U.S. patent application number 14/421917 was filed with the patent office on 2015-08-06 for gas discharge arrangement for a refrigeration compressor.
The applicant listed for this patent is Whirlpool S.A.. Invention is credited to Joao Luiz Erzinger, Marcelo Nelmo Knies, Dietmar Erich Bernhard Lilie, Rinaldo Puff.
Application Number | 20150219086 14/421917 |
Document ID | / |
Family ID | 49118248 |
Filed Date | 2015-08-06 |
United States Patent
Application |
20150219086 |
Kind Code |
A1 |
Puff; Rinaldo ; et
al. |
August 6, 2015 |
GAS DISCHARGE ARRANGEMENT FOR A REFRIGERATION COMPRESSOR
Abstract
The compressor comprises: a shell carrying a gas outlet tube and
housing a cylinder cap having a gas outlet; and a plastic discharge
tube having an inlet end and an outlet end respectively coupled to
the gas outlet and to the gas outlet tube, at least one of said
inlet and outlet ends being connected to a discharge part, defined
at the gas outlet or at the gas outlet tube, by a connecting
element having: a fixation portion, affixed inside the discharge
part; an engaging portion fitted inside one end of the discharge
tube and carrying a superficial indexing means acting against the
discharge tube; and gripping means disposed between the indexing
means and the fixation portion; and a retaining ring mounted around
the discharge tube for compressing the latter, in order to spike,
therein, the gripping means.
Inventors: |
Puff; Rinaldo; (Joinville -
Sc, BR) ; Knies; Marcelo Nelmo; (Joinville Sc,
BR) ; Erzinger; Joao Luiz; (Joinville Sc, BR)
; Lilie; Dietmar Erich Bernhard; (Joinville - Sc,
BR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Whirlpool S.A. |
Sao Paulo -Sp |
|
BR |
|
|
Family ID: |
49118248 |
Appl. No.: |
14/421917 |
Filed: |
August 16, 2013 |
PCT Filed: |
August 16, 2013 |
PCT NO: |
PCT/BR2013/000310 |
371 Date: |
February 16, 2015 |
Current U.S.
Class: |
417/312 |
Current CPC
Class: |
F04B 39/0072 20130101;
F16L 33/225 20130101; F04B 39/123 20130101; F04B 39/0055
20130101 |
International
Class: |
F04B 39/12 20060101
F04B039/12; F04B 39/00 20060101 F04B039/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 17, 2012 |
BR |
BR 10 20120207257 |
Claims
1. A gas discharge arrangement for a refrigeration compressor,
which comprises: a shell carrying a gas outlet tube and housing a
gas compression mechanism including a cylinder and a cylinder cap,
which defines, internally, a gas discharge chamber and has a gas
outlet; and a discharge tube, in a flexible plastic material,
having an inlet end, coupled to the gas outlet, and an outlet end
coupled to the gas outlet tube, characterized in that at least one
of the inlet end and outlet end of the discharge tube is connected
to a discharge part, defined in any one of the gas outlet and the
gas outlet tube, by a tubular-shaped connecting element, having: a
fixation portion, to be affixed in the interior of the respective
discharge part; an engaging portion to be fitted, with
interference, in the interior of one end of the discharge tube and
carrying a superficial indexing means, which produces a
corresponding radial deformation in the discharge tube; and at
least one gripping means, superficially disposed between the
superficial indexing means and the fixation portion; and a
retaining ring, disposed around the end of the discharge tube and
radially compressing the latter in order that the gripping means of
the engaging portion of the connecting element be spiked in said
discharge tube.
2. The arrangement, according to claim 1, characterized in that the
superficial indexing means is spaced away from the fixation portion
and projects, radially outwardly from the engaging portion, the
retaining ring being axially retained, in at least one direction,
by the radial deformation of the end of the discharge tube and, in
an opposite direction, by the fixation portion.
3. The arrangement, according to claim 2, characterized in that the
retaining ring has opposite end edges, which are respectively
seated against the radial deformation of the end of the discharge
tube and against the fixation portion of the connecting
element.
4. The arrangement, according to claim 2, characterized in that the
retaining ring has an end edge axially seated and locked against
the fixation portion of the connecting element, and a free opposite
end edge, said retaining ring being internally provided with a
circumferential groove housing and axially locking, in its
interior, the radial deformation of the adjacent end of the
discharge tube.
