Hermetic compressor having resilient internal mounting

A compressor assembly is disclosed including a compressor mechanism resiliently mounted within a hermetically sealed housing. The compressor mechanism includes a crankcase having a radially extending mounting flange portion, which is resiliently connected to the housing sidewall at a plurality of circumferentially spaced locations by a plurality of mounting assemblies. Each mounting assembly comprises a rubber bushing received within a hole in the mounting flange, and a threaded stud that extends through a hole in the bushing and engages a threaded hole in a steel block welded to the housing sidewall above the mounting flange. A washer and retaining nut on the bottom of the threaded stud suspendingly support the mounting flange. In this manner, only a peripheral portion of the washer contacts the mounting flange circumjacent the hole therein, thereby minimizing noise transmission to the housing. Lateral movement of the compressor mechanism is absorbed by the bushing.

BACKGROUND OF THE INVENTION 
The present invention relates generally to a hermetic compressor assembly 
and, more particularly, to such a compressor assembly having a compressor 
mechanism mounted within a hermetically sealed housing, wherein it is 
desired to limit the axial and lateral movement of the compressor 
mechanism relative to the housing, and to minimize the transmission of 
noise and vibration from the compressor mechanism to the housing. 
In general, compressor assemblies of the type to which the present 
invention pertains comprise a motor-compressor unit mounted within a 
hermetically sealed housing. The motor-compressor unit includes an 
electric motor drivingly coupled to a positive displacement compressor 
mechanism for compressing refrigerant. During compressor operation, the 
steady-state inertial forces produced by the rotating masses of the unit 
are substantially balanced by the provision of counterweights in both the 
motor and the compressor mechanism, and by the location of mounting means 
at the axial center of mass. Furthermore, the axially supported mass of 
the motor-compressor unit helps dampen any axial vibratory forces. 
However, gas load forces produced by gas compression, and torque forces 
imparted to the compressor by the dynamic operation of the motor during 
starting and stopping, result in vibratory forces in a lateral plane. 
Several prior art methods for immovably mounting a motor-compressor unit 
within a housing involve direct attachment therebetween, such as by 
circumferentially welding, clamping, or shrink fitting a mounting flange 
of the compressor mechanism to the housing sidewall. Alternatively, a 
mounting plate to which the compressor mechanism is attached may serve as 
the mounting flange. In one such arrangement, the housing comprises two 
interfitting portions between which the mounting flange or mounting plate 
is clamped or axially supported. Where the flange is only axially 
supported, the aforementioned lateral forces may cause rotation of the 
motor compressor unit within the housing. 
A problem associated with prior art mounting mechanisms providing direct 
mechanical attachment between the compressor mechanism and the housing, is 
that vibrations are mechanically transmitted to the housing through the 
mounting mechanism, thereby producing noise and vibration in the housing. 
Also, other noises produced by the compressor mechanism can be transmitted 
directly to the housing through the mounting mechanism. 
In order to reduce the transmission of vibration and noise from the 
compressor mechanism to the housing, there have been developed resilient 
suspension mounting systems incorporating springs and the like, which 
necessarily permit substantial movement of the compressor within the 
housing. As previously alluded to, it is desirable that the transmission 
of vibration and noise to the housing be minimized; however, it is also 
important, particularly in direct suction hermetic compressors wherein a 
suction tube extends between the housing sidewall and the compressor 
crankcase, that the compressor mechanism be limited in its movement 
relative to the housing so as to avoid damage to the compressor. 
Specifically, where the suction tube extends through a pressurized housing 
interior and includes O-ring seals at its connecting ends, damage to the 
O-ring seals could result from excessive movement of the compressor 
mechanism relative to the housing. 
While the prior art mounting mechanisms have addressed separately the 
problems of restricting compressor movement relative to the housing and 
minimizing vibration and noise transmission from the compressor to the 
housing, a satisfactory combined solution has not been proposed, 
particularly for a direct suction hermetic compressor assembly exhibiting 
the aforementioned lateral vibratory forces. Instead, the prior art 
suspension mounting mechanisms have, for the most part, emphasized axially 
oriented spring support. Such systems inherently lack lateral support, 
which results in excessive lateral movement of the compressor mechanism 
and associated damages caused thereby. 
