US2285426A - Oiling system for compressors - Google Patents

Description

June 9, 1942. w. R. FREEMAN 2,235,426

OILING SYSTEM FOR COMPRESSORS Filed Jan. 51, 1941 INVENTOR W.R.FREEMAN BY Patented June 9, 1942 ornmc; srs'rsM roa comaassoas Walter R.Jreeman, Clayton, Mo., asslgnor to Wagner Electric Corporation, St. Louis, Mo a v v. V

corporation of Delaware Application January :1, mr'serm No. 316,801 I Claims. (01. 230-2045) Y- My invention relates to compressorsfand more particularly to an oiling system therefor.

One of the objects of myinvention is to embody in an oiling system .for a compressor having a separate oil reservoir, improvedcontrol means which will permit oil to flow to' the compressor and lubricate the partsthereof only when the compressor is operating to discharge compressed fluid. v

Another object is to provide in a compressor oiling system of the kind referred to valve means for positively shutting oi the flow of oil to the to" unload the compressor.

valve" assembly and conduit a leading to theair compressor causes s'aidvalve to be subjectedto the air pressure in the receiver in' order'to be properly controlled. In addition to the shut-o3 valve in the valve assembly N, there is also em ployed valve means for simultaneously venting the air reservoir'to the atmosphere through the air cleaner wheneverthe shut-oi! valve isclosed which the reservoir is unloaded is atoll and communicates with the reservoir at a point below the check valve I2. By venting thereacompressor whenever the'compressoris either un- I loaded or not being actuated and to accomplish this notwithstanding compressed fluid from the compressor may be acting on the oil 'in the reservoir. V

Other objects of my invention will become ap parent from the following description taken in connection with the accompanying drawing in which the single figure is a view of a compressor system having embodied therein my invention for controlling the flow of oil to thecompressor.

Referring to the drawing in detail, numeral I indicates a rotary compressor of well-known design having a rotorshaft 2 driven by any suitable means such as a pulley 2. In this compressor the fluid to'be compressed, which in this particular instance is air, enters the compressor through the inlet 4 where it is compressed and discharged through the discharge outlet 5. The discharged compressed air passes through the check valve. I into the conduit I where it is conveyed into the top of an oil reservoir 8 by means of a tube 8 extending up into the reservoir, The upper end of the reservoir is connected by a conduit "to the air receiver or tank It from which the compressed air may be withdrawn to actuate anydevice desired. ,A check valve i2 is interposed between the reservoir andthe conduit II and prevents back flow of air under-pressure into the reservoir. i I J The inlet of the compressor is connected by a conduitxlS to an unloading valve assembly I which may be of any desired construction such as, for example, that shown inthe Fites application Serial No; 301,102jfiled October 25, 1939,

for Valve mechanism for unloading compressor.

This valvevassembly is adapted to be controlled by the compressed air in the receiver in order to cut oil communication from the atmosphere through the air cleaner l5 to the conduit [3 whenever the pressure in the receiver reaches a predetermined value say, for example, 100 pounds per square inch. Aconduit l5 between said 'e'rvoir toatmosphere when the compressor isfun loaded, the compressor will run more freely since any fluid discharged passes directly into the atchamber having fluid mosphere instead of into a under pressure therein; 7

Since the oil reservoir receives the discharged compressed air, the oil thereinis placedunder pressure "whenever the compressor is operated.

In order that the oil may be conveyed to the compressor bearings 1 and other moving parts, there is provided a conduit II which is connectedto the bottom oi the reservoir by a passage In accordance from the reservoir to the compressor in sucha manner that the oil will-flow only when the 'compressor is operatin and compressing air. At all other times theoil from becoming choked with oil. As shown in the figure, there is provided a valve casing 2| provided with chambers- 22 and 22-divided by a partition 24. Carried by this partition on the sideof the chamber 23 is a valve seat 2I which surrounds the end of a passage 26 in the partition for placing the conduit I. in communication with the chamber 23 which chamber communicateswith the reservoir by means of the passage 22 previously referredto. Cooperating with the I valve seat 25 is a movable valve element 21 positioned in chamber 23 and normally biased onto the seat 25 by a spring".

The chamber 22 in the valve .casingcommunicates at one end with the conduit I coining from the exhaust port of the compressor and also with the tube 9 leading to the top of the oil reservoir by way of passage 22y Positioned in the chamber 22 is a piston 20 carrying a projection it which.

extends through the partition in order to engage the valve element 21. -"The'piston has a loose fit with the wall or the chamber and'is The conduit through y with my invention I provide means for properly controlling the flow of oil 'prevented'from commun'icating with the compressor inorderto conserve, on the oil supply: and prevent the compressor to flow to the compressor.

which connects the conduit 1 to the chamber 22 in order to block this open end when positioned at the left end of the chamber. However, when the piston is moved to the right end of the chamber, the passage 29 will be uncovered and thus permit free flow of fluid from the conduit 1 to tube I. Also, when the piston is in the latter mentioned position; the projection 21 will engage and unseat the valve element 21.

In operation, when the compressor is not being driven the spring 29 will hold the valve element 21 seated and thereby prevent any oil from entering the conduit is for passage to the compressor bearings and moving parts. when the compressor is being driven and compressing air,

this compressed air will be discharged through the exhaust port and the conduit 1 to act on the piston 20. This air under pressure will force the piston to the right so that it will place the passage 29 in free communication with conduit 1 and permit the compressed air to enterthe top of the reservoir from where it can pass through the check valve l2 to the air receiver. The movement of the piston to the right also causes the valve 21 to be unseated against the bias of spring 22, thereby placing the conduit I! incommunication with the bottom of the reservoir to permit oil to flow to the compressor bearings and work- I 2,285,420 adapted to engage the open end of the fltting 22 predetermined value tion. Thus it is seen that, notwithstanding the fact that air under pressure may be present in the oil reservoir and acting on the oil at the time that thecompressor is no longer driven, the flow of oil will be cut off. Therefore-under all conditions except when the compressor is operating and discharging compressed air, communication between the oil reservoirand the compressor will I always-be cut oil. Therefore, thereis no possi-- bility of too much oil being forced into thecompressor when the compressor is no longer driven (rotor rotating) and there is still air under pressure in the reservoir. In prior constructions wherein the air pressure in the oil reservoir is employed to control a valve for shutting off the flow of oil, the flow of oil would not be stopped under these conditions.