5. The arrangement, according to claim 1, characterized in that the
superficial indexing means is defined by a circumferential rib with
a cross section in convex arc.
6. The arrangement, according to claim 1, characterized in that the
gripping means is in the form of a frusto-conical circumferential
projection, with its smaller base coinciding with the contour of
the engaging portion, and with its larger base defining an annular
step projecting outward from the engaging portion and turned to the
fixation portion.
7. The arrangement, according to claim 1, characterized in that the
engaging portion has a free end and an opposite end joined to the
fixation portion and carrying a stop means radially projecting
outwardly from the contour of the engaging portion, spaced away
from the gripping means.
8. The arrangement, according to claim 7, characterized in that the
stop means is defined by an annular flange affixed around the
opposite end of the engaging portion.
9. The arrangement, according to claim 7, characterized in that the
superficial indexing means is spaced away from the free end of the
engaging portion.
10. The arrangement, according to claim 1, characterized in that
the connecting element is made in a single piece.
11. The arrangement, according to claim 1, characterized in that
the fixation portion is cylindrical and affixed to the respective
discharge part, defined in any one of the gas outlet and the gas
outlet tube, by means of adhesive.
12. The arrangement, according to claim 1, characterized in that
the fixation portion comprises an external thread to be affixed to
the respective discharge part, defined in any one of the gas outlet
and the gas outlet tube.
13. The arrangement, according to claim 1, characterized in that
the retaining ring incorporates, externally, a stop element defined
by a circumferential shoulder, for allowing that a tool for
insertion of the retaining ring be seated on the portion of the
tube surrounding the engaging portion of the connecting element.
Description
FIELD OF THE INVENTION
[0001] The present invention refers to a discharge arrangement to
be applied to a refrigeration hermetic compressor of the type which
comprises, in the interior of a shell, a motor-compressor assembly
presenting a piston which reciprocates in the interior of a
cylinder defined in a cylinder crankcase and which is closed, at
one end, by a cylinder cap inside which a discharge chamber is
defined. The gas discharge of the compressor is provided with a
discharge tube, presenting an inlet end affixed to the cylinder cap
and open to the discharge chamber, and an opposite outlet end, open
to a gas outlet tube provided in an orifice of the hermetic shell.
The discharge tube provides a fluid communication between the
discharge chamber and the high pressure side of a refrigeration
system to which the compressor is connected.
BACKGROUND OF THE INVENTION
[0002] Vapor compression machines, such as refrigeration
compressors of the type used in refrigeration systems, carry out
the compression of a refrigerant gas in a compression unit,
internal to a shell, conducting pressurized gas to a high-pressure
side of the refrigeration system to which the compressor is
coupled. Such compressors generally include, in the interior of the
shell, a motor-compressor assembly having a cylinder crankcase
which defines a cylinder, inside which a piston is axially
displaced, by actuation of a rotary or linear electric motor.
[0003] The cylinder has an open end, through which the piston is
housed, and an opposite end closed by a valve plate, against which
is seated a cylinder cap. The valve plate is constructed to operate
jointly with at least one discharge valve turned to the interior of
the discharge chamber.
[0004] The gas compressed in the cylinder is conducted to the an
inlet end, hermetically coupled to the cylinder cap, and an
opposite end, hermetically affixed to a gas outlet tube, generally
mounted in an orifice provided in the shell of the compressor.
[0005] In the known solutions, in which the discharge tube is
metallic, the connection of said discharge tube with the cylinder
cap and with the gas outlet tube is obtained by welding, direct
brazing, or by fitting it to an intermediate body (Brazilian
document PI0300607-7 and US document 2004/0052661) mounted in the
cylinder cap.
[0006] In the constructive solution described and illustrated in
US2010/0226805A1, the mounting of the outlet end of the metallic
discharge tube in the interior of the gas outlet tube is made with
the aid of a connector in the form of a tubular sleeve, constructed
in plastic material and situated between the discharge tube and the
gas outlet tube.
[0007] In the solutions in which the discharge tube is made of
plastic material, the connection to the cylinder cap is achieved,
for example, by fitting the inlet end of the plastic discharge tube
around a tubular nozzle, projecting from the cylinder cap. However,
the retention of the plastic discharge tube to the tubular nozzle
may be achieved with the aid of several means, as, for example, by
adhesive, with or without the provision of a retaining ring
surrounding, simultaneously, the inlet end of the plastic discharge
tube and the tubular nozzle of the cylinder cap.
