US2500751A - Refrigeration apparatus - Google Patents

Description

March 14, 1950 s. A. HALFVARSON I 2,500,751

REFRIGERATION APPARATUS Filed May 19, 1947 INVENTOR 2 G'usfi vars-ore.

WITNESSES:

ATTORNEY mama 14.. 19st REFRIGERATION APPARATUS Gustaf A. Halfvarson, Springfield, Mass., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application May 19, 1941, Serial No. 748,936

' 4 Claims. (01. 230-208) This invention relates to motor-compressor units and more especially to enclosed units of this type.

It is an object of the invention to provide novel means for cooling an enclosed motor-compressor unit.

It is another object of the invention to provide novel means for circulating a heat-absorbing fluid over the motor and compressor of an enclosed unit.

It is a further object to provide novel means for conducting the heat from the motor, the compressor, and the cooling fluid of an enclosed motor-compressor unit to the enclosure of the 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 horizontal cross-sectional view of an enclosed motor-compressor unit embodying the invention; and

Fig. 2 is a view on the line IIII of Fig. 1.

Figure 3 is a detail view of a portion of the heat-conducting band.

In the drawings, the. reference numeral l8 designates the casing of a motor-compressor unit such as is used in domestic mechanical refrigerators. The casing I0 comprises the lower cup l2 and a cover l4 therefor welded to the cup l2. The lower portion of the side wall of the cup I2 is provided with fins l6 for conducting heat from the cup l2 to the ambient atmosphere. A motordriven compressor unit I1 is supported in the cup l2 on resilient springs l8. The unit I! comprises a lower cup-shaped casting and an upper cup-shaped casting 22 secured to the lower easting 28. A motor stator 24 is pressed into the upper casting 22 and carries the stator windings 26. The upper casting 22 is provided with an upper bearing 28, and the lower casting 28 with a lower bearing 38 in which bearings 28, 30, a shaft 82 is journaled. A motor rotor 34 is secured to the shaft 32 between the two bearings 28 and 38 and carries an overhanging crankarm 36 and crankpin 38 at its upper end. A compressor cylinder 48 is secured to the upper surface of the upper casting 22 and contains a reciprocating piston 42 actuated through a connecting rod 44 by the pin 38. The refrigerant vapor enters the casing [0 through a duct 45 and then passes through an inlet duct 48 into the valve chamber 46 of the compressor, is compressed, and forced from the casing in through a conduit 58.

The lower portion of the cup l2 forms an oil sump 54 which normally is filled with oil to the level of line 56. An oil pump 58 is located on the lower surface of the casting '28 and is formed by three metal discs 62, 63, and 64 held in place by bolts 65. The upper disc 62 has a central opening 66 into which the bottom of the shaft 32 extends.

Also in the central opening 66 is a paddle-type impeller wheel 61 which is driven by the shaft 32. The middle disc 63 and the lower disc 64 support the weight of the shaft 32 and also provide two ducts 68 and 18. Duct 68 communicates with the oil in the oil sump 54 and with the central opening 66 at a location near the hub of the impeller 61. The other duct 18 communicates with the central opening 66 at an area adjacent the periphery of the impeller 61 and with a central duct 14 in the crankshaft which runs longitudinally therethrough and at an angle through the crankarm 36 and the crankpin 38 and emerges on the upper face of the crankpin 38 When the motor 24, 34 is in operation, the oil pump 58 forces oil through the duct 14, through the crankpin 36 and sprays it upward in, a conical spray, as indicated by the arrows 16 in Figure 1. Lateral ducts l8 and also conduct some of the oil to the crankpin bearing and the motor bearings 28 and 30, respectively. A bleeder duct 69 connects with the opening 66 in the upper disc 62 and leads upwardly to an upper portion of the oil sump 54. This duct 68 allows refrigerant vapor bubbles which may be present in the pump 58 to escape.

The oil spraying from the upper end of the duct 14 strikes the cover l4, the compressor 48, 46, and the upper casting 22 and runs downwardly along the inner wall of the casing I0 and the surfaces of the compressor 48, 46 and the upper casting 22 and returns to the sump 54. In so doing, the oil absorbs heat from the compressor 43, 46 and the upper casting 22 of the motor and transfers heat to the inner wall of the casing III.

