US2214086A

US2214086A - Refrigerating apparatus

Info

Publication number: US2214086A
Application number: US248888A
Authority: US
Inventors: Francis I Rataiczak
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1938-12-31
Filing date: 1938-12-31
Publication date: 1940-09-10
Anticipated expiration: 1957-09-10

Description

p '1940? F. l. RATAICZAK 2,214,086

REFRIGERATING APPARATUS Filed Dec. 51; 1938 2 Sheets-Sheet l 27: 9: INVEN'FOR.

flzmvcls [BOT/71:38AM

l/I ATTORNEYS.

. Sept. 10, .1940.

F. 1. RATAICZ'AK REFRIGERATING. APPARATUS Filed Dec. 31, 71938 2 Sheets-Sheet 2 INVENTOR. Ewvc/s 1 F4 rnlrZA A,

l/IS ATTORNEYS Patented Sept; 10,'

- UNITED STATES 2,214,086 'BEFRIGERATING APPARATUS Francis 1. Rataiczak, Dayton, Ohio, assignor to General Motors Corporation, Dayton, Ohio, a

corporation of Delaware Application December 31, 1938, Serial No. 248,888

- 12 Claims.

My invention relates tocompressor units and particularly to hermetically sealed motor-compressor units embodying a rotary compressor.

The efiiciency of a rotary compressor depends in part upon the clearance between the cylinder walls and the rotating elements or equivalent devices. This clearance varies as the temperature of the unit varies. Thus, a clearance which is proper to permit the starting of the rotary compressor may decrease to such an extent as the temperature of the unit increases as to cause a binding of the moving parts. On the other hand, a clearance calculated to produce emcient operation at high temperatures, may be so excessive at low temperatures as to prevent the compressor from. picking up the load placed thereupon.

In small units such as have been employed commercially on a very large scale to produce refrigeration in a household refrigerator cabinet, this problem is not critical because the volume of refrigerant worked by the units is not of such intensity as to cause excessive heating within the unit, and fins attached to the exterior wall of the casing of these small units ordinarily sufiice to dissipate heat therefrom. As the capacity of a unit is increased to meet the requirement of refrigerating larger areas or spaces, these larger units have greater internal heat loss and it becomes increasingly more diflicult' to withdraw heat through the structure. For this reason, commercial use of rotary compressor units of the hermetically sealed type has been limited to small units because it has been impossible to properly prevent a large variation in clearance between parts of the larger units.

I overcome these problems in a large rotary compressor unit by constructing the various parts thereof, wherever possible, of metals having the same coefi'icient of expansion and contraction and by providing rapid conduction of heat from the internal parts to the primary cooling means.

An object of the present invention is to provide an improved sealed unit compressor construction.

substantially constant tolerances between the parts.

PATENT orrlce Another object of the invention is to utilize refrigerant contained in a closed refrigerating system having a hermetically sealed motor-compressor unit forming a part thereof for removing heat from the motor rotor, the main bearing of the unit and parts of the compressor in thermal contact therewith to thereby cool and maintain same at substantially a uniform temperature particularly at times during which an abnormal amount of heat is generated.

In carrying out the foregoing objects, it is a further and more specific object of my invention to provide an improved construction for and method of utilizing the flow of compressed refrigerant discharged from a compressor in 2. hermetically sealed motor-compressor unit to withdraw a small amount of condensed liquid refrig- "erant'irom its storage reservoir, to circulate the withdrawn liquefied refrigerant along with the compressed refrigerant in thermal heat exchange relation with elements located centrally of the unit and to evaporate the liquid refrigerant during its circulation with the compressed refrigerant for removing heat from the centrally located elements and transferring this absorbed heat to the primary cooling means of the sealed unit.

Still further objects reside in details of con- .struction and in novel combinations, arrangements and cooperation of parts of the structure to provide a novel and improved sealed motorcompressor unit as will more fully appear in the course of the following description.

In the drawings in which like characters designate similar parts throughout the several views:

Fig. 1 is a vertical sectional view of a 'motorcompressor-condenser imit taken on the line i-l of Fig. 2 and constructed in accordance with the present invention;

Fig. 2 is a horizontal sectional view through the 40 unit shown in Fig. 1 and is taken on the line 22 thereof; and

Fig. 3 is a fragmentary sectional View taken on the line 3-3 of Fig. 1 showing the condenser structure.