SUMMARY OF THE INVENTION 
The present invention overcomes the disadvantages of the above-described 
prior art internal mounting methods by providing an improved resilient 
mounting method for mounting a motor-compressor unit within a hermetic 
housing, wherein vibrations of the compressor mechanism occurring in the 
lateral plane are absorbed with minimal transmission of noise and 
vibration to the housing and with restricted lateral movement of the 
compressor mechanism relative to the housing. 
Generally, the invention provides a mounting mechanism wherein lateral 
movement of a compressor mechanism within a hermetic housing is absorbed 
and restrained by a resilient member, and axial support of the compressor 
mechanism is achieved by minimal contact area between the compressor 
crankcase and mounting hardware attached to the housing. 
More specifically, the invention provides, in one form thereof, a 
vertically disposed hermetic compressor assembly wherein a compressor 
mechanism is resiliently mounted within the housing by means of a 
plurality of circumferentially spaced mounting mechanisms The compressor 
mechanism includes a radially extending mounting flange having a plurality 
of vertically oriented mounting bores extending therethrough. A mounting 
mechanism associated with each mounting bore comprises an anchor member 
fixedly attached to the housing sidewall, wherein the anchor member 
extends through the mounting bore. A resilient member occupies the space 
within the mounting bore intermediate the anchor member and the mounting 
flange. Each mounting mechanism includes an axial support connected to the 
anchor member and contacting the bottom surface of the flange member 
circumjacent the mounting bore. 
An advantage of the resilient mounting system of the present invention is 
that lateral forces produced by the compressor mechanism are absorbed by a 
resilient member, thereby reducing noise and vibration transmitted to the 
housing. 
Another advantage of the resilient mounting system of the present invention 
is that axial support of the compressor mechanism is achieved through 
minimal surface area contact, thereby minimizing the transmission of noise 
through contacting mounting components. 
A further advantage of the resilient mounting system of the present 
invention is that lateral and axial movement of the compressor mechanism 
relative to the housing is limited while at the same time transmission of 
vibration and noise to the housing is minimized. 
Yet another advantage of the resilient mounting system of the present 
invention is that, in a direct suction compressor assembly, the mounting 
system enhances the use of O-ring seals for the suction inlet conduit, by 
limiting compressor movement that would otherwise destroy the seals. 
A still further advantage of the resilient mounting system of the present 
invention is that assembly of the hermetic compressor is simplified. 
The resilient mounting apparatus of the present invention, in one form 
thereof, relates to a vertically disposed compressor assembly comprising a 
compressor mechanism within a hermetically sealed housing having a 
sidewall, wherein the compressor mechanism includes a radially extending 
mounting flange having a top surface and a bottom surface. A mounting 
apparatus is provided for resiliently mounting the compressor mechanism to 
the housing sidewall, and includes a plurality of circumferentially spaced 
mounting bores formed in the mounting flange. Each mounting bore extends 
vertically through the mounting flange between the top surface and the 
bottom surface thereof. A plurality of anchoring members, corresponding to 
the plurality of mounting bores, are connected to the housing sidewall and 
extend substantially coaxially through respective mounting bores. In this 
manner, an annular space is defined intermediate each anchoring member and 
its respective mounting bore. There is also provided a plurality of 
resilient members corresponding to the plurality of mounting bores. Each 
resilient member is disposed within a respective mounting bore in a manner 
to substantially occupy the annular space. An axial support associated 
with each of anchoring members provides axial support for the compressor 
mechanism. Each axial support is connected to its respective anchoring 
member and contacts the mounting flange bottom surface at a location 
thereon circumjacent a respective mounting bore. Accordingly, the 
compressor mechanism is axially supported, and movement of the compressor 
mechanism in a lateral plane is resiliently restrained. 
