US2855139A - Refrigerating apparatus - Google Patents

Description

Oct. 7, 1958 J. WElBEL,-JR 2,355,139

REFRIGERATING APPARATUS Filed June 23, 1955 5 Sheets-Sheet 1 INVENTOR. John Weibe/ Jr.

His Aftorhey Oct. 7, 1958 I J. WEIBEL, JR 2,855,139

REFRIGERATING APPARATUS Filed June 23, 1955 5 Sheets-Sheet 2 Fig. 3

INVENTOR. John Weibel Jr.

His Attorney.

Oct. 7, 1958 J. WEIBEL, JR 2,855,139

REFRIGERATING APPARATUS Filed June 23, 1955 5 Sheets-Sheet 3 'INVENTOR. John Weibe/ Jr.

H is Attorney Oct. 7, 1958 Filed June 25, 1955 J. WEIBEL, JR

REFRIGERATING APPARATUS 5 Sheets-Sheet 4 INVENTOR. John Weibe/ Jr.

. WWW

His Attorney REFRIGERATING APPARATUS John Weibel, Jr., Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application June 23, 1955, Serial No. 517,603 i 4 Claims. ((31. 230-58) This invention relates to refrigerating apparatus and more particularly to a hermetically sealed motorcompressor assembly.

It is an object of this invention to provide a low cost direct connected reciprocating compressor which may be manufactured on a mass production basis.

Another object of this invention is to provide a motor compressor assembly having an improved bearing arrangement which simplifies the problem of assembling the parts.

Still another object of this invention is to provide an improved oil pump arrangement for supplying oil to the compressor mechanism and the main drive shaft.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to, the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Figure 1 is a vertical sectional view taken substantially on line 1-1 of Figures 3 and 4 showing one embodiment of the invention;

Figure 2 is a perspective view with parts broken away of the compressor shown in Figure 1;

Figure 3 is a fragmentary sectional view taken substantially on line 3-3 of Figure 1;

Figure 4 is a sectional view taken substantially on line 44 of Figure 1;

Figure 5 is a fragmentary pictorial view with parts broken away showing the lower bearing and oil pump construction;

Figure 6 is a fragmentary sectional view showing the oil pump;

Figure 7 is an exploded view with parts broken away showing the motor-compressor assembly; and

Figure 8 is an elevational view with parts broken away showing an alternative arrangement for supporting and enclosing the motor and compressor mechanism.

Referring to the drawings wherein preferred embodiments of the invention have been shown, reference numeral 10 generally designates one form of outer shell for enclosing the motor and compressor assembly generally designated by the reference numeral 12. The casing 10 consists of an upper inverted cup-shaped member 14 which serves as the main support for the motorcompressor assembly and a lower cup-shaped element 16 which is welded to the element 14 along the seam 18. Suitable mounting brackets 20 are secured to the lower cup-shaped element 16 for supporting the entire assembly on a suitable support which has not been shown.

The upper shell 14 has secured to its inner walls mounting lugs 22 which serve to support the main casting 24. A special mounting bracket 23 has its ends secured to two of the lugs 22 and this bracket serves to support two of the lugs 27 of the main casting 24 at the two spaced points as shown in Figures 3 and 4. Resilient rubber like mounting pads 25 are provided for damping the vibrations and bolts 29 hold the casting 24 in place on the lugs 22.

2,855,139 Patented Oct. 7, 1958 The main casting 24 in turn supports the motor stator 26 in the manner shown. The casting 24 also supports a bearing 28 in which the main drive shaft 30 is journalled. The bearing element 28 is held in place within a machined circular recess provided in the main support 24 by means of a split ring element 32. As shown in Figure 1 of the drawing the split ring is beveled so as to cam the bearing 28 downwardly. The motor rotor 34 is securedto the upper end of the drive shaft 30 in accordance with conventional practice. The lower end of the drive shaft 30 is journaled in a lower bearing portion 36 provided as a part of the main casting or frame 24.

An offset crank like portion 38 is provided on the drive shaft 30 and serves to operate a pair of connecting rods 40 which drive the pistons 42 in accordance with well known practice. A pair of counterweights 44 are secured to the offset portion of the drive shaft as shown for the purpose of balancing the crank shaft. The main casting 24 is provided with a pair of cylinder bores 46 in which the pistons 42 operate. Cylinder heads and valve plates 48 and 50 respectively are bolted directly to the casting 24 opposite the cylinder bores 46 in accordance with well known practice.

The gas to be compressed is supplied to the casing 10 through the suction line 52 which is arranged as best shown in Figures 1, 2 and 4. It will be noted that this suction line enters the upper portion of the shell 14 and that a screen 54 is provided for screening out any sediment or the like which may be supplied along with the gas and lubricant through the line 52. The incoming mixture of gas and lubricant is dumped directly into the outer shell 10 and is required to flow upwardly around the motor stator and then to flow downwardly through the motor. Holes 56 are provided in the motor rotor so as to help cool the motor.

