U.S. patent application number 11/793871 was filed with the patent office on 2008-01-10 for hermetric refrigerant compressor.
Invention is credited to Hans Peter Schoegler.
Application Number | 20080008603 11/793871 |
Document ID | / |
Family ID | 36601407 |
Filed Date | 2008-01-10 |
United States Patent
Application |
20080008603 |
Kind Code |
A1 |
Schoegler; Hans Peter |
January 10, 2008 |
Hermetric Refrigerant Compressor
Abstract
The invention relates to a hermetically enclosed refrigerant
compressor having a hermetically tight compressor housing inside of
which a piston/cylinder unit that compresses a refrigerant operates
with a suction valve having a suction opening located in a valve
plate of the unit. A suction sound damper having a filling volume
is provided on the cylinder head of the piston/cylinder unit and
refrigerant flows to the suction valve of the piston/cylinder unit
via this suction sound damper. To this end, the suction sound
damper has an entry cross-section via which refrigerant flows into
the suction sound damper, and a compensation volume is provided,
which is connected to the suction sound damper and to the interior
of the compressor housing, and inside of which refrigerant
oscillates. The compensation volume equals 0.5 to 3 times the
displacement of the piston of the piston/cylinder unit.
Inventors: |
Schoegler; Hans Peter;
(Fehring, AT) |
Correspondence
Address: |
WILLIAM COLLARD;COLLARD & ROE, P.C.
1077 NORTHERN BOULEVARD
ROSLYN
NY
11576
US
|
Family ID: |
36601407 |
Appl. No.: |
11/793871 |
Filed: |
December 22, 2005 |
PCT Filed: |
December 22, 2005 |
PCT NO: |
PCT/EP05/57110 |
371 Date: |
June 21, 2007 |
Current U.S.
Class: |
417/312 |
Current CPC
Class: |
F04B 39/123 20130101;
F04B 39/0072 20130101; F04B 39/0061 20130101 |
Class at
Publication: |
417/312 |
International
Class: |
F04B 39/00 20060101
F04B039/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 22, 2004 |
AT |
GM 933/2004 |
Claims
1. A hermetically encapsulated refrigerant compressor, comprising a
hermetically sealed compressor housing (1), in the interior of
which a piston-cylinder unit works which compresses a refrigerant
and comprises an intake valve with an intake opening (24) arranged
in a valve plate of the same, with a muffler (16) being provided on
the cylinder head (15) of the piston-cylinder unit, which muffler
comprises a filling volume (20) and through which the refrigerant
flows to the intake valve of the piston-cylinder unit, and with the
muffler (16) having an inlet cross section (18) through which
refrigerant flows into the muffler (16) and with a compensating
volume (21) being provided which is in connection with the muffler
(16) and the interior of the compressor housing (1) and in which
the refrigerant oscillates, wherein the compensating volume (21)is
0.5 to 3 times the displacement of the piston of the
piston-cylinder unit.
2. A hermetically encapsulated refrigerant compressor according to
claim 1, wherein the smallest flow cross section (32) in the
compensating volume (21) has a cross-sectional surface area which
corresponds to 1/4 to 3/4 of the cross-sectional surface area of
the intake opening (24).
3. A hermetically encapsulated refrigerant compressor according to
claim 1, wherein the cross-sectional surface area of the
compensating volume (21) is at most 1.5 times the piston head
surface area of the piston of the piston-cylinder unit.
4. A hermetically encapsulated refrigerant compressor according to
claim 1, wherein the compensating volume (21) has a circular cross
section and the ratio of the length of the compensating volume (21)
to its diameter is higher than 10.
5. A hermetically encapsulated refrigerant compressor according to
claim 1, wherein the compensating volume (21) is formed by a
compensating pipe (22) which has a substantially U-shaped cross
section and wraps around the muffler (16) at least partly.