The present invention further provides, in one form thereof, a compressor 
assembly comprising a vertically disposed hermetically sealed housing 
including a sidewall. A compressor mechanism for compressing refrigerant 
is disposed within the housing and includes a crankcase having a radially 
extending mounting flange. The mounting flange includes a top surface, a 
bottom surface, and a plurality of circumferentially spaced vertical bores 
extending therebetween. In accord with this form of the invention, a 
mounting mechanism is provided for mounting the compressor mechanism to 
the housing sidewall. The mounting mechanism includes a plurality of 
circumferentially spaced mounting blocks, each corresponding to one of the 
vertical bores, wherein each mounting block is attached to the housing 
sidewall. There is also provided a plurality of vertically disposed 
elongate stud members corresponding to the plurality of mounting blocks. 
Each stud member is connected at a top end thereof to a respective 
mounting block, and extends downwardly within the housing in spaced 
relation to the housing sidewall. The bottom end of each stud member is 
unattached. A resilient bushing is received within each vertical bore, and 
includes a central aperture through which a respective stud member 
extends. Accordingly, the bushing is intermediate the stud member and the 
vertical bore for resiliently limiting lateral movement therebetween. 
Also, the compressor mechanism is axially supported by a support member 
connected to each stud member bottom end. The support member contacts an 
annular area of the mounting flange bottom surface circumjacent a 
respective mounting bore. In one aspect of the invention according to this 
form, the resilient mounting mechanism includes a stop at the top end of 
the stud member to limit axially upward movement of the compressor 
mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
In an exemplary embodiment of the invention as shown in the drawings, and 
in particular by referring to FIG. 1, a compressor assembly 10 is shown 
having a housing generally designated at 12. The housing has a top portion 
14 and a bottom portion 18. The two housing portions are hermetically 
secured together as by welding or brazing. A mounting flange 20 is welded 
to the bottom portion 18 for mounting the compressor in a vertically 
upright position. Located within hermetically sealed housing 12 is an 
electric motor generally designated at 22 having a stator 24 and a rotor 
26. The stator is provided with windings 28. Rotor 26 has a central 
aperture 30 provided therein into which is secured a crankshaft 32 by an 
interference fit. A terminal cluster 34 is provided in bottom portion 18 
of housing 12 for connecting the compressor to a source of electric power. 
Where electric motor 22 is a three-phase motor, bidirectional operation of 
compressor assembly 10 is achieved by changing the connection of power at 
terminal cluster 34. 
Compressor assembly 10 also includes an oil sump 36 located in bottom 
portion 18. An oil sight glass 38 is provided in the sidewall of bottom 
portion 18 to permit viewing of the oil level in sump 36. A centrifugal 
oil pick-up tube 40 is press fit into a counterbore 42 in the end of 
crankshaft 32. Oil pick-up tube 40 is of conventional construction and 
includes a vertical paddle (not shown) enclosed therein. 
Also enclosed within housing 12, in the embodiment of FIG. 1, is a 
compressor mechanism generally designated at 44. Compressor mechanism 44 
comprises a crankcase 46 including a plurality of mounting lugs 48 to 
which motor stator 24 is attached such that there is an annular air gap 50 
between stator 24 and rotor 26. Crankcase 46 also includes a 
circumferential mounting flange 52 supported within housing 12 by means of 
a plurality of resilient mounting assemblies 54 in accord with the present 
invention, as shown in FIGS. 2 and 3. An annular space 53, intermediate 
the peripheral edge of flange 52 and housing top portion 14, provides 
communication between the top and bottom ends of housing 12 for return of 
lubricating oil and equalization of discharge pressure within the entire 
housing interior. 
