Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS2793506 A
Publication typeGrant
Publication dateMay 28, 1957
Filing dateMar 28, 1955
Priority dateMar 28, 1955
Publication numberUS 2793506 A, US 2793506A, US-A-2793506, US2793506 A, US2793506A
InventorsArthur M G Moody
Original AssigneeTrane Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Refrigerating apparatus with motor driven centrifugal compressor
US 2793506 A
Abstract  available in
Images(1)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

May 28, 1957 MOODY 2,793,506

A. M. G. REFRIGERATING APPARATUS WITH MOTOR DRIVEN CENTRIF'UGAL COMPRESSOR Filed March 28, 1955 IN VEN TOR. ARTHUR M. G. MOODY MMTW ATTORNEYS United States Patent REFRIGERATING APPARATUS WITH MOTOR DRIVEN CENTRIFUGAL COMPRESSOR Arthur M. G. Moody, La Crosse, Wis., assignor to The Trane Company, La Crosse, Wis., a corporation of Wisconsin This invention relates to refrigerating apparatus of the type including a motor-compressor assembly, and particularly to apparatus in which a motor and a multi-stage compressor are housed in a sealed unit.

It is an object of this invention to provide means for cooling the motor using the refrigerant of the apparatus as a heat exchange medium.

It is another Object of the invention to provide circulation of refrigerant gas from the condenser to the motor casing, thence over the rotor and stator of the motor, and thence to the cross-over pipe between the first and second stage of the compressor.

It is another object of the invention to provide passageways in the motor casing to conduct refrigerant gas in two streams to the ends of the motor to flow first over the bearings and with each stream then separating into two streams one of which flows over the stator winding and the other of which flows through the gap and outwardly through passageways in the stator.

Other objects and advantages of the invention will appear as the specification proceeds to describe the invention with reference to the accompanying drawings; in which- Figure 1 is a partly diagrammatic view of the refrigeration apparatus of my invention.

Figure 2 is a cross-sectional view of the motor-compressor assembly taken on an axial plane.

Referring now to Figure 1, an electric motor has at one end a first compressor stage 12 and at the other end a second compressor stage 14. A cross-over pipe 16 conducts gas from the discharge of the first stage to the inlet of the second stage 14. The gas discharged from the second stage 14 flows through a pipe 18 to a condenser 20. The condenser 20 may be of the shell-and-tube type in which cooling water flows through the tubing 22 and the refrigerant is in the shell outside the tubes. Refrigerant liquid condensed in condenser 20 flows by gravity through pipe 23 to a float chamber 24. Float 26 in fioat chamber 24 opens and closes to control the flow of refrigerant liquid to an evaporator 28 which is also of the shell-and-tube type in which the secondary refrigerant liquid such as water or brine flows through the tubing 30 and the refrigerant is in the shell outside the tubing 30. The secondary refrigerant liquid circulates between the evaporator 28 and the cooling load served by the refrigeration apparatus to transfer heat from the load to the evaporator 28. In removing heat from the secondary refrigerant, the refrigerant in the evaporator 28 boils forming gas which passes through the liquid eliminator 32 and thence into the suction pipe 34 to the inlet of the first stage compressor 12.

The motor 10 has a fiuid tight casing 35 secured in fluid tight relationship to compressor housings 12 and 14. A motor frame 38 is supported in said fluid tight casing 35 by a pair of rings 40 and 41 which divide the annular space between motor frame 38 and said fluid tight casing 35 into a central chamber 42 and end chambers 44 and 46. Motor frame 38 has bearings 48 and 50 which rotatably support a shaft 36. Shaft 36 extends 2,793,506 Patented May 28, 1957 at one end into compressor housing 12 and has impeller 52 secured thereto. The other end of shaft 36 extends into housing 14 and has impeller 54 secured thereto. A stator 56 is secured to the motor frame 36. Stator 56 has the usual windings 58. A plurality of radial passageways 60 extend through the stator 56. A rotor 62 is mounted on shaft 36 to rotate therewith. Rotor 62 rotates within stator 56 and has an outside diameter slightly less than the inside diameter of the stator 56 to provide a gap between the rotor 62 and stator 56. Refrigerant gas flows from the condenser 20 through a pipe 64 into branch pipes and 72 which in turn conduct the gas to the end chambers 44 and 46 respectively.

After the gas has traversed its path through the motor 10, as will be described in detail below, it flows from the motor 10 through pipe 74 which conducts the gas to the cross-over pipe 16. After entering the pipe 16, this gas flows with the gas discharged from the first stage 12 and enters the second stage 14.

