Note: Descriptions are shown in the official language in which they were submitted.
13~ 37~5
A FLOATING FRAME MOUNTING SYSTEM
AND METHOD FOR A REFRIGERATOR
The present invention relates to a refrigerator
having a refrigerator frame and a compressor, and more
particularly, to a floating frame mounting system disposed
between the housing of the compressor and the refrigerator
frame to reduce the amount of vibration transmitted from the
compressor to the refri~erator frame and thus reduce the
lo noise generated by such vibration.
To enable the prior art to be described with the aid
of a diagram, the figures of drawings will first be listed.
FIG. 1 is a perspective view of a refrigerator cut
away to illustrate the location of the mounting system of
the present invention;
FIG. 2 is a perspective view of a prior art
compressor housing mounting system for a refrigerator;
FIG. 3 is a spring mass diagram for a mounting
system of the present invention;
FIG. 4 is a graph illustrating the transmissibility
of a spring mass system as a function of frequency for three
values of B;
FIG. 5 is a perspective view of a first embodiment
of the present invention;
FIG. 6A is a diagram illustrating a rear view of
FIG. 5;
FIG. 6B is a diagram illustrating a side view of
FIG. 5;
FIG. 7 is a perspective view of a second embodiment
of the present invention;
FIG. 8A is a diagram illustrating a rear view of
FIG. 7; and
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FIG. 8B is a diagram illustrating a side view of
FIG. 7.
Known refrigerators typically include a compressor
which transmits vibration to the frame of the refrigerator
thereby generating undesirable noise. One known
refrigerator, as shown in FIG. 2, includes a reciprocating
compressor with metal springs resiliently mounting the
compressor in a compressor housing 10. Rubber isolators,
only three of which, 11, 12 and 13, are shown, resiliently
secure the compressor housing 10 to a pair of support rails
14 and 16. The rails 14 and 16 also support a condenser
coil 17 for the refrigerator, the condenser 17 being rigidly
secured to the support rails 14 and 16. Respective ends 18
and 19 of the support rails 14 and 16 are rigidly secured to
a cross rail 20 that, in turn, is rigidly secured to the
front of the refrigerator frame. Similarly, respective ends
22 and 23 of the support rails 14 and 16 are rigidly secured
to a cross rail 24 that, in turn, is rigidly secured to the
rear of the refrigerator frame. The transmissibility of
vibration from the compressor to the refrigerator frame for
the configuration of the compressor mounting system shown in
FIG. 2 generates noise at a high, undesirable level.
In accordance with the present invention, the
disadvantages of the prior art refrigerator compressor
housing mounting systems have been overcome hy the provision
in a refrigeration apparatus having a refrigerator frame, a
compressor mounting system having multiple degrees of
freedom comprising: a compressor housing; a compressor
resiliently mounted in said compressor housing, said
compressor having a first mass; a condenser; a support frame
on which is rigidly secured said compressor housing and said
condenser, said support frame, said compressor housing and
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said condenser having a second mass; and mounting means for
resiliently mounting said support frame on said refrigerator
frame to provide a multiple degree of freedom mounting
system with said second mass being greater than said first
mass so that radiated noise of the refrigeration apparatus
at the running speed of the compressor is reduced.
In one embodiment of the present invention, the
support frame includes a pair of support rails and the
refrigerator includes a pair of cross rails. A first end of
each of the support rails is resiliently mountad on one of
the cross rails, whereas a second end of each of the support
rails is resiliently mounted on the other of the cross
rails.
In a second embodiment of the present invention, the
support frame includes a pair of support rails and at least
one cross rail. The refrigerator frame also includes a
cross rail which is rigidly secured thereto. A first end of
each of the support rails is rigidly secured to the support
frame cross rail whersin the support frame cross rail is
resiliently secured to the refrigerator frame. A second end
of each of the support rails is resiliently secured to the
refrigerator frame cross rail.
The invention also consists of a method of
minimizing vibration transmitted by a compressor in a
refrigeration apparatus to the frame of the refrigeration
apparatus, the compressor having a first mass, comprising
the steps of: providing a compressor housing for resiliently
mounting said compressor therein; providing a support frame
for supporting said compressor housing and a condenser;
establishing a second mass by rigidly securing said
compressor housing and said condenser to said support frame;
and resiliently mounting said support frame to said
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refrigeration apparatus frame to provide a multiple degree
of freedom mounting system with said second mass being
greater than said first mass such that radiated noise of the
refrigeration apparatus at the running speed of the
compressor is reduced.
The mounting system of the present invention
substantially reduces the amount of vibration transmitted
from the refrigerator's compressor to the refrigerator
frame, and thus the amount of noise generated thereby, by
increasing the effective mass of the compressor housing to
include the mass of the refrigerator's condenser as well as
the mass of the floating frame mounting system.
A refrigerator 30, as shown in FIG. 1, constructed
in accordance with the principles of the present invention
includes a refrigerator frame or shell 32, a reciprocating
compressor resiliently mounted by means of metal springs in
a compressor housing 34, a condenser coil 36 and a mounting
system, generally designated 38. As shown in greater detail
in FIG. 5, the compressor housing 34 and condenser 36 are
rigidly secured to the mounting system 38 which is, in turn,
resiliently mounted on a front cross rail 40 and on a rear
cross rail 42. The front and rear cross rails 40 and 42 are
rigidly secured to the respective front and back of the
refrigerator frame 32. As will be seen from the following
discussion of FIGS. 3 and 4, by rigidly securing the
compressor housing 34 to the mounting system 38 that also
supports the condenser 36, and by further resiliently
securing the mounting system 38 to the refrigerator frame
32, the amount of vibration transmitted from the compressor
contained within the housing 34 to the refrigerator frame 32
is substantially less than the amount of vibration
transmitted to the refrigerator frame for the prior art
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mounting system ~epicted in FIG. 2.