Referring to the drawings, Fig. 1 shows a her metically sealed'unit comprising a motor, a compressor and a condenser. These elements of the sealed unit form part of a conventional closed refrigerating system which system also includes an evaporator and an expansion or the like valveor device (not shown) for controlling the flow of refrigerant from the unit to the evaporator. The unit, generally represented by the reference character 10, includes a lower metal housing H providing an oil sump'or reservoir and having an outwardly directed annular flange I2 formed on its top extremity. A dome, generally represented by the reference character I4, comprises a heavy metal ring I5, a cylindrical'member I6 and a cap member I1 all welded or otherwise suitably secured together. The dome I4 is mounted upon the lower housing II by a plurality of bolts I8 which pass through flange I2 and are screwthreaded into the ring I5. The cap I1 is provided with a box-like device which forms av juncture for electrical connections leading to and from the interior of the sealed unit. A plurality of metal fins I9 are vertically arranged in spaced apart relation around the interior of dome I4 and are welded or otherwise suitably secured to the inner wall surface of cylinder member I6 (see Fig. 3) for a purpose to be hereinafter described. The fins I9 are each corrugated as at 2I so that the corrugations are staggered and vertically inclined and each fin I9 also has a flanged portion 22 which spaces the fins apart and which is se-' cured to the wall I6. A metal spider or the like member 24 having a bearing portion 26 and an upstanding cylindrical wall portion 21 is provided with a flange 28 which is secured to the flange I2 on housing II by bolts'29. The cylindrical wall portion 21 of member 24 carries a stator 3|. A hollow member 32 constituting a rotor chamber 33 (see'Fig. 2) is mounted, such as by bolts 34, upon the lower face of member 24.: A lower bearing member 35 is provided with a flange 36 whichis secured to the hollow rotor chamber forming member 32 by bolts 31. There is a cap 4| secured by screws 42 to the lower end of bearing member 35, and this cap has an.opening 43 therein. A spring 44, located within cap 4|, bears against a ring 45 which abuts the lower end of a shaft 46. Shaft 46 extends through the lower bearing member 35, rotor chamber 33 and main bearing portion 260i the spider member 24 and projects upwardly of member 24 to provide a mounting for a rotor structure 48. The rotor structure 48 includes a hub or core 49 fitting over the upperend of shaft 46 and provided with one or more openings 5| therethrough. Rotor structure 48 is secured to: shaft 46 for rotation therewith by a key 52 and a bolt 53. The stator 3| together with the rotor structure 48 forms an electric motor for driving the compressor of unit I6 through the medium of shaft 46.

' The compressor rotor 55 located within the rotor chamber 33 (see Fig. 2) is keyed to shaft 46 by pins 56 passing through the shaft and abutting blades 51 mounted in slots provided therefor in'the rotor 55. Each blade 51 has a sealing'or rubbing block 58 associated therewith and engaging the inner wall of the hollow member 32 which forms the compressor rotor cnamber 33. It will be noted that the compressor or pump part of unit I9 includes four blades 51 with two pins 56 disposed one' above the other between two of the blades'and that the dimension over the pins 56 and their associated blades and sealing or rubbing blocks is predetermined or fixed. The compressor rotor 55 is concentric with shaft 46 while the wall of rotor chamber 33 formed by member 32 is eccentric relative to shaft 46 and rotor 55. Since the distance from the face of one block 58 to the face of its associated block is fixed, rotation of rotor 55 within the eccentric chamber 33 will cause the pins 56, blades 51 and blocks 58 to reciprocate within the slots provided'in the rotor 55. The space between rotor 55 and the wall of ch mber 33, inbetween adjacent blocks 58, thus forms suction and compression chambers for the refrigerant pump or compressor during rotation of and in accordance with the position of rotor 55 relative to refrigerant inlet and outlet ports.

