US 2504528 A
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Description (OCR text may contain errors)
April 18, 1950 w. c. HUME 25@4,528
REFRIGERATION APPARATUS Filed Sept. 6, 1944 2 Sheets-Sheet lm .m \L
Z 55 l f April 18, 1950 w. c. HUME 2,504,528
REFRIGERATION APPARATUS Filed Sept. 6, 1944 2 Sheets-Sheet 2 .Patented Apr. 18, 1950 REFRGERTON APPARATUS William C. Hume, Willow Grove, Pa., assignor, by
toPhil co Corporation,
Philadelphia, Pa., a corporation of Pennsylvania y Application September 6, 1944, Serial No. 552,888
The present invention relates to motor-compressors, more especially of a type adapted for use in refrigerating systems.
More specifically, the invention pertains to motor-compressor units of the hermetically sealed type, and has for one of its objects the provision of improved means for effectively cooling the unit and for lubricating the moving parts thereof, said means avoiding the use of intricate mechanism and involving no material change in the basic structure of the unit.
Another object of the invention is to provide an' arrangement whereby existing parts oi a sealed motor-compressor may be employed for forcibly pumping a lubricating medium, such as oil, from a permanent supply to various moving elements of the motor-compressor for cooling and lubricating the same.
Still another and more speciiic object of the invention is 'to provide an arrangement whereby the cross slide member of a Scotch-yoke-drive type of motor-compressor unit may be utilized as a lpumping member for withdrawing oil collected in the sump within the motor compressor housing and discharging the oil under pressure in the form of a spray internally oi said housing for cooling the unit.
A vmotor-compressor made in accordance with the invention is characterized by the absence of specially designed and intricate pump mechanisms which have heretofore been incorporated in motor-compressor units of the aforesaid type to cool and lubricate the same, and by the utilization of -the movement of a normal element of the motor-compressor mechanism to perform functions which heretofore have required the pro vision of such specially designed and intricate 4pump mechanisms. l
Other objects and characteristic features ci the invention will be apparent from the following description and accompanying drawings, in which:
Figure 1 is a transverse sectional view, partly in elevation, of a hermetically sealed motorcompressor unit incorporating an embodiment of the present invention;
Figure 2 is an enlarged detail of the lower portion of the motor-compressor mechanism shown in Figure 1;
Figure 3 is a section taken substantially along line 3--3 of Figure 2; I
. Figure 4 is an enlarged sectional detail view. in perspective, illustrating a cooperative port arrangement;
Figures 5 through 8 are somewhat diagram- (Cl. 23o-206) matic representations of the mechanism in suc cessive positions in the operating cycle; and
AFigure 9 is a fragmentary sectional view taken on line 9 9, Figure 3.
In the drawings, I have chosen to illustrate the invention as applied to a two-stage twin plston type hermetically sealed motor-compressor unit, but it is to be understood that the invention is applicable also to other types of motorcompressor unit, such as the single or multiple stage type employing either singlel or multiple pistons, so long as the connection between the motor and compressor components includes a Scotch yoke drive or a drive including a crossslide member. I
Referring to the drawings, 'and more particularly to Figure 1, the motor-compressor unit shown, includes a shell or housing I0 comprising a pair of opposed bowl or dome-shaped members, il and l2, sealed together, preferably by welding. about abutting peripheral anges I3 and I4.
Mounted within `the housing illupon a plurality oi resilient supports, one of which is indicated at l5 in Figure l, is a main frame I6 provided with a central vertical bore forming a bearing il for a shaft Iii; The frame i6 is provided with upstandingwall portions I 9 for supporting the stator 300i an electric motor 2i. The rotor22 of the motor 2i is located within the stator and is rigidly secured to the upper end .portion oi the shaft i8.
The shaft it is provided with an eccentric pora tion '23 depending from the end of the shaft and having its vertical axis oiset horizontally relative to the normal axis of said shaft. This ecJ centric, as more clearly shown in Figures 2 and 3, `is adapted to cooperate with a Scotch yoke as sembly 2t for reciprocating a pair of horizontally opposed pistons 25 and `26 in low and high pressure `cylinders 2l and 28, respectively. formed in the lower portion of the frame i6. The Scotch yoke assembly includes a slide member 30 connected with the eccentric 23 to move therewith and to be thereby reciprocated transversely in a space within the body 3| of the Scotch yoke sembly, which body carries the pistons 25 and .Y closed by means of a reed valve 36 of', the usual type. The high pressure cylinder 28 is likewise provided with acylinder head 3l secured to the escasas frame i8, for instance by means of machine screws 88 and, as also more clearly shown in Figure 3, has an outlet port 39 normally closed by means of a spring actuated valve 48.