A metallic heat-conducting band 82 is located in the path of the down-flowing oil between the casting 22 and the finned area of the cup l2. This heat-conducting band 82 is formed of thin spring steel stock and is divided into panels by oppositely located cuts 84, as best shown in Fig. 3. The cuts 84 each terminate in holes 86 which distribute the bending stresses when the band 82 is bent. The band 82 thus consists of a series of flexible panels connected by narrow neck portions 88. Three pins 98,- equally spaced and secured to the band 82, engage holes 92 in the upper casting 22 to hold the band 82 somewhat loosely in position. The band 82 is not pre-bent at the neck portions '0 but assumes the polygonal shape shown in Fig. 2 when the unit is assembled, because of the greater flexibility of the neck portion ll over that of the panels 06. The band 02 is so thin that it transmits little of the noise the compressor l0, l6 and of the motor, 24, 34 to the casing l0. As a consequence, it also aids little in holding the unit in position in the casing l0, but does aid in damping out some of the periodic vibrations of the motor compressor unit il.

Its chief function is to transmit heat by conduction from the upper casting 22 to the casing II. It also retards the downward flow of the oil across it, so that the contact of the oil with the upper casting 22 and the cup i2 is prolonged to increase the heat transfer between the oil and the metal surfaces of the casting '22 and cup l2. The oil at the contact areas of the band 82 with the casting 22 and the cup l2 also aids in transferring heat from the casting 22 to the band 82 and from band 82 to the cup I2. In actual practice, a band of spring steel, .006 inch thick, has given good results where the outer diameter of the casting 22 is 6 inches and the space between it and the cup 12 is inch. The band consisted of nine panels.

It will be apparent from the above that this invention provides for spraying oil from the crankpin of a vertical motor compressor unit, which oil then absorbs heat from the heat-producing portions of the motor compressor unit and transfers the heat to the casing thereof, from which it is transferred to the ambient atmos phere by cooling fins. The invention also provides a heat-conducting band which aids in transferring heat from the motor to the casing.

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 other changes and modifications without departing from the spirit thereof.

What I claim is:

1. In an enclosed motor compressor unit comprising a casing, a motor, and resilient means for supporting said motor in said casing and out of contact with the walls thereof, the side walls of said motor and easing being cylindrical, the combination with said unit of a metallic heat transfer band interposed between said motor and casing, said band comprising a series of connected and substantially flat resilient panels, each of said panels contacting said casing at its panel-connecting portions and said motor by elements of said panel intermediate said panel-connecting portions. 4

2. The motor compressor unit defined in claim 1 wherein the panels are of such thinness that they add substantially nothing to the support of tllistrnotor during the normal operation of said u 3. A compressor unit comprising a sealed casing having a vertical cylindrical portion, heat dissipating means on the outer surface of said portion, a vertical cylindrical motor resiliently mounted in said casing and spaced from the walls of said cylindrical portion, heat-conducting means interposed between said motor and said casing portion, said means comprising a series of resilient metallic panels, each of said panels contacting the walls of said casing portion at the vertical edges of said panel and said motor at an area between said edges, said area lying substantially in the same plane with said edges, at least two of the contacting portions of each panel being free to slide on the respective surfaces contacted by said portions, 8. horizontally reciprocating compressor secured to said motor and driven thereby, said casing having an oil sump in a lower portion thereof, and an oil pump driven by said motor for spraying oil from said sump over an upper portion of said motor and over an upper interior wall surface of said casing, said 011 flowing downwardly over said means on its return to the sump.

4. In a motor-driven compressor unit including a casing means having an oil sump, a motor, a compressor driven by and secured to said motor, spring means engaging said casing and said motor and adapted to resiliently support said motor and compressor within and out of contact with the walls of said casing, and resilient metal heat-conducting fins, each of said fins contacting a wall of said motor and of said casing to conduct heat from said motor to said casing, the combination with said unit of pumping means driven by said motor and adapted to withdraw oil from said sump, and conducting means for guiding the oil discharged by said pump over said fins including the portions thereof contacting said motor and easing.

GUSTAF' A. HALFVARSON.

, REFERENCES CITED The following references are of record in the file of this patent:

' UNITED STATES PATENTS Num ber

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