Compressor mechanism 44, as illustrated in the preferred embodiment, takes 
the form of a reciprocating piston, scotch yoke compressor. More 
specifically, crankcase 46 includes four radially disposed cylinders, two 
of which are shown in FIG. 1 and designated as cylinder 56 and cylinder 
58. The four radially disposed cylinders open into and communicate with a 
central suction cavity 60 defined by inside cylindrical wall 62 in 
crankcase 46. A relatively large pilot hole 64 is provided in a top 
surface 66 of crankcase 46. Various compressor components, including the 
crankshaft, are assembled through pilot hole 64. A top cover such as cage 
bearing 68 is mounted to the top surface of crankcase 46 by means of a 
plurality of bolts 70 extending through bearing 68 into top surface 66. 
When bearing 68 is assembled to crankcase 46, an O-ring seal 72 isolates 
suction cavity 60 from a discharge pressure space 74 defined by the 
interior of housing 12. 
Crankcase 46 further includes a bottom surface 76 and a bearing portion 78 
extending therefrom. Retained within bearing portion 78, as by press 
fitting, is a sleeve bearing assembly comprising a pair of sleeve bearings 
80 and 82. Two sleeve bearings are preferred rather than a single longer 
sleeve bearing to facilitate easy assembly into bearing portion 78. 
Likewise, a sleeve bearing 84 is provided in cage bearing 68, whereby 
sleeve bearings 80, 82, and 84 are in axial alignment. Sleeve bearings 80, 
82, and 84 are manufactured from steel-backed bronze. 
Referring once again to crankshaft 32, there is provided thereon journal 
portions 86 and 88, wherein journal portion 86 is received within sleeve 
bearings 80 and 82, and journal portion 88 is received within sleeve 
bearing 84. Accordingly, crankshaft 32 is rotatably journalled in 
crankcase 46 and extends through a suction cavity 60. Crankshaft 32 
includes a counterweight portion 90 and an eccentric portion 92 located 
opposite on another with respect to the central axis of rotation of 
crankshaft 32 to thereby counterbalance one another. The weight of 
crankshaft 32 and rotor 26 is supported on thrust surface 93 of crankcase 
46. 
Eccentric portion 92 is operably coupled by means of a scotch yoke 
mechanism 94 to a plurality of reciprocating piston assemblies 
corresponding to, and operably disposed within, the four radially disposed 
cylinders in crankcase 46. As illustrated in FIG. 1, piston assemblies 96 
and 98, representative of four radially disposed piston assemblies 
operable in compressor assembly 10, are associated with cylinders 56 and 
58, respectively. 
Scotch yoke mechanism 94 comprises a slide block 100 including a 
cylindrical bore 102 in which eccentric portion 92 is journalled. In the 
preferred embodiment, cylindrical bore 102 is defined by a steel backed 
bronze sleeve bearing press fit within slide block 100. A reduced diameter 
portion 103 in crankshaft 32 permits easy assembly of slide block 100 onto 
eccentric portion 92. Scotch yoke mechanism 94 also includes a pair of 
yoke members 104 and 106 which cooperate with slide block 100 to convert 
orbiting motion of eccentric portion 92 to reciprocating movement of the 
four radially disposed piston assemblies. For instance, FIG. 1 shows yoke 
member 106 coupled to piston assemblies 96 and 98, whereby when piston 
assembly 96 is at a bottom dead center (BDC) position, piston assembly 98 
will be at a top dead center (TDC) position. 
Referring once again to piston assemblies 96 and 98, each piston assembly 
comprises a piston member 108 having an annular piston ring 110 to allow 
piston member 108 to reciprocate within a cylinder to compress gaseous 
refrigerant therein. Suction ports 112 extending through piston member 108 
allow suction gas within suction cavity 60 to enter cylinder 56 on the 
compression side of piston 108. 
A suction valve assembly 114 is also associated with each piston assembly, 
and will now be described with respect to piston assembly 96 shown in FIG. 
1. Suction valve assembly 114 comprises a flat, disk-shaped suction valve 
116 which in its closed position covers suction ports 112 on a top surface 
118 of piston member 108. Suction valve 116 opens and closes by virtue of 
its own inertia as piston assembly 96 reciprocates in cylinder 56. More 
specifically, suction valve 116 rides along a cylindrical guide member 120 
and is limited in its travel to an open position by an annular valve 
retainer 122. 