- Low pressure or gaseous refrigerant flowing from the evaporator of the refrigerating system is directed through a pipe 6| and a conduit fitting, generally represented by the reference character 62 and detachably secured to unit I8, to the compressor. The conduit fitting 62 includes a pipe portion 63 positioned in a bore 64 provided in a wall of the hollow rotor chamber-forming member .32. An enlarged annular portion 65 formed on the fitting 62 is located within an opening 66 provided in the wall of the lower housing II. A flanged portion 61 of fitting 62 abuts the wall of housing I I and receives bolts 68 which are screw-threaded into housing II to detachably secure the conduit fitting 62 to the unit Ill. A gasket or the like 69 maybe placed under .the flange 61 of fitting 62 to seal the joint between the conduit. fitting and the housing I I. In

, order to seal the joint of pipe portion 63 of fitting 62 with the bore 64, I provide a resilient gasket or the like 12 which is pressedinto a counter bore 13 provided around the bore 64 in member 32. A metal washer 14 is placed in back of the gasket 12 and a spring 16 is compressed between the enlarged annular portion 65 of fitting 62 and the washer 14. The tension of spring 16 compresses the resilient gasket 12 against the wall of counter bore 13 and against the outer wall surface of the pipe portion 63 of fitting .62 to seal the pipe portion 63 within the bore64. 18 is secured within the fitting 62 to prevent the V entrance of foreign matter into the rotor chambr 33. After other various parts of unit III are assembled the pipe portion 63 -of fitting 62 together with the gasket 12, washer 14 and spring A cone-shaped screen 16 surrounding same are inserted through opening 66' in housing II and the inner end of the pipe portion 63 is pushed into the bore 64 of member 32 to thereby compress spring 16 and cause the gasket 12 to seal the joint of the fitting 62 with the bore 64. The bolts 68 are then threaded in place-to secure the fitting 62 upon the unit I0 and to thereby cause gasket 69 to seal the joint of fitting 62 with the housing II.

The hollow member 32, forming the rotor chamber 33, is provided with an outwardly projecting portion 8| to which a plate 82 is seemed; The inner part of the projecting portion 8| is hollowed out and the plate 82 in-cooperation with this hollowed out part of the projecting portion 8| forms a discharge chamber 83 for receiving refrigerant compressed and discharged by the compressor of the unit II]. An opening or a plurality of openings 84 drilled through the wall of portion 8| communicates with the rotor chamber 33. Each of the discharge ports or openings 84 is covered by a valve 85 secured by screws 86 (see Fig. 2) to a wall of chamber 83. A valve backing member or protector 81 is located over the valve 85 and is also secured by the screws 86 to member 32. A vertical opening 92 extends through a wall of chamber 33 to the upper, outer face of member 32 (see Fig. 1). An angularly disposed hole 93 drilled through the bearing portion 26 inafter more fully described. The Venturi device wall portion 21 with the body bearing formingportion 25 thereof adjacent the hole 93 is provided with a small hole 95 which communicates at its one end with hole 93 and at its other end=with a liquid refrigerant chamber or condenser 91 in which the fins 19 are mounted. A connector 98 which communicates with the condensed refrigerant chamber or reservoir 91 is adapted to have a pipe, which conveys. refrigerant liquefied by the unit 10 to an evaporator of the refrigerating system, secured thereto. A port H (see Fig. 2) is drilled through a wall of the bottom bearing member 35 and a part of this port communicates with the interior of rotor chamber 33. i0! is normally closed by a valve 02 having a valve backing member 103 thereover and secured to member 35 by screws I04. Valve 32 and member 103 may be of substantially the same type or design as the valve 35 and the member 8'1. The purpose of port l D! and its closure valve Hi2 will become apparent in the description to follow. It will be noted that oil contained within the oil sump formed by the lower housing ii is in open communication with the dome chamber formed by the member 14 through an opening or openings I08 provided in the portion of bearing member 24 which connects same with its cylindrical portion or wall 21. The pressure externally of the rotor chamber 33' is equalized throughout the interior of the sealed unit, provided by dome member 14 and the lower housing H, by the communicating passage or passages I06. The fitting 82, being sealed to the rotor chamber-forming member 32 and the valve or valves 85, closes the low pressure portion of the refrigerating system from the high pressure portion thereof existing within the sealed unit 10.

It is to be understood that the compressor or pump part of unit 10 is immersed or partly submerged within a body of oil in the oil sump formed by the lower housing I I. face HI formed in the spider member 24 and a bearing surface H2 formed in the lower bearing member 35 for shaft. 46 as well'as parts of the compressor portion of unit ID are effectively lu-'- bricated from the body'of oil in the oil sump.