The low and high pressure cylinders 21 and 28 are adapted to communicate with one another and for that purpose the cylinder heads 33 and 81 may be formed with ports 4I and 42 respectively, a duct 43 extending between and connecting said ports, for instance in the manner indicated in Figure 3. The portion of the port 4I opening into the low pressure cylinder 21 is preferably closed by means of a spring actuated valve 44 and the portion of the port 42 opening into the high pressure cylinder 28 is preferably closed by means of a reed valve 45.
A cover plate 46, which forms a bearing for the lower end portion of the shaft eccentric 28, is suitably secured to the frame I8, by means, for example, of machine bolts 41. A suitable counterweight 48 may be conveniently attached to the lower end portion of the eccentric 23 to properly balance the same during its rotating motion.
In the mechanism described above, vaporized refrigerant is withdrawn from the evaporator of the refrigerating system (not shown) through a suction line 48 during the suction stroke of the piston 25 which causes the reed valve 36 to open and to admit the vaporized refrigerant into the low pressure cylinder 21 through the port 35. During the compressionstroke of the piston 25, when the piston 26 is simultaneously undergoing its suction stroke, the vaporized refrigerant previously drawn into the low pressure cylinder 21 is initially compressed to a relatively low value and this initially compressed vaporized refrigerant is passed through the valved port 4I, duct 48 and valved port 42 into the high pressure cylinder 28 where the initially compressed vaporized refrigerant is nally compressed to a relatively high value during the compression stroke of the piston 26. From cylinder 28 the finally compressed vaporized refrigerant is forced through the valved port 39 through the discharge tube 58 into the condenser (not shown).
Reciprocation of the pistons 25 and 26 takes place by reason of the function of-the scotch yoke connection between the motor and compressor components of the unit in the manner now to bc described. Upon completion of the electric circuit to the motor stator 28 in response, for example, to demand for refrigeration Within the food compartment of the associated refrigerator (not shown), the resulting rotation of the rotor 22 in turn rotates the shaft I8 to cause a corresponding rotation of the eccentric 23 in an orbital path about the axis of the shaft 33. This movement of the shaft eccentric causes a similar movement of the slide member 38 in which movement the said member reciprocates within the scotch yoke body 3i as the latter, with the pistons 25 and 26, are reciprocated in and between the cylinders 21 and 28.
As is customary in motor-compressors of the hermetically sealed type, a body of lubricant preferably an oil heavier than the refrigerant employed in the system, is contained in a sump I at the bottom of the housing I8. Oil from the sump 5I is generally used to lubricate the moving parts of the unit, and heretofore special designed pump units have been associated with the motor-compressor assembly to force the oil under pressure to various parts of said assembly for lubricating and cooling the same.