[0008] A known mounting arrangement of the outlet end of the
plastic discharge tube in the metallic gas outlet tube of the
hermetic shell is described and illustrated in document
WO2007/011247A2 and comprises the provision of a metallic gas
outlet tube projecting to the inside and to the outside of the
hermetic shell, in order to have its outer end welded to the high
pressure tube of the refrigeration system to which the compressor
is coupled. dimensioned to tightly receive an outlet end portion of
the plastic discharge tube, which outlet end portion is disposed
along the interior of the whole extension of the gas outlet tube.
The tight fitting of the plastic discharge tube in the interior of
the metallic gas outlet tube, jointly with the longitudinal
extension of said telescopic fitting, already provides a sealing
between the two tubular extensions, said sealing being complemented
by at least one inward radial deformation of the metallic gas
outlet tube against the plastic discharge tube.
[0009] In said known compressor constructions, there are some
problems which need to be solved by means of an adequate physical
arrangement of the discharge system, including the discharge tube
and its connections with the cylinder cap and with the shell.
[0010] The use of a discharge tube in metallic material presents
some known problems, such as: the transmission of vibration from
the compression mechanism to the hermetic shell; the transmission
of gas compression noise to the hermetic shell; the resistance to
shipping and operating conditions, in order to avoid ruptures of
the discharge tube by fatigue; and also the restrictions to the
passage of gas and heat transfer from the compressed gas to the
interior of the hermetic shell.
[0011] Besides the problems presented above, in the conventional
solutions for connecting the metallic discharge tube to the parts
of cylinder cap and shell of the compressor, it may also occur
failures in the insulation of the compressor motor, resulting in
electrical current leakage in the latter, which leakage has the
discharge tube as one of the ways to flow, reaching the compressor
shell and any metallic structure associated with the latter. In
order to solve the problems mentioned above and related to the use
of a metallic discharge tube, the latter is usually provided with
an internal diameter presents a long length with several curves and
straight portions, in order to minimize both the transmission of
vibration to the shell and the possibility of occurring breakage
due to fatigue.
[0012] Besides requiring a higher amount of material and having a
complex assembly, said solution is not capable to avoid the problem
of noise being transmitted to the shell during gas compression,
which normally requires the use of dampening elements mounted on
the tube, as well as the problem of heat being transmitted from the
compressed gas to the interior of the shell, unless some type of
thermal insulation is provided on the metallic discharge tube,
which increases even more the cost of such known solution.
[0013] Aiming at solving the problems of providing a discharge tube
in metallic material, a known solution has been proposed, which
uses a flexible discharge tube, in a material of low thermal
conductivity, for example, a polymeric plastic material
(WO2007/011247A2).
[0014] While solving all the issues related to the metallic
discharge tube, said prior art solution of using a polymeric
flexible discharge tube further presents some drawbacks regarding
the necessary provision of over-injected additional elements and of
retaining rings which, besides presenting a difficult and costly
assembly, allow failures to occur upon fixation and sealing to the
gas outlet tube and to the cylinder cap, as well as failures of
structural resistance, impairing the discharge tightness.
SUMMARY OF THE INVENTION
[0015] As a function of the disadvantages of the previous
solutions, it is the object of the present invention to provide a
gas discharge arrangement in a refrigeration compressor, which is
capable of providing a reliable and resistant connection of a
discharge tube, in a flexible material, of low thermal conductivity
and not the shell of the compressor, said connection presenting a
simple construction and practical installation, which may be
adapted to different compressor constructions, substantially
reducing the transmission, to the hermetic shell, of vibrations of
the compression mechanism and noise of the gas compression.
[0016] The objective above is achieved by means of a gas discharge
arrangement to be applied to a refrigeration compressor of the type
which comprises: a shell carrying a gas outlet tube and housing a
gas compression mechanism including a cylinder and a cylinder cap,
which internally defines a gas discharge chamber and has a gas
outlet; and a discharge tube in a flexible plastic material having
an inlet end, coupled to the gas outlet, and an outlet end coupled
to the gas outlet tube.
