US2857746A

US2857746A - Refrigerating apparatus

Info

Publication number: US2857746A
Application number: US366709A
Authority: US
Inventors: Lawrence A Philipp
Original assignee: Nash Kelvinator Corp
Current assignee: American Motors Corp
Priority date: 1953-07-08
Filing date: 1953-07-08
Publication date: 1958-10-28
Anticipated expiration: 1975-10-28

Description

L- A. PHlLlPP REFRIGERATING APPARATUS Oct. 28, 1958 v 2,857,746

4 Sheets-Sheet 1 Filed July 8, 1953 68 68 INVENTOR.

W M K Oct. 28, 1958 PP 2,857,746

- REFRIGERATING APPARATUS Filed July 8, 1953 4 Sheets-Sheet 2 IIIIIJ ,IIIIIIIIIIIIIII' I N VEN TOR.

Oct. 28, 1958 A. PHlLlPP 2,857,746

REFRIGERATING APPARATUS Filed July 8, 1953 4 Sheets-Sheet 3 I INVENTOR. I MA/ea cz'flHfl/PP Mam Oct. 28, 1958 1.. A. PHILIPP 2,857,746

REFRIGERATING APPARATUS Filed July 8, 1953 4 Sheets-Sheet 4 Q7 20 I a; 5/ I W w I INVENTOR.

BY g W 8, My. [/6 [e0 Z/I I Mommy United States Patent 2,857,746 REFRIGERATING APPARATUS Lawrence A. Philipp, Detroit, Mich., assignor to Nash- Kelvinator Corporation, Detroit, Mich., a corporation of Maryland Application July 8, 1953, Serial No. 366,709

2 Claims. (Cl. 62-295) This invention relates generally to refrigerating apparatus and particularly to motor-compressor units therefor.

One of the objects of the invention is to provide an improved hermetically sealed motor-compressor unit particularly adapted for use in refrigerating apparatus having automatic defrost of the evaporator.

Another object of the invention is to provide for a hermetically sealed motor-compressor unit, an improved arrangement within the unit casing of a resilient mounting, and of resilient thrust members to limit torque induced oscillation of the unit on the mounting.

More specifically it is an object of the invention to arrange pairs of opposing springs to stabilize oscillation of the motor-compressor in opposite directions such that the forces exerted by the springs are tangential to the axis of oscillation.

Another object of the invention resides in mounting a refrigerant motor-compressor unit within a sealed casing on a resilient mounting carried by a refrigerant flow line fitting.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a front view of a refrigerator having broken away portions, and embodying features of my invention;

Fig. 2 is an enlarged, vertical sectional view of a lower portion of the refrigerator;

Fig. 3 is a view partly diagrammatical of the refrigerating system;

Fig. 4 is a view of the evaporator before being formed;

Fig. 5 is a cross sectional view of a refrigerant motorcompressor unit having broken away portions, embodying features of my invention;

Fig. 6 is a horizontal cross sectional view of the motorcompressor unit;

Fig. 7 is a sectional view of a detail of the motorcompressor unit, taken along line 7-7 of Fig. 5;

Fig. 8 is a cross sectional View with parts broken away of a modified form of motor-compressor unit embodying features of my invention;

Fig. 9 is a horizontal cross sectional view of the unit of Fig. 8;

Figs. 10 and 11 are plan and elevational views respectively of a fan shown removed from the modified motorcompressor unit;

Fig. 12 is a vertical sectional view of the modified motor-compressor unit;

- Fig. 13 is a fragmentary sectional view of a modified resilient mounting for the motor-compressor;

Fig. 14 is a fragmentary sectional view of a modified arrangement of torque opposing springs; and

Fig. 15 is a sectional view, taken along the line 1515 of Fig. 14. v

Referring to the drawings by characters of reference,

and particularly to Figs. 1 and 2, the refrigerator shown comprises in general a cabinet 20 and a refrigerating system including a refrigerant evaporator 22, a refrigerant condenser 24, and a refrigerant pump or motor-compressor unit 26. In the present arrangement, the evaporator 22 is located within the cabinet adjacent the top thereof; the motor-compressor unit 26 is located at the rear and near the bottom of the cabinet; and the condenser 24 is located behind the cabinet. In normal operation of the refrigerator, liquid refrigerant is delivered from the condenser 24 to the evaporator 22 through a capillary tube 30 and vaporized refrigerantis conducted from the evaporator 22 to the motor-compressor unit through a return conduit 32.

