US2307251A

US2307251A - Compressor lubricating system

Info

Publication number: US2307251A
Application number: US333432A
Authority: US
Inventors: Robert J Woods; Clifford J Lane
Original assignee: Bell Aircraft Corp
Current assignee: Bell Aircraft Corp
Priority date: 1940-05-04
Filing date: 1940-05-04
Publication date: 1943-01-05
Anticipated expiration: 1960-01-05

Description

Jan. 5, 1943. R. J. WOODS ETAL 2,307,251

COMPRESSOR LUBRICATING SYSTEM Filed May 4, 1940 4 Sheets-Sheet l IR OUT AIR 11v J 4'- OIL FROM TANK 0/1 To All? PUMP grwe/wto'w ROBERT J. WOODS I CLIFFORD J. LANE 3 e/W m/m Jan. 5, 1943. R. J. WOODS ET AL 1 COMPRESSOR LUBRICATING SYSTEM Filed May 4, 1940 4 Sheets-Sheet 2 ROBE/FTJ. M70054 CLIFFORD J. LANE Jan. 5, 1943. R. J. WOODS ET AL 2,307,251

I COMPRESSOR LUBRICATING SYSTEM 7 Filed May 4, 1940 4 sheets sheet 5 FIG. 5.

3 no W5 IFOBER T J. M00054 CLIFFORD J. LANE Jan. 5, 1943. R. J. WOOD/S ETAL' 2,307,251

COMPRESSOR LUBRICATING SYSTEM I Fi1ed May 4, 1940 4 Shets-Sheet 4 F/aa OIL HPOM PRESSURE SYJ'IFM 0/]. 7'0 PRESSURE SYSTEM AIR T0 O/L 70 PRESSURE 8Y6.

/// 1/2 1/0 105 I07 Elm/0 R0551? T J. W000)" 4F CLIFFOED J. LANE Patented Jan. 5, 1943 ooivniaiissoa LUBRICATING SYSTEM 1mm J. Woods, Grand Island, and Clifiord .1.

Lane, Kenmore, N. Y., assignors to Bell Aircraft Corporation, of New York Buffalo, N. Y., a corporation Application May 4, 1940, Serial No. 333,432

6 Claims.

In general, the present invention relates to lubricating systems and more particularly has reference to systems for lubricating an air compressor and separating the oil from the air, thereby permitting oil free air to be delivered to the units to be operated by the compressor. While this invention is best adapted for use in aircraft such as for operating the de-icers, starting the power plants or pumping tires, it is, of course, obvious'that its range is of broader scope.

An object of this invention is to provide in a single unit means for supplying oil to an air compressor and then separating the oil that is delivered by the compressor.

Another object of this invention is to provide a pump for supplying oil to an independently driven air compressor, means for separating the oil from the air that is delivered-by the compressor and means for preventing the oil from mingling with the air.

Yet another object of this invention is to provide in a single unit an oil pump for supplying oil from a supply tank to an air compressor, means for separating the oil from the air that is delivered by the compressor, means for transmitting the air to the units to be operated and means for returning the separated oil to the supply tank.

And a further object is to provide a lubricating system for air compressors to be used in aircraft which can be easily and cheaply manufactured and which consists of relatively few principal working parts.

. To accomplish the above and-other important objects, the invention in general embraces the idea of providing in a unitary structure means for supplying oil from a source of supply to an independently driven air pump, separating the oil from the air that is delivered by the pump, returning the oil to the source of supply and then transmitting the oil free air to the units to be operated. More specifically, the invention consists of an oil pump which comprises reduction gearing that drives the air pump and also draws oil from a supply tank and forces it to the air compressor under pressure, and the pressure can be controlled by a relief valve. A second pump is formed by including a third idler gear which functions to return the separated oil back to the supply tank. A separator such as animpeller shaped disc is attached to the drive shaft of the pump and the air from the compressor enters the impeller at the center and is discharged at the periphery. The impeller is so formed that the oil which separates from the air due to centrifugal force collects on the impeller surface and is eventually thrown ofi without passing through the air stream. The air then passes out through a suitable conduit to the units to be operated, for instance, the de-icers. An air pressure relief valve may also be incorporated to control the maximum pressure in the system.

In lieu of the above assembly,-the separator can be used alone and an outside oil pressure supply may be employed. Also, it is possible to make use of a direct drive unit and to use separate oil pumps.

In the drawings in which the same, numerals designate similar parts:

Figure 1 is a top plan view of my novel lubrieating system.

Figure 2 is a sectional view taken along'the line 2-2 of Figure 1 looking in the direction of the arrows.