[0017] According to the present invention, at least one of the
parts defined by the inlet end and by the outlet end of the
discharge tube is connected to a discharge part, defined in any one
of the gas outlet and the gas outlet tube, by a tubular-shaped
connecting element, having: a fixation portion, to be affixed in
the interior of the respective discharge part; an engaging portion
to be fitted, with interference, in the interior of one end of the
discharge tube and carrying a superficial indexing means, which
produces a corresponding radial deformation in the discharge tube;
and at least one gripping means, superficially provided between the
indexing means and the fixation portion; and a retaining ring,
disposed around the end of the discharge tube and radially
compressing said discharge tube, in order to spike, in the latter,
the gripping means of the engaging portion of the connecting
element.
[0018] The present invention provides a discharge arrangement
having a connection for a discharge tube presenting, as one of its
advantages, the fact of being easy to assemble. The construction
defined above, allows, by improve the connections of the discharge
tube in a flexible plastic material, to at least one of the
discharge parts defined by the cylinder cap and by the shell of the
compressor.
[0019] Considering that the arrangement of the present invention
also uses a discharge tube made of a non-electrically conductive
plastic material, it does not impair the thermal and electrical
insulation of the motor-compressor assembly in relation to the
hermetic shell, avoiding heat transfer and the risk of electric
current passing from the motor-compressor assembly to the shell,
through the discharge tube.
[0020] Said construction further allows for an optimized
dimensioning, not only of the discharge tube, but also of each
connecting element, with less load loss upon pumping the
refrigerant fluid.
[0021] The present arrangement also does not affect the benefits
regarding reduction of the noise transmitted to the shell, without
the need of requiring additional dampening components, due the
discharge tube being constructed in a flexible plastic
material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The invention will be described below, with reference being
made to the appended drawings, given by way of example of one way
of carrying out the invention and in which:
[0023] FIG. 1 represents an exploded perspective view of a cylinder
cap and of the respective connecting element, both constructed
according to the arrangement of the present invention;
[0024] FIG. 2 represents a perspective view similar to that of FIG.
1, but with the connecting element being mounted to the cylinder
cap;
[0025] FIG. 3 represents cross-sectional view of the assembly
illustrated in FIG. 2, said section being taken according to line
in said figure; hermetic shell of a compressor, carrying a gas
outlet tube in which is applied a respective connecting
element;
[0026] FIG. 5 represents a perspective view of the connecting
element of the arrangement of the present invention;
[0027] FIG. 6 represents a longitudinal sectional view of the
connecting element of FIG. 5, with its engaging portion being
fitted and housed in the interior of an adjacent end of the
discharge tube, by using a first embodiment of the retaining
ring;
[0028] FIG. 6A represents a partial perspective view of the
retaining ring of FIG. 6, in a diametrically sectioned
condition;
[0029] FIG. 7 represents a longitudinal sectional view of the
connecting element of FIG. 5, with is engaging portion being fitted
and housed in the interior of and adjacent end of the discharge
tube, by using a second embodiment of the retaining ring; and
[0030] FIG. 7A represents a partial perspective view of the
retaining ring of FIG. 7, in a diametrically sectioned
condition.
DESCRIPTION OF THE INVENTION
[0031] The present invention will be described below with respect
to a refrigeration compressor of the reciprocating hermetic type,
which comprises a hermetic shell 1, carrying a gas outlet tube 1a
and housing a motor-compressor assembly (not illustrated), which
comprises a gas compression mechanism including a cylinder
crankcase 2 (partially illustrated in FIG. 3), which defines a
cylinder 3 inside which is axially displaced a piston (not
illustrated), by actuation of a rotary or linear electric motor
(also not illustrated). The cylinder crankcase 2 may be constructed
in any adequate metallic alloy, well known in the state of the
art.
[0032] The cylinder 3 has an open end, inside which the piston is
lodged, and an opposite end (illustrated in FIG. 3), generally
metallic cylinder cap 10. The valve plate 4 is constructed in
metallic alloy, so as to operate jointly with at least one suction
valve, not illustrated, turned to the interior of the cylinder 3,
and with at least one discharge valve, which may take the form of a
single sheet 5 incorporating a plurality of flexible metallic
blades, not illustrated, each operating associated with a
respective discharge orifice (not illustrated) of the valve plate
4.
[0033] The valve plate 4 is seated on the cylinder crankcase 1 by
means of an annular sealing gasket, it being further provided
another annular gasket 7 disposed between the cylinder cap and the
adjacent face of the valve plate 4.