The fiow of gas through pipe 64 may be manually controlled by valve 76. If desired valve 76 may be of the thermostatic type in which a temperature sensing bulb is mounted in the gas stream leaving the motor 10.

The gas, having entered the motor 10 through pipes 70 and 72, flows to end chambers 44 and 46 from which it is conducted by shrouds 67 and 68 into an annular stream surrounding the shaft 36. On leaving the shrouds 67 and 68 part of each stream fiows over the winding 58 and into the central chamber 42 and part of each stream flows into the gap between the rotor 62 and stator 56 and then outwardly through the radial passageways 60 in the stator 56 and into the central chamber 42. Central chamber 42 thus collects the gas flowing over the windings 58 and the gas flowing from the radial passageways 60 and conducts the gas to the pipe 74.

It is thus seen that the gas space above the tubes in the condenser provides a dependable source of gas for motor cooling. Since the condenser is at a pressure substantially equal to the discharge pressure of the second stage 14 and since the pressure in the cross-over pipe 16 is substantially equal to the discharge pressure of the first stage 12, there is sufiicient pressure difference to cause a considerable flow of cooling gas through the motor.

The gas entering the cross-over pipe 16 from the motor 10 through pipe 74 is superheated because it has removed heat from the motor. This superheated gas mixe with the gas in the cross-over pipe 16 and minimizes the danger of condensation of liquid in the second stage of the compressor.

The additional gas passing through the second stage 14 permits a more efiicient second stage design by reason of the fact that the passageways in the impeller can be made slightly wider.

While the apparatus disclosed and described herein constitutes a preferred form of the invention, yet it will be understood that the apparatus is capable of alteration without departing from the scope or spirit of the invention, and that all modifications that fall within the scope of the appended claims are intended to be included herein.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a refrigerating apparatus, the combination of an evaporator for vaporizing refrigerant, a condenser for liquefying refrigerant, a two stage compressor for circulating refrigerant through said evaporator and condenser, a cross-over conduit for conducting refrigerant from the first stage of the compressor to the second stage of the compressor, a motor for driving said compressor, a fluid tight casing enclosing said motor, said fluid tight casing being in fluid tight engagement with said compressor, a first conduit connected to said condenser and to said fluid tight casing for conducting refrigerant gas from said condenser to said fluid tight casing, a second conduit, connected to said fluid tight casing and to said cross-over conduit for conducting refrigerant gas from said fluid tight casingto said cross-over conduit whereby refrigerant gas flows through said fluid tightcasing to remove heat from the motor.

2. In refrigerating apparatus, the combination of an evaporator for vaporizing refrigerant, a condenser for liquefying refrigerant, a pipe for conducting refrigerant from said condenser to said evaporator, a Centrifugal compressor having a first compressor stage and a second compressor stage, said first compressor stage being connected to receive refrigerant from said evaporator, 'a crossover conduit for conducting refrigerant from .said first compressor stage to the inlet of said second compressor stage, a pipe for conducting refrigerantfrom said second compressor stage to said condenser, a motor casing in fluid tight engagement with said centrifugal compressor, a motor frame in said motor casing, annular rings between said motorframe-and said motor casing to support said motor frame in said motor casing, said annular rings being arranged to divide the annular space between said motor frameand said motor easing into a central chamber and two end chambers, a stator mounted in said motor frame opposite said central portion, said stator having radial passageways extending therethrough,passageways in said motor frame from said end chambers to the inner ends of said radial passageways, bearings in each end of the motor frame, a shaft and rotor assembly rotatably mounted in said bearings, said shaft and rotor assembly extending into said centrifugal compressor, an impeller in each compressor stage, said impellers being secured to said shaft and rotor assembly, conduit means connected to said condenser and said end chambers for conducting refrigerant from said condenser to said end .chambers, conduit means connected to said central chamberand said cross-over conduit for conducting refrigerant from said central chamber to said cross-over conduit whereby refrigerant is caused to flow from said end chambers through the passageways in said motor frame and then through the radial passageways in the stator to remove heat from the motor.