As illustrated in FIG. 1, valve retainer 122, suction valve 116, and guide 
member 120 are secured to top surface 118 of piston member 108 by a 
threaded bolt 124 having a buttonhead 128. Threaded bolt 124 is received 
within a threaded hole 126 in yoke member 106 to secure piston assembly 96 
thereto. As shown with respect to the attachment of piston assembly 98 to 
yoke member 106, an annular recess 130 is provided in each piston member 
and a complementary boss 132 is provided on the corresponding yoke member, 
whereby boss 132 is received within recess 130 to promote positive, 
aligned engagement therebetween. 
Compressed gas refrigerant within each cylinder is discharged through 
discharge ports in a valve plate. With reference to cylinder 58 in FIG. 1, 
a cylinder head cover 134 is mounted to crankcase 46 with a valve plate 
136 interposed therebetween. A valve plate gasket is provided between 
valve plate 136 and crankcase 46. Valve plate 136 includes a coined recess 
140 into which buttonhead 128 of threaded bolt 124 is received when piston 
assembly 98 is positioned at top dead center (TDC). 
A discharge valve assembly 142 is situated on a top surface 144 of valve 
plate 136. Generally, compressed gas is discharged through valve plate 136 
past an open discharge valve 146 that is limited in its travel by a 
discharge valve retainer 148. Guide pins 150 and 152 extend between valve 
plate 136 and cylinder head cover 134, and guidingly engage holes in 
discharge valve 146 and discharge valve retainer 148 at diametrically 
opposed locations therein. Valve retainer 148 is biased against cylinder 
head cover 134 to normally retain discharge valve 146 against top surface 
144 at the diametrically opposed locations. However, excessively high mass 
flow rates of discharge gas or hydraulic pressures caused by slugging may 
cause valve 146 and retainer 148 to be guidedly lifted away from top 
surface 144 along guide pins 150 and 152. 
Referring once again to cylinder head cover 134, a discharge space 154 is 
defined by the space between top surface 144 of valve plate 136 and the 
underside of cylinder head cover 134. Cover 134 is mounted about its 
perimeter to crankcase 46 by a plurality of bolts 135, shown in FIG. 2. 
Discharge gas within discharge space 154 associated with each respective 
cylinder passes through a respective connecting passage 156, thereby 
providing communication between discharge space 154 and a top annular 
muffling chamber 158. Chamber 158 is defined by an annular channel 160 
formed in top surface 66 of crankcase 46, and cage bearing 68. As 
illustrated, connecting passage 156 passes not only through crankcase 46, 
but also through holes in valve plate 136 and the valve plate gasket. 
Top muffling chamber 158 communicates with a bottom muffling chamber 162 by 
means of passageways extending through crankcase 46. Chamber 162 is 
defined by an annular channel 164 and a muffler cover plate 166. Cover 
plate 166 is mounted against bottom surface 76 at a plurality of 
circumferentially spaced locations by bolts 168 and threaded holes 169. 
Bolts 168 may also take the form of large rivets or the like. A plurality 
of spacers 170, each associated with a respective bolt 168, space cover 
plate 166 from bottom surface 76 at the radially inward extreme of cover 
plate 166 to form an annular exhaust port 172. The radially outward 
extreme portion of cover plate 166 is biased in engagement with bottom 
surface 76 to prevent escape of discharge gas from within bottom muffling 
chamber 162 at this radially outward location. 
Compressor assembly 10 of FIG. 1 also includes a lubrication system 
associated with oil pick-up tube 40 previously described. Oil pick-up tube 
40 acts as an oil pump to pump lubricating oil from sump 36 upwardly 
through an axial oil passageway 174 extending through crankshaft 32. An 
optional radial oil passageway 176 communicating with passageway 174 may 
be provided to initially supply oil to sleeve bearing 82. The disclosed 
lubrication system also includes annular grooves 178 and 180 formed in 
crankshaft 32 at locations along the crankshaft adjacent opposite ends of 
suction cavity 60 within sleeve bearings 80 and 84. Oil is delivered into 
annular grooves 178, 180 behind annular seals 182, 184, respectively 
retained therein. Seals 182, 184 prevent high pressure gas within 
discharge pressure space 74 in the housing from entering suction cavity 60 
past sleeve bearings 84 and 80, 82, respectively. Also, oil delivered to 
annular grooves 178, 180 behind seals 182 and 184 lubricate the seals as 
well as the sleeve bearings. 