6. A hermetically encapsulated refrigerant compressor according to
claim 1, wherein the connection of the inlet cross section (18) of
the muffler (16) with the suction pipe (17) is an elastic plastic
hose (19) made of PTFE, acrylonitrile, butadiene or fluorinated
rubber.
7. A hermetically encapsulated refrigerant compressor according to
claim 6, wherein the elastic plastic hose is a bellows.
8. A hermetically encapsulated refrigerant compressor according to
claim 1, wherein the suction pipe (17) is provided with barbs.
9. A hermetically encapsulated refrigerant compressor according to
claim 1, wherein the suction pipe (17) is provided with latching
elements which cooperate with respective latching elements on the
plastic hose (19).
10. A hermetically encapsulated refrigerant compressor according to
claim 1, wherein the inlet cross section (18) and the connecting
opening (26) between compensating volume (21) and filling volume
(20) are arranged in different sections of the muffler housing.
11. A hermetically encapsulated refrigerant compressor according to
claim 1, wherein the inlet cross section (18) is simultaneously the
connecting opening (26) between compensating volume (21) and
filling volume (20).
12. A hermetically encapsulated refrigerant compressor according to
claim 11, wherein the compensating volume (21) is formed by an
encasing pipe (34) which tightly encloses the intake opening (24)
and the inlet cross section (18) respectively on the one hand and
encloses the suction pipe (17) of the refrigerant at least along a
section and faces into the compressor housing (1) on the other
hand, which suction pipe is connected with the evaporator of the
refrigerant compressor and protrudes into the interior of the
compressor housing (1).
13 A hermetically encapsulated refrigerant compressor according to
claim 12, wherein the suction pipe (17) is guided close to the
intake opening (24)in the encasing pipe (34).
14. A hermetically encapsulated refrigerant compressor according to
claim 12, wherein the encasing pipe (34) and the muffler (16) have
an integral configuration.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a hermetically encapsulated
refrigerant compressor, comprising a hermetically sealed compressor
housing, in the interior of which a piston-cylinder unit works
which compresses a refrigerant, on the cylinder head of which a
muffler is arranged through which the refrigerant flows to the
intake valve of the piston-cylinder unit, according to the preamble
of claim 1.
STATE OF THE ART
[0002] Such refrigerant compressors have long been known and are
predominantly used in refrigerators and cooling shelves. The
annually produced number is accordingly very high.
[0003] Although the power consumption of an individual refrigerant
compressor is only approximately between 50 and 150 watts, there is
a very high power consumption when regarding all refrigerant
compressors used worldwide, which consumption increases
continuously as a result of the rapidly progressing development in
poorer countries as well.
[0004] Any technical improvement made to a refrigerant compressor
and increasing the efficiency thus offers an enormous potential for
saving energy when extrapolating the refrigerant compressors used
worldwide.
[0005] The refrigerant process as such has long been known. The
refrigerant is heated in the compressor by taking up energy from
the space to be cooled and finally overheats and is pumped by means
of the refrigerant compressor to a higher pressure level where it
emits heat via a condenser and is conveyed back to the evaporator
via a throttle where there is a pressure reduction and a cooling of
the refrigerant.
[0006] The largest and most important potential for a possible
improvement of efficiency lies in the lowering of the temperature
of the refrigerant at the beginning of its compression process.
Every lowering of the intake temperature of the refrigerant into
the cylinder of the piston-cylinder unit leads to a reduction of
the required technical work for the compression process, as does
the lowering of the temperature during the compression process and,
in connection with the same, the push-out temperature.
[0007] In known hermetically encapsulated refrigerant compressors
there is a strong heating of the refrigerant on its path from the
compressor (cooling space) to the intake valve of the
piston-cylinder unit as a result of the design.