A conduit 34 connects the outlet of the motor-compressor unit 26 and the inlet of the condenser 24, and connected into conduit 34 is one end of a by-pass conduit 36 which has its other end connected to the evaporator 22 to provide a by-pass around the condenser and capillary tube. The by-pass conduit 36 has a larger flow capacity than the capillary tube 30 and functions during the defrosting period to deliver warm refrigerant vapor to the evaporator for quickly removing the frost therefrom. A normally closed solenoid valve 38 in conduit 36 controls flow therethrough and may be manually controlled, or be operated automatically in response to evaporator temperature or by any suitable timing device (not shown). Control for the solenoid has not been shown since such controls are well known in the art and form no part of the present invention. However, for a more detailed description of the defrosting system and controls therefor, reference may be had to my copending application entitled refrigerating apparatus Serial No. 262,809, filed December 21, 1951 now Patent No. 2,737,030, March 6, 1956.

The cabinet 20 comprises in general a sheet metal casing 40 and a sheet metal liner 42. Heat insulation 44 is preferably provided to decrease heat leakage into the cabinet and is disposed between the casing and liner. Below the evaporator 22, the cabinet has the usual shelves 46 and below the lowermost shelf there is a drawer 48 in which a relatively high humidity may be maintained, suitable for keeping vegetables fresh. The drawer 48 may be slidably supported on guide rails 50 which may be secured by any suitable means to the opposite liner sides. Directly behind the drawer 48, the casing 40 and liner 42 have corresponding inwardly extending or inclined

rear wall portions

52 and 54 respectively to form a space or machinery compartment 56 for the motor-compressor unit 26. I

The evaporator 22 comprises a box-like heat absorbing container 58 and a refrigerant coil 60. The coil 60 is secured to the container 58 and extends along the top, bottom and sides thereof. As illustrated, the container 60 may comprise a sleeve having one end closed by a rear panel 62 and the other or front end closed by a door 64. In constructing the evaporator, the coil 58 is first bent sinously to the desired form and then secured to one side of a flat metal sheet 66, the arrangement of the coil on the sheet being such that the runs of the coil extend longitudinally and substantially coextensive of the sheet after which the sheet and coil are bent transversely along the bend lines 68 and the ends of the sheet lapped and secured together to form the sleeve.

Opposite ends

70 and 72 of coil 58 communicate re spectively with a refrigerant accumulator 74 and a refrigerant receiver 76. The accumulator 74 and the receiver 76 are secured to the evaporator rear wall 62 in vertical spaced relation and the receiver is preferably 'located below the accumulator. As shown in Fig. 3, the accumulator 74 and the receiver 76 may be elongated tubelike containers of larger flow eapacity'than the'coil. T one end of the accumulator 74 is connected the coil end and intermediate th e erids oftl te accumulator is conne e d t herefrigerant rettirn lineBZ. V p k sfsliown in Pjigifi', the'rec'eiver "7 6 is inclinedto'the 'ta 1.' Extending into the upper fendof [thefreerver 76 ,""t he"conduit end "72 is sealed thereto and ex- :teiids jto a point"adjacent the bottom of the receiver. The bapillarytubei'30 is connected to the by pass c'onduit 136' ivhiclifin'ittirni is connected to the receiver 76 cent 'Jth'e 'upperend'thereofand in alignment with ta keport 78in co'nduit'f72, {Flow capa'cityfofthe jcondfuit 36 is greater thanlthe new; capacity of port 78 so "th'at'fdiiring norrr'ial {operation oftherefrigerator, "excessf l'i'quid refrigerant; overflowing from port 78 is "stored in' the rece v r, 'fDuring the"defrostinggperiod, vaporized refrigerant atliighft irt'ssure "entering the re deliver"76ft l 1rciu'gh by-pass '36'forces the body of liquid refrigerant therein"intothe'lower end ofcon'duit 72 'and the'riceinto the evaporator followed'by warm refriger'ant vapor. The body of liquid refrigerant is 'fo'r ced'thrjough'theevaporator and intothe motor-coinpress'or unit where it is evaporated bythe heat of said "iin'it' 'as disclosed in 'the aforesaid application. This evaporated refrigerant is circulated to theevaporator where it is'condefised and circulated through the evapotato; to the"motor-compressor unitfor reevaporation during the defrost cycle.