During operation of the unit l0 oil flows from the sor part of unit ID to lubricate the operating elements thereof. The oil is forced, by. the back and forth sliding movement of blades 51, into the main bearing surface Hi and bearing surface H2 to lubricate these surfaces and enters grooves formed in the bearing surfaces of shaft 45. The oil is caused to flow from the bearing surface II I through a passage H1, provided in member 24, and from bearing surface 2 through a passage H8, provided in member 35, to a point adjacent the refrigerant inlet 54 from where it is conveyed along with refrigerant around the chamber 33. Any appreciable amount or oil trapped between adjacent blocks 58 and blades 57 at the time the rotor 55 begins to compress the refrigerant creates an excessive pressure in the compression space between the rotor and the wall of The port A bearing surchamber 33, and this excessive pressure will open the relief valve 102 to permit the oil to escape through the port opening lfll normally closed by the'valve 102. As soon as the abnormal pressure, caused by oil in the compression chamber, has been relieved valve 102 closes to cause compression of the refrigerant during further rotation of the compressor rotor. Oil also flows upwardly in the hole H4 provided in shaft 46 'to the end of this hole and is then directed through a horizontal hole H9, provided in shaft 46, to the outer surface of the shaft to lubricate the top surface of bearing portion 26 of member 24. A collar i2l bears against the lubricated top surface of bearing portion 28 of member 24 and has a spring 122 interposed between it and the hub or core 49 of motor rotor 48. The spring 122 co: operates with spring 44, located at the lower end of shaft 46, to maintain the shaft in the aligned position shown in the drawings and to prevent I undue wear of parts of the unit.

the electric motor portion thereof and the shaft rotates the compressor rotor 55. Revolutions of rotor 55 within the eccentric chamber 33 is permitted by the blades 5'! and their rubbing blocks 58 and pins 56 reciprocating back and forth within their slots in the rotor. Gaseous refrigerant evaporated in the evaporator of the refrigerating system fiows'through the conduit fitting 82 and enters the rotor chamber 33 within the space between two adjacent blades 51 of the compressor. This refrigerant entering the rotor chamber is carried around the chamber, during rotation of the rotor 55 and its blades 51, into proximity with the refrigerant outlet port 84 where v the refrigerant is compressed. As soon'as the blade 51, in advance of another blade between which the compressed refrigerant is trapped, passes the outlet port 84 the compressed refrigerant is forced by the rotor out of the rotor chamber 33 through valve or valves 85 into the discharge chamber 83. The space between the rotor 55 and the wall of chamber 33 and between each adiacent rotor blade 51 continues to fill with refrigerant gas drawn from the evaporator, to cause the evaporator to produce a refrigerating effect, and is compressed by rotation of therotor in the manner described while the blades 51 reciprocate within the rotor 55.

.The refrigerant compressed by the compressor and caused to enter the chamber 83 flows from chamber 83 through the passage 92 and is directed through the Venturi device, formed by ring 94 within passage or passageway 93, into the passageway 93. During the flow. ofcompressed refrigerant past or through the Venturi device or ring 94 a small-amount of previously cooled and liquefied refrigerant, from the condenser chamber 91, enters the passageway 33 by way of the small passageSB. Some of the precooled liquid refrigerant entering the passage 93 and mixing with the compressed vaporous refrigerant immediately expands or Vaporizes, and in flowing through the passageway 93 this evaporating refrigerant removes heat from the bearing portion 26 of the spider member 24 and consequently cools the main bearing surface ill and parts of the compressor in intimate heat exchange relation with the bearing portion 28. The remainder of the precooled liquid refrigerant entering passageway 93 is discharged therefrom along with the compressed refrigerant and in further. evaporating is caused the hub or core 49 of motor rotor 48. Evaporation of this remaining portion of the precooled liquid refrigerant or further evaporation of the partially evaporated liquid refrigerant in the vicinity of the .motor rotor 48 cools rotor 58 and carries the heat removed therefrom along with the compressed vaporous refrigerant upwardly above the motor rotor. The revolving motor rotor directs the vaporous refrigerant laterally therefrom over the motor stator 3| and into contact with the ends of condenser fins I9 which extend above the refrigerant condensing chamber 91. As the refrigerant contacts the fins I9 it is cooled and flows downwardly over and around the fins I9 whereby it iscondensed and liquefied and drops to the bottom of chamber 91. The condensed liquefied refrigerant is stored in chamber 91 prior to being circulated, by a pipe connected to the connector 98, to the evaporator of the refrigerating system. It is, of course, to be understood that it is a portion of this cooled and liquefied refrigerant which flows through the small passage 96 to be mixed with the compressed vaporousrefrigera'nt and to be evaporated therein forcarrying out the cooling process of the bearing portion 26 of member 24, the main bearing surface III, the motor rotor 48 and consequently parts of the compressor in thermal contact with the bearing portion 26 of member 24 as described. A water cooling coil I3I, having an inlet I32 and an outlet I33, is welded or otherwise suitably secured to the outer wall surface of the cylindrical wall portion I6 of dome member I4 to augment removal of heat from the refrigerant to cool and condense -same.

