US2963216A

US2963216A - Refrigerating apparatus

Info

Publication number: US2963216A
Application number: US766247A
Authority: US
Inventors: Sr Regis D Heitchue
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1958-10-09
Filing date: 1958-10-09
Publication date: 1960-12-06
Anticipated expiration: 1977-12-06

Description

Dec. 6, 1960 R. D. HElTcHuE, SR 2,963,216

REFRIGERATING APPARATUS Filed Oct. 9, 1958 EVAPORATOR CONDENSER \NVENTOR REGlS D. HEI CHUE SR.

ATTORNY United States Patent() 2,963,216 yHarmonRATING APPARATUS Regis D. Heitchu'e, Sr., Longmeadow, Massa, assignor to Westinghouse Electric Corporation; East Pittsburgh, Pa., a corporation of Peurxsylv-im'iaV Filed Oct. 9, 19,58, `Sel' No.. 766,247 6 Claims. (Cl. 230-58)"V This inventionV relates to a motor-,compressor unit `for refrigerating systems and particularly to a unit resiliently supported in a Huid-tight casing and wherein the motor is cooled by refrigerant vapor Vflowing to the compressor.

The objective of the invention is improved performance of the motor-compressor unit, and this objective is achieved by the use of a novel arrangement for confining and directing vaporous refrigerant over certain portions of the motor-compressor unit and away from other portions of `said unit on itsy way to the inlet of the compressor.

In accordance with the invention, that endof the motor which is not enclosed by a frame is enclosed by a cover or hood that is in communication with the com pressor inlet through a tube. This cover is disposed close to the wall of the motor-compressor casing, which is provided with means for returning vaporous refrigerant to the casing. The cover has an inlet opening therein through which refrigerant, and particularly the cool refrigerant vapor entering the motor-compressor casing, is drawn by the compressor. The cover, in cooperation with the motor-compressor frame, contines refrigerant ow over and around the motor components, for the purpose of cooling the motor, and directs the main body of refrigerant ow away from other Warm portions of the motor-compressor unit, such as the compressor cylinder, the hot gas discharge line, and the pool of lubricating oil in the casing.

The invention affects the operation of the motorcompressor unit in two ways, each ofwhich increases the pumping capacity of the unit. In the first place, the motoris cooled more effectively, enabling the motor to carry increased loads without overheating. Secondly, cooler, and consequently more dense, refrigerant' vapor is delivered to the compressor inlet, so that a greater quantity of refrigerant is compressed with each stroke of the compressor piston.

Other objects, advantages and features of the invention will be yapparent from the following detailed description in which reference is made to the accompanying drawings forming a part hereof, and wherein:

Fig. 1 shows diagrammatically a refrigerating system incorporating a motor-compressor unit constructed inaccordance with this invention, the unit being shown in vertical section; and,

Fig. 2 is a plan view of the unit with the top of the casing removed.

The motor-compressor unit referred to generally by the reference numeral 1Q is a `part of a refrigerating system which also includes a discharge conduit 11, a condenser 12, an expansion device 13, an evaporator 14 and a suction conduit 15. The expansion device 13 may be of any suitable type known inthe art, such as a capillary ktube or a thermostatic expansion valve.

The refrigerating system as a whole operates in the usual manner of such apparatus,-the refrigerant gas compressed by the motor-compressor unit 10 being conveyed 2,963,216` Patented Dec.`6, 1960 ICC 2 through the discharge conduit 11 to the condenser 12, wherein the same is condensed. The liquefied refrigerant then ows. through the expansion devicel 12 which reduces theL pressure thereof. In the evaporator 14, the liquid refrigerant is vaporized by heat extracted from the substance to be cooled and the vaporized refrigerant flowsthrough the suction conduit 15 to the motor-compressory unit, wherein the same is re-compressed and recirculated.

The motors-compressory unit 10 includes a compressor 16, as motor 17 and a frame 18 for maintaining the compressor and the motor in operative relation to one another. The frame also provides bearing supports for the movable elements of' the motor and the` compressor. The compressor, the motor and the frame are resiliently supported within a uidftight casing 19 on three helical springs 20, one ofv which is illustrated in Fig. l. The springs 20 are of a compression type and are disposed vertically between casing mounted brackets 21 and lugs 22 projecting outwardly from the frame 1'8.

The motor 17 comprises a rotor 23 mounted on a kvertical axis shaft 24 and a stator 25 having windings 26 projecting from opposite ends thereof. The stator 25 is received in a tubular portion 27 of the frame 18 and is secured in place therein by a clamping ring 28 which is secured to the frame"18 by several bolts 29. The bolts 29 also pass through the rim of a cup-shaped cover or hood 30 which encloses the end of the stator 25 and the windings 26 thereon which are not enclosed by the tubular portion 27 of the frame 18. The other end of the stator 25, i.e., the end near the compressor 16, is

at least partially enclosed by the frame 18, although there are one or more openings 31 provided in this region of the frame 18 which allow lubricating oilto drain from the frame into the bottom of the casing 19 which forms a reservoir for lubricating oil.