In accordance with the present invention, oil
is' forced under pressure to various portions of the motor-compressor unit for lubricating and cooling purposes, but this is accomplished without the use of a specially designed pump unit. According to the invention, means is provided whereby the normal movement of an existing part. specifically the slide member 38 of the scotch yoke assembly 24, may be utilized to effect the pumping of the oil. To that end, head plates 52 and 53 are provided to close the opposite ends of the space within the scotch yoke body 8| thereby forming pump chambers 54 and 55 in the latter, and ports 56 and 51 are formed in the slide member 38, which communicate respectively with the chambers 54 and 55 and which ter-l minate at their inner ends in recesses in the member 38 at opposite sides respectively of the eccentric 23 as illustrated. The said inner ends of the ports 56 and 51 are disposed to register with bores 58 and 58 in the shaft I8. The bore 58, as more clearly shown in Figures l and 2, extends downwardly to the bottom of the shaft eccentric 23 and registers with an aperture 58 extending through the cover plate 46 and opening into the oil sump 5I within the compressor housing I8. As best seen in Figure 1, the bore 59 extends upwardly through and to the top of the shaft I8. Because of this construction, the portions 6I and 62 of the slide member 38 act as twin pistons in the chambers 54 and 55 respectively. i
In operation, the member 88, and associated elements as described above, functions as an oil circulating pump. The oil is drawn in through the bottom of the shaft eccentric 23, into the cross slide chambers 54 and 55 alternatively and from these chambers is forced up through the shaft 38 to be sprayed within the compressor housing I8 for cooling purposes. If desired, a suitable baille plate 68 may be provided at the top of the housing I8 opposite the discharge end of the bore 59 to assist in distributing the oil.`
The mode of operation may be better understood from consideration of the various positions illustrated in Figures 5 through 8. In the position shown in Figure 5, the slide member 38 is about to start its movement in the direction l indicated by the arrow A. Assuming that the pump is primed and the chamber 54 1s nues with oil, it will be apparent that as the slide member 38 moves through the position shown in Figure 6 towards the position shown in Figure "l, the oil in chamber 54 is forced through the port 58, as indicated by the arrow B and throughthe bore 58 which then is in communication with said port 56. At the same time. oil in the sump 5I (Figure 1) is drawn in through the bore 58 and discharged into the chamber 55 through the port 51 as indicated by arrow C in Figure 6. Upon reaching the position shown in Figure 7, the slide member 38 reverses its direction of movement and proceeds to move in the direction indicated by arrow D so that as the slide member moves throughthe position shown in Figure 8 towards the initial position shown in Figure 5 to complete the cycle. the oil accumulated in the chamber 55 is forced out through the port 51 as indicated by arrow E and through the bore 58 which by that time communicates with said port 51. During this reversedl movement of the slide member 38, oil from the sump 5I (Figure 1) is taken in through the bore 58 and discharged into the chamber 54 through the port 56 as indicated by the arrow F in Figure 8 so that the cycle of operation above described may be repeated.
Vshown in Figure 2, the bore 58 is so disposed that the oil is taken into the center line of rotation of the shaft and is discharged eccentrically so that automatic priming of the pump is accomplished.
It will now be apparent that I have provided a simple and eiective arrangement whereby proper cooling and lubrication of a hermetic motor-compressor unit may be effected without the use of separate pumping mechanism, the arrangement being such that pumping of the oil for cooling and lubricating purposes is effected by utilization of the movement of normal element of the motor-compressor construction.
It is to be understood that the aforedescribed embodiment of the invention is subject to modiiication within the scope of the appended claims.
1. In a motor-compressor unit of the type comprising a sealed housing, a lubricant sump in said housing and a lubricant-circulating system, a motor and a compressor mounted in said housing, a motor shaft, a scotch-yoke connection between the shaft and the compressor including a crossslide member having a socket and a crank pin on the shaft engaged with said socket, a housing for Said cross slide forming therewith a cylinder and piston assembly, a port in said pin connected with the sump, a second port in said pin connected with said system, and a port in each end of said slide arranged to register with said pin ports and, as the pin rotates in the slide, to register respectively and simultaneously with said ports and alternately therewith so as to effect a substantially continuous flow of lubricant from the sump to said system.
2. In combination, a rotary shaft, a reciprocatory member, a cross slide having a socket, a crank pin on the shaft engaged in said socket, a housing on said member for the cross slide, said housingandcrolsclideformingacylinderand piston assembly, a source of uid, a circulating system for said fluid, a port in said pin connected with said source, a second port in said pin connected with said system, and a port in each end of said slide arranged to register with said pin ports and, as the pin rotates in the slide, to register respectively and simultaneously with said ports and alternately therewith so as to effect a substantially continuous flow from the source to said system.
3. A refrigerant compressing unit comprising a housing having a lubricant sump and enclosing a motor and a compressor, the motor including a rotatable shaft having lubricant passages and provided with an eccentric portion, the compressor including reciprocable piston means having a yoke providing a chamber, a cross-slide member received in said chamber for reciprocation therein and having a socket disposed in engagement with the eccentric portion of the motor shaft se that rotation of said shaft and its eccentric portion imparts a reciprocating motion to said member which in. turn imparts a reciprocating motion to the yoke and piston means, and port means cooperatively disposed in the eccentric portion and slide member whereby reciprocating motion of the latter effects pumping of the lubricant from said sump to said chamber for discharge through the mentioned lubricant pas- WILLIAM C. HUME.
REFEBEN CES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Herzmark Aug. 14. 1940