Being aware of the possibility of modifications go in the particular structure herein described with lag parts. 'The piston will always be maintained inthe right hand end of the chamber 22 wheni ever the compressor is discharging compressed air, due to the, fact that this compressed air in flowing to the reservoir will impinge on the piston and maintain it in such position. The amount of oil being fed to the compressor through pipe I! will only be suflicient for proper lubrication and to replace the oil being carried out of the compressor with the compressed air.

The amount of oil is regulated by the size of the passage in the rotor shaft 2 through which the oil is fed to the compressor. As long as the Y the exhausted compressed fluid from the com-- proper level of oil is maintained in the reservoir all the oil will never be forced out of the reservoir as oil is being continuously returned to the reservoir as it is fed therefrom to the compressor.

When the air pressure in the'receiver reaches the predetermined value necessary to operate the unloading valve in the valve assembly ll, the

inlet to the compressor will be shut 0!! iromate mosphere and the compressor will thereby be unloaded. .Simultaneously with the. cutting oil of the admission of air to the compressor, the oil reservoir will also be placed in communication with the atmosphere and reliev'e 'the oil reservoir of the air under pressure." As soon asthe, comvolume of compressed air, the spring 2! wiil'bepressor discontinues discharging any appreciable come ei'fective'to seat the valve element'21 since the piston 30 is no longer held by any compressed air in the position to maintain the valve 21 uncommunication between the oil reservoir and the conduit l2. and thus prevent any oil from passing to the compressor. a i

If the compressor should be stopped, that is no longer driven by ,the pulley 2 when the compressor inlet port is not shut oil! by means of the shut-off valve, the valve element 21 will, nevertheless, be seated, and oil will no longer-be able Underthese conditions the air. pressure in the oil dome is not vented to atmospheresince the compressor unloading valve vwas not shut of! due to the fact that the air in'the receiver had not reached the This seating of the valve will cut oi! Having fully described my invention, what I I claim .as new and desire to secure by Letters Patent oi the United States is:

1. In apparatus of theclass described, a fluid compressor, an oil reservoir connected by a conduit with the compressor for lubricating the moving parts thereoiya conduit for conveying pressorhfa valve for cuttingofl' the flow of 011 between thereservoir and the compressor, and

means comprising a movable member so associated with the. fluid conveying conduit that it will be acted on and moved by the discharged com-- pressed fluid. flowing through the conduit and thereby cause thevalve position. V s s 2. In; apparatus of the class described, a'fluid compressor, an oil reservoir connected by a conduit with the compressor for lubricating the moving parts thereof, a conduit'for conveying the exhausted compressed fluid from the compressor through the reservoir, a valve for cutting oi! the flow of oil between the reservoir and the compressor, and means for opening thevalve comprising a member so associated with the fluid conveying conduit that the discharged compressed fluid will impinge thereon and cause said member to be moved to open the valve before said compressed fluid'passes to the, reservoir.-

3. In an intermittently operated fluid compressor system having-a discharge conduit and an oil reservoir for supplying the moving parts of the compressor with lubricant and which is so associated withthe compressor that discharged compressed fluid acts on the oil in the reservoir discharge compressed fluid and notwithstanding compressed fluid maybe in the reservoir, said means comprising a-valve biased to closed position and a member so associated with the discharge conduit. that it will be contacted and moved by the compressed fluid'when flowing through the conduit to thereby open the valve;

4. In apparatus of the class described, a fluid compressor, an oil reservoir connected by a conduit with the compressor for lubricatingthe moving parts thereof, a conduit for conveying 'the exhausted compressed fluid from the compressor, a valve for cutting oi! the flow of oil necessary for such operato 'be moved to open to forcev it tothe compressor, means for peventing oil from flowing tothe compressor moving parts when the'compre'ssorv is not operating tobetween the reservoir and the compressor, and bores, conduits for connecting one-of said bores means for opening the valve comprising a-.cham-' to the oil reservoir and to the compressor for her in the fluid conveying conduit means and therebvconveyi'ngoil tothe movingparts of said having spaced openings one "ofywhich'fcommuni-r f compressorfa" valve in said here for cutting ofl cates with the portion of the conduit th fjflowflof oiL a spring for seating} the valve, ing from the compressorrandi n i 1: connectin'gthe othe -bore tothe communicates with the po'rti means leading to 'the reserporr member in said chamber operati 1y c to the valve, said member-Iaapted to be' pos tioned between the two openings whe is closed and to be moved to aigp'ositio cover the second opening by the lore charged compressed fluid and there!) valve.

5. In apparatus of the {c1 compressor provided with an. exha an oil reservoir, a receiver conn 'cted oi the reservoir, a casmg i pp'g bore andeprovided with a projection ng, the valve; said piston. when the ed'by the spring being so positioned the path offlowof compressed fluid ompressoryto the I reservoir whereby 0r, unseati am? a ti willimpinge.on the piston and cause ,ee valveto open position, the valve itiongof-said-"pis'ton being such as to I r? to the reservoir.

WALTER R. FREEMAN,

and to the 1 reservoir; agp m d fluid from the, compressor when it

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