The compressor 16 is driven by the motor 17 through shaft 24 which has an eccentric 32 thereon near its lower end. The eccentric 32 imparts reciprocating motion to a connecting rod 33 and a piston 34, the latter of which moves in a cylinder 35 formed as a part of the motorcompressor frame 18. The piston 34, in moving back and forth in the cylinder 35, draws vaporous refrigerant into the compressor 16 through an inlet pipe 36 and discharges compressed refrigerant through the discharge line 11 which extends through the wall of the casing 19. The inlet pipe 36 connects the inlet of the compressor 15 with the interior of the cover 30 enclosing the remote end of the motor 17.

The suction conduit 15 of the refrigerating system extends through a depressed region 37 in the top wall of the casing 19 and admits refrigerant to the interior of the casing. `This cool refrigerant is utilized for cooling the motor 17 and is drawn` by the compressor 16 through an inlet opening 38 provided in the cover 30, over the end windings 26 at the upper end of the motor, and over portions of the rotor 23 and stator 25 of the motor before entering the inlet pipe 36.

It will be noted that, although there is no direct connection between'the suction conduit 15 and the compressor inlet pipe 36, i.e. the conduit is independent of the motor cover 30, and though the entire` internal volume ofl the motor-compressork casing 19 is atksubstantially compressor inlet pressure, the cool incoming refrigerant is made to ow over portions of the motor 17 and then directly into the compressor 16 without ,being given the opportunity to come in contact with other warm portions of the motor-compressor unit, such as the compressor cylinder 35, the discharge line 11 which contains hot compressed gas, and the pool of oil in the bottom of the casing 19. The motor 17 is thus effectively cooled and the pumping capacity of the compressor 16 is increased because the compressor is handling cooler and, consequently, more dense refrigerant vapor than it would if the refrigerant were iirst'warmed by contact with the above-mentioned warm portions of the unit.

Several detailed features which contribute to the overall improved performance of the motor-compressor unit are embodied in the unit illustrated in the drawing. One of these features concerns a relationship between the motor end cover 30 and the adjacent wall of the motor-compressor casing 19. Preferably, the motor and compressor are so supported in the casing 19 as to dispose the cover 30 in closely spaced relation to the wall of the casing 19 through which vaporous refrigerant enters from the suction conduit 15. It will also be noted that the central wall portion of the cover 30 is depressed to conform at least partially to the depressed region 37 of the wall of the casing 19. This depression in the cover 30 is effective to guide refrigerant issuing from the suction conduit into the inlet opening 38 in the cover. In addition, this cover configuration provides an annular recess 39 on the inside cover 30 which at least partially receives the windings 26 at the remote end of the stator 25. This annular recess 39 functions as a restricted flow passage for confining the ow of cool vaporous refrigerant closely about the windings 26 of the stator.

It will also be noted that the compressor inlet pipe 36 is connected to a peripheral, or side wall, region of the motor end cover 30 so that refrigerant must ow over and around the stator windings 26 before entering the inlet pipe.

It can be readily appreciated that the cover inlet opening 38 is preferably made larger than the area of the suction conduit 15 at its discharge end to insure that the major portion of the refrigerant issuing from the suction conduit 15 will find its way through the opening 38 into the area beneath the cover 30. The supporting springs for the motor 17 and the compressor 16 permit movement and vibration of these components of the unit when the unit is operating, so there is relative movement between the inlet opening 38 and the discharge end of the suction conduit 15. For this reason, the inlet opening 38 is preferably shaped like the vibration or movement pattern of this end of the motor 17 so that there will always be at least a part of the opening 38 opposite the discharge end of the suction conduit 15 during operation of the unit.

From the above description it will be seen that this invention provides a relatively simple and inexpensive arrangement for insuring effective cooling of the motor of a motor-compressor unit that is resiliently supported within an enclosing casing. Moreover, the provision of an efficient flow path for the motor cooling refrigerant enables the compressor to work with cooler refrigerant and, consequently, pump a greater quantity of refrigerant.

While the invention has been shown in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof.

What is claimed is:

1. An enclosed motor and compressor unit for a refrigerating system comprising a compressor, a motor for driving the compressor, said motor including a rotor and a stator, a frame for supporting said compressor and said motor in operative relation to one another, said frame including a portion adapted to receive said stator in a manner to at least partiallyI enclose the end of the stator near the compressor and to expose the end of the stator remote from said compressor, a cover for the exposed end of said stator `and the corresponding end of said rotor, said cover having a refrigerant inlet opening therein, tubular means providing communication between the interior of said cover and the inlet of said compressor, a common fluid-tight casing for the compressor, the motor and the frame, means for resiliently supporting said frame in said casing, and means independent of said cover for admitting vaporous refrigerant to the interior of said casing in the vicinity of the inlet opening in said cover.