[0034] The cylinder cap 10 is seated against one face of the valve
plate 4, opposite to that seated against the cylinder crankcase 2.
The cylinder cap 10 defines, internally, with the adjacent face of
the valve plate 4, a gas discharge chamber 11, which maintains a
selective fluid communication with the cylinder 3, through the
discharge orifices, upon the opening of the discharge valve, and a
constant fluid communication with a discharge side of a
refrigeration system to which the compressor is associated, through
a discharge tube 20, which communicates said discharge chamber 11
to the gas outlet tube 1a hermetically affixed through the shell 1
of the compressor, and thence, to the outside of the latter. The
gas outlet tube 1a generally connects the discharge side of the
refrigeration compressor to a discharge line of a refrigeration
system to which the refrigeration compressor is operatively
associated.
[0035] The discharge tube 20 is obtained in a plastic and flexible
material, not thermally conductive, preferably in a polymeric
material such as, for example, a PTFE polymer
(polytetrafluoroethylene). Said polymeric material presents a
coefficient of thermal conductivity much lower than that of the
metallic alloys, imparting to coefficient, allowing reducing its
length, which reduces the load loss upon pumping the refrigerant
gas.
[0036] The cylinder cap 10 takes the form of a cup, with its open
base seated on the valve plate 4 and defining a gas inlet 12 in
fluid communication with the discharge orifice(s), and a gas outlet
13, to which is coupled the discharge tube 20.
[0037] The discharge tube 20 has an inlet end 21, coupled to the
gas outlet 13 of the cylinder cap 10, and an outlet end 22 coupled
to the gas outlet tube 1a of the shell 1.
[0038] In the illustrated construction, the cylinder cap 10 is
provided with an end wall 14, opposite to its open base and to the
valve plate 4 and in which is provided the gas outlet 13. However,
it should be understood that said gas outlet 13 may be provided
laterally in the cylinder cap 10, and that such positioning of the
gas outlet 13 is not limited to the construction illustrated.
[0039] In the particular illustrated construction, the cylinder cap
10 further presents a channel 16, provided in the end wall 14 and
which is disposed orthogonally to the gas outlet 13 of the cylinder
cap 10. In said particular illustrated construction, the end wall
14 presents a lowered portion 17, to the interior of which the
channel 16 is opened through the gas outlet 13,
[0040] In the illustrated construction, the outlet nozzle 13 of the
cylinder cap 10 is configured to receive and secure, in its
interior and by any adequate means, such as, for example,
threading, gluing, or brazing, a connecting element 30, having a
tubular body projecting outwards from the outlet nozzle 13, to be
coupled to the adjacent inlet end 21 of the discharge tube 20.
[0041] The illustrated connecting element 30 is formed in a single
piece, for example, in a metallic material. Nevertheless, it should
be understood that the present invention may be carried out with a
connecting element made of a plurality of pieces produced
separately and
[0042] According to the present invention, at least one of the
inlet end 21 and outlet end 22 of the discharge tube 20 is
connected to a discharge part, defined by the gas outlet 13 of the
cylinder cap 10 or by the gas outlet tube 1a of the shell 1,
through a respective connecting element 30.
[0043] The connecting element 30 presents a fixation portion 31, to
be affixed in the interior of the respective discharge part defined
by the gas outlet 13 of the cylinder cap 10, or by the gas outlet
tube 1a of the shell 1, and an engaging portion 32 to be fitted,
with interference, in the interior of one end of the discharge tube
20 adjacent to one of the parts of gas outlet 13 of the cylinder
cap 10 and gas outlet tube 1a of the shell 1.
[0044] The engaging portion 32 of the connecting element 30 carries
a superficial indexing means 33, which produces a corresponding
radial deformation 20a in the discharge tube 20, and at least one
gripping means 34, superficially disposed between the superficial
indexing means 33 and the fixation portion 31.
[0045] In order to maintain one end of the discharge tube 20
mounted to an adjacent connecting element 30, the arrangement of
the present invention further comprises a retaining ring 40,
provided around the end of the discharge tube 20 mounted to a
connecting element 30, said retaining ring 40 radially compressing
the end of the discharge tube 20, so as to spike, in said discharge
tube end, the gripping means 34 of the engaging portion 32 of the
connecting element 30.
