US1913844A - Refrigerating apparatus - Google Patents

Description

June 13, 1933.

A. A. M CORMACK REFRIGERATING APPARATUS 2 Sheets-Sheet 1 Filed Jan. 31. 1951 ATTORNEY June 13, 1933. A A, CCOF'QMACK 1,913,844

REFRIGERATING APPARATUS Filed Jan. 51. 1931 2 Sheets-Sheet 2 iNVENTOR s" MQ'WLW BY N M -4341b ATTORNEY Patented June 13, 1933 UNITED STATES PATENT OFFICE ALEX A. MCOORMACK, OF DAYTON, OHIO, ASSIGNOR '10 FRIGIDAIRE CORPORATION,

OF DAYTON, OHIO, A CORPORATION OF DELAWARE REFRIGERATING APPARATUS Application filed January 31, 1931. Serial vIfil'o. 512,639.

This invention relates to refrigerating apparatus of the compression type and more particularly to motor compressor unlts for use with refrigerating apparatus of such type.

Refrigerating apparatus of the compression type generally includes a compressor having its discharge side connected to a condenser and' its intake side connected to an evaporator, the evaporator being in turn connected to thedischarge side of the condenser through some suitable pressure reducing means. Refrigeration is produced by evaporating the liquid refrigerant under reduced compressed into and condensed in a condenser under a considerable higher pressure and subsequently fed back to the evaporator. In order to maintain the evaporator or the re frigerator cabinet, which generally houses the evaporator, at a substantlally constant temperature, it is customary to operate the compressor intermittently. Thus it is customary to start the compressor when the temperature in the refrigerator reaches a predetermined high limit and to stop the compressor when the temperature reaches a predetermined low limit. Since thedischarge, or high pressure side of the compressor is under condenser pressure and the suction, or the low pressure side is under evaporator pressure,-it is obvious that the compressor, whether of the rotafi type, the oscillating type, the gyrator type or any other type, starts under load and consequently the motor requires ahigh starting torque unless some means is provided for permitting the motor to reach a running speed before the load is taken up.

One of the objects of the present invention is to provide improved means for loading and unloading the compressor.

More'specifically it is an object of the invention to provide improved means for employing the lubricant within the system for loading the compressor when the motor reaches a running speed and for unloading the compressor during its periods of idleness. 50 Another object is to accomplish the forepressure in the evaporator, the vapors being going objects in a simple-and inexpensive manner.

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:

Fig. 1 is a top plan view partly in eleva- 131011 and partly broken away of a compressing apparatus embodying features of the in-' vention; and I Fig. is a view of a refrigerating'system embodying features of the invention showing 05 the system partly diagrammatic and an enlarged view in cross-section of the compress- 1ng apparatus shown in Fig. 1, the view of the compressing apparatus being taken along the line 2-2 of Fig. 1.

Referring to the drawings the numeral 20 designates in general a refrigerating system which includes therein a motor-compressor unit 22, condenser 24 and cooling or evaporating element 26. The motor-compressor unit therein shown is of the type in which both the motor and compressor are enclosed Within a fluid-tight, hermetically sealed casing. However, it is to be understood that my invention is not limited to such a compressing unit. The compressing unit 22 comprises motor 30 which includes rotor 33 and stator 35, and a compressing means 37 actuated by motor 30. The compressing unit withdraws gaseous refrigerant from the evaporator 26 through a vapor conduit 42, compresses the gaseous refrigerant and delivers it to the condenser 24 wherein it is liquefied and from which it is delivered to a receiver 43 which is connected to the evaporator 26 by means of a supply conduit 45. The evaporator may be of any suitable type, and may be of the flooded float controlled valve type disclosed in the patent to R. C. Osborne 1,556,708, patented October 13, 1925. The compression means 37 is shown as driven by the electric motor 30 and the starting and stopping of the motor is controlled 'by an automatic pressure responsive switch 47 to thereby start and stop the motor in accordcharge valve 77.

ance with the refrigerant pressure conditions Within the evaporator. The pressure conditions within the evaporator vary according to the temperature conditions within the evaporator. Consequently switch 47 is responsive to temperature conditions within the evaporator.