The gas then flows downwardly through passages 60 (see Figures 3 and 7) formed in the casting 24 and then into communicating drilled holes or passages 62, through holes 63 in the valve plates 50 which convey the gas into the chamber 64 provided in each of the cylinder heads 48. The gas then flows through the usual suction port 66 and around the flexing reed 67 into the cylinder where the gas is compressed before being discharged through the corresponding outlet port 68 and outlet valve 69 into the outlet chamber 70 in the cylinder head. The outlet chamber '70 in each cylinder head communicates with hole 71 in the valve plate and passages 72 in the casting 24 which lead to the common muffler chamber 74 provided directly in the main casting 24. A cap 77 closes the bottom of the chamber 74. The compressed refrigerant leaves the chamber 74 through the passage 75 in the main casting and the outlet line 76 which passes through the wall of the upper shell portion 14 as best shown in Figures 2 and 4 of the drawings.

The construction and arrangement of the cylinder head and the inlet and outlet ports and valves carried by the valve plate 50 is intended to represent conventional construction which needs no further description as the construction thereof is well known to those skilled in the art. The arrangement of the gas passages within the main casting 24, however, is novel in that the incoming gas serves to cool vital parts of the motor-compressor assembly and a minimum number of pipe connections are necessary with the construction shown.

The main frame 24 is cast in one piece and the critical machined surfaces for supporting the rotating parts may be machined while the casting is held in a single chunk so that the motor stator supporting surface 80, the main bearing supporting surface 82 and the bottom bearing surface 84 will be concentric.

An oil pump which will pump oil irrespective of the direction of rotation of the motor is provided for supply- 3 ing lubricant under pressure to the various bearing surfaces of the motor compressor unit through passage means 85 in the main drive shaft 30. This pump is mounted adjacent the lower end of the main drive shaft 30 and consists of--a vane-86 which is arranged in'aslot 87 in the bottom surfaceof the shaft 30. This vane operates within a pumping chamber formed between the shaft and a 'mainoil pump body element 88 which also serves asa pump reversing ring. This ring is mounted for limited rotational movement within an enlargement 90 in the lower end ofxthe main-casting 24'and=is provided with a -pair of-cut- away portions 92 and 94 which selectively serve as inlet-and outlet ports'for thepumping chamber'which is formed by' the clearance between the shaft -30-and the ring element88.

In the position of the parts shown in Figure 6' of the drawing-the cut-away portion 92 is arranged in alignment with the oil-inlet opening 96 formed in the side wall of the lower end'of the main casting 24 and the cut-away portion 94 serves as the outlet port' and is arranged in alignment-with-the oil outlet passage 98. Upon reversal of direction of operation of themain shaft 30 the reversing ring 88 will be shifted so as to cause thecut-away portion 94 to lineup with the oil inlet 100 as shown'in Figure 4 and the cut-away portion 92 will line up with the oil outlet 98. The reversing ring 88 is prevented from rotating more than a limited amount by a stop pin 102carried by the casting 24. This pin projects down into a cut-away portion 104 in the one edge of the reversing ring 88 as shown.

The frictional drag between the rotating parts carried by the shaft 30 and the reversing ring 88 is relied upon to shift the ring 88 upon reversal of rotation of the main drive shaft. As best shown in Figure 1 of'the drawing the lower end of the shaft 30 and the bottom surface of the'vane 86press against a plate thrust bearing 106 and this plate tries to rotate with the shaft due to the friction between the two but the plate is secured to the reversing ring 88 so as to be limited in its rotation after it has shifted the reversing ring into one or the other of its extreme positions. A bottom oil pump cover and end thrust bearing element 108 is secured to the lower end of the main casting 24 by means of one or more bolts such as the bolt 110 shown in Figure 5. This end thrust member 108 is provided with a small central thrust projection 112 which presses against the central bottom surface of the disc 106. By virtue of the fact that the area of contact between the projection 112 and the disc 106 is much less than the area of contact between the shaft and the disc it is obvious that the disc will try to rotate with the shaftat all times'and will assist in properly positioning'the reversing ring.

By virtue of the arrangement shown and described herein it is possible to assemble the parts by inserting the drive shaft downwardly through the central cavity of the frame 24 after the pistons and connecting rods have been pushed into place. It will also be noted that each of the counter weights 44 has an'aperture 45 thru which the 'shaftmay be passed during assembly of the parts. .The entire designlends itself to quick and accurate assembly and alignment of the various elements with a minimum number and most simple form of fastening means for holding the parts assembled.

