US1688890A - Pump for mechanical refrigeration - Google Patents

Description

@. agmwsm PUMP FOR MECHANICAL REFRIGERATION Filed 06%. :50, 1926 //2 e n/or jw za Affar'nez s Patented a, 23, 1928.

I 1,688,890 UNITED STATES PATENT O FIC CHARLES C. SPREEN, OF D1311IlZtOI'l MICHIGAN, -ASSIG1\l'OR TO KELVINATOR CORPOR A- TION, OF' DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN. J l

,PUMP. FOR MECHANICAL REFRIGERATION.

Application fi led October 30, 1926. Serial No. 145,157.

My invention relates to mechanical refrigeration, and particularly to compressors for compressing the refrigerant 1n mechanical refrigeration units, and'the particular "object of my invention is to providea new and improved compressor of this type. In

the'drawings accompanying this specifica-' received and supported within alined upper and lower annular surfaces 14 and 15 provided upon a compressor casing 16 extending outwardly intermediate the upper and lower annular faces 14 and 15 to provide between itself and the cylinder sleeve 13 a refrigerant intake chamber 17 provided with an intake opening 18 controlled by a suitable shutoff valve 19; and a compressor head 20 forming the upper wall of the compression chamber 21, secured to the'compressor casin by means of a plurality of bolts 22 exten in into screw-threaded apertures 23 forme about the upper portion of the compressor casing 16, and itself comprising: a plate 24 directly engaging the upper edge of the compressor casing 16, and the upper edge of the cylinder sleeve 13, and provided with a central outlet opening 25; and adome 26 surmounting the plate 24, provided with .an upper convexed section 27 providing an out let chamber 28 in communication with the outlet opening 25 in the plate 24, having an outlet opening 29 for the flow of the compressed refrigerant from the outlet chamber 28 through a suitable shut-ofi valve 30, and containing within-the outlet chamber 28 a suitable valve unit 31 herein shown as comprising a valve plate 32 yieldably held in position closing the upper end of the outlet opening 25 of the plate 24 by means of a compressor spring 33 confined between the upper face of the valve plate 32 and the lower face of the upper end of a yielding abutment 34 itself yieldably held in position by means of a compression spring 35 confined between the upper face of the upperend of the yielding abutment 34 and the lower face of the upper end of a fixed abutment 36 fixedly mounted in" position within the compressor head 20, the .double valve mechanism being provided to permit abnormal opening of the valve for the passage of an unusualdischarg'e from the compressing chamber 21, such as a slug of oil, or the like.

In the embodiment of my invention herein shown the piston 12 comprises a body 37, a head 38 secured to the upper end of the body 37 and forming the movable wall of the compressing chamber 21, upper and lower skirts 39' and 40 depending respectively from the head 38 and the body 37 and themselves provided with alined upper and lower sur faces 41 and 42 slidably engaging the inner surface of the cylinder sleeve 13, anda bearing pin 43 mounted in the body 37 and receiving the connecting rod 44 by which the piston 12 is reciprocated within the cylinder sleeve 13; the'piston head 38 is provided with a plurality of apertures 45 communicating with a chamber 46 within the piston 12 in communication with the intake chamber 17 of the compressor casing 16 through a port 47 in the cylinder sleeve 13, and through the ports 50 in the piston body 37, and the crankcase 51; and the flow of refrigerant from the intake chamber 17 through the port 47, or the crank case 51 and ports 50, into the piston chamber 46, andthen through the apertures 45 into the compressing chamber 21, is controlled by a valve plate 48 overlying the apertures 45 andpermitting flow of refrigerant into the compressing chamber 21, but seating against the piston head 38 to prevent flow of refrigerant in the reverse direction from the compressing chamber 21 back into the intake chamber 17. v

In addition, the compressor 11 herein shown is provided with a second passageway for the inflow of refrigerant into the compressing chamber 21, comprising an extension of the port 47 providing communication through the cylinder sleeve 13 from the intake chamber 17 directly into the compressing chamber 21 at a point to be uncovered by the skirt 39 depending from the piston head 38 only when the piston 12 is in substantially its extreme retracted position.

From the above description those skilled in the art will understand that with the shut-off the compression chamber 21 valves 19 and in open position, and the refrigerating apparatus in operation, the refrigerant will flow through the shut-off valve 19 into theintake chamber- 17 and the pistonchamber 46, and that during retraction of the piston 12 this refrigerant will flow additionally through the apertures45 into thecompressing chamber 21; that upon the beginning of the compression stroke of the piston 12 the valve 48 will close the apertures 45 and the piston 12 will compress the refrigerant within until it raises the valve plate 31 and flows-out through the outlet chamber '28 and outlet shut-off valve 30; that during the final portion of the re- I traction stroke of the piston 12 communication between the intake chamber and the piston chamber f16 will be provided-additionally by the uncovering of the extension of the port 47 by the skirt 39 depending from the piston head 38, to thus permit, at this time,

' the flow of refrigerant into the compression chamber 21 directly through the cylinder sleeve 13, andto thus permit the valve 48 to seat slightly in advance of the beginning of the compression stroke of the piston 12, to

thus insure that the valve 48 is fully seated at the beginning of thecompression stroke of the piston 12; and that full charge of refrigerant into the compression chamber 21 is still permitted because of the passageway formed directly between the intake chamber 17 and the compression chamber 21 by the extension of the port 47, and uncovered durin the final portion of the retraction stroke 0 the pistOn 12.

Under these circumstances those skilled in the art will realize that I have provided a essee! compressor accomplishing at least the principal object of my invention.

At the same time those skilled in the art .will realizethat the embodiment of my invention herein shown and described inc ud'es advantagesother thanthose 5 ecifically referred to herein, and also thatt is particular embodiment of m" invention may be variousl changed an modified without departing rom the spirit of my-invention or sacrificing the advantages thereof, and it will 7 therefore be understood that the disclosure herein is illustrative only, and that my invention is not limited thereto.

I claim:

In a compressor for refrigerating apparatus a cylinder casing having an intake cham er encircling a portion thereof, a sleeve in said casing having intake ports extending in a direction axially thereof and in open communication with said intake chamber, a piston in said sleeve having a plurality of passages extending ,from the side wall and through the top w all thereof, said sleeve ports beingof greater lcngth than the distan-ce'between the inlet end of said piston passages and the piston end wall, and a movable valve associated with the piston end wall to control the-passage of refrigerant through said piston, said piston being arranged to uncover a CHARLES C. SPREEN.

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