[0008] The intake of the refrigerant occurs via a suction pipe
coming directly from the compressor during an intake stroke of the
piston-cylinder unit. In known hermetically encapsulated
refrigerant compressors, the suction pipe usually opens into the
hermetically encapsulated compressor housing, mostly close to the
inlet cross section into the muffler, from where the refrigerant
flows into the muffler and from the same directly into the intake
valve of the piston-cylinder unit. The muffler is used primarily to
keep the noise level of the refrigerant compressor as low as
possible during the intake process. Known mufflers usually consist
of several volumes which are in connection with each other and an
intake cross section through which the refrigerant is sucked from
the hermetically encapsulated compressor housing volume into the
interior of the muffler and an opening which lies close to the
intake valve of the piston-cylinder unit.
[0009] On the way between the entrance of the refrigerant into the
compressor housing and the intake valve of the piston-cylinder unit
there is (as already mentioned) an undesirable heating of the
refrigerant. Measurements have shown that at a refrigerant
temperature of 32.degree. C. in the suction pipe (predetermined by
standardized ASHRAE conditions) the refrigerant was heated already
in the first muffler volume to a temperature of approx. 54.degree.
C. already shortly before entering the compressor housing. The
cause for this undesirable heating of the refrigerant is the fact
that the refrigerant freshly flowing from the suction pipe to the
compressor housing is mixed with warmer refrigerant already
situated in the compressor housing. The mixture is principally
caused in such a way that the intake valve of the piston-cylinder
unit is merely open over a crank angle range of approx. 180.degree.
per cycle and that refrigerant can be drawn into the cylinder of
the refrigerant compressor merely within this time window. The
intake valve is closed thereafter, during the compression cycle.
The cold refrigerant has a virtually constant mass flow, even when
the intake valve is closed, as a result of which it flows in from
behind into the compressor housing and dwells there and cools the
piston-cylinder unit in motion and its components, which again
causes a heating of the refrigerant. As a result of the pressure
oscillations during the compression phase, there are further flow
processes from the compressor housing to the muffler and
vice-versa, which thus causes an additional mixing.
[0010] In order to prevent this thorough mixture of warm
refrigerant from the interior of the compressor housing with
refrigerant freshly coming from the evaporator, the outlet of the
suction pipe for the refrigerant is placed in known refrigerant
compressors close to the inlet cross section of the muffler. This
ensures that a relatively low amount of cold refrigerant can escape
from the evaporator into the interior of the compressor housing.
Subsequently, the suction pipe end was configured in such a way
that an intermediate pipe could be inserted into the same. At the
same time, the intermediate pipe was enclosed by a spiral spring
which rests on the one hand on the entrance of the suction pipe
into the housing and on the other hand on the intermediate pipe in
order to achieve a linkage of the suction pipe to the muffler. All
these known efforts to prevent a mixture of the cold refrigerant
from the evaporator with the heated refrigerant in the interior of
the compressor housing have merely caused a reduction in this
mixing, but not a complete prevention.
[0011] It is known from WO 03/038280 to directly connect the inlet
cross section of the muffler with the outlet of the suction pipe,
so that refrigerant coming from the evaporator is guided directly
into the muffler without reaching the interior of the compressor
housing and without being heated there. As a result of the already
mentioned fact that the cold refrigerant has a nearly constant mass
flow even when the intake valve is closed and flows into the
muffler (now via the direct connection), it is then necessary
however to provide a compensating volume in the muffler in order to
compensate a pressure rise in the muffler as a result of the
refrigerant that is continuously flowing in and through which
refrigerant contained in the muffler can flow out of the same again
into the compressor housing. During the next intake stroke, the
refrigerant situated in the muffler or flowing from the suction
pipe into the muffler is drawn into the piston-cylinder unit via
the intake valve on the one hand, and refrigerant situated in the
interior of the compressor housing is drawn into the compensating
volume for pressure compensation (as a result of leakage from the
piston-cylinder unit and by the mentioned flow-out from the
muffler) on the other hand.
[0012] The flow conditions occurring thereby, especially during the
overflow into the compensating volume which would not occur without
a direct connection of the suction pipe with the muffler, lead to
the likelihood of increased flow losses.