Figure 8 shows analternative arrangement for supporting and e'nclosing the motor and compressor mechanism and in this-arrangement the same motor-compressor mechanism is used but a different type of housing is used for enclosing the motor-compressor mechanism. In the modification shown in Figure 8, the compressor parts are supported within the lower cup-shaped housing element 150 to which a suitable mounting base 151 is secured for supporting the entire assembly on a support (not shown). The housing 150 is a stamped sheet metal housing which is formed with flat ledges 152- on which spring type compressor mounts 154 rest. These spring mounts engage 4 the mounting lugs 27 provided on the main compressor casting 24. The upper portion'of the housing consists of an inverted cup-shaped element 156 which is also a stamped sheet metal member which is are welded to the lower cup-shaped element along the meeting edges as indicated at 158.

The only difference between the motor-compressor mechanism shown in Figures 1 through 7 and the motorcompressor mechanism shown'in Figure 8 is that the main drive shaft 30 has been .made longer so as to project above the motor rotor and stator as shown. The upper housing element 156 is provided with-an inverted cupshaped element160 which is arranged to have its lower rim surround the shaft 30. This cup 160 will serve to limit the sidewise movement of theupper end of the motor-compressor assembly during shipment so as to prevent damage to any of the parts in the case of any severe jolt. It will be noted that in this modification the motor terminals 162 are carried'by theupper shelli portion 156 and that they are arranged'in close proximity to the upper end of the motor stator windings. It'will' also benoted that in this modification the refrigerant outlet line 166..is secured to the lower cup shaped element 150 by a clamp 153 and is wrapped around the main casting 24 so as to provide a longer length tubing between the compressor outlet and the point where the line '166'leaves.the compressor housing. This increased length of line is provided because of theincreasedamount of vibration which results' fromusing spring mounts of the type .shown in Figure 8 as compared'with the rubber mounts shown in the compressor in Figures 1 through 7.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, as may come withinthe scope of'the claims which follow.

What is claimed is as follows:

. 1. In a motor-compressor unit, a. main frame, a vertically disposed shaft journaled in said frame, a 'motor 'drivingly connected to the upper part of said shaft, compressor means drivingly connected to an intermediate portion of said shaft, and an oil pump drivingly connected to the lower portion of said shaft, an endthrust bearing element carried by said frame adjacent the lower end of said shaft, 21 housing for enclosing said motor, said compressor means and oil pump, spring means for supporting said main frame in said housing, the upper end of said drive shaft projecting above said.motor, and means carried by said housing surrounding said uppersprojecting end of said drive.shaftforlimiting sidewisernove ment of said drive shaft.

2. Refrigerating .apparatus comprising: .a .casing, a main frame supported withinnsaidcasing, a.motorsupported. on said frame, said motorincluding a vertically disposed main drive shaft compressor means supported in said-mainv frame and operated bysaid .driveshaft, said frame having. bearing surfaces engaging-saiddrive shaft, an oil pump. driven bysaiddrivesh'aft, said oil pump comprising an impeller supported by.-Jsaid drive shaft, meanscooperating with saidimpellenand forming a pumping chamber having inlet and outlet port means,

said pumping chamber including a port: reversing element surface smaller than the-cross sectional area of said shaft, said means forming a pumping chamber including a disc secured to said reversingelement andlsupported between said surface and the end of said shaft.

. 3. In a motor-compressor unit, amain frame, a vertically disposed shaft journaledin said. frame, amotor.drivingly connected to .an upper portion of .said .shaft, cornpressor means drivingly connected to an intermediate portion of said shaft, and an oil pump drivingly connected to the lower portion of said shaft, an end thrust hearing element carried by said frame adjacent the lower end of said shaft, a disc inteiposed between said end thrust bearing element and the lower end of said shaft, said disc having a larger area of contact with said shaft than with said end thrust bearing element, said pump including means forming a pumping chamber having inlet port means and outlet port means and means for interchanging the functions of said port means in response to a change in the direction of rotation of said shaft, said last named means comprising an element secured to said disc.

4. In a motor-compressor unit, a main frame, a vertically disposed shaft journaled in said frame, bearing means for said shaft, a motor drivingly connected to the upper end of said shaft, compressor means drivingly connected to an intermediate portion of said shaft, and an oil pump drivingly connected to the lower portion of said shaft for supplying oil to said bearing means, an end thrust bearing element carried by said frame adjacent the lower end of said shaft, a disc interposed between References Cited in the file of this patent UNITED STATES PATENTS 861,626 Young July 30, 1907 2,483,007 Higham Sept. 27, 1949 2,490,391 Wentling Dec. 6, 1949 2,565,077 Hol-l Aug. 21, 1951 2,628,016 Higham Feb. 10, 1953 2,741,425 Scheldorf Apr. 10, 1956 2,751,146 Moseley June 19, 1956

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