[0046] The retaining ring 40 may be obtained in any material and
present any construction which allows it, when mounted around a
respective end of the discharge tube 20 already coupled to a
respective connecting element 30, to radially compress said end of
the discharge tube against the engaging portion of the connecting
element, pressing the gripping means 34 against the wall of the
discharge retaining ring 40 is metallic.
[0047] The superficial indexing means 33 is provided in the tubular
body of the connecting element 30, in a position spaced away from
the fixation portion 31, projecting radially outwardly from the
engaging portion 32.
[0048] In the first embodiment illustrated in FIGS. 6 and 6A, the
retaining ring 40 presents a radial extension dimensioned for
allowing it to be axially retained, in one direction, by the radial
deformation 20a of the end of the discharge tube 20 and, in an
opposite direction, by the fixation portion 31. In such
construction, the retaining ring 40 is axially retained between the
radial deformation 20a of the adjacent end of the discharge tube 20
and the fixation portion 31 of said connecting element 30.
[0049] Thus, the retaining ring 40 has its opposite end edges 40a,
40b respectively seated against the radial deformation 20a and
against the fixation portion 31 of the connecting element 30.
[0050] In the illustrated constructive form, the superficial
indexing means 33 is defined by a circumferential rib 33a having a
cross section in the form of a convex arc.
[0051] Also as illustrated in FIGS. 6 and 6A, the retaining ring 40
may incorporate, externally, a stop element B generally defined by
a circumferential shoulder 41, against which may be seated a tool
(not illustrated) for inserting the retaining ring 40 around the
portion of the discharge tube 20 surrounding the engaging portion
32 of the connecting element 30. In said construction, the inner
face of the retaining ring 40 need not be compulsorily provided
with any superficial accident to cooperate with the radial
deformation 20a in the discharge tube 20.
[0052] In a second embodiment, illustrated in FIGS. 7 and 7A, the
retaining ring 40 presents an axial extension dimensioned so as to
allow the latter to extend beyond superficial indexing means 33. In
this case, the retaining ring 40 should be internally provided with
a circumferential groove 42 configured for housing, in its
interior, the radial deformation 20a of the adjacent end of the
discharge tube 20. In this construction, only the end edge 40b of
the retaining ring 40 is axially locked upon its seating against
the fixation portion 31 of the connecting element 30. The opposite
end edge 40a of the retaining ring 40 remains free, not being
seated against any retaining means. The axial locking of the
retaining ring 40, in the direction of the fixation portion 31 away
from the connecting element 30, is obtained by the radial
deformation 20a of the discharge tube 20 being housed in the
interior of the circumferential groove 42 of the retaining ring 40.
It should be understood that the cooperation between the radial
deformation 20a and the circumferential groove 42 may be achieved
so as to allow the relative axial locking, in both directions,
between the retaining ring 40 and the discharge tube 20. In this
case, the retaining ring 40 need not have its end edge 40b seated
against the fixation portion 31 of the connecting element 30.
[0053] The retaining ring 40 illustrated in FIGS. 7 and 7A may
further incorporate, externally, the stop element B which may take
the form of the already cited circumferential shoulder 41 against
which may be seated a tool (not illustrated) for inserting the
retaining ring 40 on the portion of the discharge tube 20
surrounding the engaging portion 32 of the connecting element 30.
Although not illustrated, the retention of the discharge tube to
the connecting element may be obtained by using a retaining ring
extending beyond the connecting element region provided with the
superficial indexing means 33, which could take the form of a
recessed superficial accident, such as a circumferential recess in
said connecting element, against which a portion of the compression
of the retaining ring. In this case, the retaining ring would be
provided with an internal circumferential rib which would coincide
with the deformation region of the discharge tube, obtained upon
being fitted in the circumferential recess of the connecting
element.
[0054] A described hereinafter, the superficial indexing means 33,
carried by the connecting element 30, guarantees the axial
retention of the retaining ring 40, in the direction away from the
fixation portion 31 of the connecting element 30, maintaining the
discharge tube 20 firmly affixed to the respective connecting
element 30 close to the cylinder cap 10 and/or close to the outlet
tube 1a of the shell 1.
[0055] The circumferential rib 33a must present a shape which
avoids, upon fixation of the retaining ring 40 to the discharge
tube 20, the occurrence of tensions on the discharge tube 20 during
operational and handling conditions of the compressor. As a result,
it should be understood that the convex form is only one way of
carrying out the invention, and, therefore, not considered as
limitative.