SUMMARY 0F THE INVENTION
[0013] It is therefore the object of the present invention to avoid
this disadvantage and to provide a refrigerant compressor of the
kind mentioned above in which the refrigerant temperature is kept
as low as possible at the beginning of the compression process and
thus necessarily also during the intake into the cylinder of the
piston-cylinder unit, with flow losses during the intake being
avoided to the highest possible extent. It is a further object of
the invention that the pressure fluctuations occurring in the
interior of the compressor housing and in the muffler and the noise
level during the overflow into compensating volume are kept as low
as possible.
[0014] This is achieved in accordance with the invention by the
characterizing features of claim 1.
[0015] By creating a compensating volume with a volume which
amounts to 0.5 to 3 times the displacement of the piston of the
piston-cylinder unit, it is guaranteed that the refrigerant coming
from the suction pipe will not reach the compressor housing even
when the intake valve is closed and will mix there with already
heated refrigerant. It is guaranteed at the same time that during
the intake process no refrigerant is drawn from the compressor
housing via the compensating volume into the muffler or into the
cylinder.
[0016] In addition, the noise development can be minimized which is
caused with the creation of the compensating volume by the flow
processes into the compensating volume and into the compressor
housing, so that there will not be any disturbing noise for the
operator, which is an especially important feature for household
refrigerators. Furthermore, a slightly larger compensating volume
can be produced more easily during manufacturing.
[0017] In accordance with the characterizing features of claim 2 it
is provided that the smallest cross section in the compensating
volume has a cross-sectional surface area which corresponds to 1/4
to 3/4 of the cross-sectional surface area of the intake opening.
This ensures that the pressure difference will become small, the
flow losses will decrease and the noise damping increases to the
outside.
[0018] According to the characterizing feature of claim 3, the
cross section of the compensating volume can correspond at most to
1.5 times the piston head surface area. This ensures that on the
one hand the need for space for the compensating volume will not
become too high and it is ensured on the other hand that cold and
hot suction gas will not mix or form the boundary layer as
described below.
[0019] The characterizing features of claim 4, according to which
the compensating volume has a circular cross section and the ratio
of the length of the compensating volume to its diameter is higher
than 10, describe a preferred embodiment which leads to especially
low flow losses.
[0020] In order to achieve the most compact configuration of the
muffler despite the additional compensating volume, the
characterizing features of claim 5 are provided, according to which
the compensating volume is formed by a compensating pipe which has
a substantially U-shaped cross section and wraps around the muffler
at least partly.
[0021] The characterizing features of claims 6 to 9 describe a
preferred embodiment of the connection of suction pipe and inlet
cross section into the muffler.
[0022] The characterizing features of claims 10 and 11 describe two
different embodiments of a hermetically encapsulated refrigerant
compressor, in which the inlet cross section into the muffler and
the transition from muffler to compensating volume is arranged once
separately and. once coincidentally. Depending on the need for
space in the interior of the compressor housing, the most
advantageous embodiment must be chosen. In the case where the inlet
cross section into the muffler and the transition from muffler to
compensating volume coincide, a further preferred embodiment
according to the characterizing features of claims 12 to 14 are
provided. This embodiment comes with the advantage that a tight
connection between suction pipe and muffler is not necessary.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] The invention will now be explained in closer detail by
reference to the drawings, wherein:
[0024] FIG. 1 shows a front view of a hermetically encapsulated
refrigerant compressor in accordance with the invention with a
compressor housing in a sectional view;
[0025] FIG. 2 shows a sectional side view of a refrigerant
compressor hermetically encapsulated in accordance with the
invention;
[0026] FIG. 3 shows a front view of a refrigerant compressor
hermetically encapsulated in accordance with the invention;
[0027] FIG. 4 shows a sectional view of a muffler in accordance
with the state of the art;
[0028] FIG. 5 shows a further sectional view of a known
muffler;
[0029] FIG. 6 shows a sectional view of a muffler in accordance
with the invention with a closed intake valve;
[0030] FIG. 7 shows a sectional view of a muffler in accordance
with the invention with an opened intake valve;
[0031] FIG. 8 shows an oblique view of the muffler in accordance
with the invention in the compressor housing;
[0032] FIG. 9 shows an alternative embodiment of a muffler in
accordance with the invention;
[0033] FIG. 9a shows a further alternative embodiment of a muffler
in accordance with the invention;
[0034] FIG. 10 shows an additional alternative embodiment of a
muffler in accordance with the invention;
[0035] FIG. 11 shows a detailed view of a hermetically sealed
connection between muffler and suction pipe;
[0036] FIG. 12 shows a detailed view of an alternative embodiment
of a hermetically sealed connection between muffler and suction
pipe;
[0037] FIG. 13 shows a detailed view of a further alternative
embodiment of a hermetically sealed connection between muffler and
suction pipe;
[0038] FIG. 14 shows a detailed view of a connection between a
plastic hose with a suction pipe;
[0039] FIG. 15 shows a detailed view of a connection of a plastic
hose with a suction pipe;
[0040] FIG. 16 shows a detailed view of a connection of a plastic
hose with a suction pipe;
[0041] FIG. 17 shows a detailed view of a connection of a plastic
hose with a suction pipe;
[0042] FIG. 18 shows a detailed view of a connection of a plastic
hose with a suction pipe;
[0043] FIG. 19 shows an oblique view of an alternative muffler in
accordance with the invention;
[0044] FIG. 20 shows a further oblique view of the muffler of FIG.
19 in accordance with the invention;
[0045] FIG. 21 shows a sectional view of the muffler of FIG. 19 in
accordance with the invention;
[0046] FIG. 22 shows a further sectional view of the muffler of
FIG. 19 in accordance with the invention.
[0047] FIGS. 1, 2 and 3 each show a sectional view through a
hermetically encapsulated refrigerant compressor, with FIGS. 1 and
3 each showing a view in the direction of arrow A of FIG. 2. A
piston-cylinder motor unit is elastically held by means of springs
2 in the interior of a hermetically sealing compressor housing
1.
[0048] The piston-cylinder-motor unit substantially consists of a
cylinder housing 3 and the piston 4 performing a lifting movement
therein, and a crankshaft bearing 5 which is arranged perpendicular
to the cylinder axis 6. The crankshaft bearing 5 receives a
crankshaft 7 and protrudes into a centric bore 8 of rotor 9 of an
electromotor 10. A connecting rod bearing 12 is situated at the
upper end of crankshaft 7, through which the connecting rod and
consequently the piston 4 are driven. The crankshaft 7 comprises a
lubricating oil bore 13 and is fixed to rotor 9 in the area 14. The
muffler 16 is arranged on the cylinder head 15, which muffler is to
reduce noise development to a minimum during the intake process of
the refrigerant.
[0049] FIG. 4 shows a sectional view of a muffler 16 according to
the state of the art. As is already shown in FIGS. 1, 2 and 3, the
muffler 16 is arranged on the cylinder head 15 in the interior of
the hermetically sealed compressor housing 1. The refrigerant
coming from the evaporator, which refrigerant is cold in comparison
with the warm refrigerant situated in the compressor housing 1,
flows via a suction pipe 17 into the interior of the compressor
housing 1 close to the inlet cross section 18 of the muffler 16
when such a known muffler 16 is used, where it mixes with the warm
refrigerant already situated in the compressor housing 1 and is
heated up and is drawn into the piston-cylinder unit via the
muffler 16.
