroll. Accordingly, when the stationary scroll
2
is fixed to the frame
7
, there would be caused such a risk that the stationary scroll
2
is fixed, being rotated or parallelly shifted
Hayase Isao
Matsunaga Mutsunori
Sakurai Kazuo
Tsuchiya Takeshi
Antonelli Terry Stout & Kraus LLP
Denion Thomas
Hitachi , Ltd.
Trieu Theresa
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