Figure'3 is a sectional view taken along the line 33 of Figure 2 locking in the direction of the arrows- Figure 4 is a sectional view taken along the line 4-4 of Figure 2 looking in the direction of the arrows.

Figure 5 is a sectional view taken along the line 55 of Figure 2 looking in the direction of the arrows.

Figure 6 is a front elevational view of the impeller member;

Figure 7 is a side elevational view, partly in section, of the impeller shown in Figure 6.

Figure 8 is a top plan view of a modified form of my lubricating system employing an outside oil pressure supply in lieu of the pump shown in Figures 1 to 7 inclusive.

Figure 9 is a sectional view taken along the line 9-9 of Figure 8. 7

Referring to Figures 1 and 2, it will be noted that our novel assembly comprises a motor I (preferably electric), an oil pump, and separator 2 and 3, respectively, and an air compressor 4. The oil pump and separator comprise a casting 5 which is so formed at its lower extremity as to provide an oil reservoir 6. A cover .plate I is attached to the frontface of the casting 5 by screws 8. The pump and separator housing 5 is fixed to the motor] by bolts 9 and compressor 4 is secured to the pump 2 as indicatedrat Hi. It will be appreciated from the above that we have provided in a single unit, the means for supplying the oil to the compressor, and the device for separating the oil from the air that is delivered by the compressor.

In Figures 2 and 5, we have shown our oil pumping means being comprised of reduction gearing indicated generally [2. The gearing 12 includes a drive pinion l3 keyed to shaft H which is journaled in a bearing l5. The shaft I4 is flexibly coupled as shown at I3 to stub shaft II which latter shaft is secured in bore l3 formed in the end of drive shaft l3 of the motor I. Meshing with the teeth of the pinion l3 and mounted therebelow is a large gear 23 carried by shaft 2| journaled in bearing 22. The pinion I3 and the gear 23 serve to force the oil from the supply source to the moving parts of the compressor 4. The shaft 2! is coupled as shown at 23 with drive shaft 24 of the compressor 4. Consequently, the pump and the compressor are driven by the motor I through the reduction gear- .Also meshing with the large gear 23 is a small idler pinion 25 rotatably mounted on shaft 23. As will later be more fully described, the small pinion 25 functions to return the separated 011 back to the supply tank.

In Figures 1, 3 and 5, there is illustrated a conduit 33 connected at one end to the oil supply tank (not shown) and communicating at its other end with an oil inlet 3! for the oil pump 2. The oil flows from inlet 3| through oil passage 32 to a point 33 adjacent the reduction gearing l2. The oil is then carried by the teeth of the drive pinion l3 to point 34 which communicates with oil duct 35 that extends to the air compressor 4 thus lubricating the working parts of the com- If the oil pressure should become too great, the oil will be forced from point 34 through another .oil passage 33 which has an oil relief valve 31 positioned at the end of the passage. This valve .comprises a ball 38 which is held in its closed position by one end of coil spring 39, the other end of the spring bearing against the bottom of a threaded cap 40. When the oil pressure lssuflicient to overcome the action of the spring, the ball 38 will be forced from its seat and the oil will flow past the valve and empty into oil duct 4| which is closed at its lower end by a threaded plug 42. Located substantially midway of the length of the duct 4| and at approximately right angles thereto is another oil duct 43, the outer end of which is adapted to have secured thereto an oil line 44 which returns to the oil supply tank. The inner end of the duct 43 ter-' minates at point 45 adjacent the gear 23 and the idler pinion 25.

In communication with the reservoir is the lower end of oil passage 46, and the upper end of the passage extends to point 41 which is adjacent the gear 20 and the pinion 25 for returning the oil back to the tank. The passage 45 is especially advantageous in that it will keep the oil level in the reservoir at a low point thus preventing the separator from becoming flooded during acrobatic maneuvers.

The compressor 4 is adapted to have air admitted thereto through line 53. A mixture of air and oil re-enters the pump 2 from the compressor outlet through a conduit 5| which communicates with an enlarged bore 52 formed in the pump 2. The mixture then passes into an arcuate chamber 53, that is provided with a port 54 which empties into a downwardly extending opening 55 in the cover plate I. The opening is flared at its outer end as shown at 53 adjacent the mid point of the separator 3.

It can be seen that the separator 3 includes a disc-like member 33 carried by a hub 33 which is attached to the drive shaft l3 by a pin 3|. The hub supports a plurality of radial vanes 32, and in Figure 2, it will be noted that the outer periphery of the disc is provided with a curved surface 33 which is positioned in a circumferential recase 34 formed in the outer face of cover plate I. The upper portion of the recess 34 communicates with an arcuate chamber 35 formed in the pump 2 through a bore 33. A second deflector 31 is also carried by the separator 3 and extends substantially radially to prevent the air from being discharged into the oil reservoir 3.