[0050] Mufflers 16 according to the state of the art usually
consist of several successively connected and/or parallel connected
volumes V1, V2, V.sub.n which are connected via pipes with each
other, and of an oil separator opening 31 at the lowest point. The
cold refrigerant flows via suction pipe 17 into the interior of the
compressor housing 1 where as a result of its configuration a first
thorough mixing with the warm refrigerant occurs which is already
situated in the compressor housing 1. The already mixed and heated
refrigerant then flows through the inlet cross section 18 into the
first volume V1 and then into the second volume V2 of the muffler
16 and mixes again with the warm refrigerant already situated both
in V1 as well as V2, as a result of which there is a renewed
heating of the refrigerant. In these known mufflers, the heating
between the outlet from suction pipe 17 and shortly before the
intake opening 24 in the muffler 16 is between 30K and 40K,
depending on the output of the refrigerant compressor.
[0051] FIG. 5 shows a muffler 16 which is also known from the state
of the art, namely from WO03/038280, whose inlet cross section 18
is tightly connected with the suction pipe 17. The cold refrigerant
coming from the suction pipe 17 is unable to mix with the warm
refrigerant situated in compressor housing 1 before it is drawn
into the muffler 16. A compensating volume 21 is connected to the
muffler 16, through which the pressure compensation can occur which
is required as a result of the direct connection of the muffler 16
with the suction pipe 17, such that a connection exists both to the
muffler 16 as well as into the interior of the compressor housing.
The required pressure compensation leads to flow states of the
refrigerant which can lead to the flow losses which offset the gain
in energy which is achieved by the reduction of the refrigerant
temperature at the beginning of the compression phase.
[0052] In order to avoid or minimize these flow losses, it is
necessary to arrange the compensating volume 21 in such a way that
the energy loss caused by the additionally occurring flow losses is
lower than the energy gain achieved by the improved suction. An
embodiment of a muffler in accordance with the invention is shown
in FIG. 6. Muffler 16 is shown in FIG. 6 in a sectional view. FIGS.
1, 2 and 3 also show refrigerant compressors with such a muffler 16
in accordance with the invention. The inlet cross section 18 of
muffler 16 is connected with the suction pipe 17 via a
schematically shown, hermetically sealed connection 19. A tight
connection 19 can principally be any preferably elastic connection
as known to the person skilled in the art, such as a simple rubber
tube which needs to be connected in a tight manner with the muffler
16 and the suction pipe 17. Examples for such connections are shown
in FIG. 11 to FIG. 18. The muffler 16 in accordance with the
invention delimits a filling volume 20 (with the arrangement of
several filling volumes being possible and done). Adjacent to the
muffler 16, a compensating volume 21 is arranged which is formed by
a U-shaped compensating pipe 34. The illustrated U-shaped
compensating pipe 34 offers the advantage of limiting a sufficient
compensating volume 21 and of requiring only little additional
space, and of producing the required flow conditions which minimize
the mentioned losses. The compensating volume 21 and the
compensating pipe 34 are in connection via a compensating opening
23 with the interior of the compressor housing 1 and with the
filling volume 20 of the muffler 16 via the transition opening
26.
[0053] FIG. 6 shows the flow progress of the refrigerant with
closed intake valve by means of arrows, which valve is situated
behind the intake opening 24 of the muffler 16 on the side of the
valve plate facing the piston.
[0054] The cold refrigerant flowing from the suction pipe 17 flows
via the tight connection 19 to the muffler volume 20 and from there
into the compensating volume 21, as a result of which the warmer
refrigerant situated there is pressed from the compensating pipe 34
via the compensating opening 23 into the interior of the compressor
housing 1. The line indicated with reference numeral 25 symbolizes
the boundary layer which forms between the cold and warm
refrigerant.