[0056] Upon mounting the discharge tube 20 to each connecting
element 30, one end of said discharge tube 20 is forced to pass
over the superficial indexing means 33 and, then, over the gripping
means 34, said end being forced in said fitting until reaching the
fixation portion 31 of the connecting element 30.
[0057] In said stage, the setting of the retaining ring 40
compresses the discharge tube 20 against the connecting element 30,
axially retaining said discharge tube 20 to the connecting element
30 by mechanical interference of the gripping means 34 against an
adjacent portion of the inner wall of the discharge tube 20.
[0058] The illustrated superficial indexing means 33 is dimensioned
to provoke a corresponding deformation of the said inner surface
reproduces the shape of said superficial indexing means 33,
producing the already mentioned radial deformation 20a. On the
other hand, the gripping means 34 is defined so as to cause only a
deformation in the inner surface of the discharge tube 20, said
deformation not being propagated to the outer surface of the
discharge tube 20.
[0059] The external radial deformation 20a in the discharge tube
defines an axial stop for the retaining ring 40, cooperating to
prevent the latter, after mounted, from being axially displaced
away from the fixation portion 31 of the connecting element 30 and
outside from the engaging portion 32 of the latter.
[0060] In the illustrated construction, the gripping means 34 is in
the form of a frusto-conical circumferential projection, with its
smaller base 34a coinciding with the contour of the engaging
portion 32 and with is larger base 34b defining an annular step
projecting outwardly from the engaging portion 32 and turned to the
fixation portion 31. As illustrated, the gripping means 34 may take
the form of a continuous annular projection. However, it should be
understood that said gripping means 34 may be defined by
projections in the form of tooth circumferentially distributed in
an annular arrangement, but spaced apart from each other, and that
the connecting element 30 may also present a plurality of
circumferential alignments of projections which define the gripping
means 34.
[0061] The gripping means 34 defines a radial mechanical engagement
which promotes an axial locking between the discharge tube 20 and
the engaging portion 32 of the connecting element 30, for avoiding
disconnection to occur between the parts of discharge tube 20 and
connecting element 30.
[0062] The engaging portion 32 has a free end 32a, and an opposite
end 32b joined to the fixation portion 31 and from the contour of
the engaging portion 32 and which is spaced away from the gripping
means 34.
[0063] In the illustrated construction, the stop means 35 is
defined by an annular flange affixed around the opposite end 32b of
the engaging portion 32.
[0064] For any one of the constructions above, the superficial
indexing means 33 is provided in the connecting element 30, in a
position away from the free end 32a of the engaging portion 32.
[0065] According to the present invention, the fixation portion of
the connecting element 30 is cylindrical and affixed, by adhesive,
to the respective discharge part, defined by the gas outlet 13 of
the cylinder cap 10 or by the gas outlet tube 1a of the shell 1.
However, it should be understood that the connecting element may be
affixed to the parts of cylinder cap or gas outlet tube of the
shell, through threading, welding, brazing, etc., said fixation
means not being considered as limitative to the present
invention.
[0066] Regarding the solution of affixing the connecting element 30
by threading to the part of cylinder cap 10 and/or gas outlet tube
1a of the shell 1, the fixation portion 31 of said connecting
element 30 should present an external thread 30a to be affixed to a
corresponding threaded portion provided in the respective discharge
part, defined in any one of the gas outlet 13 of the cylinder cap
10 and the gas outlet tube 1a of the shell 1.
[0067] It should be understood that the discharge arrangement of
the present invention may be carried out irrespective of the
constructive particularities of the cylinder cap 10, positioning
means, etc.
[0068] It should be further noted that the constructive variants
described herein may be presented individually, in particular
constructions, or also partially or totally combined to each
other.
[0069] The provision of the retaining ring between the fixation
superficial indexing means 33 avoids the concentration of tensions
on the external part of the discharge tube 20, reducing the risk of
fatigue and rupture of the discharge tube, resulting from the fact
that the latter is caused to move by the operational displacement
of the motor-compressor assembly in relation to the fixed hermetic
shell. In the proposed construction, said tensions are more
concentrated in the inner part of the discharge tube 20, when the
latter is submitted to the movement resulting from the compressor
operation.
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