US2178811A - Compression apparatus - Google Patents

Description

1939. M. e. SATEREN 2,178,811

COMPRESSION APPARATUS Qriginal Filed Nov. 30, 1935 2 Sheets-Sheet 1 III v BI Fic 2. I 4 w I J! I II INVENTOR m 6 501mm ATT v- NEY WITNESSES:

Nov. 7, 1939. M. G. SATEREN COMPRESSION APPARATUS 2 Sheets-Sheet 2 Original Filed Nov. 30, 1935 INVENTOR Mann N 6. 6n TEREN.

ATTO NEY WITNESSES: 'fi' Patented Nov. 7, 1939 I UNITED STATES 2,178,811 COMPRESSION APPARATUS Martin G. Sateren, West Springfield, Mass., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application November 30, 1935, Serial No. 52,375 Renewed December 21, 1938 5 Claims.

My invention relates to compression apparatus, and particularly to compression apparatus of the type wherein a motor and compressor are enclosed in a hermetically-sealed casing.

It is an object of myinvention to provide a hermetically-sealed motor compressor unit of improved design which is inexpensive to manufacture and which operates at high efilciency.

It is another object of my invention to eflzect lubrication and cooling of a hermetically-sealedmotor-compressor unit by circulating lubricant between various parts of the apparatus.

It is a further object of my invention to provide an improved suspension for a sealed motor and compressor which damps vibrations from the unit, and at the same time to efiectively cool the motorcompressor unit.

These and other objects are effected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. 1 is a vertical sectional view of my improved hermetically-sealed motor-compressor unit;

Fig. 2 is a view, partly in section, of my motorcompressor unit with portions of the enclosing casing removed;

Fig. 3 is a sectional view of the motor-compressor unit taken on the line III-III of Fig. 1, with the baffle plate removed;

Fig. 4 is a sectional view of the motor-compressor unit taken on line IV-IV of Fig. 2; and,

Fig. 5 is a detail plan view of the lubricant distributor disposed adjacent the top of the sealed casing of the motor-compressor unit.

Referring to the drawings for a detailed description of my invention, the sealed motor-compressor unit generally designated at I I is particularly adaptable for use with refrigeration apparatus wherein a refrlgerantis compressed, condensed and evaporated in a repeated cycle.

A sealed casing l2 encloses a motor and a compressor, generally indicated at l3 and I4. respectively. The casing I2 is formed from two drawn steel cup-shaped members l5 and 16 which are welded together at l1. A backing plate 9 is disposed peripherally of the welded joint I 1 to prevent the welding are from entering the interior of the casing I2 and damaging the equipment disposed therein. The cup-shaped members l5 and 16 are of suflicient extent that the weld I1 and portions of the members l5 and 16 may be removed to obtain access to the interior of the easing 12, and may be rewelded several times, thereby permitting re-use of the casing members. An inverted cup-shaped frame member l8, on which the motor l3 and compressor 14 are entirely assembled in vertical relation, provides a verticallyextending bearing l9 and a thrust bearing 20 for a drive shaft .21 between the motor and compressor.

-'I'he motor includes a rotor 22 connected to a hub 23, which is in turn pressed on the drive shaft 2 1,50 that rotational movement is imparted to the drive shaft 2| when the rotor 22 is turned. The frame member I8 is provided with an extended annular sleeve portion 24 into which a stator 25 for the motor I3 is pressed. The stator 25 is energized, from a suitable source of electrical energy, which is conveyed into the sealed casing l2 through conductors 26.

The cup-shaped frame member I8 is provided with an opening 30 in its upper closed end 21 and an eccentric bushing 28 is inserted therein. The compressor l4 includes a cylinder 29, and a pin 3| formed integrally with the cylinder 29 and extending into the eccentric bushing 28. By rotating the eccentric bushing 28, the position of the cylinder 29 is varied so that compressor head clearance may be adjusted. Such a construction is fully described and claimed in Patent Nos 1,951,558 issued to Carl F. Nystrom and assigned to the Westinghouse Electric 81 Manufacturing Company. The compressor l4 also includes a crank pin 32 and a counterweight 33 attached to the drive shaft 2|. A connecting rod 34 is attached to the crank pin 32 and the other end of the connecting rod pivotally connects with a compressor piston 35, so that the piston 35 is reciprocated in the cylinder 29. A cylinder head 38 is provided for the compressor I4 and contains suit able inlet and discharge valves (not shown) It is desirable to have low pressure. refrigerant gas prevail" in the casing I2 because the low pressure, in conjunction, with the operating temperature, results in maintaining the lubricant relatively pure, especially if a refrigerant and lubricant are utilized which are substantially miscible.