3. In refrigerating apparatus, the combination of an evaporator for vaporizing refrigerant, a condenser for liquefying refrigerant, a pipe for conducting refrigerant from said condenser to said evaporator, a first stage centrifugal compressorhaving ,an inlet connected to receive refrigerant from said evaporator, a second stage centrifugal compressor, a cross-over conduit for conducting refrigerant from said first stage centrifugal compressor to the inlet or said second stage centrifugal compressor, a pipe for conducting refrigerant from said second stage centrifugal compressor to said condenser, a motor casing in fluid tight engagement at one end with said first stage centrifugal compressor and at its other end with said second stage centrifugal compressor, a motor frame in said annular motor casing, annular rings between said motor frame and said motor casing to support said motor frame in said motor casing, said annular rings being arranged to divide the annular space between said motor frame and said motor easing into a central chamber and two end chambers, a stator mounted in said motor frame opposite said central portion, said stator having radial passageways extending therethrough, passageways in said motor frame from said endchambers to the inner ends of said radial passageways, bearings in each end of the motor frame, a shaft and rotor assembly rotatably mounted in said bearings, said shaft and rotor assembly having one end extending into said-first stage centrifugal compressor, an impeller secured to said one end of said shaft and rotor assembly, said'shaft and rotor assembly having its'other end extending-into said second stage centrifugal compressor, an impeller secured to said other end of said shaft and rotor assembly, conduit means connected to saidcondenser and said end chambers for conducting refrigerant from,,said condenser to said end chambers, conduit means connected tosaid central chamber and said cross-over conduit for conducting refrigerant from said central chamber to said cross-over conduit whereby refrigerant ,is caused to .flow from said end chambers through the passageways in saidimotor frame and then through the radial passageways in the stator toremove heat from the motor.

4. In refrigerating apparatus, the combination of an evaporator for vaporizing refrigerant, a condenser for liquefying refrigerant, a pipefor conducting refrigerant from said condenser to said evaporator, a first compressor stage, a second compressor stage, said first compressor stage being connected to receive refrig rant from said evaporator, a cross-over conduit, for conducting refrigerant from said first compressor stage to the inlet of said second compressor stage, a discharge pipe'for conducting refrigerant from said second compressor stage to said condenser, a motor casing in fluid sealing relationship with said compressor stages, a motor frame in said motor casing, hearings in each end of the motor'frame, a shaft and rotor assembly rotatably mounted in said bearings, said shaft and rotor assembly extending into said com pressor stages, an impeller in each of said compressor stages, said impellers being secured to said shaft and rotor assembly, a first conduit connected to said condenser and to said. motor casing for conducting refrigerant from said condenser to said motor casing, a second conduit connected to said motor casing and to said cross-over conduit for conducting refrigerant from said motor casing to said cross-over conduit whereby refrigerant is caused to flowfrom .said condenser to said motor casing and thence to said cross-over conduit to remove heat from the motor casing.