2. An enclosed motor and compressor unit for a refrigerating system comprising a compressor, a motor for ldriving the compressor, said motor including a rotor and a stator, a frame for supporting said compressor and said motor in operative relation to one another, said frame including a portion adapted to receive said stator in a manner to at least partially enclose the end of the stator near the compressor and to expose the end of the stator remote from said compressor, a cup-shaped cover secured to said frame for covering the exposed end of said stator and the corresponding end of said rotor, said cover having a refrigerant inlet opening therein, tubular means providing communication between the interior of said cover and the inlet of said compressor, a common fluidtight casing for the compressor, the motor and the frame, means for resiliently supporting said frame in said casing, and means provided in a wall of the casing near the inlet opening in said cover and independent of said cover for admitting vaporous refrigerant to said casing.

3. An enclosed motor and compressor unit for a refrigerating system comprising a compressor, a motor for driving the compressor, said motor including a rotor and a stator, a frame for supporting said compressor and said motor in operative relation to one another, said frame including a portion adapted to receive said stator in a manner to at least partially enclose the end of the stator near the compressor and to expose the end of the stator remote from said compressor, a cup-shaped cover secured to said frame for covering the exposed end of said stator and the corresponding end of said rotor, said cover having a refrigerant inlet opening in a central wall portion thereof, tubular means providing communication between the interior of said cover and the inlet of said compressor, a common Huid-tight casing for the compressor, the motor and the frame, means for resiliently supporting said frame in said casing with said cover in closely spaced relation to a wall of said casing, and means provided in said wall of the casing near the inlet opening in said cover and independent of said cover for admitting vaporous refrigerant to said casing.

4. An enclosed motor and compressor unit for a refrigerating system comprising a compressor, a motor for driving the compressor, said motor including a rotor and a stator having windings extending from opposite ends thereof, a frame for supporting said compressor and said motor in operative relation to one another, said frame including a portion adapted to receive said stator in a manner to at least partially enclose the windings at the end of the stator near said compressor and to expose the windings at the end of the stator remote from said compressor, a cup-shaped cover mounted on said frame and having said exposed windings of said stator disposed therein, said cover having a refrigerant inlet opening in a central wall portion thereof, tubular means connecting the inlet of said compressor to said cover in a peripheral region of said cover, whereby vaporous refrigerant entering said inlet opening in said cover is confined to ow around and in contact with said exposed stator windings in passage to the inlet of the compressor, a common fluid-tight casing for the compressor, the motor and the frame, means for resiliently supporting said frame in said casing, and means independent of said cover for admitting vaporous refrigerant to said casing near the inlet opening in said cover.

5. An enclosed motor and compressor unit for a refrigerating system comprising a compressor, a motor for driving the compressor, said motor including a rotor and a stator having windings extending from opposite ends thereof, a Iframe for supporting said compressor and said motor in operative relation to one another, said frame including a portion adapted to receive said stator in a manner to at least partially enclose the windings at the end of the stator near said compressor and to expose the windings at the end of the stator remote from said conlpressor, a cup-shaped cover having an inwardly depressed central wall portion providing an annular recess in said cover, said cover being mounted on said frame and having said exposed'windings of said stator disposed at least partially within said annular recess, said cover having a refrigerant inlet opening in said central wall portion thereof, tubular means connecting the inlet of said compressor to said cover in a peripheral region of said cover, whereby vaporous refrigerant entering said inlet opening in said cover is confined to flow around and in contact with said exposed stator windings in passage to the inlet of the compressor, a common fluid-tight casing for the compressor, the motor and the frame, means for resiliently supporting said frame in said casing, and means for admitting vaporous refrigerant to said casing near the inlet opening in said cover.

6. An enclosed motor and compressor unit for a refrigerating system comprising a compressor, a motor for driving the compressor, said motor including a rotor and a stator having windings extending from opposite ends thereof, a frame for supporting said compressor and said motor in operative relation to one another, said frame including a portion adapted to receive said stator in a manner to at least partially enclose the windings at the end of the stator near said compressor and to expose the windings at the end of the stator remote from said compressor, a cup-shaped cover having an inwardly depressed central wall portion providing an annular recess in said cover, said cover being mounted on said frame and having said exposed windings of said stator disposed at least partially within said annular recess, said cover having a refrigerant inlet opening in said central Wall portion thereof, tubular means connecting the inlet of said compressor to said cover in a peripheral region of said cover, whereby vaporous refrigerant entering said inlet opening in said cover is confined to ow around and in contact with said exposed stator windings in passage to the inlet of the compressor, a common fluid-tight casing for the compressor, the motor and the frame, means for resiliently supporting said frame in said casing with said cover in closely spaced relation to a wall of the casing, and means provided on said wall of the casing for admitting vaporous refrigerant to said casing near the inlet opening in said cover.

References Cited in the tile of this patent UNITED STATES PATENTS 2,274,942 Touborg Mar. 3, 1942 2,286,272 Higham lune 16, 1942 2,306,608 Hubacker Dec. 29, 1942 2,741,425 Scheldorf Apr. 10, 1956