Thefr'iotor cornpre's'sor unit 26 has a casing 80'which 'e eiids into themachinery compartment 56 and is rig- "idly secured 'by'brackets 82to horizontal mounting rails 84 which extendacrossand are secured to the back of 'the' c'abinet. -B'ehind'the motor-compressor unit 26 is the"(fondens'er '24 which includes a sinuous conduit se- Ecured to a'v'ertical metal'panel 86 which is turn is secured -t0 tlie cabinet 20.

An'inlet fitting 90 connects the refrigerant return line 32 to and in communication with the casing 80. The fitting'90' is secured in and to thecasing at the top thereof and extends inwardly and downwardly into the casing. The inlet fitting conducts refrigerant vapor into .thecasing 80during normal operation and liquid re- -frigerant to the upper partof'the motor-compressor "unit -for: evaporation during defrosting of the system. I zwithin'the casing 80 is a refrigerant compressor 92 which .Isuspend from'the 'fitting 90 on a resilient mount torhelical coil spring 93, The compressor 92has a body "or 'cyli'nder block 94 in an upper recessed end of which is mounted anelectric motor, including a stator 96 and a rotor 98 tofdrive a vertical crankshaft 100 for opercating the compressor. The stator 96 is secured in'an'd to the: upper end of the cylinder block 98, such as by a press fit operation, and the motor rotor 98'may be securcly press fitted onto the upper end of the crank- :Shaft'lfltl. Y A U.-shaped bracket 102 suspendsthe com- .pressOI ,98;from the mounting spring 93, the bracket 10 2 having its opposite ends secured byscrews 103 to the topof the compressor casing, adjacent opposite sides j thereof Extending upwardly over the electric pmoton thelbraeket 102 rests substantially" midway of iits-e -sm theuppq e d. of the p n 3, Wh the *bmcket i tp c i e w a clearance ap t e t ec ;;the fitting QO Secured to the lower end of the fitting 90 is ;aspring retainer 104, and betweenthe retainer 104 and the lower end of spring 96 is a rubber insulator or grommet -106 to decrease transmission of audible vibrations. r r p H Secured to, the top of rotor 98 is a circulator or fan I Q S- f r circulating gaseous refrigerant throughout the gasing 8Q to; aid in cooling the motor and compressor. ants-fi m .9 a basi m w ch in e r u r y extending blades 110 extend radially about the discharge sa s t insfifla. .t t v H ln the cylinder block, a piston (not shown), is operatively connected to and driven by the crankshaft 100.

4 Secured to one end of the cylinder block "94 is 'a valve assembly 114 and a head 116. For a more detailed description of the cylinder block 94, valve mechanism 114 and head 116, reference may be had to the patent to Ralph W. Doeg No. 2,372,938, issued April 3, 1945.

Disposed above the compressor head 116 is an intake mufiier 118 having an inlet 120 open to'the interior of casing 80, and an outlet 122 connected'to and in-communication with the cylinder head 116 Onthe opposite side of the compressor from inlet muffler 118 is asecond and outlet muffier 124 which has an inlet connected to the cylinder head 116 by a conduit1'26 and an outlet connected to a fitting 128 by a conduit 130. Conduit 130 extends from outlet mufiler 124 upwardly over the compressor motor and down, following the general contour of casing 80 to fitting 128 to provide a large flexible conduit loop which will notappreciablyoppose oscillation of the motor-compressor or'be fractured by such oscillation. Gaseous"refrigerant is drawnfrom casing 80 into an inlet"120, throughmuffier 118 into head 116 and valve 114 to the compression chamber where the refrigerant is compressed and passes "out valve assembly 114, head 116, through conduit 126 into outlet muffler 124 and then'through conduit 130 to outlet fitting 128 to the condenser24. The