Gas to be compressed is, therefore, admitted to the interior of the casing 12 through a conduit 31, and is admitted to the cylinder 29 through an inlet conduit 38, which connects to a double mufiler chamber M of a mufller 42. A conduit 43 is provided in the muffler chamber 4! for withdrawing gas from the interior of the casing l2. Compressed gas is conveyed through a mufller chamber 44 by a conduit 45 and then to the exterior of the casing 12 through a conduit 46 extending from the muffler 42 through the casing l2. The mufller 42 is preferably welded to the frame member l8. The construction and operation of the mufller is fully described and claimed in the copending application of Elliott E. Grover, S. N. 754,967, filed November 27, 1934 for Mufiling device and assigned to the Westinghouse Electric 81 Manufacturing Company. A magnetic unloader 41 is also provided for unloading the compressor at starting, and is'connected to the compressor l3 and supportedthereby.

A sheet" metal cap t: is attached to the bottom of the cup-shaped frame member I8, and closes the open end thereof, thus forming a closed chamber 53 for the motor I3. A centrifugal impeller type lubricant pump 48 is attached to the end of the drive shaft 2I which extends through the cap 52. .An inlet 49 for the lubricant pump 48 extends into a reservoir of lubricant 5I in the bottom of the sealed casing I2. A flanged opening 54 is provided in the bottom of the cap 52' and affords communication between the motor chamber 53 and the interior of the sealed casing I2. Two other openings 50 are provided in the bottom of the cap 52 and provide communication between the lubricant pump chamber formed by housing 55 and the motor chamber 53. A sheet metal housing 55 for the lubricant pump 48 is attached to the cap 52 and forms a volute 55 for the pump 48. An outlet conduit 51 for lubricant extends upwardly from the volute 55. A lubricant dam formed by a sheet metal collar 58 surrounds the flanged opening 54 in the cap 52 and is attached to the cap 52 interiorly thereof for a purpose hereinafter described.

A suspension and buffer ring 59 is disposed around the frame member I8 intermediate of the vertical extent of the sleeve 24 and is attached thereto by brackets 5| of different sizes to provide in the ring 59 thus providing a jointed three point spring suspension for the motor compressor unit interiorly of the casing I2. The spring suspension damps vibrations and noise due to operation of the motor and compressor and ensures quiet operation. Suspension springs attached to ring 59 and ears 54 by jointed connections are utilized so that no rigid connections are present between the casing I2 and the frame l8 and the horizontal component of vibration is, therefore, eliminated. The ends of the springs 53 are provided with hooked extensions which enter the openings 54A of the ears 54 and the openings 52 of the ring 59. A plurality of flexible clamps 55, provided with a nut and bolt 58a to permit the ring 59 to be slid into the clamps 50, are spotwelded interiorly of the casing I2 and encompass the ring 59 to prevent contact of the ring 59 with the casing I2 and to prevent abnormal movement of the frame I8 in the casing. The entire assembly on the frame member I8, including the motor I3 and compressor I4, is, therefore, re-

' siilently suspended from the upper bell-shaped casing member I5.

In order to cool and lubricate the motor and compressor of a hermetically-sealed internally spring mounted unit, it is essential that a copious quantity of lubricant be circulated in contact with the sealed casing to cool the lubricant and also in contact with portions of the motor-compressor unit to abstract heat therefrom.

Referring now to the lubrication and cooling of the motor-compressor unit, lubricant is withdrawn from the reservoir 5| by the lubricant pump 48 through the inlet 49, and is discharged through the volute 55 and outlet conduit 51. The

outlet conduit 51 extends through an aperture 85 in a lubricant distrbuting plate 55 at the top of the casing I2. The lubricant plate 55, shown in detail in Fig. 5, is inserted in the upper cupshaped portion of the casing I5 and is supported on the cars 54. .Some of the lubricant which strikes the top of the casing I2 drops back through the aperture 55, while other portions of the lubricant pass through aperture 58 in the central portion of the distributing plate 55. The lubricant which drops through the apertures 55 and 58 in the distributing plate 55 is caught by a lubricant pan 59 which is fastened to the compressor I4 and frame member I8 by bolts II. The lubricant pan 59 is provided with two apertures 12 above the head 35 of the compressor, a third aperture 13 above the piston 35 of the compressor I4, and another aperture 14 at the edge of the pan- 59. Lubricant caught by the pan 59,-therefore,, passes through aperture 12 and over the head 35 of the compressor I4 to cool the same.

The lubricant pan 59 is larger than the counterpan I5 is disposed below the compressor I4 and collects the lubricant which bathes the compressor head 35. Lubricant caught by the lower is disposed at the bottom of the passageway TI to direct the lubricant from the passageway I1 over the top of the frame member I8. Lubricant which passes through the aperture 13 drops on the piston 35 as it reciprocates and is collected in oil grooves 19 in the piston 35, thus lubricating the piston. Any excess lubricant not picked up by the grooves 19 also falls to the top of the frame I8. All the lubricant which falls on the top of the frame I8 runs down the sides thereof and over the extended sleeve member 24, thus cooling the motor and frame, and then drops into the reservoir 5|.

The remainder of the lubricant conveyed to the cooled by contact with the heat dissipating surfaces of the casing I2 above the lubricant reservoir BI and is then returned to the reservoir, thus maintaining the lubricant in the reservoir at a relatively low temperature to abstract heat from the motor I3, compressor I4, and frame I8 when portions of thelubricant from the reservoir 5| come in contact therewith.