The arcuate chamber 55 empties into conduit 33 which has secured thereto pipe 13 for permitting the oil free air to be delivered to the unit or units to be operated. A second bore H communicates with the chamber 65 and is positioned above the chamber, and an air relief valve 12 is disposed above the bore H to control the maximum pressure in the system.

Referring to Figure 4, it will be seen that the cover plate I is provided with a plurality of radial peripheral slots 53 which will permit the oil to be thrown by the separator through centrifugal force into the oil reservoir 3.

As heretofore pointed out, when oil is admitted to the pump 2, the drive pinion l3 forces the oil to the point 34 from whence it flows through passageway 35 to the compressor. However, oil is also forced by the teeth of the gear 23 from the point 33 to the point 45 from where it flows through passage 43 and conduit 44 back to the tank. When the mixture of oil and air returns from the'compressor to the pump, this mixture moves from the chamber 53 through mouth 54 to the mid point of the disc 53 and the oil which separates from the air due to centrifugal force. collects on the impeller surfaces and is eventually thrown through the slots 53 into the reservoir 3 without passing through the airstream.

The air then goes to the chamber 35 and into the bore 33 where it is delivered by conduit 13 to the units to be operated. The oil in the reservoir 3 moves through bore 43 to the point 41 and the teeth of the pinion 23 force the oil to the passageway 43 from whence it flows back to the oil supply tank. Consequently, there is no danger of the oil in the reservoir flowing into the system. By the above described arrangement it is believed readily apparent that we have provided a novel structure whereby oil can be supplied to an air compressor and the mixture of oil and air returned from the compressor can be separated. Also, the gearing which constitutes the oil pumping means affords a drive for the air compressor. Furthermore, with our invention there can be no danger of the separator being flooded due to acrobatic maneuvers of the airplane, a feature which is of course most advantageous.

Referring to Figures 8 and 9, it will be noted that we have disclosed in these flgures a modifled form of-our novel system. In this embodi ment it can be seen that we omit the oil pump 2 and employ an outside oil pressure supply.

In these figures it is apparent that the senarator is substantially identical with that shown in Figures 1 to 7 with the exception that the redrive shaft ll of the motor I through shaft I33. Oil from a pressure system (not shown) is admitted to the compressor 4' through feed line IIII The mixture of air and oil from' the compressor passes through conduit I02 into the oil separator 3' as shown at I04. The mixture is then admitted into the arcuate chamber 53' and is directed to the midpoint of the disc member 50' of the separator by the downwardly extending aperture 55' formed in the front plate 1"of the separator. The oil is separated-from the air by virtue of centrifugal force and collects on the surface of the disc and is thrown through the peripheral slots i8into the oil reservoir 6.

The separated air passes through opening 66 into the arcuate chamber 65 and from there is delivered to the various units to be operated by a conduit (not shown) I In view of the fact. that the roll separated from the air should not exceed a certain level in the reservoir 6' we provide the following assembly. A float valve designated generally I04 is disposed in the reservoir and is pivoted to the casing at the point I05. The opposite end of the valve'carries a valve member I06 which is adapted to be fitted in the upper end of an elbow I01 which extends through an opening provided in the lower wall of the reservoir. A tube section 108 is threaded on the elbow I 01 and a springpressed ball valve I09 is disposed therein. A conduit H0 which is in communication with the oil pressure system is removably attached to the tube section I08 by means of fittings III and H2.

It will be appreciated that when the oil level becomes too high in the reservoir 6' the valve member I06 will be lifted from its seat and the oil will be forced past valve I09 back to the oil pressure system by the internal air pressure in the separator. Of course this arrangement is particularly efiicacious in that it will prevent the oil in the reservoir from exceeding a certain level thus removing the danger of the oil re-entering the system during acrobatic maneuvers of the aircraft. I 7

From the above description it; is believed apparent that we have provided a novel system for lubricating an air compressor or the like for use in aircraft which is highly effective and which will permit oil free air to be delivered to the units to be operated by the compressor. Furthermore, there can be no danger of the separated oil re-mixing with the airafter it has been separated, nor is it possible for the oil to re-enter the system while the aircraft is performing acrobatic maneuvers. The system comprises relatively few principal working parts and can of course be easily manufactured. In addition the oil pumping means and the air compressor are driven from a single prime mover through the gearing which forms the oil pump inthe form of device shown in Figs. 1 to 7. 7

Although we have shown and described certain connection between themump and the compressor for operating the compressor, an impeller disc secured to the connection between the prime mover and the pump, a conduit for returning the I oil and air from the compressor to project them against the impeller whereby the oil and air are separated by centrifugal force, a-conduit for re-' turning the thus separated oil to'the source, and means to deliver the air to the units to be operated.

