US2907515A - Oil cooling system for compressors - Google Patents

Description

Ha -hm Oct. 6, 19 59 DAVEY 2,907,515

OIL COOLING SYSTEM FOR COMPRESSORS Filed May 8, 1958 2 Sheets-Sheet l FIG.|

INVENTOR.

PETER DAVEY BYW ms ATTORNEY Oct. 6, i959 P. E. DAVEY 2,907,515

OIL COOLING SYSTEM'FOR COMPRESSORS Filed May 8, 1958 2 Sheets-Sheet 2 FIGS INVENTOR.

PETER a. DAVE-Y H \S ATTORNEY United States atent O OIL COOLING SYSTEM FOR COMPRESSORS Peter E. Davey, Fern Creek, Ky., assignor to General Electric Company, a corporation of New York Application May 8, 1958, Serial No. 733,991

3 Claims. (Cl. 230-58) The present invention relates to an oil cooling system for hermetically sealed compressors and is more particularly concerned with an improved lubricating and oil cooling system for a sealed motor-compressor unit mounted with drive shaft axis horizontal.

In accordance with the present invention there is provided a hermetic compressor comprising a sealed casing having an oil sump in the bottom of the casing and a horizontal axis motor-compressor unit spring suspended within the casing above the sump. In order to limit tilting of the compressor unit within the casing, there are provided upper and lower brackets secured to the casing above and below the motor compressor unit and and having an oil inlet communicating with the sump.

A conduit extending from the pump and connected to the upper tubular element provides means for circulating a portion of the lubricant from the pump to the top of the casing where it is evenly distributed over the side walls of the casing by means of a baffle and screen arrangement extending between the tubular element and the casing walls. An outlet provided in the conduit connecting the pump with the upper tubular element is adapted to direct a portion of the circulating lubricant into heat exchange relationship with the motor means for returning this portion of the lubricant to the oil sump primarily includes the lower tubular element. In order that the warm oil or lubricant returning to the sump will first be mixed with cool lubricant or oil flowing down the side Walls of the casing, a partition is provided in the sump between the lower tubular element and the oil inlet to prevent direct flow of the returned motor cooling oil to the oil inlet.

For a better understanding of the invention, reference may be had to the accompanying drawings in which:

Fig. 1 is a vertical view, partly in section, of a hermetically sealed motor-compressor unit employing the oil cooling system of the present invention;

Fig.2 is an enlarged sectional view of the portion of the unit shown in Fig. 1;

Fig. 3 is a vertical sectional view taken substantially along line 3-3 of Fig. l; and

Fig. 4 is a top view of the unit of Fig. 1 with a portion of the sealed casing removed to indicate certain details of the battle and screen arrangement of the present invention.

With reference to the drawing and more particularly to Figs. 1 and 3 thereof, the disclosed embodiment of the present invention includes a sealed casing 1 containing a horizontally disposed motor-compressor unit including driven by the motor 2 through a shaft 4. It will be understood of course that this type of compressor unit is adapted to withdraw refrigerant from the evaporator component of a refrigerating system through the case 1 and to discharge compressed refrigerant from the compressor 3 to the condenser component of the system.

The motor-compressor unit is suspended within the casing 1 by means of a plurality of tension springs 5 having their upper ends secured to the casing 1 and theirv lower ends secured to the motor-compressor unit as shown in Fig. 3, it being understood that there will normally be provided a pair of such springs at each end of the motor compressor unit. With this type of suspension, means must be provided for preventing undue tilting of the motor compressor unit either during shipment or under a heavy shock and for this purpose there are provided upper and lower brackets 7 and 8 which are secured to the casing, each of the brackets having apertures 9 and 10 therein for receiving tubular elements 12 and 13 respectively secured to the upper and lower surfaces of the housing 14 closing one end of the motor 2 between the motor and the compressor 3. These tubular elements 12 and 13 are of substantially smaller diameter than the apertures 9 and 10 so that the compressor is permitted to move within limits as supported by the springs 5. n In accordance with the present invention the tubular elements 12 and 13 in addition to preventing excessive tilting of the compressor also form part of the oil-circu- More specifically the motor cooling and lubricant cooling system comprises an oil pump 18 which maybe of the general type disclosed and claimed in Patent 2,724,548Bixler issued November 22, 1955 and assigned to the same assignee as the present invention. By means of this oil pump, oil is withdrawn from the sump 15 though the oil inlet 20 extending into the sump. From the pump 18 the oil is conveyed upwardly through the interior of the housing 14 by a conduit 21 connecting the outlet of the pump to the lower end of the tubular element 12. A portion of the oil flowing through the conduit 21 escapes through the outlet 22 provided at the upper end thereof and is directed thereby over the motor 2 for the purpose of extracting heat from the motor. This portion of the oil flows downwardly over the motor and most or all of the warmed oil returns to the sump through the lower tubular element 13 which communicates with the interior of the housing 14 although some of it may flow through the lower stator slots and back to the sump,

The upper tubular element 12 is so connected to the conduit 21 that all of the oil which does not escape through the outlet 22 flows upwardly through this tubular element and onto the side walls 25 and 26 of the casing 1. In order to distribute the oil emerging from the upper tubular element 12 evenly over relatively large area of the casing side walls, there is provided an oil distribution means in the form of baffies 28 and 29 suitably secured to the upper bracket 7 and having relatively wide discharge ends extending substantially the length of the side walls 25 and 26 of the casing 1. Between the discharge ends 30 of the baffles 28 and 29 and the side walls 26 and 25, there are provided screens indicated by the numeral 34 which lie flat against the side walls as indicated in Fig. 3 and which due to their construction offer a pluv gatented Oct. 6, 1959 3 over the baflle sections 28 and 29 filters downwardly and uniformly over the side walls 25 and 26 of the casing. This oil cooled by contact with the relatively cool side walls then returns to the oil sump i5. In order to provide a positive transfer of the oil fro the outlet end of the upper tubular element 12 to the Walls 25 and 26 or at least to the sections 28 and 29, the upper tubular element 12 preferably has a closed top 35 and two small horizontal orifices 36 through which the oil is sprayed horizontally in the direction of the casing side walls and beyond the aperture 9 provided in the upper bracket 7.