Another feature of the disclosed lubrication system of compressor assembly 
10 in FIG. 1, is the provision of a pair of radially extending oil ducts 
186 from axial oil passageway 174 to a corresponding pair of openings 188 
on the outer cylindrical surface of eccentric portion 92. 
A counterweight 190 is attached to the top of shaft 32 by means of an 
off-center mounting bolt 192. An extruded hole 194 through counterweight 
190 aligns with axial oil passageway 174, which opens on the top of 
crankshaft 32 to provide an outlet for oil pumped from sump 36. An 
extruded portion 196 of counterweight 190 extends slightly into passageway 
174 which, together with bolt 192, properly aligns counterweight 190 with 
respect to eccentric portion 92. 
Referring now to FIGS. 2 and 3, a suction line connector assembly 200 is 
shown, whereby refrigerant at suction pressure is supplied from a 
refrigeration system (not shown) external of housing 12, through discharge 
pressure space 74 within the housing, into suction cavity 60 within 
crankcase 46. Generally, connector assembly 200 comprises a housing 
fitting assembly 202 having a fitting bore 204 extending therethrough, a 
suction inlet bore 206 formed in crankcase 46 that communicates with 
suction cavity 60, and a suction conduit 208. Suction conduit 208 has a 
first axial end 210 received within fitting bore 204, a second axial end 
212 received within suction inlet bore 206, and an intermediate portion 
214 extending through discharge pressure space 74. 
Housing fitting assembly 202 comprises a housing fitting member 216, a 
removable outer fitting member 218, and a threaded nut 220 that is 
rotatable yet axially retained on outer fitting member 218. Housing 
fitting member 216 is received within an aperture 222 in top portion 14 of 
the housing, and is sealingly attached thereto as by welding, brazing, 
soldering, or the like. Outer member 218 incorporates a conical screen 
filter 224 having a mounting ring 226 at the base end thereof that is slip 
fit into a counterbore 228 provided in the outer end of outer member 218. 
In such an arrangement, filter 224 may be easily removed for cleaning or 
replacement. Filter 224 is retained within counterbore 228 by means of a 
copper fitting 230 that is soldered or brazed to the suction tubing of a 
refrigeration system (not shown). In turn, copper fitting 230 is received 
within counterbore 228 and is soldered or brazed to outer member 218. 
Housing fitting assembly 202 is a slightly modified version of a fitting 
that is commercially available from Primor of Adrian, Mich. 
Suction line connector assembly 200 will now be more particularly described 
with reference to FIG. 3. Suction inlet bore 206 extends radially 
outwardly from suction cavity 60 along an axis substantially perpendicular 
to the housing sidewall. Likewise, fitting bore 204 extends through the 
housing sidewall along an axis perpendicular thereto. Upon assembly of 
compressor 10 of the preferred embodiment, it is intended that the axes of 
suction inlet bore 206 and fitting bore 204 be substantially aligned. 
However, due to machining and assembly tolerances, and dynamic forces 
acting on the compressor mechanism during operation, the bores may not be 
initially aligned nor remain so during compressor operation. Therefore, as 
described hereinafter, means are provided for sealingly engaging first end 
portion 210 within fitting bore 204 and second end portion 212 within 
suction inlet bore 206, in a manner to permit axial and angular movement 
of first end portion 210 and second end portion 212 relative to fitting 
bore 204 and suction inlet bore 206, respectively, in response to limited 
movement of compressor mechanism 44 relative to housing 12. 