Since the unit III disclosed is intended for use in large refrigerating systems such as, for

example, refrigerating systems of from one to five-ton refrigeration requirements, the demand upon the unit is far greater than in refrigeratingsystems employing a conventional small size refrigerant compressing unit, andconsequently the present unit must be of increased capacity. In such large units an intense amount of heat is generated, and unless the unit is cooled internally in the manner herein disclosed, it will not be efiicient in meeting the refrigerating requirements placed upon it. For example, heat generated by the motor rotor 48 and transmitted to bearing portion 29 of member 24 and/or heat generated in the main bearing surface III and transmitted to parts of the compressor might be so intense that the bearing surface would be damaged or so intense as to cause irregular expansion of centrally located parts of the unit relative to other parts thereof. However, my method of removing heat from the bearing surface and from the motor rotor eliminates the possibility of damaging the main bearing and avoids undue expansion of certain parts of the unit to provide a construction capable ofoperation over long periods of time; My invention permits the,constructiono a combined motorcompressor-condenser unitand provides 8. hermetically sealed unit of compact and improved structure.

It is important in a unit of the type disclosed to control the motor temperature in direct proportion to the load placed upon the compressor.

That is, over-cooling of the motor is not desired because its, efllciency has been found to be greater when a certain predeterminedminimum amount of heat is present therein or in the vicin'itythereof. However, an excess amount of heat within or in the vicinity of the motor under heavy load conditions must be removed since the heat may be rapidly conducted to the main bearing and other parts of the unit. Therefore, the size of the passages or

passageways

92 and 93 and also passage 96 relative to

passages

92 and 93 and the size of ring 94 is calibrated so that the volume of compressed vaporous refrigerant, flowing through

passages

92 and 93 and through the Venturi device, and its velocity modifies the efiect of the Venturi device formed by the ring 94-. In other words, in the structure disclosed the volume and/or velocity of the vaporous refrigerant discharged by the compressor automatically changes the effectiveness of the Venturi device to draw more or less precooled condensed liquid refrigerant from the condenser 91 through passage 96 and into the passage 93. Under heavy load conditions the compressor discharges a greater amount of refrigerant than under normal or. minimum load conditions and a greater amount of precooled liquid refrigerant is withdrawn, by the suction effect created by the Venturi device, from condenser 91 through passage 96 and into the passageway 98 to increase the cooling of the motor, the main bearing III and parts of the compressor during existence of the heavy loadcondition. By this increased cooling efiect I control the temperature of the motor and particularly its rotor, the main bearing and parts of the compressor in direct- Since the oil sump within housing II stantially equalized. This equalization of pressure within the unit Ill insures an efiective circulation of oil and efiicient lubrication of operating parts of the unit. The Venturi device forms an obstruction within passageway 93 to the flow of refrigerant therethrough to cause a slightly greater pressure, say for example approximately two pounds, to be built up in the discharge chamber 83 than in the interior of the hermetically sealed unit during operation of the compressor. Obviously, this differential in pressure existing between the discharge chamber 83 and the interior of'unit I0 is employed to render the Venturi device effective 'to withdraw liquid refrigerant from the condenser 91.

The various parts of the present unit and particularly parts of the compressor, the housing forming the main bearing for the shaft and the shaft are composed of metal having substantially the same constituents so that the expansion and contraction of all the cooperating parts will be as nearly uniform as'possible. The uniform coelficient of expansion and contraction of the metal parts together with the efiective lubrication thereof and the method of cooling the I various centrally located parts permits the tolthe main shaft bearing :I II both of which may 7 generate heat and transfer this heat to other parts of the unit are not affected by the cooling of the motor stator since they are spaced therefrom and located centrally of unit HI. Thus, it is obvious that other means in addition to the water coil l3! must be provided for removin heat from parts located centrally of the unit.

