Rotary expansible chamber devices – Working member has planetary or planetating movement – Helical working member – e.g. – scroll
Reexamination Certificate
1999-07-08
2001-09-11
Vrablik, John J. (Department: 3748)
Rotary expansible chamber devices
Working member has planetary or planetating movement
Helical working member, e.g., scroll
C418S055300
Reexamination Certificate
active
06287096
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to scroll compressor for compressing gas.
FIG. 10
shows such a scroll compressor, which was disclosed in Japanese Unexamined Patent Publication No. 5-321850. The compressor includes a fixed scroll
52
formed in a center housing part
51
. A drive shaft
56
is rotatably supported by a front housing part
55
. The front housing part
55
and the center housing part
51
form a scroll housing for accommodating a movable scroll
53
. A compression chamber
54
is defined between the movable scroll
53
and the fixed scroll
52
. The movable scroll
53
is supported by a crank mechanism
56
a.
The crank mechanism
56
a
converts rotation of the drive shaft
56
into eccentric (orbital) movement of the movable scroll
53
relative to the drive shaft
56
. Orbital movement of the movable scroll
53
causes the volume of the compression chamber
54
to change from the maximum to the minimum and then from the minimum to the maximum. As the volume of the compression chamber
54
is decreased, gas in the compression chamber
54
is compressed.
A compression reaction force generated by compressing gas acts on the rear face
55
a
of the front housing part
55
. Guide holes
55
b
(only one is shown) are formed in the rear face
55
a.
Support holes
53
b
are formed in a base plate
53
a
of the movable scroll
53
. A pin
57
is fitted in each support hole
53
b.
The distal end of each pin
57
is inserted into the corresponding guide hole
55
b
. Each pin
57
, the corresponding hole
53
b
and the corresponding guide hole
55
b
form an anti-rotation mechanism. When rotation of the drive shaft
56
is transferred to the movable scroll
53
by the crank mechanism
56
a,
the anti-rotation mechanisms prevent the movable scroll
53
from rotating, while permitting the movable scroll
53
to orbit at a predetermined radius.
The diameter of the support holes
53
b
is slightly greater than the diameter of the pins
57
such that each pin
57
rotates in the corresponding support hole
53
b.
The pins
57
are supported by the movable scroll
53
in a cantilevered manner. Therefore, when receiving a radial force, each pin
57
is slightly inclined in the corresponding hole
53
b.
When the movable scroll
53
is orbiting, inclination of the pins
57
causes the load to concentrate at the open end of the hole
53
b,
which excessively wears the open end of the hole
53
b.
The wearing of the open end of the holes
53
b
causes the inclination of the pins
57
to increase. As a result, the orbit radius of the movable scroll
53
eventually exceeds the initial value. A greater orbit radius of the scroll
53
degrades the compression efficiency of the compressor. If the pins
57
are supported by the front housing part
55
and the guide holes are formed in the base plate
53
a,
the compressor will have the same problem.
In order to prevent the pin
57
from inclining, the proximal end of each pin
57
may be fixed within the corresponding support hole
53
b,
and a bearing may be fitted to the distal end of each pin
57
. The outer surface of the bearing rolls on the wall of the guide hole
55
b
. This structure prevents the pins
57
from inclining relative to the movable scroll
53
. Thus, the holes
53
b
are not unevenly worn. However, when the compressor is started, the movable scroll
53
is slightly inclined. At this time, each bearing unevenly contacts the open end of the corresponding guide hole
55
b
. This unevenly wears the bearings and the open end of the guide holes
55
b
, which eventually increases the orbit radius of the movable scroll
53
. Accordingly, the compression efficiency of the compressor is lowered.
SUMMARY OF THE INVENTION
Accordingly, it is an objective of the present invention to provide a scroll compressor that improves the compression efficiency.
To achieve the foregoing and other objectives and in accordance with the purpose of the present invention, a scroll compressor for compressing gas is provided. The scroll compressor includes a housing having an annular groove that includes a pair of walls facing each other, a fixed scroll formed in the housing, a drive shaft rotatably supported in the housing, a movable scroll accommodated in the housing to mate with the fixed scroll and a crank mechanism. The crank mechanism is located between the drive shaft and the movable scroll for driving the movable scroll in accordance with the rotation of the drive shaft. A projection extends radially from the movable scroll along a plane perpendicular to the axis of the drive shaft. The projection is located in the annular groove and slides along the walls of the annular groove, and has a thickness measured in the axial direction of the drive shaft. The distance between the groove walls is greater than the thickness of the projection by a predetermined value. The scroll compressor further includes a restriction mechanism for inhibiting rotation of the movable scroll with respect to the axis of the movable scroll and for permitting orbital movement of the movable scroll. The restriction mechanism includes a restriction member supported by the projection or the groove walls.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.
REFERENCES:
patent: 4522574 (1985-06-01), Arai et al.
patent: 5807089 (1998-09-01), Tsumarari et al.
patent: 58-30403 (1983-02-01), None
patent: 58-70003 (1983-04-01), None
patent: 59-58188 (1984-04-01), None
patent: 59-79087 (1984-05-01), None
patent: 60-104787 (1985-06-01), None
patent: 60-182382 (1985-09-01), None
patent: 5-118324 (1993-05-01), None
patent: 05-321850 (1993-12-01), None
Fujii Toshiro
Murakami Kazuo
Nakane Yoshiyuki
Yamamoto Shinya
Yokomachi Naoya
Kabushiki Kaisha Toyoda Jidoshokki Seisakusho
Morgan & Finnegan , LLP
Vrablik John J.
LandOfFree
Anti-rotation mechanism for movable scroll in scroll 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 Anti-rotation mechanism for movable scroll in scroll compressor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Anti-rotation mechanism for movable scroll in scroll compressor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2494534