Suction inlet bore 206 includes an annular relief 232 for the purpose of 
permitting a honing or burnishing tool to bearingize a cylindrical sealing 
surface 234, which constitutes the radially outermost portion of suction 
inlet bore 206. Likewise, fitting bore is polished, or bearingized, to 
provide a smooth cylindrical sealing surface. A chamfer 236 is provided at 
the opening of suction inlet bore 206 to facilitate insertion of first end 
portion 210 of suction conduit 208. 
Suction conduit 208 comprises a short length of spun or swedged cylindrical 
tubing, wherein first end portion 210 is formed with an annular 
protuberance 238 and second end portion 212 is formed with a corresponding 
annular protuberance 240. Annular protuberances 238 and 240 are 
essentially at locations on suction conduit 208 where the diameter is 
greater than axially adjacent portions. More specifically, protuberances 
238 and 240 of the disclosed embodiment slope away from a central point of 
maximum diameter toward decreasing conduit diameter, thereby permitting 
each end of the suction conduit to pivot within its associated bore. The 
amount of pivoting is limited by the geometry of the protuberance and the 
axial penetration of the conduit within the bore. 
Although it is conceivable that a rounded, well-polished protuberance could 
provide sealing engagement of a conduit end portion within a bore, 
protuberances 238 and 240 are formed with annular seal grooves 242 and 
244, into which O-ring seals 246 and 248 are received, respectively. The 
cross-sectional diameter of each O-ring seal is greater than the depth of 
its respective groove and, therefore, the seal extends above the surface 
of the protuberance at its maximum diameter and sealingly contacts the 
cylindrical sealing surface of its associated bore. In the preferred 
embodiment, O-ring seals 246 and 248 are composed of a rubber material, 
such as neoprene or viton, and have a cross-sectional diameter of 
approximately 0.070 inches. The annular clearance between each 
protuberance and its associated bore is approximately 0.005 inches, while 
the depth of each seal groove is approximately 0.050-0.055 inches. 
Therefore, the O-ring seals are under approximately 0.10-0.15 inches 
compression when installed. 
Furthermore, the axial dimension of grooves 242 and 244 is approximately 
twice the diameter of the O-ring seal, thereby permitting O-ring seals 246 
and 248 to move axially outwardly within seal grooves 242 and 244, 
respectively, in response to the pressure differential between discharge 
pressure space 74 and the opposite side of the protuberance exposed to the 
refrigerant at suction pressure being transported through suction conduit 
208. Because each end of suction conduit 208 is subjected to opposing 
forces generated by the same pressure differential, there is no net axial 
force acting on the conduit. 
When assembling suction line connector assembly 200 of the present 
invention, outer fitting member 218, including threaded nut 220, is first 
removed. Suction conduit 208, with O-ring seals 246 and 248 installed, is 
then inserted through fitting bore 204 until first end portion 210 is 
sealingly received within fitting bore 204 and second end portion 212 is 
sealingly received within cylindrical sealing surface 236 of suction inlet 
bore 206. Outer fitting member 218 is then installed so that suction 
conduit 208 is axially restrained. Specifically, a narrowing 250 of 
fitting member 218 provides an axial stop for conduit distal end surface 
252. Likewise, step 254 in suction inlet bore 206 provides an axial stop 
for conduit proximal end surface 256. An axial space 258, which may be 
divided between either conduit end surface and its respective stop, 
permits limited radial movement of compressor mechanism 44 with respect to 
housing 12. Removal of suction conduit 208 through fitting bore 204 is 
facilitated by the provision of a step 260 formed by a counterbore made in 
second end portion 212. An expanding tool may be introduced through the 
conduit opening adjacent first end portion 210, and then engaged with step 
260 for easy retraction of the conduit. 