During operation of the motor-compressor unit, the oil cooled as it flows down the casing side walls 25 and 26 mixes with the warmer oil returning from the motor through the tubular element 13 before again being picked up for recirculation through the oil inlet tube 20. a In order to assure a thorough mixing of the two portions before recirculation and particularly to prevent direct circulation of hot oil from the tubular element 13 to the inlet 29, there is provided a partition element 38 between the tubular element 14 and the oil inlet 20. This partitioning element preferably completely surrounds the oil inlet 20 and in eifect divides the sump into two portions, that is a return portion and a reservoir or supply portion. To supply oil to the oil inlet 20, one or more apertures 39 are employed on the side of the partition away from the tubular element 13. By this arrangement all of the oil entering the supply portion within the partition 38 for circulation through the motor first flows around the partition and in so doing mixes with the cold oil from the casing walls.

While the invention has been described with reference to the particular embodiment thereof, it will be understood that modifications may be made by those skilled in the art without actually departing from the invention and it is intended, therefore, in the appended claims to cover all such variations as come within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:'

1. A hermetic compressor comprising a sealed casing having an oil sump at the bottom thereof, a horizontal axis motor-compressor unit spring-suspended within said casing above said sump; said unit including a cylindrical housing enclosing one end of said motor, means for limiting tilting of said unit within said casing comprising upper and lower brackets each having an aperture therein and being secured to said casing above and below said housing and upper and lower tubular elements respec tively secured to the top and bottom sides of said housing and loosely extending into said apertures; and a motor cooling and oil cooling system including an oil inlet communicating with said sump, an oil pump, a conduit extending through said housing and connecting said pump with said upper tubular element, said conduit having an outlet within said housing for directing lubricant into cooling contact with said motor, said lower tubular element communicating with the interior of said casing and said sump to provide a return for oil from said casing to said sump, said upper tubular element having an oil outlet at the upper end thereof, means for distributing oil from said outlet in said upper tubular element over the walls of said casing comprising a sloping baflie extending substantially from said upper tubular element to the walls of said casing, a screen disposed between the extremity of said baffie and said casing for distributing the oil from said upper tubular element over a substantial portion of the walls of said casing, and a partition in said sump between said lower tubular element and said oil inlet for preventing direct flow of oil from said lower tubularelement to said oil inlet.

'2. A hermetic compressor comprising a sealed casing having an oil sump at the bottom thereof, a horizontal axis motor-compressor unit spring-suspended within said casing above said sump; said unit including a cylindrical housing enclosing one end of said motor, means for limiting tilting of said unit within said casing comprising upper and lower brackets each having an aperture therein and being secured to said casing above and below said housing and upper and lower tubular elements respectively secured to the top and bottom sides of said housing and loosely extending into said apertures; and a motor cooling and oil cooling system including an oil inlet communicating with said sump, an oil pump, a conduit extending through said housing and connecting said pump with said upper tubular element, said conduit having an outlet within said housing for directing lubricant into cooling contact with said motor, said lower tubular element communicating with the interior of said casing and said sump for returning said motor cooling oil to said sump, said upper tubular element having an oil outlet adjacent the upper end thereof, means for distributing oil from said outlet in said upper tubular element over the walls of said casing comprising a sloping baflle extending from said upper bracket to the side walls of said casing, a screen disposed between the extremity of said baffle and said casing for distributing the oil from said upper tubular element over a substantial portion of the walls of said casing and a partition in said sump surrounding said oil inlet, said partition having passages in the side thereof opposite the side facing said lower tubular element whereby hot oil returning from said motor is mixed with cooled oil flowing down the walls of said casing before passing through said passages to said oil inlet.

3. A hermetic compressor comprising a sealed casing having an oil sump at the bottom thereof, a horizontal axis motor-compressor unit spring-suspended within said casing above said sump; said unit including a cylindrical housing enclosing one end of said motor, means for limiting tilting of said unit within said casing comprising upper and lower brackets each having an aperture therein and being secured to said casing above and below said and loosely extending into said apertures; and a motor cooling and oil cooling system including an oil inlet communicating with said sump, an oil pump, a conduit extending through said housing and connecting said pump with said upper tubular element, said conduit having an outlet within said housing for directing oil into cooling contact with said motor, said lower tubular element opening into said casing and said sump for returning oil from said casing to said sump, said upper tubular element having an oil outlet adjacent the top thereof, means for distributing oil from said upper tubular element outlet over the walls of said casing comprising a sloping baflie extending from said upper bracket to the side walls of said casing, a screen disposed between the extremity of said baffle and said casing and having one side in contact References Iited in the file of this patent V UNITED STATES PATENTS

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