A-ndresen Dec. 6, 1932 Jones Mar. '24, 1942

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1890205 *Jan 31, 1931Dec 6, 1932W B ParkynRefrigerating apparatus
US2277647 *Aug 1, 1940Mar 24, 1942Carrier CorpRefrigeration
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2891391 *Aug 26, 1957Jun 23, 1959Vilter Mfg CoRefrigerated hermetically sealed motors
US2918209 *May 14, 1957Dec 22, 1959Schueller OttoMotor-compressor unit
US2961847 *May 7, 1957Nov 29, 1960Fairchild Engine & AirplaneHigh altitude cooling system
US3057172 *Apr 3, 1961Oct 9, 1962Westinghouse Electric CorpSystems for cooling motors of refrigerant compressors
US3094272 *Dec 9, 1960Jun 18, 1963Trane CoMotor-compressor apparatus
US3112618 *Jun 15, 1960Dec 3, 1963American Radiator & StandardCooling means for refrigerant compressor motors
US3122894 *Jul 5, 1962Mar 3, 1964American Radiator & StandardHermetic motor cooling by direct expansion of system refrigerant into motor
US3146605 *Jun 2, 1961Sep 1, 1964Carrier CorpApparatus for cooling a refrigeration system motor
US3150277 *Mar 14, 1962Sep 22, 1964Worthington CorpHermetic motor cooling by liquid refrigerant
US3158009 *Jan 23, 1963Nov 24, 1964Worthington CorpRefrigeration apparatus including compressor motor cooling means
US3165905 *Aug 15, 1962Jan 19, 1965Trane CoRefrigerating machine including an economizer
US3229896 *Nov 5, 1963Jan 18, 1966American Agile CoVaneaxial fan
US3261172 *Nov 12, 1963Jul 19, 1966Vilter Manufacturing CorpCoolant system for hermetically sealed motor
US3879180 *Dec 18, 1972Apr 22, 1975Gutehoffnungshuette SterkradeMethod for treating a gas current which is obtained by coal gasification
US3913346 *May 30, 1974Oct 21, 1975Dunham Bush IncLiquid refrigerant injection system for hermetic electric motor driven helical screw compressor
US4889475 *Dec 24, 1987Dec 26, 1989Tecumseh Products CompanyTwin rotary compressor with suction accumulator
US5363674 *May 4, 1993Nov 15, 1994Ecoair Corp.Zero superheat refrigeration compression system
US5431547 *Oct 5, 1993Jul 11, 1995Phoenix Refrigeration Systems, Inc.Liquid refrigerant pump
US5540061 *Jan 5, 1993Jul 30, 1996Hitachi, Ltd.Refrigerator
US5555956 *May 27, 1994Sep 17, 1996Nartron CorporationLow capacity centrifugal refrigeration compressor
US6009722 *Nov 20, 1998Jan 4, 2000Lg Electronics Inc.Motor cooling structure for turbo
US6450781Jun 5, 2000Sep 17, 2002Samjin Co., Ltd.Centrifugal compressor assembly for a refrigerating system
US6471493 *Jan 23, 2001Oct 29, 2002Lg Electronics Inc.Assembly structure for a turbo compressor
US6729858 *May 23, 2002May 4, 2004Lg Electronics Inc.Thrust bearing cooling unit for a turbo compressor
US6943468 *Oct 6, 2004Sep 13, 2005Toyota Jidosha Kabushiki KaishaTurbocharger with rotating electric machine
US7013669 *Feb 28, 2001Mar 21, 2006I.D.E. Technologies, Ltd.Arrangement for multi-stage heat pump assembly
US7071585Aug 25, 2005Jul 4, 2006Toyota Jidosha Kabushiki KaishaTurbocharger with rotating electric machine
US7342332 *Nov 18, 2004Mar 11, 2008Hamilton Sundstrand CorporationAir bearing and motor cooling
US7394175 *Sep 21, 2005Jul 1, 2008Hamilton Sundstrand CorporationIntegral motor and air bearing cooling path
US7757502 *Apr 12, 2005Jul 20, 2010Hamilton Sundstrand CorporationRAM fan system for an aircraft environmental control system
US7856834Feb 20, 2008Dec 28, 2010Trane International Inc.Centrifugal compressor assembly and method
US7975506Feb 20, 2008Jul 12, 2011Trane International, Inc.Coaxial economizer assembly and method
US8037713Feb 20, 2008Oct 18, 2011Trane International, Inc.Centrifugal compressor assembly and method
US8198762 *Jan 31, 2008Jun 12, 2012Pratt & Whitney Canada Corp.Winding end turn cooling in an electric machine
US8496533Mar 22, 2010Jul 30, 2013Hamilton Sundstrand CorporationJournal bearing with dual pass cooling for air machine
US8499760 *Jul 6, 2012Aug 6, 2013Resmed LimitedDouble-ended blower and volutes therefor
US8627680Oct 4, 2011Jan 14, 2014Trane International, Inc.Centrifugal compressor assembly and method
US20120266887 *Jul 6, 2012Oct 25, 2012Resmed LimitedDouble-ended blower and volutes therefor
US20140127050 *Jan 15, 2014May 8, 2014Ihi CorporationElectrical motor and turbo compressor
DE1258879B *Aug 17, 1959Jan 18, 1968American Radiator & StandardKuehlvorrichtung fuer geschlossene Elektromotoren
EP1526282A1 *Oct 22, 2004Apr 27, 2005Voith Turbo GmbH & Co. KGMotor-pump unit
WO1997039291A1 *Apr 22, 1996Oct 23, 1997Aktsionernoe Obschestvo ZakrytRefrigerating system and centrifugal compressor assembly for said system
WO1997039292A1 *Apr 26, 1996Oct 23, 1997Aktsionernoe Obschestvo Zakryt5 OR 8 kW REFRIGERATING SYSTEM AND CENTRIFUGAL COMPRESSOR ASSEMBLY FOR SAID SYSTEM
Classifications
U.S. Classification62/505, 62/510, 310/54, 415/199.1, 415/178, 417/350, 417/470
International ClassificationF25B31/00, F25B1/10
Cooperative ClassificationF25B1/10, F25B31/006, F25B2400/23
European ClassificationF25B1/10, F25B31/00C