mufllers

118 and 124 function"to'rnufil" noiseoriginating at valve'114 which noise would otherwise be "transmitted hydraulically through the refrigerant flow lines. To further avoid undesirable 'noise"; it will be noted that I have arranged "the muffiersabove the level 127 of the lubricant'in the 'bottom ofthe casing 80so as not to conduct hydraulically to casing 80 any vibrations originating in the motor compressor.

In'the bottom of the cylinder block94 is a l ubricant inlet covered by a' filter container 12 9 which is secured to the block and has an inlet 131 submerged in the lubricant. Lubricant is drawn into the compressor through the filter by the "suction action of the cornp'r'essor for distribution to parts thereofto be lubric'iited. In order' to dampen oscillations of the motor-compressor on its single point mounting 93, I provide a pairof stabilizers each of which comprises a pair of helical coil 'springs 132'and 133 of conical shape that attach' the compressor to casing 80. The pairs of'spring's 132mm 133 are laterally positioned directly beneath the compressor and are arranged such that the axis of "crankshaft is b'etwee'nandtransverseto the axis-'of the springs. Also, the

springs

132 and 133 are-arranged inwardly-"of 'the outer periphery of i the compressor and such thatthe forces of th'e springs are tangential to the'axis of the crankshaft 100.

Each of the pair of springs132'and 133 are alike and as'shown in Fig. 7 are aligned, conicalcoil springs having their large ends engaging a common retainer'134 which is secured to a bracket 136 which inturn is secured by screws 138 to the underside of the' compressor block 94. The'smallerend of spring 132 abuts'an angle bracket 140- which is'secured to a flattened portion142 of casing 80 at the bottom thereof. Secured to bracket 140 is one-end of ,a rod 144 which-extends coaxially of the springs 132 and on the other end has a retainer 146 .for abutment of the smaller end of'spring 133. It

will be seenthat when the motor-compressor oscillates, springs 132 and 133 will be alternately compressed to 'limit or dampen the oscillatory action of the compressor.

which may have a lap joint 85 where the pans may be welded or be otherwise suitably secured together and hermetically sealed. In order that the unit 26 occupies as little as practical of the cabinetspace, I make the casing 80 drum shape and arrange the motor-compressor such that the axis of the crankshaft is transverse to the sides of the drum.

The modification of Figs. 8, 9 and 12 is similar to the above described motor-compressor unit and therefore like parts have been given like reference characters to avoid unnecessary repetitious description. In the modification, the motor-compressor is resiliently mounted with in casing 80 on a single coil spring 150 at the bottom of the casing, and torque induced oscillations of the motorcompressor about its single point mounting are dampened by pairs of

coil springs

152 and 154. The pairs of

springs

152 and 154 are located above the mounting spring 150; are oppositely disposed; and are arranged to exert forces tangential to the axis of rotation of crankshaft 100.

Secured to the underside of the cylinder block 94 is a casing 156 containing an oil filter 158, the casing 156 having an inlet 160 in communication with the lubricant in the bottom of casing 80. Lubricant is drawn up by the suction action of the compressor through casing 156 and filter 158 into the cylinder block for distribution to parts to be lubricated.

Secured to the bottom of the filter casing 156 is a cupshaped retainer 162 for the upper end of the mounting spring 150, the retainer having an aperture therein which aligns with the oil intake aperture in casing 156. Secured to the casing flattened portion 142 is a cup shaped retainer 164 in which is held a rubber abutment or retainer for the lower end of the'spring 150 to decrease transmission of vibrations originating in the motor-compressor to casing 80.