Lubricant for the bearings of the motor I3 and compressor I4 is conveyed throuh a conduit 88 which connects with the lubricant outlet conduit 51. Lubricant is conveyed through 'a passageway 82 to the shaft bearings I9 and 28. Lubricant which is forced upwardly through the passageway 82 also is conveyed to a passageway 83, 84 to lubricate the crank pin 32. Some of the lu- Lubricant which is forced downwardly flows through a transverse passage 85 in the frame I8 and then through passageways 8B in the rotor hub 23. Lubricant escaping from the passageways 86 is returned to the reservoir through the flanged opening 54 in the motor cap 52. The flange around the opening 54 is of such height to ensure a level of lubricant in pump housing 55 and in cap 52 within the dam 58 sufiicient to maintain the lubricant pump 48 primed. The disadvantage of a positive displacement pump is, that, when sudden lowering of pressure occurs on a mixture of lubricant and refrigerant, foaming occurs, the positive displacement pump pumps foam, and insufiicientlubrication results. However, liquid lubricant or a mixture of refrigerant and lubricant is always present in a primed pump such as the one disclosed.

As best shown in Figs. 2 and 4, lubricant is also directed from the volute 56 of the pump 48 through the two apertures 50 in the cap 52, thus flooding the lower end of the motor stator 25 with lubricant to cool the same. The level of lubricant on the stator (see Fig. l) is maintained by the lubricant dam 58, and overflow is returned to the reservoir through flanged open ing 54.

The mounting of the motor-compressor unit in the upper casing member l5 with the lubricant baflle 66 and lubricant conduit 51 in proper position, permits testing and running in of the motor compressor unit in an oil bath without the bottom portion ll; of the casing l2 being attached to the upper portion l5 of the casing. The lubrication system and other parts of the apparatus may, therefore, be fully tested and inspected with the lubricant baflie, motor, compressor and lubricant pump in proper assembled relation before the casing I2 is hermetically sealed.

From the foregoing it will be apparent that I have provided an improved hermetically sealed motor-compressor unit which is quiet and efflcient in operation and which is susceptible of test in assembled relation before sealing. Furthermore, I have provided a novel and effective cooling and lubricating system for an internally spring mounted hermetically sealed motor-compressor unit.

While I have shown my invention 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 changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specically set forth in the appended What I claim is: 1. In compression apparatus, the combination of a compressor, a motor for driving the compressor, a hermetically sealed casing for enclosing the motor and compressor embodying upper and lower separably attached portions, a lubricant reservoirin the bottom of the casing, a lubricant distributing means supported by and adjacent the top of the casing,'means supported by the upper casing portion for conveying lubricant from the reservoir to the distributing means, and means for resiliently supporting the motor and compressor from the upper casing portion, whereby the motor, compressor, upper casing portion, lubricant conveying means and lubricant distributing means may be completely assembled before attaching the lower portion of the casing.

2. In compression apparatus, the combination of a compressor, a motor for driving the compressor, a frame member upon which the motor and compressor are entirely assembled in vertical superposed relation, a hermetically sealed casing for enclosing the motor, compressor and frame member, resilient means attached to the top of the casing by a jointed connection and extending downwardly therefrom, a ring attached to the frame member, a jointed connection between the resilient means and said ring, whereby said motor, compressor and frame member are resiliently suspended in the casing, and means attached to the casing and encompassing the ring for limiting the movement of the frame member and for maintaining the ring out of contact with the casing.

3. In compression apparatus, the combination of a compressor,-a motor for driving the compressor embodying a stator and a rotor, a frame member upon which the motor and compressor are entirely assembled, a hermetically-sealed casing for enclosing the motor and compressor and the frame member, a reservoir of lubricant in the bottom of the casing, a first fixed baflle member in the upper portion of the casing, a .second fixed baflle member disposed above the frame member and the compressor, a lubricant circulating pump disposed within the casing for circulating lubricant to the first fixed baffle member, and means embodied in the first fixed baflle member for directing lubricant over the walls of the sealed casing to cool the lubricant before the cooled lubricant is returned to the reservoir, said pump directing other lubricant from the reservoir to the second fixed baflle member and said second fixed baflle member embodying means for directing lubricant therefrom over said compressor and frame member to abstract heat therefrom, said frame member totally enclosing the stator and rotor of said motor to prevent lubricant from contacting with the upper portions of the, stator and rotor and said frame member having openings in the bottom thereof to afford passage of the lubricant into contactw'with the lower portions of the motor stator to abstract heat therefrom before return of lubricant to the reservoir.

4. The combination as claimed in claim 3 wherein the frame member with the motor and compressor supported thereon is resiliently suspended in spaced relation with the interior of the sealed casing.

5. In compression apparatus, the combination of a compressor, a motor for driving tire compressor, a frame member upon which the\motor and the compressor are entirely assembled in vertical superposed relation, 8. hermetically and frame member are resiliently suspended in the casing, and means associated with the casing and encompassing the attaching means for limiting the movement of the frame member and for maintaining the attaching means out of contact with the casing. l

MARTIN G. SATEREN.

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