The motor-compressor unit 22 is enclosed within the fluid-tight casing 40 which includes an upper member 50, an intermediate member 52 and a lower member 54 suitably clamped together by screws 55 and 56. The lower member 54 and the intermediate member 52 cooperate to form a reservoir 57 for a body of lubricating oil. The intermediate member 52 serves also to provide an intake chamber 59 which is provided with a check valve 60 located at the inlet thereof to permit refrigerant to enter said chamber but prevents return thereof. The intermediate member 52 is provided with a horizontal web 62 at the top thereof which serves to separate the casing 40 into two separate chambers for compressed fluid, namely, 65 and 66. Both chambers are located on the same side of the compressor, and for instance, on the high pressure side as shown in the drawings. The web 62 is provided with a bore 7 O which provides a compression chamber for the compressing means 37.

The compressing means 37 is of the oscillating ring type which is one of the types which must be flooded with oil to accomplish any appreciable compressing action of a gaseous medium as described hereinafter. The compressing means includes a disk member 72 which forms the top wall of the compression chamber 70. The disk member 72 is provided with a downwardly depending ring 74 which oscillates within the compression chamber for compressing the fluid therein. The ring 74 is so positioned within the chamber 70 so as to provide a plurality of compression spaces during the operation of the compressing means. Thus it will be noted that a compression space is provided adjacent the outer periphery of said ring and a second compression space is provided adjacent the inner periphery of said ring during the operation of the compressing means. Each of the compression spaces is provided with a dis- An oscillating pin 80 is disposed within the compression chamber 70 to seal one compression space from the other and is arranged so as to be in engagement with at least one of the ends of the ring during pumping operation so as to prevent leakage from one compression space to the other. The compressing means 37 is arranged to be actuated by shaft 85 which is driven by rotor 33 of motor 30. The shaft 85 is journaled on one end in bearing 87 carried by web 62 and on its opposite end is journaled in a bearing 90 carried by the lower member 54 of casing 40. The shaft 85 maintains its position within the bearing 87 and 90 by means of gravity, the end of said shaft resting upon a button 95 carried by the lower member 54 of casing 40. The shaft 85 on its upper end is provided with an eccentric portion 100 which carries a ball bearing member 102 which engages the disk-shaped member 72 to thus actuate the rin 74. As shown in the drawings the compression chamber 70 is concentric With the main portion of the shaft while the ring member 74 is concentric with the eccentric portion 100 of shaft 85. Thus it will be noted that rotation of shaft 85 due to the eccentric arrangement thereon the ring 74 oscillates within the compression chamber 7 O. In order to overcome any vibration which may occur due to said eccentric arrangement I have provided counter-balancing means 105 which is carried by shaft 85 upon a 180 angle with respect to the eccentric portion of the shaft- 85. The counter-balancing means includes a portion 105 above the disk-shaped member 72 and a portion 106 which is located therebelow. Aspreviously stated the diskshaped member 72 forms the top wall of the compression chamber 70 and as will be noted said disk-shaped member rests upon the web 62 by gravity alone.

Means have been provided for sealing the joint between the disk 72 and the web 62 to thus load the compressing means after the motor has attained a running speed and for unsealing said joint for unloading the compressing means during its periods of idleness. In order to provide means for loading and unloading the compressing means I employ the lubricant within the reservoir 57 for submerging the compressing means in lubricant after the motor has attained a running speed and have also arranged for returning said lubricant to the reservoir 57 to thus insure the unflooding of the compressing means during its periods of idleness. This is accomplished by providing a spiral groove 110 on the lower end of the shaft 85. The groove 110 receives lubricant from the reservoir 57 after passing through strainer 111 and passages 111a. The groove 110 communicates with a radial bore 112 in shaft 85, which bore leads to a central passage 115. The central passage permits lubricant to flow through the open end at the top of the shaft and into the chamber 65 wherein a predetermined level of lubricant is maintained during the operation of the compressing means by means of an overflow standpipe 120 which maintains a level of lubricant in the chamber 65, during the operation of the compressing means, equal to the height of said standpipe. This body of lubricant acts to lubricate the compressing means and to seal the joint between the disk-shaped member 72 and the web 62 to thus permit the compressing means to take'up its load. The central passage 115 in shaft 85 also communicates with a radial bore 125 which leads to a spiral groove 127 in shaft 85 for supplying lubri cant to the bearing 87 while the spiral passage 110 in shaft 85 serves to supply lubricant to the bearing 90. The web 62 is provided with a drain passage 135 which permits the lubricant within the chamber 65 to drain back into the reservoir 57 during periods of idleness of compressing means 37. During pumping operation lubricant is fed to chamber 65 by the oil pump much faster than it returns to the reservoir through the drain passage 135. Thus it will be noted that when the switch 47 places the motor 30 in circuit'with the power mains the motor will start driving the compressing means 37 and in so doing will-not take up its load until a sufiicient quantity of lubricant has been conveyed to chamber 65 to thereby seal the joint between the disk member 72 and the web 62 after which the compressing means takes up its load and continues to compress until the switch 47 interrupts the electric circuit to the motor. When this occurs the lubricant in chamber 65 will return to the reservoir by means of the passage 135 to thus unload the compressing means. The operation of the compressor is as follows: The gaseous refrigerant is withdrawn from the vapor conduit 42 as previously stated and from which it is drawn into the intake chamber 59 which communicates with the compression chamber through an intake passage 140 which communicates' with a passage 142 provided in the ring 74. By this arrangement gaseous refrigerant or the refrigerant from the intake or low pressure side of the compressor is admitted to the compression chamber to be compressed. The compressed refrigerant is then discharged through valves 77 which are covered by a film of lubricant received from the oil pump 110 to thus dampen valve noises. The discharge or high pressure gas in the chamber 65 then passes to the high pressure chamber 66 through the ball bearing member 102, passages 150 and outlet passage 152 into the condenser 24 as previously described. A portion of the compressed refrigerant also passes from chamber 65 to chamber 66 through the standpipe 120. However, said standpipe is provided for maintaining a predetermined level of lubricant Within the chamber 65 during the operation of the compressing means. To aid in returning the lubricant to the reservoir 57 the rotor 33 has been provided with one or more passages 160, and the stator has been provided-with one or more passages 165.