Referring once again to mounting assemblies 54 of the present invention, it 
is necessary that these mounting assemblies limit the displacement of 
compressor mechanism 44 relative to housing 12, to prevent damage to 
suction conduit 208 and O-ring seals 246 and 248. In the preferred 
embodiment of mounting assembly 54 shown in FIG. 3, a steel mounting block 
262 is welded to the inside wall of housing top portion 14. Mounting block 
262 includes an axially oriented threaded hole 264. Mounting flange 52 of 
crankcase 46 is suspended from mounting block 262 by means of an assembly 
comprising a threaded stud 266, a spacer 268, a pair of washers 270 and 
272, a retaining nut 274, and a ring-shaped rubber grommet 276. In the 
preferred embodiment, grommet 276 is a neoprene bushing. Spacer 268 may be 
an integrally formed central portion of threaded stud 266, having 
increased diameter relative to the top and bottom threaded ends thereof. 
Alternatively, a separate sleeve-type spacer may be used. 
More specifically, threaded stud 266 is received into threaded hole 264 so 
as to extend downwardly therefrom. As shown in FIG. 3, spacer 268 is 
flanked by washers 270 and 272, and the three are retained adjacent one 
another by retaining nut 274. Where spacer 268 is an integral part of stud 
266, washer 270 is retained intermediate block 262 and spacer 268 by 
threading stud 266 into hole 264. Grommet 276 surrounds spacer 268 and, in 
turn, fills bore 278 provided in mounting flange 52 of crankcase 46. The 
diameter of washers 270 and 272 is greater than that of bore 278, whereby 
mounting assembly 54 limits axial movement of compressor mechanism 44, 
e.g., during shipping. Lateral displacement of the compressor mechanism 
during operation is resiliently restrained by the transmission of forces 
from mounting flange 52 to housing 12, through grommet 276. 
It will be appreciated that transmission of noise from compressor mechanism 
44 to housing 12 is minimized not only by grommet 276, but also by the 
small annular contacting area between mounting flange 52 and bottom washer 
272. This contacting area is minimized by the sizing of washer 272 and 
bore 278 to insure continuous annular contact for the expected maximum 
lateral displacement of the compressor mechanism relative to the housing. 
In one embodiment, the diameter of washer 272 is approximately 0.090 
inches greater than that of bore 278. It is also appreciated that grommet 
276, when made of neoprene, may initially have a diameter approximately 
0.20-0.030 inches less than bore 278. However, upon exposure of the 
grommet to the operating environment within housing 12, the grommet swells 
to fill bore 278. 
It can be seen from FIG. 3 that top washer 270 is ordinarily spaced from 
the top surface of mounting flange 52 when the compressor mechanism is 
axially supported by bottom washer 272. However, the top surface of flange 
52 will contact top washer 270 after upward movement of the compressor 
mechanism in response to a force as would be experienced during shipping. 
During compressor operation, axial movement does not ordinarily occur. The 
spacing between top washer 270 and the top surface of mounting flange 52 
is determined by the axial length of spacer 268 and is designed to protect 
the components of suction line connector assembly 200. 
FIG. 3 also shows a discharge fitting 280 provided in bottom portion 18 of 
housing 12 located directly beneath suction line connector assembly 200. 
The location of discharge fitting 280 in a central or lower portion of the 
housing provides an advantage in that the fitting acts as a dam and limits 
to about 20 lbs. the amount of refrigerant charge that will be retained by 
the compressor and required to be pumped out upon startup. 
It should be noted that the resilient mounting system of the present 
invention, according to the disclosed embodiment, permits easy assembly of 
the compressor mechanism within housing 12, prior to the attachment of top 
portion 14 to bottom portion 18. Specifically, each mounting block 262 is 
welded to the inside wall of top portion 14, after which a respective 
threaded stud 266 is attached to the mounting block with top washer 270 
retained therebetween. The compressor mechanism is then placed within the 
housing top portion such that threaded studs 266 coaxially extend through 
respective bores 278 with grommets 276 operatively placed therein. Bottom 
washer 272 is then retained against spacer 268 by retaining nut 274. The 
top and bottom housing portions are then sealingly attached. 
It will be appreciated that the foregoing is presented by way of 
illustration only, and not by way of any limitation, and that various 
alternatives and modifications may be made to the illustrated embodiment 
without departing from the spirit and scope of the invention.