From the foregoing it will be apparent that I have rendered a sealed unit which normally would be ineffective for meeting large refrig- 'eration requirements, capable of increased capacity, durable and of long life even under :abnormal load conditions. In my improved unit the rate of removing heat from the heat generating parts thereof is varied in accordance with loads imposed on the unit or in other words in response to the volume of refrigerant compressed and circulated by the unit. My invention insures increased cooling of the motor rotor and main hearing at times when an abnormal amount of heat may be generated thereby to thus maintain a substantially constant operating temperature within the unit which is capable of preventing damage-to parts thereof and which is desirable for obtaining maximum efiiciency.

While the form of embodiment of the invention -as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted. all coming within the scope of the claims which follow.

What is claimed is as follows:

1. In a refrigerating system including a condenser, an evaporator, a hermetically sealed unit including a compressor, a motor having a shaft connected with the compressor for operating same and a bearing for the shaft, the method of removing heat from the shaft hearing which comprises, withdrawing liquid refrigerant from the condener by refrigerant discharged from the compressor before the discharged refrigerant leaves the interior of the unit, circulating the withdrawn liquid refrigerant with refrigerant discharged from the compressor within the sealed unit and in intimate heat exchange relation with the shaft bearing to-evaporate the liquid refrigerant, and cooling and recondensing the evaporated refrigerant.

25In a refrigerating system including a condenser, an evaporator, a hermetically sealed unit including a compressor, a motor having a shaft connected with the compressor for operating same and a bearing for the shaft, the method of removing heat from the shaft bearing and from the motor which comprises, withdrawing liquid refrigerant from the condenser by refrigerant discharged from the compressor, circulating the withdrawn liquid refrigerant with refrigerant discharged from the compressor first in intimate heat exchange relation with the shaft bearing and thence in intimate heat exchange relation with the motor to evaporate the liquid refrigerant, and thereafter cooling and recondensing the evaporated refrigerant.

35A hermetically sealed unit comprising in combination, a casing, a refrigerant pump and an electric motor for operating the pump disposed within said casing', means for directing refrigerant discharged by said pump/1n contact with said motor, means for cooling and storage means for conveying liquid refrigeranttherefrom into said directing means, and means rendered eifective during operation of said pump for circulating the liquid refrigerant conveyed into said directing means along with refrigerant discharged from said pump and for causing evaporation of the liquid refrigerant in intimate heat exchange .relation with said motor.

4. A hermetically sealed unit comprising in combination, a casing, a refrigerant pump and an electric motor for operating the pump disposed within said casing, means for directing refrigerant discharged by said pump in contact with the rotor of said motor, means for cooling and liquefying refrigerant discharged from said pump and for storing the liquefied refrigerant within said casing, means communicating with said liquefied refrigerant storage means within said casing for conveying liquid refrigerant therefrom into said directing means, and means rendered effective by operation of said pump for circulating the liquid refrigerant conveyed into said directing means along with refrigerant discharged from said pump and for causing evaporation of the liquid refrigerant in intimate heat exchange relation with the rotor of said motor.

5. Ahermetically sealed unit comprising in combination, a casing, a refrigerant pump and an electric motor for operating the pump disposed within said casing, a shaft connecting the rotor of said motor with said pump, a bearing for said shaft, meansfor directing refrigerant discharged by said pump in contact with said shaft bearing, means for cooling and liquefying refrigerant discharged from said pump and for storing the liquefied refrigerant, means communicating with said liquefied refrigerant storage means for conveying liquid refrigerant therefrom into said directing means, and means rendered effective during Operation of said pump for circulating the liquid refrigerant conveyed into said directing means along with refrigerant discharged from said pump and for. causing evaporation of the liquid refrigerant in intimate heat exchange relation with said shaft bearing.

6. A hermetically sealed unit comprising in combination, a casing, a refrigerant pump and,

an electric motor for operating the pump disposed within said casing, a shaft connecting the rotor of said motor with said pump, a bearing 'for said shaft, means for directing refrigerant discharged by said pump in-contact with said shaft bearing and in contact with the rotor" of said motor, means for cooling and liquefying refrigerant discharged from said pump and for storing the liquefied refrigerant, means communicating With-said liquefied refrigerant storage means for conveying liquid refrigerant therefrom into said directing means, and means rendered effective during operation of said pump for circulating the liquid refrigerant conveyed into said directing means along with refrigerant discharged from said I pump and for causing evaporation of the liquid refrigerant in intimate and the rotor of said motor.