Adjacent ends of the stabilizing

springs

152 and 154 are attached to the casing 80 by

angle brackets

165 and 166 respectively, and the other ends of the

springs

152 and 154 are attached to the compressor body or casting by

brackets

168 and 170 respectively. The

brackets

165 and 166 are substantially oppositely disposed and'secured to the cylindrical wall of the drum-shaped casing 80 having horizontal legs 172 extending toward the compressor. Tabs 174 struck up out of the bracket legs 172 are provided to anchor the inner ends of

springs

152 and 154, each pair of which has its adjacent ends connected by a loop 176 that is adapted to hook onto the tabs. The opposite ends of the

springs

152 and 154 have hook ends 178 that book onto lugs 180 on the

brackets

168 and 170.

Brackets

168 and 170 are arcuate in shape to fit complementary with and against the outer cylindrical surface of the cylinder block 94 to which the brackets may be welded or be otherwise secured. Each of the

brackets

168 and 170 has midway of its ends, a channel section 182 which respectively straddle the ends of bracket legs 172 and function as stops in the event of unusual vertical movement of the motor-compressor on its mount.

A fitting 184, secured in and to the cylindrical wall of casing 80, at the top thereof, connects the return line 32 to the casing and directs refrigerant down onto the windings of the compressor motor. During defrosting of the evaporator, refrigerant in liquid state, is returned through conduit 32 to casing 80 from the evaporator 22 and is quickly vaporized by the heat of the motor. Va-

porization of the liquid refrigerant in casing 80 cools the motor-compressor and the vaporous refrigerant is conducted to the evaporator'wherein the refrigerant condenses and gives up the latent heat of vaporization to rapidly defrost the evaporator.

A pair of fans 186 and 188 are provided to circulate refrigerant throughout the casing 80. The fans 186 and 188 are vertically positioned directly beneath the fitting 184 and are secured to the upper end of the crankshaft 108 for rotation therewith. The fan 186 is secured to the upper end of crankshaft and fan 188 is secureclto and on the top of fan 186. The fan 186 may be made of sheet metal having a central depression or cup 190 from which extends a downwardly directed tubular portion 192 that is press fitted tightly onto the upper end of crankshaft 100. In the bottom of the cup 190, a plurality of radially spaced apertures 194 are provided for passage of liquid refrigerant, and secured to the bottom of the cup is a plate 198 having its periphery outwardly beyond the side of the cup so that liquid refrigerant passing down through the apertures 194 will be moved outwardly by centrifugal force along the bottom of plate 198 and at its periphery thrown off towards the motor windings. Outwardly of plate 198, the fan has radially spaced downturned blades 200 which induce circulation up through the rotor passages 202 to aid in cooling the motor-compressor.

During normal operation of the refrigerator, the gaseous refrigerant drawn from the evaporator into casing 80 by the action of the compressor is forced outwardly to the casing walls principally by the action of the upper fan 188. As shown, the fan'188 has a plate-like sheet metal base formed out of which is a plurality of upstanding, radially spaced fan blades 204. Inwardly of the blades 204, the fan base is provided with an upwardly directed frustro-conical portion 206 having an aperture for passage of liquid refrigerant down into the cup 190 of the lower fan 186. The cone-shaped base portion 206 directs gaseous refrigerant to the blades 204 of the upper fan. Preferably, a filter 210 is secured to casing 80 over the discharge end of fitting 184 to retain any foreign matter which may have gotten into the system.

By the suction action of the compressor, gaseous refrigerant is drawn into inlet 120, passing through intake muffler 118, head 116, valve assembly 114 into the compressor cylinder wherein compression takes place and the compressed refrigerant passes through the outlet side of valve assembly 114, head 116, conduit 126 to the outlet mufiler 124. From the outlet muffler 124, the compressed refrigerant passes through a conduit which extends upwardly and loops around the motor and then extends downwardly to connect to the outlet fitting 128. By extending the conduit 130 up and around the motor, the conduit is sufliciently flexible so as to offer little resistance to oscillation of the motor-compressor and without danger of fracturing the conduit. To prevent vibration of the conduit 210 to the extend of it possibly striking the motor I provide a resilient holder or rubber grommet 212 through which the conduit extends, the grommet being located intermediate the loop portion of the conduit and supported on the top of the compressor casting by a bracket 214. As shown, more clearly in Fig. 12, oppositely disposed resilient or rubber bumpers 216 may be provided to prevent metal to metal contact of the motorcompressor and its casing 80 in the event of unusual movement of the motor-compressor unit as may occur for example in shipping or mishandling.