2. In a system'of lubricating an'air compressor adapted to operate units in aircraft; an air compressor, a source of air'in communication with V the compressor, a source of oil, a prime mover,

an oil pump comprising reduction gears adapted to withdraw oil from the source and force it to the compressor, a drive connection between the primemover and the reduction gears for driving said reduction gears, a second drive connection between the reduction gears and the compressor whereby the compressor is operated, a conduit from said reduction gears to the compressor through which the oil isadapted to be forced to lubricate the compressor, a rotatable disc attached to the'drive connection'betwee'n the prime mover and the oil pump, a conduit extending from the air compressor to a point adjacent to the rotatable disc for projecting the air and oil returned from the compressor against said disc whereby they are separated by centrifugal force, a line for returning the separated oil to the source, and means to deliver the separated air to the units to be operated.

3. In a system of lubricating an air compressor adapted to operate units in aircraft, an air compressor, a source of air in communication with the compressor, a source of oil, an oil pump com-.

prising reduction gears, a prime mover, a connection between the prime mover and the oil pump for driving the reduction gears to withdraw oil from the source and force it to the compressor, a second connection between the reduction gears and the compressor whereby the com pressor is operated, a conduit extending from the reduction gears to the compressor through which the oil is forced to the compressor, an impeller disc removably fixed to the drive connection between the prime mover and the oil pump, a conduit extending, from the air compressor to the mid point of the impeller whereby the air and oil are projected against the impeller and separated by centrifugal force, means carried by the impeller for preventing the oil thus separated from re-entering the air, a line for returning the separated oil to the source, and

means to direct the separated air to the units to be operated.

specific embodiments of our invention, we are of course fully aware that numerous modifications thereof are possible by persons skilled in this art. Our invention therefore is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the annexed claims.

We claim: r

1. In a system of lubricating an air compressor which is adapted to operate units in aircraft, an air compressor, a source of air in communication with the compressor, a source of oil, a prime mover, an oil pumpadapted to withdraw oil from 4. In a system of lubricating an air compressor adapted to operate units in aircraft, an air compressor, a source of air in communication with the air compressor, a source of oil, an oil pump comprising reduction gears, a prime mover, a connection between the prime mover and the oil pump for driving the reduction gears whereby oil is withdrawn from the source and forced to the air compressor, a second drive connection between the oil pump and the compressor whereby the compressor is operated, a conduit leading from the reduction gears into the air compressor through which the oil is forced into the compressor, an impeller disc attached to the connection the source and force it into the compressor, a I

connection between the prime mover andthe oil pump for driving the pump, a second driving 15 between the prime mover and the'oil pump, a

conduit extending from the air compressor to a point adjacent to the mid point of the impeller 5. In a system of lubricating an air compressor adapted to operate units in aircraft, an air compressor, a source of air in communication with the air compressor, a source of oil, an oil pump comprising reduction gears, a prime mover, a connection between the prime mover and the oil pump for driving the oil pump to withdraw oil from the source and force it to the air compressor, a second drive connection between the oil pump and the air compressor whereby the air compressor is operated, a conduit extending from the oil pump to the air compressor through which the pump forces the oil into the air compressor, an impeller disc attached to the connection between the prime mover and the oil pump, a conduit extending from the air compressor to a point adjacent to the impeller disc for directing the air and oil into engagement with said disc whereby they are separated by centrifugal force, means provided on said impeller disc to prevent the separated oil from reentering the air, a line for directing the air to the units to be operated, and a second line extending to the source of oil, said reduction gears being adapted to force the separated oil back to the source.

6. In asystem of lubricating an air compressor adapted to operate units in aircraft, an air compressor, a source of air in communication with the compressor, a source of oil, an oil pump, a prime mover, a drive connection between the prime mover and the oil pump whereby oil is withdrawn from the source and forced to the compressor, a second drive connection between the oil pump and the air compressor whereby the air compressor is operated, a conduit extending from the oil pump to the air compressor through which the oil is forced, an impeller disc attached to the drive connection between the prime mover and the oil pump, a conduit extending from the air compressor to a point adjacent to the impeller disc whereby the oil and air returned from the compressor are directed against the impeller disc and are separated by centrifugal force, means provided on said impeller disc to prevent the separated oil from reentering the air, a line to direct the air to the units to be operated and a second line to return the oil to the source of oil.

ROBERT J. WOODS. CLIFFORD J. LANE.