7. A hermetically sealed unit comprising in combination, a casing, a refrigerantpump and an electric motor for operating the pump disposed within said casing, a shaft connecting-the rotor of said motor with said pump, a member forming a bearing for said shaft, said member having a passageway formed therein and extending lengthwise with said shaft for directing refrigerant discharged by said pump along said shaft bearing and into contact with the rotor a heat exchange relation with said shaft bearing of said motor, means for cooling a'ndliquefying 75 refrigerant dischargedfrom said pump and for storing the liquefied refrigerant within said casing, said member also having a conduit formed therein communicating with said liquefied refrigerant storage means within said casing and with said directing passageway, a Venturi device adjacent the point of communication of said conduit with said passageway, said Venturi device being rendered effective by operation of said pump for conveying liquid refrigerant from said liquid refrigerant storage means into said passagewaywhereby the liquid refrigerant is circulated along with refrigerant discharged from said pump and caused to evaporate in intimate heat exchange relation with said shaft bearing and the rotor of said motor.

8. A hermetically sealed unit comprising in combination, a casing, a refrigerant compressor, an electric motor, the rotor of said motor being mounted upon a shaft connected with the compressor for operating same, a member forming a bearing for said shaft, said motor rotor, said shaft, said bearing forming member and said compressor all being inthermal exchange relationship with one another and located. centrally of said casing, means for directing refrigerant discharged by said compressor through said bearing forming member, means for cooling and liquefying refrigerant discharged from said compressor and for storing the liquefied refrigerant, means communicating with liquefied refrigerant storage means for conveying liquid refrigerant therefrom into said directing means, and means rendered effective during operationof said compressor for circulating the liquid refrigerant conveyed into said directing means along with refrigerant discharged from said compressor and for causing evaporation of the liquid refrigerant in intimate heat exchange relation with said bearing forming member to cool same and the other elements of said unit in thermal exchange relationship therewith.

9. In a refrigerating system including a conheat exchange relation with said one element to evaporate the liquid refrigerant, and cooling and recondensing the evaporated refrigerant.

10. In a refrigerating system including a condenser, an evaporator, a hermetically sealed unit comprising a casing having located therein a compressor element and a motor element direct frigerant along with refrigerant discharged from the compressor element within the casing of the sealed unit first in intimate heat exchange relation with the shaft bearing and thence in intimate heat exchange relation with said one element to evaporate the liquid refrigerant, and

thereafter cooling and recondensing the evaporated refrigerant.

11. A hermetically sealed unit comprising in combination, a casing, a refrigerant pump member and an electric motor member for operating the pump member disposed within said casing, a shaft connecting the rotor of said motor member with said pump member, a bearing member for said shaft, means for directing refrigerant discharged by said pump member toward another of said members, means for cooling and liquefying refrigerant discharged from said pump member and for storing the liquefied refrigerant, means communicating with said liquefied refrigerant storage means for conveying liquid refrigerant therefrom into said directing means, and means rendered effective during operation of said pump member for circulating the liquid refrigerant conveyed into said directing'means along with re-' frigerant discharged from said pump member and for causing evaporation of the liquid refrig-- erant in intimate heat exchange relation with one of said members.

12. In a refrigerating system including an evaporator and a hermetically sealed unit comprising'a casing having located therein a compressor element, a motor element directly connected to the compressor element for driving same and a condenser, the method of removing heat from one of said elements which comprises, withdrawing gaseous refrigerant from said evaporator compressing same by said compressor element and discharging the compressed refrigerant from said compressor element into said casing, condensing the compressed discharged refrigerant in said condenser within said casing and before the refrigerant leaves the casing, withdrawing liquid refrigerant from the condenser within said casing by refrigerant discharged from said compressor element, circulating the liquid refrigerant withdrawn from said'condenser along with refrigerant discharged from said compressorelement. within the casing and in intimate heat exchange relation with said one element to evaporate the liquid refrigerant, and cooling and recondensing theevaporated refrigerant entirely within the casing of the sealed unit.

' FRANCIS I. -RATAICZAK.