In Figs. 14 and 15 is shown another arrangement for connecting stabilizing springs 218 at their inner ends to the unit casing 80. In this arrangement, the springs 218 are separate from each other and have hooks 220 on their adjacent ends to hook into an aperture 222 in a bracket 224 which is secured to the casing cylindrical wall and has a rubber grommet 226 in the aperture to decrease transmission of vibrations originating within the casing to the casing wall.

In Fig. 13 is shown another form of single point mounting for the motor-compressor having a coil spring 228 insulated from the bottom of the casing 80 by a rubber spring retainer or grommet 230. The retainer 230 fits onto a metal retainer 232 which is held in place by a pin 234 that extends upwardly from the bottom of the casing 80 coaxially of the spring 228. Secured to the underside of the compressor casting is a filter casing 236 out of the bottom wall of which is formed a downwardly directed cone 240 which retains the upper end of spring 228 and is open for intake of'lubricant into the filter casing. In the compressors shown in Figs. 8 and 12 I haveshown the lubricant level as at 127 which is below the compressor mufilersas is also shown and described in Connection with the compressor shown in Fig. 5.

From the foregoing description, it will now be understood that I have provided improved arrangements of the components'of'a refrigerant motor-compressor assembly particularly adapted for use in systems which utilize the unit to heat and evaporate the refrigerant subsequent to passing the Warm refrigerant through and quickly defrosting the evaporator. 'It'will also be understood that I have arranged the compressor and its motor on ,a single point mounting supported by the return line inlet fitting directly above the motor to-discharge against the motor windings for =rapid' vaporization-of the refrigerant. Furthermore, I have provided'an improved arrangement of springs -to stabilize oscillation of the of the invention or from.the scope of the appended claims.

Iclaim:

lxRefr igeratingapparatus comprising a cabinet having a food storage compartment and a machinery compartment, a refrigerant evaporator arranged'to cool said food storage compartment, a casing extending into said machinery compartment, refrigerant conduit meansto conduct refrigerant from said casing to said evaporator, return conduit means to conduct refrigerant fromsaid evaporator to said casing, a fitting connecting said return conduit-means to said casing and extending thereinto at the .upper parbthereof, a motor-compressor unit resiliently suspended from-said fitting within said casing, and a pair of coiled compression springs horizontally positioned-and secured to the lower portion of said motorcompressor unit and to the lower portion of said casing with the-axis of rotation of said unit being between and transverse to the axis of said springs to limit the oscillatory action of said motor-compressor unit.

2. Refrigerating apparatus comprising a cabinet having a foodstorage-compartment and a machinery compartment, arefrigerant evaporator arranged to cool said food storage compartment, a casing extending into said machinery compartment, refrigerant conduit means to conduct refrigerant from said casing to said evaporator, return conduit means to conduct refrigerant from said evaporator to said casing, a fitting connecting said return conduit means to said casing and extending thereinto at the .upper part thereof, a motor-compressor unit resiliently suspended from said fitting within said casing, and a pairof conical coiled compression springs horizontally positioned and secured to the lower portion of said motor-compressor unit and to the lower portion of said casing with the axis of rotation of said unit being between and transverse to the axis of said, springs to limit the oscillatory action of said motor compressor unit.

- References Cited in thefile of this patent -UNITED STATES PATENTS 2,021,298 Forsberg Nov. 19, 1935 2,042,497 Bixler June 2, 1936 2,463,035 Heitchue Mar. 1, 1949 2,540,062 Touborg Jan. 30, 1951 2,587,246 Touborg- Feb. 26, 1952 2,638,753 Doeg May 19, 1953 2,666,301 Doeg Jan. 19, 1954 FOREIGN PATENTS 554,074 France June 5, 1925