FIG. 3 is a spring mass diagram for a system having
two degrees of freedom with a first mass, Ml and a second
mass, M2. In both the systems of the prior art shown in
FIG. 2 and of the present invention illustrated in FIGS. 1,
5 and 7, Ml represents the mass of the refrigerator's
compressor. The constant Kl represents the spring constant
associated with the metal springs which resiliently mount
the compressor in its housing, housing 10 for the prior art
and housing 34 for the system of the present invention. For
the prior art system shown in FIG. 2, the mass M2 represent
the mass of the compressor housing 10 whereas the constant
K2 represents the spring constant associated with the rubber
isolators 11-13 which resiliently secure the compressor
housing 10 to the support rails 14 and 16 of the prior art
mounting system. For the mounting system of the present
invention illustrated in FIGS. 1, 5 and 7, the mass M2
represents the effective mass of the compressor, i.e., the
sum of the masses of the compressor housing 34, the
con~enser 36 and the mounting system 38, whereas the
constant K2 represent the spring constant associated with
the apparatus that resiliently secures the mounting system
38 to the frame of the refrigerator 32 as discussed in
detail below with reference to FIGS. 5 and 7. A ratio, B,
equal to the ratio of M2 to Ml, is much greater for the
system of the present invention shown in FIGS. 1, 5 and 7
than it is for the prior art system shown in FIG. 2 since
the effective mass of the compressor housing M2 for the
system of the present invention is much greater than that of
the prior art.
FIG. 4 illustrates the transmissibility of a system
with two degrees of freedom as a function of the frequency
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ratio of the system for various values of the mass ratio, ~,
wherein the frequency ratio represents the ratio of the
frequency of the driven system to the natural frequency of
the system. As is seen in FIG. 4, at the frequency ratio of
interest, 13.4, the transmission of vibration from the
excitation of the mass Ml to the frame resiliently
supporting the mass M2 decreases as the mass ratio B
increases. Therefore, by increasing the effective mass of
the compressor housing M2 to increase the mass ratio B, the
system of the present invention decreases the amount of
vibration transmitted from the compressor to the
refrigerator frame 32 and thus decreases the amount of noise
generated thereby.
The mounting system 38 of the present invention, as
shown in greater detail in FIGS. 5, 6A and 6B includes a
pair of support rails 50 and 52 to which the compressor
housing 34 is rigidly secured. The condenser 36 is also
mounted across the support rails 50 and 52 and rigidly
secured thereto. Rubber isolators, such as rubber grommets
56, 57, 58 and 59 are disposed between respective ends 60,
61, 62 and 63 of the support rails 50 and 52 and the cross
rails 40, 42 to resiliently mount the support rails 50 and
52 to the cross rails 40 and 42 of the refrigerator frame
32. The ends 60-63 of the support rails 50 and 52 and the
rubber grommets 56-59 are secured to the cross rails 42 and
40 by respective bolts 64, 6S, 66 and 67 extending through
apertures in the ends 60-63, grommets 56-59 and cross rails
42 and 40. Because the compressor housing 34 and condenser
36 are rigidly secured to the support rails 50 and 52 of the
mounting system 38, and the mounting system 38 is
resiliently secured to the cross rails 40 and 42 of the
refrigerator frame 32, the effective mass of the compressor
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housing M2, is equal to the sum of the masses of the
compressor housing 34, condenser 36 and support rails 50 and
52.
As shown in FIGS. 7, 8A and 8B, the second
embodiment of the mounting system 38 includes the support
rails 50 and 52 to which the compressor housing 34 is
rigidly secured by means of bolts 53-55 and to which the
condenser 36 is also rigidly secured. In this embodiment,
the mounting system 38 also includes a rear cross rail 82 to
which ends 60 and 62 of the respective support rails 50 and
52 are rigidly secured by spot welds 70 and 72 or the like.
The ends 61 and 63 of the support rails 50 and 52 are
resiliently secured to the cross rail 40 of the refrigerator
frame 32 by grommets 57 and 59 as discussed above with
reference to FIG. 5. A pair of rubber grommets 84 and 86
are disposed between the cross rail 82 of the mounting
system of FIGS. 7, 8A and 8B and the refrigerator frame 32
to resiliently mount the cross rail 82 on the refrigerator
frame 32. Because the cross rail 82 in FIGS. 7, 8A and 8B
is rigidly secured to the support rails 50 and 52 to which
the compressor housing 34 and condenser 36 are rigidly
secured, the effective mass of the compressor housing M2 is
equal to the sum of the masses of the compressor housing 34,
the condenser 36, the support rails 50 and 52 and the cross
rail 82 so as to further increase the mass ratio ~ and to
substantially reduce the transmission of vibration from the
compressor resiliently mounted in the housing 34 to the
frame 32 of the refrigerator 10.
In still another embodiment of the present
invention, the support rails 50 and 52 may be rigidly
secured to the cross rail 40 as well as to the cross rail 82
so that the grommets 57 and 59 shown in FIG. 7 would be
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replaced by spot welds or the like. Grommets 90 and 92
would then be used to resiliently secure the cross rail 40
to the frame 32 of the refrigerator 30. In this embodiment
the effective mass of the compressor housing would include
the compressor housing 34, the condenser 36, the support
rails 50 and 52 and the cross rails 40 and 82 to increase
the mass ratio ~ and to reduce the amount of noise generated
by the transmission of vibration from the compressor to the
refrigerator frame.
Many modifications and variations of the present
invention are possible in light of the above teachings.
Thus, it is to be understood that, within the scope of the
appended claims, the invention may be practiced otherwise
than as described hereinabove.