[0055] FIG. 7 shows the same muffler 16 in accordance with the
invention, plus flow progress with opened intake valve. In this
case, the refrigerant is drawn in both from the compensating volume
21 and from the filling volume 20 and the suction pipe 17. Since
the refrigerant in the compensating volume 21 has a lower
temperature than the warm refrigerant situated in the interior of
the compressor housing 1, the mixing temperature of the
refrigerants from the mentioned intake regions is lower than the
mixing temperature of the refrigerants when using mufflers known
from the state of the art, as a result of which the aforementioned
undesirable temperature increase is prevented. As a result of the
inventive feature that the compensating volume 21 has 0.5 to 3
times the lifting volume of the piston of the piston-cylinder unit,
warm refrigerant is unable to flow from the interior of the
compressor housing into the muffler, which in this embodiment is
volume 20. Due to the fact that the smallest flow cross section 32
has a cross-sectional surface area in the compensating volume 21
which corresponds to 1/4 to 3/4 of the cross-sectional surface area
of the intake opening 24, it is ensured that the pressure
difference between muffler 16 and the interior of the compressor
housing 1 is low and at the same time the noise damping in the
interior of the compressor housing is high. An enlargement of the
compensating volume also contributes to this, with the same being
at least half, preferably 0.5 to 3 times the displacement of the
piston of the piston-cylinder unit.
[0056] At the same time, the flow losses are minimized by the
muffler in accordance with the invention and the refrigerant can
easily flow into the compensating volume or from the same without
negatively influencing the refrigerant process.
[0057] For the purpose of better clarity, FIG. 8 shows an oblique
view of the muffler 16 in accordance with the invention in the
compressor housing 1 without the piston-cylinder motor unit.
[0058] FIG. 9 shows an alternative embodiment of a muffler 16 in
accordance with the invention, plus compensating volume 21. The
compensating volume 21 and the muffler 16 are formed by an encasing
pipe 34 which encases the intake opening 24 on the one hand and
opens into the same, and encases an end section of the suction pipe
17 along a section on the other hand. The cold refrigerant flowing
from the suction pipe 17 flows during the entire intake cycle into
the section of the encasing pipe 34 forming the filling volume 20
of the muffler 16. In the subsequent compression cycle, the filling
volume 20 of the muffler 16 can no longer receive any further
refrigerant from the suction pipe 17 as a result of the closed
intake valve, which is why the refrigerant flows back into the
compensating volume 21 which is also formed by a section of the
encasing pipe 34 and displaces the warm refrigerant contained
therein via the compensating opening 23 into the interior of the
compression housing 1.
[0059] As already described in FIGS. 5 and 6, this leads to the
formation a boundary layer 25 between warm and cold refrigerant,
which layer is movable depending on the intake cycle. During the
next intake cycle, cold refrigerant can be drawn into the cylinder
both from the suction pipe 17 as well as from the compensating
volume 21 of the encasing pipe 34. The relevant aspect is that the
boundary layer does not exceed the line designated with reference
numeral 33, which in this embodiment simultaneously forms the inlet
cross section 18 into the muffler 16 and the transitional opening
26, in the direction of intake opening 24 in order to prevent a
thorough mixture of warm and cold refrigerant prior to the intake
process.
[0060] At the same time, no cold refrigerant is allowed to be
displaced from the suction pipe 17 from the compensating volume 21
into the compressor housing 1. The boundary layer 25 must thus not
be displaced behind the line marked in FIG. 9 with reference
numeral 23 (compensating opening). Irrespective of the embodiment,
a precise adjustment of the volume of the compensating volume 21 to
the refrigerating output and thus to the displacement of the
piston-cylinder unit is necessary.
[0061] FIG. 9a shows a further alternative embodiment of a muffler
16 plus compensating volume 21, in which the muffler 16 is provided
with an additional volume 20 in comparison with that of FIG. 9. In
all other respects this variant is identical to the one shown in
FIG. 9.
[0062] FIG. 10 shows an additional alternative embodiment of a
muffler 16 in accordance with the invention. The reference numerals
were maintained accordingly. As can be seen on the basis of the
large number of different designs, the configuration of the
compensating volume can principally be chosen freely as long as the
features of compensating volume 21 in accordance with the invention
which is situated upstream of the outlet opening of suction pipe 17
are maintained concerning its volume and the smallest flow cross
section 32. Only then will optimal energy savings be achieved and
the efficiency of the refrigerant compressor will be improved
accordingly.