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, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. A compressor for refrigerating apparatus comprising ,in combination a casing, means separating said casing into a plurality of chambers on the high pressure side of said compressor, one of said chambers providing a reservoir for lubricant, compressing means in a second chamber, means for conveying lubricant from said reservoir to said second chamber for sealing said compressing means during the operation thereof, a drain for maintaining a predetermined level of lubricant sufiicient to load the compressor in said second chamber during the operation of said compressing means, and a second drain below said first named drain and of less capacity than the flow of oil during operation for returning the lubricant to said reservoir and unloading the compressor during periods of idleness of said compressing means.

2. A rotary compressor for refrigerating apparatus comprising a side for compressed fluid and a side for fluid to be compressed, a casing, means separating said casing into a plurality of chambers continuously on one of said sides of the compressor, one of said chambers providing a reservoir for lubricant, compressing means in a second chamber, means for conveying lubricant from said reservoir to said second chamber for sealing said compressing means during the operation thereof, a drain for maintaining a predetermined level of lubricant sufiicient to load the compressor in said'second chamber during the operation of said compressing means, and a second drain below said first named drain and of less capacity than the flow of oil during operation for returning said compressing means.

3. A compressor for refrigerating apparatus comprising in combination a casing, means separating said easing into a plurality of chambers on the high pressure side of said compressor, one of said chambers providing a reservoir for lubricant, said means providing a compression space communicating with a second chamber, a disk-shaped member forming the top wall of said compression space, compresslng means in said compression space actuated by said disk shaped member, means for conveying lubricant from said reservoir to said latter chamber for sealing the joint between said diskshaped member and said means providing a compression space during the operation of said compressing means, and means for returning the lubricant to said reservoir during periods of idleness of said compressing means.

4. A compressor for refrigerating appa- 12 ratus comprising in combination a casing means separating said easing into two chambers on the high pressure side of said compressor, one of said chambers being above the other with the lower chamber providing a reservoir for lubricant, compressing means in the upper chamber, a motor 1n the lower chamber for actuating said compressing means, means for conveying lubricant fromv said reservoir to said upper chamber for sealing said compressing means during the operation thereof, means for maintaining a predetermined level of lubricant in said upper chamber during the operation of said compressing means, and means for draining the lubricant in the upper chamber to said reservoir in the lower chamber during inoperativeness of said compressing means.

5. A compressor for refrigerating app-a ratus having an upper lubricant reservoir, a lower lubricant reservoir, a refrigerant compressor lubricated by lubricant in said upper reservoir, a drain from said upper reservoir to said lower reservoir for draining said upper reservoir to a compressor unloading level, an overflow from said upper reservoir to said lower reservoir at a higher level than said unloading level, and means operated concurrently with said compressor for raising lubricant from said lower lubricant reservoir to said upper lubricant reservoir at a faster rate than the lubricant flow through said drain.

In testimony whereof I hereto affix my signature.

ALEX A. MOCORMACK.

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