Pumps – Motor driven – Electric or magnetic motor
Reexamination Certificate
2000-04-24
2001-07-10
Walberg, Teresa (Department: 3742)
Pumps
Motor driven
Electric or magnetic motor
Reexamination Certificate
active
06257846
ABSTRACT:
BACKGROUND OF THE INVENTION
1. (Field of the Invention)
The present invention relates generally to a sealed compressor for use in a refrigerator, an air conditioner or the like and, in particular but not exclusively, to pipe connectors for connecting suction and discharge pipes to a sealed casing of the sealed compressor. The present invention also relates to a method of joining the pipe connectors to the sealed casing.
2. (Description of Related Art)
FIG. 1
depicts a conventional sealed compressor having a sealed casing
101
in which a motor section
102
and a compression section
103
are both accommodated. The sealed casing
101
is provided with a suction pipe connector
104
secured thereto through which a refrigerant is introduced thereinto and a discharge pipe connector
105
secured thereto through which a compressed refrigerant is discharged therefrom. The suction pipe connector
104
and the discharge pipe connector
105
lead to an evaporator (not shown) and a condenser (not shown), respectively, to form a refrigeration cycle. Because both the evaporator and the condenser are connected to copper pipes, a material which can be readily connected to the copper pipes, for example, by copper-brazing is selected for the suction pipe connector
104
and the discharge pipe connector
105
. For this reason, both the suction pipe connector
104
and the discharge pipe connector
105
are generally made of copper pipes. When each of the suction pipe connector
104
and the discharge pipe connector
105
is secured to the sealed casing
101
, which is generally made of steel, it is the general practice that a portion of the pipe connector
104
or
105
is first inserted into a hole defined in the sealed casing
101
and is then rigidly secured thereto by silver-brazing with the use of flux.
More specifically, as shown in
FIG. 1
, the sealed casing
101
has a hole defined therein in alignment with a suction hole
106
defined in the compression section
103
. An external suction sleeve
107
is inserted into the hole of the sealed casing
101
and is secured thereto. The compression section
103
also has a suction sleeve insertion hole
108
defined therein so as to be continuous to the suction hole
106
. The suction sleeve insertion hole
108
is positioned radially outwardly of the suction hole
106
and has a diameter slightly larger than that of the suction hole
106
. The suction pipe connector
104
includes the external suction sleeve
107
referred to above and an internal suction sleeve
109
pressed into the suction sleeve insertion hole
108
so that a low-pressure refrigerant to be introduced into the sealed casing
101
may be separated from a high-pressure refrigerant inside the sealed casing
101
. The length of the internal suction sleeve
109
is determined so that an outer end thereof may be positioned radially outwardly of an outer end of the external suction sleeve
107
. After a suction pipe
110
has been inserted into the internal suction sleeve
109
pressed into the suction sleeve insertion hole
108
, the suction pipe
110
, the internal suction sleeve
109
and the external suction sleeve
107
are simultaneously hermetically secured together by brazing, thereby separating the external atmosphere, the low-pressure refrigerant introduced into the sealed casing
101
, and the high-pressure refrigerant inside the sealed casing
101
from one another.
In the above-described construction, the internal suction sleeve
109
is made of a copper pipe or a copper-plated steel pipe, while the external suction sleeve
107
and the discharge pipe connector
105
both secured to the sealed casing
101
are generally made of copper pipes. The suction pipe
110
is also generally made of a copper pipe.
The sealed compressor of the above-described construction has problem in that in applications where a copper pipe is hermetically connected to the steel sealed casing
101
by silver-brazing, flux is inevitably required, which must be removed after the brazing. Removal of he flux is generally carried out in hot water in which the flux dissolves.
On the other hand, HFC refrigerants listed as candidates for alternative refrigerants that cause no destruction of the ozone layer are generally used with an ester-based lubricant compatible therewith. The ester-based lubricant has a tendency to cause hydrolysis, which in turn produces acids. Accordingly, if a compressor contains an HFC refrigerant, it is necessary to manage the compressor so that the amount of water contained therein may be as small as possible. Furthermore, even if the amount of chlorine contained in the flux is extremely small, it acts to promote decomposition of the HFC refrigerant and that of the ester-based lubricant. Because of this, complete removal of the flux is required.
Conversely, silver-brazing requires a process in which water and chlorine-containing impurities remain that must be mostly removed during the manufacture of a compressor for use with an alternative refrigerant. In addition, it is difficult to immerse a relatively large body such as the sealed casing in hot water, and if the compressor is of a complicated structure, it is very difficult and time-consuming to completely remove water that has been used for removal of the flux.
Also, during brazing, members to be joined together must be heated to a temperature at which a brazing material melts. To this end, such members are generally heated with flames of, for example, a torch. By so doing, copper pipes as the connectors are annealed and reduced in strength. The flames produce on the members an oxide layer, which sometimes promotes deterioration of a lubricant or a refrigerant.
Furthermore, because the copper pipe connector has a relatively large thermal expansion coefficient, the pipe connector expands due to heat generated during brazing and contracts due to subsequent cooling, thus deteriorating the sealing properties between the pipe connector and the insertion hole thereof. Also, component parts of the compression section are likely to be deviated from their desired positions by relatively large forces applied thereto. If a steel pipe is used for the pipe connector, it must be finished into a desired size and then copper-plated, resulting in an increase in the manufacturing cost.
SUMMARY OF THE INVENTION
The present invention has been developed to overcome the above-described disadvantages.
It is accordingly an objective of the present invention to provide a sealed compressor having a sealed casing to which pipe connectors are hermetically joined without brazing which requires flux and flames.
Another objective of the present invention is to provide a method of joining pipe connectors to the sealed casing without brazing.
In accomplishing the above and other objectives, the sealed compressor according to the present invention includes a sealed casing in which a motor section and a compression section are both accommodated, and also includes a first sleeve having a first end and a second end opposite to each other. The first end is inserted into a sleeve insertion hole defined in the compression section to allow a refrigerant to flow therethrough, while the second end is hermetically brazed to a copper pipe disposed outside the sealed casing. The first sleeve is formed by deep-drawing a copper-plated steel plate into a generally cylindrical shape.
The deep-drawing reduces the manufacturing cost of the first sleeve. Furthermore, the use of the copper-plated steel plate enables the first sleeve to be resistance-welded to the sealed casing and to be copper-brazed to the copper pipe.
Advantageously, the first sleeve is inserted into a second sleeve, wherein the second end is flared and wherein the second sleeve is hermetically brazed to an external surface of the first sleeve, while the copper pipe is hermetically brazed to an internal surface of the first sleeve.
Because copper deposits formed on internal and external surfaces of the first sleeve are exposed outside, the first sleeve can be brazed to both the second sleeve and t
Fukuhara Hiroyuki
Muramatsu Shigeru
Takano Hiroshi
Matsushita Electric - Industrial Co., Ltd.
Patel Vinod D
Walberg Teresa
Wenderoth , Lind & Ponack, L.L.P.
LandOfFree
Sealed compressor having pipe connectors and method of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sealed compressor having pipe connectors and method of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sealed compressor having pipe connectors and method of... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2485093