[0063] The question as to how the different compensating volumes 21
and the mufflers 16 are arranged is of lower importance as long as
the features in accordance with the invention are realized and the
gas column and the boundary layer 25 is allowed to oscillate in the
compensating volume.
[0064] The muffler 16 in the embodiment according to FIG. 9 merely
consists of a filling volume 20 which extends in a substantially
conical manner, and in the embodiment according to FIG. 9a of a
filling volume 20a extending in a substantially conical manner and
of the filling volume 20, and in the embodiment according to FIG.
10 of the volumes V2 and V1. It is understood that the parallel or
serial arrangement of additional volumes of the muffler 16 is
possible at any time and leads to improved sound-damping properties
of the muffler 16.
[0065] In the embodiment according to FIG. 9, the compensating
volume 21 consists of a cylindrical volume. In the embodiment
according to FIG. 9a, it also consists of a cylindrical volume and
in the embodiment according to FIG. 10 of the volumes 21a and 21b .
The further arrangement of the compensating volumes, whether
parallel or serial, is obviously possible, with the same
contributing to sound damping, like 21b for example. The smallest
flow cross section 32 in accordance with the invention can be
realized either by a baffle as in FIG. 9, 9a and 10, or by a
spatial constriction as shown in FIG. 3. Alternatively, the entire
compensating volume 21 can have a constant cross section with the
features in accordance with the invention.
[0066] FIGS. 11 to 18 show different embodiments of the
hermetically sealed connection from suction pipe 17 to muffler 16
in accordance with the invention. Only when this connection is
actually tight, which means in other words that no warm refrigerant
is drawn from the compressor housing 1 into the muffler 16, the
compensating volume 21 will show its optimal effect, if it concerns
an embodiment as described in FIG. 6 and FIG. 7.
[0067] The simplest connection is shown in FIG. 11. In this case,
the elastic bellows 19 is merely pushed over the suction pipe 17
without any additional fixing, but preferably glued.
[0068] FIGS. 12 and 13 show a more complex but stable
connection.
[0069] In FIG. 12, the wall of the compressor housing 1 comprises
an inwardly facing nose 28 over which the elastic plastic hose 19
is pushed, which nose simultaneously protrudes into the inlet cross
section 18 of the muffler 16. The plastic hose 19 which can also be
arranged as an elastic pipe is enclosed by a spiral spring 27 which
ensures required stability and fixing. An 0-ring 29 is each
arranged both in the area of the nose 28 as well as in the area of
the inlet cross section 18, which ring ensures the required
tightness.
[0070] In FIG. 13, the muffler 16 also comprises a respective nose
protruding into the interior of the compressor housing 1.
[0071] FIGS. 14 to 18 show different fastening possibilities 30
between elastic connecting means 19 and suction pipe 17 which can
be arranged either as a toothing (FIG. 17, FIG. 18) or as barbs
(FIG. 16) arranged on the elastic connecting means, or as simple
shoulders (FIG. 14, FIG. 15).
[0072] In an embodiment of the compensating volume 21 including
muffler 1 as described in FIGS. 9, 9a and 10, lacks the requirement
of such a tight connection between muffler 16 and suction pipe 17
for the reasons as described above.
[0073] FIG. 19, FIG. 20, FIG. 21 and FIG. 22 show a further
embodiment of a muffler 16 plus compensating volume 21 as already
schematically described in FIGS. 9, 9a and 10. The suction pipe 17
is guided close to the inlet cross section 18 of the muffler 16.
The inlet cross section 18 is connected by means of a plastic hose
19 tightly with the suction pipe 17.
[0074] The remaining parts of the refrigerant compressor were not
drawn for reasons of clarity in FIG. 19, FIG. 20, FIG. 21 and FIG.
22.
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